Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mic...Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mice were used to examine the lineage differentiation of SOX2-positive cells during the development of cerebral cortex.Primary NSCs/astrocytes culture,ChIP-seq and Western Blot were adopted to analyze and verify the expression of candidate genes.Pharmacological manipulation,neurosphere formation,photochemical ischemia,immunofluorescence staining and behavior tests were adopted to evaluate the effects of activating DRD2 signaling on astrocytic dedifferentiation.Results:Immunofluorescence staining demonstrated the NSC-astrocyte switch of SOX2-expression in the normal development of cerebral cortex.ChIP-seq revealed enrichment of DRD2 signaling by SOX2-bound enhancers in NSCs and SOX2-bound promoters in astrocytes.Western Blot and immunofluorescence staining verified the expression of DRD2 in NSCs and reactive astrocytes.Application of quinagolide hydrocholoride(QH),an agonist of DRD2,significantly promoted astrocytic dedifferentiation both in vitro and in vivo following ischemia.In addition,quinagolide hydrocholoride treatment improved locomotion recovery.Conclusion:Activating DRD2 signaling facilitates astrocytic dedifferentiation and may be used to treat ischemic stroke.展开更多
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism....Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.展开更多
A model of transmembrane helices of dopamine D2 receptor was constructed using the X ray coordinates of bacteriorhodopsin (BR) as a template. Based on the results from the model and the site directed mutagenesis exp...A model of transmembrane helices of dopamine D2 receptor was constructed using the X ray coordinates of bacteriorhodopsin (BR) as a template. Based on the results from the model and the site directed mutagenesis experience, the binding pocket, including nine amino acid residues beside indispensable Asp86, Ser141 and Ser144 residues, was defined. In order to testify the 3D structure of dopamine D2 receptor and specially test the binding sites, two sets of D2 receptor agonists (one was rigid and the other flexible) were selected for docking. A good result of correlation between logIC 50 and binding energy E b indicates that the predicted model is reliable for the investigation of the receptor ligand interaction and design of new active molecules.展开更多
AIM：To investigate the effect of dopamine on bone morphogenesis protein-2（BMP-2）expression in retinal pigment epithelium（RPE）cells in vitro.METHODS：ARPE-19 cells as a human RPE cell line were cultured with dopam...AIM：To investigate the effect of dopamine on bone morphogenesis protein-2（BMP-2）expression in retinal pigment epithelium（RPE）cells in vitro.METHODS：ARPE-19 cells as a human RPE cell line were cultured with dopamine for different times（2,4,6,8,12,16and 24h）or with different concentrations（0.1,1,2,5,10,20,and 100μg/m L）in vitro.BMP-2 m RNA expression level in ARPE-19 cells was analyzed with real-time polymerase chain reaction（PCR）analysis and BMP-2 protein level was measured with Western blot analysis.The active form of BMP-2 in the culture medium was measured with enzymelinked immunosorbent assay（ELISA）.RESULTS：The expression level of BMP-2 increased significantly cultured with 20μg/m L dopamine,at different time points（P〈0.05）.BMP-2 m RNA level peaked 2h and the protein level peaked at 6 and 8h after treatment.The concentrations of secreted BMP-2 elevated at 12h and peaked at 24h（P〈0.05）in a time-dependent manner.Treated with 100μg/m L dopamine for 6h,the expression levels of BMP-2 m RNA and protein in ARPE-19 cells were enhanced significantly compared to that in the untreated cells（P〈0.05）.And secreted BMP-2 protein in the cell culture supernatant was also increased（P〈0.05）.CONCLUSION：Dopamine up-regulate BMP-2 expression in RPE cells,and this may be associated with its inhibitive effect on myopia development.展开更多
AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggle...AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggles in guinea pig, whose retinal Müller cells were cultured using the enzyme-digesting method. Retinal Müller cells were divided into 5 groups: normal control, myopia, myopia plus GF109203X, myopia plus PMA, myopia plus DMSO. PKC activities were detected by the non-radioactive methods. TGFβ2 and tyrosine hydroxylase (TH) proteins were analyzed by Western Blotting in retinal Müller cells. Dopamine was determined by the high-performance liquid chromatography- electrochemical detection in suspensions. RESULTS: After 14 days deprived, the occluded eyes became myopic with ocular axle elongating. Müller cells of guinea pigs were obtained using enzyme digestion. Compared with normal control group, the increase in PKC activity and the up-regulation in TGFβ2 expression were found in retinal Müller cells of myopic eyes, with the decrease of TH and dopamine content (P <0.05). After PKC activated by PMA, TGFβ2 and TH content were up-regulated with the increase of dopamine content (P <0.05). While the PKC activities was inhibited by GF109203X, proteins of TGFβ2 and TH were down-regulated in the myopic eyes, with the decrease of dopamine content (P <0.05). CONCLUSION: TGFβ2 and dopamine are modulated by PKC in Müller cells of the myopic eyes in guinea pig.展开更多
A novel nano-SnO2/graphite electrode has been prepared via polishing procedure to produce active and stable surface. The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid...A novel nano-SnO2/graphite electrode has been prepared via polishing procedure to produce active and stable surface. The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid into two well-defined peaks by 230 mV. The mechanism of discrimination of dopamine from ascorbic acid is discussed. Dopamine and ascorbic acid can be determined simultaneously with the modified electrode. The electrode shows good sensitivity, selectivity and stability.展开更多
Background: Mechanisms underlying overeating-induced obesity in post-menopausal woman include functional lack of 17β-estradiol dysregulating dopamine D2 receptors, thereby inducing food addiction, glucose craving or ...Background: Mechanisms underlying overeating-induced obesity in post-menopausal woman include functional lack of 17β-estradiol dysregulating dopamine D2 receptors, thereby inducing food addiction, glucose craving or alcohol dependence through reward circuitry. This study aimed at further understanding 17β-estradiol and dopamine D2 receptors interferences in the etiology of woman obesity. Method: Seventy-two Wistar female rats weighing 200 - 205 g, individually-housed, were divided into non-ovariectomized control (C = 6 groups) and ovariectomized rats (OVX = 6 groups) which were concurrently subjected to the following treatments: Non-drug-treated (DMSO vehicle), 17β-estradiol (E2, 5 μg/kg, s.c.), sulpiride (SUL, 20 mg/kg, i.p.), bromocriptine (BR, 0.1 mg/kg, i.p.), E2 + SUL or E2 + BR, designating the 6 constitutive groups of either control or ovariectomy. Within each experimental group, consumption of different solutions (10% alcohol, 10% sucrose and water) as well as food intake and body weight were daily measured, for 10 consecutive days. Results: This study indicated that D2S was a specific inducer of alcohol and food intakes, but reduced sugar consumption. In addition, 17β- estradiol regulated the body weight set point, modulating D2S functions towards increased food intake at lower weights and decreased food intake at higher weights. D2S met the slow genomic actions induced by 17β-estradiol. Conversely, D2L inhibited alcohol and food intakes, but induced specifically sugar consumption, thereby regulating blood glucose levels and promoting energy expenditure in reducing body weight. Indeed, 17β-estradiol exerted a tonic inhibition on D2L which was released by OVX, exacerbating sugar intake and increasing body weight. D2L mediated the rapid metabolic effects of 17β-estradiol. Conclusion: Our results supported physiological data reporting that activation of the mostly expressed presynaptically D2S-class autoreceptors decreased dopamine release stimulating food intake, whereas activation of the predominantly postsynaptic isoform D2L receptors increased dopamine activity inhibiting food intake. Our studies indicated that 17β-estradiol acted on the two types of D2 receptors showing opposite functions to equilibrate energy intake vs. expenditure for weight set point regulation. Our data also supported biochemical findings reporting that 17β-estradiol induced D2 genes transcriptional regulation, thereby involving both types of D2 receptors in the etiology of obesity. The combined dysregulated effects of D2L and D2S receptors, as 17β-estradiol was lacking, would be causal factors underlying the etiology of obesity.展开更多
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,a...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.展开更多
Behavioral and molecular characterization of cell-type specific populations governing fear learning and behavior is a promising avenue for the rational identification of potential therapeutics for fear-related disorde...Behavioral and molecular characterization of cell-type specific populations governing fear learning and behavior is a promising avenue for the rational identification of potential therapeutics for fear-related disorders.Identification of cell-type specific changes in neuronal translation following fear learning allows for targeted pharmacological intervention during fear extinction learning,mirroring possible treatment strategies in humans.Here we identify the central amygdala(Ce A)Drd2-expressing population as a fear-supporting population that is molecularly distinct from other,previously identified fear-supporting CeA populations.Sequencing of actively translating transcripts of Drd2 neurons identifies m RNAs that are differentially regulated following fear learning including Npy5r,Rxrg,Sst5r,Fgf3,Erb B4,Fkbp14,Dlk1,Ssh3 and Adora2a.Direct pharmacological manipulation of NPY5R,RXR,and ADORA2A confirms their importance in fear behavior and validates the present approach of identifying pharmacological targets for the modulation of emotional learning.展开更多
Parkinson’s disease (PD) is characterized by degeneration of nigrostriatal dopamine (DA) neurons. The primary drug used to treat PD symptoms is L-DOPA, but side effects such as dyskinesias limit its use. Previous fin...Parkinson’s disease (PD) is characterized by degeneration of nigrostriatal dopamine (DA) neurons. The primary drug used to treat PD symptoms is L-DOPA, but side effects such as dyskinesias limit its use. Previous findings show that L-DOPA treatment induces extracellular signal-regulated kinase (ERK1/2), a MAP-kinase protein. γ-aminobutyric acid (GABA) is intimately involved in basal ganglia function. Our previous study using a unilaterally lesioned rat model of PD indicated that elevating GABA levels by GABA transaminase inhibitor, aminooxyacetic acid significantly attenuated L-DOPA-induced ERK phosphorylation in the striatum and substantia nigra (SN). The aim of the present study was to assess the role of GABA-A and GABA-B receptor by using a selective agonists, muscimol and baclofen respectively, on L-DOPA-induced ERK phosphorylation in the striatum and SN. Unilaterally 6-OHDA-lesioned rats were prescreened by apomorphine induced rotation test for the extent of DA loss. Lesioned rats were treated with L-DOPA alone or after muscimol or baclofen pretreatment. Appropriate control groups were used. Phospho-ERK levels, tyrosine hydroxylase (to ascertain DA loss) and substance P (an indirect marker for DA loss) levels were assessed by immunohistochemistry using coronal slices at the level of striatum and SN. L-DOPA administration induced a robust increase (>300%) in phospho-ERK1/2 levels in the striatum and SN. Muscimol as well as baclofen pretreatment attenuated the L-DOPA-induced increase in phospho-ERK1/2 levels by >60% in the striatum and SN. Muscimol and baclofen pretreatment also greatly reduced the number of L-DOPA induced phospho-ERK1/2 stained cells in the striatum as well as the contralateral rotational behavior. The present data taken together with our previous study indicate that the L-DOPA induced increase in ERK1/2 is attenuated by GABA via a GABA-A and GABA-B receptor linked mechanism. The study provides further insight into a dopamine-GABA-ERK interaction in the therapeutic and/or side effects of L-DOPA in the basal ganglia.展开更多
BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, th...BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial. OBJECTIVE： To determine tyrosine hydroxylase （TH） expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field （LF-PEF） stimulation, and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors. DESIGN, TIME AND SETTING： A parallel, controlled, cell experiment was performed at the Laboratory of Cell Biology, School of Life Science, East China Normal University, between January and October 2006. MATERIALS： PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China. Nerve growth factor was purchased from PeproTech, USA. The protein kinase A inhibitor, H-89, and mitogen-activated protein kinase kinase inhibitor, U0126, were purchased from Sigma, USA. METHODS： （1） Following routine culture in Dulbecco＇s modified eagle medium, primary PC12 cells were stimulated under LF-PEF （pulse frequency 50.Hz, pulse width 20 μs, peak field strength 1 V/m） for 5, 10, 15, 20, and 30 minutes. （2） Inhibitors （H-89 or U0126, 1 μmol/L） were added 30 minutes before LF-PEF stimulation for 10 minutes. MAIN OUTCOME MEASURES： （1） TH expression was determined by Western blot in PC12 cells at 0.5, 1,2, 3, and 4 days after LF-PEF stimulation. Similarly, DA was measured by high-performance liquid chromatography in media at 2, 3, 4, or 5 days after LF-PEE （2） TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEE RESULTS： （1） Short-term LF-PEF stimulation （5 and 10 minutes） increased TH expression and media DA levels after short-term culture （2 days） （P 〈 0.01）, but both parameters decreased with longer culture （3 4 days） （P 〈 0.01）. Long-term LF-PEF stimulation （15, 20, or 30 minutes） decreased TH and DA synthesis, followed by a rapid increase （P 〈 0.01）. （2） H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes, while the inhibition rate of U0126 was 53.2%. CONCLUSION： Short-term LF-PEF first promotes then inhibits, while long-term LF-PEF first inhibits then promotes, TH and DA synthesis. LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.展开更多
OBJECTIVE Cognitive inflexibility plays a critical role in the compulsive drug taking,a central characteristic of drug addictions,yet its underlying neurochemical mechanisms are not well understood.The present study e...OBJECTIVE Cognitive inflexibility plays a critical role in the compulsive drug taking,a central characteristic of drug addictions,yet its underlying neurochemical mechanisms are not well understood.The present study examined the impact of morphine withdrawal on reversal learning.METHODS Reversal learning was tested in a four-choices digging task.Some brain tissues were harvested 2 h after the behavioral experiment for the further measurement.RESULTS We found that after long-term abstinence for a month from chronic morphine exposure,mice exhibited a profound reversal learning deficit.We further found that dopamine D2 receptor(D2R)system in the frontal-striatal circuit is significantly down-regulated,at both receptor and downstream signals levels.Subsequent pharmacological experiments demonstrated that aripiprazole,a D2R partial agonist,prevented the D2R downregulation and rescued the reversal learning deficit.CONCLUSION Together,our findings provide valuable insights into the causal relationship between D2R system in the frontal-striatal circuit and the cognitive inflexibility caused by abused drugs and offer a promising possibility of an effective therapeutic intervention for drug addictions.展开更多
BACKGROUND： It has been demonstrated that the septal nucleus is involved in the pathogenesis of schizophrenia. Based on autopsies of schizophrenia patients, studies have shown a reduced number of septal nucleus neuro...BACKGROUND： It has been demonstrated that the septal nucleus is involved in the pathogenesis of schizophrenia. Based on autopsies of schizophrenia patients, studies have shown a reduced number of septal nucleus neurons and glia. In addition, experimental rat models of schizophrenia have shown increased dopamine receptor D2 binding sites in the basal ganglia, septal nuclei, and substantia nigra. Previous studies have demonstrated that the septal nucleus modulates dopamine metabolic disorder and dopamine D2 receptor balance. OBJECTIVE： Dopamine D2 receptor expression in a rat model of schizophrenia, combined with antipsychotic drugs, was analyzed in the prefrontal lobe, striatum, and brainstem. In situ hybridization was used to observe the effects of stereotactic septal nucleus lesions on dopamine D2 receptor expression in the brains of methylamphetamine-treated rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed in the Laboratory of General Institute of Psychosurgery, Third Hospital of Chinese PLA from November 2005 to June 2006. MATERIALS： A total of 120 healthy, adult Sprague Dawley rats, weighing approximately 200 g, were included. Methylamphetamine （Sigma, USA） and an in situ hybridization detection kit for dopamine D2 receptor （Boster, China） were also used for this study. METHODS： All rats were randomly allocated to the following 4 groups, with 30 rats in each group： normal control, simple administration, septal nucleus lesion, and sham-operated groups. In the normal control group, rats were not administered or lesioned. In the remaining 3 groups, rats were intraperitoneally administered 10 mg/kg methylamphetamine, once per day, for 15 successive days to establish a schizophrenia model. Following successful model establishment, rats from the septal nucleus lesion group were subjected to stereotactic septal nucleus lesions. The cranial bone was exposed in rats from the sham-operated group, and the septal nucleus was not lesioned. MAIN OUTCOME MEASURES： At 7 days post-surgery, dopamine D2 receptor expression in the prefrontal lobe, striatum, and brainstem were detected by in situ hybridization. RESULTS： Dopamine D2 receptor expression in the rat prefrontal lobe, striatum, and brainstem was significantly higher in the simple administration group and sham-operated group, compared with the normal control group （P 〈 0.01）. In the septal nucleus lesion group, dopamine D2 receptor expression was significantly less than the simple administration and sham-operated groups, （P 〈 0.01）. There was no significant difference in dopamine D2 receptor expression between the simple administration and sham-operated groups （P 〉 0.05）. CONCLUSION： Septal nucleus lesions reduce dopamine D2 receptor expression in the prefrontal lobe, striatum, and brainstem in a rat model of schizophrenia, indicating that the septal nucleus modulates dopamine D2 receptor expression.展开更多
文摘Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mice were used to examine the lineage differentiation of SOX2-positive cells during the development of cerebral cortex.Primary NSCs/astrocytes culture,ChIP-seq and Western Blot were adopted to analyze and verify the expression of candidate genes.Pharmacological manipulation,neurosphere formation,photochemical ischemia,immunofluorescence staining and behavior tests were adopted to evaluate the effects of activating DRD2 signaling on astrocytic dedifferentiation.Results:Immunofluorescence staining demonstrated the NSC-astrocyte switch of SOX2-expression in the normal development of cerebral cortex.ChIP-seq revealed enrichment of DRD2 signaling by SOX2-bound enhancers in NSCs and SOX2-bound promoters in astrocytes.Western Blot and immunofluorescence staining verified the expression of DRD2 in NSCs and reactive astrocytes.Application of quinagolide hydrocholoride(QH),an agonist of DRD2,significantly promoted astrocytic dedifferentiation both in vitro and in vivo following ischemia.In addition,quinagolide hydrocholoride treatment improved locomotion recovery.Conclusion:Activating DRD2 signaling facilitates astrocytic dedifferentiation and may be used to treat ischemic stroke.
基金supported by the Research Project of the Shanghai Health Commission,No.2020YJZX0111(to CZ)the National Natural Science Foundation of China,Nos.82021002(to CZ),82272039(to CZ),82171252(to FL)+1 种基金a grant from the National Health Commission of People’s Republic of China(PRC),No.Pro20211231084249000238(to JW)Medical Innovation Research Project of Shanghai Science and Technology Commission,No.21Y11903300(to JG).
文摘Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.
文摘A model of transmembrane helices of dopamine D2 receptor was constructed using the X ray coordinates of bacteriorhodopsin (BR) as a template. Based on the results from the model and the site directed mutagenesis experience, the binding pocket, including nine amino acid residues beside indispensable Asp86, Ser141 and Ser144 residues, was defined. In order to testify the 3D structure of dopamine D2 receptor and specially test the binding sites, two sets of D2 receptor agonists (one was rigid and the other flexible) were selected for docking. A good result of correlation between logIC 50 and binding energy E b indicates that the predicted model is reliable for the investigation of the receptor ligand interaction and design of new active molecules.
文摘AIM：To investigate the effect of dopamine on bone morphogenesis protein-2（BMP-2）expression in retinal pigment epithelium（RPE）cells in vitro.METHODS：ARPE-19 cells as a human RPE cell line were cultured with dopamine for different times（2,4,6,8,12,16and 24h）or with different concentrations（0.1,1,2,5,10,20,and 100μg/m L）in vitro.BMP-2 m RNA expression level in ARPE-19 cells was analyzed with real-time polymerase chain reaction（PCR）analysis and BMP-2 protein level was measured with Western blot analysis.The active form of BMP-2 in the culture medium was measured with enzymelinked immunosorbent assay（ELISA）.RESULTS：The expression level of BMP-2 increased significantly cultured with 20μg/m L dopamine,at different time points（P〈0.05）.BMP-2 m RNA level peaked 2h and the protein level peaked at 6 and 8h after treatment.The concentrations of secreted BMP-2 elevated at 12h and peaked at 24h（P〈0.05）in a time-dependent manner.Treated with 100μg/m L dopamine for 6h,the expression levels of BMP-2 m RNA and protein in ARPE-19 cells were enhanced significantly compared to that in the untreated cells（P〈0.05）.And secreted BMP-2 protein in the cell culture supernatant was also increased（P〈0.05）.CONCLUSION：Dopamine up-regulate BMP-2 expression in RPE cells,and this may be associated with its inhibitive effect on myopia development.
基金National Natural Science Foundation of China(No. 30600694)
文摘AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggles in guinea pig, whose retinal Müller cells were cultured using the enzyme-digesting method. Retinal Müller cells were divided into 5 groups: normal control, myopia, myopia plus GF109203X, myopia plus PMA, myopia plus DMSO. PKC activities were detected by the non-radioactive methods. TGFβ2 and tyrosine hydroxylase (TH) proteins were analyzed by Western Blotting in retinal Müller cells. Dopamine was determined by the high-performance liquid chromatography- electrochemical detection in suspensions. RESULTS: After 14 days deprived, the occluded eyes became myopic with ocular axle elongating. Müller cells of guinea pigs were obtained using enzyme digestion. Compared with normal control group, the increase in PKC activity and the up-regulation in TGFβ2 expression were found in retinal Müller cells of myopic eyes, with the decrease of TH and dopamine content (P <0.05). After PKC activated by PMA, TGFβ2 and TH content were up-regulated with the increase of dopamine content (P <0.05). While the PKC activities was inhibited by GF109203X, proteins of TGFβ2 and TH were down-regulated in the myopic eyes, with the decrease of dopamine content (P <0.05). CONCLUSION: TGFβ2 and dopamine are modulated by PKC in Müller cells of the myopic eyes in guinea pig.
文摘A novel nano-SnO2/graphite electrode has been prepared via polishing procedure to produce active and stable surface. The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid into two well-defined peaks by 230 mV. The mechanism of discrimination of dopamine from ascorbic acid is discussed. Dopamine and ascorbic acid can be determined simultaneously with the modified electrode. The electrode shows good sensitivity, selectivity and stability.
文摘Background: Mechanisms underlying overeating-induced obesity in post-menopausal woman include functional lack of 17β-estradiol dysregulating dopamine D2 receptors, thereby inducing food addiction, glucose craving or alcohol dependence through reward circuitry. This study aimed at further understanding 17β-estradiol and dopamine D2 receptors interferences in the etiology of woman obesity. Method: Seventy-two Wistar female rats weighing 200 - 205 g, individually-housed, were divided into non-ovariectomized control (C = 6 groups) and ovariectomized rats (OVX = 6 groups) which were concurrently subjected to the following treatments: Non-drug-treated (DMSO vehicle), 17β-estradiol (E2, 5 μg/kg, s.c.), sulpiride (SUL, 20 mg/kg, i.p.), bromocriptine (BR, 0.1 mg/kg, i.p.), E2 + SUL or E2 + BR, designating the 6 constitutive groups of either control or ovariectomy. Within each experimental group, consumption of different solutions (10% alcohol, 10% sucrose and water) as well as food intake and body weight were daily measured, for 10 consecutive days. Results: This study indicated that D2S was a specific inducer of alcohol and food intakes, but reduced sugar consumption. In addition, 17β- estradiol regulated the body weight set point, modulating D2S functions towards increased food intake at lower weights and decreased food intake at higher weights. D2S met the slow genomic actions induced by 17β-estradiol. Conversely, D2L inhibited alcohol and food intakes, but induced specifically sugar consumption, thereby regulating blood glucose levels and promoting energy expenditure in reducing body weight. Indeed, 17β-estradiol exerted a tonic inhibition on D2L which was released by OVX, exacerbating sugar intake and increasing body weight. D2L mediated the rapid metabolic effects of 17β-estradiol. Conclusion: Our results supported physiological data reporting that activation of the mostly expressed presynaptically D2S-class autoreceptors decreased dopamine release stimulating food intake, whereas activation of the predominantly postsynaptic isoform D2L receptors increased dopamine activity inhibiting food intake. Our studies indicated that 17β-estradiol acted on the two types of D2 receptors showing opposite functions to equilibrate energy intake vs. expenditure for weight set point regulation. Our data also supported biochemical findings reporting that 17β-estradiol induced D2 genes transcriptional regulation, thereby involving both types of D2 receptors in the etiology of obesity. The combined dysregulated effects of D2L and D2S receptors, as 17β-estradiol was lacking, would be causal factors underlying the etiology of obesity.
文摘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.
文摘Behavioral and molecular characterization of cell-type specific populations governing fear learning and behavior is a promising avenue for the rational identification of potential therapeutics for fear-related disorders.Identification of cell-type specific changes in neuronal translation following fear learning allows for targeted pharmacological intervention during fear extinction learning,mirroring possible treatment strategies in humans.Here we identify the central amygdala(Ce A)Drd2-expressing population as a fear-supporting population that is molecularly distinct from other,previously identified fear-supporting CeA populations.Sequencing of actively translating transcripts of Drd2 neurons identifies m RNAs that are differentially regulated following fear learning including Npy5r,Rxrg,Sst5r,Fgf3,Erb B4,Fkbp14,Dlk1,Ssh3 and Adora2a.Direct pharmacological manipulation of NPY5R,RXR,and ADORA2A confirms their importance in fear behavior and validates the present approach of identifying pharmacological targets for the modulation of emotional learning.
文摘Parkinson’s disease (PD) is characterized by degeneration of nigrostriatal dopamine (DA) neurons. The primary drug used to treat PD symptoms is L-DOPA, but side effects such as dyskinesias limit its use. Previous findings show that L-DOPA treatment induces extracellular signal-regulated kinase (ERK1/2), a MAP-kinase protein. γ-aminobutyric acid (GABA) is intimately involved in basal ganglia function. Our previous study using a unilaterally lesioned rat model of PD indicated that elevating GABA levels by GABA transaminase inhibitor, aminooxyacetic acid significantly attenuated L-DOPA-induced ERK phosphorylation in the striatum and substantia nigra (SN). The aim of the present study was to assess the role of GABA-A and GABA-B receptor by using a selective agonists, muscimol and baclofen respectively, on L-DOPA-induced ERK phosphorylation in the striatum and SN. Unilaterally 6-OHDA-lesioned rats were prescreened by apomorphine induced rotation test for the extent of DA loss. Lesioned rats were treated with L-DOPA alone or after muscimol or baclofen pretreatment. Appropriate control groups were used. Phospho-ERK levels, tyrosine hydroxylase (to ascertain DA loss) and substance P (an indirect marker for DA loss) levels were assessed by immunohistochemistry using coronal slices at the level of striatum and SN. L-DOPA administration induced a robust increase (>300%) in phospho-ERK1/2 levels in the striatum and SN. Muscimol as well as baclofen pretreatment attenuated the L-DOPA-induced increase in phospho-ERK1/2 levels by >60% in the striatum and SN. Muscimol and baclofen pretreatment also greatly reduced the number of L-DOPA induced phospho-ERK1/2 stained cells in the striatum as well as the contralateral rotational behavior. The present data taken together with our previous study indicate that the L-DOPA induced increase in ERK1/2 is attenuated by GABA via a GABA-A and GABA-B receptor linked mechanism. The study provides further insight into a dopamine-GABA-ERK interaction in the therapeutic and/or side effects of L-DOPA in the basal ganglia.
基金the National Natural Science Foundation of China,No.50677022
文摘BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial. OBJECTIVE： To determine tyrosine hydroxylase （TH） expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field （LF-PEF） stimulation, and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors. DESIGN, TIME AND SETTING： A parallel, controlled, cell experiment was performed at the Laboratory of Cell Biology, School of Life Science, East China Normal University, between January and October 2006. MATERIALS： PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China. Nerve growth factor was purchased from PeproTech, USA. The protein kinase A inhibitor, H-89, and mitogen-activated protein kinase kinase inhibitor, U0126, were purchased from Sigma, USA. METHODS： （1） Following routine culture in Dulbecco＇s modified eagle medium, primary PC12 cells were stimulated under LF-PEF （pulse frequency 50.Hz, pulse width 20 μs, peak field strength 1 V/m） for 5, 10, 15, 20, and 30 minutes. （2） Inhibitors （H-89 or U0126, 1 μmol/L） were added 30 minutes before LF-PEF stimulation for 10 minutes. MAIN OUTCOME MEASURES： （1） TH expression was determined by Western blot in PC12 cells at 0.5, 1,2, 3, and 4 days after LF-PEF stimulation. Similarly, DA was measured by high-performance liquid chromatography in media at 2, 3, 4, or 5 days after LF-PEE （2） TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEE RESULTS： （1） Short-term LF-PEF stimulation （5 and 10 minutes） increased TH expression and media DA levels after short-term culture （2 days） （P 〈 0.01）, but both parameters decreased with longer culture （3 4 days） （P 〈 0.01）. Long-term LF-PEF stimulation （15, 20, or 30 minutes） decreased TH and DA synthesis, followed by a rapid increase （P 〈 0.01）. （2） H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes, while the inhibition rate of U0126 was 53.2%. CONCLUSION： Short-term LF-PEF first promotes then inhibits, while long-term LF-PEF first inhibits then promotes, TH and DA synthesis. LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.
文摘OBJECTIVE Cognitive inflexibility plays a critical role in the compulsive drug taking,a central characteristic of drug addictions,yet its underlying neurochemical mechanisms are not well understood.The present study examined the impact of morphine withdrawal on reversal learning.METHODS Reversal learning was tested in a four-choices digging task.Some brain tissues were harvested 2 h after the behavioral experiment for the further measurement.RESULTS We found that after long-term abstinence for a month from chronic morphine exposure,mice exhibited a profound reversal learning deficit.We further found that dopamine D2 receptor(D2R)system in the frontal-striatal circuit is significantly down-regulated,at both receptor and downstream signals levels.Subsequent pharmacological experiments demonstrated that aripiprazole,a D2R partial agonist,prevented the D2R downregulation and rescued the reversal learning deficit.CONCLUSION Together,our findings provide valuable insights into the causal relationship between D2R system in the frontal-striatal circuit and the cognitive inflexibility caused by abused drugs and offer a promising possibility of an effective therapeutic intervention for drug addictions.
文摘BACKGROUND： It has been demonstrated that the septal nucleus is involved in the pathogenesis of schizophrenia. Based on autopsies of schizophrenia patients, studies have shown a reduced number of septal nucleus neurons and glia. In addition, experimental rat models of schizophrenia have shown increased dopamine receptor D2 binding sites in the basal ganglia, septal nuclei, and substantia nigra. Previous studies have demonstrated that the septal nucleus modulates dopamine metabolic disorder and dopamine D2 receptor balance. OBJECTIVE： Dopamine D2 receptor expression in a rat model of schizophrenia, combined with antipsychotic drugs, was analyzed in the prefrontal lobe, striatum, and brainstem. In situ hybridization was used to observe the effects of stereotactic septal nucleus lesions on dopamine D2 receptor expression in the brains of methylamphetamine-treated rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed in the Laboratory of General Institute of Psychosurgery, Third Hospital of Chinese PLA from November 2005 to June 2006. MATERIALS： A total of 120 healthy, adult Sprague Dawley rats, weighing approximately 200 g, were included. Methylamphetamine （Sigma, USA） and an in situ hybridization detection kit for dopamine D2 receptor （Boster, China） were also used for this study. METHODS： All rats were randomly allocated to the following 4 groups, with 30 rats in each group： normal control, simple administration, septal nucleus lesion, and sham-operated groups. In the normal control group, rats were not administered or lesioned. In the remaining 3 groups, rats were intraperitoneally administered 10 mg/kg methylamphetamine, once per day, for 15 successive days to establish a schizophrenia model. Following successful model establishment, rats from the septal nucleus lesion group were subjected to stereotactic septal nucleus lesions. The cranial bone was exposed in rats from the sham-operated group, and the septal nucleus was not lesioned. MAIN OUTCOME MEASURES： At 7 days post-surgery, dopamine D2 receptor expression in the prefrontal lobe, striatum, and brainstem were detected by in situ hybridization. RESULTS： Dopamine D2 receptor expression in the rat prefrontal lobe, striatum, and brainstem was significantly higher in the simple administration group and sham-operated group, compared with the normal control group （P 〈 0.01）. In the septal nucleus lesion group, dopamine D2 receptor expression was significantly less than the simple administration and sham-operated groups, （P 〈 0.01）. There was no significant difference in dopamine D2 receptor expression between the simple administration and sham-operated groups （P 〉 0.05）. CONCLUSION： Septal nucleus lesions reduce dopamine D2 receptor expression in the prefrontal lobe, striatum, and brainstem in a rat model of schizophrenia, indicating that the septal nucleus modulates dopamine D2 receptor expression.
