bims-noxint Biomed News
on NADPH oxidases in tumorigenesis
Issue of 2021‒01‒31
seven papers selected by
Laia Caja Puigsubira
Uppsala University

  1. Mol Cell Biochem. 2021 Jan 30.
    Ahmad A, Nawaz MI, Siddiquei MM, Abu El-Asrar AM.
      NADPH oxidase (NOX) is a main producers of reactive oxygen species (ROS) that may contribute to the early pathogenesis of diabetic retinopathy (DR). ROS has harmful effects on endogenous neuro-survival factors brain-derived neurotrophic factor (BDNF) and sirtuin 1 (SIRT1) are necessary for the growth and survival of the retina. The role of NOX isoforms NOX4 in triggering ROS in DR is not clear. Here we determine the protective effects of a plant-derived NOX inhibitor apocynin (APO) on NOX4-induced ROS production which may contribute to the depletion of survival factors BDNF/SIRT1 or cell death in the diabetic retinas. Human retinal Müller glial cells (MGCs) were treated with hypoxia mimetic agent cobalt chloride (CoCl2) in the absence or presence of APO. Molecular analysis demonstrates that NOX4 is upregulated in CoCl2-treated MGCs and in the diabetic retinas. Increased NOX4 was accompanied by the downregulation of BDNF/SIRT1 expression or in the activation of apoptotic marker caspase-3. Whereas, APO treatment downregulates NOX4 and subsequently upregulates BDNF/SIRT1 or alleviate caspase-3 expression. Accordingly, in the diabetic retina we found a positive correlation in NOX4 vs ROS (p = 0.025; R2 = 0.488) and caspase-3 vs ROS (p = 0.04; R2 = 0.428); whereas a negative correlation in BDNF vs ROS (p = 0.009; R2 = 0.596) and SIRT1 vs ROS (p = 0.0003; R2 = 0.817) respectively. Taken together, NOX4-derived ROS could be a main contributor in downregulating BDNF/SIRT1 expression or in the activation of caspase-3. Whereas, APO treatment may minimize the deleterious effects occurring due to hyperglycemia and/or diabetic mimic hypoxic condition in early pathogenesis of DR.
    Keywords:  Apocynin (APO); Diabetic Retinopathy (DR); NADPH oxidase (NOX) 4; Neuroprotective; Reactive Oxygen Species (ROS)
  2. Redox Biol. 2020 Dec 23. pii: S2213-2317(20)31046-6. [Epub ahead of print]40 101841
    Herranz-Itúrbide M, López-Luque J, Gonzalez-Sanchez E, Caballero-Díaz D, Crosas-Molist E, Martín-Mur B, Gut M, Esteve-Codina A, Jaquet V, Jiang JX, Török NJ, Fabregat I.
      Liver is a unique organ in displaying a reparative and regenerative response after acute/chronic damage or partial hepatectomy, when all the cell types must proliferate to re-establish the liver mass. The NADPH oxidase NOX4 mediates Transforming Growth Factor-beta (TGF-β) actions, including apoptosis in hepatocytes and activation of stellate cells to myofibroblasts. Aim of this work was to analyze the impact of NOX4 in liver regeneration by using two mouse models where Nox4 was deleted: 1) general deletion of Nox4 (NOX4-/-) and 2) hepatocyte-specific deletion of Nox4 (NOX4hepKO). Liver regeneration was analyzed after 2/3 partial hepatectomy (PH). Results indicated an earlier recovery of the liver-to-body weight ratio in both NOX4-/- and NOX4hepKO mice and an increased survival, when compared to corresponding WT mice. The regenerative hepatocellular fat accumulation and the parenchyma organization recovered faster in NOX4 deleted livers. Hepatocyte proliferation, analyzed by Ki67 and phospho-Histone3 immunohistochemistry, was accelerated and increased in NOX4 deleted mice, coincident with an earlier and increased Myc expression. Primary hepatocytes isolated from NOX4 deleted mice showed higher proliferative capacity and increased expression of Myc and different cyclins in response to serum. Transcriptomic analysis through RNA-seq revealed significant changes after PH in NOX4-/- mice and support a relevant role for Myc in a node of regulation of proliferation-related genes. Interestingly, RNA-seq also revealed changes in the expression of genes related to activation of the TGF-β pathway. In fact, levels of active TGF-β1, phosphorylation of Smads and levels of its target p21 were lower at 24 h in NOX4 deleted mice. Nox4 did not appear to be essential for the termination of liver regeneration in vivo, neither for the in vitro hepatocyte response to TGF-β1 in terms of growth inhibition, which suggest its potential as therapeutic target to improve liver regeneration, without adverse effects.
    Keywords:  Hepatectomy; Liver regeneration; MYC; NADPH oxidase; NOX4; TGF-BETA
  3. Am J Respir Cell Mol Biol. 2021 Jan 29.
    Qin W, Jeffers A, Owens S, Chauhan P, Komatsu S, Qian G, Guo X, Ikebe M, Idell S, Tucker TA.
      Pleural organization may occur after empyema or complicated parapneumonic effusion and can result in restrictive lung disease with pleural fibrosis (PF). Pleural mesothelial cells; PMCs, may contribute to PF through acquisition of a profibrotic phenotype; meso-mesenchymal transition (MesoMT), which is characterized by increased expression of α-smooth muscle actin (α-SMA) and other myofibroblast markers. While MesoMT has been implicated in the pathogenesis of PF, the role of the reactive oxygen species and the NADPH oxidase family in pleural remodeling remains unclear. Here we show that NOX1 expression is enhanced in nonspecific human pleuritis. and is induced in PMCs by thrombin. 4-Hydroxynonenal (HNE), an indicator of reactive oxygen species damage, was likewise increased in our mouse model of pleural injury. NOX1 downregulation blocked thrombin- and Xa-mediated MesoMT as did pharmacological inhibition of NOX1 with ML-171. NOX1 inhibition also reduced phosphorylation of Akt, p65, and Tyrosine 216-GSK-3β, signaling molecules previously shown to be implicated in MesoMT. Conversely, ML-171 did not reverse established MesoMT. NOX4 down-regulation attenuated TGF-β- and thrombin-mediated MesoMT. However, NOX1 downregulation did not affect NOX4 expression. NOX1 and NOX4 deficient mice were also protected in our mouse model of S. pneumoniae-mediated pleural fibrosis. These data show that NOX1 and NOX4 are critical determinants of MesoMT.
    Keywords:  NADPH oxidase; pleural fibrosis; pleural mesothelial cells
  4. ESC Heart Fail. 2021 Jan 29.
    Wang M, Murdoch CE, Brewer AC, Ivetic A, Evans P, Shah AM, Zhang M.
      AIMS: Endothelial activation and inflammatory cell infiltration have important roles in the development of cardiac fibrosis induced by renin-angiotensin system activation. NADPH oxidases (Nox proteins) are expressed in endothelial cells (ECs) and alter their function. Previous studies indicated that Nox2 in ECs contributes to angiotensin II (AngII)-induced cardiac fibrosis. However, the effects of EC Nox4 on cardiac fibrosis are unknown.METHODS AND RESULTS: Transgenic (TG) mice overexpressing endothelial-restricted Nox4 were studied alongside wild-type (WT) littermates as controls. At baseline, Nox4 TG mice had significantly enlarged hearts compared with WT, with elongated cardiomyocytes (increased by 18.5%, P < 0.01) and eccentric hypertrophy but well-preserved cardiac function by echocardiography and in vivo pressure-volume analysis. Animals were subjected to a chronic AngII infusion (AngII, 1.1 mg/kg/day) for 14 days. Whereas WT/AngII developed a 2.1-fold increase in interstitial cardiac fibrosis as compared with WT/saline controls (P < 0.01), TG/AngII mice developed significant less fibrosis (1.4-fold increase, P > 0.05), but there were no differences in cardiac hypertrophy or contractile function between the two groups. TG hearts displayed significantly decreased inflammatory cell infiltration with reduced levels of vascular cell adhesion molecule 1 in both the vasculature and myocardium compared with WT after AngII treatment. TG microvascular ECs stimulated with AngII in vitro supported significantly less leukocyte adhesion than WT ECs.
    CONCLUSIONS: A chronic increase in endothelial Nox4 stimulates physiological cardiac hypertrophy and protects against AngII-induced cardiac fibrosis by inhibiting EC activation and the recruitment of inflammatory cells.
    HIGHLIGHTS: Mice with endothelium-specific overexpression of Nox4 (EndoNox4 TG) exhibit eccentric hypertrophy with well-preserved cardiac function at baseline. EndoNox4 TG mice develop significantly less interstitial cardiac fibrosis in response to chronic pressure AngII stimulation, independent of cardiac hypertrophy. Overexpression of Nox4 in endothelial cells reduces AngII-induced endothelial activation. An increase in endothelial Nox4 inhibits AngII-induced recruitment of inflammatory cells in the heart.
    Keywords:  Angiotensin II; Endothelial dysfunction; Inflammation; Myocardial fibrosis; Nox4
  5. Clin Epigenetics. 2021 Jan 26. 13(1): 18
    Li H, Peng C, Zhu C, Nie S, Qian X, Shi Z, Shi M, Liang Y, Ding X, Zhang S, Zhang B, Li X, Xu G, Lv Y, Wang L, Friess H, Kong B, Zou X, Shen S.
      BACKGROUND: Hypoxia is a characteristic of the tumor microenvironments within pancreatic cancer (PC), which has been linked to its malignancy. Recently, hypoxia has been reported to regulate the activity of important carcinogenic pathways by changing the status of histone modification. NOX4, a member of NADPH oxidase (NOX), has been found to be activated by hypoxia and promote cancer progression in several cancers. But whether it is involved in the epigenetic changes of tumor cells induced by hypoxia is still unclear, and its biological roles in PC also need to be explored.METHODS: A hypoxic-related gene signature and its associated pathways in PC were identified by analyzing the pancreatic cancer gene expression data from GEO and TCGA database. Candidate downstream gene (NOX4), responding to hypoxia, was validated by RT-PCR and western blot. Then, we evaluated the relationship between NOX4 expression and clinicopathologic parameters in 56 PC patients from our center. In vitro and in vivo assays were preformed to explore the phenotype of NOX4 in PC. Immunofluorescence, western blot and chromatin immunoprecipitation assays were further applied to search for a detailed mechanism.
    RESULTS: We quantified hypoxia and developed a hypoxia signature, which was associated with worse prognosis and elevated malignant potential in PC. Furthermore, we found that NADPH oxidase 4 (NOX4), which was induced by hypoxia and upregulated in PC in a HIF1A-independent manner, caused inactivation of lysine demethylase 5A (KDM5A), increased the methylation modification of histone H3 and regulated the transcription of EMT-associated gene_ snail family transcriptional repressor 1 (SNAIL1). This served to promote the invasion and metastasis of PC. NOX4 deficiency repressed hypoxia-induced EMT, reduced expression of H3K4ME3 and impaired the invasion and metastasis of PC cells; however, knockdown of KDM5A reversed the poor expression of H3KEME3 induced by NOX4 deficiency, thereby promoting EMT.
    CONCLUSIONS: This study highlights the prognostic role of hypoxia-related genes in PC and strong correlation with EMT pathway. Our results also creatively discovered that NOX4 was an essential mediator for hypoxia-induced histone methylation modification and EMT in PC cells.
    Keywords:  Epithelial-to-mesenchymal transition; Histone methylation modification; Hypoxia; NOX4; SNAIL1
  6. CNS Drugs. 2021 Jan 30.
    Gage MC, Thippeswamy T.
      Neurological diseases share common neuroinflammatory and oxidative stress pathways. Both phenotypic and molecular changes in microglia, astrocytes, and neurons contribute to the progression of disease and present potential targets for disease modification. Src family kinases (SFKs) are present in both neurons and glial cells and are upregulated following neurological insults in both human and animal models. In neurons, SFKs interact with post-synaptic protein domains to mediate hyperexcitability and neurotoxicity. SFKs are upstream of signaling cascades that lead to the modulation of neurotransmitter receptors and the transcription of pro-inflammatory cytokines as well as producers of free radicals through the activation of glia. Inducible nitric oxide synthase (iNOS/NOS-II) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), the major mediators of reactive nitrogen/oxygen species (RNS/ROS) production in the brain, are also upregulated along with the pro-inflammatory cytokines following neurological insult and contribute to disease progression. Persistent neuronal hyperexcitability, RNS/ROS, and cytokines can exacerbate neurodegeneration, a common pathognomonic feature of the most prevalent neurological disorders such as Alzheimer's disease, Parkinson's disease, and epilepsy. Using a wide variety of preclinical disease models, inhibitors of the SFK-iNOS-NOX2 signaling axis have been tested to cure or modify disease progression. In this review, we discuss the SFK-iNOS-NOX2 signaling pathway and their inhibitors as potential CNS targets for major neurological diseases.
  7. ACS Sens. 2021 Jan 28.
    Song X, Bai S, He N, Wang R, Xing Y, Lv C, Yu F.
      Pulmonary fibrosis is a fatal chronic lung disease, leading to poor prognosis and high mortality. Accumulating evidence suggests that oxidative stress characterized by excessive production of hydrogen peroxide (H2O2) is an important molecular mechanism causing pulmonary fibrosis. We conceive a new type of mitochondria-targeted near-infrared fluorescent probe Mito-Bor to investigate changes in the level of endogenous H2O2 in living cells and mice models with pulmonary fibrosis. In the design strategy of the Mito-Bor probe, we selected azo-BODIPY as the fluorophore owing to its near-infrared fluorescence, strong photochemical stability, and low biological toxicity. Under physiological conditions, the response moiety 4-bromomethylphenylboronic acid pinacol ester could easily detect H2O2, and turn the fluorescence switch on. The modification of the lipophilic triphenylphosphine cation on the fluorophore would allow the probe to easily pass through the phospholipid bilayer of cells, and the internal positive charge could contribute to the selectivity of the mitochondria accumulation. The Mito-Bor probe provides high selectivity, low limit of detection, high biocompatibility, and excellent photostability. It can be used to detect changes in the level of H2O2 in living cells and in vivo. Therefore, the probe is applied to investigate the fluctuation of the H2O2 level during the process of inducing pulmonary fibrosis in cells, with changes in its fluorescence intensity correlating with the concentration of H2O2 and indicating the level of oxidative stress in fibroblasts. Conversely, pulmonary fibrosis can be modulated by adjusting the level of H2O2 in cells. A further study in mice models of bleomycin-induced pulmonary fibrosis confirms that NADPH oxidase 4 (NOX4) acts as a "button" to regulate H2O2 levels. The direct inhibition of NOX4 can significantly reduce the level of H2O2, which can delay the progression of lung fibrosis. These results provide an innovative way for the clinical treatment of pulmonary fibrosis.
    Keywords:  fluorescent probes; hydrogen peroxide; in vivo imaging; near-infrared; pulmonary fibrosis