2014-10-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/645256摘要：儘管近來再灌注策略及藥物治療的新進展，急性心肌梗塞（myocardial infarction，MI)存活患者發展 成心臟衰竭（heart failure，HF)的風險仍然很高。越來越多的證據顯示，心肌損傷引起之發炎反應的 加重、延長、或擴大可能會加劇心臟重塑和功能障礙。因此，及時的調控梗塞後發炎反應可能是保護 心肌免於發展成HF的關鍵。藉由塑膠吸附（plastic adherence)特性從骨鑛(bone marrow，BM)分離出來的間葉幹細胞 (mesenchymal stem cells，MSCs)是多種不同基質細胞（stromal cells)組成的群體，具有多向分化能 力和免疫調節特性。過去十年已有多個臨床前和臨床研究以BM細胞治療梗塞或衰竭的心臟。一般認 為BM細胞治療安全性可接受，然其療效則頗有爭議。可能原因之一是不同來源的BM細胞造成免疫 調節功能有所差異。因此，發展新策略篩選並增強具免疫調節功能的MSC子群體以用於抗發炎治療 應有其必要性。本實驗室近期發現，CXCR4拮抗劑TG-0054可減輕局部和全身發炎反應並保持心肌梗塞後左心 室功能免於惡化。此免疫調節功能是由被驅動至周邊血液（peripheral blood，PB )的CD271+ MSCs 所完成。我們推測，CD271+CXCR4+ MSCs是BM基質細胞中因應組織損傷而被驅動到PB並發揮免 疫抑製作用的子群體。本子計晝（Subproject 4)研究目標為篩選具合格的免疫抑制效價的MSCs並提高其抗發炎效能， 以應用於治療心肌受損後的HF。在期程安排上，我們將於第一年建立一個從BM或PB篩選及增殖 CD271+CXCR4+ MSCs的方法，找出可提高CD271+CXCR4+ MSCs免疫效力的培養條件，並為每批製 備的MSCs定義一個免疫抑制指數。第二年我們將利用豬心肌梗塞模型，研究分離自PB的 CD271+CXCR4+ mononuclear cells和由骨髓抽取物純化養殖具不同免疫抑制指數的CD271+CXCR4+ MSCs之抗發炎療效，以確認in vitro定義的免疫抑制指數和in vivo抗發炎療效之關性。另一方面將結 合可降解的生醫材料和CD271+CXCR4+ MSC球體，以開發治療心肌梗塞後心臟衰竭的新策略。我們 計劃在第三年利用豬隻心血管疾病模型，研究CD271+CXCR4+ MSCs是否藉由誘發TR1-like細胞抑制 發炎反應，以及5-MTP和PGE2在CD271+CXCR4+ MSC的抗發炎過程中所扮演角色，以闡明 CD271+CXCR4+ MSCs在in vivo的免疫調節機制。<br> Abstract: Despite recent advances in reperfusion strategies and pharmacotherapy, patients who survive the acute myocardial infarction (MI) are at high risk of developing heart failure (HF). A growing body of evidence suggests that accentuation, prolongation, or expansion of inflammatory responses to myocardial injury may aggravate cardiac remodeling and dysfunction. Therefore, timely modulation of the post-infarction inflammatory reaction may be crucial to protect the myocardium from development of HF.Mesenchymal stem cells (MSCs) isolated from bone marrow (BM) by virtue of their plastic adherence are heterogeneous population of stromal cells with a multilineage differentiation capacity and immunomodulatory properties. Over the past decade transplantation of BM-derived cells into the infarcted or failing heart have been investigated in both the preclinical and clinical arenas. It is generally recognized that BM-derived cell therapy is safe, however, the beneficial effects are modest and even controversial. One possible reason is the heterogeneity of cell types in terms of their immunoregulatory function. Therefore, strategies to select and enhance MSC subsets based on immunoregulatory potency are necessary for further application in anti-inflammation therapy.Our recent work demonstrates that TG-0054, a novel CXCR4 antagonist, attenuates local as well as systemic inflammation, and preserves left ventricular function after MI. This immunomodulation function is accomplished by the CD271+ MSCs mobilized into peripheral blood (PB). We speculate that the CD271+CXCR4+ MSCs are a subset of stromal cells in BM that are mobilized to PB and exert immunosuppressive action in response to tissue damage.The objectives of this sub-project are to identify MSC preparations with qualified immunosuppressive potency and to improve the efficacy of MSC-mediated anti -inflammatory therapy for HF. In the first year, we propose to establish a protocol for isolation and expansion of CD271+CXCR4+ MSCs from BM and PB, to identify culture conditions that will enhance the immunosuppressive potency of CD271+CXCR4+ MSCs, and to define an immunosuppressive index for each MSC preparation. In the second year, we will correlate the immunosuppressive index defined in vitro and the anti -inflammatory potency in by investigating the anti-inflammatory effects of CD271+CXCR4+ PB mononuclear cells and culture expanded CD271+CXCR4+ MSCs with various immunosuppressive index in pig MI models. Furthermore, we will develop a cell-based strategy using biodegradable biomaterials and CD271+CXCR4+ MSC spheroids for the treatment of MI-induced HF. In the third year, we plan to elucidate the immunomodulation mechanisms of CD271+CXCR4+ MSCs in vivo by determining the involvement of Tr1-like cells as well as the roles of 5-MTP and PGE2 on CD271+CXCR4+ MSC-mediated anti-inflammation in pig models of cardiovascular diseases.