Fig. 6

miR-338-3p was involved in TGF-β1-dependent regulation of granulosa cell proliferation. (A) After the primary human GCs were routinely cultured in vitro for 24 h, the original culture medium was replaced with cell-starvation medium and the cells were cultured an additional 24 h. The cell-starvation medium was then replaced with culture medium supplemented with different concentrations of TGF-β1 (0, 1, or 2 ng/ml), and the cells were treated in this manner for 6 h. After the treatment was completed, total RNA was extracted from the GCs and real-time PCR was performed to analyse miR-338-3p expression. U6 RNA was detected as the internal reference. (B) The GCs were routinely seeded in 96-well plates and then transfected with miR-338-3p mimics/NC when the cell density reached approximately 70%. At 6 h post-transfection, the original culture medium was replaced with culture medium supplemented with TGFβ1 or control growth medium. The OD₄₅₀ values were measured after 0, 24, 48, and 72 h by performing cell-viability assays, and cell-growth curves were plotted. The “mimics” group represents the miR-338-3p-overexpression group transfected with miR-338-3p mimics, and the “mimics-NC” group represents the NC group transfected with NC mimics. **P < 0.01; ***P < 0.001; ****P < 0.0001