Polymorphisms near SOCS3 are associated with obesity and glucose homeostasis traits in Hispanic Americans from the Insulin Resistance Atherosclerosis Family Study

Support Provided by Caregivers for Community-Dwelling Diabetic Hispanic Adults with Intellectual Disabilities and Comorbid Conditions

Diabetes is an age-related chronic health condition and a major public health concern. Diabetes is one of the significant causes of morbidity and mortality and a major contributing factor to dementia. Recent research reveals that Hispanic Americans are at an increased risk of chronic conditions such as diabetes, dementia, and obesity. Recent research also revealed that diabetes develops at least ten years earlier in Hispanics and Latinos than in neighboring non-Hispanic whites. Furthermore, the management of diabetes and providing necessary/timely support is a challenging task for healthcare professionals. Caregiver support is an emerging area of research for people with diabetes, mainly family caregiver support work for Hispanic and Native Americans. Our article discusses several aspects of diabetes, factors associated with diabetes among Hispanics, its management, and how caregivers can support individuals with diabetes.

Effects of Backfat Thickness on Oxidative Stress and Inflammation of Placenta in Large White Pigs

The purpose of this study was to evaluate the impact of the backfat thickness of sows on reproductive performance and on lipid metabolism, oxidative stress, and inflammation. At farrowing, 60 sows were assigned to three groups: the low-backfat-thickness group (LBF, n = 20): sows’ backfat thickness was between 9 and 12 mm; the medium-backfat-thickness group (MBF, n = 20): sows’ backfat thickness was between 13 and 20 mm; and the high-backfat-thickness group (HBF, n = 20): sows’ backfat thickness was between 21 and 25 mm. Maternal and fetal blood and placental samples were collected. Compared with the LBF and HBF groups, the MBF group delivered a significantly greater number of live piglets than the LBF or HBF groups. The different backfat thicknesses of sows had different effects on the lipid-related hormones and adipokines of maternal and fetal serum and placenta. Sows with poor or excessive backfat displayed higher levels of oxidative stress and higher levels of pro-inflammatory cytokines. According to these data, the thickness of a sow’s backfat affects the characteristics of farrowing piglets and their lipid metabolism, as well as placental inflammation, maternal inflammation, and oxidative stress. A moderate backfat thickness (between 13 and 20 mm) was associated with greater reproductive performance in sows.

Genetic variation in satiety signaling and hypothalamic inflammation: merging fields for the study of obesity

Although obesity has been a longstanding health crisis, the genetic architecture of the disease remains poorly understood. Genome-wide association studies have identified many genomic loci associated with obesity, with genes being enriched in the brain, particularly in the hypothalamus. This points to the role of the central nervous system (CNS) in predisposition to obesity, and we emphasize here several key genes along the satiety signaling pathway involved in genetic susceptibility. Interest has also risen regarding the chronic, low-grade obesity-associated inflammation, with a growing concern toward inflammation in the hypothalamus as a precursor to obesity. Recent studies have found that genetic variation in inflammatory genes play a role in obesity susceptibility, and we highlight here several key genes. Despite the interest in the genetic variants of these pathways individually, there is a lack of research that investigates the relationship between the two. Understanding the interplay between genetic variation in obesity genes enriched in the CNS and inflammation genes will advance our understanding of obesity etiology and heterogeneity, improve genetic risk prediction analyses, and highlight new drug targets for the treatment of obesity. Additionally, this increased knowledge will assist in physician's ability to develop personalized nutrition and medication strategies for combating the obesity epidemic. Though it often seems to present universally, obesity is a highly individual disease, and there remains a need in the field to develop methods to treat at the individual level.

Association analysis of SOCS3, JAK2 and STAT3 gene polymorphisms and genetic susceptibility to type 2 diabetes mellitus in Chinese population

AIM

The association of polymorphisms in the three genes of SOCS3, JAK2 and STAT3 with genetic susceptibility to type 2 diabetes mellitus (T2DM) was explored, and its interaction with environmental factors such as hypertension and triglycerides was analyzed.

METHODS

The Hardy-Weinberg balance test was used to analyze the random balance of genes in the population. The analysis of the association of SNPs with T2DM was performed using Pearson's chi-square test. Haplotype frequency distribution, SNPs-SNPs interaction and environmental factors were analyzed by chi-square test and logistic regression.

RESULTS

The genotype distribution of SNPs rs2280148 of the SOCS3 gene was statistically significant. The allele frequency distribution of SNPs (rs4969168/rs2280148) was statistically different. After covariate correction, the SOCS3 gene locus (rs4969168) showed an association with T2DM in additive model, while the rs2280148 locus showed an association with T2DM in all three models. The locus (rs10974914/rs10815157) allele and genotype frequency distribution of JAK2 were statistically significant. After covariate correction, two SNPs in the gene showed association with T2DM in both additive and recessive models. The distribution of genotype frequencies of SNPs rs1053005 locus in gene STAT3 was statistically significant between the two groups. In recessive genetic models, rs1053005 locus polymorphisms was associated with T2DM. Haplotype S3 (G G)/S 4 (G T) of the SOCS3 gene as well as haplotype J2 (A G)/J 3 (G C) of the JAK2 gene were closely associated with T2DM. There was an interaction between SNPs rs4969168 and SNPs rs2280148 in the SOCS3 gene. There was an interaction between the SOCS3, JAK2 and STAT3 genes and hypertension/triglycerides.

CONCLUSION

The SOCS3 and JAK2 genes may be associated with T2DM in the Chinese population, in which SNPs carrying the A allele (rs4969168)/G allele (rs2280148)/C allele (rs10815157) have a reduced risk of T2DM. Haplotype S3 (G G)/S 4 (G T) of the SOCS3 gene and haplotype J2 (A G)/J 3 (G C) of the JAK2 gene may be influencing factor for T2DM. The interaction between SNPs rs4969168 and SNPs rs2280148 increases the risk of T2DM. Hypertension and triglycerides may interact with SNPs of T2DM susceptibility genes.

SOCS3 Gene Polymorphism and Hypertension Susceptibility in Chinese Population: A Two-Center Case-Control Study

Endothelial inflammation and vascular damage are essential risk factors contributing to hypertension. Suppressor of cytokine signaling 3 (SOCS3) is involved in the regulation of multiple inflammatory pathways. A large number of studies have shown that the anti-inflammatory effect of SOCS3 in hypertension, obesity, and allergic reactions has brought more insights into the inhibition of inflammation. Therefore, we selected a tagSNP of SOCS3 (rs8064821) to investigate whether they are contributing to the risk of hypertension in the Chinese population. In total, 532 patients with hypertension and 569 healthy controls were enrolled for two central of China. SOCS3 rs8064821 C>A polymorphism was genotyped using TaqMan assay. SOCS3 rs8064821 CA genotype was associated with an increased risk of hypertension (OR = 1.821, 95%CI = 1.276-2.600, P = 0.001). Rs8064821 A allele was associated with higher SOCS3 mRNA level in PBMCs from healthy donors. SOCS3 rs8064821 C>A polymorphism may contribute to the risk of hypertension in the Chinese population by regulating the expression of SOCS3.

Innate-Immunity Genes in Obesity

The main functions of adipose tissue are thought to be storage and mobilization of the body’s energy reserves, active and passive thermoregulation, participation in the spatial organization of internal organs, protection of the body from lipotoxicity, and ectopic lipid deposition. After the discovery of adipokines, the endocrine function was added to the above list, and after the identification of crosstalk between adipocytes and immune cells, an immune function was suggested. Nonetheless, it turned out that the mechanisms underlying mutual regulatory relations of adipocytes, preadipocytes, immune cells, and their microenvironment are complex and redundant at many levels. One possible way to elucidate the picture of adipose-tissue regulation is to determine genetic variants correlating with obesity. In this review, we examine various aspects of adipose-tissue involvement in innate immune responses as well as variants of immune-response genes associated with obesity.

The mediation role of SOCS3 methylation in the effect of serum testosterone on type 2 diabetes

BACKGROUND

Previous studies reported that testosterone and DNA methylation of suppressor of cytokine signaling-3 (SOCS3) were associated with type 2 diabetes (T2D). Testosterone affects SOCS3 gene expression. Therefore, we aimed to investigate how the SOCS3 methylation mediates the relationship between testosterone and T2D among Chinese rural adults.

METHODS

A case-control study comprised 365 T2D patients and 651 controls was conducted. Liquid chromatography-tandem mass spectrometry and MethylTarget were used to determine the levels of serum testosterone and DNA methylation of SOCS3 gene, respectively. The odds ratio (OR) of testosterone or SOCS3 methylation for T2D was calculated using logistic regression models, and β value of testosterone for SOCS3 methylation was evaluated by linear regression models. Furthermore, through mediation analysis the mediating effect of SOCS3 methylation on the association of testosterone with T2D was estimated.

RESULTS

After adjusting for multiple variables, the protective effect of testosterone on T2D was found in men (OR = 0.61, 95% confidence interval [CI]: 0.47-0.80), and the methylation of Chr17:76356190 or Chr17:76356199 was negatively related to T2D in both men and women. Moreover, testosterone was positively associated with Chr17:76356190 methylation in men and Chr17:76356199 methylation in women (both P < .05). The mediation analysis showed that the Chr17:76356190 methylation partly mediated effect of testosterone on T2D in men was approximately 8.2%.

CONCLUSIONS

High levels of serum testosterone in men and Chr17:76356190 and Chr17:76356199 (SOCS3) methylation were related to a lower prevalent T2D. In addition, Chr17:76356190 methylation partially mediated the effect of testosterone on T2D in Chinese rural men.

Gene Expression Profile and Co-Expression Network of Pearl Gentian Grouper under Cold Stress by Integrating Illumina and PacBio Sequences

Simple Summary

In this study, we investigated the liver transcriptomic responses of pearl gentian grouper towards cold stress. Some cold-related key genes and biological pathways were screened, of which energy-related metabolic pathways and genes had higher expression levels under cold stress. This suggested that energy homeostasis plays a crucial role in the physiological adjustments of pearl gentian grouper when exposed to the cold stress environment. Our results will expedite the understanding of different fishes adaptive mechanisms to profound environmental temperature changes and provide insights into the molecular breeding of cold-tolerant pearl gentian grouper varieties.

Abstract

Pearl gentian grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) is a fish of high commercial value in the aquaculture industry in Asia. However, this hybrid fish is not cold-tolerant, and its molecular regulation mechanism underlying cold stress remains largely elusive. This study thus investigated the liver transcriptomic responses of pearl gentian grouper by comparing the gene expression of cold stress groups (20, 15, 12, and 12 °C for 6 h) with that of control group (25 °C) using PacBio SMRT-Seq and Illumina RNA-Seq technologies. In SMRT-Seq analysis, a total of 11,033 full-length transcripts were generated and used as reference sequences for further RNA-Seq analysis. In RNA-Seq analysis, 3271 differentially expressed genes (DEGs), two low-temperature specific modules (tan and blue modules), and two significantly expressed gene sets (profiles 0 and 19) were screened by differential expression analysis, weighted gene co-expression networks analysis (WGCNA), and short time-series expression miner (STEM), respectively. The intersection of the above analyses further revealed some key genes, such as PCK, ALDOB, FBP, G6pC, CPT1A, PPARα, SOCS3, PPP1CC, CYP2J, HMGCR, CDKN1B, and GADD45Bc. These genes were significantly enriched in carbohydrate metabolism, lipid metabolism, signal transduction, and endocrine system pathways. All these pathways were linked to biological functions relevant to cold adaptation, such as energy metabolism, stress-induced cell membrane changes, and transduction of stress signals. Taken together, our study explores an overall and complex regulation network of the functional genes in the liver of pearl gentian grouper, which could benefit the species in preventing damage caused by cold stress.

Insulin on the brain: The role of central insulin signalling in energy and glucose homeostasis

Insulin signals to the brain where it coordinates multiple physiological processes underlying energy and glucose homeostasis. This review explores where and how insulin interacts within the brain parenchyma, how brain insulin signalling functions to coordinate energy and glucose homeostasis and how this contributes to the pathogenesis of metabolic disease.

SOCS3 methylation mediated the effect of sedentary time on type 2 diabetes mellitus: The Henan Rural Cohort study

BACKGROUND AND AIMS

To assess the associations of sedentary time, suppressor of cytokine signaling (SOCS)-3 DNA methylation with type 2 diabetes mellitus (T2DM), and further identify the role of SOCS3 methylation in mediating the association of sedentary time with T2DM in a Chinese rural population.

METHODS AND RESULTS

A case-control study including 1032 participants from the Henan Rural Cohort study was conducted. Restricted cubic spline analysis and logistic regression model were performed to evaluate the associations between sedentary time, SOCS3 methylation and T2DM. The mediation effect of SOCS3 methylation on the association between sedentary time and T2DM was assessed. Sensitivity analysis was conducted by excluding individuals with diagnosed T2DM. Linear dose-response relationships were found between sedentary time, methylation level of Chr17:76356190 (one novel site on SOCS3) and T2DM. Compared with the first quartile (less than 5 h/d) of sedentary time, the adjusted odds ratio (OR, 95% confidence interval, 95%CI) for those in the third (7-10 h/d) and fourth (≥10 h/d) quartiles were 1.87 (1.22-2.85) and 3.54 (2.14-5.85), respectively. Participants in the fourth quartile of methylation level of Chr17:76356190 had lower risk of T2DM than those in the first quartile (OR (95%CI): 0.23 (0.14-0.38)). Mediation analysis showed 9.66% (6.38%-14.80%) of the association between sedentary time and T2DM was attributable to Chr17:76356190. The comparable effect estimates were observed between sedentary time, methylation level of Chr17:76356190 and undiagnosed T2DM.

CONCLUSION

Sedentary time and methylation level of Chr17:76356190 were both independently associated with T2DM in the Chinese rural population. Furthermore, Chr17:76356190 appeared to partially mediate the effect of sedentary time on T2DM.

CHINESE CLINICAL TRIAL REGISTRATION

ChiCTR-OOC-15006699 (URL: http://www.chictr.org.cn/showproj.aspx?proj=11375).

Inhibition of JAK2/STAT3/SOCS3 signaling attenuates atherosclerosis in rabbit

Background

Previous studies have indicated that the JAK/STAT signaling pathway is involved in modulating arterial adventitia inflammation response. In this study, we designed experiments to further investigate the effect of JAK2/STAT3/SOCS3 signaling in rabbit atherosclerosis process.

Methods

Atherosclerosis was induced in the abdominal arteries of rabbits by balloon injury of the aorta supplemented by the atherogenic diet. Simultaneously, in the process of atherosclerosis, animals underwent either ruxolitinib treatment or not for 12 weeks. At the end of the experimental period, all rabbits were sacrificed. The plaque areas in abdominal artery, the lipid burden of plaque and the calcium burden of plaque were detected by H&E staining, Oil Red O staining and Alizarin Red staining, respectively. In addition, rabbit plasma lipids and inflammatory cytokines were measured by biochemical test kits or ELISA kits. Finally, the expression and phosphorylation levels of JAK2/STAT3/SOCS3 pathway-related proteins were detected by RT-qPCR, western blot and immunohistochemistry assays.

Results

H&E staining and CT scan analysis showed that rabbit atherosclerosis model was constructed successfully. Ruxolitinib, an inhibitor of the Janus kinase 2 (JAK2), substantially reduced the area of atherosclerotic plaques in rabbits treated with high fat diet and balloon injury of the aorta. Moreover, ruxolitinib significantly decreased IL-6, IL-1β, IFN-γ and TNF-α, but increased IL-10 and IL-17 levels in plasma of atherosclerotic rabbits. Additionally, ruxolitinib reduced plasma TC, TG and LDL-C contents and AIP value, while enhanced HDL-C level in atherosclerotic rabbits. Furthermore, we found that JAK2 and STAT3 phosphorylation were up-regulated in rabbits with atherosclerosis when compared with those of the control group, followed by the expression of SOCS3 was also increased due to the activation of JAK2 and STAT3. Interestingly, ruxolitinib could inactivate JAK2 and STAT3 pathway and decrease SOCS3 expression.

Conclusion

Taken together, the inhibition of JAK2/STAT3/SOCS3 signaling pathway may be a novel method for the clinical treatment of artery atherosclerosis.

Fruit and vegetable intake modifies the associations between suppressor of cytokine signaling 3 genetic variants and type 2 diabetes

PURPOSE

Type 2 diabetes is a complex disease determined by variable genes and environmental factors. The study was designed to investigate the effect of interactions of four polymorphisms of suppressor of cytokine signaling 3 (SOCS3) with fruit and vegetable (F&V) intake on type 2 diabetes in a rural population of China.

METHODS

A total of 4411 participants from the rural areas of Henan, China were included in the study. Multivariate logistic regression and restricted cubic splines were used to estimate the associations between polymorphisms and risk allele score of SOCS3 and type 2 diabetes in different groups. Haplotype analysis was conducted to examine the effects of linkage inheritance at these four loci on type 2 diabetes.

RESULTS

Three of the four polymorphisms showed significant associations with type 2 diabetes in the less F&V intake group after adjusting the covariates, the odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were 1.24 (1.08-1.41) for rs4969168, 1.16 (1.02-1.32) for rs9892622, and 1.21 (1.06-1.39) for rs9914220. No significant association was detected in the more F&V intake group. The obvious dose-response relationship between the risk allele score and type 2 diabetes was also noted only in the less F&V intake group.

CONCLUSIONS

Variants of SOCS3 gene were associated with type 2 diabetes and the associations could be modified by the F&V intake.

Investigating Gene-Gene and Gene-Environment Interactions in the Association Between Overnutrition and Obesity-Related Phenotypes

Introduction: Animal studies suggested that NFKB1, IKBKB, and SOCS3 genes could be involved in the association between overnutrition and obesity. This study aims to investigate interactions involving these genes and macronutrient intakes affecting obesity-related phenotypes. Methods: We used a traditional statistical method, logistic regression, and compared it to alternative statistical method, multifactor dimensionality reduction (MDR) and penalized logistic regression (PLR), to better detect genes/environment interactions in the Toronto Nutrigenomics and Health Study (n = 1639) using dichotomized body mass index (BMI) and waist circumference as obesity-related phenotypes. Exposure variables included genotype on 54 single nucleotide polymorphisms (NFKB1: 18, IKBKB: 9, SOCS3: 27), macronutrient (carbohydrates, protein, fat) and alcohol intakes and ethno-cultural background. Results: After correction for multiple testing, no interaction was found using logistic regression. MDR identified interactions between SOCS3 rs6501199 and rs4969172, and IKBKB rs3747811 affecting BMI in the Caucasian population; SOCS3 rs6501199 and NFKB1 rs1609798 affecting WC in the Caucasian population; and SOCS3 rs4436839 and IKBKB rs3747811 affecting WC in the South Asian population. PLR found a main effect of SOCS3 rs12944581 on BMI among the South Asian population. Conclusion: While MDR and PLR had discordant results, some models support results from previous studies. These results emphasize the need to use alternative statistical methods to investigate high-order interactions and suggest that variants in the nutrient-responsive hypothalamic IKKB/NF-kB signaling pathway may be involved in obesity pathogenesis.

Understanding the growing epidemic of type 2 diabetes in the Hispanic population living in the United States

The prevalence and incidence of type 2 diabetes (T2D) among the Hispanic population in the United States are higher than the national average. This is partly due to sociocultural factors, such as lower income and decreased access to education and health care, as well as a genetic susceptibility to obesity and higher insulin resistance. This review focuses on understanding the Hispanic population living in the United States from a multidisciplinary approach and underlines the importance of cultural, social, and biological factors in determining the increased risk of T2D in this population. An overview of the acute and chronic complications of T2D upon this population is included, which is of paramount importance to understand the toll that diabetes has upon this population, the health system, and society as a whole. Specific interventions directed to the Hispanic populations are needed to prevent and alleviate some of the burdens of T2D. Different prevention strategies based on medications, lifestyle modifications, and educational programmes are discussed herein. Diabetes self-management education (DSME) is a critical element of care of all people with diabetes and is considered necessary to improve patient outcomes. To be more effective, programmes should take into consideration cultural factors that influence the development and progression of diabetes. These interventions aim to enhance long-term effects by reducing the incidence, morbidity, and mortality of T2D in the Hispanic population of the United States.

Epigenome-wide association analysis revealed that SOCS3 methylation influences the effect of cumulative stress on obesity

Chronic stress has a significant impact on obesity. However, how stress influences obesity remains unclear. We conducted an epigenome-wide DNA methylation association analysis of obesity (N=510) and examined whether cumulative stress influenced the DNA methylation on body weight. We identified 20 CpG sites associated with body mass index at the false discovery rate q<0.05, including a novel site, cg18181703, in suppressor of cytokine signaling 3 (SOCS3) gene (coefficient β=-0.0022, FDR q=4.94×10-5). The interaction between cg18181703 and cumulative adverse life stress contributed to variations in body weight (p=0.002). Individuals with at least five major life events and lower methylation of cg1818703 showed a 1.38-fold higher risk of being obese (95%CI: 1.17-1.76). Our findings suggest that aberrant in DNA methylation is associated with body weight and that methylation of SOCS3 moderates the effect of cumulative stress on obesity.

Blood-Based DNA Methylation Biomarkers for Type 2 Diabetes: Potential for Clinical Applications

Type 2 diabetes (T2D) is a leading cause of death and disability worldwide. It is a chronic metabolic disorder that develops due to an interplay of genetic, lifestyle, and environmental factors. The biological onset of the disease occurs long before clinical symptoms develop, thus the search for early diagnostic and prognostic biomarkers, which could facilitate intervention strategies to prevent or delay disease progression, has increased considerably in recent years. Epigenetic modifications represent important links between genetic, environmental and lifestyle cues and increasing evidence implicate altered epigenetic marks such as DNA methylation, the most characterized and widely studied epigenetic mechanism, in the pathogenesis of T2D. This review provides an update of the current status of DNA methylation as a biomarker for T2D. Four databases, Scopus, Pubmed, Cochrane Central, and Google Scholar were searched for studies investigating DNA methylation in blood. Thirty-seven studies were identified, and are summarized with respect to population characteristics, biological source, and method of DNA methylation quantification (global, candidate gene or genome-wide). We highlight that differential methylation of the TCF7L2, KCNQ1, ABCG1, TXNIP, PHOSPHO1, SREBF1, SLC30A8, and FTO genes in blood are reproducibly associated with T2D in different population groups. These genes should be prioritized and replicated in longitudinal studies across more populations in future studies. Finally, we discuss the limitations faced by DNA methylation studies, which include including interpatient variability, cellular heterogeneity, and lack of accounting for study confounders. These limitations and challenges must be overcome before the implementation of blood-based DNA methylation biomarkers into a clinical setting. We emphasize the need for longitudinal prospective studies to support the robustness of the current findings of this review.

An epigenome-wide study of body mass index and DNA methylation in blood using participants from the Sister Study cohort

BACKGROUND/OBJECTIVES

The relationship between obesity and chronic disease risk is well-established; the underlying biological mechanisms driving this risk increase may include obesity-related epigenetic modifications. To explore this hypothesis, we conducted a genome-wide analysis of DNA methylation and body mass index (BMI) using data from a subset of women in the Sister Study.

SUBJECTS/METHODS

The Sister Study is a cohort of 50 884 US women who had a sister with breast cancer but were free of breast cancer themselves at enrollment. Study participants completed examinations which included measurements of height and weight, and provided blood samples. Blood DNA methylation data generated with the Illumina Infinium HumanMethylation27 BeadChip array covering 27,589 CpG sites was available for 871 women from a prior study of breast cancer and DNA methylation. To identify differentially methylated CpG sites associated with BMI, we analyzed this methylation data using robust linear regression with adjustment for age and case status. For those CpGs passing the false discovery rate significance level, we examined the association in a replication set comprised of a non-overlapping group of 187 women from the Sister Study who had DNA methylation data generated using the Infinium HumanMethylation450 BeadChip array. Analysis of this expanded 450 K array identified additional BMI-associated sites which were investigated with targeted pyrosequencing.

RESULTS

Four CpG sites reached genome-wide significance (false discovery rate (FDR) q<0.05) in the discovery set and associations for all four were significant at strict Bonferroni correction in the replication set. An additional 23 sites passed FDR in the replication set and five were replicated by pyrosequencing in the discovery set. Several of the genes identified including ANGPT4, RORC, SOCS3, FSD2, XYLT1, ABCG1, STK39, ASB2 and CRHR2 have been linked to obesity and obesity-related chronic diseases.

CONCLUSIONS

Our findings support the hypothesis that obesity-related epigenetic differences are detectable in blood and may be related to risk of chronic disease.

Epigenetic associations of type 2 diabetes and BMI in an Arab population

Background

The prevalence of type 2 diabetes (T2D) and obesity has dramatically increased within a few generations, reaching epidemic levels. In addition to genetic risk factors, epigenetic mechanisms triggered by changing environment are investigated for their role in the pathogenesis of these complex diseases. Epigenome-wide association studies (EWASs) have revealed significant associations of T2D, obesity, and BMI with DNA methylation. However, populations from the Middle East, where T2D and obesity rates are highest worldwide, have not been investigated so far.

Methods

We performed the first EWAS in an Arab population with T2D and BMI and attempted to replicate 47 EWAS associations previously reported in Caucasians. We used the Illumina Infinium HumanMethylation450 BeadChip to quantify DNA methylation in whole blood DNA from 123 subjects of 15 multigenerational families from Qatar. To investigate the effect of differing genetic background and environment on the epigenetic associations, we further assessed the effect of replicated loci in 810 twins from UK.

Results

Our EWAS suggested a novel association between T2D and cg06721411 (DQX1; p value = 1.18 × 10⁻⁹). We replicated in the Qatari population seven CpG associations with BMI (SOCS3, p value = 3.99 × 10⁻⁶; SREBF1, p value = 4.33 × 10⁻⁵; SBNO2, p value = 5.87 × 10⁻⁵; CPT1A, p value = 7.99 × 10⁻⁵; PRR5L, p value = 1.85 × 10⁻⁴; cg03078551, intergenic region on chromosome 17; p value = 1.00 × 10⁻³; LY6G6E, p value = 1.10 × 10⁻³) and one with T2D (TXNIP, p value = 2.46 × 10⁻⁵). All the associations were further confirmed in the UK cohort for both BMI and T2D. Meta-analysis increased the significance of the observed associations and revealed strong heterogeneity of the effect sizes (apart from CPT1A), although associations at these loci showed concordant direction in the two populations.

Conclusions

Our study replicated eight known CpG associations with T2D or BMI in an Arab population. Heterogeneity of the effects at all loci except CPT1A between the Qatari and UK studies suggests that the underlying mechanisms might depend on genetic background and environmental pressure. Our EWAS results provide a basis for comparison with other ethnicities.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0177-6) contains supplementary material, which is available to authorized users.

Regulation of Macrophage, Dendritic Cell, and Microglial Phenotype and Function by the SOCS Proteins

Macrophages are innate immune cells of dynamic phenotype that rapidly respond to external stimuli in the microenvironment by altering their phenotype to respond to and to direct the immune response. The ability to dynamically change phenotype must be carefully regulated to prevent uncontrolled inflammatory responses and subsequently to promote resolution of inflammation. The suppressor of cytokine signaling (SOCS) proteins play a key role in regulating macrophage phenotype. In this review, we summarize research to date from mouse and human studies on the role of the SOCS proteins in determining the phenotype and function of macrophages. We will also touch on the influence of the SOCS on dendritic cell (DC) and microglial phenotype and function. The molecular mechanisms of SOCS function in macrophages and DCs are discussed, along with how dysregulation of SOCS expression or function can lead to alterations in macrophage/DC/microglial phenotype and function and to disease. Regulation of SOCS expression by microRNA is discussed. Novel therapies and unanswered questions with regard to SOCS regulation of monocyte-macrophage phenotype and function are highlighted.

Suppressor of cytokine signaling 3 A+930-->G (rs4969168) polymorphism is associated with apolipoprotein A1 and low-density lipoprotein cholesterol

This study aimed to detect the association of the suppressor of cytokine signaling 3 gene (SOCS3) A+930-->G (rs4969168) single nucleotide polymorphism (SNP) and environmental factors with serum lipid levels in the Han and Mulao populations. Genotyping of the SOCS3 A+930-->G (rs4969168) SNP was performed in 752 of Han and 690 of Mulao participants using polymerase chain reaction and restriction fragment length polymorphism. The genotype and allele frequencies were significantly different between the Han and Mulao populations (GG, 57.71% vs. 51.16%, GA, 36.97% vs. 41.16%, AA, 5.32% vs. 7.68%, P = 0.023; G, 76.20% vs. 71.74%, A, 23.80% vs. 28.26%; P = 0.006; respectively). Serum apolipoprotein (Apo) A1 levels in Han were different among the genotypes (P < 0.05). Subgroup analyses showed that the levels of ApoA1 in Han females, and ApoA1 and low-density lipoprotein cholesterol (LDL-C) in Mulao males were different among the genotypes (P < 0.05). Serum lipid parameters were also associated with several environmental factors in both ethnic groups (P < 0.05-0.001). These findings suggest that there may be a racial/ethnic- and/or sex-specific association between the SOCS3 A+930-->G (rs4969168) SNP and serum lipid parameters in some populations.

Correlation of lipid metabolic disturbance with SOCS-3 gene variation in the Uygur nationality women in Xinjiang

To study the correlation of lipid metabolic disturbance with gene variation of suppressor of cytokine signaling 3 (SOCS-3) in the Uygur nationality women in Xinjiang. We Selected 1379 Uygur nationality women as research objects and proceeded genotype assay for 3 representative loci (rs12953258, rs4969168 and rs9914220) to analyze them. There were significant difference in genotypic frequency in rs12953258 between lipid metabolic disturbance group and lipid embolism group (P=0.032) and between high density lipoprotein cholesterol (HDL-C) abnormal and normal group (P=0.029). Logistic regression analysis showed that the AA genotype of rs12953258 might be a risk factors of lipid metabolic disturbance in the Uygur nationality women in Xinjiang [CC/AA: OR=3.271, 95% CI (1.092-9.797), P=0.034]. The AA genotype might be associated with HDL-C decrease and triacylglycerol increase. The AA genotype Uygur nationality women with abnormal body mass index (BMI) were more sensitive to lipid metabolic disturbance disease. SOCS-3 gene variation may be associated with lipid metabolic disturbance in the Uygur nationality women in Xinjiang, prevalence of lipid metabolic disturbance increases significantly in crowd carrying AA genotype with abnormal BMI.

Genetic variations in the SOCS3 gene in patients with Graves' ophthalmopathy

AIMS

To explore the role of the suppressor of cytokine signalling 3 (SOCS3) gene in Graves' ophthalmopathy (GO) patients.

METHODS

A case-control study was conducted in a Chinese Han population by recruiting 114 Graves' disease (GD) patients with GO and 156 GD patients without GO. We determined SOCS3 mRNA and protein levels in Epstein-Barr virus-transformed lymphoblastoid cell lines (EBV-LCLs) from peripheral blood mononuclear cells (PBMCs) by quantitative real-time (QRT)-PCR analysis and western blot analysis. We also genotyped five single nucleotide polymorphisms (SNPs) in the SOCS3 locus (SOCS3 rs12952093, rs4969170, rs4969168, rs4969169 and rs2280148) in all 270 GD patients using ligase detection reaction and multiplex PCR analyses. QRT-PCR and western blot assays were then performed to compare SOCS3 mRNA and protein levels between the rs4969170 AA and GG genotype groups from 20 GO patients.

RESULTS

Basal SOCS3 mRNA and protein expression levels were significantly increased in patients with GO (p<0.05). The SOCS3 rs4969170 AA genotype was strongly associated with GO (OR=3.5, 95% CI 1.6 to 7.5, p=0.001). The AA genotype carriers had significantly higher SOCS3 mRNA and protein levels than those with the GG genotype (p<0.05).

CONCLUSIONS

Patients with GD who carry the AA genotype of the rs4969170 SNP in SOCS3 are more susceptible to the development of GO.

The role of progranulin in diabetes and kidney disease

Progranulin (PGRN) is a cysteine rich secreted protein, expressed in epithelial cells, immune cells, neurons, and adipocytes. It was first identified for its growth factor-like properties, being involved in early embryogenesis and tissue remodeling, acting as an anti-inflammatory molecule. In the central nervous system, PGRN has neurotrophic and neuroprotective actions. There is also evidence of PGRN effects on cancer, contributing to tumor proliferation, invasion and cell survival. Recently, PGRN was recognized as an adipokine related to obesity and insulin resistance, revealing its metabolic function and pro-inflammatory properties. In obesity and type 2 diabetes mellitus, PGRN levels are increased. In renal disease, there is a relevant association, however, it is not known if it could contribute to kidney damage or if it is only a route of PGRN elimination. PGRN is an emerging molecule which demands studies in different fields. Possibly, it plays distinct functions in different tissues/cells and metabolic conditions. Here, we discuss potential mechanisms and recent data of PGRN pro-inflammatory actions, regarding obesity, insulin resistance, type 2 diabetes mellitus and kidney disease.

Suppressor of cytokine signalling (SOCS) proteins as guardians of inflammatory responses critical for regulating insulin sensitivity

Overactivation of immune pathways in obesity is an important cause of insulin resistance and thus new approaches aimed to limit inflammation or its consequences may be effective for treating Type 2 diabetes. The SOCS (suppressors of cytokine signalling) are a family of proteins that play an essential role in mediating inflammatory responses in both immune cells and metabolic organs such as the liver, adipose tissue and skeletal muscle. In the present review we discuss the role of SOCS1 and SOCS3 in controlling immune cells such as macrophages and T-cells and the impact this can have on systemic inflammation and insulin resistance. We also dissect the mechanisms by which SOCS (1-7) regulate insulin signalling in different tissues including their impact on the insulin receptor and insulin receptor substrates. Lastly, we discuss the important findings from SOCS whole-body and tissue-specific null mice, which implicate an important role for these proteins in controlling insulin action and glucose homoeostasis in obesity.

Obesity pharmacotherapy: current perspectives and future directions

The rising tide of obesity and its related disorders is one of the most pressing health concerns worldwide, yet existing medicines to combat the problem are disappointingly limited in number and effectiveness. Recent advances in mechanistic insights into the neuroendocrine regulation of body weight have revealed an expanding list of molecular targets for novel, rationally designed antiobesity pharmaceutical agents. Antiobesity drugs act via any of four mechanisms: 1) decreasing energy intake, 2) increasing energy expenditure or modulating lipid metabolism, 3) modulating fat stores or adipocyte differentiation, and 4) mimicking caloric restriction. Various novel drug candidates and targets directed against obesity are currently being explored. A few of them are also in the later phases of clinical trials. This review discusses the development of novel antiobesity drugs based on current understanding of energy homeostasis

Genetic association analysis of 30 genes related to obesity in a European American population

OBJECTIVE

Obesity, which is frequently associated with diabetes, hypertension and cardiovascular diseases, is primarily the result of a net excess of caloric intake over energy expenditure. Human obesity is highly heritable, but the specific genes mediating susceptibility in non-syndromic obesity remain unclear. We tested candidate genes in pathways related to food intake and energy expenditure for association with body mass index (BMI).

METHODS

We reanalyzed 355 common genetic variants of 30 candidate genes in seven molecular pathways related to obesity in 1982 unrelated European Americans from the New York Cancer Project. Data were analyzed by using a Bayesian hierarchical generalized linear model. The BMIs were log-transformed and then adjusted for covariates, including age, age(2), gender and diabetes status. The single-nucleotide polymorphisms (SNPs) were modeled as additive effects.

RESULTS

With the stipulated adjustments, nine SNPs in eight genes were significantly associated with BMI: ghrelin (GHRL; rs35683), agouti-related peptide (AGRP; rs5030980), carboxypeptidase E (CPE; rs1946816 and rs4481204), glucagon-like peptide-1 receptor (GLP1R; rs2268641), serotonin receptors (HTR2A; rs912127), neuropeptide Y receptor (NPY5R;Y5R1c52), suppressor of cytokine signaling 3 (SOCS3; rs4969170) and signal transducer and activator of transcription 3 (STAT3; rs4796793). We also found a gender-by-SNP interaction (rs1745837 in HTR2A), which indicated that variants in the gene HTR2A had a stronger association with BMI in males. In addition, NPY1R was detected as having a significant gene effect even though none of the SNPs in this gene was significant.

CONCLUSION

Variations in genes AGRP, CPE, GHRL, GLP1R, HTR2A, NPY1R, NPY5R, SOCS3 and STAT3 showed modest associations with BMI in European Americans. The pathways in which these genes participate regulate energy intake, and thus these associations are mechanistically plausible in this context.

Common variants in SOCS7 gene predict obesity, disturbances in lipid metabolism and insulin resistance

BACKGROUND AND AIMS

Specific Suppressor of Cytokine Signaling (SOCS) members, such as SOCS7, may play a role in the development of insulin resistance (IR) owing to their ability to inhibit insulin signaling pathways. The objective was to explore the association between common variants and related haplotypes in SOCS7 gene and metabolic traits related to obesity, lipid metabolism and IR.

METHODS AND RESULTS

780 unrelated men were included in a cross-sectional study. We selected three tagged SNPs that capture 100% of SNPs with minor allele frequency ≥ 0.10. Analyses were done separately for each SNP and followed up by haplotype analysis. rs8074124C was associated with both obesity (p = 0.005) and abdominal obesity (p = 0.002) and allele C carriers showed, in comparison with TT carriers, lower BMI (p = 0.001) and waist circumference (p = 0.001). rs8074124CC- carriers showed lower fasting insulin (p = 0.017) and HOMA-IR (p = 0.018) than allele T carriers. rs12051836C was associated with hypertriglyceridemia (p = 0.009) and hypertriglyceridemic waist (p = 0.006). rs12051836CC- carriers showed lower fasting insulin (p = 0.043) and HOMA-IR (p = 0.042). Haplotype-based association analysis (rs8074124 and rs12051836 in that order) showed associations with lipid and obesity -related phenotypes, consistent with single locus analysis. Haplotype analysis also revealed association between haplotype CT and both decreased HDL-C (p = 0.026) and HDL-C (p = 0.014) as a continuous variable.

CONCLUSIONS

We found, for the first time, significant associations between SOCS7 common variants and related haplotypes and obesity, IR and lipid metabolism disorders.

Association of suppressor of cytokine signalling 3 polymorphisms with insulin resistance in patients with chronic hepatitis C

Suppressor of cytokine signalling 3 is thought to be associated with insulin resistance in patients with chronic hepatitis C. We evaluated the role of suppressor of cytokine signalling 3 polymorphisms in determining insulin resistance in patients with chronic hepatitis C. Two hundred and ninety untreated hepatitis C virus-infected patients without diabetes and cirrhosis were genotyped for the SNPs rs4969168, rs4969170 and rs12952093 of suppressor of cytokine signalling 3 using the TaqMan Genotyping Assay. We found that the rs4969170 AA genotype and rs4969170 A allele frequency were significantly more common in the insulin-resistant group than the non-insulin-resistant group (89.5% vs 76.1%, OR = 2.693, 95% CI: 1.221-5.939, P = 0.012 and 94.8% vs 88.0%, OR = 2.463, 95% CI: 1.151-5.271, P = 0.017, respectively). Haplotype G-C was likely associated with non-insulin resistance (adjusted P = 0.011). Multiple logistic regression analysis indicates that the independent risk factors for insulin resistance are the SNP rs4969170 AA genotype (OR = 3.005, 95% CI: 1.194-7.560, P = 0.019), HCV genotype 1 (OR = 2.524, 95% CI: 1.099-5.794, P = 0.029) and BMI (OR = 0.514, 95% CI: 0.265-0.999, P = 0.05).

Exploring differences in adiposity in two U.S. Hispanic populations of Mexican origin using social, behavioral, physiologic and genetic markers: the IRAS Family Study

OBJECTIVE

The census classification of Hispanic origin is used in epidemiological studies to group individuals, even though there is geographical, cultural, and genetic diversity within Hispanic Americans of purportedly similar backgrounds. We observed differences in our measures of adiposity between our two Mexican American populations, and examined whether these differences were attributed to social, behavioral, physiologic or genetic differences between the two populations.

RESEARCH DESIGN AND METHODS

In the IRAS Family Study, we examined 478 Hispanics from San Antonio, Texas and 447 Hispanics from the San Luis Valley, Colorado. Associations with body mass index (BMI), visceral adipose tissue area (VAT), and subcutaneous adipose tissue area (SAT) using social, behavioral, physiologic and genetic variables were examined.

RESULTS

Hispanics of Mexican origin in our clinic population in San Antonio had significantly higher mean BMI (31.09 vs. 28.35 kg/m2), VAT (126.3 vs. 105.5 cm2), and SAT (391.6 vs. 336.9 cm2), than Hispanics of Mexican origin in the San Luis Valley. The amount of variation in adiposity explained by clinic population was 4.5% for BMI, 2.8% for VAT, and 2.7% for SAT. After adjustment, clinic population was no longer associated with VAT and SAT, but remained associated with BMI, although the amount of variation explained by population was substantially less (1.0% for BMI).

CONCLUSION

Adiposity differences within this population of Mexican origin can be largely explained by social, behavioral, physiologic and genetic differences.

Association of two polymorphisms within and near SOCS3 gene with obesity in three nationalities in Xinjiang province of China

AIM

SOCS3 gene plays an important role in the pathogenesis of obesity in animal models, but the data from human studies are relatively limited. To address this issue, a genetic association analysis on nationalities with different genetic background living in the similar environmental conditions was performed.

METHODS

Two thousand seven hundred eleven subjects were randomly recruited from the Kazakh, Uygur and Han nationalities in Xinjiang of China. SNP polymorphisms rs4969168 and rs9892622 within or near the SOCS3 gene were genotyped using TaqMan-MGB™ assay. Association study between the two polymorphisms and obesity-related traits (body mass index [BMI]; waist-to-hip ratio [WHR]; weight; height, waist, and hip measurements) was conducted.

RESULTS

Significant association was found between rs4969168 and the obesity-related traits, including BMI (25.32 ± 3.49 kg/m(2) for AA, 24.60 ± 3.70 kg/m(2) for AG, 24.39 ± 3.42 kg/m(2) for GG, P=0.042), weight (65.58 ± 11.42 kg for AA, 63.50 ± 11.30 kg for AG, 62.00 ± 10.78 kg for GG, P=0.011) in the Han nationality, but not in the Kazakh or Uygur nationalities. Rs9892622 was significantly associated with BMI, WHR, and WAIST in the Uygur males. Rs9892622 was also associated with BMI in Kazakh males. Linear regression analysis verified the above findings. However, neither of the two polymorphisms was associated with obesity-related traits in the total population.

CONCLUSION

The polymorphism rs4969168 within or near the SOCS3 gene has a significant effect in the Han nationality, while rs9892622 was associated with obesity in Uygur and Kazakh nationalities in Xinjiang of China.

A novel integrative network approach to understand the interplay between cardiovascular disease and other complex disorders

There is accumulating evidence that the proteins encoded by the genes associated with a common disorder interact with each other, participate in similar pathways and share GO terms. It has been anticipated that the functional modules in a disease related functional linkage network can be integrated with bibliomics to reveal association with other complex disorders. In this study, the cardiovascular disease functional linkage network (CFN) containing 1536 nodes and 3345 interactions was constructed using proteins encoded by 234 genes associated with the disease. Integration of CFN with bibliomics showed that 227 out of 566 functional modules are significantly associated with one or more diseases. Analysis of functional modules revealed the possible regulatory roles of SP1 and CXCL12 in the pathogenesis of cardiovascular disease (CVD) and modulation of their activities may be considered as potential therapeutic tools. The integration of CFN with bibliomics also indicated significant relations of CVD with other complex disorders. In a stratified map the members of 227 functional modules and 58 diseases in 15 disease classes were combined. In this map, leprosy, listeria monocytogenes, myasthenia, hemorrhagic diathesis and Protein S deficiency, which were not previously reported to be associated with CVD, showed significant associations. Several cancers arising from epithelial cells were also found to be linked to other diseases through hub proteins, VEGFA and PTGS2.

Neurobiology of overeating and obesity: the role of melanocortins and beyond

The alarming increase in the incidence of obesity and obesity-associated disorders makes the etiology of obesity a widely studied topic today. As opposed to 'homeostatic feeding', where food intake is restricted to satisfy one's biological needs, the term 'non-homeostatic' feeding refers to eating for pleasure or the trend to over-consume (palatable) food. Overconsumption is considered a crucial factor in the development of obesity. Exaggerated consumption of (palatable) food, coupled to a loss of control over food intake despite awareness of its negative consequences, suggests that overeating may be a form of addiction. At a molecular level, insulin and leptin resistance are hallmarks of obesity. In this review, we specifically address the question how leptin resistance contributes to enhanced craving for (palatable) food. Since dopamine is a key player in the motivation for food, the interconnection between dopamine, leptin and neuropeptides related to feeding will be discussed. Understanding the mechanisms by which these neuropeptidergic systems hijack the homeostatic feeding mechanisms, thus leading to overeating and obesity is the primary aim of this review. The melanocortin system, one of the crucial neuropeptidergic systems modulating feeding behavior will be extensively discussed. The inter-relationship between neuronal populations in the arcuate nucleus and other areas regulating energy homeostasis (lateral hypothalamus, paraventricular nucleus, ventromedial hypothalamus etc.) and reward circuitry (the ventral tegmental area and nucleus accumbens) will be evaluated and scrutinized.

The genetic contribution to non-syndromic human obesity

The last few years have seen major advances in common non-syndromic obesity research, much of it the result of genetic studies. This Review outlines the competing hypotheses about the mechanisms underlying the genetic and physiological basis of obesity, and then examines the recent explosion of genetic association studies that have yielded insights into obesity, both at the candidate gene level and the genome-wide level. With obesity genetics now entering the post-genome-wide association scan era, the obvious question is how to improve the results obtained so far using single nucleotide polymorphism markers and how to move successfully into the other areas of genomic variation that may be associated with common obesity.