HCV-Induced Oxidative Stress: Battlefield-Winning Strategy. Oxid Med Cell Longev. 2016;2016:7425628. [PMID: 27293514 PMCID: PMC4880679 DOI: 10.1155/2016/7425628]

DHCR24 in Tumor Diagnosis and Treatment: A Comprehensive Review

As an important nutrient in the human body, cholesterol can not only provide structural components for the body's cells, but also can be transformed into a variety of active substances to regulate cell signaling pathways. As an important cholesterol synthase, DHCR24 participates in important regulatory processes in the body. The application of DHCR24 in tumor clinical diagnosis and treatment also attracts much attention. This article reviews the structure and regulatory characteristics of DHCR24, and the research of DHCR24 on tumor progression. We summarize the possible mechanisms of DHCR24 promoting tumor progression through reactive oxygen species (ROS), p53, Ras and PI3K-AKT pathways. Through our review, we hope to provide more research ideas and reference value for the application of DHCR24 in tumor prevention and treatment.

HCV spontaneous clearers showed low senescence profile in people living with HIV under long ART

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) increases immune activation, inflammation, and oxidative stress that could lead to premature senescence. Different HCV infections, either acute or chronic infection, could lead to distinct premature cellular senescence in people living with HIV (PLWHIV). Observational study in 116 PLWHIV under antiretroviral treatment with different HCV status: (i) n = 45 chronically infected with HCV (CHC); (ii) n = 36 individuals who spontaneously clarify HCV (SC); (iii) n = 35 HIV controls. Oxidative stress biomarkers were analyzed at lipid, DNA, protein, and nitrates levels, as well as antioxidant capacity and glutathione reductase enzyme. Replicative senescence was evaluated by relative telomere length (RTL) measurement. Additionally, 26 markers of Senescence-Associated Secretory Phenotype (SASP) were analyzed by multiplex immunoassays (Luminex xMAP technology). Differences were evaluated by generalized linear model (GLMs) adjusted by most significant covariates. The SC group had a senescence signature similar to the HIV control group and slightly lower SASP levels. However, significant differences were observed with respect to the CHC group, where an increase in the nitrate concentration [adjusted arithmetic mean ratio, aAMR = 1.73 (1.27-2.35), p < 0.001, q = 0.009] and the secretion of 13 SASP-associated factors [granulocyte macrophage colony-stimulating factor (GM-CSF), interferon-β, interleukin (IL)-1β, IL-2, IL-8, IL-13, tumor necrosis factor (TNF)-α, IL-1α, IL-1RA, IL-7, IL-15, C-X-C motif chemokine ligand 10 (IP-10), stem cell factor (SCF); q < 0.1)] was detected. The CHC group also showed higher values of IL-1α, IP-10, and placental growth factor 1 (PIGF-1) than HIV controls. The SC group showed a slightly lower senescence profile than the HIV group, which could indicate a more efficient control of viral-induced senescence due to their immune strengths. Chronic HCV infection in PLWHIV led to an increase in nitrate and elevated SASP biomarkers favoring the establishment of viral persistence.

The Effect of N6-Methyladenosine Regulators and m6A Reader YTHDC1-Mediated N6-Methyladenosine Modification Is Involved in Oxidative Stress in Human Aortic Dissection

Aortic dissection (AD) develops pathological changes in the separation of the true and false aortic lumen, with high lethality. m6A methylation and oxidative stress have also been shown to be involved in the onset of AD. Through bioinformatics methods, three differentially expressed m6A regulators (YTHDC1, YTHDC2, and RBM15) were excavated from the GSE52093 dataset in the Gene Expression Omnibus (GEO) database, and functional enrichment analysis of the differentially expressed genes (DEGs) regulated by m6A regulators was performed. Then, the genes with oxidative stress-related functions among these genes were found. The protein interaction network of the oxidative stress-related genes and the competing endogenous RNA- (ceRNA-) miRNA-mRNA network were constructed. Among them, DHCR24, P4HB, and PDGFRA, which have m6A differences in AD samples, were selected as key genes. We also performed immune infiltration analysis, as well as cell-gene correlation analysis, on samples from the dataset. The results showed that YTHDC1 was positively correlated with macrophage M1 and negatively correlated with macrophage M2. Finally, we extracted AD and healthy aorta RNA and protein from human tissues that were taken from AD patients and patients who received heart transplants, performed quantitative real-time PCR (qRT-PCR) on YTHDC2 and RBM15, and performed qRT-PCR and western blot (WB) detection on YTHDC1 to verify their differences in AD. The mRNA and protein levels of YTHDC1 were consistent with the results of bioinformatics analysis and were downregulated in AD. Immunofluorescence (IF) was used to colocalize YTHDC1 and endothelial cell marker CD31. After knocking down YTHDC1 in human umbilical vein endothelial cells (HUVECs), reactive oxygen species (ROS) levels had a tendency to increase and the expression of peroxide dismutase SOD2 was decreased. This study provides assistance in discovering the role of m6A regulator YTHDC1 in AD. In particular, m6A modification participates in oxidative stress and jointly affects AD.

Comprehensive analysis of pyroptosis-related gene signatures for glioblastoma immune microenvironment and target therapy

Glioblastoma (GBM) is a malignant brain tumour, but its subtypes (mesenchymal, classical, and proneural) show different prognoses. Pyroptosis is a programmed cell death relating to tumour progression, but its association with GBM is poorly understood. In this work, we collected 73 GBM samples (the Xiangya GBM cohort) and reported that pyroptosis involves tumour-microglia interaction and tumour response to interferon-gamma. GBM samples were grouped into different subtypes, cluster 1 and cluster 2, based on pyroptosis-related genes. Cluster 1 samples manifested a worse prognosis and had a more complicated immune landscape than cluster 2 samples. Single-cell RNA-seq data analysis supported that cluster 1 samples respond to interferon-gamma more actively. Moreover, the machine learning algorithm screened several potential compounds, including nutlin-3, for cluster 1 samples as a novel treatment. In vitro experiments supported that cluster 1 cell line, T98G, is more sensitive to nutlin-3 than cluster 2 cell line, LN229. Nutlin-3 can trigger oxidative stress by increasing DHCR24 expression. Moreover, pyroptosis-resistant genes were upregulated in LN229, which may participate against nutlin-3. Therefore, we hypothesis that GBM may be able to upregulate pyroptosis resistant related genes to against nutlin-3-triggered cell death. In summary, we conclude that pyroptosis highly associates with GBM progression, tumour immune landscape, and tumour response to nutlin-3.

Antioxidant and antiviral activity of fullerol against Zika virus

Neglected for years, Zika virus (ZIKV) has become one of the most relevant arboviruses in current public health. The recent Zika fever epidemic in the Americas generated a worldwide alert due to the association with diseases such as Guillain-Barré syndrome and congenital syndromes. Among the pathogenesis of ZIKV, recent studies suggest that oxidative stress plays an important role during infection and that compounds capable of modulating oxidative stress are promising as therapeutics. Furthermore, so far there are no specific and efficient antiviral drug or vaccine available against ZIKV. Thus, fullerol was evaluated in the context of infection by ZIKV, since it is a carbon nanomaterial known for its potent antioxidant action. In this study, fullerol did not alter cell viability at the concentrations tested, proving to be inert, beyond to presenting high antioxidant power at low concentrations. ZIKV infection of human glioblastoma increased the production of reactive oxygen species by 60% and modulated the Nrf-2 pathway activity negatively. After treatment with fullerol, both conditions were restored to baseline levels. Additionally, fullerol was able to reduce viral production by up to 90%. Therefore, our results suggest that fullerol as a promising candidate in the control of ZIKV infections, presenting both antioxidant and antiviral action.

Effects of Vanadium Inhalation and Sweetened Beverage Ingestion in Mice: Morphological and Biochemical Changes in the Liver

The aim of this report was to evaluate the morphological and biochemical changes in the liver by the inhalation of vanadium and consumption of sweetened beverages in a subchronic murine model. Forty CD-1 male mice were randomly divided into four groups: control, vanadium (V), sucrose 30% (S), and vanadium-sucrose (V + S). V was inhaled (1.4 mg/m³) for 1h, twice/week; 30% sucrose solution was given orally ad libitum. Blood samples were obtained for AST, ALT, and LDH determination. Liver samples were processed for histological and oxidative stress immunohistochemical evaluation with 4-hydroxynonenal at weeks 4 and 8 of exposure. Regarding liver function tests, a statistically significant increase (P < 0.05) was observed in groups V, S, and V + S at weeks 4 and 8 compared to the control group. A greater number of hepatocytes with meganuclei and binuclei were observed in V and V + S at week 8 compared to the other groups. Steatosis and regenerative changes were more extensive in the eighth week V + S group. 4-Hydroxynonenal immunoreactivity increased in the V + S group at both exposure times compared to the other groups; however, the increment was more evident in the V + S group at week 4 compared to the V + S group at week 8. An increase in De Ritis ratio (>1) was noticed in experimental groups at weeks 4 and 8. Findings demonstrate that in the liver, V, S, and V + S induced oxidative stress and regenerative changes that increased with the length of exposure. Results support possible potentiation of liver damage in areas with high air pollution and high-sweetened beverage consumption.

A novel therapeutic strategy for hepatocellular carcinoma: Immunomodulatory mechanisms of selenium and/or selenoproteins on a shift towards anti-cancer

Selenium (Se) is an essential trace chemical element that is widely distributed worldwide. Se exerts its immunomodulatory and nutritional activities in the human body in the form of selenoproteins. Se has increasingly appeared as a potential trace element associated with many human diseases, including hepatocellular carcinoma (HCC). Recently, increasing evidence has suggested that Se and selenoproteins exert their immunomodulatory effects on HCC by regulating the molecules of oxidative stress, inflammation, immune response, cell proliferation and growth, angiogenesis, signaling pathways, apoptosis, and other processes in vitro cell studies and in vivo animal studies. Se concentrations are generally low in tissues of patients with HCC, such as blood, serum, scalp hair, and toenail. However, Se concentrations were higher in HCC patient tissues after Se supplementation than before supplementation. This review summarizes the significant relationship between Se and HCC, and details the role of Se as a novel immunomodulatory or immunotherapeutic approach against HCC.

Noncoding RNAs: modulators and modulatable players during infection-induced stress response

The human genome has an almost equal distribution of unique and transposable genetic elements. Although at the transcriptome level, a relatively higher contribution from transposable elements derived RNA has been reported. This is further highlighted with evidence from pervasive transcription. Of the total RNA, noncoding RNAs (ncRNAs) are significant contributors to the transcriptome pool with sizeable fraction from repetitive elements of the human genome, inclusive of Long Interspersed Nuclear Elements (LINEs) and Short Interspersed Nuclear Elements (SINEs). ncRNAs are increasingly being implicated in diverse functional roles especially during conditions of stress. These stress responses are driven through diverse mediators, inclusive of long and short ncRNAs. ncRNAs such as MALAT1, GAS5, miR-204 and miR-199a-5p have been functionally involved during oxidative stress, endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Also, within SINEs, Alu RNAs derived from primate-specific Alu repeats with ~11% human genome contribution, playing a significant role. Pathogenic diseases, including the recent COVID-19, leads to differential regulation of ncRNAs. Although, limited evidence suggests the need for an inquest into the role of ncRNAs in determining the host response towards pathogen challenge.

Crm1-Dependent Nuclear Export of Bach1 is Involved in the Protective Effect of Hyperoside on Oxidative Damage in Hepatocytes and CCl4-induced Acute Liver Injury

Background

Nrf2-Bach1 antioxidant signaling pathway is considered as one of the most important mechanisms of cellular resistance to oxidative injury. The effect of hyperoside (Hyp) on the expression and distribution of Bach1, the relationship of Hyp's antioxidative effect and the influence of Bach1 remains unclear.

Purpose

The aim of this study was to investigate the role and mechanisms of Bach1 in the protective effect of Hyp on oxidative liver injury.

Methods

The protective effect of Hyp on oxidative stress injury was observed in vivo and in vitro. Next, the influence of Hyp on Bach1 expression and distribution, and competitive combination of Nrf2-Bach1 with ARE in H₂O₂-induced L02 cell was studied by Western blot, RT-PCR, immunofluorescence and CHIP assay. Finally, the expressions of Crm1, ERK and p38 and their roles on Hyp mediated nuclear export of Bach1 were investigated by Western blot.

Results

Hyp ameliorated the pathological damage, reduced the liver index, AST, ALT and MDA activities, and increased SOD and GSH levels in the CCl₄-induced acute liver injury mouse model. Hyp attenuated H₂O₂-induced oxidative stress injury in L02 cells. Hyp promoted the early rapid redistribution of Bach1 from nucleus to cytoplasm. CHIP analyses demonstrated that Hyp enhanced the levels of Nrf2-ARE complex, and weakened the levels of Bach1-ARE complex within three hours. In addition, Hyp enhanced transport protein Crm1 expression and ERK1/2 activity. And LMB, a Crm1 inhibitor, attenuated the effect of Hyp on Bach1 nuclear export and anti-oxidation. U0126, an ERK1/2 inhibitor, reduced the effect of Hyp on Crm1 expression and the Bach1 redistribution.

Conclusion

The hepatoprotective mechanism of Hyp was related to improve Bach1 nuclear export depending on ERK1/2-Crm1 to upregulate the level of Nrf2 binding to ARE.

The Impact of Hepatitis C Virus Genotypes on Oxidative Stress Markers and Catalase Activity

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. Chronic HCV infections are usually associated with increased oxidative stress in the liver tissue. The intensity of oxidative stress may be a detrimental factor in liver injury and may determine the severity of the disease. The aim of the present case-control study was to determine the level of lipid peroxidation (TBARS), protein oxidative modification (AOPP), and catalase activity in sera of patients infected with HCV, in relation to different HCV genotypes and viral load. Considering the HCV patients with chronic hepatitis C (52) and control subject (50) recruitment, the study was designed as a case-control-type. The HCV RNA isolation, viral load, and HCV genotyping were performed according to the standard protocols. A significant difference compared to control healthy subjects was reported for TBAR (p < 0.001), AOPP (p = 0.001), and catalase activity (p = 0.007). In a gender-based comparison, a significantly higher level of AOPP for females was reported (p < 0.001). As stratified by HCV genotype, the most common was HCV-1 (HCV-1a and HCV 1b), with the overall participation of more than 60%, followed by genotype 3, while the least represented was genotype 2. No significant difference was documented among genotypes in regard to oxidative stress markers, although somewhat higher TBARS level, but not significant, was registered in patients infected with genotype 1b. A statistically significant positive correlation was found between the concentration of HCV genome copies and AOPP (r = 0.344; p = 0.012). A high level of HCV viral load was more likely to have a higher TBARS, but still without statistical significance (p = 0.072). In conclusion, the results obtained confirmed an imbalance between the ROS production and antioxidative defense system in HCV-infected patients. Since oxidative stress may have a profound influence on disease progression, fibrosis, and carcinogenesis, our results may meet the aspirations of mandatory introduction of antioxidants as early HCV therapy to counteract ROS consequences.

Oxidative stress, immunological and cellular hypoxia biomarkers in hepatitis C treatment-naïve and cirrhotic patients

INTRODUCTION

Hepatitis C virus (HCV) is the main cause of chronic liver disease, with calamitous complications. Its highest rate is recorded in Egypt. This study investigated whether oxidative stress, immunological chaos and cellular hypoxia are implicated in the pathophysiology of the disease.

MATERIAL AND METHODS

This cross-sectional study aimed to evaluate the changes in blood oxidative stress, cellular hypoxia/angiogenesis and cellular immunological biomarkers in hospital-diagnosed treatment-naïve HCV-infected Upper Egyptian chronic liver disease patients vs. healthy controls (n = 40). The consecutively included patients comprised 120 with normal serum enzymes (HCV-NE) and 130 with high serum enzymes (HCV-HE), along with 120 cirrhotic patients.

RESULTS

Oxidative stress biomarkers - malondialdehyde (MDA), total peroxides and oxidative stress index (OSI) - were significantly lower in controls vs. each of the patient groups. Cirrhotic patients presented the highest levels. However, total antioxidants (TAO) showed non-significant differences among the four groups. The cellular hypoxia/angiogenesis biomarkers - lactate, vascular endothelial cell growth factor (VEGF) and its soluble receptor 1 (sVEGFR1) - vs. controls were massively increased in patient groups. VEGF was lowest while sVEGFR1 was highest among cirrhotic patients. Immunological biomarkers, - granulocyte/monocyte-colony stimulating factor (GM-CSF) and total immunoglobulin G (IgG) - were massively increased in patient groups vs. controls. GM-CSF was lowest in HCV-HE and IgG was highest in cirrhotic patients. sVEGFR1 correlated with the progression towards cirrhosis.

CONCLUSIONS

Oxidative stress is implicated in the progress of HCV infection with marked induction of cellular hypoxia and dysfunctional angiogenesis, and a futile immunological reaction. sVEGFR1 level correlated with progression towards HCV-induced liver fibrosis.

Ligation-Mediated Polymerase Chain Reaction Detection of 8-Oxo-7,8-Dihydro-2'-Deoxyguanosine and 5-Hydroxycytosine at the Codon 176 of the p53 Gene of Hepatitis C-Associated Hepatocellular Carcinoma Patients

Molecular mechanisms underlying Hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) pathogenesis are still unclear. Therefore, we analyzed the levels of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and other oxidative lesions at codon 176 of the p53 gene, as well as the generation of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M₁dG), in a cohort of HCV-related HCC patients from Italy. Detection of 8-oxodG and 5-hydroxycytosine (5-OHC) was performed by ligation mediated-polymerase chain reaction assay, whereas the levels of M₁dG were measured by chromatography and mass-spectrometry. Results indicated a significant 130% excess of 8-oxodG at –TGC– position of p53 codon 176 in HCV-HCC cases as compared to controls, after correction for age and gender, whereas a not significant increment of 5-OHC at –TGC– position was found. Then, regression models showed an 87% significant excess of M₁dG in HCV-HCC cases relative to controls. Our study provides evidence that increased adduct binding does not occur randomly on the sequence of the p53 gene but at specific sequence context in HCV-HCC patients. By-products of lipid peroxidation could also yield a role in HCV-HCC development. Results emphasize the importance of active oxygen species in inducing nucleotide lesions at a p53 mutational hotspot in HCV-HCC patients living in geographical areas without dietary exposure to aflatoxin B₁.

Role of cytoglobin, a novel radical scavenger, in stellate cell activation and hepatic fibrosis

Cytoglobin (Cygb), a stellate cell-specific globin, has recently drawn attention due to its association with liver fibrosis. In the livers of both humans and rodents, Cygb is expressed only in stellate cells and can be utilized as a marker to distinguish stellate cells from hepatic fibroblast-derived myofibroblasts. Loss of Cygb accelerates liver fibrosis and cancer development in mouse models of chronic liver injury including diethylnitrosamine-induced hepatocellular carcinoma, bile duct ligation-induced cholestasis, thioacetamide-induced hepatic fibrosis, and choline-deficient L-amino acid-defined diet-induced non-alcoholic steatohepatitis. This review focuses on the history of research into the role of reactive oxygen species and nitrogen species in liver fibrosis and discusses the current perception of Cygb as a novel radical scavenger with an emphasis on its role in hepatic stellate cell activation and fibrosis.

Oxidative Stress Management in Chronic Liver Diseases and Hepatocellular Carcinoma

Chronic viral hepatitis B and C and non-alcoholic fatty liver disease (NAFLD) have been widely acknowledged to be the leading causes of liver cirrhosis and hepatocellular carcinoma. As anti-viral treatment progresses, the impact of NAFLD is increasing. NAFLD can coexist with chronic viral hepatitis and exacerbate its progression. Oxidative stress has been recognized as a chronic liver disease progression-related and cancer-initiating stress response. However, there are still many unresolved issues concerning oxidative stress, such as the correlation between the natural history of the disease and promising treatment protocols. Recent findings indicate that oxidative stress is also an anti-cancer response that is necessary to kill cancer cells. Oxidative stress might therefore be a cancer-initiating response that should be down regulated in the pre-cancerous stage in patients with risk factors for cancer, while it is an anti-cancer cell response that should not be down regulated in the post-cancerous stage, especially in patients using anti-cancer agents. Antioxidant nutrients should be administered carefully according to the patients’ disease status. In this review, we will highlight these paradoxical effects of oxidative stress in chronic liver diseases, pre- and post-carcinogenesis.

Flaviviridae Viruses and Oxidative Stress: Implications for Viral Pathogenesis

Oxidative stress is induced once the balance of generation and neutralization of reactive oxygen species (ROS) is broken in the cell, and it plays crucial roles in a variety of natural and diseased processes. Infections of Flaviviridae viruses trigger oxidative stress, which affects both the cellular metabolism and the life cycle of the viruses. Oxidative stress associated with specific viral proteins, experimental culture systems, and patient infections, as well as its correlations with the viral pathogenesis attracts much research attention. In this review, we primarily focus on hepatitis C virus (HCV), dengue virus (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV), West Nile virus (WNV), and tick-borne encephalitis virus (TBEV) as representatives of Flaviviridae viruses and we summarize the mechanisms involved in the relevance of oxidative stress for virus-associated pathogenesis. We discuss the current understanding of the pathogenic mechanisms of oxidative stress induced by Flaviviridae viruses and highlight the relevance of autophagy and DNA damage in the life cycle of viruses. Understanding the crosstalk between viral infection and oxidative stress-induced molecular events may offer new avenues for antiviral therapeutics.

Hepatitis C: From inflammatory pathogenesis to anti-inflammatory/hepatoprotective therapy

Hepatitis C virus (HCV) infection commonly causes progressive liver diseases that deteriorate from chronic inflammation to fibrosis, cirrhosis and even to hepatocellular carcinoma. A long-term, persistent and uncontrolled inflammatory response is a hallmark of these diseases and further leads to hepatic injury and more severe disease progression. The levels of inflammatory cytokines and chemokines change with the states of infection and treatment, and therefore, they may serve as candidate biomarkers for disease progression and therapeutic effects. The mechanisms of HCV-induced inflammation involve classic pathogen pattern recognition, inflammasome activation, intrahepatic inflammatory cascade response, and oxidative and endoplasmic reticulum stress. Direct-acting antivirals (DAAs) are the first-choice therapy for effectively eliminating HCV, but DAAs alone are not sufficient to block the uncontrolled inflammation and severe liver injury in HCV-infected individuals. Some patients who achieve a sustained virologic response after DAA therapy are still at a long-term risk for progression to liver cirrhosis and hepatocellular carcinoma. Therefore, coupling with anti-inflammatory/hepatoprotective agents with anti-HCV effects is a promising therapeutic regimen for these patients during or after treatment with DAAs. In this review, we discuss the relationship between inflammatory mediators and HCV infection, summarize the mechanisms of HCV-induced inflammation, and describe the potential roles of anti-inflammatory/hepatoprotective drugs with anti-HCV activity in the treatment of advanced HCV infection.

Oxidative stress is bane in chronic liver diseases: Clinical and experimental perspective

Oxidative stress plays an important role in the pathogenesis of various chronic liver diseases (CLD) and increasing evidence have confirmed the contributory role of oxidative stress in the pathogenesis of drugs and chemical-induced CLD. Chronic liver injury is manifested as necrosis, cholestasis, fibrosis, and cirrhosis. Chronic administration of anti-tubercular, anti-retroviral, immunosuppressive drugs is reported to induce free radical generation during their biotransformation in the liver. Further, these reactive intermediates are said to induce profibrogenic cytokines, several inflammatory markers, collagen synthesis during the progression of hepatic fibrosis. Oxidative stress and free radicals are reported to induce activation and proliferation of hepatic stellate cells in the injured liver leading to the progression of CLD. Hence, to counteract or to scavenge these reactive intermediates, several plant-derived antioxidant principles have been effectively employed against oxidative stress and came out with promising results in human and experimental models of CLD. This review summarizes the relationships between oxidative stress and different liver pathogenesis induced by drugs and xenobiotics, focusing upon different chronic liver injury induced by alcohol, antitubercular drugs and hyperactivity of antiretroviral drugs in HIV patients, viral hepatitis infection induced oxidative stress.