Plant growth, productivity, and seed yield depend on the efficient uptake, metabolism, and allocation of nutrients. Nitrogen is an essential macronutrient needed in high amounts. Plants have evolved efficient and sele...Plant growth, productivity, and seed yield depend on the efficient uptake, metabolism, and allocation of nutrients. Nitrogen is an essential macronutrient needed in high amounts. Plants have evolved efficient and selective transport systems for nitrogen uptake and transport within the plant to sustain development, growth, and finally reproduction. This review summarizes current knowledge on membrane proteins involved in transport of amino acids and peptides. A special emphasis was put on their function in planta. We focus on uptake of the organic nitrogen by the root, source-sink partitioning, and import into floral tissues and seeds.展开更多
Animal gastrointestinal tract is not only a digestive organ, but also a nutrient sensing organ which detects luminal nutrient and thus can regulate food intake. There are many amino acid sensing receptors and transpor...Animal gastrointestinal tract is not only a digestive organ, but also a nutrient sensing organ which detects luminal nutrient and thus can regulate food intake. There are many amino acid sensing receptors and transporters in the gut. Amino acids sensing by these receptors and transporters can stimulate the intestinal endocrine cells to release a variety of gut hormones. These hormones trigger a series of physiological effects via the nerve system. This review summarized the recent advance on the amino acid sensing receptors and transporters in the gastrointestinal tract, the gut hormones released from the intestinal endocrine cells and the hormones-induced signal transduction between the gut and brain. A better understanding of these processes may help to gain further insight into the specific role of amino acids in digestion and provide guidelines in developing strategy for the better use of amino acids in the diet.展开更多
This study was designed to compare the effect of methionine(Met)sources(DL-methionine[DLM]and DL-2-hydroxy-4-methylthio-butanoic acid(HMTBa))and their supplementation levels on broiler growth performance and redox sta...This study was designed to compare the effect of methionine(Met)sources(DL-methionine[DLM]and DL-2-hydroxy-4-methylthio-butanoic acid(HMTBa))and their supplementation levels on broiler growth performance and redox state.A 2 x 2 factorial arrangement was used with 2 sources(DLM and HMTBa)and 2 supplementation levels(0.05% and 0.252%)of Met.A total of 480 one-day-old broiler chicks were randomly divided into 4 treatments with 8 replicates per treatment(15 birds per replicate).The experiment lasted for 21 d.Broiler growth performance,redox capacity,redox-related genes expression,and Met transporters in different tissues were tested.Broilers fed high Met supplementation levels had improved(P<0.05)body weight(BW).average daily gain(ADG)and feed conversion ratio(FCR).Similarly,broilers fed high Met levels had better(P<0.05)antioxidant abilities in the serum,small intestine,and liver.Whereas,interactive effects(P<0.05)were also observed between Met sources and levels.Compared with DLM.birds fed HMTBa diets had decreased(P<0.05)total glutathione(T-GSH)and oxidized glutathione(GSSG)contents in duodenum,ileum,and liver.Similarly,broilers fed HMTBa supplemented diets had increased(P<0.05)thioredoxin(Trx)gene expression in the duodenum and ileum,but decreased(P<0.05)glutaredoxin(Grx).glutathione reductase(CSR).and glutathione synthetase(GSS)genes expression.Furthermore,lower gene expression of Na+ and Cl-dependent neutral and cationic amino acid transporter(ATB0,+).and Na+ dependent neutral amino acid transporter(B0 AT)in the duodenum brush border,but higher gene expression of diamine acetyltransferase 1(SAT1)and Na+-independent branched-chain and aromatic amino acid transporter(LAT1)in the jejunum and ileum basement membrane along with higher expression of the proton dependent monocarboxylate transporter 1(MCT1)gene in the ileum were detected in birds fed HMTBa diets.In conclusion.DLM can be effectively used in glutathione synthesis to exert antioxidant functions,whereas HMTBa favors S-adenosylmethionine(SAM)synthesis and t展开更多
目的:探讨溶质载体家族38成员2(solute carrier family 38 member 2,SLC38A2)对自然杀伤(natural killer,NK)细胞肿瘤杀伤活性的影响。方法:采用实时荧光定量PCR法检测谷氨酰胺缺失NK细胞和节食小鼠脾脏中谷氨酰胺相关氨基酸转运蛋白(SL...目的:探讨溶质载体家族38成员2(solute carrier family 38 member 2,SLC38A2)对自然杀伤(natural killer,NK)细胞肿瘤杀伤活性的影响。方法:采用实时荧光定量PCR法检测谷氨酰胺缺失NK细胞和节食小鼠脾脏中谷氨酰胺相关氨基酸转运蛋白(SLC38A2、SLC1A5、SLC7A5、SLC7A1和SLC1A4)mRNA的表达情况。通过慢病毒感染的方法将携带有SLC38A2基因重组慢病毒载体转入NK-92MI细胞使SLC38A2过表达。在SLC38A2过表达或谷氨酰胺浓度提高后,利用乳酸脱氢酶释放实验检测NK-92MI细胞对胰腺癌细胞PANC-1和肝癌细胞HUH-7的杀伤活性,并通过FCM法(FITC-Annexin V/7-AAD染色)检测NK-92MI细胞对PANC-1和HUH-7细胞凋亡的影响。最后,通过FCM法进一步检测NK-92MI细胞中杀伤效应分子干扰素-γ(interferon-γ,IFN-γ)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的表达水平以及脱颗粒标志分子CD107a的表达水平。结果:在缺失谷氨酰胺的培养条件下以及节食小鼠模型中获得的NK细胞中氨基酸转运蛋白SLC38A2 mRNA的表达显著增高(P<0.001和P<0.01)。成功构建SLC38A2过表达的NK-92MI细胞;SLC38A2过表达或谷氨酰胺处理均可以明显提升NK-92MI细胞对胰腺癌PANC-1和肝癌HUH-7细胞的杀伤能力(P均<0.05),同时对肿瘤细胞的凋亡具有明显的促进作用(P均<0.01)。流式细胞分析结果显示,过表达SLC38A2的NK-92MI细胞在杀伤肿瘤细胞的过程中,细胞内IFN-γ和TNF-α的含量均显著增加(P均<0.001),细胞膜表面CD107a的表达水平显著提高(P<0.001)。结论:氨基酸转运蛋白SLC38A2能显著增强NK细胞对肿瘤细胞的杀伤活性。展开更多
基金Research in M.T.＇s laboratory was supported by the US National Science Foundation （IOS 0135344 and IOS 0448506） and by the Agricultural and Food Research Initiative Competitive Grant no. 2010-65115-20382 from the USDA National Institute of Food and Agriculture. Work in D.R.＇s laboratory was supported by grants from the Swiss National Science Foundation 3100A0-107507 and 31003A 127340, and EU Marie Curie Research Training Network ＇VaTEP - Vacuolar Transport Equipment for Growth Regulation of Plants＇ （M RTN-CT-2006-035833）. No conflict of interest declared.
文摘Plant growth, productivity, and seed yield depend on the efficient uptake, metabolism, and allocation of nutrients. Nitrogen is an essential macronutrient needed in high amounts. Plants have evolved efficient and selective transport systems for nitrogen uptake and transport within the plant to sustain development, growth, and finally reproduction. This review summarizes current knowledge on membrane proteins involved in transport of amino acids and peptides. A special emphasis was put on their function in planta. We focus on uptake of the organic nitrogen by the root, source-sink partitioning, and import into floral tissues and seeds.
基金supported by the National Key Basic Research Program of China (2013CB127300)Natural Science Foundation of China (31430082)+1 种基金Jiangsu Province Natural Science Foundation (BK20130058)the Collaborative Innovation Center of Meat Production and Processing
文摘Animal gastrointestinal tract is not only a digestive organ, but also a nutrient sensing organ which detects luminal nutrient and thus can regulate food intake. There are many amino acid sensing receptors and transporters in the gut. Amino acids sensing by these receptors and transporters can stimulate the intestinal endocrine cells to release a variety of gut hormones. These hormones trigger a series of physiological effects via the nerve system. This review summarized the recent advance on the amino acid sensing receptors and transporters in the gastrointestinal tract, the gut hormones released from the intestinal endocrine cells and the hormones-induced signal transduction between the gut and brain. A better understanding of these processes may help to gain further insight into the specific role of amino acids in digestion and provide guidelines in developing strategy for the better use of amino acids in the diet.
基金supported by Beijing Technology Program[Z181100009318008]Beijing Agricultural Innovation Consortium(BAlC04-2018)
文摘This study was designed to compare the effect of methionine(Met)sources(DL-methionine[DLM]and DL-2-hydroxy-4-methylthio-butanoic acid(HMTBa))and their supplementation levels on broiler growth performance and redox state.A 2 x 2 factorial arrangement was used with 2 sources(DLM and HMTBa)and 2 supplementation levels(0.05% and 0.252%)of Met.A total of 480 one-day-old broiler chicks were randomly divided into 4 treatments with 8 replicates per treatment(15 birds per replicate).The experiment lasted for 21 d.Broiler growth performance,redox capacity,redox-related genes expression,and Met transporters in different tissues were tested.Broilers fed high Met supplementation levels had improved(P<0.05)body weight(BW).average daily gain(ADG)and feed conversion ratio(FCR).Similarly,broilers fed high Met levels had better(P<0.05)antioxidant abilities in the serum,small intestine,and liver.Whereas,interactive effects(P<0.05)were also observed between Met sources and levels.Compared with DLM.birds fed HMTBa diets had decreased(P<0.05)total glutathione(T-GSH)and oxidized glutathione(GSSG)contents in duodenum,ileum,and liver.Similarly,broilers fed HMTBa supplemented diets had increased(P<0.05)thioredoxin(Trx)gene expression in the duodenum and ileum,but decreased(P<0.05)glutaredoxin(Grx).glutathione reductase(CSR).and glutathione synthetase(GSS)genes expression.Furthermore,lower gene expression of Na+ and Cl-dependent neutral and cationic amino acid transporter(ATB0,+).and Na+ dependent neutral amino acid transporter(B0 AT)in the duodenum brush border,but higher gene expression of diamine acetyltransferase 1(SAT1)and Na+-independent branched-chain and aromatic amino acid transporter(LAT1)in the jejunum and ileum basement membrane along with higher expression of the proton dependent monocarboxylate transporter 1(MCT1)gene in the ileum were detected in birds fed HMTBa diets.In conclusion.DLM can be effectively used in glutathione synthesis to exert antioxidant functions,whereas HMTBa favors S-adenosylmethionine(SAM)synthesis and t
