Altered Expression of miR-518b and miR-519a in the placenta is associated with low fetal birth weight.

OBJECTIVES: Previous studies have suggested that the expression and function of placenta-specific microRNAs (miRNAs) are associated with placenta trophoblastic proliferation and invasion. This study investigated whether the altered expression of placenta-specific miRNAs was involved in the development of fetal growth. METHODS: Placenta tissues were obtained from pregnant women with large for gestational age (LGA), intrauterine growth retardation (IUGR), and appropriate for gestational age (AGA) infants (n = 30 in each group). Real-time quantitative reverse transcription-polymerase chain reaction was used to analyze the expression of relative placenta-specific miRNAs in human placental tissues from three different groups. RESULTS: Compared with the LGA and healthy control (AGA) groups; the expression of miR-518b was decreased, whereas miR-519a was significantly increased in the placentas from the IUGR group (p < 0.05). CONCLUSION: This study suggests that altered expression of placenta-specific miRNAs (miR-518b and miR-519a) may be involved in the development of IUGR.

Human umbilical cord mesenchymal stem cell-derived exosome-mediated transfer of microRNA-133b boosts trophoblast cell proliferation, migration and invasion in preeclampsia by restricting SGK1.

OBJECTIVE: Exosomes have been documented to function in human diseases, yet their transfer of microRNA (miRNA) in preeclampsia (PE) has seldom been reported. This study intends to discuss the role of miR-133b derived from exosomes in human umbilical cord mesenchymal stem cells (hUC-MSCs) in trophoblast cell development in PE. METHODS: Placentas from PE patients and normal pregnant women were collected. The hUC-MSCs and their exosomes were obtained and identified. Trophoblast cell HPT-8 and HTR8-S/Vneo were obtained and co-cultured with hUC-MSCs-derived exosomes that had been transfected with different miR-133b plasmids. MiR-133b and glucocorticoid-regulated kinase 1 (SGK1) expression in placental tissues and HPT-8 and HTR8-S/Vneo cells was determined. HTR8-S/Vneo and HPT-8 cell proliferation, cell cycle distribution, apoptosis rate, migration and invasion were detected. RESULTS: MiR-133b was down-regulated and SGK1 was up-regulated in placental tissues of PE patients. MiR-133b expression was inversely related to SGK1 expression in HTR8-S/Vneo and HPT-8 cells co-cultured with hUC-MSC-derived exosomes. Exosomes promoted HTR8-S/Vneo and HPT-8 cell proliferation, migration and invasion abilities, cell cycle entry and inhibited apoptosis. Elevated exosome-derived miR-133b from hUC-MSCs boosted HTR8-S/Vneo and HPT-8 cell proliferation, cell cycle progression, migration and invasion and limited cell apoptosis. MiR-133b targeted SGK1. CONCLUSION: Collectively, we demonstrate that miR-133b is down-regulated and SGK1 is up-regulated in PE, and miR-133b derived from exosomes in hUM-MSCs facilitates trophoblast cell proliferation, migration and invasion in PE via constraining SGK1.