RESUMO
A comprehensive study of the functioning of antioxidant system in rats with rotenone-induced parkinsonism was conducted. The development of pathology led to inhibition of the majority of the studied antioxidant enzymes in the brain and blood serum of animals, which can be associated with decompensation of oxidative stress under conditions of prolonged mitochondrial dysfunction. These changes apparently make an important contribution into neuronal degeneration in the cerebral cortex and striatum and motor disorders in experimental animals.
Assuntos
Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Doença de Parkinson Secundária/enzimologia , Superóxido Dismutase/metabolismo , Animais , Antioxidantes/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Encéfalo/patologia , Catalase/genética , Expressão Gênica , Glutationa Peroxidase/genética , Glutationa Redutase/genética , Glutationa Transferase/genética , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Mitocôndrias/genética , Estresse Oxidativo , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/genética , Doença de Parkinson Secundária/patologia , Ratos , Ratos Wistar , Rotenona/toxicidade , Superóxido Dismutase/genéticaRESUMO
The depletion of dopamine in the striatum region and Lewy bodies are the hallmark characteristics of Parkinson's disease. The pathology also includes the upregulation of various Parkinson's disease (PARK) genes and kinases. Two such kinases, LRRK2 and GSK-3ß have been directly implicated in the formation of tau and alpha-synuclein proteins, causing PD. Hesperidin (HES) is a flavanone glycoside that has multiple therapeutic benefits including neuroprotective effects. In this study, we examined the neuroprotective effects of HES against 6-hydroxydopamine (6-OHDA) induced-neurotoxicity in the in-vitro and in-vivo model. Hesperidin significantly protected the SH-SY5Y cells' stress against 6-OHDA induced toxicity by downregulating biomarkers of oxidative stress. Furthermore, HES downregulated the kinases lrrk2 and gsk3ß along with casp3, casp9, and polg in the zebrafish model. The treatment with HES also improved the locomotor pattern of zebrafish that was affected by 6-OHDA. This study suggests that hesperidin could be a drug of choice in targeting kinases against a 6-OHDA model of PD.
Assuntos
Antiparkinsonianos/uso terapêutico , Quinase 3 da Glicogênio Sintase/biossíntese , Hesperidina/uso terapêutico , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/biossíntese , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson Secundária/tratamento farmacológico , Proteínas de Peixe-Zebra/biossíntese , Animais , Caspases/metabolismo , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Hidroxidopaminas , Locomoção/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Peixe-ZebraRESUMO
Mitochondrial dysfunction is considered to be one of the important pathogenesis in Parkinson's disease (PD). We previously showed that pyrroloquinoline quinone (PQQ) could protect SH-SY5Y cells and dopaminergic neurons from cytotoxicity and prevent mitochondrial dysfunction in rotenone-induced PD models. In the present study we investigated the mechanisms underlying the protective effects of PQQ in a mouse PD model, which was established by intraperitoneal injection of rotenone (3 mg·kg-1·d-1, ip) for 3 weeks. Meanwhile the mice were treated with PQQ (0.8, 4, 20 mg·kg-1·d-1, ip) right after rotenone injection for 3 weeks. We showed that PQQ treatment dose-dependently alleviated the locomotor deficits and nigral dopaminergic neuron loss in PD mice. Furthermore, PQQ treatment significantly diminished the reduction of mitochondria number and their pathological change in the midbrain. PQQ dose-dependently blocked rotenone-caused reduction in the expression of PGC-1α and TFAM, two key activators of mitochondrial gene transcription, in the midbrain. In rotenone-injured human neuroblastoma SH-SY5Y cells, PTMScan Direct analysis revealed that treatment with PQQ (100 µM) differentially regulated protein phosphorylation; the differentially expressed phosphorylated proteins included the signaling pathways related with adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway. We conducted Western blot analysis and confirmed that AMPK was activated by PQQ both in PD mice and in rotenone-injured SH-SY5Y cells. Pretreatment with AMPK inhibitor dorsomorphin (4 µM) significantly attenuated the protective effect and mitochondrial biogenesis by PQQ treatment in rotenone-injured SH-SY5Y cells. Taken together, PQQ promotes mitochondrial biogenesis in rotenone-injured mice and SH-SY5Y cells via activation of AMPK signaling pathway.
Assuntos
Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Biogênese de Organelas , Cofator PQQ/uso terapêutico , Doença de Parkinson Secundária/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Locomoção/efeitos dos fármacos , Masculino , Camundongos Endogâmicos ICR , Proteínas do Tecido Nervoso/efeitos dos fármacos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Fosforilação/efeitos dos fármacos , RotenonaRESUMO
Partial degeneration of dopaminergic neurons in the substantia nigra (SN), induces locomotor disability in animals but with time it is spontaneously compensated for by neurons surviving in the tissue by increasing their functional efficiency. Such compensation probably increases energy requirements and astrocyte support could be essential for this ability. We studied the effect of degeneration of dopaminergic neurons induced by the selective toxin 6-hydroxydopamine and/or death of 30% of astrocytes induced by chronic infusion of the glial toxin fluorocitrate on functioning of the mitochondrial electron transfer chain (ETC) complexes (Cxs) I, II, IV and their higher assembled forms, supercomplexes in the rat SN. Astrocyte death decreased Cx I and IV performance, while significantly increased the amount of Cx II protein SDHA, indicating system adaptation. After death of 50% of dopaminergic neurons in the SN, we observed increased mitochondrial Cxs performing, especially Cx I and IV in the remaining cells. It corresponded with reduction of behavioural deficits. Those results support the hypothesis that the compensatory ability of surviving neurons requires meeting their higher energetic demand by ETC. When astrocytes were defective, the neurons remaining after partial lesion were not able to enhance their functioning anymore and compensate for deficits. It proves in vivo that astrocytic support is important for compensatory potential of neurons in the SN. Neuro-glia cooperation is fundamental for compensation for early deficits in the nigrostriatal system.
Assuntos
Astrócitos/enzimologia , Neurônios Dopaminérgicos/enzimologia , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Epigênese Genética , Mitocôndrias/metabolismo , Doença de Parkinson Secundária/enzimologia , Animais , Astrócitos/patologia , Masculino , Mitocôndrias/patologia , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/patologia , Ratos , Ratos WistarRESUMO
We aim herein to assess the neurotoxic effects of subchronic Cu-exposition (0125%) for 6 weeks on dopaminergic and astroglial systems then locomotor activity in rats as well as the probable therapeutic efficiency of curcumin-I (30â¯mg/kg B.W.). We found that intoxicated rats showed a significant impairment of Tyrosine Hydroxylase (TH) within substantia nigra pars compacta (SNc), ventral tegmental area (VTA) and the striatal outputs together with loss expression of GFAP in these structures. This was linked with an evident decrease in locomotor performance. Co-treatment with curcumin-I inverted these damages and exhibited a significant neuroprotective potential, thus, both TH expression and locomotor performance was reinstated in intoxicated rats. These results prove a profound dopaminergic and astroglial damages following subchronic Cu exposition and new beneficial curative potential of curcumin against subchronic Cu-induced astroglial and dopaminergic neurotoxicity. Consequently, we suggest that Cu neurotoxicity may be strengthened in vivo firstly by attacking and weaking the astroglial system, and curcumin could be prized as a powerful and preventive target for the neurodegenerative diseases related metal element, especially Parkinson's disease.
Assuntos
Astrócitos/enzimologia , Cobre/toxicidade , Curcumina/farmacologia , Doença de Parkinson Secundária/tratamento farmacológico , Parte Compacta da Substância Negra/enzimologia , Tirosina 3-Mono-Oxigenase/biossíntese , Área Tegmentar Ventral/enzimologia , Animais , Astrócitos/patologia , Masculino , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Parte Compacta da Substância Negra/patologia , Ratos , Ratos Wistar , Área Tegmentar Ventral/patologiaRESUMO
Copper (Cu) is an important trace element for the organism survival, which ensures the normal functioning of different biosystems. However, excessive levels of this heavy metal are responsible for profound physiological alterations including the central nervous system. Numerous findings sustain the involvement of heavy metals, as an environmental risk factor such as copper (Cu), in the neuropathology of Parkinson's disease (PD) which is a chronic neurodegenerative disorder that principally affects the motor system. The classic and evident symptoms of PD namely rigidity, tardiness of movement, and difficulty with walking, result from progressive dopaminergic neurons death within substantia nigra. Whereas, few pharmacological trials have shown a beneficial role against Cu neurotoxicity, Aloe arborescens is one of the powerful medicinal plants with an array of therapeutic effects. Thus, we aimed through the present study, to evaluate the impact of acute Cu intoxication (10µg/g B.W. i.p) for 3days on the dopaminergic system and locomotor performance, together with the possible restorative effect of oral administration of aqueous extract of Aloe arborescens gel (AEAAG) (200mg/kg B.W.). By means of immunohistochemistry, we noted, in the Cu intoxicated rats, a significant loss of TH (tyrosine hydroxylase) expression within substantia nigra compacta (SNc), ventral tegmental area (VTA) and the subsequent striatal outputs, those alterations were correlated to behavioral abnormalities such as a severe drop of locomotor performance. While AEAAG administration to Cu intoxicated rats showed a noticeable beneficial effect; this potential was featured by a complete recovery of the TH expression and locomotor behavior deficiencies in the intoxicated rats. The present investigation have brought, on the one hand, an experimental evidence of an altered dopaminergic innervations following Cu intoxication and on the other hand, a new pharmacological property of Aloe arborescens that may be used as a neuroprotective plant for neurodegenerative disorders, such as PD, touching the dopaminergic system trigged by heavy metals.
Assuntos
Aloe/química , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson Secundária/terapia , Preparações de Plantas/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Cobre , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Intoxicação por Metais Pesados/terapia , Imuno-Histoquímica , Masculino , Atividade Motora/efeitos dos fármacos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Ratos , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Parkinson's disease is one of the most common neurodegenerative disease found in aged peoples. Plentiful studies are being conducted to find a suitable and effective cure for this disease giving special impetus on use of herbal plants. The study aimed at investigating the effect of ethanolic extract of Mucuna pruriens (Mp) on level of nitric oxide (NO) in paraquat (PQ) induced Parkinson's disease (PD) mouse model and its subsequent contribution to lipid peroxidation. Twenty four Swiss albino mice were divided into three groups; Control, PQ and PQ+Mp. PQ doses were given intraperitoneally, twice in a week and oral dose of ethanolic extract of Mp seed was given for 9 weeks. Nitrite content and lipid peroxidation was measured in all treated groups along with respective controls. RNA was isolated from the nigrostriatal tissue of control and the treated mice and was reverse transcribed into cDNA. PCR was performed to amplify iNOS mRNA and western blot analysis was performed to check its protein level. We had also perfused the mice in all treated group and performed Tyrosine hydroxylase (TH) and iNOS immunoreactivity in substantia nigra region of mice brain. PQ-treatment increased nitrite content, expression of iNOS and lipid peroxidation compared to respective controls. Mp treatment resulted in a significant attenuation of iNOS expression, nitrite content and lipid peroxidation demonstrating that it reduces nitric oxide in PQ-induced Parkinson's disease. Interestingly; we also observed that mRNA, protein expression and immunoreactivity of iNOS was significantly decreased after Mp treatment and TH immunoreactivity was significantly improved after the treatment of Mp. Our results demonstrated that Mp protects the dopaminergic neurons from the NO injury in substantia nigra.
Assuntos
Mucuna/química , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/biossíntese , Doença de Parkinson Secundária/enzimologia , Extratos Vegetais/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/enzimologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Paraquat , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/psicologia , RNA/biossíntese , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Substância Negra/efeitos dos fármacos , Substância Negra/enzimologia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Neutral sphingomyelinase is known to be implicated in growth arrest, differentiation, proliferation, and apoptosis. Although previous studies have reported the involvement of neutral sphingomyelinase in hippocampus physiopathology, its behavior in the hippocampus during Parkinson's disease remains undetected. In this study, we show an upregulation of inducible nitric oxide synthase and a downregulation of neutral sphingomyelinase in the hippocampus of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP-) induced mouse model of Parkinson's disease. Moreover, the stimulation of neutral sphingomyelinase activity with vitamin 1,25-dihydroxyvitamin D3 reduces specifically saturated fatty acid sphingomyelin by making sphingomyelin a less rigid molecule that might influence neurite plasticity. The possible biological relevance of the increase of neutral sphingomyelinase in Parkinson's disease is discussed.
Assuntos
Hipocampo/enzimologia , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Esfingomielina Fosfodiesterase/metabolismo , Animais , Calcitriol/farmacologia , Linhagem Celular , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Mediadores da Inflamação/metabolismo , Intoxicação por MPTP/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo II/metabolismo , Doença de Parkinson Secundária/patologia , Esfingomielinas/metabolismoRESUMO
Parkinson's disease (PD) is the second most common neurodegenerative disorder, but there are few treatments currently available. The autophagy pathway plays an important role in the pathogenesis of PD; modulating this pathway is considered to be a promising treatment strategy. Piperine (PIP) is a Chinese medicine with anti-inflammatory and antioxidant effects. The present study investigated the neuroprotective effects of PIP on rotenone-induced neurotoxicity in SK-N-SH cells, primary rat cortical neurons, and in a mouse model. Mice were administered rotenone (10mg/kg) for 6 weeks; PIP (25mg/kg, 50mg/kg) was subsequently administered for 4 weeks. We found that PIP treatment attenuated rotenone-induced motor deficits, and rescued the loss of dopaminergic neurons in the substantia nigra. PIP increased cell viability and restored mitochondrial functioning in SK-N-SH cells and primary neurons. In addition, PIP induced autophagy by inhibiting mammalian target of rapamycin complex 1(mTORC1) via activation of protein phosphotase 2A (PP2A). However, inhibiting PP2A activity with okadaic acid reduced these protective effects, suggesting that PP2A is a target of PIP. These findings demonstrate that PIP exerts neuroprotective effects in PD models via induction of autophagy, and may be an effective agent for PD treatment.
Assuntos
Alcaloides/farmacologia , Autofagia/efeitos dos fármacos , Benzodioxóis/farmacologia , Doença de Parkinson Secundária/tratamento farmacológico , Doença de Parkinson Secundária/enzimologia , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Proteína Fosfatase 2/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Sobrevivência Celular , Neurônios Dopaminérgicos/metabolismo , Humanos , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Fármacos Neuroprotetores , Ratos , Rotenona , Substância Negra/efeitos dos fármacosRESUMO
Parkinson's disease (PD) is the second most common progressive neurodegenerative movement disorder. Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the first ratelimiting step in the nicotinamide adenine dinucleotide (NAD+) biosynthetic pathway in mammals, is a substrate for NAD+dependent enzymes, such as sirtuin 1 (SIRT1), and contributes to cell fate decisions. However, the role of NAMPT in PD has remained to be fully elucidated. In the present study, PC12 cells were treated with the neurotoxin 6-hydroxydopamine (6OHDA) to establish an in vitro model of PD, following which an obvious inhibitory effect on the levels of NAMPT and NAD+ as well as the NAD+/NADH ratio was detected. In addition, preincubation with FK866, a highly specific NAMPT inhibitor, enhanced the inhibitory effects of 6OHDA on the viability of PC12, while preincubation with nicotinamide mononucleotide (NMN), am enzymatic product of NAMPT, had the opposite effect. Furthermore, it was revealed that NMN markedly attenuated 6OHDAinduced decreases in superoxide dismutase activity and glutathione levels, as well as 6OHDAinduced increases in malondialdehyde and lactate dehydrogenase in PC12 cells. Furthermore, 6OHDA significantly reduced SIRT1 activity in PC12 cells, which was inhibited by NMN. The pharmacological activator resveratrol also significantly inhibited 6OHDAmediated decreases in PC12 cell viability while reversing 6OHDAinduced decreases in SIRT1 levels. The results of the present study suggested that NMT protected against 6OHDAinduced decreases in PC12 cell viability, and that SIRT1 activation had a role in this process. Treatment with NMN to activate SIRT1 may represent a novel therapeutic strategy for treating PD.
Assuntos
Citocinas/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Oxidopamina/toxicidade , Doença de Parkinson Secundária/enzimologia , Sirtuína 1/metabolismo , Acrilamidas/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Citocinas/antagonistas & inibidores , L-Lactato Desidrogenase/metabolismo , Malondialdeído/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Células PC12 , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/tratamento farmacológico , Piperidinas/farmacologia , Ratos , Sirtuína 1/antagonistas & inibidoresRESUMO
Oxidative stress is a major cause of sporadic Parkinson's disease (PD). Here, we demonstrated that c-Abl plays an important role in oxidative stress-induced neuronal cell death. C-Abl, a nonreceptor tyrosine kinase, was activated in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced acute PD model. Conditional knockout of c-Abl in neurons or treatment of mice with STI571, a c-Abl family kinase inhibitor, reduced the loss of dopaminergic neurons and ameliorated the locomotive defects induced by short-term MPTP treatment. By combining the SILAC (stable isotope labeling with amino acids in cell culture) technique with other biochemical methods, we identified p38α as a major substrate of c-Abl both in vitro and in vivo and c-Abl-mediated phosphorylation is critical for the dimerization of p38α. Furthermore, p38α inhibition mitigated the MPTP-induced loss of dopaminergic neurons. Taken together, these data suggested that c-Abl-p38α signaling may represent a therapeutic target for PD.
Assuntos
Neurônios Dopaminérgicos/fisiologia , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Doença de Parkinson Secundária/enzimologia , Proteínas Proto-Oncogênicas c-abl/metabolismo , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Sequência de Aminoácidos , Animais , Morte Celular , Ativação Enzimática , Feminino , Células HEK293 , Humanos , Mesilato de Imatinib/farmacocinética , Mesilato de Imatinib/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Dados de Sequência Molecular , Estresse Oxidativo , Doença de Parkinson Secundária/patologia , Fosforilação , Ligação Proteica , Mapas de Interação de Proteínas , Multimerização Proteica , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Transdução de SinaisRESUMO
Activities of monoamine oxidases A and B were examined on the models of presymptomatic and early symptomatic stages of Parkinson's disease developed in mice treated with MPTP, a specific neurotoxin affecting dopaminergic neurons. Activity of monoamine oxidases A, the key enzyme of dopamine degradation, is increased in neuronal somas during the symptomatic stage, and it is augmented in the axons during both stages. Neuronal activity of monoamine oxidases A is higher during the symptomatic stage than that during the presymptomatic stage, which can explain depletion of intercellular dopamine and appearance of motor disturbances. Activity of monoamine oxidase B in the striatum is reduced during the presymptomatic stage, but returns to the control level during the symptomatic stage. Variation in monoamine oxidase activity seems to reflect the compensatory mechanisms triggered in degrading nigrostriatal dopaminergic system.
Assuntos
Monoaminoxidase/metabolismo , Doença de Parkinson Secundária/enzimologia , Substância Negra/enzimologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Doenças Assintomáticas , Corpo Estriado/enzimologia , Masculino , Camundongos Endogâmicos C57BL , Doença de Parkinson Secundária/induzido quimicamenteRESUMO
A modification of experimental model of Parkinson's disease is proposed presuming the stereotaxic infusion of rotenone solution using a special device into the cental part of substantia nigra (SN) pars compacta of adult Wistar rats. It was shown that 10 days after infusion of the neurotoxin the density of dopaminergic (DA) neurons in the infusion area drops nearly six-fold, to 20.2±3.2 neurons/mm2, with respect to the corresponding value in non-affected controlateral SN, 119.0±3.3 neurons/mm2. Electron microscopy has shown ultrastructural impairments in mitochondria of SN neurons in the infusion area displayed mainly as a cristae disarray. The absence of overall toxicity and selectivity of the brain tissue impairments provide an evidence that the proposed rotenone model modification is adequate and can be used to study the effects of DA neuronal degeneration typical of Parkinson's disease.
Assuntos
Neurônios Dopaminérgicos/patologia , Mitocôndrias/patologia , Doença de Parkinson Secundária/patologia , Substância Negra/patologia , Animais , Comportamento Animal , Contagem de Células , Modelos Animais de Doenças , Neurônios Dopaminérgicos/enzimologia , Injeções Intraventriculares , Masculino , Aprendizagem em Labirinto , Microscopia Eletrônica , Mitocôndrias/metabolismo , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Doença de Parkinson Secundária/fisiopatologia , Ratos , Ratos Wistar , Rotenona , Técnicas Estereotáxicas , Substância Negra/fisiopatologia , Tirosina 3-Mono-Oxigenase/metabolismo , DesacopladoresRESUMO
AIMS: Loss-of-function mutations in GBA1, which cause the autosomal recessive lysosomal storage disease, Gaucher disease (GD), are also a key genetic risk factor for the α-synucleinopathies, including Parkinson's disease (PD) and dementia with Lewy bodies. GBA1 encodes for the lysosomal hydrolase glucocerebrosidase and reductions in this enzyme result in the accumulation of the glycolipid substrates glucosylceramide and glucosylsphingosine. Deficits in autophagy and lysosomal degradation pathways likely contribute to the pathological accumulation of α-synuclein in PD. In this report we used conduritol-ß-epoxide (CBE), a potent selective irreversible competitive inhibitor of glucocerebrosidase, to model reduced glucocerebrosidase activity in vivo, and tested whether sustained glucocerebrosidase inhibition in mice could induce neuropathological abnormalities including α-synucleinopathy, and neurodegeneration. RESULTS: Our data demonstrate that daily systemic CBE treatment over 28 days caused accumulation of insoluble α-synuclein aggregates in the substantia nigra, and altered levels of proteins involved in the autophagy lysosomal system. These neuropathological changes were paralleled by widespread neuroinflammation, upregulation of complement C1q, abnormalities in synaptic, axonal transport and cytoskeletal proteins, and neurodegeneration. INNOVATION: A reduction in brain GCase activity has been linked to sporadic PD and normal aging, and may contribute to the susceptibility of vulnerable neurons to degeneration. This report demonstrates that systemic reduction of GCase activity using chemical inhibition, leads to neuropathological changes in the brain reminiscent of α-synucleinopathy. CONCLUSIONS: These data reveal a link between reduced glucocerebrosidase and the development of α-synucleinopathy and pathophysiological abnormalities in mice, and support the development of GCase therapeutics to reduce α-synucleinopathy in PD and related disorders.
Assuntos
Complemento C1q/metabolismo , Glucosilceramidase/antagonistas & inibidores , Inositol/análogos & derivados , Microglia/fisiologia , Agregação Patológica de Proteínas/enzimologia , alfa-Sinucleína/metabolismo , Animais , Autofagia , Transporte Axonal , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Ativação do Complemento , Glucosilceramidase/metabolismo , Inositol/farmacologia , Masculino , Camundongos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Agregação Patológica de Proteínas/induzido quimicamente , Proteínas/metabolismo , Transmissão SinápticaRESUMO
Hydrogen sulfide (H2S) was first proposed to be a neuromodulator in 1996. After that, multiple biological functions of H2S have been revealed. In brain, it regulates intracellular calcium, intracellular pH, and cAMP level in different brain cells via regulation of the functions of different proteins. In pathological situations, H2S produces anti-inflammatory, -oxidant, and -apoptotic effects, and therefore is potentially used to treat neurodegenerative diseases, especially Parkinson's disease (PD). In this chapter, we summarized the methods commonly used to create PD animal models followed by description of evaluations of PD pathology. The PD models described in this chapter included those caused by various neurotoxins like 6-hydroxydopamine, rotenone, and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Methods for examination of dopaminergic neuron loss and microglial activation in both substantia nigra and striatum are also described. The role of H2S and its therapeutic potentials are discussed in the last section of this chapter.
Assuntos
Sulfeto de Hidrogênio/farmacologia , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson Secundária/tratamento farmacológico , Animais , Encéfalo/enzimologia , Encéfalo/patologia , Modelos Animais de Doenças , Ensaios Enzimáticos , Humanos , Sulfeto de Hidrogênio/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson Secundária/enzimologia , Doença de Parkinson Secundária/patologiaRESUMO
Repeated systemic administration of the mitochondrial complex I inhibitor rotenone produces a rodent model of Parkinson's disease (PD). Mechanisms of relatively selective rotenone-induced damage to nigrostriatal dopaminergic neurons remain incompletely understood. According to the 'catecholaldehyde hypothesis,' buildup of the autotoxic dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL) contributes to PD pathogenesis. Vesicular uptake blockade increases DOPAL levels, and DOPAL is detoxified mainly by aldehyde dehydrogenase (ALDH). We tested whether rotenone interferes with vesicular uptake and intracellular ALDH activity. Endogenous and F-labeled catechols were measured in PC12 cells incubated with rotenone (0-1000 nM, 180 min), without or with F-dopamine (2 µM) to track vesicular uptake and catecholamine metabolism. Rotenone dose dependently increased DOPAL, F-DOPAL, and 3,4-dihydroxyphenylethanol (DOPET) levels while decreasing dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels and the ratio of dopamine to the sum of its deaminated metabolites. In test tubes, rotenone did not affect conversion of DOPAL to DOPAC by ALDH when NAD(+) was supplied, whereas the direct-acting ALDH inhibitor benomyl markedly increased DOPAL and decreased DOPAC concentrations in the reaction mixtures. We propose that rotenone builds up intracellular DOPAL by decreasing ALDH activity and attenuating vesicular sequestration of cytoplasmic catecholamines. The results provide a novel mechanism for selective rotenone-induced toxicity in dopaminergic neurons. We report that rotenone, a mitochondrial complex I inhibitor that produces an animal model of Parkinson's disease, increases intracellular levels of the toxic dopamine metabolite 3,4-dihydroxyphenyl-acetaldehyde (DOPAL), via decreased DOPAL metabolism by aldehyde dehydrogenase (ALDH) and decreased vesicular sequestration of cytoplasmic dopamine by the vesicular monoamine transporter (VMAT). The results provide a novel mechanism for rotenone-induced toxicity in dopaminergic neurons.
Assuntos
Aldeído Desidrogenase/metabolismo , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/enzimologia , Rotenona/farmacologia , Desacopladores/farmacologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Neoplasias Encefálicas/metabolismo , Dopamina/metabolismo , Complexo I de Transporte de Elétrons/efeitos dos fármacos , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos , NAD/metabolismo , Células PC12 , RatosRESUMO
BACKGROUND: Even with numerous studies the cause of Parkinson's disease (PD) remains elusive. It has been hypothesized that interactions between genetic and environmental factors may play an important role in the pathogenesis of PD. OBJECTIVES: To examine the gene-gene and gene-environment interaction on PD risk with respect to gene polymorphism of cytochrome P450 2D6 (CYP2D6) and glutathione S-transferases pi 1 (GSTP1), organochlorine pesticides (OCPs) and metals. METHODS: This study included 70 patients of PD and 100 age-matched controls. The restriction fragment length polymorphism was used for analysis of genetic polymorphism. OCPs and serum metal levels were estimated by using gas chromatography and an autoanalyser respectively. RESULTS: The CYP2D6*4 mt and GSTP1 *B allelic variants were significantly associated with increase in PD risk. We found a statistically significant difference in ß -hexachlorocyclohexane (ß-HCH), dieldrin, 1,1-dichloro-2,2-bis(pchlorophenyl) ethylene (pp'-DDE) and copper levels between the patients and controls. We found significantly high levels of ß-HCH, dieldrin and pp'-DDE in the CYP2D6*4 mt allelic variants, ß-HCH and pp'-DDE in the GSTP1*B allelic variants and dieldrin in the GSTP1*C allelic variants when comparing CYP2D6*4 non-mt, GSTP1 non-*B and GSTP1 non-*C allelic variants in patients of PD respectively. CONCLUSION: This study demonstrates that the CYP2D6*4 and GSTP1 genes may be considered as candidate genes for PD and they may also interact with ß- HCH, dieldrin and pp'-DDE to influence the risk for PD.
Assuntos
Epistasia Genética , Interação Gene-Ambiente , Doença de Parkinson Secundária/genética , Doença de Parkinson/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP2D6/metabolismo , Feminino , Frequência do Gene , Predisposição Genética para Doença , Glutationa S-Transferase pi/genética , Glutationa S-Transferase pi/metabolismo , Humanos , Hidrocarbonetos Clorados/efeitos adversos , Hidrocarbonetos Clorados/sangue , Masculino , Metais/efeitos adversos , Metais/sangue , Pessoa de Meia-Idade , Doença de Parkinson/sangue , Doença de Parkinson/diagnóstico , Doença de Parkinson/enzimologia , Doença de Parkinson Secundária/sangue , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/diagnóstico , Doença de Parkinson Secundária/enzimologia , Praguicidas/efeitos adversos , Praguicidas/sangue , Fenótipo , Fatores de RiscoRESUMO
Cardiac sympathetic neurodegeneration and dysautonomia affect patients with sporadic and familial Parkinson's disease (PD) and are currently proposed as prodromal signs of PD. We have recently developed a nonhuman primate model of cardiac dysautonomia by iv 6-hydroxydopamine (6-OHDA). Our in vivo findings included decreased cardiac uptake of a sympathetic radioligand and circulating catecholamines; here we report the postmortem characterization of the model. Ten adult rhesus monkeys (5-17 yrs old) were used in this study. Five animals received 6-OHDA (50 mg/kg i.v.) and five were age-matched controls. Three months post-neurotoxin the animals were euthanized; hearts and adrenal glands were processed for immunohistochemistry. Quantification of immunoreactivity (ir) of stainings was performed by an investigator blind to the treatment group using NIH ImageJ software (for cardiac bundles and adrenals, area above threshold and optical density) and MBF StereoInvestigator (for cardiac fibers, area fraction fractionator probe). Sympathetic cardiac nerve bundle analysis and fiber area density showed a significant reduction in global cardiac tyrosine hydroxylase-ir (TH; catecholaminergic marker) in 6-OHDA animals compared to controls. Quantification of protein gene protein 9.5 (pan-neuronal marker) positive cardiac fibers showed a significant deficit in 6-OHDA monkeys compared to controls and correlated with TH-ir fiber area. Semi-quantitative evaluation of human leukocyte antigen-ir (inflammatory marker) and nitrotyrosine-ir (oxidative stress marker) did not show significant changes 3 months post-neurotoxin. Cardiac nerve bundle α-synuclein-ir (presynaptic protein) was reduced (trend) in 6-OHDA treated monkeys; insoluble proteinase-K resistant α-synuclein (typical of PD pathology) was not observed. In the adrenal medulla, 6-OHDA monkeys had significantly reduced TH-ir and aminoacid decarboxylase-ir. Our results confirm that systemic 6-OHDA dosing to nonhuman primates induces cardiac sympathetic neurodegeneration and loss of catecholaminergic enzymes in the adrenal medulla, and suggests that this model can be used as a platform to evaluate disease-modifying strategies aiming to induce peripheral neuroprotection.
Assuntos
Fibras Autônomas Pós-Ganglionares/patologia , Doença de Parkinson Secundária/patologia , Medula Suprarrenal/enzimologia , Medula Suprarrenal/patologia , Animais , Descarboxilases de Aminoácido-L-Aromático/metabolismo , Fibras Autônomas Pós-Ganglionares/enzimologia , Células Cromafins/enzimologia , Modelos Animais de Doenças , Feminino , Coração/inervação , Macaca mulatta , Masculino , Miocárdio/enzimologia , Degeneração Neural/enzimologia , Oxidopamina , Doença de Parkinson Secundária/enzimologia , Simpatectomia , Tirosina 3-Mono-Oxigenase/metabolismo , alfa-Sinucleína/metabolismoRESUMO
The 6-Hydroxydopamine (6-OHDA) rat model of Parkinson's disease is essential for a better understanding of the pathological processes underlying the human disease and for the evaluation of promising therapeutic interventions. This work evaluated whether a single striatal injection of 6-OHDA causes progressive apoptosis of dopamine (DA) neurons and activation of glycogen synthase kinase 3ß (GSK-3ß) and caspase-3 in the substantia nigra compacta (SNc). The loss of DA neurons was shown by three neuron markers; tyrosine hydroxylase (TH), NeuN, and ß-III tubulin. Apoptosis activation was determined using Apostain and immunostaining against cleaved caspase-3 and GSK-3ß pY216. We also explored the possibility that cleaved caspase-3 is produced by microglia and astrocytes. Our results showed that the 6-OHDA caused loss of nigral TH(+) cells, progressing mainly in rostrocaudal and lateromedial directions. In the neostriatum, a severe loss of TH(+) terminals occurred from day 3 after lesion. The disappearance of TH(+) cells was associated with a decrease in NeuN and ß-III tubulin immunoreactivity and an increase in Apostain, cleaved caspase-3, and GSK-3ß pY216 in the SNc. Apostain immunoreactivity was observed from days 3 to 21 postlesion. Increased levels of caspase-3 immunoreactivity in TH(+) cells were detected from days 1 to 15, and the levels then decreased to day 30 postlesion. The cleaved caspase-3 also collocated with microglia and astrocytes indicating its participation in glial activation. Our results suggest that caspase-3 and GSK-3ß pY216 activation might participate in the DA cell death and that the active caspase-3 might also participate in the neuroinflammation caused by the striatal 6-OHDA injection.
Assuntos
Apoptose , Caspase 3/metabolismo , Neurônios Dopaminérgicos/enzimologia , Quinase 3 da Glicogênio Sintase/metabolismo , Doença de Parkinson Secundária/enzimologia , Substância Negra/enzimologia , Animais , Antígenos Nucleares/metabolismo , Citoesqueleto/metabolismo , Ativação Enzimática , Glicogênio Sintase Quinase 3 beta , Masculino , Proteínas do Tecido Nervoso/metabolismo , Oxidopamina , Doença de Parkinson Secundária/induzido quimicamente , Ratos , Ratos Wistar , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Studies have suggested that cognitive deficits can precede motor alterations in Parkinson's disease (PD). However, in general, classic animal models are based on severe motor impairment after one single administration of neurotoxins, and thereby do not express the progressive nature of the pathology. A previous study showed that the repeated administration with a low dose (0.1mg/kg) of the monoamine depleting agent reserpine induces a gradual appearance of motor signs of pharmacological parkinsonism in rats. Here, we showed this repeated treatment with reserpine induced a memory impairment (evaluated by the novel object recognition task) before the gradual appearance of the motor signs. Additionally, these alterations were accompanied by decreased tyrosine hydroxylase (TH) striatal levels and reduced number of TH+ cells in substantia nigra pars compacta (SNpc). After 30 days without treatment, reserpine-treated animals showed normal levels of striatal TH, partial recovery of TH+ cells in SNpc, recovery of motor function, but not reversal of the memory impairment. Furthermore, the motor alterations were statistically correlated with decreased TH levels (GD, CA1, PFC and DS) and number of TH+ cells (SNpc and VTA) in the brain. Thus, we extended previous results showing that the gradual appearance of motor impairment induced by repeated treatment with a low dose of reserpine is preceded by short-term memory impairment, as well as accompanied by neurochemical alterations compatible with the pathology of PD.