[Protective effects of Sphingosine-1-phosphate (S1P) on hypertrophic response in H9c2 cardiomyocytes].

Objective: To investigate the effects of sphingosine-1-phosphate (S1P) on cardiac hypertrophic response in H9c2 cells.

Methods: H9c2 cells were randomly divided into four groups: normal control group, S1P (1 μmol/L) treated group, Phenylephrine (PE) (100 μmol/L) treated group, PE (100 μmol/L) treated group combined with S1P (1 μmol/L) treatment. Each group has 3 duplicated wells. After 24 hours, the size of H9c2 cells in each group was detected by Actin-Trakcer Green immunofluorescence staining. Transcriptional levels of hypertrophic markers ( ANP, BNP and β-MHC) in H9c2 cells were determined by real-time PCR. Western blot was performed to examine the expression level of ANP in each group. Then H9c2 cells were randomly divided into five groups: normal control group, PE (100 μmol/L) treated group, PE (100 μmol/L) with S1P low-dose (0.1 μmol/L) treated group, PE (100 μmol/L) with S1P middle-dose (1 μmol/L) treated group and PE (100 μmol/L) with S1P high-dose (10 μmol/L) treated group. Each group has 3 duplicated wells. After 24 hours, Western blot was performed to examine the expressions of phosphorylated Janus kinase 2 (JAK2) and signal transducers and activators of transcription 3 (STAT3) under low, medium and high concentrations of S1P. Each experiment was repeated three times.

Results: Compared with normal control group, the surface area of H9c2 cells in PE group was increased significantly (P＜0.05), meanwhile, the transcription levels of ANP, BNP and β-MHC were increased significantly (all P＜0.05), and the expression of ANP was also increased significantly (P＜0.05) in PE group. While compared with PE group, the surface area of H9c2 cells in PE + S1P group was decreased significantly (P＜0.05), the transcription levels of ANP, BNP and β-MHC and the expression of ANP were also decreased significantly (all P＜0.05) in PE + S1P group. After treated with PE and different concentrations of S1P, the expressions of p-JAK2 and p-STAT3 were increased significantly compared with the normal control group and PE group (P＜0.05), in a dose-dependent manner.

Conclusion: S1P could protect H9c2 cells against hypertrophic response induced by PE, which may be achieved by activating JAK2/STAT3 signal pathway.