MicroRNA-22, Specificity protein-1 and Cystathionine β-synthase in early onset Preeclampsia: significance in trophoblast invasion

IntroductionTrophoblast cell invasion during human placentation is majorly regulated by the balance between MMPs 2, 9 and their inhibitors [tissue inhibitors of matrix metalloproteinases (TIMPs 1, 2)]. Exogenous NaHS (hydrogen sulphide donor) treatment was shown to significantly increase the expression levels of matrix metalloproteinases (MMPs 2, 9) in human bladder cancer EJ cells. Epigentically, the gene expression of hydrogen sulphide synthesising enzyme CBS (cystathionine {beta}-synthase) could be further regulated by various mi-RNAs via the transcription factors like Sp1. Specificity protein 1 (Sp1) has been identified as a target gene for miR-22 to regulate the invasion and metastasis of gastric cancer cells. However, the mechanism of MMPs regulation by either CBS, Sp1 and miRNA-22 in the pregnancies having early onset preeclampsia is not known. Aim of the studyTo determine and compare the expression of MMPs 2, 9, TIMPs 1, 2, CBS, Sp-1 and miR-22 in early onset preeclamptic patients and normotensive, non-proteinuric controls at both transcription and translation levels. Materials and methods30 pregnant women were enrolled from Department of Obstetrics and Gynaecology, AIIMS, New Delhi, India. EOPE women (n=15) after clinical diagnosis as per ACOG guidelines were enrolled as cases and normotensive, non-proteinuric pregnant women (n=15) were enrolled as controls. Protocol of the study was approved by Institute Ethics Committee, AIIMS, New Delhi. 30 caesarean delivered placentae (15 each of patients and controls) were collected to analyse the mRNA and protein expression/levels of MMPs 2, 9, TIMPs 1, 2, CBS, and Sp1. Protein activity of MMP-2 and 9 was determined. Gene expression of miR-22 was observed in placentae of the recruited patients and controls. Data were analysed by STATA 14 and Graph Pad Prism 8. ResultsSignificantly reduced mRNA and protein expression/levels of MMPs 2, 9, CBS and Sp1 whereas elevated for those of TIMP-1 and TIMP-2 was observed in EOPE patients as compared to controls. Gelatinolytic activity of MMP-2 and 9 was also found significantly reduced in placentae from EOPE patients whereas gene expression of miR-22 was found significantly up regulated in the early onset preeclamptic patients in comparison to controls. ConclusionThis is the first study of its kind which implicates that insufficient trophoblastic invasion may be because of down regulation of MMPs 2, 9, CBS, Sp1 and concomitant up regulation of TIMPs 1, 2 and miR-22 in the early onset preeclamptic patients as compared to controls.