scholarly journals SKAP2 is required for defense against K. pneumoniae infection and neutrophil respiratory burst

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Giang T Nguyen ◽  
Lamyaa Shaban ◽  
Matthias Mack ◽  
Kenneth D Swanson ◽  
Stephen C Bunnell ◽  
...  
Keyword(s):  
Adaptor Protein ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Ros Production ◽  
Oxygen Species ◽  
Bacterial Clearance ◽  
Pulmonary Infections ◽  
Wild Type ◽  
Neutrophil Respiratory Burst

Klebsiella pneumoniae is a respiratory, blood, liver, and bladder pathogen of significant clinical concern. We show that the adaptor protein, SKAP2, is required for protection against K. pneumoniae (ATCC 43816) pulmonary infections. Skap2-/- mice had 100-fold higher bacterial burden when compared to wild-type and burden was controlled by SKAP2 expression in innate immune cells. Skap2-/- neutrophils and monocytes were present in infected lungs, and the neutrophils degranulated normally in response to K. pneumoniae infection in mice; however, K. pneumoniae-stimulated reactive oxygen species (ROS) production in vitro was abolished. K. pneumoniae-induced neutrophil ROS response required the activity of SFKs, Syk, Btk, PLCγ2, and PKC. The loss of SKAP2 significantly hindered the K. pneumoniae-induced phosphorylation of SFKs, Syk, and Pyk2 implicating SKAP2 as proximal to their activation in pathogen-signaling pathways. In conclusion, SKAP2-dependent signaling in neutrophils is essential for K. pneumoniae-activated ROS production and for promoting bacterial clearance during infection.

scholarly journals Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Cellular Aging ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

scholarly journals The Responses of Bioactive Betanin Pigment and Its Derivatives from a Red Beetroot (Beta vulgaris L.) Betalain-Rich Extract to Hypochlorous Acid

2021 ◽  
Vol 22 (3) ◽  
pp. 1155
Author(s):  
Karolina Starzak ◽  
Katarzyna Sutor ◽  
Tomasz Świergosz ◽  
Boris Nemzer ◽  
Zbigniew Pietrzkowski ◽  
...  
Keyword(s):  
Beta Vulgaris ◽  
Hypochlorous Acid ◽  
Innate Immune ◽  
Inflammatory Factors ◽  
Oxygen Species ◽  
Plant Pigments ◽  
Important Food ◽  
Inflammatory Conditions ◽  
Ph Range

Neutrophils produce hypochlorous acid (HOCl) as well as other reactive oxygen species as part of a natural innate immune response in the human body; however, excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. Comparison of the in vitro anti-hypochlorite activities of a novel betalain-rich red beetroot (Beta vulgaris L.) extract with its pure betalainic pigments revealed that the extract had the highest anti-hypochlorite activity, far exceeding the activity of all of the betalainic derivatives and selected reference antioxidants. This suggests that it may be an important food-based candidate for management of inflammatory conditions induced by excessive HOCl production. Among all pigments studied, betanidin exhibited the highest activity across the pH range.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

scholarly journals Oral Exposure to House Dust Mite Activates Intestinal Innate Immunity

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 561
Author(s):  
Sara Benedé ◽  
Leticia Pérez-Rodríguez ◽  
Mónica Martínez-Blanco ◽  
Elena Molina ◽  
Rosina López-Fandiño
Keyword(s):  
House Dust ◽  
House Dust Mite ◽  
Immune Cells ◽  
Oral Route ◽  
Innate Immune ◽  
Oral Exposure ◽  
Lymphoid Tissues ◽  
Innate Immune Cells ◽  
Dust Mite

Scope: House dust mite (HDM) induces Th2 responses in lungs and skin, but its effects in the intestine are poorly known. We aimed to study the involvement of HDM in the initial events that would promote sensitization through the oral route and eventually lead to allergy development. Methods and results: BALB/c mice were exposed intragastrically to proteolytically active and inactive HDM, as such, or in combination with egg white (EW), and inflammatory and type 2 responses were evaluated. Oral administration of HDM, by virtue of its proteolytic activity, promoted the expression, in the small intestine, of genes encoding tight junction proteins, proinflammatory and Th2-biasing cytokines, and it caused expansion of group 2 innate immune cells, upregulation of Th2 cytokines, and dendritic cell migration and activation. In lymphoid tissues, its proteolytically inactivated counterpart also exerted an influence on the expression of surface DC molecules involved in interactions with T cells and in Th2 cell differentiation, which was confirmed in in vitro experiments. However, in our experimental setting we did not find evidence for the promotion of sensitization to coadministered EW. Conclusion: Orally administered HDM upregulates tissue damage factors and also acts as an activator of innate immune cells behaving similarly to potent oral Th2 adjuvants.

scholarly journals Vitamin E-Coated Dialyzer Inhibits Oxidative Stress

2017 ◽  
Vol 44 (4) ◽  
pp. 288-293 ◽  
Author(s):  
Shiho Yamadera ◽  
Yuya Nakamura ◽  
Masahiro Inagaki ◽  
Isao Ohsawa ◽  
Hiromichi Gotoh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin E ◽  
Synthetic Polymer ◽  
Intracellular Reactive Oxygen Species ◽  
Ros Production ◽  
Oxygen Species ◽  
In Vitro Methods ◽  
Stress Effects ◽  
Intracellular Ros

Aim: To examine the effects of vitamin E-coated dialyzer on oxidative stress in vitro. Methods: A dialyzer with a synthetic polymer membrane (APS-11SA) and vitamin E-coated dialyzer (VPS-11SA) were connected to a blood tubing line, and U937 cells were circulated in the device. The circulating fluid was collected at 1, 2, 5, 10, 25, and 50 cycles, which are estimated numbers of passes through the dialyzer. Intracellular reactive oxygen species (ROS) production, malondialdehyde (MDA), and Cu/Zn-superoxide dismutase (SOD) were quantified. Results: Intracellular ROS production was increased in the first cycle by APS-11SA and was decreased throughout the experiment by VPS-11SA. Intracellular ROS production in the VPS-11SA device was lower, and MDA levels were decreased. MDA levels were lower during VPS-11SA processing than during APS-11SA processing. Cu/Zn-SOD levels remained unchanged. Conclusion: Our results highlight anti-oxidative-stress effects of a vitamin E-coated dialyzer.

Hyperglycemia Induces Generation of Reactive Oxygen Species and Accelerates Apoptotic Cell Death in Salivary Gland Cells

Pathobiology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Naoyuki Matsumoto ◽  
Daisuke Omagari ◽  
Ryoko Ushikoshi-Nakayama ◽  
Tomoe Yamazaki ◽  
Hiroko Inoue ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Salivary Gland ◽  
Tissue Injury ◽  
Ros Production ◽  
Oxygen Species ◽  
Saliva Secretion ◽  
Salivary Gland Tissue ◽  
Gland Tissue

<b><i>Introduction:</i></b> Type-2 diabetes mellitus (T2DM) is associated with several systemic vascular symptoms and xerostomia. It is considered that hyperglycemia-induced polyuria and dehydration cause decreased body-water volume, leading to decreased saliva secretion and, ultimately, xerostomia. In T2DM, increased production of reactive oxygen species (ROS) causes tissue damage to vascular endothelial cells as well as epithelial tissue, including pancreas and cornea. Hence, a similar phenomenon may occur in other tissues and glands in a hyperglycemic environment. <b><i>Methods:</i></b> Salivary gland tissue injury was examined, using T2DM model mouse (db/db). Transferase‐mediated dUTP nick‐end labeling (TUNEL) was conducted to evaluate tissue injury. The levels of malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine, Bax/Bcl-2 ratio were measured as indicator of oxidative stress. Moreover, in vitro ROS production and cell injury was evaluated by mouse salivary gland-derived normal cells under high-glucose condition culture. <b><i>Results:</i></b> In vivo and in vitro analysis showed a higher percentage of TUNEL-positive cells and higher levels of MDA and 8-hydroxy-2′-deoxyguanosine in salivary gland tissue of db/db mice. This suggests damage of saliva secretion-associated lipids and DNA by hyperglycemic-induced oxidative stress. To analyze the mechanism by which hyperglycemia promotes ROS production, mouse salivary gland-derived cells were isolated. The cell culture with high-glucose medium enhanced ROS production and promotes apoptotic and necrotic cell death. <b><i>Conclusion:</i></b> These findings suggest a novel mechanism whereby hyperglycemic-induced ROS production promotes salivary gland injury, resulting in hyposalivation.

Abstract 1772: Cardiomyocyte Damage-Released S100A1 Protein Evokes A Proinflammatory Phenotype In Cardiac Fibroblasts

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
David Rohde ◽  
Melanie Boerries ◽  
Herzog Nicole ◽  
Gang Qiu ◽  
Philipp Ehlermann ◽  
...  
Keyword(s):  
Western Blotting ◽  
Immune Cells ◽  
Nuclear Translocation ◽  
Cardiac Fibroblasts ◽  
Innate Immune ◽  
Host Cells ◽  
Boyden Chamber ◽  
Innate Immune Cells ◽  
Danger Signal

Background: S100A1, a cardiomyocyte specific inotropic calcium sensor protein, is released from infarcted human myocardium in the extracellular environment and circulation, reaching peak serum levels (1–2 μM) 8–9 hours after clinical onset. As growing evidence indicates that S100 proteins can act as pre-existing danger signals triggering the innate immune system into action upon release from injured host cells, we hypothesized that damage-released S100A1 can act as a cardiac danger signal alerting innate immune cells. Methods and Results: Here we report for the first time that necrotic cardiomyocytes release S100A1 protein in vitro, which is exclusively internalized by cardiac fibroblasts (CFs) in a clathrin- and caveolin-independent manner as shown by IF. Internalized S100A1 specifically activated MAPKs/SAPKs (p38, ERK1/2 and JNK) resulting in nuclear translocation of p65 (NF-kB) as assessed by Western blotting, EMSA and IF. In turn, S100A1 triggered an inflammatory gene program in CFs including enhanced expression of adhesion molecules, integrins, chemokines and cytokines including I-CAM, V-CAM, CD11b/18, IL1-alpha, MCP-1, TNF-alpha, SDF-1 among others as obtained by RT-PCR, Western blotting and ELISA. This resulted in enhanced chemoattraction and adhesion of monocytotic and stem cells to S100A1-activated CF as shown by Boyden-chamber and adhesion assays. In line with their proinflammatory transition, S100A1-activated CFs exhibited decreased collagen-1/-3 expression and de-novo collagen production, enhanced collagenolytic MMP-9 abundance and activity and increased levels of the antiangiogenic matricellular factor thrombospondin-2 reflecting extracellular matrix net degradation. Importantly, the immun-modulatory and antifibrotic actions of S100A1 protein in vitro were restricted to CFs, RAGE independent and occurred at concentrations (0.1–1 μM) that were found in patients after AMI. Conclusion: Our in vitro results indicate that S100A1 has the properties of a pre-exisiting endogenous cardiomyocyte danger signal transforming cardiac fibroblasts into immunmodulatory cells that might recruit innate immune cells to the site of cardiac injury and link cardiomyocyte damage to post-MI inflammation.

scholarly journals Hyperglycemic Memory of Innate Immune Cells Promotes In Vitro Proinflammatory Responses of Human Monocytes and Murine Macrophages

2021 ◽  
pp. ji1901348
Author(s):  
Kathrin Thiem ◽  
Samuel T. Keating ◽  
Mihai G. Netea ◽  
Niels P. Riksen ◽  
Cees J. Tack ◽  
...  
Keyword(s):  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Human Monocytes ◽  
Murine Macrophages ◽  
Proinflammatory Responses

Abstract 098: MicroRNA Regulation of NADPH Oxidase Mediates the Antioxidant Effect of Renal Paraoxonase 2

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Santiago Cuevas ◽  
Yu Yang ◽  
Laureano D Asico ◽  
John Jones ◽  
Ines Armando ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Antioxidant Effect ◽  
Receptor Subtype ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Compensatory Response ◽  
Microrna Regulation ◽  
Dopamine 2 Receptor ◽  
Renal Expression

Increased renal generation of reactive oxygen species (ROS) is important in the pathogenesis of hypertension caused by absent or dysfunctional dopamine receptor subtype. Germline deletion of the dopamine 2 receptor in mice increases renal NADPH oxidase (NOX) activity and decreases expression paraoxonase 2 (PON2) and results in ROS-dependent hypertension. We determined if microRNA (miR) is involved in PON2-mediated regulation of NOX. Silencing PON2 in human renal proximal tubules cells decreased PON2 (-60±4%, n=3,*P<0.05) and increased NOX2 (110±15%, n=3,*P<0.05) and NOX4 (80±10%, n=3,*P<0.05) proteins, NOX activity (50±6%, n=3,*P<0.05), and ROS production (57±3%, n=4,*P<0.05). Inhibition of NOX activity by diphenyleneiodonium normalized the increase in ROS caused by PON2 silencing. Renal-selective silencing of Pon2 in mice by the renal subcapsular infusion of Pon2 siRNA decreased PON2 (~50%), and increased NOX2 (191±11%,n=3, P<0.05), NOX4 (60±4%,n=3, P<0.05), NOX activity (94±23%, n=3, P<0.05), and blood pressure (BP) (+41±6 mmHg, n=3, P<0.05). Pon2-/- mice also had higher BP than wild-type littermates (+15±2 mmHg,n=3/4,*P<0.05) but less than observed with renal-selective silencing indicating extrarenal compensation. Renal NOX2 (220±64%, n=3/4,*P<0.05) and NOX activity (195±77%, n=3,*P<0.05) were also increased in Pon2-/- mice. However, the renal expression of NOX4 was similar in Pon2-/- and wild-type littermates. The renal expressions of miR-23b, miR-34a and miR-155 (reported to regulate NOX expression) were also similar in Pon2-/- mice and wild-type littermates. However, renal miR-146a expression was decreased (-25±4%, n=3/4,*P<0.05) while miR-204 (150±12%, n=3/4,*P<0.05) and NFAT expressions (21±7%, n=3/4,*P<0.05) were increased in Pon2-/- mice. The increase in miR-204 could be a compensatory response because miR-204 has been shown to decrease NFAT expression. It is known that NFAT and NOX2 can positively regulate each other’s expression while miR-146a negatively regulates NOX4 expression and inflammation. We conclude that PON2 by increasing miR-146a and decreasing NFAT expression negatively regulates NOX activity and reduce ROS production that would contribute to the maintenance of normal BP.

183 ADDITION OF DIPHENYLENEIODONIUM OR DEHYDROEPIANDROSTERONE TO CULTURE MEDIA INHIBITS REACTIVE OXYGEN SPECIES PRODUCTION DURING THE EARLY CLEAVAGE STAGES OF IN VITRO-PRODUCED PORCINE EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 208
Author(s):  
N. W. K. Karja ◽  
K. Kikuchi ◽  
M. Ozawa ◽  
M. Fahrudin ◽  
T. Somfai ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Culture Media ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Blastocyst Stage ◽  
Control Group ◽  
Ros Production ◽  
Oxygen Species

Nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase), an enzyme required to catalyze the oxidation of NADPH to NADP during the metabolism of glucose via the pentose phosphate pathway (PPP), was considered as contributing to intracellular reactive oxygen species (ROS) production. Production of superoxide anion and H2O2 via NADPH oxidase has been reported on a rabbit blastocyst surface (Manes and Lai 1995 J. Reprod. Fertil. 104, 69–75). The objective of this study was to examine the effects on in vitro development and intracellular ROS content after the addition of diphenyleneiodonium (DPI), an inhibitor of NADPH oxidase, or dehydroepiandrosterone (DHEA), an inhibitor of glucose-6-phosphate dehydrogenase (G6PDH), to culture medium during the early embryonic development of in vitro-produced (IVP) porcine embryos. To confirm that these inhibitors lead to reduction in NADPH concentration in the embryo and hence likely to be inhibiting the PPP, a brilliant cresyl blue (BCB) test was performed on Day 2 (the day of insemination = Day 0) of culture. Porcine cumulus–oocyte complexes were matured and fertilized in vitro as described previously (Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041). Prezumptive zygotes were then cultured in NCSU-37 supplemented with 5.5 mM glucose and DPI at concentrations of 0.5 or 1 nM or DHEA at concentrations of 10 or 100 �M (DPI-0.5, DPI-1, DHEA-10 and DHEA-100 groups, respectively) from Day 0 to Day 2 of culture. All of the embryos were cultured subsequently until Day 6 in NCSU-37 supplemented with only 5.5 mM glucose. Data were analyzed by ANOVA. On Day 6, the development to the blastocyst stage of embryos in DPI-0.5, DPI-1, DHEA-10, and DHEA-100 groups were 16.1, 17.6, 16.1, and 19.5%, respectively, which were not significantly different from that of the control group (17.5%) (n d 165 per group, 5 replicates). However, the mean cell number in blastocysts derived from DPI-1, DHEA-10, and DHEA-100 groups (40.8 � 2.3, 39.3 � 1.7, and 42.5 � 2.7, respectively) was significantly higher (P &lt; 0.01) than those in the control (33.4 � 1.6) and DPI-0.5 (32.7 � 1.6) groups. At 20 min after an exposure to BCB, the percentage of BCB+ embryos in DPI-1, DHEA-10, and DHEA-100 groups (73.8, 79.9, and 77.8%, respectively) were significantly higher (P &lt; 0.01) than those in the control and DPI-0.5 groups (42% and 53.9%, respectively) (n = 81-92 per group, 6 replicates), indicating that these two inhibitors effectively induce the reduction of NADPH concentration in the embryos. Moreover, the addition of DPI at 1 nM or DHEA at 10 or 100 �M significantly decreased the H2O2 content of Day 2 embryos as compared with control embryos (n = 48-53 per group, 7 replicates). These results suggest that the addition of either DPI or DHEA to the medium during the first 2 days of culture did not impair the development of the embryos to the blastocyst stage. Decrease of cellular ROS production in Day 2 embryos in this study is interpreted as a result of inhibition of the NADPH oxidase by DPI or of the G6PDH by DHEA.

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