title: The Signaling Mechanism of TGF-β1 Induced Bovine Mammary Epithelial Cell Apoptosis.
abstract: The present study showed that Transforming growth factor beta 1 (TGF-β1) can induce apoptosis of bovine mammary epithelial cells. This apoptosis was also observed with phosphorylation of Smad2/3 within 0.5-2 h. Afterwards the signal transferred into the nucleus. Moreover, intracellular free Ca(2+) concentration was significantly elevated as well as Caspase-3 activated and DNA lysised, thereby inducing the programmed cell death. This signaling pathway of TGF-β1 was blocked by SB-431542 (10(-2) μM) via inhibiting ALK-5 kinase activity, which thus reversed the anti-proliferation and apoptosis effect of TGF-β1 in mammary epithelial cells. These results indicated that TGF-β1 induced apoptosis of bovine mammary epithelial cells through the ALK-5-Smad2/3 pathway, which plays an important role in inhibiting survival of mammary epithelial cells. Moreover, intracellular Ca(2+) also played a critical role in TGF-β1-induced cell apoptosis.
authors: Department of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China ; Jiangsu Animal Husbandry and Veterinary College, Taizhou 225300, China .
authors: He-Shuang
authors: HS
authors: Di
authors: Jiangsu Animal Husbandry and Veterinary College, Taizhou 225300, China .
authors: Li-Gang
authors: LG
authors: Wang
authors: Department of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Gen-Lin
authors: GL
authors: Wang
authors: Department of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Lei
authors: L
authors: Zhou
authors: Department of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Yuan-Yuan
authors: YY
authors: Yang
keywords: ALK-5; Mammary Epithelial Cell; TGF-β1; [Ca2+]i; p-Smad2/3