The aim of this study is to investigate the protective effect of idebenone (IDE) combined with borneol (BO) against Parkinson's disease (PD). In this study, wild-type AB zebrafish and transgenic Tg ( vmat2: GFP) zebrafish with green fluorescence labeled dopamine neurons were used to establish the PD model with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP). Following drug treatment, the behavioral performance and dopamine neuron morphology of zebrafish were evaluated, and regulation of dopamine signaling pathway-related genes was determined using RT-qPCR. The results showed that IDE combined with BO improved the behavioral disorders of zebrafish such as bradykinesia and shortening movement distance, also effectively reversed the damage of MPTP-induced dopaminergic neurons. At the same time, the expression of dopamine synthesis and transportation-related genes was up-regulated, and the normal function of the signal transduction pathway was restored. The combination showed a better therapeutic effect compared to the IDE monotherapy group. This study reveals the protective mechanism of IDE combined with BO on the central nervous system for the first time, which provides an important experimental basis and theoretical reference for clinical combination strategy in PD treatment.
Animals ; Zebrafish ; Signal Transduction/drug effects* ; Animals, Genetically Modified ; Dopamine/metabolism* ; Neuroprotective Agents/pharmacology* ; Disease Models, Animal ; Camphanes/pharmacology* ; Ubiquinone/pharmacology* ; Parkinson Disease/drug therapy* ; Dopaminergic Neurons/metabolism*

Parkinson's disease (PD), a chronic and common neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the dense part of the substantia nigra and abnormal aggregation of alpha-synuclein. Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by chronic insulin resistance and deficiency in insulin secretion. Extensive evidence has confirmed shared pathogenic mechanisms underlying PD and T2DM, such as oxidative stress caused by insulin resistance, mitochondrial dysfunction, inflammation, and disorders of energy metabolism. Conventional drugs for treating T2DM, such as metformin and glucagon-like peptide-1 receptor agonists, affect nerve repair. Even drugs for treating PD, such as levodopa, can affect insulin secretion. This review summarizes the relationship between PD and T2DM and related therapeutic drugs from the perspective of insulin signaling pathways in the brain.
Humans ; Parkinson Disease/drug therapy* ; Diabetes Mellitus, Type 2/pathology* ; Signal Transduction/physiology* ; Receptor, Insulin/metabolism* ; Animals ; Insulin Resistance/physiology* ; Insulin/metabolism*

Under the guidance of the traditional Chinese medicine(TCM) theory of "Zangfu-organs of spleen and stomach" and the modern theory of "microbiota-gut-brain axis", this study explored the effects of Nardostachys jatamansi on the gut microbiota of rats with Parkinson's disease(PD). The 40 SD rats were randomly divided into the control group, PD model group, levodopa group, and Nardostachys jatamansi ethanol extract group. The PD model was established by subcutaneous injection of rotenone in the neck and back area. After 14 days of intragastric administration, the PD rats' behaviors were analyzed through open field test, inclined plane test, and pole test. After the behavioral tests, the striatum, colon, and colon contents of rats in each group were collected. Western blot was employed to detect the protein expression of tyrosine hydroxylase(TH) and α-synuclein(α-syn) in striatum and that of α-syn in colon. Enzyme linked immunosorbent assay(ELISA) was used to detect the levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), and nuclear factor-kappa B(NF-κB) in striatum and colon. High-throughput sequencing of 16 S rRNA gene was conducted to detect the differences in microbial diversity, abundance, differential phyla, and dominant bacteria of rats between groups. The results indicated that Nar. ethanol extract could relieve dyskinesia, reverse the increased levels of α-syn, TNF-α, IL-1β, and NF-κB in striatum, and improve the protein expression of TH in striatum of PD rats. The α diversity analysis indicated a significant decrease in diversity and abundance of gut microbiota in the PD model. The results of linear discriminant analysis effect size(LEfSe) of dominant bacteria indicated that Nardostachys jatamansi ethanol extract increased the relative abundance of Clotridiaceae, Lachnospiraceae, and Anaerostipes, and reversed the increased relative abundance of Proteobacteria, Gammaproteobacteria, Enterobacteriaceae, and Escherichia-Shigella in PD model group to exhibit the neuroprotective effect. In summary, the results indicated that Nar. ethanol extract exert the therapeutic effect on PD rats. Specifically, the extract may regulate gut microbiota, decrease the levels of proinflammatory cytokines, and reduce the protein aggregation of α-syn in the colon and striatum to alleviate intestinal inflammation and neuroinflammation. This study provides a basis for combining the theory of "Zangfu-organs of spleen and stomach" with the theory of "microbiota-gut-brain axis" to treat PD.
Animals ; Gastrointestinal Microbiome ; NF-kappa B/metabolism* ; Nardostachys/metabolism* ; Parkinson Disease/drug therapy* ; Rats ; Rats, Sprague-Dawley

Previous studies have shown that electroacupuncture (EA) promotes recovery of motor function in Parkinson's disease (PD). However the mechanisms are not completely understood. Clinically, the subthalamic nucleus (STN) is a critical target for deep brain stimulation treatment of PD, and vesicular glutamate transporter 1 (VGluT1) plays an important role in the modulation of glutamate in the STN derived from the cortex. In this study, a 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD was treated with 100 Hz EA for 4 weeks. Immunohistochemical analysis of tyrosine hydroxylase (TH) showed that EA treatment had no effect on TH expression in the ipsilateral striatum or substantia nigra pars compacta, though it alleviated several of the parkinsonian motor symptoms. Compared with the hemi-parkinsonian rats without EA treatment, the 100 Hz EA treatment significantly decreased apomorphine-induced rotation and increased the latency in the Rotarod test. Notably, the EA treatment reversed the 6-OHDA-induced down-regulation of VGluT1 in the STN. The results demonstrated that EA alleviated motor symptoms and up-regulated VGluT1 in the ipsilateral STN of hemi-parkinsonian rats, suggesting that up-regulation of VGluT1 in the STN may be related to the effects of EA on parkinsonian motor symptoms via restoration of function in the cortico-STN pathway.
Adrenergic Agents ; toxicity ; Animals ; Apomorphine ; pharmacology ; Disease Models, Animal ; Dopamine Agonists ; pharmacology ; Electroacupuncture ; methods ; Functional Laterality ; drug effects ; Male ; Medial Forebrain Bundle ; injuries ; Motor Activity ; drug effects ; physiology ; Neurons ; drug effects ; metabolism ; Oxidopamine ; toxicity ; Parkinson Disease, Secondary ; chemically induced ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Subthalamic Nucleus ; drug effects ; metabolism ; pathology ; Tyrosine 3-Monooxygenase ; metabolism ; Up-Regulation ; drug effects ; physiology ; Vesicular Glutamate Transport Protein 1 ; metabolism

OBJECTIVETo 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.

METHODSThe 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).

CONCLUSIONBC could increase DA content in PD model mice with the optimal proportion as 54.00: 44.88: 82.50.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; Animals ; Disease Models, Animal ; Dopamine ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Mass Spectrometry ; Mice ; Mice, Inbred C57BL ; Motor Activity ; Parkinson Disease ; drug therapy ; metabolism

BACKGROUNDNurr1 plays an essential role in the development, survival, and function maintenance of midbrain dopaminergic (DA) neurons, and it is a potential target for Parkinson's disease (PD). Nurr1 mRNA can be detected in peripheral blood mononuclear cells (PBMCs), but whether there is any association of altered Nurr1 expression in PBMC with the disease and DA drug treatments remains elusive. This study aimed to measure the Nurr1 mRNA level in PBMC and evaluate the effect of Nurr1 expression by DA agents in vivo and in vitro.

METHODSThe mRNA levels of Nurr1 in PBMC of four subgroups of 362 PD patients and 193 healthy controls (HCs) using real-time polymerase chain reaction were measured. The nonparametric Mann-Whitney U-test and Kruskal-Wallis test were performed to evaluate the differences between PD and HC, as well as the subgroups of PD. Multivariate linear regression analysis was used to evaluate the independent association of Nurr1 expression with Hoehn and Yahr scale, age, and drug treatments. Besides, the Nurr1 expression in cultured PBMC was measured to determine whether DA agonist pramipexole affects its mRNA level.

RESULTSThe relative Nurr1 mRNA levels in DA agonists treated subgroup were significant higher than those in recent-onset cases without any anti-PD treatments (de novo) (P < 0.001) and HC groups (P < 0.010), respectively. Furthermore, the increase in Nurr1 mRNA expression was seen in DA agonist and L-dopa group. Multivariate linear regression showed DA agonists, L-dopa, and DA agonists were independent predictors correlated with Nurr1 mRNA expression level in PBMC. In vitro, in the cultured PBMC treated with 10 μmol/L pramipexole, the Nurr1 mRNA levels were significantly increased by 99.61%, 71.75%, 73.16% in 2, 4, and 8 h, respectively (P < 0.001).

CONCLUSIONSDA agonists can induce Nurr1 expression in PBMC, and such effect may contribute to DA agonists-mediated neuroprotection on DA neurons.

Adult ; Aged ; Aged, 80 and over ; Dopamine Agonists ; therapeutic use ; Female ; Humans ; Leukocytes, Mononuclear ; drug effects ; metabolism ; Male ; Middle Aged ; Nuclear Receptor Subfamily 4, Group A, Member 2 ; genetics ; Parkinson Disease ; drug therapy ; genetics ; RNA, Messenger ; genetics ; Young Adult

OBJECTIVETo investigate the effect of curcumin on oligomer formation and mitochondrial ATP-sensitive potassium channels (mitoKATP) induced by overexpression or mutation of α-synuclein.

METHODSRecombinant plasmids α-synuclein-pEGFP-A53T and α-synuclein-pEGFP-WT were transfected into PC12 cells by lipofectamin method, and intervened by application of curcumin (20 μmol/L) and 5-hydroxydecanoate (5-HD). Oligomer formation in the cultured cells was identified by Western blotting and Dot blotting. Cytotoxicity and apoptosis of the PC12 cells were measured by lactate dehydrogenase (LDH) and JC-1 assays. mitoKATP were identified by Western blotting and whole cell patch clamp.

RESULTSCurcumin has significantly reduced the oligomer formation induced by overexpression or mutation of α-synuclein in the cultured cells. LDH has decreased by 36.3% and 23.5%, and red/green fluorescence ratio of JC-1 was increased respectively by 48.46% and 50.33% after application of curcumin (P<0.05). Protein expression of Kir6.2 has decreased and mitoKATP channel current has significantly increased (P<0.05).

CONCLUSIONCurcumin can inhibit α-synuclein gene overexpression or mutation induced α-synuclein oligomers formation. It may block apoptosis induced by wild-type overexpression or mutation of α-synuclein. By stabilizing mitochondrial membrane potential. Opening of mitoKATP channel may have been the initiating protective mechanism of apoptosis induced by wild-type overexpression or mutation of α-synuclein. Curcumin may antagonize above cytotoxicity through further opening the mitoKATP channel.

Animals ; Apoptosis ; drug effects ; Cell Line ; Curcumin ; pharmacology ; Humans ; KATP Channels ; chemistry ; genetics ; metabolism ; Mitochondria ; drug effects ; genetics ; metabolism ; Mutation ; drug effects ; PC12 Cells ; Parkinson Disease ; drug therapy ; genetics ; metabolism ; physiopathology ; Rats ; alpha-Synuclein ; genetics

Mammalian cells remove misfolded proteins using various proteolytic systems, including the ubiquitin (Ub)-proteasome system (UPS), chaperone mediated autophagy (CMA) and macroautophagy. The majority of misfolded proteins are degraded by the UPS, in which Ub-conjugated substrates are deubiquitinated, unfolded and cleaved into small peptides when passing through the narrow chamber of the proteasome. The substrates that expose a specific degradation signal, the KFERQ sequence motif, can be delivered to and degraded in lysosomes via the CMA. Aggregation-prone substrates resistant to both the UPS and the CMA can be degraded by macroautophagy, in which cargoes are segregated into autophagosomes before degradation by lysosomal hydrolases. Although most misfolded and aggregated proteins in the human proteome can be degraded by cellular protein quality control, some native and mutant proteins prone to aggregation into beta-sheet-enriched oligomers are resistant to all known proteolytic pathways and can thus grow into inclusion bodies or extracellular plaques. The accumulation of protease-resistant misfolded and aggregated proteins is a common mechanism underlying protein misfolding disorders, including neurodegenerative diseases such as Huntington's disease (HD), Alzheimer's disease (AD), Parkinson's disease (PD), prion diseases and Amyotrophic Lateral Sclerosis (ALS). In this review, we provide an overview of the proteolytic pathways in neurons, with an emphasis on the UPS, CMA and macroautophagy, and discuss the role of protein quality control in the degradation of pathogenic proteins in neurodegenerative diseases. Additionally, we examine existing putative therapeutic strategies to efficiently remove cytotoxic proteins from degenerating neurons.
Alzheimer Disease/drug therapy/metabolism ; Amyloid beta-Peptides/metabolism ; Amyotrophic Lateral Sclerosis/drug therapy/metabolism ; Animals ; Autophagy/drug effects ; DNA-Binding Proteins/metabolism ; Humans ; Huntington Disease/drug therapy/genetics/metabolism ; Lysosomes/metabolism ; Molecular Targeted Therapy ; Mutation ; Nerve Tissue Proteins/genetics/metabolism ; Neurodegenerative Diseases/drug therapy/*metabolism ; Parkinson Disease/drug therapy/metabolism ; PrPSc Proteins/metabolism ; Prion Diseases/drug therapy/metabolism ; Proteasome Endopeptidase Complex/metabolism ; Proteolysis ; Proteostasis Deficiencies/metabolism ; Superoxide Dismutase/metabolism ; Ubiquitin/metabolism ; alpha-Synuclein/metabolism ; tau Proteins/metabolism

OBJECTIVETo investigate the effects of paeonol on neuron cell model of Parkinson disease (PD).

METHODSThe cell model of Parkinson disease was induced by treatment of 1-Methyl-4-phenylpyridinium (MPP+) in PC12 cells, the PD model cells were treated with 1 μmol/L, 3 μmol/L or 9 μmol/L paeonol for 24h, respectively. Cell viability and LDH leakage were detected by MTT and lactate dehydrogenase (LDH) assay; the apoptosis of PC12 cells was assessed by Hoechst 33258 staining and flow cytometry; reactive oxygen species (ROS) production was detected by DCFH-DA method; and the ratio of Bax/Bcl-2 and activation of caspase-3 were determined by Western blotting.

RESULTSMPP+ treatment significantly reduced cell viability, increased LDH leakage, enhanced the proportion of apoptotic cells and ROS production. In addition, MPP+ treatment dramatically increased the Bax/Bcl-2 ratio, and the activation of caspase-3. Compared to PD model group, paeonol treatment significantly enhanced cell viability, decreased LDH leakage, inhibited the proportion of apoptotic cells and ROS production, reduced the Bax/Bcl-2 ratio and the activated caspase-3 protein.

CONCLUSIONPaeonol can prevent PC12 cells from apoptosis induced by MPP+, and the mechanism may be associated with the down-regulation of ROS production, Bax/Bcl-2 ratio and Caspase-3 activation.

1-Methyl-4-phenylpyridinium ; Acetophenones ; pharmacology ; Animals ; Apoptosis ; Caspase 3 ; metabolism ; Cell Survival ; Down-Regulation ; Fluoresceins ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; Parkinson Disease ; drug therapy ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Reactive Oxygen Species ; metabolism ; bcl-2-Associated X Protein ; metabolism

Animals ; Dynorphins ; metabolism ; Parkinson Disease ; drug therapy ; metabolism ; Peptides ; pharmacology ; Rats ; Scorpion Venoms ; pharmacology