MicroRNA-145 suppresses mouse granulosa cell proliferation by targeting activin receptor IB.

MicroRNAs (miRNAs) are a class of 21- to 25-nucleotide non-coding RNAs, some of which are important gene regulators involved in folliculogenesis. In this study, we used CCK-8, real-time PCR and Western blot assays to demonstrate that miR-145 inhibits mouse granulosa cell (mGC) proliferation. Combined with the results of luciferase reporter assays that studied the 3'-untranslated region of ACVRIB mRNA, these assays identified ACVRIB as a direct target of miR-145. The ectopic expression of miR-145 reduced the levels of both ACVRIB mRNA and protein and also interfered with activin-induced Smad2 phosphorylation. Altogether, this study revealed that miR-145 suppresses mGC proliferation by targeting ACVRIB.