Directed differentiation of human induced pluripotent stem cells into midbrain / 南方医科大学学报

OBJECTIVE@#To establish an efficient protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into functional midbrain dopaminergic progenitor cells (DAPs) in vitro.@*METHODS@#hiPSCs were induced to differentiate into DAPs in two developmental stages. In the first stage (the first 13 days), hiPSCs were induced into intermediate cells morphologically similar to primitive neuroepithelial cells (NECs) in neural induction medium containing a combination of small molecule compounds. In the second stage, the intermediate cells were further induced in neural differentiation medium until day 28 to obtain DAPs. After CM-DiI staining, the induced DAPs were stereotactically transplanted into the right medial forebrain bundle (MFB) of rat models of Parkinson's disease (PD). Eight weeks after transplantation, the motor behaviors of PD rats was evaluated. Immunofluorescence assay of brain sections of the rats was performed at 2 weeks after transplantation to observe the survival, migration and differentiation of the transplanted cells in the host brain microenvironment.@*RESULTS@#hiPSCs passaged stably on Matrigel showed a normal diploid karyotype, expressed the pluripotency markers OCT4, SOX2, and Nanog, and were positive for alkaline phosphatase. The primitive neuroepithelial cells obtained on day 13 formed dense cell colonies in the form of neural rosettes and expressed the neuroepithelial markers (SOX2, Nestin, and PAX6, 91.3%-92.8%). The DAPs on day 28 highly expressed the specific markers (TH, FOXA2, LMX1A and NURR1, 93.3-96.7%). In rat models of PD, the hiPSCs-DAPs survived and differentiated into TH+, FOXA2+ and Tuj1+ neurons at 2 weeks after transplantation. Eight weeks after transplantation, the motor function of PD rats was significantly improved as shown by water maze test (P < 0.0001) and apomorphine-induced rotation test (P < 0.0001) compared with rats receiving vehicle injection.@*CONCLUSION@#HiPSCs can be effectively induced to differentiate into DAPs capable of differentiating into functional neurons both in vivo and in vitro. In rat models of PD, the transplanted hiPSCs-DAPs can survive for more than 8 weeks in the MFB and differentiate into multiple functional neurocytes to ameliorate neurological deficits of the rats, suggesting the potential value of hiPSCs-DAPs transplantation for treatment of neurological diseases.

Progress in research on neuroprotective mechanism of glucagon-like peptide-1 receptor agonists and analogues in Parkinson's disease / 中国生物制品学杂志

@#Parkinson's disease(PD)is the second common neurodegenerative disease that mostly occurs in middle-aged and elderly people. Currently,Levodopa is the main first-line treatment drug,but the long-term efficacy of patients is not good,and even side effects such as“on-off”phenomenon and orthostatic hypotension occur. Glucagon-like peptide-1receptor agonists(GLP-1RA)and analogues are endogenous peptide hormones that can be released into the blood and enter the central nervous system to exert neuroprotection by crossing the blood-brain barrier. Numerous studies have shown that GLP-1RA can improve movement disorders and restore dopaminergic neuron activity in PD. However,the mechanism of GLP-1RA is not yet fully clear. This paper summarized the mechanism of GLP-1RA and its analogues in improving PD movement disorders and restoring dopaminergic neuron activity,and reviewed the aspects of reducing neuroinflammation,inhibiting oxidative stress,inhibiting apoptosis,regulating mitochondrial morphology,increasing neuronal protrusions,enhancing autophagy,and regulating intestinal flora homeostasis,so as to provide new ideas for research of the mechanisms of PD and development of GLP-1RA-related new drugs.

Interpretation of presynaptic dopaminergic PET imaging results / 中华核医学与分子影像杂志

Presynaptic dopaminergic PET imaging is a useful method for the diagnosis of parkinsonism. Based on the expert consensus on operation and clinical application of dopamine transporter brain PET imaging technology published in 2020, this paper further recommends the relevant elements of result interpretation of presynaptic dopaminergic PET imaging.

Demethylenetetrahydroberberine protects dopaminergic neurons in a mouse model of Parkinson's disease / 中国天然药物

Parkinson's disease (PD) is a multifactorial disorder of the nervous system where a progressive loss of dopaminergic neurons exist. However, the pathogenesis of PD remains undefined, which becomes the main limitation for the development of clinical PD treatment. Demethylenetetrahydroberberine (DMTHB) is a novel derivative of natural product berberine. This study was aimed to explore the neuroprotective effects and pharmacological mechanism of DMTHB on Parkinson's disease using C57BL/6 mice. A PD model of mice was induced by administration of MPTP (20 mg·kg-1) and probenecid (200 mg·kg-1) twice per week for five weeks. The mice were administered with DMTHB daily by gavage at the dose of 5 and 50 mg·kg-1 for one- week prophylactic treatment and five-week theraputic treatment. The therapeutic effects of DMTHB were evaluated by behavior tests (the open field, rotarod and pole tests), immunohistochemical staining of tyrosine hydroxylase (TH), Nissl staining and biochemical assays. The molecular mechanisms of DMTHB on the key biomarkers of PD pathological states were analyzed by Western blot (WB) and qRT-PCR. DMTHB treatment alleviated the behavioral disorder induced by MPTP-probenecid. Nissl staining and TH staining showed that the damage of dopaminergic neurons in the substantia nigra was remarkably suppressed by DMTHB treatment. Western blot results showed that the ratio of Bcl-2/Bax and TH increased, but the level of α-synuclein (α-syn) was remarkably reduced, which indicated that the apoptosis of dopaminergic neurons in mice was significantly reduced. The protein phosphorylation of p-PI3K, p-AKT and p-mTOR also increased about 2-fold, compared with the model group. Furthermore, qRT-PCR results demonstrated that the mRNA levels of pro-inflammatory cytokines, IL-1β and TNF-α, were reduced, but the level of anti-inflammatory cytokine IL-10 increased after DMTHB treatment. Finally, the cellular assay displayed that DMTHB was also a strong antioxidant to protect neuron cell line PC12 by scavenging ROS. In this study, we demonstrated DMTHB alleviates the behavioral disorder and protects dopaminergic neurons through multiple-target effects includubg anti-apoptotic, anti-inflammatory and antioxidant effects.

O-GlcNAcylation in Ventral Tegmental Area Dopaminergic Neurons Regulates Motor Learning and the Response to Natural Reward / 神经科学通报·英文版

Protein O-GlcNAcylation is a post-translational modification that links environmental stimuli with changes in intracellular signal pathways, and its disturbance has been found in neurodegenerative diseases and metabolic disorders. However, its role in the mesolimbic dopamine (DA) system, especially in the ventral tegmental area (VTA), needs to be elucidated. Here, we found that injection of Thiamet G, an O-GlcNAcase (OGA) inhibitor, in the VTA and nucleus accumbens (NAc) of mice, facilitated neuronal O-GlcNAcylation and decreased the operant response to sucrose as well as the latency to fall in rotarod test. Mice with DAergic neuron-specific knockout of O-GlcNAc transferase (OGT) displayed severe metabolic abnormalities and died within 4-8 weeks after birth. Furthermore, mice specifically overexpressing OGT in DAergic neurons in the VTA had learning defects in the operant response to sucrose, and impaired motor learning in the rotarod test. Instead, overexpression of OGT in GABAergic neurons in the VTA had no effect on these behaviors. These results suggest that protein O-GlcNAcylation of DAergic neurons in the VTA plays an important role in regulating the response to natural reward and motor learning in mice.

Effect of propofol on dopaminergic neurons of mice with Parkinson′s disease / 中华麻醉学杂志

Objective:To evaluate the effect of propofol on dopaminergic neurons of mice with Parkinson′s disease (PD).Methods:Forty-eight pathogen-free healthy male C57BL/6 mice, aged 8-12 weeks, weighing 22-32 g, were divided into 3 groups ( n=16 each) using a random number table method: control group (group C), group PD and propofol group (group Pro). The neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropypridine (MPTP) was intraperitoneally injected for 7 consecutive days in PD and Pro groups, while the equal volume of normal saline was given for 7 consecutive days in group C. At 30 min after intraperitoneal injection of MPTP, propofol 25 mg/kg was intraperitoneally injected in group Pro, while the equal volume of normal saline was given daily in group C and group PD.At day 8 after the end of establishment of the model, gait analysis system experiment and rotarod test were used to record the step distance and retention time.The animals were sacrificed after the behavioral tests, and the brain tissues were removed for the dopamine neuron count in substantia nigra (by immunohistochemistry) and for determination of the expression of alpha-Synuclein (α-Syn) and Tyrosine hydroxylase (TH) in the substantia nigra (by Western blot). Results:Compared with group C, the step distance was significantly decreased, retention time were shortened, the dopamine neuron count in substantia nigra was decreased, the expression of TH was down-regulated, and expression of α-Syn in substantia nigra was up-regulated in group PD ( P<0.05), and no significant change was found in the parameters mentioned above in group Pro ( P>0.05). Compared with group PD, the step distance was significantly increased, retention time were prolonged, the dopamine neuron count in substantia nigra was increased, the expression of TH was up-regulated, and expression of α-Syn in substantia nigra was down-regulated in group Pro ( P<0.05). Conclusion:Propofol has protective effect on dopaminergic neurons of PD mice, and the mechanism may be related to the down-regulation of α-Syn expression in substantia nigra.

Effects of VHL inhibitor on rotenone-induced Caenorhabditis elegans model of Parkinson′s disease / 中国药科大学学报

@#To investigate the effects of VHL (von Hippel-Lindau) inhibitor on Caenorhabditis elegans (C.elegans) model of Parkinson''s disease (PD),C.elegans were exposed to rotenone and treated with VHL inhibitor VH298.The death,dopaminergic neurodegeneration and mitochondrial unfolded protein response (mito-UPR) of transgenic strains with the markers zcIs9 and otIs181 exposed to different concentrations of rotenone were investigated. The death,dopaminergic neurodegeneration,and changes of behaviors including head thrashes,body bends and foraging behavior of C.elegans model of PD treated with different concentrations of VH298 were explored.The results showed that different concentrations of rotenone can lead to the death,dopaminergic neurodegeneration and abnormal mito-UPR of transgenic nematodes with zcIs9; otIs181,while the VHL inhibitor can decrease the death rate and alleviate dopaminergic neurodegeneration of rotenone-induced C.elegans model of PD.The VHL inhibitor can also attenuate the behavioral abnormalities of head thrashes,body bends and foraging behavior of C.elegans model.These results suggest that rotenone may cause mitochondrial damage in the transgenic nematodes with zcIs9; otIs181, and then destroy mitochondrial homeostasis,thereby resulting in dopaminergic neurodegeneration and death of the nematodes. The VHL inhibitor VH298 may promote the survival of rotenone-induced C.elegans model of PD,and alleviate dopaminergic neurodegeneration,thereby improving the behavioral abnormalities of C.elegans model of PD.

Dopamina e comportamento alimentar: polimorfismos em receptores dopaminérgicos e fenótipos relacionados à obesidade / Dopamine and eating behavior: dopaminergic receptor polymorphisms and obesity related phenotypes

Dentre os sistemas neurais responsáveis pela ingestão dos alimentos, destaca-se a via dopaminérgica mesolímbica que, através da liberação de dopamina nos núcleos de accumbens, desperta prazer e motivação para recompensas químicas e naturais. Esta via de recompensa age através dos receptores dopaminérgicos transmembranares, que variam de DRD1 a DRD5. Desta forma, considerando os efeitos prazerosos despertados pela ingestão alimentar, é plausível que variações genéticas em genes do sistema dopaminérgico possam ter um papel na arquitetura genética da obesidade. Este estudo tem como objetivo realizar uma revisão narrativa da literatura sobre a influência de variantes genéticas nos receptores dopaminérgicos em fenótipos relacionados com a obesidade. Em conjunto, os principais achados desta revisão indicaram que os genes codificadores dos receptores DRD2 e DRD4 possam ser os mais relevantes no contexto da obesidade e fenótipos relacionados. No entanto, a obesidade é uma doença complexa e multifatorial e novos estudos são ainda necessários para uma melhor compreensão do impacto da dopamina nos desfechos relacionado à obesidade. É importante também destacar que esses efeitos podem ser específicos para subgrupos de pacientes e que outros fatores, além das variantes genéticas, devem ser considerados. (AU)

Among the neural systems responsible for food ingestion, the mesolimbic dopaminergic pathway stands out by eliciting pleasure and motivation for chemical and natural rewards through the release of dopamine in the nucleus accumbens. This reward pathway is regulated by transmembrane dopaminergic receptors, which range from DRD1 to DRD5. Thus, considering the pleasurable effects aroused by food intake, it is plausible that genetic variations in genes of the dopaminergic system may have a role in the genetic architecture of obesity. This study aims to conduct a narrative review of the literature on the influence of genetic variants of dopaminergic receptors on obesity-related phenotypes. Taken together, the main findings of this review indicated that the genes encoding the DRD2 and DRD4 receptors may be the most relevant in the context of obesity and related phenotypes. However, obesity is a complex and multifactorial disease and new studies are still being conducted to better understand the impact of dopamine on obesity-related outcomes. It is also important to note that these effects can be specific to subgroups of patients and that other factors, in addition to genetic variants, must be considered. (AU)

Pharmacological interventions in corticobasal degeneration: a review / Intervenções farmacológicas na degeneração corticobasal: uma revisão

ABSTRACT. Corticobasal degeneration (CBD) is a sporadic tauopathy that presents with a varied combination of motor, cognitive, and behavioral features, making its diagnosis difficult. CBD has high morbidity and poor prognosis, with no effective therapy at present. We searched the PubMed/MEDLINE database for articles published from 1990 to 2019, using the keywords "corticobasal degeneration" AND "treatment." The PRISMA method was adopted. Retrieved articles were characterized as having one of two methodological approaches: (1) studies aimed at primary tauopathy treatment and (2) symptomatic management. Review articles (based on CBD expert groups), case reports, case series, and pilot clinical trials were selected. Few attempts have been made to study drug options and drug efficacy in CBD systematically, and an effective treatment is not yet available. Treatment is symptomatic and based on similarity with other diseases due to the scarcity of studies specifically addressing CBD. CBD seems not to spark interest in more clinical trials for its low prevalence and reliability in clinical diagnosis.

RESUMO. A degeneração corticobasal (DCB) é uma tauopatia esporádica que se apresenta com uma combinação variada de características motoras, cognitivas e comportamentais, dificultando seu diagnóstico. O CBD tem alta morbidade e mau prognóstico, sem terapia efetiva no momento. Pesquisamos o banco de dados PubMed / MEDLINE para artigos publicados de 1990 a 2019, usando as palavras-chave "degeneração corticobasal" e "tratamento". O método PRISMA foi adotado. Os artigos recuperados foram caracterizados como tendo uma de duas abordagens metodológicas: (1) estudos voltados para o tratamento da tauopatia primária e (2) manejo sintomático. Artigos de revisão (baseados em grupos de especialistas em CBD), relatos de casos, séries de casos e ensaios clínicos piloto foram selecionados. Poucas tentativas foram feitas para estudar as opções de drogas e eficácia de drogas no CBD de forma sistemática, e um tratamento eficaz ainda não está disponível. O tratamento é sintomático e baseado na semelhança com outras doenças devido à escassez de estudos que abordem especificamente o CBD. O CBD parece não despertar o interesse em mais ensaios clínicos por sua baixa prevalência e confiabilidade no diagnóstico clínico.

Autophagy inhibitor 3-methyladenine could not modulate rotenone neurotoxicity in primary mesencephalic cell culture / El inhibidor de la autofagia 3-metiladenina no logra modular la neurotoxicidad de la rotenona en el cultivo primario de células mesencefálicas

Dysregulated autophagy, whether excessive or downregulated, has been thought to be associated with neurodegenerative disorders including Parkinson's disease. Accordingly, the present study was carried out to investigate whether 3-methyladenine, an autophagy inhibitor, can modulate the effects of rotenone on dopaminergic neurons in primary mesencephalic cell culture. Cultures were prepared from embryonic mouse mesencephala at gestation day 14. Four groups of cultures were treated on the 10th DIV for 48 h as follows: the first was kept as an untreated control, the second was treated with 3-methyladenine alone (1, 10, 100, 200 mM), the third was treated with 20 nM rotenone and the fourth was co-treated with 20 nM rotenone and 3-methyladenine (1, 10, 100, 200 mM). On the 12th DIV, cultured cells were stained immunohistochemically against tyrosine hydroxylase and culture media were used to measure the levels of lactate dehydrogenase. 3methyladenine had no effects on both the survival of dopaminergic neurons and the release of lactate dehydrogenase. Rotenone significantly decreased the number of dopaminergic neurons and increased the levels of lactate dehydrogenase in the culture media. When cultures concomitantly treated with 3-methyladenine and rotenone, 3-methyladenine had no effect against rotenone-induced dopaminergic cell damage and lactate dehydrogenase release into the culture medium. In conclusion, the autophagy inhibitor 3-methyladenine could not modulate rotenone-induced dopaminergic cell damage in primary mesencephalic cell culture.

Se estima que la autofagia desregulada, ya sea excesiva o con baja regulación, está asociada con trastornos neurodegenerativos, incluyendo la enfermedad de Parkinson. En consecuencia, el se realizó este estudio para investigar si la 3metiladenina, un inhibidor de la autofagia,puede modular los efectos de la rotenona en las neuronas dopaminérgicas en el cultivo primario de células mesencefálicas. Los cultivos se prepararon a partir de mesencéfalo de ratón embrionario el día 14 de gestación. Cuatro grupos de cultivos se trataron en el 10º DIV durante 48 h de la siguiente manera: el primer grupo se mantuvo como un control no tratado, el segundo se trató con 3-metiladenina sola (1, 10, 100, 200 mM), el tercer grupo se trató con rotenona 20 nM y el cuarto se trató conjuntamente con rotenona 20 nM y 3-metiladenina (1, 10, 100, 200 mM). En el 12º DIV; las células cultivadas fueron tratadas mediante tinción inmunohistoquímica en tirosina hidroxilasa y se usaron medios de cultivo para medir los niveles de lactato deshidrogenasa. La 3-metiladenina no tuvo efectos tanto en la supervivencia de las neuronas dopaminérgicas como en la liberación de lactato deshidrogenasa. La rotenona disminuyó significativamente el número de neuronas dopaminérgicas y se observó un aumento de los niveles de lactato deshidrogenasa en los medios de cultivo. Cuando los cultivos tratados concomitantemente con 3-metiladenina y rotenona, la 3metiladenina no tuvo efecto contra el daño celular dopaminérgico inducido por la rotenona y la liberación de lactato deshidrogenasa en el medio de cultivo. En conclusión, el inhibidor de la autofagia 3-metiladenina no moduló el daño celular dopaminérgico inducido por la rotenona en el cultivo celular mesencefálico primario.

O uso do cloridrato de piridoxina para induzir estro em cadelas / The use of pyridoxine chloridrate to induce estrus in female dogs

Os agonistas dopaminérgicos são utilizados para induzir estro em cadelas, pois atuam na síntese e liberação de prolactina. Objetivou-se avaliar o efeito da piridoxina como indutor de estro em cadelas por agir na neurotransmissão dopaminérgica. Foram selecionadas 40 cadelas em anestro, divididas em quatro grupos experimentais, tratadas com 10mg/kg/dia (G1) e 50mg/kg/dia (G2) de cloridrato de piridoxina, 5µg/kg/dia (G3) de cabergolina e grupo controle/placebo (G4) por até 20 dias. Foram realizadas citologias vaginais a cada 24h para acompanhamento do ciclo estral e análises hormonais (FSH, LH e PRL) no dia zero e 120h do início do tratamento. As cadelas do G3 (100%) manifestaram proestro após 12 dias de tratamento aproximadamente, tempo inferior aos demais grupos (P<0,05). Apenas uma cadela do G1 e uma do G2 ficaram gestantes contra oito fêmeas do G3 e nenhuma do G4 (P<0,05). As concentrações plasmáticas de prolactina foram reduzidas nas fêmeas do G2 e G3 (P<0,05). As demais avaliações hormonais não sofreram influência do tratamento (P>0,05). O cloridrato de piridoxina foi ineficiente para induzir estro em cadelas, mas foi capaz de suprimir a prolactina, de forma semelhante à cabergolina, quando utilizado na dose de 50mg/kg/dia.(AU)

Dopaminergic agonists are used to induce estrus in female dogs as they act in the synthesis and release of prolactin. The objective of this study was to evaluate the effect of pyridoxine as an inducer of estrus by acting on dopaminergic neurotransmission. A total of 40 female dogs in anestrous were divided into four experimental groups treated with 10mg/kg/day (G1) and 50mg/kg/day (G2) of pyridoxine hydrochloride, 5µg/kg/day (G3) of cabergoline and control group/placebo (G4) for up to 20 days. Vaginal cytologies were performed every 24h for follow-up of the estrous cycle and hormonal analyzes (FSH, LH and PRL) on day zero and 120 hours after the start of treatment. The female dogs from G3 (100%) showed proestrus after 12 days of treatment, less time than the other groups (P< 0.05). Only one female from G1 and one from G2 were pregnant against eight from G3 and none from G4 (P< 0.05). Plasma concentrations of prolactin were reduced by treatment in females from G2 and G3 (P< 0.05). The other hormonal evaluations were not influenced by the treatment (P> 0.05). Pyridoxine chloridrate was inefficient to induce estrus in female dogs but was able to suppress prolactin when used at a dose of 50mg/kg/day.(AU)

Resolution of headache after reduction of prolactin levels in hyperprolactinemic patients / Resolução de cefaleia após redução dos níveis de prolactina em pacientes com hiperprolactinemia

Abstract Prolactin (PRL) secreting adenomas are associated with high incidence of headache. The role of hyperprolactinemia in the headache context is not clear, nor is the effect of its treatment on headache. Methods: The present longitudinal study evaluated hyperprolactinemic patients (69), in terms of presence and characteristics of headache before and after hyperprolactinemia treatment. Results: Headache was reported by 45 (65.2%) patients, independent of the etiology of hyperprolactinemia. The migraine phenotype was the most prevalent (66.6%). Medications used in the treatment of headache not changed during the study. The first line of treatment of hyperprolactinemia was dopaminergic agonists. In the last reevaluation, PRL level under treatment was within the reference range in 54.7% of the cases, and it was observed complete or partial resolution of the headache in 75% of the cases. The median PRL at this time in patients with complete headache resolution was 17 ng/mL, in those who reported partial recovery was 21 ng/mL, and in those in whom the headache did not change was 66 ng/mL, with a significant difference between the group with complete headache resolution vs. the group with unchanged headache (p=0.022). In the cases with complete headache resolution, the median fall on PRL levels was 89% and in those cases with partial headache resolution 86%, both significantly different (p<0.001) from the fall in the cases with an unchanged headache. Conclusion: Data allow us to conclude that, in this series, in the majority of cases the reduction in the level of PRL was followe3d by cessation or relief of the pain.

Resumo Os adenomas secretores de prolactina (PRL) estão associados à alta incidência de cefaleia. O papel da hiperprolactinemia no contexto da dor de cabeça não está claro, nem o efeito da redução dos níveis da PRL na cefaleia. Métodos: O presente estudo longitudinal avaliou pacientes hiperprolactinêmicos (69), quanto à presença e às características da cefaleia antes e após o tratamento da hiperprolactinemia. Resultados: Cefaleia foi relatada por 45 (65,2%) pacientes, independente da etiologia da hiperprolactinemia. O fenótipo de enxaqueca foi mais prevalente (66,6%). Os medicamentos usados ​​no tratamento da cefaleia não foram alterados durante o estudo. A primeira linha de tratamento da hiperprolactinemia foram os agonistas dopaminérgicos. Na última reavaliação, o nível de PRL sob tratamento estava dentro da faixa de referência em 54,7% dos casos, observando-se resolução completa ou parcial da cefaleia em 75% dos casos. A mediana de PRL neste momento em pacientes com resolução completa da cefaleia foi de 17 ng/mL, nos que relataram recuperação parcial foi de 21 ng/mL, e naqueles em que a cefaleia não se alterou foi de 66 ng/mL, com uma diferença significativa entre o grupo com resolução completa da cefaleia versus o grupo com cefaleia inalterada (p=0,022). Nos casos com resolução completa da cefaleia, a queda mediana nos níveis de PRL foi de 89% e nos casos com resolução parcial de cefaleia de 86%, ambos significativamente diferentes (p<0,001) da queda nos casos com cefaleia inalterada. Conclusão: Os dados permitem concluir que, nesta série, na maioria dos casos, a redução do nível de PRL foi seguida pela cessação ou alívio da dor.

Effect of benzo(a)pyrene on dopaminergic neurons and α-synuclein in brain and its mechanism involved / 北京大学学报(医学版)

OBJECTIVE@#To analyze the effect of benzopyrene on the decrease of dopaminergic neurons, and the increase and aggregation of α-synuclein, which are the pathological features of Parkinson's disease, and to explore its possible mechanisms.@*METHODS@#Eight-month-old transgenic mice with human SNCA gene were randomly divided into a BaP-exposed group and a control group. BaP and solvent corn oil were injected intraperitoneally to BaP-exposed group and control group respectively, once a day for 60 days. The motor dysfunction of mice was tested by rotarod test. The effects of BaP on the decrease of dopaminergic neurons and increase and aggregation of α-synuclein were observed by immunohistochemistry and Western blot experiments respectively, and the expression of related mRNA was detected by quantitative real-time PCR (qRT-PCR). Twenty genes were tested in the study, mainly related to neurotransmitter transporter (2 genes), neurotransmitter receptor function (10 genes), cellular autophagy (5 genes), and α-synuclein aggregation and degradation (3 genes).@*RESULTS@#After BaP exposure, the movement time of the mice in the rotarod test was significantly reduced (P<0.05). The substantia nigra dopami-nergic neurons in the mice were significantly reduced, which was 62% of the control group (P<0.05), and the expression of α-synuclein in the midbrain increased, which was 1.36 times that of the control group (P<0.05). After BaP exposure, mRNA expressions of 14 genes in the midbrain of the mice were significantly down-regulated (P<0.05). Alpha-synuclein degradation and cell autophagy (5 genes), neuron transporters (2 genes), and neurotransmitter receptor functions (5 genes) were involved. The expression of one gene, Synphilin-1, was significantly up-regulated (P<0.01), which was related to α-synuclein aggregation.@*CONCLUSION@#BaP exposure not only inhibited function of neurotransmitter receptor and dopamine transporter, but also interfered cell autophagy, thereby hindering the degradation of α-synuclein, which could lead to decrease of dopaminergic neurons in substantia nigra and increase and aggregation of α-synuclein in midbrain, as the significant pathology of Parkinson's disease. Therefore, BaP exposure may increase the risk of Parkinson's disease.

Protective Effects of Gallic Acid on the MPTP-Mediated Dopaminergic Neurons Damage in Parkinson's Disease / 中国药学杂志

OBJECTIVE: To study the neuroprotective effects of gallic acid in animal models of Parkinson's disease (PD) and its related molecular mechanisms. METHODS: Thirty-six mice were randomly divided into control group, 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine(MPTP) group and gallic acid group. Mice in MPTP group and gallic acid group were given an intraperitoneal injection of 30 mg•kg-1 MPTP daily for 7 d. The mice in control group were given the same amount of normal saline at the same time. The mice in gallic acid group received oral administration of 200 mg•kg-1 gallic acid daily from the first day, gallic acid was administered continuously for 14 d, and mice in MPTP group and control group received the same amount of normal saline. After 7 d of drug administration, the behavioral function was evaluated by rod climbing test and suspension test. The expression of tyrosine hydroxylase(TH) in the substantia nigra and striatum were detected by immunohistochemistry. The number of apoptotic neurons in the substantia nigra were measured by TUNEL assay. SIRT3 mRNA levels were analyzed by qRT-PCR, and protein expression levels were detected by Western blot. RESULTS: Compared with the control group, the ability of motor coordination weakened, the TH expression levels decreased in the substantia nigra and striatum, the number of apoptotic neurons in the substantia nigra significantly increased, the SIRT3 mRNA and protein levels in the substantia nigra obviously declined, and the SOD2 protein expression also dramatically reduced in the MPTP group, the differences between the groups were all statistically significant (P<0.05). After treatment with gallic acid, the ability of motor coordination enhanced, the TH expression level elevated, the number of apoptotic neurons markedly reduced, SIRT3 mRNA and protein levels increased, and SOD2 protein expression also up-regulated in the gallic acid group. Compared with the MPTP group, the differences were all statistically significant (P<0.05). CONCLUSION: Gallic acid can improve the behavioral dysfunction and inhibit dopaminergic neurons damage in PD mice. The mechanism of action may be related to the up-regulation of SIRT3 gene expression.

Progress in Molecular Mechanisms and Cell Transplantation Therapy of Parkinson's Disease / 中国药学杂志

Neuron is the basic structure and functional unit of nervous system. Once the neurons are damaged or lost, the balance of neuroregulation will be destroyed and a series of nervous system diseases will be induced. Parkinson's disease (PD) is a kind of chronic neurodegenerative disease caused by selective loss of many dopaminergic neurons in the dense region of the substantia nigra in the ventral midbrain. At present, conventional drugs and adjuvant therapies can only relieve clinical symptoms to a certain extent, but cannot fundamentally delay the progress of the disease. With the rapid development of stem cells and reprogramming technologies around the world, cell transplantation to deal with neurodegenerative diseases including Parkinson's disease has become a new and potential therapy. This paper mainly summarizes the molecular mechanisms of Parkinson's disease, the preparation of autogenous dopaminergic neurons and the research progresses of dopaminergic neurons transplantation in the treatment of Parkinson's disease.

Role of sirt3 in molecular mechanism of melatonin protecting dopaminergic neurons in Parkinson' s disease / 中国药理学通报

Aim To investigate the role of SIRT3 in the molecular mechanism of melatonin protecting do-paminergic neurons in Parkinson' s disease ( PD). Methods Forty-eight mice were randomly divided into control group, model group and treatment group. The mice in treatment group received intraperitoneal injection of melatonin (10 mg • kg"1) and MPTP (30 mg • kg ~1). The mice in model group only received intraperitoneal injection of MPTP (30 mg • kg~1 ) , and the mice in control group received the same a-mount of normal saline. Melatonin was administered continuously for 14 days. The expressions of TH and lba-1 in substantia nigra were analyzed by immunohis-tochemistry. The levels of oxidative stress ( ROS, MDA, SOD) and inflammatory factors (TNF-a, IL-lp) in the midbrain were measured by ELISA. SIRT3 mRNA level was analyzed by qRT-PCR, and protein expression level was detected by immunocytochemistry assay and Western blot. Results Compared to control group, the TH expression decreased and Iba-1 expression increased in the substantia nigra, the oxidative stress and inflammatory injury in the midbrain were significantly enhanced, the SIRT3 mRNA and protein levels in the substantia nigra obviously declined, the SOD2 protein expression was also dramatically reduced, and the iNOS protein expression was elevated in model group; the differences between the groups were all statistically significant ( P < 0. 05 ). After treatment with melatonin, the TH expression increased, Iba-1 expression decreased, oxidative stress and inflammatory injury markedly decreased, SIRT3 mRNA and protein levels were elevated, SOD2 protein expression was up-regulated, and iNOS protein expression was down-regulated in treatment group. Compared to model group, the differences were all statistically significant ( P < 0.05). Conclusions Melatonin can counteract the damage of dopaminergic neurons by up-regulating the expression of SIRT3 in PD animal model. Its mechanisms of action are related to inhibiting microglia activation, and alleviating oxidative stress and inflammation injury.

Construction of mutant NDUFS7 plasmid and its effects on neural cells / 中国药科大学学报

@#To investigate the effects of NDUFS7 gene mutation on neurons, the mutant plasmid of pcDNA3.1(+)-NDUFS7 Q208STOP was constructed and transfected into differentiated SH-SY5Y cells. The effect of transfecting mutant plasmid on the viability of dopaminergic neural cells was detected by MTT assay. The effect of transfection of mutant plasmid on apoptosis was detected by Annexin Ⅴ-FITC/PI staining followed by flow cytometry assay. The changes in the expression levels of apoptosis-related proteins Bax and Bcl-2 in cells after transfection of mutant plasmid were detected by Western blot. The effects of transfection of mutant plasmid on the mitochondrial membrane potential in differentiated SH-SY5Y cells and the intervention effect of antioxidant Trolox were examined using JC-1 fluorescent probe. The intervention effect of Trolox on the apoptosis of differentiated SH-SY5Y cells transfected with mutant plasmid was detected by PI/Hoechst staining. The results showed that the subunit mutation of mitochondrial complex I in dopaminergic neurons could lead to decreased neuronal viability and increased apoptosis, while antioxidants could alleviate the abnormal mitochondrial membrane potential and apoptosis caused by transfection of mutant plasmids, suggesting that transfection of mutant plasmid of NDUFS7 gene could lead to apoptosis by causing abnormal mitochondrial function in dopaminergic neurons.

The therapeutic effect of quercetin on the transgenic PD drosophila model with LRRK2 mutation / 西安交通大学学报(医学版)

Objective: To study the therapeutic effect and mechanism of quercetin on Parkinson's disease (PD) model induced by a leucine-rich repeat kinase 2 (LRRK2) gene mutation. Methods: PD transgenic drosophila model Ddc-Gal4; UAS-LRRK2/G2019S was generated by Gal4/UAS hybridization and selectively expressed G2019S mutant LRRK2 in dopaminergic neurons. PD transgenic drosophila and control were fed with corn medium supplemented with quercetin in 1, 10 and 100 μmol/L for the treatment group, or with standard corn medium in PD model group and blank control group. The life span and locomotor ability were observed and compared between the quercetin treatment group and the PD drosophila model group. The brains of the drosophila were dissected and stained with TH immunofluorescence antibody to observe the survival rate of dopaminergic neurons. The brain tissues were also measured with Western blot to detect the protein expression levels of TH, GCLC, p-LRRK2, and p-p38MAPK. Results: The group treated with 10 μmol/L quercetin showed the best therapeutic effect on the prolongation of life span and improvement of locomotor ability compared with PD transgenic drosophila model without any treatment. The locomotor activity of drosophila was significantly improved at week 6 and the loss of dopaminergic neurons in the brain of the PD model drosophila was effectively diminished by quercetin. Quercetin also significantly lowered the level of phosphorylated LRRK2 in the PD transgenic drosophila compared with the PD model group (P<0.05), indicating the inhibiting effect of quercetin on the activity of LRRK2 kinase of the PD model. In addition, quercetin could activate the antioxidant-signaling pathway and inhibit the p38MAPK signaling pathway. Results: Quercetin can activate the antioxidant-signaling pathway and inhibit the LRRK2 kinase activity, which can further regulate MAPK signaling pathway and reduce the neurotoxicity of LRRK2 mutation and protect dopaminergic neurons in PD transgenic drosophila model.

Preventive effects of Topiramate on methylphenidate induced behavioral disorders / Efectos preventivos de topiramato en los trastornos del comportamiento inducidos por metilfenidato

Neuronal cell damage is often caused by prolonged misuse of Methylphenidate (MPH). Topiramate (TPM) carries neuroprotective properties but its assumed mechanism remains unclear. The present study evaluates in vivo role of various doses of TPM and its mechanism against MPH-induced motor activity and related behavior disorder. Thus, we used domoic acid (DOM), bicuculline (BIC), Ketamine (KET), Yohimibine (YOH) and Haloperidole (HAL) as AMPA/kainite, GABAA, NMDA, ɑ2 adrenergic and D2 of dopamine receptor antagonists respectively. Open Field Test (OFT), Elevated Plus Maze (EPM) and Forced Swim Test (FST) were used to study motor activity, anxiety and depression level. TPM (100 and 120 mg/kg) reduced MPH-induced rise and inhibited MPH-induced promotion in motor activity disturbance, anxiety and depression. Pretreatment of animals with KET, HAL, YOH and BIC inhibited TPM- improves anxiety and depression through the interacting with Dopaminergic, GABAA, NMDA and ɑ2-adrenergic receptors.

El daño a las células neuronales a menudo es causado por el uso prolongado de metilfenidato (MPH). El topiramato (TPM) tiene propiedades neuroprotectoras, pero su mecanismo de acción no es claro. El presente estudio evalúa el papel in vivo de varias dosis de TPM y su mecanismo contra la actividad motora inducida por MPH y el trastorno de comportamiento relacionado. Utilizamos ácido domoico (DOM), bicuculina (BIC), ketamina (KET), yohimbina (YOH) y haloperidol (HAL), así como antagonistas AMPA/kainato, GABAA, NMDA, ɑ2-adrenérgico y D2 dopaminérgicos, respectivamente. Se utilizaron las pruebas de campo abierto (OFT), elevación de laberinto (EPM) y natación forzada (FST) para estudiar la actividad motora, la ansiedad y el nivel de depresión. El TPM (100 y 120 mg/kg) redujo el aumento inducido por MPH e inhibió la promoción inducida por MPH en la alteración de la actividad motora, la ansiedad y la depresión. El tratamiento previo de animales con KET, HAL, YOH y BIC inhibió el TPM, mejora la ansiedad y la depresión a través de la interacción con los receptores dopaminérgicos, GABAA, NMDA y ɑ2-adrenérgico.

Delayed Treatment of Capsaicin Produces Partial Motor Recovery by Enhancing Dopamine Function in MPP⁺-lesioned Rats via Ciliary Neurotrophic Factor

Transient receptor potential vanilloid subtype 1 (TRPV1) on astrocytes prevents ongoing degeneration of nigrostriatal dopamine (DA) neurons in MPP⁺-lesioned rats via ciliary neurotrophic factor (CNTF). The present study determined whether such a beneficial effect of astrocytic TRPV1 could be achieved after completion of injury of DA neurons, rather than ongoing injury, which seems more relevant to therapeutics. To test this, the MPP⁺-lesioned rat model utilized here exhibited approximately 70~80% degeneration of nigrostriatal DA neurons that was completed at 2 weeks post medial forebrain bundle injection of MPP⁺. TRPV1 agonist, capsaicin (CAP), was intraperitoneally administered. CNTF receptor alpha neutralizing antibody (CNTFRαNAb) was nigral injected to evaluate the role of CNTF endogenously produced by astrocyte through TRPV1 activation on DA neurons. Delayed treatment of CAP produced a significant reduction in amphetamine-induced rotational asymmetry. Accompanying this behavioral recovery, CAP treatment increased CNTF levels and tyrosine hydroxylase (TH) activity in the substantia nigra pars compacta (SNpc), and levels of DA and its metabolites in the striatum compared to controls. Interestingly, behavioral recovery and increases in biochemical indices were not reflected in trophic changes of the DA system. Instead, behavioral recovery was temporal and dependent on the continuous presence of CAP treatment. The results suggest that delayed treatment of CAP increases nigral TH enzyme activity and striatal levels of DA and its metabolites by CNTF endogenously derived from CAP-activated astrocytes through TRPV1, leading to functional recovery. Consequently, these findings may be useful in the treatment of DA imbalances associated with Parkinson's disease.