bims-noxint Biomed News
on NADPH oxidases in tumorigenesis
Issue of 2020–03–08
eleven papers selected by
Laia Caja Puigsubira, Uppsala University



  1. Hypertension. 2020 Mar 02. HYPERTENSIONAHA11914100
      Hypertension is a risk factor for the vascular permeability and neovascularization that threatens vision in diabetic retinopathy. Excess reactive oxygen species derived from the Nox (NADPH oxidase) isoforms, Nox1 and Nox4, contributes to vasculopathy in diabetic retinopathy; however, if Nox1/4 inhibition is beneficial in hypertensive diabetic retinopathy is unknown. Here, we determined that diabetic spontaneously hypertensive rats had exacerbated retinal vascular permeability and expression of angiogenic and inflammatory factors, compared with normotensive diabetic Wistar Kyoto rats. GKT136901, a specific dual inhibitor of Nox1 and Nox4, prevented these events in diabetic Wistar Kyoto rats and spontaneously hypertensive rats. Retinal neovascularization does not develop in diabetic rodents, and therefore, the oxygen-induced retinopathy model is used to evaluate this pathology. We previously demonstrated that Nox1/4 inhibition reduced retinal neovascularization in oxygen-induced retinopathy. However, although Nox5 is expressed in human retina, its contribution to retinopathy has not been studied in vivo, largely due to its absence from the rodent genome. We generated transgenic mice with inducible human Nox5 expressed in endothelial cells (vascular endothelial-cadherin+Nox5+mice). In vascular endothelial-cadherin+Nox5+ mice with oxygen-induced retinopathy, retinal vascular permeability and neovascularization, as well as the expression of angiogenic and inflammatory factors, were increased compared with wild-type littermates. In bovine retinal endothelial cells, which express Nox1, Nox4, and Nox5, Nox1/4 inhibition, as well as Nox5 silencing RNA, reduced the high glucose-induced upregulation of oxidative stress, angiogenic, and inflammatory factors. Collectively, these data indicate the potential of Nox1, Nox4, and Nox5 inhibition to reduce vision-threatening damage to the retinal vasculature.
    Keywords:  NADPH oxidase; diabetes mellitus; diabetic retinopathy; hypertension; rats
    DOI:  https://doi.org/10.1161/HYPERTENSIONAHA.119.14100
  2. Antioxid Redox Signal. 2020 Mar 04.
      Significance: Fibrosis is a stereotypic, multicellular tissue response to diverse types of injuries that fundamentally result from a failure of cell/tissue regeneration. This complex tissue remodeling response disrupts cellular/matrix composition and homeostatic cell-cell interactions, leading to loss of normal tissue architecture and progressive loss of organ structure/function. Fibrosis is a common feature of chronic diseases that may affect the lung, kidney, liver, and heart. Recent Advances: There is emerging evidence to support a combination of genetic, environmental, and age-related risk factors contributing to susceptibility and/or progression of fibrosis in different organ systems. A core pathway in fibrogenesis involving these organs is the induction and activation of nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes. Critical Issues: We explore current pharmaceutical approaches to targeting NOX enzymes, including repurposing of currently U.S. Food and Drug Administration (FDA)-approved drugs. Specific inhibitors of various NOX homologs will aid establishing roles of NOXs in the various organ fibroses and potential efficacy to impede/halt disease progression. Future Directions: The discovery of novel and highly specific NOX inhibitors will provide opportunities to develop NOX inhibitors for treatment of fibrotic pathologies.
    Keywords:  NADPH oxidases; aging; clinical; myofibroblasts; pharmacology; tissue repair and remodeling
    DOI:  https://doi.org/10.1089/ars.2020.8032
  3. PLoS One. 2020 ;15(3): e0229747
      Angiotensin II (Ang II) is a key contributor to glomerular disease by predominantly resulting in podocyte injury, whereas the underlying molecular mechanisms has not been fully understood. This study aimed to investigate if and how ADP-ribosylation factor 6 (Arf6), a small GTP-binding protein, involves Ang II-induced cellular injury in cultured human podocytes. Cellular injury was evaluated with caspase 3 activity, reactive oxygen species (ROS) level and TUNEL assay. Arf6 activity was measured using an Arf6-GTP Pull-Down Assay. Ang II significantly enhanced Arf6 expressions accompanied by increase of Arf6-GTP. The TUNEL-positive cells as well as activated caspase 3, NADPH oxidase 4 protein (Nox4) and ROS levels were dramatically increased in Ang II-treated podocytes, which was prevented by secinH3, an Arf6 activity inhibitor. Induction of ROS by Ang II was inhibited in podocytes with Nox4 knockdown. Ang II-induced elevation of Nox4 and ROS was prevented by Arf6 knockdown. Phpspho-Erk1/2Thr202/Tyr204 levels were upregulated remarkably following Ang II treatment, and Erk inhibitor LY3214996 significantly downregulated Nox4 expression. In addition, Ang II decreased CD2AP expression. Overexpression of CD2AP prevented Ang II-induced upregulation of Arf6-GTP. Our data demonstrated that Ang II promotes ROS production and podocytes injury through activation of Arf6-Erk1/2-Nox4 signaling. We also provided evidence that Ang II activates Arf6 by degradation of CD2AP.
    DOI:  https://doi.org/10.1371/journal.pone.0229747
  4. Antioxidants (Basel). 2020 Mar 01. pii: E204. [Epub ahead of print]9(3):
      Migration of vascular smooth muscle cells (VSMCs) is essential for vascular reconstruction in hypertension and several vascular diseases. Our recent study showed that extracellular vesicles derived from vascular adventitial fibroblasts of normal rats inhibited VSMC proliferation by delivering miR155-5p to VSMCs. It is unknown whether miR155-5p inhibits cell migration and oxidative stress in VSMCs of spontaneously hypertensive rats (SHR) and in angiotensin II (Ang II)-treated VSMCs. The purpose of this study was to determine the role of miR155-5p in VSMC migration and its underlying mechanisms. Primary VSMCs were isolated from the aortic media of Wistar-Kyoto rats (WKY) and SHR. Wound healing assay and Boyden chamber assay were used to evaluate VSMC migration. A miR155-5p mimic inhibited, and a miR155-5p inhibitor promoted the migration of VSMC of SHR but had no significant effect on the migration of VSMC of WKY. The miR155-5p mimic inhibited angiotensin-converting enzyme (ACE) mRNA and protein expression in VSMCs. It also reduced superoxide anion production, NAD(P)H oxidase (NOX) activity, as well as NOX2, interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) expression levels in VSMCs of SHR but not in VSMCs of WKY rats. Overexpression of miR155-5p inhibited VSMC migration and superoxide anion and IL-1β production in VSMCs of SHR but had no impact on exogenous Ang II-induced VSMC migration and on superoxide anion and IL-1β production in WKY rats and SHR. These results indicate that miR155-5p inhibits VSMC migration in SHR by suppressing ACE expression and its downstream production of Ang II, superoxide anion, and inflammatory factors. However, miR155-5p had no effects on exogenous Ang II-induced VSMC migration.
    Keywords:  hypertension; inflammation; microRNA; oxidative stress; vascular smooth muscle cells
    DOI:  https://doi.org/10.3390/antiox9030204
  5. Circ Res. 2020 Mar 05.
      Rationale: Diabetes mellitus (DM) is a complex, multisystem disease, affecting large populations worldwide. Chronic CaMKII activation may occur in DM and be arrhythmogenic. Diabetic hyperglycemia was shown to activate CaMKII by (1) O-linked attachment of N-acetylglucosamine (O-GlcNAc) at S280 leading to arrhythmia and (2) a reactive-oxygen species (ROS) mediated oxidation of CaMKII, that can increase post-infarction mortality. Objective: To test whether high extracellular [glucose] (Hi-Glu) promotes ventricular myocyte ROS generation and the role played by CaMKII. Methods and Results: We tested how extracellular Hi-Glu influences ROS production in adult ventricular myocytes, using H2DCFDA and genetically targeted Grx-roGFP2 redox sensors. Hi-Glu (30 mmol/L) significantly increased the rate of ROS generation, an effect prevented in myocytes pretreated with CaMKII inhibitor KN-93 or from either global or cardiac specific CaMKIIδ knockout mice. CaMKII knockout or inhibition also prevented Hi-Glu induced sarcoplasmic reticulum (SR) Ca2+ release events (Ca2+ sparks). Thus, CaMKII activation is required for Hi-Glu induced ROS generation and SR Ca leak in cardiomyocytes. To test the involvement of O-GlcNAc-CaMKII pathway, we inhibited GlcNAcylation removal by Thiamet G (Thm-G), which mimicked the Hi-Glu-induced ROS production. Conversely, inhibition of GlcNAcylation (OSMI-1) prevented ROS induction in response to either Hi-Glu or Thm-G. Moreover, in a CRSPR-based knock-in mouse in which the functional GlcNAcylation site on CaMKIIδ was ablated (S280A) neither Hi-Glu nor Thm-G induced myocyte ROS generation. So CaMKIIδ-S280 is required for the Hi-Glu-induced (and GlcNAc-dependent) ROS production. To identify the ROS source(s), we used different inhibitors of NOX2 (Gp91ds-tat peptide), NOX4 (GKT137831), mitochondrial ROS (Mito-Tempo) and NOS pathway inhibitors (L-NAME, L-NIO and L-NPA). Only NOX2 inhibition or KO prevented Hi-Glu/Thm-G induced ROS generation. Conclusions: Diabetic hyperglycemia induces acute cardiac myocyte ROS production by NOX2 that requires O-GlcNAcylation of CaMKIIδ at S280. This novel ROS induction may exacerbate pathological consequences of diabetic hyperglycemia.
    Keywords:  NOX2 complex; ROS
    DOI:  https://doi.org/10.1161/CIRCRESAHA.119.316288
  6. FEBS Lett. 2020 Mar 02.
      Reactive oxygen species participate in regulating intracellular signaling pathways. Herein, we investigated the reported opposite effects of hydrogen peroxide (H2 O2 ) on metabolic signaling mediated by activated α1 - and β-adrenoceptors (ARs) in hepatocytes. In isolated rat hepatocytes, stimulation of α1 -AR increases H2 O2 production via NADPH oxidase 2 (NOX2) activation. We find that the H2 O2 thus produced is essential for α1 -AR-mediated activation of the classical hepatic glycogenolytic, gluconeogenic and ureagenic responses. However, H2 O2 inhibits β-AR-mediated activation of these metabolic responses. We show that H2 O2 mediates its effects on α1 -AR and β-AR by permeating cells through aquaporin 8 channels and promoting Ca2+ mobilization. Thus, our findings reveal a novel NOX2- H2 O2 -aquaporin 8-Ca2+ signaling cascade acting downstream of α1 -AR in hepatocytes, which, by negatively regulating β-AR signaling, establishes negative crosstalk between the two pathways.
    Keywords:  Adrenaline; Ca2+mobilization; Epinephrine; Gluconeogenesis; Glycogenolysis; H2O2; Hepatocytes; Signaling; Ureagenesis; α1-adrenergic receptors; β-adrenergic receptors
    DOI:  https://doi.org/10.1002/1873-3468.13763
  7. Cell Metab. 2020 Mar 03. pii: S1550-4131(20)30062-0. [Epub ahead of print]31(3): 642-653.e6
      Hydrogen peroxide (H2O2) is a key redox intermediate generated within cells. Existing probes for H2O2 have not solved the problem of detection of the ultra-low concentrations of the oxidant: these reporters are not sensitive enough, or pH-dependent, or insufficiently bright, or not functional in mammalian cells, or have poor dynamic range. Here we present HyPer7, the first bright, pH-stable, ultrafast, and ultrasensitive ratiometric H2O2 probe. HyPer7 is fully functional in mammalian cells and in other higher eukaryotes. The probe consists of a circularly permuted GFP integrated into the ultrasensitive OxyR domain from Neisseria meningitidis. Using HyPer7, we were able to uncover the details of H2O2 diffusion from the mitochondrial matrix, to find a functional output of H2O2 gradients in polarized cells, and to prove the existence of H2O2 gradients in wounded tissue in vivo. Overall, HyPer7 is a probe of choice for real-time H2O2 imaging in various biological contexts.
    Keywords:  D-amino acid oxidase; H(2)O(2); H(2)O(2) gradients; HyPer7; cell migration; chemogenetics; genetically encoded probes; hydrogen peroxide; mitochondria; redox signaling
    DOI:  https://doi.org/10.1016/j.cmet.2020.02.003
  8. Redox Biol. 2020 Feb 26. pii: S2213-2317(19)31494-6. [Epub ahead of print]32 101479
      The incidence and severity of acute kidney injury (AKI) is increased yearly in diabetic patients. Although the mechanisms for this remain unclear, the prevention of AKI in diabetic nephropathy is feasible and of value. As we detected highly activation of TGF-β/Smad3 signaling in both human biopsy and mouse model of diabetic nephropathy, we hypothesized that Smad3 activation in diabetic kidneys may increase AKI sensitivity. We tested our hypothesis in vitro using TGF-β type II receptor (TGF-βRII) disrupted tubular epithelial cells (TECs) and in vivo in mice with streptozotocin (STZ)-induced diabetic nephropathy before the induction of ischemia/reperfusion (I/R) injury. We found that high glucose (HG)-cultured TECs showed increased inflammation, apoptosis and oxidative stress following hypoxia/reoxygenation (H/R) injury. Disruption of TGF-βRII attenuated cell injury induced by H/R in HG-treated TECs. Consistently, Smad3 knockdown in diabetic kidney attenuated I/R-induced AKI. Mechanistically, Smad3 binds to p53 and enhances p53 activity in cells treated with HG and H/R, which may lead to TECs apoptosis. Additionally, ChIP assay showed that Smad3 bound with the promoter region of NOX4 and induced ROS production and inflammation. In conclusion, our results demonstrate that Smad3 promotes AKI susceptibility in diabetic mice by interacting with p53 and NOX4.
    Keywords:  AKI; Diabetic nephropathy; Inflammation; Oxidative stress; Smad; TGF-β
    DOI:  https://doi.org/10.1016/j.redox.2020.101479
  9. Redox Biol. 2020 Feb 24. pii: S2213-2317(19)31589-7. [Epub ahead of print] 101476
       OBJECTIVE: Dysregulated adipokine profiles contribute to the pathogenesis of diabetic cardiovascular complications. Endothelial cell (EC) dysfunction, a common pathological alteration in cardiovascular disorders, is exaggerated in diabetes. However, it is unclear whether and how dysregulated adipokines may contribute to diabetic EC dysfunction.
    METHODS AND RESULTS: Serum C1q/TNF-Related Protein 5 (CTRP5) were determined in control/diabetes patients, and control/diabetic mice (high-fat diet, HFD). We observed for the first time that serum total CTRP5 was increased, high molecular weight (HMW) form was decreased, but the globular form (gCTRP5) was significantly increased in diabetic patients. These pathological alterations were reproduced in diabetic mice. To determine the pathological significance of increased gCTRP5 in diabetes, in vivo, ex vivo and in vitro experiments were performed. Diabetic atherosclerosis and EC dysfunction were significantly attenuated by the in vivo administration of CTRP5 neutralization antibody (CTRP5Ab). EC apoptosis was significantly increased in diabetic EC (isolated from HFD animal aorta) or high glucose high lipid (HGHL) cultured HUVECs. These pathological alterations were further potentiated by gCTRP5 and attenuated by CTRP5Ab. Pathway specific discovery-driven approach revealed that Nox1 expression was one of the signaling molecules commonly activated by HFD, HGHL, and gCTRP5. Treatment with CTRP5Ab reversed HFD-induced Nox1 upregulation. Finally, Nox1siRNA was used to determine the causative role of Nox1 in gCTRP5 induced EC apoptosis in diabetes. Results showed that gCTRP5 activated the mitochondrial apoptotic signal of EC in diabetes, which was blocked by the silencing Nox1 gene.
    CONCLUSION: We demonstrated for the first time that gCTRP5 is a novel molecule contributing to diabetic vascular EC dysfunction through Nox1-mediated mitochondrial apoptosis, suggesting that interventions blocking gCTRP5 may protect diabetic EC function, ultimately attenuate diabetic cardiovascular complications.
    Keywords:  CTRPs; Diabetes; Endothelial dysfunction; Oxidative stress
    DOI:  https://doi.org/10.1016/j.redox.2020.101476
  10. Antioxid Redox Signal. 2020 Mar 02.
      NADPH oxidases represent an original pharmacological target because they are the only enzymes whose main function is to produce reactive oxygen species. It is also a double target with the need for stimulation in chronic granulomatosis and inhibition reported in other pathologies (vascular, cancerous, neurological...). The complexity of the involvement of NADPH oxidases in pathophysiology has not yet made it possible to obtain a drug that effectively inhibits these enzymes at the clinical level. This issue of the forum aims to take stock of the obstacles and limitations to the development of these inhibitors both in their preclinical and clinical evaluation.
    DOI:  https://doi.org/10.1089/ars.2020.8069
  11. Cancer Res. 2020 Mar 02.
      Determining mechanisms of resistance to αPD-1/PD-L1 immune-checkpoint immunotherapy is key to developing new treatment strategies. Cancer-associated fibroblasts (CAF) have many tumor-promoting functions and promote immune evasion through multiple mechanisms, but as yet, no CAF-specific inhibitors are clinically available. Here we generated CAF-rich murine tumor models (TC1, MC38, and 4T1) to investigate how CAFs influence the immune microenvironment and affect response to different immunotherapy modalities [anticancer vaccination, TC1 (HPV E7 DNA vaccine), αPD-1, and MC38] and found that CAFs broadly suppressed response by specifically excluding CD8+ T cells from tumors (not CD4+ T cells or macrophages); CD8+ T-cell exclusion was similarly present in CAF-rich human tumors. RNA sequencing of CD8+ T cells from CAF-rich murine tumors and immunochemistry analysis of human tumors identified significant upregulation of CTLA-4 in the absence of other exhaustion markers; inhibiting CTLA-4 with a nondepleting antibody overcame the CD8+ T-cell exclusion effect without affecting Tregs. We then examined the potential for CAF targeting, focusing on the ROS-producing enzyme NOX4, which is upregulated by CAF in many human cancers, and compared this with TGFβ1 inhibition, a key regulator of the CAF phenotype. siRNA knockdown or pharmacologic inhibition [GKT137831 (Setanaxib)] of NOX4 "normalized" CAF to a quiescent phenotype and promoted intratumoral CD8+ T-cell infiltration, overcoming the exclusion effect; TGFβ1 inhibition could prevent, but not reverse, CAF differentiation. Finally, NOX4 inhibition restored immunotherapy response in CAF-rich tumors. These findings demonstrate that CAF-mediated immunotherapy resistance can be effectively overcome through NOX4 inhibition and could improve outcome in a broad range of cancers. SIGNIFICANCE: NOX4 is critical for maintaining the immune-suppressive CAF phenotype in tumors. Pharmacologic inhibition of NOX4 potentiates immunotherapy by overcoming CAF-mediated CD8+ T-cell exclusion. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/00/0/000/F1.large.jpg.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-19-3158