Liver regeneration is associated with lipid reorganization in membranes of the endoplasmic reticulum  

作　　者：Anatoly I. Bozhkov Natalia G. Menzyanova Vadim V. Davydov Natalia I. Kurguzova Vadim I. Sidorov Anastasia S. Vasilieva 

机构地区：[1]Research Institute of Biology of V.N. Karazin Kharkov National University, sq. Svobody, 4, 61022 Kharkov, Ukraine [2]Institute of Fundamental Biology and Biotechnology of Siberian Federal University, pr. Svobodny, 79, 660041 Krasnoyarsk, Russia [3]Ryazan State Medical University named after academician I.P.. Pavlov, Visokovoltnaya 9, 390026 Ryazan, Russia

出　　处：《Frontiers in Biology》2016年第5期396-403,共8页生物学前沿（英文版）

摘　　要：BACKGROUND： In recent years, an adaptive endoplasmic reticulum （ER） stress response has been actively investigated. The ER membrane, isolated from the intact and regenerating liver, may be an appropriate model for investigating the association between structural and functional characteristics of ER in vivo and their corresponding behavioral characteristics in vitro. The rate of lipid synthesis and that of intracellular lipid exchange between the ER and cytosol were investigated in the intact and regenerating liver （13 h after partial hepatectomy）. Particularly, membrane characteristics, surface potential, and glucose 6- phosphatase （G6Pase） activity were investigated, along with the degradation rate of G6Pase in vitro, which was estimated by the loss of G6Pase activity, formation of lipid peroxides, and size of excreted membrane vesicles. METHODS： The rate of lipid synthesis was determined by measuring the intensity of radioactive precursor （C^14-sodium acetate） in different fractions of lipids （phospholipids, non-esterified fatty acids, and triacylglycerides） after 30 min exposure. The rate of lipid metabolism was assessed by measuring the quantity oflipids with radioactive labels emerging in the cytosol of hepatocytes （CPM）. Viscosity and surface potential were determined by fluorescent probes. RESULTS： It was observed that after 13 h of partial hepatectomy, the rate of lipid synthesis in the ER of hepatocytes in the regenerating liver was 3 times lower than that in ER ofhepatocytes in the intact liver, wherein the rate of incorporation of newly synthesized lipids in cytosol was several times higher in the regenerating liver. Increase in the rate of exchange of neutral lipids in cells of the regenerating liver was accompanied by lipid reconstruction in the ER, changing the structural and functional characteristics of the membrane. Such membrane rebuilding also contributed to the rate of degradation of the ER in vitro, which that must be taken into account during development of systBACKGROUND： In recent years, an adaptive endoplasmic reticulum （ER） stress response has been actively investigated. The ER membrane, isolated from the intact and regenerating liver, may be an appropriate model for investigating the association between structural and functional characteristics of ER in vivo and their corresponding behavioral characteristics in vitro. The rate of lipid synthesis and that of intracellular lipid exchange between the ER and cytosol were investigated in the intact and regenerating liver （13 h after partial hepatectomy）. Particularly, membrane characteristics, surface potential, and glucose 6- phosphatase （G6Pase） activity were investigated, along with the degradation rate of G6Pase in vitro, which was estimated by the loss of G6Pase activity, formation of lipid peroxides, and size of excreted membrane vesicles. METHODS： The rate of lipid synthesis was determined by measuring the intensity of radioactive precursor （C^14-sodium acetate） in different fractions of lipids （phospholipids, non-esterified fatty acids, and triacylglycerides） after 30 min exposure. The rate of lipid metabolism was assessed by measuring the quantity oflipids with radioactive labels emerging in the cytosol of hepatocytes （CPM）. Viscosity and surface potential were determined by fluorescent probes. RESULTS： It was observed that after 13 h of partial hepatectomy, the rate of lipid synthesis in the ER of hepatocytes in the regenerating liver was 3 times lower than that in ER ofhepatocytes in the intact liver, wherein the rate of incorporation of newly synthesized lipids in cytosol was several times higher in the regenerating liver. Increase in the rate of exchange of neutral lipids in cells of the regenerating liver was accompanied by lipid reconstruction in the ER, changing the structural and functional characteristics of the membrane. Such membrane rebuilding also contributed to the rate of degradation of the ER in vitro, which that must be taken into account during development of syst

关 键 词：REGENERATION neutral lipids microsomes in vitro 

分 类 号：S562.01[农业科学—作物学] TS974[轻工技术与工程]