The cardinal symptoms of Parkinson disease (PD) are asymmetrical bradykinesia, rigidity, resting tremor and postural instability. However, the presence and spectrum of, and disability caused by, nonmotor symptoms (NMS) are being increasingly recognized. NMS include dementia, psychosis, depression and apathy, and are a major source of disability in later stages of PD, in association with axial symptoms that are resistant to levodopa therapy. The model of clinical progression of PD should, therefore, incorporate NMS, instead of being restricted to motor signs and levodopa-induced motor complications. Patients with disabling motor complications are classified as having advanced PD, which has been thought to represent the ultimate stage of disease. However, deep brain stimulation to treat motor complications has dramatically changed this scenario, with implications for the definition of advanced-stage disease. As treatment improves and survival times increase, patients are increasingly progressing to a later phase of disease in which they are highly dependent on caregivers, and disability is dominated by motor symptoms and NMS that are resistant to levodopa. In this article, we review the changing landscape of the later stages of PD, and propose a definition of late-stage PD to designate patients who have progressed beyond the advanced stage.
"Alzheimer ' s ( AD ) and Parkinson ' s disease ( PD ) are the most prevalent and highly characterized neurodegenerative disorders ( Ballard et al . 2011 ; Coelho and Ferreira 2012 ) . AD is characterized by the abnormal deposition of the Tau protein , with increased pro - duction and impaired clearance of the beta amyloid peptides generated from neurons ( O ' Brien and Wong 2011 ) . "
[Show abstract][Hide abstract] ABSTRACT: MicroRNAs (miRNAs) are endogenous, non-coding small RNAs that regulate gene expression at the post-transcriptional level. Recent studies have shown that miRNAs are aberrantly expressed in various human diseases, ranging from cancer to cardiovascular hypertrophy. The expression profiles of the miRNAs clearly differentiate the normal from the pathological state and thus their potential as novel biomarkers in the diagnosis and prognosis of several human diseases is immense. Emerging data on the role of miRNAs in the pathogenesis of various human diseases have paved the way to test their ability to act as novel therapeutic tools. In the present review, we will explore the current knowledge about the role of miRNAs in various human diseases. In addition, we will focus on the emerging evidences demonstrating the potential of miRNAs as novel biomarkers and the strategies to use them as therapeutic tools.
Cell and Tissue Research 02/2014; 358(1). DOI:10.1007/s00441-013-1787-3 · 3.57 Impact Factor
"The apparent symptoms of PD are movement disorders, including muscle rigidity, bradykinesia, and tremors. Nevertheless, behavioral and cognitive problems, including dementia, depression, anxiety, and sleep disturbances, are also involved in the later stages of the disease . Two clinical-pathological findings describe both familial and sporadic PD: the development of Lewy bodies (aggregation of α-synuclein) in the brain tissue and the selective loss of midbrain dopaminergic (DA) neurons in the substantia nigra . "
[Show abstract][Hide abstract] ABSTRACT: Parkinson's disease (PD) is the second most common degenerative disorder of the central nervous system that impairs motor skills and cognitive function. To date, the disease has no effective therapies. The identification of new drugs that provide benefit in arresting the decline seen in PD patients is the focus of much recent study. However, the lengthy time frame for the progression of neurodegeneration in PD increases both the time and cost of examining potential therapeutic compounds in mammalian models. An alternative is to first evaluate the efficacy of compounds in Caenorhabditis elegans models, which reduces examination time from months to days. n-Butylidenephthalide is the naturally-occurring component derived from the chloroform extract of Angelica sinensis. It has been shown to have anti-tumor and anti-inflammatory properties, but no reports have yet described the effects of n-butylidenephthalide on PD. The aim of this study was to assess the potential for n-butylidenephthalide to improve PD in C. elegans models.
In the current study, we employed a pharmacological strain that expresses green fluorescent protein specifically in dopaminergic neurons (BZ555) and a transgenic strain that expresses human α-synuclein in muscle cells (OW13) to investigate the antiparkinsonian activities of n-butylidenephthalide. Our results demonstrate that in PD animal models, n-butylidenephthalide significantly attenuates dopaminergic neuron degeneration induced by 6-hydroxydopamine; reduces α-synuclein accumulation; recovers lipid content, food-sensing behavior, and dopamine levels; and prolongs life-span of 6-hydroxydopamine treatment, thus revealing its potential as a possible antiparkinsonian drug. n-Butylidenephthalide may exert its effects by blocking egl-1 expression to inhibit apoptosis pathways and by raising rpn-6 expression to enhance the activity of proteasomes.
n-Butylidenephthalide may be one of the effective neuroprotective agents for PD.
PLoS ONE 01/2014; 9(1):e85305. DOI:10.1371/journal.pone.0085305 · 3.23 Impact Factor
"Parkinson’s disease (PD) is a common movement disorder characterized by a progressive degeneration of dopaminergic (DA) neurons in the substantia nigra (SNc) –. Different genetic and environmental factors contribute to disease etiology. "
[Show abstract][Hide abstract] ABSTRACT: Mortalin is an essential component of the molecular machinery that imports nuclear-encoded proteins into mitochondria, assists in their folding, and protects against damage upon accumulation of dysfunctional, unfolded proteins in aging mitochondria. Mortalin dysfunction associated with Parkinson's disease (PD) increases the vulnerability of cultured cells to proteolytic stress and leads to changes in mitochondrial function and morphology. To date, Drosophila melanogaster has been successfully used to investigate pathogenesis following the loss of several other PD-associated genes. We generated the first loss-of-Hsc70-5/mortalin-function Drosophila model. The reduction of Mortalin expression recapitulates some of the defects observed in the existing Drosophila PD-models, which include reduced ATP levels, abnormal wing posture, shortened life span, and reduced spontaneous locomotor and climbing ability. Dopaminergic neurons seem to be more sensitive to the loss of mortalin than other neuronal sub-types and non-neuronal tissues. The loss of synaptic mitochondria is an early pathological change that might cause later degenerative events. It precedes both behavioral abnormalities and structural changes at the neuromuscular junction (NMJ) of mortalin-knockdown larvae that exhibit increased mitochondrial fragmentation. Autophagy is concomitantly up-regulated, suggesting that mitochondria are degraded via mitophagy. Ex vivo data from human fibroblasts identifies increased mitophagy as an early pathological change that precedes apoptosis. Given the specificity of the observed defects, we are confident that the loss-of-mortalin model presented in this study will be useful for further dissection of the complex network of pathways that underlie the development of mitochondrial parkinsonism.
PLoS ONE 12/2013; 8(12):e83714. DOI:10.1371/journal.pone.0083714 · 3.23 Impact Factor
Jean-François Houvenaghel, Florence Le Jeune, Thibaut Dondaine, Aurore Esquevin, Gabriel Hadrien Robert, Julie Péron, Claire Haegelen, Sophie Drapier, Pierre Jannin, Clément Lozachmeur, Soizic Argaud, Joan Duprez, Dominique Drapier, Marc Vérin, Paul Sauleau
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