Effects and significance of α-synuclein on β-arrestin 2 expression in Parkinson' disease in a mouse model / 中华老年医学杂志

Objective:To investigate the effects and significance of α-synuclein(α-syn)on the expression level of β-arrestin 2 in Parkinson's disease(PD)in a mouse model.Methods:Twenty-eight C57BL/6J mice with similar motor skills were randomly divided into a model group and a control group, with 14 mice in each group.A PD model was established by injecting preformed fibrils of α-syn into the striatum of the brain, and behavioral changes were monitored after 4 weeks.The expression levels of α-syn, the dopamine receptor(DR), tyrosine hydroxylase(TH), inflammatory factors, β-arrestin 2 and the nuclear transcription factor-κB(NF-κB)signaling pathway-related proteins were determined by Western blotting.The interaction between α-syn and β-arrestin 2 was detected by fluorescence resonance energy transfer(FRET), and the regulation of α-syn on β-arrestin 2 transcriptional activation was detected by the dual luciferase report assay.Results:After 4 weeks of modeling, compared with the control group, the average movement speed of mice in the model group was significantly reduced( t=9.415, P<0.001), the movement track was sparse and concentrated around the open field, and the time needed to climb the pole was significantly prolonged( t=16.412, P<0.001). Compared with the control group, the relative expression of α-synin in astrocytes in the model group increased significantly, the relative expressions of D1DR and TH decreased significantly[(1.14±0.18) vs.(0.53±0.16), (0.67±0.13) vs.(1.15±0.11), (0.46±0.05) vs.(0.81±0.06)]( t=9.810, 10.917 and 17.356, all P<0.001), the relative expression of tumor necrosis factor-α, interleukin-1β, interleukin-6 and NF-κB signaling pathway-related proteins increased significantly( t=3.583, 4.284, 5.396, 11.747, 16.375 and 18.294, all P<0.001), and the relative expression of β-arrestin 2 protein[(0.42±0.11) vs.(1.33±0.14)]in astrocytes decreased significantly( t=19.795, P<0.001). The FRET results suggested a possible direct interaction between α-syn and β-arrestin 2.The results of the dual luciferase report assay showed that the transcription activity of β-arrestin 2 was significantly increased after α-syn gene knockout. Conclusions:The α-syn may induce inflammation in astrocytes by activating the NF-κB signaling pathway and participate in the pathogenesis of PD by reducing dopamine biosynthesis and inhibiting its physiological function through negative regulation of β-arrestin 2.

[Impact of oxidative stress on renal dopamine D(1) receptor dysfunction in offspring of diabetic rat dams].

Objective: To explore the effects of oxidative stress on renal dopamine D(1) receptor dysfunction in offspring of diabetic rat dams. Methods: The pregnant Sprague Dawley (SD) rats (n=10) were randomly divided into the diabetic group (a single intraperitoneal injection of 35 mg/kg streptozotocin on day 0 of gestation) and control group (injected with the equal volume of 0.9% saline on day 0 of gestation) according to the random number table (n=5 each group). The offspring rats were divided into 4 groups including offspring of control dams treated with vehicle, offspring of control dams treated with antioxidant, offspring of diabetic dams treated with vehicle and offspring of diabetic dams treated with antioxidant (n=10 each group). After birth, the offspring rats were treated with normal drinking water or antioxidant (tempol, 1.0 mmol/L) from the age of 4 weeks until the end of the study (20 weeks). The blood pressure was monitored continuously by non-invasive tail-cuff method. The renal oxidative markers including superoxide dismutase (SOD) and malondialdehyde (MDA) activity and D(1) receptor agonist (fenoldopam)-mediated urinary and sodium excretion were detected. Furthermore, the protein expression of renal G protein-coupled receptor kinase 2 (GRK2), GRK4, dopamine D(1) receptor and the phosphorylation level of D(1) receptor were detected. Results: The mean arterial pressure of offspring from the diabetic dams treated with vehicle was significantly higher than that of offspring from control dams treated with vehicle (P=0.013), while the mean arterial pressure of offspring from diabetic dams treated with antioxidant was significantly lower than that of offspring from the diabetic dams treated with vehicle (P=0.038). The fenoldopam-mediated urinary flow and urinary sodium excretion rate were significantly lower in offspring of diabetic dams treated with vehicle than those in offspring of control dams treated with vehicle (P<0.01), which were significantly higher in offspring of diabetic dams treated with antioxidant as compared to offspring of diabetic dams treated with vehicle (both P<0.01). There was no significant difference in fenoldopam-mediated urinary flow and urinary sodium excretion rate in offspring of control dams treated with antioxidant or vehicle (urinary flow: P=0.772; urinary sodium excretion rate: P=0.716). Compared with offspring of control dams treated with vehicle, the renal MDA activity was significantly increased, while the SOD activity was significantly decreased in offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.013). The renal MDA activity was significantly decreased, while the SOD activity was significantly increased in offspring of diabetic dams treated with antioxidant in comparison with offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.035).The renal GRK2 and GRK4 protein expression in offspring of diabetic dams treated with vehicle were significantly higher than those in offspring of control dams treated with vehicle (P<0.01), while the expression levels of renal GRK2 and GRK4 in offspring of diabetic dams treated with antioxidant were significantly downregulated compared with offspring of diabetic dams treated with vehicle (P<0.01). There was no significant difference in the protein expression of dopamine D(1) receptor among 4 groups (P=0.735). The level of dopamine D(1) receptor phosphorylation in offspring of diabetic dams treated with vehicle was significantly higher than that in offspring of control dams treated with vehicle (P<0.01), while the dopamine D(1) receptor phosphorylation level was significantly lower in offspring of diabetic dams treated with antioxidant compared to that in offspring of diabetic dams treated with vehicle (P<0.01). Conclusion: Oxidative stress is involved in the dopamine D(1) receptors dysfunction in the offspring of diabetic dams.

Effect of herb-partitioned moxibustion on dopamine levels and dopamine receptor 1 expression in the colon and central nervous system in rats with Crohn's disease.

OBJECTIVE: To observe the effect of herb-partitioned moxibustion at the Tianshu (ST 25) and Qihai (CV 6) acupoints in rats with Crohn's disease, and explore the underlying mechanism from dopamine (DA) and dopamine receptor 1 (D1R) in the colon, spinal dorsal horn and hypothalamus. METHODS: The rats were randomly divided into the normal, model (CD), herb-partitioned moxibustion (Mox) and mesalazine (Mesa) groups. Damage in the colons was scored and observed by hematoxylin and eosin staining. DA and D1R protein expression in the colonic mucosa were detected by immunohistochemistry. The concentrations of DA and D1R in the spinal dorsal horn and hypothalamus were measured by enzyme-linked immunosorbent assay, and D1R mRNA expression was evaluated by quantitative real-time polymerase chain reaction. RESULTS: In the colon, compared with the normal group, DA, D1R protein expressions and D1R mRNA expression were significantly higher in the model group, while decreased in the Mox group and the Mesa group. In the spinal dorsal horn and hypothalamus, compared with the normal group, the concentrations of DA and D1R, and the D1R mRNA expressions were significantly higher in the model group, and decreased in the Mox group and the Mesa group. CONCLUSION: Herb-partitioned moxibustion at the Tianshu (ST 25) and Qihai (CV 6) acupoints relieved ulceration in CD rats, the underlying mechanism maybe relative with the regulation of DA and D1R in the colon, spinal dorsal horn and hypothalamus by moxibustion.

Impact of oxidative stress on renal dopamine D1 receptor dysfunction in offspring of diabetic rat dams / 中华心血管病杂志

Objective@#To explore the effects of oxidative stress on renal dopamine D1 receptor dysfunction in offspring of diabetic rat dams.@*Methods@#The pregnant Sprague Dawley (SD) rats (n=10) were randomly divided into the diabetic group (a single intraperitoneal injection of 35 mg/kg streptozotocin on day 0 of gestation) and control group (injected with the equal volume of 0.9% saline on day 0 of gestation) according to the random number table (n=5 each group). The offspring rats were divided into 4 groups including offspring of control dams treated with vehicle, offspring of control dams treated with antioxidant, offspring of diabetic dams treated with vehicle and offspring of diabetic dams treated with antioxidant (n=10 each group). After birth, the offspring rats were treated with normal drinking water or antioxidant (tempol, 1.0 mmol/L) from the age of 4 weeks until the end of the study (20 weeks). The blood pressure was monitored continuously by non-invasive tail-cuff method. The renal oxidative markers including superoxide dismutase (SOD) and malondialdehyde (MDA) activity and D1 receptor agonist (fenoldopam)-mediated urinary and sodium excretion were detected. Furthermore, the protein expression of renal G protein-coupled receptor kinase 2 (GRK2), GRK4, dopamine D1 receptor and the phosphorylation level of D1 receptor were detected.@*Results@#The mean arterial pressure of offspring from the diabetic dams treated with vehicle was significantly higher than that of offspring from control dams treated with vehicle (P=0.013), while the mean arterial pressure of offspring from diabetic dams treated with antioxidant was significantly lower than that of offspring from the diabetic dams treated with vehicle (P=0.038). The fenoldopam-mediated urinary flow and urinary sodium excretion rate were significantly lower in offspring of diabetic dams treated with vehicle than those in offspring of control dams treated with vehicle (P<0.01), which were significantly higher in offspring of diabetic dams treated with antioxidant as compared to offspring of diabetic dams treated with vehicle (both P<0.01). There was no significant difference in fenoldopam-mediated urinary flow and urinary sodium excretion rate in offspring of control dams treated with antioxidant or vehicle (urinary flow: P=0.772; urinary sodium excretion rate: P=0.716). Compared with offspring of control dams treated with vehicle, the renal MDA activity was significantly increased, while the SOD activity was significantly decreased in offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.013). The renal MDA activity was significantly decreased, while the SOD activity was significantly increased in offspring of diabetic dams treated with antioxidant in comparison with offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.035).The renal GRK2 and GRK4 protein expression in offspring of diabetic dams treated with vehicle were significantly higher than those in offspring of control dams treated with vehicle (P<0.01), while the expression levels of renal GRK2 and GRK4 in offspring of diabetic dams treated with antioxidant were significantly downregulated compared with offspring of diabetic dams treated with vehicle (P<0.01). There was no significant difference in the protein expression of dopamine D1 receptor among 4 groups (P=0.735). The level of dopamine D1 receptor phosphorylation in offspring of diabetic dams treated with vehicle was significantly higher than that in offspring of control dams treated with vehicle (P<0.01), while the dopamine D1 receptor phosphorylation level was significantly lower in offspring of diabetic dams treated with antioxidant compared to that in offspring of diabetic dams treated with vehicle (P<0.01).@*Conclusion@#Oxidative stress is involved in the dopamine D1 receptors dysfunction in the offspring of diabetic dams.

Reduction of Severity of Recurrent Psychotic Episode by Sustained Treatment with Aripiprazole in a Schizophrenic Patient with Dopamine Supersensitivity: A Case Report.

Dopamine supersensitivity psychosis (DSP) is a type of acute exacerbation of recurrent psychosis caused by long-term treatment with antipsychotics in schizophrenic patients. Although DSP is exceedingly troublesome for clinicians, effective treatment has not yet been established. Based on clinical research and our animal study, we hypothesize that aripiprazole, an atypical antipsychotic, may reduce the exacerbation of recurrent psychotic episodes. We report the case of a 46-year-old female who suffered from schizophrenia with DSP. In this case, sustained treatment with a high dose of aripiprazole gradually reduced the　 severity of her recurrent psychotic episodes. In conclusion, sustained treatment with aripiprazole may reduce the exacerbation of recurrent psychotic episodes in schizophrenic patients with DSP, and may be an effective treatment of DSP.

Multiple modalities PET/CT neuroimaging for the diagnosis of Parkinson's disease and multiple system atrophy: statistical parametric mapping analysis / 中华神经科杂志

Objective To investigate the topographic distributions of dopamine transporter (DAT),dopamine D2 receptor and glucose in Parkinson's disease (PD) and multiple system atrophy (MSA) using positron emission tomography/computed tomography (PET/CT) scanning and statistical parametric mapping (SPM) analysis.Methods Seventy subjects (39 PD patients,15 MSA patients and 16 normal controls) who came from People's Liberation Army General Hospital from September 2013 to November 2015 underwent DAT,D2 receptor and glucose brain PET/CT scans using 11 C-methyl-N-2-β-carbomethoxy-3-β-(4-fluorophenyl) tropane (11C-β-CFT),11C-raclopride and 18F-fluorodeoxyglucose (18 F-FDG) as radiotracers,respectively.The uptake patterns were analyzed using SPM software.Results Striatal DAT binding decreased in the putamen in PD patients compared with controls (Z =5.21-5.77,P =0.002-0.016).D2 receptor showed no significant differences.However,glucose uptake decreased in cingulate gyrus(Z =4.51-4.67,P =0.010-0.017).For MSA patients,both DAT and D2 receptor binding decreased in the putamen(Z =2.13-3.42,P =0.000-0.016).Glucose uptake decreased in the bilateral putamen,cerebellum and part of frontal temporal lobes (Z =1.86-3.75,P =0.000-0.032).Conclusion Multiple modalities PET/CT scans using the ligands 11 C-β-CFT,11C-raclopride,and 18F-FDG are valuable in diagnosis of MSA and differential diagnosis of MSA from PD.

Reduction of Severity of Recurrent Psychotic Episode by Sustained Treatment with Aripiprazole in a Schizophrenic Patient with Dopamine Supersensitivity: A Case Report

Dopamine supersensitivity psychosis (DSP) is a type of acute exacerbation of recurrent psychosis caused by long-term treatment with antipsychotics in schizophrenic patients. Although DSP is exceedingly troublesome for clinicians, effective treatment has not yet been established. Based on clinical research and our animal study, we hypothesize that aripiprazole, an atypical anti-psychotic, may reduce the exacerbation of recurrent psychotic episodes. We report the case of a 46-year-old female who suffered from schizophrenia with DSP. In this case, sustained treatment with a high dose of aripiprazole gradually reduced the severity of her recurrent psychotic episodes. In conclusion, sustained treatment with aripiprazole may reduce the exacerbation of recurrent psychotic episodes in schizophrenic patients with DSP, and may be an effective treatment of DSP.

Non-displaceable binding potential changes of striatal dopamine D2 receptors in patients with first-episode major depressive disorder and the correlation with clinical features / 中华核医学与分子影像杂志

Objective To observe non-displaceable binding potential (BPND) changes of striatal dopamine D2 receptors(SDDR) in patients with first-episode major depressive disorder (MDD) using 11C-Raclopride PET/CT,and to analyze the relationship between BPND and Hamilton rating scale for depression (HAM-D).Methods From December 2014 to December 2015,patients with first-episode MDD and age/gender-matched healthy controls underwent brain MRI and 11C-Raclopride PET/CT in this prospective study.BPND of bilateral SDDR was calculated by molecular imaging and kinetic analysis toolbox (MIAKAT).BPND changes of bilateral SDDR and their relationship with HAM-D score were analyzed.Paired t test,two-sample t test and Pearson correlation analysis were used.Results A total of 20 MDD patients (8 males,12 females,average age: (32.80±9.76) years) and 20 healthy controls (9 males,11 females,average age:(29.25±6.93) years) were enrolled in this study.The 11C-Raclopride uptake in brain tissue of the MDD group and control group were mainly distributed in bilateral striatum,and very few 11C-Raclopride was distributed in bilateral cerebral cortex and cerebellum.In MDD group,the BPND level of bilateral SDDR had no statistical differences(t values: 0.69,0.35,both P>0.05),and similar results were found in the control group(t values: 0.28,0.24,both P>0.05).Compared with the control group,however,the MDD group had lower BPND level of bilateral SDDR(t values: 3.13-4.41,all P<0.05).The BPND of bilateral caudate nucleus and/or putamen D2 receptors was correlated with HAM-D total score,anxiety/somatization factor score,cognitive impairment factor score,retardation factor score and sleep disturbance factor score(r values: from-0.688 to-0.453,all P<0.05).Conclusions The binding potential of SDDR in patients with first-episode MDD is declined,and the BPND level of SDDR is correlated with symptoms of depression.The abnormality of SDDR may be an important molecular mechanism of the abnormality of midbrain-striatal dopamine reward circuits in MDD patients.

Frequência de polimorfismos genéticos rs1800497, rs1799732, rs6280 e a ocorrência da esquizofrenia refratária / Frecuencia de polimorfismos genéticos rs1800497, rs1799732, rs6280 y la ocurrencia de la esquizofrenia refractory / Frequency of genetic polymorphisms rs1800497, rs1799732, rs6280 and the occurrence of schizophrenia refractory

Introdução: a esquizofrenia é considerada um dos mais severos e complexos transtornos mentais que acomete tanto a qualidade de vida do indivíduo que convive com a doença quanto a de sua família. Caracteriza-se principalmente por sintomas denominados positivos (alteração no processo do pensamento, percepções e afeto) e negativos (embotamento afetivo-volitivo,perdas cognitivas e sintomas depressivos). Os fatores de risco para este transtorno são epifenômenos de processos fisiopatológicos que resultam de uma interação gene-ambiente ainda pouco compreendida. A hipótese da dopamina é o principal conceito que fundamenta a atividade antipsicótica, conforme esta, os sintomas positivos estariam relacionados a níveis elevados de dopamina na via mesolímbica, enquanto os sintomas negativos e cognitivos,possivelmente estão associados a níveis diminuídos desse neurotransmissor na viamesocortical. Os antipsicóticos cessam os sintomas da esquizofrenia, no entanto, 40% dospacientes permanecem resistentes (refratários) ao tratamento. Os pacientes com esquizofreniarefratária ao tratamento apresentam menor capacidade de síntese de dopamina do que aquelescom boa resposta aos antipsicóticos de primeira geração, sendo que uma adequada resposta aotratamento medicamentoso coincidi com uma maior densidade de sinapses dopaminérgicas,isto subsidia uma base biológica para a refratariedade. O polimorfismo de nucleotídeo simplesé uma variação da sequência de DNA devido a uma única diferença de nucleotídeos entre osalelos. Alguns deles podem ter efeitos funcionais e podem alterar a regulação positiva da expressão do receptor induzida por dopamina. Três principais destes polimorfismos foramabordados neste estudo: rs1800497, rs1799732 e rs6280. Objetivo: investigar a frequência dospolimorfismos rs1800497, rs1799732 e rs6280 e a ocorrência da esquizofrenia refratária

Introduction: Schizophrenia is considered one of the most severe and complex mentaldisorders that affect both the quality of life of the individual living with the disease and that ofhis family. It is characterized mainly by symptoms denominated positive (alteration in thethought process, perceptions and affection) and negative (affective-volitional blunting,cognitive losses and depressive symptoms). The risk factors for this disorder areepiphenomena of pathophysiological processes that result from a gene-environmentinteraction still poorly understood. The hypothesis of dopamine is the main conceptunderlying antipsychotic activity, as this, positive symptoms would be related to elevateddopamine levels in the mesolimbic pathway, while negative and cognitive symptoms arepossibly associated with decreased levels of this neurotransmitter in the mesocorticalpathway. Antipsychotics cease the symptoms of schizophrenia, however, 40% of patientsremain resistant (refractory) to treatment. Patients with treatment-refractory schizophreniahave a lower capacity for dopamine synthesis than those with a good response to first-generation antipsychotics, and an adequate response to drug treatment coincided with a higherdensity of dopaminergic synapses, this subsidizes a biological basis for refractoriness. Singlenucleotide polymorphism is a variation of the DNA sequence due to a single nucleotidedifference between the alleles. Some of them may have functional effects and may alter thepositive regulation of dopamine-induced receptor expression. Three major of thesepolymorphisms were addressed in this study: rs1800497, rs1799732 and rs6280. Objective:to investigate the frequency of polymorphisms rs1800497, rs1799732 and rs6280 and theoccurrence of refractory schizophrenia

Nicergoline improves the depressive behavior of vascular depression in rats by regulating monoamine neurotransmitter receptors expression in hippocampal CA1 region and serum apolipoprotein E4 level / 国际脑血管病杂志

Objective To investigate the effects of nicergoline on expressions of 5-hydroxytryptamine 1A receptor (5-HT1AR), D2 dopamine receptor (D2DR),α2A adrenaline receptor (α2AAR) in the hippocampal CA1 region and the serum level of apolipoprotein E4 (ApoE4) in a rat model of vascular depression (VD) . Methods Forty-eight male Sprague-Daw ley rats w ere randomly al ocated into a normal control group, a model group, fluoxetine group, a low-dose nicergoline group, a medium-dose nicergoline group, and a nicergoline high-dose group ( n=8 in each group). A rat model of VD w as induced by the ligation of bilateral common carotid arteries combined w ith chronic unpredictable mild stress (CUMS) plus single housing. The rats did not conduct CUMS or single housing in the normal control group, and the rats in the model group conducted CUMS and single housing. The rats in the fluoxetine group w ere given fluoxetine 1.3 mg/(kg· d) for gastric lavage for 3 w eeks at the beginning of CUMS and single housing. The rats in the low -, medium-and high-dose nicergoline groups w ere given nicergoline 0.9, 1.9 and 3.8 mg/(kg· d), respectively for gastric lavage for 3 w eeks at the beginning of CUMS and single housing. The normal control group and the model group w ere given equal volume of distil ed w ater for gastric lavage, once a day for 3 w eeks. Depression-like behavior w as evaluated using sucrose solution consumption and open-field test. Immunohistochemical staining and Western blot were used to detect the expressions of 5-HT1AR, D2DR, andα2AAR in the hippocampal CA1 region. Enzyme linked immunosorbent assay w as used to detect serum ApoE4 level. Results Before CUMS, the scores of horizontal and vertical movement and sucrose solution consumption in the model group, the fluoxetine group and each nicergoline group w ere decreased significantly compared w ith the normal control group (al P<0.01);w hile at 21 days after CUMS, those in the fluoxetine group and the nicergoline medium-and high-dose groups w ere significantly higher than those in the model group (al P<0.05). There w ere no significant differences betw een the fluoxetine group and each nicergoline group. The expression levels of 5-HT1A R, D2DR, α2A AR, and the serum ApoE4 in the model group, the fluoxetine group, and each nicergoline group w ere significantly higher than those in the normal control group. Those of the fluoxetine group and the nicergoline medium -and high-dose groups were significantly lower than the model group (al P<0.01), while there were no significant differences betw een the fluoxetine group and each nicergoline group. Conclusions Nicergoline can improve the depression-like behavior in VD rats. Its mechanism may be associated w ith the dow nregulation of 5-HT1AR, D2DR, α2AAR expressions and serum ApoE4 level.

Constructing the dual luciferase reporter vector containing human DRD1 promoter region / 中国组织工程研究

BACKGROUND:The polymorphisms of dopamine receptor in promoter region wil affect the expression of the receptor, thereby affecting the dopaminergic neurotransmitter, final y lead to related diseases. OBJECTIVE:To construct the dual luciferase reporter vector containing human DRD1 promoter region and determine its activity, which could provide the basic tool for studying the transcriptional regulation of DRD1 gene. METHODS:DRD1 promoter sequence was amplified by PCR using the human blood genomic DNA and cloned into pGM-T vector. After sequencing, the correctly constructed vectors were ligated to the firefly luciferase reporter plasmid pGL3-Basic. The cloned pGL3-Basic vectors were transfected into HEK293 using cationic liposome method. In the meanwhile, PGL3-Basic vector with no promoter was co-transfected with pGL3-TK plasmid as negative control group. The relative fluorescence intensity was measured by chemiluminescence. RESULTS AND CONCLUSION:(1) Recombinant luciferase reporter gene vectors were confirmed by restriction analysis and sequencing. (2) Compared with the negative control group, the HEK293 cel s transfected by recombinant vectors presented transcriptional activity. (3) In conclusion, luciferase reporter gene vectors containing DRD1 promoter region are successful y constructed and can provide the basic tool for further study on the transcriptional regulation of DRD1.

Similar striatal D2/D3 dopamine receptor availability in adults with Tourette syndrome compared with healthy controls: A [(11) C]-(+)-PHNO and [(11) C]raclopride positron emission tomography imaging study.

Pharmacological and anatomical evidence implicates striatal dopamine receptors in Tourette syndrome (TS). Nevertheless, results of positron emission tomography (PET) studies of the dopamine system in TS have been inconsistent. We investigated striatal D2/3 dopamine receptors in TS using the radioligands [(11) C]raclopride and [(11) C]-(+)-PHNO, an agonist that binds preferentially to D3 receptors, thus allowing higher sensitivity and measurement of receptors in a high affinity state. Eleven adults with TS and 11 matched healthy control (HC) participants underwent [(11) C]raclopride and [(11) C]-(+)-PHNO PET scans. General linear model was used for voxelwise contrasts of striatal binding potentials (BPND ) between TS and HC participants. Analysis of variance was performed to investigate main effect of radioligand. In addition, BPND values were extracted for ventral, motor, and associative striatum. Finally, we examined the relationship between BPND measures and symptom severity in TS participants. Main effects analyses showed that [(11) C]-(+)-PHNO BPND was higher in ventral striatum, whereas [(11) C]raclopride BPND was higher in motor and associative striatum. There were no significant group differences between TS and HC. Furthermore, TS and HC participants had similar [(11) C]-(+)-PHNO and [(11) C]raclopride BPND in the three striatal subregions. Moreover, there was no significant correlation between BPND and symptom severity. TS and HC participants had similar striatal D2/3 receptor availability measures. These results challenge the assumption that striatal dopamine receptors have a major role in the pathophysiology of TS. Consistent with previous findings, [(11) C]-(+)-PHNO localized preferentially to ventral striatal, D3 receptor-rich regions, in contrast to [(11) C]raclopride, which localized preferentially in the dorsal striatum.

Brain imaging of 18 F-Fallypride in healthy volunteers / 中华核医学与分子影像杂志

Objective To evaluate dopamine D2/D3 receptors status in striatal and extra?striatal re?gions with 18 F?Fallypride PET/CT. Methods A total of 11 healthy volunteers ( 4 males, 7 females, age (43.5±13.7) years) underwent PET/CT at 1 h after 18F?Fallypride injection. Imaging data was analyzed u?sing visual and ROI methods. The SUV ratios of different brain regions to cerebellar lobe were calculated. In?formed consent was obtained from all volunteers. The study was approved by the Ethics Committee of the PLA General Hospital. Results 18 F?Fallypride was widely distributed in striatal and extra?striatal brain re?gions. Distribution of 18 F?Fallypride was consistent in all healthy subjects and the rank order of receptor con?centration(brain region SUV/cerebellum SUV) was putamen(15.72±3.69)>pituitary(10.24±6.55)>cau?date(8.38±1.26)>amygdala(6.92±1.32)>thalamus(4.87±1.50)>colliculi(3.91±1.08)>substantia nigra (3.20±0.95)>cortex(temporal cortex: 2.11±1.34, parietal cortex: 1.51±0.57, occipital cortex: 1.31± 0?11, frontal cortex:1?30±0.25). Conclusion 18F?Fallypride PET/CT is suitable to study D2/D3 recep?tors status in striatal and extra?striatal brain regions.

Expression of dopamine D1 receptors in hippocampal dentate gyrus in rats with vascular dementia / 吉林大学学报(医学版)

Objective To observe the extracellular content of dopamine (DA)and expression of D1 receptors in hippocampal dentage gyrus (DG)in the model rats with vascular dementia (VD),and to investigate the relationship between them.Methods 12 male SD rats were randomly divided VD group and sham-operation group,and the VD model was prepared by permanent bilateral carotid occlusion.The extracellular content of DA in the DG was determined by in vivo microdialysis and HPLC,and the expression of D1 receptors was measured by immunehisto-chemistry.Results The DA content in the DG of the rats in VD group was lower than that in sham-operation group (P 0.05).Conclusion The DA content in the hippocampal DG is decreased in the VD rats,and its function may be compensated by the up-regulation of D1 receptors in the DG hilus.

Role of spinal dopamine D2 receptors in a rat model of neuropathic pain / 中华麻醉学杂志

Objective To evaluate the role of spinal dopamine D2 receptors in a rat model of neuropathic pain.Methods Thirty healthy male Sprague-Dawley rats,aged 6-8 weeks,weighing 180-200 g,wcre randomly divided into 5 groups (n =6 each) using a random number table:control group (group C),sham operation group (group S),neuropathic pain group (group NP),normal saline group (group N) and dopamine D2 receptor agonist quinpirole group (group Q).Neuropathic pain was produced by chronic constriction injury of the sciatic nerve (CCI) in rats anesthetized with intraperitoneal 2％ pentobarbital sodium 40 mg/kg.At 7 days after CCI,normal saline 10 μl was injected intrathecally over 30 s in group N,and quinpirole 10 μg (in 10 μl of normal saline) was injected intrathecally over 30 s in group Q.At 1 day before CCI,3 and 7 days aher CCI,and 30 min and 1,2,4,8 and 16 h after administration,mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured.Results There was no significant difference in MWT and TWL at each time point between group C and group S.MWT was significantly lower,and TWL was shorter at T1-8 in NP,N and Q groups than in C and S groups.Compared with group N,no significant change was found in MWT and TWL at each time point in N group,and MWT was significantly increased,and TWL was prolonged at T4-6 in group Q.Conclusion Inhibited function of spinal dopamine D2 receptors is involved in the maintenance of neuropathic pain in rats.

Study on relationship between single nucleotide polymorphisms polymorphisms of DDC and DRD1 and clinical phenotype feature in autistic children / 中国医师杂志

Objective To investigate the association between single nucleotide polymorphisms (SNPs) of DOPA decarboxylase (DDC) and dopamine receptor-1 (DRD1) and clinical phenotype feature in autistic children.Methods TaqMan probes real-time polymerase chain reaction (PCR) was used to determine genotype and allele of SNPs of DDC gene (rs6592961) and DRD1 (rs251937) gene in 97 autism children.The Children Autism Rating Scale (CARS) was used to evaluate clinical phenotype feature.Results There was no significant difference in the distribution of the allelic frequency and genotype between mild-medium group and severe group of CARS scores (P ＞ 0.05).For DDC gene (rs6592961),significant difference was found in subscale between genotypes G/G and A/A (P =0.043).For DRD1 gene (rs251937),significant difference was found in subscale between genotypes T/T and C/C (P =0.029).Conclusions In DDC gene (rs6592961),the children with G/G genotype were more obvious than the children with A/A genotype.In DRD1 gene (rs251937),the children with T/T genotype were more obvious than the children with C/C genotype.

Effect of GDNF on depressive-like behavior, spatial learning and key genes of the brain dopamine system in genetically predisposed to behavioral disorders mouse strains.

The effect of glial cell line-derived neurotrophic factor (GDNF) on behavior and brain dopamine system in predisposed to depressive-like behavior ASC (Antidepressant Sensitive Cataleptics) mice in comparison with the parental "nondepressive" CBA mice was studied. In 7days after administration (800ng, i.c.v.) GDNF decreased escape latency time and the path traveled to reach hidden platform in Morris water maze in ASC mice. GDNF enhanced depressive-like behavioral traits in both "nondepressive" CBA and "depressive" ASC mice. In CBA mice, GDNF decreased functional response to agonists of D1 (chloro-APB hydrobromide) and D2 (sumanirole maleate) receptors in tail suspension test, reduced D2 receptor gene expression in the substantia nigra and increased monoamine oxydase A (MAO A) gene expression in the striatum. GDNF increased D1 and D2 receptor genes expression in the nucleus accumbens of ASC mice but failed to alter expression of catechol-O-methyltransferase, dopamine transporter, MAO B and tyrosine hydroxylase genes in both investigated mouse strains. Thus, GDNF produced long-term genotype-dependent effect on behavior and the brain dopamine system. GDNF pretreatment (1) reduced D1 and D2 receptors functional responses and D2 receptor gene expression in s. nigra of CBA mice; (2) increased D1 and D2 receptor genes expression in n. accumbens of ASC mice and (3) improved spatial learning in ASC mice. GDNF enhanced depressive-like behavior both in CBA and ASC mice. The data suggest that genetically defined variance in the cross-talk between GDNF and brain dopamine system contributes to the variability of GDNF-induced responses and might be responsible for controversial GDNF effects.

Sestrin2 decreases renal oxidative stress, lowers blood pressure, and mediates dopamine D2 receptor-induced inhibition of reactive oxygen species production.

The dopamine D2 receptor (D2R) decreases renal reactive oxygen species (ROS) production and regulates blood pressure, in part, via positive regulation of paraoxonase 2. Sestrin2, a highly conserved antioxidant protein, regulates intracellular ROS level by regenerating hyperoxidized peroxiredoxins. We hypothesized that sestrin2 may be involved in preventing excessive renal ROS production and thus contribute to the maintenance of normal blood pressure. Moreover, the D2R may decrease ROS production, in part, through the regulation of sestrin2. Renal sestrin2 expression was lower (-62±13%) in D2R(-/-) than in D2R(+/+) mice. Silencing D2R in human renal proximal tubule cells decreased sestrin2 expression (-53±3%) and increased hyperoxidized peroxiredoxins (2.9-fold). Stimulation of D2R in renal proximal tubule cells increased sestrin2 expression (1.6-fold), decreased hyperoxidized peroxiredoxins (-61±3%), and reduced ROS production (-31±4%). Silencing sestrin2 in renal proximal tubule cells increased hyperoxidized peroxiredoxins (2.1-fold) and ROS production (1.3-fold). Silencing sestrin2 also abolished D2R-induced decrease in peroxiredoxin hyperoxidation and partially prevented the inhibitory effect of D2R stimulation on ROS production. Silencing paraoxonase 2 increased sestrin2 ubiquitinylation (2.8-fold), decreased sestrin2 expression (-30±3%), and increased ROS production (1.3-fold), peroxiredoxin hyperoxidation (2.9-fold), and lipid peroxidation (2.3-fold), and blocked the increase in sestrin2 that occurs with D2R stimulation. In vivo renal selective silencing of sestrin2 by the renal subcapsular infusion of sestrin2 small interfering RNA (3 µg/day; 7 days) in mice increased renal oxidative stress (1.3-fold) and blood pressure. These results suggest that the D2R, via paraoxonase 2 and sestrin2, keeps normal renal redox balance, which contributes to the maintenance of normal blood pressure.

Dopamine receptor gene d4 polymorphisms and early sexual onset: gender and environmental moderation in a sample of african-american youth.

PURPOSE: Early sexual onset and its consequences disproportionately affect African-American youth, particularly male youth. The dopamine receptor D4 gene (DRD4) has been linked to sexual activity and other forms of appetitive behavior, particularly for male youth and in combination with environmental factors (gene × environment [G × E] effects). The differential susceptibility perspective suggests that DRD4 may exert this effect by amplifying the effects of both positive and negative environments. We hypothesized that DRD4 status would amplify the influence of both positive and negative neighborhood environments on early sexual onset among male, but not female, African-Americans. METHODS: Hypotheses were tested with self-report, biospecimen, and census data from five prospective studies of male and female African-American youth in rural Georgia communities, N = 1,677. Early sexual onset was defined as intercourse before age 14. RESULTS: No significant G × E findings emerged for female youth. Male youth with a DRD4 long allele were more likely than those with two DRD4 short alleles to report early sexual onset in negative community environments and not to report early onset in positive community environments. CONCLUSIONS: Dopaminergic regulation of adolescent sexual behaviors may operate differently by gender. DRD4 operated as an environmental amplification rather than a vulnerability factor.

Single-nucleotide polymorphisms of the dopamine D2 receptor increase inflammation and fibrosis in human renal proximal tubule cells.

The dopamine D2 receptor (D2R) negatively regulates inflammation in mouse renal proximal tubule cells (RPTCs), and lack or downregulation of the receptor in mice increases the vulnerability to renal inflammation independent of blood pressure. Some common single-nucleotide polymorphisms (SNPs; rs6276, rs6277, and rs1800497) in the human DRD2 gene are associated with decreased D2R expression and function, as well as high blood pressure. We tested the hypothesis that human RPTCs (hRPTCs) expressing these SNPs have increased expression of inflammatory and injury markers. We studied immortalized hRPTCs carrying D2R SNPs and compared them with cells carrying no D2R SNPs. RPTCs with D2R SNPs had decreased D2R expression and function. The expressions of the proinflammatory tumor necrosis factor-α and the profibrotic transforming growth factor-ß1 and its signaling targets Smad3 and Snail1 were increased in hRPTC with D2R SNPs. These cells also showed induction of epithelial mesenchymal transition and production of extracellular matrix proteins, assessed by increased vimentin, fibronectin 1, and collagen I a1. To test the specificity of these D2R SNP effects, hRPTC with D2R SNPs were transfected with a plasmid encoding wild-type DRD2. The expression of D2R was increased and that of transforming growth factor-ß1, Smad3, Snail1, vimentin, fibronectin 1, and collagen I a1 was decreased in hRPTC with D2R SNPs transfected with wild-type DRD2 compared with hRPTC-D2R SNP transfected with empty vector. These data support the hypothesis that D2R function has protective effects in hRPTCs and suggest that carriers of these SNPs may be prone to chronic renal disease and high blood pressure.