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Effect of different hormones on â-casein and lactoferrin expression in mammary epithelial cells
An inverse relationship in expression patterns for lactoferrin (LTF) and caseins occurs throughout the lactation cycle: when LTF expression is high, casein expression is low and vice versa. The objective of this study was to investigate the effect of different hormones on β-casein (CSN2) and LTF expression in mammary epithelial cells. Primary bovine mammary epithelial cells were treated with eight kinds of induction mediums to induce expression of CSN2 and LTF, including group A dexamethasone&prolactin&insulin (1 μg/mL, 5 μg/mL, 5 μg/mL), group B dexamethasone&prolactin&insulin (1 μg/mL, 10 μg/mL, 5 μg/mL), group C beta estradiol (5 μg/mL), group D 10 ng IGF-Ι, group E 100 ng IGF-Ι, group F 200 ng IGF-Ι, group G 400 ng IGF-Ι, group H 1000 ng IGF-Ι. Materials administered in groups C-H did not include dexamethasone&prolactin&insulin. Relative mRNA expression of CSN2 and LTF was detected at 24h after induction by qPCR. Data was analyzed by One-way ANOVA and pearson correlation procedure of SAS 9.0. The results showed that 100ng IGF-Ι was the most suitable inducing material for beta-casein (P<0.05) and no significant difference of LTF expression among groups was observed (P>0.05). Correlation coefficient of CSN2 and LTF expression was -0.277. It was concluded that CSN2 expression in bovine mammary epithelial cells depended on hormone and IGF-Ι, but not LTF. More research is needed to explore the relationship between β-casein and lactoferrin.Keywords: β-casein, lactoferrin, mammary epithelial cell