Genetics of Parkinson's disease and Parkinsonism
ABSTRACT Until 10 years ago, conventional wisdom held that Parkinson's disease was not a genetic disorder. Since that time, there have been a plethora of genetic findings, culminating in the cloning of several genes that derive from the loci given the nomenclature PARK1-PARK12 (OMIM 168600). Recently, these research findings have begun to impact clinical practice, and this impact is likely to increase. The primary purpose of this article is to outline these genetic advances, discuss their importance for current practice in clinical and related settings, and outline briefly how they are influencing research into the causes of and possible future treatments for this prevalent disorder.
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- "These include α-synuclein [PARK1/4] (Polymeropoulos et al., 1997), parkin [PARK2] (Kitada et al., 1998), DJ-1 [PARK7] (Bonifati et al., 2003), PINK1 [PARK 6] (Valente et al., 2004), and LRRK2 [PARK8] (Paisan- Ruiz et al., 2004). Silencing the over-expression of these genes by using viral vectors such as the lentivirus, adenovirus, and herpes virus as well as polyplexes, may represent a novel therapeutic approach by preventing the progression the disease (Hardy et al., 2006). However, it is essential to evaluate the safety of these vectors to prevent inflammatory responses, which may trigger additional neurodegeneration and worsen the symptoms of PD (Du et al., 1996; McCown et al., 1996). "
ABSTRACT: The prevalence of Parkinson’s disease (PD) increases with age and is projected to increase in parallel to the rising average age of the population. The disease can have significant health-related, social, and financial implications not only for the patient and the caregiver, but for the health care system as well. While the neuropathology of this neurodegenerative disorder is fairly well understood, its etiology remains a mystery, making it difficult to target therapy. The currently available drugs for treatment provide only symptomatic relief and do not control or prevent disease progression, and as a result patient compliance and satisfaction are low. Several emerging pharmacotherapies for PD are in different stages of clinical development. These therapies include adenosine A2A receptor antagonists, glutamate receptor antagonists, monoamine oxidase inhibitors, anti-apoptotic agents, and antioxidants such as coenzyme Q10, N-acetyl cysteine, and edaravone. Other emerging non-pharmacotherapies include viral vector gene therapy, microRNAs, transglutaminases, RTP801, stem cells and glial derived neurotrophic factor (GDNF). In addition, surgical procedures including deep brain stimulation, pallidotomy, thalamotomy and gamma knife surgery have emerged as alternative interventions for advanced PD patients who have completely utilized standard treatments and still suffer from persistent motor fluctuations. While several of these therapies hold much promise in delaying the onset of the disease and slowing its progression, more pharmacotherapies and surgical interventions need to be investigated in different stages of PD. It is hoped that these emerging therapies and surgical procedures will strengthen our clinical aramamentum for improved treatment of PD.Pharmacology [?] Therapeutics 11/2014; 144(2). DOI:10.1016/j.pharmthera.2014.05.010 · 9.72 Impact Factor
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- "Parkinson's disease (PD) is an age-related neurodegenerative disease affecting 2% of the population above 65-years and is clinically characterized by bradykinesia, rigidity, and resting tremor. The neuropathological hallmark of the disease is the progressive loss of dopaminergic neurons in the substantia nigra (Moore et al., 2005; Hardy et al., 2006). Although the majority of cases are idiopathic , mutations in the Leucine-rich repeat kinase 2 (LRRK2) gene (PARK8; OMIM 609007) cause late-onset PD. "
ABSTRACT: Mutations in Leucine-rich repeat kinase 2 gene (LRRK2) are associated with familial and sporadic Parkinson's disease (PD). LRRK2 is a complex protein that consists of multiple domains executing several functions, including GTP hydrolysis, kinase activity, and protein binding. Robust evidence suggests that LRRK2 acts at the synaptic site as a molecular hub connecting synaptic vesicles to cytoskeletal elements via a complex panel of protein-protein interactions. Here we investigated the impact of pharmacological inhibition of LRRK2 kinase activity on synaptic function. Acute treatment with LRRK2 inhibitors reduced the frequency of spontaneous currents, the rate of synaptic vesicle trafficking and the release of neurotransmitter from isolated synaptosomes. The investigation of complementary models lacking LRRK2 expression allowed us to exclude potential off-side effects of kinase inhibitors on synaptic functions. Next we studied whether kinase inhibition affects LRRK2 heterologous interactions. We found that the binding among LRRK2, presynaptic proteins and synaptic vesicles is affected by kinase inhibition. Our results suggest that LRRK2 kinase activity influences synaptic vesicle release via modulation of LRRK2 macro-molecular complex.Frontiers in Molecular Neuroscience 05/2014; 7:49. DOI:10.3389/fnmol.2014.00049 · 4.08 Impact Factor
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- "Parkinson’s disease (PD) is a degenerative neurological disorder characterized primarily by loss of dopaminergic (DA) neurons from the substantia nigra pars compacta (SNpc). Genetic and biochemical evidences have established a close link between the protein alpha-synuclein (α-SYN) and the pathogenesis of the disease [1,2]. The disease may be triggered by mutations or overexpression of α-SYN, and all cases of PD are associated with accumulation of insoluble α-SYN [2,3]. "
ABSTRACT: Background The protein alpha-synuclein (α-SYN), which is found in the Lewy bodies of dopamine-producing (DA) neurons in the substantia nigra (SN), has an important role in the pathogenesis of Parkinson’s disease (PD). Previous studies have shown that neuroinflammation plays a key role in PD pathogenesis. In an AAV-synuclein mouse model of PD, we have found that over-abundance of α-SYN triggers the expression of NF-κB p65, and leads to microglial activation and DA neurodegeneration. We also have observed that Fcγ receptors (FcγR), proteins present on the surface of microglia that bind immunoglobulin G (IgG) and other ligands, are key modulators of α-SYN-induced neurodegeneration. Methods In order to study the role of FcγRs in the interactions of α-SYN and microglia, we treated the primary microglial cultures from wild-type (WT) and FcγR−/− mice with aggregated human α-SYN in vitro. Results Using immunocytochemistry, we found that α-SYN was taken up by both WT and FcγR−/− microglia, however, their patterns of internalization were different, with aggregation in autophagosomes in WT cells and more diffuse localization in FcγR−/− microglia. In WT microglia, α-SYN induced the nuclear accumulation of NF-κB p65 protein and downstream chemokine expression while in FcγR−/− mouse microglia, α-SYN failed to trigger the enhancement of nuclear NF-κB p65, and the pro-inflammatory signaling was reduced. Conclusions Our results suggest that α-SYN can interact directly with microglia and can be internalized and trafficked to autophagosomes. FcγRs mediate this interaction, and in the absence of the gamma chain, there is altered intracellular trafficking and attenuation of pro-inflammatory NF-κB signaling. Therefore, blocking either FcγR signaling or downstream NF-κB activation may be viable therapeutic strategies in PD.Journal of Neuroinflammation 11/2012; 9(1):259. DOI:10.1186/1742-2094-9-259 · 5.41 Impact Factor