Molecular Mechanism And Experimental Study Of SATB1 Mediated ?-catenin Signalling Molecule In The Pathogenesis Of Preeclampsia

Objective: To detect the location and expression of both SATB1 and?-catenin signaling molecule in human placenta;To evaluate the levels of soluble Endoglin(sEng)and soluble fms-like tyrosine kinase-1(sFlt-1)in maternal sera from normal third trimester pregnancy or preeclampsia;To discuss the role of SATB1 and ?-catenin signaling molecule in regulation of trophoblast function in preeclampsia.The extravillous trophoblast cell line HTR8/Svneo induced with hypoxia/reoxygenation exposure has been used to mimic oxidative stress insult of placental trophoblast;Recombinant plasmid and special stimulator were employed to identify the molecular mechanisms in our hypothetical regulatory pathway and evaluate the therapeutic effect;And to explore the therapeutic potentials of target gene in PE.Methods:(1)The mRNA expression of SATB1 was compared between placenta tissues from normal pregnancy and PE;Western blotting and Immunohistochemical method were used to measure the localization and expression of SATB1 and ?-catenin protein;Matrix metalloproteinase(MMP)and their specific tissue inhibitors(TIMP)were detected by WB;ELISA was used to measure the levels of sFlt-1 and s Eng in serum.(2)HTR8 treated with H/R exposure were adopted to mimic ischemia/reperfusion insult of placental trophoblast to explore the roles ofSATB1 in the regulation of trophoblast function.(3)SATB1 up-regulated by lentivirus which containing SATB1 gene sequence or slienced by SATB1-shRNA,Wnt signaling activator LiCl and inhibitor DKK-1 were employed to further explore the potential molecular mechanism.We measured the levels of protein and the concentrations of sFlt-1 and sEng to confirm the hypothetical regulatory pathway in which H/R insult�SATB1?�?-catenin suppression�trophoblast dysfunction.(4)Villous explants were employed to further confirm the mechanism of hypothetical regulatory pathway in apoptosis,invasion capability in trophoblast and the pathogenesis of PE.Results:(1)The levels of SATB1 mRNA and protein were significantly decreased in PE placenta compared with normal control groups.In addition,we also identified the levels of sFlt-1 and sEng were higher in PE group compared with normotensive control groups.Positive stained cells were mostly detected in placental trophoblast.(2)H/R treatment induced significant down-regulation of SATB1,nuclear ?-catenin and MMPs,as well as elevated sFlt-1,sEng and TIMPs in HTR8;and down-regulation of SATB1 showed the similar results.However,up-regulation of SATB1 enhanced the activation of ?-catenin and MMP2/9and reduced the secretion of sFlt-1 and sEng.Whereas activation of Wnt signaling had no effects on SATB1 production,but strongly increased the activation of MMP2/9 and reduced the levels of TIMP1/2,s Flt-1 and sEng in HTR8 under H/R condition.While cells with up-regulated SATB1 failed to increase the expression of MMP2/9 and decrease the levels of TIMP1/2,sFlt-1 and s Eng after treated with DKK-1.(3)H/R treatment induced significant cell apoptosis and intracellular ROS,impaired migration and invasion capabilities in trophoblast.However,up-regulation of SATB1 or?-catenin activation attenuates cell apoptosis and intracellular ROSformation,enhanced migration and invasion were also demonstrated.Moreover,up-regulation of SATB1 failed to alleviate the impaired trophoblast function when Wnt signaling inhibited by DKK-1.Conclusions:(1)SATB1 participate in the pathogenesis of PE by regulating Wnt signaling pathway directly or indirectly.(2)We established a regulatory pathway in trophoblast in which oxidative stress inducing SATB1 down-regulation,leading to ?-catenin signaling inhibition,then increasing sFlt-1 and sEng secretion and ultimately causing trophoblast dysfunction.(3)The current study enlighten us a new promising therapeutic targets including gene therapy and signaling pathway intervention in the study of PE.