NOX2-Derived Reactive Oxygen Species in Cancer

Inhibition of SIRT4 promotes bladder cancer progression and immune escape via attenuating CD8+ T cells function

BACKGROUND

Bladder cancer (BCa) is one of the most common malignancies of the urinary system and is characterized by a high recurrence rate and significant mortality. Sirtuin 4 (SIRT4), a member of the NAD+-dependent deacetylase and ADP-ribosyltransferase family, is involved in regulating cellular metabolism, DNA repair, and longevity, potentially influencing tumor progression and immune escape. This study aimed to elucidate the role of SIRT4 in BCa.

METHODS

The correlation between the sirtuin family and immunotherapy sensitivity in BCa patients was analyzed via IMvigor210 data. The clinical significance and immunological role of SIRT4 across multiple cancer types were assessed by evaluating its associations with clinicopathologic features, prognosis, tumor mutation burden (TMB), microsatellite instability (MSI), immune cell infiltration, and immune response genes across 33 datasets from The Cancer Genome Atlas (TCGA). SIRT4 expression was confirmed in BCa tissues, and its functions were examined via proliferation and migration assays. CD8+ T cells were isolated from the peripheral blood of healthy individuals and activated with CD3 and CD28 antibodies and recombinant IL2. Coculture assays involving BCa cells and activated CD8+ T cells, alongside ELISA, were conducted to evaluate the immunological function of SIRT4.

RESULTS

SIRT4 was positively associated with the immunotherapy response of BCa patients on the basis of IMvigor210 data. Its expression was downregulated in 11 tumor types but upregulated in 3. SIRT4 was significantly correlated with tumor stage in 2 tumor types and showed varying associations with overall survival, progression-free survival, and disease-specific survival. Additionally, SIRT4 was correlated with TMB in 10 tumor types and with MSI in 8. GSEA indicated that SIRT4 was negatively associated with the immune response in 9 tumor types, excluding BCa. It was positively correlated with immune cell infiltration in 2 tumor types and negatively correlated in 6. The TCGA data revealed that SIRT4 was positively associated with activated NK cell infiltration but negatively associated with M1 macrophages, neutrophils, resting NK cells, and activated memory CD4 T cells. Enrichment analyses revealed positive correlations with various chemokines, immunoinhibitors, immunostimulators, lymphocytes, MHC molecules, and MHC receptors, suggesting that SIRT4 may enhance the immune response in BCa. Further experiments confirmed that SIRT4 was downregulated in BCa tissues compared with adjacent normal tissues. Inhibition of SIRT4 promoted BCa cell proliferation and migration, whereas knockdown of SIRT4 impaired the chemotaxis and tumor-killing ability of CD8+ T cells in the BCa tumor microenvironment.

CONCLUSIONS

In summary, SIRT4 inhibits the progression and immune escape of BCa, indicating its potential as a novel biomarker and immune checkpoint for immunotherapy.

The immunomodulatory potential of chickpea protein hydrolysate via ROS and NO pathways

The uncontrolled overproduction of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) is linked to chronic inflammation, although they are also essential signaling molecules for the immune system against infectious agents. Bioactive compounds hold promise as functional bioactive nutrients, contributing to the immunomodulatory response. This study investigates the potential of chickpea protein hydrolysate to modulate ROS/RNS stress and inflammatory responses in a cellular low-grade chronic inflammatory model. This study was focused on their effects on endogenous antioxidant enzyme activities and key pro-inflammatory markers. ROS and nitric oxide (NO) production and molecular biology techniques were used to evaluate cell metabolism. Hydrolysate exposure notably increased ROS and NO release in a dose-dependent manner, while also exhibiting significant anti-inflammatory effects by inhibiting NF-κB and NLRP3 inflammasome components in treated cells. Therefore, chickpea protein hydrolysates hold promise as functional bioactive compounds for use in therapeutic applications, promoting human health and well-being.

Signaling by neutrophil G protein-coupled receptors that regulate the release of superoxide anions

In human peripheral blood, the neutrophil granulocytes (neutrophils) are the most abundant white blood cells. These professional phagocytes are rapidly recruited from the bloodstream to inflamed tissues by chemotactic factors that signal danger. Neutrophils, which express many receptors that are members of the large family of G protein-coupled receptors (GPCRs), are critical for the elimination of pathogens and inflammatory insults, as well as for the resolution of inflammation leading to tissue repair. Danger signaling molecular patterns such as the N-formylated peptides that are formed during bacterial and mitochondrial protein synthesis and recognized by formyl peptide receptors (FPRs) and free fatty acids recognized by free fatty acid receptors (FFARs) regulate neutrophil functions. Short peptides and short-chain fatty acids activate FPR1 and FFA2R, respectively, while longer peptides and fatty acids activate FPR2 and GPR84, respectively. The activation profiles of these receptors include the release of reactive oxygen species (ROS) generated by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Activation of the oxidase and the production of ROS are processes that are regulated by proinflammatory mediators, including tumor necrosis factor α and granulocyte/macrophage colony-stimulating factor. The receptors have signaling and functional similarities, although there are also important differences, not only between the two closely related neutrophil FPRs, but also between the FPRs and the FFARs. In neutrophils, these receptors never walk alone, and additional mechanistic insights into the regulation of the GPCRs and the novel regulatory mechanisms underlying the activation of NADPH oxidase advance our understanding of the role of receptor transactivation in the regulation of inflammatory reactions.

LC3-associated phagocytosis and human diseases: Insights from mechanisms to therapeutic potential

LC3-associated phagocytosis (LAP) is a distinct type of autophagy that involves the sequestration of extracellular material by phagocytes. Beyond the removal of dead cells and cellular debris from eukaryotic cells, LAP is also involved in the removal of a variety of pathogens, including bacteria, fungi, and viruses. These events are integral to multiple physiological and pathological processes, such as host defense, inflammation, and tissue homeostasis. Dysregulation of LAP has been associated with the pathogenesis of several human diseases, including infectious diseases, autoimmune diseases, and neurodegenerative diseases. Thus, understanding the molecular mechanisms underlying LAP and its involvement in human diseases may provide new insights into the development of novel therapeutic strategies for these conditions. In this review, we summarize and highlight the current consensus on the role of LAP and its biological functions in disease progression to propose new therapeutic strategies. Further studies are needed to illustrate the precise role of LAP in human disease and to determine new therapeutic targets for LAP-associated pathologies.

Dissecting the pleiotropic roles of reactive oxygen species (ROS) in lung cancer: From carcinogenesis toward therapy

Lung cancer is a major cause of morbidity and mortality. The specific pulmonary structure to directly connect with ambient air makes it more susceptible to damage from airborne toxins. External oxidative stimuli and endogenous reactive oxygen species (ROS) play a crucial role in promoting lung carcinogenesis and development. The biological properties of higher ROS levels in tumor cells than in normal cells make them more sensitive and vulnerable to ROS injury. Therefore, the strategy of targeting ROS has been proposed for cancer therapy for decades. However, it is embarrassing that countless attempts at ROS-based therapies have had very limited success, and no FDA approval in the anticancer list was mechanistically based on ROS manipulation. Even compared with the untargetable proteins, such as transcription factors, ROS are more difficult to be targeted due to their chemical properties. Thus, the pleiotropic roles of ROS provide therapeutic potential for anticancer drug discovery, while a better dissection of the mechanistic action and signaling pathways is a prerequisite for future breakthroughs. This review discusses the critical roles of ROS in cancer carcinogenesis, ROS-inspired signaling pathways, and ROS-based treatment, exemplified by lung cancer. In particular, an eight considerations rule is proposed for ROS-targeting strategies and drug design and development.

Impact of Surgery-Induced Myeloid-derived Suppressor Cells and the NOX2/ROS Axis on Postoperative Survival in Human Pancreatic Cancer

Preclinical studies imply that surgery triggers inflammation that may entail tumor outgrowth and metastasis. The potential impact of surgery-induced inflammation in human pancreatic cancer is insufficiently explored. This study included 17 patients with periampullary cancer [pancreatic ductal adenocarcinoma (PDAC) n = 14, ampullary carcinoma n = 2, cholangiocarcinoma n = 1] undergoing major pancreatic cancer surgery with curative intent. We analyzed the potential impact of preoperative and postoperative immune phenotypes and function on postoperative survival with >30 months follow-up. The surgery entailed prompt expansion of monocytic myeloid-derived suppressor cells (M-MDSC) that generated NOX2-derived reactive oxygen species (ROS). Strong induction of immunosuppressive M-MDSC after surgery predicted poor postoperative survival and coincided with reduced functionality of circulating natural killer (NK) cells. The negative impact of surgery-induced M-MDSC on survival remained significant in separate analysis of patients with PDAC. M-MDSC-like cells isolated from patients after surgery significantly suppressed NK cell function ex vivo, which was reversed by inhibition of NOX2-derived ROS. High NOX2 subunit expression within resected tumors from patients with PDAC correlated with poor survival whereas high expression of markers of cytotoxic cells associated with longer survival. The surgery-induced myeloid inflammation was recapitulated in vivo in a murine model of NK cell-dependent metastasis. Surgical stress thus induced systemic accumulation of M-MDSC-like cells and promoted metastasis of NK cell-sensitive tumor cells. Genetic or pharmacologic suppression of NOX2 reduced surgery-induced inflammation and distant metastasis in this model. We propose that NOX2-derived ROS generated by surgery-induced M-MDSC may be targeted for improved outcome after pancreatic cancer surgery.

SIGNIFICANCE

Pancreatic cancer surgery triggered pronounced accumulation of NOX2+ myeloid-derived suppressor cells that inhibited NK cell function and negatively prognosticated postoperative patient survival. We propose the targeting of M-MDSC as a conceivable strategy to reduce postoperative immunosuppression in pancreatic cancer.

IL-17 signaling protects against Helicobacter pylori-induced gastric cancer

Helicobacter pylori infection is the predominant risk factor for the development of gastric cancer. Risk is enhanced by specific H. pylori virulence factors, diet, and the inflammatory response. Chronic activation of T helper (Th) 1 and Th17 pathways contributes to prolonged inflammation; yet, higher expression of IL-17 receptor (IL-17RA) is a favorable prognostic marker for survival after gastric cancer diagnosis. The protective impact of IL-17RA signaling is not understood. To investigate if IL-17RA signaling protects during H. pylori-induced carcinogenesis, the transgenic InsGAStg/tg mouse, which is prone to H. pylori-induced gastric cancer, was utilized. InsGAStg/tg mice and InsGAStg/tgIl17ra-/- mice were infected with a cag type 4 secretion system (T4SS) positive H. pylori strain for up to 6 months. Six weeks post-infection, IL-17RA deficiency led to increased bacterial burden, increased gastritis, and development of lymphoid follicles. Increased inflammation was associated with heightened cellular proliferation and earlier loss of parietal and chief cells in InsGAStg/tgIl17ra-/- mice. Gastric cancers developed more frequently by 3- and 6-months post-infection in H. pylori-infected InsGAStg/tgIl17ra-/- mice compared to InsGAStg/tg mice. Chronic inflammation was exacerbated with IL-17RA deficiency, characterized by elevated Th1/Th17 cytokines, increased B cell infiltration, and enhanced IgA production, despite reduced expression of the polymeric immunoglobulin receptor. Further, paragastric lymph nodes of InsGAStg/tgIl17ra-/- mice were enlarged relative to controls and displayed altered gene expression profiles. Increased inflammation was accompanied by a significant increase in Cybb expression, which encodes NADPH oxidase 2, suggesting that increased oxidative damage may occur in the absence of IL-17RA. Further, there is increased phosphorylation of histone 2AX in IL-17RA deficient mice, indicating that the DNA damage response is highly activated. These data suggest that IL-17RA signaling activates a protective pathway to prevent excessive inflammation which otherwise can lead to increased oxidative stress, DNA damage, and drive gastric carcinogenesis after H. pylori infection.

The Association between NADPH Oxidase 2 (NOX2) and Drug Resistance in Cancer

NADPH oxidase, as a major source of intracellular reactive oxygen species (ROS), assumes an important role in the immune response and oxidative stress response of the body. NADPH oxidase 2 (NOX2) is the first and most representative member of the NADPH oxidase family, and its effects on the development of tumor cells are gaining more and more attention. Our previous study suggested that NCF4 polymorphism in p40phox, a key subunit of NOX2, affected the outcome of diffuse large B-cell lymphoma patients treated with rituximab. It hypothesized that NOX2-mediated ROS could enhance the cytotoxic effects of some anti-tumor drugs in favor of patients with tumors. Several reviews have summarized the role of NOX2 and its congeners-mediated ROS in anti-tumor therapy, but few studies focused on the relationship between the expression of NOX2 and anti-tumor drug resistance. In this article, we systematically introduced the NOX family, represented by NOX2, and a classification of the latest inhibitors and agonists of NOX2. It will help researchers to have a more rational and objective understanding of the dual role of NOX2 in tumor drug resistance and is expected to provide new ideas for oncology treatment and overcoming drug resistance in cancer.

Selection and validation of genes related to oxidative stress production and clearance in macrophages infected with Mycobacterium tuberculosis

Background

In the fight against tuberculosis, besides chemotherapy, the regulation of oxidative stress (OS) has also aroused people's interest in host-oriented therapy. However, there is limited research on the genes involved in reactive oxygen species (ROS) production and clearance in macrophages infected with Mycobacterium tuberculosis (MTB). This study analyzes and explores this to provide a basis for exploring new targets for antituberculosis treatments.

Methods

We established a macrophage model infected with MTB, counted intracellular bacteria, and determined the ROS produced using flow cytometry. We conducted ribonucleic acid sequencing, screened differentially expressed genes through transcriptomic methods, and validated the expression of them through reverse transcription-quantitative polymerase chain reaction.

Results

The ROS of macrophages increased with intracellular bacteria at 4 h after infection with MTB and reached its peak at 48 h, surpassing the uninfected macrophages (p < 0.05). A total of 1,613 differentially expressed genes were identified after infection with MTB, of which 458 were associated with ROS, with over 50% involved in the response of organelles and biological processes to stimuli. We analyzed and identified six genes. After macrophage infection with MTB, the expression of CAMK2B increased, whereas the expression of CYBB decreased (p < 0.05). The expression of GPX3 and SOD2 increased, whereas the expression of CAT decreased (p < 0.05).

Conclusion

The ROS-related differentially expressed genes between MTB infected and uninfected macrophages may be related to some organelles and involved in various biological processes, molecular functions, and signaling pathways. Among them, CAMK2B, GPX3, and SOD2 may be related to ROS.

Small-molecule redox modulators with anticancer activity: A comprehensive mechanistic update

The pursuit of effective anticancer therapies has led to a burgeoning interest in the realm of redox modulation. This review provides a comprehensive exploration of the intricate mechanisms by which diverse anticancer molecules leverage redox pathways for therapeutic intervention. Redox modulation, encompassing the fine balance of oxidation-reduction processes within cells, has emerged as a pivotal player in cancer treatment. This review delves into the multifaceted mechanisms of action employed by various anticancer compounds, including small molecules and natural products, to disrupt cancer cell proliferation and survival. Beginning with an examination of the role of redox signaling in cancer development and resistance, the review highlights how aberrant redox dynamics can fuel tumorigenesis. It then meticulously dissects the strategies employed by anticancer agents to induce oxidative stress, perturb redox equilibrium, and trigger apoptosis within cancer cells. Furthermore, the review explores the challenges and potential side effects associated with redox-based treatments, along with the development of novel redox-targeted agents. In summary, this review offers a profound understanding of the dynamic interplay between redox modulation and anticancer molecules, presenting promising avenues to revolutionize cancer therapy and enhance patient outcomes.

Exploring the crosstalk between endothelial cells, immune cells, and immune checkpoints in the tumor microenvironment: new insights and therapeutic implications

The tumor microenvironment (TME) is a highly intricate milieu, comprising a multitude of components, including immune cells and stromal cells, that exert a profound influence on tumor initiation and progression. Within the TME, angiogenesis is predominantly orchestrated by endothelial cells (ECs), which foster the proliferation and metastasis of malignant cells. The interplay between tumor and immune cells with ECs is complex and can either bolster or hinder the immune system. Thus, a comprehensive understanding of the intricate crosstalk between ECs and immune cells is essential to advance the development of immunotherapeutic interventions. Despite recent progress, the underlying molecular mechanisms that govern the interplay between ECs and immune cells remain elusive. Nevertheless, the immunomodulatory function of ECs has emerged as a pivotal determinant of the immune response. In light of this, the study of the relationship between ECs and immune checkpoints has garnered considerable attention in the field of immunotherapy. By targeting specific molecular pathways and signaling molecules associated with ECs in the TME, novel immunotherapeutic strategies may be devised to enhance the efficacy of current treatments. In this vein, we sought to elucidate the relationship between ECs, immune cells, and immune checkpoints in the TME, with the ultimate goal of identifying novel therapeutic targets and charting new avenues for immunotherapy.

Mechanisms and applications of radiation-induced oxidative stress in regulating cancer immunotherapy

Radiotherapy (RT) is an effective treatment option for cancer patients, which induces the production of reactive oxygen species (ROS) and causes oxidative stress (OS), leading to the death of tumor cells. OS not only causes apoptosis, autophagy and ferroptosis, but also affects tumor immune response. The combination of RT and immunotherapy has revolutionized the management of various cancers. In this process, OS caused by ROS plays a critical role. Specifically, RT-induced ROS can promote the release of tumor-associated antigens (TAAs), regulate the infiltration and differentiation of immune cells, manipulate the expression of immune checkpoints, and change the tumor immune microenvironment (TME). In this review, we briefly summarize several ways in which IR induces tumor cell death and discuss the interrelationship between RT-induced OS and antitumor immunity, with a focus on the interaction of ferroptosis with immunogenic death. We also summarize the potential mechanisms by which ROS regulates immune checkpoint expression, immune cells activity, and differentiation. In addition, we conclude the therapeutic opportunity improving radiotherapy in combination with immunotherapy by regulating OS, which may be beneficial for clinical treatment.

Unlocking the power of NOX2: A comprehensive review on its role in immune regulation

Reactive oxygen species (ROS) are a family of highly reactive molecules with numerous, often pleiotropic functions within the cell and the organism. Due to their potential to destroy biological structures such as membranes, enzymes and organelles, ROS have long been recognized as harmful yet unavoidable by-products of cellular metabolism leading to "oxidative stress" unless counterbalanced by cellular anti-oxidative defense mechanisms. Phagocytes utilize this destructive potential of ROS released in high amounts to defend against invading pathogens. In contrast, a regulated and fine-tuned release of "signaling ROS" (sROS) provides essential intracellular second messengers to modulate central aspects of immunity, including antigen presentation, activation of antigen presenting cells (APC) as well as the APC:T cell interaction during T cell activation. This regulated release of sROS is foremost attributed to the specialized enzyme NADPH-oxidase (NOX) 2 expressed mainly in myeloid cells such as neutrophils, macrophages and dendritic cells (DC). NOX-2-derived sROS are primarily involved in immune regulation and mediate protection against autoimmunity as well as maintenance of self-tolerance. Consequently, deficiencies in NOX2 not only result in primary immune-deficiencies such as Chronic Granulomatous Disease (CGD) but also lead to auto-inflammatory diseases and autoimmunity. A comprehensive understanding of NOX2 activation and regulation will be key for successful pharmaceutical interventions of such ROS-related diseases in the future. In this review, we summarize recent progress regarding immune regulation by NOX2-derived ROS and the consequences of its deregulation on the development of immune disorders.

Integrated glycoproteomic characterization of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC), a common form of RCC, is responsible for the high mortality rate of kidney cancer. Dysregulations of glycoproteins have been shown to associate with ccRCC. However, the molecular mechanism has not been well characterized. Here, a comprehensive glycoproteomic analysis is conducted using 103 tumors and 80 paired normal adjacent tissues. Altered glycosylation enzymes and corresponding protein glycosylation are observed, while two of the major ccRCC mutations, BAP1 and PBRM1, show distinct glycosylation profiles. Additionally, inter-tumor heterogeneity and cross-correlation between glycosylation and phosphorylation are observed. The relation of glycoproteomic features to genomic, transcriptomic, proteomic, and phosphoproteomic changes shows the role of glycosylation in ccRCC development with potential for therapeutic interventions. This study reports a large-scale tandem mass tag (TMT)-based quantitative glycoproteomic analysis of ccRCC that can serve as a valuable resource for the community.

Knockdown of Stromal Interaction Molecule 1 (STIM1) Suppresses Acute Myeloblastic Leukemia-M5 Cell Line Survival Through Inhibition of Reactive Oxygen Species Activities

Objective

This study aimed to investigate the role of the stromal interaction molecule 1 (STIM1) gene in the survival of the acute myeloblastic leukemia (AML)-M5 cell line (THP-1).

Materials and Methods

The STIM1 effect was assessed via dicersubstrate siRNA-mediated STIM1 knockdown. The effect of STIM1 knockdown on the expression of AKT and MAPK pathway-related genes and reactive oxygen species (ROS) generation-related genes was tested using real-time polymerase chain reaction. Cellular functions, including ROS generation, cell proliferation, and colony formation, were also evaluated following STIM1 knockdown.

Results

The findings revealed that STIM1 knockdown reduced intracellular ROS levels via downregulation of NOX2 and PKC. These findings were associated with the downregulation of AKT, KRAS, MAPK, and CMYC. BCL2 was also downregulated, while BAX was upregulated following STIM1 knockdown. Furthermore, STIM1 knockdown reduced THP-1 cell proliferation and colony formation.

Conclusion

This study has demonstrated the role of STIM1 in promoting AML cell proliferation and survival through enhanced ROS generation and regulation of AKT/MAPK-related pathways. These findings may help establish STIM1 as a potential therapeutic target for AML treatment.

Structure, Activation, and Regulation of NOX2: At the Crossroad between the Innate Immunity and Oxidative Stress-Mediated Pathologies

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) is a multisubunit enzyme complex that participates in the generation of superoxide or hydrogen peroxide (H₂O₂) and plays a key role in several biological functions. Among seven known NOX isoforms, NOX2 was the first identified in phagocytes but is also expressed in several other cell types including endothelial cells, platelets, microglia, neurons, and muscle cells. NOX2 has been assigned multiple roles in regulating many aspects of innate and adaptive immunity, and human and mouse models of NOX2 genetic deletion highlighted this key role. On the other side, NOX2 hyperactivation is involved in the pathogenesis of several diseases with different etiologies but all are characterized by an increase in oxidative stress and inflammatory process. From this point of view, the modulation of NOX2 represents an important therapeutic strategy aimed at reducing the damage associated with its hyperactivation. Although pharmacological strategies to selectively modulate NOX2 are implemented thanks to new biotechnologies, this field of research remains to be explored. Therefore, in this review, we analyzed the role of NOX2 at the crossroads between immunity and pathologies mediated by its hyperactivation. We described (1) the mechanisms of activation and regulation, (2) human, mouse, and cellular models studied to understand the role of NOX2 as an enzyme of innate immunity, (3) some of the pathologies associated with its hyperactivation, and (4) the inhibitory strategies, with reference to the most recent discoveries.

Prognostic value of NOX2 as a potential biomarker for lung adenocarcinoma using TCGA and clinical validation

Lung adenocarcinoma (LUAD) is associated with high morbidity and mortality; therefore, effective biomarkers are essential. In recent years, a rapid increase in the efficiency of high‑throughput sequencing technologies and the continuous improvement of comprehensive online databases have facilitated the study of the genomic changes that affect tumor progression, including the identification of tumor biomarkers. Therefore, the identification of genes that may affect the progression and prognosis of LUAD is necessary. In the present study, the CIBERSORT and ESTIMATE bioinformatics packages were used to evaluate data from The Cancer Genome Atlas, including assessment of the proportion of tumor‑infiltrating immune cells in the tumor microenvironment, Cox regression analysis of differentially expressed genes and cross analysis of protein‑protein interaction networks. Myeloid cell NADPH oxidase isoform 2 (NOX2), an indispensable gene in the immune system, was demonstrated to serve a vital role in LUAD pathogenesis. Western blotting and immunohistochemistry confirmed that, at the protein level, NOX2 expression was increased in normal cells compared with cancer cells. Furthermore, reverse transcription‑quantitative PCR results at the mRNA level were consistent with these results, which confirmed that the abundance of NOX2 was significantly reduced in LUAD patients. NOX2 may be used as a novel marker and an independent prognostic indicator of LUAD. Its potential function was enriched in tumor immune and metabolic signaling pathways, which could provide clues for the study of the signaling pathways and molecular networks related to the disease progression of LUAD, which would be helpful for the assessment of prognosis in the clinical setting.

NOX as a Therapeutic Target in Liver Disease

The nicotinamide adenine dinucleotide phosphate hydrogen oxidase (NADPH oxidase or NOX) plays a critical role in the inflammatory response and fibrosis in several organs such as the lungs, pancreas, kidney, liver, and heart. In the liver, NOXs contribute, through the generation of reactive oxygen species (ROS), to hepatic fibrosis by acting through multiple pathways, including hepatic stellate cell activation, proliferation, survival, and migration of hepatic stellate cells; hepatocyte apoptosis, enhancement of fibrogenic mediators, and mediation of an inflammatory cascade in both Kupffer cells and hepatic stellate cells. ROS are overwhelmingly produced during malignant transformation and hepatic carcinogenesis (HCC), creating an oxidative microenvironment that can cause different and various types of cellular stress, including DNA damage, ER stress, cell death of damaged hepatocytes, and oxidative stress. NOX1, NOX2, and NOX4, members of the NADPH oxidase family, have been linked to the production of ROS in the liver. This review will analyze some diseases related to an increase in oxidative stress and its relationship with the NOX family, as well as discuss some therapies proposed to slow down or control the disease's progression.

Modulation of Reactive Oxygen Species in Cancers: Recent Advances

Oxidation-reduction reactions played a significant role in the chemical evolution of life forms on oxygenated earth. Cellular respiration is dependent on such redox reactions, and any imbalance leads to the accumulation of reactive oxygen species (ROS), resulting in both chronic and acute illnesses. According to the International Agency for Research on Cancer (IARC), by 2040, the global burden of new cancer cases is expected to be around 27.5 million, with 16.3 million cancer deaths due to an increase in risk factors such as unhealthy lifestyle, environmental factors, aberrant gene mutations, and resistance to therapies. ROS play an important role in cellular signalling, but they can cause severe damage to tissues when present at higher levels. Elevated and chronic levels of ROS are pertinent in carcinogenesis, while several therapeutic strategies rely on altering cellular ROS to eliminate tumour cells as they are more susceptible to ROS-induced damage than normal cells. Given this selective targeting potential, therapies that can effectively modulate ROS levels have been the focus of intense research in recent years. The current review describes biologically relevant ROS, its origins in solid and haematological cancers, and the current status of evolving antioxidant and pro-oxidant therapies in cancers.

NADPH Oxidase 2 Has a Crucial Role in Cell Cycle Progression of Esophageal Squamous Cell Carcinoma

BACKGROUND

NADPH oxidases (NOXs) are transmembrane proteins that generate reactive oxygen species. Recent studies have reported that NOXs are involved in tumor progression in various cancers. However, the expression and role of NOX2 in esophageal squamous cell carcinoma (ESCC) remain unclear. This study aimed to clarify the pathophysiologic role of NOX2 in patients with ESCC and cell lines.

METHODS

Two human ESCC cell lines (TE5 and KYSE170) were used for NOX2 transfection experiments, and the effects on cell proliferation, cell cycle, cell motility, and cell survival were analyzed. An mRNA microarray analysis was also performed to assess gene expression profiles. Additionally, NOX2 immunohistochemistry was performed on 130 primary ESCC tumor samples to assess the prognostic value of NOX2 in patients with ESCC.

RESULTS

NOX2 depletion significantly inhibited cell proliferation with the G₀/G₁ arrest and resulted in apoptosis in two cell lines. Microarray analysis revealed a strong relationship between NOX2 gene expression and the signaling pathway of cell cycle regulation by the B-cell translocation gene 2 (BTG2) family, including BTG2, CCNE2, E2F1, and CDK2 genes. Immunohistochemical staining revealed that high NOX2 protein expression was significantly associated with deeper tumor invasion and selected as one of the independent prognostic factors associated with the 5-year OS rate in patients with ESCC.

CONCLUSIONS

NOX2 expression in ESCC cells affects tumorigenesis, especially cell cycle progression via the BTG2-related signaling pathway, as well as the prognosis of patients with ESCC. NOX2 may be a novel biomarker and therapeutic target for ESCC.

Identification of differentially expressed autophagy genes associated with osteogenic differentiation in human bone marrow mesenchymal stem cells

BACKGROUND

Mesenchymal stem cells derived from human tissues have been widely used for tissue regeneration because of their strong self-renewal capacity and multi-potential properties. Autophagy plays a vital role in maintaining bone homeostasis. However, the mechanism underlying this role for autophagy in the osteogenic differentiation of mesenchymal stem cells remains to be elucidated.

METHODS

Two microarray datasets were downloaded from the GEO database. Fourteen bone marrow mesenchymal stem cell samples comprising control and induction groups were selected to identify differentially expressed autophagy-related genes via multiple bioinformatics approaches, followed by functional analysis. Interactions among differentially expressed autophagy genes, miRNAs, and transcription factors were analyzed and visualized using Cytoscape software. The association between hub differentially expressed genes and autophagy was validated by qRT-PCR.

RESULTS

Ten autophagy-related genes (including VPS8, NDRG4, and CYBB) were identified as osteogenic hub genes. Correlation analysis revealed that CYBB was highly correlated with the sensitivity to multiple drugs, such as imexon, megestrol acetate, and isotretinoin. The regulatory network displayed a complex connection among miRNAs, transcription factors, and differentially expressed autophagy genes. Friends' analysis showed that NDRG4 was highly closely related to other hub genes (P < 0.05). Furthermore, NDRG4 expression was downregulated in the induction group (P < 0.01). NDRG4 was significantly correlated with infiltrating immune cells, including monocytes, eosinophils, type 17 T helper cells, neutrophils, activated CD8 T cells, and immature B cells. Levels of the 10 autophagy-related genes (including VPS8, NDRG4, and CYBB) were successfully validated based on in vitro experiments.

CONCLUSION

We identified candidate molecules to further investigate their functions in osteogenesis, providing novel insights into the role of autophagy in mesenchymal stem cell differentiation.

The Antileukemic and Anti-Prostatic Effect of Aeroplysinin-1 Is Mediated through ROS-Induced Apoptosis via NOX Activation and Inhibition of HIF-1a Activity

Aeroplysinin-1 is a brominated isoxazoline alkaloid that has exhibited a potent antitumor cell effect in previous reports. We evaluated the cytotoxicity of aeroplysinin-1 against leukemia and prostate cancer cells in vitro. This marine alkaloid inhibited the cell proliferation of leukemia Molt-4, K562 cells, and prostate cancer cells Du145 and PC-3 with IC₅₀ values of 0.12 ± 0.002, 0.54 ± 0.085, 0.58 ± 0.109 and 0.33 ± 0.042 µM, respectively, as shown by the MTT assay. Furthermore, in the non-malignant cells, CCD966SK and NR8383, its IC₅₀ values were 1.54 ± 0.138 and 6.77 ± 0.190 μM, respectively. In a cell-free system, the thermal shift assay and Western blot assay verified the binding affinity of aeroplysinin-1 to Hsp90 and Topo IIα, which inhibited their activity. Flow cytometry analysis showed that the cytotoxic effect of aeroplysinin-1 is mediated through mitochondria-dependent apoptosis induced by reactive oxygen species (ROS). ROS interrupted the cellular oxidative balance by activating NOX and inhibiting HIF-1α and HO-1 expression. Pretreatment with N-acetylcysteine (NAC) reduced Apl-1-induced mitochondria-dependent apoptosis and preserved the expression of NOX, HO-1, and HIF-1a. Our findings indicated that aeroplysinin-1 targeted leukemia and prostate cancer cells through multiple pathways, suggesting its potential application as an anti-leukemia and prostate cancer drug lead.

Impact of CYBA genotypes on severity and progression of multiple sclerosis

BACKGROUND AND PURPOSE

The NOX2 enzyme of myeloid cells generates reactive oxygen species (ROS) that have been implicated in the pathology of multiple sclerosis (MS). We aimed to determine the impact of genetic variation within CYBA, which encodes the functional CYBA/p22phox subunit of NOX2, on MS severity and progression.

METHODS

One hundred three MS patients with up to 49 (median = 17) years follow-up time from first MS diagnosis were genotyped at the single nucleotide polymorphisms rs1049254 and rs4673 within CYBA. Results were matched with disease severity and time to diagnosis of secondary progressive MS (SPMS). NOX2-mediated formation of ROS was measured by chemiluminescence in blood myeloid cells from healthy donors (n = 55) with defined genotypes at rs1049254 and rs4673.

RESULTS

The rs1049254/G and rs4673/A CYBA alleles were associated with reduced formation of ROS and were thus defined as low-ROS alleles. Patients carrying low-ROS alleles showed reduced multiple sclerosis severity score (p = 0.02, N = 103, linear regression) and delayed onset of SPMS (p = 0.02, hazard ratio [HR] = 0.46, n = 100, log-rank test). In a cohort examined after 2005, patients carrying low-ROS CYBA alleles showed >20 years longer time to secondary progression (p = 0.003, HR = 0.29, n = 59, log-rank test).

CONCLUSIONS

These results implicate NOX2 in MS, in particular for the development of secondary progressive disease, and point toward NOX2-reductive therapy aiming to delay secondary progression.

Identification of hub genes and transcription factors in patients with rheumatoid arthritis complicated with atherosclerosis

The aim of this study was to explore the overlapping key genes, pathway networks and transcription factors (TFs) related to the pathogenesis of rheumatoid arthritis (RA) and atherosclerosis. The gene expression profiles of RA and atherosclerosis were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between RA and atherosclerosis were identified. The biological roles of common DEGs were explored through enrichment analysis. Hub genes were identified using protein–protein interaction networks. TFs were predicted using Transcriptional Regulatory Relationships Unraveled by Sentence Based Text Mining (TRRUST) database. The hub genes and TFs were validated with other datasets. The networks between TFs and hub genes were constructed by CytoScape software. A total of 131 DEGs (all upregulated) were identified. Functional enrichment analyses indicated that DEGs were mostly enriched in leukocyte migration, neutrophil activation, and phagocytosis. CytoScape demonstrated 12 hub genes and one gene cluster module. Four of the 12 hub genes (CSF1R, CD86, PTPRC, and CD53) were validated by other datasets. TRRUST predicted two TFs, including Spi-1 proto-oncogene (SPI1) and RUNX family transcription factor 1(RUNX1). The expression of RUNX1 was validated with another dataset. Our study explored the common pathogenesis of RA and atherosclerosis. These results may guide future experimental research and clinical transformation.

Multi-faced roles of reactive oxygen species in anti-tumor T cell immune responses and combination immunotherapy

T cells play a central role in anti-tumor immunity, and reactive oxygen species (ROS) lie at the crossroad on the anti-tumor T cell responses. To activate efficient T cell immunity, a moderate level of ROS is needed, however, excessive ROS would cause toxicity to the T cells, because the improper level leads to the formation and maintenance of an immunosuppressive tumor microenvironment. Up to date, strategies that modulate ROS, either increasing or decreasing, have been widely investigated. Some of them are utilized in anti-tumor therapies, showing inevitable impacts on the anti-tumor T cell immunity with both obverse and reverse sides. Herein, the impacts of ROS-increasing and ROS-decreasing treatments on the T cell responses in the tumor microenvironment are reviewed and discussed. At the same time, outcomes of combination immunotherapies are introduced to put forward inspirations to unleash the potential of immunotherapies.

Cannabidiol modulation of oxidative stress and signalling

Cannabidiol (CBD), one of the primary non-euphoric components in the Cannabis sativa L. plant, has undergone clinical development over the last number of years as a therapeutic for patients with Lennox-Gastaut syndrome and Dravet syndromes. This phytocannabinoid demonstrates functional and pharmacological diversity, and research data indicate that CBD is a comparable antioxidant to common antioxidants. This review gathers the latest knowledge regarding the impact of CBD on oxidative signalling, with focus on the proclivity of CBD to regulate antioxidants and control the production of reactive oxygen species. CBD is considered an attractive therapeutic agent for neuroimmune disorders, and a body of literature indicates that CBD can regulate redox function at multiple levels, with a range of downstream effects on cells and tissues. However, pro-oxidant capacity of CBD has also been reported, and hence caution must be applied when considering CBD from a therapeutic standpoint. Such pro- and antioxidant functions of CBD may be cell- and model-dependent and may also be influenced by CBD dose, the duration of CBD treatment and the underlying pathology.