bims-noxint Biomed News
on NADPH oxidases in tumorigenesis
Issue of 2020‒04‒12
ten papers selected by
Laia Caja Puigsubira
Uppsala University

  1. Biochem Pharmacol. 2020 Apr 03. pii: S0006-2952(20)30178-7. [Epub ahead of print] 113950
    Pintard C, Ben Khemis M, Liu D, My-Chan Dang P, Hurtado-Nedelec M, El-Benna J.
      Neutrophils are key cells in innate immunity and inflammation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to enhance many neutrophil functions such as upregulation of reactive oxygen species (ROS) production, degranulation and cell survival via the activation of the ERK1/2 pathway. ERK1/2 activation pathway is redox sensitive and could be modulated by ROS. In order to investigate whether NADPH oxidase NOX2-derived ROS could contribute to GM-CSF-induced ERK1/2 phosphorylation, we tested the effect of two selective NOX2 inhibitors, diphenylene iodonium (DPI) and apocynin. Results showed that, while both DPI and apocynin strongly inhibited neutrophil ROS production, only apocynin, but not DPI, inhibited GM-CSF-induced ERK1/2 phosphorylation, suggesting that ROS are not involved in this process. Apocynin did not affect GM-CSF-induced p38MAPKinase phosphorylation, another redox sensitive kinase. Interestingly, apocynin inhibited GM-CSF-induced MEK1/2 and AKT phosphorylation without affecting fMLF-induced phosphorylation of these proteins. GM-CSF is known to inhibit neutrophils apoptosis and to promote cell survival via the AKT-ERK1/2 pathway. In this regard, we found that apocynin also inhibited GM-CSF-induced anti-apoptotic effect in neutrophils. These results suggest that NADPH oxidase NOX2-derived ROS are not involved in GM-CSF-induced ERK1/2 phosphorylation and that apocynin inhibits GM-CSF-induced ERK1/2 phosphorylation pathway independently of its inhibitory action on NADPH oxidase NOX2. Thus, apocynin can exert an anti-inflammatory effect not only by limiting neutrophil ROS production but also by decreasing neutrophil survival at inflammatory site.
    Keywords:  Apocynin; ERK1/2; GM-CSF; NADPH oxidase NOX2; Neutrophils; Reactive oxygen species
  2. Free Radic Biol Med. 2020 Apr 05. pii: S0891-5849(20)30359-2. [Epub ahead of print]
    Nocella C, Cammisotto V, Bartimoccia S, Castellani V, Loffredo L, Pastori D, Pignatelli P, Sanguigni V, Violi F, Carnevale R.
      NOX2 has a key role for cellular production of reactive oxidant species (ROS) and although the mechanism of its activation is well known, little is known about its regulation. Metallo-proteinases (MMPs) regulate numerous protein activities both in physiological and pathological conditions but their interplay with NOX2 and ROS formation is still unclear. We performed experimental studies in human platelets and polymorphonuclear leukocytes (PMNs) to investigate the interplay of MMP2 with NOX2 activity. In collagen-stimulated platelets and in PMA-stimulated PMNs from healthy subjects, an immediate burst of ROS was detected at 10 min to then decline at 20 min. Coincidentally, sNOX2-dp, a split-off product of NOX2, increased and peaked at 10 min. ROS production was persistent whereas sNOX2dp is not released in cells treated with MMP2 inhibitor compared to other MMPs inhibitors. Western blot analysis showed the highest MMP2 expression on the cell membrane 10 min after stimulation. Moreover, the co-immunoprecipitation assay confirms the interaction between MMP2 and NOX2 that formed an active immuno-complex. Treating cells with NOX2ds-tat, an inhibitor of NADPH oxidase, significantly reduced ROS formation, sNOX2-dp, MMP2 expression and MMP2-NOX2-complex, which were all restored if cells were added with H2O2. The study provides the first evidence that MMP2 has a key role in blunting platelet NOX2 activity and eventually ROS formation.
    Keywords:  Matrix metalloproteinase-2; NOX2; Oxidative stress; Platelets; ROS
  3. J Immunol Res. 2020 ;2020 7812709
    Liao J, Yang X, Lin Q, Liu S, Xie Y, Xia Y, Li HH.
      Background: Ubiquitin-like modifier activating enzyme 1 (UBA1) is the first and major E1 activating enzyme in ubiquitin activation, the initial step of the ubiquitin-proteasome system. Defects in the expression or activity of UBA1 correlate with several neurodegenerative and cardiovascular disorders. However, whether UBA1 contributes to atherosclerosis is not defined.Methods and Results: Atherosclerosis was induced in apolipoprotein E-knockout (Apoe-/-) mice fed on an atherogenic diet. UBA1 expression, detected by immunohistochemical staining, was found to be significantly increased in the atherosclerotic plaques, which confirmed to be mainly derived from lesional CD68+ macrophages via immunofluorescence costaining. Inactivation of UBA1 by the specific inhibitor PYR-41 did not alter the main metabolic parameters during atherogenic diet feeding but suppressed atherosclerosis development with less macrophage infiltration and plaque necrosis. PYR-41 did not alter circulating immune cells determined by flow cytometry but significantly reduced aortic mRNA levels of cytokines related to monocyte recruitment (Mcp-1, Vcam-1, and Icam-1) and macrophage proinflammatory responses (Il-1β and Il-6). Besides, PYR-41 also suppressed aortic mRNA expression of NADPH oxidase (Nox1, Nox2, and Nox4) and lesional oxidative stress levels, determined by DHE staining. In vitro, PYR-41 blunted ox-LDL-induced lipid deposition and expression of proinflammatory cytokines (Il-1β and Il-6) and NADPH oxidases (Nox1, Nox2, and Nox4) in cultured RAW264.7 macrophages.
    Conclusions: We demonstrated that UBA1 expression was upregulated and mainly derived from macrophages in the atherosclerotic plaques and inactivation of UBA1 by PYR-41 suppressed atherosclerosis development probably through inhibiting macrophage proinflammatory response and oxidative stress. Our data suggested that UBA1 might be explored as a potential pharmaceutical target against atherosclerosis.
  4. Curr Mol Pharmacol. 2020 Apr 06.
    Nishiyama K, Tanaka T, Nishimura A, Nishida M.
      BACKGROUND: Transient receptor potential (TRP) channels, especially canonical TRP channel subfamily members 3 (TRPC3) and 6 (TRPC6), have attracted attention as a putative therapeutic target of heart | 1 failure. Moreover, TRPC3 and TRPC6 channels are physiologically important for maintaining cellular homeostasis. How TRPC3/C6 channels alter intracellular signaling from adaptation to maladaptation has been discussed for many years. We recently showed that formation of a protein signal complex between TRPC3 and NADPH oxidase (Nox) 2 caused by environmental stresses (e.g., hypoxia, nutritional deficiency, and anticancer drug treatment) promotes Nox2-dependent reactive oxygen species production and cardiac stiffness, including myocardial atrophy and interstitial fibrosis, in rodents. In fact, pharmacological prevention of the TRPC3-Nox2 protein complex can maintain cardiac flexibility in mice after anti-cancer drug treatment.CONCLUSION: In this mini-review, we discuss the relationship between TRPC3/C6 channels and cardiovascular disease, and propose a new therapeutic strategy by focusing on pathology-specific protein- protein interactions.
    Keywords:  Nox2; TRPC3; TRPC6; drug repurposing; oncocardiology; protein–protein interaction
  5. Bone. 2020 Apr 06. pii: S8756-3282(20)30136-8. [Epub ahead of print] 115356
    Williams KM, Leser JM, Gould NR, Joca HC, Lyons JS, Khairallah RJ, Ward CW, Stains JP.
      Skeletal remodeling is driven in part by the osteocyte's ability to respond to its mechanical environment by regulating the abundance of sclerostin, a negative regulator of bone mass. We have recently shown that the osteocyte responds to fluid shear stress via the microtubule network-dependent activation of NADPH oxidase 2 (NOX2)-generated reactive oxygen species and subsequent opening of TRPV4 cation channels, leading to calcium influx, activation of CaMKII, and rapid sclerostin protein downregulation. In addition to the initial calcium influx, purinergic receptor signaling and calcium oscillations occur in response to mechanical load and prior to rapid sclerostin protein loss. However, the independent contributions of TRPV4-mediated calcium influx and purinergic calcium oscillations to the rapid sclerostin protein downregulation remain unclear. Here, we showed that NOX2 and TRPV4-dependent calcium influx is required for calcium oscillations, and that TRPV4 activation is both necessary and sufficient for sclerostin degradation. In contrast, calcium oscillations are neither necessary nor sufficient to acutely decrease sclerostin protein abundance. However, blocking oscillations with apyrase prevented fluid shear stress induced changes in osterix (Sp7), osteoprotegerin (Tnfrsf11b), and sclerostin (Sost) gene expression. In total, these data provide key mechanistic insights into the way bone cells translate mechanical cues to target a key effector of bone formation, sclerostin.
    Keywords:  Calcium oscillations; Calcium signaling; NOX2; Osteocyte; Sclerostin; TRPV4
  6. Front Cell Dev Biol. 2020 ;8 176
    Lv F, Li N, Kong M, Wu J, Fan Z, Miao D, Xu Y, Ye Q, Wang Y.
      The lipid-storage hepatic stellate cells (HSC) play as pivotal role in liver fibrosis being able to trans-differentiate into myofibroblasts in response to various pro-fibrogenic stimuli. In the present study we investigated the role of CDKN2a/p16, a negative regulator of cell cycling, in HSC activation and the underlying mechanism. Levels of p16 were significantly down-regulated in activated HSCs isolated from mice induced to develop liver fibrosis compared to quiescent HSCs isolated from the control mice ex vivo. There was a similar decrease in p16 expression in cultured HSCs undergoing spontaneous activation or exposed to TGF-β treatment in vitro. More important, p16 down-regulation was observed to correlate with cirrhosis in humans. In a classic model of carbon tetrachloride (CCl4) induced liver fibrosis, fibrogenesis was far more extensive in mice with p16 deficiency (KO) than the wild type (WT) littermates. Depletion of p16 in cultured HSCs promoted the synthesis of extracellular matrix (ECM) proteins. Mechanistically, p16 deficiency accelerated reactive oxygen species (ROS) generation in HSCs likely through the p38 MAPK signaling. P38 inhibition or ROS cleansing attenuated ECM production in p16 deficient HSCs. Taken together, our data unveil a previously unappreciated role for p16 in the regulation of HSC activation. Screening for small-molecule compounds that can boost p16 activity may yield novel therapeutic strategies against liver fibrosis.
    Keywords:  CDKN2a/p16; ROS; hepatic stellate cell; liver fibrosis; p38 MAPK
  7. Redox Biol. 2020 Mar 30. pii: S2213-2317(20)30286-X. [Epub ahead of print] 101523
    Zeng C, Duan F, Hu J, Luo B, Huang B, Lou X, Sun X, Li H, Zhang X, Yin S, Tan H.
      Dilated cardiomyopathy (DCM) is one of the most common causes of heart failure, and the underlying mechanism remains largely elusive. Here we investigated whether NLRP3 inflammasome-mediated pyroptosis contributes to non-ischemic DCM and dissected the underlying mechanism. We found that hyper activated NLRP3 inflammasome with pyroptotic cell death of cardiomyocytes were presented in the myocardial tissues of DCM patients, which were negatively correlated with cardiac function. Doxorubicin (Dox)-induced DCM characterization disclosed that NLRP3 inflammasome activation and pyroptosis occurred in Dox-treated heart tissues, but were very marginal in either NLRP3-/- or caspase-1-/- mice. Mechanistically, Dox enhanced expressions of NOX1 and NOX4 and induced mitochondrial fission through dynamin-related protein 1 (Drp1) activation, leading to NLRP3 inflammasome-mediated pyroptosis in cardiomyocytes via caspase-1-dependent manner. Conversely, both inhibitions of NOX1 and NOX4 and Drp1 suppressed Dox-induced NLPR3 inflammasome activation and pyroptosis. The alterations of NOX1 and NOX4 expression, Drp1 phosphorylation and mitochondrial fission were validated in DCM patients and mice. Importantly, Dox-induced Drp1-mediated mitochondrial fission and the consequent NLRP3 inflammasome activation and pyroptosis were reversed by NOX1 and NOX4 inhibition in mice. This study demonstrates for the first time that cardiomyocyte pyroptosis triggered by NLRP3 inflammasome activation via caspase-1 causally contributes to myocardial dysfunction progression and DCM pathogenesis.
    Keywords:  Dilated cardiomyopathy; Heart failure; Mitochondrial fission; NLRP3 inflammasome; NOX; Pyroptosis
  8. Antioxidants (Basel). 2020 Apr 02. pii: E296. [Epub ahead of print]9(4):
    Cammisotto V, Pastori D, Nocella C, Bartimoccia S, Castellani V, Marchese C, Scavalli AS, Ettorre E, Viceconte N, Violi F, Pignatelli P, Carnevale R.
      BACKGROUND: High levels of proprotein convertase subtilisin/kexin 9 (PCSK9) is predictive of cardiovascular events (CVEs) in atrial fibrillation (AF). We hypothesized that PCSK9 may directly induce platelet activation (PA).METHODS: We measured platelet aggregation, recruitment, Thromboxane B2 (TxB2) formation and soluble P-selectin levels as markers of PA and soluble Nox2-derived peptide (sNox2-dp), H2O2, isoprostanes and oxidized Low-Density-Lipoprotein (oxLDL) to analyze oxidative stress (OS) in 88 patients having PCSK9 values < (n = 44) or > (n = 44) 1.2 ng/mL, balanced for age, sex and cardiovascular risk factors. Furthermore, we investigated if normal (n = 5) platelets incubated with PCSK9 (1.0-2.0 ng/mL) alone or with LDL (50 µg/mL) displayed changes of PA, OS and down-stream signaling.
    RESULTS: PA and OS markers were significantly higher in patients with PCSK9 levels > 1.2 ng/mL compared to those with values < 1.2 ng/mL (p < 0.001). Levels of PCSK9 significantly correlated with markers of PA and OS. Platelets incubation with PCSK9 increased PA, OS and p38, p47 and Phospholipase A2 (PLA2) phosphorylation. These changes were amplified by adding LDL and blunted by CD36 or Nox2 inhibitors. Co-immunoprecipitation analysis revealed an immune complex of PCSK9 with CD36.
    CONCLUSIONS: We provide the first evidence that PCSK9, at concentration found in the circulation of AF patients, directly interacts with platelets via CD36 receptor and activating Nox2: this effect is amplified in presence of LDL.
    Keywords:  CD36; PCSK9; ROS; oxidative stress; platelets
  9. Immunopharmacol Immunotoxicol. 2020 Apr 05. 1-8
    Zhang X, Jin J, Xie A.
      Objective: Nod-like receptor protein 3 (NLRP3) inflammasome plays anessentialrole in neuroinflammation in the Parkinson's disease (PD) progression. Laquinimodis an immunomodulator that is clinically used for the treatment of multiple sclerosis. This study aims to investigate whether laquinimod possessesa protective effect against MPP+-induced NLRP3 activation.Materials and methods: In a variety of tests on human SH-SY5Y neuronal cells, 1-methyl-4-phenyl Pyridine (MPP+) was used to mimic the microenvironment of PD. Activation of NLRP3 inflammasome was measured by western blot analysis and enzyme linked immunosorbent assay (ELISA).Results: Laquinimod had a significant protective impact against MPP+-induced neurotoxicity. Our results demonstrate that laquinimod prevented MPP+-induced reduction of cell proliferation, the release of lactate dehydrogenase (LDH), and apoptosis. Importantly, treatment with laquinimod significantly inhibited the activation of the NLRP3 inflammasome by reducing the levels of its components, including NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and cleaved caspase 1 (P10). Consistently, laquinimod prevented MPP+-induced secretions of interleukin 1β (IL-1β) and interleukin-18 (IL-18). Additionally, laquinimod also reduced the expression of other related factors, such as intracellular reactive oxygen species (ROS), NADPH oxidase 4 (NOX-4), thioredoxin-interacting protein (TxNIP). Furthermore, laquinimod prevented the reduction of sirtuin 1 (SIRT1) from MPP+ stimulation. Inhibition of SIRT1 abolished the protective effects of laquinimod against the activation of the NLRP3 inflammasome, suggesting the involvement of SIRT1 in this process.Conclusion: These findings suggest that laquinimod treatment might be a possible therapeutic strategy for neuroinflammation in PD.
    Keywords:  MPP+; NLRP3 inflammasome; Parkinson’s disease; SIRT1; laquinimod
  10. Front Pharmacol. 2020 ;11 264
    Fan X, Wei W, Huang J, Liu X, Ci X.
      Cisplatin (CDDP) is a widely used chemotherapeutic agent for various solid tumors, but its severe side effects, particularly nephrotoxicity, limit its clinical application. Isoorientin (Iso) is a flavonoid-like compound known to have antioxidant effects. As oxidative injury plays a vital role in CDDP-induced acute kidney injury (AKI), the effect of Iso on CDDP-induced nephrotoxicity has not yet been researched. We assessed the effects of Iso against CDDP-induced nephrotoxicity in vitro using mTEC cells and further explored the mechanisms underlying CDDP-induced renal dysfunction in vivo in WT and Nrf2-/- mice. The results showed that Iso treatment significantly reduced CDDP-induced nephrotoxicity via attenuating cell damage in vitro and via ameliorating renal injury, as determined by biochemical markers, in mice. The molecular mechanism underlying this protection was also investigated. Iso up-regulated the expression levels of SIRT1 and SIRT6 in vivo and in vitro. In addition, Iso activated Nrf2 translocation and the expression levels of its downstream antioxidant enzymes, such as HO-1 and NQO1, whereas it inhibited the expression level of NOX4, thus decreasing oxidative stress. Notably, the protective effects of Iso observed in WT mice were completely abolished in Nrf2-/- mice. Collectively, these data indicate that the protective effect of Iso on CDDP-induced nephrotoxicity by SIRT1- and SIRT6-mediated Nrf2 activation regulates oxidative stress, inflammation and apoptosis. The absence of Nrf2 exacerbates CDDP-induced renal damage, and the pharmacological activation of Nrf2 may represent a novel therapy to prevent kidney injury.
    Keywords:  Isoorientin; Nrf2; cisplatin; nephrotoxicity; oxidative stress