Impact Of STAT3 Signaling Pathway On The Expression Of VEGF And SFlt-1 In Trophoblasts

Objective: Abnormal expression of trophoblast cells may affect placental function and lead to pregnancy related diseases.To investigate the effect of STAT3 pathway on the expression of VEGF and s Flt-1 in trophoblast cells by detecting the changes of expression of VEGF and s Flt-1 behind the pathway in the immortalized human villus trophoblast cell line HTR8-SVneo cell induced by Poly(I:C).Method:1 HTR8 was stimulated by Poly(I: C);cells stimulated for 0h,2h,4h,6h,12 h,and 24 h were collected.The expression changes of s Flt-1 and VEGF mRNA were detected by RT-PCR;2 The experiment was attended by five groups:(1)HTR8-SVneo cell;(2)HTR8-SVneo cell+poly(I:C);(3)HTR8-SVneo cell+si RNA;(4)HTR8-SVneo cell+si RNA STAT3;(5)HTR8-SVneo cell+si RNA STAT3+poly(I:C);3 STAT3 and p-STAT3 in Groups(1),(3)and(4)were determined by Western blotting analysis to see whether the transfection was successful and they even were determined to investigate whether Poly affected the expression of STAT3 in trophoblast cell HTR8-SVneo.4 The expression change of s Flt-1 and VEGF mRNA in Groups(1),(2),(4)and(5)was measured by RT-PCR to investigate the effect of STAT3 on VEGF and s Flt-1 in trophoblast cell HTR8-SVneo and whether it played a role in inflammatory disease.Result:1 The expression of s Flt-1 mRNA was significantly higher than that of the control group after 2h,4h and 12 h stimulations by Poly(I: C)(10ug / ml)(t1=5.59,P1=0.005;t2=3.75,P2=0.020;t3=2.979,P3=0.041).The expression ofVEGF mRNA was significantly restrained after 2h,4h,12 h stimulations(t1=3.02,P1=0.039;t2=3.004,P2=0.040;t3=2.979,P3=0.410).In terms of the time dependent analysis,the effects of Poly(I: C)on expressions of s Flt-1 and VEGF mRNA were the most obvious at 2h and 4h.2 After 48 h of HTR8-SVneo transfecting STAT3 si RNA,Western blotting analysis was adopted to measure STAT3 and p-STAT3 in Groups(1),(3)and(4).The results showed that STAT3 and p-STAT3 were significantly decreased in HTR8-SVneo after transfected with STAT3 si RNA compared with those in Groups(1)and(3),suggesting that transfection was successful.3 The results of the Western blotting analysis of STAT3 and p-STAT3 in Groups(1)and(2)showed that compared with Group(1),the STAT3 expression in Group(2)had no significant change but the p-STAT3 expression was significantly reduced,with statistically significance.4 Compared with Group(1),s Flt-1mRNA in Group(4)was significantly increased(t=3.66,P=0.021)while VEGF mRNA was significantly decreased(t=3.03,P=0.038),suggesting that STAT3 had effect on VEGF and s Flt-1 in trophoblast cell HTR8-SVneo.5 After Poly(I:C)(10ug / ml)inducement,the expression of s Flt-1mRNA in Group(5)was higher than that in Group(2),with statistical significance(t=2.80,P=0.048),but VEGF mRNA was lower than that in Group(2),with statistical significance(t1=2.79,P=0.049),suggesting that Poly(I:C)affect VEGF and s Flt-1 through the STAT3 pathway.Conclusion:1 Inhibition of STAT3 pathway could reduce the expression of VEGF in Poly(I:C)-mediated trophoblast cells;2 Inhibition of STAT3 pathway could increase the expression of s Flt-1 in Poly(I:C)-mediated trophoblast cells;3 Alterations in the STAT3 signaling pathway may affect the function of trophoblast cells.