Peripheral blood mononuclear cells (PBMCs): a possible model for studying cardiovascular biology systems

Gene expression profiling in elderly patients with familial hypercholesterolemia with and without coronary heart disease

BACKGROUND AND AIMS

Elderly familial hypercholesterolemia (FH) patients are at high risk of coronary heart disease (CHD) due to high cholesterol burden and late onset of effective cholesterol-lowering therapies. A subset of these individuals remains free from any CHD event, indicating the potential presence of protective factors. Identifying possible cardioprotective gene expression profiles could contribute to our understanding of CHD prevention and future preventive treatment. Therefore, this study aimed to investigate gene expression profiles in elderly event-free FH patients.

METHODS

Expression of 773 genes was analysed using the Nanostring Metabolic Pathways Panel, in peripheral blood mononuclear cells (PBMCs) from FH patients ≥65 years without CHD (FH event-free, n = 44) and with CHD (FH CHD, n = 39), and from healthy controls ≥70 years (n = 39).

RESULTS

None of the genes were differentially expressed between FH patients with and without CHD after adjusting for multiple testing. However, at nominal p < 0.05, we found 36 (5%) differentially expressed genes (DEGs) between the two FH groups, mainly related to lipid metabolism (e.g. higher expression of ABCA1 and ABCG1 in FH event-free) and immune responses (e.g. lower expression of STAT1 and STAT3 in FH event-free). When comparing FH patients to controls, the event-free group had fewer DEGs than the CHD group; 147 (19%) and 219 (28%) DEGs, respectively.

CONCLUSIONS

Elderly event-free FH patients displayed a different PBMC gene expression profile compared to FH patients with CHD. Differences in gene expression compared to healthy controls were more pronounced in the CHD group, indicating a less atherogenic gene expression profile in event-free individuals. Overall, identification of cardioprotective factors could lead to future therapeutic targets.

Omega-3 fatty acids and individual variability in plasma triglyceride response: A mini-review

Cardiovascular disease (CVD) is a leading cause of death worldwide. Supplementation with the marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is associated with lower CVD risk. However, results from randomized controlled trials that examine the effect of omega-3 supplementation on CVD risk are inconsistent. This risk-reducing effect may be mediated by reducing inflammation, oxidative stress and serum triglyceride (TG) levels. However, not all individuals respond by reducing TG levels after omega-3 supplementation. This inter-individual variability in TG response to omega-3 supplementation is not fully understood. Hence, we aim to review the evidence for how interactions between omega-3 fatty acid supplementation and genetic variants, epigenetic and gene expression profiling, gut microbiota and habitual intake of omega-3 fatty acids can explain why the TG response differs between individuals. This may contribute to understanding the current controversies and play a role in defining future personalized guidelines to prevent CVD.

The physical exercise-induced oxidative/inflammatory response in peripheral blood mononuclear cells: Signaling cellular energetic stress situations

Peripheral blood mononuclear cells (PBMCs) are a variety of specialized immune cells produced in the bone marrow from hematopoietic stem cells (HSCs) that work together to protect our bodies from harmful pathogens. From a metabolic point of view, these cells can serve as sentinel tissue source for distinguishing multiple types of whole-body physiological perturbations. The significant interaction of PBMCs with systemic physiology makes these cells an attractive target for several interventions such as physical exercise. Analyses of oxidative/inflammatory and metabolic markers of PBMCs obtained from unhealthy and healthy humans have been used in monitoring immune response in different exercise conditions. It is already a common consensus that regular practice of physical exercise, that is planned, structured, and repetitive, influences personal health by altering the metabolic state and the immune system. However, the role of distinct metabolic processes responsible for maintaining metabolic balance during physical exercise in PBMCs is not fully understood. Furthermore, a complete dose-response analysis between different exercise protocols and biomarkers capable of predicting physical performance needs to be better elucidated. The absence of published reviews on this topic compromises the understanding of the crosstalk between the metabolic adaptations of PBMCs and exercise-induced changes in the immune system. Given the above, this review highlights the main findings in the literature involving the responses of PBMCs in the inflammatory/oxidative stress induced by physical exercise. The present review also highlights how distinct phenotypes and functional diversity of PBMCs make these cells an accessible alternative for assessing exercise-induced metabolic adaptations.

Exercise sustains the hallmarks of health

Exercise has long been known for its active role in improving physical fitness and sustaining health. Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases. It is well-documented that exercise maintains and restores homeostasis at the organismal, tissue, cellular, and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions. Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health, including the integrity of barriers, containment of local perturbations, recycling and turnover, integration of circuitries, rhythmic oscillations, homeostatic resilience, hormetic regulation, as well as repair and regeneration. Furthermore, we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise. This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions. We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life.

Changes in the expression of meteorin-like (METRNL), irisin (FNDC5), and uncoupling proteins (UCPs) after bariatric surgery

OBJECTIVE

Bariatric surgery is currently the most effective treatment for severe obesity. This study aims to investigate the changes in expression levels of meteorin-like protein (METRNL), irisin (FNDC5), and uncoupling proteins (UCP) 1/2/3 following bariatric surgery to understand their involvement in enhancing metabolism after surgery.

METHOD

A total of 40 participants were enrolled in this interventional study, 20 with obesity BMI ≥ 35 kg/m² and 20 with BMI ≤ 25 kg/m² . Bariatric surgery (laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass) was performed. The levels of various molecules of interest were analyzed before and after surgery.

RESULTS

Gene expression analysis revealed significantly higher levels of METRNL, UCP1, and UCP3 in individuals with obesity when compared with healthy individuals before surgery (p < 0.05). Gene expression levels of METRNL and UCP2 showed a significant increase after bariatric surgery (p < 0.05). METRNL plasma level was significantly higher in individuals with obesity before surgery (mean [SEM], 55,222.6 [1,421.1] pg/mL, p = 0.0319), as well as at 6 and 12 months (57,537.3 [1,303.9] pg/mL, p = 0.0005; 59,334.9 [1,214.3] pg/mL, p < 0.0001) after surgery.

CONCLUSION

The changes in the levels of various molecules of interest support their possible involvement in the inflammatory and thermogenic responses following bariatric surgery.

Gene expression of klotho & antioxidative enzymes in peripheral blood mononuclear cells of essential hypertension patients in Indian population

Background & objectives:

Oxidative stress is known to have a causal role in hypertension. Klotho has emerged as a novel anti-aging molecule to inhibit oxidative stress at cellular level. This study aimed at evaluating the gene expression of klotho and antioxidative enzymes, manganese superoxide dismutase (Mn-SOD) and catalase, in peripheral blood mononuclear cells of essential hypertensive patients as compared to normotensive healthy controls.

Methods:

Ninety-nine newly diagnosed hypertensives and 103 age- and BMI-matched controls were recruited. The participants were non-diabetic and not on any medication. Soluble α-klotho levels were detected using enzyme-linked immunosorbent assay. Gene expression was evaluated by quantitative real-time polymerase chain reaction.

Results:

Soluble α-klotho levels were significantly lower (27%, P=0.001) in patients as compared to controls. The trend remained same when compared against 44 out of 103 controls considered for gene expression analysis. Relative gene expression of klotho and catalase were 3-fold and 1.25-fold lower in patients as compared to controls, respectively. ΔCt value-based gene expression were also significantly lower for both genes (P=0.001). A decreasing but non-significant trend was observed for Mn-SOD gene expression. ΔCt value-based gene expression of catalase positively correlated with that of Mn-SOD in patient (rs=0.448) and control (rs=0.547) groups (P<0.001). In patients, the gene expression of Klotho positively correlated with that of catalase (rs=0.498, P=0.001), but not Mn-SOD (rs=0.155, P=0.126).

Interpretation & conclusions:

In the present study on newly diagnosed hypertensives, klotho and catalase gene expression were found to be significantly lower as compared to controls, indicating the role of oxidative stress in this patient group. In addition, a significant correlation between Klotho and catalase gene expression suggests a role for klotho in essential hypertension with respect to antioxidant defence.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

Obesity status modifies the association between rs7556897T>C in the intergenic region SLC19A3-CCL20 and blood pressure in French children

Background Growing evidence reports an association between inflammatory markers, obesity and blood pressure (BP). Specifically, the intergenic single nucleotide polymorphism (SNP) rs7556897T > C (MAF = 0.34) located between SLC19A3 and the CCL20 was shown to be associated with chronic inflammatory diseases. In addition, CCL20 expression was found increased in pancreatic islets of obese rodents and human pancreatic β cells under the influence of inflammation. In this study, we hypothesized that SNP rs7556897 could affect BP levels, thus providing a link between inflammation, BP and obesity. Methods BP was measured under supine position with a manual sphygmomanometer; values reported were the means of three readings. We analyzed rs7556897 in 577 normal weight and 689 obese French children. Using real-time polymerase chain reaction (PCR), we quantified CCL20 and SLC19A3 expression in adipose tissue and peripheral blood mononuclear cells (PBMCs) of normal weight and overweight children. Results The rs7556897C allele was negatively associated with diastolic BP in normal weight children (β = -0.012 ± 0.004, p = 0.006) but positively associated in obese children (β = 2.178 ± 0.71, p = 0.002). A significant interaction between rs7556897T > C and the obesity status (obese or normal weight) was detected (β = 3.49, p = 9.79 × 10-5) for BP in a combined population analysis. CCL20 mRNA was only expressed in the adipose tissue of overweight children, and its expression levels were 10.7×  higher in PBMCs of overweight children than normal weight children. Finally, CCL20 mRNA levels were positively associated with rs7556897T > C in PBMCs of 58 normal weight children (β = 0.43, p = 0.002). SLC19A3 was not expressed in PBMCs, and in adipose tissue, it showed same levels of expression in normal weight and overweight children. The gene expression results may highlight a specific involvement of CCL20 via communicating obesity/inflammation pathways that regulate BP. Conclusions Childhood obesity reverses the effect of rs7556897T > C on diastolic BP, possibly via the modulation of CCL20 expression levels.

Peripheral Blood Mononuclear Cells Expression Levels of miR-196a and miR-100 in Coronary Artery Disease Patients

As a chronic inflammatory disease, coronary artery disease (CAD) is a common cause of death worldwide. Dysregulation of microRNA expression levels in peripheral blood mononuclear cells (PBMCs) may contribute to CAD and serve as a potential diagnostic biomarker. Here, we evaluated PBMC expression of two CAD-related inflammatory miRNAs, miR-196a and miR-100, in PBMCs of CAD patients with significant stenosis (CAD, n: 72), patients with insignificant coronary stenosis (ICAD, n: 30), and controls (n: 74) and checked whether they can segregate study groups. MiRNA expression was evaluated using the standard stem-loop RT-qPCR method. MiR-196a expression was downregulated in ICAD compared to CADs and healthy groups. MiR100 expression levels were not different between groups. The receiver operating characteristic (ROC) curve analysis acquainted that miR-196a expression levels in PBMC could segregate CAD individuals or any of its clinical manifestations (i.e. unstable angina, stable angina, acute myocardial infarction) from ICADs. In conclusion, this study reported a distinct miR-196a expression pattern in PBMCs of all patient groups and recommended a biomarker potential for miR-196a in discriminating ICADs from CADs or healthy controls.

Profiling of immune-related gene expression in children with familial hypercholesterolaemia

BACKGROUND

Innate and adaptive immune responses are pivotal in atherosclerosis, but their association with early-stage atherosclerosis in humans is incompletely understood. In this regard, untreated children with familial hypercholesterolaemia may serve as a human model to investigate the effect of elevated low-density lipoprotein (LDL)-cholesterol.

OBJECTIVES

We aimed to study the immunological and inflammatory pathways involved in early atherosclerosis by examining mRNA molecules in peripheral blood mononuclear cells (PBMCs) from children with FH.

METHODS

We analysed the level of 587 immune-related mRNA molecules using state-of-the-art Nanostring technology in PBMCs from children with (n = 30) and without (n = 21) FH, and from FH children before and after statin therapy (n = 10).

RESULTS

176 genes (30%) were differentially expressed between the FH and healthy children at P < 0.05. Compared to healthy children, the dysregulated pathways in FH children included the following: T cells (18/19); B cells (5/6); tumour necrosis factor super family (TNFSF) (6/8); cell growth, proliferation and differentiation (5/7); interleukins (5/9); toll-like receptors (2/5); apoptosis (3/7) and antigen presentation (1/7), where the ratio denotes higher expressed genes to total number of genes. Statin therapy reversed expression of thirteen of these mRNAs in FH children.

CONCLUSION

FH children display higher PBMC expression of immune-related genes mapped to several pathways, including T and B cells, and TNFSF than healthy children. Our results suggest that LDL-C plays an important role in modulating expression of different immune-related genes, and novel data on the involvement of these pathways in the early atherosclerosis may represent future therapeutic targets for prevention of atherosclerotic progression.

Metabolomic and gene expression analysis to study the effects of dietary saturated and polyunsaturated fats

PURPOSE OF REVIEW

Give an update on recent dietary intervention studies that have used peripheral blood mononuclear cell gene expression analysis and/or metabolic profiling to understand how intake of polyunsaturated and saturated fat affects and biological pathways linked to cardiovascular disease.

RECENT FINDINGS

Several studies showed that intake of fish oil and vegetable oil, high in omega-3 fatty acids, reduced expression level of genes involved in inflammation. One intervention study showed that gene transcripts encoding genes involved inflammation and lipid metabolism increased after intake of polyunsaturated fat (mainly omega-6 fatty acids) compared to saturated fat. Additionally, using targeted metabolomics, the concentrations of atherogenic lipoprotein particles and several metabolites including palmitoylcarnitine, myristoylcarnitine, and kynurenine were reduced after intake of polyunsaturated fat compared to saturated fat, whereas acetate and acetoacetate were increased. The use of targeted metabolomics showed that overfeeding with polyunsaturated fat reduced the serum concentration of ceramides, dihydroceramides, glucosylceramides, and lactosylceramides, whereas overfeeding with saturated fat increased serum concentration of these metabolites.

SUMMARY

The use of gene expression profiling and metabolomics are promising tools to identify possible new biomarkers linking fat quality to cardiovascular disease risk.

Increased protein intake affects pro-opiomelanocortin (POMC) processing, immune function and IGF signaling in peripheral blood mononuclear cells of home-dwelling old subjects using a genome-wide gene expression approach

Background

Adequate protein intake among older adults is associated with better health outcomes such as immune function and metabolic regulation of skeletal muscle, but conflicting results make it difficult to define the optimal intake. To further understand the impact of protein intake on metabolic processes, the aim of the study was to explore genome-wide gene expression changes in peripheral blood mononuclear cells (PBMCs) in home-dwelling old subjects after increased protein intake for 12 weeks.

Method

In a parallel double-blind randomized controlled intervention study, subjects (≥ 70 years) received a protein-enriched milk (2 × 20 g protein/day, n = 14, mean (±SD) age 76.9 ± 4.9 years) or an isocaloric carbohydrate drink (n = 17, mean (±SD) age 77.7 ± 4.8 years) for breakfast and evening meal for 12 weeks. PBMCs were isolated before and after the intervention. Microarray analysis was performed using Illumina technology. Serum levels of gut peptides and insulin growth factor (IGF)-1 were also measured.

Results

In total 758 gene transcripts were regulated after increased protein intake, and 649 gene transcripts were regulated after intake of carbohydrates (p < 0.05). Forty-two of these genes were overlapping. After adjusting for multiple testing, 27 of the 758 gene transcripts were regulated (FDR, q-value < 0.25) after protein intake. Of these 25 were upregulated and two downregulated. In particular, genes and signaling pathways involved in pro-opiomelanocortin (POMC) processing, immune function, and IGF signaling were significantly altered.

Conclusions

PBMCs can be used to study gene expression changes after long-term protein intake, as many signaling pathways were regulated after increased protein intake. The functional significance of these findings needs to be further investigated.

Trial registration

ClinicalTrials.gov, ID no. NCT02218333. The study was registered on August 18, 2014.

Nrf2, NF-κB and PPARβ/δ mRNA Expression Profile in Patients with Coronary Artery Disease

BACKGROUND

Oxidative stress and inflammation are present in coronary artery disease (CAD) and are linked to the activation of the transcription nuclear factor kappa B (NF-κB). To attenuate these complications, transcription factors like nuclear factor erythroid 2-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) can be activated to inhibit NF-κB. However, the available data on expression of NF-κB, Nrf2 and PPARβ/δ in CAD patients are limited.

OBJECTIVE

To evaluate the expression of the transcription factors NF-κB and Nrf2 and PPAR𝛽/𝛿 in CAD patients.

METHODS

Thirty-five patients (17 men, mean age 62.4 ? 7.55 years) with CAD and twelve patients (5 men, mean age 63.50 ? 11.46 years) without CAD were enrolled. Peripheral blood mononuclear cells (PBMCs) were isolated and processed for mRNA expression of Nrf2, NF-κB, NADPH: quinone oxidoreductase 1 (NQO1) and PPARβ/δ mRNAs using quantitative real-time polymerase chain reaction (qPCR). p < 0.05 was considered statistically significant.

RESULTS

There was no difference in the mRNA expressions of Nrf2 (1.35 ? 0.57), NF-κB (1.08 ? 0.50) or in the antioxidant enzyme NQO1 (1.05 ? 0.88) in the CAD group compared to the group without CAD (1.16 ? 0.76, 0.95 ? 0.33, 0.81 ? 0.55, respectively). However, PPARβ/δ was highest expressed in the CAD group (1.17 ? 0.86 vs. 0.56 ? 0.34, p = 0.008).

CONCLUSION

The main finding of this study was the PPARβ/δ being more expressed in the PBMC of patients with CAD compared to the control group, whereas no differences were observed in Nrf2 or NF-κB mRNA expressions.

Gene Expression and Cardiometabolic Phenotypes of Vitamin D-Deficient Overweight and Obese Black Children

Associations between whole blood transcriptome and clinical phenotypes in vitamin D-deficient overweight and obese children can provide insight into the biological effects of vitamin D and obesity. We determined differentially expressed genes (DEGs) in relation to body mass index (BMI) in vitamin D-deficient black children with a BMI ≥ 85th percentile and ascertained the cardiometabolic phenotypes associated with the DEGs. We examined whole-blood transcriptome gene expression by RNA sequencing and cardiometabolic profiling in 41, 10- to 18-year-old children. We found 296 DEGs in association with BMI after adjusting for age, race, sex, and pubertal status. Cardiometabolic phenotypes associated with the BMI-related DEGs, after adjusting for age, sex, pubertal status, and %total body fat, were (i) flow-mediated dilation (marker of endothelial function), (ii) c-reactive protein (marker of inflammation), and (iii) leptin (adipocytokine). Canonical pathways of relevance for childhood obesity and its phenotypes that were significantly associated with the BMI-related DEGs affected immune cell function/inflammation, vascular health, metabolic function, and cell survival/death; several immune and inflammatory pathways overlapped across the three phenotypes. We have identified transcriptome-based biomarkers associated with BMI in vitamin D-deficient, overweight and obese black children. Modulating effects of vitamin D supplementation on these biomarkers and their related phenotypes need further exploration.

Transglutaminase 2 Up-Regulation Is Associated with Inflammatory Response in PBMC from Healthy Subjects with Hypovitaminosis D

Recent evidence indicated that transglutaminase 2 (TG2) is involved in the adaptive immune response. Peripheral blood mononuclear cells (PBMC) have largely been used to characterize molecular mechanisms occurring in the activation of immune response. Given that the maintenance of immune system functions requires an optimal vitamin D status, we aimed to assess the involvement of TG2/NF-κB signaling in cytokine production in PBMC isolated from adult subjects with different vitamin D status. We observed TG2 up-regulation and a significant positive correlation between TG2 expression and tumor necrosis factor (TNF)-α mRNA levels in PBMC of recruited patients. The mRNA levels of TG2 and TNF-α were higher in PBMC of subjects having hypovitaminosis D, namely plasma 25(OH)vitamin D3 levels lower than 50 nmol/L, than in those with normal vitamin D levels. Moreover, NF-κB up-regulation and nuclear translocation were detected, concomitantly with TG2 as well as TNF-α increased expression, in PBMC of vitamin D-deficient subjects. The present findings confirm that an increase in TG2 expression exacerbates the activation of NF-κB and the production of pro-inflammatory cytokines, and suggest a link between vitamin D deficiency, TG2 up-regulation, and inflammation.

Transcriptome analysis in blood cells from children reveals potential early biomarkers of metabolic alterations

OBJECTIVES

The development of effective strategies to prevent childhood obesity and its comorbidities requires new, reliable early biomarkers. Here, we aimed to identify in peripheral blood cells potential transcript-based biomarkers of unhealthy metabolic profile associated to overweight/obesity in children.

METHODS

We performed a whole-genome microarray analysis in blood cells to identify genes differentially expressed between overweight and normal weight children to obtain novel transcript-based biomarkers predictive of metabolic complications.

RESULTS

The most significant enriched pathway of differentially expressed genes was related to oxidative phosphorylation, for which most of genes were downregulated in overweight versus normal weight children. Other genes were involved in carbohydrate metabolism/glucose homoeostasis or in lipid metabolism (for example, TCF7L2, ADRB3, LIPE, GIPR), revealing plausible mechanisms according to existing biological knowledge. A set of differentially expressed genes was identified to discriminate in overweight children those with high or low triglyceride levels.

CONCLUSIONS

Functional microarray analysis has revealed a set of potential blood-cell transcript-based biomarkers that may be a useful approach for early identification of children with higher predisposition to obesity-related metabolic alterations.

Prevailing vitamin D status influences mitochondrial and glycolytic bioenergetics in peripheral blood mononuclear cells obtained from adults

BACKGROUND

Circulating peripheral blood mononuclear cells (PBMCs) are exposed to metabolic and immunological stimuli that influence their functionality. We hypothesized that prevailing vitamin D status [25(OH)D] would modulate the bioenergetic profile of PBMCs derived from humans.

MATERIALS AND METHODS

38 participants (16 males, 22 females) ranging in body fat from 14-51% were studied. PBMCs were isolated from whole blood, counted and freshly seeded for bioenergetic analysis using the Seahorse XF^e96 flux analyser. Whole body energy metabolism via indirect calorimetry, body composition by dual-energy X-ray absorptiometry, and relevant clinical biochemistry were measured. Data was analysed based on 25(OH)D cut-offs of <50nmol/L (Group 1, n=12), 50-75nmol/L (Group 2, n=15) and ≥75nmol/L (Group 3, n=11). A multivariate general linear model adjusting for age, fat mass, fat-free mass, parathyroid hormone and insulin sensitivity was used.

RESULTS

There were significant differences in cellular mitochondrial function between groups. Group 1 had significantly higher basal respiration (p=0.001), non-mitochondrial respiration (p=0.009), ATP production (p=0.001), proton leak (p=0.018), background glycolysis (p=0.023) and glycolytic reserve (p=0.039) relative to either Group 2 or Group 3; the latter two did not differ on any measures. There were no differences in bioenergetic health index (BHI), resting metabolic rates and systemic inflammatory markers between groups.

CONCLUSIONS

Inadequate vitamin D status adversely influenced bioenergetic parameters of PBMCs obtained from adults, in a pattern consistent with increased oxidative metabolism and activation of these cells.

New insight into determining indicators of metabolic status in women: Expression of PPARγ and FABP4 in PBMCs

Adiposity and its metabolic disturbances could be regulated by adipocyte-specific peroxisome proliferator-activated receptor gamma and fatty acid-binding protein4. Although these two proteins are mainly expressed in adipose tissues, they can also be expressed in peripheral blood mononuclear cells, which could be useful for predicting body composition and blood parameters. Thus, this cross-sectional study was performed during January 2013-January 2014 with 229 women (age range, 22-52 years) who were classified as obese or nonobese. Serum glucose, insulin, lipids, and body composition were measured in the fasting state. Peripheral blood mononuclear cells were isolated to extract ribonucleic acid (RNA) and to determine gene expression by real time polymerase chain reaction (PCR). All serum parameters and components of body composition were significantly higher in obese than in nonobese women. Gene expression analysis showed that serum levels of glucose and lipids, except high-density lipoprotein (HDL), were higher in the group that expressed high fatty acid-binding protein4. Increased expression of the peroxisome proliferator-activated receptor gamma was associated with a significant reduction of blood sugar and increased HDL and other lipids and visceral fat. Therefore, it seems that the level of expression of these genes in peripheral blood mononuclear cells may indicate metabolic status.

Effects of a healthy Nordic diet on gene expression changes in peripheral blood mononuclear cells in response to an oral glucose tolerance test in subjects with metabolic syndrome: a SYSDIET sub-study

Background

Diet has a great impact on the risk of developing features of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVD). We evaluated whether a long-term healthy Nordic diet (ND) can modify the expression of inflammation and lipid metabolism-related genes in peripheral blood mononuclear cells (PBMCs) during a 2-h oral glucose tolerance test (OGTT) in individuals with MetS.

Methods

A Nordic multicenter randomized dietary study included subjects (n = 213) with MetS, randomized to a ND group or a control diet (CD) group applying an isocaloric study protocol. In this sub-study, we included subjects (n = 89) from three Nordic centers: Kuopio (n = 26), Lund (n = 30), and Oulu (n = 33) with a maximum weight change of ±4 kg, high-sensitivity C-reactive protein concentration ≤10 mg L⁻¹, and baseline body mass index <39 kg m⁻². PBMCs were isolated, and the mRNA gene expression analysis was measured by quantitative real-time polymerase chain reaction (qPCR). We analyzed the mRNA expression changes of 44 genes before and after a 2hOGTT at the beginning and the end of the intervention.

Results

The healthy ND significantly down-regulated the expression of toll-like receptor 4 (TLR4), interleukin 18 (IL18), and thrombospondin receptor (CD36) mRNA transcripts and significantly up-regulated the expression of peroxisome proliferator-activated receptor delta (PPARD) mRNA transcript after the 2hOGTT compared to the CD.

Conclusions

A healthy ND is able to modify the gene expression in PBMCs after a 2hOGTT. However, more studies are needed to clarify the biological and clinical relevance of these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12263-016-0521-4) contains supplementary material, which is available to authorized users.

Dopaminergic Receptors and Tyrosine Hydroxylase Expression in Peripheral Blood Mononuclear Cells: A Distinct Pattern in Central Obesity

Background

Dopamine (DA) may be involved in central obesity (CO), an inflammatory condition, through its role in the central nervous system and in periphery, where it may affect immune cell function through five different DA receptors (DR). Whether dopaminergic pathways in peripheral immune cells are implicated in the inflammatory condition linked to CO is however unknown.

Methods

In a cohort of blood donors with and without CO, categorized by waist circumference (WC) (CO: WC ≥0.80 m in women and ≥0.94 m in men), we studied the expression of DR and tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of DA, in peripheral blood mononuclear cells (PBMCs) and their relation with anthropometric and metabolic/endocrine and inflammatory parameters. DR D_1-5 and TH expression was assessed by semi quantitative real-time PCR. As inflammatory markers we investigated the immunophenotype of monocyte subsets by flow cytometry, staining for CD14, CD16, CD11b and CD36.

Results

CO individuals showed higher plasma levels of leptin and higher inflammatory pattern of monocytes compared with non-CO. PBMC expression of DR D₂, DR D₄ and DR D₅ as well as of TH were lower in CO in comparison with non-CO. DR D₂, and DR D₅ expression correlated with lower WC and weight, and with lower inflammatory pattern of monocytes, and TH expression correlated with lower WC. DR D₄ expression correlated with lower plasma levels of glycosylated hemoglobin, and DR D₂ expression correlated with lower CO.

Conclusions

Results show that CO is associated with peripheral inflammation and downregulation of dopaminergic pathways in PBMCs, possibly suggesting DR expressed on immune cells as pharmacological targets in obesity for better metabolic outcome.

Effect of olive oil phenolic compounds on the expression of blood pressure-related genes in healthy individuals

PURPOSE

To investigate whether the ingestion of olive oil having different phenolic contents influences the expression of blood pressure-related genes, involved in the renin-angiotensin-aldosterone system, in healthy humans.

METHODS

A randomized, double-blind, crossover human trial with 18 healthy subjects, who ingested 25 mL/day of olive oils (1) high (366 mg/kg, HPC) and (2) low (2.7 mg/kg, LPC) in phenolic compounds for 3 weeks, preceded by 2-week washout periods. Determination of selected blood pressure-related gene expression in peripheral blood mononuclear cells (PBMNC) by qPCR, blood pressure and systemic biomarkers.

RESULTS

HPC decreased systolic blood pressure compared to pre-intervention values and to LPC, and maintained diastolic blood pressure values compared to LPC. HPC decreased ACE and NR1H2 gene expressions compared with pre-intervention values, and IL8RA gene expression compared with LPC.

CONCLUSIONS

The introduction to the diet of an extra-virgin olive oil rich in phenolic compounds modulates the expression of some of the genes related to the renin-angiotensin-aldosterone system. These changes could underlie the decrease in systolic blood pressure observed.

Effects of Exercise on Gene Expression of Inflammatory Markers in Human Peripheral Blood Cells: A Systematic Review

Regular physical activity seems to be one of the most important contributors to prevent disease and promote health. Being physically active reduces the risk of developing chronic diseases such as cardiovascular disease, diabetes, and some types of cancers. The molecular mechanisms are however not fully elucidated. Depending on duration and intensity, exercise will cause disruption of muscle fibers triggering a temporary inflammatory response. This response may not only involve the muscle tissue, but also peripheral tissues such as white blood cells, which are important components of the immune system. The immune system plays a vital role in the development of atherosclerosis, thereby making white blood cells relevant to study when looking at molecular mechanisms induced by physical activity. In this review, we summarize the existing literature on exercise and gene expression in human white blood cells, and discuss these results in relation to inflammation and atherosclerosis.

The impact of cryopreservation on human peripheral blood leucocyte bioenergetics

Circulating immune cells are considered a source for biomarkers in health and disease, since they are exposed to nutritional, metabolic and immunological stimuli in the vasculature. Cryopreservation of leucocytes is routinely used for long-term storage and determination of phenotypic/functional changes at a later date. Exploring the role of bioenergetics and mitochondrial (dys)function in leucocytes is often examined by using freshly isolated cells. The aim of the pilot study described herein was to assess leucocyte bioenergetics in cryopreserved cells. Leucocytes were isolated from whole blood, counted and frozen in liquid nitrogen (LN2) for a period of 3 months. Cells were thawed at regular intervals and bioenergetic analysis performed using the Seahorse XFe96 flux analyser. Cryogenic storage reduced cell viability by 20%, but cell bioenergetic responses were largely intact for up to 1 month storage in LN2. However, after 1 month storage, mitochondrial function was impaired as reflected by decreasing basal respiration, ATP production, maximum (MAX) respiration, reserve capacity and coupling efficiency. Conversely, glycolytic activity was increased after 1 month, most notably the enhanced glycolytic response to 25 mM glucose without any change in glycolytic capacity. Finally, calculation of bioenergetic health index (BHI) demonstrated that this potential diagnostic parameter was sensitive to cryopreservation. The present study has demonstrated for the first time that cryopreservation of primary immune cells modified their metabolism in a time-dependent fashion, indicated by attenuated aerobic respiration and enhanced glycolytic activity. Taken together, we recommend caution in the interpretation of bioenergetic responses or BHI in cryopreserved samples.

An acute bout of exercise modulate the inflammatory response in peripheral blood mononuclear cells in healthy young men

CONTEXT

Exercise increases the levels of circulating inflammatory mediators.

OBJECTIVE

Does an acute bout of exercise affect the mRNA gene expression level of inflammatory markers in peripheral blood mononuclear cells (PBMCs) and contribute to the circulating levels of inflammatory mediators?

MATERIALS AND METHODS

Ten healthy, non-smoking men (22-28 years old) performed 1-hour cycling at 70% of VO2 max.

RESULTS

The gene transcripts of CXCL16, IL-1β, IL-8, COX-2, TXB21 and GATA3 were significantly up-regulated in PBMCs. Serum levels of CXCL16, IL-6, TNFα and IL-10 were also significantly increased after exercise.

DISCUSSION AND CONCLUSION

Increased mRNA transcription of inflammatory genes in PBMCs may contribute to increased level of inflammatory markers after an acute bout of exercise. The increased mRNA levels of GATA-3 and TXB21 may indicate that T cell lymphocytes are activated and secrete cytokines into the circulation. It needs to be further investigated if exercise changes the Th1/Th2 balance.

Peripheral blood mononuclear cells as a source to detect markers of homeostatic alterations caused by the intake of diets with an unbalanced macronutrient composition

Peripheral blood mononuclear cells (PBMCs) are accessible in humans, and their gene expression pattern was shown to reflect overall physiological response of the body to a specific stimulus, such as diet. We aimed to study the impact of sustained intake (4months) of diets with an unbalanced macronutrient proportion (rich in fat or protein) administered isocalorically to a balanced control diet, as physiological stressors on PBMC whole-genome gene expression in rats, to better understand the effects of these diets on metabolism and health and to identify biomarkers of nutritional imbalance. Dietary macronutrient composition (mainly increased protein content) altered PBMC gene expression, with genes involved in immune response being the most affected. Intake of a high-fat (HF) diet decreased the expression of genes related to antigen recognition/presentation, whereas the high-protein (HP) diet increased the expression of these genes and of genes involved in cytokine signaling and immune system maturation/activation. Key energy homeostasis genes (mainly related to lipid metabolism) were also affected, reflecting an adaptive response to the diets. Moreover, HF diet feeding impaired expression of genes involved in redox balance regulation. Finally, we identified a common gene expression signature of 7 genes whose expression changed in the same direction in response to the intake of both diets. These genes, individually or together, constitute a potential risk marker of diet macronutrient imbalance. In conclusion, we newly show that gene expression analysis in PBMCs allows for detection of diet-induced physiological deviations that distinguish from a diet with a proper and equilibrated macronutrient composition.

Marine n-3 Fatty Acids and Gene Expression in Peripheral Blood Mononuclear Cells

Intake of marine n-3 fatty acids has been shown to have beneficial effects on cardiovascular disease. Gene expression analyses in peripheral blood mononuclear cells (PBMCs) are used to understand the underlying mechanisms of action of marine n-3 fatty acids. The aim of this review was to summarize the effects mediated by marine n-3 fatty acids on gene expression in PBMCs. A systematic literature search was conducted in PubMed in May 2014 and 14 papers were included. Targeted gene expression studies were reported in 9 papers and focused on genes involved in lipid metabolism and inflammation. Whole genome transcriptome analyses were conducted in 5 papers, and processes and pathways related to atherosclerotic plaque formation such as inflammation, oxidative stress response, cell cycle, cell adhesion, and apoptosis were modulated after fish oil supplementation. PBMC gene expression profiling has a potential to clarify further the molecular effects of fish oil consumption on human health.

Peripheral blood mononuclear cells: a potential source of homeostatic imbalance markers associated with obesity development

Peripheral blood mononuclear cells (PBMC) have a great potential for nutrition and obesity studies. PBMC reflect the nutritional response of key organs involved in energy homeostasis maintenance, which is altered in the obese state. Here, we aimed to determine the usefulness of PBMC as a source of early markers of obesity. To that purpose, we analysed whether PBMC could reflect the insensitivity to changes in feeding conditions associated with obesity during the development of this pathology. Expression of key genes central to energy metabolism was measured by Q-PCR in PBMC samples of normoweight (control) and cafeteria-fed (obese) rats in feeding, fasting and refeeding conditions. Samples were obtained monthly from 2 (beginning of cafeteria diet-feeding) to 6 months of age. In general terms, expression of genes related to fatty acid synthesis (Fasn, Srebp1) and adipogenesis (Pparg) decreased with fasting and increased with refeeding. Conversely, the expression of a key gene regulating beta-oxidation (Cpt1a) and the gene for an orexigenic neuropeptide (Npy)-in accordance with their metabolic role-increased with fasting and decreased with refeeding. This expression pattern disappeared in obese rats, in which insensitivity to feeding conditions was observed after only 1 month of cafeteria diet-feeding. Thus, during development, PBMC accurately reflect nutritional regulation of energy homeostasic genes and the insensitivity to feeding associated with obesity, even in the earlier stages with a low degree of overweight. For this reason, this set of blood cells could constitute a potential source of biomarkers of early homeostatic imbalance which would be useful in nutrition studies that could help prevent the occurrence of obesity.

Functional epistatic interaction between rs6046G>A in F7 and rs5355C>T in SELE modifies systolic blood pressure levels

Background

Although numerous genetic studies have been performed, only 0.9% of blood pressure phenotypic variance has been elucidated. This phenomenon could be partially due to epistatic interactions. Our aim was to identify epistatic interaction(s) associated with blood pressure levels in a pre-planned two-phase approach.

Methods and Results

In a discovery cohort composed of 3,600 French individuals, we found rs6046A allele in F7 associated with decreased blood pressure levels (P≤3.7×10⁻³) and rs5355T allele in SELE associated with decreased diastolic blood pressure levels (P = 5×10⁻³). Both variants interacted in order to influence blood pressure levels (P≤0.048). This interaction was replicated with systolic blood pressure in 4,620 additional European individuals (P = 0.03). Similarly, in this replication cohort, rs6046A was associated with decreased blood pressure levels (P≤8.5×10⁻⁴). Furthermore, in peripheral blood mononuclear cells of a subsample of 90 supposed healthy individuals, we found rs6046A positively associated with NAMPT mRNA levels (P≤9.1×10⁻⁵), suggesting an eventual involvement of NAMPT expression in blood pressure regulation. Confirming this hypothesis, further transcriptomic analyses showed that increased NAMPT mRNA levels were positively correlated with ICAM1, SELL, FPR1, DEFA1-3, and LL-37 genes expression (P≤5×10⁻³). The last two mRNA levels were positively associated with systolic blood pressure levels (P≤0.01) and explained 4% of its phenotypic variation.

Conclusion

These findings reveal the importance of epistatic interactions in blood pressure genetics and give new insights for the role of inflammation in its complex regulation.

Relevance of selenoprotein transcripts for selenium status in humans

The most commonly used methods for assessing the selenium (Se) status in humans involve analysis of Se concentration, selenoprotein activity, and concentration in the blood and its compartments. Recently, it has been suggested that the expression of selenoprotein mRNA in circulating blood leukocytes could differently reflect Se status, due to prioritization of specific selenoprotein synthesis in response to dietary Se supply. Whereas the Se levels required for optimization of selenoprotein P level and plasma glutathione peroxidise activity are well known, estimation of Se level that is required for maximal mRNA expression of selenoprotein in humans is the subject of current investigations. Studies on rats suggest that whole blood selenoprotein mRNA level can be used as the relevant molecular biomarker for assessing Se status, and suboptimal Se intake may be sufficient to achieve effective expression. Human studies, however, did not confirm this hypothesis. According to studies on rodents and humans discussed in this review, it appears that suboptimal Se intake may be sufficient to satisfy molecular requirements of Se and it is lower than current recommended dietary intake in humans. The use of selenoprotein transcripts as a molecular biomarker of Se status requires further studies on a large group of healthy individuals with different baseline Se, including data regarding genetic polymorphism of selenoproteins and data regarding potential modifiers of Se metabolism.

Identification of cis- and trans-acting genetic variants explaining up to half the variation in circulating vascular endothelial growth factor levels

RATIONALE

Vascular endothelial growth factor (VEGF) affects angiogenesis, atherosclerosis, and cancer. Although the heritability of circulating VEGF levels is high, little is known about its genetic underpinnings.

OBJECTIVE

Our aim was to identify genetic variants associated with circulating VEGF levels, using an unbiased genome-wide approach, and to explore their functional significance with gene expression and pathway analysis.

METHODS AND RESULTS

We undertook a genome-wide association study of serum VEGF levels in 3527 participants of the Framingham Heart Study, with preplanned replication in 1727 participants from 2 independent samples, the STANISLAS Family Study and the Prospective Investigation of the Vasculature in Uppsala Seniors study. One hundred forty single nucleotide polymorphism (SNPs) reached genome-wide significance (P<5×10(-8)). We found evidence of replication for the most significant associations in both replication datasets. In a conditional genome-wide association study, 4 SNPs mapping to 3 chromosomal regions were independently associated with circulating VEGF levels: rs6921438 and rs4416670 (6p21.1, P=6.11×10(-506) and P=1.47×10(-12)), rs6993770 (8q23.1, P=2.50×10(-16)), and rs10738760 (9p24.2, P=1.96×10(-34)). A genetic score including these 4 SNPs explained 48% of the heritability of serum VEGF levels. Six of the SNPs that reached genome-wide significance in the genome-wide association study were significantly associated with VEGF messenger RNA levels in peripheral blood mononuclear cells. Ingenuity pathway analyses showed found plausible biological links between VEGF and 2 novel genes in these loci (ZFPM2 and VLDLR).

CONCLUSIONS

Genetic variants explaining up to half the heritability of serum VEGF levels were identified. These new insights provide important clues to the pathways regulating circulating VEGF levels.

Early cardiac gene transcript levels in peripheral blood mononuclear cells in patients with untreated essential hypertension

OBJECTIVES

To assess the expression of early cardiac genes, implicated in the hypertrophic growth response of the adult heart, in peripheral blood mononuclear cells in patients with essential hypertension and its relationship to ambulatory blood pressure monitoring (ABPM) parameters and to echocardiographic left ventricular mass.

METHODS

Twenty-four-hour ABPM, echocardiography and blood sampling were performed in 62 untreated participants with essential hypertension. Blood samples from 38 healthy individuals were included for comparison. Peripheral blood mononuclear cells (PBMCs) were isolated and gene transcript levels were determined by quantitative real-time reverse transcription PCR.

RESULTS

Myocardin (3.92±0.68 versus 2.09±0.67, P<0.001), GATA4 (3.48±0.68 versus 0.32±0.08, P<0.001) and Nkx2.5 (208.91±35.01 versus 129.75±49.70, P<0.001) were upregulated in hypertensive patients compared with controls. In hypertensive patients, transcript levels of myocardin (r=0.698, P<0.001) and GATA4 (r=0.374, P=0.003) showed significant positive correlations with 24-h systolic blood pressure (BP) as well as with mean BP, (r=0.626, P<0.001) and (r=0.340, P=0.007), respectively. A significant positive correlation between myocardin and 24-h pulse pressure (r=0.467, P<0.001) was also observed. Myocardin (r=-0.606, P<0.001) and GATA4 (r=-0.453, P<0.001) transcript levels also showed significant negative correlations with the mean 24-h dipping status. Additionally, myocardin (r=0.341, P=0.007), GATA4 (r=0.337, P=0.007) and Nkx2.5 (r=0.325, P=0.010) transcript levels showed significant positive correlations with left ventricular mass index.

CONCLUSION

Myocardin and GATA4 transcript levels correlate significantly with 24-h ABPM parameters, rendering them potential candidate biomarkers in hypertension. Early cardiac gene transcript levels in PBMCs of hypertensive patients are associated with left ventricular mass and may reflect activation of the hypertrophic response gene network in these patients.

An oat bran meal influences blood insulin levels and related gene sets in peripheral blood mononuclear cells of healthy subjects

The understanding of how fibre-rich meals regulate molecular events at a gene level is limited. This pilot study aimed to investigate changes in gene expression in peripheral blood mononuclear cells (PBMCs) from healthy subjects after consumption of an oat bran-rich meal. Fifteen subjects (8 men and 7 women, aged 20-28 years) ingested meals with oat bran or a control meal after an overnight fast. Blood samples for analysis of postprandial glucose, insulin and triglyceride concentrations were taken during 3 h, while PBMCs for microarray gene expression profiling from five men and five women were taken before and 2 h after the meal. Analysis of transcriptome data was performed with linear mixed models to determine differentially expressed genes in response either to meal intake or meal content, and enrichment analysis was used to identify functional gene sets responding to meal intake and specifically to oat bran intake. Meal intake as such affected gene expression for genes mainly involved in metabolic stress; indicating increased inflammation due to the switch from fasting to fed state. The oat bran meal affected gene sets associated with a lower insulin level, compared with the control meal. The gene sets included genes involved in insulin secretion and β-cell development, but also protein synthesis and genes related to cancer diseases. The oat bran meal also significantly lowered postprandial blood insulin IAUC compared to control. Further studies are needed to compare these acute effects with the long-term health effects of oat bran.

Effect of marine n-3 fatty acids on circulating inflammatory markers in healthy subjects and subjects with cardiovascular risk factors

Objective

The aim of the present paper was to review the literature in order to summarize the effects of marine n-3 fatty acids on circulating inflammatory markers among healthy subjects, subjects with high risk of developing cardiovascular disease (CVD) and in patients with CVD in human intervention studies.

Methods

A systematic literature search in PubMed was performed. Intervention studies describing the effects of marine n-3 fatty acids on circulating inflammatory markers in healthy subjects, subjects with high risk of CVD and patients with CVD were included. The following exclusion criteria were used: (1) interventions assessing inflammatory markers with ex vivo methods (2) interventions with children (3) articles describing animal or cell culture studies. Twenty-two articles were included. Additionally, 13 papers from their literature lists were included based on the same inclusion and exclusion criteria as the literature search.

Results and conclusion

Intervention studies with marine n-3 fatty acids administered from either fish or fish oil demonstrate different results on inflammatory markers. No firm conclusion can be drawn about the effect of marine n-3 fatty acids on circulating inflammatory markers in healthy individuals, individuals with high risk of developing CVD or individuals with CVD related diseases.

Peripheral blood mononuclear cells as a model to study the response of energy homeostasis-related genes to acute changes in feeding conditions

Peripheral blood mononuclear cells (PBMCs) are readily accessible biological material and a potential tissue source to discover novel biomarkers of response to environmental exposures including nutrition. We analyzed whether PBMCs could reflect molecular changes that take place in response to different feeding conditions in key organs/tissues involved in energy homeostasis. We studied energy balance-related genes whose expression was altered in normoweight (control) rats and in diet-induced (cafeteria) obese rats in response to ad libitum feeding, 14-h fasting, and 6-h refeeding after fasting, using whole-genome microarray analysis. In PBMCs, the expression of the genes central to energy metabolism was altered by the feeding conditions. The number of affected genes was 75 in the control rats, but only 23 in the cafeteria obese rats. Most of these genes play a role in metabolic pathways regulated by nutritional changes, such as lipid metabolism (the metabolic pathway mainly reflected in blood cells), carbohydrate metabolism, central energy metabolism, respiratory chain/mitochondrial ATPase system, and food intake regulation. Importantly, our results showed a similar behavior to that of the mesenteric white adipose tissue. In conclusion, metabolic adaptations to acute changes in feeding conditions are reflected in the expression of genes central to energy homeostasis in PBMCs of normoweight rats, while response is impaired in cafeteria obese animals. The lower number of genes affected in obese animals indicates impaired nutritional regulation. PBMCs appear as a suitable potential model to characterize metabolic adaptations to food intake and body weight maintenance in experimental animals. These findings may also inform the development of future peripheral tissue models in the emerging field of clinical nutrigenomics.

Candidate gene microarray analysis in peripheral blood cells for studying hypertension/obesity

AIMS

The gene expression of 182 cardiovascular candidate genes was measured in high quality groups of individuals (n = 20) by microarrays to determine whether a subset of genes would discriminate obese and hypertensive individuals, in spite of the existence of a close link between these two cardiovascular risk factors.

MATERIALS & METHODS

The results were validated on the 20 subjects used for microarray analysis and on 62 additional individuals by real-time PCR.

RESULTS

The first analysis, where patient groups were compared with healthy subjects, revealed 15 out of 182 genes that differed in hypertensive, obese or obesity-related hypertensive individuals. These genes were ALOX5, APOA2, SELL, RGS2, CD14, FPR1, CAMP, DEFA3, DEFA4, CBS, CHRM1, ICAM1, NR1H2, SCNN1B and TGFB1. A second analysis was carried out in which patient groups were compared with each other, demonstrating FPR1 and DEFA3 as being significant genes discriminating patient groups. Furthermore, an analysis stratified by sex revealed that, with the exception of DEFA3, there are no other common genes between men and women.

DISCUSSION

We were able to indentify a number of interesting genes that distinguish patient and healthy subject groups as well as patient groups between them.

CONCLUSION

In addition, it seems that gender plays an important role, at least for some of the genes we tested. These findings may have important implications in the screening and etiology of hypertension or obesity, and could further help to focus on these specific mRNAs as antisense therapy targets.

The STANISLAS Cohort: a 10-year follow-up of supposed healthy families. Gene-environment interactions, reference values and evaluation of biomarkers in prevention of cardiovascular diseases

The description of this familial longitudinal cohort was published in this journal 10 years ago, in 1998. To date, 117 publications on the STANISLAS Cohort (SC) have appeared, corresponding to five main categories of results: familial resemblance and heritability; genetics and gene-environment interactions; mRNA and proteins as gene products; reference values and biological variations of proteins; and finally preventive medicine and prepathological epidemiological data. More than 600 data values on demographic and laboratory data have been collected on each individual taking part out of the 1006 families at the beginning and for all three recruitments. Serum and plasma are stored in liquid nitrogen for all participants for all three recruitments. DNA has been extracted from all participants and mRNA from 357 families. They are stored at -80 degrees C. Owing to the SC study, heritability and many gene-environment interactions have been described. The expression of 166 genes related to cardiovascular diseases was measured in peripheral blood mononuclear cells RNA. Reference values for proteins and vitamins have been established in addition to reference values for the carotid and femoral intima media thickness in adults and children. The data obtained contribute to a better understanding of the relation between the studied polymorphisms (161 polymorphic sites) and health, and predisposition to obesity, high blood pressure and metabolic syndrome. To the best of our knowledge, the SC study is internationally the only longitudinal family cohort of subjects who are presumed to be healthy, which enables the study of the chain DNA-RNA-proteins.

Leptin expression in Peripheral Blood Mononuclear Cells (PBMCs) is related with blood pressure variability

BACKGROUND

Leptin is an adipokine initially considered as a molecule related exclusively to obesity but advances in research revealed its multiple roles in other physio-pathological mechanisms and particularly in the inflammatory ones. The aim of the present study was to demonstrate the presence of leptin in human Peripheral Blood Mononuclear Cells (PBMCs) and to quantify its mRNA in this type of tissue, closely related to inflammation.

METHODS

Leptin mRNA was present in PBMCs of healthy individuals. Its expression was further studied in 83 individuals in relation to constitutional factors, anthropometric variables, blood pressure, lipid profile, glucose and markers of inflammation (C-reactive protein, lymphocyte count).

RESULTS

Expression levels were significantly associated with systolic blood pressure (SBP) (p = 0.03) and diastolic blood pressure (DBP) (p = 0.003). Using a multiple regression analysis model, we showed that leptin mRNA levels explained 11% of the variation of SBP (p = 0.007) and of DBP (p = 0.003). These percentages remained at the same magnitude for SBP (9%) and for DBP (10%), after introducing BMI in the model.

CONCLUSION

We report here for the first time, leptin expression in human PBMCs of healthy individuals. The associations found with blood pressure suggest a possible role of leptin in blood pressure regulation via PBMCs.

Pharmacogenomics and antihypertensive drugs: a path toward personalized medicine

Pharmacogenomics focuses on genes and the transcriptome and proteome. It has the potential to enhance healthcare management by improving disease diagnosis and implementing treatments adapted to each patient. Previously, pharmacogenetics of candidate genes focused on clinical research. It is now extended by using genome-wide approaches to elucidate the inherited basis of differences between individuals in their response to drugs. We summarize relevant polymorphisms of genes involved in the pharmacokinetics and pharmacodynamics of antihypertensive drugs and we give an overview of the state of pharmacogenomic research in hypertension medicine. Even if things are getting better, current pharmacogenetic studies still lack power, adequate selection of candidate genes and knowledge of their functions at the physiological level. Finally, some specific end point phenotypes (i.e., peptides or proteins related to the metabolic cycle targeted by the drug) should be integrated to propose data that are easily applicable to personalized medicine.