Project description:In this study, we attempted to identify the heterogeneity and temporal dynamics of leukocytes at single-cell level in mouse heart after inducing MI using the longitudinal single-cell RNA sequencing and spatial transcriptome sequencing.
Project description:In this study, we attempted to identify the heterogeneity and temporal dynamics of leukocytes at single-cell level in mouse heart after inducing MI using the longitudinal single-cell RNA sequencing and spatial transcriptome sequencing.
Project description:Affymetrix microarray analysis of molecular changes after myocardial infarction. Samples of heart tissue were analyzed after myocardial infarction from WT and reg3beta knock-out mice. Samples from scar tissue and samples adjacent to the scar were analyzed. In the experiment we primarily compared infarction zone of wild-type to infarction zone of knock-out animals, and remote zone of wild-type to remote zone of knock-outs.
Project description:Induction of the inhibitory Smad, Smad7 serves as a negative feedback mechanism that restrains TGF-b-mediated actions in injured tissues. In inflammatory cells, Smad7 has been suggested to exert both pro-inflammatory actions attributed to inhibition of TGF-b-induced suppression of inflammation, and anti-inflammatory effects due to disruption of the TAK-1/NF-kB system. Myocardial infarction triggers a macrophage-driven inflammatory response that plays a central role in cardiac repair, but also contributes to adverse remodeling and fibrosis. We hypothesized that Smad7 upregulation in infarct macrophages may play a modulatory role in cardiac repair, by restraining effects of TGF-b. To test the hypothesis, we investigated the response of Myeloid cell-specific Smad7 knockout mice (MyS7KO) following myocardial infarction protocols, and we examined the in vitro effects of Smad7 in isolated macrophages. Smad7 was upregulated in a subset of infarct macrophages, peaking 7 days after infarction. Myeloid cell-specific Smad7 loss did not affect baseline macrophage gene expression and had no significant effects on homeostatic functions. Although RNA-seq analysis predicted that, in the absence of Smad7, infarct macrophages may have attenuated activation of inflammatory pathways and suppressed TREM1 signaling, myeloid cell-specific Smad7 loss had no significant effects on ventricular dysfunction, adverse remodeling, scar remodeling and collagen deposition after myocardial infarction. In isolated macrophages, TGF-b attenuated pro-inflammatory cytokine and chemokine expression, modulated synthesis of matrix remodeling genes, and had profound effects on macrophage profile, inducing genes associated with activation of sphingosine-1 phosphate and integrin signaling pathways, and inhibiting cholesterol biosynthesis genes. However, RNA-seq and PCR array experiments showed that Smad7 loss has minimal effects on TGF-b-mediated macrophage responses, restraining synthesis of only a small fraction of TGF-b-induced genes, such as Itga5, Olfml3 and Fabp7. Smad7 absence did not affect the anti-inflammatory actions of TGF-b in TNF-stimulated cells. In conclusion, our findings suggest a limited role for macrophage Smad7 in regulation of post-infarction inflammation and repair, and demonstrate that the anti-inflammatory effects of TGF-b in macrophages are not restrained by endogenous Smad7 induction.
Project description:Induction of the inhibitory Smad, Smad7 serves as a negative feedback mechanism that restrains TGF-b-mediated actions in injured tissues. In inflammatory cells, Smad7 has been suggested to exert both pro-inflammatory actions attributed to inhibition of TGF-b-induced suppression of inflammation, and anti-inflammatory effects due to disruption of the TAK-1/NF-kB system. Myocardial infarction triggers a macrophage-driven inflammatory response that plays a central role in cardiac repair, but also contributes to adverse remodeling and fibrosis. We hypothesized that Smad7 upregulation in infarct macrophages may play a modulatory role in cardiac repair, by restraining effects of TGF-b. To test the hypothesis, we investigated the response of Myeloid cell-specific Smad7 knockout mice (MyS7KO) following myocardial infarction protocols, and we examined the in vitro effects of Smad7 in isolated macrophages. Smad7 was upregulated in a subset of infarct macrophages, peaking 7 days after infarction. Myeloid cell-specific Smad7 loss did not affect baseline macrophage gene expression and had no significant effects on homeostatic functions. Although RNA-seq analysis predicted that, in the absence of Smad7, infarct macrophages may have attenuated activation of inflammatory pathways and suppressed TREM1 signaling, myeloid cell-specific Smad7 loss had no significant effects on ventricular dysfunction, adverse remodeling, scar remodeling and collagen deposition after myocardial infarction. In isolated macrophages, TGF-b attenuated pro-inflammatory cytokine and chemokine expression, modulated synthesis of matrix remodeling genes, and had profound effects on macrophage profile, inducing genes associated with activation of sphingosine-1 phosphate and integrin signaling pathways, and inhibiting cholesterol biosynthesis genes. However, RNA-seq and PCR array experiments showed that Smad7 loss has minimal effects on TGF-b-mediated macrophage responses, restraining synthesis of only a small fraction of TGF-b-induced genes, such as Itga5, Olfml3 and Fabp7. Smad7 absence did not affect the anti-inflammatory actions of TGF-b in TNF-stimulated cells. In conclusion, our findings suggest a limited role for macrophage Smad7 in regulation of post-infarction inflammation and repair, and demonstrate that the anti-inflammatory effects of TGF-b in macrophages are not restrained by endogenous Smad7 induction.
Project description:We applied single-cell transcriptomics to identify cellular and molecular heterogeneity in distinct heart cell populations in myocardial infarction versus sham surgery mice.
Project description:We demonstrate an age-independent loss of type H bone endothelium in heart failure after myocardial infarction in both mice and in humans. Using single-cell RNA sequencing, we delineate the transcriptional heterogeneity of human bone marrow endothelium showing increased expression of inflammatory genes, including IL1B and MYC, in ischemic heart failure. Endothelial-specific overexpression of MYC was sufficient to induce type H bone endothelial cells, whereas inhibition of NLRP3-dependent IL-1 production partially prevents the post-myocardial infarction loss of type H vasculature in mice.
Project description:We demonstrate an age-independent loss of type H bone endothelium in heart failure after myocardial infarction in both mice and in humans. Using single-cell RNA sequencing, we delineate the transcriptional heterogeneity of human bone marrow endothelium showing increased expression of inflammatory genes, including IL1B and MYC, in ischemic heart failure. Endothelial-specific overexpression of MYC was sufficient to induce type H bone endothelial cells, whereas inhibition of NLRP3-dependent IL-1 production partially prevents the post-myocardial infarction loss of type H vasculature in mice.