No abstract

14-3-3 proteins are an acidic protein family that is highly conserved and widely distributed in eukaryotic cells. Recent studies have found that 14-3-3 proteins play critical roles in cell signal transductions, cell growth and differentiation, and protein synthesis. 14-3-3γ is an important member of 14-3-3 protein family. In our previous study, we found that 14-3-3γ was upregulated by estrogen in dairy cow mammary epithelial cell (DCMEC), but the function and mechanism of 14-3-3γ is not known. In this experiment, we first cultured and purified the primary DCMEC and found 14-3-3γ located both in the cytoplasm and nucleus by using immunofluorescence assay. Methionine, lysine, estrogen, and prolactin could upregulate the expression of 14-3-3γ, stimulate the secretion of β-casein and triglyceride, and raise the cell viability of DCMEC. We constructed a stable 14-3-3γ overexpression cell line of DCMEC and found that the expressions of mTOR and p-mTOR, the secretion of triglyceride and β-casein (CSN2), and the cell viability of DCMEC were all upregulated. We also observed the effects of 14-3-3γ gene silencing and gained consistent results with 14-3-3γ overexpression. These findings reveal that 14-3-3γ affects the mTOR pathway and regulates lactogenesis in DCMECs.

We investigated the effects of dietary selenium (Se) supplementation on the development of chicken testis and the expression of selenoprotein W (SelW), glutathione peroxidase4 (GPx4), luteinizing hormone/choriogonadotropin receptor (LHCGR), and angiotensin converting enzyme (ACE). Sixty roosters were assigned randomly into the control group fed with a basic diet (containing 0.3 mg Se/kg) and the experimental group fed with a diet (containing 0.6 mg Se/kg). The testes were collected individually at age of 6, 9, and 12 weeks. Se was supplemented in chicken feed for 15 days before sampling. The results indicated that dietary Se affected the number of cells in the seminiferous tubules and viability of Sertoli cells in vitro culture. SelW and GPx4 expression in the testes increased significantly in the experimental group compared to that in the control group. LHCGR expression in the testes increased significantly in the experimental group after 12 weeks compared to that in the control group. In contrast, ACE expression was inhibited in the experimental group compared to that in the control group. These results suggest that dietary supplementation with Se improved development of the seminiferous tubules at the cellular level and that SelW, GPx4, LHCGR, and ACE are involved.