Transcriptional activity of genes encoding interferon gamma (IFNgamma) and its receptor assessed in peripheral blood mononuclear cells in patients with cardiac syndrome X

Polymorphisms in Cytokine Receptor and Regulator Genes are Associated with Levels of Exercise in Women Prior to Breast Cancer Surgery

Background: Little is known about the genetic characteristics associated with exercise in women undergoing breast cancer surgery. Purpose: In a sample of women who were evaluated prior to breast cancer surgery (n = 310), we evaluated for differences in demographic and clinical characteristics between patients who did and did not exercise on a regular basis and evaluated for associations between polymorphisms in genes for pro- and anti-inflammatory cytokines, their receptors, and their transcriptional regulators. Methods: Patients completed an investigator-developed exercise questionnaire. Based on the recommended level of exercise (≥150 minutes/week), survivors were classified into no exercise (NoEx), less exercise (LessEx), or recommended exercise (RecEx) groups. Candidate gene analyses were done to identify relationships between polymorphisms and exercise group membership (i.e., NoEx vs. RecEx). Only 23.5% of the total sample met the recommendations for regular exercise. Results: Compared to the RecEx group (n = 78), patients in the NoEx group (n = 120) had less education; were less likely to report being White or Asia/Pacific Islander; more likely to report a lower household income; had a higher body mass index (BMI), had a poorer functional status; had a higher comorbidity burden; were more likely to self-report high blood pressure; and were more likely to have received neoadjuvant chemotherapy. Polymorphisms in IFNGR1 and NFKB1 were associated with membership in the NoEx group. Conclusions: While they warrant replication, our findings suggest that variations in cytokine-related genes may play a role in exercise behavior, and that clinicians need to assess for barriers to regular exercise and educate patients on its benefits.

Identification of a single nucleotide polymorphism indicative of high risk in acute myocardial infarction

Background & objectives:

Acute myocardial infarction (AMI) is a major health concern in India. The aim of the study was to identify single nucleotide polymorphisms (SNPs) associated with AMI in patients using dedicated chip and validating the identified SNPs on custom-designed chips using high-throughput microarray analysis.

Methods:

In pilot phase, 48 AMI patients and 48 healthy controls were screened for SNPs using human CVD55K BeadChip with 48,472 SNP probes on Illumina high-throughput microarray platform. The identified SNPs were validated by genotyping additional 160 patients and 179 controls using custom-made Illumina VeraCode GoldenGate Genotyping Assay. Analysis was carried out using PLINK software.

Results:

From the pilot phase, 98 SNPs present on 94 genes were identified with increased risk of AMI (odds ratio of 1.84-8.85, P=0.04861-0.003337). Five of these SNPs demonstrated association with AMI in the validation phase (P<0.05). Among these, one SNP rs9978223 on interferon gamma receptor 2 [IFNGR2, interferon (IFN)-gamma transducer 1] gene showed a significant association (P=0.00021) with AMI below Bonferroni corrected P value (P=0.00061). IFNGR2 is the second subunit of the receptor for IFN-gamma, an important cytokine in inflammatory reactions.

Interpretation & conclusions:

The study identified an SNP rs9978223 on IFNGR2 gene, associated with increased risk in AMI patient from India.

Transcriptional Activity of Gene Encoding Subunits R1 and R2 of Interferon Gamma Receptor in Peripheral Blood Mononuclear Cells in Patients with Slow Coronary Flow

Background

Slow coronary flow (SCF) is a coronary artery disorder characterized with delayed opacification of epicardial coronary arteries without obstructive coronary disease. The pathophysiological mechanisms of SCF remain unclear. One of the possible mechanisms that may participate in the pathology of SCF is endothelial dysfunction related to the inflammatory process. Interferon gamma (IFN-γ) is an inflammatory cytokine that acts through its specific receptor composed of two subunits, IFN-γR1 and IFN-γR2. Transcriptional activity of the gene encoding these subunits influences IFN-γ activity. This study aimed to investigate the gene expression of IFN-γ receptor subunits in peripheral blood mononuclear cells (PBMC) from patients with SCF.

Methods

The study was performed with 30 patients (22 male/8 female) aged 35–76 (52.8±11.7 years) with SCF and 15 sex- (11 male/4 female), Body Max Index (BMI)- and age-matched (54.73±9.42 years) healthy subjects. Total mRNA was extracted from PBMC and was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The relative expression values (2^-ΔΔCt) between control and case groups were determined and the Mann-Whitney U test was used for statistical analysis.

Results

There was a significant increase in the gene expression of IFN-γR1 in PBMC from SCF patients vs. controls (P< 0.0001); but the differences in IFN-γR2 gene expression were statistically insignificant between patient and control groups (P= 0.853).

Conclusions

It can be concluded that IFN-γ gene expression may influence the function of microvasculature and thereby contribute to the pathophysiology of SCF.

Transcriptomics to study the effect of a Mediterranean-inspired diet on inflammation in Crohn's disease patients

Background

Inflammation is an essential immune response; however, chronic inflammation results in disease including Crohn's disease. Therefore, reducing the inflammation can yield a significant health benefit, and one way to achieve this is through diet. We developed a Mediterranean-inspired anti-inflammatory diet and used this diet in a 6-week intervention in a Crohn's disease population. We examined changes in inflammation and also in the gut microbiota. We compared the results of established biomarkers, C-reactive protein and the micronuclei assay, of inflammation with results from a transcriptomic approach.

Results

Data showed that being on our diet for 6 weeks was able to reduce the established biomarkers of inflammation. However, using transcriptomics, we observed significant changes in gene expression. Although no single gene stood out, the cumulative effect of small changes in many genes combined to have a beneficial effect. Data also showed that our diet resulted in a trend of normalising the microbiota.

Conclusions

This study showed that our Mediterranean-inspired diet appeared to benefit the health of people with Crohn's disease. Our participants showed a trend for reduced markers of inflammation and normalising of the microbiota. The significant changes in gene expression after 6 weeks highlighted the increased sensitivity of using transcriptomics when compared to the established biomarkers and open up a new era of dietary intervention studies.

Gene expression of peripheral blood mononuclear cells as a tool in dietary intervention studies: What do we know so far?

Peripheral blood mononuclear cells (PBMCs) generally refer to monocytes and lymphocytes, representing cells of the innate and adaptive immune systems. PBMCs are a promising target tissue in the field of nutrigenomics because they seem to reflect the effects of dietary modifications at the level of gene expression. In this review, we describe and discuss the scientific literature concerning the use of gene expression at the mRNA level measured from PBMCs in dietary interventions studies conducted in humans. A search of literature was undertaken using PubMed (last assessed November 24, 2011) and 20 articles were selected for discussion. Currently, results from these studies showed that PBMCs seem to reflect liver environment and complement adipose tissue findings in transcriptomics. PBMC gene expression after dietary intervention studies can be used for studying the response of certain genes related to fatty acid and cholesterol metabolism, and to explore the response of dietary interventions in relation to inflammation. However, PBMC transcriptomics from dietary intervention studies have not resulted yet in clear confirmation of candidate genes related to disease risk. Use of microarray technology in larger well-designed dietary intervention studies is still needed for exploring PBMC potential in the field of nutrigenomics.

Altered transcriptional activity of gene encoding GAPDH in peripheral blood mononuclear cells from patients with cardiac syndrome X - an important part in pathology of microvascular angina?

INTRODUCTION

Cardiac syndrome X (CSX) is characterized by anginal pain with ECG suggestive of ischaemia and normal coronary arteries at angiography. Pathology of CSX involves microvascular dysfunction and is possibly linked with metabolic syndrome. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an enzyme involved in glycolysis. The GAPDH gene is a "housekeeping" gene and is used for normalization in quantitative gene expression assays. The aim of the study was to evaluate GAPDH gene expression in CSX.

MATERIAL AND METHODS

The study was performed in 35 CSX patients and 10 control subjects. mRNA was extracted from peripheral blood mononuclears and the mRNA was assessed by QRT-PCR.

RESULTS

GAPDH gene expression was enhanced in CSX patients vs. controls (93022 ±23837 copies/μg vs. 1067 ±240 copies/μg respectively; p < 0.001). Moreover, transcriptional activity of the GAPDH gene was heterogeneous within the CSX group.

CONCLUSIONS

GAPDH gene expression is markedly enhanced in CSX, which reflects carbohydrate metabolism disturbances and makes the GAPDH gene unsuitable as an endogenous control in patients with CSX.

Definitions and incidence of cardiac syndrome X: review and analysis of clinical data

There is no consensus regarding the definition of cardiac syndrome X (CSX). We systematically reviewed recent literature using a standardized search strategy. We included 57 articles. A total of 47 studies mentioned a male/female distribution. A meta-analysis yielded a pooled proportion of females of 0.56 (n = 1,934 patients, with 95% confidence interval: 0.54-0.59). As much as 9 inclusion criteria and 43 exclusion criteria were found in the 57 articles. Applying these criteria to a population with normal coronary angiograms and treated in 1 year at a general hospital, the attributable CSX incidence varied between 3 and 11%. The many inclusion and exclusion criteria result in a wide range of definitions of CSX and these have large effects on the incidence. This shows the need for a generally accepted definition of CSX.