| Objective:To investigate the effects of Ziyin Tongluo Formula (ZYTLF)-containing serum on the proliferation and differentiation of mouse osteoblastic precursor cells (MC3T3-E1) and the estrogen receptor α (ERα)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Methods:Cell proliferation was assessed by CCK-8 assay after treatment with 5%, 10%, or 15% ZYTLF-containing serum for 6, 12, or 24 h. Osteogenic differentiation was evaluated by alkaline phosphatase (ALP) staining (day 7) and Alizarin Red S staining (day 21). Cells were divided into four groups: control, blank serum, teriparatide (10 nmol/L), and ZYTLF-containing serum. Western blotting was performed to detect osteogenic proteins (Runx2, OCN, Col I) and ERα, p-PI3K/PI3K, p-Akt/Akt expression. An ERα inhibitor (ICI 182780, 1 μmol/L) intervention group was established. RT-qPCR and Western blotting analyzed ZYTLF-containing serum’s regulatory effects on osteogenic markers (Runx2, OCN, Col I), ERα, and PI3K/Akt signaling. Results:No significant differences were observed between the blank serum group and the control group. In contrast, compared with the blank serum group, treatment with 10% ZYTLF-containing serum significantly enhanced the proliferation of MC3T3-E1 cells (P<0.05), increased alkaline phosphatase (ALP) activity, and promoted mineralization nodule formation (P<0.05). Concurrently, this treatment upregulated protein expression of osteogenic markers including Runx2, osteocalcin (OCN), collagen type I (Col I), and ERα (P<0.05). Furthermore, the PI3K/Akt pathway was activated, as evidenced by elevated ratios of phosphorylated PI3K to total PI3K (p-PI3K/PI3K) and phosphorylated Akt to total Akt (p-Akt/Akt) (P<0.05). Following intervention with the ERα inhibitor ICI 182780 (1 μmol/L), mRNA and protein expression levels of the aforementioned osteogenic markers (Runx2, OCN, Col I) and pathway components (ERα, p-PI3K/PI3K, p-Akt/Akt) were markedly suppressed (P<0.05). Notably, supplementation with ZYTLF-containing serum effectively reversed these inhibitory effects (P<0.05). Conclusion: ZYTLF-containing serum promotes osteoblast proliferation and differentiation by activating the ERα-PI3K-Akt signaling pathway, indicating mediation by the ERα/PI3K/Akt axis. |