BACKGROUND Preclinical experiments have shown that donor blood cells, modified in vitro by an alkylating agent (modified immune cells [MICs]), induced long-term specific immunosuppression against the allogeneic donor.METHODS In this phase I trial, patients received either 1.5 × 106 MICs per kg BW on day –2 (n = 3, group A), or 1.5 × 108 MICs per kg BW on day –2 (n = 3, group B) or day –7 (n = 4, group C) before living donor kidney transplantation in addition to post-transplantation immunosuppression. The primary outcome measure was the frequency of adverse events (AEs) until day 30 (study phase) with follow-up out to day 360.RESULTS MIC infusions were extremely well tolerated. During the study phase, 10 treated patients experienced a total of 69 AEs that were unlikely to be related or not related to MIC infusion. No donor-specific human leukocyte antigen Abs or rejection episodes were noted, even though the patients received up to 1.3 × 1010 donor mononuclear cells before transplantation. Group C patients with low immunosuppression during follow-up showed no in vitro reactivity against stimulatory donor blood cells on day 360, whereas reactivity against third-party cells was still preserved. Frequencies of CD19+CD24hiCD38hi transitional B lymphocytes (Bregs) increased from a median of 6% before MIC infusion to 20% on day 180, which was 19- and 68-fold higher, respectively, than in 2 independent cohorts of transplanted controls. The majority of Bregs produced the immunosuppressive cytokine IL-10. MIC-treated patients showed the Immune Tolerance Network operational tolerance signature.CONCLUSION MIC administration was safe and could be a future tool for the targeted induction of tolerogenic Bregs.TRIAL REGISTRATION EudraCT number: 2014-002086-30; ClinicalTrials.gov identifier: NCT02560220FUNDING Federal Ministry for Economic Affairs and Technology, Berlin, Germany, and TolerogenixX GmbH, Heidelberg, Germany.
Christian Morath, Anita Schmitt, Christian Kleist, Volker Daniel, Gerhard Opelz, Caner Süsal, Eman Ibrahim, Florian Kälble, Claudius Speer, Christian Nusshag, Luiza Pego da Silva, Claudia Sommerer, Lei Wang, Ming Ni, Angela Hückelhoven-Krauss, David Czock, Uta Merle, Arianeb Mehrabi, Anja Sander, Matthes Hackbusch, Christoph Eckert, Rüdiger Waldherr, Paul Schnitzler, Carsten Müller-Tidow, Jörg D. Hoheisel, Shakhawan A. Mustafa, Mohamed S.S. Alhamdani, Andrea S. Bauer, Jochen Reiser, Martin Zeier, Michael Schmitt, Matthias Schaier, Peter Terness
Colitis caused by Clostridium difficile infection is a growing cause of human morbidity and mortality, especially after antibiotic use in health care settings. The natural immunity of newborn infants and protective host immune mediators against C. difficile infection are not fully understood, with data suggesting that inflammation can be either protective or pathogenic. Here, we show an essential role for IL-17A produced by γδ T cells in host defense against C. difficile infection. Fecal extracts from children with C. difficile infection showed increased IL-17A and T cell receptor γ chain expression, and IL-17 production by intestinal γδ T cells was efficiently induced after infection in mice. C. difficile–induced tissue inflammation and mortality were markedly increased in mice deficient in IL-17A or γδ T cells. Neonatal mice, with naturally expanded RORγt+ γδ T cells poised for IL-17 production were resistant to C. difficile infection, whereas elimination of γδ T cells or IL-17A each efficiently overturned neonatal resistance against infection. These results reveal an expanded role for IL-17–producing γδ T cells in neonatal host defense against infection and provide a mechanistic explanation for the clinically observed resistance of infants to C. difficile colitis.
Yee-Shiuan Chen, Iuan-Bor Chen, Giang Pham, Tzu-Yu Shao, Hansraj Bangar, Sing Sing Way, David B. Haslam
Regenerative pain medicine, which seeks to harness the body’s own reparative capacity, is rapidly emerging as a field within pain medicine and orthopedics. It is increasingly appreciated that common analgesic mechanisms for these treatments depend on neuroimmune modulation. In this Review, we discuss recent progress in mechanistic understanding of nociceptive sensitization in chronic pain with a focus on neuroimmune modulation. We also examine the spectrum of regenerative outcomes, including preclinical and clinical outcomes. We further distinguish the analgesic mechanisms of regenerative therapies from those of cellular replacement, creating a conceptual and mechanistic framework to evaluate future research on regenerative medicine.
Thomas Buchheit, Yul Huh, William Maixner, Jianguo Cheng, Ru-Rong Ji
Facioscapulohumeral muscular dystrophy (FSHD) results from expression of the full-length double homeobox 4 (DUX4-FL) retrogene in skeletal muscle. However, even in cases of severe FSHD the presence of DUX4 is barely detectable. In this issue of the JCI, Bosnakovski et al. used an inducible, muscle-specific human DUX4 to reproduce the low-level, sporadic DUX4 expression of human FSHD muscle as well the myopathology seen in human FSHD disease. Notably, dysregulated fibroadipogenic progenitors accumulated in affected muscles, thus providing a mechanism for the replacement of muscle by fibrosis and fat.
Carlo Serra, Kathryn R. Wagner
The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide. Although gene-environment interactions have been implicated in the etiology of several disorders, the impact of paternal and/or maternal metabolic syndrome on the clinical phenotypes of offspring and the underlying genetic and epigenetic contributors of NAFLD have not been fully explored. To this end, we used the liver-specific insulin receptor knockout (LIRKO) mouse, a unique nondietary model manifesting 3 hallmarks that confer high risk for the development of NAFLD: hyperglycemia, insulin resistance, and dyslipidemia. We report that parental metabolic syndrome epigenetically reprograms members of the TGF-β family, including neuronal regeneration–related protein (NREP) and growth differentiation factor 15 (GDF15). NREP and GDF15 modulate the expression of several genes involved in the regulation of hepatic lipid metabolism. In particular, NREP downregulation increases the protein abundance of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and ATP-citrate lyase (ACLY) in a TGF-β receptor/PI3K/protein kinase B–dependent manner, to regulate hepatic acetyl-CoA and cholesterol synthesis. Reduced hepatic expression of NREP in patients with NAFLD and substantial correlations between low serum NREP levels and the presence of steatosis and nonalcoholic steatohepatitis highlight the clinical translational relevance of our findings in the context of recent preclinical trials implicating ACLY in NAFLD progression.
Dario F. De Jesus, Kazuki Orime, Dorota Kaminska, Tomohiko Kimura, Giorgio Basile, Chih-Hao Wang, Larissa Haertle, Renzo Riemens, Natalie K. Brown, Jiang Hu, Ville Männistö, Amélia M. Silva, Ercument Dirice, Yu-Hua Tseng, Thomas Haaf, Jussi Pihlajamäki, Rohit N. Kulkarni
Infection with the Gram-negative bacterium Helicobacter pylori remains the most important modifiable risk factor for the development of gastric cancer, a leading cause of cancer-related deaths worldwide. How the interactions between H. pylori and its host shape the gastric environment during chronic infection warrants further investigation. In this issue of the JCI, Palrasu et al. used human cell lines and mouse models to provide mechanistic insight into H. pylori’s ability to delay apoptosis in gastric epithelial cells by actively driving the degradation of a proapoptotic factor, SIVA1. Their findings suggest that promoting the survival of gastric epithelial cells has implications not only for H. pylori pathogenesis but for host tumorigenesis.
José B. Sáenz, Jason C. Mills
The mechanisms by which prostate cancer shifts from an indolent castration-sensitive phenotype to lethal castration-resistant prostate cancer (CRPC) are poorly understood. Identification of clinically relevant genetic alterations leading to CRPC may reveal potential vulnerabilities for cancer therapy. Here we find that CUB domain-containing protein 1 (CDCP1), a transmembrane protein that acts as a substrate for SRC family kinases (SFKs), is overexpressed in a subset of CRPC. Notably, CDCP1 cooperates with the loss of the tumor suppressor gene PTEN to promote the emergence of metastatic prostate cancer. Mechanistically, we find that androgens suppress CDCP1 expression and that androgen deprivation in combination with loss of PTEN promotes the upregulation of CDCP1 and the subsequent activation of the SRC/MAPK pathway. Moreover, we demonstrate that anti-CDCP1 immunoliposomes (anti–CDCP1 ILs) loaded with chemotherapy suppress prostate cancer growth when administered in combination with enzalutamide. Thus, our study identifies CDCP1 as a powerful driver of prostate cancer progression and uncovers different potential therapeutic strategies for the treatment of metastatic prostate tumors.
Abdullah Alajati, Mariantonietta D’Ambrosio, Martina Troiani, Simone Mosole, Laura Pellegrini, Jingjing Chen, Ajinkya Revandkar, Marco Bolis, Jean-Philippe Theurillat, Ilaria Guccini, Marco Losa, Arianna Calcinotto, Gaston De Bernardis, Emiliano Pasquini, Rocco D’Antuono, Adam Sharp, Ines Figueiredo, Daniel Nava Rodrigues, Jonathan Welti, Veronica Gil, Wei Yuan, Tatjana Vlajnic, Lukas Bubendorf, Giovanna Chiorino, Letizia Gnetti, Verónica Torrano, Arkaitz Carracedo, Laura Camplese, Susumu Hirabayashi, Elena Canato, Gianfranco Pasut, Monica Montopoli, Jan Hendrik Rüschoff, Peter Wild, Holger Moch, Johann De Bono, Andrea Alimonti
Fibroblasts are key effector cells in tissue remodeling. They remain persistently activated in fibrotic diseases, resulting in progressive deposition of extracellular matrix. Although fibroblast activation may be initiated by external factors, prolonged activation can induce an “autonomous,” self-maintaining profibrotic phenotype in fibroblasts. Accumulating evidence suggests that epigenetic alterations play a central role in establishing this persistently activated pathologic phenotype of fibroblasts. We demonstrated that in fibrotic skin of patients with systemic sclerosis (SSc), a prototypical idiopathic fibrotic disease, TGF-β induced the expression of DNA methyltransferase 3A (DNMT3A) and DNMT1 in fibroblasts in a SMAD-dependent manner to silence the expression of suppressor of cytokine signaling 3 (SOCS3) by promoter hypermethylation. Downregulation of SOCS3 facilitated activation of STAT3 to promote fibroblast-to-myofibroblast transition, collagen release, and fibrosis in vitro and in vivo. Reestablishment of the epigenetic control of STAT3 signaling by genetic or pharmacological inactivation of DNMT3A reversed the activated phenotype of SSc fibroblasts in tissue culture, inhibited TGF-β–dependent fibroblast activation, and ameliorated experimental fibrosis in murine models. These findings identify a pathway of epigenetic imprinting of fibroblasts in fibrotic disease with translational implications for the development of targeted therapies in fibrotic diseases.
Clara Dees, Sebastian Pötter, Yun Zhang, Christina Bergmann, Xiang Zhou, Markus Luber, Thomas Wohlfahrt, Emmanuel Karouzakis, Andreas Ramming, Kolja Gelse, Akihiko Yoshimura, Rudolf Jaenisch, Oliver Distler, Georg Schett, Jörg H.W. Distler
Facioscapulohumeral muscular dystrophy (FSHD) is caused by loss of repression of the DUX4 gene; however, the DUX4 protein is rare and difficult to detect in human muscle biopsies, and pathological mechanisms are obscure. FSHD is also a chronic disease that progresses slowly over decades. We used the sporadic, low-level, muscle-specific expression of DUX4 enabled by the iDUX4pA-HSA mouse to develop a chronic long-term muscle disease model. After 6 months of extremely low sporadic DUX4 expression, dystrophic muscle presented hallmarks of FSHD histopathology, including muscle degeneration, capillary loss, fibrosis, and atrophy. We investigated the transcriptional profile of whole muscle as well as endothelial cells and fibroadiopogenic progenitors (FAPs). Strikingly, differential gene expression profiles of both whole muscle and, to a lesser extent, FAPs, showed significant overlap with transcriptional profiles of MRI-guided human FSHD muscle biopsies. These results demonstrate a pathophysiological similarity between disease in muscles of iDUX4pA-HSA mice and humans with FSHD, solidifying the value of chronic rare DUX4 expression in mice for modeling pathological mechanisms in FSHD and highlighting the importance FAPs in this disease.
Darko Bosnakovski, Ahmed S. Shams, Ce Yuan, Meiricris T. da Silva, Elizabeth T. Ener, Cory W. Baumann, Angus J. Lindsay, Mayank Verma, Atsushi Asakura, Dawn A. Lowe, Michael Kyba
Approximately half of the world’s population is infected with the stomach pathogen Helicobacter pylori. Infection with H. pylori is the main risk factor for distal gastric cancer. Bacterial virulence factors, such as the oncoprotein CagA, augment cancer risk. Yet despite high infection rates, only a fraction of H. pylori–infected individuals develop gastric cancer. This raises the question of defining the specific host and bacterial factors responsible for gastric tumorigenesis. To investigate the tumorigenic determinants, we analyzed gastric tissues from human subjects and animals infected with H. pylori bacteria harboring different CagA status. For laboratory studies, well-defined H. pylori strain B128 and its cancerogenic derivative strain 7.13, as well as various bacterial isogenic mutants were employed. We found that H. pylori compromises key tumor suppressor mechanisms: the host stress and apoptotic responses. Our studies showed that CagA induces phosphorylation of XIAP E3 ubiquitin ligase, which enhances ubiquitination and proteasomal degradation of the host proapoptotic factor Siva1. This process is mediated by the PI3K/Akt pathway. Inhibition of Siva1 by H. pylori increases survival of human cells with damaged DNA. It occurs in a strain-specific manner and is associated with the ability to induce gastric tumor.
Manikandan Palrasu, Elena Zaika, Wael El-Rifai, Monica Garcia-Buitrago, Maria Blanca Piazuelo, Keith T. Wilson, Richard M. Peek Jr., Alexander I. Zaika
Lamin A is a component of the inner nuclear membrane that, together with epigenetic factors, organizes the genome in higher order structures required for transcriptional control. Mutations in the lamin A/C gene cause several diseases belonging to the class of laminopathies, including muscular dystrophies. Nevertheless, molecular mechanisms involved in the pathogenesis of lamin A–dependent dystrophies are still largely unknown. The polycomb group (PcG) of proteins are epigenetic repressors and lamin A interactors, primarily involved in the maintenance of cell identity. Using a murine model of Emery-Dreifuss muscular dystrophy (EDMD), we show here that lamin A loss deregulated PcG positioning in muscle satellite stem cells, leading to derepression of non–muscle-specific genes and p16INK4a, a senescence driver encoded in the Cdkn2a locus. This aberrant transcriptional program caused impairment in self-renewal, loss of cell identity, and premature exhaustion of the quiescent satellite cell pool. Genetic ablation of the Cdkn2a locus restored muscle stem cell properties in lamin A/C–null dystrophic mice. Our findings establish a direct link between lamin A and PcG epigenetic silencing and indicate that lamin A–dependent muscular dystrophy can be ascribed to intrinsic epigenetic dysfunctions of muscle stem cells.
Andrea Bianchi, Chiara Mozzetta, Gloria Pegoli, Federica Lucini, Sara Valsoni, Valentina Rosti, Cristiano Petrini, Alice Cortesi, Francesco Gregoretti, Laura Antonelli, Gennaro Oliva, Marco De Bardi, Roberto Rizzi, Beatrice Bodega, Diego Pasini, Francesco Ferrari, Claudia Bearzi, Chiara Lanzuolo
Seizures often herald the clinical appearance of gliomas or appear at later stages. Dissecting their precise evolution and cellular pathogenesis in brain malignancies could inform the development of staged therapies for these highly pharmaco-resistant epilepsies. Studies in immunodeficient xenograft models have identified local interneuron loss and excess glial glutamate release as chief contributors to network disinhibition, but how hyperexcitability in the peritumoral microenvironment evolves in an immunocompetent brain is unclear. We generated gliomas in WT mice via in utero deletion of key tumor suppressor genes and serially monitored cortical epileptogenesis during tumor infiltration with in vivo electrophysiology and GCAMP7 calcium imaging, revealing a reproducible progression from hyperexcitability to convulsive seizures. Long before seizures, coincident with loss of inhibitory cells and their protective scaffolding, gain of glial glutamate antiporter xCT expression, and reactive astrocytosis, we detected local Iba1+ microglial inflammation that intensified and later extended far beyond tumor boundaries. Hitherto unrecognized episodes of cortical spreading depolarization that arose frequently from the peritumoral region may provide a mechanism for transient neurological deficits. Early blockade of glial xCT activity inhibited later seizures, and genomic reduction of host brain excitability by deleting MapT suppressed molecular markers of epileptogenesis and seizures. Our studies confirmed xenograft tumor–driven pathobiology and revealed early and late components of tumor-related epileptogenesis in a genetically tractable, immunocompetent mouse model of glioma, allowing the complex dissection of tumor versus host pathogenic seizure mechanisms.
Asante Hatcher, Kwanha Yu, Jochen Meyer, Isamu Aiba, Benjamin Deneen, Jeffrey L. Noebels
Systemic sclerosis (SSc) is an autoimmune fibrotic disease whose pathogenesis is poorly understood and lacks effective therapies. We undertook quantitative analyses of T cell infiltrates in the skin of 35 untreated patients with early diffuse SSc and here show that CD4+ cytotoxic T cells and CD8+ T cells contribute prominently to these infiltrates. We also observed an accumulation of apoptotic cells in SSc tissues, suggesting that recurring cell death may contribute to tissue damage and remodeling in this fibrotic disease. HLA-DR–expressing endothelial cells were frequent targets of apoptosis in SSc, consistent with the prominent vasculopathy seen in patients with this disease. A circulating effector population of cytotoxic CD4+ T cells, which exhibited signatures of enhanced metabolic activity, was clonally expanded in patients with systemic sclerosis. These data suggest that cytotoxic T cells may induce the apoptotic death of endothelial and other cells in systemic sclerosis. Cell loss driven by immune cells may be followed by overly exuberant tissue repair processes that lead to fibrosis and tissue dysfunction.
Takashi Maehara, Naoki Kaneko, Cory A. Perugino, Hamid Mattoo, Jesper Kers, Hugues Allard-Chamard, Vinay S. Mahajan, Hang Liu, Samuel J.H. Murphy, Musie Ghebremichael, David Fox, Aimee S. Payne, Robert Lafyatis, John H. Stone, Dinesh Khanna, Shiv Pillai
Immunosuppression continues to be a necessary component of transplantation, despite its association with a multitude of adverse effects. Numerous efforts have been made to circumvent the need for immunosuppression by using various techniques to achieve donor hyporesponsiveness. In this issue of the JCI, Morath et al. take this endeavor forward. Prior to transplantation, the researchers infused recipients with donor-modified immune cells and achieved immunologic hyporesponsiveness. This successful phase I trial also provides a possible avenue for achieving transplantation without the requisite immunosuppression.
Sam Kant, Daniel C. Brennan
BACKGROUND. Since December 2019, an outbreak of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, and is now becoming a global threat. We aimed to delineate and compare the immunologic features of severe and moderate COVID-19. METHODS. In this retrospective study, the clinical and immunologic characteristics of 21 patients (17 male and 4 female) with COVID-19 were analyzed. These patients were classified as severe (11 cases) and moderate (10 cases) according to the Guidelines released by the National Health Commission of China. RESULTS. The median age of severe and moderate cases was 61.0 and 52.0 years, respectively. Common clinical manifestations included fever, cough and fatigue. Compared to moderate cases, severe cases more frequently had dyspnea, lymphopenia, and hypoalbuminemia, with higher levels of alanine aminotransferase, lactate dehydrogenase, C-reactive protein, ferritin and D-dimer as well as markedly higher levels of IL-2R, IL-6, IL-10, and TNF-α. Absolute number of T lymphocytes, CD4+T and CD8+T cells decreased in nearly all the patients, and were markedly lower in severe cases (294.0, 177.5 and 89.0 × 106/L) than moderate cases (640.5, 381.5 and 254.0 × 106/L). The expressions of IFN-γ by CD4+T cells tended to be lower in severe cases (14.1%) than moderate cases (22.8%). CONCLUSION. The SARS-CoV-2 infection may affect primarily T lymphocytes particularly CD4+T and CD8+ T cells, resulting in decrease in numbers as well as IFN-γ production. These potential immunological markers may be of importance due to their correlation with disease severity in COVID-19.
Guang Chen, Di Wu, Wei Guo, Yong Cao, Da Huang, Hongwu Wang, Tao Wang, Xiaoyun Zhang, Huilong Chen, Haijing Yu, Xiaoping Zhang, Minxia Zhang, Shiji Wu, Jianxin Song, Tao Chen, Meifang Han, Shusheng Li, Xiaoping Luo, Jianping Zhao, Qin Ning
The pandemic coronavirus infectious disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is rapidly spreading across the globe. In this issue of the JCI, Chen and colleagues compared the clinical and immunologic characteristics between moderate versus severe COVID-19. The authors found that respiratory distress on admission is associated with unfavorable outcomes. Increased cytokine levels (IL-6, IL-10 and TNFα), lymphopenia (in CD4+ and CD8+ T cells), and decreased IFNγ expression in CD4+ T cells are associated with severe COVID-19. Overall, this study characterized the cytokine storm in severe COVID-19 and provides insights into immune therapeutics and vaccine design.
Savannah F. Pedersen, Ya-Chi Ho
The physical integrity of endothelial cells (ECs) lining the blood vessels regulates the inflammatory response. Both innate immunity and inflammatory disorders hinge on the EC-neutrophil interaction. Neutrophil binding, rolling, and migrating along and between ECs is associated with vascular permeability. In this issue of the JCI, Owen-Woods et al. tracked neutrophils in vivo in venules of mouse striated muscle and revealed how endothelial permeability can affect neutrophil trafficking. Strikingly, many neutrophils that migrated between EC junctions were able to rejoin the blood circulation. Further, the chemokine and neutrophil chemoattractant, CXCL1, drove this reverse transendothelial migration (rTEM). This paradigm-shifting study provides a mechanism for distal organ damage as well as an explanation for sepsis-associated acute respiratory distress syndrome.
Alex Marki, Klaus Ley
BACKGROUND Glucose-6-phosphate dehydrogenase (G6PD) deficiency decreases the ability of red blood cells (RBCs) to withstand oxidative stress. Refrigerated storage of RBCs induces oxidative stress. We hypothesized that G6PD-deficient donor RBCs would have inferior storage quality for transfusion as compared with G6PD-normal RBCs.METHODS Male volunteers were screened for G6PD deficiency; 27 control and 10 G6PD-deficient volunteers each donated 1 RBC unit. After 42 days of refrigerated storage, autologous 51-chromium 24-hour posttransfusion RBC recovery (PTR) studies were performed. Metabolomics analyses of these RBC units were also performed.RESULTS The mean 24-hour PTR for G6PD-deficient subjects was 78.5% ± 8.4% (mean ± SD), which was significantly lower than that for G6PD-normal RBCs (85.3% ± 3.2%; P = 0.0009). None of the G6PD-normal volunteers (0/27) and 3 G6PD-deficient volunteers (3/10) had PTR results below 75%, a key FDA acceptability criterion for stored donor RBCs. As expected, fresh G6PD-deficient RBCs demonstrated defects in the oxidative phase of the pentose phosphate pathway. During refrigerated storage, G6PD-deficient RBCs demonstrated increased glycolysis, impaired glutathione homeostasis, and increased purine oxidation, as compared with G6PD-normal RBCs. In addition, there were significant correlations between PTR and specific metabolites in these pathways.CONCLUSION Based on current FDA criteria, RBCs from G6PD-deficient donors would not meet the requirements for storage quality. Metabolomics assessment identified markers of PTR and G6PD deficiency (e.g., pyruvate/lactate ratios), along with potential compensatory pathways that could be leveraged to ameliorate the metabolic needs of G6PD-deficient RBCs.TRIAL REGISTRATION ClinicalTrials.gov NCT04081272.FUNDING The Harold Amos Medical Faculty Development Program, Robert Wood Johnson Foundation grant 71590, the National Blood Foundation, NIH grant UL1 TR000040, the Webb-Waring Early Career Award 2017 by the Boettcher Foundation, and National Heart, Lung, and Blood Institute grants R01HL14644 and R01HL148151.
Richard O. Francis, Angelo D’Alessandro, Andrew Eisenberger, Mark Soffing, Randy Yeh, Esther Coronel, Arif Sheikh, Francesca Rapido, Francesca La Carpia, Julie A. Reisz, Sarah Gehrke, Travis Nemkov, Tiffany Thomas, Joseph Schwartz, Chaitanya Divgi, Debra Kessler, Beth H. Shaz, Yelena Ginzburg, James C. Zimring, Steven L. Spitalnik, Eldad A. Hod
Hypoxia-inducible factor (HIF) is strikingly upregulated in many types of cancer, and there is great interest in applying inhibitors of HIF as anticancer therapeutics. The most advanced of these are small molecules that target the HIF-2 isoform through binding the PAS-B domain of HIF-2α. These molecules are undergoing clinical trials with promising results in renal and other cancers where HIF-2 is considered to be driving growth. Nevertheless, a central question remains as to whether such inhibitors affect physiological responses to hypoxia at relevant doses. Here, we show that pharmacological HIF-2α inhibition with PT2385, at doses similar to those reported to inhibit tumor growth, rapidly impaired ventilatory responses to hypoxia, abrogating both ventilatory acclimatization and carotid body cell proliferative responses to sustained hypoxia. Mice carrying a HIF-2α PAS-B S305M mutation that disrupts PT2385 binding, but not dimerization with HIF-1β, did not respond to PT2385, indicating that these effects are on-target. Furthermore, the finding of a hypomorphic ventilatory phenotype in untreated HIF-2α S305M mutant mice suggests a function for the HIF-2α PAS-B domain beyond heterodimerization with HIF-1β. Although PT2385 was well tolerated, the findings indicate the need for caution in patients who are dependent on hypoxic ventilatory drive.
Xiaotong Cheng, Maria Prange-Barczynska, James W. Fielding, Minghao Zhang, Alana L. Burrell, Joanna D.C.C. Lima, Luise Eckardt, Isobel L.A. Argles, Christopher W. Pugh, Keith J. Buckler, Peter A. Robbins, Emma J. Hodson, Richard K. Bruick, Lucy M. Collinson, Fraydoon Rastinejad, Tammie Bishop, Peter J. Ratcliffe
BACKGROUND Mirabegron is a β3-adrenergic receptor (β3-AR) agonist approved only for the treatment of overactive bladder. Encouraging preclinical results suggest that β3-AR agonists could also improve obesity-related metabolic disease by increasing brown adipose tissue (BAT) thermogenesis, white adipose tissue (WAT) lipolysis, and insulin sensitivity.METHODS We treated 14 healthy women of diverse ethnicities (27.5 ± 1.1 years of age, BMI of 25.4 ± 1.2 kg/m2) with 100 mg mirabegron (Myrbetriq extended-release tablet, Astellas Pharma) for 4 weeks in an open-label study. The primary endpoint was the change in BAT metabolic activity as measured by [18F]-2-fluoro-d-2-deoxy-d-glucose (18F-FDG) PET/CT. Secondary endpoints included resting energy expenditure (REE), plasma metabolites, and glucose and insulin metabolism as assessed by a frequently sampled intravenous glucose tolerance test.RESULTS Chronic mirabegron therapy increased BAT metabolic activity. Whole-body REE was higher, without changes in body weight or composition. Additionally, there were elevations in plasma levels of the beneficial lipoprotein biomarkers HDL and ApoA1, as well as total bile acids. Adiponectin, a WAT-derived hormone that has antidiabetic and antiinflammatory capabilities, increased with acute treatment and was 35% higher upon completion of the study. Finally, an intravenous glucose tolerance test revealed higher insulin sensitivity, glucose effectiveness, and insulin secretion.CONCLUSION These findings indicate that human BAT metabolic activity can be increased after chronic pharmacological stimulation with mirabegron and support the investigation of β3-AR agonists as a treatment for metabolic disease.TRIAL REGISTRATION Clinicaltrials.gov NCT03049462.FUNDING This work was supported by grants from the Intramural Research Program of the NIDDK, NIH (DK075112, DK075116, DK071013, and DK071014).
Alana E. O’Mara, James W. Johnson, Joyce D. Linderman, Robert J. Brychta, Suzanne McGehee, Laura A. Fletcher, Yael A. Fink, Devika Kapuria, Thomas M. Cassimatis, Nathan Kelsey, Cheryl Cero, Zahraa Abdul Sater, Francesca Piccinini, Alison S. Baskin, Brooks P. Leitner, Hongyi Cai, Corina M. Millo, William Dieckmann, Mary Walter, Norman B. Javitt, Yaron Rotman, Peter J. Walter, Marilyn Ader, Richard N. Bergman, Peter Herscovitch, Kong Y. Chen, Aaron M. Cypess