Tgf β1

Third‐passage hAMSCs were subjected to routine culture in six‐well plates (Corning). At 30%–40% confluency, the induction group medium was changed to DMEM/F12 + 10 ng/ml TGF‐β1 + 10 ng/ml LEGF + 10 ng/ml PDGF‐BB + 1 × 10⁻⁶ M β‐estradiol (all from Solarbio, China) + endometrium‐conditioned medium containing 2% FBS. Control hAMSCs were incubated in DMEM/F12 alone containing 2% FBS. The medium was changed at 2 days, with the entire culture process lasting 3 days.

We chose DMEM/F12 (Gibco, USA) as the human tubuloepithelial cell (HK-2) culture medium. The medium was supplemented with 1% penicillin, 1% streptomycin, and 10% foetal bovine serum (Gibco, USA) according to the ratio. The cells were placed in a humidified incubator (5% CO₂, 37°C). HK-2 cells at a confluency of 50-60% were placed in a 24-well plate and starved for 48 h (0.2% foetal bovine serum) (Biological Industries, Israel). After starvation, the medium was changed, and 10 ng/mL TGF-β1 (Solarbio, China) was added to the culture medium for 48 h. Then, LV-miR-214-OE (a lentivirus expressing the sequence of human pri-miR-214-3p), LV-miR-214-KD (a lentivirus having an oligonucleotide against the mature sequence of human miR-214-3p), or LV-NC-OE/LV-NC-KD negative controls were transfected into HK-2 cells for 12 h. The medium containing the lentivirus was replaced with fresh medium. The lentivirus used was from Wanlei Biological Technology (Shenyang, China).