Meltem Yalçın1, Mehtap Kaçar2,3. 1. Department of Physiology, Faculty of Medicine, Yeditepe University, İnönü District, Kayışdağı Street, August 26 Campus, Atasehir, İstanbul, Turkey, 34755. 2. Department of Physiology, Faculty of Medicine, Yeditepe University, İnönü District, Kayışdağı Street, August 26 Campus, Atasehir, İstanbul, Turkey, 34755. mehtap.kacar@yeditepe.edu.tr. 3. Department of Pathophysiology, Graduate School of Health Sciences, Yeditepe University, İnönü District, Kayışdağı Street, August 26 Campus, Atasehir, İstanbul, Turkey, 34755. mehtap.kacar@yeditepe.edu.tr.
Abstract
BACKGROUND: Dysfunctions in the lipogenic process controlled by the hepatic mTOR/S6K1/SREBP-1c signaling pathway may contribute to the pathogenesis of various chronic diseases. In the present study, we aimed to determine age-related changes in the mTOR/S6K1/SREBP1 pathway in rat liver tissues. METHODS AND RESULTS: We performed Western Blot analysis to determine age-related changes in the mTOR/S6K1/SREBP1 pathway in Sprague Dawley male rats liver tissues of six different age groups representing neonatal, infant, weaning, puberty, young adult, adult life periods, and Oil Red O staining to evaluate age-related lipid accumulation. We observed an increase in Akt and p-Akt levels with age in compared to the 0-day-old group. Total mTOR and SREBP1 expression increased from the 0-day-old to the 28-day-old group but decreased in the following age groups. p-mTOR and p-S6K1 levels in the 0-day-old group were higher than the other groups. S6K1 expression was lowest in the 0-day-old group and showed changes among the age groups. Lipid accumulation was seen in liver sections taken from the 12-month-old group. mTOR/S6K1/SREBP1 pathway expression showed changes with age during the neonatal-adult life cycle stages in rat liver tissues. CONCLUSION: We suggest that understanding the molecular mechanisms age-related changes of lipogenesis function is necessary to contribute to the development of therapeutic approaches.
BACKGROUND: Dysfunctions in the lipogenic process controlled by the hepatic mTOR/S6K1/SREBP-1c signaling pathway may contribute to the pathogenesis of various chronic diseases. In the present study, we aimed to determine age-related changes in the mTOR/S6K1/SREBP1 pathway in rat liver tissues. METHODS AND RESULTS: We performed Western Blot analysis to determine age-related changes in the mTOR/S6K1/SREBP1 pathway in Sprague Dawley male rats liver tissues of six different age groups representing neonatal, infant, weaning, puberty, young adult, adult life periods, and Oil Red O staining to evaluate age-related lipid accumulation. We observed an increase in Akt and p-Akt levels with age in compared to the 0-day-old group. Total mTOR and SREBP1 expression increased from the 0-day-old to the 28-day-old group but decreased in the following age groups. p-mTOR and p-S6K1 levels in the 0-day-old group were higher than the other groups. S6K1 expression was lowest in the 0-day-old group and showed changes among the age groups. Lipid accumulation was seen in liver sections taken from the 12-month-old group. mTOR/S6K1/SREBP1 pathway expression showed changes with age during the neonatal-adult life cycle stages in rat liver tissues. CONCLUSION: We suggest that understanding the molecular mechanisms age-related changes of lipogenesis function is necessary to contribute to the development of therapeutic approaches.
Authors: Katrin Düvel; Jessica L Yecies; Suchithra Menon; Pichai Raman; Alex I Lipovsky; Amanda L Souza; Ellen Triantafellow; Qicheng Ma; Regina Gorski; Stephen Cleaver; Matthew G Vander Heiden; Jeffrey P MacKeigan; Peter M Finan; Clary B Clish; Leon O Murphy; Brendan D Manning Journal: Mol Cell Date: 2010-07-30 Impact factor: 17.970
Authors: Joshua L Owen; Yuanyuan Zhang; Soo-Han Bae; Midhat S Farooqi; Guosheng Liang; Robert E Hammer; Joseph L Goldstein; Michael S Brown Journal: Proc Natl Acad Sci U S A Date: 2012-08-27 Impact factor: 11.205