BACKGROUND & AIMS:
:Sirtuin 3 (SIRT3) is a deacetylase important for antioxidant protection, cell longevity, and aging. We hypothesized that SIRT3 improve oxidative resistance of aged cells and improve cell therapy in aged patients. In vitro, the proliferation and oxidative resistance of human mesenchymal stem cells (hMSCs) significantly declined with age. The expression and activity of antioxidant enzymes, including catalase (CAT) and manganese superoxide dismutase (MnSOD), increased after transfection of SIRT3 in hMSCs from older donors (O-hMSCs). The protein level of Forkhead box O3a (FOXO3a) in nucleus increased after SIRT3 overexpression. The antioxidant capacity of O-hMSCs increased after SIRT3 overexpression. 3-Amino-1,2,4-triazole (3-AT, CAT inhibitor) or diethyldithiocarbamate (DETC, SOD inhibitor) that was used to inhibit CAT or SOD activity significantly blocked the antioxidant function of SIRT3. When two inhibitors were used together, the antioxidant function of SIRT3 almost disappeared. Following myocardial infarction and intramyocardial injections of O-hMSCs in rats in vivo, the survival rate of O-hMSCs increased by SIRT3 transfection. The cardiac function of rats was improved after SIRT3-overexpressed O-hMSC transplantation. The infarct size, collagen content, and expression levels of matrix metalloproteinase 2 (MMP2) and MMP9 decreased. Besides, the protein level of vascular endothelial growth factor A and vascular density increased after cell transplantation with SIRT3-modified O-hMSCs. These results indicate that damage resistance of hMSCs decline with age and SIRT3 might protect O-hMSCs against oxidative damage by activating CAT and MnSOD through transferring FOXO3a into nucleus. Meanwhile, the therapeutic effect of aged hMSC transplantation can be improved by SIRT3 overexpression.
背景与目标:
: Sirtuin 3 (SIRT3) 是一种对抗氧化保护,细胞寿命和衰老很重要的脱乙酰基酶。我们假设SIRT3改善老年细胞的氧化抗性并改善老年患者的细胞治疗。在体外,随着年龄的增长,人间充质干细胞 (hMSCs) 的增殖和氧化抗性显着下降。在年龄较大的供体 (O-hmsc) 的hmsc中转染SIRT3后,抗氧化酶 (包括过氧化氢酶 (CAT) 和锰超氧化物歧化酶 (MnSOD)) 的表达和活性增加。SIRT3过表达后,细胞核中叉头盒O3a (FOXO3a) 的蛋白水平增加。SIRT3过表达后,O-hMSCs的抗氧化能力增加。用于抑制CAT或SOD活性的3-氨基-1,2,4-三唑 (3-AT,CAT抑制剂) 或二乙基二硫代氨基甲酸酯 (DETC,SOD抑制剂) 显着阻断了sirt3的抗氧化功能。当两种抑制剂一起使用时,SIRT3的抗氧化功能几乎消失。在大鼠体内进行心肌梗塞和心肌内注射O-hMSCs后,SIRT3转染可提高O-hMSCs的存活率。SIRT3-overexpressed o-hmsc移植后大鼠的心功能得到改善。梗死面积,胶原含量以及基质金属蛋白酶2 (MMP2) 和MMP9的表达水平降低。此外,SIRT3-modified O-hMSCs移植后,血管内皮生长因子A的蛋白水平和血管密度增加。这些结果表明,hMSCs的抗坏性随着年龄的增长而下降,SIRT3可能通过将FOXO3a转移到细胞核中激活CAT和MnSOD来保护O-hMSCs免受氧化损伤。同时,SIRT3过表达可以改善老年hMSC移植的治疗效果。