Asymmetric Opening of Mitochondrial Permeability Transition Pore in Mouse Brain Hemispheres: A Link to the Mitochondrial Calcium Uniporter Complex

Abstract The prolonged entry of large amounts of calcium into the mitochondria through the mitochondrial calcium uniporter complex (MCUC) may cause the permeability transition pore (mPTP) to open, which contributes to the pathogenesis of several diseases. Tissue-specific differences in mPTP opening due to variable expression of MCUC components may contribute to disease outcomes. We designed this study to determine differential mPTP opening in mitochondria isolated from different regions of mouse brain and kidney and to compare it with the expression of MCUC components. mPTP opening was measured using mitochondria isolated from the left/right brain hemispheres (LH/RH, respectively) and from kidney cortex/medulla, while the expression level of MCUC components was assessed from total cellular RNA. Interestingly, LH mitochondria showed less calcium-induced mPTP opening as compared to RH mitochondria at two different calcium concentrations. Conversely, mPTP opening was similar in the renal cortex and renal medulla mitochondria. However, the kidney mitochondria demonstrated bigger and faster mPTP opening as compared to the brain mitochondria. Furthermore, asymmetric mPTP opening in the LH and RH mitochondria was not associated with the expression of MCUC components. In brief, this study demonstrates thus far unreported asymmetric mPTP opening in mouse brain hemispheres that is not associated with the mRNA levels of MCUC components.

Study on the mechanism of Wuzi-Yanzong-Wan-medicated serum interfering with the mitochondrial permeability transition pore in the GC-2 cell induced by atractyloside / 中国天然药物

Wuzi-Yanzong-Wan (WZYZW) is a classic prescription for male infertility. Our previous investigation has demonstrated that it can inhibit sperm apoptosis via affecting mitochondria, but the underlying mechanisms are unclear. The purpose of the present study was to explore the actions of WZYZW on mitochondrial permeability transition pore (mPTP) in mouse spermatocyte cell line (GC-2 cells) opened by atractyloside (ATR). At first, WZYZW-medicated serum was prepared from rats following oral administration of WZYZW for 7 days. GC-2 cells were divided into control group, model group, positive group, as well as 5%, 10%, 15% WZYZW-medicated serum group. Cyclosporine A (CsA) was used as a positive control. 50 μmol·L-1 ATR was added after drugs incubation. Cell viability was assessed using CCK-8. Apoptosis was detected using flow cytometry and TUNEL method. The opening of mPTP and mitochondrial membrane potential (MMP) were detected by Calcein AM and JC-1 fluorescent probe respectively. The mRNA and protein levels of voltage-dependent anion channel 1 (VDAC1), cyclophilin D (CypD), adenine nucleotide translocator (ANT), cytochrome C (Cyt C), caspase 3, 9 were detected by RT-PCR (real time quantity PCR) and Western blotting respectively. The results demonstrated that mPTP of GC-2 cells was opened after 24 hours of ATR treatment, resulting in decreased MMP and increased apoptosis. Pre-protection with WZYZ-medicated serum and CsA inhibited the opening of mPTP of GC-2 cells induced by ATR associated with increased MMP and decreased apoptosis. Moreover, the results of RT-qPCR and WB suggested that WZYZW-medicated serum could significantly reduce the mRNA and protein levels of VDAC1 and CypD, Caspase-3, 9 and CytC, as well as a increased ratio of Bcl/Bax. However, ANT was not significantly affected. Therefore, these findings indicated that WZYZW inhibited mitochondrial mediated apoptosis by attenuating the opening of mPTP in GC-2 cells. WZYZW-medicated serum inhibited the expressions of VDAC1 and CypD and increased the expression of Bcl-2, which affected the opening of mPTP and exerted protective and anti-apoptotic effects on GC-2 cell induced by ATR.

The effect of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) on mice myocardial morphology / O efeito do 1-metil-4-fenil-1, 2, 3, 6 tetrahidropiridina (MPTP) na morfologia do miocárdio de camundongo

Studies have demonstrated sympathetic cardiac denervation in the MPTP mouse model. MPTP toxicity causes sympathetic nerve damage and depletion of heart norepinephrine. Previous evaluations of impairments in heart innervation have been based on imaging, electrophysiological and biochemical methods. However, these studies lacked information that can be obtained from morphoquantitative analyses. Thus, this study aimed to apply a design-based stereological method for evaluating the morphoquantitative alterations of myocardium following treatment with the neurotoxin MPTP in the C57/BL mouse. Our results showed that MPTP reduced the number of cardiomyocytes in the left ventricle.(AU)

Estudos têm demonstrado a desnervação simpática cardíaca no modelo da administração do MPTP em camundongo. A toxicidade do MPTP causa lesão ao nervo simpático e depleção da norepinefrina. As avaliações dos danos na inervação do coração são baseadas em métodos de imagem, eletrofisiológico e bioquímico. Contudo, estes estudos carecem de informações provenientes de análises morfoquantitativas. Assim, objetivou-se aplicar métodos estereológicos para avaliar as alterações morfoquantitativas do miocárdio após o tratamento com a neurotoxina MPTP no camundongo C57/BL. Nossos resultados mostraram que o MPTP causa redução no número de cardiomiócitos no ventrículo esquerdo.(AU)

Neuroprotective Effect of β-Lapachone in MPTP-Induced Parkinson's Disease Mouse Model: Involvement of Astroglial p-AMPK/Nrf2/HO-1 Signaling Pathways

Parkinson's disease is a neurodegenerative disease characterized by the progressive loss of dopaminergic neurons within the substantia nigra pars compacta. In the present study, we investigated whether β-Lapachone (β-LAP), a natural naphthoquinone compound isolated from the lapacho tree (Tabebuia avellanedae), elicits neuroprotective effects in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. β-LAP reduced the tyrosine hydroxylase (TH)-immuno-reactive fiber loss induced by MPTP in the dorsolateral striatum, and alleviated motor dysfunction as determined by the rotarod test. In addition, β-LAP protected against MPTP-induced loss of TH positive neurons, and upregulated B-cell lymphoma 2 protein (Bcl-2) expression in the substantia nigra. Based on previous reports on the neuroprotective role of nuclear factor-E2-related factor-2 (Nrf2) in neurodegenerative diseases, we investigated whether β-LAP induces upregulation of the Nrf2-hemeoxygenae-1 (HO-1) signaling pathway molecules in MPTP-injected mouse brains. Western blot and immunohistochemical analyses indicated that β-LAP increased HO-1 expression in glial fibrillary acidic protein-positive astrocytes. Moreover, β-LAP increased the nuclear translocation and DNA binding activity of Nrf2, and the phosphorylation of upstream adenosine monophosphate-activated protein kinase (AMPK). β-LAP also increased the localization of p-AMPK and Nrf2 in astrocytes. Collectively, our data suggest that β-LAP exerts neuroprotective effect in MPTP-injected mice by upregulating the p-AMPK/Nrf2/HO-1 signaling pathways in astrocytes.

Abnormal Mitochondria in a Non-human Primate Model of MPTP-induced Parkinson's Disease: Drp1 and CDK5/p25 Signaling

Mitochondria continuously fuse and divide to maintain homeostasis. An impairment in the balance between the fusion and fission processes can trigger mitochondrial dysfunction. Accumulating evidence suggests that mitochondrial dysfunction is related to neurodegenerative diseases such as Parkinson's disease (PD), with excessive mitochondrial fission in dopaminergic neurons being one of the pathological mechanisms of PD. Here, we investigated the balance between mitochondrial fusion and fission in the substantia nigra of a non-human primate model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD. We found that MPTP induced shorter and abnormally distributed mitochondria. This phenomenon was accompanied by the activation of dynamin-related protein 1 (Drp1), a mitochondrial fission protein, through increased phosphorylation at S616. Thereafter, we assessed for activation of the components of the cyclin-dependent kinase 5 (CDK5) and extracellular signal-regulated kinase (ERK) signaling cascades, which are known regulators of Drp1(S616) phosphorylation. MPTP induced an increase in p25 and p35, which are required for CDK5 activation. Together, these findings suggest that the phosphorylation of Drp1(S616) by CDK5 is involved in mitochondrial fission in the substantia nigra of a non-human primate model of MPTP-induced PD.

Protective Effect of Right Ventricular Mitochondrial Damage by Cyclosporine A in Monocrotaline-induced Pulmonary Hypertension

BACKGROUND AND OBJECTIVES: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). METHODS: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. RESULTS: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. CONCLUSIONS: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.

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.

MPTP-induced vulnerability of dopamine neurons in A53T α-synuclein overexpressed mice with the potential involvement of DJ-1 downregulation

Familial Parkinson's disease (PD) has been linked to point mutations and duplication of the α-synuclein (α-syn) gene. Mutant α-syn expression increases the vulnerability of neurons to exogenous insults. In this study, we developed a new PD model in the transgenic mice expressing mutant hemizygous (hemi) or homozygous (homo) A53T α-synuclein (α-syn Tg) and their wildtype (WT) littermates by treatment with sub-toxic (10 mg/kg, i.p., daily for 5 days) or toxic (30 mg/kg, i.p., daily for 5 days) dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Tyrosine hydroxylase and Bcl-2 levels were reduced in the α-syn Tg but not WT mice by sub-toxic MPTP injection. In the adhesive removal test, time to remove paper was significantly increased only in the homo α-syn Tg mice. In the challenging beam test, the hemi and homo α-syn Tg mice spent significantly longer time to traverse as compared to that of WT group. In order to find out responsible proteins related with vulnerability of mutant α-syn expressed neurons, DJ-1 and ubiquitin enzyme expressions were examined. In the SN, DJ-1 and ubiquitin conjugating enzyme, UBE2N, levels were significantly decreased in the α-syn Tg mice. Moreover, A53T α-syn overexpression decreased DJ-1 expression in SH-SY5Y cells. These findings suggest that the vulnerability to oxidative injury such as MPTP of A53T α-syn mice can be explained by downregulation of DJ-1.

Capsaicin prevents degeneration of dopamine neurons by inhibiting glial activation and oxidative stress in the MPTP model of Parkinson's disease

The effects of capsaicin (CAP), a transient receptor potential vanilloid subtype 1 (TRPV1) agonist, were determined on nigrostriatal dopamine (DA) neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease (PD). The results showed that TRPV1 activation by CAP rescued nigrostriatal DA neurons, enhanced striatal DA functions and improved behavioral recovery in MPTP-treated mice. CAP neuroprotection was associated with reduced expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β) and reactive oxygen species/reactive nitrogen species from activated microglia-derived NADPH oxidase, inducible nitric oxide synthase or reactive astrocyte-derived myeloidperoxidase. These beneficial effects of CAP were reversed by treatment with the TRPV1 antagonists capsazepine and iodo-resiniferatoxin, indicating TRPV1 involvement. This study demonstrates that TRPV1 activation by CAP protects nigrostriatal DA neurons via inhibition of glial activation-mediated oxidative stress and neuroinflammation in the MPTP mouse model of PD. These results suggest that CAP and its analogs may be beneficial therapeutic agents for the treatment of PD and other neurodegenerative disorders that are associated with neuroinflammation and glial activation-derived oxidative damage.

Effect of Baichanting Compound on Dopamine Contents in Parkinson's Disease Model Mice / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Baichanting Compound (BC) on dopamine (DA) in striatum of Parkinson's disease (PD) mice, and to screen the optimal component proportion.</p><p><b>METHODS</b>The PD model was established in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced C57BL/6 mice. By using uniform design, they were intervened by three extracts of BC in different proportions [Acanthopanax senticosus extract (X1): white peony root extract (X2): Uncaria rhynchophylla extract (X3) = 30.00: 34.92: 82.50, 48.00: 19.98: 72.19, 18.00: 44.88: 61.88, 36.00: 29.94: 51.56, 54.00: 15.00: 41.25, 24.00: 39.90: 30.94, 42.00: 24.96: 20.63). Equal volume of 5% carboxymethylcellulose sodium was administered to mice in the model group and the normal group by gastrogavage. All medication was lasted for 20 successive days. The dopamine (DA) content was determined by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS). Except 10 in the normal group, 20 PD model mice were screened and divided into the model group and the BC group (with the optimal proportion) according to random digit table. BC extract in optimal proportion was administered to mice in the BC group by gastrogavage, while equal volume of 5% carboxymethylcellulose sodium was administered to mice in the model group and the normal group by gastrogavage. All medication was lasted for 20 successive days. Praxiology was observed in each group. DA content in striatum was also detected. Results Compared with the normal group, the DA content in striatum decreased significantly in the model group (P < 0.01), suggesting a successful PD modeling. Compared with the model group, the DA content in striatum increased significantly in 1 and 2 groups (P<0.05). According to results of quadratic polynomial stepwise regression statistics, the regression equation obtained was: Y = 0.265 + 0.026 X 2 - 0.056 X 3 + 0.334 x 10(-3) x X1 x X3 + 0.691 x 10(-3) X X3(2). X3 extract was the main factor influencing the effectiveness (P < 0.01). The optimal proportion of BC was predicted by the regression equation: X1 = 54.00 mg/(kg x d), X2 = 44.88 mg/(kg x d), the X3 = 82.50 mg/(kg x d). The pole climbing time was shortened, times of autonomic activities increased, DA content was elevated, all with statistical difference in BC groups (P < 0.01, P < 0.05).</p><p><b>CONCLUSION</b>BC could increase DA content in PD model mice with the optimal proportion as 54.00: 44.88: 82.50.</p>

Behavior, PET and Histology in Novel Regimen of MPTP Marmoset Model of Parkinson's Disease for Long-Term Stem Cell Therapy

Stem cell technologies are particularly attractive in Parkinson's disease (PD) research although they occasionally need long-term treatment for anti-parkinsonian activity. Unfortunately, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) widely used as a model for PD has several limitations, including the risk of dose-dependent mortality and the difficulty of maintenance of PD symptoms during the whole experiment period. Therefore, we tested if our novel MPTP regimen protocol (2 mg/kg for 2 consecutive days and 1 mg/kg for next 3 consecutive days) can be maintained stable parkinsonism without mortality for long-term stem cell therapy. For this, we used small-bodied common marmoset monkeys (Callithrix jacchus) among several nonhuman primates showing high anatomical, functional, and behavioral similarities to humans. Along with no mortality, the behavioral changes involved in PD symptoms were maintained for 32 weeks. Also, the loss of jumping ability of the MPTP-treated marmosets in the Tower test was not recovered by 32 weeks. Positron emission tomography (PET) analysis revealed that remarkable decreases of bindings of ¹⁸F-FP-CIT were observed at the striatum of the brains of the marmosets received MPTP during the full period of the experiment for 32 weeks. In the substantia nigra of the marmosets, the loss of tyrosine hydroxylase (TH) immunoreactivity was also observed at 32 weeks following the MPTP treatment. In conclusion, our low-dose MPTP regimen protocol was found to be stable parkinsonism without mortality as evidenced by behavior, PET, and TH immunohistochemistry. This result will be useful for evaluation of possible long-term stem cell therapy for anti-parkinsonian activity.

CB2 receptor activation prevents glial-derived neurotoxic mediator production, BBB leakage and peripheral immune cell infiltration and rescues dopamine neurons in the MPTP model of Parkinson's disease

The cannabinoid (CB2) receptor type 2 has been proposed to prevent the degeneration of dopamine neurons in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice. However, the mechanisms underlying CB2 receptor-mediated neuroprotection in MPTP mice have not been elucidated. The mechanisms underlying CB2 receptor-mediated neuroprotection of dopamine neurons in the substantia nigra (SN) were evaluated in the MPTP mouse model of Parkinson's disease (PD) by immunohistochemical staining (tyrosine hydroxylase, macrophage Ag complex-1, glial fibrillary acidic protein, myeloperoxidase (MPO), and CD3 and CD68), real-time PCR and a fluorescein isothiocyanate-labeled albumin assay. Treatment with the selective CB2 receptor agonist JWH-133 (10 μg kg⁻¹, intraperitoneal (i.p.)) prevented MPTP-induced degeneration of dopamine neurons in the SN and of their fibers in the striatum. This JWH-133-mediated neuroprotection was associated with the suppression of blood-brain barrier (BBB) damage, astroglial MPO expression, infiltration of peripheral immune cells and production of inducible nitric oxide synthase, proinflammatory cytokines and chemokines by activated microglia. The effects of JWH-133 were mimicked by the non-selective cannabinoid receptor WIN55,212 (10 μg kg⁻¹, i.p.). The observed neuroprotection and inhibition of glial-mediated neurotoxic events were reversed upon treatment with the selective CB2 receptor antagonist AM630, confirming the involvement of the CB2 receptor. Our results suggest that targeting the cannabinoid system may be beneficial for the treatment of neurodegenerative diseases, such as PD, that are associated with glial activation, BBB disruption and peripheral immune cell infiltration.

Bee venom phospholipase A2 ameliorates motor dysfunction and modulates microglia activation in Parkinson's disease alpha-synuclein transgenic mice

α-Synuclein (α-Syn) has a critical role in microglia-mediated neuroinflammation, which leads to the development of Parkinson's disease (PD). Recent studies have shown that bee venom (BV) has beneficial effects on PD symptoms in human patients or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxin-induced PD mice. This study investigated whether treatment with BV-derived phospholipase A2 (bvPLA2) would improve the motor dysfunction and pathological features of PD in human A53T α-Syn mutant transgenic (A53T Tg) mice. The motor dysfunction of A53T Tg mice was assessed using the pole test. The levels of α-Syn, microglia and the M1/M2 phenotype in the spinal cord were evaluated by immunofluorescence. bvPLA2 treatment significantly ameliorated motor dysfunction in A53T Tg mice. In addition, bvPLA2 significantly reduced the expression of α-Syn, the activation and numbers of microglia, and the ratio of M1/M2 in A53T Tg mice. These results suggest that bvPLA2 could be a promising treatment option for PD.

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.

[Comparison of the intranasal and intraperitoneal injection of MPTP on density of dark neurons in pars compacta of substantia nigra in animal model of Parkinson's disease]

Background and Objective: Parkinson disease [PD] is the second most common neurologic disorder that results following degeneration of dopaminergic neurons in the pars compacta of substintia nigra [SNc]. The 1-methyl-1,2,3,6-tetrahydropiridine [MPTP] is a chemical neurotoxin that widely used in animal models of PD. This study was carried out to evaluate the numerical density of dark neurons [DNs] in the SNc in mice subjected to intraperitoneal and intranasal injection of different doses of MPTP

Methods: In this experimental study, 90 male adult BALB/c mice were randomly allocated int four experimental groups including: group 1 [MPTP was injected via i.p. at the dose of 20mg/kg per 2 hours for 4 times], group 2 [MPTP was injected via i.p. at the dose of 30mg/kg for 5 consecutive days], group 3 [MPTP was injected via i.n. at a single dose of 1mg/kg], group 4 [MPTP was injected via i.n. at a single dose of 1mg/kg], four sham and one normal groups. 20 days after the final injection, the animal's brain were removed and stained by toluidine blue. Numerical density of DNs was counted

Results: Intranasal injection of MPTP significantly increased density of dark neurons in the pars compacta of substintia nigra in compare to intraperitoneally injection of MPTP [P<0.05]

Conclusion: Intranasal injection of MPTP is more effective manner to induce degeneration of neurons in substintia nigra in animal model of Parkinson's disease

Modeling Parkinson's disease in the common marmoset (Callithrix jacchus): overview of models, methods, and animal care / 한국실험동물학회지

The common marmoset (Callithrix jacchus) is a small-bodied, popular New World monkey and is used widely in reproductive biology, neuroscience, and drug development, due to its comparative ease of handling, high reproductive efficiency, and its unique behavioral characters. In this review, we discuss the marmoset models in Parkinson's disease (PD), which is a neurological movement disorder primarily resulting from a degeneration of dopaminergic neurons with clinical features of tremor, rigidity, postural instability, and akinesia. The most common PD models involve the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or 6-hydroxydopamine to study the pathogenesis and to evaluate novel therapies. Following the systemic or local administration of these neurotoxins, the marmosets with very severe Parkinson's symptoms are recommended to be placed in an intensive care unit with artificial feeding to increase survival rate. All procedures with MPTP should be conducted in a special room with enclosed cages under negative-pressure by trained researchers with personal protection. Behavioral tests are conducted to provide an external measure of the brain pathology. Along with several biomarkers, including alpha-synuclein and DJ-1, non-invasive neuroimaging techniques such as positron emission tomography and magnetic resonance imaging are used to evaluate the functional changes associated with PD. With the recent growing interest in potential and novel therapies such as stem cell and gene therapy for PD in Korea, the marmoset can be considered as a suitable non-human primate model in PD research to bridge the gap between rodent studies and clinical applications.

A dysfunction of CD4+ T lymphocytes in peripheral immune system of Parkinson's disease model mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Parkinson's disease (PD), a neurodegenerative disorder, has been reported to be associated with brain neuroinflammation in its pathogenesis. Herein, changes in peripheral immune system were determined to better understand PD pathogenesis and provide possible target for treatment of PD through improvement of immune disorder.</p><p><b>METHODS</b>1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was intraperitoneally injected into mice to prepare PD model. Expression levels of pro-inflammatory and anti-inflammatory cytokines and transcription factors of CD4+ T lymphocyte subsets in spleen and mesenteric lymph nodes and concentrations of the cytokines in serum were examined on day 7 after MPTP injection. Percentages of CD4+ T lymphocyte subsets were measured by flow cytometry.</p><p><b>RESULTS</b>MPTP induced PD-like changes such as motor and behavioral deficits and nigrostriatal impairment. Expression levels of the pro-inflammatory cytokines including interferon (IFN)-γ, interleukin (IL)-2, IL-17 and IL-22, in spleen and mesenteric lymph nodes were upregulated and their concentrations in serum were elevated in PD progression. But, the concentrations of the anti-inflammatory cytokines including IL-4, IL-10 and transforming growth factor (TGF)-β were not altered in the two lymphoid tissues or serum of PD mice. In addition, expression of T-box in T cells (T-bet), the specific transcription factor of helper T (Th) 1 cells, was downregulated, but expression of transcription factor forkhead box p3 (Foxp3), the transcription factor of regulatory T (Treg) cells, was upregulated. In support of the results, the numbers of IFN-γ-producing CD4+ cells (Th1 cells) were reduced but CD4+CD25+ cells (Treg cells) were elevated in both the lymphoid tissues of PD mice.</p><p><b>CONCLUSION</b>PD has a dysfunction of peripheral immune system. It manifests enhancement of proinflammatory response and CD4+ T cell differentiation bias towards Treg cells away from Th1 cells.</p>

P38 MAPK signaling pathway regulates nuclear factor-κB and inducible nitric oxide synthase expressions in the substantia nigra in a mouse model of Parkinson's disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of P38 mitogen-activated protein kinase (P38 MAPK) signaling pathway in regulating the expression of nuclear factor-κB (NF-κB) and inducible nitric oxide synthase (iNOS) in the substantia nigra (SN) of a mouse model of Parkinson's disease (PD).</p><p><b>METHODS</b>C57BL/6N mice were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish an subacute PD model, and the behavioral changes of the mice were observed. Immunohistochemistry and Western blotting were employed to detect the expressions of tyrosine hydroxylase (TH), NF-κB, iNOS and phosphorylated P38 (p-P38) in the midbrain before and after treatment with SB203580.</p><p><b>RESULTS</b>Compared with the control mice, the PD mouse models presented with typical symptoms of PD and showed significantly increased number of p-P38-, NF-κB-, and iNOS-positive cells in the SN area (P<0.01) with significantly reduced number of TH-positive neurons (P<0.01). After SB203580 treatment, the number of p-P38-, NF-κB-, and iNOS-positive cells was reduced obviously (P<0.01) and the number of TH-positive neurons in the SN increased significantly in the PD model mice (P<0.01).</p><p><b>CONCLUSION</b>P38 MAPK signaling pathway may play an important role in modulating NF-κB and iNOS expression in the SN in the early stage of MPTP-induced subacute PD, and SB203580 can inhibit P38 signaling pathway to protect the DA neurons in PD model mice.</p>

Proposed Motor Scoring System in a Porcine Model of Parkinson's Disease induced by Chronic Subcutaneous Injection of MPTP

Destruction of dopaminergic neurons in the substantia nigra pars compacta (SNpc) is a common pathophysiology of Parkinson's disease (PD). Characteristics of PD patients include bradykinesia, muscle rigidity, tremor at rest and disturbances in balance. For about four decades, PD animal models have been produced by toxin-induced or gene-modified techniques. However, in mice, none of the gene-modified models showed all 4 major criteria of PD. Moreover, distinguishing between PD model pigs and normal pigs has not been well established. Therefore, we planned to produce a pig model for PD by chronic subcutaneous administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), neurotoxin. Changes in behavioral patterns of pigs were thoroughly evaluated and a new motor scoring system was established for this porcine model that was based on the Unified Parkinson's Disease Rating Scale (UPDRS) in human PD patients. In summary, this motor scoring system could be helpful to analyze the porcine PD model and to confirm the pathology prior to further examinations, such as positron emission tomography-computed tomography (PET-CT), which is expensive, and invasive immunohistochemistry (IHC) of the brain.

Therapeutic effect of a natural squamosamide derivative FLZ on Parkinson's disease model mice induced by LPS plus MPTP / 药学学报

The aim of this study is to investigate the protective effect of N-[2-(4-hydroxyphenyl)ethyl]-2-(2, 5-dimethoxyphenyl)-3-(3-methoxy-4-hydroxyphenyl)acrylamide (FLZ), a novel synthetic squamosamide cyclic derivative, against Parkinson's disease (PD) model mice induced by the inflammatory bacterial endotoxin, lipopolysaccharides (LPS) and the neurotoxin 1-methy-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). C57/BL mice were ip injected LPS (5 mg x kg(-1)) once. One week following the LPS injection, mice received a subcutaneous injection of MPTP (25 mg x kg(-1)) once daily for 2 days. Eight weeks later, FLZ (25, 50 and 75 mg x kg(-1)) was orally administered to mice once daily for 60 days. The motor ability of the mice was evaluated by rod climbing test and footprint test. The dopamine (DA) levels in mouse striatum were determined by high performance liquid chromatography system. The tyrosine hydroxylase (TH)-positive cells were showed by immunohistochemical analysis. FLZ treatment significantly improved motor dysfunction of mice challenged by LPS plus MPTP. The increase of TH-positive cell numbers and elevation of DA levels may be contributed to the beneficial effects of FLZ on motor behavior. This study showed FLZ has significant therapeutic effect on LPS plus MPTP induced chronic PD model, which indicates its potential as a new candidate drug to treat PD.