Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact
  • Clinical Research and Public Health
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Video Abstracts
  • Reviews
    • View all reviews ...
    • Complement Biology and Therapeutics (May 2025)
    • Evolving insights into MASLD and MASH pathogenesis and treatment (Apr 2025)
    • Microbiome in Health and Disease (Feb 2025)
    • Substance Use Disorders (Oct 2024)
    • Clonal Hematopoiesis (Oct 2024)
    • Sex Differences in Medicine (Sep 2024)
    • Vascular Malformations (Apr 2024)
    • View all review series ...
  • Viewpoint
  • Collections
    • In-Press Preview
    • Clinical Research and Public Health
    • Research Letters
    • Letters to the Editor
    • Editorials
    • Commentaries
    • Editor's notes
    • Reviews
    • Viewpoints
    • 100th anniversary
    • Top read articles

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Video Abstracts
  • In-Press Preview
  • Clinical Research and Public Health
  • Research Letters
  • Letters to the Editor
  • Editorials
  • Commentaries
  • Editor's notes
  • Reviews
  • Viewpoints
  • 100th anniversary
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact

Issue published December 2, 2013 Previous issue | Next issue

  • Volume 123, Issue 12
Go to section:
  • Conversations with Giants in Medicine
  • Review
  • Hindsight
  • Commentaries
  • Research Articles
  • Erratum
  • Corrigenda

On the cover: Retinoblastoma protein in the enteric nervous system

The enteric nervous system controls critical aspects of intestinal motility, and disruption of this network may contribute to serious intestinal diseases, such as chronic intestinal pseudo-obstruction. On page 5152, Fu et al. explore the role of the cell cycle regulator retinoblastoma 1 (RB1) in enteric nervous system development. Their study demonstrates that loss of RB1 causes abnormal bowel contractility and endoreplication specifically in NO-producing enteric neurons. This image shows enteric neurons (HuC/D; red), including enlarged NO-producing neurons as well as neurites (TuJ1; green) and DNA (DRAQ5; blue) from the distal small bowel of an Rb1 knockout mouse.
Conversations with Giants in Medicine
A conversation with Thomas Südhof
Ushma S. Neill
Ushma S. Neill
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):4984-4985. https://doi.org/10.1172/JCI74014.
View: Text | PDF

A conversation with Thomas Südhof

  • Text
  • PDF
Abstract

Authors

Ushma S. Neill

×
Review
Lorcaserin and pimavanserin: emerging selectivity of serotonin receptor subtype–targeted drugs
Herbert Y. Meltzer, Bryan L. Roth
Herbert Y. Meltzer, Bryan L. Roth
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):4986-4991. https://doi.org/10.1172/JCI70678.
View: Text | PDF

Lorcaserin and pimavanserin: emerging selectivity of serotonin receptor subtype–targeted drugs

  • Text
  • PDF
Abstract

Serotonin (5-hydroxytryptamine, or 5-HT) receptors mediate a plethora of physiological phenomena in the brain and the periphery. Additionally, serotonergic dysfunction has been implicated in nearly every neuropsychiatric disorder. The effects of serotonin are mediated by fourteen GPCRs. Both the therapeutic actions and side effects of commonly prescribed drugs are frequently due to nonspecific actions on various 5-HT receptor subtypes. For more than 20 years, the search for clinically efficacious drugs that selectively target 5-HT receptor subtypes has been only occasionally successful. This review provides an overview of 5-HT receptor pharmacology and discusses two recent 5-HT receptor subtype–selective drugs, lorcaserin and pimavanserin, which target the 5HT2C and 5HT2A receptors and provide new treatments for obesity and Parkinson’s disease psychosis, respectively.

Authors

Herbert Y. Meltzer, Bryan L. Roth

×
Hindsight
Macrophages, fat, and the emergence of immunometabolism
Anthony W. Ferrante Jr.
Anthony W. Ferrante Jr.
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):4992-4993. https://doi.org/10.1172/JCI73658.
View: Text | PDF

Macrophages, fat, and the emergence of immunometabolism

  • Text
  • PDF
Abstract

Over the last century, our modern concepts and understanding of metabolism and immunology have evolved largely in parallel. Notably, during the last decade, there has been a sharpened focus on the convergence of metabolism and immune function. In part motivated by studies originally published in the JCI, we now recognize that the immune system monitors the metabolic state of tissues and organisms and responds in kind by modulating metabolic function. The complexity of these interactions, both adaptive and pathologic, continues to be studied and revealed, with the hope that harnessing the reins that control immune function may one day be used for metabolic benefit.

Authors

Anthony W. Ferrante Jr.

×
Commentaries
Mind your rhythms: an important role for circadian genes in neuroprotection
Colleen A. McClung
Colleen A. McClung
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):4994-4996. https://doi.org/10.1172/JCI73059.
View: Text | PDF

Mind your rhythms: an important role for circadian genes in neuroprotection

  • Text
  • PDF
Abstract

Circadian rhythms govern nearly every physiological process in our brains and bodies. At the most basic level, the molecular clockwork in each cell interacts with metabolic cycles to influence the redox state, allowing for increased cellular activity at specific times of day. In this issue of the JCI, Musiek et al. show that genetic disruptions in the positive arm of the molecular clock can lead to severe astrogliosis, which likely occurs through disruptions in output genes that keep oxidative stress in check. This study demonstrates the importance of proper circadian protein function in the maintenance of neuronal integrity.

Authors

Colleen A. McClung

×

ADCK4 “reenergizes” nephrotic syndrome
Laura Malaga-Dieguez, Katalin Susztak
Laura Malaga-Dieguez, Katalin Susztak
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):4996-4999. https://doi.org/10.1172/JCI73168.
View: Text | PDF

ADCK4 “reenergizes” nephrotic syndrome

  • Text
  • PDF
Abstract

Steroid-resistant nephrotic syndrome has a poor prognosis and often leads to end-stage renal disease development. In this issue of the JCI, Ashraf and colleagues used exome sequencing to identify mutations in the aarF domain containing kinase 4 (ADCK4) gene that cause steroid-resistant nephrotic syndrome. Patients with ADCK4 mutations had lower coenzyme Q10 levels, and coenzyme Q10 supplementation ameliorated renal disease in a patient with this particular mutation, suggesting a potential therapy for patients with steroid-resistant nephrotic syndrome with ADCK4 mutations.

Authors

Laura Malaga-Dieguez, Katalin Susztak

×

Heavy LIFting: tumor promotion and radioresistance in NPC
Micah Luftig
Micah Luftig
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):4999-5001. https://doi.org/10.1172/JCI73416.
View: Text | PDF

Heavy LIFting: tumor promotion and radioresistance in NPC

  • Text
  • PDF
Abstract

The epithelial-derived nasopharyngeal carcinoma (NPC) is a rare tumor in most of the world; however, it is common in southern China, northern Africa, and Alaska. NPC is often left undiagnosed and untreated until a late stage of disease. Furthermore, while radiation therapy is effective against this tumor, local recurrence due to radioresistance is an important clinical problem. In this issue, Liu et al. report on their identification of the IL-6 family cytokine leukemia inhibitory factor (LIF) as a serum predictor of local NPC recurrence following radiation therapy. The authors developed this initial finding to discover a role for the LIF/LIFR/mTORC1 signaling axis in NPC tumor cell growth as well as radioresistance.

Authors

Micah Luftig

×

Tuning mTOR activity for immune balance
Kai Yang, Hongbo Chi
Kai Yang, Hongbo Chi
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5001-5004. https://doi.org/10.1172/JCI73202.
View: Text | PDF

Tuning mTOR activity for immune balance

  • Text
  • PDF
Abstract

The mTOR pathway orchestrates diverse physiological processes, including T cell functions and fate decisions; however, the regulation of mTOR-dependent T cell differentiation remains elusive. In this issue, Park et al. examine the role of TSC1, an mTOR signaling regulator, in T cell differentiation and the balance between T cell–mediated immunity and tolerance. They found that enhanced mTOR activity in Tsc1-deficient T cells promotes Th1 and Th17 differentiation, leading to increased intestinal inflammation in murine colitis. Tsc1-deficient Tregs had impaired suppressive activity in inflammatory conditions. These defects were associated with the acquisition of effector-like phenotypes and could be further exacerbated by concomitant loss of transcription factor Foxo3. This study highlights that TSC1-mediated control of mTOR activity impinges on the balance between immunity and tolerance by dictating effector and regulatory T cell responses.

Authors

Kai Yang, Hongbo Chi

×

Thrombocytopathy and type 2B von Willebrand disease
Jerry Ware
Jerry Ware
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5004-5006. https://doi.org/10.1172/JCI73169.
View: Text | PDF

Thrombocytopathy and type 2B von Willebrand disease

  • Text
  • PDF
Abstract

The knowledge gained from “experiments of nature” has always been paramount in identifying key players in pathophysiologic pathways. This is well characterized by naturally occurring bleeding and thrombotic disorders. In most cases, it is the absence of a particular protein that leads to recognition of its importance for normal physiology. On the other hand, gain-of-function mutations highlight not only the presence of the protein, but also how it regulates a particular physiologic response. In this issue of the JCI, Casari and colleagues define a previously unrecognized consequence of variant type 2B von Willebrand factor (vWF) binding to blood platelets. More than 30 years after an initial description of type 2B variant vWF, the consequence of this spontaneous variant vWF binding to platelets is viewed as a dysregulation of platelet signaling pathways contributing to the type 2B bleeding phenotype.

Authors

Jerry Ware

×

BAFF-ling autoantibodies
Stefanie Sarantopoulos, Maureen A. Su
Stefanie Sarantopoulos, Maureen A. Su
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5006-5008. https://doi.org/10.1172/JCI73166.
View: Text | PDF

BAFF-ling autoantibodies

  • Text
  • PDF
Abstract

There is emerging evidence that autoantibodies directed against cytokines modulate the severity of autoimmune disease. Identification of cytokine-targeted autoantibodies in patients can be informative for diagnosis and predicting clinical outcome. In this issue of the JCI, Price and colleagues used a multiplex protein microarray to identify autoantibodies in serum from SLE patients. They found autoantibodies directed against the B cell–activating factor (BAFF) were associated with greater disease severity. This study highlights the contribution of cytokine-directed autoantibodies in disease and describes a valuable tool for identifying autoantibodies against serum antigens.

Authors

Stefanie Sarantopoulos, Maureen A. Su

×
Research Articles
Germinal center dysregulation by histone methyltransferase EZH2 promotes lymphomagenesis
Marieta Caganova, … , I-hsin Su, Stefano Casola
Marieta Caganova, … , I-hsin Su, Stefano Casola
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5009-5022. https://doi.org/10.1172/JCI70626.
View: Text | PDF | Corrigendum

Germinal center dysregulation by histone methyltransferase EZH2 promotes lymphomagenesis

  • Text
  • PDF
Abstract

Protection against deadly pathogens requires the production of high-affinity antibodies by B cells, which are generated in germinal centers (GCs). Alteration of the GC developmental program is common in many B cell malignancies. Identification of regulators of the GC response is crucial to develop targeted therapies for GC B cell dysfunctions, including lymphomas. The histone H3 lysine 27 methyltransferase enhancer of zeste homolog 2 (EZH2) is highly expressed in GC B cells and is often constitutively activated in GC-derived non-Hodgkin lymphomas (NHLs). The function of EZH2 in GC B cells remains largely unknown. Herein, we show that Ezh2 inactivation in mouse GC B cells caused profound impairment of GC responses, memory B cell formation, and humoral immunity. EZH2 protected GC B cells against activation-induced cytidine deaminase (AID) mutagenesis, facilitated cell cycle progression, and silenced plasma cell determinant and tumor suppressor B-lymphocyte–induced maturation protein 1 (BLIMP1). EZH2 inhibition in NHL cells induced BLIMP1, which impaired tumor growth. In conclusion, EZH2 sustains AID function and prevents terminal differentiation of GC B cells, which allows antibody diversification and affinity maturation. Dysregulation of the GC reaction by constitutively active EZH2 facilitates lymphomagenesis and identifies EZH2 as a possible therapeutic target in NHL and other GC-derived B cell diseases.

Authors

Marieta Caganova, Chiara Carrisi, Gabriele Varano, Federica Mainoldi, Federica Zanardi, Pierre-Luc Germain, Laura George, Federica Alberghini, Luca Ferrarini, Asoke K. Talukder, Maurilio Ponzoni, Giuseppe Testa, Takuya Nojima, Claudio Doglioni, Daisuke Kitamura, Kai-M. Toellner, I-hsin Su, Stefano Casola

×

Balancing GRK2 and EPAC1 levels prevents and relieves chronic pain
Huijing Wang, … , Niels Eijkelkamp, Annemieke Kavelaars
Huijing Wang, … , Niels Eijkelkamp, Annemieke Kavelaars
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5023-5034. https://doi.org/10.1172/JCI66241.
View: Text | PDF

Balancing GRK2 and EPAC1 levels prevents and relieves chronic pain

  • Text
  • PDF
Abstract

Chronic pain is a major clinical problem, yet the mechanisms underlying the transition from acute to chronic pain remain poorly understood. In mice, reduced expression of GPCR kinase 2 (GRK2) in nociceptors promotes cAMP signaling to the guanine nucleotide exchange factor EPAC1 and prolongs the PGE2-induced increase in pain sensitivity (hyperalgesia). Here we hypothesized that reduction of GRK2 or increased EPAC1 in dorsal root ganglion (DRG) neurons would promote the transition to chronic pain. We used 2 mouse models of hyperalgesic priming in which the transition from acute to chronic PGE2-induced hyperalgesia occurs. Hyperalgesic priming with carrageenan induced a sustained decrease in nociceptor GRK2, whereas priming with the PKCε agonist ΨεRACK increased DRG EPAC1. When either GRK2 was increased in vivo by viral-based gene transfer or EPAC1 was decreased in vivo, as was the case for mice heterozygous for Epac1 or mice treated with Epac1 antisense oligodeoxynucleotides, chronic PGE2-induced hyperalgesia development was prevented in the 2 priming models. Using the CFA model of chronic inflammatory pain, we found that increasing GRK2 or decreasing EPAC1 inhibited chronic hyperalgesia. Our data suggest that therapies targeted at balancing nociceptor GRK2 and EPAC1 levels have promise for the prevention and treatment of chronic pain.

Authors

Huijing Wang, Cobi J. Heijnen, Cindy T.J. van Velthoven, Hanneke L.D.M. Willemen, Yoshihiro Ishikawa, Xinna Zhang, Anil K. Sood, Anne Vroon, Niels Eijkelkamp, Annemieke Kavelaars

×

CX3CR1-dependent renal macrophage survival promotes Candida control and host survival
Michail S. Lionakis, … , Mihai G. Netea, Philip M. Murphy
Michail S. Lionakis, … , Mihai G. Netea, Philip M. Murphy
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5035-5051. https://doi.org/10.1172/JCI71307.
View: Text | PDF

CX3CR1-dependent renal macrophage survival promotes Candida control and host survival

  • Text
  • PDF
Abstract

Systemic Candida albicans infection causes high morbidity and mortality and is associated with neutropenia; however, the roles of other innate immune cells in pathogenesis are poorly defined. Here, using a mouse model of systemic candidiasis, we found that resident macrophages accumulated in the kidney, the main target organ of infection, and formed direct contacts with the fungus in vivo mainly within the first few hours after infection. Macrophage accumulation and contact with Candida were both markedly reduced in mice lacking chemokine receptor CX3CR1, which was found almost exclusively on resident macrophages in uninfected kidneys. Infected Cx3cr1–/– mice uniformly succumbed to Candida-induced renal failure, but exhibited clearance of the fungus in all other organs tested. Renal macrophage deficiency in infected Cx3cr1–/– mice was due to reduced macrophage survival, not impaired proliferation, trafficking, or differentiation. In humans, the dysfunctional CX3CR1 allele CX3CR1-M280 was associated with increased risk of systemic candidiasis. Together, these data indicate that CX3CR1-mediated renal resident macrophage survival is a critical innate mechanism of early fungal control that influences host survival in systemic candidiasis.

Authors

Michail S. Lionakis, Muthulekha Swamydas, Brett G. Fischer, Theo S. Plantinga, Melissa D. Johnson, Martin Jaeger, Nathaniel M. Green, Andrius Masedunskas, Roberto Weigert, Constantinos Mikelis, Wuzhou Wan, Chyi-Chia Richard Lee, Jean K. Lim, Aymeric Rivollier, John C. Yang, Greg M. Laird, Robert T. Wheeler, Barbara D. Alexander, John R. Perfect, Ji-Liang Gao, Bart-Jan Kullberg, Mihai G. Netea, Philip M. Murphy

×

Mice generated by in vitro fertilization exhibit vascular dysfunction and shortened life span
Emrush Rexhaj, … , Claudio Sartori, Urs Scherrer
Emrush Rexhaj, … , Claudio Sartori, Urs Scherrer
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5052-5060. https://doi.org/10.1172/JCI68943.
View: Text | PDF

Mice generated by in vitro fertilization exhibit vascular dysfunction and shortened life span

  • Text
  • PDF
Abstract

Children conceived by assisted reproductive technologies (ART) display a level of vascular dysfunction similar to that seen in children of mothers with preeclamspia. The long-term consequences of ART-associated vascular disorders are unknown and difficult to investigate in healthy children. Here, we found that vasculature from mice generated by ART display endothelial dysfunction and increased stiffness, which translated into arterial hypertension in vivo. Progeny of male ART mice also exhibited vascular dysfunction, suggesting underlying epigenetic modifications. ART mice had altered methylation at the promoter of the gene encoding eNOS in the aorta, which correlated with decreased vascular eNOS expression and NO synthesis. Administration of a deacetylase inhibitor to ART mice normalized vascular gene methylation and function and resulted in progeny without vascular dysfunction. The induction of ART-associated vascular and epigenetic alterations appeared to be related to the embryo environment; these alterations were possibly facilitated by the hormonally stimulated ovulation accompanying ART. Finally, ART mice challenged with a high-fat diet had roughly a 25% shorter life span compared with control animals. This study highlights the potential of ART to induce vascular dysfunction and shorten life span and suggests that epigenetic alterations contribute to these problems.

Authors

Emrush Rexhaj, Ariane Paoloni-Giacobino, Stefano F. Rimoldi, Daniel G. Fuster, Manuel Anderegg, Emmanuel Somm, Elisa Bouillet, Yves Allemann, Claudio Sartori, Urs Scherrer

×

Serotonin 2C receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis
Eric D. Berglund, … , Yong Xu, Joel K. Elmquist
Eric D. Berglund, … , Yong Xu, Joel K. Elmquist
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5061-5070. https://doi.org/10.1172/JCI70338.
View: Text | PDF | Corrigendum

Serotonin 2C receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis

  • Text
  • PDF
Abstract

Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor–expressing neurons that mediate the effects of serotonin and serotonin 2C receptor agonists on energy and glucose homeostasis are unknown. Here, we show that mice lacking serotonin 2C receptors (Htr2c) specifically in pro-opiomelanocortin (POMC) neurons had normal body weight but developed glucoregulatory defects including hyperinsulinemia, hyperglucagonemia, hyperglycemia, and insulin resistance. Moreover, these mice did not show anorectic responses to serotonergic agents that suppress appetite and developed hyperphagia and obesity when they were fed a high-fat/high-sugar diet. A requirement of serotonin 2C receptors in POMC neurons for the maintenance of normal energy and glucose homeostasis was further demonstrated when Htr2c loss was induced in POMC neurons in adult mice using a tamoxifen-inducible POMC-cre system. These data demonstrate that serotonin 2C receptor–expressing POMC neurons are required to control energy and glucose homeostasis and implicate POMC neurons as the target for the effect of serotonin 2C receptor agonists on weight-loss induction and improved glycemic control.

Authors

Eric D. Berglund, Chen Liu, Jong-Woo Sohn, Tiemin Liu, Mi Hwa Kim, Charlotte E. Lee, Claudia R. Vianna, Kevin W. Williams, Yong Xu, Joel K. Elmquist

×

von Willebrand factor mutation promotes thrombocytopathy by inhibiting integrin αIIbβ3
Caterina Casari, … , Cécile V. Denis, Marijke Bryckaert
Caterina Casari, … , Cécile V. Denis, Marijke Bryckaert
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5071-5081. https://doi.org/10.1172/JCI69458.
View: Text | PDF

von Willebrand factor mutation promotes thrombocytopathy by inhibiting integrin αIIbβ3

  • Text
  • PDF
Abstract

von Willebrand disease type 2B (vWD-type 2B) is characterized by gain-of-function mutations in von Willebrand factor (vWF) that enhance its binding to the glycoprotein Ib-IX-V complex on platelets. Patients with vWD-type 2B have a bleeding tendency that is linked to loss of vWF multimers and/or thrombocytopenia. In this study, we uncovered evidence that platelet dysfunction is a third possible mechanism for bleeding tendency. We found that platelet aggregation, secretion, and spreading were diminished due to inhibition of integrin αIIbβ3 in platelets from mice expressing a vWD-type 2B–associated vWF (vWF/p.V1316M), platelets from a patient with the same mutation, and control platelets pretreated with recombinant vWF/p.V1316M. Impaired platelet function coincided with reduced thrombus growth. Further, αIIbβ3 activation and activation of the small GTPase Rap1 were impaired by vWF/p.V1316M following exposure to platelet agonists (thrombin, ADP, or convulxin). Conversely, thrombin- or ADP-induced Ca2+ store release, which is required for αIIbβ3 activation, was normal, indicating that vWF/p.V1316M acts downstream of Ca2+ release and upstream of Rap1. We found normal Syk phosphorylation and PLCγ2 activation following collagen receptor signaling, further implying that vWF/p.V1316M acts directly on or downstream of Ca2+ release. These data indicate that the vWD-type 2B mutation p.V1316M is associated with severe thrombocytopathy, which likely contributes to the bleeding tendency in vWD-type 2B.

Authors

Caterina Casari, Eliane Berrou, Marilyne Lebret, Frédéric Adam, Alexandre Kauskot, Régis Bobe, Céline Desconclois, Edith Fressinaud, Olivier D. Christophe, Peter J. Lenting, Jean-Philippe Rosa, Cécile V. Denis, Marijke Bryckaert

×

Transmembrane protein ESDN promotes endothelial VEGF signaling and regulates angiogenesis
Lei Nie, … , Jeffrey R. Bender, Mehran M. Sadeghi
Lei Nie, … , Jeffrey R. Bender, Mehran M. Sadeghi
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5082-5097. https://doi.org/10.1172/JCI67752.
View: Text | PDF

Transmembrane protein ESDN promotes endothelial VEGF signaling and regulates angiogenesis

  • Text
  • PDF
Abstract

Aberrant blood vessel formation contributes to a wide variety of pathologies, and factors that regulate angiogenesis are attractive therapeutic targets. Endothelial and smooth muscle cell–derived neuropilin-like protein (ESDN) is a neuropilin-related transmembrane protein expressed in ECs; however, its potential effect on VEGF responses remains undefined. Here, we generated global and EC-specific Esdn knockout mice and demonstrated that ESDN promotes VEGF-induced human and murine EC proliferation and migration. Deletion of Esdn in the mouse interfered with adult and developmental angiogenesis, and knockdown of the Esdn homolog (dcbld2) in zebrafish impaired normal vascular development. Loss of ESDN in ECs blunted VEGF responses in vivo and attenuated VEGF-induced VEGFR-2 signaling without altering VEGF receptor or neuropilin expression. Finally, we found that ESDN associates with VEGFR-2 and regulates its complex formation with negative regulators of VEGF signaling, protein tyrosine phosphatases PTP1B and TC-PTP, and VE-cadherin. These findings establish ESDN as a regulator of VEGF responses in ECs that acts through a mechanism distinct from neuropilins. As such, ESDN may serve as a therapeutic target for angiogenesis regulation.

Authors

Lei Nie, Xiaojia Guo, Leila Esmailzadeh, Jiasheng Zhang, Abolfazl Asadi, Mark Collinge, Xuan Li, Jun-Dae Kim, Melissa Woolls, Suk-Won Jin, Alexandre Dubrac, Anne Eichmann, Michael Simons, Jeffrey R. Bender, Mehran M. Sadeghi

×

The mechanism of anti-CD20–mediated B cell depletion revealed by intravital imaging
Fabricio Montalvao, … , Nico Van Rooijen, Philippe Bousso
Fabricio Montalvao, … , Nico Van Rooijen, Philippe Bousso
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5098-5103. https://doi.org/10.1172/JCI70972.
View: Text | PDF Brief Report

The mechanism of anti-CD20–mediated B cell depletion revealed by intravital imaging

  • Text
  • PDF
Abstract

Anti-CD20 Ab therapy has proven successful for treating B cell malignancies and a number of autoimmune diseases. However, how anti-CD20 Abs operate in vivo to mediate B cell depletion is not fully understood. In particular, the anatomical location, the type of effector cells, and the mechanism underlying anti-CD20 therapy remain uncertain. Here, we found that the liver is a major site for B cell depletion and that recirculation accounts for the decrease in B cell numbers observed in secondary lymphoid organs. Using intravital imaging, we established that, upon anti-CD20 treatment, Kupffer cells (KCs) mediate the abrupt arrest and subsequent engulfment of B cells circulating in the liver sinusoids. KCs were also effective in depleting malignant B cells in a model of spontaneous lymphoma. Our results identify Ab-dependent cellular phagocytosis by KCs as a primary mechanism of anti-CD20 therapy and provide an experimental framework for optimizing the efficacy of therapeutic Abs.

Authors

Fabricio Montalvao, Zacarias Garcia, Susanna Celli, Béatrice Breart, Jacques Deguine, Nico Van Rooijen, Philippe Bousso

×

Differential AKT dependency displayed by mouse models of BRAFV600E-initiated melanoma
Victoria Marsh Durban, … , Wayne Phillips, Martin McMahon
Victoria Marsh Durban, … , Wayne Phillips, Martin McMahon
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5104-5118. https://doi.org/10.1172/JCI69619.
View: Text | PDF

Differential AKT dependency displayed by mouse models of BRAFV600E-initiated melanoma

  • Text
  • PDF
Abstract

Malignant melanoma is frequently driven by mutational activation of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) accompanied by silencing of the phosphatase and tensin homology (PTEN) tumor suppressor. Despite the implied importance of PI3K signaling in PTENNull melanomas, mutational activation of the gene encoding the catalytic subunit of PI3Kα (PIK3CA), is rarely detected. Since PTEN has both PI3-lipid phosphatase–dependent and –independent tumor suppressor activities, we investigated the contribution of PI3K signaling to BRAFV600E-induced melanomagenesis using mouse models, cultured melanoma cells, and PI3K pathway–targeted inhibitors. These experiments revealed that mutationally activated PIK3CAH1047R cooperates with BRAFV600E for melanomagenesis in mice. Moreover, pharmacological inhibition of PI3Ks prevented growth of BRAFV600E/PTENNull melanomas in vivo and in tissue culture. Combined inhibition of BRAFV600E and PI3K had more potent effects on the regression of established BRAFV600E/PTENNull melanomas and cultured melanoma cells than individual blockade of either pathway. Surprisingly, growth of BRAFV600E/PIK3CAH1047R melanomas was dependent on the protein kinase AKT; however, AKT inhibition had no effect on growth of BRAFV600E/PTENNull melanomas. These data indicate that PTEN silencing contributes a PI3K-dependent, but AKT-independent, function in melanomagenesis. Our findings enhance our knowledge of how BRAFV600E and PI3K signaling cooperate in melanomagenesis and provide preclinical validation for combined pathway–targeted inhibition of PI3K and BRAFV600E in the therapeutic management of BRAFV600E/PTENNull melanomas.

Authors

Victoria Marsh Durban, Marian M. Deuker, Marcus W. Bosenberg, Wayne Phillips, Martin McMahon

×

Systems pharmacology identifies drug targets for Stargardt disease–associated retinal degeneration
Yu Chen, … , Akiko Maeda, Krzysztof Palczewski
Yu Chen, … , Akiko Maeda, Krzysztof Palczewski
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5119-5134. https://doi.org/10.1172/JCI69076.
View: Text | PDF

Systems pharmacology identifies drug targets for Stargardt disease–associated retinal degeneration

  • Text
  • PDF
Abstract

A systems pharmacological approach that capitalizes on the characterization of intracellular signaling networks can transform our understanding of human diseases and lead to therapy development. Here, we applied this strategy to identify pharmacological targets for the treatment of Stargardt disease, a severe juvenile form of macular degeneration. Diverse GPCRs have previously been implicated in neuronal cell survival, and crosstalk between GPCR signaling pathways represents an unexplored avenue for pharmacological intervention. We focused on this receptor family for potential therapeutic interventions in macular disease. Complete transcriptomes of mouse and human samples were analyzed to assess the expression of GPCRs in the retina. Focusing on adrenergic (AR) and serotonin (5-HT) receptors, we found that adrenoceptor α 2C (Adra2c) and serotonin receptor 2a (Htr2a) were the most highly expressed. Using a mouse model of Stargardt disease, we found that pharmacological interventions that targeted both GPCR signaling pathways and adenylate cyclases (ACs) improved photoreceptor cell survival, preserved photoreceptor function, and attenuated the accumulation of pathological fluorescent deposits in the retina. These findings demonstrate a strategy for the identification of new drug candidates and FDA-approved drugs for the treatment of monogenic and complex diseases.

Authors

Yu Chen, Grazyna Palczewska, Debarshi Mustafi, Marcin Golczak, Zhiqian Dong, Osamu Sawada, Tadao Maeda, Akiko Maeda, Krzysztof Palczewski

×

Protein microarray analysis reveals BAFF-binding autoantibodies in systemic lupus erythematosus
Jordan V. Price, … , Emily C. Baechler, Paul J. Utz
Jordan V. Price, … , Emily C. Baechler, Paul J. Utz
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5135-5145. https://doi.org/10.1172/JCI70231.
View: Text | PDF

Protein microarray analysis reveals BAFF-binding autoantibodies in systemic lupus erythematosus

  • Text
  • PDF
Abstract

Autoantibodies against cytokines, chemokines, and growth factors inhibit normal immunity and are implicated in inflammatory autoimmune disease and diseases of immune deficiency. In an effort to evaluate serum from autoimmune and immunodeficient patients for Abs against cytokines, chemokines, and growth factors in a high-throughput and unbiased manner, we constructed a multiplex protein microarray for detection of serum factor–binding Abs and used the microarray to detect autoantibody targets in SLE. We designed a nitrocellulose-surface microarray containing human cytokines, chemokines, and other circulating proteins and demonstrated that the array permitted specific detection of serum factor–binding probes. We used the arrays to detect previously described autoantibodies against cytokines in samples from individuals with autoimmune polyendocrine syndrome type 1 and chronic mycobacterial infection. Serum profiling from individuals with SLE revealed that among several targets, elevated IgG autoantibody reactivity to B cell–activating factor (BAFF) was associated with SLE compared with control samples. BAFF reactivity correlated with the severity of disease-associated features, including IFN-α–driven SLE pathology. Our results showed that serum factor protein microarrays facilitate detection of autoantibody reactivity to serum factors in human samples and that BAFF-reactive autoantibodies may be associated with an elevated inflammatory disease state within the spectrum of SLE.

Authors

Jordan V. Price, David J. Haddon, Dodge Kemmer, Guillaume Delepine, Gil Mandelbaum, Justin A. Jarrell, Rohit Gupta, Imelda Balboni, Eliza F. Chakravarty, Jeremy Sokolove, Anthony K. Shum, Mark S. Anderson, Mickie H. Cheng, William H. Robinson, Sarah K. Browne, Steven M. Holland, Emily C. Baechler, Paul J. Utz

×

Inhibition of Coxsackievirus-associated dystrophin cleavage prevents cardiomyopathy
Byung-Kwan Lim, … , Ju Chen, Kirk U. Knowlton
Byung-Kwan Lim, … , Ju Chen, Kirk U. Knowlton
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5146-5151. https://doi.org/10.1172/JCI66271.
View: Text | PDF Brief Report

Inhibition of Coxsackievirus-associated dystrophin cleavage prevents cardiomyopathy

  • Text
  • PDF
Abstract

Heart failure in children and adults is often the consequence of myocarditis associated with Coxsackievirus (CV) infection. Upon CV infection, enteroviral protease 2A cleaves a small number of host proteins including dystrophin, which links actin filaments to the plasma membrane of muscle fiber cells (sarcolemma). It is unknown whether protease 2A–mediated cleavage of dystrophin and subsequent disruption of the sarcolemma play a role in CV-mediated myocarditis. We generated knockin mice harboring a mutation at the protease 2A cleavage site of the dystrophin gene, which prevents dystrophin cleavage following CV infection. Compared with wild-type mice, we found that mice expressing cleavage-resistant dystrophin had a decrease in sarcolemmal disruption and cardiac virus titer following CV infection. In addition, cleavage-resistant dystrophin inhibited the cardiomyopathy induced by cardiomyocyte-restricted expression of the CV protease 2A transgene. These findings indicate that protease 2A–mediated cleavage of dystrophin is critical for viral propagation, enteroviral-mediated cytopathic effects, and the development of cardiomyopathy.

Authors

Byung-Kwan Lim, Angela K. Peter, Dingding Xiong, Anna Narezkina, Aaron Yung, Nancy D. Dalton, Kyung-Kuk Hwang, Toshitaka Yajima, Ju Chen, Kirk U. Knowlton

×

Retinoblastoma protein prevents enteric nervous system defects and intestinal pseudo-obstruction
Ming Fu, … , J. William Harbour, Robert O. Heuckeroth
Ming Fu, … , J. William Harbour, Robert O. Heuckeroth
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5152-5164. https://doi.org/10.1172/JCI67653.
View: Text | PDF

Retinoblastoma protein prevents enteric nervous system defects and intestinal pseudo-obstruction

  • Text
  • PDF
Abstract

The retinoblastoma 1 (RB1) tumor suppressor is a critical regulator of cell cycle progression and development. To investigate the role of RB1 in neural crest–derived melanocytes, we bred mice with a floxed Rb1 allele with mice expressing Cre from the tyrosinase (Tyr) promoter. TyrCre+;Rb1fl/fl mice exhibited no melanocyte defects but died unexpectedly early with intestinal obstruction, striking defects in the enteric nervous system (ENS), and abnormal intestinal motility. Cre-induced DNA recombination occurred in all enteric glia and most small bowel myenteric neurons, yet phenotypic effects of Rb1 loss were cell-type specific. Enteric glia were twice as abundant in mutant mice compared with those in control animals, while myenteric neuron number was normal. Most myenteric neurons also appeared normal in size, but NO-producing myenteric neurons developed very large nuclei as a result of DNA replication without cell division (i.e., endoreplication). Parallel studies in vitro found that exogenous NO and Rb1 shRNA increased ENS precursor DNA replication and nuclear size. The large, irregularly shaped nuclei in NO-producing neurons were remarkably similar to those in progeria, an early-onset aging disorder that has been linked to RB1 dysfunction. These findings reveal a role for RB1 in the ENS.

Authors

Ming Fu, Solange Landreville, Olga A. Agapova, Luke A. Wiley, Michael Shoykhet, J. William Harbour, Robert O. Heuckeroth

×

TSC1 regulates the balance between effector and regulatory T cells
Yoon Park, … , Mitchell Kronenberg, Yun-Cai Liu
Yoon Park, … , Mitchell Kronenberg, Yun-Cai Liu
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5165-5178. https://doi.org/10.1172/JCI69751.
View: Text | PDF

TSC1 regulates the balance between effector and regulatory T cells

  • Text
  • PDF
Abstract

Mammalian target of rapamycin (mTOR) plays a crucial role in the control of T cell fate determination; however, the precise regulatory mechanism of the mTOR pathway is not fully understood. We found that T cell–specific deletion of the gene encoding tuberous sclerosis 1 (TSC1), an upstream negative regulator of mTOR, resulted in augmented Th1 and Th17 differentiation and led to severe intestinal inflammation in a colitis model. Conditional Tsc1 deletion in Tregs impaired their suppressive activity and expression of the Treg marker Foxp3 and resulted in increased IL-17 production under inflammatory conditions. A fate-mapping study revealed that Tsc1-null Tregs that lost Foxp3 expression gained a stronger effector-like phenotype compared with Tsc1–/– Foxp3+ Tregs. Elevated IL-17 production in Tsc1–/– Treg cells was reversed by in vivo knockdown of the mTOR target S6K1. Moreover, IL-17 production was enhanced by Treg-specific double deletion of Tsc1 and Foxo3a. Collectively, these studies suggest that TSC1 acts as an important checkpoint for maintaining immune homeostasis by regulating cell fate determination.

Authors

Yoon Park, Hyung-Seung Jin, Justine Lopez, Chris Elly, Gisen Kim, Masako Murai, Mitchell Kronenberg, Yun-Cai Liu

×

ADCK4 mutations promote steroid-resistant nephrotic syndrome through CoQ10 biosynthesis disruption
Shazia Ashraf, … , Corinne Antignac, Friedhelm Hildebrandt
Shazia Ashraf, … , Corinne Antignac, Friedhelm Hildebrandt
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5179-5189. https://doi.org/10.1172/JCI69000.
View: Text | PDF

ADCK4 mutations promote steroid-resistant nephrotic syndrome through CoQ10 biosynthesis disruption

  • Text
  • PDF
Abstract

Identification of single-gene causes of steroid-resistant nephrotic syndrome (SRNS) has furthered the understanding of the pathogenesis of this disease. Here, using a combination of homozygosity mapping and whole human exome resequencing, we identified mutations in the aarF domain containing kinase 4 (ADCK4) gene in 15 individuals with SRNS from 8 unrelated families. ADCK4 was highly similar to ADCK3, which has been shown to participate in coenzyme Q10 (CoQ10) biosynthesis. Mutations in ADCK4 resulted in reduced CoQ10 levels and reduced mitochondrial respiratory enzyme activity in cells isolated from individuals with SRNS and transformed lymphoblasts. Knockdown of adck4 in zebrafish and Drosophila recapitulated nephrotic syndrome-associated phenotypes. Furthermore, ADCK4 was expressed in glomerular podocytes and partially localized to podocyte mitochondria and foot processes in rat kidneys and cultured human podocytes. In human podocytes, ADCK4 interacted with members of the CoQ10 biosynthesis pathway, including COQ6, which has been linked with SRNS and COQ7. Knockdown of ADCK4 in podocytes resulted in decreased migration, which was reversed by CoQ10 addition. Interestingly, a patient with SRNS with a homozygous ADCK4 frameshift mutation had partial remission following CoQ10 treatment. These data indicate that individuals with SRNS with mutations in ADCK4 or other genes that participate in CoQ10 biosynthesis may be treatable with CoQ10.

Authors

Shazia Ashraf, Heon Yung Gee, Stephanie Woerner, Letian X. Xie, Virginia Vega-Warner, Svjetlana Lovric, Humphrey Fang, Xuewen Song, Daniel C. Cattran, Carmen Avila-Casado, Andrew D. Paterson, Patrick Nitschké, Christine Bole-Feysot, Pierre Cochat, Julian Esteve-Rudd, Birgit Haberberger, Susan J. Allen, Weibin Zhou, Rannar Airik, Edgar A. Otto, Moumita Barua, Mohamed H. Al-Hamed, Jameela A. Kari, Jonathan Evans, Agnieszka Bierzynska, Moin A. Saleem, Detlef Böckenhauer, Robert Kleta, Sherif El Desoky, Duygu O. Hacihamdioglu, Faysal Gok, Joseph Washburn, Roger C. Wiggins, Murim Choi, Richard P. Lifton, Shawn Levy, Zhe Han, Leonardo Salviati, Holger Prokisch, David S. Williams, Martin Pollak, Catherine F. Clarke, York Pei, Corinne Antignac, Friedhelm Hildebrandt

×

Antibodies against low-density lipoprotein receptor–related protein 4 induce myasthenia gravis
Chengyong Shen, … , Wen-Cheng Xiong, Lin Mei
Chengyong Shen, … , Wen-Cheng Xiong, Lin Mei
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5190-5202. https://doi.org/10.1172/JCI66039.
View: Text | PDF

Antibodies against low-density lipoprotein receptor–related protein 4 induce myasthenia gravis

  • Text
  • PDF
Abstract

Myasthenia gravis (MG) is the most common disorder affecting the neuromuscular junction (NMJ). MG is frequently caused by autoantibodies against acetylcholine receptor (AChR) and a kinase critical for NMJ formation, MuSK; however, a proportion of MG patients are double-negative for anti-AChR and anti-MuSK antibodies. Recent studies in these subjects have identified autoantibodies against low-density lipoprotein receptor–related protein 4 (LRP4), an agrin receptor also critical for NMJ formation. LRP4 autoantibodies have not previously been implicated in MG pathogenesis. Here we demonstrate that mice immunized with the extracellular domain of LRP4 generated anti-LRP4 antibodies and exhibited MG-associated symptoms, including muscle weakness, reduced compound muscle action potentials (CMAPs), and compromised neuromuscular transmission. Additionally, fragmented and distorted NMJs were evident at both the light microscopic and electron microscopic levels. We found that anti-LRP4 sera decreased cell surface LRP4 levels, inhibited agrin-induced MuSK activation and AChR clustering, and activated complements, revealing potential pathophysiological mechanisms. To further confirm the pathogenicity of LRP4 antibodies, we transferred IgGs purified from LRP4-immunized rabbits into naive mice and found that they exhibited MG-like symptoms, including reduced CMAP and impaired neuromuscular transmission. Together, these data demonstrate that LRP4 autoantibodies induce MG and that LRP4 contributes to NMJ maintenance in adulthood.

Authors

Chengyong Shen, Yisheng Lu, Bin Zhang, Dwight Figueiredo, Jonathan Bean, Jiung Jung, Haitao Wu, Arnab Barik, Dong-Min Yin, Wen-Cheng Xiong, Lin Mei

×

Apelin is a positive regulator of ACE2 in failing hearts
Teruki Sato, … , Yumiko Imai, Keiji Kuba
Teruki Sato, … , Yumiko Imai, Keiji Kuba
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5203-5211. https://doi.org/10.1172/JCI69608.
View: Text | PDF

Apelin is a positive regulator of ACE2 in failing hearts

  • Text
  • PDF
Abstract

Angiotensin converting enzyme 2 (ACE2) is a negative regulator of the renin-angiotensin system (RAS), catalyzing the conversion of Angiotensin II to Angiotensin 1-7. Apelin is a second catalytic substrate for ACE2 and functions as an inotropic and cardioprotective peptide. While an antagonistic relationship between the RAS and apelin has been proposed, such functional interplay remains elusive. Here we found that ACE2 was downregulated in apelin-deficient mice. Pharmacological or genetic inhibition of angiotensin II type 1 receptor (AT1R) rescued the impaired contractility and hypertrophy of apelin mutant mice, which was accompanied by restored ACE2 levels. Importantly, treatment with angiotensin 1-7 rescued hypertrophy and heart dysfunctions of apelin-knockout mice. Moreover, apelin, via activation of its receptor, APJ, increased ACE2 promoter activity in vitro and upregulated ACE2 expression in failing hearts in vivo. Apelin treatment also increased cardiac contractility and ACE2 levels in AT1R-deficient mice. These data demonstrate that ACE2 couples the RAS to the apelin system, adding a conceptual framework for the apelin-ACE2–angiotensin 1-7 axis as a therapeutic target for cardiovascular diseases.

Authors

Teruki Sato, Takashi Suzuki, Hiroyuki Watanabe, Ayumi Kadowaki, Akiyoshi Fukamizu, Peter P. Liu, Akinori Kimura, Hiroshi Ito, Josef M. Penninger, Yumiko Imai, Keiji Kuba

×

Histone deacetylase 6–mediated selective autophagy regulates COPD-associated cilia dysfunction
Hilaire C. Lam, … , Stefan W. Ryter, Augustine M.K. Choi
Hilaire C. Lam, … , Stefan W. Ryter, Augustine M.K. Choi
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5212-5230. https://doi.org/10.1172/JCI69636.
View: Text | PDF | Corrigendum

Histone deacetylase 6–mediated selective autophagy regulates COPD-associated cilia dysfunction

  • Text
  • PDF
Abstract

Chronic obstructive pulmonary disease (COPD) involves aberrant airway inflammatory responses to cigarette smoke (CS) that are associated with epithelial cell dysfunction, cilia shortening, and mucociliary clearance disruption. Exposure to CS reduced cilia length and induced autophagy in vivo and in differentiated mouse tracheal epithelial cells (MTECs). Autophagy-impaired (Becn1+/– or Map1lc3B–/–) mice and MTECs resisted CS-induced cilia shortening. Furthermore, CS increased the autophagic turnover of ciliary proteins, indicating that autophagy may regulate cilia homeostasis. We identified cytosolic deacetylase HDAC6 as a critical regulator of autophagy-mediated cilia shortening during CS exposure. Mice bearing an X chromosome deletion of Hdac6 (Hdac6–/Y) and MTECs from these mice had reduced autophagy and were protected from CS-induced cilia shortening. Autophagy-impaired Becn1–/–, Map1lc3B–/–, and Hdac6–/Y mice or mice injected with an HDAC6 inhibitor were protected from CS-induced mucociliary clearance (MCC) disruption. MCC was preserved in mice given the chemical chaperone 4-phenylbutyric acid, but was disrupted in mice lacking the transcription factor NRF2, suggesting that oxidative stress and altered proteostasis contribute to the disruption of MCC. Analysis of human COPD specimens revealed epigenetic deregulation of HDAC6 by hypomethylation and increased protein expression in the airways. We conclude that an autophagy-dependent pathway regulates cilia length during CS exposure and has potential as a therapeutic target for COPD.

Authors

Hilaire C. Lam, Suzanne M. Cloonan, Abhiram R. Bhashyam, Jeffery A. Haspel, Anju Singh, J. Fah Sathirapongsasuti, Morgan Cervo, Hongwei Yao, Anna L. Chung, Kenji Mizumura, Chang Hyeok An, Bin Shan, Jonathan M. Franks, Kathleen J. Haley, Caroline A. Owen, Yohannes Tesfaigzi, George R. Washko, John Quackenbush, Edwin K. Silverman, Irfan Rahman, Hong Pyo Kim, Ashfaq Mahmood, Shyam S. Biswal, Stefan W. Ryter, Augustine M.K. Choi

×

KDM2A promotes lung tumorigenesis by epigenetically enhancing ERK1/2 signaling
Klaus W. Wagner, … , John V. Heymach, Min Gyu Lee
Klaus W. Wagner, … , John V. Heymach, Min Gyu Lee
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5231-5246. https://doi.org/10.1172/JCI68642.
View: Text | PDF

KDM2A promotes lung tumorigenesis by epigenetically enhancing ERK1/2 signaling

  • Text
  • PDF
Abstract

Epigenetic dysregulation has emerged as a major contributor to tumorigenesis. Histone methylation is a well-established mechanism of epigenetic regulation that is dynamically modulated by histone methyltransferases and demethylases. The pathogenic role of histone methylation modifiers in non–small cell lung cancer (NSCLC), which is the leading cause of cancer deaths worldwide, remains largely unknown. Here, we found that the histone H3 lysine 36 (H3K36) demethylase KDM2A (also called FBXL11 and JHDM1A) is frequently overexpressed in NSCLC tumors and cell lines. KDM2A and its catalytic activity were required for in vitro proliferation and invasion of KDM2A-overexpressing NSCLC cells. KDM2A overexpression in NSCLC cells with low KDM2A levels increased cell proliferation and invasiveness. KDM2A knockdown abrogated tumor growth and invasive abilities of NSCLC cells in mouse xenograft models. We identified dual-specificity phosphatase 3 (DUSP3) as a key KDM2A target gene and found that DUSP3 dephosphorylates ERK1/2 in NSCLC cells. KDM2A activated ERK1/2 through epigenetic repression of DUSP3 expression via demethylation of dimethylated H3K36 at the DUSP3 locus. High KDM2A levels correlated with poor prognosis in NSCLC patients. These findings uncover an unexpected role for a histone methylation modifier in activating ERK1/2 in lung tumorigenesis and metastasis, suggesting that KDM2A may be a promising therapeutic target in NSCLC.

Authors

Klaus W. Wagner, Hunain Alam, Shilpa S. Dhar, Uma Giri, Na Li, Yongkun Wei, Dipak Giri, Tina Cascone, Jae-Hwan Kim, Yuanqing Ye, Asha S. Multani, Chia-Hsin Chan, Baruch Erez, Babita Saigal, Jimyung Chung, Hui-Kuan Lin, Xifeng Wu, Mien-Chie Hung, John V. Heymach, Min Gyu Lee

×

p53 isoforms regulate aging- and tumor-associated replicative senescence in T lymphocytes
Abdul M. Mondal, … , David P. Lane, Curtis C. Harris
Abdul M. Mondal, … , David P. Lane, Curtis C. Harris
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5247-5257. https://doi.org/10.1172/JCI70355.
View: Text | PDF

p53 isoforms regulate aging- and tumor-associated replicative senescence in T lymphocytes

  • Text
  • PDF
Abstract

Cellular senescence contributes to aging and decline in tissue function. p53 isoform switching regulates replicative senescence in cultured fibroblasts and is associated with tumor progression. Here, we found that the endogenous p53 isoforms Δ133p53 and p53β are physiological regulators of proliferation and senescence in human T lymphocytes in vivo. Peripheral blood CD8+ T lymphocytes collected from healthy donors displayed an age-dependent accumulation of senescent cells (CD28–CD57+) with decreased Δ133p53 and increased p53β expression. Human lung tumor-associated CD8+ T lymphocytes also harbored senescent cells. Cultured CD8+ blood T lymphocytes underwent replicative senescence that was associated with loss of CD28 and Δ133p53 protein. In poorly proliferative, Δ133p53-low CD8+CD28– cells, reconstituted expression of either Δ133p53 or CD28 upregulated endogenous expression of each other, which restored cell proliferation, extended replicative lifespan and rescued senescence phenotypes. Conversely, Δ133p53 knockdown or p53β overexpression in CD8+CD28+ cells inhibited cell proliferation and induced senescence. This study establishes a role for Δ133p53 and p53β in regulation of cellular proliferation and senescence in vivo. Furthermore, Δ133p53-induced restoration of cellular replicative potential may lead to a new therapeutic paradigm for treating immunosenescence disorders, including those associated with aging, cancer, autoimmune diseases, and HIV infection.

Authors

Abdul M. Mondal, Izumi Horikawa, Sharon R. Pine, Kaori Fujita, Katherine M. Morgan, Elsa Vera, Sharlyn J. Mazur, Ettore Appella, Borivoj Vojtesek, Maria A. Blasco, David P. Lane, Curtis C. Harris

×

JUNB/AP-1 controls IFN-γ during inflammatory liver disease
Martin K. Thomsen, … , Lola Martinez, Erwin F. Wagner
Martin K. Thomsen, … , Lola Martinez, Erwin F. Wagner
Published November 8, 2013
Citation Information: J Clin Invest. 2013;123(12):5258-5268. https://doi.org/10.1172/JCI70405.
View: Text | PDF

JUNB/AP-1 controls IFN-γ during inflammatory liver disease

  • Text
  • PDF
Abstract

Understanding the molecular pathogenesis of inflammatory liver disease is essential to design efficient therapeutic approaches. In hepatocytes, the dimeric transcription factor c-JUN/AP-1 is a major mediator of cell survival during hepatitis, although functions for other JUN proteins in liver disease are less defined. Here, we found that JUNB was specifically expressed in human and murine immune cells during acute liver injury. We analyzed the molecular function of JUNB in experimental models of hepatitis, including administration of concanavalin A (ConA) or α-galactosyl-ceramide, which induce liver inflammation and injury. Mice specifically lacking JUNB in hepatocytes displayed a mild increase in ConA-induced liver damage. However, targeted deletion of Junb in immune cells and hepatocytes protected against hepatitis in experimental models that involved NK/NKT cells. The absence of JUNB in immune cells decreased IFN-γ expression and secretion from NK and NKT cells, leading to reduced STAT1 pathway activation. Systemic IFN-γ treatment or adenovirus-based IRF1 delivery to Junb-deficient mice restored hepatotoxicity, and we demonstrate that Ifng is a direct transcriptional target of JUNB. These findings demonstrate that JUNB/AP-1 promotes cell death during acute hepatitis by regulating IFN-γ production in NK and NKT cells and thus functionally antagonizes the hepatoprotective function of c-JUN/AP-1 in hepatocytes.

Authors

Martin K. Thomsen, Latifa Bakiri, Sebastian C. Hasenfuss, Rainer Hamacher, Lola Martinez, Erwin F. Wagner

×

Leukemia inhibitory factor promotes nasopharyngeal carcinoma progression and radioresistance
Shu-Chen Liu, … , Kai-Ping N. Chow, Yu-Sun Chang
Shu-Chen Liu, … , Kai-Ping N. Chow, Yu-Sun Chang
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5269-5283. https://doi.org/10.1172/JCI63428.
View: Text | PDF

Leukemia inhibitory factor promotes nasopharyngeal carcinoma progression and radioresistance

  • Text
  • PDF
Abstract

Radioresistance of EBV-associated nasopharyngeal carcinoma (NPC) is associated with poor prognosis for patients with this form of cancer. Here, we found that NPC patients had increased serum levels of leukemia inhibitory factor (LIF) and that higher LIF levels correlated with local tumor recurrence. Furthermore, in vitro studies with NPC cells and in vivo xenograft mouse studies demonstrated that LIF critically contributes to NPC tumor growth and radioresistance. Using these model systems, we found that LIF treatment activated the mTORC1/p70S6K signaling pathway, enhanced tumor growth, inhibited DNA damage responses, and enhanced radioresistance. Treatment with either soluble LIF receptor (sLIFR), a LIF antagonist, or the mTOR inhibitor rapamycin reversed LIF-mediated effects, resulting in growth arrest and increased sensitivity to γ irradiation. Immunohistochemical (IHC) analyses of human NPC biopsies revealed that LIF and LIFR were overexpressed in tumor cells and that LIF expression correlated with the presence of the activated p-p70S6K. Finally, we found that the EBV-encoded protein latent membrane protein 1 (LMP1) enhances LIF production. Together, our findings indicate that LIF promotes NPC tumorigenesis and suggest that serum LIF levels may predict local recurrence and radiosensitivity in NPC patients.

Authors

Shu-Chen Liu, Ngan-Ming Tsang, Wen-Che Chiang, Kai-Ping Chang, Chuen Hsueh, Ying Liang, Jyh-Lyh Juang, Kai-Ping N. Chow, Yu-Sun Chang

×

Enhanced autophagy ameliorates cardiac proteinopathy
Md. Shenuarin Bhuiyan, … , Junichi Sadoshima, Jeffrey Robbins
Md. Shenuarin Bhuiyan, … , Junichi Sadoshima, Jeffrey Robbins
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5284-5297. https://doi.org/10.1172/JCI70877.
View: Text | PDF

Enhanced autophagy ameliorates cardiac proteinopathy

  • Text
  • PDF
Abstract

Basal autophagy is a crucial mechanism in cellular homeostasis, underlying both normal cellular recycling and the clearance of damaged or misfolded proteins, organelles and aggregates. We showed here that enhanced levels of autophagy induced by either autophagic gene overexpression or voluntary exercise ameliorated desmin-related cardiomyopathy (DRC). To increase levels of basal autophagy, we generated an inducible Tg mouse expressing autophagy-related 7 (Atg7), a critical and rate-limiting autophagy protein. Hearts from these mice had enhanced autophagy, but normal morphology and function. We crossed these mice with CryABR120G mice, a model of DRC in which autophagy is significantly attenuated in the heart, to test the functional significance of autophagy activation in a proteotoxic model of heart failure. Sustained Atg7-induced autophagy in the CryABR120G hearts decreased interstitial fibrosis, ameliorated ventricular dysfunction, decreased cardiac hypertrophy, reduced intracellular aggregates and prolonged survival. To determine whether different methods of autophagy upregulation have additive or even synergistic benefits, we subjected the autophagy-deficient CryABR120G mice and the Atg7-crossed CryABR120G mice to voluntary exercise, which also upregulates autophagy. The entire exercised Atg7-crossed CryABR120G cohort survived to 7 months. These findings suggest that activating autophagy may be a viable therapeutic strategy for improving cardiac performance under proteotoxic conditions.

Authors

Md. Shenuarin Bhuiyan, J. Scott Pattison, Hanna Osinska, Jeanne James, James Gulick, Patrick M. McLendon, Joseph A. Hill, Junichi Sadoshima, Jeffrey Robbins

×

Inhibition of the TRPC5 ion channel protects the kidney filter
Thomas Schaldecker, … , Astrid Weins, Anna Greka
Thomas Schaldecker, … , Astrid Weins, Anna Greka
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5298-5309. https://doi.org/10.1172/JCI71165.
View: Text | PDF

Inhibition of the TRPC5 ion channel protects the kidney filter

  • Text
  • PDF
Abstract

An intact kidney filter is vital to retention of essential proteins in the blood and removal of waste from the body. Damage to the filtration barrier results in albumin loss in the urine, a hallmark of cardiovascular disease and kidney failure. Here we found that the ion channel TRPC5 mediates filtration barrier injury. Using Trpc5-KO mice, a small-molecule inhibitor of TRPC5, Ca2+ imaging in isolated kidney glomeruli, and live imagining of podocyte actin dynamics, we determined that loss of TRPC5 or its inhibition abrogates podocyte cytoskeletal remodeling. Inhibition or loss of TRPC5 prevented activation of the small GTP-binding protein Rac1 and stabilized synaptopodin. Importantly, genetic deletion or pharmacologic inhibition of TRPC5 protected mice from albuminuria. These data reveal that the Ca2+-permeable channel TRPC5 is an important determinant of albuminuria and identify TRPC5 inhibition as a therapeutic strategy for the prevention or treatment of proteinuric kidney disease.

Authors

Thomas Schaldecker, Sookyung Kim, Constantine Tarabanis, Dequan Tian, Samy Hakroush, Philip Castonguay, Wooin Ahn, Hanna Wallentin, Hans Heid, Corey R. Hopkins, Craig W. Lindsley, Antonio Riccio, Lisa Buvall, Astrid Weins, Anna Greka

×

Human Treg responses allow sustained recombinant adeno-associated virus–mediated transgene expression
Christian Mueller, … , James M. Wilson, Terence R. Flotte
Christian Mueller, … , James M. Wilson, Terence R. Flotte
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5310-5318. https://doi.org/10.1172/JCI70314.
View: Text | PDF

Human Treg responses allow sustained recombinant adeno-associated virus–mediated transgene expression

  • Text
  • PDF
Abstract

Recombinant adeno-associated virus (rAAV) vectors have shown promise for the treatment of several diseases; however, immune-mediated elimination of transduced cells has been suggested to limit and account for a loss of efficacy. To determine whether rAAV vector expression can persist long term, we administered rAAV vectors expressing normal, M-type α-1 antitrypsin (M-AAT) to AAT-deficient subjects at various doses by multiple i.m. injections. M-specific AAT expression was observed in all subjects in a dose-dependent manner and was sustained for more than 1 year in the absence of immune suppression. Muscle biopsies at 1 year had sustained AAT expression and a reduction of inflammatory cells compared with 3 month biopsies. Deep sequencing of the TCR Vβ region from muscle biopsies demonstrated a limited number of T cell clones that emerged at 3 months after vector administration and persisted for 1 year. In situ immunophenotyping revealed a substantial Treg population in muscle biopsy samples containing AAT-expressing myofibers. Approximately 10% of all T cells in muscle were natural Tregs, which were activated in response to AAV capsid. These results suggest that i.m. delivery of rAAV type 1–AAT (rAAV1-AAT) induces a T regulatory response that allows ongoing transgene expression and indicates that immunomodulatory treatments may not be necessary for rAAV-mediated gene therapy.

Authors

Christian Mueller, Jeffrey D. Chulay, Bruce C. Trapnell, Margaret Humphries, Brenna Carey, Robert A. Sandhaus, Noel G. McElvaney, Louis Messina, Qiushi Tang, Farshid N. Rouhani, Martha Campbell-Thompson, Ann Dongtao Fu, Anthony Yachnis, David R. Knop, Guo-jie Ye, Mark Brantly, Roberto Calcedo, Suryanarayan Somanathan, Lee P. Richman, Robert H. Vonderheide, Maigan A. Hulme, Todd M. Brusko, James M. Wilson, Terence R. Flotte

×

Insulin receptor substrate signaling suppresses neonatal autophagy in the heart
Christian Riehle, … , Morris F. White, E. Dale Abel
Christian Riehle, … , Morris F. White, E. Dale Abel
Published November 1, 2013
Citation Information: J Clin Invest. 2013;123(12):5319-5333. https://doi.org/10.1172/JCI71171.
View: Text | PDF

Insulin receptor substrate signaling suppresses neonatal autophagy in the heart

  • Text
  • PDF
Abstract

The induction of autophagy in the mammalian heart during the perinatal period is an essential adaptation required to survive early neonatal starvation; however, the mechanisms that mediate autophagy suppression once feeding is established are not known. Insulin signaling in the heart is transduced via insulin and IGF-1 receptors (IGF-1Rs). We disrupted insulin and IGF-1R signaling by generating mice with combined cardiomyocyte-specific deletion of Irs1 and Irs2. Here we show that loss of IRS signaling prevented the physiological suppression of autophagy that normally parallels the postnatal increase in circulating insulin. This resulted in unrestrained autophagy in cardiomyocytes, which contributed to myocyte loss, heart failure, and premature death. This process was ameliorated either by activation of mTOR with aa supplementation or by genetic suppression of autophagic activation. Loss of IRS1 and IRS2 signaling also increased apoptosis and precipitated mitochondrial dysfunction, which were not reduced when autophagic flux was normalized. Together, these data indicate that in addition to prosurvival signaling, insulin action in early life mediates the physiological postnatal suppression of autophagy, thereby linking nutrient sensing to postnatal cardiac development.

Authors

Christian Riehle, Adam R. Wende, Sandra Sena, Karla Maria Pires, Renata Oliveira Pereira, Yi Zhu, Heiko Bugger, Deborah Frank, Jack Bevins, Dong Chen, Cynthia N. Perry, Xiaocheng C. Dong, Steven Valdez, Monika Rech, Xiaoming Sheng, Bart C. Weimer, Roberta A. Gottlieb, Morris F. White, E. Dale Abel

×

Impaired periamygdaloid-cortex prodynorphin is characteristic of opiate addiction and depression
Sarah Ann R. Anderson, … , Nora D. Volkow, Yasmin L. Hurd
Sarah Ann R. Anderson, … , Nora D. Volkow, Yasmin L. Hurd
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5334-5341. https://doi.org/10.1172/JCI70395.
View: Text | PDF

Impaired periamygdaloid-cortex prodynorphin is characteristic of opiate addiction and depression

  • Text
  • PDF
Abstract

Negative affect is critical for conferring vulnerability to opiate addiction as reflected by the high comorbidity of opiate abuse with major depressive disorder (MDD). Rodent models implicate amygdala prodynorphin (Pdyn) as a mediator of negative affect; however, evidence of PDYN involvement in human negative affect is limited. Here, we found reduced PDYN mRNA expression in the postmortem human amygdala nucleus of the periamygdaloid cortex (PAC) in both heroin abusers and MDD subjects. Similar to humans, rats that chronically self-administered heroin had reduced Pdyn mRNA expression in the PAC at a time point associated with a negative affective state. Using the in vivo functional imaging technology DREAMM (DREADD-assisted metabolic mapping, where DREADD indicates designer receptors exclusively activated by designer drugs), we found that selective inhibition of Pdyn-expressing neurons in the rat PAC increased metabolic activity in the extended amygdala, which is a key substrate of the extrahypothalamic brain stress system. In parallel, PAC-specific Pdyn inhibition provoked negative affect–related physiological and behavioral changes. Altogether, our translational study supports a functional role for impaired Pdyn in the PAC in opiate abuse through activation of the stress and negative affect neurocircuitry implicated in addiction vulnerability.

Authors

Sarah Ann R. Anderson, Michael Michaelides, Parisa Zarnegar, Yanhua Ren, Pernilla Fagergren, Panayotis K. Thanos, Gene-Jack Wang, Michael Bannon, John F. Neumaier, Eva Keller, Nora D. Volkow, Yasmin L. Hurd

×

Whole-brain circuit dissection in free-moving animals reveals cell-specific mesocorticolimbic networks
Michael Michaelides, … , Nora D. Volkow, Yasmin L. Hurd
Michael Michaelides, … , Nora D. Volkow, Yasmin L. Hurd
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5342-5350. https://doi.org/10.1172/JCI72117.
View: Text | PDF Technical Advance

Whole-brain circuit dissection in free-moving animals reveals cell-specific mesocorticolimbic networks

  • Text
  • PDF
Abstract

The ability to map the functional connectivity of discrete cell types in the intact mammalian brain during behavior is crucial for advancing our understanding of brain function in normal and disease states. We combined designer receptor exclusively activated by designer drug (DREADD) technology and behavioral imaging with μPET and [18F]fluorodeoxyglucose (FDG) to generate whole-brain metabolic maps of cell-specific functional circuits during the awake, freely moving state. We have termed this approach DREADD-assisted metabolic mapping (DREAMM) and documented its ability in rats to map whole-brain functional anatomy. We applied this strategy to evaluating changes in the brain associated with inhibition of prodynorphin-expressing (Pdyn-expressing) and of proenkephalin-expressing (Penk-expressing) medium spiny neurons (MSNs) of the nucleus accumbens shell (NAcSh), which have been implicated in neuropsychiatric disorders. DREAMM revealed discrete behavioral manifestations and concurrent engagement of distinct corticolimbic networks associated with dysregulation of Pdyn and Penk in MSNs of the NAcSh. Furthermore, distinct neuronal networks were recruited in awake versus anesthetized conditions. These data demonstrate that DREAMM is a highly sensitive, molecular, high-resolution quantitative imaging approach.

Authors

Michael Michaelides, Sarah Ann R. Anderson, Mala Ananth, Denis Smirnov, Panayotis K. Thanos, John F. Neumaier, Gene-Jack Wang, Nora D. Volkow, Yasmin L. Hurd

×

Immune response to RB1-regulated senescence limits radiation-induced osteosarcoma formation
Maya Kansara, … , Mark J. Smyth, David M. Thomas
Maya Kansara, … , Mark J. Smyth, David M. Thomas
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5351-5360. https://doi.org/10.1172/JCI70559.
View: Text | PDF

Immune response to RB1-regulated senescence limits radiation-induced osteosarcoma formation

  • Text
  • PDF
Abstract

Ionizing radiation (IR) and germline mutations in the retinoblastoma tumor suppressor gene (RB1) are the strongest risk factors for developing osteosarcoma. Recapitulating the human predisposition, we found that Rb1+/– mice exhibited accelerated development of IR-induced osteosarcoma, with a latency of 39 weeks. Initial exposure of osteoblasts to carcinogenic doses of IR in vitro and in vivo induced RB1-dependent senescence and the expression of a panel of proteins known as senescence-associated secretory phenotype (SASP), dominated by IL-6. RB1 expression closely correlated with that of the SASP cassette in human osteosarcomas, and low expression of both RB1 and the SASP genes was associated with poor prognosis. In vivo, IL-6 was required for IR-induced senescence, which elicited NKT cell infiltration and a host inflammatory response. Mice lacking IL-6 or NKT cells had accelerated development of IR-induced osteosarcomas. These data elucidate an important link between senescence, which is a cell-autonomous tumor suppressor response, and the activation of host-dependent cancer immunosurveillance. Our findings indicate that overcoming the immune response to senescence is a rate-limiting step in the formation of IR-induced osteosarcoma.

Authors

Maya Kansara, Huei San Leong, Dan Mei Lin, Sophie Popkiss, Puiyi Pang, Dale W. Garsed, Carl R. Walkley, Carleen Cullinane, Jason Ellul, Nicole M. Haynes, Rod Hicks, Marieke L. Kuijjer, Anne-Marie Cleton-Jansen, Philip W. Hinds, Mark J. Smyth, David M. Thomas

×

Topical hypochlorite ameliorates NF-κB–mediated skin diseases in mice
Thomas H. Leung, … , Susan J. Knox, Seung K. Kim
Thomas H. Leung, … , Susan J. Knox, Seung K. Kim
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5361-5370. https://doi.org/10.1172/JCI70895.
View: Text | PDF

Topical hypochlorite ameliorates NF-κB–mediated skin diseases in mice

  • Text
  • PDF
Abstract

Nuclear factor-κB (NF-κB) regulates cellular responses to inflammation and aging, and alterations in NF-κB signaling underlie the pathogenesis of multiple human diseases. Effective clinical therapeutics targeting this pathway remain unavailable. In primary human keratinocytes, we found that hypochlorite (HOCl) reversibly inhibited the expression of CCL2 and SOD2, two NF-κB–dependent genes. In cultured cells, HOCl inhibited the activity of inhibitor of NF-κB kinase (IKK), a key regulator of NF-κB activation, by oxidizing cysteine residues Cys114 and Cys115. In NF-κB reporter mice, topical HOCl reduced LPS-induced NF-κB signaling in skin. We further evaluated topical HOCl use in two mouse models of NF-κB–driven epidermal disease. For mice with acute radiation dermatitis, topical HOCl inhibited the expression of NF-κB–dependent genes, decreased disease severity, and prevented skin ulceration. In aged mice, topical HOCl attenuated age-dependent production of p16INK4a and expression of the DNA repair gene Rad50. Additionally, skin of aged HOCl-treated mice acquired enhanced epidermal thickness and proliferation, comparable to skin in juvenile animals. These data suggest that topical HOCl reduces NF-κB–mediated epidermal pathology in radiation dermatitis and skin aging through IKK modulation and motivate the exploration of HOCl use for clinical aims.

Authors

Thomas H. Leung, Lillian F. Zhang, Jing Wang, Shoucheng Ning, Susan J. Knox, Seung K. Kim

×

Inhibition of mitochondrial fragmentation diminishes Huntington’s disease–associated neurodegeneration
Xing Guo, … , Daria Mochly-Rosen, Xin Qi
Xing Guo, … , Daria Mochly-Rosen, Xin Qi
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5371-5388. https://doi.org/10.1172/JCI70911.
View: Text | PDF

Inhibition of mitochondrial fragmentation diminishes Huntington’s disease–associated neurodegeneration

  • Text
  • PDF
Abstract

Huntington’s disease (HD) is the result of expression of a mutated Huntingtin protein (mtHtt), and is associated with a variety of cellular dysfunctions including excessive mitochondrial fission. Here, we tested whether inhibition of excessive mitochondrial fission prevents mtHtt-induced pathology. We developed a selective inhibitor (P110-TAT) of the mitochondrial fission protein dynamin-related protein 1 (DRP1). We found that P110-TAT inhibited mtHtt-induced excessive mitochondrial fragmentation, improved mitochondrial function, and increased cell viability in HD cell culture models. P110-TAT treatment of fibroblasts from patients with HD and patients with HD with iPS cell–derived neurons reduced mitochondrial fragmentation and corrected mitochondrial dysfunction. P110-TAT treatment also reduced the extent of neurite shortening and cell death in iPS cell–derived neurons in patients with HD. Moreover, treatment of HD transgenic mice with P110-TAT reduced mitochondrial dysfunction, motor deficits, neuropathology, and mortality. We found that p53, a stress gene involved in HD pathogenesis, binds to DRP1 and mediates DRP1-induced mitochondrial and neuronal damage. Furthermore, P110-TAT treatment suppressed mtHtt-induced association of p53 with mitochondria in multiple HD models. These data indicate that inhibition of DRP1-dependent excessive mitochondrial fission with a P110-TAT–like inhibitor may prevent or slow the progression of HD.

Authors

Xing Guo, Marie-Helene Disatnik, Marie Monbureau, Mehrdad Shamloo, Daria Mochly-Rosen, Xin Qi

×

Circadian clock proteins regulate neuronal redox homeostasis and neurodegeneration
Erik S. Musiek, … , David M. Holtzman, Garret A. FitzGerald
Erik S. Musiek, … , David M. Holtzman, Garret A. FitzGerald
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5389-5400. https://doi.org/10.1172/JCI70317.
View: Text | PDF

Circadian clock proteins regulate neuronal redox homeostasis and neurodegeneration

  • Text
  • PDF
Abstract

Brain aging is associated with diminished circadian clock output and decreased expression of the core clock proteins, which regulate many aspects of cellular biochemistry and metabolism. The genes encoding clock proteins are expressed throughout the brain, though it is unknown whether these proteins modulate brain homeostasis. We observed that deletion of circadian clock transcriptional activators aryl hydrocarbon receptor nuclear translocator–like (Bmal1) alone, or circadian locomotor output cycles kaput (Clock) in combination with neuronal PAS domain protein 2 (Npas2), induced severe age-dependent astrogliosis in the cortex and hippocampus. Mice lacking the clock gene repressors period circadian clock 1 (Per1) and period circadian clock 2 (Per2) had no observed astrogliosis. Bmal1 deletion caused the degeneration of synaptic terminals and impaired cortical functional connectivity, as well as neuronal oxidative damage and impaired expression of several redox defense genes. Targeted deletion of Bmal1 in neurons and glia caused similar neuropathology, despite the retention of intact circadian behavioral and sleep-wake rhythms. Reduction of Bmal1 expression promoted neuronal death in primary cultures and in mice treated with a chemical inducer of oxidative injury and striatal neurodegeneration. Our findings indicate that BMAL1 in a complex with CLOCK or NPAS2 regulates cerebral redox homeostasis and connects impaired clock gene function to neurodegeneration.

Authors

Erik S. Musiek, Miranda M. Lim, Guangrui Yang, Adam Q. Bauer, Laura Qi, Yool Lee, Jee Hoon Roh, Xilma Ortiz-Gonzalez, Joshua T. Dearborn, Joseph P. Culver, Erik D. Herzog, John B. Hogenesch, David F. Wozniak, Krikor Dikranian, Benoit I. Giasson, David R. Weaver, David M. Holtzman, Garret A. FitzGerald

×

AKT activation promotes PTEN hamartoma tumor syndrome–associated cataract development
Caterina Sellitto, … , Richard T. Mathias, Thomas W. White
Caterina Sellitto, … , Richard T. Mathias, Thomas W. White
Published November 25, 2013
Citation Information: J Clin Invest. 2013;123(12):5401-5409. https://doi.org/10.1172/JCI70437.
View: Text | PDF

AKT activation promotes PTEN hamartoma tumor syndrome–associated cataract development

  • Text
  • PDF
Abstract

Mutations in the human phosphatase and tensin homolog (PTEN) gene cause PTEN hamartoma tumor syndrome (PHTS), which includes cataract development among its diverse clinical pathologies. Currently, it is not known whether cataract formation in PHTS patients is secondary to other systemic problems, or the result of the loss of a critical function of PTEN within the lens. We generated a mouse line with a lens-specific deletion of Pten (PTEN KO) and identified a regulatory function for PTEN in lens ion transport. Specific loss of PTEN in the lens resulted in cataract. PTEN KO lenses exhibited a progressive age-related increase in intracellular hydrostatic pressure, along with, increased intracellular sodium concentrations, and reduced Na+/K+-ATPase activity. Collectively, these defects lead to lens swelling, opacities and ultimately organ rupture. Activation of AKT was highly elevated in PTEN KO lenses compared to WT mice. Additionally, pharmacological inhibition of AKT restored normal Na+/K+-ATPase activity in primary cultured lens cells and reduced lens pressure in intact lenses from PTEN KO animals. These findings identify a direct role for PTEN in the regulation of lens ion transport through an AKT-dependent modulation of Na+/K+-ATPase activity, and provide a new animal model to investigate cataract development in PHTS patients.

Authors

Caterina Sellitto, Leping Li, Junyuan Gao, Michael L. Robinson, Richard Z. Lin, Richard T. Mathias, Thomas W. White

×
Erratum
Predicting time to ovarian carcinoma recurrence using protein markers
Ji-Yeon Yang, … , Gordon B. Mills, Roel G.W. Verhaak
Ji-Yeon Yang, … , Gordon B. Mills, Roel G.W. Verhaak
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):5410-5410. https://doi.org/10.1172/JCI74035.
View: Text | PDF | Amended Article

Predicting time to ovarian carcinoma recurrence using protein markers

  • Text
  • PDF
Abstract

Authors

Ji-Yeon Yang, Kosuke Yoshihara, Kenichi Tanaka, Masayuki Hatae, Hideaki Masuzaki, Hiroaki Itamochi, Masashi Takano, Kimio Ushijima, Janos L. Tanyi, George Coukos, Yiling Lu, Gordon B. Mills, Roel G.W. Verhaak

×
Corrigenda
Long-term IL-33–producing epithelial progenitor cells in chronic obstructive lung disease
Derek E. Byers, … , Steven L. Brody, Michael J. Holtzman
Derek E. Byers, … , Steven L. Brody, Michael J. Holtzman
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):5410-5410. https://doi.org/10.1172/JCI74125.
View: Text | PDF | Amended Article

Long-term IL-33–producing epithelial progenitor cells in chronic obstructive lung disease

  • Text
  • PDF
Abstract

Authors

Derek E. Byers, Jennifer Alexander-Brett, Anand C. Patel, Eugene Agapov, Geoffrey Dang-Vu, Xiaohua Jin, Kangyun Wu, Yingjian You, Yael Alevy, Jean-Philippe Girard, Thaddeus S. Stappenbeck, G. Alexander Patterson, Richard A. Pierce, Steven L. Brody, Michael J. Holtzman

×

ATP11B mediates platinum resistance in ovarian cancer
Myrthala Moreno-Smith, … , Gabriel Lopez-Berestein, Anil K. Sood
Myrthala Moreno-Smith, … , Gabriel Lopez-Berestein, Anil K. Sood
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):5411-5411. https://doi.org/10.1172/JCI73904.
View: Text | PDF | Amended Article

ATP11B mediates platinum resistance in ovarian cancer

  • Text
  • PDF
Abstract

Authors

Myrthala Moreno-Smith, J.B. Halder, Paul S. Meltzer, Tamas A. Gonda, Lingegowda S. Mangala, Rajesha Rupaimoole, Chunhua Lu, Archana S. Nagaraja, Kshipra M. Gharpure, Yu Kang, Cristian Rodriguez-Aguayo, Pablo E. Vivas-Mejia, Behrouz Zand, Rosemarie Schmandt, Hua Wang, Robert R. Langley, Nicholas B. Jennings, Cristina Ivan, Jeremy E. Coffin, Guillermo N. Armaiz, Justin Bottsford-Miller, Sang Bae Kim, Margaret S. Halleck, Mary J.C. Hendrix, William Bornman, Menashe Bar-Eli, Ju-Seog Lee, Zahid H. Siddik, Gabriel Lopez-Berestein, Anil K. Sood

×

Sema3E–Plexin D1 signaling drives human cancer cell invasiveness and metastatic spreading in mice
Andrea Casazza, … , Paolo M. Comoglio, Luca Tamagnone
Andrea Casazza, … , Paolo M. Comoglio, Luca Tamagnone
Published December 2, 2013
Citation Information: J Clin Invest. 2013;123(12):5411-5411. https://doi.org/10.1172/JCI74037.
View: Text | PDF | Amended Article

Sema3E–Plexin D1 signaling drives human cancer cell invasiveness and metastatic spreading in mice

  • Text
  • PDF
Abstract

Authors

Andrea Casazza, Veronica Finisguerra, Lorena Capparuccia, Andrea Camperi, Jakub M. Swiercz, Sabrina Rizzolio, Charlotte Rolny, Claus Christensen, Andrea Bertotti, Ivana Sarotto, Mauro Risio, Livio Trusolino, Jurgen Weitz, Martin Schneider, Massimilano Mazzone, Paolo M. Comoglio, Luca Tamagnone

×
Advertisement

Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts