Lisa M Dyer1,2, Jessica D Kepple1, Lingbao Ai1, Wan-Ju Kim1, Virginia L Stanton1, Mary K Reinhard3, Lindsey R F Backman1, W Scott Streitfeld1, Nivetha Ramesh Babu1, Nicolai Treiber4, Karin Scharffetter-Kochanek4, Peter J McKinnon5, Kevin D Brown6. 1. Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, 1600 SW Archer Road, Box 1000245, Gainesville, FL, 32610, USA. 2. Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. 3. Department of Infectious Disease and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA. 4. Department of Dermatology and Allergic Diseases, University of Ulm, Ulm, Germany. 5. Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, USA. 6. Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, 1600 SW Archer Road, Box 1000245, Gainesville, FL, 32610, USA. kdbrown1@ufl.edu.
Abstract
PURPOSE: ATM activates the NF-κB transcriptional complex in response to genotoxic and oxidative stress. The purpose of this study was to examine if the NF-κB target gene and critical antioxidant SOD2 (MnSOD) in cultured mammary epithelium is also ATM-dependent, and what phenotypes arise from deletion of ATM and SOD2 within the mammary gland. METHODS: SOD2 expression was studied in human mammary epithelial cells and MCF10A using RNAi to knockdown ATM or the NF-κB subunit RelA. To study ATM and SOD2 function in mammary glands, mouse lines containing Atm or Sod2 genes containing LoxP sites were mated with mice harboring Cre recombinase under the control of the whey acidic protein promoter. Quantitative PCR was used to measure gene expression, and mammary gland structure was studied using histology. RESULTS: SOD2 expression is ATM- and RelA-dependent, ATM knockdown renders cells sensitive to pro-oxidant exposure, and SOD mimetics partially rescue this sensitivity. Mice with germline deletion of Atm fail to develop mature mammary glands, but using a conditional knockout approach, we determined that Atm deletion significantly diminished the expression of Sod2. We also observed that these mice (termed AtmΔ/Δ) displayed a progressive lactation defect as judged by reduced pup growth rate, aberrant lobulo-alveolar structure, diminished milk protein gene expression, and increased apoptosis within lactating glands. This phenotype appears to be linked to dysregulated Sod2 expression as mammary gland-specific deletion of Sod2 phenocopies defects observed in AtmΔ/Δ dams. CONCLUSIONS: We conclude that ATM is required to promote expression of SOD2 within the mammary epithelium, and that both ATM and SOD2 play a crucial role in mammary gland homeostasis.
PURPOSE:ATM activates the NF-κB transcriptional complex in response to genotoxic and oxidative stress. The purpose of this study was to examine if the NF-κB target gene and critical antioxidant SOD2 (MnSOD) in cultured mammary epithelium is also ATM-dependent, and what phenotypes arise from deletion of ATM and SOD2 within the mammary gland. METHODS:SOD2 expression was studied in human mammary epithelial cells and MCF10A using RNAi to knockdown ATM or the NF-κB subunit RelA. To study ATM and SOD2 function in mammary glands, mouse lines containing Atm or Sod2 genes containing LoxP sites were mated with mice harboring Cre recombinase under the control of the whey acidic protein promoter. Quantitative PCR was used to measure gene expression, and mammary gland structure was studied using histology. RESULTS:SOD2 expression is ATM- and RelA-dependent, ATM knockdown renders cells sensitive to pro-oxidant exposure, and SOD mimetics partially rescue this sensitivity. Mice with germline deletion of Atm fail to develop mature mammary glands, but using a conditional knockout approach, we determined that Atm deletion significantly diminished the expression of Sod2. We also observed that these mice (termed AtmΔ/Δ) displayed a progressive lactation defect as judged by reduced pup growth rate, aberrant lobulo-alveolar structure, diminished milk protein gene expression, and increased apoptosis within lactating glands. This phenotype appears to be linked to dysregulated Sod2 expression as mammary gland-specific deletion of Sod2 phenocopies defects observed in AtmΔ/Δ dams. CONCLUSIONS: We conclude that ATM is required to promote expression of SOD2 within the mammary epithelium, and that both ATM and SOD2 play a crucial role in mammary gland homeostasis.
Authors: Biserka Mulac-Jericevic; John P Lydon; Francesco J DeMayo; Orla M Conneely Journal: Proc Natl Acad Sci U S A Date: 2003-08-01 Impact factor: 11.205
Authors: Andrey A Yurchenko; Tatiana E Deniskova; Nikolay S Yudin; Arsen V Dotsev; Timur N Khamiruev; Marina I Selionova; Sergey V Egorov; Henry Reyer; Klaus Wimmers; Gottfried Brem; Natalia A Zinovieva; Denis M Larkin Journal: BMC Genomics Date: 2019-05-08 Impact factor: 3.969