Exosomal miR-494 Regulates the Biological Behavior of Trophoblasts by Targeting mTOR in Unexplained Recurrent Spontaneous Abortion

Abstract

Recurrent spontaneous abortion (RSA) is a pregnancy disorder, and trophoblasts are involved in its complex pathogenesis. This study aimed to identify the functional role of exosomal miR-494 in promoting the development of unexplained RSA (uRSA). 15 uRSA tissues and 15 healthy controls were collected to compare the exosomal miR-494 expression. The ultracentrifugation method was used for serum exosome isolation, and exosome characteristics were examined using transmission electron microscopy (TEM). The affection of exosomal miR-494 on HTR-8/SVneo cells were determined by CCK-8, EdU, Wound healing, and Transwell assays. Our findings demonstrated that miR-494 levels were markedly lower in placental tissue and plasma exosomes from patients with uRSA than in normal pregnant women. Furthermore, treatment with miR-494-overexpressing exosomes reduced the viability, invasion, and migration of HTR-8/SVneo cells. In terms of regulation, exosomal miR-494 downregulated mTOR levels in HTR-8/SVneo cells. Mechanism research suggested that exosomal miR-494 reduces the viability, invasion, and migration of trophoblasts by targeting mTOR. Exosomal miR-494 and mTOR are potential predicative biomarkers and therapeutic targets for uRSA patients.

Keywords: Exosome; HTR-8/SVneo; mTOR; miR-494; uRSA.