Effect of Achyranthis Bidentatae Radix-Paeoniae Radix Alba on Neuroinflammation and RhoA/ROCK2 Signaling Pathway in Parkinson's Disease Mouse Model / 中国实验方剂学杂志

ObjectiveTo investigate the protective effect and mechanism of Achyranthis Bidentatae Radix-Paeoniae Radix Alba on dopaminergic neurons in Parkinson's disease mouse model with the syndrome of ascendant hyperactivity of liver Yang. MethodThe C57BL/6 mice were randomly assigned into normal group， a model group， low-， medium， and high-dose （3.25， 6.5， 13 g·kg-1） Achyranthis Bidentatae Radix-Paeoniae Radix Alba groups， and a selegiline group （0.01 g·kg-1）. The mouse model of Parkinson's disease with the syndrome of ascendant hyperactivity of liver yang was established by intragastric administration of Fuzitang combined with intraperitoneal injection of 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine （MPTP）. The behavioral changes were evaluated by rotarod test and pole test. The protein levels of Ras homolog gene family member A （RhoA）， Rho-associated coiled-coil containing protein kinase 2 （ROCK2）， myosin light chain 1 （MLC1）， and α-synuclein in the substantia nigra were determined by Western blot. Real-time fluorescence quantitative PCR （Real-time PCR） was employed to determine the mRNA levels of RhoA， ROCK2， and MLC1 in the substantia nigra. Enzyme-linked immunosorbent assay （ELISA） was used to measure the levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）. The ultrastructural changes of mouse neurons were observed under a transmission electron microscope. ResultCompared with the normal group， the modeling shortened the latency to fall， increased the average total time in the pole test （P<0.01）， and up-regulated the levels of RhoA， ROCK2， MLC1， TNF-α， α-synuclein， and IL-1β in the substantia nigra （P<0.05）. Compared with the model group， different doses of Achyranthis Bidentatae Radix-Paeoniae Radix Alba and selegiline prolonged the latency to fall， shortened the average total time in the pole test （P<0.05， P<0.01）， and down-regulated the levels of ROCK2， MLC1， α-synuclein， TNF-α， and IL-1β in a dose-dependent manner （P<0.05）. Further， the modeling decreased the number of cytoplasmic organelles and caused mitochondrial swelling and abnormal shape of endoplasmic reticulum compared with the normal group. The neurons in high-dose Achyranthis Bidentatae Radix-Paeoniae Radix Alba and selegiline groups showed intact nuclei， clear cell boundary， and normal endoplasmic reticulum shape. ConclusionThe combination of Achyranthis Bidentatae Radix and Paeoniae Radix Alba may improve the motor coordination ability of Parkinson's disease mouse model with the syndrome of ascendant hyperactivity of liver yang by inhibiting the neuroinflammation mediated by the RhoA/ROCK2 signaling pathway in the brain.

Study on anti-Parkinson's disease activity of Eucommia ulmoides based on network pharmacology and zebrafish model / 中国药理学通报

Aim To investigate anrl further verify the anti-PD activity and underlying mechanism of Eucom¬mia ulmoides and based on network pharmacological methods and zebrafish Parkinson's disease ( PD) mod¬el.Methods The DISGENET database and TCMSP database were used to screen the active components, key targets of Eucommia ulmoides and PD related tar¬gets.The network diagram of active components-tar- gets-PD was drawn.The protein interaction network di¬agram was constnicted.GO enrichment analysis and KEGG pathway enrichment analysis were performed.Hie behavioral detection was verified by and quantita¬tive real-time PCR (qRT-PCR) based on zebrafish PD model.Results The network pharmacological study screened the potential targets associated with anti-PD action of Eucommia ulmoides.Protein-protein interac¬tion network ( PPI) analysis showed that there was tight interaction among thees targets.GO and KEGG enrichment analysis showed that Eucommia ulmoides could regulate the levels of PD neurotransmitter and the activity of dopamine neurotransmitter receptor, in¬volved in dopaminergic synapses and other related sig¬naling pathways.In vivo zebrafish PD model experi¬ments confirmed the anti-PD activity of Eucommia ul¬moides, which was related to the regulation of dopam¬inergic nervous system.Conclusions The anti-PD activity, active components, and potential targets of Eucommia ulmoides are revealed in this study.In vivo experiments verified that Eucommia ulmoides can alle¬viate PD-like symptoms in zebrafish, and it also reveals that Eucommia ulmoides exert anti-PD activity by regu¬lating dopaminergic nervous system.

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.

Kangxian Yixin Prescription Interferes with Mitochondrial Permeability Transition Pore to Inhibit Cardiomyocyte Apoptosis / 中国实验方剂学杂志

Objective:To explore the mechanism of Kangxian Yixin prescription in regulating mitochondrial permeability transition pore（mPTP）and inhibiting cardiomyocyte apoptosis. Method:H9c2 cardiomyocytes were cultured routinely. After 8 h of starvation，the cells were divided into the normal group，model group，Kangxian Yixin prescription（0.25 g·L^-1） group，and cyclosporin A（CsA，10 μmol·L^-1） group and treated with the corresponding drugs for 24 h for follow-up experiments. The H9c2 cardiomyocyte hypertrophy model was induced by norepinephrine（NE），whose optimal concentration was determined by real-time polymerase chain reaction （Real-time PCR）. The degree of mPTP opening was detected by flow cytometry， followed by the measurement of mRNA and protein expression levels of apoptosis-related factors cyclophilin D（Cyp-D），cytochrome C（Cyt-C），and cysteine aspartate-specific protease-3（Caspase-3） after mPTP opening and the quantification of mitochondrial membrane potential. Result:When the concentration of NE was 200 μmol·L^-1， the mRNA expression levels of atrial natriuretic peptide（ANP） and brain natriuretic peptide（BNP） were the highest， implying that it was the optimal concentration to induce H9c2 cell hypertrophy. Compared with the normal group，the model group exhibited excessive opening of mPTP，weakened relative fluorescence intensity in mitochondria， decreased mitochondrial membrane potential（<italic>P</italic><0.05，<italic>P</italic><0.01），and elevated mRNA and protein expression of Cyp-D，Cyt-C，and Caspase-3（<italic>P</italic><0.05）. Compared with the model group，both Kangxian Yixin prescription and CsA inhibited mPTP opening，enhanced the relative fluorescence intensity of mitochondria， increased mitochondrial membrane potential（<italic>P</italic><0.05，<italic>P</italic><0.01），and lowered the mRNA and protein expression of Cyp-D，Cyt-C，and Caspase-3 （<italic>P</italic><0.05）. Conclusion:Kangxian Yixin prescription inhibits cardiomyocyte apoptosis possibly by regulating mPTP opening and inhibiting the expression of apoptosis-related factors Cyp-D，Cyt-C， and Caspase-3.

Maternal hypothyroidism during pregnancy alters the function of the retinol-binding protein 4-mediated mitochondrial permeability conversion pore in the kidneys of offspring rats

OBJECTIVES To determine the role of the RBP4/PiC/SIRT3 signaling pathway in the opening of the mitochondria permeability transition pore (mPTP) in offspring rats with hypothyroidism during pregnancy. METHODS Sixty Sprague-Dawley (SD) rats were employed in this study. Pregnancy was deemed successful when a sperm was found in the uterus. After one week of pregnancy, offspring rats were divided into the following groups: overall hypothyroidism group (OH group), subclinical hypothyroidism group (SCH group), and normal control group (CON group). The establishment of the hypothyroidism model was confirmed when the serum thyroid stimulating hormone (TSH) levels were higher than normal value and TT4 level was within the normal range. The renal mitochondria of offspring rats were extracted on the 14th postnatal day (P14) and 35th postnatal day (P35). RESULTS At P14, no significant differences in the degree of mPTP opening and expression of phosphoric acid carrier vector (PiC) were detected between the rats in the OH group and the SCH group. However, the expression level of silent mating-type information regulation 3 homolog (SIRT3) was markedly reduced. Retinol-binding protein 4 (RBP4) expression increased in the rats from the OH group, relative to that in those from the SCH group. At P35, the degree of mPTP opening and the expression levels of PiC and RBP4 in the OH group were higher than those in the SCH group. However, SIRT3 expression in the OH group was lower than that observed in the SCH group. CONCLUSION RBP4 plays an important role in early renal mitochondrial damage and renal impairment in rats suffering from hypothyroidism during pregnancy. The RBP4/PiC/SIRT3 pathway is thus involved in the opening of the renal mPTP in offspring rats with hyperthyroidism.

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)

Study on preventive and therapeutic effects of Erzhi Pills on mice with Parkinson's disease induced by MPTP / 中国中药杂志

The aim of this study was to investigate the preventive and therapeutic effects of Erzhi Pills on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine( MPTP)-induced Parkinson's disease( PD) in mice,and explore its possible mechanism of action. Mice were intraperitoneally injected with MPTP( 30 mg·kg-1,0. 01 m L·g-1) once daily to induce PD for 8 days. In the treatment group,Erzhi Pills were given by intragastric administration( 2. 5 g·kg-1,once daily for 30 days). The normal group received an equal volume of normalsaline. In terms of behavior,the limb movement coordination ability of the mice was detected by climbing,hanging and swimming experiments. The spatial learning and memory ability of the mice was detected by Morris water maze test. The content of MDA,as well as the activity of GSH-PX and SOD were determined in mice serum. Western blot was used to detect the protein expression levels of TH,MAOB and apoptosis-related factors CHOP and caspase-12 in brain tissues. Immunohistochemistry was used to detect the expression of TH in section of brain tissues in mice. The results showed that in behavioral aspects,as compared with the model group,the scores of limb movement ability as well as scores of spatial learning and memory ability were significantly improved in the treatment groups( P<0. 05). In terms of serological indicators,as compared with the model group,the activities of SOD and GSH-PX were significantly increased in the serum of treatment groups,and the content of MDA was significantly decreased( P<0. 05). The results of Western blot showed that as compared with the model group,the protein levels of TH in the brain tissues of the mice in treatment group were significantly up-regulated,while the protein levels of MAOB and apoptosis-related factors CHOP and caspase-12 were significantly down-regulated( P<0. 05). The results of immunohistochemistry showed that the number of TH positive cells in the brain tissues of the mice in the treatment group was significantly increased as compared with the model group( P<0. 05). In summary,Erzhi Pills have a certain preventive and therapeutic effect on MPTP-induced PD mice,which can significantly improve the limb motor coordination ability and spatial learning and memory ability of PD mice. Its mechanism may be related to down-regulating the expression of apoptosis-related factors CHOP and caspase-12,reducing the dopaminergic neuron damage and inhibiting dopaminergic neuronal apoptosis.

Rotarod test and Catalepsy bar test: behavioral testing and neuromodulation of Aloe vera in MPTP induced Parkinson’s disease animal model

Background: Aloe vera (Family Liliaceae) has been used for the treatment of diabetes, skin disorders and as anti-inflammatory agent. Objectives: behavioral testing of antiparkinsonian effect of Aloe vera in MPTP induced animal model.Methods: Rotarod test and Catalepsy bar test were used for behavioral assessment. Assessment of oxidative stress was done in the striatal region of the brain by reduced glutathione (GSH) measurement.Results: A. vera (200 and 400mg/kg, p.o.) was found to significantly increase the retention time in rota rod test and significantly decrease the latency period in catalepsy bar test as compared to MPTP groups. A. vera was found to have significant anti-oxidative effect in the striatal region of the brain by GSH measurement.Conclusions: Thus, it can be proposed that A. vera has a potential anti-parkinson effect in mice.

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.

The comparison of neurobehavioral changes and impaired locations between the mouse model of manganism and Parkinson’s disease / 中华劳动卫生职业病杂志

Objective@#To investigate the effect of manganese chloride (MnCl2) or 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) on the neurobehavioral and histopathology in C57BL/6 mice and provide evidence for the diagnosis, treatment and prevention of manganism.@*Methods@#Adult male C57BL/6 mice were treated with MnCl2 and MPTP respectively by intraperitoneal injection at the doses of 5, 10, 20mg Mn/kg and 30mg MPTP/kg. Controls were injected equivalent normal saline. All animals were administrated 5 times a week for 4 consecutive weeks and sacrificed after behavior tests on the fifth week. Balance ability, anxiety and depression level and cognitive function were tested respectively by vertical pole test, open field locomotion test and Morris swim task. The neuron pathological changes of striatum and substantia nigra were examined through HE-staining pathological section by using optical microscope.@*Results@#Compared with the control group, the high dose of MnCl2 reduced body weight obviously (P<0.01) . The results of vertical pole test showed that MnCl2 and MPTP lengthened the pole-climbing time and turnaround time. Open field locomotion test showed that movement distance, stand-up time and central field time were decreased after the exposure of MnCl2 or MPTP. In the Morris swim task, the escape latency time increased and the target quadrant activity time decreased significantly after the injection of MPTP as well as high-dose MnCl2, comparing with controls (P<0.05) . Moreover, the escape latency time of high dose MnCl2 prolonged prominently comparing with MPTP grou (P<0.05) . The results of histopathology showed that acidophilic changes elevated in MnCl2 and MPTP group, comparing with controls. Furthermore, in striatum the oxyphil cells number increased in MnCl2 high-dose group comparing with MPTP group (P<0.01) . On the contrary, there were more oxyphil cells in MPTP group comparing with MnCl2 groups in substantia nigra (P<0.01) .@*Conclusion@#Both manganese and MPTP can induce the impairment of dopaminergic neural system, but the symptons and injured location of manganism are inconsistent with PD models induced by MPTP.

Relationship Between the Anxious Symptoms and the Neurotransmitter in Parkinson's Mice with Different Dosages of MPTP

ABSTRACT This study aims to explore the relationship between the anxious symptoms and the impairment of 5-hydroxytryptamine system in PD mice induced by different dosages of MPTP. The mice from the three model groups, the low-dose, dose and high-dose group, took longer time in the dark box than those in the control group (P<0.05). However, no statistically significant differences were found among the model groups. The number of open arm entry (OE) and the open arm time (OT) were significant lower in the model group than those in the control group in the elevated plus-maze test (P＜0.05). The percentage of OE in modle group was significantly lower compared with the control group (P＜0.05). The concentrations of striatum DA, HVA, 5-HT, and 5-HIAA were significantly reduced in the three model groups compared to the control group (P＜0.05). The 5-HT concentrations of high-dose group was significantly lower than those of the control group in the prefrontal cortex (P＜0.05). Anxiety symptoms were appeared in the three model groups of early PD mice, but no difference existed among these groups. The 5-hydroxytryptamine system was damaged after MPTP injection, which could lead to anxiety. However, the impairment of 5-hydroxytryptamine system induced by MPTP was dose-independent.

Exploration of establishing a tree shrew model of chronic gastrointestinal mucosal injury / 中国比较医学杂志

Objective To explore the feasibility of establishing a tree shrew model of chronic gastrointestinal mucosal injury. Methods A total of 12 adult male tree shrews were randomly divided into 3 groups. The experimental groups 1 and 2 were administered with intraperitoneal injection of 2 mg/(kg·d)and 1 mg/(kg·d)of 1-methyl-4-phenyl-1,2, 3,6-tetrahydropyridine(MPTP)once every day for 56 days, respectively. The control group was given the same volume of sterile saline at the corresponding time points. Changes in the body weight of the tree shrews were observed. The contents of dopamine in the cerebrospinal fluid were detected. Gastrointestinal morphology was observed by stereoscope and histopathological changes of the gastrointestinal mucosa were examined by HE staining. Results The body weight and the contents of dopamine in the cerebrospinal fluid of the tree shrews in the model group were significantly decreased(P< 0.05 for both). Pathological changes to some extent of the gastric antrum, the gastric body and the duodenum were observed, without obvious differences between the 2 mg/kg group and the 1 mg/kg group. No obvious changes were found in the control group. Conclusions Long-term intraperitoneal injection with a low dose of MPTP is a feasible method for the establishment of a tree shrew model of chronic gastrointestinal mucosal injury. The optimal dose is 2 mg/(kg·d)every day for 56 days.

The protective effect of QZXK in nerve injury using zebrafish model induced by MPTP / 中国药理学通报

Aim To investigate the protective effect of Qi ZhiXiaoke granules ( QZXK ) on nerve injury using zebrafish and nerve cell injury models. Methods The nerve injury model was established using wild zebrafish AB line, 72 hours after fertilization treated with 1-methyl-4-phenyl-1 , 2 , 3 , 6-four pyridine ( MPTP ) .Then QZXK of different doses were administered for three days,and the trajectory of the zebrafish behavior was recorded and analyzed. Neuroblastoma PC12 cells were incubated with different concentrations of QZXK and MPTP,and the cell viability of PC12 cells was de-tected by MTT. The mitochondrial membrane potential and expression of apoptosis related protein Caspase3 were measured by kits. Results Compared with con-trol group,MPTP reduced the movement distance of ze-brafish,and with the increase of concentration, QZXK promoted the movement distance and reversed the swimming behavior abnormality of zebrafish. Compared with control group, QZXK could inhibit the apoptosis induced by MPTP and promote the cell viability of PC12 cells with MPTP. QZXK improved the membranepotential and decreased the expression of Caspase3 . Conclusions QZXK exerts neuroprotective effect in the process of nerve injury induced by MPTP. The mechanism may be related with inhibiting apoptosis of neural cells. These experiment provides experimental and theoretical foundation for QZXK promoting cogni-tive function.

The protective effects of cordycepin on MPTP-induced dopaminergic neuron damage in mice and its mechanism / 中国药理学通报

Aim To observe the protective effects of cordycepin ( Cor) on dopaminergic neurons in 1-meth-yl-4-phenyl-1 , 2 , 3 , 6-tetrahydropyridine ( MPTP )-in-duced mouse model of Parkinson's disease ( PD) and to explore its mechanism. Methods C57BL/6 mice were administered with MPTP to establish the PD mod-el. Mice in Cor groups were pretreated with Cor (2.5,5.0 and 10.0 mg·kg-1 ) by intragastric administra-tion, respectively. The motor functions of the mice were observed in the open-field test, rotarod test and pole test. The content of DA, the numbers of TH-im-munoreactive cells and apoptotic cells were measured respectively by HPLC-ECD, immunohistochemistry staining and TUNEL staining. The expression of apop-tosis related proteins and MAPK signaling pathway-re-lated proteins ( p38 , p-p38 , ERK1/2 , p-ERK1/2 JNK1/2 and p-JNK1/2 ) were determined by Western blot. Results Cor could significantly improve the mo-tor dysfunction in PD mice. The contents of DA, DOPAC and HVA in the striatum remarkably increased after administration of Cor in MPTP-induced mice. Mo-reover, Cor could obviously reduce both the loss of TH-immunoreactive neurons and the numbers of TUNEL-positive cells in substantia nigra pars compacta ( SNpc) of PD mice. The protein expressions of Bax and cleaved caspase-3 were markedly down-regulated,whereas those of Bcl-2 and the ration of Bcl-2/Bax were significantly up-regulated by Cor pre-treatment followed by MPTP treatment. Furthermore, the protein expressions of p-p38 , p-ERK1/2 and p-JNK1/2 signif-icantly decreased in substantia nigra in Cor groups. Conclusions The results suggest that Cor can protect DA neurons against MPTP-induced injury by inhibiting apoptosis, which may be closely relevant to the inhibi-tion of MAPK signaling pathways.

Neuron-protective effect of subanesthestic-dosage ketamine on mice of Parkinson's disease

Objective To discuss the neuron-protective effect and possible mechanism of subanesthestic-dosage ketamine on Parkinson's disease mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Methods A total of 30 mice were divided equally into three groups, model control group (MC group), ketamine treatment group (KT group), and blank control group (BC group), respectively. The Parkinson's disease mice of MC group and KT groups were established by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (20 mg/kg/d), while mice in KT group were treated by intraperitoneal injection of subanesthestic-dosage ketamine (8 mg/kg). Differences on behaviors and the number of nigra dopaminergic neurons of mice in each group were compared through the behavioral test and tyrosine hydroxylase immunohistochemistry experiments after the treatments. Furthermore, Western blot was used to test the expression of autophagy-related gene LC3-Ⅱ Beclin1, Parkin, PINK1, and mTOR. Results Compared with the BC group, the neuroethology scores were lower and the amount of TH positive cells were less both in MC and MT groups; In KT group, the neuroethology scores were higher and the amount of tyrosine hydroxylase positive cells were significantly more than that in MC group (P < 0.05). Moreover, expression levels of autophagy-related proteins LC3-II, Beclin1, Parkin, and PINK1 were higher, while the mTOR expression level was lower than that in MC group. Conclusions The subanesthestic-dosage ketamine has some protective effects on the coordinating ability of movement and cognitive ability of Parkinson's disease mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. This is probably due to that the autophagy activity of cells is activated by subanesthestic-dosage ketamine and that the neurons are protected.

Regulation mechanism and targeted drugs of mitochondrial permeability transition pore on programmed cell death: Research advances / 国际药学研究杂志

Since its discovery in the 1970s, the mitochondrial permeability transition(mPT)has been proposed to be a strategic regulator of programmed cell death(PCD). The mPT denotes an increase in the mitochondrial inner membrane permeability to solutes with molecular masses up to about 1.5×103. It is presumed to be mediated by an opening of a channel, the mPT pore(mPTP), whose molecular nature remains a mystery. Intense research efforts have focused on elucidating the molecular components of the mPTP because it may help to better understand and treat various pathologies ranging from neurodegenerative and cardiac diseases to cancer. This article briefly reviews the new progress of mPTP structural models and its specific molecular mechanisms of regulating PCD, then demonstrates the feasibility of using the mPTP-targeting agents as a potential alternative strategy for effective management of PCD.

Neuron-protective effect of subanesthestic-dosage ketamine on mice of Parkinson's disease

OBJECTIVE@#To discuss the neuron-protective effect and possible mechanism of subanesthestic-dosage ketamine on Parkinson's disease mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.@*METHODS@#A total of 30 mice were divided equally into three groups, model control group (MC group), ketamine treatment group (KT group), and blank control group (BC group), respectively. The Parkinson's disease mice of MC group and KT groups were established by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (20 mg/kg/d), while mice in KT group were treated by intraperitoneal injection of subanesthestic-dosage ketamine (8 mg/kg). Differences on behaviors and the number of nigra dopaminergic neurons of mice in each group were compared through the behavioral test and tyrosine hydroxylase immunohistochemistry experiments after the treatments. Furthermore, Western blot was used to test the expression of autophagy-related gene LC3-Ⅱ, Beclin1, Parkin, PINK1, and mTOR.@*RESULTS@#Compared with the BC group, the neuroethology scores were lower and the amount of TH positive cells were less both in MC and MT groups; In KT group, the neuroethology scores were higher and the amount of tyrosine hydroxylase positive cells were significantly more than that in MC group (P < 0.05). Moreover, expression levels of autophagy-related proteins LC3-II, Beclin1, Parkin, and PINK1 were higher, while the mTOR expression level was lower than that in MC group.@*CONCLUSIONS@#The subanesthestic-dosage ketamine has some protective effects on the coordinating ability of movement and cognitive ability of Parkinson's disease mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. This is probably due to that the autophagy activity of cells is activated by subanesthestic-dosage ketamine and that the neurons are protected.

Regulation mechanism and targeted drugs of mitochondrial permeability transition pore on programmed cell death:research advances / 国际药学研究杂志

Since its discovery in the 1970s,the mitochondrial permeability transition(mPT)has been proposed to be a strate?gic regulator of programmed cell death(PCD). The mPT denotes an increase in the mitochondrial inner membrane permeability to sol?utes with molecular masses up to about 1.5×103. It is presumed to be mediated by an opening of a channel,the mPT pore(mPTP), whose molecular nature remains a mystery. Intense research efforts have focused on elucidating the molecular components of the mPTP because it may help to better understand and treat various pathologies ranging from neurodegenerative and cardiac diseases to cancer. This article briefly reviews the new progress of mPTP structural models and its specific molecular mechanisms of regulating PCD , then demonstrates the feasibility of using the mPTP-targeting agents as a potential alternative strategy for effective management of PCD.

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.

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.