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 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 CD166 Engagement Augments Mouse and Human Hematopoietic Stem and Progenitor Function Via Activation of Stem Cell-Associated and Cell Cycle Pathways

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1282-1282
Author(s):  
Joydeep Ghosh ◽  
Jing Zhang ◽  
Chi Zhang ◽  
Xinxin Huang ◽  
Safa F. Mohamad ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Signaling Pathways ◽  
Fold Increase ◽  
Marker Genes ◽  
Pathway Enrichment Analysis ◽  
Hematopoietic Stem ◽  
Upregulated Genes ◽  
The Impact ◽  
Cells Cultured

Abstract Functions of hematopoietic stem and progenitor cells are regulated by cellular signaling networks and by the cellular and non-cellular elements of the hematopoietic niche. CD166 is highly expressed on both human and murine hematopoietic stem cells (HSC) and on murine osteoblasts and has been identified as a critical regulator of their functions. CD166 engages in trans-homophilic interactions with other CD166 molecules. However how homophilic or heterophilic engagement of CD166 (with CD6) improves HSC function is unknown. Since we described that CD166 is expressed on murine and human HSC and murine osteoblasts, we hypothesized that CD166-CD166 homophilic engagement is critical for the hematopoiesis enhancing activity (HEA) that is mediated by osteoblasts. CD166+LSK cells cultured for 7d on either WT osteoblasts or recombinant murine CD166 (rmCD166) showed increased colony forming units (CFU) compared to CD166-LSK cells cultured identically (p<0.05). Moreover, after 7d, the frequency of Lin-Sca1+ cells was higher in co-cultures containing rmCD166 and CD166+LSK than cultures initiated with CD166-LSK (p<0.05). Next, we determined the effect of loss of CD166 expression on progenitors and osteoblasts on hematopoietic functions using CD166 knockout mice (CD166-/-). CD166-/-LSK cells co-cultured with rmCD166 showed decreased CFU production compared to WT LSK cultured similarly (p<0.05). In addition, WT HSC cultured on CD166-/-osteoblasts for 7d showed decreased fold change in CFU relative to WT HSC cultured over WT osteoblasts (p<0.05). In vivo transplantation studies to corroborate our in vitro results are ongoing. To determine if CD166-CD166 interactions also enhance hematopoietic functions of human HSC, we cultured CD34+CD166+ and CD34+CD166- HSC isolated from cord blood with recombinant human CD166 (rhCD166). On d7, CD34+CD166+ HSC cultured with rhCD166 showed 30±4-fold increase in CFU production compared to d0, whereas CD34+CD166- HSC had only 9±0.4-fold increase. Taken together, these data suggest that CD166-CD166 homophilic interactions enhance hematopoietic functions and loss of this homophilic interaction negatively impacts HSC. To elucidate the underlying signaling mechanism of CD166-CD166 mediated HEA, we cultured WT or CD166-/-SLAM LSK cells with rmCD166 for 20hr and performed single-cell (sc) RNA seq. We analyzed for differential gene expression (DEG) using LGMT model and identified 518 upregulated and 174 downregulated genes in CD166-/-HSC compared to WT. Following pathway enrichment analysis of DEGs, we identified 148 canonical pathways enriched by the upregulated genes in CD166-/-HSC, including cell cycle, translational regulation, and mitochondria-related signaling pathways. 268 pathways were impacted by the downregulated genes in CD166-/-HSC, including oxidative stress response, and metabolism. Moreover, CXCR4 signaling, PDGF signaling and glucocorticoid receptor signaling pathways were also downregulated in CD166-/-HSC. A cell trajectory reflecting associations among cells revealed a single cluster of CD166-/-HSC. CD166-/-HSC are linked with low expression of stemness marker genes, and high expression of genes regulating cell cycle, oxidative phosphorylation, and glucose metabolism. In addition, ER-stress and oxidative stress responsive genes are overexpressed in CD166-/-HSC. In CD166-/-HSC, genes of all enriched pathways were highly connected in the co-expressed networks, which indicates that in HSC, the impact of loss of CD166 on cell cycle, metabolism, growth factors and stemness pathways is highly associated. Sixteen hub genes including Suclg1, Eif4a1, Cox4i2, Jak3, Runx3, and Cdk6 were identified in the co-expression network. We next applied bi-clustering algorithm QUBIC to identify modules of co-upregulated genes to analyze the transcriptomic variations of DEG in CD166-/-HSC and identified 39-gene co-upregulation modules forming one big block in CD166-/-HSC and 35-gene modules forming three blocks in WT HSC indicating that modules closely corresponded to CD166's impact over different cell states rather than on individual pathways. Overall, our studies suggest that homophilic CD166 interactions involving HSC are required for maintenance of essential pathways that sustain HSC function and progenitor cell production including stemness, mitochondrial function, metabolism, cell cycle and growth factor signaling. Disclosures No relevant conflicts of interest to declare.

scholarly journals Tough Sprouting – Impact of Cadmium on Physiological State and Germination Rate of Soybean Seeds

2020 ◽  
Vol 89 (2) ◽  
Author(s):  
Jagna Chmielowska-Bąk ◽  
Renata Holubek ◽  
Marina Frontasyeva ◽  
Inga Zinicovscaia ◽  
Selin İşidoğru ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Germination Rate ◽  
Physiological State ◽  
Germination Percentage ◽  
External Factors ◽  
Slight Reduction ◽  
Soybean Seeds ◽  
Short Term ◽  
Internal And External Factors ◽  
The Impact

Seed germination is the earliest process in plant development and is crucial for further plant growth and fitness. The process is regulated by various internal and external factors, including soil pollutants such as nonessential metals. In the present study, we examined in detail the impact of short-term imbibition in Cd solutions at several concentrations (5, 10, and 25 mg/L) on germination rate and physiological state of soybean seeds. The results showed that although Cd was readily absorbed by the seeds, the metal had no effect on seeds cell viability, oxidative stress intensity, or germination percentage. In contrast, imbibition in Cd solution led to slight reduction in antioxidant capacity of seeds. Seedlings grown from seeds pretreated with metal showed no differences in growth in relation to the control. Taken together, the results indicate that soybean seeds are relatively tolerant even to high Cd concentration (up to 25 mg/L).

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.

High-level resistance to oxidative stress in Lactococcus lactis conferred by Bacillus subtilis catalase KatE

Microbiology ◽  
2005 ◽  
Vol 151 (9) ◽  
pp. 3011-3018 ◽  
Author(s):  
T. Rochat ◽  
A. Miyoshi ◽  
J. J. Gratadoux ◽  
P. Duwat ◽  
S. Sourice ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bacillus Subtilis ◽  
Lactococcus Lactis ◽  
Fold Increase ◽  
Inducible Promoter ◽  
Optimization Strategy ◽  
High Level ◽  
The Impact ◽  
Level Resistance

Lactococcus lactis, a lactic acid bacterium widely used for food fermentations, is often exposed to damaging stress conditions. In particular, oxidative stress leads to DNA, protein and membrane damages that can be lethal. As L. lactis has no catalase, the impact of production of the Bacillus subtilis haem catalase KatE on its oxidative stress resistance was tested. This cytoplasmic catalase was engineered for extracellular expression in L. lactis with an optimization strategy based on fusion to the nisin-inducible promoter and a lactococcal signal peptide (SPUsp45). The production of KatE by L. lactis conferred an 800-fold increase in survival after 1 h exposure to 4 mM hydrogen peroxide, and a 160-fold greater survival in long-term (3 days) survival of aerated cultures in a cydA mutant, which is unable to respire. The presence of KatE protected DNA from oxidative damage and limited its degradation after long-term aeration in a cydA/recA mutant, defective in DNA repair. L. lactis is thus able to produce active catalase that can provide efficient antioxidant activity.

scholarly journals Effects of Exogenous N-Acyl-Homoserine Lactone as Signal Molecule on Nitrosomonas Europaea under ZnO Nanoparticle Stress

2019 ◽  
Vol 16 (16) ◽  
pp. 3003
Author(s):  
Junkang Wu ◽  
Huan Gao ◽  
Jinyu Ye ◽  
Yan Chang ◽  
Ran Yu ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Membrane Integrity ◽  
Amoa Gene ◽  
Nitrosomonas Europaea ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Zno Nanoparticle ◽  
Nano Zno ◽  
Monooxygenase Activity ◽  
The Impact

Despite the adverse effects of emerging ZnO nanoparticles (nano-ZnO) on wastewater biological nitrogen removal (BNR) systems being widely documented, strategies for mitigating nanoparticle (NP) toxicity impacts on nitrogen removal have not been adequately addressed. Herein, N-acyl-homoserine lactone (AHL)-based quorum sensing (QS) was investigated for its effects against nano-ZnO toxicity to a model nitrifier, Nitrosomonas europaea. The results indicated that AHL-attenuated nano-ZnO toxicity, which was inversely correlated with the increasing dosage of AHL from 0.01 to 1 µM. At 0.01 µM, AHL notably enhanced the tolerance of N. europaea cells to nano-ZnO stress, and the inhibited cell proliferation, membrane integrity, ammonia oxidation rate, ammonia monooxygenase activity and amoA gene expression significantly increased by 18.2 ± 2.1, 2.4 ± 0.9, 58.7 ± 7.1, 32.3 ± 1.7, and 7.3 ± 5.9%, respectively, after 6 h of incubation. However, increasing the AHL dosage compromised the QS-mediated effects and even aggravated the NPs’ toxicity effects. Moreover, AHLs, at all tested concentrations, significantly increased superoxide dismutase activity, indicating the potential of QS regulations to enhance cellular anti-oxidative stress capacities when facing NP invasion. These results provide novel insights into the development of QS regulation strategies to reduce the impact of nanotoxicity on BNR systems.

scholarly journals Docosahexaenoic Acid Attenuates Mitochondrial Alterations and Oxidative Stress Leading to Cell Death Induced by Very Long-Chain Fatty Acids in a Mouse Oligodendrocyte Model

2020 ◽  
Vol 21 (2) ◽  
pp. 641 ◽  
Author(s):  
Thomas Nury ◽  
Margaux Doria ◽  
Gérard Lizard ◽  
Anne Vejux
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Docosahexaenoic Acid ◽  
Membrane Integrity ◽  
Long Chain Fatty Acids ◽  
Western Blot Assay ◽  
Cytotoxic Effects ◽  
The Impact ◽  
Long Chain ◽  
Chain Fatty Acids

In the case of neurodegenerative pathologies, the therapeutic arsenal available is often directed towards the consequences of the disease. The purpose of this study is, therefore, to evaluate the ability of docosahexaenoic acid (DHA), a molecule present in certain foods and considered to have health benefits, to inhibit the cytotoxic effects of very long-chain fatty acids (C24:0, C26:0), which can contribute to the development of some neurodegenerative diseases. The effect of DHA (50 µM) on very long-chain fatty acid-induced toxicity was studied by several complementary methods: phase contrast microscopy to evaluate cell viability and morphology, the MTT test to monitor the impact on mitochondrial function, propidium iodide staining to study plasma membrane integrity, and DHE staining to measure oxidative stress. A Western blot assay was used to assess autophagy through modification of LC3 protein. The various experiments were carried out on the cellular model of 158N murine oligodendrocytes. In 158N cells, our data establish that DHA is able to inhibit all tested cytotoxic effects induced by very long-chain fatty acids.

Changes in lipid peroxidation during pregnancy and after delivery in rats: effect of pinealectomy

Reproduction ◽  
2000 ◽  
pp. 143-149 ◽  
Author(s):  
RM Sainz ◽  
RJ Reiter ◽  
JC Mayo ◽  
J Cabrera ◽  
DX Tan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Oxidative Damage ◽  
Energy Demand ◽  
Physiological State ◽  
High Energy ◽  
Free Radical Scavengers ◽  
Radical Scavengers ◽  
Oxygen Requirement ◽  
Pregnant Rats

Pregnancy is a physiological state accompanied by a high energy demand of many bodily functions and an increased oxygen requirement. Because of the increased intake and utilization of oxygen, increased levels of oxidative stress would be expected. In the present study, the degree of lipid peroxidation was examined in different tissues from non-pregnant and pregnant rats after the delivery of their young. Melatonin and other indole metabolites are known to be direct free radical scavengers and indirect antioxidants. Thus the effect of pinealectomy at 1 month before pregnancy on the accumulation of lipid damage was investigated in non-pregnant and pregnant rats after the delivery of their young. Malonaldehyde and 4-hydroxyalkenal concentrations were measured in the lung, uterus, liver, brain, kidney, thymus and spleen from intact and pinealectomized pregnant rats soon after birth of their young and at 14 and 21 days after delivery. The same parameters were also evaluated in intact and pinealectomized non-pregnant rats. Shortly after delivery, lipid oxidative damage was increased in lung, uterus, brain, kidney and thymus of the mothers. No differences were detected in liver and spleen. Pinealectomy enhanced this effect in the uterus and lung. It is concluded that during pregnancy high levels of oxidative stress induce an increase in oxidative damage to lipids, which in some cases is inhibited by the antioxidative actions of pineal indoles.

Recent data on the causative agent of pale green dwarf (Acholeplasma laidlawii var. granulum incertae sedis) in Ukraine: pathogenicityand virulence factors and host reactions

2015 ◽  
Vol 2 (1) ◽  
pp. 30-34
Author(s):  
K. Korobkova ◽  
V. Patyka
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Proteolytic Enzymes ◽  
Physiological State ◽  
Plant Cells ◽  
Temporary Increase ◽  
Adhesive Properties ◽  
The Impact ◽  
Signaling Interactions ◽  
Pale Green

Contemporary state of the distribution of mycoplasma diseases of cultivated crops in Ukraine was analyzed. The changes of the physiological state of plant cells under the impact of mollicutes were investigated. It was demonstrated that there is temporary increase in the activity of peroxidase, catalase, polyphenoloxidase, phenylalanine-ammonia-lyase at the early stages of interaction. The adhesive properties are changed in the mollicutes under the impact of plant lectin; there is synthesis of new polypeptides. It was determined that the phytopathogenic acholeplasma is capable of producing a complex of proteolytic enzymes into the culture me- dium. It was concluded that when plant cells are infected with acholeplasma, a number of signaling interactions and metabolic transformations condition the recognition of pathogenesis and ensure the aggregate response of a plant to stress in the form of defense reactions. It was assumed that some specifi cities of the biology of phy- topathogenic acholeplasma determine their avoiding the immune mechanisms of plants and promote long-term persistence of mollicutes.

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