Sodium Tanshinone ⅡA Sulfonate Inhibits Pulmonary Hypertension By Targeted Restoration Of Pulmonary Endothelial BMPRⅡ Signaling Transduction

Objective To investigate whether sodium tanshinone ⅡA sulfonate(STS)can target bone morphogenetic protein receptor typeⅡ(BMPR2)in chronic hypoxic pulmonary hypertension(CHPH)model,and reverse pulmonary hypertension by affecting BMPR2 signaling pathway.And to further clarify the underlying molecular mechanism how STS regulates the BMPR2 expression.Method 1.We established the CHPH rat model and determined the changes of related indexes with/without STS treatment,and(1)observed the right ventricular systolic pressure,right heart hypertrophy index,cardiac output and hematoxylin-eosin staining of lung tissue to observe the pathological indicators of pulmonary artery to determine the model was successful established and the therapeutic effect of STS on pulmonary hypertension model;(2)detected BMPR2 and caveolin 1(CAV1)expression in rat lung tissue;(3)observed the apoptosis of rat pulmonary microvascular endothelial cells(PMVEC)by immunofluorescence double staining,namely α-smooth muscle actin(α-SMA)and cleaved-caspase3;2.Primary cultured rat PMVEC,and subsequent to(1)determine the effects of STS treatment on the total protein and mRNA expression of BMPR2;(2)detect the BMPR2 protein expression by WB method after treatment of PMVEC with cycloheximide(chx);(3)detect the BMPR2 and CAV1 protein localization by membrane protein separation experiment;(4)detect the role of STS on BMPR2 protein function by treatment with recombinant BMP9 protein,and detected the activation of BMPR2 downstream signaling transduction,such as the p-smad1/5/8 protein levels.Results 1.The CHPH model was successfully established: The right ventricular systolic pressure,right heart hypertrophy index,cardiac output and pulmonary vascular remodeling were significantly decreased in the STS treatment group compared with the CHPH control model,and the apoptosis of endothelial cells was significantly inhibited in the STS treatment group.2.In the CHPH model,the expression of BMPR2 in the STS-treated group was significantly higher than that in the control group,and the expression of p-smad1/5/8 in the downstream of the BMPR2 signaling pathway significantly increased in the STS treatment group,moreover the trend of CAV1 and BMPR2 was consistent.3.The mRNA expression of BMPR2 and CAV1 in PMVEC had no significant change after STS treatment,and its corresponding total protein expression significant effect.4.STS can significantly inhibit the degradation of PMVEC BMPR2 protein compared with the control group.5.STS significantly restored the expression of BMPR2 and CAV1 proteins in rat PMVEC membrane protein fraction.6.STS can significantly promote the activation of BMP9-iduced phosphorylation of p-smad1/5/8.Conclusion The above experimental procedure was to explore the target and mechanism of STS in the treatment of CHPH,which was to inhibit the apoptosis of endothelial cells by targeting BMPR2 signaling transduction in PMVEC;The molecular mechanism of STS targeted BMPR2 protein,was that STS can inhibit BMPR2 protein degradation,increase BMPR2 protein localization in the membrane and affect the dual regulation mechanism of protein expression downstream of the BMPR2 signaling pathway.