Effects of Exosome miR-494 on Proliferation, Migration, and Invasion of Trophoblastic Cells by Regulating the PTEN/PI3K/Akt Pathway.

Objective: To investigate the effects of the exosomal miR-494 targeting phospholipinositol 3-kinase (PI3K)/protein kinase B (AKT)/rapamycin target protein (mTOR) pathway on proliferation, migration, and invasion of trophoblast cells.

Methods: Decidual macrophages were randomly divided into control group, mimic NC group, miR-494 mimic group, inhibitor NC group, and miR-494 inhibitor group. Each group was transfected with corresponding miR-494 mimic NC, miR-494 mimic, and inhibitor NC and miR-494 inhibitor, while the cells of control group were only replaced with fresh medium. 48 h after transfection, the exosomes were extracted and identified by differential centrifugation. The 25 nmol/L exosomes were co-cultured with HTR-8 cells and were named as exosome control group, mimic NC exosome group, miR-494 mimic exosome group, inhibitor NC exosome group, and miR-494 inhibitor exosome group, respectively. The expression level of miR-494 in the cells was detected by qRT-PCR, cell proliferation activity was detected by CCK-8, the number of migrating cells was detected by Transwell assay, and the protein expression levels of p-PI3K, p-Akt, and p-mTOR were detected by western blot.

Results: The exosomes are elliptical or crescent-shaped bilayers with particle diameters ranging from 30 nm to 150 nm, expressing CD9, CD63, and TSG101. Compared with exosome control group and mimic NC exosome group, miR-494 mimic exosome group showed increased miR-494 expression level and cell proliferation activity, increased migratory cell number, decreased PTEN protein expression, and increased P-PI3K and P-Akt expression (<0.05). Compared with exosome control group and inhibitor NC exosome group, miR-494 inhibitor exosome group decreased the expression level of miR-494 and cell proliferation activity, the number of migrating cells decreased, and the expression of PTEN protein increased. The protein expressions of P-PI3K, P-Akt, and P-mTOR were decreased (<0.05).

Conclusion: Targeted inhibition of PTEN/PI3K/Akt signaling pathway by exosome miR-494 can promote proliferation, migration, and invasion of trophoblastic cells.