bims-noxint Biomed News
on NADPH oxidases in tumorigenesis
Issue of 2020–02–23
eight papers selected by
Laia Caja Puigsubira, Uppsala University



  1. Mediators Inflamm. 2019 ;2019 3153240
      Higher concentrations of reactive oxygen species (ROS) have been associated with epithelial cell damage, cell shedding, and airway hyperresponsiveness. Previous studies have indicated that transforming growth factor-beta (TGF-β) mediates ROS production and NADPH oxidase (NOX) activity. In our previous study, we also observed that TGF-β3 increases mucus secretion in airway epithelial cells in an autophagy-dependent fashion. Although it is well known that the relationship between ROS and autophagy is cell context-dependent, the exact mechanism of action remains unclear. The following study examined whether ROS act as upstream of autophagy activation in response to TGF-β3 induction. Using an allergic inflammation mouse model induced by house dust mite (HDM), we observed elevated lung amounts of TGF-β3 accompanied by increased ROS levels. And we found that ROS levels were elevated and NOX4 expression was increased in TGF-β3-induced epithelial cells, while the lack of NOX4 in the epithelial cells could reduce ROS generation and autophagy-dependent MUC5AC expression treated with TGF-β3. Furthermore, our studies demonstrated that the Smad2/3 pathway was involved in TGF-β3-induced ROS generation by promoting NOX4 expression. The inhibition of ROS generation by N-Acetyl-L-cysteine (NAC) resulted in a decrease in mucus expression and autophagy activity in vivo as well as in vitro. Finally, TGF-β3-neutralizing antibody significantly reduced the ROS generation, mucus expression, and autophagy activity and also decreased the phosphorylation of Smad2 and Smad3. Taken together, the obtained results revealed that persistent TGF-β3 activation increased ROS levels in a NOX4-dependent pathway and subsequently induced autophagy as well as MUC5AC expression in the epithelial cells.
    DOI:  https://doi.org/10.1155/2019/3153240
  2. Cancer Immunol Res. 2020 Feb 19. pii: canimm.0507.2019. [Epub ahead of print]
      Cancer-associated fibroblasts (CAFs) represent a functionally heterogenous population of activated fibroblasts that constitutes a major component of tumor stroma. Although CAFs have been shown to promote tumor growth and mediate resistance to chemotherapy, the mechanisms by which they may contribute to immune suppression within the tumor microenvironment (TME) in lung squamous cell carcinoma (LSCC) remain largely unexplored. Here, we identified a positive correlation between CAF and monocytic myeloid cell abundances in 501 primary LSCCs by mining TCGA datasets. We further validated this finding in an independent cohort using imaging mass cytometry and found a significant spatial interaction between CAFs and monocytic myeloid cells in the TME. To delineate the interplay between CAFs and monocytic myeloid cells, we used chemotaxis assays to show that LSCC patient-derived CAFs promoted recruitment of CCR2+ monocytes via CCL2, which could be reversed by CCR2 inhibition. Using a three-dimensional culture system, we found that CAFs polarized monocytes to adopt a myeloid-derived suppressor cell (MDSC) phenotype, characterized by robust suppression of autologous CD8+ T-cell proliferation and IFNγ production. We further demonstrated that inhibiting IDO1 and NADPH oxidases, NOX2 and NOX4, restored CD8+ T-cell proliferation by reducing reactive oxygen species (ROS) generation in CAF-induced MDSCs. Taken together, our study highlights a pivotal role of CAFs in regulating monocyte recruitment and differentiation and demonstrated that CCR2 inhibition and ROS scavenging abrogate the CAF-MDSC axis, illuminating a potential therapeutic path to reversing the CAF-mediated immunosuppressive microenvironment.
    DOI:  https://doi.org/10.1158/2326-6066.CIR-19-0507
  3. Neurochem Res. 2020 Feb 18.
      Traumatic brain injury (TBI) has become a leading cause of death and disability all over the world. Pharmacological suppression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) can inhibit oxidative stress which is implicated in the pathology of TBI. GSK2795039 was reported to target NOX2 to inhibit [Formula: see text] and ROS production. The present study aimed to investigate the effect of GSK2795039 on NOX2 activity and neurological deficits in a TBI mouse model. TBI mouse model was established by a weight-drop to mouse skull. GSK2795039 at a dose of 100 mg/kg was administrated to mice 30 min before TBI. NOX2 expression and activity were detected by Western blot and biochemical method. Neurological damage and apoptosis were detected by behavioral test and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. GSK2795039 significantly inhibited NOX2 expression and activity in the TBI mouse model. It also attenuated TBI-induced neurological deficits, apoptosis, and neurological recovery. The results indicate that GSK2795039 can be used as a potential drug for TBI treatment.
    Keywords:  Apoptosis; GSK2795039; NOX2 inhibitor; Neurological deficits; Traumatic brain injury
    DOI:  https://doi.org/10.1007/s11064-020-02987-3
  4. Arch Biochem Biophys. 2020 Feb 17. pii: S0003-9861(19)30874-4. [Epub ahead of print] 108306
      Maternal endotoxemia has been shown to increase renal collagen deposition in the offspring. Renal fibrosis is a hallmark of progressive chronic kidney disease. It was investigated whether maternal reactive oxygen species (ROS) leads to renal fibrosis or exacerbates unilateral ureteral obstruction (UUO)-induced renal fibrosis in the offspring of dams treated with lipopolysaccharide (LPS). Furthermore, it was studied the role of matrix metalloproteinases (MMPs) in these changes. Adults Wistar rats were obtained from dams submitted to LPS administration through the third part of gestation. To evaluate the role of maternal ROS, part of the dams received α-tocopherol simultaneously with LPS. Part of the offspring in each group was submitted to UUO at adulthood when sub-groups were treated with NADPH oxidase inhibitor, apocynin. Maternal LPS administration increased proteinuria, systolic arterial pressure and renal collagen deposition in adult offspring. LPS offspring rats also presented higher MMP-2 activity in parallel to a decreased renal cortical TIMP-2 content. These changes were correlated to increased amounts of TGF-β1 and NOX2. Maternal α-tocopherol treatment prevented collagen deposition and reduced arterial pressure in adult offspring. α-Tocopherol also inhibited maternal endotoxemia-induced changes in TGF-β1/NOX2/MMP-2 signaling. UUO led to increased collagen deposition in the contralateral kidneys of LPS offspring, which was correlated to increased NADPH oxidase activity and prevented by NADPH oxidase inhibition. In summary, maternal endotoxemia led to alterations in the TGF-β1/NOX2/MMP-2 signaling pathway in renal tissue concomitant with collagen deposition, therefore contributing to hypertension in adult offspring.
    Keywords:  Maternal endotoxemia; Matrix metalloproteinases; NADPH oxidase; Reactive oxygen species; Renal fibrosis
    DOI:  https://doi.org/10.1016/j.abb.2020.108306
  5. Polymers (Basel). 2020 Feb 13. pii: E443. [Epub ahead of print]12(2):
      Osteoarthritis (OA) is the most common joint disorder that has had an increasing prevalence due to the aging of the population. Recent studies have concluded that OA progression is related to oxidative stress and reactive oxygen species (ROS). ROS are produced at low levels in articular chondrocytes, mainly by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and ROS production and oxidative stress have been found to be elevated in patients with OA. The cartilage of OA-affected rat exhibits a significant induction of p47phox, a cytosolic subunit of the NADPH oxidase, similarly to human osteoarthritis cartilage. Therefore, this study tested whether siRNA p47phox that is introduced with poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (p47phox si_NPs) can alleviate chondrocyte cell death by reducing ROS production. Here, we confirm that p47phox si_NPs significantly attenuated oxidative stress and decreased cartilage damage in mono-iodoacetate (MIA)-induced OA. In conclusion, these data suggest that p47phox si_NPs may be of therapeutic value in the treatment of osteoarthritis.
    Keywords:  PLGA nanoparticles; monosodium iodoacetate; osteoarthritis; p47phox; reactive oxygen species
    DOI:  https://doi.org/10.3390/polym12020443
  6. Biomolecules. 2020 Feb 17. pii: E320. [Epub ahead of print]10(2):
      Reactive oxygen species (ROS) are byproducts of aerobic respiration and signaling molecules that control various cellular functions. Nrf2 governs the gene expression of endogenous antioxidant synthesis and ROS-eliminating enzymes in response to various electrophilic compounds that inactivate the negative regulator Keap1. Accumulating evidence has shown that mitochondrial ROS (mtROS) activate Nrf2, often mediated by certain protein kinases, and induce the expression of antioxidant genes and genes involved in mitochondrial quality/quantity control. Mild physiological stress, such as caloric restriction and exercise, elicits beneficial effects through a process known as "mitohormesis." Exercise induces NOX4 expression in the heart, which activates Nrf2 and increases endurance capacity. Mice transiently depleted of SOD2 or overexpressing skeletal muscle-specific UCP1 exhibit Nrf2-mediated antioxidant gene expression and PGC1α-mediated mitochondrial biogenesis. ATF4 activation may induce a transcriptional program that enhances NADPH synthesis in the mitochondria and might cooperate with the Nrf2 antioxidant system. In response to severe oxidative stress, Nrf2 induces Klf9 expression, which represses mtROS-eliminating enzymes to enhance cell death. Nrf2 is inactivated in certain pathological conditions, such as diabetes, but Keap1 down-regulation or mtROS elimination rescues Nrf2 expression and improves the pathology. These reports aid us in understanding the roles of Nrf2 in pathophysiological alterations involving mtROS.
    Keywords:  ATF4; Keap1; Klf9; Nrf2; PGC1α; Sirt6; mitochondrial ROS
    DOI:  https://doi.org/10.3390/biom10020320
  7. Circ Res. 2020 Feb 17.
      Rationale: Despite increasing understanding of the prognostic importance of vascular stiffening linked to perivascular fibrosis in hypertension, the molecular and cellular regulation of this process is poorly understood. Objective: To study the functional role of microRNA-214 (miR-214) in the induction of perivascular fibrosis and endothelial dysfunction driving vascular stiffening. Methods and Results: Out of 381 miRs screened in the perivascular tissues (PVAT) in response to angiotensin II (Ang II)-mediated hypertension, miR-214 showed the highest induction (8-fold, p=0.0001). MiR-214 induction was pronounced in perivascular and circulating T cells, but not in PVAT adipocytes. Global deletion of miR-214-/- prevented Ang II-induced periaortic fibrosis Col1a1, Col3a1, Col5a1 and Tgfb1 expression, hydroxyproline accumulation and vascular stiffening, without difference in blood pressure. Mechanistic studies revealed that miR-214-/- mice were protected against endothelial dysfunction, oxidative stress and increased Nox2, all of which were induced by Ang II in WT mice. Ang II-induced recruitment of T cells into PVAT was abolished in miR-214-/- mice. Adoptive transfer of miR-214-/- T cells into RAG1-/- mice resulted in reduced perivascular fibrosis compared to the effect of WT T cells. Ang II induced hypertension caused significant change in the expression of 1380 T cell genes in WT, but only 51 in miR-214-/-. T cell activation, proliferation and chemotaxis pathways were differentially affected. miR-214-/- prevented Ang II-induction of pro-fibrotic T cell cytokines (IL-17, TNF-alpha, IL-9 and IFN-ý)and chemokine receptors (CCR1, CCR2, CCR4, CCR5, CCR6 and CXCR3). This manifested in reduced in vitro and in vivo T cell chemotaxis resulting in attenuation of profibrotic perivascular inflammation. Translationally, we show that miR-214 is increased in plasma of hypertensive patients and is directly correlated to pulse wave velocity as a measure of vascular stiffness. Conclusions: T cell-derived miR-214 controls pathological perivascular fibrosis in hypertension mediated by T cell recruitment and local profibrotic cytokine release.
    Keywords:  T cell; collagen; inflammation; miR-214; perivascular fat
    DOI:  https://doi.org/10.1161/CIRCRESAHA.119.315428
  8. Inflamm Bowel Dis. 2020 Feb 17. pii: izaa017. [Epub ahead of print]
       BACKGROUND: Genetic defects of pediatric-onset inflammatory bowel disease (IBD) provide critical insights into molecular factors controlling intestinal homeostasis. NOX1 has been recently recognized as a major source of reactive oxygen species (ROS) in human colonic epithelial cells. Here we assessed the functional consequences of human NOX1 deficiency with respect to wound healing and epithelial migration by studying pediatric IBD patients presenting with a stop-gain mutation in NOX1.
    METHODS: Functional characterization of the NOX1 variant included ROS generation, wound healing, 2-dimensional collective chemotactic migration, single-cell planktonic migration in heterologous cell lines, and RNA scope and immunohistochemistry of paraffin-embedded patient tissue samples.
    RESULTS: Using exome sequencing, we identified a stop-gain mutation in NOX1 (c.160C>T, p.54R>*) in patients with pediatric-onset IBD. Our studies confirmed that loss-of-function of NOX1 causes abrogated ROS activity, but they also provided novel mechanistic insights into human NOX1 deficiency. Cells that were NOX1-mutant showed impaired wound healing and attenuated 2-dimensional collective chemotactic migration. High-resolution microscopy of the migrating cell edge revealed a reduced density of filopodial protrusions with altered focal adhesions in NOX1-deficient cells, accompanied by reduced phosphorylation of p190A. Assessment of single-cell planktonic migration toward an epidermal growth factor gradient showed that NOX1 deficiency is associated with altered migration dynamics with loss of directionality and altered cell-cell interactions.
    CONCLUSIONS: Our studies on pediatric-onset IBD patients with a rare sequence variant in NOX1 highlight that human NOX1 is involved in regulating wound healing by altering epithelial cytoskeletal dynamics at the leading edge and directing cell migration.
    Keywords:  IBD; NOX1; ROS; migration
    DOI:  https://doi.org/10.1093/ibd/izaa017