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Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI131493.
Abstract
Leptomeningeal anastomoses or pial collateral vessels play a critical role in cerebral blood flow (CBF) restoration following ischemic stroke. The magnitude of this adaptive response is postulated to be controlled by the endothelium, although the underlying molecular mechanisms remain under investigation. Here we demonstrated that endothelial genetic deletion, using EphA4f/f/Tie2-Cre and EphA4f/f/VeCahderin-CreERT2 mice and vessel painting strategies, implicated EphA4 receptor tyrosine kinase as a major suppressor of pial collateral remodeling, CBF and functional recovery following permanent middle cerebral artery occlusion. Pial collateral remodeling is limited by the cross talk between EphA4-Tie2 signaling in vascular endothelial cells, which is mediated through p-Akt regulation. Furthermore, peptide inhibition of EphA4 resulted in acceleration of the pial arteriogenic response. Our findings demonstrate EphA4 is a negative regulator of Tie2 receptor signaling which limits pial collateral arteriogenesis following cerebrovascular occlusion. Therapeutic targeting of EphA4 and/or Tie2 represents an attractive new strategy for improving collateral function, neural tissue health and functional recovery following ischemic stroke.
Authors
Benjamin Okyere, William A. Mills III, Xia Wang, Michael Chen, Jiang Chen, Amanda Hazy, Yun Qian, John B. Matson, Michelle H. Theus
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI127425.
Abstract
Hereditary hemorrhagic telangiectasia (HHT), a genetic bleeding disorder leading to systemic arteriovenous malformations (AVMs), is caused by loss-of-function mutations in the ALK1-ENG-Smad1/5/8 pathway. Evidence suggests that HHT pathogenesis strongly relies on overactivated PI3K-Akt-mTOR and VEGFR2 pathways in endothelial cells (ECs). In the BMP9/10-immunoblocked (BMP9/10ib) neonatal mouse model of HHT, we report here that the mTOR inhibitor, sirolimus, and the receptor tyrosine-kinase inhibitor, nintedanib, could synergistically fully block, but also reversed, retinal AVMs to avert retinal bleeding and anemia. Sirolimus plus nintedanib prevented vascular pathology in the oral mucosa, lungs, and liver of the BMP9/10ib mice, as well as significantly reduced gastrointestinal bleeding and anemia in inducible ALK1-deficient adult mice. Mechanistically, in vivo in BMP9/10ib mouse ECs, sirolimus and nintedanib blocked the overactivation of mTOR and VEGFR2, respectively. Furthermore, we found that sirolimus activated ALK2-mediated Smad1/5/8 signaling in primary ECs—including in HHT patient blood outgrowth ECs—and partially rescued Smad1/5/8 activity in vivo in BMP9/10ib mouse ECs. These data demonstrate that the combined correction of endothelial Smad1/5/8, mTOR, and VEGFR2 pathways opposes HHT pathogenesis. Repurposing of sirolimus plus nintedanib might provide therapeutic benefit in HHT patients.
Authors
Santiago Ruiz, Haitian Zhao, Pallavi Chandakkar, Julien Papoin, Hyunwoo Choi, Aya Nomura-Kitabayashi, Radhika Patel, Matthew Gillen, Li Diao, Prodyot K. Chatterjee, Mingzhu He, Yousef Al-Abed, Ping Wang, Christine N. Metz, S. Paul Oh, Lionel Blanc, Fabien Campagne, Philippe Marambaud
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI126896.
Abstract
EGFR mutated lung adenocarcinoma patients treated with gefitinib and osimertinib show a therapeutic benefit limited by the appearance of secondary mutations, such as EGFRT790M and EGFRC797S. It is generally assumed that these secondary mutations render EGFR completely unresponsive to the inhibitors, but contrary to this, we uncovered here that gefitinib and osimertinib increased STAT3 phosphorylation (pSTAT3) in EGFRT790M and EGFRC797S tumoral cells. Interestingly, we also found that concomitant Notch inhibition with gefitinib or osimertinib treatment induced a pSTAT3-dependent strong reduction in the levels of the transcriptional repressor HES1. Importantly, we showed that tyrosine kinase inhibitor resistant tumors, with EGFRT790M and EGFRC797S mutations, were highly responsive to the combined treatment of Notch inhibitors with gefitinib and osimertinib respectively. Finally, in patients with EGFR mutations treated with tyrosine kinase inhibitors, HES1 protein levels increased during relapse and correlated with shorter progression-free survival. Therefore, our results offer a proof of concept for an alternative treatment to chemotherapy in lung adenocarcinoma osimertinib treated patients after disease progression.
Authors
Emilie Bousquet Mur, Sara Bernardo, Laura Papon, Maicol Mancini, Eric Fabbrizio, Marion Goussard, Irene Ferrer, Anais Giry, Xavier Quantin, Jean-Louis Pujol, Olivier Calvayrac, Herwig P. Moll, Yaël Glasson, Nelly Pirot, Andrei Turtoi, Marta Cañamero, Kwok-Kin Wong, Yosef Yarden, Emilio Casanova, Jean-Charles Soria, Jacques Colinge, Christian W. Siebel, Julien Mazieres, Gilles Favre, Luis Paz-Ares, Antonio Maraver
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI130675.
Abstract
The corneocyte lipid envelope composed of covalently bound ceramides and fatty acids is important to the integrity of the permeability barrier in the stratum corneum, and its absence is a prime structural defect in various skin diseases associated with defective skin barrier function. SDR9C7 encodes a short chain dehydrogenase/reductase family 9C member 7 (SDR9C7) recently found mutated in ichthyosis. In a patient with SDR9C7 mutation and a mouse Sdr9c7 knockout model we show loss of covalent binding of epidermal ceramides to protein, a structural fault in the barrier. For reasons unresolved, protein binding requires lipoxygenase-catalyzed transformations of linoleic acid (18:2) esterified in ω-O-acylceramides. In Sdr9c7-/- epidermis, quantitative LC-MS assays revealed almost complete loss of a species of ω-O-acylceramide esterified with linoleate-9,10-trans-epoxy-11E-13-ketone; other acylceramides related to the lipoxygenase pathway were in higher abundance. Recombinant SDR9C7 catalyzed NAD+-dependent dehydrogenation of linoleate 9,10-trans-epoxy-11E-13-alcohol to the corresponding 13-ketone, while ichthyosis mutants were inactive. We propose, therefore, that the critical requirement for lipoxygenases and SDR9C7 is in producing acylceramide containing the 9,10-epoxy-11E-13-ketone, a reactive moiety known for its non-enzymatic coupling to protein. This suggests a mechanism for coupling of ceramide to protein and provides important insights into skin barrier formation and pathogenesis.
Authors
Takuya Takeichi, Tetsuya Hirabayashi, Yuki Miyasaka, Akane Kawamoto, Yusuke Okuno, Shijima Taguchi, Kana Tanahashi, Chiaki Murase, Hiroyuki Takama, Kosei Tanaka, William E. Boeglin, M. Wade Calcutt, Daisuke Watanabe, Michihiro Kono, Yoshinao Muro, Junko Ishikawa, Tamio Ohno, Alan R. Brash, Masashi Akiyama
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI124000.
Abstract
The mechanisms that modulate the kinetics of muscle relaxation are critically important for muscle function. A prime example of the impact of impaired relaxation kinetics is nemaline myopathy caused by mutations in KBTBD13 (NEM6). In addition to weakness, NEM6 patients have slow muscle relaxation, compromising contractility and daily-life activities. The role of KBTBD13 in muscle is unknown, and the pathomechanism underlying NEM6 is undetermined. A combination of transcranial magnetic stimulation-induced muscle relaxation, muscle fiber- and sarcomere-contractility assays, low angle X-ray diffraction and super-resolution microscopy revealed that the impaired muscle relaxation kinetics in NEM6 patients are caused by structural changes in the thin filament, a sarcomeric microstructure. Using homology modeling, binding- and contractility assays with recombinant KBTBD13, novel Kbtbd13-knockout and Kbtbd13R408C-knockin mouse models and a GFP-labeled Kbtbd13- transgenic zebrafish model we discovered that KBTBD13 binds to actin – a major constituent of the thin filament - and that mutations in KBTBD13 cause structural changes impairing muscle relaxation kinetics. We propose that this actin-based impaired relaxation is central to NEM6 pathology.
Authors
Josine M. de Winter, Joery P. Molenaar, Michaela Yuen, Robbert van der Pijl, Shengyi Shen, Stefan Conijn, Martijn van de Locht, Menne Willigenburg, Sylvia J.P. Bogaards, Esmee S.B. van Kleef, Saskia Lassche, Malin Persson, Dilson E. Rassier, Tamar E. Sztal, Avnika A. Ruparelia, Viola Oorschot, Georg Ramm, Thomas E. Hall, Zherui Xiong, Christopher N. Johnson, Frank Li, Balazs Kiss, Noelia Lozano-Vidal, Reinier A. Boon, Manuela Marabita, Leonardo Nogara, Bert Blaauw, Richard J. Rodenburg, Benno Kϋsters, Jonne Doorduin, Alan H. Beggs, Henk Granzier, Ken Campbell, Weikang Ma, Thomas Irving, Edoardo Malfatti, Norma B. Romero, Robert J. Bryson-Richardson, Baziel G.M. van Engelen, Nicol C. Voermans, Coen A.C. Ottenheijm
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI126598.
Abstract
Immunotherapy targeting programmed cell death-1 (PD-1) induces durable antitumor efficacy in many types of cancer. However, such clinical benefit is limited because of the insufficient reinvigoration of antitumor immunity with the drug alone; therefore, rational therapeutic combinations are required to improve its efficacy. In our preclinical study, we evaluated the antitumor effect of U3-1402, a human epidermal growth factor receptor 3 (HER3)–targeting antibody-drug conjugate, and its potential synergism with PD-1 inhibition. Using a syngeneic mouse tumor model that is refractory to anti–PD-1 therapy, treatment with U3-1402 exhibited an obvious antitumor effect via direct lysis of tumor cells. Disruption of tumor cells by U3-1402 enhanced the infiltration of innate and adaptive immune cells. Chemotherapy with exatecan derivative (Dxd: the drug payload of U3-1402) revealed that the enhanced antitumor immunity produced by U3-1402 was associated with the induction of alarmins including HMGB-1 via tumor-specific cytotoxicity. Notably, U3-1402 significantly sensitized the tumor to PD-1 blockade, as a combination of U3-1402 and the PD-1 inhibitor significantly enhanced antitumor immunity. Further, clinical analyses indicated that tumor-specific HER3 expression was frequently observed in patients with PD-1 inhibitor–resistant solid tumors. Overall, U3-1402 is a promising candidate as a partner of immunotherapy for such patients.
Authors
Koji Haratani, Kimio Yonesaka, Shiki Takamura, Osamu Maenishi, Ryoji Kato, Naoki Takegawa, Hisato Kawakami, Kaoru Tanaka, Hidetoshi Hayashi, Masayuki Takeda, Naoyuki Maeda, Takashi Kagari, Kenji Hirotani, Junji Tsurutani, Kazuto Nishio, Katsumi Doi, Masaaki Miyazawa, Kazuhiko Nakagawa
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI126381.
Abstract
While the impact of T helper 17 (Th17) cells in autoimmunity is undisputable, their pathogenic effector mechanism is still enigmatic. We have discovered SNARE complex proteins in Th17 cells enabling a vesicular glutamate release pathway inducing local intracytoplasmic calcium release and subsequent damage in neurons. This pathway is glutamine dependent and triggered by binding of β1-integrin to VCAM-1 on neurons in inflammatory context. Glutamate secretion could be blocked by inhibiting either glutaminase or KV1.3 channels, known to be linked to integrin expression and highly expressed on stimulated T cells. While KV1.3 is not expressed in the CNS tissue, intrathecal administration of a KV1.3 channel blocker or a glutaminase inhibitor ameliorated disability in experimental neuroinflammation. In humans, T cells from multiple sclerosis patients secreted higher levels of glutamate, and cerebrospinal fluid glutamine levels were increased. Altogether, our findings demonstrate that β1-integrin- and KV1.3 channel-dependent signaling stimulates glutamate release from Th17 cells upon direct cell-cell contact between Th17 cells and neurons.
Authors
Katharina Birkner, Beatrice Wasser, Tobias Ruck, Carine Thalman, Dirk Luchtman, Katrin Pape, Samantha Schmaul, Lynn Bitar, Eva-Maria Krämer-Albers, Albrecht Stroh, Sven G. Meuth, Frauke Zipp, Stefan Bittner
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI128267.
Abstract
Efficacy of dendritic cell (DC) cancer vaccines is classically thought to depend on their antigen-presenting cell (APC) activity. Studies show, however, that DC vaccine priming of cytotoxic T lymphocytes (CTL) requires the activity of endogenous DC, suggesting that exogenous DC stimulate anti-tumor immunity by transferring antigen (Ag) to endogenous DC. Such Ag transfer functions are most commonly ascribed to monocytes, implying that undifferentiated monocytes would function equally well as a vaccine modality and need not be differentiated to DC to be effective. Here, we used several murine cancer models to test the anti-tumor efficacy of undifferentiated monocytes loaded with protein or peptide Ag. Intravenously injected monocytes displayed anti-tumor activity superior to DC vaccines in several cancer models, including aggressive intracranial glioblastoma. Ag-loaded monocytes induced robust CTL responses via Ag transfer to splenic CD8+ DC in a manner independent of monocyte APC activity. Ag transfer required cell-cell contact and the formation of connexin 43-containing gap junctions between monocytes and DC. These findings demonstrate the existence of an efficient gap junction-mediated Ag transfer pathway between monocytes and CD8+ DC and suggest that administration of tumor Ag-loaded undifferentiated monocytes may serve as a simple and efficacious immunotherapy for the treatment of human cancers.
Authors
Min-Nung Huang, Lowell T. Nicholson, Kristen A. Batich, Adam M. Swartz, David Kopin, Sebastian Wellford, Vijay K. Prabhakar, Karolina Woroniecka, Smita K. Nair, Peter E. Fecci, John H. Sampson, Michael D. Gunn
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI127341.
Abstract
Iron deficiency is common worldwide and is associated with adverse pregnancy outcomes. The increasing prevalence of indiscriminate iron supplementation during pregnancy also raises concerns about the potential adverse effects of iron excess. We examined how maternal iron status affects the delivery of iron to the placenta and fetus. Using mouse models, we documented maternal homeostatic mechanisms which protect the placenta and fetus from maternal iron excess. We determined that under physiological conditions or in iron deficiency, fetal and placental hepcidin does not regulate fetal iron endowment. With maternal iron deficiency, critical transporters mediating placental iron uptake (transferrin receptor 1, TFR1) and export (ferroportin, FPN) were strongly regulated. In mice, not only was TFR1 increased but FPN was surprisingly decreased to preserve placental iron, in the face of fetal iron deficiency. In human placentas from pregnancies with mild iron deficiency, TFR1 was increased but without a change in FPN. However, induction of more severe iron deficiency in human trophoblast in vitro resulted in the regulation of both TFR1 and FPN, similarly to the mouse model. This placental adaptation prioritizing placental iron is mediated by the iron-regulatory protein 1 and is important for the maintenance of mitochondrial respiration, thus ultimately protecting the fetus from the potentially dire consequences of generalized placental dysfunction.
Authors
Veena Sangkhae, Allison L. Fisher, Shirley Wong, Mary Dawn Koenig, Lisa Tussing-Humphreys, Alison Chu, Melisa Lelić, Tomas Ganz, Elizabeta Nemeth
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI129161.
Abstract
CD8+ T cell responses are necessary for immune control of simian immunodeficiency virus (SIV). However, the key parameters that dictate antiviral potency remain elusive, conceivably because most studies to date have been restricted to analyses of circulating CD8+ T cells. We conducted a detailed clonotypic, functional, and phenotypic survey of SIV-specific CD8+ T cells across multiple anatomical sites in chronically infected rhesus macaques with high (> 10,000 copies/mL plasma) or low burdens of viral RNA (< 10,000 copies/mL plasma). No significant differences in response magnitude were identified across anatomical compartments. Rhesus macaques with low viral loads (VLs) harbored higher frequencies of polyfunctional CXCR5+ SIV-specific CD8+ T cells in various lymphoid tissues and higher proportions of unique Gag-specific CD8+ T cell clonotypes in the mesenteric lymph nodes relative to rhesus macaques with high VLs. In addition, public Gag-specific CD8+ T cell clonotypes were more commonly shared across distinct anatomical sites than the corresponding private clonotypes, which tended to form tissue-specific repertoires, especially in the peripheral blood and the gastrointestinal tract. Collectively, these data suggest that functionality and tissue localization are important determinants of CD8+ T cell-mediated efficacy against SIV.
Authors
Carly E. Starke, Carol L. Vinton, Kristin Ladell, James E. McLaren, Alexandra M. Ortiz, Joseph C. Mudd, Jacob K. Flynn, Stephen H. Lai, Fan Wu, Vanessa M. Hirsch, Samuel Darko, Daniel C. Douek, David A. Price, Jason M. Brenchley
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI128043.
Abstract
Tuberculosis (TB) remains a major infectious disease worldwide. TB treatment displays a bi-phasic bacterial clearance, in which the majority of bacteria clear within the first month of treatment, but residual bacteria remains non-responsive to treatment and eventually may become resistant. Here, we have shown that Mycobacterium tuberculosis (M.tb) is taken up by mesenchymal stem cells (MSCs), where it established dormancy and became highly non-responsive to isoniazid, a major constituent of Directly Observed Treatment Short-course (DOTS). Dormant M.tb induced quiescence in MSCs and promoted their long-term survival. Unlike macrophages, where M.tb resides in early-phagosomal compartments, in MSCs the majority of bacilli were found in the cytosol, where they promoted rapid lipid-synthesis, hiding within lipid-droplets. Inhibition of lipid-synthesis prevented dormancy and sensitized the organisms to isoniazid. Thus, we have established that M.tb gains dormancy in MSCs, which thus serve as a long-term natural-reservoir of dormant M.tb. Interestingly, in the murine-model of TB, induction of autophagy eliminated M.tb from MSCs and consequently, the addition of rapamycin to an isoniazid treatment regimen successfully attained sterile clearance and prevented disease reactivation.
Authors
Samreen Fatima, Shashank Shivaji Kamble, Ved Prakash Dwivedi, Debapriya Bhattacharya, Santosh Kumar, Anand Ranganathan, Luc Van Kaer, Sujata Mohanty, Gobardhan Das
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI129382.
Abstract
β-thalassemia is a genetic anemia caused by partial or complete loss of β-globin synthesis leading to ineffective erythropoiesis and RBCs with short life-span. Currently, there is no efficacious oral medication modifying anemia for patients with beta-thalassemia. The inappropriately low levels of the iron regulatory hormone hepcidin enable excessive iron absorption by ferroportin, the unique cellular iron exporter in mammals, leading to organ iron overload and associated morbidities. Correction of unbalanced iron absorption and recycling by induction of hepcidin synthesis or treatment with hepcidin mimetics ameliorates β-thalassemia. However, hepcidin modulation or replacement strategies currently in clinical development all require parenteral drug administration. We identified oral ferroportin inhibitors by screening a library of small molecular weight compounds for modulators of ferroportin internalization. Restricting iron availability by VIT-2763, the first clinical stage oral ferroportin inhibitor, ameliorated anemia and the dysregulated iron homeostasis in the Hbbth3/+ mouse model of beta-thalassemia intermedia. VIT-2763 not only improved erythropoiesis but also corrected the proportions of myeloid precursors in spleens of Hbbth3/+ mice. VIT-2763 is currently developed as an oral drug targeting ferroportin for the treatment of β-thalassemia.
Authors
Vania Manolova, Naja Nyffenegger, Anna Flace, Patrick Altermatt, Ahmet Varol, Cédric Doucerain, Hanna Sundstrom, Franz Dürrenberger
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI130730.
Abstract
Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal-dominant connective tissue disorder caused by heterozygous mutations in the COL3A1 gene, which encodes the pro-alpha 1 chain of collagen III. Loss of structural integrity of the extracellular matrix is believed to drive the signs and symptoms of this condition, including spontaneous arterial dissection and/or rupture, the major cause of mortality. We created two mouse models of vEDS that carry heterozygous mutations in Col3a1 that encode glycine substitutions analogous to those found in patients, and showed that signaling abnormalities in the PLC/IP3/PKC/ERK pathway (phospholipase C/inositol 1,4,5-triphosphate/protein kinase C/extracellular signal-regulated kinase) are major mediators of vascular pathology.Treatment with pharmacologic inhibitors of ERK1/2 or PKC-beta prevented death due to spontaneous aortic rupture. Additionally, we found that pregnancy- and puberty-associated accentuation of vascular risk, also seen in vEDS patients, is rescued by attenuation of oxytocin and androgen signaling, respectively. Taken together, our results provide evidence that targetable signaling abnormalities contribute to the pathogenesis of vEDS, highlighting unanticipated therapeutic opportunities.
Authors
Caitlin J. Bowen, Juan Francisco Calderón Giadrosic, Zachary Burger, Graham Rykiel, Elaine C. Davis, Mark R. Helmers, Kelly Benke, Elena Gallo MacFarlane, Harry C. Dietz
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI131958.
Abstract
Recent occurrences of filoviruses and the arenavirus Lassa virus (LASV) in overlapping endemic areas of Africa highlight the need for a prophylactic vaccine that would confer protection against all of these viruses that cause lethal hemorrhagic fever (HF). We developed a quadrivalent formulation of Vesiculovax that contains recombinant vesicular stomatitis virus (rVSV) vectors expressing filovirus glycoproteins and also contains a rVSV vector expressing the glycoprotein of a lineage IV strain of LASV. Cynomolgus macaques were vaccinated twice with the quadrivalent formulation, followed by challenge 28 days after the boost vaccination with each of the three corresponding filoviruses (Ebola, Sudan, Marburg) or a heterologous contemporary lineage II strain of LASV. Serum IgG and neutralizing antibody responses specific for all four glycoproteins were detected in all vaccinated animals. A modest and balanced cell-mediated immune response specific for the glycoproteins was also detected in most of the vaccinated macaques. Regardless of the levels of total glycoprotein-specific immune response detected after vaccination, all immunized animals were protected from disease and death following lethal challenges. These findings indicate that vaccination with attenuated rVSV vectors each expressing a single HF virus glycoprotein may provide protection against those filoviruses and LASV most commonly responsible for outbreaks of severe HF in Africa.
Authors
Robert W. Cross, Rong Xu, Demetrius Matassov, Stefan Hamm, Theresa E. Latham, Cheryl S. Gerardi, Rebecca M. Nowak, Joan B. Geisbert, Ayuko Ota-Setlik, Krystle N. Agans, Amara Luckay, Susan E. Witko, Lena Soukieh, Daniel J. Deer, Chad E. Mire, Heinz Feldmann, Christian Happi, Karla A. Fenton, John H. Eldridge, Thomas W. Geisbert
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI127515.
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is considered to be a highly immunosuppressive and heterogenous neoplasm. Despite improved knowledge regarding the genetic background of the tumor and better understanding of the tumor microenvironment, immune checkpoint inhibitor therapy (targeting CTLA4, PD1, PDL1) has not been very successful against PDAC. The robust desmoplastic stroma, along with an extensive extracellular matrix (ECM) that is rich in hyaluronan, plays an integral role in this immune evasion. Hexosamine biosynthesis pathway (HBP), a shunt pathway of glycolysis, is a metabolic node in cancer cells that can promote survival pathways on one hand and influence the hyaluronan synthesis in the ECM on the other. The rate-limiting enzyme of the pathway, glutamine-fructose amidotransferase (GFAT1), uses glutamine and fructose 6-phosphate to eventually synthesize UDP-GlcNAc. In the current manuscript, we targeted this glutamine-utilizing enzyme by a small molecule glutamine analog (6-diazo-5-oxo-L-norleucine or DON). Our results showed that DON decreased the self-renewal potential and metastatic ability of tumor cell. Further, treatment with DON decreased hyaluronan and collagen in the tumor microenvironment, leading to an extensive remodeling of the ECM, and an increased infiltration CD8+ T-cells. Additionally, treatment with DON sensitized pancreatic tumors to anti-PD1 therapy resulting in tumor regression and prolonged survival.
Authors
Nikita S. Sharma, Vineet K. Gupta, Vanessa T. Garrido, Roey Hadad, Brittany C. Durden, Kousik Kesh, Bhuwan Giri, Anthony Ferrantella, Vikas Dudeja, Ashok Saluja, Sulagna Banerjee
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI129937.
Abstract
Background: Proteinuria is considered as an unfavorable clinical condition that accelerates renal and cardiovascular disease. However, it is not clear if all forms of proteinuria are damaging. Mutations in CUBN cause Imerslund-Gräsbeck syndrome (IGS) featured by intestinal malabsorption of vitamin B12 and in some cases proteinuria. CUBN encodes for cubilin, an intestinal and proximal tubular uptake receptor containing 27 CUB domains for ligand binding. Methods: We used next-generation sequencing for renal disease genes to genotype cohorts of patients with suspected hereditary renal disease and chronic proteinuria. CUBN variants were analyzed using bioinformatics, structural modeling and epidemiological methods. Results: We identified 39 patients, in whom biallelic pathogenic variants in the CUBN gene are associated with chronic isolated proteinuria with childhood onset. Since the proteinuria displayed a high proportion of albuminuria, glomerular diseases such as steroid-resistant nephrotic syndrome or Alport syndrome were often the primary clinical diagnosis, motivating renal biopsies and proteinuria-lowering treatments. Yet, renal function was normal in all cases. By contrast, we did not find any biallelic pathogenic CUBN variants in patients with reduced renal function or focal segmental glomerulosclerosis. Unlike the more N-terminal IGS mutations, 37 out of the 41 proteinuria-associated CUBN variants led to modifications or truncations after the vitamin B12-binding domain. Finally, we show that four C-terminal CUBN variants are associated with albuminuria and moderately increased GFR in meta-analyses of large population-based cohorts. Conclusions: Collectively, our data suggest an important role for the C-terminal half of cubilin in renal albumin reabsorption. Albuminuria due to reduced cubilin function could be an unexpectedly common benign condition in humans that may not require any proteinuria-lowering treatment or renal biopsies.
Authors
Mathilda Bedin, Olivia Boyer, Aude Servais, Yong Li, Laure Villoing-Gaudé, Marie-Josephe Tête, Alexandra Cambier, Julien Hogan, Veronique Baudouin, Saoussen Krid, Albert Bensman, Florie Lammens, Ferielle Louillet, Bruno Ranchin, Cecile Vigneau, Iseline Bouteau, Corinne Isnard-Bagnis, Christoph J. Mache, Tobias Schäfer, Lars Pape, Markus Gödel, Tobias B. Huber, Marcus Benz, Günter Klaus, Matthias Hansen, Kay Latta, Olivier Gribouval, Vincent Morinière, Carole Tournant, Maik Grohmann, Elisa Kuhn, Timo Wagner, Christine Bole-Feysot, Fabienne Jabot-Hanin, Patrick Nitschké, Tarunveer S. Ahluwalia, Anna Köttgen, Christian Brix Folsted Andersen, Carsten Bergmann, Corinne Antignac, Matias Simons
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI129061.
Abstract
Tyrosine kinase inhibitors (TKIs) induce molecular remission in the majority of patients with chronic myelogenous leukemia (CML), but persistence of CML stem cells hinders cure and necessitates indefinite TKI therapy. We report that CML stem cells upregulate expression of pleiotrophin (PTN) and require cell-autonomous PTN signaling for CML pathogenesis in BCR/ABL+ mice. Constitutive PTN deletion substantially reduced the numbers of CML stem cells capable of initiating CML in vivo. Hematopoietic cell–specific deletion of PTN suppressed CML development in BCR/ABL+ mice, suggesting that cell-autonomous PTN signaling was necessary for CML disease evolution. Mechanistically, PTN promoted CML stem cell survival and TKI resistance via induction of Jun and the unfolded protein response. Human CML cells were also dependent on cell-autonomous PTN signaling and anti–PTN antibody suppressed human CML colony formation and CML repopulation in vivo. Our results suggest that targeted inhibition of PTN has therapeutic potential to eradicate CML stem cells.
Authors
Heather A. Himburg, Martina Roos, Tiancheng Fang, Yurun Zhang, Christina M. Termini, Lauren Schlussel, Mindy M. Kim, Amara Pang, Jenny Kan, Liman Zhao, Hyung Suh, Joshua P. Sasine, Gopal Sapparapu, Peter M. Bowers, Gary Schiller, John P. Chute
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI126645.
Abstract
Novel approaches for adjunctive therapy are urgently needed for infections complicated by antibiotic-resistant pathogens and for patients with compromised immunity. Necrotizing fasciitis (NF) is a destructive skin and soft tissue infection. Despite treatment with systemic antibiotics and radical debridement of necrotic tissue, lethality remains high. The key iron regulatory hormone hepcidin was originally identified as a cationic antimicrobial peptide (AMP), but its putative expression and role in the skin, a major site of AMP production, has never been investigated. We report here that hepcidin production is induced in the skin of patients with Group A Streptococcal (GAS) NF. In a GAS-induced NF model, mice lacking hepcidin in keratinocytes failed to restrict systemic spread of infection from an initial tissue focus. Unexpectedly, this effect was due its ability to promote production of the CXCL1 chemokine by keratinocytes resulting in neutrophil recruitment. Unlike CXCL1, hepcidin is resistant to degradation by major GAS proteases and could therefore serve as a reservoir to maintain steady state levels of CXCL1 in infected tissue. Finally, injection of synthetic hepcidin at the site of infection can limit or completely prevent systemic spread of GAS infection suggesting that hepcidin agonists could have a therapeutic role in NF.
Authors
Mariangela Malerba, Sabine Louis, Sylvain Cuvellier, Srikanth Mairpady Shambat, Camille Hua, Camille Gomart, Agnès Fouet, Nicolas Ortonne, Jean-Winoc Decousser, Annelies S. Zinkernagel, Jacques R.R. Mathieu, Carole Peyssonnaux
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI130952.
Abstract
Polymorphonuclear neutrophils (PMNs) are increasingly recognized to influence solid tumor development, but why their effects are so context-dependent and even frequently divergent remains poorly understood. Using an autochthonous mouse model of uterine cancer and the administration of respiratory hyperoxia as a means to improve tumor oxygenation, we provide in vivo evidence that hypoxia is a potent determinant of tumor-associated PMN phenotypes and direct PMN-tumor cell interactions. Upon relief of tumor hypoxia, PMNs were recruited less intensely to the tumor-bearing uterus but the recruited cells much more effectively killed tumor cells, an activity our data moreover suggested was mediated via their production of NADPH oxidase-derived reactive oxygen species and MMP-9. Simultaneously, their ability to promote tumor cell proliferation, which appeared mediated via their production of neutrophil elastase, was rendered less effective. Relieving tumor hypoxia thus greatly improved net PMN-dependent tumor control, leading to a massive reduction in tumor burden. Remarkably, this outcome was T cell-independent. Together, these findings identify key hypoxia-regulated molecular mechanisms through which PMNs directly induce tumor cell death and proliferation in vivo and suggest that the contrasting properties of PMNs in different tumor settings may in part reflect the effects of hypoxia on direct PMN-tumor cell interactions.
Authors
Karim Mahiddine, Adam Blaisdell, Stephany Ma, Amandine Créquer-Grandhomme, Clifford A. Lowell, Adrian Erlebacher
Citation Information: J Clin Invest. 2019. https://doi.org/10.1172/JCI130892.
Abstract
Patients with bladder cancer (BCa) with clinical lymph node (LN) metastasis have extremely poor prognosis. VEGF-C has been demonstrated to play vital roles in LN metastasis in BCa. However, approximately 20% of BCa with LN metastasis exhibits low VEGF-C expression, suggesting a VEGF-C-independent mechanism for LN metastasis of BCa. Herein, we demonstrated that BCa cell-secreted exosomes-mediated lymphangiogenesis promoted LN metastasis in BCa, which was in a VEGF-C-independent manner. We identified an exosomal long noncoding RNA (lncRNA), termed lymph node metastasis-associated transcript 2 (LNMAT2), stimulated HLEC tube formation and migration in vitro and enhanced tumor lymphangiogenesis and LN metastasis in vivo. Mechanistically, LNMAT2 was loaded to BCa cell-secreted exosomes by directly interacting with heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1). Subsequently, exosomal LNMAT2 was internalized by HLECs and epigenetically upregulated prospero homeobox 1 (PROX1) expression by recruitment of hnRNPA2B1 and increasing the H3K4 trimethylation level in the PROX1 promoter, ultimately resulting in lymphangiogenesis and lymphatic metastasis. Therefore, our findings highlight a VEGF-C-independent mechanism of exosomal lncRNA-mediated LN metastasis and identify LNMAT2 as a therapeutic target for LN metastasis in BCa.
Authors
Changhao Chen, Yuming Luo, Wang He, Yue Zhao, Yao Kong, Hongwei Liu, Guangzheng Zhong, Yuting Li, Jun Li, Jian Huang, Rufu Chen, Tianxin Lin
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ISSN: 0021-9738 (print), 1558-8238 (online)