HO-1/CO系统对骨髓间充质干细胞移植修复急性肾损伤的调控效应

Bone marrow-derived mesenchymal stem cells (BMSC) transplantation is helpful for the treatment of acute kidney injury (AKI). The efficiency, however, is limited. The main reason is due to the low survival of the homing BMSC in the AKI microenvironment with hypoxia condition, oxidative stress and inflammation. Reports represented that hemeoxygenase-1/carbon monoxide (HO-1/CO) system, which has a definite repair effect on renal injury, has the abilities of anti-oxidation, anti-inflammation and anti-apoptosis. As a result, HO-1/CO is expected to have the ability of enhancing the survival of BMSC. However, the expression of HO-1 in BMSC is very little, and furthermore, the CO expression is mostly induced by HO-1. In this study, BMSC is transfected with HO-1 gene, in order to obtain stable and remarkable expression of HO-1 and CO. In the in vitro experiment, the effect of HO-1 gene transfection on the proliferation, apoptosis and differentiation of BMSC cultured with the AKI kidney homogenate was detected, and the possible mechanisms are also discussed. In the in vivo experiment, AKI rat models are transplanted with the HO-1 gene-modified BMSC. Survival of the rats, renal function, renal histology, BMSC homing and proliferation, apoptosis and differentiation of the homing BMSC were all assayed. In conclusion, the purpose of this study is to increase the survival of the transplanted BMSC and the AKI repair effect. The HO-1 gene-modified BMSC transplantation is expected to be a better choice for the cell-based therapies of AKI.

骨髓间充质干细胞（BMSC）移植为急性肾损伤（AKI）治疗提供了新途径，但改善能力有限，主要原因在于归巢至肾脏的BMSC在肾脏微环境的缺氧、氧化应激、炎症等影响下存活率低。研究表明，本身具有肾脏保护作用的血红素加氧酶-1/一氧化碳（HO-1/CO）系统具有明确的抗氧化、抗炎、抗凋亡作用，有望提高移植后的BMSC存活率。但BMSC仅微量表达HO-1，而CO主要依赖HO-1诱导产生。本项目拟将HO-1基因转染BMSC，以期达到HO-1和CO的稳定高效表达。通过离体实验，观察HO-1基因转染对AKI肾脏匀浆干预的BMSC增殖、凋亡、分化的影响，探讨相关机制；结合动物实验，分析AKI大鼠行HO-1转染BMSC移植后的生存率、肾功能、肾组织病理、移植BMSC的肾脏分布及增殖分化等指标变化规律，达到增强移植BMSC存活率和AKI修复效率的目的，为AKI的细胞移植治疗提供新途径。

骨髓间充质干细胞（BMSCs）移植为急性肾损伤（AKI）治疗提供了新途径，但改善能力有限，主要原因在于归巢至肾脏的BMSCs在肾脏微环境的缺氧、氧化应激、炎症等影响下存活率低。研究表明，本身具有肾脏保护作用的血红素加氧酶-1/一氧化碳（HO-1/CO）系统具有明确的抗氧化、抗炎、抗凋亡作用，有望提高移植后的BMSCs存活率。但BMSCs仅微量表达HO-1，而CO主要依赖HO-1诱导产生。本项目构建了可高效表达HO-1的大鼠BMSCs（HO-1-BMSCs），同时构建了eGFP-BMSCs为空载体对照，实现了大鼠BMSCs的HO-1高效表达。实验结果显示：基因修饰并未改变BMSCs活力及多向分化潜能。在体外AKI微环境下，经HO-1基因修饰的BMSCs的凋亡减弱，增殖能力增加，向肾小管上细胞转分化能力也有显著增加。HO-1的过表达，微环境中的氧化应激减弱， NF-κB活化抑制，AKT、ERK磷酸化增强，为发挥作用的可能信号机制。HO-1-BMSCs体内移植入AKI大鼠后，移植定位在肾脏中的BMSCs数量显著增加，大鼠的肾损伤也有显著改善。