Project description: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:Vascularization and efficient perfusion are long-standing challenges in cardiac tissue engineering. Here, we engineer perfusable microvascular constructs, wherein human embryonic stem cell-derived endothelial cells (hESC-ECs) are seeded both into patterned microchannels and the surrounding collagen matrix. In vitro, the hESC-ECs lining the luminal walls readily sprout and anastomose with de novo-formed endothelial tubes in the matrix under flow. When implanted on infarcted rat hearts, the perfusable microvessel grafts integrate with coronary vasculature to a greater degree than non-perfusable self-assembled constructs at 5 days post-implantation. Optical microangiography imaging reveal that perfusable grafts have 6-fold greater vascular density, 2.5-fold higher vascular velocities and >20-fold higher volumetric perfusion rates. Implantation of perfusable grafts containing additional hESC-derived cardiomyocytes show higher cardiomyocyte and vascular density. Thus, pre-patterned vascular networks enhance vascular remodeling and accelerate coronary perfusion, potentially supporting cardiac tissues after implantation. These findings should facilitate the next generation of cardiac tissue engineering design.
Project description:microRNAs control cardiac remodeling post myocardial infarction, though the cellular and molecular mechanisms remain unclear. We used microarrays to examine microRNA profiles in mice hearts 21 days after ligation of left anterior descending coronary artery (LAD) versus sham control.
Project description:We have observed that DBA/2J and C57Bl6/N mice exhibit different responses to permanent coronary artery ligation, with mice in a C57 background having about a 14-fold increase in cardiomyocyte S-phase activity as compared to DBA mice. We mapped the responsible gene to the distal arm of Chromosome 3 in the C57 background. We then RNA-Seq analyses on hearts from normal and infarcted DBA and C57 mice, with the hope of identifying candidate genes within the region of interest on the distal arm of Chromosome 3 which are differentially expressed. These genes identified Tnni3k as a potential candidate contributing to the elevated S-phase phenotype.
