bims-noxint 2021-07-25 papers

bims-noxint

Biomed News

on NADPH oxidases in tumorigenesis

Issue of 2021–07–25
eight papers selected by
Laia Caja Puigsubira, Uppsala University

NADPH Oxidases in the Central Nervous System: regional and cellular localization and the possible link to brain diseases.
Rac-dependent Feedforward Autoactivation of NOX2 leads to Oxidative Burst.
Reactive Oxygen Species Mediate Activity-Regulated Dendritic Plasticity Through NADPH Oxidase and Aquaporin Regulation.
Lysine demethylase KDM6B regulates HIF-1α mediated systemic and cellular responses to intermittent hypoxia.
NADPH oxidase 5 has a crucial role in cellular motility of colon cancer cells.
Endothelial Nox2 Limits Systemic Inflammation and Hypotension in Endotoxemia by Controlling Expression of Toll-Like Receptor 4.
Angiotensin II Induces Differentiation of Human Neuroblastoma Cells by Increasing MAP2 and ROS Levels.
NADPH Oxidase Limits Collaborative Pattern-Recognition Receptor Signaling to Regulate Neutrophil Cytokine Production in Response to Fungal Pathogen-Associated Molecular Patterns.

Antioxid Redox Signal. 2021 Jul 23.

NADPH Oxidases in the Central Nervous System: regional and cellular localization and the possible link to brain diseases.

Jie Fang, Rui Sheng, Zheng-Hong Qin.

SIGNIFICANCE: The significant role of NADPH oxidase (Nox) in signal transduction is mediated by the production of reactive oxygen species (ROS), especially in the central nervous system (CNS). The pathogenesis of some neurologic and psychiatric diseases is regulated by ROS, which acts as a second messenger or pathogen. Recent advances: In CNS, the involvement of Nox-derived ROS has been implicated in the regulation of multiple signals, including cell survival/apoptosis, neuroinflammation, migration, differentiation, proliferation, and synaptic plasticity, as well as the integrity of the blood-brain barrier (BBB). In these processes, the intracellular signals mediated by the members of the NADPH oxidase family vary among different tissues. The present review illuminates the regions and cellular, subcellular localization of Nox isoforms in the brain, the signal transduction, and the role of NOX enzymes in pathophysiology, respectively.
CRITICAL ISSUES: Different signal transduction cascades are coupled to ROS derived from various Nox homologs with varying degrees. Therefore, a critical issue worth noting is that the varied role of the homologs of NOX enzymes in different signaling pathways and also they mediate different phenotypes in the diverse pathophysiological condition. This substantiates the effectiveness of selective Nox inhibitors in the central nervous system.
FUTURE DIRECTIONS: Further investigation to elucidate the role of various homologs of NOX enzymes in acute and chronic brain diseases and signaling mechanisms, development of more specific NOX inhibitors for the treatment of CNS disease are urgently needed.

DOI: https://doi.org/10.1089/ars.2021.0040
J Biol Chem. 2021 Jul 19. pii: S0021-9258(21)00784-5. [Epub ahead of print] 100982

Rac-dependent Feedforward Autoactivation of NOX2 leads to Oxidative Burst.

Hanh My Hoang, Hope Elizabeth Johnson, Jongyun Heo.

  NADPH oxidase 2 (NOX2) produces the superoxide anion radical (O2-), which has functions in both cell signaling and immune defense. NOX2 is a multimeric-protein complex consisting of several protein subunits including the GTPase Rac. NOX2 uniquely facilitates an oxidative burst, which is described by initially slow O2- production which increases over time. The NOX2 oxidative burst is considered critical to immune defense because it enables expedited O2- production in response to infections. However, the mechanism of the initiation and progression of this oxidative burst and its implications for regulation of NOX2 have not been clarified. In this study, we show that the NOX2 oxidative burst is a result of autoactivation of NOX2 coupled with the redox function of Rac. NOX2 autoactivation begins when active Rac triggers NOX2 activation and the subsequent production of O2-, which in turn activates redox-sensitive Rac. This activated Rac further activates NOX2, amplifying the feedforward cycle and resulting in a NOX2-mediated oxidative burst. Using mutagenesis-based kinetic and cell analyses, we show that enzymatic activation of Rac is exclusively responsible for production of the active Rac trigger that initiates NOX2 autoactivation, while redox-mediated Rac activation is the main driving force of NOX2 autoactivation and contributes to generation of ∼98% of the active NOX2 in cells. The results of this study provide insight into the regulation of NOX2 function, which could be used to develop therapeutics to control immune responses associated with dysregulated NOX2 oxidative bursts.

Keywords:  NOX1; NOX2; Rac; allostery; autoactivation; redox; superoxide

DOI:  https://doi.org/10.1016/j.jbc.2021.100982
Front Cell Neurosci. 2021 ;15 641802

Reactive Oxygen Species Mediate Activity-Regulated Dendritic Plasticity Through NADPH Oxidase and Aquaporin Regulation.

Serene Dhawan, Philip Myers, David M D Bailey, Aaron D Ostrovsky, Jan Felix Evers, Matthias Landgraf.

  Neurons utilize plasticity of dendritic arbors as part of a larger suite of adaptive plasticity mechanisms. This explicitly manifests with motoneurons in the Drosophila embryo and larva, where dendritic arbors are exclusively postsynaptic and are used as homeostatic devices, compensating for changes in synaptic input through adapting their growth and connectivity. We recently identified reactive oxygen species (ROS) as novel plasticity signals instrumental in this form of dendritic adjustment. ROS correlate with levels of neuronal activity and negatively regulate dendritic arbor size. Here, we investigated NADPH oxidases as potential sources of such activity-regulated ROS and implicate Dual Oxidase (but not Nox), which generates hydrogen peroxide extracellularly. We further show that the aquaporins Bib and Drip, but not Prip, are required for activity-regulated ROS-mediated adjustments of dendritic arbor size in motoneurons. These results suggest a model whereby neuronal activity leads to activation of the NADPH oxidase Dual Oxidase, which generates hydrogen peroxide at the extracellular face; aquaporins might then act as conduits that are necessary for these extracellular ROS to be channeled back into the cell where they negatively regulate dendritic arbor size.

Keywords:  Drosophila; NADPH oxidases; aquaporins; dendrites; plasticity; reactive oxygen species

DOI:  https://doi.org/10.3389/fncel.2021.641802
Physiol Genomics. 2021 Jul 23.

Lysine demethylase KDM6B regulates HIF-1α mediated systemic and cellular responses to intermittent hypoxia.

Jayasri Nanduri, Ning Wang, Benjamin L Wang, Nanduri R Prabhakar.

  Intermittent hypoxia (IH) is a hallmark manifestation of Obstructive Sleep Apnea (OSA). Rodents treated with IH exhibit hypertension. Hypoxia-inducible factor (HIF)-1-dependent transcriptional activation of NADPH oxidases (Nox) and the resulting increase in reactive oxygen species (ROS) levels is a major molecular mechanism underlying IH/OSA-induced hypertension. Jumanji C (JmjC)-containing histone lysine demethylases (JmjC-KDMs) are coactivators of HIF-1-dependent transcriptional activation. In the present study, we tested the hypothesis that JmjC-KDMs are required for IH-evoked HIF-1 transcriptional activation of Nox4 and the ensuing hypertension. Studies were performed on pheochromocytoma (PC)12 cells and rats. IH increased KDM6B protein and enzyme activity in PC12 cells in a HIF-1-independent manner as evidenced by unaltered KDM6B activation by IH in HIF-1α shRNA treated cells. Cells treated with IH showed increased HIF-1-dependent Nox4 transcription as indicated by increased HIF-1α binding to hypoxia responsive element (HRE) sequence of the Nox4 gene promoter demonstrated by chromatin immunoprecipitation (ChiP) assay. Pharmacological blockade of KDM6B with GSKJ4, a specific KDM6 inhibitor, or genetic silencing of KDM6B with shRNA abolished IH-induced Nox4 transcriptional activation by blocking HIF-1α binding to the promoter of the NOX4 gene. Treating IH exposed rats with GSKJ4 showed: a) absence of KDM6B activation and HIF-1-dependent Nox4 transcription in the adrenal medullae, as well as b) absence of elevated plasma catecholamines and hypertension. Collectively, these findings indicate that KDM6B functions as a coactivator of HIF-1-mediated Nox4 transactivation and demonstrate a hitherto uncharacterized role for KDM's in IH-induced hypertension by HIF-1.

Keywords:  Hypoxia inducible factor; NADPH oxidase; intermittent hypoxia; lyisne demethylases; sleep apnea

DOI:  https://doi.org/10.1152/physiolgenomics.00045.2021
Int J Oncol. 2021 Aug;pii: 63. [Epub ahead of print]59(2):

NADPH oxidase 5 has a crucial role in cellular motility of colon cancer cells.

Naoki Ashizawa, Hiroki Shimizu, Katsutoshi Shoda, Shinji Furuya, Hidenori Akaike, Naohiro Hosomura, Yoshihiko Kawaguchi, Hidetake Amemiya, Hiromichi Kawaida, Makoto Sudo, Shingo Inoue, Hiroshi Kono, Keita Katsurahara, Atsushi Shiozaki, Daisuke Ichikawa.

  NADPH oxidases (NOXs) are a family of transmembrane proteins that generate reactive oxygen species. It was previously reported that patients with colon cancer who had high NOX5 expression had poor prognosis. However, no studies have investigated the cellular functions of NOX5 in colon cancer. The present study aimed to clarify the relationship between NOX5 and cancer development using an in vitro model. Reverse transcription‑quantitative PCR was performed to determine the NOX5 expression levels of colon cancer cell lines. NOX5‑knockdown experiments were conducted, and the effect on cell proliferation, migration, and invasion were analyzed. In addition, mRNA microarray was conducted to assess changes in gene profile. NOX5 mRNA expression was high in HCT116 cells and moderate in SW48 cells. NOX5 knockdown significantly inhibited cell migration and invasion in both HCT116 and SW48 cells; however, NOX5 knockdown reduced cell proliferation in only HCT116 cells. mRNA microarrays revealed a strong relationship between NOX5 expression levels and integrin‑linked kinase signaling pathways. The NOX5 expression in colon cancer cells affected cancer progression, especially cell motility. NOX5 may be a novel therapeutic target for the future development of treatments for colon cancer.

Keywords:  ILK signaling; NOX; ROS; cellular motility; colon cancer

DOI:  https://doi.org/10.3892/ijo.2021.5243
Shock. 2021 Aug 01. 56(2): 268-277

Endothelial Nox2 Limits Systemic Inflammation and Hypotension in Endotoxemia by Controlling Expression of Toll-Like Receptor 4.

Silvia Cellone Trevelin, Can Martin Sag, Min Zhang, José Carlos Alves-Filho, Thiago Mattar Cunha, Célio Xavier Dos Santos, Greta Sawyer, Thomas Murray, Alison Brewer, Francisco Rafael Martins Laurindo, Andrea Protti, Lucia Rossetti Lopes, Aleksandar Ivetic, Fernando Queiroz Cunha, Ajay M Shah.

ABSTRACT: Leukocyte Nox2 is recognized to have a fundamental microbicidal function in sepsis but the specific role of Nox2 in endothelial cells (EC) remains poorly elucidated. Here, we tested the hypothesis that endothelial Nox2 participates in the pathogenesis of systemic inflammation and hypotension induced by LPS. LPS was injected intravenously in mice with Tie2-targeted deficiency or transgenic overexpression of Nox2. Mice with Tie2-targeted Nox2 deficiency had increased circulating levels of TNF-α, enhanced numbers of neutrophils trapped in lungs, and aggravated hypotension after LPS injection, as compared to control LPS-injected animals. In contrast, Tie2-driven Nox2 overexpression attenuated inflammation and prevented the hypotension induced by LPS. Because Tie2-Cre targets both EC and myeloid cells we generated bone marrow chimeric mice with Nox2 deletion restricted to leukocytes or ECs. Mice deficient in Nox2 either in leukocytes or ECs had reduced LPS-induced neutrophil trapping in the lungs and lower plasma TNF-α levels as compared to control LPS-injected mice. However, the pronounced hypotensive response to LPS was present only in mice with EC-specific Nox2 deletion. Experiments in vitro with human vein or aortic endothelial cells (HUVEC and HAEC, respectively) treated with LPS revealed that EC Nox2 controls NF-κB activation and the transcription of toll-like receptor 4 (TLR4), which is the recognition receptor for LPS. In conclusion, these results suggest that endothelial Nox2 limits NF-κB activation and TLR4 expression, which in turn attenuates the severity of hypotension and systemic inflammation induced by LPS.

DOI: https://doi.org/10.1097/SHK.0000000000001706
J Renin Angiotensin Aldosterone Syst. 2021 ;2021 6191417

Angiotensin II Induces Differentiation of Human Neuroblastoma Cells by Increasing MAP2 and ROS Levels.

Bryan Jael Collazo, Dariana Morales-Vázquez, Jaylene Álvarez-Del Valle, Javier E Sierra-Pagan, Juan Carlos Medina, Jarold Méndez-Álvarez, Yamil Gerena.

Introduction: The roles of angiotensin II (Ang II) in the brain are still under investigation. In this study, we investigated if Ang II influences differentiation of human neuroblastoma cells with simultaneous activation of NADPH oxidase and reactive oxygen species (ROS). Moreover, we investigated the Ang II receptor type involved during differentiation.
Methods: Human neuroblastoma cells (SH-SY5Y; 5 × 105 cells) were exposed to Ang II (600 nM) for 24 h. Differentiation was monitored by measuring MAP2 and NF-H levels. Cell size and ROS were analyzed by flow cytometry, and NADPH oxidase activation was assayed using apocynin (500 μM). Ang II receptors (ATR) activation was assayed using ATR blockers or Ang II metabolism inhibitors (10-7 M).
Results: (1) Cell size decreased significantly in Ang II-treated cells; (2) MAP2 and ROS increased significantly in Ang II-treated cells with no changes in viability; (3) MAP2 and ROS decreased significantly in cells incubated with Ang II plus apocynin. (4) A significant decrease in MAP2 was observed in cells exposed to Ang II plus PD123.319 (AT2R blocker).
Conclusion: Our findings suggest that Ang II influences differentiation of SH-SY5Y by increasing MAP2 through the AT2R. The increase in MAP2 and ROS were also mediated through NADPH oxidase with no cell death.

DOI: https://doi.org/10.1155/2021/6191417
J Immunol. 2021 Jul 23. pii: ji2001298. [Epub ahead of print]

NADPH Oxidase Limits Collaborative Pattern-Recognition Receptor Signaling to Regulate Neutrophil Cytokine Production in Response to Fungal Pathogen-Associated Molecular Patterns.

Dae-Goon Yoo, Luana C Paracatu, Evan Xu, Xin Lin, Mary C Dinauer.

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by genetic defects in leukocyte NADPH oxidase, which has both microbicidal and immunomodulatory roles. Hence, CGD is characterized by recurrent bacterial and fungal infections as well as aberrant inflammation. Fungal cell walls induce neutrophilic inflammation in CGD; yet, underlying mechanisms are incompletely understood. This study investigated the receptors and signaling pathways driving aberrant proinflammatory cytokine production in CGD neutrophils activated by fungal cell walls. Although cytokine responses to β-glucan particles were similar in NADPH oxidase-competent and NADPH oxidase-deficient mouse and human neutrophils, stimulation with zymosan, a more complex fungal particle, induced elevated cytokine production in NADPH oxidase-deficient neutrophils. The dectin-1 C-type lectin receptor, which recognizes β-glucans (1-3), and TLRs mediated cytokine responses by wild-type murine neutrophils. In the absence of NADPH oxidase, fungal pathogen-associated molecular patterns engaged additional collaborative signaling with Mac-1 and TLRs to markedly increase cytokine production. Mechanistically, this cytokine overproduction is mediated by enhanced proximal activation of tyrosine phosphatase SHP2-Syk and downstream Card9-dependent NF-κB and Card9-independent JNK-c-Jun. This activation and amplified cytokine production were significantly decreased by exogenous H2O2 treatment, enzymatic generation of exogenous H2O2, or Mac-1 blockade. Similar to zymosan, Aspergillus fumigatus conidia induced increased signaling in CGD mouse neutrophils for activation of proinflammatory cytokine production, which also used Mac-1 and was Card9 dependent. This study, to our knowledge, provides new insights into how NADPH oxidase deficiency deregulates neutrophil cytokine production in response to fungal cell walls.

DOI: https://doi.org/10.4049/jimmunol.2001298