Inflammation
Heart-resident CCR2+ macrophages promote neutrophil extravasation through TLR9/MyD88/CXCL5 signaling
Abstract
It is well established that maladaptive innate immune responses to sterile tissue injury represent a fundamental mechanism of disease pathogenesis. In the context of cardiac ischemia reperfusion injury, neutrophils enter inflamed heart tissue, where they play an important role in potentiating tissue damage and contributing to contractile dysfunction. The precise mechanisms that govern how neutrophils are recruited to and enter the injured heart are incompletely understood. Using a model of cardiac transplant–mediated ischemia reperfusion injury and intravital 2-photon imaging of beating mouse hearts, we determined that tissue-resident CCR2+ monocyte–derived macrophages are essential mediators of neutrophil recruitment into ischemic myocardial tissue. Our studies revealed that neutrophil extravasation is mediated by a TLR9/MyD88/CXCL5 pathway. Intravital 2-photon imaging demonstrated that CXCL2 and CXCL5 play critical and nonredundant roles in guiding neutrophil adhesion and crawling, respectively. Together, these findings uncover a specific role for a tissue-resident monocyte-derived macrophage subset in sterile tissue inflammation and support the evolving concept that macrophage ontogeny is an important determinant of function. Furthermore, our results provide the framework for targeting of cell-specific signaling pathways in myocardial ischemia reperfusion injury.
Authors
Wenjun Li, Hsi-Min Hsiao, Ryuji Higashikubo, Brian T. Saunders, Ankit Bharat, Daniel R. Goldstein, Alexander S. Krupnick, Andrew E. Gelman, Kory J. Lavine, Daniel Kreisel
Abstract
Current methods of drug screening in human blood focus on the immediate products of the affected pathway and mostly rely on approaches that lack sensitivity and the capacity for multiplex analysis. We have developed a sensitive and selective method based on ultra-performance liquid chromatography–tandem mass spectrometry to scan the effect of drugs on the bioactive eicosanoid lipidome in vitro and ex vivo. Using small sample sizes, we can reproducibly measure a broad spectrum of eicosanoids in human blood and capture drug-induced substrate rediversion and unexpected shifts in product formation. Microsomal prostaglandin E synthase-1 (mPGES-1) is an antiinflammatory drug target alternative to COX-1/-2. Contrasting effects of targeting mPGES-1 versus COX-1/-2, due to differential substrate shifts across the lipidome, were observed and can be used to rationalize and evaluate drug combinations. Finally, the in vitro results were extrapolated to ex vivo studies by administration of the COX-2 inhibitor, celecoxib, to volunteers, illustrating how this approach can be used to integrate preclinical and clinical studies during drug development.
Authors
Liudmila L. Mazaleuskaya, John A. Lawson, Xuanwen Li, Gregory Grant, Clementina Mesaros, Tilo Grosser, Ian A. Blair, Emanuela Ricciotti, Garret A. FitzGerald
Abstract
Significant morbidity in cystic fibrosis (CF) results from chronic lung inflammation, most commonly due to
Authors
Kong Chen, Brian T. Campfield, Sally E. Wenzel, Jeremy P. McAleer, James L. Kreindler, Geoffrey Kurland, Radha Gopal, Ting Wang, Wei Chen, Taylor Eddens, Kathleen M. Quinn, Mike M. Myerburg, William T. Horne, Jose M. Lora, Brian K. Albrecht, Joseph M. Pilewski, Jay K. Kolls
Abstract
Conventional memory CD8+ T cells and mucosal-associated invariant T cells (MAIT cells) are found in blood, liver, and mucosal tissues and have similar effector potential following activation, specifically expression of IFN-γ and granzyme B. To better understand each subset’s unique contributions to immunity and pathology, we interrogated inflammation- and TCR-driven activation requirements using human memory CD8+ T and MAIT cells isolated from blood and mucosal tissue biopsies in ex vivo functional assays and single cell gene expression experiments. We found that MAIT cells had a robust IFN-γ and granzyme B response to inflammatory signals but limited responsiveness when stimulated directly via their TCR. Importantly, this is not due to an overall hyporesponsiveness to TCR signals. When delivered together, TCR and inflammatory signals synergize to elicit potent effector function in MAIT cells. This unique control of effector function allows MAIT cells to respond to the same TCR signal in a dichotomous and situation-specific manner. We propose that this could serve to prevent responses to antigen in noninflamed healthy mucosal tissue, while maintaining responsiveness and great sensitivity to inflammation-eliciting infections. We discuss the implications of these findings in context of inflammation-inducing damage to tissues such as BM transplant conditioning or HIV infection.
Authors
Chloe K. Slichter, Andrew McDavid, Hannah W. Miller, Greg Finak, Brenda J. Seymour, John P. McNevin, Gabriela Diaz, Julie L. Czartoski, M. Juliana McElrath, Raphael Gottardo, Martin Prlic
Abstract
Dopamine D2 receptor (DRD2) deficiency increases renal inflammation and blood pressure in mice. We show here that long-term renal-selective silencing of
Authors
Prasad R. Konkalmatt, Laureano D. Asico, Yanrong Zhang, Yu Yang, Cinthia Drachenberg, Xiaoxu Zheng, Fei Han, Pedro A. Jose, Ines Armando
Abstract
Infections are an important cause of morbidity and mortality in patients with decompensated cirrhosis and ascites. Hypothesizing that innate immune dysfunction contributes to susceptibility to infection, we assessed ascitic fluid macrophage phenotype and function. The expression of complement receptor of the immunoglobulin superfamily (CRIg) and CCR2 defined two phenotypically and functionally distinct peritoneal macrophage subpopulations. The proportion of CRIghi macrophages differed between patients and in the same patient over time, and a high proportion of CRIghi macrophages was associated with reduced disease severity (model for end-stage liver disease) score. As compared with CRIglo macrophages, CRIghi macrophages were highly phagocytic and displayed enhanced antimicrobial effector activity. Transcriptional profiling by RNA sequencing and comparison with human macrophage and murine peritoneal macrophage expression signatures highlighted similarities among CRIghi cells, human macrophages, and mouse F4/80hi resident peritoneal macrophages and among CRIglo macrophages, human monocytes, and mouse F4/80lo monocyte-derived peritoneal macrophages. These data suggest that CRIghi and CRIglo macrophages may represent a tissue-resident population and a monocyte-derived population, respectively. In conclusion, ascites fluid macrophage subset distribution and phagocytic capacity is highly variable among patients with chronic liver disease. Regulating the numbers and/or functions of these macrophage populations could provide therapeutic opportunities in cirrhotic patients.
Authors
Katharine M. Irvine, Xuan Banh, Victoria L. Gadd, Kyle K. Wojcik, Juliana K. Ariffin, Sara Jose, Samuel Lukowski, Gregory J. Baillie, Matthew J. Sweet, Elizabeth E. Powell
Abstract
The
Authors
Keisuke Maeshima, Stephanie M. Stanford, Deepa Hammaker, Cristiano Sacchetti, Li-fan Zeng, Rizi Ai, Vida Zhang, David L. Boyle, German R. Aleman Muench, Gen-Sheng Feng, John W. Whitaker, Zhong-Yin Zhang, Wei Wang, Nunzio Bottini, Gary S. Firestein
Abstract
Reperfusion injury can exacerbate tissue damage in ischemic stroke, but little is known about the mechanisms linking ROS to stroke severity. Here, we tested the hypothesis that protein methionine oxidation potentiates NF-κB activation and contributes to cerebral ischemia/reperfusion injury. We found that overexpression of methionine sulfoxide reductase A (MsrA), an antioxidant enzyme that reverses protein methionine oxidation, attenuated ROS-augmented NF-κB activation in endothelial cells, in part, by protecting against the oxidation of methionine residues in the regulatory domain of calcium/calmodulin-dependent protein kinase II (CaMKII). In a murine model, MsrA deficiency resulted in increased NF-κB activation and neutrophil infiltration, larger infarct volumes, and more severe neurological impairment after transient cerebral ischemia/reperfusion injury. This phenotype was prevented by inhibition of NF-κB or CaMKII. MsrA-deficient mice also exhibited enhanced leukocyte rolling and upregulation of E-selectin, an endothelial NF-κB–dependent adhesion molecule known to contribute to neurovascular inflammation in ischemic stroke. Finally, bone marrow transplantation experiments demonstrated that the neuroprotective effect was mediated by MsrA expressed in nonhematopoietic cells. These findings suggest that protein methionine oxidation in nonmyeloid cells is a key mechanism of postischemic oxidative injury mediated by NF-κB activation, leading to neutrophil recruitment and neurovascular inflammation in acute ischemic stroke.
Authors
Sean X. Gu, Ilya O. Blokhin, Katina M. Wilson, Nirav Dhanesha, Prakash Doddapattar, Isabella M. Grumbach, Anil K. Chauhan, Steven R. Lentz
Abstract
BACKGROUND. Some adult patients presenting with unexplained pyrexia, serositis, skin rashes, arthralgia, myalgia, and other symptoms commonly found in autoinflammatory disorders may not fit a specific diagnosis, either because their clinical phenotype is nondiagnostic or genetic tests are negative. We used the term undifferentiated systemic autoinflammatory disorder (uSAID) to describe such cases. Given that well-defined autoinflammatory diseases show responses to IL-1 blockade, we evaluated whether anakinra was useful for both diagnosing and treating uSAID patients.
METHODS. We performed a retrospective analysis of consecutive patients presenting with uSAID between 2012–2015 who were treated with the recombinant IL-1 receptor antagonist anakinra. uSAID was diagnosed after excluding malignancy, infection, and pathogenic mutations in known hereditary fever syndromes (HFS) genes and where clinical criteria for adult onset Still’s disease (AOSD) were not met.
RESULTS. A total of 11 patients presented with uSAID (5 males and 6 females), with a mean time to diagnosis of 3.5 years (1–8 years). Patients were unresponsive or only partially controlled on disease-modifying antirheumatic drug (DMARD)/steroid treatment. Anakinra controlled symptoms within 4–6 weeks of starting treatment in 9 of 11 cases. Two patients discontinued therapy — one due to incomplete response and another due to severe injection-site reactions.
CONCLUSION. This retrospective case series demonstrates that the spectrum of poorly defined autoinflammatory disorders that show responsiveness to anakinra is considerable. Anakinra seems a viable treatment option for these patients, who are unresponsive to standard steroid/DMARD treatments. Moreover, given the mechanisms of action, response to anakinra implicates underlying IL-1 dysregulation in the disease pathogenesis of responding uSAIDs patients.
Authors
Stephanie R. Harrison, Dennis McGonagle, Sharmin Nizam, Stephen Jarrett, Jeroen van der Hilst, Michael F. McDermott, Sinisa Savic
Abstract
Rheumatoid arthritis (RA) is a debilitating disease characterized by persistent accumulation of leukocytes within the articular cavity and synovial tissue. Metabololipidomic profiling of arthritic joints from omega-3 supplemented mice identified elevated levels of specialized proresolving lipid mediators (SPM) including resolvin D1 (RvD1). Profiling of human RA synovial fluid revealed physiological levels of RvD1, which — once applied to human neutrophils — attenuated chemotaxis. These results prompted analyses of the antiarthritic properties of RvD1 in a model of murine inflammatory arthritis. The stable epimer 17
Authors
Lucy V. Norling, Sarah E. Headland, Jesmond Dalli, Hildur H. Arnardottir, Oliver Haworth, Hefin R. Jones, Daniel Irimia, Charles N. Serhan, Mauro Perretti
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