[Improvement effect of cinnamaldehyde on reserpine-induced Parkinson's disease rat model].

In order to study the neuroprotective mechanism of cinnamaldehyde on reserpine-induced Parkinson's disease(PD) rat models, 72 male Wistar rats were randomly divided into blank group, model group, Madopar group, and cinnamaldehyde high-, medium-, and low-dose groups. Except for the blank group, the other groups were intraperitoneally injected with reserpine of 0.1 mg·kg~(-1) once every other morning, and cinnamaldehyde and Madopar solutions were gavaged every afternoon. Open field test, rotarod test, and oral chewing movement evaluation were carried out in the experiment. The brain was taken and fixed. The positive expression of dopamine receptor D1(DRD1) was detected by TSA, and the changes in neurotransmitters such as dopamine(DA) and 3,4-dihydroxyphenylacetic acid(DOPAC) in the brain were detected by enzyme-linked immunosorbent assay(ELISA). The protein and mRNA expression levels of tyrosine hydroxylase(TH) and α-synuclein(α-Syn) in substantia nigra(SN) were detected by RT-PCR and Western blot. The results showed that after the injection of reserpine, the hair color of the model group became yellow and dirty; the arrest behavior was weakened, and the body weight was reduced. The spontaneous movement and exploration behavior were reduced, and the coordination exercise ability was decreased. The number of oral chewing was increased, but the cognitive ability was decreased, and the proportion of DRD1 positive expression area in SN was decreased. The expression of TH protein and mRNA was down-regulated, and that of α-Syn protein and mRNA was up-regulated. After cinnamaldehyde intervention, it had an obvious curative effect on PD model animals. The spontaneous movement behavior, the time of staying in the rod, the time of movement, the distance of movement, and the number of standing times increased, and the number of oral chewing decreased. The proportion of DRD1 positive expression area in SN increased, and the protein and mRNA expression levels of α-Syn were down-regulated. The protein and mRNA expression levels of TH were up-regulated. In addition, the levels of DA, DOPAC, and homovanillic acid(HVA) neurotransmitters in the brain were up-regulated. This study can provide a new experimental basis for clinical treatment and prevention of PD.

Effects of electroacupuncture on Sirt3/NLRP3/GSDMD signaling pathway in the substantia nigra of midbrain of rats with Parkinson's disease. / ç”µé’ˆå¯¹å¸•é‡‘æ£®ç— å¤§é¼ ä¸­è„‘é»‘è´¨Sirt3/NLRP3/GSDMD信号通路的影响.

OBJECTIVES: To observe the effects on tyrosine hydroxylase (TH), α-synaptic nucleoprotein (α-syn), sirtuin 3 (Sirt3), NOD-like receptor 3 (NLRP3) and gasdermin-D (GSDMD) in the substantia nigra of midbrain after electroacupuncture (EA) at "Fengfu"(GV16), "Taichong" (LR3) and "Zusanli" (ST36) in rats of Parkinson's disease (PD), so as to explore the mechanism of EA in treatment of PD. METHODS: SD rats were randomly divided into control, model and EA groups, with 10 rats in each group. The PD model was established by injecting rotenone into the neck and back, lasting 28 days. In the EA group, EA was applied to GV16, LR3 and ST36, 30 min each time, once daily, consecutively for 28 days. The open-field test was adopted to detect the total distance of autonomic movement of rats, and the pole climbing test was used to detect the body coordination ability of rats. In the substania nigra of midbrain, the positive expression of TH was determined using immunohistochemistry, the mRNA expression levels of α - syn, Sirt3, NLRP3 and GSDMD were detected by quantitative real-time fluorescence PCR, and the protein expression levels of NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and cysteinyl aspartate specific proteinase (Caspase)-1 were detected by Western blot. RESULTS: Compared with the control group, the total distance of autonomous movement was decreased (P<0.01) in the model group, and the score of pole climbing experiment was increased (P<0.01)；in the midbrain substantia nigra the positive expression of TH was decreased (P<0.01)；the mRNA expression level of Sirt3 was decreased (P<0.01), and those of α-syn, NLRP3 and GSDMD were increased (P<0.01)；while the protein expression levels of NLRP3, ASC and Caspase-1 were increased (P<0.01). When compared with the model group, the total distance of autonomous movement in open field experiment was increased (P<0.01) in the EA group and the score of pole climbing experiment was lower (P<0.05)；in the midbrain substantia nigra the positive expression of TH was increased (P<0.01)；the mRNA expression level of Sirt3 in the midbrain substantia nigra was increased (P<0.01), and those of α-syn, NLRP3 and GSDMD were reduced (P<0.01)；while the protein expression levels of NLRP3, ASC and Caspase-1 decreased (P<0.01, P<0.05). CONCLUSIONS: EA at "GV16" "LR3" and "ST36" can repair the neuronal injury, clear the abnormal accumulation of α-syn in the substania nigra of midbrain, and ameliorate mitochondrial damage in PD rats, which may be obtained by regulating Sirt3/NLRP3/GSDMD signaling pathway, so as to delay the occurrence and development of Parkinson's disease.

Effect of electroacupuncture on brain-gut oxidative stress in Parkinson's disease mice. / ç”µé’ˆå¯¹å¸•é‡‘æ£®ç— å°é¼ è„‘è‚ æ°§åŒ–åº”æ¿€çš„å½±å“.

OBJECTIVES: To observe the effect of electroacupuncture (EA) on behavior, oxidative stress factors in colon and substantia nigra of Parkinson's disease (PD) mice, so as to explore the mechanism of EA in treating PD. METHODS: C57BL/6 mice were randomly divided into blank, model and EA groups, with 12 mice in each group. The PD mouse model was established by continuous gavage of rotenone for 4 weeks. Mice in the EA group received EA (2 Hz/15 Hz) at "Baihui" (GV20), "Quchi" (LI11) and "Zusanli" (ST36) for 20 min, 5 days a week for 2 weeks. After intervention, gait analysis was used to evaluate the motor ability and motor coordination. Ink propulsion rate was used to evaluate the intestinal transport function. The level of reactive oxygen species (ROS) in the colon was detected by flow cytometry. The contents of total protein (TP), malondialdehyde (MDA) and activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) in colon and substantia nigra were detected by ELISA. The expression of nuclear factor E2-related factor 2 (Nrf2) in substantia nigra was detected by immunofluorescence staining. RESULTS: Compared with the blank group, the average speed, step rate, normal step ratio, distance between the front and hind feet, stride length, swing speed and maximum intensity of the maximum contact area of mice in the model group were decreased (P<0.000 1, P<0.01, P<0.001), the maximum change rate of gait was increased (P<0.001) in the model group. The intestinal propulsion rate, the activities of GSH-Px and SOD in the colon and substantia nigra, and the positive expression of Nrf2 in substantia nigra were decreased (P<0.000 1, P<0.01, P<0.05), while the fluorescence intensity of ROS in the colon, the contents of MDA in colon and substantia nigra were increased (P<0.01). Compared with the model group, the average speed, step rate, normal step ratio, distance between the front and hind feet, stride length, swing speed, and maximum intensity of the maximum contact area of the mice in the EA group were increased (P<0.01, P<0.05, P<0.001, P<0.000 1), the maximum change rate of gait was decreased (P<0.01). The intestinal propulsion rate, the activities of GSH-Px and SOD in the colon and substantia nigra, the positive expression of Nrf2 in substantia nigra were increased (P<0.001, P<0.05, P<0.000 1), while the ROS fluorescence intensity in the colon, the MDA contents in the colon and substantia nigra were decreased (P<0.01). CONCLUSIONS: EA can improve the movement disorder, gait disorder and intestinal motor function of PD mice, and protect dopaminergic neurons from damage, which may be related to its effect in antagonistic brain-gut oxidative stress.

Effect of electroacupuncture on oxidative stress and cell apoptosis induced by ferroptosis in mice with Parkinson's disease. / ç”µé’ˆå¯¹å¸•é‡‘æ£®ç— å°é¼ é“æ­»äº¡è¯±å¯¼çš„æ°§åŒ–åº”æ¿€åŠç»†èƒžå‡‹äº¡çš„å½±å“.

OBJECTIVES: To observe the effect of electroacupuncture (EA) on ferroptosis and apoptosis-related proteins in the substantia nigra of midbrain in mice with Parkinson's disease (PD), so as to explore its possible mechanisms in the treatment of PD. METHODS: Twenty-four C57BL/6 mice were randomly divided into blank, model and EA groups, with 8 mice in each group. The PD model was established by continuous gavage of rotenone for 4 weeks. EA was applied at "Baihui" (GV20), "Quchi" (LI11) and "Zusanli" (ST36) for 20 min, once a day for 14 days, with 2-day rest after every 5-day treatment. The open field test was used to evaluate the residence time in the central area, ave-rage movement speed, and total distance of the open field. Western blot was used to detect the protein expression le-vels of divalent metal ion transporter 1 (DMT1), membrane ferroportin 1 (FPN1), glutathione peroxidase 4 (GPX4), proapoptotic protein Bax, and anti apoptotic protein Bcl-2 in the substantia nigra. Immunohistochemical method was used to detect the morphological changes of neurons and the positive expression of tyrosine hydroxylase (TH) in the substantia nigra of mice. RESULTS: After 4 weeks of modeling, compared with the blank group, the residence time in the central area, average speed and total distance of open field were significantly lower (P<0.000 1, P<0.01, P<0.001)；the protein expression levels of DMT1 and Bax in the substantia nigra were increased (P<0.001, P<0.000 1), while the protein expression levels of FPN1, GPX4 and Bcl-2, and the optical density of TH+ cells in the substantia nigra were decreased (P<0.000 1, P<0.001) in the model group. In comparison with the model group, the residence time in the central area, average speed, and total distance of the EA group were increased (P<0.01, P<0.05)；the protein expression levels of DMT1 and Bax in the substantia nigra were decreased (P<0.01, P<0.001), while the protein expression levels of FPN1, GPX4, and Bcl-2, and the optical density of TH+ cells in the substantia nigra were increased (P<0.000 1, P<0.01, P<0.001, P<0.05). CONCLUSIONS: EA has a protective effect on dopaminergic neurons in the substantia nigra of midbrain in PD model mice, which may be related with its effect in regulating oxidative stress and cell apoptosis induced by ferroptosis.

Purple pitanga extract (Eugenia uniflora) attenuates oxidative stress induced by MPTP.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been widely used due to its specific and reproducible neurotoxic effect on the nigrostriatal system, being considered a convenient model of dopaminergic neurodegeneration to study interventions therapeutics. The purple pitanga (Eugenia uniflora) is a polyphenol-rich fruit with antioxidant and antidepressant properties, among others. Therefore, this study investigated the effect of purple pitanga extract (PPE) on acute early oxidative stress induced by intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in rats. Male Wistar rats were pre-treated orally with PPE (1000 mg/kg) or vehicle. After 24 h, MPTP (0.1 mg/10µL/nostril) or vehicle was administered bilaterally into the animal's nostrils, and 6 h later, the olfactory bulb (OB), striatum (ST), and substantia nigra (SN) were collected to evaluate the oxidative stress parameters. Our findings revealed that OB and SN were the most affected areas after 6 h of MPTP infusion; an early increase in reactive oxygen species (ROS) levels was observed, while pretreatment with a single dose of PPE prevented this increment. No differences in thiobarbituric acid reactive species (TBARS) and 3-nitrotyrosine (3-NT) formation were observed, although 4-hydroxy-2-nonenal (4-HNE) levels increased, which is the most toxic form of lipid peroxidation, in the MPTP group. The PPE pretreatment could prevent this increase by increasing the NPSH levels previously decreased by MPTP. Furthermore, PPE prevents the Na+/K + ATPase strongly inhibited by MPTP, showing the neuroprotective capacity of the PPE by inhibiting the MPTP-generated oxidation. Thus, we demonstrated for the first time the antioxidant and neuroprotective effects of PPE against the early MPTP neurotoxicity.

Therapeutic Effects of Geranium Oil in MPTP-Induced Parkinsonian Mouse Model.

Parkinson's disease (PD) is an incurable neurodegenerative disease characterized by motor and non-motor disabilities resulting from neuronal cell death in the substantia nigra and striatum. Microglial activation and oxidative stress are two of the primary mechanisms driving that neuronal death. Here, we evaluated the effects of geranium oil on 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine (MPTP) mouse model for PD, on microglial activation, and oxidative stress. We demonstrate that oral treatment with geranium oil improved motor performance in this model. The therapeutic effects of geranium oil were observed as a significant increase in rotarod latency and distance among the mice treated with geranium oil, as compared to vehicle-treated MPTP mice. Geranium oil also prevented dopaminergic neuron death in the substantia nigra of the treated mice. These therapeutic effects can be partially attributed to the antioxidant and anti-inflammatory properties of geranium oil, which were observed as attenuated accumulation of reactive oxygen species and inhibition of the secretion of proinflammatory cytokines from geranium oil-treated activated microglial cells. A repeated-dose oral toxicity study showed that geranium oil is not toxic to mice. In light of that finding and since geranium oil is defined by the FDA as generally recognized as safe (GRAS), we do not foresee any toxicity problems in the future and suggest that geranium oil may be a safe and effective oral treatment for PD. Since the MPTP model is only one of the preclinical models for PD, further studies are needed to confirm that geranium oil can be used to prevent or treat PD.

Zinc Deficiency Exacerbates Behavioral Impediments and Dopaminergic Neuron Degeneration in a Mouse Model of Parkinson Disease.

BACKGROUND: Circulating zinc (Zn) concentrations are lower than normal in patients with Parkinson disease (PD). It is unknown whether Zn deficiency increases the susceptibility to PD. OBJECTIVES: The study aimed to investigate the effect of dietary Zn deficiency on behaviors and dopaminergic neurons in a mouse model of PD and to explore potential mechanisms. METHODS: Male C57BL/6J mice aged 8-10 wk were fed Zn adequate (ZnA; 30 µg/g) or Zn deficient (ZnD; <5 µg/g) diet throughout the experiments. Six weeks later 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was injected to generate the PD model. Controls were injected with saline. Thus, 4 groups (Saline-ZnA, Saline-ZnD, MPTP-ZnA, and MPTP-ZnD) were formed. The experiment lasted 13 wk. Open field test, rotarod test, immunohistochemistry, and RNA sequencing were performed. Data were analyzed with t-test, 2-factor ANOVA, or Kruskal-Wallis test. RESULTS: Both MPTP and ZnD diet treatments led to a significant reduction in blood Zn concentrations (PMPTP = 0.012, PZn = 0.014), reduced total distance traveled (PMPTP < 0.001, PZn = 0.031), and affected the degeneration of dopaminergic neurons in the substantia nigra (PMPTP < 0.001, PZn = 0.020). In the MPTP-treated mice, the ZnD diet significantly reduced total distance traveled by 22.4% (P = 0.026), decreased latency to fall by 49.9% (P = 0.026), and reduced dopaminergic neurons by 59.3% (P = 0.002) compared with the ZnA diet. RNA sequencing analysis revealed a total of 301 differentially expressed genes (156 upregulated; 145 downregulated) in the substantia nigra of ZnD mice compared with ZnA mice. The genes were involved in a number of processes, including protein degradation, mitochondria integrity, and α-synuclein aggregation. CONCLUSIONS: Zn deficiency aggravates movement disorders in PD mice. Our results support previous clinical observations and suggest that appropriate Zn supplementation may be beneficial for PD.

Pharmacological characterization of the small molecule 03A10 as an inhibitor of α-synuclein aggregation for Parkinson's disease treatment.

Aggregation of α-synuclein, a component of Lewy bodies (LBs) or Lewy neurites in Parkinson's disease (PD), is strongly linked with disease development, making it an attractive therapeutic target. Inhibiting aggregation can slow or prevent the neurodegenerative process. However, the bottleneck towards achieving this goal is the lack of such inhibitors. In the current study, we established a high-throughput screening platform to identify candidate compounds for preventing the aggregation of α-synuclein among the natural products in our in-house compound library. We found that a small molecule, 03A10, i.e., (+)-desdimethylpinoresinol, which is present in the fruits of Vernicia fordii (Euphorbiaceae), modulated aggregated α-synuclein, but not monomeric α-synuclein, to prevent further elongation of α-synuclein fibrils. In α-synuclein-overexpressing cell lines, 03A10 (10 µM) efficiently prevented α-synuclein aggregation and markedly ameliorated the cellular toxicity of α-synuclein fibril seeds. In the MPTP/probenecid (MPTP/p) mouse model, oral administration of 03A10 (0.3 mg· kg-1 ·d-1, 1 mg ·kg-1 ·d-1, for 35 days) significantly alleviated behavioral deficits, tyrosine hydroxylase (TH) neuron degeneration and p-α-synuclein aggregation in the substantia nigra (SN). As the Braak hypothesis postulates that the prevailing site of early PD pathology is the gastrointestinal tract, we inoculated α-synuclein preformed fibrils (PFFs) into the mouse colon. We demonstrated that α-synuclein PFF inoculation promoted α-synuclein pathology and neuroinflammation in the gut and brain; oral administration of 03A10 (5 mg· kg-1 ·d-1, for 4 months) significantly attenuated olfactory deficits, α-synuclein accumulation and neuroinflammation in the olfactory bulb and SN. We conclude that 03A10 might be a promising drug candidate for the treatment of PD. 03A10 might be a novel drug candidate for PD treatment, as it inhibits α-synuclein aggregation by modulating aggregated α-synuclein rather than monomeric α-synuclein to prevent further elongation of α-synuclein fibrils and prevent α-synuclein toxicity in vitro, in an MPTP/p mouse model, and PFF-inoculated mice.

Neuroprotective potential of plant derived parenchymal stem cells extract on environmental and genetic models of Parkinson disease through attenuation of oxidative stress and neuroinflammation.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by both motor and non-motor features. The current treatment regimen for PD are dopamine enhancers which have been reported to worsen the disease prognosis after long term treatment, thus, the need for better treatment options. This study sought to investigate the protective action of Double Stem Cell® (DSC), a blend of stem cells extracts from Swiss apples (Malus Domestica) and Burgundy grapes (Vitis vinifera) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism in mice and genetic model of PD in Drosophila melanogaster. Male albino mice were pretreated with MPTP (4 × 20 mg/kg, i.p., two hourly in 8 h), twelve hours before administration of DSC (8, 40, or 200 mg/kg, p.o.). Thereafter, behavioural, biochemical and immunohistochemical assays were carried out. The impact of vehicle or DSC supplementation on α-synuclein aggregation was evaluated in Drosophila melanogaster using the UAS-Gal4 system, female DDC-Gal4 flies were crossed with male UAS-α-synuclein, the progenies were examined for fecundity, locomotion, memory, and lifespan. MPTP-induced motor deficits in open field test (OFT), working memory impairment (Y-maze test (YMT)) and muscle incoordination (rotarod test) were ameliorated by DSC (8, 40 or 200 mg/kg) through dose-dependent and significant improvements in motor, cognitive and motor coordination. Moreso, MPTP exposure caused significant increase in lipid peroxidation and decrease in antioxidant enzymes activities (glutathione, catalase and superoxide dismutase) in the midbrain which were attenuated by DSC. MPTP-induced expression of microglia (iba-1), astrocytes (glia fibrillary acidic protein; GFAP) as well as degeneration of dopamine neurons (tyrosine hydroxylase positive neurons) in the substantia nigra (SN) were reversed by DSC. Supplementation of flies feed with graded concentration of DSC (0.8, 4 or 20 mg/ml) did not affect fecundity but improved climbing activity and lifespan. Findings from this study showed that Double Stem Cell improved motor and cognitive functions in both mice and Drosophila through attenuation of neurotoxin-induced oxidative stress and neuroinflammation.

Ca2+ channels couple spiking to mitochondrial metabolism in substantia nigra dopaminergic neurons.

How do neurons match generation of adenosine triphosphate by mitochondria to the bioenergetic demands of regenerative activity? Although the subject of speculation, this coupling is still poorly understood, particularly in neurons that are tonically active. To help fill this gap, pacemaking substantia nigra dopaminergic neurons were studied using a combination of optical, electrophysiological, and molecular approaches. In these neurons, spike-activated calcium (Ca2+) entry through Cav1 channels triggered Ca2+ release from the endoplasmic reticulum, which stimulated mitochondrial oxidative phosphorylation through two complementary Ca2+-dependent mechanisms: one mediated by the mitochondrial uniporter and another by the malate-aspartate shuttle. Disrupting either mechanism impaired the ability of dopaminergic neurons to sustain spike activity. While this feedforward control helps dopaminergic neurons meet the bioenergetic demands associated with sustained spiking, it is also responsible for their elevated oxidant stress and possibly to their decline with aging and disease.

Lippia grata essential oil complexed with ß-cyclodextrin ameliorates biochemical and behavioral deficits in an animal model of progressive parkinsonism.

Parkinson's disease (PD) is identified by the loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNpc), and is correlated to aggregates of proteins such as α-synuclein, Lewy's bodies. Although the PD etiology remains poorly understood, evidence suggests a main role of oxidative stress on this process. Lippia grata Schauer, known as "alecrim-do-mato", "alecrim-de-vaqueiro", "alecrim-da-chapada", is a native bush from tropical areas mainly distributed throughout the Central and South America. This plant species is commonly used in traditional medicine for relief of pain and inflammation conditions, and that has proven antioxidant effects. We evaluated the effects of essential oil of the L. grata after its complexed with ß-cyclodextrin (LIP) on PD animal model induced by reserpine (RES). Behavioral assessments were performed across the treatment. Upon completion the treatment, the animals were euthanized, afterwards their brains were isolated and processed for immunohistochemical and oxidative stress analysis. The LIP treatment delayed the onset of the behavior of catalepsy, decreased the number of oral movements and prevented the memory impairment on the novel object recognition task. In addition, the treatment with LIP protected against dopaminergic depletion in the SNpc and dorsal striatum (STRd), and decreased the α-syn immunoreactivity in the SNpc and hippocampus (HIP). Moreover, there was reduction of the oxidative stability index. These findings demonstrated that the LIP treatment has neuroprotective effect in a progressive parkinsonism model, suggesting that LIP could be an important source for novel treatment approaches in PD.

Calcium carbonate supplementation causes motor dysfunction.

We previously showed that a diet containing calcium carbonate causes impairments in spatial and recognition memory in mice. In this study, we investigated the effects of calcium carbonate supplementation on motor function. Motor function was determined using different tests that have been used to analyze different aspects of Parkinsonism. A catalepsy test for akinesia; a muscular strength assessment, pole test, beam-walking test, and gait analysis for motor coordination and balance assessment; and an open-field test for locomotor activity assessment were performed. The mice were fed diets containing 0.6% or 1.0% calcium carbonate for eight weeks, after which they were evaluated for motor functions. The diets containing calcium carbonate caused significant motor dysfunction, as revealed by the different tests, although the spontaneous locomotor activity did not change. Calcium carbonate supplementation decreased the dopamine content in the basal ganglia, including the striatum and substantia nigra, and the number of tyrosine hydroxylase-positive neurons in the substantia nigra. In addition, administration of L-dopa led to at least a partial recovery of motor dysfunction, suggesting that calcium carbonate supplementation causes motor dysfunction by decreasing the dopamine content in the basal ganglia. These results suggest that mice with calcium carbonate-induced motor dysfunction may be useful as a new animal model for Parkinson's disease and Huntington's disease.

In situ analysis of acupuncture protecting dopaminergic neurons from lipid peroxidative damage in mice of Parkinson's disease.

OBJECTIVES: Acupuncture stimulation has proven to protect dopaminergic neurons from oxidative damage in animal models of Parkinson's disease (PD), but it remains unclear about the in situ information of biochemical components in dopaminergic neurons. Here, we aimed to analyse in situ changes of biochemical components and lipid peroxidation levels in dopaminergic neurons in PD mice treated with acupuncture by synchrotron FTIR micro-spectroscopy technique. MATERIALS AND METHODS: About 9-10-week-old C57BL/6 mice were used to establish PD model by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg for 5 days). Acupuncture stimulation was performed once a day for 12 days. Behaviour test was determined using the rotarod instrument. Biochemical compositions of dopaminergic neurons in substantia nigra pars compacta were analysed by synchrotron FTIR micro-spectroscopy technique. The number and ultrastructure of dopaminergic neurons were respectively observed by immunofluorescence and transmission electron microscopy (TEM). RESULTS: We found that the number and protein expression of dopaminergic neurons in MPTP-treated mice were reduced by about half, while that in the mice treated by acupuncture were significantly restored. Acupuncture treatment also restored the motor ability of PD mice. The results of single cell imaging with synchrotron FTIR micro-spectroscopy technique showed that the proportion of lipid in MPTP treated mice increased significantly. Especially the ratio of CH2 asymmetric stretching and CH3 asymmetric stretching increased significantly, suggesting that MPTP induced lipid peroxidation damage of dopaminergic neurons. It is also supported by the result of TEM, such as mitochondrial swelling or atrophy, loss of mitochondrial crests and mitochondrial vacuolization. Compared with MPTP treated mice, the proportion of lipid in acupuncture treated mice decreased and the mitochondrial structure was restored. CONCLUSIONS: Acupuncture can inhibit the level of lipid peroxides in dopaminergic neurons and protect neurons from oxidative damage. The study provides a promising method for in situ analysis of biochemical compositions in PD mice and reveals the mechanism of acupuncture in treating neurodegenerative diseases.

Nrf2 Deficiency Attenuates Testosterone Efficiency in Ameliorating Mitochondrial Function of the Substantia Nigra in Aged Male Mice.

Reduced testosterone level is a common feature of aging in men. Aging, as a risk factor for several neurodegenerative disorders, shows declined mitochondrial function and downregulated mitochondrial biogenesis and mitochondrial dynamics. Mitochondrial biogenesis and mitochondrial dynamics are crucial in maintaining proper mitochondrial function. Supplementation with testosterone is conducive to improving mitochondrial function of males during aging. Nuclear factor erythroid 2-related factor 2 (Nrf2), a regulator of redox homeostasis, is involved in the ameliorative effects of testosterone supplementation upon aging. To explore Nrf2 role in the effects of testosterone supplementation on mitochondrial function during aging, we studied the efficiency of testosterone supplementation in improving mitochondrial function of Nrf2 knockout- (KO-) aged male mice by analyzing the changes of mitochondrial biogenesis and mitochondrial dynamics. It was found that wild-type- (WT-) aged male mice showed low mitochondrial function and expression levels of PGC-1α, NRF-1\NRF-2, and TFAM regulating mitochondrial biogenesis, as well as Drp1, Mfn1, and OPA1 controlling mitochondrial dynamics in the substantia nigra (SN). Nrf2 KO aggravated the defects above in SN of aged male mice. Testosterone supplementation to WT-aged male mice significantly ameliorated mitochondrial function and upregulated mitochondrial biogenesis and mitochondrial dynamics, which were not shown in Nrf2 KO-aged male mice due to Nrf2 deficiency. Testosterone deficiency by gonadectomy (GDX) decreased mitochondrial function, downregulated mitochondrial biogenesis, and altered mitochondrial dynamics balance in young male mice. Supplementation with testosterone to Nrf2 KO-GDX mice only ameliorated the alterations above but did not reverse them to sham level. Nrf2 deficiency attenuated testosterone efficiency in ameliorating mitochondrial function in the SN of aged male mice through mitochondrial biogenesis and mitochondrial dynamics to some extent. Activation of Nrf2 might contribute to testosterone-upregulating mitochondrial biogenesis and mitochondrial dynamics in the SN during aging to produce efficient mitochondria for ATP production.

[Neuroprotective effect of cinnamaldehyde in MPTP-induced mouse model of subacute Parkinson's disease].

This paper aims to explore the neuroprotective effect of cinnamaldehyde(CA) in mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced subacute Parkinson's disease(PD) and the mechanism. To be specific, male C57 BL/6 mice(n=72, SPF) were randomized into control group, model group, positive control(madopar 0.1 mg·g~(-1)) group, and low-dose, me-dium-dose, and high-dose CA groups(0.15, 0.30, 0.60 mg·g~(-1)). MPTP(intraperitoneal injection, 0.03 mg·g~(-1), once a day for 5 days) was used to induce subacute PD in mice except for the control group. The administration began from the day of modeling and lasted 19 days. On the 0 th, 12 th, and 19 th day, the open field test, pole test, and rotarod test were carried out. After the tests, the mice were killed and brains were separated. In addition, the organ index was measured. The number of cells in substantia nigra(SN) in the midbrain of MPTP-induced PD model mice was detected based on hematoxylin and eosin(HE) staining. The levels of tyrosine hydroxylase(TH)-and α-synuclein(α-Syn)-positive cells in SN were determined by immunohistochemical staining, and the protein levels of TH and α-Syn in SN by Western blot. The results showed that the MPTP-stimulated mice had abnormal behaviors such as erect hair, arched back, rigidity of the tail, slow movement, and tremor, decreased number of crossings and rearing, increased frequency of urination and defecation, longer time of pole climbing, and shorter time of staying on the rotating rod. In addition, the mice showed obvious damage of neurons in the SN and reduced neuron cells in irregular arrangement with some shrinking. In addition, the average optical density of TH in SN decreased and that of α-Syn increased. All these suggested the successful modeling. CA displayed obvious therapeutic effect on the PD mice, as manifested by the increased number of crossings and rearing, decreased frequency of urination and defecation, shorter time of climbing pole, longer time of staying on the rotating rod, and more neuron cells in the SN with a few pykno-tic cells. Moreover, CA significantly alleviated the decrease of TH and the overexpression of α-Syn in SN. As a result, the MPTP-induced injury of dopaminergic neurons was alleviated. The performance of 0.3 mg·g~(-1) CA was the best. This study is expected to lay a scientific basis for the development of CA products.

[Electroacupuncture improves behavioral activities by suppressing neuroinflammation and TLR4/NF-κB signaling in substantia nigra of midbrain in Parkinson's disease rats].

OBJECTIVE: To observe the effect of electroacupuncture(EA) at "Fengfu" (GV16) and "Taichong"(LR3) on the expression of tyrosine hydroxylase (TH), α-synuclein (α-syn) and microglial-related microglial (MG), Toll-like receptor 4（TLR4）/nuclear factor kappa B （NF-κB） signaling pathway in the substantia nigra (SN) of midbrain in Rotenone-induced Parkinson's disease (PD) rats, so as to explore its mechanisms underlying improvement of PD. METHODS: SD male rats were randomly divided into normal control, PD model and EA groups (n=12 in each group). The PD model was established by subcutaneous injection of rotenone (1 mg/kg) at the back of neck. EA (2 Hz, 1 mA) was applied to bilateral GV16 and LR3, once daily for 2 weeks. The rats' behavior(hair color, reaction capacity, locomotion and gait state)scores (0-10 points) were given and the autonomic movement state (trajectory of autonomous motion, total distance, average speed and duration of motion in 8 min) was detected by using open field tests. The immunoactivity of TH and α-syn in the SN tissue were determined by using immunohistochemistry staining, and the number of Iba-1-labelled microglia (MG) was detected by using immunofluorescence staining. The expression levels of TLR4 and NF-κB P65 proteins in the SN were detected by Western blot, and the contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the SN were determined by using enzyme-linked immunosorbent assay. RESULTS: In comparison with the normal group, the behavioral score, α-syn immunoactivity, number of Iba-1 labelled microglia, expression of TLR4 and NF-κB P65 proteins and the contents of TNF-α and IL-6 in the SN were significantly increased (P<0.01), whereas the total distance, average speed, duration of motion of the autonomic movement in 8 min, and the TH immunoactivity were remarkably decreased in the model group (P<0.01). After EA intervention, compared with the model group, the increase of the behavioral score, α-syn immunoactivity, number of Iba-1-labelled microglia, expression of TLR4 and NF-κB P65 proteins, the contents of TNF-α and IL-6 in the SN, and the decrease of the total distance, average speed, duration of motion of the autonomic movement in 8 min, and the TH immunoactivity were reversed (P<0.05, P<0.01). CONCLUSION: EA can improve the behavioral manifestations of PD rats, which may be associated with its functions in down-regulating the abnormal accumulation of pathological α-syn, TLR4/NF-κB signaling, inhibiting activities of microglia and in up-regulating the expression of TH in the SN of midbrain.

Iron as the concert master in the pathogenic orchestra playing in sporadic Parkinson's disease.

About 60 years ago, the discovery of a deficiency of dopamine in the nigro-striatal system led to a variety of symptomatic therapeutic strategies to supplement dopamine and to substantially improve the quality of life of patients with Parkinson's disease (PD). Since these seminal developments, neuropathological, neurochemical, molecular biological and genetic discoveries contributed to elucidate the pathology of PD. Oxidative stress, the consequences of reactive oxidative species, reduced antioxidative capacity including loss of glutathione, excitotoxicity, mitochondrial dysfunction, proteasomal dysfunction, apoptosis, lysosomal dysfunction, autophagy, suggested to be causal for ɑ-synuclein fibril formation and aggregation and contributing to neuroinflammation and neural cell death underlying this devastating disorder. However, there are no final conclusions about the triggered pathological mechanism(s) and the follow-up of pathological dysfunctions. Nevertheless, it is a fact, that iron, a major component of oxidative reactions, as well as neuromelanin, the major intraneuronal chelator of iron, undergo an age-dependent increase. And ageing is a major risk factor for PD. Iron is significantly increased in the substantia nigra pars compacta (SNpc) of PD. Reasons for this finding include disturbances in iron-related import and export mechanisms across the blood-brain barrier (BBB), localized opening of the BBB at the nigro-striatal tract including brain vessel pathology. Whether this pathology is of primary or secondary importance is not known. We assume that there is a better fit to the top-down hypotheses and pathogens entering the brain via the olfactory system, then to the bottom-up (gut-brain) hypothesis of PD pathology. Triggers for the bottom-up, the dual-hit and the top-down pathologies include chemicals, viruses and bacteria. If so, hepcidin, a regulator of iron absorption and its distribution into tissues, is suggested to play a major role in the pathogenesis of iron dyshomeostasis and risk for initiating and progressing ɑ-synuclein pathology. The role of glial components to the pathology of PD is still unknown. However, the dramatic loss of glutathione (GSH), which is mainly synthesized in glia, suggests dysfunction of this process, or GSH uptake into neurons. Loss of GSH and increase in SNpc iron concentration have been suggested to be early, may be even pre-symptomatic processes in the pathology of PD, despite the fact that they are progression factors. The role of glial ferritin isoforms has not been studied so far in detail in human post-mortem brain tissue and a close insight into their role in PD is called upon. In conclusion, "iron" is a major player in the pathology of PD. Selective chelation of excess iron at the site of the substantia nigra, where a dysfunction of the BBB is suggested, with peripherally acting iron chelators is suggested to contribute to the portfolio and therapeutic armamentarium of anti-Parkinson medications.

Differential Effect of Iron and Myelin on Susceptibility MRI in the Substantia Nigra.

Background The heterogeneous composition of substantia nigra (SN), including iron, nigrosome-1 substructure, and myelinated white matter, complicates the interpretation of MRI signals. Purpose To investigate R2* and quantitative susceptibility mapping (QSM) in the SN subdivisions of participants with Parkinson disease and healthy control subjects. Materials and Methods In this prospective study conducted from November 2018 to November 2019, participants with Parkinson disease and sex-matched healthy control subjects underwent 3-T MRI. R2* and QSM values were measured and compared in the anterior SN and posterior SN at the rostral (superior) and caudal (inferior) levels. Postmortem MRI and histology correlation of midbrain tissues was evaluated to investigate the effect of myelin and iron in the SN on R2* and QSM values. Results Forty individuals were evaluated: 20 healthy control subjects (mean age, 61 years ± 3 [standard deviation]; 10 men) and 20 participants with Parkinson disease (mean age, 61 years ± 4; 10 men). The R2* values of participants with Parkinson disease were higher in all subdivisions of the SN compared with R2* values in healthy control subjects (all P < .05). For QSM, no evidence of a difference was found in the rostral posterior SN (healthy control subjects, 54.1 ppb ± 21.0; Parkinson disease, 62.2 ppb ± 19.8; P = .49). The combination of rostral R2* and caudal QSM values resulted in an area under the receiver operating characteristic curve of 0.84. R2* values showed higher correlation with QSM values at the caudal level than at the rostral level within each group (all P < .001). Postmortem investigation demonstrated that R2* and QSM values showed weak correlation in the myelin-rich areas (r = 0.22 and r = 0.36, P < .001) and strong correlation in myelin-scanty areas (r ranged from approximately 0.52 to approximately 0.78, P < .001) in the SN. Conclusion Considering the iron and myelin distribution in the substantia nigra subdivisions, the subdivisional analysis of substantia nigra using R2* and quantitative susceptibility mapping might aid in specifically differentiating individuals with Parkinson disease from healthy control subjects. © RSNA, 2021 Online supplemental material is available for this article.

Complementary Transcriptomic and Proteomic Analysis in the Substantia Nigra of Parkinson's Disease.

Parkinson's disease (PD) is a disease that involves brain damage and is associated with neuroinflammation, mitochondrial damage, and cell aging. However, the pathogenic mechanism of PD is still unknown. Sequencing data and proteomic data can describe the fluctuation of molecular abundance in diseases at the mRNA level and protein level, respectively. In order to explore new targets in the pathogenesis of PD, the study analyzed molecular changes from the database by combining transcriptomic and proteomic analysis. Differentially expressed genes and differentially abundant proteins were summarized and analyzed. Enrichment and cluster analysis emphasized the importance of neurotransmitter release, mitochondrial damage, and vesicle transport. The molecular network revealed a subnetwork of 9 molecules related to SCNA and TH and revealed hub gene with differential expression at both mRNA and protein levels. It found that ACHE and CADPS could be used as new targets in PD, emphasizing that impaired nerve signal transmission and vesicle transport affect the pathogenesis of PD. Our research emphasized that the joint analysis and verification of transcriptomics and proteomics were devoted to understanding the comprehensive views and mechanism of pathogenesis in PD.

Effect of Roucongrong (Herba Cistanches Deserticolae) decoction on the substantia nigra through Wnt/ß-catenin signaling pathway in rats with Parkinson's disease induced by 6-hydroxydopamine hydrochloride.

OBJECTIVE: To investigate the effect of Roucongrong (Herba Cistanches Deserticolae) decoction on the substantia nigra in rats with Parkinson's disease (PD) induced by 6-hydroxydopamine hydrochloride (6-OHDA). To further determine whether the Wnt/ß-catenin signaling pathway is involved in the action. METHODS: A rat model of PD was established by intracranial injection of 6-OHDA. Subsequently, three concentrations of Roucongrong (Herba Cistanches Deserticolae) decoction were prepared and administered to rats by gavage therapy for 14 d. Behavioral changes were measured in PD rats. In vivo tyrosine hydroxylase (TH) levels in the substantia nigra were examined by immunohistochemistry. Additionally, gene and protein expression levels of members of the Wnt/ß-catenin signaling pathway were examined by Western blotting and polymerase chain reaction. Lastly, a Wnt/ß-catenin inhibitor was used to investigate the mechanism of action in 1-methyl-4-phenylpyridinium (MPP + )- treated MES23.5 cells in vitro. RESULTS: Roucongrong (Herba Cistanches Deserticolae) decoction improved performance in the stride and gait adjustment tests in PD rats. It also increased TH in the substantia nigra and altered the expression of genes and proteins in the Wnt/ß-catenin signaling pathway. Wnt/ß-catenin inhibitor reduced the effect of Roucongrong (Herba Cistanches Deserticolae) decoction in MPP +-treated MES23.5 cells. CONCLUSION: Roucongrong (Herba Cistanches Deserticolae) decoction may promote neuronal survival in PD in vivo and in vitro by increasing TH content in the substantia nigra and by activating the Wnt/ß-catenin signaling pathway.