bims-noxint Biomed News
on NADPH oxidases in tumorigenesis
Issue of 2019‒05‒05
eleven papers selected by
Laia Caja Puigsubira
Uppsala University

  1. Oxid Med Cell Longev. 2019 ;2019 9192413
    Bai SC, Xu Q, Li H, Qin YF, Song LC, Wang CG, Cui WH, Zheng Z, Yan DW, Li ZJ, Li D, Wan X, Zhang HF.
      Oxidative stress induced by long-term glucocorticoid (GC) use weakens the repair capacity of bone tissue. Nicotinamide adenine dinucleotide phosphate, reduced form (NADPH) oxidase (NOX) is a superoxide-generating enzyme that plays an important role in regulating bone metabolism. To clarify the role of nonphagocytic NOX isoforms in osteoblast reactive oxygen species (ROS) generation and apoptosis, dexamethasone was used to establish a high-dose GC environment in vitro. A dose-dependent increase in intracellular ROS generation was demonstrated, which was accompanied by increased osteoblastic MC3T3-E1 cell apoptosis. Addition of the ROS inhibitor NAC (N-acetyl-L-cysteine) or NOX inhibitor DPI (diphenyleneiodonium) reversed this effect, indicating that NOX-derived ROS can induce osteoblast apoptosis under high-dose dexamethasone stimulation. NOX1, NOX2, and NOX4 are NOX homologs recently identified in bone tissue. To clarify the NOX isoforms that play a role in osteoblast ROS generation, Nox1, Nox2, and Nox4 mRNA expression and NOX2 and NOX4 protein expression were analyzed. Nox1 and Nox4 mRNA expression was elevated in a dose-dependent manner after culture in 100 nM, 250 nM, 500 nM, or 1000 nM dexamethasone, and the increased expression of NOX1 mRNA was more significant compared with NOX4 mRNA. Small interfering RNAs (siRNAs) were used to confirm the role of NOX1 and NOX4 in ROS generation. To clarify the signaling pathway in ROS-induced osteoblast apoptosis, mitogen-activated protein kinase (MAPK) signaling molecules were analyzed. Phosphorylated ASK1 and p38 levels were significantly higher in the 1000 nM dexamethasone group, which NAC or DPI markedly attenuated. However, the total mRNA and protein levels of ASK1 and p38 between the dexamethasone group and control were not significantly different. This is related to ROS regulating the posttranslational modification of ASK1 and p38 in MC3T3-E1 cell apoptosis. Altogether, NOX1- and NOX4-derived ROS plays a pivotal role in high-dose dexamethasone-induced preosteoblast apoptosis by increasing phosphorylated ASK1 and p38 and may be an important mechanism in steroid-induced avascular necrosis of the femoral head (SANFH).
  2. Biochem Biophys Res Commun. 2019 Apr 25. pii: S0006-291X(19)30778-8. [Epub ahead of print]
    Tang Y, Huang Q, Liu C, Ou H, Huang D, Peng F, Liu C, Mo Z.
      NADPH oxidase (Nox) is the main source of reactive oxygen species in vascular diseases, which have been implicated in promoting VSMCs phenotypic switch. P22phox, the indispensable component of the complex Nox, is required for their activity and stability. Krüppel-like factor 4 (KLF4) is an important transcriptional regulator of VSMCs phenotypic switch. Both KLF4 and p22phox are involved in the proliferation, migration and differentiation of VSMC. This study aims to determine whether and how p22phox regulates KLF4 expression in phenotypic switching of VSMCs. In cultured primary rat VSMCs, we noticed that the expression of P22phox was significantly increased in combination with VSMCs phenotypic switch and up-regulated KLF4 expression in Ang-II-treated cells. Ang-II-induced VSMC dedifferentiation, proliferation, migration, KLF4 expression, H2O2 production and the phosphorylation of AKT, ERK1/2 were all inhibited by knockdown of P22phox. Furthermore, H2O2 treatment effectively enhanced the phosphorylation of AKT, ERK1/2 and the expression of KLF4, whereas LY294002 (a specific inhibitor of PI3K), U0126 (a specific inhibitor of ERK1/2) significantly attenuated the H2O2-induced up-regulation of KLF4. In conclusion, these results demonstrated that p22phox promotes Ang-II-induced VSMC phenotypic switch via the H2O2-ERK1/2/AKT-KLF4 signaling pathway.
    Keywords:  Ang-II; KLF4; Reactive oxygen species; VSMC phenotypic switch; p22phox
  3. J Cell Physiol. 2019 Apr 30.
    Chen P, Miao Y, Yan P, Wang XJ, Jiang C, Lei Y.
      Diabetic retinopathy (DR) remains the leading cause of blindness in adults with diabetes mellitus. Numerous microRNAs (miRNAs) have been identified to modulate the pathogenesis of DR. The main purpose of this study was to evaluate the potential roles of miR-455-5p in high glucose (HG)-treated retinal pigment epithelial (RPE) cells and underlying mechanisms. Our present investigation discovered that the expression of miR-455-5p was apparently downregulated in ARPE-19 cells stimulated with HG. In addition, forced expression of miR-455-5p markedly enhanced cell viability and restrained HG-induced apoptosis accompanied by decreased BCL2-associated X protein (Bax)/B-cell leukemia/lymphoma 2 (Bcl-2) ratio and expression of apoptotic marker cleaved caspase-3 during HG challenged. Subsequently, augmentation of miR-455-5p remarkably alleviated HG-triggered oxidative stress injury as reflected by decreased the production of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) content as well as NADPH oxidase 4 expression, concomitant with enhanced the activities of superoxide dismutase, catalase, and GPX stimulated with HG. Furthermore, enforced expression of miR-455-5p effectively ameliorated HG-stimulated inflammatory response as exemplified by repressing the secretion of inflammatory cytokines interleukin 1β (IL-1β), IL-6, and tumour necrosis factor-α in ARPE-19 cells challenged by HG. Most importantly, we successfully identified suppressor of cytokine signaling 3 (SOCS3) as a direct target gene of miR-455-5p, and miR-455-5p negatively regulated the expression of SOCS3. Mechanistically, restoration of SOCS3 abrogated the beneficial effects of miR-455-5p on apoptosis, accumulation of ROS, and inflammatory factors production in response to HG. Taken together, these findings demonstrated that miR-455-5p relieved HG-induced damage through repressing apoptosis, oxidant stress, and inflammatory response by targeting SOCS3. The study gives evidence that miR-455-5p may serve as a new potential therapeutic agent for DR treatment.
    Keywords:  MiR-455-5p; SOCS3; apoptosis; diabetic retinopathy; inflammatory response; oxidative stress
  4. Eur J Pharmacol. 2019 Apr 29. pii: S0014-2999(19)30286-9. [Epub ahead of print]
    Sampaio TL, de Menezes RRPPB, Lima DB, Costa Silva RA, de Azevedo IEP, Magalhães EP, Marinho MM, Dos Santos RP, Costa Martins AM.
      Acute Kidney Injury (AKI) is associated with high morbidity and mortality. Ischemia and reperfusion (I/R) are events that lead to AKI through hypoxia, reactive oxygen species (ROS) production, oxidative stress and apoptosis. We aimed to evaluate the mechanism of nephroprotection mediated by Bisabolol in human tubular kidney cells after injury by I/R in vitro. HK2 cells were exposed to I/R and treated with Bisabolol. Cell viability was accessed by MTT assay. Cells were submitted to flow cytometry to evaluate necrotic/apoptotic cells, reactive oxygen species production and mitochondrial transmembrane depolarization. TBARS and GSH were used as parameters of redox balance. Also, KIM-1 supernatant levels were measured. In order to identify an interaction between bisabolol and NOX4, molecular docking and enzymatic assays were performed. Expression of isoform NOX4 on treated cells was examined by western-blot. Finally, cells were visualized by scanning electron microscopy. Bisabolol improved cell viability and prevented cell death by apoptosis, indicated also by the decreased levels of KIM-1. It was observed a decrease on reactive oxygen species production and mitochondrial depolarization, with antioxidant regulation by increased GSH and decreased lipid peroxidation. It was also demonstrated that bisabolol treatment can inhibit NOX4. Finally, SEM images showed that bisabolol reduced I/R-induced cell damage. Bisabolol treatment protects HK2 cells against oxidative damage occasioned by I/R. This effect is related to inhibition of apoptosis, decrease on KIM-1 release, reactive oxygen species accumulation and mitochondrial dysfunction. Bisabolol inhibited NOX4 activity in the tubular cells, impairing reactive oxygen species synthesis.
    Keywords:  Bisabolol; Kidney ischemia/reoxygenation; NADPH oxidase
  5. J Exp Med. 2019 May 03. pii: jem.20181616. [Epub ahead of print]
    Tiwari P, Blank A, Cui C, Schoenfelt KQ, Zhou G, Xu Y, Khramtsova G, Olopade F, Shah AM, Khan SA, Rosner MR, Becker L.
      Obesity is associated with increased incidence and severity of triple-negative breast cancer (TNBC); however, mechanisms underlying this relationship are incompletely understood. Here, we show that obesity reprograms mammary adipose tissue macrophages to a pro-inflammatory metabolically activated phenotype (MMe) that alters the niche to support tumor formation. Unlike pro-inflammatory M1 macrophages that antagonize tumorigenesis, MMe macrophages are pro-tumorigenic and represent the dominant macrophage phenotype in mammary adipose tissue of obese humans and mice. MMe macrophages release IL-6 in an NADPH oxidase 2 (NOX2)-dependent manner, which signals through glycoprotein 130 (GP130) on TNBC cells to promote stem-like properties including tumor formation. Deleting Nox2 in myeloid cells or depleting GP130 in TNBC cells attenuates obesity-augmented TNBC stemness. Moreover, weight loss reverses the effects of obesity on MMe macrophage inflammation and TNBC tumor formation. Our studies implicate MMe macrophage accumulation in mammary adipose tissue as a mechanism for promoting TNBC stemness and tumorigenesis during obesity.
  6. Am J Physiol Lung Cell Mol Physiol. 2019 May 01.
    Chatterjee S, Tao JQ, Johncola A, Guo W, Caporale A, Langham MC, Wehrli FW.
      The effects of e-cigarette (e-cig) aerosol inhalation by nonsmokers have not been examined to date. The present study was designed to evaluate the acute response to aerosol inhalation of non nicotinized e-cigarettes in terms of oxidative stress and indices of endothelial activation in human pulmonary microvascular endothelial cells (HPMVEC). Ten smoking-naïve healthy subjects (mean age ± SD = 28.7± 5.5 years) were subjected to an e-cig challenge following which their serum was monitored for markers of inflammation [C-reactive protein (CRP) and soluble intercellular adhesion molecule (sICAM)] and nitric oxide metabolites (NOx). The oxidative stress and inflammation burden of the circulating serum on the vascular network was also assessed by measuring reactive oxygen species (ROS) production and induction of ICAM-1 expression on HPMVEC. Our results show that serum indices of oxidative stress and inflammation increased significantly (p<0.05 as compared to baseline), reaching a peak at approximately 1-2 h post e-cig aerosol inhalation, and returning to baseline levels at 6 h. The circulatory burden of the serum (ICAM-1 and ROS) increased significantly at 2 h and returned to baseline values 6 h post e-cig challenge. ROS production by HPMVEC was found to occur via activation of the NADPH oxidase 2 (NOX2) pathways. These findings suggest that in the absence of nicotine, acute e-cig aerosol inhalation leads to a transient increase in oxidative stress and inflammation. This can adversely affect the vascular endothelial network by promoting oxidative stress and immune cell adhesion. E-cig inhalation can potentially drive the onset of vascular pathologies.
    Keywords:  e-cigarette; inflammation; oxidative stress; pulmonary endothelial activation; reactive oxygen species
  7. Curr Opin Struct Biol. 2019 Apr 30. pii: S0959-440X(18)30180-5. [Epub ahead of print]59 91-97
    Magnani F, Mattevi A.
      NADPH oxidases (NOXs) are integral membrane enzymes that produce reactive oxygen species. Humans have seven NOX enzymes that feature a very similar catalytic core but distinct regulatory mechanisms. The recent structural elucidation of the NOX catalytic domains has been a step forward in the field. NADPH, FAD, and two hemes form a linear array of redox cofactors that transfer electrons across to the two sides of the membrane. Oxygen is reduced through an unusual outer sphere mechanism that does not involve any covalent intermediate with the heme iron. Several recent studies have expanded the roles of NOXs in cell signaling, innate immune response, and cell proliferation including oncogenic transformation. This work reinforces NOX-generated ROS as powerful signaling molecules. A challenging question is to understand the specific mechanisms of enzyme regulation and to harness the growing insight on NOXs' structure and biochemistry to generate more powerful small-molecule modulators of NOX activities.
  8. Oxid Med Cell Longev. 2019 ;2019 4546975
    Cao X, Yu S, Wang Y, Yang M, Xiong J, Yuan H, Dong B.
      Alcoholic cardiomyopathy (ACM) caused by alcohol consumption manifests mainly as by maladaptive myocardial function, which eventually leads to heart failure and causes serious public health problems. The (pro)renin receptor (PRR) is an important member of the local tissue renin-angiotensin system and plays a vital role in many cardiovascular diseases. However, the mechanism responsible for the effects of PRR on ACM remains unclear. The purpose of this study was to determine the role of PRR in myocardial fibrosis and the deterioration of cardiac function in alcoholic cardiomyopathy. Wistar rats were fed a liquid diet containing 9% v/v alcohol to establish an alcoholic cardiomyopathy model. Eight weeks later, rats were injected with 1 × 109v.g./100 μl of recombinant adenovirus containing EGFP (scramble-shRNA), PRR, and PRR-shRNA via the tail vein. Cardiac function was assessed by echocardiography. Cardiac histopathology was measured by Masson's trichrome staining, immunohistochemical staining, and dihydroethidium staining. In addition, cardiac fibroblasts (CFs) were cultured to evaluate the effects of alcohol stimulation on the production of the extracellular matrix and their underlying mechanisms. Our results indicated that overexpression of PRR in rats with alcoholic cardiomyopathy exacerbates myocardial oxidative stress and myocardial fibrosis. Silencing of PRR expression with short hairpin RNA (shRNA) technology reversed the myocardial damage mediated by PRR. Additionally, PRR activated phosphorylation of ERK1/2 and increased NOX4-derived reactive oxygen species and collagen expression in CFs with alcohol stimulation. Administration of the ERK kinase inhibitor (PD98059) significantly reduced NOX4 protein expression and collagen production, which indicated that PRR increases collagen production primarily through the PRR-ERK1/2-NOX4 pathway in CFs. In conclusion, our study demonstrated that PRR induces myocardial fibrosis and deteriorates cardiac function through ROS from the PRR-ERK1/2-NOX4 pathway during ACM development.
  9. Cardiovasc Toxicol. 2019 Apr 29.
    Zhang DD, Liang YF, Qi J, Kang KB, Yu XJ, Gao HL, Liu KL, Chen YM, Shi XL, Xin GR, Fu LY, Kang YM, Cui W.
      Carbon monoxide (CO) presents anti-inflammatory and antioxidant activities as a new gaseous neuromessenger produced by heme oxygenase-1 (HO-1) in the body. High salt-induced hypertension is relevant to the levels of pro-inflammatory cytokines (PICs) and oxidative stress in the hypothalamic paraventricular nucleus (PVN). We explored whether CO in PVN can attenuate high salt-induced hypertension by regulating PICs or oxidative stress. Male Dahl Salt-Sensitive rats were fed high-salt (8% NaCl) or normal-salt (0.3% NaCl) diet for 4 weeks. CORM-2, ZnPP IX, or vehicle was microinjected into bilateral PVN for 6 weeks. High-salt diet increased the levels of MAP, plasma norepinephrine (NE), reactive oxygen species (ROS), and the expressions of COX2, IL-1β, IL-6, NOX2, and NOX4 significantly in PVN (p < 0.05), but decreased the expressions of HO-1 and Cu/Zn-SOD in PVN (p < 0.05). Salt increased sympathetic activity as measured by circulating norepinephrine, and increased the ratio of basal RSNA to max RSNA, in part by decreasing max RSNA. PVN microinjection of CORM-2 decreased the levels of MAP, NE, RSNA, ROS and the expressions of COX2, IL-1β, IL-6, NOX2, NOX4 significantly in PVN of hypertensive rat (p < 0.05), but increased the expressions of HO-1 and Cu/Zn-SOD significantly (p < 0.05), which were all opposite to the effects of ZnPP IX microinjected in PVN (p < 0.05). We concluded that exogenous or endogenous CO attenuates high salt-induced hypertension by regulating PICs and oxidative stress in PVN.
    Keywords:  Carbon monoxide; High salt-induced hypertension; Hypothalamic paraventricular nucleus (PVN); Oxidative stress; Pro-inflammatory cytokines (PICs)
  10. Free Radic Biol Med. 2019 Apr 25. pii: S0891-5849(19)30257-6. [Epub ahead of print]
    Tumova S, Kerimi A, Williamson G.
      Endothelial functionality profoundly contributes to cardiovascular health. The effects of flavonoids shown to improve endothelial performance include regulating blood pressure by modulating endothelial nitric oxide synthase and NADPH oxidases, but their impact on glucose uptake and metabolism has not been explored. We treated human umbilical vein endothelial cells (HUVEC) with the flavonoid quercetin and its circulating metabolites acutely and chronically, then assessed glucose uptake, glucose metabolism, gene transcription and protein expression. Acute treatment had no effect on glucose uptake, ruling out any direct interaction with sugar transporters. Long term treatment with quercetin, but not quercetin 3-O-glucuronide or 3'-O-sulfate, significantly increased glucose uptake. Heme oxygenase-1 (HO-1) was induced by quercetin but not its conjugates, but was not implicated in the glucose uptake stimulation since hemin, a classical inducer of HO-1, did not affect glucose metabolism. Quercetin increased stability of the transcription factor hypoxia induced factor 1 α (HIF1α), a powerful stimulant of glucose metabolism, which was also paralleled by treatment with a prolyl-4-hydroxylase inhibitor dimethyloxalylglycine (DMOG). 6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), which regulates the rate of glycolysis, was upregulated by both quercetin and DMOG. Pyruvate dehydrogenase kinase (PDK) isoforms regulate pyruvate dehydrogenase; PDK2 and PDK4 was down-regulated by both effectors, but only DMOG also upregulated PDK1 and PDK3. Quercetin, but not DMOG, increased glucose-6-phosphate dehydrogenase. Chronic quercetin treatment also stimulated glucose transport across the HUVEC monolyer in a 3D culture model. Gene expression of several flavonoid transporters was repressed by quercetin, but this was either abolished (Organic anion transporter polypeptide 4C1) or reversed (Multidrug resistance gene 1) by both conjugates. We conclude that quercetin and its circulating metabolites differentially modulate glucose uptake/metabolism in endothelial cells, through effects on HIF1α and transcriptional regulation of energy metabolism.
  11. Clin Rheumatol. 2019 Apr 27.
    El-Ghoneimy DH, Hesham M, Hasan R, Tarif M, Gouda S.
      OBJECTIVES: To evaluate the neutrophil extracellular traps (NETs) assay and NADPH oxidase (Nox2) activity in pediatric systemic lupus erythematosus (pSLE) in relation to each other and SLE characteristics.METHODS: This cross-sectional study included 50 children and adolescents with pSLE who were clinically evaluated and underwent routine laboratory work up of SLE (CBC, ESR, 24 hrs urinary proteins, serum creatinine, complement-3 (C3), anti-dsDNA, and antiphospholipid antibodies). NETs assay and dihydrorhodamine (DHR) test were done for patient group and 50 age- and sex-matched control group.
    RESULTS: The level of NETs was found significantly elevated among the patients (median 74.6 mU/ml) as compared to the controls (median 8.9 mU/ml) (p < 0.001), while values of DHR test were comparable between patients (median 95.5%) and controls (median 96.1%) (P = 0.55). There was a significant negative correlation between levels of NETs and DHR (p < 0.001). A significant positive correlation was noted between the 24 hrs urinary protein and NETs level (p < 0.001), but a significant negative correlation with DHR (p < 0.0001). Both NETs and DHR test values did not differ significantly between classes of lupus nephritis. NETs showed a significant positive correlation with anti-dsDNA titer (p = 0.004) and SLEDAI (p < 0.001), but a negative correlation with C3 (p < 0.001). DHR test was positively correlated with C3 levels (p = 0.003), but negatively correlated with anti-dsDNA titers (p = 0.008) and SLEDAI (p < 0.001).
    CONCLUSION: NETs seem to have strong association with biomarkers of pSLE activity. On the other hand, Nox2 activity of the neutrophils was noted to be linked to quiescent state of SLE.
    KEY POINTS: • Neutrophils have displayed different actions in pSLE through the NETs and Nox2 activity. • The inverse correlation between NETs and Nox2 activity makes the later a non-fundamental pathway for NETs formation. • NETs are associated with pSLE flare and LN activity, while neutrophil Nox2 activity is related to disease remission.
    Keywords:  Dihydrorhodamine flow cytometry; NETosis; Neutrophil Nox2 activity; Neutrophil extracellular traps (NETs); Pediatric systemic lupus erythematosus