VITAMIN C REDUCES DOXORUBICIN-INDUCED NITROSATIVE STRESS BY REGULATION OF NITRIC OXIDE SYNTHASE

BM-MSCs were exposed cell stressors mimicking the ischemic myocardium such as oxidative stress, hypoxia and inflammation. BM-MSC proliferation was documented by MTT assays whereas cell migration was determined by wound healing assay. Levels of anti-apopotic factor Bcl-xL was assessed by western blot as well as Akt activation. RESULTS: BM-MSCs were characterized by docmentation of key surface markers (CD44, CD29, CD105) and by multilineage differentiation assays. Proliferation curves were unaltered following preconditioning BM-MSCs with VEGF or AG490, in the concentration ranges studied. There was no difference in the proliferation profile when preconditioned BM-MSCs were exposed to oxidative stress, hypoxia or LPS. In vitrowound closure was improvedwhen cellswere preconditionedwith 20 to 60uMof AG490. Similar findings were found for both concentrations of VEGF.The effectwas evenmore noticeablewhen preconditioned MSCs were exposed to inflammatory stimuli for 24h. Bcl-xL expression levels were increased with VEGF preconditioning in hypoxic and inflammatory condition. Similarly, AG490 produced resulted in increased Bcl-XL expression although to a greater extent when preocnditionned with doses between at 20 and 40uM. Akt Phosphorylation was enhanced after exposure to hypoxia and LPS in AG490 and VEGF pre-treated cells. CONCLUSION: Our study findings indicate that AG490 and VEGF are promising preconditioning agents that can promote survival of MSCs, under stress conditions.