ABSTRACT: In this study, we examined if KLF4 and c-MYC (KM)-transduced murine cardiac mesenchymal progenitors (CMPs) played a role in the differentiation into adipocytes in the absence of adipogenic stimulation cocktails. These progenitors exhibited increased expression of adipogenic-related genes, such as C/EBPα, PPARγ, and Fabp4, activation of the PPAR signaling pathway, and formation of cytoplasmic lipid droplets within 10 days. Moreover, these KM genes sharply increased following a reperfusion insult, resulting in increased ectopic fat formation. Thus, understanding CMP adipogenesis will clarify the pathophysiology of ischemic reperfusion injury and myocardial infarction and may pave the way for better treatment strategies. Adult mouse cardiac mesenchymal progenitor cells were treated with OSKM for 0, 4, 6, or 8 days.
Project description:In this study, we examined if KLF4 and c-MYC (KM)-transduced murine cardiac mesenchymal progenitors (CMPs) played a role in the differentiation into adipocytes in the absence of adipogenic stimulation cocktails. These progenitors exhibited increased expression of adipogenic-related genes, such as C/EBPα, PPARγ, and Fabp4, activation of the PPAR signaling pathway, and formation of cytoplasmic lipid droplets within 10 days. Moreover, these KM genes sharply increased following a reperfusion insult, resulting in increased ectopic fat formation. Thus, understanding CMP adipogenesis will clarify the pathophysiology of ischemic reperfusion injury and myocardial infarction and may pave the way for better treatment strategies.
Project description:Background and Objective: Currently, the cells for transplantation were derived from either autologous or allogeneic tissue. The former has a drawback that the quality of donor cells could depend on the patient’s condition, and the quantity could also be limited. To solve these problems, we investigated the potential of allogeneic cardiac mesenchymal progenitors (CMPs) derived from postmortem heart, which might be an immunological privileged like bone marrow-derived mesenchymal progenitors. Materials and Methods: We examined whether viable CMPs could be isolated from murine postmortem cardiac tissue that was harvested 24 hours postmortem. After two to three weeks propagation with high dose of basic fibroblast growth factor, we performed the cellular characteristics analyses, which included proliferation and differentiation property flow cytometric analyses, and microarray analyses. Results: Postmortem CMPs had longer lag phase after seeding than CMPs from living tissues, but they demonstrated the similar characteristics in all above examinations. In addition, global gene expression analysis by microarray indicated the similar characteristics between the cell derived from postmortem and living tissue. Conclusion: These results indicate allogeneic postmortem CMPs could have promising potential for cell transplantation as clinical applications, because of circumventing the issue of brain death. The samples were collected fom living or postmortem cardiac tissue (24 hr at 4C). We generated cardiac mesenchymal progenitors (CMPs) from these cardiac tissue, and compared global gene expression by AgilentMouse GE 8x60k Microarray. Adult, or fetal mouse heart RNAs were used as positive control. Adult mouse total heart RNAs were purchased from Clontech. Fetal mouse heart was extracted from fetus which is embryonic day 16.5 C57BL/6 strain. Tg means Transgenic mouse (C57BL/6-Tg(Myh6-EGFP)MG2).
Project description:The cardiac stroma contains multipotent mesenchymal progenitors. However, lineage relationships within cardiac stromal cells are poorly defined. Here, we identify heart-resident PDGFRa+ SCA-1+ cells as cardiac Fibro/Adipogenic Progenitors (cFAPs) and show that they respond to ischemic damage by generating SCA-1- fibrogenic cells. Pharmacological blockade of this differentiation step with an anti-fibrotic tyrosine kinase inhibitor decreases post-myocardial infarction (MI) remodeling and leads to improvement in heart function.
Project description:The cardiac stroma contains multipotent mesenchymal progenitors. However, lineage relationships within cardiac stromal cells are poorly defined. Here, we identify heart-resident PDGFRa+ SCA-1+ cells as cardiac Fibro/Adipogenic Progenitors (cFAPs) and show that they respond to ischemic damage by generating SCA-1- fibrogenic cells. Pharmacological blockade of this differentiation step with an anti-fibrotic tyrosine kinase inhibitor decreases post-myocardial infarction (MI) remodeling and leads to improvement in heart function.
Project description:High levels of Hes1 expression are frequently found in BCR-ABL-positive chronic myelogenous leukemia in blast crisis (CML-BC). In mouse bone marrow transplantation (BMT) models, co-expression of BCR-ABL and Hes1 induces CML-BC–like disease; however the underlying mechanism remained elusive. Here, based on gene expression analysis, we show that MMP-9 is upregulated by Hes1 in common myeloid progenitors (CMPs). Analysis of promoter activity demonstrated that Hes1 upregulated MMP-9 by activating NF-kB. Analysis of 20 samples from CML-BC patients showed that MMP-9 was highly expressed in three, with two exhibiting high levels of Hes1 expression. Interestingly, MMP-9 deficiency impaired the cobblestone area-forming ability of CMPs expressing BCR-ABL and Hes1 that were in conjunction with a stromal cell layer. In addition, these CMPs secreted MMP-9, promoting the release of soluble Kit-ligand (sKitL) from stromal cells, thereby enhancing proliferation of the leukemic cells. In accordance, mice transplanted with CMPs expressing BCR-ABL and Hes1 exhibited high levels of sKitL as well as MMP-9 in the serum. Importantly, MMP-9 deficiency impaired the development of CML-BC–like disease induced by BCR-ABL and Hes1 in mouse BMT models. The present results suggest that Hes1 promotes the development of CML-BC, partly through MMP-9 upregulation in leukemic cells. Common myeloid progenitors (CMPs; Lineage negative, c-Kit positive, Sca-1 negative, Fc-gamma-receptor low, CD34 positive fraction) were sorted with a FACSAria cell sorter (Becton Dickinson). Retroviruses were generated by transfecting Plat-E packaging cells with retrovirus vector pMYs-Hes1-IRES-GFP or empty vector (pMYs-IRES-GFP) using FuGENE 6 (Roche Diagnostics). Infection of retrovirus harboring Hes1 (pMYs-Hes1-IRES-GFP) or empty vector (pMYs-IRES-GFP) into progenitors was performed using RetroNectin (Takara Bio). Hes1-transfected CMPs and Mock-transduced CMPs were isolated 36 hours after infection with a FACSAria cell sorter. One sample of Hes1-transfected CMPs and one sample of mock-transduced CMPs were analyzed with GeneChip Mouse Genome 430 2.0 Array.
Project description:The healthy growth of adipose tissue depends on the capacity of progenitor cells to undergo denovo adipogenesis. However, the cellular hierarchy and mechanisms governing adipocyteprogenitor differentiation are incompletely understood. Here, we identify a lineage hierarchy25 consisting of distinct mesenchymal cell types present in mouse and human adipose tissue. Cellsmarked by Dpp4 expression are highly proliferative, multipotent progenitors that give rise toIcam1+ committed pre-adipocytes and a related adipogenic population marked by Clec11a andCd142 expression. TGFβ maintains DPP4+ cell identity and inhibits adipogenic commitment ofDPP4+ and CD142+ cells. Intriguingly, DPP4+ progenitors reside in the reticular interstitium that30 envelope many organs including adipose depots. Altogether, this study defines the adipose lineagehierarchy and identifies a new anatomical niche for multipotent mesenchymal progenitors.
Project description:The healthy growth of adipose tissue depends on the capacity of progenitor cells to undergo denovo adipogenesis. However, the cellular hierarchy and mechanisms governing adipocyteprogenitor differentiation are incompletely understood. Here, we identify a lineage hierarchy25 consisting of distinct mesenchymal cell types present in mouse and human adipose tissue. Cellsmarked by Dpp4 expression are highly proliferative, multipotent progenitors that give rise toIcam1+ committed pre-adipocytes and a related adipogenic population marked by Clec11a andCd142 expression. TGFβ maintains DPP4+ cell identity and inhibits adipogenic commitment ofDPP4+ and CD142+ cells. Intriguingly, DPP4+ progenitors reside in the reticular interstitium that30 envelope many organs including adipose depots. Altogether, this study defines the adipose lineagehierarchy and identifies a new anatomical niche for multipotent mesenchymal progenitors.
Project description:Early reperfusion of ischemic cardiac tissue remains the most effective intervention for improving clinical outcome following myocardial infarction. However, abrupt increases in intracellular Ca2+ during myocardial reperfusion cause cardiomyocyte death and consequent loss of cardiac function, referred to as ischemia/reperfusion (IR) injury. Cardiac IR is accompanied by dynamic changes in expression of microRNAs (miRNAs), which inhibit specific mRNA targets. miR-214 is up-regulated during ischemic injury and heart failure in mice and humans, but its potential role in these processes is unknown. We show that genetic deletion of miR-214 in mice causes loss of cardiac contractility, increased apoptosis, and excessive fibrosis in response to IR injury. The microarray contains 6 samples, each containing cDNA pooled from 3 mice per group. There are no replicates. The array was designed to make 3 different pairwise comparisons between the following: P14 WT and miR-214 KO hearts; adult WT and miR-214 KO skeletal muscle; adult WT and miR-214 KO hearts