Insulin resistance is associated with DNA damage in peripheral blood cells in non-diabetic patients with genotype 1 chronic hepatitis C

Abstract

Background. In chronic liver diseases of different etiologies, including viral hepatitis, genotoxic effects of oxidative stress have been shown, both in clinical and in experimental conditions, suggesting that this mechanism may contribute to the evolution of the disease. Aim. To evaluate DNA damage in the peripheral blood of untreated non-diabetic patients with chronic hepatitis C and control subjects, and its correlation with demographic, anthropometric, biochemical, and histological parameters in the patient sample. Patients and methods. This study comprised 100 subjects of both genders, 60 of whom were treatment-naïve patients with positive serology for genotype 1 hepatitis C. The remaining 40 were blood donors with negative serology for hepatitis who were used as control subjects, and matched by gender, age, weight, and BMI. DNA damage was determined using the comet assay in the total peripheral blood. Results. The DNA damage evaluated by the comet assay revealed higher values in the group of patients with hepatitis compared with that in the control group. The relationships of the comet assay with the studied variables were assessed using multivariate analysis; significant correlations were only identified with insulin (r = 0.343, p = 0.008) and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) (r = 0.331, p = 0.011). Conclusion. Patients with genotype 1 chronic hepatitis C have higher rates of DNA damage, as determined by comet assay and this alteration is correlated with the HOMA index of insulin resistance.     

Ageing is associated with a decline in peripheral blood CD56bright NK cells

Background  

Natural killer (NK) cells are cytotoxic lymphocytes that lack CD3 and express variable levels of CD16, CD56 and CD57. In recent years NK cells have been categorised into two major groups based on the level of CD56 expression. This phenotypic classification correlates with functional activity as CD56^bright NK cells are the major cytokine producing subset whereas CD56^dim NK cells exhibit greater cytotoxic activity. Previous studies have revealed a reduction in total NK cell numbers in association with ageing and this study sought to determine the potential influence of ageing on the number of NK cell subsets within peripheral blood.     

Depletion of regulatory T cells in HIV infection is associated with immune activation

Immune activation during chronic HIV infection is a strong clinical predictor of death and may mediate CD4(+) T cell depletion. Regulatory T cells (Tregs) are CD4(+)CD25(bright)CD62L(high) cells that actively down-regulate immune responses. We asked whether loss of Tregs during HIV infection mediates immune activation in a cross-sectional study of 81 HIV-positive Ugandan volunteers. We found that Treg number is strongly correlated with both CD4(+) and CD8(+) T cell activation. In multivariate modeling, this relationship between Treg depletion and CD4(+) T cell activation was stronger than any other clinical factor examined, including viral load and absolute CD4 count. Tregs appear to decline at different rates compared with other CD4(+) T cells, resulting in an increased regulator to helper ratio in many patients with advanced disease. We hypothesize that this skewing may contribute to T cell effector dysfunction. Our findings suggest Tregs are a major contributor to the immune activation observed during chronic HIV infection.     

Viral adaptation to host immune responses occurs in chronic hepatitis B virus (HBV) infection, and adaptation is greatest in HBV e antigen-negative disease

Hepatitis B virus (HBV)-specific T-cell responses are important in the natural history of HBV infection. The number of known HBV-specific T-cell epitopes is limited, and it is not clear whether viral evolution occurs in chronic HBV infection. We aimed to identify novel HBV T-cell epitopes by examining the relationship between HBV sequence variation and the human leukocyte antigen (HLA) type in a large prospective clinic-based cohort of Asian patients with chronic HBV infection recruited in Australia and China (n = 119). High-resolution 4-digit HLA class I and II typing and full-length HBV sequencing were undertaken for treatment-naïve individuals (52% with genotype B, 48% with genotype C, 63% HBV e antigen [HBeAg] positive). Statistically significant associations between HLA types and HBV sequence variation were identified (n = 49) at 41 sites in the HBV genome. Using prediction programs, we determined scores for binding between peptides containing these polymorphisms and associated HLA types. Among the regions that could be tested, HLA binding was predicted for 14/18 (78%). We identified several HLA-associated polymorphisms involving likely known anchor residues that resulted in altered predicted binding scores. Some HLA-associated polymorphisms fell within known T-cell epitopes with matching HLA restriction. Enhanced viral adaptation (defined as the presence of the relevant HLA and the escaped amino acid) was independently associated with HBeAg-negative disease (P = 0.003). Thus, HBV appears to be under immune pressure in chronic HBV infection, particularly in HBeAg-negative disease.     

Hyperoxidized peroxiredoxins in peripheral blood mononuclear cells of asthma patients is associated with asthma severity

AimsOxidative stress is involved in the pathogenesis of asthma, and peroxiredoxins (PRDX) may be critical in controlling intracellular oxidative stress. The aim of this study was to evaluate expressions of PRDX and their hyperoxidized forms in asthmatic individuals.Main methodsThe levels of expression of PRDX1, PRDX2, PRDX3, and PRDX6 and their hyperoxidized forms (PRDX-SO₃) were measured in PBMCs from asthma patients and control subjects. In addition, cells from these subjects were treated with hydrogen peroxide (H₂O₂) and their intracellular concentrations of reactive oxygen species (ROS) were measured.Key findingsThe ratios of hyperoxidized to total PRDX (PRDX-SO_3/PRDX) in PBMCs were significantly higher in asthma patients than in normal subjects and were correlated with disease severity, with the highest ratio seen in patients with severe asthma. Furthermore, H₂O₂ treatment of PBMCs, particularly lymphocytes, increased intracellular ROS concentrations with greater and more persistent increases observed in cells from asthmatic than from control subjects.SignificanceHyperoxidation of PRDX may serve as a biomarker of asthma severity and may predict enhanced susceptibility to oxidative stress load in PBMCs of asthmatics.     

IL-21 is associated with natural resistance to HIV-1 infection in a Colombian HIV exposed seronegative cohort

Higher IL-21 levels were associated with natural resistance to HIV infection in an Italian cohort. Thus we wanted to confirm such association in HIV exposed seronegative individuals (HESN) from Colombia. Cells from HESN were less susceptible to infection and expressed higher IL-21 mRNA levels than healthy controls at both baseline and 7-days post-infection; similar results were observed for IL-6, perforin, and granzyme. These results suggest that IL-21/IL-6 increase may be a distinctive quality in the profile of HIV-1 resistance, at least during sexual exposure. However, further studies are necessary to confirm the specific protective mechanisms of these cytokines.     

Adherence to Mediterranean diet is associated with methylation changes in inflammation-related genes in peripheral blood cells

Epigenetic processes, including DNA methylation, might be modulated by environmental factors such as the diet, which in turn have been associated with the onset of several diseases such as obesity or cardiovascular events. Meanwhile, Mediterranean diet (MedDiet) has demonstrated favourable effects on cardiovascular risk, blood pressure, inflammation and other complications related to excessive adiposity. Some of these effects could be mediated by epigenetic modifications. Therefore, the objective of this study was to investigate whether the adherence to MedDiet is associated with changes in the methylation status from peripheral blood cells. A subset of 36 individuals was selected within the Prevención con Dieta Mediterránea (PREDIMED)-Navarra study, a randomised, controlled, parallel trial with three groups of intervention in high cardiovascular risk volunteers, two with a MedDiet and one low-fat control group. Changes in methylation between baseline and 5 years were studied. DNA methylation arrays were analysed by several robust statistical tests and functional classifications. Eight genes related to inflammation and immunocompetence (EEF2, COL18A1, IL4I1, LEPR, PLAGL1, IFRD1, MAPKAPK2, PPARGC1B) were finally selected as changes in their methylation levels correlated with adherence to MedDiet and because they presented sensitivity related to a high variability in methylation changes. Additionally, EEF2 methylation levels positively correlated with concentrations of TNF-α and CRP. This report is apparently the first showing that adherence to MedDiet is associated with the methylation of the reported genes related to inflammation with a potential regulatory impact.     

Detection of fetal cells with 47,XY,+21 karyotype in maternal peripheral blood

Fetal cells were isolated from the peripheral blood of a pregnant woman at 19 weeks of gestation whose fetus had Down syndrome. An amniocentesis had been performed 2 weeks earlier because of abnormalities detected on an antenatal sonogram. Fetal cells were separated by fluorescence-activated cell sorting using monoclonal antibody to the transferrin receptor (TfR). Fluorescence in situ hybridization studies with probes for chromosomes Y and 21 revealed a small number of 47,XY,+21 cells in the TfR^- sorted fraction. Although preliminary, the results of this study suggest the possibility that one day, fetal chromosome aneuploidy will be routinely diagnosed from maternal venous blood samples.     

Gastrointestinal nematode infection is associated with variation in innate immune responsiveness

Ex vivo monocyte cytokine responses (IL-1beta, TNF-alpha, IL-12p70, IL-10, TGF-beta) to bacterial TLR2 and TLR4 ligands were quantified in 47 gastrointestinal (GI) nematode-exposed children in Pemba Island, Tanzania. Worminess (estimated by faecal egg counts (FEC)) had a positive relationship with pro-inflammatory TNF-alpha and IL-1beta responsiveness to the TLR ligands. In particular, there was a strong significant relationship with TNF-alpha response to TLR4 ligand (LPS). There were no significant associations between regulatory responses (IL-10, TGF-beta) and worminess. These results are consistent with the possibility that GI nematodes modulate innate responses and may indicate a potential mechanism for interactions between GI nematodiasis and important bystander pathogens.     

TWIST1, MMP-21, and HLAG-1 co-overexpression is associated with ESCC aggressiveness

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of cancer, requiring reliable biomarkers for prognosis and therapeutic responsiveness. TWIST1, as an important factor responsible for metastasis of several cancers, is involved in tumor invasion and metastasis through indirectly regulation of MMP-21 expression. On the other hand, NF-ĸβ which is a regulator of HLAG-1 has direct interaction with TWIST1 protein. In this retrospective study we investigated the clinical significance of TWIST1, MMP-21, and HLAG-1 expression in ESCC, and the possible correlation between these genes and progression of the disease. The gene expression analyses of TWIST1, MMP-21, and HLA-G1 were performed by relative comparative real-time polymerase chain reaction in 58 ESCCs compared with corresponding margin-normal esophageal tissues. Significant overexpression of HLAG-1, TWIST1, and MMP-21 messenger RNA was observed in 22.4%, 41.4%, and 60.3% of tumor samples, respectively. Concomitant overexpression of TWIST1/MMP-21 and TWIST1/HLAG-1 were significantly correlated to each other in various clinicopathological features, including depth of tumor invasion, stage of tumor progression, lymphatic invasion, and grade of tumor cell differentiation ( P < 0.05). The current study is the first report of coexpression of TWIST1, MMP-21, and HLAG-1 in ESCC. Such findings suggest an oncogenic role for concomitant expression of these genes in ESCC invasion and metastasis.     

Glutathione and its associated enzymes in peripheral blood cells in different stages of chronic renal insufficiency

Summary Reduced glutathione (GSH) levels and glutathione reductase (GR) and glutathione S-transferase (GST) activities were investigated in the erythrocytes and lymphocytes of non-dialyzed patients with varying degrees of chronic renal insufficiency, and also of patients on regular hemodialysis treatment. GSH, GR and GST levels were higher in erythrocytes and lymphocytes of examined patients as compared to their corresponding age-matched healthy controls. A correlation was found between the degree of renal insufficiency and the above parameters tested. A routine hemodialysis did not significantly affect erythrocyte and lymphocyte GSH content and activities of its associated enzymes. The increased GSH levels as well as GSH-linked enzyme activities of blood cells in uremia may be a protective mechanism for the cells due to the accumulation of toxic, oxidizing, wastes in the blood as a result of the uremic state. This view is supported by the results ofin vitro experiments, which have shown that GR and GST activities of normal human lymphocytes are increased when incubated with plasma from uremic patients.     

Association between microRNA-21, microRNA-150, and micro-RNA-451 expression and clinical outcome of patients with acute lymphoblastic leukemia

Background

Acute lymphoblastic leukemia (ALL) occurs owing to the defective maturation, increased proliferation, and lack of differentiation of lymphoid cells. Evaluation of the expression levels of microRNAs (miRNAs) could help in the prognosis and improve the clinical outcome of ALL patients. Given the role of miR-21, miR-150, and miR-451 as oncogenes and tumor suppressors in lymphocytes, this study explored the relation between the expression levels of these miRNAs and the clinical outcomes of ALL patients.

Methods

cDNA synthesis and RT-PCR were performed for peripheral blood samples from 41 patients with ALL, as well as for U937 and Jurkat cell lines to examine the expression of miR-451, miR-150, and miR-21 after miRNA purification. We also performed an epidemiological analysis in which Mann–Whitney and Chi-square tests were used to investigate the relationship between the expression of miRNAs and other clinical and laboratory data. Binary logistic regression models were used to estimate the odds ratio in univariate and multivariate analyses for clinical outcomes.

Results

miR-21 and miR-150 expression was found to be decreased, while miR-451 expression showed no difference compared to the control group. There was a significant relationship between miR-451 expression and hemoglobin (Hb) levels, as well as between miR-150 expression and clinical outcomes of ALL patients.

Conclusion

Increased expression of miR-451 decreased the Hb levels; reduced expression of miR-150 was associated with increased relapse rate in patients. Age, increased WBC, and decreased Hb levels were associated with increased relapse rates in ALL patients. Therefore, miR-150 could be used as a biomarker to determine the clinical outcome of ALL patients.

     

Control of heterologous hepatitis C virus infection in chimpanzees is associated with the quality of vaccine-induced peripheral T-helper immune response

Prophylactic hepatitis C virus (HCV) vaccine trials with human volunteers are pending. There is an important need for immunological end points which correlate with vaccine efficacy and which do not involve invasive procedures, such as liver biopsies. By using a multicomponent DNA priming-protein boosting vaccine strategy, na?ve chimpanzees were immunized against HCV structural proteins (core, E1, and E2) as well as a nonstructural (NS3) protein. Following immunization, exposure to the heterologous HCV 1b J4 subtype resulted in a peak of plasma viremia which was lower in both immunized animals. Compared to the na?ve infection control and nine additional historical controls which became chronic, vaccinee 2 (Vac2) rapidly resolved the infection, while the other (Vac1) clearly controlled HCV infection. Immunization induced antibodies, peptide-specific gamma interferon (IFN-gamma), protein-specific lymphoproliferative responses, IFN-gamma, interleukin-2 (IL-2), and IL-4 T-helper responses in both vaccinees. However, the specificities were markedly different: Vac2 developed responses which were lower in magnitude than those of Vac1 but which were biased towards Th1-type cytokine responses for E1 and NS3. This proof-of-principle study in chimpanzees revealed that immunization with a combination of nonstructural and structural antigens elicited T-cell responses associated with an alteration of the course of infection. Our findings provide data to support the concept that the quality of the response to conserved epitopes and the specific nature of the peripheral T-helper immune response are likely pivotal factors influencing the control and clearance of HCV infection.     

Antigen-specific T regulatory-1 cells are associated with immunosuppression in a chronic helminth infection (onchocerciasis)

Different mechanisms underlie the phenomenon of peripheral tolerance. Recently, a new subset of CD4+ T cells, called T regulatory-1 (Tr1) cells, was described which show suppressor functions in vitro and in vivo and are characterized by a predominant production of IL-10 and/or TGF-beta. Tr1 cells have so far been generated experimentally in an IL-10-rich environment and hold promise for exploitation in the suppression of alloreactions and inflammatory or allergic dispositions. However, these cells have not been characterized in infectious diseases. Here we show that in the chronic helminth infection onchocerciasis (river blindness), where patients have relatively little sign of dermatitis despite the presence of millions of small worms in the skin, T cells can be obtained which bear characteristics of Tr1 cells, producing no IL-2 or IL-4 but substantial amounts of IL-10, variable amounts of IL-5, and some IFN-gamma. These cells display elevated amounts of CTLA-4 after stimulation and are able to inhibit other T cells in coculture, in contrast to Th1 and Th2 clones. This is the first time that this type of suppressor T cell has been cloned as naturally occurring during an infectious disease.     

BimEL-dependent apoptosis induced in peripheral blood lymphocytes with n-butyric acid is moderated by variation in expression of c-myc and p21(WAF1)

We have examined the effect of sodium butyrate (SB) on the viability of normal peripheral blood lymphocytes (PBLs) in vitro and the effect of this agent on the expression of 20 apoptosis-related genes. Data suggest that PBL treated with 2 mmol L(-1) SB resisted for at least 8 h the destructive activity of the agent, but eventually 30% of cells died within 72 h. As documented by flow cytometry and cytochrome c release study, cells underwent mitochondrial-derived apoptosis. While the expression of the majority of genes examined by RT-PCR and Western blots remained indifferent to 2 mmol L(-1) SB, the cellular levels of BimEL, c-myc, p53, and p21(WAF1) varied profoundly with the time of SB treatment. The Bax activator BimEL increased rapidly, driving cells toward apoptosis likely controlled by c-myc and p21(WAF1) activities. The c-myc, exercising the role of mediator of the function of BimEL and inhibitor of p21(WAF1) expression, decreased significantly for several hours after adding SB but within 48 h it returned to close to its original value. An apoptosis inhibitor and executive caspase substrate p21(WAF1) increased early at the beginning of treatment but subsequently, within a time frame of 72 h, profoundly dropped in terms of both a caspase-dependent and caspase-independent way. We suggest that variations in c-myc and p21(WAF1) expression delay apoptosis making PBL resistant to SB for several hours, and together with fast catabolism of SB in vivo protect PBL against the destructive activity of this anti-cancerous metabolite of colonic bacteria.     

Up-regulated lncRNA-PVT1 expression in peripheral blood mononuclear cells of patients with coronary artery disease is correlated with decreased interleukin-10 production

Molecular Biology Reports - Plasmacytoma variant translocation 1 (PVT1) is a newly discovered long non-coding RNA, which has not been previously studied in the inflammatory responses of the...     

Mitochondrial DNA copy number in peripheral blood cells declines with age and is associated with general health among elderly

The role of the mitochondria in disease, general health and aging has drawn much attention over the years. Several attempts have been made to describe how the numbers of mitochondria correlate with age, although with inconclusive results. In this study, the relative quantity of mitochondrial DNA compared to nuclear DNA, i.e. the mitochondrial DNA copy number, was measured by PCR technology and used as a proxy for the content of mitochondria copies. In 1,067 Danish twins and singletons (18–93 years of age), with the majority being elderly individuals, the estimated mean mitochondrial DNA copy number in peripheral blood cells was similar for those 18–48 years of age [mean relative mtDNA content: 61.0; 95 % CI (52.1; 69.9)], but declined by ?0.54 mtDNA 95 % CI (?0.63; ?0.45) every year for those older than approximately 50 years of age. However, the longitudinal, yearly decline within an individual was more than twice as steep as observed in the cross-sectional analysis [decline of mtDNA content: ?1.27; 95 % CI (?1.71; ?0.82)]. Subjects with low mitochondrial DNA copy number had poorer outcomes in terms of cognitive performance, physical strength, self-rated health, and higher all-cause mortality than subjects with high mitochondrial DNA copy number, also when age was controlled for. The copy number mortality association can contribute to the smaller decline in a cross-sectional sample of the population compared to the individual, longitudinal decline. This study suggests that high mitochondrial DNA copy number in blood is associated with better health and survival among elderly.