ABSTRACT
Objective To study and confirm that mouse bone marrow-derived mesenchymal stem cells (MSCs) could promote the repair of mouse pulmonary microvascular endothelial cells (PMVECs) by transferring mitochondria, providing a new idea for the treatment of ARDS. Methods This study was divided into four groups: control group, injuryed group, group of MSC and MSC-oli (loss-of-function of mitochondrial). PMVECs induced by lipopolysaccharide (LPS) were co-cultured with MSC and MSC-oli in transwell chamber. The transfer of mitochondria was observed under confocal microscopy. The expression of mitochondria-associated proteins(CYP1A1,CYP1A2), synthesis-related proteins (eNOS, iNOS) and connexin protein (VE-cadherin) were detected by Western Blot. The permeability of endothelial cell was evaluated by fluorescein isothiocyanate-dextran method. And the apoptosis rate of endothelial cells was evaluated by flow cytometry and JC-1 membrane potential. Results It showed that both MSC and MSC-oli groups could deliver mitochondria from MSC to PMVEC under confocal fluorescence microscopy. The results of Western blot showed the expression of CYP1A1, CYP1A2 and eNOS in endothelial cells of MSC-oli group was significantly lower than that in MSC group (P<0.05). The expression of iNOS was significantly higher than that in MSC group (P<0.05). But there was no significant difference in the expression of VE-cadherin (P>0.05). The dextran method showed that the permeability was significant reduced in MSC-oli group compared with the MSC group (P<0.05). Flow cytometry and JC-1 membrane potential showed that the rate of apoptosis was lower in MSC-oli group compared to the MSC-oli group (P<0.05). Conclusion MSCs could alleviate the damage of PMVECs by transmitting mitochondria.