Stress In Neurodegeneration Research Articles

Prolidase Enzyme Activity as a Potential Biomarker for Blast-Induced Traumatic Brain Injury: A Study in a Rat Model

AbstractBlast-induced traumatic brain injury (TBI) poses a significant threat to individuals exposed to explosive events. We hypothesized that blast-induced neurotrauma is an oxidative stress to brain and hence prolidase (PD) enzyme, which is an antioxidant is recommended; its serum levels are better markers of degree of injury in the acute phase for TBI in a rat blast injury model. Results revealed that PD enzyme activity in the hippocampus showed a slight increase across high, medium, and low blast pressures, but remained lower than the sham group. However, serum PD enzyme activity levels were significantly higher in the blast-exposed groups compared to the sham group. Tau protein levels were significantly elevated in the blast-exposed groups. Longitudinal analysis demonstrated a decline in hippocampal PD activity over time, while tau protein levels progressively increased, suggesting a shift from initial oxidative stress to neurodegeneration. These findings suggest that blast injury triggers oxidative stress and subsequent neurodegenerative processes. The correlation with tau protein levels further supports the involvement of oxidative stress in neurodegeneration. In conclusion, this study provides insights into the underlying pathophysiological mechanisms of blast-induced TBI and highlights the potential utility of PD enzyme activity as a diagnostic marker.

Involvement of Proteasomal and Endoplasmic Reticulum Stress in Neurodegeneration After Global Brain Ischemia

A brief period of transient global brain ischemia leads to selective ischemic neurodegeneration associated with death of hippocampal CA1 pyramidal neurons days after reperfusion. The mechanism of such selective and delayed neurodegeneration is still uncertain. Our work aimed to study the involvement of proteasomal and endoplasmic reticulum (ER) stress in ischemic neurodegeneration. We have performed laser scanning confocal microscopy analysis of brain slices from control and experimental animals that underwent global brain ischemia for 15 min and varying times of reperfusion. We have focused on ubiquitin, PUMA, a proapoptotic protein of the Bcl-2 family overexpressed in response to both proteasomal and ER stress, and p53, which controls expression of PUMA. We have also examined the expression of HRD1, an E3 ubiquitin ligase that was shown to be overexpressed after ER stress. We have also examined potential crosstalk between proteasomal and ER stress using cellular models of both proteasomal and ER stress. We demonstrate that global brain ischemia is associated with an appearance of distinct immunoreactivity of ubiquitin, PUMA and p53 in pyramidal neurons of the CA1 layer of the hippocampus 72 h after ischemic insults. Such changes correlate with a delay and selectivity of ischemic neurodegeneration. Immunoreactivity of HRD1 observed in all investigated regions of rat brain was transiently absent in both CA1 and CA3 pyramidal neurones 24 h after ischemia in the hippocampus, which does not correlate with a delay and selectivity of ischemic neurodegeneration. We do not document significant crosstalk between proteasomal and ER stress. Our results favour dysfunction of the ubiquitin proteasome system and consequent p53-induced expression of PUMA as the main mechanisms responsible for selective and delayed degeneration of pyramidal neurons of the hippocampal CA1 layer in response to global brain ischemia.

Marine Macroalgae Polyphenols as Potential Neuroprotective Antioxidants in Neurodegenerative Diseases

Polyphenols are beneficial natural compounds with antioxidant properties that have recently gain a lot of interest for their potential therapeutic applications. Marine polyphenols derived from marine macroalgae have been discovered to possess interesting antioxidant properties; therefore, these compounds can be included in several areas of drug development. Authors have considered the use of polyphenol extracts from seaweeds as neuroprotective antioxidants in neurodegenerative diseases. Marine polyphenols may slow the progression and limit neuronal cell loss due to their antioxidant activity; therefore, the use of these natural compounds would improve the quality of life for patients affected with neurodegenerative diseases. Marine polyphenols have distinct characteristics and potential. Among seaweeds, brown algae are the main sources of polyphenols, and present the highest antioxidant activity in comparison to red algae and green algae. The present paper collects the most recent in vitro and in vivo evidence from investigations regarding polyphenols extracted from seaweeds that exhibit neuroprotective antioxidant activity. Throughout the review, oxidative stress in neurodegeneration and the mechanism of action of marine polyphenol antioxidant activity are discussed to evidence the potential of algal polyphenols for future use in drug development to delay cell loss in patients with neurodegenerative disorders.

Cannabidiol for neurodegenerative disorders: A comprehensive review.

Despite the significant advances in neurology, the cure for neurodegenerative conditions remains a formidable task to date. Among various factors arising from the complex etiology of neurodegenerative diseases, neuroinflammation and oxidative stress play a major role in pathogenesis. To this end, some phytocannabinoids isolated from Cannabis sativa (widely known as marijuana) have attracted significant attention as potential neurotherapeutics. The profound effect of ∆9-tetrahydrocannabinol (THC), the major psychoactive component of cannabis, has led to the discovery of the endocannabinoid system as a molecular target in the central nervous system (CNS). Cannabidiol (CBD), the major non-psychoactive component of cannabis, has recently emerged as a potential prototype for neuroprotective drug development due to its antioxidant and anti-inflammatory properties and its well-tolerated pharmacological behavior. This review briefly discusses the role of inflammation and oxidative stress in neurodegeneration and demonstrates the neuroprotective effect of cannabidiol, highlighting its general mechanism of action and disease-specific pathways in Parkinson's disease (PD) and Alzheimer's disease (AD). Furthermore, we have summarized the preclinical and clinical findings on the therapeutic promise of CBD in PD and AD, shed light on the importance of determining its therapeutic window, and provide insights into identifying promising new research directions.

Expression of PON1, PON2, PON3 and MPO Genes in Patients with Depressive Disorders.

Background: Taking into account the role of oxidative stress in neurodegeneration, we sought to evaluate the expression of genes for select enzymes with antioxidant properties (paraoxonases PON1, PON2 and PON3 and myeloperoxidase MPO) at the mRNA and protein levels in patients with depressive disorders. We further sought to determine the impact of oxidative stress in the etiopathogenesis of this group of mood disorders. Methods: A total of 290 subjects (190 depressed patients, 100 healthy controls) took part in the study. Sociodemographic and clinical data were collected. The severity of depressive symptoms was assessed using the Hamilton Depression Rating Scale (HDRS). Venous blood was collected. RT-PCR was used to assess gene expression at the mRNA level, while enzyme-linked immunosorbent assay (ELISA) was used to assess gene expression at the protein level. Results: The expression of the PON2 and PON3 genes at the protein level was significantly higher in depressive patients than in healthy controls. mRNA expression of the PON1, PON2 and PON3 genes was slightly higher in patients with depressive disorders than in the control group, however, this relationship was not statistically significant. On the other hand, the expression of the MPO gene at both mRNA and protein levels was significantly lower in patients with depressive disorder than in the control group. Conclusions: Our results are not in agreement with many studies on enzymes involved in maintaining oxidative balance. Our findings may not support the utility of paraoxonases (PON) or myeloperoxidase (MPO) as promising biomarker candidates of depression pending larger and well controlled studies.

TDP-43 and ER Stress in Neurodegeneration: Friends or Foes?

Nuclear depletion, abnormal modification, and cytoplasmic aggregation of TAR DNA-binding protein 43 (TDP-43) are linked to a group of fatal neurodegenerative diseases called TDP-43 proteinopathies, which include amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Although our understanding of the physiological function of TDP-43 is rapidly advancing, the molecular mechanisms associated with its pathogenesis remain poorly understood. Accumulating evidence suggests that endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are important players in TDP-43 pathology. However, while neurons derived from autopsied ALS and FTLD patients revealed TDP-43 deposits in the ER and displayed UPR activation, data originated from in vitro and in vivo TDP-43 models produced contradictory results. In this review, we will explore the complex interplay between TDP-43 pathology, ER stress, and the UPR by breaking down the evidence available in the literature and addressing the reasons behind these discrepancies. We also highlight underexplored areas and key unanswered questions in the field. A better synchronization and integration of methodologies, models, and mechanistic pathways will be crucial to discover the true nature of the TDP-43 and ER stress relationship and, ultimately, to uncover the full therapeutic potential of the UPR.

Current Views on the Role of Stress in the Pathogenesis of Chronic Neurodegenerative Diseases.

The review summarizes the results of studies on the cellular and molecular mechanisms mediating the impact of stress on the pathogenesis of neurodegenerative brain pathologies (Alzheimer's disease, Parkinson's disease, etc.) and presents current information on the role of stress in the hyperphosphorylation of tau protein, aggregation of beta-amyloid, and hyperactivation of the hypothalamic-pituitary-adrenal axis involved in the hyperproduction of factors that contribute to the pathogenetic role of stress in neurodegeneration. The data on the participation of microglia in the effects of stress on the pathogenesis of neurodegenerative diseases are presented.

Power Failure of Mitochondria and Oxidative Stress in Neurodegeneration and Its Computational Models.

The brain needs more energy than other organs in the body. Mitochondria are the generator of vital power in the living organism. Not only do mitochondria sense signals from the outside of a cell, but they also orchestrate the cascade of subcellular events by supplying adenosine-5′-triphosphate (ATP), the biochemical energy. It is known that impaired mitochondrial function and oxidative stress contribute or lead to neuronal damage and degeneration of the brain. This mini-review focuses on addressing how mitochondrial dysfunction and oxidative stress are associated with the pathogenesis of neurodegenerative disorders including Alzheimer’s disease, amyotrophic lateral sclerosis, Huntington’s disease, and Parkinson’s disease. In addition, we discuss state-of-the-art computational models of mitochondrial functions in relation to oxidative stress and neurodegeneration. Together, a better understanding of brain disease-specific mitochondrial dysfunction and oxidative stress can pave the way to developing antioxidant therapeutic strategies to ameliorate neuronal activity and prevent neurodegeneration.

Protein Network Analysis to Prioritize Key Genes and Pathway for Stress-Mediated Neurodegeneration

Background:Oxidative Stress (OS) has been implicated in the pathophysiology of many neurodegenerative diseases. OS can cause cellular damage that results in cell death due to overproduction of reactive oxygen species (ROS) that may play the crucial role in the disease progression. An impaired mechanism in correlation with reduced expression of antioxidant proteins is the very common feature among most of the age-related disorders. Variousin-vitroandin-vivostudies suggest the major contribution of oxidative stress in neurodegeneration. Role of Nrf2 gene is well established as a neuroprotective gene especially in concern with stress-mediated neurodegeneration. Nrf2 is a bZIP transcription factor that forms the heterodimer with small Maf protein and transcription factor AP1 that regulates transcription by binding to ARE which coordinates the transcription of genes involved in phase II detoxification and an antioxidant defense that is used to protect the cell from oxidative stress.Aim:The currentinsilicostudy was attempted to prioritize key genes and pathway in stress-mediated neurodegeneration through network-based analysis.Methods:Protein-protein interaction network was constructed and analyzed using 63 Nrf2 regulating candidate genes obtained from NCBI database based on literature studies usingSTRING 10.0database andCytoscape v 3.6.0software plug-inNetwork Analyzer.Further, the functional enrichment analysis of identified gene was done usingPANTHER GENE ONTOLOGYsoftware and DAVID tool.Results:Based on network topological parameter, TP53, JUN, MYC, NFE2L2, AKT1, PIK3CA & UBC were identified as the key gene in the network. Among them, TP53 gene was obtained as a super hub gene with the highest Betweenness Centrality (BC) and node degree. The functional enrichment analysis was done usingPANTHER GENE ONTOLOGYsoftware and DAVID tool reveals their significant role in neurotrophin signaling pathway, MAPK signaling pathway, cellular response to stress & in the regulation of stress.Conclusion:The network analysis will help in prioritizing genes in the pathway that helps in understanding the underlying mechanism of disease. Thus, further study on these genes and their biological mechanism and pathway may, therefore, provide a potential target for the treatment of stress-mediated neurodegeneration.

Degrees of stress in neurodegeneration

Neuroscience In the neurodegenerative disorder amyotrophic lateral sclerosis (ALS), the nuclear protein called transactive response DNA binding protein of 43 kDa (TDP-43) accumulates in stress granules within the cytoplasm of neurons and glia and is linked to disease pathology. McGurk et al. report that TDP-43 binds to poly(ADP-ribose) (PAR), which triggers phase separation of TDP-43 and its subsequent recruitment to stress granules. Under short-term stress, phosphorylated TDP-43, which is considered a hallmark of disease, is unexpectedly excluded from stress granules. This finding indicates that the granules initially prevent phosphorylated TDP-43 aggregation unless stress is prolonged. This work also points to an approach to ALS treatment by inhibition of PAR polymerase (PARP) to reduce PAR production. For instance, a small-molecule inhibitor of PARP that prevents cancer-cell proliferation also blocks cytoplasmic TDP-43 aggregation. Mol. Cell 10.1016/j.molcel.2018.07.002 (2018).

The Underlying Role of Oxidative Stress in Neurodegeneration: A Mechanistic Review.

Neurodegeneration is a condition in which progressive loss of function and structure of neurons occurs. Several lines of evidence suggest that oxidative stress has a central role in neurodegenerative diseases. The aim was to survey molecular mechanisms underlying the involvement of oxidative stress in developing different neurodegenerative diseases. Original and review articles were retrieved through a PubMed and Google scholar search (from 1989 to 2015) using the following key words: "oxidative stress", "nerve degeneration" and "neurodegenerative diseases". A comprehensive analysis of the obtained articles confirmed strong involvement of oxidative stress in the pathophysiology of neurodegenerative diseases through a variety of mechanisms including induction of oxidation of nucleic acids, proteins and lipids, formation of advanced glycation end products, mitochondrial dysfunction, glial cell activation, amyloid β deposition and plaque formation, apoptosis, cytokine production and inflammatory responses, and proteasome dysfunction. Regarding the pivotal role of oxidative stress in neurodegeneration, modulation of free radical production or alleviating their harmful effects can be considered as a potential therapeutic strategy for preventing and controlling neurodegenerative diseases. Accordingly; boosting endogenous antioxidant capacity besides providing exogenous sources of antioxidants merits future research in order to discover new therapeutic agents.

Neuroprotective and anti-inflammatory role of Tinospora cordifolia in MPTP induced parkinsonian mouse model

Parkinson’s disease, an age related neurodegenerative disorder, is characterized by progressive loss of dopaminergic neurons in substantia nigra pars compacta of the mid brain and projecting neurons in striatum. Recently, several studies regarding parkinson’s disease have proven the role of oxidative stress in neurodegeneration and neuroinflammation. In this context, our study evaluates the neuroprotective effect of Tinospora Cordifolia Aqueous Extract (TCAE) in parkinsonian mice. From the immunohistochemistry and western blot analysis, it is evident that TCAE inhibits the MPTP-induced activation of NF-κB and its associated pro-inflammatory cytokines. Through, Real time PCR analysis it was revealed that pro-inflammatory cytokines were found to be up regulated in MPTP intoxicated mice while TCAE treatment significantly restored their levels. In addition, the expression level of IL-10 was found decreased in diseased condition which was further restored by TCAE treatment. Tyrosine hydroxylase, an important enzyme which is used as marker in parkinson’s disease, its expression was found to be reduced in MPTP mice while on giving TCAE, its level was significantly restored. Our result clearly indicates that Tinospora cordifolia provides neuroprotection against MPTP induced nigrostriatal dopaminergic neurodegeneration and shows potent anti-inflammatory activity.

Detoxification of Carbonyl Compounds by Carbonyl Reductase in Neurodegeneration.

Oxidative stress in the brain is the major cause of neurodegenerative disorders, including Alzheimer's, Parkinson's, Huntington's, and Creutzfeldt-Jakob diseases or amyotrophic lateral sclerosis. Under conditions of oxidative stress, the production of highly reactive oxygen species (ROS) overwhelms antioxidant defenses, resulting in the modification of macromolecules and their deposition in neuronal cell tissues. ROS plays an important role in neuronal cell death that they generate reactive aldehydes from membrane lipid peroxidation. Several neuronal diseases are associated with increased accumulation of abnormal protein adducts of reactive aldehydes, which mediate oxidative stress-linked pathological events, including cell growth inhibition and apoptosis induction. Combining findings on neurodegeneration and oxidative stress in Drosophila with studies on the metabolic characteristics of the human enzyme CBR1, it is clear now that CBR1 has a potential physiological role of neuroprotection in humans. Several studies suggest that CBR1 represents a significant pathway for the detoxification of reactive aldehydes derived from lipid peroxidation and that CBR1 in humans is essential for neuronal cell survival and to confer protection against oxidative stress-induced brain degeneration. Recently, it was discovered that HIF1alpha, AP-1, and Nrf2 could all regulate CBR1 at the transcriptional level. Nrf2 is known to regulate the transcription of antioxidant enzymes, and CBR1 functions as an antioxidant enzyme, suggesting that transcriptional regulation of CBR1 is a major contributor to the control of oxidative stress in neurodegeneration.

Circadian Rhythms of Oxidative Stress Markers and Melatonin Metabolite in Patients with Xeroderma Pigmentosum Group A.

Xeroderma pigmentosum group A (XPA) is a genetic disorder in DNA nucleotide excision repair (NER) with severe neurological disorders, in which oxidative stress and disturbed melatonin metabolism may be involved. Herein we confirmed the diurnal variation of melatonin metabolites, oxidative stress markers, and antioxidant power in urine of patients with XPA and age-matched controls, using enzyme-linked immunosorbent assay (ELISA). The peak of 6-sulfatoxymelatonin, a metabolite of melatonin, was seen at 6:00 in both the XPA patients and controls, though the peak value is lower, specifically in the younger age group of XPA patients. The older XPA patients demonstrated an increase in the urinary levels of 8-hydroxy-2′-deoxyguanosine and hexanoyl-lysine, a marker of oxidative DNA damage and lipid peroxidation, having a robust peak at 6:00 and 18:00, respectively. In addition, the urinary level of total antioxidant power was decreased in the older XPA patients. Recently, it is speculated that oxidative stress and antioxidant properties may have a diurnal variation, and the circadian rhythm is likely to influence the NER itself. We believe that the administration of melatonin has the possibility of ameliorating the augmented oxidative stress in neurodegeneration, especially in the older XPA patients, modulating the melatonin metabolism and the circadian rhythm.

The Immp2l mutation causes age‐dependent degeneration of cerebellar granule neurons prevented by antioxidant treatment

Reactive oxygen species are implicated in age-associated neurodegeneration, although direct invivo evidence is lacking. We recently showed that mice with a mutation in the Inner Mitochondrial Membrane Peptidase 2-like (Immp2l) gene had elevated levels of mitochondrial superoxide, impaired fertility and age-associated phenotypes, including kyphosis and ataxia. Here we show that ataxia and cerebellar hypoplasia occur in old mutant mice (>16months). Cerebellar granule neurons (CGNs) are significantly underrepresented; Purkinje cells and cells in the molecular layer are not affected. Treating mutant mice with the mitochondria-targeted antioxidant SkQ1 from 6weeks to 21months protected cerebellar granule neurons. Apoptotic granule neurons were observed in mutant mice but not in age-matched normal control mice or SkQ1-treated mice. Old mutant mice showed increased serum protein carbonyl content, cerebellar 4-hydroxynonenal (HNE), and nitrotyrosine modification compared to old normal control mice. SOD2 expression was increased in Purkinje cells but decreased in granule neurons of old mutant mice. Mitochondrial marker protein VDAC1 also was decreased in CGNs of old mutant mice, suggesting decreased mitochondrial number. SkQ1 treatment decreased HNE and nitrotyrosine modification, and restored SOD2 and VDAC1 expression in CGNs of old mutant mice. Neuronal expression of nitric oxide synthase was increased in cerebella of young mutant mice but decreased in old mutant mice. Our work provides evidence for a causal role of oxidative stress in neurodegeneration of Immp2l mutant mice. The Immp2l mutant mouse model could be valuable in elucidating the role of oxidative stress in age-associated neurodegeneration.

Berberine and neurodegeneration: A review of literature.

The excessive production of reactive oxygen species in nervous tissues is considered one of the major risk factors of neurodegenerative diseases. During the last two decades, much attention has been paid to the antioxidant and anti-inflammatory activity of natural products and compounds isolated from natural products which are often characterized by high efficacy and low adverse effects. Berberine is an isoquinoline alkaloid, widely present in different medicinal herbs, especially in the genus Berberis. It is mainly used as antidiarrhoeal, antibacterial, antifungal, and antiprotozoal agent. However, current research has focused on its beneficial role in neurodegenerative diseases, mainly due to its powerful antioxidant effect. The therapeutic potential of Berberine in different neurodegenerative diseases such as Alzheimer, Parkinson and Huntington disease has been brought to evidence by numerous studies. However, a limited number of reviews focus on the beneficial role of Berberine against neurodegeneration. The main objective of this review is to discuss the role of oxidative stress in neurodegeneration and the potential role of antioxidant compounds, in particular Berberine which is analyzed in its chemical structure, source, bioavailability, therapeutic potential, with special attention to its mechanism of action at a molecular level.

Adaptive endoplasmic reticulum stress alters cellular responses to the extracellular milieu.

The ability to respond to perturbations in endoplasmic reticulum (ER) function is a critical property for all cells. In the presence of chronic ER stress, the cell must adapt so that cell survival is favored or the stress may promote apoptosis. In some pathological processes, such as neurodengeneration, persistent ER stress can be tolerated for an extended period, but eventually cell death occurs. It is not known how an adaptive response converts from survival into apoptosis. To gain a better understanding of the role of adaptive ER stress in neurodegeneration, in this study, with a neuronal cell line SH-SY5Y and primary motor neuron-glia cell mixed cultures, we induced adaptive ER stress and modified the extracellular environment with physiologically relevant changes that alone did not activate ER stress. Our data demonstrate that an adaptive ER stress favored neuronal cell survival, but when cells were exposed to additional physiological insults the level of ER stress was increased, followed by activation of the caspase pathway. Our results indicate that an adaptive ER stress response could be converted to apoptosis when the external cellular milieu changed, suggesting that the conversion from prosurvival to proapoptotic pathways can be driven by the external milieu. This conversion was due at least partially to an increased level of ER stress.

Quercetin encapsulation in modified silica nanoparticles: potential use against Cu(II)-induced oxidative stress in neurodegeneration

Neurodegenerative diseases entail deeply complex processes, intimately associated with progressive brain damage reflecting cellular demise. Biochemical reactivity linked to such processes in Alzheimer’s disease involves, among others, metal-induced oxidative stress contributing to neuronal cell death. Prominent among redox active metals inducing oxidative stress is Cu(II). Poised to develop molecular technology counteracting oxidative stress, efforts were launched to prepare bioactive hybrid nanoparticles, capable of working as host-carriers of potent antioxidants, such as the natural flavonoid quercetin. Employing synthetic protocols consistent with the assembly of silica nanoparticles, PEGylated and CTAB-modified materials were synthesized. Subsequent concentration-dependent loading of quercetin led to well-defined molecular carriers, the antioxidant efficiency of which was determined through drug release studies using UV-visible spectroscopy. The physicochemical characterization (elemental analysis, particle size, z-potential, FT-IR, thermogravimetric analysis, scanning electron microscopy) of the empty and loaded silica nanoparticles led to the formulation of optimized material linked to the delivery of the encapsulated antioxidant to primary rat hippocampal cultures under oxidative stress. Entrapment and drug release studies showed a) the competence of hybrid nanoparticles as far as the loading capacity in quercetin (concentration dependence), b) congruence with the physicochemical features determined, and c) the release profile of the nanoparticle load under oxidative stress in neuronal cultures. The bio-activity profile of quercetin nanoparticles in a neurodegenerative environment brought on by Cu(II) a) denotes the improved specificity of antioxidant reactivity counteracting oxidative stress, and b) sets the stage for the development of molecular protection and preventive medical nanotechnology of relevance to neurodegenerative Alzheimer’s disease.

From adaption to death: endoplasmic reticulum stress as a novel target of selective neurodegeneration?

From adaption to death: endoplasmic reticulum stress as a novel target of selective neurodegeneration?

Oxidative Stress Mechanisms Underlying Parkinson’s Disease-Associated Neurodegeneration in C. elegans

Oxidative stress is thought to play a significant role in the development and progression of neurodegenerative diseases. Although it is currently considered a hallmark of such processes, the interweaving of a multitude of signaling cascades hinders complete understanding of the direct role of oxidative stress in neurodegeneration. In addition to its extensive use as an aging model, some researchers have turned to the invertebrate model Caenorhabditis elegans (C. elegans) in order to further investigate molecular mediators that either exacerbate or protect against reactive oxygen species (ROS)-mediated neurodegeneration. Due to their fully characterized genome and short life cycle, rapid generation of C. elegans genetic models can be useful to study upstream markers of oxidative stress within interconnected signaling pathways. This report will focus on the roles of C. elegans homologs for the oxidative stress-associated transcription factor Nrf2, as well as the autosomal recessive, early-onset Parkinson’s disease (PD)-associated proteins Parkin, DJ-1, and PINK1, in neurodegenerative processes.