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Impaired immune cell cytotoxicity in severe COVID-19 is IL-6 dependent

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Abstract

Background: Coronavirus disease 19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2. Anti-viral immune response is crucial to achieve pathogen clearance, however in some patients an excessive and aberrant host immune response can lead to an acute respiratory distress syndrome. The comprehension of the mechanisms that regulate pathogen elimination, immunity, and pathology is essential to better characterize disease progression and widen the spectrum of therapeutic options. Methods: We performed a flow cytometric characterization of immune cells subsets from 30 COVID-19 patients and correlated these data with clinical outcomes. Results: COVID-19 patients showed decreased numbers of circulating T, B and NK cells, and exhibited a skewing of CD8+ T cells towards a terminally differentiated/senescent phenotype. In agreement, T CD4+, T CD8+ but also NK cells displayed reduced anti-viral cytokine production capability. Moreover, a reduced cytotoxic potential was identified in COVID-19 patients, particularly in those that required intensive care. The latter group of patients showed also increased serum IL-6 levels, that correlated to the frequency of granzyme-expressing NK cells. Off-label treatment with tocilizumab restored the cytotoxic potential of NK cells. Conclusion: In conclusion, the association between IL-6 serum levels and the impairment of cytotoxic activity suggests the possibility that targeting this cytokine may restore anti-viral mechanisms. Funding: This study was supported by funds of Dept. of Experimental and Clinical Medicine of University of Florence (ex-60%) derived from Ministero dell’Istruzione, dell’Università e della Ricerca (Italy).

Authors

Alessio Mazzoni, Lorenzo Salvati, Laura Maggi, Manuela Capone, Anna Vanni, Michele Spinicci, Jessica Mencarini, Roberto Caporale, Benedetta Peruzzi, Alberto Antonelli, Michele Trotta, Lorenzo Zammarchi, Luca Ciani, Leonardo Gori, Chiara Lazzeri, Andrea Matucci, Alessandra Vultaggio, Oliviero Rossi, Fabio Almerigogna, Paola Parronchi, Paolo Fontanari, Federico Lavorini, Adriano Peris, Gian Maria Rossolini, Alessandro Bartoloni, Sergio Romagnani, Francesco Liotta, Francesco Annunziato, Lorenzo Cosmi

New York City COVID-19 resident physician exposure during exponential phase of pandemic

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Background From March 2-April 12, 2020, New York City (NYC) experienced exponential growth of the COVID-19 pandemic due to novel coronavirus (SARS-CoV-2). Little is known regarding how physicians have been affected. We aimed to characterize COVID-19 impact on NYC resident physicians. Methods IRB-exempt and expedited cross-sectional analysis through survey to NYC residency program directors (PDs) April 3–12, 2020, encompassing events from March 2–April 12, 2020. Results From an estimated 340 residency programs around NYC, recruitment yielded 91 responses, representing 24 specialties and 2,306 residents. 45.1% of programs reported at least one resident with confirmed COVID-19: 101 resident physicians were confirmed COVID-19-positive, with an additional 163 residents presumed positive for COVID-19 based on symptoms but awaiting or unable to obtain testing. Two COVID-19-positive residents were hospitalized, with one in intensive care. Among specialties with >100 residents represented, negative binomial regression indicated that infection risk differed by specialty (p=0.039). 80% of programs reported quarantining a resident. 90/91 programs reported reuse or extended mask use, and 43 programs reported that personal protective equipment (PPE) was suboptimal. 65 programs (74.7%) have redeployed residents elsewhere to support COVID-19 efforts. Conclusion Many resident physicians around NYC have been affected by COVID-19 through direct infection, quarantine, or redeployment. Lack of access to testing and concern regarding suboptimal PPE are common among residency programs. Infection risk may differ by specialty. Funding AHA, MPB, RWSC, CGM, LRDG, JDH: NEI Core Grant P30EY019007, RPB Unrestricted Grant. ACP and JS: Parker Family Chair. SXX: University of Pennsylvania.

Authors

Mark P. Breazzano, Junchao Shen, Aliaa H. Abdelhakim, Lora Dagi Glass, Jason Horowitz, Sharon X. Xie, C. Gustavo De Moraes, Alice Chen-Plotkin, Royce W.S. Chen

COVID-19, microangiopathy, hemostatic activation, and complement

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Abstract

In COVID-19, complement activation may contribute to hemostatic activation leading to pathological features such as microvascular injury and coagulopathy.

Authors

Wen-Chao Song, Garret A. FitzGerald

Dysfunction of the ciliary ARMC9/TOGARAM1 protein module causes Joubert syndrome

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Joubert syndrome (JBTS) is a recessive neurodevelopmental ciliopathy, characterized by a pathognomonic hindbrain malformation. All known JBTS-genes encode proteins involved in the structure or function of primary cilia, ubiquitous antenna-like organelles essential for cellular signal transduction. Here, we use the recently identified JBTS-associated protein ARMC9 in tandem-affinity purification and yeast two-hybrid screens to identify a novel ciliary module whose dysfunction underlies JBTS. In addition to known JBTS-associated proteins CEP104 and CSPP1, we identify CCDC66 and TOGARAM1 as ARMC9 interaction partners. We show that TOGARAM1 variants cause JBTS and disrupt TOGARAM1 interaction with ARMC9. Using a combination of protein interaction analyses and characterization of patient-derived fibroblasts, CRISPR/Cas9-engineered zebrafish and hTERT-RPE1 cells, we demonstrate that dysfunction of ARMC9 or TOGARAM1 results in short cilia with decreased axonemal acetylation and polyglutamylation, but relatively intact transition zone function. Aberrant cold- and serum-induced ciliary loss in both ARMC9 and TOGARAM1 patient cell lines suggests a role for this new JBTS-associated protein module in ciliary stability.

Authors

Brooke L. Latour, Julie C. Van De Weghe, Tamara D.S. Rusterholz, Stef J.F. Letteboer, Arianna Gomez, Ranad Shaheen, Matthias Gesemann, Arezou Karamzade, Mostafa Asadollahi, Miguel Barroso-Gil, Manali Chitre, Megan E. Grout, Jeroen van Reeuwijk, Sylvia E.C. van Beersum, Caitlin V. Miller, Jennifer C. Dempsey, Heba Morsy, Michael J. Bamshad, Deborah A. Nickerson, Stephan C.F. Neuhauss, Karsten Boldt, Marius Ueffing, Mohammad Keramatipour, John A. Sayer, Fowzan S. Alkuraya, Ruxandra Bachmann-Gagescu, Ronald Roepman, Dan Doherty

Rathke’s cleft-like cysts arise from Isl1 deletion in murine pituitary progenitors

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The transcription factor ISL1 is expressed in pituitary gland stem cells and the thyrotrope and gonadotrope lineages. Pituitary-specific Isl1 deletion causes hypopituitarism with increased stem cell apoptosis, reduced differentiation of thyrotropes and gonadotropes, and reduced body size. Conditional Isl1 deletion causes development of multiple Rathke’s cleft-like cysts, with 100% penetrance. Foxa1 and Foxj1 are abnormally expressed in the pituitary gland and associated with a ciliogenic gene expression program in the cysts. We confirmed expression of FOXA1, FOXJ1 and stem cell markers in human Rathke's cleft cyst tissue, but not craniopharyngiomas, which suggests these transcription factors are useful, pathological markers for diagnosis of Rathke's cleft cysts. These studies support a model whereby expression of ISL1 in pituitary progenitors drives differentiation into thyrotropes and gonadotropes, and without it, activation of FOXA1 and FOXJ1 permits development of an oral epithelial cell fate with mucinous cysts. This pituitary specific Isl1 mouse knockout sheds light on the etiology of Rathke's cleft cysts and the role of ISL1 in normal pituitary development.

Authors

Michelle L. Brinkmeier, Hironori Bando, Adriana C. Camarano, Shingo Fujio, Koji Yoshimoto, Flávio S. J. de Souza, Sally A. Camper

Donor monocyte-derived macrophages promote human acute graft versus host disease

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Myelopoiesis is invariably present, and contributes to pathology, in animal models of graft versus host disease (GVHD). In humans, a rich inflammatory infiltrate bearing macrophage markers has also been described in histological studies. In order to determine the origin, functional properties and role in pathogenesis of these cells, we isolated single cell suspensions from acute cutaneous GVHD and subjected them to genotype, transcriptome and in vitro functional analysis. A donor-derived population of CD11c+CD14+ cells was the dominant population of all leukocytes in GVHD. Surface phenotype and nanostring gene expression profiling indicated the closest steady-state counterpart of these cells to be monocyte-derived macrophages. In GVHD, however, there was upregulation of monocyte antigens SIRPα and S100A8/9, and transcripts associated with leukocyte trafficking, pattern recognition, antigen presentation, and co-stimulation. Isolated GVHD macrophages stimulated greater proliferation and activation of allogeneic T cells, and secreted higher levels of inflammatory cytokines than their steady-state counterparts. In HLA-matched mixed leukocyte reactions, we also observed differentiation of activated macrophages with a similar phenotype. These exhibited cytopathicity to a cell line and mediated pathological damage to skin explants, independently of T cells. Together, these results define the origin, functional properties and potential pathogenic roles of human GVHD macrophages.

Authors

Laura Jardine, Urszula Cytlak, Merry Gunawan, Gary Reynolds, Kile Green, Xiao-nong Wang, Sarah Pagan, Maharani Paramitha, Christopher A. Lamb, Anna Long, Erin Hurst, Smeera Nair, Graham H. Jackson, Amy Publicover, Venetia Bigley, Muzlifah Haniffa, AJ Simpson, Matthew Collin

Human CD83-targeted chimeric antigen receptor T cells prevent and treat graft-versus-host disease

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Graft-versus-host disease (GVHD) remains an important cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HCT). For decades, GVHD prophylaxis has included calcineurin-inhibitors, despite their incomplete efficacy and impairment of graft-versus-leukemia (GVL). Distinct from pharmacologic immune suppression, we have developed a novel, human CD83-targeted chimeric antigen receptor (CAR) T cell for GVHD prevention. CD83 is expressed on allo-activated, conventional CD4+ T cells (Tconv) and proinflammatory dendritic cells (DC); which are both implicated in GVHD pathogenesis. Human CD83 CAR T cells eradicate pathogenic CD83+ target cells, significantly increase the ratio of regulatory T cells (Treg) to allo-activated Tconv, and provide durable prevention of xenogeneic GVHD. CD83 CAR T cells are also capable of treating xenogeneic GVHD. We show human, acute myeloid leukemia (AML) expresses CD83 and myeloid leukemia cell lines are readily killed by CD83 CAR T cells. Human CD83 CAR T cells are a promising cell-based approach to prevent two critical complications of allo-HCT; GVHD and relapse. Thus, human CD83 CAR T cells warrant clinical investigation in GVHD prevention and treatment, as well as targeting CD83+ AML.

Authors

Bishwas Shrestha, Kelly Walton, Jordan Reff, Elizabeth M. Sagatys, Nhan Tu, Justin C. Boucher, Gongbo Li, Tayyeb Ghafoor, Martin Felices, Jeffrey Miller, Joseph Pidala, Bruce R. Blazar, Claudio Anasetti, Brian C. Betts, Marco L. Davila

Residual endotoxin induces primary graft dysfunction through ischemia-reperfusion-primed alveolar macrophages

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Despite the widespread use of antibiotics, bacterial pneumonias in donors strongly predispose to the fatal syndrome of primary graft dysfunction (PGD) following lung transplantation. We report that bacterial endotoxin persists in human donor lungs after pathogen is cleared with antibiotics and is associated with neutrophil infiltration and PGD. In mouse models, depletion of tissue-resident alveolar macrophages (TRAM) attenuated neutrophil recruitment in response to endotoxin as shown by compartmental staining and intravital imaging. Bone marrow chimeric mice revealed that neutrophils were recruited by TRAM through activation of TLR4 in a MyD88-dependent manner. Intriguingly, low levels of endotoxin, insufficient to cause donor lung injury, promoted TRAM-dependent production of CXCL2, increased neutrophil recruitment, and led to PGD, which was independent of donor non-classical monocytes. Reactive oxygen species (ROS) increased in human donor lungs starting from the warm-ischemia phase and were associated with increased transcription and translocation to the plasma membrane of TLR4 in donor TRAM. Consistently, scavenging ROS or inhibiting their production to prevent TLR4 transcription/translocation or blockade of TLR4 or co-receptor CD14 on donor TRAM prevented neutrophil recruitment in response to endotoxin and ameliorated PGD. Our studies demonstrate that residual endotoxin after successful treatment of donor bacterial pneumonia promotes PGD through ischemia-reperfusion-primed donor TRAM..

Authors

Mahzad Akbarpour, Emilia Lecuona, Stephen Chiu, Qiang Wu, Melissa Querrey, Ramiro Fernandez, Felix Luis Nunez-Santana, Haiying Sun, Sowmya Ravi, Chitaru Kurihara, James M. Walter, Nikita Joshi, Ziyou Ren, Scott C. Roberts, Alan R. Hauser, Daniel Kreisel, Wenjun Li, Navdeep Chandel, Alexander V. Misharin, Thalachallour Mohanakumar, G.R. Scott Budinger, Ankit Bharat

Taste-related reward is associated with weight loss following bariatric surgery

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Background: Bariatric surgeries are the most effective treatments for successful and sustained weight loss but individuals vary in treatment response. Understanding the neurobiological and behavioral mechanisms accounting for this variation could lead to the development of personalized therapeutic approaches and improve treatment outcomes. The primary objectives were to investigate changes in taste preferences and taste-induced brain responses after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) and to identify potential taste-related predictors of weight loss. Methods: Women, ages 18 to 55, with a body mass index ≥ 35 kg/m2 and approved for bariatric surgery at the Johns Hopkins Center for Bariatric Surgery were recruited for participation. Demographics, anthropometrics, liking ratings, and neural responses to varying concentrations of sucrose+fat mixtures were assessed pre- and post-surgery via visual analogue scales and functional magnetic resonance imaging. Results: Bariatric surgery produced decreases in liking for sucrose-sweetened mixtures. Greater preference for sucrose-sweetened mixtures prior to surgery was associated with greater weight loss in RYGB but not VSG. In the RYGB group only, individuals who showed lower taste-induced activation in the ventral tegmental area (VTA) prior to surgery and greater changes in taste-induced VTA activation two weeks following surgery experienced better weight loss. Conclusions: The anatomical and/or metabolic changes associated with RYGB may more effectively “reset” the neural processing of reward stimuli, thereby rescuing the blunted activation in the mesolimbic pathway found in patients with obesity. Further, these findings suggest that RYGB may be particularly effective in patients with a preference for sweet foods. Trial Registration: Not Applicable.Funding: K23DK100559 and The Dalio Philanthropies. Funding: K23DK100559 and The Dalio Philanthropies.

Authors

Kimberly R. Smith, Afroditi Papantoni, Maria G. Veldhuizen, Vidyulata Kamath, Civonnia Harris, Timothy H. Moran, Susan Carnell, Kimberley E. Steele

Targeting the innate immunoreceptor RIG-I overcomes melanoma-intrinsic resistance to T cell immunotherapy

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Understanding tumor resistance to T cell immunotherapies is critical to improve patient outcomes. Our study revealed a role for transcriptional suppression of the tumor-intrinsic HLA class I (HLA-I) antigen processing and presentation machinery (APM) in therapy resistance. Low HLA-I APM mRNA levels in melanoma metastases prior to immune checkpoint blockade (ICB) correlated with non-responsiveness to therapy and poor clinical outcome. Patient-derived melanoma cells with silenced HLA-I APM escaped recognition by autologous CD8+ T cells. However, targeted activation of the innate immunoreceptor RIG-I initiated de novo HLA-I APM transcription thereby overcoming T cell resistance. Antigen presentation was restored in interferon (IFN)-sensitive but also immunoedited IFN-resistant melanoma models through RIG-I-dependent stimulation of an IFN-independent salvage pathway involving IRF1 and IRF3. Likewise, enhanced HLA-I APM expression was detected in RIG-I (DDX58)-high melanoma biopsies, correlating with improved patient survival. Induction of HLA-I APM by RIG-I synergized with antibodies blocking PD-1 and TIGIT inhibitory checkpoints in boosting the anti-tumor T cell activity of ICB non-responders. Overall, the herein identified IFN-independent effect of RIG-I on tumor antigen presentation and T cell recognition proposes innate immunoreceptor targeting as a strategy to overcome intrinsic T cell resistance of IFN-sensitive and IFN-resistant melanomas and improve clinical outcomes in immunotherapy.

Authors

Lina Such, Fang Zhao, Derek Liu, Beatrice Thier, Vu Thuy Khanh Le-Trilling, Antje Sucker, Christoph Coch, Natalia Pieper, Sebastian Howe, Hilal Bhat, Halime Kalkavan, Cathrin Ritter, Robin Brinkhaus, Selma Ugurel, Johannes Köster, Ulrike Seifert, Ulf Dittmer, Martin Schuler, Karl Sebastian Lang, Thomas A Kufer, Gunther Hartmann, Jürgen Christian Becker, Susanne Horn, Soldano Ferrone, David Liu, Eliezer M. Van Allen, Dirk Schadendorf, Klaus Griewank, Mirko Trilling, Annette Paschen

Inhibition of DNAJ-HSP70 interaction improves strength in muscular dystrophy

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Dominant mutations in the HSP70 co-chaperone DNAJB6 cause a late onset muscle disease termed limb girdle muscular dystrophy type D1 (LGMDD1), which is characterized by protein aggregation and vacuolar myopathology. Disease mutations reside within the G/F domain of DNAJB6, but the molecular mechanisms underlying dysfunction are not well understood. Using yeast, cell culture, and mouse models of LGMDD1, we found that the toxicity associated with disease-associated DNAJB6 required its interaction with HSP70, and that abrogating this interaction genetically or with small molecules was protective. In skeletal muscle, DNAJB6 localizes to the Z-disc with HSP70. Whereas HSP70 normally diffused rapidly between the Z-disc and sarcoplasm, the rate of HSP70’s diffusion in LGMDD1 mouse muscle was diminished likely because it has an unusual affinity for the Z-disc and mutant DNAJB6. Treating LGMDD1 mice with a small molecule inhibitor of the DNAJ-HSP70 complex re-mobilized HSP70, improved strength and corrected myopathology. These data support a model in which LGMDD1 mutations in DNAJB6 are a gain-of-function disease that is, counter-intuitively, mediated via HSP70 binding. Thus, therapeutic approaches targeting HSP70:DNAJB6 may be effective in treating this inherited muscular dystrophy.

Authors

Rocio Bengoechea, Andrew R. Findlay, Ankan K. Bhadra, Hao Shao, Kevin C. Stein, Sara K. Pittman, Jill Daw, Jason E. Gestwicki, Heather L. True, Conrad C. Weihl

Selective role of Nck1 in atherogenic inflammation and plaque formation

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While Canakinumab Anti-Inflammatory Thrombosis Outcomes Study (CANTOS) established the role of treating inflammation in atherosclerosis, our understanding of endothelial activation at atherosclerosis-prone sites remains limited. Disturbed flow at atheroprone regions primes plaque inflammation by enhancing endothelial NF-κB signaling. Herein, we demonstrate a role for the Nck adaptor proteins in disturbed flow-induced endothelial activation. Although highly similar, only Nck1 deletion, but not Nck2 deletion, limited flow-induced NF-κB activation and proinflammatory gene expression. Nck1 knockout mice showed reduced endothelial activation and inflammation in both models of disturbed flow and high fat diet-induced atherosclerosis, whereas Nck2 deletion did not. Bone marrow chimeras confirmed that vascular Nck1, but not hematopoietic Nck1, mediated this effect. Domain swap experiments and point mutations identified the Nck1 SH2 domain and the first SH3 domain as critical for flow-induced endothelial activation. We further characterized Nck1’s proinflammatory role by identifying interleukin-1 type I receptor kinase-1 (IRAK-1) as a Nck1-selective binding partner, demonstrating IRAK-1 activation by disturbed flow required Nck1 in vitro and in vivo, showing endothelial Nck1 and IRAK-1 staining in early human atherosclerosis, and demonstrating that disturbed flow-induced endothelial activation required IRAK-1. Taken together, our data reveal a hitherto unknown link between Nck1 and IRAK-1 in atherogenic inflammation.

Authors

Mabruka Alfaidi, Christina H. Acosta, Dongdong Wang, James G. Traylor, A. Wayne Orr

Noggin regulates foregut progenitor cell programming and mis-expression leads to esophageal atresia

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Esophageal atresia (EA/TEF) are common congenital abnormalities of the gastrointestinal tract. The etiology of EA/TEF is not well understood. We hypothesized that EA/TEF may be the direct consequence of abnormal expression of Noggin (NOG) signaling cascade. Here we showed that, in neonates with EA/TEF, NOG was missing from the atretic esophagus, resulting in immature esophagus that contains respiratory glands, and cilia. When using mouse esophageal organoid units (EOUs) or tracheal organoid units (TOU) as a model of foregut development in vitro, NOG determined the fate of foregut progenitors by allowing expression of esophageal epithelium proteins. When NOG was present in the culture of mTOU, it altered the cell morphology of the organoid unit epithelium, allowing expression of squamous cell proteins normally found in esophagus. On the other hand, when NOG was inhibited in mEOU, the organoid epithelium began to express respiratory markers mimicking the phenotype seen in pathology samples of human EA/TEF. Moreover, human EOU derived from EA/TEF patients were small, fibrotic and lack esophageal epithelium, but when NOG was added, the EOU grew larger, healthier and express esophageal proteins. These results indicate that Noggin is a critical regulator of cell fate decisions between esophageal and pulmonary morphogenesis.

Authors

Carolina Pinzon-Guzman, Sreedhara Sangadala, Katherine M. Riera, Evgenya Y. Popova, Elizabeth Manning, Won Jae Huh, Matthew S. Alexander, Julia S. Shelton, Scott D. Boden, James R. Goldenring

Blocking endothelial apoptosis revascularises the retina in a model of ischemic retinopathy

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Aberrant, neovascular retinal blood vessel growth is a vision-threatening complication in ischemic retinal diseases. It is driven by retinal hypoxia frequently caused by capillary non-perfusion and endothelial cell (EC) loss. We investigated the role of EC apoptosis in this process using a mouse model of ischemic retinopathy, in which vessel closure and EC apoptosis cause capillary regression and retinal ischemia followed by neovascularisation. Protecting ECs from apoptosis in this model did not prevent capillary closure or retinal ischemia. Nonetheless, it prevented the clearance of ECs from closed capillaries, delaying vessel regression and allowing ECs to persist in clusters throughout the ischemic zone. In response to hypoxia, these preserved ECs underwent a vessel sprouting response and rapidly reassembled into a functional vascular network. This alleviated retinal hypoxia, preventing subsequent pathogenic neovascularisation. Vessel reassembly was not limited by VEGFA neutralisation, suggesting it was not dependent on the excess VEGFA produced by the ischemic retina. Neutralisation of ANG2 did not prevent vessel reassembly, but did impair subsequent angiogenic expansion of the reassembled vessels. Blockade of EC apoptosis may promote ischemic tissue re-vascularisation by preserving ECs within ischemic tissue that retain the capacity to reassemble a functional network and rapidly restore blood supply.

Authors

Zoe L. Grant, Lachlan Whitehead, Vickie H. Y. Wong, Zheng He, Richard Y. Yan, Abigail R. Miles, Andrew V. Benest, David O. Bates, Claudia Prahst, Katie Bentley, Bang V. Bui, Robert C.A. Symons, Leigh Coultas

Chemotherapy-induced S100A10 recruits KDM6A to facilitate OCT4-mediated breast cancer stemness

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Breast cancer stem cells (BCSCs) play a critical role in cancer recurrence and metastasis. Chemotherapy induces BCSC specification through increased expression of pluripotency factors, but how their expression is regulated is not fully understood. Here, we delineate a hypoxia-inducible factor 1 (HIF-1)-controlled pathway that epigenetically activates pluripotency factor gene transcription in response to chemotherapy. Paclitaxel induces HIF-1-dependent expression of S100A10, which forms a complex with ANXA2 that interacts with histone chaperone SPT6 and histone demethylase KDM6A. S100A10, ANXA2, SPT6, and KDM6A are recruited to OCT4 binding sites and KDM6A erases H3K27me3 chromatin marks, facilitating transcription of genes encoding the pluripotency factors NANOG, SOX2, and KLF4, which along with OCT4 are responsible for BCSC specification. Silencing of S100A10, ANXA2, SPT6, or KDM6A expression blocks chemotherapy-induced enrichment of BCSCs, impairs tumor initiation, and increases time to tumor recurrence after chemotherapy is discontinued. Pharmacological inhibition of KDM6A also impairs chemotherapy-induced BCSC enrichment. These results suggest that targeting HIF-1/S100A10-dependent and KDM6A-mediated epigenetic activation of pluripotency factor gene expression in combination with chemotherapy may block BCSC enrichment and improve clinical outcome.

Authors

Haiquan Lu, Yangyiran Xie, Linh Tran, Jie Lan, Yongkang Yang, Naveena L. Murugan, Ru Wang, Yueyang J. Wang, Gregg L. Semenza

Dynamic transcriptome analysis unveils key pro-resolving factors of chronic inflammatory arthritis

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Despite recent advances in understanding chronic inflammation remission, global analyses have not been explored to systematically discover genes or pathways underlying the resolution dynamics of chronic inflammatory diseases. Here, we performed time-course gene expression profiling of mouse synovial tissues along progression and resolution of collagen-induced arthritis (CIA) and identified genes associated with inflammation resolution. Through network analysis of these genes, we predicted three key secretory factors responsible for the resolution of CIA: Itgb1, Rps3, and Ywhaz. These factors were predominantly expressed by regulatory T cells and anti-inflammatory M2 macrophages, suppressing production of pro-inflammatory cytokines. In particular, Ywhaz was elevated in the sera of mice with arthritis resolution and in the urine of rheumatoid arthritis (RA) patients with good therapeutic responses. Moreover, adenovirus-mediated transfer of the Ywhaz gene to the affected joints substantially inhibited arthritis progression in mice with CIA and suppressed expression of pro-inflammatory cytokines in joint tissues, lymph nodes, and spleens, suggesting Ywhaz as an excellent target for RA therapy. Therefore, our comprehensive analysis of dynamic synovial transcriptomes provides previously unidentified anti-arthritic genes, Itgb1, Rps3, and Ywhaz, which can serve as molecular markers to predict disease remission, as well as therapeutic targets for chronic inflammatory arthritis.

Authors

Jin-Sun Kong, Ji-Hwan Park, Seung-Ah Yoo, Ki-Myo Kim, Yeung-Jin Bae, Yune-Jung Park, Chul-Soo Cho, Daehee Hwang, Wan-Uk Kim

Maternal diesel particle exposure promotes offspring asthma through NK cell-derived granzyme B

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Mothers living near high-traffic roads before or during pregnancy have increased odds of having children with asthma. Mechanisms are unknown. Using a mouse model, here we showed that maternal exposure to diesel exhaust particles (DEP) predisposed offspring to allergic airway disease/AAD (murine counterpart of human asthma) through programming of their NK cells; predisposition to AAD did not develop in ‘DEP’ pups that lacked NK cells and was induced in normal pups receiving NK cells from wild type ‘DEP’ pups. “DEP’ NK cells expressed GATA3 and co-secreted IL-13 and the ‘killer’ protease granzyme B in response to allergen challenge. Extracellular granzyme B did not kill but instead it stimulated protease-activated receptor 2 (PAR2) to cooperate with IL-13 in the induction of IL-25 in airway epithelial cells. Through loss-of-function and reconstitution experiments in pups, we showed that NK cells and granzyme B were required for IL-25 induction and activation of the type-2 immune response, and IL-25 mediated NK cell effects on type-2 response and AAD. Lastly, experiments using human cord blood and airway epithelial cells suggested that DEP might induce an identical pathway in humans. Collectively, we described an NK cell-dependent endotype of AAD that emerged in early life as a result of maternal exposure to DEP.

Authors

Qian Qian, Bidisha Paul Chowdhury, Zehua Sun, Jerica Lenberg, Rafeul Alam, Eric Vivier, Magdalena M. Gorska

MKRN3 inhibits the reproductive axis through actions in kisspeptin-expressing neurons

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The identification of loss-of-function mutations in MKRN3 in patients with central precocious puberty (CPP) in association with the decrease in MKRN3 expression in the medial basal hypothalamus (MBH) of mice prior to the initiation of reproductive maturation suggest that MKRN3 is acting as a ‘brake’ on GnRH secretion during childhood. In the current study, we investigated the mechanism by which MKRN3 prevents premature manifestation of the pubertal process. We showed that, as in mice, MKRN3 expression is high in the hypothalamus of rats and nonhuman primates early in life, declining as puberty approaches, and is independent of sex steroid hormones. We demonstrated that Mkrn3 is expressed in Kiss1 neurons of the mouse hypothalamic arcuate nucleus (ARC) and that MKRN3 repressed promoter activity of human KISS1 and TAC3, two key stimulators of GnRH secretion. We further showed that MKRN3 has ubiquitinase activity, that this activity is reduced by MKRN3 mutations affecting the RING finger domain, and that these mutations compromised the ability of MKRN3 to repress KISS1 and TAC3 promoter activity. These results indicate that MKRN3 acts to prevent puberty initiation, at least in part, by repressing KISS1 and TAC3 transcription and that this action may involve a MKRN3-directed ubiquitination-mediated mechanism.

Authors

Ana Paula Abreu, Carlos A. Toro, Yong Bhum Song, Victor M Navarro, Martha A. Bosch, Aysegul Eren, Joy N. Liang, Rona S. Carroll, Ana Claudia Latronico, Oline K. Ronnekleiv, Carlos F Aylwin, Alejandro Lomniczi, Sergio R. Ojeda, Ursula B Kaiser

Elevated circulating amyloid concentrations in obesity and diabetes promote vascular dysfunction

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Diabetes, obesity and Alzheimer’s disease (AD) are associated with vascular complications and impaired nitric oxide (NO) production. Furthermore, increased β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), APP and β-amyloid (Aβ) are linked with vascular disease development and raised BACE1 and Aβ accompany hyperglycemia and hyperlipidemia. However, the causal relationship between obesity and diabetes, raised Aβ and vascular dysfunction is unclear. We report that diet-induced obesity (DIO) in mice raised plasma and vascular Aβ42 that correlated with decreased NO bioavailability, endothelial dysfunction and raised blood pressure. Genetic or pharmacological reduction of BACE1 activity and Aβ42 prevented and reversed, respectively, these outcomes. In contrast, expression of human mutant APP in mice or Aβ42 infusion into control diet-fed mice to mimic obese levels impaired NO production, vascular relaxation and raised blood pressure. In humans, raised plasma Aβ42 correlated with diabetes and endothelial dysfunction. Mechanistically, higher Aβ42 reduced endothelial NO synthase (eNOS), cyclic GMP and protein kinase G (PKG) activity independently of diet whereas endothelin-1 was increased by diet and Aβ42. Lowering Aβ42 reversed the DIO deficit in the eNOS-cGMP-PKG pathway and decreased endothelin-1. Our findings suggest that BACE1 inhibitors may have therapeutic value in the treatment of vascular disease associated with diabetes.

Authors

Paul J. Meakin, Bethany M. Coull, Zofia Tuharska, Christopher McCaffery, Ioannis Akoumianakis, Charalambos Antoniades, Jane Brown, Kathryn J. Griffin, Fiona Platt, Claire H. Ozber, Nadira Y. Yuldasheva, Natallia Makava, Anna Skromna, Alan Russell Prescott, Alison D. McNeilly, Moneeza K. Siddiqui, Colin Neil Alexander Palmer, Faisel Khan, Michael LJ Ashford

Nonalcoholic fatty liver disease in CLOCK mutant mice

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Nonalcoholic fatty liver disease (NAFLD) is becoming a major health issue as obesity increases around the world. We studied the effect of a circadian locomotor output cycles kaput (CLOCK) mutant (ClkΔ19/Δ19) protein on hepatic lipid metabolism in C57Bl6 Clkwt/wt and apolipoprotein E–deficient (Apoe−/−) mice. Both ClkΔ19/Δ19 and ClkΔ19/Δ19Apoe−/− mice developed a full spectrum of liver diseases (steatosis, steatohepatitis, cirrhosis, and hepatocellular carcinoma) recognized in human NAFLD when challenged with a Western diet, lipopolysaccharide, or CoCl2. We identified induction of cluster of differentiation 36 (CD36) and hypoxia-inducible factor 1α (HIF1α) proteins as contributing factors for NAFLD. Mechanistic studies showed that wild-type CLOCK protein interacted with the E-box enhancer elements in the promoters of the proline hydroxylase domain (PHD) proteins to increase expression. In ClkΔ19/Δ19 mice, PHD levels were low, and HIF1α protein levels were increased. When its levels were high, HIF1α interacted with the Cd36 promoter to augment expression and enhance fatty acid uptake. Thus, these studies establish a novel regulatory link among circadian rhythms, hypoxia response, fatty acid uptake, and NAFLD. The mouse models described here may be useful for further mechanistic studies in the progression of liver diseases and in the discovery of drugs for the treatment of these disorders.

Authors

Xiaoyue Pan, Joyce Queiroz, M. Mahmood Hussain