Interleukin-6 gene polymorphism, chronic stress and atherosclerosis: interleukin-6-174G>C polymorphism, chronic stress and risk of early atherosclerosis in the Cardiovascular Risk in Young Finns Study

The effects of IGF-1 and IGFBP-2 treatments on the atherosclerosis in the aorta and the coronary arteries of the high cholesterol diet-fed rabbits

Several studies have demonstrated suppression of aortic atherosclerosis by insulin like growth factor-1 (IGF-1) in hypercholesterolemic rabbits. Though a recent study has reported that IGF-1 exerts anti-atherogenic effects in coronary arteries, the mechanisms of IGF-1 in coronary arteries need to be further verified. Studies about insulin like growth factor binding protein-2 (IGFBP-2) in atherosclerosis are rarely. The objective of this study is to examine the effects of IGF-1 and IGFBP-2 on the atherosclerosis development in the aorta and coronary arteries of the high-cholesterol diet (HCD)-fed rabbits. New Zealand white rabbits were fed either normal chow (n = 5) or a diet containing 1.0 % cholesterol (n = 18) for 12 weeks. Cholesterol-fed rabbits were given IGF-1 or IGFBP-2 or saline intravenously (each n = 6) for 10 weeks. The results revealed that IGF-1 decreased total cholesterol (TC) and low-density lipoprotein (LDL) levels (p < 0.05), whereas IGFBP-2 did not. IGF-1 significantly attenuated atherosclerotic lesions and reduced accumulated macrophages within the coronary artery plaques, whereas IGFBP-2 deteriorated these changes. Moreover, IGF-1 reduced serum platelet-activating factor acetylhydrolase levels, C reactive protein (CRP), and inhibited the protein expression levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). IGFBP-2 elevated serum 8-hydroxy-2'-deoxyguanosine levels, CRP, and promoted the protein expression levels of TNF-α and IL-6. In conclusion, IGF-1 can substantially suppress plaque formation in coronary arteries with a marked inhibition of macrophage accumulation likely via its anti-inflammatory properties, whereas IGFBP-2 plays an opposite effect on atherosclerosis. The present study highlighted a theoretical basis for pharmacological treatment of atherosclerosis.

Polygenic liabilities underlying job stress and exhaustion over a 10-year follow-up: A general population study

We investigated whether individuals, who have a high polygenic loading for schizophrenia and major depression (PGL) but have not developed the respective disorders, are still susceptible to experience milder forms of ill-being in terms of job strain or exhaustion. We used the population-based Young Finns Study data (n = 928). PGL was assessed with a cumulative score of the polygenic risk scores for schizophrenia and depression. Participants (24-49-year-olds) evaluated their exhaustion levels and perceived job characteristics over a 10-year follow-up (2001, 2007, 2011). Participants with diagnosed psychotic or affective disorders were excluded. We found that high PGL did not predict less favorable perceptions of job environment (job strain, demands, control, satisfaction, social support at work) but high PGL predicted a higher trajectory of exhaustion in early adulthood and middle age. Additionally, high (vs. low) PGL predicted a stronger increase in exhaustion at increased levels of job strain. These findings remained after controlling for sex, socioeconomic factors, health behaviors, and cognitive performance. In conclusion, individuals with high PGL may have an elevated liability to experience exhaustion especially in early adulthood and middle age (despite they perceive their job environment similarly than others), and especially and at high levels of job strain.

Chronic Stress A Potential Suspect Zero of Atherosclerosis: A Systematic Review

Atherosclerosis (AS) is a chronic vascular inflammatory disease, in which the lipid accumulation in the intima of the arteries shows yellow atheromatous appearance, which is the pathological basis of many diseases, such as coronary artery disease, peripheral artery disease and cerebrovascular disease. In recent years, it has become the main cause of death in the global aging society, which seriously endangers human health. As a result, research on AS is increasing. Lesions of atherosclerosis contain macrophages, T cells and other cells of the immune response, together with cholesterol that infiltrates from the blood. Recent studies have shown that chronic stress plays an important role in the occurrence and development of AS. From the etiology of disease, social, environmental and genetic factors jointly determine the occurrence of disease. Atherosclerotic cardio-cerebrovascular disease (ASCVD) is often caused by chronic stress (CS). If it cannot be effectively prevented, there will be biological changes in the body environment successively, and then the morphological changes of the corresponding organs. If the patient has a genetic predisposition and a combination of environmental factors triggers the pathogenesis, then chronic stress can eventually lead to AS. Therefore, this paper discusses the influence of chronic stress on AS in the aspects of inflammation, lipid metabolism, endothelial dysfunction, hemodynamics and blood pressure, plaque stability, autophagy, ferroptosis, and cholesterol efflux.

Risky emotional family environment in childhood and depression-related cytokines in adulthood: The protective role of compassion

BACKGROUND

Previously, compassion has been found to protect against depressive symptoms, while emotional adversities in childhood are suggested to increase inflammatory responses. The current study investigated (a) whether emotional family environment in childhood predicts levels of such cytokines in adulthood that are previously found to be elevated in depression (interleukin [IL]-2, IL-6, IL-1b, monocyte chemoattractant protein-1, interferon-gamma [IFN-γ], and tumor necrosis factor alpha [TNF-α]) and (b) whether these associations are modified by compassion in adulthood.

METHODS

The participants (N = 1,198-1,523) came from the prospective population-based Young Finns data. Emotional family environment and parental socioeconomic factors were evaluated in 1980; participants' compassion in 2001; and participants' cytokine levels and adulthood covariates in 2007.

RESULTS

Risky emotional family environment in childhood predicted higher levels of IL-2, IL-6, IFN-γ, and TNF-α in adulthood. Additionally, there were significant interaction effects between compassion and emotional risk in childhood, when predicting IL-2, IL-6, and TNF-α. Specifically, individuals who grew up in a risky emotional family environment had on average higher levels of IL-2, IL-6, and TNF-α in adulthood when combined with low compassion.

CONCLUSIONS

In individuals coming from risky emotional family environments, high compassion for others may protect against elevated levels of cytokines previously linked with depression.

Hypertension and Age-Related Cognitive Impairment: Common Risk Factors and a Role for Precision Aging

Purpose of Review

Precision Aging® is a novel concept that we have recently employed to describe how the model of precision medicine can be used to understand and define the multivariate risks that drive age-related cognitive impairment (ARCI). Hypertension and cardiovascular disease are key risk factors for both brain function and cognitive aging. In this review, we will discuss the common mechanisms underlying the risk factors for both hypertension and ARCI and how the convergence of these mechanisms may be amplified in an individual to drive changes in brain health and accelerate cognitive decline.

Recent Findings

Currently, our cognitive health span does not match our life span. Age-related cognitive impairment and preventing and treating ARCI will require an in-depth understanding of the interrelated risk factors, including individual genetic profiles, that affect brain health and brain aging. Hypertension and cardiovascular disease are important risk factors for ARCI. And, many of the risk factors for developing hypertension, such as diabetes, smoking, stress, viral infection, and age, are shared with the development of ARCI. We must first understand the mechanisms common to the converging risk factors in hypertension and ARCI and then design person-specific therapies to optimize individual brain health.

Summary

The understanding of the convergence of shared risk factors between hypertension and ARCI is required to develop individualized interventions to optimize brain health across the life span. We will conclude with a discussion of possible steps that may be taken to decrease ARCI and optimize an individual’s cognitive life span.

Association between rs1800795 polymorphisms in the interleukin-6 gene and vasculitis: A meta-analysis

Interleukin (IL)-6 is associated with the development and progression of vasculitis, and inhibitors of this cytokine are used to treat this disease. Polymorphisms of the promoter region of IL-6 are associated with the production and expression of IL-6. The aim of this study was to perform a meta-analysis of eligible studies to derive a precise estimate of the association between IL6 polymorphisms and susceptibility to vasculitis. A meta-analysis was conducted to identify the associations between IL6 rs1800795 (-174 G/C) polymorphisms and vasculitis. A total of 13 studies involving 1,294 vasculitis patients and 1,594 controls were considered in the meta-analysis. There were significant associations between IL6 rs1800795 polymorphisms and vasculitis in allele contrast, dominant genetic model, and heterozygote vs. dominant homozygote comparison (OR 0.80, 95% CI 0.67-0.94, P =0.009 and OR 0.76, 95% CI 0.63-0.92, P =0.005, respectively). In subgroup analysis based on subtype, there were significant associations between IL6 polymorphisms and susceptibility in large and medium vessel vasculitis, but not in small and variable vessel vasculitis. The GC genotype of IL6 rs1800795 was suggested by the analyses to be related to low prevalence of vasculitis, especially for large and medium vessels.

Chronic stress: a critical risk factor for atherosclerosis

Chronic stress refers to the non-specific systemic reaction that occurs when the body is stimulated by various internal and external negative factors over a long time. The physiological response to chronic stress exposure has long been recognized as a potent modulator in the occurrence of atherosclerosis. Furthermore, research has confirmed the correlation between atherosclerosis and cardiovascular events. Chronic stress is pervasive during negative life events and may lead to the formation of plaque. Several epidemiological studies have shown that chronic stress is an independent risk factor for the development of vascular disease and for increased morbidity and mortality in patients with pre-existing coronary artery disease. One possible mechanism for this process is that chronic stress causes endothelial injury, directly activating macrophages, promoting foam cell formation and generating the formation of atherosclerotic plaque. This mechanism involves numerous variables, including inflammation, signal pathways, lipid metabolism and endothelial function. The mechanism of chronic stress in atherosclerosis should be further investigated to provide a theoretical basis for efforts to eliminate the effect of chronic stress on the cardiocerebral vascular system.

Chronic stress: a crucial promoter of cell apoptosis in atherosclerosis

Objective

Chronic stress may lead to augmented incidence rates of coronary and cerebrovascular diseases associated with atherosclerosis. However, few studies have focused on the effect of chronic stress on atherosclerosis plaque formation. Therefore, this study was designed to directly evaluate how chronic stress affects atherosclerosis.

Methods

Thirty rabbits were divided into three groups: the control group, balloon-injury operation + high-fat diet model group, and chronic stress + balloon-injury operation + high-fat diet model group. Physical and social stress were induced, and proteomic methods were applied to identify specific markers.

Results

After protein determination, the chronic stress + balloon-injury operation + high-fat diet model group exhibited significant upregulation of the following apoptosis-related proteins: UBE2K, caspase 3, caspase 9, BAX, P53, and FAS. In particular, real-time polymerase chain reaction showed that the protein expression of caspase 9 was significantly downregulated in the stress group compared with the non-stress groups. However, the other proteins showed significantly increased expression in the stress group.

Conclusion

Chronic stress may promote cell apoptosis in the physiopathologic process of atherosclerosis.

Gene polymorphism associated with TNF-α (G308A) IL-6 (C174G) and susceptibility to coronary atherosclerotic heart disease: A meta-analysis

To evaluate the association between gene polymorphisms of TNF-α G308A, IL-6 C174G, and coronary atherosclerotic heart disease (CHD) risk.We used computers to collect related case-control studies. After screening, a meta-analysis was conducted to assess the strength of association by Stata 12.0 software.Thirty-five articles were included. Among them, 17 studies were related to TNF-α (G308A) gene mutation and CHD, and 18 studies examined IL-6 (C174G) gene mutation. According to the results of subgroup analysis of ethnicity, it suggested that TNF-α (G308A) polymorphism was not significantly associated with CHD risk under all models in Asians (P > .05). There were no connected of IL-6 C174G polymorphism with CHD risk under all models in Caucasians after subgroup analysis (P > .05).The present evidence shows that TNF-α (G308A) have no connected with the risk of CHD in Asians; IL-6 (C174G) gene were not associated with the risk of CHD in Caucasians.

Association of interleukin 6, interleukin 7 receptor alpha, and interleukin 12B gene polymorphisms with multiple sclerosis

Pro-inflammatory and anti-inflammatory cytokines have been shown to play a crucial role in the pathophysiology of multiple sclerosis (MS). We investigated the association between interleukin (IL) IL6-174 G/C (rs1800795), IL7RA C/T (rs6897932), and IL-12B A1188C (rs3212227) gene polymorphisms (SNPs) and MS. The study consisted of 297 unrelated MS patients and 135 healthy individuals. In IL6-174G/C (rs1800795), a significant association between the C allele and MS risk [OR 1.41, 95% CI (1.05-1.92); P = 0.025] was found. Carriage of genotypes CC and CG were more common in MS patients [OR 1.58, 95% CI (1.04-2.39); P = 0.031] and also in female MS patients [OR 1.68, 95% CI (1.02-2.79); P = 0.043]. However, after applying Bonferroni's correction the differences did not remain significant. No significant association between the IL7RA C/T (rs6897932) and IL12B A1188C (rs3212227) gene polymorphisms and MS susceptibility was observed. Regarding IL-12B A1188C (rs3212227), a significant association between the CC genotype and MS progression, expressed as MSSS, was demonstrated in the female MS group. Our results indicate that the distribution of IL6-174G/C (rs1800795) SNP was marginally associated with MS susceptibility. We also showed that IL-12B A1188C (rs3212227) can contribute to the progression of the disease in the Czech population.

Genetic Contributions of Inflammation to Depression

This paper describes the effects of immune genes genetic variants and mRNA expression on depression's risk, severity, and response to antidepressant treatment, through a systematic review on all papers published between 2000 and 2016. Our results, based largely on case-control studies, suggest that common genetic variants and gene-expression pathways are involved in both immune activation and depression. The most replicated and relevant genetic variants include polymorphisms in the genes for interleukin (IL)-1β, IL-6, IL-10, monocyte chemoattractant protein-1, tumor necrosis factor-alpha, C-reactive protein, and phospholipase A2. Moreover, increased blood cytokines mRNA expression (especially of IL-1β) identifies patients that are less likely to respond to conventional antidepressants. However, even for the most replicated findings there are inconsistent results, not only between studies, but also between the immune effects of the genetic variants and the resulting effects on depression. We find evidence that these discrepant findings may be explained, at least in part, by the heterogeneity of the depression immunophenotype, by environmental influences and gene × environment interactions, and by the complex interfacing of genetic variants with gene expression. Indeed, some of the most robust findings have been obtained in patients developing depression in the context of treatment with interferon-alpha, a widely used model to mimic depression in the context of inflammation. Further 'omics' approaches, through GWAS and transcriptomics, will finally shed light on the interaction between immune genes, their expression, and the influence of the environment, in the pathogenesis of depression.

IL6-174 G>C Polymorphism (rs1800795) Association with Late Effects of Low Dose Radiation Exposure in the Portuguese Tinea Capitis Cohort

Head and neck cancers, and cardiovascular disease have been described as late effects of low dose radiation (LDR) exposure, namely in tinea capitis cohorts. In addition to radiation dose, gender and younger age at exposure, the genetic background might be involved in the susceptibility to LDR late effects. The -174 G>C (rs1800795) SNP in IL6 has been associated with cancer and cardiovascular disease, nevertheless this association is still controversial. We assessed the association of the IL6-174 G>C SNP with LDR effects such as thyroid carcinoma, basal cell carcinoma and carotid atherosclerosis in the Portuguese tinea capitis cohort. The IL6-174 G>C SNP was genotyped in 1269 individuals formerly irradiated for tinea capitis. This sampling group included thyroid cancer (n = 36), basal cell carcinoma (n = 113) and cases without thyroid or basal cell carcinoma (1120). A subgroup was assessed for atherosclerosis by ultrasonography (n = 379) and included matched controls (n = 222). Genotypes were discriminated by real-time PCR using a TaqMan SNP genotyping assay. In the irradiated group, we observed that the CC genotype was significantly associated with carotid plaque risk, both in the genotypic (OR = 3.57, CI = 1.60–7.95, p-value = 0.002) and in the recessive (OR = 3.02, CI = 1.42–6.42, p-value = 0.004) models. Irradiation alone was not a risk factor for carotid atherosclerosis. We did not find a significant association of the IL6-174 C allele with thyroid carcinoma or basal cell carcinoma risk. The IL6-174 CC genotype confers a three-fold risk for carotid atherosclerotic disease suggesting it may represent a genetic susceptibility factor in the LDR context.

Effect of G(-174)C polymorphism in interleukin-6 gene on cardiovascular disease in type 2 diabetes patients

Interleukin-6 (IL-6) is an important pro-inflammatory cytokine of relevance to cardiovascular diseases. The aim of this case-control study was to evaluate the association between the G(-174)C functional polymorphism in the IL-6 gene and risk of cardiovascular disease (CVD) in type 2 diabetes patients. We examined 1090 patients with T2DM and 612 controls. All subjects were genotyped for the G(-174)C polymorphism by polymerase chain reaction (PCR) and restriction analysis. There were no significant differences in the distribution of genotypes and alleles between T2DM patients and healthy controls. Significantly higher C allele frequency was observed in CVD+ patients compared to CVD- subgroup (53% vs. 32%, p<0.0001). The odds ratio for C allele was 2.4 (95% CI 1.99-2.9, p<0.0001) and for CC genotype 4.55 (95% CI 3.12-6.63, p<0.000). When the distribution of G(-174)C polymorphism was compared in subgroups with different clinical phenotypes of CVD, a significant association of CC genotype with myocardial infarction was observed. Forty eight percent of patients with MI had the CC genotype compared to 22% of patients without MI (p<0.0001). In conclusion, type 2 diabetes patients carrying the C allele of the IL-6 G(-174)C polymorphism have a significantly increased risk of CVD.

Analysis of a Functional IL-6 Gene Polymorphism in HLAB27 Associated and Intermediate Uveitis Gives New Insight in Disease Pathogenesis and Commonality with Other Autoimmune Diseases

Purpose. Interleukin 6 (IL-6) plays a crucial role in both adaptive and innate immunity. The rs1800795 gene polymorphism of IL-6 is associated with various autoimmune diseases, like multiple sclerosis. Methods. 134 patients with HLAB27 positive iridocyclitis, 84 patients with intermediate uveitis, 132 controls, and 65 HLAB27 positive controls were recruited for the present case-control study. Main outcome measures were genotype distribution and allelic frequencies determined by polymerase chain reaction. Results. The frequency of carriers of the minor allele for rs1800795 was significantly higher in patients with intermediate uveitis compared to controls (p = 0.04; OR: 1.46; CI: 1.02–2.11). Frequencies of the minor allele for rs1800795 did not differ significantly in patients with HLAB27 associated uveitis when compared to controls (p > 0.05). Conclusion. These findings further deepen our understanding of the commonality between multiple sclerosis and intermediate uveitis. Given the functionality of the investigated polymorphism, new pathophysiological insights are gained that help to evaluate possible therapeutic targets.

Gene of the month: Interleukin 6 (IL-6)

The Interleukin 6 (IL-6) gene encodes the classic proinflammatory cytokine IL-6. It is also known as interferon-β2 (IFN-β2), B cell stimulatory factor-2 and hybridoma/plasmacytoma growth factor. IL-6 is a multifunctional cytokine with a central role in many physiological inflammatory and immunological processes. Due to its major role in initiation as well as resolving inflammation, deregulation of IL-6 is a mainstay of chronic inflammatory and autoimmune diseases. Additionally, IL-6 has been shown to be implicated in pathogenesis of many human malignancies. Thus, a better understanding of IL-6 and its role in various pathological conditions could enable the development of strategies to use it as a therapeutic target. This short review focuses on the structure, regulation and biological activities of IL-6. In addition we discuss the role of IL-6 in diseases with inflammatory background and cancer and also the therapeutic applications of anti-IL-6 agents.