Purpose: This study aimed to investigate the role of miR-21  expression in the reduction of placental function in GDM patients.
Materials and Methods: qRT-PCR was used to detect the differential expression of miR-21  in the serum of gestational diabetes mellitus (GDM) and normal pregnant women, and to verify the functional target gene PPAR-α  of miR-21 by double fluorescence experiments. Cellular experiments were performed to verify the effect of PPAR-α  on cell function.
Results: miR-21  is down-regulated in the serum and placenta of GDM patients compared to normal pregnant women. In the case of insulin resistance, miR-21-5p  knockdown promoted glucose uptake, but no significant effect was found under physiological condition. Functional studies have shown that reduced PPAR-α  expression can restore miR-21 knockdown-mediated cell growth and metastasis inhibition. Additionally, decreased expression of miR-21  but increased expression of -PPAR-α  was observed in patients with GDM and GDM rats.
Conclusion: The expression of the placental miR-21-5p , which inhibits cell growth and infiltration by up-regulating PPAR-α , is downregulated in pregnant GDM patients, which in turn may affect the placental function.
Keywords: gestational diabetes mellitus, miRNA-21 , insulin resistance, PPAR-α