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Frontiers in Aging Neuroscience 2021Parkinson's disease (PD) is one of the most common neurodegenerative maladies with unforeseen complex pathologies. While this neurodegenerative disorder's neuropathology...
Failure of Glial Cell-Line Derived Neurotrophic Factor (GDNF) in Clinical Trials Orchestrated By Reduced NR4A2 (NURR1) Transcription Factor in Parkinson's Disease. A Systematic Review.
Parkinson's disease (PD) is one of the most common neurodegenerative maladies with unforeseen complex pathologies. While this neurodegenerative disorder's neuropathology is reasonably well known, its etiology remains a mystery, making it challenging to aim therapy. Glial cell-line derived neurotrophic factor (GDNF) remains an auspicious therapeutic molecule for treating PD. Neurotrophic factor derived from glial cell lines is effective in rodents and nonhuman primates, but clinical findings have been equivocal. Laborious exertions have been made over the past few decades to improve and assess GDNF in treating PD (clinical studies). Definitive clinical trials have, however, failed to demonstrate a survival advantage. Consequently, there seemed to be a doubt as to whether GDNF has merit in the potential treatment of PD. The purpose of this cutting edge review is to speculate as to why the clinical trials have failed to meet the primary endpoint. We introduce a hypothesis, "Failure of GDNF in clinical trials succumbed by nuclear receptor-related factor 1 (Nurr1) shortfall." We demonstrate how Nurr1 binds to GDNF to induce dopaminergic neuron synthesis. Due to its undisputable neuro-protection aptitude, we display Nurr1 (also called Nr4a2) as a promising therapeutic target for PD.
PubMed: 33716718
DOI: 10.3389/fnagi.2021.645583 -
Journal of Neuromuscular Diseases 2021Parkinson's disease (PD) is a disabling neurological condition characterized by the loss of dopaminergic neurons. Currently, the treatment for PD is symptomatic and...
Parkinson's disease (PD) is a disabling neurological condition characterized by the loss of dopaminergic neurons. Currently, the treatment for PD is symptomatic and compensates for the endogenous loss of dopamine production. In cases where the pharmacological therapy is only partly beneficial or results in major wearing-off complications, surgical interventions such as deep brain stimulation may be an alternative treatment. The disease cause often remains unknown, but in some patients, a monogenic cause can be identified. Mutations in at least six genes, LRRK2, SNCA, and VPS35 (dominant forms) or Parkin/PRKN, PINK1, and DJ1/PARK7 (recessive forms) have been unequivocally linked to PD pathogenesis. We here systematically screened 8,576 publications on these monogenic PD forms. We identified 2,226 mutation carriers from 456 papers. Levodopa was the most widely applied treatment; only 34 patients were indicated to be untreated at the time of reporting. Notably, detailed treatment data was rarely mentioned including response quantification (good, moderate, minimal) in 951 and/or dose in 293 patients only. Based on available data, levodopa showed an overall good outcome, especially in LRRK2, VPS35, Parkin, and PINK1 mutation carriers ("good" response in 94.6-100%). Side effects of levodopa therapy were reported in ∼15-40%of levodopa-treated patients across genes with dyskinesias as the most frequent one. Non-levodopa medication was indicated to be administered to <200 patients with mainly good outcome. Only a few reports were available on outcomes of brain surgery. Here, most mutation carriers showed a good response. Importantly, none of the available treatments is harmful to one genetic form but effective in another one. In the light of different medication schemes, the progressive nature of PD, and side effects, an improvement of therapeutic options for PD is warranted including a treatabolome database to guide clinicians in treatment decisions. Further, novel disease-cause-modifying drugs are needed.
Topics: Antiparkinson Agents; Humans; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Levodopa; Mutation; Parkinson Disease; Protein Deglycase DJ-1; Protein Kinases; Ubiquitin-Protein Ligases; Vesicular Transport Proteins; alpha-Synuclein
PubMed: 33459660
DOI: 10.3233/JND-200598 -
Frontiers in Aging Neuroscience 2020Bone marrow stromal cells (BMSCs) has been reported to have beneficial effects in improving behavioral deficits, and rescuing dopaminergic neuron loss in rodent models...
Bone marrow stromal cells (BMSCs) has been reported to have beneficial effects in improving behavioral deficits, and rescuing dopaminergic neuron loss in rodent models of Parkinson's disease (PD). However, their pooled effects for dopaminergic neuron have yet to be described. To review the neuroprotective effect of naïve BMSCs in rodent models of PD. The PubMed, EMBASE, and Web of Science databases were searched up to September 30, 2020. Inclusion criteria according to PICOS criteria were as follows: (1) population: rodents; (2) intervention: unmodified BMSCs; (3) comparison: not specified; (4) primary outcome: tyrosine hydroxylase level in the substantia nigra pars compacta and rotational behavior; secondary outcome: rotarod test, and limb function; (5) study: experimental studies. Multiple prespecified subgroup and meta-regression analysis were conducted. Following quality assessment, random effects models were used for this meta-analysis. Twenty-seven animal studies were included. The median quality score was 4.7 (interquartile range, 2-8). Overall standardized mean difference between animals treated with naïve BMSCs and controls was 2.79 (95% confidence interval: 1.70, 3.87; < 0.001) for densitometry of tyrosine hydroxylase-positive staining; -1.54 (95% confidence interval: -2.11, -0.98; < 0.001) for rotational behavior. Significant heterogeneity among studies was observed. Results of this meta-analysis suggest that naïve BMSCs therapy increased dopaminergic neurons and ameliorated behavioral deficits in rodent models of PD.
PubMed: 33362527
DOI: 10.3389/fnagi.2020.539933 -
Frontiers in Neurology 2020Parkinson's disease (PD) is a progressive neurodegenerative disease whose main neuropathological feature is the loss of dopaminergic neurons of the substantia nigra...
Parkinson's disease (PD) is a progressive neurodegenerative disease whose main neuropathological feature is the loss of dopaminergic neurons of the substantia nigra (SN). There is also an increase in iron content in the SN in postmortem and imaging studies using iron-sensitive MRI techniques. However, MRI results are variable across studies. We performed a systematic meta-analysis of SN iron imaging studies in PD to better understand the role of iron-sensitive MRI quantification to distinguish patients from healthy controls. We also studied the factors that may influence iron quantification and analyzed the correlations between demographic and clinical data and iron load. We searched PubMed and ScienceDirect databases (from January 1994 to December 2019) for studies that analyzed iron load in the SN of PD patients using T2, R2, susceptibility weighting imaging (SWI), or quantitative susceptibility mapping (QSM) and compared the values with healthy controls. Details for each study regarding participants, imaging methods, and results were extracted. The effect size and confidence interval (CI) of 95% were calculated for each study as well as the pooled weighted effect size for each marker over studies. Hence, the correlations between technical and clinical metrics with iron load were analyzed. Forty-six articles fulfilled the inclusion criteria including 27 for T2/R2 measures, 10 for SWI, and 17 for QSM (3,135 patients and 1,675 controls). Eight of the articles analyzed both R2 and QSM. A notable effect size was found in the SN in PD for R2 increase (effect size: 0.84, 95% CI: 0.60 to 1.08), for SWI measurements (1.14, 95% CI: 0.54 to 1.73), and for QSM increase (1.13, 95% CI: 0.86 to 1.39). Correlations between imaging measures and Unified Parkinson's Disease Rating Scale (UPDRS) scores were mostly observed for QSM. The consistent increase in MRI measures of iron content in PD across the literature using R2, SWI, or QSM techniques confirmed that these measurements provided reliable markers of iron content in PD. Several of these measurements correlated with the severity of motor symptoms. Lastly, QSM appeared more robust and reproducible than R2 and more suited to multicenter studies.
PubMed: 32547468
DOI: 10.3389/fneur.2020.00366