XIAO Qian,BAO Lu-er,CHEN Chen,et al.Effect of S1PR1 on pressure overload-induced cardiac remodeling in mice[J].Journal of Tongji University(Medical Science),2018,39(6):46-53. [点击复制]
(Dept. of Cardiac Surgery, East Hospital, Tongji University, Shanghai 200120, China;Dept. of Cardiac Surgery, East Hospital, Tongji University, Shanghai 200120, China; Dept. of Heart Failure, East Hospital, Tongji University, Shanghai 200120, China; Heart Failure Institute, East Hospital, Tongji University, Shanghai 200120, China)
Abstract:
Objective To investigate the protective effect and possible mechanism of sphingosine 1-phosphate receptor 1(S1PR1) on ventricular remodeling induced by stress overload in mice. Methods The transverse aortic constriction (TAC) model was established in female C57BL/6 mice. The TAC mice were given intraperitoneal injection of S1PR1 agonist SEW2871 5mg/(kg·d)(TAC+SEW group, n=5) or Dulbeccos modified eagle medium(DMEM)(TAC+DMSO group, n=5); and the mice in sham operation group were given intraperitoneal injection of DMEM(sham group, n=5). After 30 d of administration, the heart function of mice in each group was examined by cardiac ultrasonography. The cardiac H9C2 cells were stimulated with angiotensin II (Ang II，0.5μmol/L) to induce hypertrophy. The S1PR1 gene overexpressing human umbilical vein endothelial cells(HUVECs)(S1PR1 group) and S1PR1 gene silencing HUVECs(shRNA group) were established by corresponding plasmid transfection, and the untransfected HUVESc served as NC group. The protein expression level of extracellular regulated protein kinase 1/2(ERK1/2) in HUVEC cells was detected by Western blot. The culture supernatant of HUVEC cells was collected and co-cultured with H9C2 cells under the stimulation of Ang II for 48h. The cells were divided into four groups： the culture supernatant of NC group without Ang II stimulation(CTL), the culture supernatant of NC group with Ang II stimulation(Ang II+NC), the culture supernatant of S1PR1 group with Ang II stimulation (Ang II+S1PR1) and the culture supernatant of S1PR1 group with Ang II stimulation group pretreated with ERK1/2 antagonist U0126(Ang II+S1PR1+U0126). After 48h of drug treatment, the size of cardiomyocytes was measured by ImageJ software. Results After 30d of drug treatment, the echocardiography results showed that the left ventricular ejection fraction in SEW2871 group(59.65%±6.12%) was significantly higher than that in DMSO group(41.16%±11.91%)(P<0.05). Immunohistochemistry results showed that the degree of myocardial fibrosis in SEW2871 group was lower than that in DMSO group(P<0.05). The results of Western blot showed that the levels of p-ERK1/2 in the S1PR1 group was significantly higher than that in NC group and shRNA group(t=3.598, 3.200, P<0.05). The area of H9C2 cells in S1PR1 group[(22.52±4.13)μm2] was significantly reduced compared with NC group[(34.98±12.92)μm2] and S1PR1+U0126 group[(80.60±36.60)μm2](P<0.05). Conclusion The S1PR1 activation can remarkably improve cardiac function, ameliorate ventricular remodeling and reduce myocardial fibrosis and hypertrophy induced by pressure overload. The expression of S1PR1 in vascular endothelial cells can modify the hypertrophy of cardiac myocytes, which may be accomplished by activating the ERK1/2 signaling pathway.
