Repair effect of transplantation of rat bone marrow mesenchymal stem cells on the irradiation injured lung of rat

Abstract

Objective To investigate the repair effect of bone marrow mesenchymal stem cells (MSCs) transplantation on the irradiation injured lung of rat and possible mechanisms.Methods Rat bone MSCs were extracted by density gradient centrifugation combined with adherrnce method.Female Lewis rats were randomly divided into three groups:normal control group,60COγ irradiation group,60COγ irradiation + MSCs transplantation group.Tracking of MSCs were determined by PCR and Y chromosome fluorescent in situ hybridization (Y-FISH).The apoptosis of the lung cells was assessed by TUNEL staining.The level of tumor neerosisfactor-α(TNF-α) in lung was measured by ELISA.Results Y chromosome sequence was amplified in the irradiated recipient' s lung of rat.Moreover,cells with Sry gene were found in injured lung by Y-FISH in 60COγ irradiation + MSCs transplantation group.Some of the Y chromosome positive cells also expressed SP-C,the marker of type Ⅱ pneumocytes.The apoptotic indexes of the injured lung in 60COγ irradiation group and 60COγ irradiation + MSCs transplantation group were higher than those in normal control group.The apoptosis rates of the injured lung in 60COγ irradiation + MSCs transplantation group were lower than those in 60COγ irradiation group.The TNF-α levels of the injured lung in 60COγ irradiation group and 60COγ irradiation + MSCs transplantation group were significantly higher than those in normal control group.The TNF-α levels of the injured lung in 60COγ irradiation + MSCs transplantation group was significantly lower than that in 60COγ irradiation group.Conclusions MSCs transplantation can reduce the injured lung by 60COγ irradiation,through inhibits the apoptosis of injured lung,downregulates of the expression of TNF-α,and differentiate into type Ⅱ pneumocytes. Key words: Mesenchymal stem cells ; Tumor necrosis factor-α ; Irradiation ; Apoptosis