A secretome atlas of cardiac fibroblasts from healthy and infarcted mouse hearts
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ABSTRACT: Cardiac fibroblasts (CF) are key players after myocardial infarction (MI), but their signaling is only incompletely understood. Here we report a first secretome atlas of CF in control (cCF) and post-MI mouse hearts (miCF), combining a rapid cell isolation technique with SILAC and click chemistry. In CF, numerous paracrine factors involved in immune homeostasis are identified. Comparing secretome, transcriptome (SLAMseq), and cellular proteome disclose protein turnover. In miCF at day 5 post-MI, significantly upregulated proteins include SLIT2, FN1, and CRLF1 in mouse and human samples. Comparing the miCF secretome at days 3 and 5 post-MI reveals the dynamic nature of protein secretion. Specific in-vivo labeling of miCF proteins via biotin ligase TurboID using the POSTN promotor mirrors the in-vitro data. In summary, we identify numerous paracrine factors specifically secreted from CF in mice and humans. This secretome atlas may lead to new biomarkers and/or therapeutic targets for the activated CF.
Project description:Cardiac fibroblasts (CF) are key players in cardiac remodeling, but their intercellular communication is only incompletely understood. Here we analyzed the secretome of healthy cardiac fibroblasts (cCF) and cardiac fibroblasts isolated from post-myocardial infarction (postMI) hearts) using metabolic labeling combined with click chemistry.
Project description:Myocardial infarction (MI) is the leading cause for hear failure (HF). Following MI, the non-infarcted region of left ventricle (LV) is critical for maintaining heart function, and disruption of the LV contributes greatly to post-MI HF. Transcriptomic profiling by high-throughput sequencing was performed in a chronic HF pig model, to explore the molecular changes in the post-MI LV related to cardiovascular deterioration. Samples were taken from heart tissue of MI-induced pigs and from control pigs not subjected to MI. Regions of the heart where samples were taken included the site of ischemia (LV ischemia), area bordering ischemia (LV border), area remote to ischemia (LV remote) and the right ventricle (RV).
Project description:Cardiac fibroblasts (CF) are key players in cardiac remodeling, but their intercellular communication is only incompletely understood. Here we analyzed the secretome of cardiac fibroblasts (cCF) after stimulation with TGFß or hypoxia and respective non-treated controls using metabolic labeling combined with click chemistry.
Project description:Loss of CFTR function in the pancreatic duct leads to dysregulated luminal pH causing premature activation of digestive enzymes and tissue necrosis. Drastic alterations in pancreatic tissue architecture and cellular composition changes the microenvironment of the islets. Given that CFTR is expressed in the pancreatic ducts, we hypothesized that loss of functional CFTR impacts islet function by modifying the ductal secretome. To this end, we developed a long-term in vitro pancreatic duct epithelial cell culture system and polarized both WT and CFTR-KO (CF) ferret duct epithelial cells. We profiled the apical and basolateral secretome, and the cellular proteome of both WT and CF duct epithelium using quantitative mass spectrometry. Bioinformatic analysis of differentially secreted proteins mapped to their cognate receptors provided a list of putative paracrine interactions that affect islet function. Signaling pathways and upstream regulators that alter the secretome and cellular proteome profile were computationally mined to characterize disease causing mechanisms. In this study, we provide a proteomic roadmap of perturbed autocrine and paracrine signals from the CF pancreatic duct.
Project description:Cardiac fibrosis is a common feature of ischemic heart disease and cardiac fibroblasts (CF) are key players in cardiac remodeling of the injured heart after myocardial infarction (MI). Fibrosis increases myocardial stiffness, thereby impairing cardiac function, which ultimately progresses to end-stage heart failure. Little is known, however, on the secretome of CF and cell-to-cell communication of CF is only incompletely understood. Here, we in vivo labeled secreted proteins by expressing TurboID under control of the POSTN promotor in cardiac fibroblasts of mouse with myocardial infarction, enriched biotinylated proteins and analyzed them using LC-MS.
Project description:Myocardial infarction (MI) triggers a reparative response involving fibroblast proliferation and differentiation driving extracellular matrix modulation necessary to form a stabilizing scar. Recently, it was shown that a genetic variant of the base excision repair enzyme endonuclease VIII-like 3 (NEIL3) was associated with increased risk of MI in humans. Here, we report elevated myocardial NEIL3 expression in heart failure patients and marked myocardial upregulation of Neil3 following MI in mice, especially in a fibroblast-enriched cell fraction. Neil3-/- mice showed increased mortality after MI compared to WT, caused by myocardial rupture. Neil3-/- hearts displayed enrichment of mutations in genes involved in mitogenesis of fibroblasts and transcriptome analysis revealed dysregulated fibrosis. Correspondingly, proliferation of vimentin+ and aSMA+ (myo)fibroblasts was increased in Neil3-/- hearts following MI. We propose that NEIL3 operates in genomic regions crucial for regulation of cardiac fibroblast proliferation and thereby controls extracellular matrix modulation after MI.
Project description:Myocardial infarction (MI) triggers a reparative response involving fibroblast proliferation and differentiation driving extracellular matrix modulation necessary to form a stabilizing scar. Recently, it was shown that a genetic variant of the base excision repair enzyme endonuclease VIII-like 3 (NEIL3) was associated with increased risk of MI in humans. Here, we report elevated myocardial NEIL3 expression in heart failure patients and marked myocardial upregulation of Neil3 following MI in mice, especially in a fibroblast-enriched cell fraction. Neil3-/-mice showed increased mortality after MI compared to WT, caused by myocardial rupture. Epigenomic analysis suggested dysregulated myofibroblast proliferation and differentiation in Neil3-/-hearts and several differentially expressed genes were downstream targets of differentially methylated/hydroxymethylated transcriptional regulators. Furthermore, proliferation of Vimentin+ and SMA+ (myo)fibroblasts was increased in Neil3 -/-hearts following MI. We propose that NEIL3-dependent modulation of epigenetic DNA methylation regulates cardiac fibroblast proliferation and thereby controls extracellular matrix modulation after MI.
Project description:Senescent cells secrete a plethora of factors with potent paracrine signaling capacity. Strikingly, senescence, which acts as a defense against cell transformation, exerts pro-tumorigenic activities through its secretome by promoting numerous tumor-specific features, such as cellular proliferation, epithelial-mesenchymal transition and invasiveness. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has the unique activity of activating cell death exclusively in tumor cells. Given that the senescence-associated secretome supports cell transformation, we asked whether factor(s) of this secretome would establish a program required for the acquisition of TRAIL sensitivity. We found that conditioned media from several types of senescent cells (CMS) efficiently sensitized pre-transformed cells to TRAIL, while the same was not observed with normal or immortalized cells. Dynamic transcription profiling analysis of CMS-exposed pre-transformed cells revealed paracrine autoregulatory loop of senescence-associated secretome factors and a dominant role of CMS-induced MYC. Sensitization to TRAIL coincided with MYC upregulation and massive changes in gene regulation. CMS-induced MYC silenced its target gene CFLAR, encoding the apoptosis inhibitor FLIPL, thus leading to the acquisition of TRAIL sensitivity. Altogether, our results reveal that senescent cell-secreted factors exert a TRAIL sensitizing effect on pre-transformed cells by modulating the expression of MYC and CFLAR. Notably, CMS dose-dependent sensitization to TRAIL was observed with TRAIL-insensitive cancer cells and confirmed in co-culture experiments. Dissection and characterization of TRAIL-sensitizing CMS factors and the associated signaling pathway(s) may provide a mechanistic insight in the acquisition of TRAIL sensitivity and lead to novel concepts for the apoptogenic therapy of pre-malignant and TRAIL-resistant tumors. Pre-transformed BJEL cells were incubated with CMS for 0, 1, 3, 6, 8, 16 or 24 h respectively. Total RNA has been extracted from each time point and used for gene expression analysis (Affymetrix Human Gene 1.0 ST Arrays).
Project description:Ly6Clow macrophages promote scar formation and prevent early infarct expansion after myocardial infarction (MI). Although CD4+ T cells influence the regulation of Ly6Clow macrophages after MI, the mechanism remains largely unknown. Here, we focused on IL-21 and uncovered its physiological relevance in post-MI hearts. CD4+ T cells harvested from the infarcted heart produce IL-21 upon stimulation, and IL-21 receptor was expressed on Ly6Clo macrophages in the infarcted heart. The survival rate after MI was significantly improved in IL-21-deficient mice compared with WT mice. Moreover, transcriptome analysis of infarcted heart tissue demonstrated that inflammation was persistent in WT mice compared with IL-21-deficient mice. The number of neutrophils was significantly decreased, whereas the number of Ly6Clow macrophages was significantly increased in IL-21-deficient mice. Consistently, IL-21 enhanced the apoptosis of Ly6Clow macrophages. Furthermore, RNA-seq analysis of Ly6Chi and Ly6Clo macrophages stimulated with or without IL-21 for 24 hours revealed that IL-21 induces inflammatory responses in both Ly6Chi and Ly6Clo macrophages. Finally, the treatment with IL-21 receptor Fc protein significantly increased the survival after MI. Thus, the deletion of IL-21 improves survival after MI by preventing Ly6Clo macrophage apoptosis.