Acidic digestion is an important digestive process of marine fish.In fish stomach,two enzymes are involved in the secretion of hydrochloric acid(HCl)and proteomic digestion:H^(+)/K^(+)-ATPase and pepsinogen.However,th...Acidic digestion is an important digestive process of marine fish.In fish stomach,two enzymes are involved in the secretion of hydrochloric acid(HCl)and proteomic digestion:H^(+)/K^(+)-ATPase and pepsinogen.However,the starting of digestive function in fish is still unclear.To reveal the details of acidic digestion of turbot Scophthalmus maximus in early development,a 40 day of turbot larvae culture was conducted.The H^(+)/K^(+)-ATPase gene from the turbot S.maximus(smH^(+)/K^(+)-ATPase)was identified and characterized.Based on our previous discription on pepsinogen of turbot S.maximus,we combined pepsinogen and H^(+)/K^(+)-ATPase and analyzed the mechanism of acidic digestion in turbot.Results show that the spatial and temporal expression profiles of H^(+)/K^(+)-ATPase agreed with pepsinogen A and C in turbot,indicating a synergetic action between H^(+)/K^(+)-ATPase and pepsinogen during the acidic digestion process.In addition,the turbot juveniles showed a faster growth after the expressions of H^(+)/K^(+)-ATPase gene and pepsinogen gene,demonstrating that pepsin had a higher digestive efficiency,for which a compound diet should be provided to the fish from Day 22 onward.This study provided a reference for biology research and aquaculture of turbot and other marine fishes.展开更多
Summary： Abnormal cholesterol metabolism is associated with an elevated risk of developing athero- sclerosis, hypertension, and diabetes etc. Na＋/K＋-ATPase was found to regulate cholesterol synthesis, distribution ...Summary： Abnormal cholesterol metabolism is associated with an elevated risk of developing athero- sclerosis, hypertension, and diabetes etc. Na＋/K＋-ATPase was found to regulate cholesterol synthesis, distribution and trafficking. This study aimed to examine the effect of high-fat diet on cholesterol me- tabolism in rats and the role of Na＋/K＋-ATPase/Src/ERK signaling pathway in the process. Forty male SD rats were evenly divided into high-fat diet group and control group at random. Animals in the former group were fed on high-fat diet for 12 weeks, and those fed on basic diet served as control. Blood lipids, including total cholesterol （TC）, triglyceride （TG）, high density lipoprotein-cholesterol （HDL-C）, and low density lipoprotein-cholesteral （LDL-C） levels, were detected at 3, 6 and 12 weeks. The ratio of cholesterol content in cytoplasm to that in cell membrane was detected in liver tissues. RT-PCR and Western blotting were used to measure the expression of lipid metabolism-associated genes （HMG-CoA reductase and SREBP-2） after 12-week high-fat diet. Na＋/K＋-ATPase/Src/ERK signaling path- way-related components （Na＋/K＋-ATPase ctl, Src-PY418 and pERK1/2） were also measured by West- ern blotting. The results showed that the serum TC, TG, and LDL-C levels were significantly higher in high-fat diet group than those in control group, while the HDL-C level was significantly lower in high-fat diet group at 6 weeks （P〈0.01）. High-fat diet led to an increase in the cholesterol content in the cytoplasm and cell membrane. The ratio of cholesterol content in cytoplasm to that in cell membrane was elevated over time. The expression of HMG-CoA reductase and SREBP-2 was significantly sup- pressed at mRNA and protein levels after 12-week high-fat diet （P〈0.05）. Moreover, high-fat diet pro- moted the expression of Na＋/K＋-ATPase α1 but suppressed the phosphorylation of Src-PY418 and ERK1/2 at 12 weeks （P〈0.05）. It was concluded that high-fat diet regulates cholesterol metabolism, and Na＋/K＋-ATPase signaling pathway is involved in the process possibly by regulating the expression of lipid metabolism-associated proteins HMG-CoA reductase and SREBP-2.展开更多
基金Supported by the National Key Research and Development Program(No.2018YFD0901204)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0402)+3 种基金the Major Agricultural Application Technology Innovation Project of Shandong Province(No.SD2019YY011)the Qingdao National Laboratory for Marine Science and Technology(No.2018SDKJ0502-2)the China Agriculture Research System(No.CARS-47),the Major Science and Technology for Scientific and Technological Innovation Projects(Shandong)(No.2019JZZY020710)the STS Project(Nos.KFZD-SW-106,ZSSD-019,2017T3017,2019T3022)。
文摘Acidic digestion is an important digestive process of marine fish.In fish stomach,two enzymes are involved in the secretion of hydrochloric acid(HCl)and proteomic digestion:H^(+)/K^(+)-ATPase and pepsinogen.However,the starting of digestive function in fish is still unclear.To reveal the details of acidic digestion of turbot Scophthalmus maximus in early development,a 40 day of turbot larvae culture was conducted.The H^(+)/K^(+)-ATPase gene from the turbot S.maximus(smH^(+)/K^(+)-ATPase)was identified and characterized.Based on our previous discription on pepsinogen of turbot S.maximus,we combined pepsinogen and H^(+)/K^(+)-ATPase and analyzed the mechanism of acidic digestion in turbot.Results show that the spatial and temporal expression profiles of H^(+)/K^(+)-ATPase agreed with pepsinogen A and C in turbot,indicating a synergetic action between H^(+)/K^(+)-ATPase and pepsinogen during the acidic digestion process.In addition,the turbot juveniles showed a faster growth after the expressions of H^(+)/K^(+)-ATPase gene and pepsinogen gene,demonstrating that pepsin had a higher digestive efficiency,for which a compound diet should be provided to the fish from Day 22 onward.This study provided a reference for biology research and aquaculture of turbot and other marine fishes.
基金supported by a grant from the National Natural Science Foundation of China(No.81200637)
文摘Summary： Abnormal cholesterol metabolism is associated with an elevated risk of developing athero- sclerosis, hypertension, and diabetes etc. Na＋/K＋-ATPase was found to regulate cholesterol synthesis, distribution and trafficking. This study aimed to examine the effect of high-fat diet on cholesterol me- tabolism in rats and the role of Na＋/K＋-ATPase/Src/ERK signaling pathway in the process. Forty male SD rats were evenly divided into high-fat diet group and control group at random. Animals in the former group were fed on high-fat diet for 12 weeks, and those fed on basic diet served as control. Blood lipids, including total cholesterol （TC）, triglyceride （TG）, high density lipoprotein-cholesterol （HDL-C）, and low density lipoprotein-cholesteral （LDL-C） levels, were detected at 3, 6 and 12 weeks. The ratio of cholesterol content in cytoplasm to that in cell membrane was detected in liver tissues. RT-PCR and Western blotting were used to measure the expression of lipid metabolism-associated genes （HMG-CoA reductase and SREBP-2） after 12-week high-fat diet. Na＋/K＋-ATPase/Src/ERK signaling path- way-related components （Na＋/K＋-ATPase ctl, Src-PY418 and pERK1/2） were also measured by West- ern blotting. The results showed that the serum TC, TG, and LDL-C levels were significantly higher in high-fat diet group than those in control group, while the HDL-C level was significantly lower in high-fat diet group at 6 weeks （P〈0.01）. High-fat diet led to an increase in the cholesterol content in the cytoplasm and cell membrane. The ratio of cholesterol content in cytoplasm to that in cell membrane was elevated over time. The expression of HMG-CoA reductase and SREBP-2 was significantly sup- pressed at mRNA and protein levels after 12-week high-fat diet （P〈0.05）. Moreover, high-fat diet pro- moted the expression of Na＋/K＋-ATPase α1 but suppressed the phosphorylation of Src-PY418 and ERK1/2 at 12 weeks （P〈0.05）. It was concluded that high-fat diet regulates cholesterol metabolism, and Na＋/K＋-ATPase signaling pathway is involved in the process possibly by regulating the expression of lipid metabolism-associated proteins HMG-CoA reductase and SREBP-2.
