Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Metho...Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Methods Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR). Results Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.Conclusions Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.展开更多
Objective.To evaluate the effects of high-fructose diet on expression of orex in and its receptors,orexin1receptor and orexin2receptor in rat hypothalamus tissue,and to analysis the interaction of related fa ctors inv...Objective.To evaluate the effects of high-fructose diet on expression of orex in and its receptors,orexin1receptor and orexin2receptor in rat hypothalamus tissue,and to analysis the interaction of related fa ctors involved in regulating orexin and its receptors.Methods.Insulin resistan ce rat model induced by high fructose confirmed by the gold standard eug-lycaem ic clamping was employed and mRNA expression of orexin and its receptors OX 1 R and OX 2 R in hypothalamus,mRNA expression of leptin in adipose tissue were measured by reverse transcription poly-merase chain reaction.Serum insulin and triglyc eride levels were measured by chemiluminescence im-munoassay and biochemical en zyme techniques.Results.Expression of orexin mRNA decreased about 40%in hi gh fructose diet rats compared to control group,whereas expressi on of orexin1receptor and orexin2receptor mRNA increased up to4.4and5.1f old.Leptin mRNA expression in adipose tissue increased about 3 0%in comparison with control group.Blood glucose,serum insuli n and triglyceride have shown signi ?ficant higher levels than those in contro l group.Glucose infusion rate was much low-er in comparison with control group.Conclusi ons.High?fructose diet induces insulin resistance in rats with impact on orexi n and leptin regulations.Blood glucose,serum insulin,lipid metabolism and lep tin play an interactive role on orexin and its receptors regulation in rats.展开更多
Objective Sleep disturbance,which is characterized by excessive daytime sleepiness and sleep attacks,is frequently observed in patients with Parkinson’s disease（PD）.Loss of orexin neurons in hypothalamus and the re...Objective Sleep disturbance,which is characterized by excessive daytime sleepiness and sleep attacks,is frequently observed in patients with Parkinson’s disease（PD）.Loss of orexin neurons in hypothalamus and the resultant decreased level of orexin in cerebrospinal fluid（CSF）found in narcolepsy patients may also play an essential role in the pathogenesis of sleep disturbance.The present study aimed to investigate the possible changes in the orexin system during PD progression.Methods After the establishment of a rat PD model by injecting 6-hydroxydopamine（6-OHDA）into the medial forebrain bundle,the numbers of orexin-A-and tyrosine hydroxylase（TH）-positive neurons,and the levels of orexin-A fibers and orexin-A in CSF were examined by immunohistochemistry and ELISA assay,respectively.Results Compared to the TH-containing neurons that exhibited fast degeneration in response to 6-OHDA,orexin-A-containing neurons were less sensitive to 6-OHDA.The number of orexin-A-positive neurons began to decrease at day 21 after operation,and at day 49,it decreased by 30%of the initial level.The orexin-A level in CSF of PD rats did not show any obvious fluctuations compared to the control,and there was no obvious reduction in the density of orexin-A-positive fibers in brain areas such as tuberomammillary nucleus.Conclusion These results reveal for the first time the dynamic changes of orexin system during the progression of PD.This may provide valuable information for drug development to reverse the loss of orexin neurons and sleep disturbance in PD patients.展开更多
Previous studies have shown that reduced sleep duration,sleep fragmentation,and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling.At the same time,blood-br...Previous studies have shown that reduced sleep duration,sleep fragmentation,and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling.At the same time,blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease.However,currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency.This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital.Patients were divided into two groups:those with insufficient sleep(sleep duration≤6 hours,n=19,age 61.58±8.54 years,10 men)and those with normal sleep durations(sleep duration>6 hours,n=31,age 63.19±10.09 years,18 men).Demographic variables were collected to evaluate cognitive function,neuropsychiatric symptoms,and activities of daily living.The levels of orexin,its receptor proteins,and several blood-brain barrier factors were measured in cerebrospinal fluid.Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains.Furthermore,levels of orexin and its receptors were upregulated in the cerebrospinal fluid,and the blood–brain barrier was destroyed.Both these events precipitated each other and accelerated the progression of Alzheimer's disease.These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation.Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease.展开更多
该文采用RT-PCR和cDNA末端快速扩增技术(rapid-amplification of cDNA ends,RACE)的方法,从尼罗罗非鱼(Oreochromis niloticus)下丘脑总RNA中获得了尼罗罗非鱼Orexin前体基因的cDNA全长序列。该cDNA全长648bp,其中开放阅读框的长423bp,...该文采用RT-PCR和cDNA末端快速扩增技术(rapid-amplification of cDNA ends,RACE)的方法,从尼罗罗非鱼(Oreochromis niloticus)下丘脑总RNA中获得了尼罗罗非鱼Orexin前体基因的cDNA全长序列。该cDNA全长648bp,其中开放阅读框的长423bp,编码Orexin前体蛋白为140个氨基酸,包括37个氨基酸的信号肽、43个氨基酸的Orexin-A、28个氨基酸的Orexin-B和末尾32个氨基酸组成的功能不详的多肽。采用Real-time PCR技术对尼罗罗非鱼Orexin前体基因的组织表达模式以及在摄食前后、饥饿和再投喂状态下的表达量变化进行了研究。结果显示,在脑部和外周等18个组织中都检测到了Orexin前体基因的表达,其中在下丘脑中表达量最高;在摄食前后,尼罗罗非鱼Orexin前体基因的表达量显著低于在摄食状态中;饥饿2、4、6和8d后,Orexin前体基因在下丘脑中的表达量与正常投喂组相比均显著升高,饥饿4d再投喂后,表达量又恢复至正常水平。这些结果表明,Orexin在尼罗罗非鱼摄食中可能有着重要的调节作用。展开更多
基金Supported by Important FinancialIssueof Shi-Wu Programming Key Problem in Liaoning Provinceand Financial Issue for Scientific Research in the Department of Education.
文摘Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Methods Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR). Results Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.Conclusions Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.
文摘Objective.To evaluate the effects of high-fructose diet on expression of orex in and its receptors,orexin1receptor and orexin2receptor in rat hypothalamus tissue,and to analysis the interaction of related fa ctors involved in regulating orexin and its receptors.Methods.Insulin resistan ce rat model induced by high fructose confirmed by the gold standard eug-lycaem ic clamping was employed and mRNA expression of orexin and its receptors OX 1 R and OX 2 R in hypothalamus,mRNA expression of leptin in adipose tissue were measured by reverse transcription poly-merase chain reaction.Serum insulin and triglyc eride levels were measured by chemiluminescence im-munoassay and biochemical en zyme techniques.Results.Expression of orexin mRNA decreased about 40%in hi gh fructose diet rats compared to control group,whereas expressi on of orexin1receptor and orexin2receptor mRNA increased up to4.4and5.1f old.Leptin mRNA expression in adipose tissue increased about 3 0%in comparison with control group.Blood glucose,serum insuli n and triglyceride have shown signi ?ficant higher levels than those in contro l group.Glucose infusion rate was much low-er in comparison with control group.Conclusi ons.High?fructose diet induces insulin resistance in rats with impact on orexi n and leptin regulations.Blood glucose,serum insulin,lipid metabolism and lep tin play an interactive role on orexin and its receptors regulation in rats.
基金supported by the grant from National Natural Science Foundation of China(No.30871004,31071012)
文摘Objective Sleep disturbance,which is characterized by excessive daytime sleepiness and sleep attacks,is frequently observed in patients with Parkinson’s disease（PD）.Loss of orexin neurons in hypothalamus and the resultant decreased level of orexin in cerebrospinal fluid（CSF）found in narcolepsy patients may also play an essential role in the pathogenesis of sleep disturbance.The present study aimed to investigate the possible changes in the orexin system during PD progression.Methods After the establishment of a rat PD model by injecting 6-hydroxydopamine（6-OHDA）into the medial forebrain bundle,the numbers of orexin-A-and tyrosine hydroxylase（TH）-positive neurons,and the levels of orexin-A fibers and orexin-A in CSF were examined by immunohistochemistry and ELISA assay,respectively.Results Compared to the TH-containing neurons that exhibited fast degeneration in response to 6-OHDA,orexin-A-containing neurons were less sensitive to 6-OHDA.The number of orexin-A-positive neurons began to decrease at day 21 after operation,and at day 49,it decreased by 30%of the initial level.The orexin-A level in CSF of PD rats did not show any obvious fluctuations compared to the control,and there was no obvious reduction in the density of orexin-A-positive fibers in brain areas such as tuberomammillary nucleus.Conclusion These results reveal for the first time the dynamic changes of orexin system during the progression of PD.This may provide valuable information for drug development to reverse the loss of orexin neurons and sleep disturbance in PD patients.
基金supported by the National Key Research and Development Program of China,Nos.2016YFC1306300(to XMW),2016YFC1306000the National Key R&D Program of China-European Commission Horizon 2020,No.2017YFE0118800-779238(to YXW)+15 种基金the Notional Natural Science Foundation of Chino,Nos.81970992(to WZ),81571229(to WZ),81071015(to WZ),30770745(to WZ)Capital's Funds for Health Improvement and Research(CFH),No.2022-2-2048(to WZ)the Key Technology R&D Program of Beijing Municipal Education Commission,No.kz201610025030(to WZ)the Natural Science Foundation of Beijing,No.7082032(to WZ)the Key Project of the Natural Science Foundation of Beijing,No.4161004(to WZ)Capitol Clinical Characteristic Applicotion Research,No.Z121107001012161(to WZ)Project of Scientific and Technological Development of Traditional Chinese Medicine in Beijing,No.JJ2018-48(to WZ)High Level Technical Personnel Training Project of Beijing Health System of China,No.2009-3-26(to WZ)Excellent Personnel Training Project of Beijing,No.20071D0300400076(to WZ)Important National Science&Technology Specific Project,No.2011ZX09102-003-01(to WZ)Beijing Healthcare Research Project,No.JING-15-2(to WZ)Basic-Clinicol Research Cooperation Funding of Capitol Medical University of China,Nos.2015-JL-PT-X04(to WZ),10JL49(to WZ),14JL15(to WZ)the Natural Science Foundation of Capital Medical UniversityBeijingChina,No.PYZ2018077(to PG)Youth Research Fund of Beijing Tianton Hospital of Capital Medical University of China,Nos.2015-YQN-14(to PG),2015-YQN-15,2015-YQN-17。
文摘Previous studies have shown that reduced sleep duration,sleep fragmentation,and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling.At the same time,blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease.However,currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency.This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital.Patients were divided into two groups:those with insufficient sleep(sleep duration≤6 hours,n=19,age 61.58±8.54 years,10 men)and those with normal sleep durations(sleep duration>6 hours,n=31,age 63.19±10.09 years,18 men).Demographic variables were collected to evaluate cognitive function,neuropsychiatric symptoms,and activities of daily living.The levels of orexin,its receptor proteins,and several blood-brain barrier factors were measured in cerebrospinal fluid.Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains.Furthermore,levels of orexin and its receptors were upregulated in the cerebrospinal fluid,and the blood–brain barrier was destroyed.Both these events precipitated each other and accelerated the progression of Alzheimer's disease.These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation.Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease.
