Expression And Significance Of RhoA/Rho Kinase Pathway And Hsp27in Myometrium Of Parturient Women In Postpartum Hemorrhage By Uterine Atony

ObjectiveTo investigate the expression and alteration of RhoA and Rho kinase and heatshock protein27(Hsp27) in myometrium of patients with postpartum hemorrhage(PPH), discuss the significance of RhoA/Rho kinase pathway and Hsp27in thepathogenesis of PPH, analyze the relationship between RhoA/Rho kinase and Ser15phosphorylated Hsp27.Methodssixty term pregnant women，who delivered through cesarean section at the FujianMaternity and Children Health Hospital from January2011to October2011,wereselected and divided into2groups:30in postpartum hemorrhage caused by uterineatony and30in normal group.The levels of contraction of myometrium were detectedby RM6240biological experimental system; the RhoA, ROCKⅠ, ROCKⅡandHsp27mRNA expression in myometrium were detected by Real-time fluorescencequantitative RT-PCR; the levels of RhoA, ROCK Ⅰ, ROCK Ⅱ, Hsp27,Ser15phosphorylated Hsp27protein levels in myometrium were detected by Western Blot;the levels of Hsp27in maternal serum were detected by Enzyme-linkedimmunosorbent assay (ELISA).Results1. In study group, the levels of myometrium contractile amplitude, frequency andcontraction were lower than that of their controls (P<0.05, P<0.05, P<0.01).2. When adding the Rho kinase inhibitor Y-27632to strips, the levels ofmyometrium contraction in both study group and control group were lower thanuntreated(P<0.05, P<0.01, P<0.01).3.The expressions of RhoA mRNA, ROCK Ⅰ mRNA, ROCK Ⅱ mRNA,Hsp27mRNA in the study group were lower than that of their controls(P<0.05,P<0.01, P<0.01, P<0.01).4. The expressions of RhoA, ROCKⅠ, ROCKⅡ, Hsp27, Ser15phosphorylatedHsp27protein in the study group were lower than that of their controls(P<0.01,P<0.05, P<0.05, P<0.05, P<0.01).5. The levels of Hsp27in maternal serum was no significant difference between the2groups (P>0.05).6. The expression of RhoA mRNA and ROCKⅠmRNA, ROCKⅡmRNA werepositively correlated in2groups, and the same were found in the expression of RhoAprotein and ROCKⅠprotein, ROCKⅡ protein. The expression of RhoA protein,ROCKⅠprotein, ROCKⅡ protein and Ser15phosphorylated Hsp27protein werepositively correlated in2groups.7. Both groups, RhoA mRNA, ROCKⅠmRNA, ROCKⅡmRNA, Hsp27mRNAlevels in myometrium were positively related to the level of myometrium contraction,and the same were found in the expression of RhoA protein, ROCKⅠprotein, ROCKⅡ protein, Hsp27, Ser15phosphorylated Hsp27protein and the level of myometriumcontraction.Conclusions1. The uterine smooth muscle can keep automatic contraction in vitro.So theapplication of muscle isometric tension experiment in the study of myometriumcontraction is feasible and objective.2. Reduced RhoA/Rho kinase expression in myometrium may be involved in thepathogenesis of PPH caused by uterine atony.3. There were correlations between RhoA and Rho kinase, suggested that RhoAmaybe intercoordinate with Rho kinase to regulate the contraction of myometrium.4. There exists Hsp27, Ser15phosphorylated Hsp27in uterine smooth muscle andwere positively related to the level of myometrium contraction, suggested that Hsp27can regulate the congtraction of myometrium.5. The lower expression of Hsp27and Ser15phosphorylated Hsp27inmyometrium maybe play an important role in the pathogenesis of PPH caused byuterine atony.6. The expression of Ser15phosphorylated Hsp27was positively correlated withthe level of RhoA/Rho kinase, suggested that RhoA/Rho kinase may be the upstreamof Hsp27and the RhoA/Rho kinase signal pathway may strengthen the role of Hsp27in the pathogenesis of PPH caused by uterine atony.