Role of NADPH oxidase in cooperative reactive oxygen species generation in dopaminergic neurons induced by combined treatment with dieldrin and lindane

Role of nutraceutical against exposure to pesticide residues: power of bioactive compounds

Pesticides play a crucial role in modern agriculture, aiding in the protection of crops from pests and diseases. However, their indiscriminate use has raised concerns about their potential adverse effects on human health and the environment. Pesticide residues in food and water supplies are a serious health hazards to the general public since long-term exposure can cause cancer, endocrine disruption, and neurotoxicity, among other health problems. In response to these concerns, researchers and health professionals have been exploring alternative approaches to mitigate the toxic effects of pesticide residues. Bioactive substances called nutraceuticals that come from whole foods including fruits, vegetables, herbs, and spices have drawn interest because of their ability to mitigate the negative effects of pesticide residues. These substances, which include minerals, vitamins, antioxidants, and polyphenols, have a variety of biological actions that may assist in the body's detoxification and healing of harm from pesticide exposure. In this context, this review aims to explore the potential of nutraceutical interventions as a promising strategy to mitigate the toxic effects of pesticide residues.

Glutamatergic transmission associated with locomotion-related neurotoxicity to lindane over generations in Caenorhabditis elegans

Organochlorine pesticide lindane in the environment and biota results in the potential risks on ecosystem and human health. Lindane can adversely affect the locomotion and nervous system, yet the potential neurotoxicity of lindane over generations remains uncertain. In this study, the neurotoxicity and underlying mechanisms in Caenorhabditis elegans (C. elegans) were investigated after parental (P0) exposure to lindane at environmentally relevant concentrations over generations. Exposure to lindane at concentrations of 10-100 ng/L significantly decreased body bends and head thrashes in P0 generation. Significant decrease of fluorescence labeled different neurotransmitters, and clear morphological changes by exposure to lindane at 10-100 ng/L suggested that lindane could induce the neuronal damage in C. elegans. During the transgenerational process, decreased locomotive behaviors were also observed in F1-F3 generations, and head thrashes returned to normal levels in F4 generation. Moreover, lindane exposure down-regulated the expression of dat-1, dop-1, glr-1 and mod-1genes, while up-regulated unc-30 gene in P0 generation, which recovered to normal levels in F4 generation. Interestingly, eat-4 continued to be regulated from inhibition to stimulation in P0-F4 generations, suggesting that glutamatergic transmission may more contribute to the neurotoxicity of lindane over generations.

NADPH Oxidases in the Central Nervous System: Regional and Cellular Localization and the Possible Link to Brain Diseases

Significance: The significant role of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) in signal transduction is mediated by the production of reactive oxygen species (ROS), especially in the central nervous system (CNS). The pathogenesis of some neurologic and psychiatric diseases is regulated by ROS, acting as a second messenger or pathogen. Recent Advances: In the CNS, the involvement of Nox-derived ROS has been implicated in the regulation of multiple signals, including cell survival/apoptosis, neuroinflammation, migration, differentiation, proliferation, and synaptic plasticity, as well as the integrity of the blood/brain barrier. In these processes, the intracellular signals mediated by the members of the Nox family vary among different tissues. The present review illuminates the regions and cellular, subcellular localization of Nox isoforms in the brain, the signal transduction, and the role of NOX enzymes in pathophysiology, respectively. Critical Issues: Different signal transduction cascades are coupled to ROS derived from various Nox homologues with varying degrees. Therefore, a critical issue worth noting is the varied role of the homologues of NOX enzymes in different signaling pathways and also they mediate different phenotypes in the diverse pathophysiological condition. This substantiates the effectiveness of selective Nox inhibitors in the CNS. Future Directions: Further investigation to elucidate the role of various homologues of NOX enzymes in acute and chronic brain diseases and signaling mechanisms, and the development of more specific NOX inhibitors for the treatment of CNS disease are urgently needed. Antioxid. Redox Signal. 35, 951-973.

Organochlorine Pesticide Dieldrin Suppresses Cellular Interferon-Related Antiviral Gene Expression

Organochlorine pesticides (OCPs) are persistent pollutants linked to diverse adverse health outcomes. Environmental exposure to OCPs has been suggested to negatively impact the immune system but their effects on cellular antiviral responses remain unknown. Transcriptomic analysis of N27 rat dopaminergic neuronal cells unexpectedly detected high level expression of genes in the interferon (IFN)-related antiviral response pathways including the IFN-induced protein with tetratricopeptide repeats 1 and 2 (Ifit1/2) and the MX Dynamin Like GTPases Mx1 and Mx2. Interestingly, treatment of N27 cells with dieldrin markedly downregulated the expression of many of these genes. Dieldrin exterted a similar effect in inhibiting IFIT2 and MX1 gene expression in human SH-SY5Y neuronal cells induced by an RNA viral mimic, polyinosinic: polycytidylic acid (poly I:C) and IFIT2/3 gene expression in human pulmonary epithelial cells exposed to human influenza H1N1 virus. Mechanistically, dieldrin induced a rapid rise in levels of intracellular reactive oxygen species (iROS) and a decrease in intracellular glutathione (GSH) levels in SH-SY5Y cells. Treatment with N-acetylcysteine, an antioxidant and GSH biosynthesis precursor, effectively blocked both dieldrin-induced increases in iROS and its inhibition of poly I:C-induced upregulation of IFIT and MX gene expression, suggesting a role for intracellular oxidative status in dieldrin's modulation of antiviral gene expression. This study demonstrates that dieldrin modulates key genes of the cellular innate immune responses that are normally involved in the host's cellular defense against viral infections. Our findings have potential relevance to understanding the organismal effects of environmentally persistent organochlorine contaminants on the mammalian cellular immune system.

Functional Pathway Identification With CRISPR/Cas9 Genome-wide Gene Disruption in Human Dopaminergic Neuronal Cells Following Chronic Treatment With Dieldrin

Organochlorine pesticides, once widely used, are extremely persistent and bio-accumulative in the environment. Epidemiological studies have implicated that environmental exposure to organochlorine pesticides including dieldrin is a risk factor for the development of Parkinson's disease. However, the pertinent mechanisms of action remain poorly understood. In this study, we carried out a genome-wide (Brunello library, 19 114 genes, 76 411 sgRNAs) CRISPR/Cas9 screen in human dopaminergic SH-SY5Y neuronal cells exposed to a chronic treatment (30 days) with dieldrin to identify cellular pathways that are functionally related to the chronic cellular toxicity. Our results indicate that dieldrin toxicity was enhanced by gene disruption of specific components of the ubiquitin proteasome system as well as, surprisingly, the protein degradation pathways previously implicated in inherited forms of Parkinson's disease, centered on Parkin. In addition, disruption of regulatory components of the mTOR pathway which integrates cellular responses to both intra- and extracellular signals and is a central regulator for cell metabolism, growth, proliferation, and survival, led to increased sensitivity to dieldrin-induced cellular toxicity. This study is one of the first to apply a genome-wide CRISPR/Cas9-based functional gene disruption screening approach in an adherent neuronal cell line to globally decipher cellular mechanisms that contribute to environmental toxicant-induced neurotoxicity and provides novel insight into the dopaminergic neurotoxicity associated with chronic exposure to dieldrin.

Pharmacology of apocynin: a natural acetophenone

Apocynin is a naturally occurring acetophenone, found in the roots of Apocynum cannabinum and Picrorhiza kurroa. Various chemical and pharmaceutical modifications have been carried out to enhance the absorption and duration of action of apocynin, like, formulation of chitosan-based apocynin-loaded solid lipid nanoparticles, chitosan-oligosaccharide based nanoparticles, and biodegradable polyanhydride nanoparticles. Apocynin has been subjected to a wide range of experimental screening and has proved to be useful for amelioration of a variety of disorders, like diabetic complications, neurodegeneration, cardiovascular disorders, lung cancer, hepatocellular cancer, pancreatic cancer, and pheochromocytoma. Apocynin has been primarily reported as an NADPH oxidase (NOX) inhibitor and prevents translocation of its p47^phox subunit to the plasma membrane, observed in neurodegeneration and hypertension. However, recent studies highlight its off-target effects that it is able to function as a scavenger of non-radical oxidant species, which is relevant for its activity against NOX 4 mediated production of hydrogen peroxide. Additionally, apocynin has shown inhibition of eNOS-dependent superoxide production in diabetic cardiomyopathy, reduction of NLRP3 activation and TGFβ/Smad signaling in diabetic nephropathy, diminished VEGF expression and decreased retinal NF-κB activation in diabetic retinopathy, inhibition of P38/MAPK/Caspase3 pathway in pheochromocytoma, inhibition of AKT-GSK3β and ERK1/2 pathways in pancreatic cancer, and decreased FAK/PI3K/Akt signaling in hepatocellular cancer. This review aims to discuss the pharmacokinetics and mechanisms of the pharmacological actions of apocynin.

Neuropathological Mechanisms Associated with Pesticides in Alzheimer's Disease

Environmental toxicants have been implicated in neurodegenerative diseases, and pesticide exposure is a suspected environmental risk factor for Alzheimer’s disease (AD). Several epidemiological analyses have affirmed a link between pesticides and incidence of sporadic AD. Meanwhile, in vitro and animal models of AD have shed light on potential neuropathological mechanisms. In this paper, a perspective on neuropathological mechanisms underlying pesticides’ induction of AD is provided. Proposed mechanisms range from generic oxidative stress induction in neurons to more AD-specific processes involving amyloid-beta (Aβ) and hyperphosphorylated tau (p-tau). Mechanisms that are more speculative or indirect in nature, including somatic mutation, epigenetic modulation, impairment of adult neurogenesis, and microbiota dysbiosis, are also discussed. Chronic toxicity mechanisms of environmental pesticide exposure crosstalks in complex ways and could potentially be mutually enhancing, thus making the deciphering of simplistic causal relationships difficult.

Deep proteome profiling reveals novel pathways associated with pro-inflammatory and alcohol-induced microglial activation phenotypes

Microglia, the resident immune cells of the brain, can exhibit a broad range of activation phenotypes, many of which have been implicated in several diseases and disorders of the central nervous system including those related to alcohol abuse. Given the complexity of global-scale molecular changes that define microglial activation, accurate phenotypic classification in the context of alcohol exposure is still lacking. We employed an optimized method for deep, quantitative proteome profiling of primary microglia in order to characterize their response to acute exposure to alcohol (ethanol) as well as the pro-inflammatory driver and TLR4 agonist, LPS. From this analysis, 5,062 total proteins were identified where 4,857 and 4,928 of those proteins were quantifiable by label-free quantitation in ethanol and LPS treatment groups, respectively. This study highlights the subtle, yet significant proteomic changes that occur in ethanol-treated microglia, which do not align with the robust pro-inflammatory phenotype induced by TLR4 activation. Specifically, our results indicate inhibition of several upstream regulators associated with inflammation, opposing effects on pathways such as phagocytosis upon comparison to TLR4-mediated pro-inflammatory phenotype, and a potential metabolic shift associated with increased expression of proteins related to OXPHOS and lipid homeostasis. Data are available via ProteomeXchange with identifier PXD14466. SIGNIFICANCE: Alcohol abuse has a significant impact on the central nervous system, which includes the pathophysiological mechanisms resulting from glial cell activation. Microglia, in particular, are the resident immune cells of the brain and exhibit a broad range of activation phenotypes. The molecular changes that drive microglial activation phenotype are complex and have yet to be fully characterized in the context of alcohol exposure. Our study highlights the first and most comprehensive characterization of alcohol-induced proteomic changes in primary microglia to date and has shed light on novel immune-related and metabolic pathways that are altered due to alcohol exposure. The results from this study provide an important foundation for future work aimed to understand the complexity of alcohol-induced microglial activation in vivo and other translational models of acute and chronic alcohol exposure.

NADPH Oxidase Mediates Membrane Androgen Receptor-Induced Neurodegeneration

Oxidative stress (OS) is a common characteristic of several neurodegenerative disorders, including Parkinson disease (PD). PD is more prevalent in men than in women, indicating the possible involvement of androgens. Androgens can have either neuroprotective or neurodamaging effects, depending on the presence of OS. Specifically, in an OS environment, androgens via a membrane-associated androgen receptor (mAR) exacerbate OS-induced damage. To investigate the role of androgens on OS signaling and neurodegeneration, the effects of testosterone and androgen receptor activation on the major OS signaling cascades, the reduced form of NAD phosphate (NADPH) oxidase (NOX)1 and NOX2 and the Gαq/inositol trisphosphate receptor (InsP3R), were examined. To create an OS environment, an immortalized neuronal cell line was exposed to H2O2 prior to cell-permeable/cell-impermeable androgens. Different inhibitors were used to examine the role of G proteins, mAR, InsP3R, and NOX1/2 on OS generation and cell viability. Both testosterone and DHT/3-O-carboxymethyloxime (DHT)-BSA increased H2O2-induced OS and cell death, indicating the involvement of an mAR. Furthermore, classical AR antagonists did not block testosterone's negative effects in an OS environment. Because there are no known antagonists specific for mARs, an AR protein degrader, ASC-J9, was used to block mAR action. ASC-J9 blocked testosterone's negative effects. To determine OS-related signaling mediated by mAR, this study examined NOX1, NOX2, Gαq. NOX1, NOX2, and the Gαq complex with mAR. Only NOX inhibition blocked testosterone-induced cell loss and OS. No effects of blocking either Gαq or G protein activation were observed on testosterone's negative effects. These results indicate that androgen-induced OS is via the mAR-NOX complex and not the mAR-Gαq complex.