Hypoxia induced with cobalt chloride could protect mesenchymal stem cellsfrom harsh environment: An in vitro study

IntroductionApplication of stem cells encountered some problems such as low cell viability and apoptosis induction following transplantation in body due to harsh environments. Pre-conditioning of the cells with cytotoxicfactors might improvetheir efficiencybut their mechanism is not clear.ObjectivesOurstudy investigated how Cobalt(II) chlorideexerts its protective effects on MSCs after preconditioning.MethodsBone marrow mesenchymal stem cells were cultured with0 (control),5, 10, 20, 50, 70, 90, 100, 120, 150, 200Μmof Cobalt chloride for 6, 12, 24 and 48 hours, followed by treatment with lethal dose of CoCl2(300 μM) for 24 hours. Cells viability was determined by trypan blue. Inaddition, TUNEL assay was performedto study cell apoptosis.ResultsOur findings indicated that preconditioningaffected themesenchymal stem cells dose dependently, as120μMafter 6,and 20μMafter 12 and 24hsignificantlyincreasedcell viability compared to the control group. But, longer exposure time did not changerate of viable cells significantlycompared to control group (P > 0.05). Moreover, treatment of 5μMCoCl2significantly decreased apoptosisrate after 48 hours(P < 0.05), although this decrease in apoptosis wasnot remarkable in other groups.ConclusionCell therapy needs novel strategiesfor improvement ofits efficacy after transplantation.Our findings suggestedthat preconditioningof the cells with hypoxia induced by CoCl2 can improve the cellsurvival and decreasedapoptosis. Preconditioning might providecellularresistance and pave the pathway for application of cell therapy in further clinical trials more confidently

Keywords:

Preconditioning , Cobalt chloride , Apoptosis , MSCs