scholarly journals Effects of Fluoride Exposure on Primary Human Melanocytes from Dark and Light Skin

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 114
Author(s):  
Shilpi Goenka ◽  
Sanford R. Simon
Keyword(s):  
Oxidative Stress ◽  
Membrane Integrity ◽  
Fluoride Exposure ◽  
Cell Culture Systems ◽  
Light Skin ◽  
Human Melanocytes ◽  
The Impact ◽  
Lp Cells ◽  
Higher Sensitivity

Fluoride exposure has adverse effects on human health that have been studied in vitro in cell culture systems. Melanocytes are the melanin pigment-producing cells that have a significant role in the regulation of the process of melanogenesis, which provides several health benefits. Melanocytes are present in the oral cavity, skin, brain, lungs, hair, and eyes. However, to date, there has been no study on the effects of fluoride exposure on melanocytes. Hence, in the current study, we have studied the effects of sodium fluoride (NaF) exposure on neonatal human epidermal melanocytes (HEMn) derived from two different skin phototypes, lightly pigmented (LP) and darkly pigmented (DP). We have assessed the impact of a 24 h and 72 h NaF exposure on metabolic activity and membrane integrity of these cells. In addition, we have evaluated whether NaF exposure might have any impact on the physiological functions of melanocytes associated with the production of melanin, which is regulated by activity of the enzyme tyrosinase. We have also assessed if NaF exposure might induce any oxidative stress in LP and DP melanocytes, by evaluation of production of reactive oxygen species (ROS) and measurement of mitochondrial membrane potential (MMP) levels. Our results showed that HEMn-LP cells showed a higher sensitivity to NaF cytotoxicity than HEMn-DP cells, with significant cytotoxicity at concentrations >1 mM, while concentration range 0.25–1 mM were nontoxic and did not lead to oxidative stress, and also did not alter the levels of intracellular melanin or cellular tyrosinase activity, indicating that treatment up to 1 mM NaF is generally safe to melanocytes from both pigmentation phototypes.

scholarly journals Oxidative Stress Compromises Lymphocyte Function in Neonatal Dairy Calves

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 255
Author(s):  
Wilmer Cuervo ◽  
Lorraine M. Sordillo ◽  
Angel Abuelo
Keyword(s):  
Oxidative Stress ◽  
Immune Responses ◽  
Immune Cell ◽  
Lymphocyte Activation ◽  
Dairy Calves ◽  
Lymphocyte Function ◽  
Newborn Calves ◽  
Ifn Γ ◽  
The Impact

Dairy calves are unable to mount an effective immune response during their first weeks of life, which contributes to increased disease susceptibility during this period. Oxidative stress (OS) diminishes the immune cell capabilities of humans and adult cows, and dairy calves also experience OS during their first month of life. However, the impact that OS may have on neonatal calf immunity remains unexplored. Thus, we aimed to evaluate the impact of OS on newborn calf lymphocyte functions. For this, we conducted two experiments. First, we assessed the association of OS status throughout the first month of age and the circulating concentrations of the cytokines interferon-gamma (IFN-γ) and interleukin (IL) 4, as well as the expression of cytokine-encoding genes IFNG, IL2, IL4, and IL10 in peripheral mononuclear blood cells (PBMCs) of 12 calves. Subsequently, we isolated PBMCs from another 6 neonatal calves to investigate in vitro the effect of OS on immune responses in terms of activation of lymphocytes, cytokine expression, and antibody production following stimulation with phorbol 12-myristate 13-acetate or bovine herpesvirus-1. The results were compared statistically through mixed models. Calves exposed to high OS status in their first month of age showed higher concentrations of IL-4 and expression of IL4 and IL10 and lower concentrations of IFN-γ and expression of IFNG and IL2 than calves exposed to lower OS. In vitro, OS reduced lymphocyte activation, production of antibodies, and protein and gene expression of key cytokines. Collectively, our results demonstrate that OS can compromise some immune responses of newborn calves. Hence, further studies are needed to explore the mechanisms of how OS affects the different lymphocyte subsets and the potential of ameliorating OS in newborn calves as a strategy to augment the functional capacity of calf immune cells, as well as enhance calves’ resistance to infections.

scholarly journals The Impact of Medium Chain and Polyunsaturated ω-3-Fatty Acids on Amyloid-β Deposition, Oxidative Stress and Metabolic Dysfunction Associated with Alzheimer´s Disease

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1991
Author(s):  
Janine Mett
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Energy Metabolism ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Membrane Integrity ◽  
Amyloid Β ◽  
The Elderly ◽  
Medium Chain ◽  
The Impact

Alzheimer’s disease (AD), the most common cause of dementia in the elderly population, is closely linked to a dysregulated cerebral lipid homeostasis and particular changes in brain fatty acid (FA) composition. The abnormal extracellular accumulation and deposition of the peptide amyloid-β (Aβ) is considered as an early toxic event in AD pathogenesis, which initiates a series of events leading to neuronal dysfunction and death. These include the induction of neuroinflammation and oxidative stress, the disruption of calcium homeostasis and membrane integrity, an impairment of cerebral energy metabolism, as well as synaptic and mitochondrial dysfunction. Dietary medium chain fatty acids (MCFAs) and polyunsaturated ω-3-fatty acids (ω-3-PUFAs) seem to be valuable for disease modification. Both classes of FAs have neuronal health-promoting and cognition-enhancing properties and might be of benefit for patients suffering from mild cognitive impairment (MCI) and AD. This review summarizes the current knowledge about the molecular mechanisms by which MCFAs and ω-3-PUFAs reduce the cerebral Aβ deposition, improve brain energy metabolism, and lessen oxidative stress levels.

scholarly journals Dietary Supplement Enriched in Antioxidants and Omega-3 Promotes Glutamine Synthesis in Müller Cells: A Key Process against Oxidative Stress in Retina

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3216
Author(s):  
Maryvonne Ardourel ◽  
Chloé Felgerolle ◽  
Arnaud Pâris ◽  
Niyazi Acar ◽  
Khaoula Ramchani Ben Othman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Müller Cells ◽  
Nutritional Supplement ◽  
Glutamine Metabolism ◽  
Muller Cells ◽  
Omega 3 ◽  
Glutamine Synthesis ◽  
The Impact

To prevent ocular pathologies, new generation of dietary supplements have been commercially available. They consist of nutritional supplement mixing components known to provide antioxidative properties, such as unsaturated fatty acid, resveratrol or flavonoids. However, to date, only one preclinical study has evaluated the impact of a mixture mainly composed of those components (Nutrof Total®) on the retina and demonstrated that in vivo supplementation prevents the retina from structural and functional injuries induced by light. Considering the crucial role played by the glial Müller cells in the retina, particularly to regulate the glutamate cycle to prevent damage in oxidative stress conditions, we questioned the impact of this ocular supplement on the glutamate metabolic cycle. To this end, various molecular aspects associated with the glutamate/glutamine metabolism cycle in Müller cells were investigated on primary Müller cells cultures incubated, or not, with the commercially mix supplement before being subjected, or not, to oxidative conditions. Our results demonstrated that in vitro supplementation provides guidance of the glutamate/glutamine cycle in favor of glutamine synthesis. These results suggest that glutamine synthesis is a crucial cellular process of retinal protection against oxidative damages and could be a key step in the previous in vivo beneficial results provided by the dietary supplementation.

scholarly journals Physiological State, Growth Mode, and Oxidative Stress Play a Role in Cd(II)-Mediated Inhibition of Nitrosomonas europaea 19718

2008 ◽  
Vol 74 (8) ◽  
pp. 2447-2453 ◽  
Author(s):  
Kartik Chandran ◽  
Nancy G. Love
Keyword(s):  
Oxidative Stress ◽  
16S Rrna ◽  
Physiological State ◽  
Membrane Integrity ◽  
Fold Increase ◽  
Nitrosomonas Europaea ◽  
Growth Mode ◽  
Batch Cultures ◽  
Growth Modes ◽  
The Impact

ABSTRACT The goal of this study was to determine the impact of physiological growth states (batch exponential and batch stationary growth) and growth modes (substrate-limited chemostat, substrate-sufficient exponential batch, and substrate-depleted stationary batch growth) on several measures of growth and responses to Cd(II)-mediated inhibition of Nitrosomonas europaea strain 19718. The specific oxygen uptake rate (sOUR) was the most sensitive indicator of inhibition among the different responses analyzed, including total cell abundance, membrane integrity, intracellular 16S rRNA/DNA ratio, and amoA expression. This observation remained true irrespective of the physiological state, the growth mode, or the mode of Cd(II) exposure. Based on the sOUR, a strong time-dependent exacerbation of inhibition (in terms of an inhibition coefficient [Ki ]) in exponential batch cultures was observed. Long-term inhibition levels (based on Ki estimates) in metabolically active chemostat and exponential batch cultures were also especially severe and comparable. In contrast, the inhibition level in stationary-phase cultures was 10-fold lower and invariable with exposure time. Different strategies for surviving substrate limitation (a 10-fold increase in amoA expression) and starvation (the retention of 16S rRNA levels) in N. europaea cultures were observed. amoA expression was most negatively impacted by Cd(II) exposure in the chemostat cultures, was less impacted in exponential batch cultures, and was least impacted in stationary batch cultures. Although the amoA response was consistent with that of the sOUR, the amoA response was not as strong. The intracellular 16S rRNA/DNA ratio, as determined by fluorescence in situ hybridization, also did not uniformly correlate with the sOUR under conditions of inhibition or no inhibition. Finally, Cd(II)-mediated inhibition of N. europaea was attributed partially to oxidative stress.

scholarly journals TSH Combined with TSHR Aggravates Diabetic Peripheral Neuropathy by Promoting Oxidative Stress and Apoptosis in Schwann Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Jingwen Fan ◽  
Qi Pan ◽  
Qun Gao ◽  
Wenqing Li ◽  
Fei Xiao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Peripheral Neuropathy ◽  
Diabetic Peripheral Neuropathy ◽  
Cell Model ◽  
Cell Damage ◽  
Motor Nerve ◽  
Thyroid Stimulating Hormone ◽  
Motor Nerve Conduction Velocity ◽  
The Impact

Subclinical hypothyroidism (SCH) is associated with diabetic peripheral neuropathy (DPN); however, the mechanism underlying this association remains unknown. This study is aimed at examining neurofunctional and histopathological alterations in a type 2 diabetes (T2DM) mouse model of SCH and investigating the impact of thyroid-stimulating hormone (TSH) in an in vitro DPN cell model established using RSC96 cells under high glucose (HG) and palmitic acid (PA) stimulation. Our results indicated that T2DM, in combination with SCH, aggravated abnormal glucose and lipid metabolism in T2DM and dramatically destroyed the peripheral nervous system by increasing paw withdrawal latency, decreasing motor nerve conduction velocity, and exacerbating ultrastructural deterioration of the damaged sciatic nerve caused by diabetes. Furthermore, the results of our in vitro experiments showed that TSH intensified HG/PA-induced RSC96 cell damage by inducing oxidative stress, mitochondrial dysfunction, and apoptosis. More importantly, TSHR knockout or inhibition of PA-induced TSHR palmitoylation could alleviate the apoptosis induced by TSH. Overall, in this study, the novel mechanisms by which TSH, as an independent risk factor for DPN progression, aggravating Schwann cell apoptosis and demyelination, are elucidated. These findings indicate that TSHR could be a potential target for both the prevention and treatment of DPN and, possibly, other microvascular diseases, and have implication in the clinical management of patients with DPN.

scholarly journals A peptide of a type I toxin-antitoxin system induces Helicobacter pylori morphological transformation from spiral-shape to coccoids

2019 ◽  
Author(s):  
Lamya El Mortaji ◽  
Alejandro Tejada-Arranz ◽  
Aline Rifflet ◽  
Ivo G Boneca ◽  
Gérard Pehau-Arnaudet ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Helicobacter Pylori ◽  
Membrane Integrity ◽  
Type I ◽  
Morphological Transformation ◽  
Bacterial Chromosomes ◽  
Concentration Result ◽  
H Pylori ◽  
Plasmid Stabilization

SummaryToxin-antitoxin systems are found in many bacterial chromosomes and plasmids with roles ranging from plasmid stabilization to biofilm formation and persistence. In these systems, the expression/activity of the toxin is counteracted by an antitoxin, which in type I systems is an antisense-RNA. While the regulatory mechanisms of these systems are mostly well-defined, the toxins’ biological activity and expression conditions are less understood. Here, these questions were investigated for a type I toxin-antitoxin system (AapA1-IsoA1) expressed from the chromosome of the human pathogen Helicobacter pylori. We show that expression of the AapA1 toxin in H. pylori causes growth arrest associated with rapid morphological transformation from spiral-shaped bacteria to round coccoid cells. Coccoids are observed in patients and during in vitro growth as a response to different stress conditions. The AapA1 toxin, first molecular effector of coccoids to be identified, targets H. pylori inner membrane without disrupting it, as visualized by Cryo-EM. The peptidoglycan composition of coccoids is modified with respect to spiral bacteria. No major changes in membrane potential or ATP concentration result from AapA1 expression, suggesting coccoid viability. Single-cell live microscopy tracking the shape conversion suggests a possible association of this process with cell elongation/division interference. Oxidative stress induces coccoid formation and is associated with repression of the antitoxin promoter and enhanced processing of its transcript, leading to an imbalance in favor of AapA1 toxin expression.Our data support the hypothesis of viable coccoids with characteristics of dormant bacteria that might be important in H. pylori infections refractory to treatment.Significance StatementHelicobacter pylori, a gastric pathogen causing 800,000 deaths in the world annually, is encountered both in vitro and in patients as spiral-shaped bacteria and as round cells named coccoids. We discovered that the toxin from a chromosomal type I toxin-antitoxin system is targeting H. pylori membrane and acting as an effector of H. pylori morphological conversion to coccoids. We showed that these round cells maintain their membrane integrity and metabolism, strongly suggesting that they are viable dormant bacteria. Oxidative stress was identified as a signal inducing toxin expression and coccoid formation. Our findings reveal new insights into a form of dormancy of this bacterium that might be associated with H. pylori infections refractory to treatment.

scholarly journals Protective Effects of α-tocopherol on the Activity and Antioxidant Profile of Bovine Spermatozoa Subjected to Ferrous Ascorbate-Induced Oxidative Stress

2016 ◽  
Vol 64 (4) ◽  
pp. 1245-1255
Author(s):  
Eva Tvrdá ◽  
Eva Tušimová ◽  
Katarína Zbyňovská ◽  
Tomáš Jambor ◽  
Norbert Lukáč
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Properties ◽  
Additional Line ◽  
Sod Activity ◽  
Spermatozoa Motility ◽  
Antioxidant Profile ◽  
Ferrous Ascorbate ◽  
Bovine Spermatozoa ◽  
The Impact

As spermatozoa are highly vulnerable to oxidative stress development, in vitro antioxidants offer an additional line of defense to the male reproductive system against oxidative insults. α‑tocopherol (α-TOC) is the most abundant form of vitamin E identified in the seminal plasma and spermatozoa membranes, being able to terminate numerous oxidative chain reactions causing substantial damage to biomolecules vital for sperm survival. This study was designed to shed more light on the in vitro effects of α‑tocopherol with respect to the vitality and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate-induced oxidative stress. Spermatozoa were washed out from 50 bovine ejaculates, suspended in 2.9 % sodium citrate and subjected to α-TOC treatment (10, 50, 100 and 500 μmol/L) in the presence or absence of ferrous ascorbate (FeAA; 150 μmol/L FeSO4 and 750 μmol/L ascorbic acid) during a 6h in vitro culture. Spermatozoa motion parameters were assessed using the SpermVision™ computer-aided sperm analysis (CASA) system. Cell viability was examined with the metabolic activity (MTT) assay, and the nitroblue-tetrazolium (NBT) test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the experiments in order to assess the intracellular activity of superoxide dismutase (SOD), catalase (CAT), as well as glutathione (GSH) and malondialdehyde (MDA) concentrations. Treatment with FeAA reduced both spermatozoa motility parameters (P < 0.001) as well as viability (P < 0.05 with respect to Time 0 h; P < 0.01 in case of Time 2 h and P < 0.001 in relation to Time 6 h), decreased the antioxidant parameters of the samples (P < 0.001 in case of SOD; P < 0.01 with respect to CAT and GSH) but increased the superoxide production (P < 0.01 in case of Time 0h and P < 0.001 with respect to Times 2 h and 6 h) and lipid peroxidation (P < 0.001). α‑TOC administration resulted in a preservation of the spermatozoa motility characteristics (P < 0.001 with respect to 500 μmol/L α-TOC), viability (P < 0.001 in case of 500 μmol/L α-TOC and P < 0.05 with respect to 100 μmol/L α-TOC) and antioxidant profile (P < 0.01 related to the impact of 500 μmol/L α-TOC on the SOD activity; P < 0.05 in relation to CAT; P < 0.01 with respect GSH; 100-500 μmol/L α-TOC), with 500 μmol/L α-TOC being the most effective. Our results suggest that α‑tocopherol possesses significant antioxidant properties that may prevent the deleterious effects caused by free radicals to spermatozoa, and extend the fertilization potential of male reproductive cells.

scholarly journals Role of Food Antioxidants in Modulating Gut Microbial Communities: Novel Understandings in Intestinal Oxidative Stress Damage and Their Impact on Host Health

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1563
Author(s):  
Muhammad Shahid Riaz Rajoka ◽  
Rohit Thirumdas ◽  
Hafiza Mahreen Mehwish ◽  
Muhammad Umair ◽  
Mohsin Khurshid ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Microbial Communities ◽  
Food Additives ◽  
Antioxidant Compounds ◽  
Dietary Polyphenols ◽  
Microbial Species ◽  
Microbial Dysbiosis ◽  
Dietary Components ◽  
The Impact

Dietary components have an important role on the structure and function of host gut microbial communities. Even though, various dietary components, such as carbohydrates, fats, proteins, fibers, and vitamins, have been studied in depth for their effect on gut microbiomes, little attention has been paid regarding the impact of several food antioxidants on the gut microbiome. The long-term exposure to reactive oxygen species (ROS) can cause microbial dysbiosis which leads to numerous intestinal diseases such as microbiota dysbiosis, intestinal injury, colorectal cancers, enteric infections, and inflammatory bowel diseases. Recently, it has been shown that the food derived antioxidant compounds might protect the host from intestinal oxidative stress via modulating the composition of beneficial microbial species in the gut. The present review summarizes the impact of food antioxidants including antioxidant vitamins, dietary polyphenols, carotenoids, and bioactive peptides on the structure as well as function of host gut microbial communities. Several in vitro, animal model, and clinical studies indicates that food antioxidants might modify the host gut microbial communities and their health status. However, still further clarification is needed as to whether changes in certain microbial species caused by food additives may lead to changes in metabolism and immune function.

scholarly journals 4-[1-ethyl-1-methylhexy]-phenol Induces Apoptosis and Interrupts Ca2+ Homeostasis via ROS Pathway in Sertoli TM4 cells

2021 ◽  
Author(s):  
Xiaozhen Liu ◽  
Fuxiang Li ◽  
Zhaoliang Zhu ◽  
Gaoyi Peng ◽  
Danfei Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Atpase Activity ◽  
Chain Structure ◽  
Side Chain ◽  
Ros Generation ◽  
Intracellular Ca ◽  
Ros Scavenger ◽  
Induced Apoptosis ◽  
The Impact

Abstract Biological effect of an individual nonylphenol (NP) isomer extremely relies upon the side chain structure. This research was designed to evaluate the impact of NP isomer, 4-[1-ethyl-1-methylhexy]-phenol (NP65), on Sertoli cells in vitro. Sertoli TM4 cells were exposed to various concentration (0, 0.1, 1, 10, or 20 μM) of NP65 for 24 h, and the outcomes indicated that treatment of NP65 induced reactive oxygen species (ROS) generation, oxidative stress as well as apoptosis for Sertoli TM4 cells. In addition, it was found that NP65 exposure affected homeostasis of Ca2+ in Sertoli TM4 cells by increasing cytoplasm [Ca2+]i, inhibiting Ca2+-ATPase activity and decreasing cAMP concentration. Pretreatment with ROS scavenger, N-acetylcysteine (NAC), attenuated NP65-induced oxidative stress as well as apoptosis for TM4 cells. Furthermore, NAC blocked NP65-induced disorders of Ca2+ homeostasis by attenuating the growth of intracellular [Ca2+]i and the inhibition of Ca2+-ATPase and cAMP activities. Thus, we have demonstrated that NP65 induced apoptosis as well as acted as a potent inhibitor of Ca2+-ATPase activity and resulted in disorder of Ca2+ homeostasis in Sertoli TM4 cells, ROS participated in the process. Our results supported the view that oxidative stress acted an essential role within the development of apoptosis and Ca2+ overload in TM4 cells as a consequence of NP65 stimulation.

Genomics: An In Vitro Toxicology Point of View

2002 ◽  
Vol 30 (2_suppl) ◽  
pp. 129-131 ◽  
Author(s):  
Raffaella Corvi
Keyword(s):  
Gene Expression ◽  
Cell Culture ◽  
Dna Microarray ◽  
High Throughput ◽  
Point Of View ◽  
In Vitro Toxicology ◽  
Predictive Toxicology ◽  
Cell Culture Systems ◽  
The Impact

Genomics, and in particular its derived discipline, toxicogenomics, are rapidly developing technologies, which permit studies on the impact of chemicals and drugs on gene expression in particular biological systems. Enormous amounts of data will be provided in the context of mechanistic and predictive toxicology from the use of the DNA microarray approach for the simultaneous analysis of the expression pattern of multiple genes. The high-throughput requirement of these approaches necessitates in vitro cell culture systems. This article will give a short overview of the areas of ECVAM's research in which this technology will initially be applied.

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