Superoxide dismutating molecules rescue the toxic effects of PINK1 and parkin loss

Elevated Level of PINK1/Parkin-Mediated Mitophagy Pathway Involved to the Inhibited Activity of Mitochondrial Superoxide Dismutase in Rat Brains and Primary Hippocampal Neurons Exposed to High Level of Fluoride

To reveal the molecular mechanism of brain damage induced by chronic fluorosis, expression of PTEN-induced kinase 1 (PINK1)/parkin RBR E3 ubiquitin-protein ligase (Parkin)-mediated mitophagy pathway and activity of mitochondrial superoxide dismutase (SOD) were investigated in rat brains and primary cultured neurons exposed to high level of fluoride. Sprague-Dawley (SD) rats were treated with fluoride (0, 5, 50, and 100 ppm) for 3 and 6 months. The primary neurons were exposed to 0.4 mM (7.6 ppm) fluoride and thereafter treated with 100 nM rapamycin (a stimulator of mitophagy) or 50 μM 3-methyladenine (3-MA, an inhibitor of mitophagy) for 24 h. The expressions of PINK1/Parkin at the protein level and the activity of SOD in mitochondria of rat brains and cultured neurons were determined by Western blotting and biochemical method, respectively. The results showed that the rats exposed to fluoride exhibited different degrees of dental fluorosis. In comparison to controls, the expressions of PINK1 and Parkin were significantly higher in the rat brains and primary neurons exposed to high fluoride. In addition, a declined activity of mitochondrial SOD was determined. Interestingly, rapamycin treatment enhanced but 3-MA inhibited the changes of PINK1/Parkin pathway and SOD activity, and the correlations between the inhibited SOD activity and the elevated PINK1/Parkin proteins were observed. The results suggest that the inhibition of mitochondrial SOD activity induced by fluorosis may stimulate the expressions of mitophagy (PINK1/ Parkin) pathway to maintain the mitochondrial homeostasis.

Resorcinol alleviates alpha-terpineol-induced cell death in Schizosaccharomyces pombe via increased activity of the antioxidant enzyme Sod2

Alpha-terpineol, popular monoterpenoid alcohol, is known to cause cytotoxicity in a few cancer cells or to have antioxidant activity, but underlying mechanisms or apoptotic processes in yeast cell death should be understood. We used the fission yeast (Schizosaccharomyces pombe) as a unicellular model to monitor cellular toxicology and physiological mechanisms for the involvement of alpha-terpineol in cell death. Alpha-terpineol caused Reactive oxygen species (ROS) overproduction and following cytotoxicity and apoptosis in a dose-dependent manner. The effect of oxidative stress was proved using sod1 and sod2 mutants (antioxidant-limited cells), and the results showed that apoptosis was caused by alpha-terpineol-driven oxidation. In addition, resorcinol, a herbal extract from medicinal plants, showed protective activity against alpha-terpineol cytotoxicity. Survival rates, apoptotic cell death ratios, oxidation levels, and antioxidant gene expressions were completely altered; surprisingly sod1 and sod2 levels dramatically increased. However, sod2 was highly upregulated in response to resorcinol treatment with alpha-terpineol. The potential role of the Sod2 enzyme was proved using sod2 mutant cells that do not have a mitochondrial radical-clearing activity. Consequently, the dose-dependent and ROS-mediated cytotoxic/apoptotic effects of alpha-terpineol and the Sod2-dependent protective and antioxidant effects of resorcinol were demonstrated in unicellular model organism S. pombe by this study.

A water-soluble manganese(II) octanediaoate/phenanthroline complex acts as an antioxidant and attenuates alpha-synuclein toxicity

The overproduction of reactive oxygen species (ROS) induces oxidative stress, a well-known process associated with aging and several human pathologies, such as cancer and neurodegenerative diseases. A large number of synthetic compounds have been described as antioxidant enzyme mimics, capable of eliminating ROS and/or reducing oxidative damage. In this study, we investigated the antioxidant activity of a water-soluble 1,10-phenantroline-octanediaoate Mn²⁺-complex on cells under oxidative stress, and assessed its capacity to attenuate alpha-synuclein (aSyn) toxicity and aggregation, a process associated with increased oxidative stress. This Mn²⁺-complex exhibited a significant antioxidant potential, reducing intracelular oxidation and increasing oxidative stress resistance in S. cerevisiae cells and in vivo, in G. mellonella, increasing the activity of the intracellular antioxidant enzymes superoxide dismutase and catalase. Strikingly, the Mn²⁺-complex reduced both aSyn oligomerization and aggregation in human cell cultures and, using NMR and DFT/molecular docking we confirmed its interaction with the C-terminal region of aSyn. In conclusion, the Mn²⁺-complex appears as an excellent lead for the design of new phenanthroline derivatives as alternative compounds for preventing oxidative damages and oxidative stress - related diseases.

Mitochondrial electron transport chain defects modify Parkinson's disease phenotypes in a Drosophila model

INTRODUCTION

Mitochondrial defects have been implicated in Parkinson's disease (PD) since complex I poisons were found to cause accelerated parkinsonism in young people in the early 1980s. More evidence of mitochondrial involvement arose when many of the genes whose mutations caused inherited PD were discovered to be subcellularly localized to mitochondria or have mitochondrial functions. However, the details of how mitochondrial dysfunction might impact or cause PD remain unclear. The aim of our study was to better understand mitochondrial dysfunction in PD by evaluating mitochondrial respiratory complex mutations in a Drosophila melanogaster (fruit fly) model of PD.

METHODS

We have conducted a targeted heterozygous enhancer/suppressor screen using Drosophila mutations within mitochondrial electron transport chain (ETC) genes against a null PD mutation in parkin. The interactions were assessed by climbing assays at 2-5 days as an indicator of motor function. A strong enhancer mutation in COX5A was examined further for L-dopa rescue, oxygen consumption, mitochondrial content, and reactive oxygen species. A later timepoint of 16-20 days was also investigated for both COX5A and a suppressor mutation in cyclope. Generalized Linear Models and similar statistical tests were used to verify significance of the findings.

RESULTS

We have discovered that mutations in individual genes for subunits within the mitochondrial respiratory complexes have interactions with parkin, while others do not, irrespective of complex. One intriguing mutation in a complex IV subunit (cyclope) shows a suppressor rescue effect at early time points, improving the gross motor defects caused by the PD mutation, providing a strong candidate for drug discovery. Most mutations, however, show varying degrees of enhancement or slight suppression of the PD phenotypes. Thus, individual mitochondrial mutations within different oxidative phosphorylation complexes have different interactions with PD with regard to degree and direction. Upon further investigation of the strongest enhancer (COX5A), the mechanism by which these interactions occur initially does not appear to be based on defects in ATP production, but rather may be related to increased levels of reactive oxygen species.

CONCLUSIONS

Our work highlights some key subunits potentially involved in mechanisms underlying PD pathogenesis, implicating ETC complexes other than complex I in PD.

Evidence for Oxidative Pathways in the Pathogenesis of PD: Are Antioxidants Candidate Drugs to Ameliorate Disease Progression?

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that arises due to a complex and variable interplay between elements including age, genetic, and environmental risk factors that manifest as the loss of dopaminergic neurons. Contemporary treatments for PD do not prevent or reverse the extent of neurodegeneration that is characteristic of this disorder and accordingly, there is a strong need to develop new approaches which address the underlying disease process and provide benefit to patients with this debilitating disorder. Mitochondrial dysfunction, oxidative damage, and inflammation have been implicated as pathophysiological mechanisms underlying the selective loss of dopaminergic neurons seen in PD. However, results of studies aiming to inhibit these pathways have shown variable success, and outcomes from large-scale clinical trials are not available or report varying success for the interventions studied. Overall, the available data suggest that further development and testing of novel therapies are required to identify new potential therapies for combating PD. Herein, this review reports on the most recent development of antioxidant and anti-inflammatory approaches that have shown positive benefit in cell and animal models of disease with a focus on supplementation with natural product therapies and selected synthetic drugs.

Maintenance of mitochondrial integrity in midbrain dopaminergic neurons governed by a conserved developmental transcription factor

Progressive degeneration of dopaminergic (DA) neurons in the substantia nigra is a hallmark of Parkinson’s disease (PD). Dysregulation of developmental transcription factors is implicated in dopaminergic neurodegeneration, but the underlying molecular mechanisms remain largely unknown. Drosophila Fer2 is a prime example of a developmental transcription factor required for the birth and maintenance of midbrain DA neurons. Using an approach combining ChIP-seq, RNA-seq, and genetic epistasis experiments with PD-linked genes, here we demonstrate that Fer2 controls a transcriptional network to maintain mitochondrial structure and function, and thus confers dopaminergic neuroprotection against genetic and oxidative insults. We further show that conditional ablation of Nato3, a mouse homolog of Fer2, in differentiated DA neurons causes mitochondrial abnormalities and locomotor impairments in aged mice. Our results reveal the essential and conserved role of Fer2 homologs in the mitochondrial maintenance of midbrain DA neurons, opening new perspectives for modeling and treating PD.

Mitochondrial dysfunction in dopaminergic neurons is a pathological hallmark of Parkinson’s disease. Here, the authors find a conserved mechanism by which a single transcription factor controls mitochondrial health in dopaminergic neurons during the aging process.

An assessment of the rescue action of resveratrol in parkin loss of function-induced oxidative stress in Drosophila melanogaster

Loss-of-function mutations in parkin is associated with onset of juvenile Parkinson's disease (PD). Resveratrol is a polyphenolic stilbene with neuroprotective activity. Here, we evaluated the rescue action of resveratrol in parkin mutant D. melanogaster. The control flies (w1118) received diet-containing 2% ethanol (vehicle), while the PD flies received diets-containing resveratrol (15, 30 and 60 mg/kg diet) for 21 days to assess survival rate. Consequently, similar treatments were carried out for 10 days to evaluate locomotor activity, oxidative stress and antioxidant markers. We also determined mRNA levels of Superoxide dismutase 1 (Sod1, an antioxidant gene) and ple, which encodes tyrosine hydroxylase, the rate-limiting step in dopamine synthesis. Our data showed that resveratrol improved survival rate and climbing activity of PD flies compared to untreated PD flies. Additionally, resveratrol protected against decreased activities of acetylcholinesterase and catalase and levels of non-protein thiols and total thiols displayed by PD flies. Moreover, resveratrol mitigated against parkin mutant-induced accumulations of hydrogen peroxide, nitric oxide and malondialdehyde. Resveratrol attenuated downregulation of ple and Sod1 and reduction in mitochondrial fluorescence intensity displayed by PD flies. Overall, resveratrol alleviated oxidative stress and locomotor deficit associated with parkin loss-of-function mutation and therefore might be useful for the management of PD.

Metabolic Alterations in a Drosophila Model of Parkinson's Disease Based on DJ-1 Deficiency

Parkinson’s disease (PD) is the second-most common neurodegenerative disorder, whose physiopathology is still unclear. Moreover, there is an urgent need to discover new biomarkers and therapeutic targets to facilitate its diagnosis and treatment. Previous studies performed in PD models and samples from PD patients already demonstrated that metabolic alterations are associated with this disease. In this context, the aim of this study is to provide a better understanding of metabolic disturbances underlying PD pathogenesis. To achieve this goal, we used a Drosophila PD model based on inactivation of the DJ-1β gene (ortholog of human DJ-1). Metabolomic analyses were performed in 1-day-old and 15-day-old DJ-1β mutants and control flies using ¹H nuclear magnetic resonance spectroscopy, combined with expression and enzymatic activity assays of proteins implicated in altered pathways. Our results showed that the PD model flies exhibited protein metabolism alterations, a shift fromthe tricarboxylic acid cycle to glycolytic pathway to obtain ATP, together with an increase in the expression of some urea cycle enzymes. Thus, these metabolic changes could contribute to PD pathogenesis and might constitute possible therapeutic targets and/or biomarkers for this disease.

Mafusol and its combination with REXOD as correctors of reduced blood circulation in the skin associated with normoglycemia or diabetes mellitus complicated by exogenous hypercholesterolemia

Introduction: The search for and development of new highly active medications and their combinations of the appropriate direction of action remains an urgent problem due to the complications of diabetes mellitus, especially burdened with atherosclerosis, including skin and vascular lesions.

Materials and methods: The acute toxicity, histoprotective and dermatoprotective effects of mafusol, rexod, alprostadil and their combinations were studied in male rats with normoglycemia and alloxan diabetes complicated by exogenous hypercholesterolemia.

Results: The combination of mafusol with rexod is less toxic than mafusol. In arteriovenous insufficiency of the tail, ischemia of the skin fold and skin flap, mafusol (6.25, 12.5 and 25.0 mg/kg in terms of fumarate), rexod (0.01 and 0.02 mg/kg) and especially their combination (6.25 and 0.01 mg/kg) have significant histoprotective, dermatoprotective, hypoglycemic and lipid-lowering effects, both in normoglycemia and alloxan diabetes complicated by exogenous hypercholesterolemia. Alprostadil (10 mg/kg) and especially its combination with mafusol (6.25 mg/kg) have a dermatoprotective effect.

Discussion: Rexod reduces the acute toxicity of mafusol. The dermatoprotective effect of mafusol, rexod and, to a greater extent, their combination may be associated with increased microhemocirculation, antihypoxic properties and activation of energy processes in the skin, normalization of carbohydrate and lipid metabolism in alloxan diabetes, complicated by exogenous hypercholesterolemia, increased reserve capacity of the antioxidant system, and possibly with the ability of mafusol and rexod to reduce blood viscosity and improve rheological properties of the blood. The combination of mafusol with alprostadil increases the dermatoprotective activity of the latter.

Conclusion: Combinations of mafusol with rexod and alprostadil can be recommended for clinical study as dermatoprotective agents for treating traumatic injuries and diabetes mellitus complicated by atherosclerosis.

"Metal elements and pesticides as risk factors for Parkinson's disease - A review"

Essential metals including iron (Fe) and manganese (Mn) with known physiological functions in human body play an important role in cell homeostasis. Excessive exposure to these essential as well as non-essential metals including mercury (Hg) and Aluminum (Al) may contribute to pathological conditions, including PD. Each metal could be toxic through specific pathways. Epidemiological evidences from occupational and ecological studies besides various in vivo and in vitro studies have revealed the possible pathogenic role and neurotoxicity of different metals. Pesticides are substances that aim to mitigate the harm done by pests to plants and crops, and are extensively used to boost agricultural production. This review provides an outline of our current knowledge on the possible association between metals and PD. We have discussed the potential association between these two, furthermore the chemical properties, biological and toxicological aspects as well as possible mechanisms of Fe, Mn, Cu, Zn, Al, Ca, Pb, Hg and Zn in PD pathogenesis. In addition, we review recent evidence on deregulated microRNAs upon pesticide exposure and possible role of deregulated miRNA and pesticides to PD pathogenesis.

Molecular Mechanisms Underlying Reciprocal Interactions Between Sleep Disorders and Parkinson's Disease

Sleep-wake disruptions are among the most prevalent and burdensome non-motor symptoms of Parkinson's disease (PD). Clinical studies have demonstrated that these disturbances can precede the onset of typical motor symptoms by years, indicating that they may play a primary function in the pathogenesis of PD. Animal studies suggest that sleep facilitates the removal of metabolic wastes through the glymphatic system via convective flow from the periarterial space to the perivenous space, upregulates antioxidative defenses, and promotes the maintenance of neuronal protein homeostasis. Therefore, disruptions to the sleep-wake cycle have been associated with inefficient metabolic clearance and increased oxidative stress in the central nervous system (CNS). This leads to excessive accumulation of alpha-synuclein and the induction of neuronal loss, both of which have been proposed to be contributing factors to the pathogenesis and progression of PD. Additionally, recent studies have suggested that PD-related pathophysiological alterations during the prodromal phase disrupt sleep and circadian rhythms. Taken together, these findings indicate potential mechanistic interactions between sleep-wake disorders and PD progression as proposed in this review. Further research into the hypothetical mechanisms underlying these interactions would be valuable, as positive findings may provide promising insights into novel therapeutic interventions for PD.

Role of Commensal Microbes in the γ-Ray Irradiation-Induced Physiological Changes in Drosophila melanogaster

Ionizing radiation induces biological/physiological changes and affects commensal microbes, but few studies have examined the relationship between the physiological changes induced by irradiation and commensal microbes. This study investigated the role of commensal microbes in the γ-ray irradiation-induced physiological changes in Drosophila melanogaster. The bacterial load was increased in 5 Gy irradiated flies, but irradiation decreased the number of operational taxonomic units. The mean lifespan of conventional flies showed no significant change by irradiation, whereas that of axenic flies was negatively correlated with the radiation dose. γ-Ray irradiation did not change the average number of eggs in both conventional and axenic flies. Locomotion of conventional flies was decreased after 5 Gy radiation exposure, whereas no significant change in locomotion activity was detected in axenic flies after irradiation. γ-Ray irradiation increased the generation of reactive oxygen species in both conventional and axenic flies, but the increase was higher in axenic flies. Similarly, the amounts of mitochondria were increased in irradiated axenic flies but not in conventional flies. These results suggest that axenic flies are more sensitive in their mitochondrial responses to radiation than conventional flies, and increased sensitivity leads to a reduced lifespan and other physiological changes in axenic flies.

Riding the tiger - physiological and pathological effects of superoxide and hydrogen peroxide generated in the mitochondrial matrix

Elevated mitochondrial matrix superoxide and/or hydrogen peroxide concentrations drive a wide range of physiological responses and pathologies. Concentrations of superoxide and hydrogen peroxide in the mitochondrial matrix are set mainly by rates of production, the activities of superoxide dismutase-2 (SOD2) and peroxiredoxin-3 (PRDX3), and by diffusion of hydrogen peroxide to the cytosol. These considerations can be used to generate criteria for assessing whether changes in matrix superoxide or hydrogen peroxide are both necessary and sufficient to drive redox signaling and pathology: is a phenotype affected by suppressing superoxide and hydrogen peroxide production; by manipulating the levels of SOD2, PRDX3 or mitochondria-targeted catalase; and by adding mitochondria-targeted SOD/catalase mimetics or mitochondria-targeted antioxidants? Is the pathology associated with variants in SOD2 and PRDX3 genes? Filtering the large literature on mitochondrial redox signaling using these criteria highlights considerable evidence that mitochondrial superoxide and hydrogen peroxide drive physiological responses involved in cellular stress management, including apoptosis, autophagy, propagation of endoplasmic reticulum stress, cellular senescence, HIF1α signaling, and immune responses. They also affect cell proliferation, migration, differentiation, and the cell cycle. Filtering the huge literature on pathologies highlights strong experimental evidence that 30-40 pathologies may be driven by mitochondrial matrix superoxide or hydrogen peroxide. These can be grouped into overlapping and interacting categories: metabolic, cardiovascular, inflammatory, and neurological diseases; cancer; ischemia/reperfusion injury; aging and its diseases; external insults, and genetic diseases. Understanding the involvement of mitochondrial matrix superoxide and hydrogen peroxide concentrations in these diseases can facilitate the rational development of appropriate therapies.

Oxidative Stress in Parkinson's Disease: Potential Benefits of Antioxidant Supplementation

Parkinson's disease (PD) occurs in approximately 1% of the population over 65 years of age and has become increasingly more common with advances in age. The number of individuals older than 60 years has been increasing in modern societies, as well as life expectancy in developing countries; therefore, PD may pose an impact on the economic, social, and health structures of these countries. Oxidative stress is highlighted as an important factor in the genesis of PD, involving several enzymes and signaling molecules in the underlying mechanisms of the disease. This review presents updated data on the involvement of oxidative stress in the disease, as well as the use of antioxidant supplements in its therapy.

An optimized procedure for quantitative analysis of mitophagy with the mtKeima system using flow cytometry

Mitophagy is the process by which mitochondria are selectively targeted and removed via autophagic machinery to maintain mitochondrial homeostasis in the cell. Recently, flow cytometry-based assays that utilize the fluorescent mtKeima reporter system have allowed for quantitative assessment of mitophagy at a single-cell level. However, clear guidelines for appropriate flow cytometry workflow and downstream analysis are lacking and studies using flow cytometry in mtKeima-expressing cells often display incorrect and arbitrary binary mitophagic or nonmitophagic cutoffs that prevent proper quantitative analyses. In this paper we propose a novel method of mtKeima data analysis that preserves subtle differences present within flow cytometry data in a manner that ensures reproducibility.

Induction of Autophagy by Vasicinone Protects Neural Cells from Mitochondrial Dysfunction and Attenuates Paraquat-Mediated Parkinson's Disease Associated α-Synuclein Levels

Mitochondrial dysfunction and disturbed mitochondrial dynamics were found to be common phenomena in the pathogenesis of Parkinson's disease (PD). Vasicinone is a quinazoline alkaloid from Adhatoda vasica. Here, we investigated the autophagy/mitophagy-enhancing effect of vasicinone and explored its neuroprotective mechanism in paraquat-mimic PD modal in SH-SY5Y cells. Vasicinone rescued the paraquat-induced loss of cell viability and mitochondrial membrane potential. Subsequently, the accumulation of mitochondrial reactive oxygen species (ROS) was balanced by an increase in the expression of antioxidant enzymes. Furthermore, vasicinone restored paraquat-impaired autophagy and mitophagy regulators DJ-1, PINK-1 and Parkin in SH-SY5Y cells. The vasicinone mediated autophagy pathways were abrogated by treatment with the autophagy inhibitor 3-MA, which lead to increases α-synuclein accumulation and decreased the expression of p-ULK and ATG proteins and the autophagy marker LC3-II compared to that observed without 3-MA treatment. These results demonstrated that vasicinone exerted neuroprotective effects by upregulating autophagy and PINK-1/Parkin mediated mitophagy in SH-SY5Y cells.

The STING pathway does not contribute to behavioural or mitochondrial phenotypes in Drosophila Pink1/parkin or mtDNA mutator models

Mutations in PINK1 and Parkin/PRKN cause the degeneration of dopaminergic neurons in familial forms of Parkinson's disease but the precise pathogenic mechanisms are unknown. The PINK1/Parkin pathway has been described to play a central role in mitochondrial homeostasis by signalling the targeted destruction of damaged mitochondria, however, how disrupting this process leads to neuronal death was unclear until recently. An elegant study in mice revealed that the loss of Pink1 or Prkn coupled with an additional mitochondrial stress resulted in the aberrant activation of the innate immune signalling, mediated via the cGAS/STING pathway, causing degeneration of dopaminergic neurons and motor impairment. Genetic knockout of Sting was sufficient to completely prevent neurodegeneration and accompanying motor deficits. To determine whether Sting plays a conserved role in Pink1/parkin related pathology, we tested for genetic interactions between Sting and Pink1/parkin in Drosophila. Surprisingly, we found that loss of Sting, or its downstream effector Relish, was insufficient to suppress the behavioural deficits or mitochondria disruption in the Pink1/parkin mutants. Thus, we conclude that phenotypes associated with loss of Pink1/parkin are not universally due to aberrant activation of the STING pathway.

Antioxidant Therapy in Parkinson's Disease: Insights from Drosophila melanogaster

Reactive oxygen species (ROS) play an important role as endogenous mediators in several cellular signalling pathways. However, at high concentrations they can also exert deleterious effects by reacting with many macromolecules including DNA, proteins and lipids. The precise balance between ROS production and their removal via numerous enzymatic and nonenzymatic molecules is of fundamental importance for cell survival. Accordingly, many neurodegenerative disorders, including Parkinson’s disease (PD), are associated with excessive levels of ROS, which induce oxidative damage. With the aim of coping with the progression of PD, antioxidant compounds are currently receiving increasing attention as potential co-adjuvant molecules in the treatment of these diseases, and many studies have been performed to evaluate the purported protective effects of several antioxidant molecules. In the present review, we present and discuss the relevance of the use of Drosophila melanogaster as an animal model with which to evaluate the therapeutic potential of natural and synthetic antioxidants. The conservation of most of the PD-related genes between humans and D. melanogaster, along with the animal’s rapid life cycle and the versatility of genetic tools, makes fruit flies an ideal experimental system for rapid screening of antioxidant-based treatments.

Oxidative stress in the aging substantia nigra and the etiology of Parkinson's disease

Parkinson's disease prevalence is rapidly increasing in an aging global population. With this increase comes exponentially rising social and economic costs, emphasizing the immediate need for effective disease‐modifying treatments. Motor dysfunction results from the loss of dopaminergic neurons in the substantia nigra pars compacta and depletion of dopamine in the nigrostriatal pathway. While a specific biochemical mechanism remains elusive, oxidative stress plays an undeniable role in a complex and progressive neurodegenerative cascade. This review will explore the molecular factors that contribute to the high steady‐state of oxidative stress in the healthy substantia nigra during aging, and how this chemical environment renders neurons susceptible to oxidative damage in Parkinson's disease. Contributing factors to oxidative stress during aging and as a pathogenic mechanism for Parkinson's disease will be discussed within the context of how and why therapeutic approaches targeting cellular redox activity in this disorder have, to date, yielded little therapeutic benefit. We present a contemporary perspective on the central biochemical contribution of redox imbalance to Parkinson's disease etiology and argue that improving our ability to accurately measure oxidative stress, dopaminergic neurotransmission and cell death pathways in vivo is crucial for both the development of new therapies and the identification of novel disease biomarkers.

CRISPR/Cas: An intriguing genomic editing tool with prospects in treating neurodegenerative diseases

The CRISPR/Cas genome editing tool has led to a revolution in biological research. Its ability to target multiple genomic loci simultaneously allows its application in gene function and genomic manipulation studies. Its involvement in the sequence specific gene editing in different backgrounds has changed the scenario of treating genetic diseases. By unravelling the mysteries behind complex neuronal circuits, it not only paved way in understanding the pathogenesis of the disease but helped in the development of large animal models of different neuronal diseases; thereby opened the gateways of successfully treating different neuronal diseases. This review explored the possibility of using of CRISPR/Cas in engineering DNA at the embryonic stage, as well as during the functioning of different cell types in the brain, to delineate implications related to the use of this super-specialized genome editing tool to overcome various neurodegenerative diseases that arise as a result of genetic mutations.