Zhen Hong

Validation of the Chinese non-motor symptoms scale for Parkinson's disease: results from a Chinese pilot study.

OBJECTIVESnTo evaluate a Chinese version of the Non-Motor Symptoms Scale (NMSS) in Parkinsons disease (PD) as an instrument for measuring non-motor symptoms (NMSs) in Chinese patients with Parkinsons disease.nnnMETHODSnWe conducted a psychometric analysis of the Chinese version of NMSS using a cross-sectional study of 126 patients with PD. The battery also included the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Mini-Mental State Examination (MMSE), the Geriatric Depression Scale (GDS), and the Hamilton Anxiety Scale (HAMA), and was conducted by neurologists.nnnRESULTSnThere were significant correlations between the NMSS and PSQI scores (rS=0.63, P<0.001), as well as the NMSS and ESS scores (rS=0.38, P<0.001). Furthermore, significant positive correlations between NMSS and GDS, NMSS and HAMA, and NMSS and disease duration were also observed. Importantly, the sleep/fatigue index of the NMSS significantly correlated with the PSQI and ESS findings, the mood/cognition index of the NMSS significantly correlated with the GDS and HAMA findings, and the attention/memory index of the NMSS significantly correlated with the MMSE findings.nnnCONCLUSIONnThe Chinese version of the NMSS can be considered a comprehensive, useful measure for NMS evaluation in Chinese PD patients.

Blockade of the translocation and activation of c-Jun N-terminal kinase 3 (JNK3) attenuates dopaminergic neuronal damage in mouse model of Parkinson's disease

Increasing evidence suggests that c-Jun N-terminal kinase (JNK) is an important kinase mediating neuronal death in Parkinsons disease (PD) model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). JNK3, the only neural-specific isoform, may play an important role in mediating the neurotoxic effects of MPTP in dopaminergic neuronal injury. To analyze the variation in JNK3 activation, the levels of phospho-JNK3 were measured at the various time points of occurrence of MPTP-induced lesions. In our study, we observed that during MPTP intoxication, two peaks of JNK3 activation appeared at 8 and 24h. To further define the mechanism of JNK3 activation and translocation, the antioxidant N-acetylcysteine (NAC), the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine, and the alpha-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate (KA) receptor antagonist 6,7-dinitroquinoxaline-2,3(1H,4H)-dione (DNQX) were administered to the mice 30 min after each of the four MPTP injections. The results revealed that NAC clearly inhibited JNK3 activation during the early intoxication, whereas ketamine preferably attenuated JNK3 activation during the latter intoxication. DNQX had no significant effects on JNK3 activation during intoxication. Consequently, reactive oxygen species (ROS) and the NMDA receptor were closely associated with JNK3 activation following MPTP intoxication. NAC and ketamine exerted a preventive effect against MPTP-induced loss of tyrosine hydroxylase-positive neurons and suppressed the nuclear translocation of JNK3, suggesting that NAC and ketamine can prevent MPTP-induced dopaminergic neuronal death by suppressing JNK3 activation.

Tripchlorolide protects against MPTP-induced neurotoxicity in C57BL/6 mice.

Many current studies of Parkinsons disease (PD) suggest that inflammation is involved in the neurodegenerative process. Tripchlorolide (TW397), a traditional Chinese herbal compound with anti‐inflammatory and immunosuppressive properties, has been shown to protect dopaminergic neurons against, and restore their function after, the neurotoxicity induced by 1‐methyl‐4‐phenylpyridinium ions in vitro. This study was designed to investigate the effect of TW397 in vivo in the PD model of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐lesioned C57BL/6 mice. In the animals that received vehicle‐only (i.e., no TW397) treatment with MPTP i.p. injection, the survival ratios of tyrosine hydroxylase‐immunoreactive (TH‐IR) neurons in the substantia nigra pars compacta and TH‐IR fibres in the striatum were only 59 and 13%, respectively, compared with the normal controls. Intriguingly, in conjunction with MPTP, treatment with TW397, 1u2003µg/kg for 16u2003days, once per day, dramatically improved the survival rate of the TH‐IR neurons and TH‐IR fibres to 80 and 43% of the control. The treatment with TW397 also significantly improved the level of dopamine in the substantia nigra and striatum to 157 and 191%, respectively, of the MPTP‐ plus vehicle‐treated group. In addition, in MPTP‐treated animals the rota‐rod performances of those treated with 0.5 or 1u2003µg/kg TW397 were significantly improved, by ∼2‐ and 3‐fold, respectively, relative to vehicle‐treated animals. The neuroprotective effect of TW397 was coincident with an attenuated astroglial response within the striatum. These data demonstrate a neuroprotective action of TW397 in vivo against MPTP toxicity, with important implications for the treatment of PD.

Predominant release of lysosomal enzymes by newborn rat microglia after LPS treatment revealed by proteomic studies.

Growing evidence suggest that microglia may play an important role in the pathogenesis of neurodegenerative disease including Parkinsons disease, Alzheimers disease, and so forth. The activation of microglia may cause neuronal damage through the release of reactive oxygen species and proinflammatory cytokines. However, the early response of microglial cells remains unclear before cells can secrete the proinflammatory cytokines. Here, a time course analysis showed the earliest expression of inducible nitric oxide synthase and cyclooxygenase-2 at 3 and 24 h following lipopolysaccharide (LPS) treatment. To further define initial response proteins of microglia after LPS treatment, we utilized a novel mass spectrometry-based quantitative proteomic technique termed SILAC (for stable isotope labeling by amino acids in cell culture) to compare the protein profiles of the cell culture-conditioned media of 1 h LPS-treated microglia as compared with controls. The proteomic analysis identified 77 secreted proteins using SignalP; of these, 28 proteins were associated with lysosome of cells and 13 lysosome-related proteins displayed significant changes in the relative abundance after 1 h LPS treatment. Four proteins were further evaluated with Western blot, demonstrating good agreement with quantitative proteomic data. These results suggested that microglia first released some lysosomal enzymes which may be involved in neuronal damage process. Furthermore, ammonium chloride, which inhibits microglia lysosomal enzyme activity, could prevent microglia from causing neuronal injury. Hence, in addition to the numerous novel proteins that are potentially important in microglial activation-mediated neurodegeneration revealed by the search, the study has indicated that the early release of lysosomal enzymes in microglial cells would contribute to LPS-activated inflammatory response.

K252a Prevents Nigral Dopaminergic Cell Death Induced by 6-Hydroxydopamine through Inhibition of Both Mixed-Lineage Kinase 3/c-Jun NH2-Terminal Kinase 3 (JNK3) and Apoptosis-Inducing Kinase 1/JNK3 Signaling Pathways

It is well documented that the mitogen-activated protein kinase pathway plays a pivotal role in rats with 6-hydroxydopamine (6-OHDA)-induced unilateral lesion in the nigrostriatal system. Our recent studies have shown that mixed-lineage kinase 3 (MLK3) and apoptosis-inducing kinase 1 (ASK1) are all involved in neuronal cell death induced by ischemia, which is mediated by the MLK3/c-Jun NH2-terminal kinase 3 (JNK3) and ASK1/JNK signaling pathway. To investigate whether these pathways are correlated with 6-OHDA-induced lesion as well, we examined the phosphorylation of MLK3, ASK1, and JNK3 in 6-OHDA rats. The results showed that both MLK3 and ASK1 could activate JNK3 and then subsequently enhance the neuronal death through its downstream pathways (i.e., nuclear and non-nuclear pathway). K252a have wide-range effects including Trk inhibition, MLK3 inhibition, and activation of phosphatidylinositol 3 kinase and mitogen-activated protein kinase kinase signaling pathways through interactions with distinct targets and is a well known neuroprotective compound. We found that K252a could protect dopaminergic neurons against cell program death induced by 6-OHDA lesion, and the phenotypes of 6-OHDA rat model treated with K252a were partial rescued. The inhibition of K252a on the activation of MLK3/JNK3 and ASK1/JNK3 provided a link between 6-OHDA lesion and stress-activated kinases. It suggested that both proapoptotic MLK3/JNK3 and ASK1/JNK3 cascade may play an important role in dopaminergic neuronal death in 6-OHDA insult. Thus, the JNK3 signaling may eventually emerge as a prime target for novel therapeutic approaches to treatment of Parkinson disease, and K252a may serve as a potential and important neuroprotectant in therapeutic aspect in Parkinson disease.

Sleep disorders in Chinese patients with Parkinson's disease: validation study of a Chinese version of Parkinson's disease sleep scale

To evaluate the Chinese version of the Parkinsons disease sleep scale (PDSS) as an instrument for measuring sleep disorders in Chinese patients with Parkinsons disease (PD). The objective of the present study was to carry out a metric analysis of a Chinese version of PDSS using a cross-sectional study of 126 patients with PD who participated in the study. Usual measures for PD patients including the Pittsburgh sleep quality index (PSQI), the Epworth sleepiness scale (ESS), the Geriatric Depression Scale (GDS), and the Hamilton Anxiety Scale (HAMA) were applied by neurologists. The intra-class correlation coefficient was 0.880, and test-retest reliability for total PDSS score was 0.914. The Mean total PDSS score was 118.38+/-26.07. There was a significant correlation between the PDSS and PSQI, between the PDSS and ESS, between the PDSS and GDS, between the PDSS and HAMA, between the PDSS and the disease durations, and between the PDSS and the LDE, respectively. The Chinese version of PDSS met some basic standards required for sleep disorders measures. It could lead to better understanding the sleep disorders of PD of China in future studies.

Phosphoproteome Study Reveals Hsp27 as a Novel Signaling Molecule Involved in GDNF-Induced Neurite Outgrowth

Glial-cell-line-derived neurotrophic factor (GDNF) is a most potent survival factor for dopaminergic neurons. In addition, GDNF was also found to promote neurite outgrowth in dopaminergic neurons. However, despite the potential clinical and physiological importance of GDNF, its mechanism of action is unclear. Therefore, we employed a state-of-the-art proteomic technique, DIGE (Difference in two-dimensional gel electrophoresis), to quantitatively compare profiles of phosphoproteins of PC12-GFRalpha1-RET cells (that stably overexpress GDNF receptor alpha1 and RET) 0.5 and 10 h after GDNF challenge with control. A total of 92 differentially expressed proteins were successfully identified by mass spectrometry. Among them, the relative levels of phosphorylated Hsp27 increased significantly both in 0.5 and 10 h GDNF-treated PC12-GFRalpha1-RET cells. Confocal microscopy and Western blot results showed that the phosphorylation of Hsp27 after GDNF treatment was accompanied by its nuclear translocation. After the mRNA of Hsp27 was interfered, neurite outgrowth of PC12-GFRalpha1-RET cells induced by GDNF was significantly blocked. Furthermore, the percentage of neurite outgrowth induced by GDNF was also reduced by the expression of dominant-negative mutants of Hsp27, in which specific serine phosphorylation residues (Ser15, Ser78 and Ser82) were substituted with alanine. Our data also revealed that p38 MAPK and ERK are the upstream regulators of Hsp27 phosphorylation. Hence, in addition to the numerous novel proteins that are potentially important in GDNF mediated differentiation of dopaminergic cells revealed by our study, our data has indicated that Hsp27 is a novel signaling molecule involved in GDNF-induced neurite outgrowth of dopaminergic neurons.

Transthyretin-related hereditary amyloidosis in a Chinese family with TTR Y114C mutation.

Background: Transthyretin-related hereditary amyloidosis is an autosomal dominant inherited disease caused by mutations in the transthyretin (TTR) gene. Corresponding to the various transthyretin gene mutations and a wide range of geographical distribution, transthyretin-related hereditary amyloidosis presents diverse characteristics in genotype-phenotype correlation. Objective/Method: Here, we identify the clinical characteristics of a Chinese family affected by transthyretin-related hereditary amyloidosis with TTR Tyr114Cys mutation. Results/Conclusion: The pathogenic mechanism studies showed that the protein encoded by TTR Tyr114Cys is more easily depolymerized to form amyloid fibrils. Moreover, the cytotoxicity of the TTR Tyr114Cys may be attributed to its ability to persistently activate the extracellular-signal-regulated kinase 1/2 pathway.

Identification of ciliary neurotrophic factor receptor α as a mediator of neurotoxicity induced by α-synuclein

Accumulating evidence suggests that extracellular α‐synuclein (eSNCA) plays an important role in the pathogenesis of Parkinsons disease or related synucleinopathies by inducing neurotoxicity directly or indirectly via microglial or astroglial activation. However, the mechanisms by which this occurs remain to be characterized. To explore these mechanisms, we combined three biochemical techniques – stable isotope labeling of amino acid in cell cultures (SILAC), biotin labeling of plasma membrane proteins followed by affinity purification, and analysis of unique proteins binding to SNCA peptides on membrane arrays. The SILAC proteomic analysis identified 457 proteins, of which, 245 or 172 proteins belonged to membrane or membrane associated proteins, depending on the various bioinformatics tools used for interpretation. In dopamine neuronal cells treated with eSNCA, the levels of 86 membrane proteins were increased and 35 were decreased compared with untreated cells. In peptide array analysis, 127 proteins were identified as possibly interacting with eSNCA. Of those, seven proteins were overlapped with the membrane proteins that displayed alterations in relative abundance after eSNCA treatment. One was ciliary neurotrophic factor receptor, which appeared to modulate eSNCA‐mediated neurotoxicity via mechanisms related to JAK1/STAT3 signaling but independent of eSNCA endocytosis.

Identification of glial‐cell‐line‐derived neurotrophic factor‐regulated proteins of striatum in mouse model of Parkinson disease

Glial‐cell‐line‐derived neurotrophic factor (GDNF) is a potent survival factor for dopaminergic neurons, and hence serves as a therapeutic candidate for the treatment of Parkinsons disease. However, despite the potential clinical and physiological importance of GDNF, its mechanism of action is unclear. Therefore, we employed a state‐of‐the‐art proteomic technique, DIGE, along with MS and a bioinformatics tool called Database for Annotation, Visualization and Integrated Discovery (DAVID), to profile proteome changes in the parkinsonian mouse striatum after GDNF challenge. Forty‐six unique differentially expressed proteins were successfully identified, which were found either up‐regulated and/or down‐regulated at the two time points 4 and 72u2009h compared with the control. Proteins involved in cell differentiation and system development formed the largest part of the proteins regulated under GDNF. Furthermore, the aberrant expression of HSPs and mitochondria‐associated proteins were noticeable. Moreover, mitochondrial stress 70 protein and heat shock cognate 71u2009kDa protein, whose relative levels increased significantly in GDNF‐treated striatum, were further evaluated with Western blot and RT‐PCR, demonstrating a good agreement with quantitative proteomic data. These data will provide some clues for understanding the mechanisms by which GDNF promotes the survival of dopaminergic neurons.