Human Extravillous Trophoblast Cell-Derived Follistatin Promotes the Viability and Proliferation of Human Umbilical Vein Endothelial Cells by Activating the AMPK Signaling Pathway

Abstract

Background: Gestational diabetes mellitus (GDM) elevates the risk of complications in pregnant women and fetuses. The follistatin (FST) expression is decreased during GDM. However, its precise impact and the underlying mechanisms in human umbilical vein endothelial cell (HUVEC) are not fully understood. Therefore, this study aimed to delve into the impact of FST on HUVEC and to elucidate the underlying molecular mechanisms. Methods: FST level in GDM was bioinformatically analyzed using two datasets, GSE49524 and GSE87295. Human extravillous trophoblast cells (HTR-8/SVneo) were cultured in a high glucose (HG) medium and subsequently transfected with lentiviral vectors overexpressing FST or its negative control. Moreover, HUVEC was grown in HTR-8/SVneo cell culture media replete with Compound C (CC, an inhibitor of adenosine monophosphate (AMP)-activated protein kinase (AMPK)), and FST level was observed using enzyme linked immunosorbent assay (ELISA). Furthermore, the expression levels of FST, glucose-6-phosphatase (G6Pase), proliferating cell nuclear antigen (PCNA), marker of proliferation Ki-67 (Ki67), phosphorylated AMPK (pAMPK), AMPK, histone deacetylase 4 (HDAC4), and phosphorylated histone deacetylase 4 (pHDAC4) were assessed in the treated HUVECs utilizing quantitative real time polymerase chain reaction (qRT-PCR) and western blot analysis. Additionally, the viability and proliferation of HUVECs were determined through 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and 5-ethynyl-2′-deoxyuridine (EdU) staining assays. Results: HG treatment inhibited FST level in HTR-8/SVneo cells as well as in their cell culture medium (p < 0.01). Furthermore, overexpression of FST promoted the viability and proliferation of HUVECs, increased the levels of Ki67, PCNA, and pAMPK, and decreased G6Pase and pHDAC4 levels in HG-induced HUVECs (p < 0.05). Additionally, CC treatment further counteracted the influences of overexpressed FST on pAMPK/AMPK and pHDAC4/HDAC4 ratios, G6Pase, Ki67, and PCNA levels, and the viability and proliferation in HUVECs (p < 0.05). Conclusion: In summary, HTR-8/SVneo-derived FST promoted the viability and proliferation of HUVEC by activating the AMPK signaling pathway.