As key molecular chaperone proteins, heat shock proteins (HSPs) represent an important cellular protective mechanism against neuronal cell death in various models of neurological disorders. In this study, we investigated the effect as well as the molecular mechanism of geldanamycin (GA), an inhibitor of Hsp90, on 1-methyl-4-pheny-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurotoxicity, a mouse model of Parkinson disease. Neurochemical analysis showed that pretreatment with GA (via intracerebral ventricular injection 24 h prior to MPTP treatment) increased residual dopamine content and tyrosine hydroxylase immunoreactivity in the striatum 24 h after MPTP treatment. To dissect out the molecular mechanism underlying this neuroprotection, we showed that the GA-mediated protection against MPTP was associated with a reduction of cytosolic Hsp90 and an increase in Hsp70, with no significant changes in Hsp40 and Hsp25 levels. Furthermore, in parallel with the induction of Hsp70, striatal nuclear HSF1 levels and HSF1 binding to heat shock element sites in the Hsp70 promoter were significantly enhanced by the GA pretreatment. Together these results suggested that the molecular cascade leading to the induction of Hsp70 is critical to the neuroprotection afforded by GA against MPTP-induced neurotoxicity in the brain and that pharmacological inhibition of Hsp90 may represent a potential therapeutic strategy for Parkinson disease. PD4 is the second most common human neurodegenerative disorder, affecting 1-3% of people over 65 years old and ϳ10% of those over 80 years old (1-4). The hallmark of PD pathology is the progressive loss of dopaminergic neurons in substantia nigra, leading to profound depletion of dopamine in the striatum, and consequently severe movement abnormalities (1, 3, 4). These pathological changes of PD are associated with formation of Lewy bodies (enriched for ␣-synuclein) in neuritis of dopaminergic and non-dopaminergic neurons (1, 5). For the last three decades, despite the symptomatic relief offered by L-3,4-dihydroxyphenylalanine, no effective neuroprotective strategy for PD has emerged to halt or slow down dopaminergic neurodegeneration (1, 3-6).Heat shock proteins (HSPs) represent an important cellular protective mechanism against a variety of stresses and insults (7-9). HSPs are a large family of evolutionary conserved proteins consisting of subfamilies with molecular masses of ϳ110, 90, 70, 60,40,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]10,11). Some HSPs (such as Hsp40 and Hsp90) are constitutively expressed, whereas others (such as Hsp70 and Hsp27) are mainly induced after exposure of cells to environmental and physiological stressors (12)(13)(14)(15). A large body of evidence supports a critical role for HSPs in cellular protection against a variety of stressors and insults, including heat, hypoxia, ischemia, excitotoxicity, glucose deprivation, cancer, and aging (13, 16 -24 (32,33). Similarly, overexpression of Hsp70 in dopaminergic neurons using adeno-associa...
BackgroundsLong non-coding RNA (LncRNA) have been reported to be involved in the pathogenesis of neurodegenerative diseases, but whether it can serve as a biomarker for Alzheimer disease (AD) is not yet known.MethodsThe present study selected four specific LncRNA (17A, 51A, BACE1 and BC200) as possible AD biomarker. RT-qPCR was performed to validate the LncRNA. Receiver operating characteristic curve (ROC) and area under the ROC curve (AUC) were applied to study the potential of LncRNA as a biomarker in a population of 88 AD patients and 72 control individuals.ResultsWe found that the plasma LncRNA BACE1 level of AD patients was significantly higher than that of healthy controls (p = 0.006). Plasma level of LncRNA 17A, 51A and BC200 did not show a significant difference between two groups (p = 0.098, p = 0.204 and p = 0.232, respectively). ROC curve analysis showed that LncRNA BACE1 was the best candidate of these LncRNA (95% CI: 0.553–0.781, p = 0.003). In addition, no correlation was found for expression of these LncRNA in both control and AD groups with age or MMSE scale (p > 0.05).ConclusionsOur present study compared the plasma level of four LncRNA between AD and non-AD patients, and found that the level of the BACE1 is increased in the plasma of AD patients and have a high specificity (88%) for AD, indicating BACE1 may be a potential candidate biomarker to predict AD.Electronic supplementary materialThe online version of this article (10.1186/s12883-017-1008-x) contains supplementary material, which is available to authorized users.
Background New therapies are urgently needed for Alzheimer’s disease (AD). Sodium oligomannate (GV-971) is a marine-derived oligosaccharide with a novel proposed mechanism of action. The first phase 3 clinical trial of GV-971 has been completed in China. Methods We conducted a phase 3, double-blind, placebo-controlled trial in participants with mild-to-moderate AD to assess GV-971 efficacy and safety. Participants were randomized to placebo or GV-971 (900 mg) for 36 weeks. The primary outcome was the drug-placebo difference in change from baseline on the 12-item cognitive subscale of the Alzheimer’s Disease Assessment Scale (ADAS-cog12). Secondary endpoints were drug-placebo differences on the Clinician’s Interview-Based Impression of Change with caregiver input (CIBIC+), Alzheimer’s Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, and Neuropsychiatric Inventory (NPI). Safety and tolerability were monitored. Results A total of 818 participants were randomized: 408 to GV-971 and 410 to placebo. A significant drug-placebo difference on the ADAS-Cog12 favoring GV-971 was present at each measurement time point, measurable at the week 4 visit and continuing throughout the trial. The difference between the groups in change from baseline was − 2.15 points (95% confidence interval, − 3.07 to − 1.23; p < 0.0001; effect size 0.531) after 36 weeks of treatment. Treatment-emergent adverse event incidence was comparable between active treatment and placebo (73.9%, 75.4%). Two deaths determined to be unrelated to drug effects occurred in the GV-971 group. Conclusions GV-971 demonstrated significant efficacy in improving cognition with sustained improvement across all observation periods of a 36-week trial. GV-971 was safe and well-tolerated. Trial registration ClinicalTrials.gov, NCT02293915. Registered on November 19, 2014
Studies with multiple sclerosis patients and animal models of experimental autoimmune encephalomyelitis (EAE) implicate adenosine and adenosine receptors in modulation of neuroinflammation and brain injury. Although the involvement of the A1 receptor has been recently demonstrated, the role of the adenosine A2A receptor (A2AR) in development of EAE pathology is largely unknown. Using mice with genetic inactivation of the A2A receptor, we provide direct evidence that loss of the A2AR exacerbates EAE pathology in mice. Compared with wild‐type mice, A2AR knockout mice injected with myelin oligodendroglia glycoprotein peptide had a higher incidence of EAE and exhibited higher neurological deficit scores and greater decrease in body weight. A2AR knockout mice displayed increased inflammatory cell infiltration and enhanced microglial cell activation in cortex, brainstem, and spinal cord. In addition, demyelination and axonal damage in brainstem were exacerbated, levels of Th1 cytokines increased, and Th2 cytokines decreased. Collectively, these findings suggest that extracellular adenosine acting at A2ARs triggers an important neuroprotective mechanism. Thus, the A2A receptor is a potential target for therapeutic approaches to multiple sclerosis.
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