bims-noxint Biomed News
on NADPH oxidases in tumorigenesis
Issue of 2019‒11‒24
eight papers selected by
Laia Caja Puigsubira
Uppsala University

  1. Antioxidants (Basel). 2019 Nov 18. pii: E566. [Epub ahead of print]8(11):
    Barygina V, Becatti M, Prignano F, Lotti T, Taddei N, Fiorillo C.
      Although the role of reactive oxygen species-mediated (ROS-mediated) signalling in physiologic and pathologic skin conditions has been proven, no data exist on the skin cells ROS-mediated communication. Primary fibroblasts were obtained from lesional and non-lesional skin of psoriatic patients. ROS, superoxide anion, calcium and nitric oxide levels and lipoperoxidation markers and total antioxidant content were measured in fibroblasts. NADPH oxidase activity and NOX1, 2 and 4 expressions were assayed and NOX4 silencing was performed. Fibroblasts and healthy keratinocytes co-culture was performed. MAPK pathways activation was studied in fibroblasts and in co-cultured healthy keratinocytes. Increased intracellular calcium, •NO and ROS levels as well as an enhanced NADPH oxidase 4 (NOX4)-mediated extracellular ROS release was shown in lesional psoriatic vs. control fibroblasts. Upon co-culture with lesional fibroblasts, keratinocytes showed p38 and ERK MAPKs pathways activation, ROS, Ca2+ and •NO increase and cell cycle acceleration. Notably, NOX4 knockdown significantly reduced the observed effects of lesional fibroblasts on keratinocyte cell cycle progression. Co-culture with non-lesional psoriatic and control fibroblasts induced slight cell cycle acceleration, but notable intracellular ROS accumulation and ERK MAPK activation in keratinocytes. Collectively, our data demonstrate that NOX4 expressed in dermal fibroblasts is essential for the redox paracrine regulation of epidermal keratinocytes proliferation.
    Keywords:  NADPH oxidase; NOX4; ROS signalling; co-culture; fibroblasts; keratinocytes; psoriasis; redox
  2. Front Immunol. 2019 ;10 2567
    Liu M, Bedouhene S, Hurtado-Nedelec M, Pintard C, Dang PM, Yu S, El-Benna J.
      Production of superoxide anion and other reactive oxygen species (ROS) by neutrophils has a vital role in host defense against microbes. However, over-production can induce cell injury participating to inflammation. Superoxide anion is produced by the phagocyte NADPH oxidase/NOX2, a multicomponent enzyme system consisting of six proteins: two trans-membrane proteins (gp91 phox and p22 phox ) and four soluble cytosolic proteins (p40 phox , p67 phox , p47 phox , and the small G-proteins, Rac1/2). Phosphorylation of p47 phox on several serines regulates NADPH oxidase activation. LPS released by gram negative bacteria can enhance or prime neutrophil superoxide production in combination with other agonists such as the bacterial peptide formyl-Met-Leu-Phe (fMLP). Since the pathways involved in LPS-induced priming are not completely understood, we investigated the role of the prolyl cis/trans isomerase Pin1 in this process. Two different Pin1 inhibitors, PiB, and Juglone are able to block LPS-induced priming of ROS production by human neutrophils in a concentration dependent manner. PiB and Juglone did not inhibit LPS-induced CD11b translocation neither CD62L shedding. LPS induced an increase of Pin1 activity in neutrophils similar to TNFα and fMLP. Since the phosphorylation of p47 phox on Ser345 is critical for NADPH oxidase up-regulation, we investigated the effect of LPS on this process. Results show that LPS induced the phosphorylation of p47 phox mainly on serine 345 and induced the activation of p38MAPKinase and ERK1/2. These results suggest that the prolyl cis/trans isomerase Pin1 may control LPS-induced priming of superoxide production in human neutrophils. Pharmacological targeting of Pin1 could be a valuable approach in sepsis.
    Keywords:  LPS; NADPH oxidase; NOX2; Pin1; ROS; neutrophils; p47phox; priming
  3. Islets. 2019 Nov 21. 1-13
    Li J, Wu N, Chen X, Chen H, Yang X, Liu C.
      Curcumin possesses medicinal properties that are beneficial in various diseases, such as heart disease, cancer, and type 2 diabetes mellitus (T2 DM). It has been proposed that pancreatic beta cell dysfunction in T2 DM is promoted by oxidative stress caused by NADPH oxidase over-activity. The aim of the present study was to evaluate the efficacy of curcumin as a protective agent against high glucose/palmitate (HP)-induced islet cell damage and in streptozotocin (STZ)-induced DM rats. INS-1 cells were exposed to HP with or without curcumin. Cell proliferation, islet cell morphological changes, reactive oxygen species production, superoxide dismutase and catalase activity, insulin levels, NADPH oxidase subunit expression, and the expression of apoptotic factors by INS-1 cells were observed. Our results show that curcumin can effectively inhibit the impairment of cell proliferation and activated oxidative stress, increase insulin levels, and reduce the high expression of NADPH oxidase subunits and apoptotic factors induced by HP in INS-1 cells. The STZ-induced DM rat model was also used to determine whether curcumin can protect islets in vivo. Our results show that curcumin significantly reduced pathological damage and increased insulin levels of islets in STZ-induced DM rats. Curcumin also successfully inhibited the high expression of NADPH oxidase subunits and apoptotic factors in STZ-induced DM rats. These results suggest that curcumin is able to attenuate HP-induced oxidative stress in islet cells and protect these cells from apoptosis by modulating the NADPH pathway. In view of its efficiency, curcumin has potential for translation applications in protecting islets from glucolipotoxicity.
    Keywords:  Curcumin; NADPH oxidases; diabetes mellitus; glucolipotoxicty; islet; oxidative stress
  4. Arch Med Sci. 2019 Oct;15(6): 1589-1598
    Sinphitukkul K, Manotham K, Eiam-Ong S, Eiam-Ong S.
      Introduction: Previous in vitro studies demonstrated that aldosterone nongenomically induces transglutaminase (TG) and reactive oxygen species (ROS), which enhanced angiotensin II receptor (ATR) dimerization. There are no in vivo data in the kidney.Material and methods: Male Wistar rats were intraperitoneally injected with normal saline solution, or aldosterone (Aldo: 150 μg/kg BW); or received pretreatment with eplerenone (mineralocorticoid receptor (MR) blocker, Ep. + Aldo), or with apocynin (nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, Apo. + Aldo) 30 min before aldosterone. Thirty minutes after aldosterone injection, protein abundances of dimeric and monomeric forms of AT1R and AT2R, and protein abundances and localizations of TG2 and p47phox, a cytosolic subunit of NADPH oxidase, were determined by Western blot analysis and immunohistochemistry, respectively.
    Results: Protein abundances of dimeric forms of AT1R and AT2R were enhanced by 170% and 70%, respectively. Apocynin could block dimeric forms of both receptors while eplerenone inhibited only AT2R. Monomeric protein levels of both receptors were maintained. Aldosterone significantly enhanced TG2 and p47phox protein abundances, which were blunted by eplerenone or apocynin. Aldosterone stimulated p47phox protein expression in both the cortex and the medulla while TG2 was induced mostly in the medulla. Eplerenone or apocynin normalized the immunoreactivity of both TG2 and p47phox.
    Conclusions: This is the first in vivo study demonstrating that aldosterone nongenomically increases renal TG2 and p47phox protein expression and then activates AT1R and AT2R dimerizations. Aldosterone-stimulated AT1R and AT2R dimerizations are mediated through activation of NADPH oxidase. Aldosterone-induced AT1R dimer formation is an MR-independent pathway, whereas the formation of AT2R dimer is modulated in an MR-dependent manner.
    Keywords:  NADPH oxidase; aldosterone; angiotensin II receptor dimerization; mineralocorticoid receptor; nongenomic action; rat kidney
  5. Contemp Clin Trials. 2019 Nov 15. pii: S1551-7144(19)30607-X. [Epub ahead of print] 105892
    Reutens AT, Jandeleit-Dahm K, Thomas M, Bach LA, Colman PG, Davis TME, D'Emden M, Ekinci EI, Fulcher G, Hamblin PS, Kotowicz MA, MacIsaac RJ, Morbey C, Simmons D, Soldatos G, Wittert G, Wu T, Cooper ME, Shaw JE.
      PURPOSE: Kidney disease caused by type 1 diabetes can progress to end stage renal disease and can increase mortality risk. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) plays a major role in producing oxidative stress in the kidney in diabetes, and its activity is attenuated by GKT137831, an oral Nox inhibitor with predominant inhibitory action on Nox-1 and Nox - 4. Previous studies have demonstrated renoprotective effects with GKT137831 in various experimental models of type 1 diabetes-related kidney disease. This study will evaluate the effect of GKT137831 in treating clinical diabetic kidney disease.DESIGN: This is a multi-center, randomised, placebo-controlled trial, parallel arm study evaluating the effect on albuminuria of treatment with GKT137831 200 mg BID for 48 weeks. The study will randomize 142 participants who have persistent albuminuria and estimated glomerular filtration rate (eGFR) at baseline of at least 40 ml/min/1.73m2.
    PRIMARY OUTCOME MEASURES: Difference between arms in urine albumin to creatinine ratio. Secondary outcome measures include eGFR.
    CONCLUSION: This study is important because it may identify a new way of halting renal disease progression in people with type 1 diabetes and albuminuria already receiving standard of care treatment.
    Keywords:  Albuminuria; Diabetic nephropathy;; NADPH oxidase; Type 1 diabetes
  6. Int J Mol Sci. 2019 Nov 18. pii: E5789. [Epub ahead of print]20(22):
    Huang Y, Mao Z, Zhang X, Yang X, Sawada N, Takeda M, Yao J.
      Gap junctions (Gjs), formed by specific protein termed connexins (Cxs), regulate many important cellular processes in cellular immunity. However, little is known about their effects on humoral immunity. Here we tested whether and how Gj protein connexin43 (Cx43) affected antibody production in spleen cells. Detection of IgG in mouse tissues and serum revealed that wild-type (Cx43+/+) mouse had a significantly higher level of IgG than Cx43 heterozygous (Cx43+/-) mouse. Consistently, spleen cells from Cx43+/+ mouse produced more IgG under both basal and lipopolysaccharide (LPS)-stimulated conditions. Further analysis showed that LPS induced a more dramatic activation of ERK and cell proliferation in Cx43+/+ spleen cells, which was associated with a higher pro-oxidative state, as indicated by the increased NADPH oxidase 2 (NOX2), TXNIP, p38 activation and protein carbonylation. In support of a role of the oxidative state in the control of lymphocyte activation, exposure of spleen cells to exogenous superoxide induced Cx43 expression, p38 activation and IgG production. On the contrary, inhibition of NOX attenuated the effects of LPS. Collectively, our study characterized Cx43 as a novel molecule involved in the control of spleen cell activation and IgG production. Targeting Cx43 could be developed to treat certain antibody-related immune diseases.
    Keywords:  B cells; connexin43; immunoglobulin; oxidative stress; spleen cells
  7. Front Cell Dev Biol. 2019 ;7 245
    Li Z, Chen B, Dong W, Kong M, Shao Y, Fan Z, Yu L, Wu D, Lu J, Guo J, Xu Y.
      Trans-differentiation of endothelial cells to myofibroblast contributes to liver fibrosis. Reactive oxygen species (ROS) plays a key role in endothelial-mesenchymal transition (EndMT) although the underlying epigenetic mechanism is unclear. Here we report that endothelial conditional knockout of Brg1, a chromatin remodeling protein, attenuated liver fibrosis in mice. Brg1 deficiency in endothelial cells was paralleled by a decrease in ROS production and blockade of EndMT both in vivo and in vitro. The ability of BRG1 to regulate ROS production and EndMT was abolished by NOX4 depletion or inhibition. Further analysis revealed that BRG1 interacted with SMAD3 and AP-1 to mediate TGF-β induced NOX4 transcription in endothelial cells. Mechanistically, BRG1 recruited various histone modifying enzymes to alter the chromatin structure surrounding the NOX4 locus thereby activating its transcription. In conclusion, our data uncover a novel epigenetic mechanism that links NOX4-dependent ROS production to EndMT and liver fibrosis. Targeting the BRG1-NOX4 axis may yield novel therapeutics against liver fibrosis.
    Keywords:  EndMT; ROS; epigenetics; liver fibrosis; transcriptional regulation
  8. Life Sci. 2019 Nov 19. pii: S0024-3205(19)31013-6. [Epub ahead of print] 117086
    Liu Y, Wang M, Xu W, Zhang H, Qian W, Li X, Cheng X.
      BACKGROUND/AIMS: Recent studies have found vitamin D deficiency promotes fat deposition into the hepatocytes, thus contributing to the development of nonalcoholic fatty liver disease (NAFLD), which is a hepatic manifestation of metabolic syndrome. This study aimed to investigate the potential effects of vitamin D on NAFLD with the involvement of the p53 pathway.METHODS: Initially, an in vivo high-fat diet (HFD)-induced NAFLD mouse model was established. Then the HFD-induced NAFLD mice were treated with vitamin D. Next, the serum levels of TNF-α, GSH-px and malondialdehyde (MDA) were assessed using ELISA and ROS content was evaluated by flow cytometry, followed by the measurement of expression of Duox1, Duox2, SOD1, SOD2, PRDX1 I, ACC, SREBP1c, MTTP, PPARα, p53, p21 and p16 using RT-qPCR and Western blot analysis. Positive expression of FAS and FASL proteins was measured using immunohistochemistry. TUNEL and Senescence-associated β-galactosidase (SA-β-Gal) staining were subsequently conducted to assess the senescence and apoptosis of hepatocytes.
    RESULTS: HFD-induced mice treated with vitamin D presented with significantly increased GSH-px levels, as well as protein expression of SOD1, SOD2, PRDX1, MTTP and PPARα, but decreased MDA and ROS levels, expression of Duox1, Duox2, ACC, SREBP1c, p53, p21 and p16, positive expression of FAS and FASL proteins as well as impaired senescence and apoptosis of hepatocytes.
    CONCLUSION: Active vitamin D supplementation could potentially impede hepatocyte senescence and apoptosis via suppression of the p53 pathway, thus preventing the progression of NAFLD. Our study provides available evidence on the potential clinical utility of vitamin D supplementation in NAFLD.
    Keywords:  Active vitamin D; Apoptosis; Nonalcoholic fatty liver disease; Oxidative stress; Senescence; p53 pathway