Obesity-associated complications are causing increasing morbidity and mortality worldwide. Expansion of adipose tissue in obesity leads to a state of low-grade chronic inflammation and dysregulated metabolism, resulting in insulin resistance and metabolic syndrome. Adipose tissue macrophages (ATMs) accumulate in obesity and are a source of proinflammatory cytokines that further aggravate adipocyte dysfunction. Macrophages are rich sources of cyclooxygenase (COX), the rate limiting enzyme for prostaglandin E2 (PGE2) production. When mice were fed a high-fat diet (HFD), ATMs increased expression of COX-2. Selective myeloid cell COX-2 deletion resulted in increased monocyte recruitment and proliferation of ATMs, leading to increased proinflammatory ATMs with decreased phagocytic ability. There were increased weight gain and adiposity, decreased peripheral insulin sensitivity and glucose utilization, increased adipose tissue inflammation and fibrosis, and abnormal adipose tissue angiogenesis. HFD pair-feeding led to similar increases in body weight, but mice with selective myeloid cell COX-2 still exhibited decreased peripheral insulin sensitivity and glucose utilization. Selective myeloid deletion of the macrophage PGE2 receptor subtype, EP4, produced a similar phenotype, and a selective EP4 agonist ameliorated the metabolic abnormalities seen with ATM COX-2 deletion. Therefore, these studies demonstrated that an ATM COX-2/PGE2/EP4 axis plays an important role in inhibiting adipose tissue dysfunction.
Yu Pan, Shirong Cao, Jiaqi Tang, Juan P. Arroyo, Andrew S. Terker, Yinqiu Wang, Aolei Niu, Xiaofeng Fan, Suwan Wang, Yahua Zhang, Ming Jiang, David H. Wasserman, Ming-Zhi Zhang, Raymond C. Harris
BACKGROUND Hyaluronan (HA), an extracellular matrix glycosaminoglycan, has been implicated in the pathophysiology of COVID-19 infection, pulmonary hypertension, pulmonary fibrosis, and other diseases, but is not targeted by any approved drugs. We asked whether hymecromone (4-methylumbelliferone [4-MU]), an oral drug approved in Europe for biliary spasm treatment that also inhibits HA in vitro and in animal models, could be repurposed as an inhibitor of HA synthesis in humans.METHODS We conducted an open-label, single-center, dose-response study of hymecromone in healthy adults. Subjects received hymecromone at 1200 (n = 8), 2400 (n = 9), or 3600 (n = 9) mg/d divided into 3 doses daily, administered orally for 4 days. We assessed safety and tolerability of hymecromone and analyzed HA, 4-MU, and 4-methylumbelliferyl glucuronide (4-MUG; the main metabolite of 4-MU) concentrations in sputum and serum.RESULTS Hymecromone was well tolerated up to doses of 3600 mg/d. Both sputum and serum drug concentrations increased in a dose-dependent manner, indicating that higher doses lead to greater exposures. Across all dose arms combined, we observed a significant decrease in sputum HA from baseline after 4 days of treatment. We also observed a decrease in serum HA. Additionally, higher baseline sputum HA levels were associated with a greater decrease in sputum HA.CONCLUSION After 4 days of exposure to oral hymecromone, healthy human subjects experienced a significant reduction in sputum HA levels, indicating this oral therapy may have potential in pulmonary diseases where HA is implicated in pathogenesis.TRIAL REGISTRATION ClinicalTrials.gov NCT02780752.FUNDING Stanford Medicine Catalyst, Stanford SPARK, Stanford Innovative Medicines Accelerator program, NIH training grants 5T32AI052073-14 and T32HL129970.
Joelle I. Rosser, Nadine Nagy, Riya Goel, Gernot Kaber, Sally Demirdjian, Jamie Saxena, Jennifer B. Bollyky, Adam R. Frymoyer, Ana E. Pacheco-Navarro, Elizabeth B. Burgener, Jayakumar Rajadas, Zhe Wang, Olga Arbach, Colleen E. Dunn, Anissa Kalinowski, Carlos E. Milla, Paul L. Bollyky
Highly effective modulator therapies dramatically improve the prognosis for those with cystic fibrosis (CF). The triple combination of elexacaftor, tezacaftor, and ivacaftor (ETI) benefits many, but not all, of those with the most common F508del mutation in the CF transmembrane conductance regulator (CFTR). Here, we showed that poor sweat chloride concentration responses and lung function improvements upon initiation of ETI were associated with elevated levels of active transforming growth factor β1 (TGF-β1) in the upper airway. Furthermore, TGF-β1 impaired the function of ETI-corrected F508del-CFTR, thereby increasing airway surface liquid (ASL) absorption rates and inducing mucus hyperconcentration in primary CF bronchial epithelial cells in vitro. TGF-β1 not only decreased CFTR mRNA but was also associated with increases in the mRNA expression of tumor necrosis factor alpha (TNFA) and cyclooxygenase-2 (COX2) and TNF-⍺ protein. Losartan improved TGF-β1-mediated inhibition of ETI-corrected F508del-CFTR function and reduced TNFA and COX2 mRNA and TNF⍺ protein expression. This occurred likely by improving correction of mutant CFTR rather than increasing its mRNA (without an effect on potentiation), thereby reversing the negative effects of TGF-β1 and improving ASL hydration in the CF airway epithelium in vitro. Importantly, these effects were independent of type 1 angiotensin II receptor inhibition.
Michael D. Kim, Charles D. Bengtson, Makoto Yoshida, Asef J. Niloy, John S. Dennis, Nathalie Baumlin, Matthias Salathe
Dysregulation of Toll-like receptor (TLR) signaling contributes to the pathogenesis of autoimmune diseases. Here, we provide genetic evidence that tankyrase, a member of the poly(ADP-ribose) polymerase (PARP) family, negatively regulates TLR2 signaling. We show that mice lacking tankyrase in myeloid cells developed severe systemic inflammation with high serum inflammatory cytokine levels. We provide mechanistic evidence that tankyrase deficiency resulted in tyrosine phosphorylation and activation of TLR2 and show that phosphorylation of tyrosine 647 within the TIR domain by SRC and SYK kinases was critical for TLR2 stabilization and signaling. Last, we show that the elevated cytokine production and inflammation observed in mice lacking tankyrase in myeloid cells were dependent on the adaptor protein 3BP2, which is required for SRC and SYK activation. These data demonstrate that tankyrase provides a checkpoint on the TLR-mediated innate immune response.
Yoshinori Matsumoto, Ioannis D. Dimitriou, Jose La Rose, Melissa Lim, Susan Camilleri, Napoleon Law, Hibret A. Adissu, Jiefei Tong, Michael F. Moran, Andrzej Chruscinski, Fang He, Yosuke Asano, Takayuki Katsuyama, Ken-ei Sada, Jun Wada, Robert Rottapel
A disequilibrium between immunosuppressive regulatory T cells (Tregs) and inflammatory interleukin (IL)-17-producing Th17 cells is a hallmark of autoimmune diseases, including multiple sclerosis (MS). However, the molecular mechanisms underlying Treg and Th17 imbalance in central nervous system (CNS) autoimmunity remain largely unclear. Identifying factors which drive this imbalance is of high clinical interest. Here, we report a major disease-promoting role for microRNA-92a (miR-92a) in CNS autoimmunity. MiR-92a was elevated in experimental autoimmune encephalomyelitis (EAE), and its loss attenuated EAE. Mechanistically, miR-92a mediated EAE susceptibility in a T cell-intrinsic manner by restricting Treg induction and suppressive capacity, while supporting Th17 responses, by directly repressing the transcription factor, Foxo1. Although miR-92a did not directly alter Th1 differentiation, it appeared to indirectly promote Th1 cells by inhibiting Treg responses. Correspondingly, miR-92a inhibitor therapy ameliorated EAE by concomitantly boosting Treg cell responses and dampening inflammatory T cell responses. Analogous to mice, miR-92a was elevated in MS patient CD4+ T cells, and miR-92a silencing in patient T cells promoted Treg development whereas it limited Th17 differentiation. Together, our results demonstrate that miR-92a drives CNS autoimmunity by sustaining the Treg/Th17 imbalance and implicate miR-92a as a potential therapeutic target for MS.
Mai Fujiwara, Radhika Raheja, Lucien P. Garo, Amrendra K. Ajay, Ryoko Kadowaki-Saga, Sukrut H. Karandikar, Galina Gabriely, Rajesh Krishnan, Vanessa Beynon, Anu Paul, Amee Patel, Shrishti Saxena, Dan Hu, Brian C. Healy, Tanuja Chitnis, Roopali Gandhi, Howard L. Weiner, Gopal Murugaiyan
Host defense and inflammation are regulated by the NF-κB essential modulator (NEMO), a scaffolding protein with a broad immune cell and tissue expression profile. Hypomorphic mutations in inhibitor of NF-κB kinase regulatory subunit gamma (IKBKG) encoding NEMO typically present with immunodeficiency. Here, we characterized a pediatric autoinflammatory syndrome in 3 unrelated male patients with distinct X-linked IKBKG germline mutations that led to overexpression of a NEMO protein isoform lacking the domain encoded by exon 5 (NEMO-Δex5). This isoform failed to associate with TANK binding kinase 1 (TBK1), and dermal fibroblasts from affected patients activated NF-κB in response to TNF but not TLR3 or RIG-I–like receptor (RLR) stimulation when isoform levels were high. By contrast, T cells, monocytes, and macrophages that expressed NEMO-Δex5 exhibited increased NF-κB activation and IFN production, and blood cells from these patients expressed a strong IFN and NF-κB transcriptional signature. Immune cells and TNF-stimulated dermal fibroblasts upregulated the inducible IKK protein (IKKi) that was stabilized by NEMO-Δex5, promoting type I IFN induction and antiviral responses. These data revealed how IKBKG mutations that lead to alternative splicing of skipping exon 5 cause a clinical phenotype we have named NEMO deleted exon 5 autoinflammatory syndrome (NDAS), distinct from the immune deficiency syndrome resulting from loss-of-function IKBKG mutations.
Younglang Lee, Alex W. Wessel, Jiazhi Xu, Julia G. Reinke, Eries Lee, Somin M. Kim, Amy P. Hsu, Jevgenia Zilberman-Rudenko, Sha Cao, Clinton Enos, Stephen R. Brooks, Zuoming Deng, Bin Lin, Adriana A. de Jesus, Daniel N. Hupalo, Daniela G.P. Piotto, Maria T. Terreri, Victoria R. Dimitriades, Clifton L. Dalgard, Steven M. Holland, Raphaela Goldbach-Mansky, Richard M. Siegel, Eric P. Hanson
Clearance of dying cells by efferocytosis is necessary for cardiac repair after myocardial infarction (MI). Recent reports have suggested a protective role for vascular endothelial growth factor C (VEGFC) during acute cardiac lymphangiogenesis post MI. Here we report that defective efferocytosis by macrophages after experimental MI leads to a reduction in cardiac lymphangiogenesis and Vegfc expression. Cell-intrinsic evidence for efferocytic-induction of Vegfc was revealed after adding apoptotic cells to cultured primary macrophages, which subsequently triggered Vegfc transcription and VEGFC secretion. Similarly, cardiac macrophages elevated Vegfc expression levels after MI, and mice deficient for myeloid Vegfc exhibited impaired ventricular contractility, adverse tissue remodeling and reduced lymphangiogenesis. These results were observed in mouse models of permanent coronary occlusion and clinically relevant ischemia and reperfusion. Interestingly, myeloid Vegfc deficiency also led to increases in acute infarct size, prior to the amplitude of the acute cardiac lymphangiogenesis response. RNA sequencing and cardiac flow cytometry revealed that myeloid Vegfc deficiency was also characterized by a defective inflammatory response, and macrophages-produced VEGFC was directly effective at suppressing pro-inflammatory macrophage activation. Taken together, our findings indicate that cardiac macrophages promote healing through the promotion of myocardial lymphangiogenesis and the suppression of inflammatory cytokines.
Kristofor E. Glinton, Wanshu Ma, Connor W. Lantz, Lubov S. Grigoryeva, Matthew DeBerge, Xiaolei Liu, Maria Febbraio, Mark Kahn, Guillermo Oliver, Edward B. Thorp
Brown adipose tissue (BAT), a crucial heat-generating organ, regulate whole-body energy metabolism by mediating thermogenesis. BAT inflammation is implicated in the pathogenesis of mitochondrial dysfunction and impaired thermogenesis. However, the link between BAT inflammation and systematic metabolism remains unclear. Herein, we use mice with BAT deficiency of thioredoxin-2 (TRX2), a protein that scavenges mitochondrial reactive oxygen species (ROS), to evaluate the impact of BAT inflammation on metabolism and thermogenesis and its underlying mechanism. Our results describe that BAT-specific TRX2 ablation improves systematic metabolic performance via enhancing lipid uptake, which protects mice from diet-induced obesity, hypertriglyceridemia, and insulin resistance. TRX2 deficiency impairs adaptive thermogenesis by suppressing fatty acid oxidation. Mechanistically, loss of TRX2 induces excessive mitochondrial ROS, mitochondrial integrity disruption, and cytosolic release of mitochondrial DNA, which in turn activate aberrant innate immune responses in BAT, including the cGAS-STING and the NLRP3 inflammasome pathways. We identify NLRP3 as a key converging point, as its inhibition reverses both the thermogenesis defect and the metabolic benefits seen under nutrient overload in BAT-specific Trx2-deficient mice. In conclusion, we identify TRX2 as a critical hub integrating oxidative stress, inflammation, and lipid metabolism in BAT; uncovering an adaptive mechanism underlying the link between BAT inflammation and systematic metabolism.
Yanrui Huang, Jenny H. Zhou, Haifeng Zhang, Alberto Canfrán-Duque, Abhishek K. Singh, Rachel J. Perry, Gerald Shulman, Carlos Fernandez-Hernando, Wang Min
The tumour microenvironment (TME) is reprogrammed by cancer cells and participates in all stages of tumour progression. The contribution of stromal cells to the reprogramming of the TME is not well-understood. Here we provide solid evidence of the role of the cytokine Oncostatin M (OSM) as central node for multicellular interactions between immune and non-immune stromal cells and the epithelial cancer cell compartment. Oncostatin M Receptor (OSMR) deletion in a multistage breast cancer model halted tumour progression. We ascribed causality to the stromal function of OSM axis by demonstrating reduced tumour burden of syngeneic tumours implanted in mice lacking OSMR. Single-cell and bioinformatic analysis of murine and human breast tumours revealed that OSM expression was restricted to myeloid cells, whereas OSMR was detected predominantly in fibroblasts and, to a lower extent, cancer cells. Myeloid-derived OSM reprogrammed fibroblasts to a more contractile and tumorigenic phenotype, elicited the secretion of VEGF and pro-inflammatory chemokines CXCL1 and CXCL16, leading to increased neutrophil and macrophage recruitment. Collectively, our data support that stromal OSM:OSMR axis reprograms the immune and non-immune microenvironment and plays a key role in breast cancer progression.
Angela M Araujo, Andrea Abaurrea, Peio Azcoaga, Joanna I. López-Velazco, Sara Manzano, Javier Rodriguez, Ricardo Rezola, Leire Egia-Mendikute, Fátima Valdés-Mora, Juana M. Flores, Liam Jenkins, Laura Pulido, Iñaki Osorio-Querejeta, Patricia Fernández-Nogueira, Nicola Ferrari, Cristina Viera, Natalia Martin-Martin, Alexandar Tzankov, Serenella Eppenberger-Castori, Isabel Alvarez-Lopez, Ander Urruticoechea, Paloma Bragado, Nicholas Coleman, Asis Palazon, Arkaitz Carracedo, David Gallego-Ortega, Fernando Calvo, Clare M. Isacke, Maria M. Caffarel, Charles H. Lawrie
The causative role of inflammation in hypertension-related cardiovascular diseases is evident and calls for development of specific immunomodulatory therapies. We tested the therapeutic efficacy and mechanisms of action of developmental endothelial locus-1 (DEL-1), an endogenous anti-inflammatory factor, in angiotensin-II (ANGII)- and DOCA (deoxycorticosterone acetate)-salt-induced cardiovascular organ damage and hypertension. By using mice with endothelial overexpression of DEL-1 (EC-Del1) and performing preventive and interventional studies by injecting recombinant DEL-1 in mice, we showed that DEL-1 improved endothelial function and abrogated aortic adventitial fibrosis, medial thickening and loss of elastin. DEL-1 also protected the mice from cardiac concentric hypertrophy, interstitial and perivascular coronary fibrosis and improved left-ventricular function and myocardial coronary perfusion. DEL-1 prevented aortic stiffness and abolished the progression of hypertension. Mechanistically, DEL-1 acted by inhibiting αvβ3-integrin dependent activation of pro-MMP2 in mice and in human isolated aorta. Moreover, DEL-1 stabilized αvβ3-integrin dependent CD25+FoxP3+ Treg numbers and IL-10 levels, which were associated with decreased pro-inflammatory cell recruitment of inflammatory cells and reduced production of pro-inflammatory cytokines in cardiovascular organs. The demonstrated effects and immune-modulating mechanisms of DEL-1 in abrogation of cardiovascular remodeling and progression of hypertension identify DEL-1 as a potential therapeutic factor.
Theresa Failer, Michael Amponsah-Offeh, Aleš Neuwirth, Ioannis Kourtzelis, Pallavi Subramanian, Peter Mirtschink, Mirko Peitzsch, Klaus Matschke, Sems M. Tugtekin, Tetsuhiro Kajikawa, Xiaofei Li, Anne Steglich, Florian Gembardt, Annika C. Wegner, Christian Hugo, George Hajishengallis, Triantafyllos Chavakis, Andreas Deussen, Vladimir Todorov, Irakli Kopaliani
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