为了研究高原动物对青藏高原高寒、低氧等极端生境的适应机理,进一步探讨高原动物对高原反应——高原脑水肿抗性的分子机理,运用基因克隆与生物信息学相关技术和方法,对牦牛脑AQP4(水通道蛋白4,AQP4)基因CDS全长序列进行克隆、基因序列...为了研究高原动物对青藏高原高寒、低氧等极端生境的适应机理,进一步探讨高原动物对高原反应——高原脑水肿抗性的分子机理,运用基因克隆与生物信息学相关技术和方法,对牦牛脑AQP4(水通道蛋白4,AQP4)基因CDS全长序列进行克隆、基因序列比对及其生物信息学特征分析。结果表明,牦牛AQP4的CDS含有一个966 bp的开放阅读框,编码322个氨基酸;牦牛AQP4基因编码蛋白分子量34.69 k D,理论等电点(p I)7.59,其编码蛋白含有6次跨膜结构,属于疏水性蛋白;二级结构主要由α-螺旋、延伸及无规则卷曲构成;AQP4基因编码产物氨基酸同源性及系统进化分析发现,牦牛AQP4基因编码氨基酸序列与黄牛、绵羊等物种间同源性较高,系统进化情况与其亲缘关系远近一致。展开更多
OBJECTIVE Senna and rhubarb are classified as stimulative laxatives,and known to have similar effective constituents,the anthraquinones.Being protected by theβ-glucoside bond,the anthraquinones can reach the intestin...OBJECTIVE Senna and rhubarb are classified as stimulative laxatives,and known to have similar effective constituents,the anthraquinones.Being protected by theβ-glucoside bond,the anthraquinones can reach the intestines where they are degraded into complex metabolites by enzymes secreted from the intestinal microbiome.It is these complex metabolites that produce the laxative effects.Then the similarities and differences of action between the anthraquinones require further elucidation.METHODS Here,we studied metabolites of senna anthraquinones(SAQ),rhubarb anthraquinones(RAQ)and their chemical marker,sennoside A(SA),in a rat diarrhea model.In the in vitro biotransformation experiments,SAQ,RAQ and SA were incubated with rat fecal flora solution and the metabolites produced were analyzed using HPLC.In the in vivo studies,the same compounds were investigated for purgation induction,with measurement of histopathology and multiple aquaporins(Aqps)gene expression in six organs.RESULTS SAQ and RAQ had similar principal constituents but could be degraded into different metabolites.A similar profile of Aqps down-regulation for all compounds was seen in the colon,suggesting a similar mechanism of action for purgation.However,in the kidneys and livers of the diarrhea-rats,down-regulation of Aqps was found in the RAQ-rats whereas up-regulation of Aqps was seen in the SAQ-rats.Furthermore,the RAQ-rats showed lower aquaporin 2(Aqp2)protein expression in the kidneys,whilst the SA-rats and SAQ-rats had higher Aqp2 protein expression in the kidneys.This may have implications for side effects of SAQ or RAQ in patients with chronic kidney or liver diseases.CONCLUSION SAQ and RAQ showed similar laxative actions with a similar mechanism,they could display different actions in rat kidneys and livers.We suggest that the clinical usage of senna or rhubarb products should be clarified for patients having chronic kidney or liver diseases.展开更多
OBJECTIVE To examine the effects of aquaporin 4(AQP4) on opioid addiction and underlie the mechanism behind it. METHODS(1) In the heroin-induced self-administration(SA) experiment,we explored the role of AQP4 on heroi...OBJECTIVE To examine the effects of aquaporin 4(AQP4) on opioid addiction and underlie the mechanism behind it. METHODS(1) In the heroin-induced self-administration(SA) experiment,we explored the role of AQP4 on heroin-induced psychological addiction. After the mice were trained to learn heroin-induced SA under a fixedratio1(FR1) reinforcement program for 7 d,we randomly switched the heroin doses to 0.00625,0.0125,0.025,0.05 or 0.1 mg·kg^(-1)per infusion to counterbalance assignment design. In the end,all mice underwent extinction training and reinstatement testing.(2) In oral sucrose self-administration,5% sucrose solution was used for the mice and the procedures were similar to heroin SA.(3) In morphine-induced hyperactivity test,mice were habituated in the test apparatus for 30 min and then were given saline(10 mL·kg^(-1),sc) or morphine(10 or 20 mg·kg^(-1),sc) to record the locomotion for 1.5 h.(4) For the in vivo microdialysis experiment,mice were surgically implanted with intracranial guide cannula into nucleus accumbens(AP +1.4 mm,ML ±0.9 mm,DV-3.8 mm from bregma). After 5 d of recovery from surgery,the mice were challenged by saline(10 mL·kg^(-1),sc)or morphine(10 mg·kg^(-1),sc),and then samples were collected every 20 min. RESULTS We found that AQP4 deletion had no effects on sucrose-seeking and sucrose-taking,but it significantly attenuated heroin-taking and heroin-seeking behaviors in heroin self-administration. Besides these,AQP4 deletion had no effects on basal level of locomotion,but dramatically decreased morphine-induced hyperactivity.Furthermore,the in vivo microdialysis studies showed that AQP4 deficiency inhibited morphine(10mg · kg^(-1),sc)-induced elevation of extracellular dopamine levels in nucleus accumbens in mice.CONCLUSION Our present findings demonstrate that AQP4 was potentially involved in the properties of opioid rewarding by inhibiting dopamine release in nucleus accumbens(NAc).展开更多
文摘为了研究高原动物对青藏高原高寒、低氧等极端生境的适应机理,进一步探讨高原动物对高原反应——高原脑水肿抗性的分子机理,运用基因克隆与生物信息学相关技术和方法,对牦牛脑AQP4(水通道蛋白4,AQP4)基因CDS全长序列进行克隆、基因序列比对及其生物信息学特征分析。结果表明,牦牛AQP4的CDS含有一个966 bp的开放阅读框,编码322个氨基酸;牦牛AQP4基因编码蛋白分子量34.69 k D,理论等电点(p I)7.59,其编码蛋白含有6次跨膜结构,属于疏水性蛋白;二级结构主要由α-螺旋、延伸及无规则卷曲构成;AQP4基因编码产物氨基酸同源性及系统进化分析发现,牦牛AQP4基因编码氨基酸序列与黄牛、绵羊等物种间同源性较高,系统进化情况与其亲缘关系远近一致。
文摘OBJECTIVE Senna and rhubarb are classified as stimulative laxatives,and known to have similar effective constituents,the anthraquinones.Being protected by theβ-glucoside bond,the anthraquinones can reach the intestines where they are degraded into complex metabolites by enzymes secreted from the intestinal microbiome.It is these complex metabolites that produce the laxative effects.Then the similarities and differences of action between the anthraquinones require further elucidation.METHODS Here,we studied metabolites of senna anthraquinones(SAQ),rhubarb anthraquinones(RAQ)and their chemical marker,sennoside A(SA),in a rat diarrhea model.In the in vitro biotransformation experiments,SAQ,RAQ and SA were incubated with rat fecal flora solution and the metabolites produced were analyzed using HPLC.In the in vivo studies,the same compounds were investigated for purgation induction,with measurement of histopathology and multiple aquaporins(Aqps)gene expression in six organs.RESULTS SAQ and RAQ had similar principal constituents but could be degraded into different metabolites.A similar profile of Aqps down-regulation for all compounds was seen in the colon,suggesting a similar mechanism of action for purgation.However,in the kidneys and livers of the diarrhea-rats,down-regulation of Aqps was found in the RAQ-rats whereas up-regulation of Aqps was seen in the SAQ-rats.Furthermore,the RAQ-rats showed lower aquaporin 2(Aqp2)protein expression in the kidneys,whilst the SA-rats and SAQ-rats had higher Aqp2 protein expression in the kidneys.This may have implications for side effects of SAQ or RAQ in patients with chronic kidney or liver diseases.CONCLUSION SAQ and RAQ showed similar laxative actions with a similar mechanism,they could display different actions in rat kidneys and livers.We suggest that the clinical usage of senna or rhubarb products should be clarified for patients having chronic kidney or liver diseases.
文摘OBJECTIVE To examine the effects of aquaporin 4(AQP4) on opioid addiction and underlie the mechanism behind it. METHODS(1) In the heroin-induced self-administration(SA) experiment,we explored the role of AQP4 on heroin-induced psychological addiction. After the mice were trained to learn heroin-induced SA under a fixedratio1(FR1) reinforcement program for 7 d,we randomly switched the heroin doses to 0.00625,0.0125,0.025,0.05 or 0.1 mg·kg^(-1)per infusion to counterbalance assignment design. In the end,all mice underwent extinction training and reinstatement testing.(2) In oral sucrose self-administration,5% sucrose solution was used for the mice and the procedures were similar to heroin SA.(3) In morphine-induced hyperactivity test,mice were habituated in the test apparatus for 30 min and then were given saline(10 mL·kg^(-1),sc) or morphine(10 or 20 mg·kg^(-1),sc) to record the locomotion for 1.5 h.(4) For the in vivo microdialysis experiment,mice were surgically implanted with intracranial guide cannula into nucleus accumbens(AP +1.4 mm,ML ±0.9 mm,DV-3.8 mm from bregma). After 5 d of recovery from surgery,the mice were challenged by saline(10 mL·kg^(-1),sc)or morphine(10 mg·kg^(-1),sc),and then samples were collected every 20 min. RESULTS We found that AQP4 deletion had no effects on sucrose-seeking and sucrose-taking,but it significantly attenuated heroin-taking and heroin-seeking behaviors in heroin self-administration. Besides these,AQP4 deletion had no effects on basal level of locomotion,but dramatically decreased morphine-induced hyperactivity.Furthermore,the in vivo microdialysis studies showed that AQP4 deficiency inhibited morphine(10mg · kg^(-1),sc)-induced elevation of extracellular dopamine levels in nucleus accumbens in mice.CONCLUSION Our present findings demonstrate that AQP4 was potentially involved in the properties of opioid rewarding by inhibiting dopamine release in nucleus accumbens(NAc).
