Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan.
Dow University of Health Sciences, Ojha Campus, Gulzar-e-Hijri, Suparco Road, KDA Scheme-33, Karachi, Pakistan.
Mol Cell Biochem. 2020 Jul;470(1-2):99-113. doi: 10.1007/s11010-020-03750-6. Epub 2020 May 15.
Small molecules are widely used to induce stem cell differentiation. 2'-deoxycytidine (2-DC) belongs to the cytidine family. It stimulates the expression of cardiac-specific genes and proteins, and directs mesenchymal stem cells towards cardiomyogenic differentiation. We aim to investigate the role of 2-DC-treated human umbilical cord mesenchymal stem cells (UC-MSCs) into myogenic lineage and explore their application in regeneration of infarcted myocardium. UC-MSCs were treated with 5, 10, 20, and 40 µM 2-DC following optimization by cytotoxicity analysis. Rat model of myocardial infarction (MI) was induced by ligating left anterior descending coronary artery. Normal, and 2-DC treated UC-MSCs were transplanted in the left ventricular wall immediately after ligation. Echocardiographic measurements were performed to assess cardiac function. Tissue architecture of the myocardium was examined by histological analysis to determine fate of the transplanted cells. MSCs were successfully isolated from human umbilical cord tissue. 2-DC treatment did not produce any significant cytotoxic effect in UC-MSCs at all concentrations. qPCR analysis of treated UC-MSCs showed induction of myogenic differentiation, which is more pronounced at 20 μM concentration. Fluorescently labeled 2-DC-treated UC-MSCs showed significant (**P < 0.01) homing in the infarcted myocardium as compared to normal UC-MSCs. Hearts transplanted with 2-DC-treated UC-MSCs significantly (***P < 0.001) improved the cardiac systolic and diastolic functions and pumping ability as compared to normal UC-MSCs and MI groups. Fibrotic area and left ventricular wall thickness were significantly improved (***P < 0.001) in 2-DC-treated group as compared to normal UC-MSCs. Immunohistochemical staining showed co-localization of fluorescently labeled cells and patches of differentiated myocytes which were stained for cardiac proteins in the infarct zone implying that the treated UC-MSCs regenerated cardiomyocytes. We report for the first time that 2-DC induces cardiac differentiation in UC-MSCs. Transplanted cells differentiated into functional cardiomyocytes and significantly improved cardiac performance. These pre-differentiated cardiac progenitors showed better survival, homing, and distribution in the infarcted zone. 2-DC treated cells not only improved cardiac function, but also restored tissue homeostasis, suggesting a better therapeutic option for the regeneration of cardiac tissue in the clinical setup.
小分子被广泛用于诱导干细胞分化。2'-脱氧胞苷（2-DC）属于胞苷家族。它能刺激心脏特异性基因和蛋白的表达，并将间充质干细胞定向分化为心肌细胞。我们旨在研究 2-DC 处理的人脐带间充质干细胞（UC-MSCs）向肌源性谱系的作用，并探索其在梗死心肌再生中的应用。通过细胞毒性分析对 UC-MSCs 进行优化后，用 5、10、20 和 40μM 2-DC 处理。结扎左前降支冠状动脉诱导大鼠心肌梗死（MI）模型。在结扎后立即将正常和 2-DC 处理的 UC-MSCs 移植到左心室壁。通过超声心动图测量评估心功能。通过组织学分析检查心肌组织结构，以确定移植细胞的命运。从人脐带组织中成功分离出 MSCs。2-DC 在所有浓度下对 UC-MSCs 均无明显细胞毒性作用。经处理的 UC-MSCs 的 qPCR 分析显示肌源性分化诱导，在 20μM 浓度下更为明显。荧光标记的 2-DC 处理的 UC-MSCs 与正常 UC-MSCs 相比，在梗死心肌中的归巢显著（**P<0.01）。与正常 UC-MSCs 和 MI 组相比，移植 2-DC 处理的 UC-MSCs 的心脏收缩和舒张功能以及泵血能力显著提高（***P<0.001）。与正常 UC-MSCs 相比，2-DC 处理组的纤维化面积和左心室壁厚度显著改善（***P<0.001）。免疫组织化学染色显示，荧光标记的细胞与在梗死区染色的心脏蛋白的分化肌细胞斑的共定位，表明处理后的 UC-MSCs 再生了心肌细胞。我们首次报道 2-DC 诱导 UC-MSCs 心脏分化。移植细胞分化为功能性心肌细胞，显著改善心脏功能。这些预先分化的心脏祖细胞在梗死区表现出更好的存活、归巢和分布。2-DC 处理的细胞不仅改善了心脏功能，而且恢复了组织内稳态，这为临床心脏组织再生提供了更好的治疗选择。
