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.

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.

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.

Acute Restraint Stress Augments 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Neurotoxicity via Increased Toxin Uptake into the Brain in C57BL/6 Mice / 神经科学通报·英文版

As an environmental risk factor, psychological stress may trigger the onset or accelerate the progression of Parkinson's disease (PD). Here, we evaluated the effects of acute restraint stress on striatal dopaminergic terminals and the brain metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which has been widely used for creating a mouse model of PD. Exposure to 2 h of restraint stress immediately after injection of a low dose of MPTP caused a severe loss of striatal dopaminergic terminals as indicated by decreases in the dopamine transporter protein and dopamine levels compared with MPTP administration alone. Both striatal 1-methyl-4-phenylpyridinium ion (MPP) and MPTP concentrations were significantly increased by the application of restraint stress. Striatal monoamine oxidase-B, which catalyzes the oxidation of MPTP to MPP, was not changed by the restraint stress. Our results indicate that the enhanced striatal dopaminergic terminal loss in the stressed mice is associated with an increase in the transport of neurotoxin into the brain.

Effect of TRPC6 knock-out on the mouse neuroinflammation induced by MPTP / 中国比较医学杂志

Objective To measure the level of microglia TRPC6 in mouse MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced neuroinflammation model and investigate its role in cytokine production and dopaminergic neuron damages. Methods Microglia were sorted by magnetic beads labeled with CD11b antibody and the level of TRPC6 in MPTP-induced neuroinflammation models was measured by western blotting. The proliferation of microglia and damages of dopaminergic neurons induced by MPTP were analyzed by immunofluorescence in CD11b-TRPC6 -/ - mice. Meanwhile, the expression of cryαB and cytokines in microglia was measured by western blotting and real-time quantitative PCR, respectively. Results The level of microglia TRPC6 in MPTP-induced neuroinflammation model was up-regulated. The expression of cryαB was increased and the cytokine level was down-regulated in the microglia in MPTP-injected CD11b-TRPC6 -/ - mice. Moreover, the dopaminergic neuron survival was improved in the MPTP-induced neuroinflammation model after TRPC6 knock-out in the microglia. Conclusions The expression of TRPC6 in microglia is up-regulated after MPTP injection, while in CD11b-TRPC6 -/ - mice the MPTP-induced cytokine expression is reduced, contributing to the improvement of dopaminergic neuron survival.

A High-fat Diet Induces a Loss of Midbrain Dopaminergic Neuronal Function That Underlies Motor Abnormalities

Movement defects in obesity are associated with peripheral muscle defects, arthritis, and dysfunction of motor control by the brain. Although movement functionality is negatively correlated with obesity, the brain regions and downstream signaling pathways associated with movement defects in obesity are unclear. A dopaminergic neuronal pathway from the substantia nigra (SN) to the striatum is responsible for regulating grip strength and motor initiation through tyrosine hydroxylase (TH) activity-dependent dopamine release. We found that mice fed a high-fat diet exhibited decreased movement in open-field tests and an increase in missteps in a vertical grid test compared with normally fed mice. This motor abnormality was associated with a significant reduction of TH in the SN and striatum. We further found that phosphorylation of c-Jun N-terminal kinase (JNK), which modulates TH expression in the SN and striatum, was decreased under excess-energy conditions. Our findings suggest that high calorie intake impairs motor function through JNK-dependent dysregulation of TH in the SN and striatum.

Traditional Chinese medicine for modern treatment of Parkinson's disease / 中国结合医学杂志

Parkinson's disease (PD) is a chronic and progressive degenerative disorder of brain commonly seen among the elderly. As conventionally medical therapy is of limited relief and potential side effects, complementary and alternative medicine (CAM) has attracted growing public and professional attention. Therapies such as acupuncture, musical/rhythmic therapy and deep brain stimulation have been gradually proved positively in clinic. In this review, we retrospected the scientifific or evidence-based-medicine advances of application and research for modern treatment of PD by CAM, especially traditional Chinese medicine in categories.

Protective effect of protocatechuic acid on midbrain dopaminergic neurons injured by 1-methyl-4-phenylpyridinium / 中草药

Objective: To investigate the effects of protocatechuic acid (PCA) on the midbrain dopaminergic neurons injured by 1-methyl-4-phenylpyridinium (MPP+). Methods: Midbrain neuron cells from KM mice pregnant 14 d were used in this experiment, and divided into control group, model group, low-, mid-, and high-dose (0.05, 0.1, and 0.5 mmol/L) groups. MTT method was used to determine the neuronal survival rate. The activity of lactate dehydrogenase (LDH) in culture, content of intracellular reactive oxygen species (ROS), activity of mitochondrial complex I, and mitochondrial membrane potential were further determined. Results: PCA can enhance the viability of dopaminergic neurons damaged by MPP+, reduce the release of LDH and the generation of ROS, increase the activity of the mitochondrial complex Ι, and prevent the reduction of mitochondrial membrane potential. Conclusion: PCA has the neroprotective effects against MPP+-induced damage of midbrain dopaminergic neurons.

Acupuncture points for treating Parkinson's disease based on animal studies / 中国结合医学杂志

Parkinson's disease (PD) is a well-known neurodegenerative disease caused by dopaminergic cell death in the nigrostriatal pathway. Recent studies have shown that acupuncture can be a potential therapy for the treatment of PD, but it is not clear which acupuncture points (acupoints) play major roles in reliving symptoms of PD. Yanglingquan (GB 34), Zusanli (ST 36), Fengfu (GV 16), Taichong (LR 3), Baihui (GV 20) and Dazhui (GV 14) acupoints have frequently been to investigate the effectiveness and action mechanism of acupuncture for treating PD, but it is not clear why they were selected. This review summarizes the current understanding of the acupoints for PD treatment based on Oriental medicine theories and on the accumulated findings from previous animal studies. The results of this study will be useful to development of a strategy for future research in this field.

Efficient Induction of Neural Precursor Cells from Fibroblasts Using Stromal Cell-Derived Inducing Activity

The direct lineage conversion of fibroblasts into neuronal or neural precursor cells (NPCs) has become a hot issue in recent years as an attractive approach in the field of stem cell regenerative medicine. In this study, we adopted the stromal feeder co-culture method during the early conversion period to enhance conversion efficiency. Stromal cells are often used in directed differentiation of dopaminergic (DA) neurons from pluripotent stem cells. We co-cultured rat embryonic fibroblasts (REFs) on γ-irradiated sonic hedgehog-overexpressing MS5 stromal (MS5-SHH) cells after transduction with Brn2, Ascl1, Myt1L, and BclxL-GFP (BAMXGFP) transcription factors to REFs. One week after co-culture, transduced cells (GFP+ cells) that proliferated on MS5-SHH cells were separated from MS5-SHH cells through a 40 µm cell strainer. Subsequently, the converted cells (GFP+ cells) were expanded on fibronectin-coated culture plates in NPC expansion medium. The induced NPCs (iNPCs) expressed NPC potential (NESTIN+/SOX2+) earlier than seen with non-co-culture methods and were efficiently differentiated into DA neurons by overexpression of Nurr1 and Foxa2 genes, which are specific transcription factors for midbrain DA neuron development. These observations indicated that direct conversion to NPCs using an MS5 stromal cells co-culture method is a suitable technique for efficient generation of iNPC/DA neurons from fibroblasts.

Effects of (−)-Sesamin on Memory Deficits in MPTP-lesioned Mouse Model of Parkinson's Disease

This study investigated the effects of (−)-sesamin on memory deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD). MPTP lesion (30 mg/kg/day, 5 days) in mice showed memory deficits including habit learning memory and spatial memory. However, treatment with (−)-sesamin (25 and 50 mg/kg) for 21 days ameliorated memory deficits in MPTP-lesioned mouse model of PD: (−)-sesamin at both doses improved decreases in the retention latency time of the passive avoidance test and the levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid, improved the decreased transfer latency time of the elevated plus-maze test, reduced the increased expression of N-methyl-D-aspartate (NMDA) receptor, and increased the reduced phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB). These results suggest that (−)-sesamin has protective effects on both habit learning memory and spatial memory deficits via the dopaminergic neurons and NMDA receptor-ERK1/2-CREB system in MPTP-lesioned mouse model of PD, respectively. Therefore, (−)-sesamin may serve as an adjuvant phytonutrient for memory deficits in PD patients.

CX3CR1 mediates the neuroprotective effect of triptolide on 1-methyl-4-phenylpyridinium-induced hemiparkinson rats / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the effect of triptolide on the inhibition of microglial activation in 1-methyl-4-phenyl pyridinium ( MPP+)-induced hemiparkinson disease rats.METHODS:The rat model of Parkinson disease was es-tablished by intranigral injection of MPP +.The rats were randomly divided into sham group, MPP+group, triptolide group and vehicle group.The survival of dopaminergic neurons was detected by the immunofluorescence of tyrosine hydroxylase ( TH) in the substantia nigra ( SN) .The activation of microglia was determined by immunofluorescence of OX-42 ( micro-glia marker) in the SN.The expression of chemokine receptor CX3CR1 in SN was measured by Western blotting.RE-SULTS:Intranigral injection of MPP+increased the fluorescence intensity of the microglial marker, and promoted DA neu-ron degenerative death.Immunohistological analysis showed that the OX-42 density was decreased (P<0.01) and tyrosine hydroxylase (TH) positive neurons were increased in the triptolide group (P<0.01).The expression of CX3CR1 was lower in triptolide group than that in model group (P<0.05).CONCLUSION:Triptolide may improve PA neurons func-tion in MPP+-induced rats through inhibiting CX3CR1 expression and microglial activation.

In vitro study of bone marrow mesenchymal stem cells differentiated into dopaminergic neuron-like calls / 国际生物医学工程杂志

Objective Bone marrow mesenchymal stem cells (BMSCs) were induced to differentiate to the special histological types of neurons in vitro.The morphological change of cells and positive expression of specific antigen on membrane were studied,and the function of connection between the induced BMSCs was also detected.The feasibility of BMSCs differentiate to the special histological types of neurons was investigated.Methods BMSCs were divided into group Ⅰ (induced with bFGF+GDNF),group Ⅱ (induced with bFGF+GDNF+WHI-P131 +Shh),and control group (no revulsive).The morphologic change of cells was observed,and the positive rate of neuron specific surface antigen and the content of dopamine were detected.Formation of mature synaptic structure was detected by immunohistochemical assay of postsynaptic density protein 95 (PSD-95) expression,and synaptic loop was shown by FM1-43 stain synaptic vesicles.Results By immunohistochemical staining,the positive rates of dopamine transporter (DAT) and tyrosine hydroxylase (TH) in group Ⅱ were significantly higher than those in group Ⅰ,and dopamine can been detected in cell culture supematant of group Ⅱ.After BMSCs was induced into dopamine neuron-like cells,number and length of cell protrusions,positive rate of PSD-95 and fluorescence intensity of FM1-43 in group Ⅱ were significantly higher than those of group Ⅰ.Conclusions There were no significant change in positive rate of neuron-specific surface markers,rate of cell survival and differentiation rate after BMSCs differentiated to dopaminergic neuron-like cells.The number and length of cell protrusions,content of dopamine in cell culture supematant,positive rate of dopaminergic neuron-specific surface antigen (DAT and TH),synaptic function index (positive rate of PSD-95 and fluorescence intensity of synaptic loop) of group Ⅱ were all significantly higher than that of group Ⅰ.

Heptachlor induced nigral dopaminergic neuronal loss and Parkinsonism-like movement deficits in mice

Epidemiological studies have suggested an association between pesticide exposure and Parkinson's disease. In this study, we examined the neurotoxicity of an organochlorine pesticide, heptachlor, in vitro and in vivo. In cultured SH-SY5Y cells, heptachlor induced mitochondria-mediated apoptosis. When injected into mice intraperitoneally on a subchronic schedule, heptachlor induced selective loss of dopaminergic neurons in the substantia nigra pars compacta. In addition, the heptachlor injection induced gliosis of microglia and astrocytes selectively in the ventral midbrain area. When the general locomotor activities were monitored by open field test, the heptachlor injection did not induce any gross motor dysfunction. However, the compound induced Parkinsonism-like movement deficits when assessed by a gait and a pole test. These results suggest that heptachlor can induce Parkinson's disease-related neurotoxicities in vivo.

Relationship between Microglial Activation and Dopaminergic Neuronal Loss in 6-OHDA-induced Parkinsonian Animal Model / 체질인류학회지

This study assessed the dynamics of morphological and immunophenotypic properties of activated microglia in a 6-hydroxydopamine (6-OHDA) induced Parkinsonian animal model. Neurodegeneration in the substantia nigra pars compacta (SNc) was induced by unilateral injection of 6-OHDA into the medial forebrain bundle. Parkinsonian animal model were sacrificed at 1, 2, 4 and 8 weeks after 6-OHDA injection. Changes in the functional activity of activated microglia were identified using different monoclonal antibodies: OX6 for major histocompatibility complex (MHC) class II, ED1 for phagocytic activity. Phagocytic microglia, characterized by ED1- or OX6-immunoreactivity, appeared in the SNc at 1 week after 6-OHDA injection, activated microglia selectively adhered to degenerating axons, dendrites and dopaminergic neuron somas in the SNc. This was followed by significant loss of these fibers and nigral dopaminergic neurons. Activation of microglia into phagocytic stage was most pronounced at 2 week after 6-OHDA injection and gradually subsided, but phagocytic microglia persisted until 8 weeks after 6-OHDA injection. Taken together, our results indicate that activated microglia is lead to persistently neuron cell death and promotes loss of dopaminergic neuron by degeneration of the dopaminergic neurons.

Effect of MMS2 in the process of angiotensin Ⅱ induced neural stem cells differentiated to dopaminergic neurons / 国际生物医学工程杂志

Objective To explore the possible effects of methyl methanesulfonate sensitive 2(MMS2)in the process of angiotensin Ⅱ inducing differentiation of neural stem cells (NSCs) into dopaminegic phenotype neurons. Methods NSCs were isolated from the brain of newborn rats and were cultured in the serum-free medium.Identification of neural precursor cells was done by Nestin immunocyt ochemical staining. Then the second generation of NSCs was divided into the following six groups: A, control; B, AⅡ; C, AT1 antagonist ZD7155; D, ZD7155+AⅡ; E, AT2 antagonist PD123319; F, PD123319+AⅡ. The detection of expression of MMS2 and TH mRNA level was done by real-time PCR. The silence of the expression of MMS2 in NSCs was brought about via the transfection of MMS2-siRNA, and then the NSCs were induced to differentiate into dopaminegic neurons. The expression of TH mRNA level in the cells of the groups after transfection was detected by real-time PCR. Results Nestin-positive cells were observed in suspended growth in the medium.Real-Time PCR revealed that the MMS2 and TH mRNA expression of group B and D were significantly higher than that of the control group(P<0.05), There was no significant difference in MMS2 and TH mRNA expression between group C, E, F and the control, respectively. Conclusion AⅡ increased the expression of MMS2 mRNA in NSCs and induced the differentiation of NSCs into DA neurons via AT2 recepter. MMS2 may play important roles in the process of angiotensin Ⅱ inducing NSCs to differentiate into dopaminergic neurons.

L-PDMP, Ganglioside Synthesis Enhancer Protects Dopaminergic Neurons from Death by Proteasomal Inhibition and the Accumulation of alpha-synuclein / 체질인류학회지

Gangliosides are components of the membranous constituents and abundant in the nervous system. And they are implicated in a wide range of biological activities including the regulation of cell proliferation, differentiation and lysosomal activity. But they have a diverse action to induce neuronal cell death by the interaction with some ligands. The interference of their biosynthesis is accompanied by the intracellular accumulation of unwanted and neurotoxic proteins and might underlie the neurodegeneration diseases including Parkinson's disease. However the mechanism has not been elucidated. In this study, we report that the enhancement of biosynthesis of ganglioside GD3 protects the intracellular accumulation of alpha-synuclein and neuronal death. PC12 cells, dopaminergic neurons are cultured with synthetic proteasomal inhibitor (PSI, Z-lle-Glu(OtBu)-Ala-Leu-al) and L-PDMP (GD3 synthetase enhancer, L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol). We found that the neuronal viability was recovered by L-PDMP from the proteasomal inhibition and also the expression of activated caspase-3 and PARP was reduced. L-PDMP decreased in the intracellular accumulation of alpha-synuclein. Interestingly, PSI induced the expression of ganglioside3 in PC12 cell. Our findings suggest that proteasomal inhibition may modulate the biosynthesis of GD3 and L-PDMP protects dopaminergic neurons from death by proteasomal inhibition and the accumulation of alpha-synuclein.

Advance in Mechanism of Differentiation of Dopaminergic Neurons from Neural Stem Cells(review) / 中国康复理论与实践

@#Parkinson's disease is a progressive neurodegenerative disorder in central nervous system caused by the loss of midbrain dopaminergic neurons. At present, dopaminergic neurons differentiated both in vivo and in vitro from neural stem cells act as an important cell source for the cell-replacement therapy of Parkinson's disease. This paper reviewed the major molecular mechanism, signaling pathway and important environment factors involved in differentiation of dopaminergic neurons from neural stem cells, based on the research findings in recent 10 years.

Neuroprotective Effect of Celecoxib against Degeneration of Dopaminergic Neurons in Rat Model of Parkinson Disease / 中国医科大学学报

Objective To observe the neuroprotective effect of celecoxib against degeneration of dopaminergic neurons caused by lipopolysaccharide in vivo.Methods The rat model of Parkinson disease(PD)was established by intranigral injection of lipopolysaccharide.Sprague-Dawley rats were randomly divided into control group,PD group,and celecoxib group.Behavioural changes were recorded,and the expressions of tyrosine hydroxylase(TH)and cyclooxygenase-2(COX-2)were determined by immunohistochmistry and Western blot.Results No behavioral change was found in control group.There was significant difference in the number of circling behavior between PD and celecoxib groups(196.90±9.52 vs 109.30±9.38,P＜0.01).The number of TH-positive cells and the expression of TH protein in rat substantia nigra were significantly higher in celecoxib group than in PD group(P＜0.01).Compared with PD group,the number of COX-2positive cells and the expression of COX-2 protein were significant lower in celecoxib group(P＜0.01).Conclusion Celecoxib has neuroprotective effect on the degeneration of dopaminergic neurons caused by lipopolysaccharide in vivo.

Effects of MPTP on spatial learning ability/memory and dopaminergic neurons in Nigra of senescence accelerated-prone 8 mice / 第二军医大学学报

Objective: To observe the effects of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) on the spatial learning ability/memory and dopaminergic neurons in the Nigra of senescence accelerated-prone 8 (SAMP8) mice. Methods: Three-month old male SAMP8 mice were injected with MPTP (36 mg/ kg,s. c.) for 5 days,and animals in the control group were injected with NS (36 ml/kg, s. c.) in the same manner. Morris water maze was used to examine the searching strategy, seeking-platform latency,and the swimming time in the aimed quadrant. Immunohistochemistry was used to observe the changes of TH-ir positive neurons in substantia nigra. Results: The number of TH-ir neurons in substantia nigra pars compacta was significantly reduced in MPTP group compared with the control group(P<0.01). Morris water maze showed that the searching strategy of animals in MPTP group was worse than in the control group, with the seeking-platform latency of MPTP mice significantly prolonged (P<0.01), the time spent in the aimed quadrant significantly decreased (P<0.01) and time in the opposite quadrant significantly prolonged (P<0.05). Conclusion: MPTP can cause damage to the dopaminergic neurons in the substantia nigra of SAMP8 mice,which is subsequently followed by deficit in the spatial learning and memory in the animals.