松弛素保护心肌微血管内皮细胞缺氧复氧损伤的机制.

BACKGROUND: Relaxin can significantly improve cardiac and renal dysfuction caused by pathological factors, inhibit myocardial hypertrophy, have an anti-fibrosis effect, and improve ischemia-reperfusion injury. However, its protective mechanism against hypoxia-reoxygenation injury of endothelial cells remains unclear. OBJECTIVE: To investigate the protective mechanism of relaxin against hypoxia-reoxygenation injury of myocardial microvascular endothelial cells. METHODS: Mouse myocardial microvascular endothelial cell line (H5V cells) was used for the experiment. Cells were treated by three different interventions: in control group, cells were normally cultured for 33 hours; in model group, cells were treated by 6-hour hypoxia followed by 3-hour reoxygenation); and in relaxin group, 24 hours of routine culture (180 ng/mL relaxin), 6 hours of hypoxia and 3 hours of reoxygenation (180 ng/mL relaxin) were given to simulate myocardial hypoxia-reperfusion injury. Cell permeability and Caspase-3 activity were then detected. Levels of tumor necrosis factor-α, interleukin-1β and interleukin-6 in cell supernatants were detected by ELISA. Expressions of VE-cadherin, Akt, and GSK-3β at mRNA and protein levels were detected by RT-PCR and western blot, respectively. RESULTS AND CONCLUSION: Compared with the control group, the cell permeability and expression of caspase-3 increased significantly in the model group (P < 0.05). Compared with the model group, the cell permeability and expression of caspase-3 decreased in the relaxin group (P < 0.05). Moreover, the levels of tumor necrosis factor-α, interleukin-1β and interleukin-6 were elevated in the model group, while the levels were significantly decreased after relaxin treatment (all P < 0.05). There were no significantly changes in the mRNA and protein expressions of VE-cadherin, Akt1, and GSK-3β mRNA among three groups (all P > 0.05). Compared with the control group, the expression of phosphorylated VE-cadherin, Akt1 and GSK-3β were decreased in the model group (P < 0.05), and relaxin treatment reversed these changes to the control levels (P < 0.05). To conclude, relaxin treatment could enhance VE-cadherin expression, reduce hypoxiareoxygenation-induced microvascular endothelial cell damage, inhibit inflammatory cytokine release, and reduce cell apoptosis, which may be related to the activation of the Akt/GSK-3β signaling pathway. [ABSTRACT FROM AUTHOR]