Xudong Sun1, Renxu Chang2, Yan Tang1, Shengbin Luo1, Chunhui Jiang1, Hongdou Jia1, Qiushi Xu1, Zhihao Dong1, Yusheng Liang3, Juan J Loor3, Chuang Xu4. 1. Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Daqing, 163319, Heilongjiang Province, China. 2. College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China. 3. Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, 61801, USA. 4. Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Daqing, 163319, Heilongjiang Province, China. xuchuang7175@163.com.
Abstract
BACKGROUND: Bovine mammary epithelial cells after calving undergo serious metabolic challenges and oxidative stress both of which could compromise autophagy. Transcription factor EB (TFEB)-mediated autophagy is an important cytoprotective mechanism against oxidative stress. However, effects of TFEB-mediated autophagy on the oxidative stress of bovine mammary epithelial cells remain unknown. Therefore, the main aim of the study was to investigate the role of TFEB-mediated autophagy in bovine mammary epithelial cells experiencing oxidative stress. RESULTS: H2O2 challenge of the bovine mammary epithelial cell MAC-T increased protein abundance of LC3-II, increased number of autophagosomes and autolysosomes while decreased protein abundance of p62. Inhibition of autophagy via bafilomycin A1 aggravated H2O2-induced reactive oxygen species (ROS) accumulation and apoptosis in MAC-T cells. Furthermore, H2O2 treatment triggered the translocation of TFEB into the nucleus. Knockdown of TFEB by siRNA reversed the effect of H2O2 on protein abundance of LC3-II and p62 as well as the number of autophagosomes and autolysosomes. Overexpression of TFEB activated autophagy and attenuated H2O2-induced ROS accumulation. Furthermore, TFEB overexpression attenuated H2O2-induced apoptosis by downregulating the caspase apoptotic pathway. CONCLUSIONS: Our results indicate that activation of TFEB mediated autophagy alleviates H2O2-induced oxidative damage by reducing ROS accumulation and inhibiting caspase-dependent apoptosis.
BACKGROUND:Bovine mammary epithelial cells after calving undergo serious metabolic challenges and oxidative stress both of which could compromise autophagy. Transcription factor EB (TFEB)-mediated autophagy is an important cytoprotective mechanism against oxidative stress. However, effects of TFEB-mediated autophagy on the oxidative stress of bovine mammary epithelial cells remain unknown. Therefore, the main aim of the study was to investigate the role of TFEB-mediated autophagy in bovine mammary epithelial cells experiencing oxidative stress. RESULTS:H2O2 challenge of the bovine mammary epithelial cell MAC-T increased protein abundance of LC3-II, increased number of autophagosomes and autolysosomes while decreased protein abundance of p62. Inhibition of autophagy via bafilomycin A1 aggravated H2O2-induced reactive oxygen species (ROS) accumulation and apoptosis in MAC-T cells. Furthermore, H2O2 treatment triggered the translocation of TFEB into the nucleus. Knockdown of TFEB by siRNA reversed the effect of H2O2 on protein abundance of LC3-II and p62 as well as the number of autophagosomes and autolysosomes. Overexpression of TFEB activated autophagy and attenuated H2O2-induced ROS accumulation. Furthermore, TFEB overexpression attenuated H2O2-induced apoptosis by downregulating the caspase apoptotic pathway. CONCLUSIONS: Our results indicate that activation of TFEB mediated autophagy alleviates H2O2-induced oxidative damage by reducing ROS accumulation and inhibiting caspase-dependent apoptosis.
Authors: N Hanschke; M Kankofer; L Ruda; M Höltershinken; U Meyer; J Frank; S Dänicke; J Rehage Journal: J Dairy Sci Date: 2016-08-04 Impact factor: 4.034