Project description:Background—Mesenchymal stem cells (MSCs) have shown therapeutic potency for treating cardiovascular diseases, but their therapeutic efficacy shows significant heterogeneity depending on their tissue of origin. We herein sought to identify the optimal source of MSCs for cardiovascular disease therapy. Methods—Heart- and bone marrow (BM)-derived GFP+ cells positive for the MSCs marker, Nestin, were flow cytometrically sorted from 7-day-postnatal Nestin-GFP transgenic mice. To study their biological characteristics in vitro, we characterized their self-renewal capacity, multi-lineage differentiation ability, and surface markers. To investigate their therapeutic potential in vivo, we intramyocardially injected Nestin+ cells (3×105) into the infarct border zone of mice subjected to acute myocardial infarction (MI), and performed echocardiography and Masson’s-Trichrome staining at 1 and 3 weeks post-MI. We characterized gene profiles with RNA-sequencing analysis, and analyzed the putative reparative mechanism, that of Periostin-mediated M2 macrophages polarization, by immunofluorescence staining, qPCR, ELISA, and flow cytometry in vivo and in vitro. Results—In vitro, the heart- and BM-derived Nestin+ cells (Nes+cMSCs and Nes+bmMSCs, respectively) were found to possess self-renewal ability, show similar tri-lineage differentiation potentials, and express some MSCs-related surface markers. Importantly, Nes+cMSCs significantly improved cardiac function, attenuated left ventricular (LV) remodeling, and decreased infarct size in the mouse MI model, compared with Nes+bmMSCs- or saline-treated MI controls. Nes+cMSC treatment notably reduced the total number of CD68+ pan-macrophages while inducing the polarization of macrophages toward an anti-inflammatory M2 phenotype in ischemic myocardium, compared with the saline-treated MI control. Periostin, which was highly expressed in Nes+cMSCs, could promote the polarization of M2-subtype macrophages in vitro and in vivo. Finally, Periostin knockdown remarkably reduced the therapeutic effects of Nes+cMSCs, inhibiting the survival and LV remodeling of MI model mice and significantly decreasing the number of M2 macrophages at lesion sites. Conclusions—Nestin+ cMSCs have greater efficacy than Nestin+ bmMSCs for cardiac repair following acute MI, using a reparative mechanism that acts at least partly through Periostin-mediated M2 macrophage polarization.
Project description:Adverse cardiac remodeling after myocardial infarction (MI) causes structural and functional changes in the heart leading to heart failure. The initial pro-inflammatory response followed by an anti-inflammatory or reparative response post-MI is essential for minimizing the myocardial damage, healing, and scar formation. Bone marrow-derived macrophages (BMDMs) are recruited to the injured myocardium and essential for cardiac repair as they can adopt both pro-inflammatory (M1) or anti-inflammatory/reparative (M2) phenotypes to modulate inflammatory and reparative response, respectively. YAP and TAZ are the key mediators of the Hippo signaling pathway and essential for cardiac regeneration and repair. However, their role in macrophage polarization and post-MI inflammation, remodeling, and healing are not well established. Here, we demonstrate that expression of YAP and TAZ is increased in macrophages undergoing M1 or M2 polarization. Genetic deletion of YAP/TAZ leads to impaired M1 polarization and enhanced M2 polarization. Consistently, YAP activation/overexpression enhanced M1 and impaired M2 polarization. We show that YAP/TAZ promote M1 polarization by increasing IL6 expression, and impede M2 polarization by decreasing Arg1 expression through interaction with the HDAC3-NCoR1 repressor complex. These changes in macrophages polarization due to YAP/TAZ deletion results in reduced fibrosis, and hypertrophy and increased angiogenesis, leading to improved cardiac function after MI. Also, YAP activation augmented MI-induced cardiac fibrosis and remodeling. In summary, we identify YAP/TAZ as important regulators of macrophage-mediated pro- and anti-inflammatory responses post-MI.
Project description:Macrophage recruitment into tumors is correlated with poor outcomes in cancer, which correlate with STAT6-dependent M2 macrophage polarization and wound healing-type responses. Using penetrant, genetic models of neuroblastoma, we found macrophage recruitment was protective against tumor formation while disabling STAT6-mediated M2 polarization had no effect on tumorigenesis, progression or expression of key immunosuppressive pathways. Thus while macrophages are drivers of cancer in this model, non-classical M2 STAT6-independent pathways are plausible targets for cancer therapy.
Project description:Macrophages polarize towards different subpopulations with distinct and partly antagonistic functions in various diseases. IFNγ/LPS-polarized M1-type macrophages can have antiangiogenic activity, whereas IL-4-induced M2-type macrophages can be proangiogenic and profibrotic. Therapeutic strategies to inhibit M2-type polarization while promoting M1-type polarization could serve to inhibit pathological angiogenesis and fibrosis. Here, by combining global quantitative time-course proteomics and phosphoproteomics with a small-molecule inhibitor screen we identify signaling events that promote specifically IL-4-induced and not IFNγ/LPS-induced macrophage polarization and found that the MEK inhibitor trametinib and the HDAC inhibitor panobinostat potently prevent M2-type macrophage polarization without inhibiting M1-type polarization. In contrast, selective B-Raf inhibition promotes M2-type polarization. Trametinib and panobinostat also blocked M2-type macrophage polarization and concomitantly angiogenesis and fibrosis in models of wound healing and neovascular age-related macular degeneration in vivo. Thus, these pharmacologic inhibitors could be utilized therapeutically to selectively block IL4-induced macrophage polarization and reduce pathologic angiogenesis and fibrosis.
Project description:Macrophages polarize towards different subpopulations with distinct and partly antagonistic functions in various diseases. IFNγ/LPS-polarized M1-type macrophages can have antiangiogenic activity, whereas IL-4-induced M2-type macrophages can be proangiogenic and profibrotic. Therapeutic strategies to inhibit M2-type polarization while promoting M1-type polarization could serve to inhibit pathological angiogenesis and fibrosis. Here, by combining global quantitative time-course proteomics and phosphoproteomics with a small-molecule inhibitor screen we identify signaling events that promote specifically IL-4-induced and not IFNγ/LPS-induced macrophage polarization and found that the MEK inhibitor trametinib and the HDAC inhibitor panobinostat potently prevent M2-type macrophage polarization without inhibiting M1-type polarization. In contrast, selective B-Raf inhibition promotes M2-type polarization. Trametinib and panobinostat also blocked M2-type macrophage polarization and concomitantly angiogenesis and fibrosis in models of wound healing and neovascular age-related macular degeneration in vivo. Thus, these pharmacologic inhibitors could be utilized therapeutically to selectively block IL4-induced macrophage polarization and reduce pathologic angiogenesis and fibrosis.
Project description:Macrophages polarize towards different subpopulations with distinct and partly antagonistic functions in various diseases. IFNγ/LPS-polarized M1-type macrophages can have antiangiogenic activity, whereas IL-4-induced M2-type macrophages can be proangiogenic and profibrotic. Therapeutic strategies to inhibit M2-type polarization while promoting M1-type polarization could serve to inhibit pathological angiogenesis and fibrosis. Here, by combining global quantitative time-course proteomics and phosphoproteomics with a small-molecule inhibitor screen we identify signaling events that promote specifically IL-4-induced and not IFNγ/LPS-induced macrophage polarization and found that the MEK inhibitor trametinib and the HDAC inhibitor panobinostat potently prevent M2-type macrophage polarization without inhibiting M1-type polarization. In contrast, selective B-Raf inhibition promotes M2-type polarization. Trametinib and panobinostat also blocked M2-type macrophage polarization and concomitantly angiogenesis and fibrosis in models of wound healing and neovascular age-related macular degeneration in vivo. Thus, these pharmacologic inhibitors could be utilized therapeutically to selectively block IL4-induced macrophage polarization and reduce pathologic angiogenesis and fibrosis.
Project description:Macrophages polarize towards different subpopulations with distinct and partly antagonistic functions in various diseases. IFNγ/LPS-polarized M1-type macrophages can have antiangiogenic activity, whereas IL-4-induced M2-type macrophages can be proangiogenic and profibrotic. Therapeutic strategies to inhibit M2-type polarization while promoting M1-type polarization could serve to inhibit pathological angiogenesis and fibrosis. Here, by combining global quantitative time-course proteomics and phosphoproteomics with a small-molecule inhibitor screen we identify signaling events that promote specifically IL-4-induced and not IFNγ/LPS-induced macrophage polarization and found that the MEK inhibitor trametinib and the HDAC inhibitor panobinostat potently prevent M2-type macrophage polarization without inhibiting M1-type polarization. In contrast, selective B-Raf inhibition promotes M2-type polarization. Trametinib and panobinostat also blocked M2-type macrophage polarization and concomitantly angiogenesis and fibrosis in models of wound healing and neovascular age-related macular degeneration in vivo. Thus, these pharmacologic inhibitors could be utilized therapeutically to selectively block IL4-induced macrophage polarization and reduce pathologic angiogenesis and fibrosis.
Project description:Macrophages polarize towards different subpopulations with distinct and partly antagonistic functions in various diseases. IFNγ/LPS-polarized M1-type macrophages can have antiangiogenic activity, whereas IL-4-induced M2-type macrophages can be proangiogenic and profibrotic. Therapeutic strategies to inhibit M2-type polarization while promoting M1-type polarization could serve to inhibit pathological angiogenesis and fibrosis. Here, by combining global quantitative time-course proteomics and phosphoproteomics with a small-molecule inhibitor screen we identify signaling events that promote specifically IL-4-induced and not IFNγ/LPS-induced macrophage polarization and found that the MEK inhibitor trametinib and the HDAC inhibitor panobinostat potently prevent M2-type macrophage polarization without inhibiting M1-type polarization. In contrast, selective B-Raf inhibition promotes M2-type polarization. Trametinib and panobinostat also blocked M2-type macrophage polarization and concomitantly angiogenesis and fibrosis in models of wound healing and neovascular age-related macular degeneration in vivo. Thus, these pharmacologic inhibitors could be utilized therapeutically to selectively block IL4-induced macrophage polarization and reduce pathologic angiogenesis and fibrosis.
Project description:Small extracellular vesicles (sEVs) play a critical role in cardiac cell therapy by delivering molecular cargo and mediating cellular signaling. Among sEV cargo molecule types, microRNA (miRNA) is particularly potent and highly heterogenous. However, not all miRNAs in sEV are beneficial. Two previous studies utilizing computational modeling identified miR-192-5p and miR-432-5p as potentially deleterious in cardiac function and repair. Here, we show that knocking down miR-192-5p and miR-432-5p in cardiac c-kit+ cell-derived sEVs enhances the therapeutic capabilities of sEVs in vitro and in a rat in vivo model of cardiac ischemia reperfusion. miR-192-5p and miR-432-5p depleted CPC-sEVs enhance cardiac function by reducing fibrosis, enhancing mesenchymal stromal cell-like cell mobilization, and inducing macrophage polarization to the M2 phenotype. Knocking down deleterious miRNAs from sEV could be a promising therapeutic strategy for treatment of chronic myocardial infarction.
Project description:Cardiac fibroblasts convert to myofibroblasts with injury to mediate healing after acute myocardial infarction and to mediate long-standing fibrosis with chronic disease. Myofibroblasts remain a poorly defined cell-type in terms of their origins and functional effects in vivo. Methods: Here we generate Postn (periostin) gene-targeted mice containing a tamoxifen inducible Cre for cellular lineage tracing analysis. This Postn allele identifies essentially all myofibroblasts within the heart and multiple other tissues. Results: Lineage tracing with 4 additional Cre-expressing mouse lines shows that periostin-expressing myofibroblasts in the heart derive from tissue-resident fibroblasts of the Tcf21 lineage, but not endothelial, immune/myeloid or smooth muscle cells. Deletion of periostin+ myofibroblasts reduces collagen production and scar formation after myocardial infarction. Periostin-traced myofibroblasts also revert back to a less activated state upon injury resolution. Conclusions: Our results define the myofibroblast as a periostin-expressing cell-type necessary for adaptive healing and fibrosis in the heart, which arises from Tcf21+ tissue-resident fibroblasts. Fluidigm C1 whole genome transcriptome analysis of lineage mapped cardiac myofibroblasts