Effect of Soybean Isoflavones on Proliferation and Related Gene Expression of Sow Mammary Gland Cells In Vitro

SIMPLE SUMMARY: Isoflavones (ISO) improved the milk quality of sow, but no reports are available to elucidate the signaling mechanisms. To test the possible mechanisms, we investigated the effect of soybean ISO on the proliferation and related gene expression of sow mammary gland cells in vitro. The results showed that the cell proliferation and related gene or protein expression were enhanced by soybean ISO supplementation. Our findings indicated that ISO could promote the proliferation of sow mammary gland cells, which might be an additive to improve the lactation capacity and lactation performance of sows. ABSTRACT: The present study was conducted to investigate the effects of synthetic soybean isoflavones (ISO) on the proliferation and related gene expression of sow mammary gland cells. Cells were cultured with 0 (control), 10, 20, or 30 μM of ISO under incubation conditions. After a 48 h incubation, these ISO-incubated cells proliferated more (p < 0.05) than the control cells. Cyclin E expression was higher (p < 0.05) in the 10 μM ISO and 20 μM ISO treatment groups than in the control group. Cyclin D1 and p21 expressions decreased (p < 0.05) with the 10 μM ISO treatment for 48 h. The relative mRNA abundances of the cells’ IG-1R (Insulin-like growth factor-1R), EGFR (Epidermal growth factor receptor), STAT3 (Signal transducer and activator of transcription 3) and AKT (protein kinase B) were enhanced (p < 0.05) by the 20 μM ISO treatment for 24 h and 48 h in the medium. The relative mRNA abundances of κ-casein at 48 h of incubation and β-casein at 24 h and 48 h of incubation were increased (p < 0.05) by 10 μM of ISO supplementation. It was concluded that ISO improved the proliferation of sow mammary gland cells, possibly by regulating cyclins and function genes expression in the cell proliferation signaling pathway.