-94 G/A polymorphism in the dopamine D1 receptor gene is associated with schizophrenia in a Chinese Han population from Shandong province

The correlation between -94 G/A polymorphism in the dopamine D1 receptor gone and schizophrenia remains poorly understood despite extensive research. This study sought to evaluate the genotypes and allele frequencies of the -94 G/A polymorphism in the dopamine D1 receptor gone by real-time PCR using TaqMan fluorescent probes. One hundred and sixty-two patients with schizophrenia and 101 healthy controls living in Shandong province of China were evaluated. Experimental results showed that the G/A genotype distribution was significantly higher in the schizophrenia patients than in healthy controls. The frequencies of G allele and A allele were not significantly different between the schizophrenia patients and the controls. Thus, the -94 G/A polymorphism in the dopamine D1 receptor gone was found to be associated with schizophrenia in a Chinese Han population from Shandong province.

Disruption of dopamine D1 receptor phosphorylation at serine 421 attenuates cocaine-induced behaviors in mice

Dopamine D1 receptors（D1Rs） play a key role in cocaine addiction, and multiple protein kinases such as GRKs, PKA, and PKC are involved in their phosphorylation. Recently, we reported that protein kinase D1 phosphorylates the D1 R at S421 and promotes its membrane localization. Moreover, this phosphorylation of S421 is required for cocaineinduced behaviors in rats. In the present study, we generated transgenic mice over-expressing S421A-D1 R in the forebrain. These transgenic mice showed reduced phospho-D1R（S421） and its membrane localization, and reduced downstream ERK1/2 activation in the striatum. Importantly, acute and chronic cocaine-induced locomotor hyperactivity and conditioned place preference were significantly attenuated in these mice. These findings provide in vivo evidence for the critical role of S421 phosphorylation of the D1 R in its membrane localization and in cocaine-induced behaviors. Thus, S421 on the D1 R represents a potential pharmacotherapeutic target for cocaine addiction and other drug-abuse disorders.

Effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization in high myopia mice

AIM:To evaluate effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization(CNV)in high myopia mice.METHODS:The C57BL/6J mice were deprived of the right eye for 4wk,and the high myopia was diagnosed by optometry,the diopter was less than-6.00 D,and CNV was induced by 532 nm laser.The changes of dopamine D1 receptor(DRD1),dopamine D2 receptor(DRD2),and vascular endothelial growth factor A(VEGFA)were detected by Western blot technology at 0.5,1,2h,and 7d after 0.01%,0.05%,and 0.1%atropine eye drops,respectively,the area of CNV was measured.RESULTS:Significant increases were observed on the expression of DRD2 in mouse high myopia model at 0.5,1,2h,7d with 0.05%and 0.1%atropine eye drops(P<0.05).Significant decreases were observed on the expression of DRD1 and VEGFA in mouse high myopia model at 0.5,1,2h,7d with 0.05%and 0.1%atropine eye drops(P<0.05).The area of CNV induced by laser in the drug-treated group was significantly smaller than that in the control group,and the higher the concentration,the more significant the inhibitory effect(P<0.05).CONCLUSION:The 0.01%,0.05%,0.1%atropine eye drops can decrease the level of VEGFA and inhibit high myopia CNV indirectly by up-regulating the level of DRD2 and down-regulating the level of DRD1,and the effect of 0.05%and 0.1%atropine eye drops is more significant.

The dopamine receptor D4 regulates the proliferation of pulmonary arteries smooth muscle in broilers by downregulating AT1R

The major cause of pulmonary vascular remodeling in broilers is abnormal proliferation of vascular smooth muscle cells(VSMCs),and one of the main causes of pulmonary hypertension syndrome(PHS)in broilers is pulmonary artery vascular remodeling.Forty Arbor Acres(AA)broilers were randomly divided into four groups(n=10):a control group(deionized water,Og/L NaCl),a freshwater group(FW,deionized water+1 g/L NaCl),highly salinized freshwater group 1(H-SFW-1,deionized water+2.5 g/L NaCl)and highly salinized freshwater group 2(H-SFW-2,deionized water+5 g/L NaCl).The results of in vivo experiments showed that vascular smooth muscle of the broilers could be significantly proliferated by intake of high-salinity fresh water(H-SFW-1&H-SFW-2),which significantly increased the content of angiotensin II(Ang II)and the expression of angiotensin II type 1(AT1)receptor protein.Meanwhile,it significantly decreased the expression of dopamine receptor D4(DRD4)protein.The results of in vitro experiments showed that exogenous Ang II induced the proliferation of primary VSMCs in broilers,which could be significantly inhibited by DRD4 agonists(D4A,HY-101384A)and enhanced by DRD4 inhibitors(D4I;HY-B0965).In addition,the results of immunoblotting and fluorescence quantitative PCR showed that AT1 receptors could be negatively regulated by DRD4 in VSMCs of broilers,either at the transcriptional or translational level.At the same time,the expression of AT1 receptor could be increased by DRD4 inhibition by D4I and decreased by DRD4 activation by D4A.The negative regulatory effect of DRD4 on AT1 receptor occurred in a dose-dependent manner.These results indicate that long-term intake of highly salinized fresh water can cause PHS in broilers,accompanied by varying degrees of proliferation of pulmonary artery smooth muscle.This mechanism may involve response of its receptor being induced by increased Ang II,while DRD4 can negatively regulate it.

多巴胺D1受体RNA干扰载体的构建及其沉默效应鉴定

目的:构建多巴胺D1受体(DRD1)表达干扰载体,为研究DRD1在神经细胞中的作用及抗惊厥药物打下基础。方法:根据GenBank中DRD1基因序列,设计10个干扰序列并构建DRD1干扰载体。对NG-108-15进行脂质体转染后,GFP标记检测转染效果。Real-time PCR和Western印迹检测NG-108-15中DRD1的表达量。结果:构建的10个干扰载体均能采用脂质体法转染到NG-108-15细胞中。转染后NG-108-15中DRD1 mRNA和蛋白的表达均明显下降。其中转染pGPU6-GFP-Neo-si-DRD1-5载体的NG-108-15中DRD1 mRNA表达水平最低,而转染pGPU6-GFP-Neo-si-DRD1-1,-2,-6,-7载体的NG-108-15中DRD1蛋白表达水平最低。结论:成功构建了DRD1表达干扰载体。

烟碱上调大鼠脑纹状体多巴胺D1受体mRNA表达诱导其行为改变

目的 通过观察烟碱对大鼠脑纹状体D1,D2 受体mRNA表达的影响 ,研究烟碱诱导大鼠行为改变的可能机制 ,以进一步探讨烟碱对帕金森病具有保护效应的作用机理。 方法 SD大鼠 2 4只 ,随机分为生理盐水组(12只 )、烟碱组 (12只 )。分别给予生理盐水、烟碱 4mg/kg·d,2次 /d ,共 14d。每次注射药物后 0 .5h观察大鼠行为活动 ,并于末次注射药物后 0 .5h处死动物 ,快速分离纹状体 ,采用RT PCR方法检测大鼠纹状体D1,D2 受体mRNA的表达。结果 烟碱组大鼠于用药后第 3天 ,出现走动增多 ,易激惹 ,定型活动明显 ,并于第 714天达到高峰。在大鼠纹状体内 ,烟碱组D1受体mRNA表达比对照组上升 2 3% (分别为 98.6 3± 1.13,6 5 .2 9± 1.4 5 ,P <0 .0 1) ,两组D2 受体mRNA的表达无显著性差异 (P >0 .0 1)。 结论 烟碱可能通过上调大鼠纹状体D1受体mRNA的表达而诱导大鼠理毛、张口等行为改变 ;烟碱可能有部分D1受体激动样作用。

左旋千金藤啶碱D1激动作用增加6—OHDA损毁大鼠的DARPP—32磷酸化效应

为了进一步阐明ＳＰＤ对大鼠纹状体突触后Ｄ１受体的激动作用特性，本文应用反磷酸化在体内测定及放射配体结合方法，分别观察ＳＰＤ对６ＯＨＤＡ损毁大鼠纹状体ＤＡＲＰＰ３２体内磷酸化作用及突触后Ｄ１受体密度的影响。结果表明：皮下给予ＳＰＤ（２０，４０ｍｇ／ｋｇ，２１ｄ），损毁侧纹状体ＤＡＲＰＰ３２体外［３２Ｐ］的掺入量较健侧下降５０％（Ｐ＜００１）。换言之，损毁侧纹状体内ＤＡＲＰＰ３２的磷酸化程度增加了。然而，ＳＰＤ使损毁导致Ｄ１受体上调的作用减弱（Ｂｍａｘ从３８５０±２６１ｆｍｏｌ／ｍｇ降至３１９７±２０１ｆｍｏｌ／ｍｇ水平）。因此，ＳＰＤ激动Ｄ１受体，使６ＯＨＤＡ损毁大鼠纹状体内ＤＡＲＰＰ３２磷酸化作用加强，而受体密度减少。这是ＳＰＤ调节脑内Ｄ１受体信号转导功能的重要机制。

The hypothalamic-spinal dopaminergic system:a target for pain modulation

Nociceptive signals conveyed to the dorsal horn of the spinal cord by primary nociceptors are subject to extensive modulation by local neurons and by supraspinal descending pathways to the spinal cord before being relayed to higher brain centers. Descending modulatory pathways to the spinal cord comprise,among others, noradrenergic, serotonergic, γ-aminobutyric acid(GABA)ergic, and dopaminergic fibers.The contributions of noradrenaline, serotonin, and GABA to pain modulation have been extensively investigated. In contrast, the contributions of dopamine to pain modulation remain poorly understood.The focus of this review is to summarize the current knowledge of the contributions of dopamine to pain modulation. Hypothalamic A11 dopaminergic neurons project to all levels of the spinal cord and provide the main source of spinal dopamine. Dopamine receptors are expressed in primary nociceptors as well as in spinal neurons located in different laminae in the dorsal horn of the spinal cord, suggesting that dopamine can modulate pain signals by acting at both presynaptic and postsynaptic targets. Here, I will review the literature on the effects of dopamine and dopamine receptor agonists/antagonists on the excitability of primary nociceptors, the effects of dopamine on the synaptic transmission between primary nociceptors and dorsal horn neurons, and the effects of dopamine on pain in rodents. Published data support both anti-nociceptive effects of dopamine mediated by D2-like receptors and pro-nociceptive effects mediated by D1-like receptors.

Cyclin-dependent kinase 5 is required for suppressing D1-dependent signaling mediated through muscarinic 4 in isolated medium spiny neurons

OBJECTIVE Previous studies have demonstrated acetylcholine muscarinic 4(M4) receptor regulates DARPP-32 phosphorylation at Thr75 in isolated medium spiny neurons(MSNs),indicating antagonistic mechanism with D1 dependent signal cascade,but the exact molecular mechanisms remain unclearly.In this study,we investigated the roles of M4 receptor in modulation D1 dependent signal to integrate striatal DA inputs in isolated MSNs.METHODS(1)Lentivirus technology was employed to genetically knock down the M4 receptor of MSNs;(2) Apomorphine(APO),acts as a dopamine receptor agonist,while SCH23390,acts as a selective antagonist for D1,were used to study the pharmacologically profiles with D1 receptor stimulation or blockade,respectively.Then the no subtype-selective muscarinic agonist oxotremorine M(OX) were used to show that mAchRs activation,in order to dissect the particular function of M4,a selective M4 antagonist,MT3 was used;(3) Intracellular cAMP production of MSNs was measured by using time resolved fluorescence resonance energy transfer detection method;(4) Laser confocal was used to explore the expression of M4 and D1 in MSNs;(5) Immunofluorescence cytochemistry and Western blotting were used to confirm the alteration of signaling molecular including P-CREB,DARPP-32 P-Thr34,DARPP-32 P-Thr75,cyclin-dependent kinase 5(CDK5) as wel as p25/35,which are involved in DA-dependent signaling modulations.RESULTS Firstly,TR-FRET assay revealed APO(10-2 mol·L^(-1))significantly increased the level of intracellular cAMP(vs control,n=3,P<0.01),also Western blotting results showed that APO(10-6 mol · L^(-1))increased DARPP-32 Thr34 phosphorylation(vs control,n=3,P<0.01),and these effect were reversed by D1 receptor antagonist SCH23390(vs APO,n=3,P<0.01).Interestingly,we confirmed that OX(10-6 mol · L^(-1)) down-regulated APO-induced DARPP-32 Thr34 phosphorylation(vs APO,n=3,P<0.01),due to its effects on DARPP-32 phosphorylation at Thr75.The results presented the antagonistic mechanism of mAchRs stimulation with D1 dependent signal cascade in MSNs.Meanwhile,OX(10-7,10-6 and10^(-5) mol·L^(-1)) stimulated DARPP-32 phosphorylation at Thr75,and simultaneously up regulated P25/35 and CDK5 activity(vs control,n=3,P<0.01) by using Western blotting assay.Furthermore,roscovitine(10^(-5) mol · L^(-1)),acts as a CDK5 inhibitor,suppressed CDK5 activity(vs control,n=10,P<0.01),and fully inhibited OX-induced DARPP-32 Thr75 phosphorylation(vs OX,n=10,P<0.01).More important,pretreated with roscovitine(10^(-5) mol·L^(-1)),the effect of APO on DARPP-32 Thr34 phosphorylation was potentiated(vs APO,n=3,P<0.05).The result presented CDK5 is required in suppression of APO on DARPP-32 Thr34 phosphorylation mediated through mAchRs stimulation.In addition,laser confocal results showed that the CDK5 up-regulation was mostly confined to MSNs co-expressing M4,which means that M4 participated in CDK5-mediated phosphorylation of DARPP-32 at Thr75.Consistently,immunofluorescence and Western blotting results confirmed that both genetic knockdown and pharmacologic inhibition of M4 receptors with MT3(10-7 mol · L^(-1)) down-regulated the OX-induced the expression of CDK5(vs OX,n=3,P<0.01) and P25/35(vs OX,n=3,P<0.01)in isolated MSNs.CONCLUSION M4 receptor may play an important role in antagonistic regulation D1 dependent signaling,in which CDK5 is required for suppressing D1-DARPP-32 Thr34 phosphorylation in isolated medium spiny neurons.

New therapeutic strategies targeting D1-type dopamine receptors for neuropsychiatric disease

The neurotransmitter dopamine acts via two major classes of receptors, Dl-type and D2-type. D1 receptors are highly expressed in the striatum and can also be found in the cerebral cortex. Here we review the role of D1 dopamine signaling in two major domains： L-DOPA-induced dyskinesias in Parkinson＇s disease and cognition in neuropsychiatric disorders. While there are many drugs targeting D2-type receptors, there are no drugs that specifically target D1 receptors. It has been difficult to use selective Dl-receptor agonists for clinical applications due to issues with bioavailability, binding affinity, pharmacological kinetics, and side effects. We propose potential therapies that selectively modulate D1 dopamine signaling by targeting second messengers downstream of D1 receptors, aUosteric modulators, or by making targeted modifications to Dl-receptor machinery. The development of therapies specific to Dl-receptor signaling could be a new frontier in the treatment of neurological and psychiatric disorders.

Increased dopamine and its receptor dopamine receptor D1 promote tumor growth in human hepatocellular carcinoma

Background:Dopamine and dopamine receptor D1(DRD1),a member of the dopamine receptor family,have been indicated to play important roles in cancer progression,but dopamine secretion in hepatocellular carcinoma(HCC)and the effects of DRD1 on HCC remain unclear.This study was designed to explore the contribution of the dopaminergic system to HCC and determine the relationship between DRD1 and prognosis in HCC patients.Methods:The dopamine metabolic system was monitored using enzyme-linked immunosorbent assays(ELISAs).The expression of DRD1 was detected by microarray analysis,immunohistochemistry(IHC),and quantitative real-time PCR(qRT-PCR).Stable DRD1 knockout and overexpression cell lines were established for investigation.Transwell,colony formation,and Cell Counting Kit 8(CCK8)assays were performed to assess the malignant behaviors of cancer cells.The cAMP/PI3K/AKT/cAMP response element-binding(CREB)signaling pathway was evaluated by Western blot.This pathway,which is agitated by DRD1 in striatal neurons,had been proven to participate in tumor progression.Xenograft HCC tumors were generated for in vivo experiments.Results:Dopamine secretion increased locally in HCC due to an imbalance in dopamine metabolism,including the upregulation of dopa decarboxylase(DDC)and the downregulation of monoamine oxidase A(MAOA).Dopamine promoted the proliferation and metastasis of HCC.DRD1 was highly expressed in HCC tissues and positive DRD1 expression was related to a poor prognosis in HCC patients.The upregulation of DRD1 agitated malignant activities,including proliferation and metastasis in HCC by regulating the cAMP/PI3K/AKT/CREB pathway,and the downregulation of DRD1 had opposing effects.The effects of dopamine on HCC was reversed by depleting DRD1.SCH23390,a selective DRD1 antagonist,inhibited the proliferation and metastasis of HCC cells both in vitro and in vivo.Conclusion:Dopamine secretion was locally increased in HCC and promoted HCC cell proliferation and metastasis.DRD1 was found to exert positive effects on HCC progression and play a vital role in the dopamine system,and could be a potential therapeutic target and prognostic biomarker for HCC.

多巴胺D_1类受体在小鼠巨噬细胞上的表达及其对ox-LDL诱导的小鼠巨噬细胞增殖的影响

目的检测小鼠巨噬细胞上的多巴胺D1类受体表达及探讨其对ox-LDL诱导的小鼠巨噬细胞增殖的影响。方法以小鼠巨噬细胞RAW264.7为靶细胞,Western blot法检测多巴胺D1类受体的表达。不同浓度的ox-LDL(10、20、40μg/mL)诱导RAW264.7细胞的增殖,观察在多巴胺受体激动剂(Fenoldopam)10-7mol/L、拮抗剂(SCH23390)10-6mol/L及MAPK信号通路的特异性阻断剂(PD98059)10-6mol/L存在的情况下,RAW264.7增殖的变化情况,细胞增殖用3H-TdR掺入量表示。Western blot法检测磷酸化的ERK、总ERK1/2及增殖细胞核抗原PCNA的表达。结果多巴胺D1类受体在RAW264.7细胞上表达。Fenoldopam(10-7mol/L)、PD98059(10-6mol/L)能明显抑制ox-LDL(20μg/ml)诱导的RAW264.7细胞增殖,且SCH23390(10-6mol/L)预处理可以逆转Fenoldopam(10-7mol/L)对RAW264.7细胞增殖的抑制作用。在MAPK阻断剂PD98059存在的情况下,Fenoldopam作用丧失,此外,Fenoldopam(10-7mol/L)可降低ox-LDL升高的PCNA以及磷酸化ERK水平。结论小鼠巨噬细胞RAW264.7上有多巴胺D1类受体的表达,且刺激多巴胺D1类受体可明显抑制ox-LDL诱导的RAW264.7细胞增殖作用,该作用可能通过影响MAPK/ERK这一信号转导通路来实现。

Relationship between electroacupuncture analgesia and dopamine receptors in nucleus accumbens

目的：研究多巴胺受体拮抗剂左旋四氢巴马汀（ｌＴＨＰ）加强电针镇痛（ＥＡＡ）的原理，阐明中枢神经系统内多巴胺（ＤＡ）系统在ＥＡＡ中的作用．方法：分别将Ｄ１受体激动剂ＳＫ＆Ｆ３８３９３和Ｄ２受体激动剂ｑｕｉｎｐｉｒｏｌｅｈｙｄｒｏｃｈｌｏｒｉｄｅ（Ｑｕｉ）注射入大鼠伏膈核，观察对ＥＡＡ及ｌＴＨＰ加强ＥＡＡ的作用．结果：ＳＫ＆Ｆ３８３９３（５μｇ，１０μｇ）明显对抗了ｌＴＨＰ加强ＥＡＡ的作用，１０μｇＳＫ＆Ｆ３８３９３则减弱ＥＡＡ；Ｑｕｉ（１０μｇ，２０μｇ），对ＥＡＡ及ｌＴＨＰ加强ＥＡＡ的作用没有显著影响．结论：伏膈核内Ｄ１受体活动在ＥＡＡ及ｌＴＨＰ加强ＥＡＡ中起重要作用，Ｄ２受体没有显著作用．

丰富环境及居住方式对快速老化小鼠认知功能和海马CA1区N-甲基-D-天门冬氨酸受体1的影响

目的:观察不同环境和居住方式对快速老化(SAMP8)小鼠认知功能和海马CA1区N-甲基-D-天门冬氨酸受体1(NMDAR1)的影响,探讨环境及社会支持系统提高认知功能延缓衰老的可能机制。方法:健康雄性6月龄SAMP8小鼠32只,随机分为丰富环境+群居组(A组)、丰富环境+独居组(B组)、普通环境+群居组(C组)和普通环境+独居组(D组)。环境和居住方式干预2个月后通过Morris水迷宫实验测定小鼠的认知功能,免疫组织化学方法测定海马CA1区NMDAR1免疫反应性的表达。结果:Morris水迷宫结果:随训练天数增加,各组潜伏期均有缩短;A组潜伏期明显短于其他各组(P<0.05),空间探索试验中跨越平台次数最多(P<0.05)。B组和C组两者相比无明显差异,但都优于D组(P<0.05)。抗NMDAR1免疫组化染色结果:D组免疫反应产物表达最少,染色最淡;A组可见NMDAR1蛋白免疫反应产物表达较多,细胞排列紧密,染色较深。光密度值分析显示A组光密度值最高,D组光密度值最低。结论:丰富环境和群居能改善SAMP8小鼠的学习记忆及认知功能;增加海马CA1区NMDAR1的蛋白含量;但环境和居住方式是SAMP8小鼠认知功能和海马的独立性保护因素,二者无交互作用。

多巴胺受体D_1基因-48A/G多态性与原发性高血压病的关联研究

目的探讨多巴胺受体D1基因 4 8A/G多态性与原发性高血压病相关性。方法运用聚合酶链反应一限制性片段长度多态性法 (PCR RFLP)分析了解 - 4 8A/G基因型在原发性高血压病组和正常血压对照组的分布情况。结果等位基因A ,G在原发性高血压病组和对照组的分布频率分别为 0 78,0 2 2和 0 86 ,0 14 ,基因频率分布符合Hardy Weinberg平衡 ,样本具有群体代表性 ,两组人群的基因型和等位基因频率存在明显统计学差异 (P <0 0 1,P <0 0 1)。原发性高血压组中G等位基因 ,舒张压明显高于A等位基因 (P <0 0 5 )。结论在中国人群中 ,多巴胺受体D1基因 4

原发性高血压与多巴胺受体D_1基因多态性的相关性研究

目的 探讨多巴胺受体D1基因 4 8A/G多态性与原发性高血压 (PH)的相关性。方法 运用聚合酶链反应—限制性片段长度多态性分析 (PCR RFLP)方法 ,了解 - 48A/G基因型在PH组和正常血压对照 (NT)组的分布情况。结果 等位基因A、G在PH组和NT组的分布频率分别为 0 .78、0 .2 2和 0 .86、0 .14,基因频率分布符合Hardy Weinderg平衡 ,样本具有群体代表性 ,两组人群的基因型和等位基因频率存在明显统计学差异 (P <0 .0 1,P <0 .0 1)。PH组中G等位基因、舒张压明显高于A等位基因 (P <0 .0 5 )。结论 本组人群中 ,多巴胺受体D1基因 -48A/G多态性与PH显著性相关。

左旋千金藤啶碱与奋乃静治疗精神分裂症双盲比较

目的 :研究左旋千金藤啶碱 (SPD)特有的D1受体激动 D2 受体阻滞双重作用对精神分裂症的治疗效果。方法 :住院病人 61例随机分为SPD组和奋乃静组的双盲对照研究。SPD组 (n =31)服用SPD 2 2 5～ 62 5mg·d- 1,奋乃静组 (n =30 )服用奋乃静 16～ 4 4mg·d- 1,分别为 8wk。结果 :SPD组完全缓解率为 71% (2 2 /31) ,奋乃静组为 5 0 %(15 /30 ) ;显著进步分别为 10 % (3/31) ,2 3%(7/30 )。SPD组的有效率为 80 % ,奋乃静组为73%。SPD组的简明精神病量表 (BPRS)疗效在 2 ,4wk时显著强于奋乃静组 (P <0 .0 5 )。SPD组的阴性症状评定量表 (SANS)和阳性症状评定量表(SAPS)疗效显著强于奋乃静组 (P <0 .0 5 )。SPD组的治疗作用显效快。SPD组无锥体外系不良反应 ,SPD组的TESS总分低于奋乃静组 (P <0 .0 5 )。结论 :SPD对精神分裂症有疗效 ,出现快 ,对阳性和阴性症状疗效优于奋乃静 。

Sevoflurane plays a reduced role in cognitive impairment compared with isoflurane: limited effect on fear memory retention

Isoflurane and sevoflurane are both inhalation anesthetics,but in clinical application,sevoflurane has been considered to be less suitable for long-term anesthesia because of its catabolic compounds and potential nephrotoxicity.Nevertheless,recent studies have shown that these two inhalation anesthetics are similar in hepatorenal toxicity,cost,and long-term anesthetic effect.Moreover,sevoflurane possibly has less cognitive impact on young mice.In this study,C57BL/6 mice aged 8–10 weeks were exposed to 1.2%isoflurane or 2.4%sevoflurane for 6 hours.Cognitive function and memory were examined in young mice using the novel object recognition,contextual fear conditioning,and cued-fear extinction tests.Western blot assay was performed to detect expression levels of D1 dopamine receptor,catechol-O-methyltransferase,phospho-glycogen synthase kinase-3β,and total glycogen synthase kinase-3βin the hippocampus.Our results show that impaired performance was not detected in mice exposed to sevoflurane during the novel object recognition test.Contextual memory impairment in the fear conditioning test was shorter in the sevoflurane group than the isoflurane group.Long-term sevoflurane exposure did not affect memory consolidation,while isoflurane led to memory consolidation and reduced retention.Downregulation of hippocampal D1 dopamine receptors and phosphorylated glycogen synthase kinase-3β/total glycogen synthase kinase-3βand upregulation of catechol-O-methyltransferase may be associated with differing memory performance after exposure to isoflurane or sevoflurane.These results confirm that sevoflurane has less effect on cognitive impairment than isoflurane,which may be related to expression of D1 dopamine receptors and catechol-O-methyltransferase and phosphorylation of glycogen synthase kinase-3βin the hippocampus.This study was approved by the Institutional Animal Care and Use Committee,Nanjing University,China on November 20,2017(approval No.20171102).

芹菜素介导Caveolin-1对脑缺血大鼠认知功能的改善作用

目的探讨芹菜素对脑缺血大鼠认知功能的改善作用及潜在的分子机制。方法选择清洁级健康雄性SD大鼠32只,采用随机数字表法分为假手术组、模型组、低剂量芹菜素干预组(低芹菜素组)及高剂量芹菜素干预组(高芹菜素组),每组8只。采用线栓法制备大鼠大脑中动脉缺血再灌注模型,假手术组不阻断大脑中动脉。采用水迷宫来检测大鼠脑缺血后空间学习记忆功能,RT-qPCR法检测缺血侧海马小凹蛋白1(Caveolin-1)、N-甲基-D-天冬氨酸受体亚单位2B(NR2B)mRNA表达,采用Western blot法检测缺血侧海马Caveolin-1蛋白表达,免疫组化法检测缺血侧海马NR2B表达部位及水平。结果模型组大鼠第26、27天逃避潜伏期均大于假手术组,差异均有统计学意义(t=2.138、3.001,均P<0.05)。高、低芹菜素组大鼠第27天逃避潜伏期均小于模型组,差异均有统计学意义(t=2.193、2.283,均P<0.05)。模型组大鼠空间探索时间小于假手术组,差异有统计学意义(t=2.789,P<0.01);高、低芹菜素组大鼠,空间探索时间均大于模型组,差异均有统计学意义(t=2.368、2.060,均P<0.05)。模型组Caveolin-1表达升高,高芹菜素组Caveolin-1 mRNA和蛋白表达较模型组增加,差异均有统计学意义(t=2.321、2.553,P<0.05)。模型组NR2B表达减少,芹菜素干预能上调其表达(P<0.05)。结论芹菜素可通过促进Caveolin-1、NR2B表达,起到改善大鼠脑缺血后认知功能的作用。

Gut-brain crosstalk regulates craving for fatty food

Patients undergoing Roux-en-Y gastric bypass(RYGB)surgery elicit striking loss of body weight. Anatomical restructuring of the gastrointestinal(GI) tract, leading to reduced caloric intake and changes in food preference, are thought to be the primary drivers of weight loss in bariatric surgery patients. However, the mechanisms by which RYGB surgery causes a reduced preference for fatty foods remain elusive. In a recent report, Hankir et al described how RYGB surgery modulated lipid nutrient signals in the intestine of rats to blunt their craving for fatty food. The authors reported that RYGB surgery restored an endogenous fat-satiety signaling pathway, mediated via oleoylethanolamide(OEA), that was greatly blunted in obese animals. In RYGB rats, high fat diet(HFD) led to increased production of OEA that activated the intestinal peroxisome proliferation activator receptors-α(PPARα). In RYGB rats, activation of PPARα by OEA was accompanied by enhanced dopamine neurotransmission in the dorsal striatum and reduced preference for HFD. The authors showed that OEA-mediated signals to the midbrain were transmitted via the vagus nerve. Interfering with either the production of OEA in enterocytes, or blocking of vagal and striatal D1 receptors signals eliminated the decreased craving for fat in RYGB rats. These studies demonstrated that bariatric surgery led to alterations in the reward circuitry of the brain in RYGB rats and reduced their preference for HFD.