2015-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/658255摘要：已有愈來愈多的臨床試驗（如 SCIPIO與 ALCADIA）初步證實應用人類成體心臟前軀細胞(CPC)作細胞治療的安全性及有效改善左室收縮功能與減少心肌梗塞大小之益處。然而，目前仍欠缺能促進成體心臟幹細胞生長以利心臟修復和減少再塑的新治療藥物。 我們前期的研究藉由 Nkx2.5 enhancer-eGFP 轉基因報告小鼠標記 Nkx2.5+ CPCs表現 GFP，可在出生後和成體小鼠心臟中發現存留的 Nkx2.5+ CPCs，並發現 A83-01（TGFβRI抑制劑）可經由MEK相關途徑，刺激 Nkx2.5+ CPCs生長。分析小鼠全基因 cDNA微陣列，並以即時 PCR定量確認轉錄程度，發現抑制 TGFβRI會增加DLK1, JAG1, survivin, VEGFD之表現，並抑制WISP1, frizzled Wnt receptor (fzd6)與 TGF-β1之表現。因此，A83-01可抑制Wnt3a活化非典型Wnt訊息路徑產生之抑制 CPCs生長作用。然而，仍需要進一步研究釐清抑制 TGFβRI後如何影響Wnt及 Notch表現及訊息傳遞來促進 CPC生長。 基於此，本兩年期研究計畫目標在(1) 第一年：釐清抑制 TGF-βRI 後增加之DLK1 及 JAG1 在促進 CPC 生長之角色及機制，以及非典型 Wnt 訊息抑制CPC生長之機制; (2) 第二年：將 CPCs與促進 CPCs增生小分子以微珠支架包裹殖入心肌梗塞疤痕區或代償失調性心衰竭心臟中，優化其修復心肌和再生功效。 本研究能提供調控成體心臟幹細胞生長之新見解，以利發現理想藥理標的及調節劑。此外，利用微珠支架包裹 CSCs 與擴增藥物可能能增加移植成功率並減少藥物可能之全身性副作用。 <br> Abstract: A growing number of clinical trials, including SCIPIO (Stem Cell Infusion in Patients with Ischemic cardiOmyopathy) and ALCADIA (AutoLogous Human Cardiac‐Derived Stem Cell to Treat Ischemic cArdiomyopathy), have demonstrated the safety and the benefit of using adult resident cardiac stem/progenitor cells (CPCs) for cell therapy to improve LV systolic function and reduce infarct size in patients with heart failure after myocardial infarction. While new pharmacotherapies remain an ongoing need to repopulate the resident CPCs for cardiac self-repair and mitigating remodeling. Using the Nkx2.5 enhancer-eGFP transgenic reporter mice to label cardiac Nkx2.5+ cells with an embryonic phenotype, we have previously found a population of the resident Nkx2.5+ CPCs, possessing the potential to differentiate into cardiomyocytes or smooth muscle cells, in the hearts of postnatal and adult mice. Furthermore, A83, a TGFβRI inhibitor, was found to enhance resident Nkx2.5+ CPC proliferation in vitro and in vivo via MEK-dependent manner. Mouse whole genome cDNA microarray analysis with real-time PCR validation proved that A83 could markedly up-regulate DLK1, JAG1, surviving and VEGFD, and down-regulated WISP1, frizzled Wnt receptor (fzd6) and TGF-β1. Wnt3a could markedly inhibited Nkx2.5+ CPC self-renewal, which could be blocked by A83 but not by canonical Wnt inhibitor KY02111. It indicated A83 could attenuate non-canonical Wnt receptor expression to reverse Wnt-mediated inhibition. However, it needs further investigation to clarify the signaling networks among Wnt- and Notch- pathways after TGFβRI inhibition in regulating CPC proliferation. Based on our series study, the goals of the present two-year project are (1) to further clarify the role of DLK1 and JAG1 in enhancing self-renewal of CPC after TGFβRI inhibition, and to characterize non-canonical Wnt signaling in inhibiting CPC growth in the first year; (2) to optimize the regeneration strategy through encapsulating CPC and A83 in alginate microspheres for patch onto the scar region of infarcted hearts or the decompensated heart in the second year. The two-year project can offer new insights into the molecular mechanisms in regulating self-renewal of adult resident CPCs for discovering the ideal pharmacological targets and modulators. Furthermore, the engraftment of the microspheres encapsulated with CPCs and drug on the scar region of post-MI heart could offer an option for elevating the successful rate of cell therapy with the benefit of reducing systemic adverse effect of the drug.心臟幹細胞/前驅細胞Nkx2.5心肌梗塞心臟再塑心臟再生Cardiac stem/progenitor cellNkx2.5myocardial infarctioncardiac remodelingcardiac regeneration.