rs10501087, rs1491850 and rs11030094 polymorphisms associated with delayed progression in early-stage Parkinson's disease.

Parkinson's disease (PD) is heterogenous in its presentation, progression and response to therapies. Genetic polymorphisms may account for some of this variability. Several single nucleotide polymorphisms (SNPs) in the brain-derived neurotrophic factor gene have been associated with differing clinical outcomes from different dopaminergic replacement strategies, and one of these, the rs6265 SNP, has been associated with a milder clinical phenotype in the unmedicated, early-stage of PD.

α-Synuclein antisense oligonucleotides as a disease-modifying therapy for Parkinson's disease.

Parkinson's disease (PD) is a prevalent neurodegenerative disease with no approved disease-modifying therapies. Multiplications, mutations, and single nucleotide polymorphisms in the SNCA gene, encoding α-synuclein (aSyn) protein, either cause or increase risk for PD. Intracellular accumulations of aSyn are pathological hallmarks of PD.

Correction to: Lewy body-like alpha-synuclein inclusions trigger reactive microgliosis prior to nigral degeneration.

After publication of the original article [1] it was noted that the name of author, D. Luke Fisher, was erroneously typeset in both the PDF and online formats of the manuscript as Luke D. Fisher.

Bdnf variant is associated with milder motor symptom severity in early-stage Parkinson's disease.

Introduction: Parkinson's disease (PD) progression is heterogeneous. Variants in PD-related genes may alter disease progression or severity. We examined if the single nucleotide variant rs6265 in the gene Bdnf alters clinical phenotype in early-stage, unmedicated PD.

Lewy body-like alpha-synuclein inclusions trigger reactive microgliosis prior to nigral degeneration.

Background: Converging evidence suggests a role for microglia-mediated neuroinflammation in Parkinson's disease (PD). Animal models of PD can serve as a platform to investigate the role of neuroinflammation in degeneration in PD. However, due to features of the previously available PD models, interpretations of the role of neuroinflammation as a contributor to or a consequence of neurodegeneration have remained elusive.

Spatial patterns of neuroimaging biomarker change in individuals from families with autosomal dominant Alzheimer's disease: a longitudinal study.

Background: Models of Alzheimer's disease propose a sequence of amyloid β (Aβ) accumulation, hypometabolism, and structural decline that precedes the onset of clinical dementia. These pathological features evolve both temporally and spatially in the brain. In this study, we aimed to characterise where in the brain and when in the course of the disease neuroimaging biomarkers become abnormal.

Nortriptyline inhibits aggregation and neurotoxicity of alpha-synuclein by enhancing reconfiguration of the monomeric form.

The pathology of Parkinson's disease and other synucleinopathies is characterized by the formation of intracellular inclusions comprised primarily of misfolded, fibrillar α-synuclein (α-syn). One strategy to slow disease progression is to prevent the misfolding and aggregation of its native monomeric form. Here we present findings that support the contention that the tricyclic antidepressant compound nortriptyline (NOR) has disease-modifying potential for synucleinopathies.

Subthalamic Nucleus Deep Brain Stimulation Employs trkB Signaling for Neuroprotection and Functional Restoration.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is the most common neurosurgical treatment for Parkinson's disease motor symptoms. In preclinical models, STN DBS provides neuroprotection for substantia nigra (SN) dopamine neurons and increases BDNF in the nigrostriatal system and primary motor cortex. However, whether BDNF signaling in the SN participates in the neuroprotective effects of DBS remains unknown.

Impact of age and vector construct on striatal and nigral transgene expression.

Therapeutic protein delivery using viral vectors has shown promise in preclinical models of Parkinson's disease (PD) but clinical trial success remains elusive. This may partially be due to a failure to include advanced age as a covariate despite aging being the primary risk factor for PD. We investigated transgene expression following intracerebral injections of recombinant adeno-associated virus pseudotypes 2/2 (rAAV2/2), 2/5 (rAAV2/5), 2/9 (rAAV2/9), and lentivirus (LV) expressing green fluorescent protein (GFP) in aged versus young adult rats.

Intrastriatal injection of pre-formed mouse α-synuclein fibrils into rats triggers α-synuclein pathology and bilateral nigrostriatal degeneration.

Previous studies demonstrate that intrastriatal injections of fibrillar alpha-synuclein (α-syn) into mice induce Parkinson's disease (PD)-like Lewy body (LB) pathology formed by aggregated α-syn in anatomically interconnected regions and significant nigrostriatal degeneration. The aim of the current study was to evaluate whether exogenous mouse α-syn pre-formed fibrils (PFF) injected into the striatum of rats would result in accumulation of LB-like intracellular inclusions and nigrostriatal degeneration. Sprague-Dawley rats received unilateral intrastriatal injections of either non-fibrillized recombinant α-syn or PFF mouse α-syn in 1- or 2- sites and were euthanized at 30, 60 or 180 days post-injection (pi).

Interrogating the aged striatum: robust survival of grafted dopamine neurons in aging rats produces inferior behavioral recovery and evidence of impaired integration.

Advanced age is the primary risk factor for Parkinson's disease (PD). In PD patients and rodent models of PD, advanced age is associated with inferior symptomatic benefit following intrastriatal grafting of embryonic dopamine (DA) neurons, a pattern believed to result from decreased survival and reinnervation provided by grafted neurons in the aged host. To help understand the capacity of the aged, parkinsonian striatum to be remodeled with new DA terminals, we used a grafting model and examined whether increasing the number of grafted DA neurons in aged rats would translate to enhanced behavioral recovery.

Tricyclic antidepressant treatment evokes regional changes in neurotrophic factors over time within the intact and degenerating nigrostriatal system.

In addition to alleviating depression, trophic responses produced by antidepressants may regulate neural plasticity in the diseased brain, which not only provides symptomatic benefit but also potentially slows the rate of disease progression in Parkinson's disease (PD). Recent in vitro and in vivo data provide evidence that neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) may be key mediators of the therapeutic response to antidepressants. As such, we conducted a cross-sectional time-course study to determine whether antidepressant-mediated changes in neurotrophic factors occur in relevant brain regions in response to amitriptyline (AMI) treatment before and after intrastriatal 6-hydroxydopamine (6OHDA).

Chronic amitriptyline treatment attenuates nigrostriatal degeneration and significantly alters trophic support in a rat model of parkinsonism.

In addition to alleviating depression, long-term adaptive changes induced by antidepressants may regulate neural plasticity in the diseased brain, providing symptomatic and disease-modifying effects in Parkinson's disease. The present study investigated whether chronic treatment with a frequently prescribed tricyclic antidepressant was neuroprotective in a 6-hydroxydopamine (6-OHDA) rat model of parkinsonism. In lesioned animals, chronic amitriptyline (AMI; 5 mg/kg) treatment resulted in a significant sparing of tyrosine hydroxylase-immunoreactive (THir) neurons in the substantia nigra pars compacta (SNpc) compared with saline treatment.

Inhibition of glucosylceramide synthase stimulates autophagy flux in neurons.

Aggregate-prone mutant proteins, such as α-synuclein and huntingtin, play a prominent role in the pathogenesis of various neurodegenerative disorders; thus, it has been hypothesized that reducing the aggregate-prone proteins may be a beneficial therapeutic strategy for these neurodegenerative disorders. Here, we identified two previously described glucosylceramide (GlcCer) synthase inhibitors, DL-threo-1-Phenyl-2-palmitoylamino-3-morpholino-1-propanol and Genz-123346(Genz), as enhancers of autophagy flux. We also demonstrate that GlcCer synthase inhibitors exert their effects on autophagy by inhibiting AKT-mammalian target of rapamycin (mTOR) signaling.

Behavioral characterization of A53T mice reveals early and late stage deficits related to Parkinson's disease.

Parkinson's disease (PD) pathology is characterized by the formation of intra-neuronal inclusions called Lewy bodies, which are comprised of alpha-synuclein (α-syn). Duplication, triplication or genetic mutations in α-syn (A53T, A30P and E46K) are linked to autosomal dominant PD; thus implicating its role in the pathogenesis of PD. In both PD patients and mouse models, there is increasing evidence that neuronal dysfunction occurs before the accumulation of protein aggregates (i.

Tricyclic antidepressants delay the need for dopaminergic therapy in early Parkinson's disease.

This study examined whether antidepressants delay the need for dopaminergic therapy or change the degree of motor impairment and disability in a population of early Parkinson's disease (PD) patients. Preclinical studies have indicated that antidepressants modulate signaling pathways involved in cell survival and plasticity, suggesting they may serve to both treat PD-associated depression and slow disease progression. A patient-level meta-analysis included 2064 patients from the treatment and placebo arms of the following trials: FS1, FS-TOO, ELLDOPA, QE2, TEMPO, and PRECEPT.

Transplantation of subventricular zone neural precursors induces an endogenous precursor cell response in a rat model of Parkinson's disease.

Realistically, future stem cell therapies for neurological conditions including Parkinson's disease (PD) will most probably entail combination treatment strategies, involving both the stimulation of endogenous cells and transplantation. Therefore, this study investigates these two modes of neural precursor cell (NPC) therapy in concert in order to determine their interrelationships in a rat PD model. Human placental alkaline phosphatase (hPAP)-labeled NPCs were transplanted unilaterally into host rats which were subsequently infused ipsilaterally with 6-hydroxydopamine (6-OHDA).

3,4-Methylenedioxy-N-methamphetamine (ecstasy) promotes the survival of fetal dopamine neurons in culture.

The current study examined whether modest concentrations of MDMA could increase the survival and/or neurite outgrowth of fetal midbrain dopamine (DA) neurons in vitro since increased DA neurite outgrowth has been previously observed in vivo from prenatal exposure. MDMA concentrations in fetal brain were quantified to determine relevant in vivo concentrations to employ in vitro. A dose response study in vitro demonstrated that MDMA, at concentrations observed in vivo, resulted in increased, DA-specific, neuron survival.

Increased cell suspension concentration augments the survival rate of grafted tyrosine hydroxylase immunoreactive neurons.

The poor survival rate (5-20%) of grafted embryonic dopamine (DA) neurons is one of the primary factors preventing cell replacement from becoming a viable treatment for Parkinson's disease. Previous studies have demonstrated that graft volume impacts grafted DA neuron survival, indicating that transplant parameters influence survival rates. However, the effects of mesencephalic cell concentration on grafted DA neuron survival have not been investigated.