Obesity Traits Research Articles

Pleiotropic genetic influence on birth weight and childhood obesity

Childhood obesity is a global public health problem. Understanding the molecular mechanisms that underlie early origins of childhood obesity can facilitate interventions. Consistent phenotypic and genetic correlations have been found between childhood obesity traits and birth weight (a proxy for in-utero growth), suggesting shared genetic influences (pleiotropy). We aimed to (1) investigate whether there is significant shared genetic influence between birth weight and childhood obesity traits, and (2) to identify genetic loci with shared effects. Using a statistical approach that integrates summary statistics and functional annotations for paired traits, we found strong evidence of pleiotropy (P < 3.53 × 10–127) and enrichment of functional annotations (P < 1.62 × 10–39) between birth weight and childhood body mass index (BMI)/obesity. The pleiotropic loci were enriched for regulatory features in skeletal muscle, adipose and brain tissues and in cell lines derived from blood lymphocytes. At 5% false discovery rate, 6 loci were associated with birth weight and childhood BMI and 13 loci were associated with birth weight and childhood obesity. Out of these 19 loci, one locus (EBF1) was novel to childhood obesity and one locus (LMBR1L) was novel to both birth weight and childhood BMI/obesity. These findings give evidence of substantial shared genetic effects in the regulation of both fetal growth and childhood obesity.

Coding Variants are Relevant to the Expression of Obesity-Related Genes for Pediatric Adiposity.

Heredity has a remarkable effect on obesity in an obesogenic environment. Despite the numerous genetic variants that contribute to obesity-related traits, none has been identified in Chinese children. This study aimed to identify novel variants associated with childhood obesity in China. Promising single-nucleotide variants were obtained using whole-exome sequencing from 76 children who had obesity and 74 children with normal weight, and their associations with obesity-related traits in an additional 6,334-child cohort were investigated. The effects of the genome-wide significant (P < 5E-8) variants on the expression of the implicated genes in blood and adipose tissue were then depicted using transcriptome sequencing. Two coding variants associated with obesity with genome-wide significance were identified: rs1059491 (P = 2.57E-28) in SULT1A2 and rs189326455 (P = 8.98E-12) in MAP3K21. In addition, rs1059491 was also significantly associated with several obesity traits. Transcriptome sequencing demonstrated that rs1059491 and rs189326455 were expression quantitative trait loci relevant to the expression levels of several obesity-related genes, such as SULT1A2, ATXN2L, TUFM, and MAP3K21. This work identified two coding variants that were significantly associated with pediatric adiposity and were expression quantitative trait loci for obesity-related genes. This study provides new insights into the pathophysiology of Chinese childhood obesity.

Association of gut microbiome with fasting triglycerides, fasting insulin and obesity status in Mexican children.

The association of gut microbiota with obesity and its cardio-metabolic complications in paediatric populations is still controversial. We investigated the association of obesity and cardio-metabolic traits with gut microbiota on 167 and 163 children with normal weight and obesity from Mexico City and Oaxaca, Mexico. Anthropometric and biochemical traits were measured. The microbial communities were determined by high-throughput sequencing of bacterial 16S rRNA gene v3-v4 region. The gut microbial community structure was associated with obesity and fasting plasma insulin (FPI) in Mexico City (PObesity = 0.012, PFPI = 0.0003) and Oaxaca (PObesity = 0.034, PFPI = 0.016), and with triglycerides (TG) in Oaxaca (P = .0002). The Firmicutes/Bacteroidetes ratio was positively associated with TG in Oaxaca (P = .003). Firmicutes and Bacteroidetes phyla were positively and negatively associated with obesity (Mexico City: PFirmicutes = 0.013, PBacteroidetes = 0.009) and TG (Oaxaca: PFirmicutes = 0.002, PBacteroidetes = 0.004). In Oaxaca, Verrucomicrobia was negatively associated with obesity (P = .004). In Mexico City, the bacterial genus Fusicatenibacter, Romboutsia, Ruminococcaceae, Ruminiclostridium, Blautia, Clostridium, Anaerostipes and Intestinibacter were associated with obesity and FPI, while in Oaxaca, Bacteroides, Alistipes and Clostridium were associated with TG. The gut microbial community structure in children is associated with obesity and FPI in Mexico City, and with obesity, FPI and TG in Oaxaca.

Distribution and effect of ghrelin genotype on plasma lipid and apolipoprotein profiles in obese and nonobese Chinese subjects.

The hormone ghrelin has an important role in a wide range of metabolic and nonmetabolic processes. Ghrelin gene polymorphisms have been reported to influence obesity or lipid abnormalities in some ethnic groups. This study was conducted mainly to examine the possible association of ghrelin - 604G > A and Leu72Met polymorphisms with obesity and related traits in a Southwest Chinese population. Three hundred and eighty-six Han Chinese individuals (118 obese and 268 normal weight control subjects) in the Chengdu area were studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Clinical and biochemical parameters were also analyzed. The genotype and allele frequencies of ghrelin gene polymorphisms in participants with obesity showed no significant difference compared to those in nonobese controls. However, in the nonobese control group, carriers of genotype Met/Met at the Leu72Met site had higher serum TC and LDL-C concentrations than those of the Leu/Leu genotype (P < 0.05). When nonobese subjects were stratified by sex, the genotype-dependent effects on TC and LDL-C were more evident, although this was observed only in females. In addition, genotype-related effects on these lipid parameters at this site were observed in male obese subjects only. The Leu72Met polymorphism of the ghrelin gene is associated with altered plasma TC and LDL-C concentrations, and the effects on TC and LDL-C levels are sex-dependent in both nonobese and obese subjects in the Chinese population of the Chengdu area.

Causal Inference for Genetic Obesity, Cardiometabolic Profile and COVID-19 Susceptibility: A Mendelian Randomization Study.

BackgroundCross-sectional observational studies have reported obesity and cardiometabolic co-morbidities as important predictors of coronavirus disease 2019 (COVID-19) hospitalization. The causal impact of these risk factors is unknown at present.MethodsWe conducted multivariable logistic regression to evaluate the observational associations between obesity traits (body mass index [BMI], waist circumference [WC]), quantitative cardiometabolic parameters (systolic blood pressure [SBP], serum glucose, serum glycated hemoglobin [HbA1c], low-density lipoprotein [LDL] cholesterol, high-density lipoprotein [HDL] cholesterol and triglycerides [TG]) and SARS-CoV-2 positivity in the UK Biobank cohort. One-sample MR was performed by using the genetic risk scores of obesity and cardiometabolic traits constructed from independent datasets and the genotype and phenotype data from the UK Biobank. Two-sample MR was performed using the summary statistics from COVID-19 host genetics initiative. Cox proportional hazard models were fitted to assess the risk conferred by different genetic quintiles of causative exposure traits.ResultsThe study comprised 1,211 European participants who were tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and 387,079 participants who were either untested or tested negative between 16 March 2020 to 31 May 2020. Observationally, higher BMI, WC, HbA1c and lower HDL-cholesterol were associated with higher odds of COVID-19 infection. One-sample MR analyses found causal associations between higher genetically determined BMI and LDL cholesterol and increased risk of COVID-19 (odds ratio [OR]: 1.15, confidence interval [CI]: 1.05–1.26 and OR: 1.58, CI: 1.21–2.06, per 1 standard deviation increment in BMI and LDL cholesterol respectively). Two-sample MR produced concordant results. Cox models indicated that individuals in the higher genetic risk score quintiles of BMI and LDL were more predisposed to COVID-19 (hazard ratio [HR]: 1.24, CI: 1.03–1.49 and HR: 1.37, CI: 1.14–1.65, for the top vs the bottom quintile for BMI and LDL cholesterol, respectively).ConclusionWe identified causal associations between BMI, LDL cholesterol and susceptibility to COVID-19. In particular, individuals in higher genetic risk categories were predisposed to SARS-CoV-2 infection. These findings support the integration of BMI into the risk assessment of COVID-19 and allude to a potential role of lipid modification in the prevention and treatment.

Identification of Candidate Genes and Pathways Associated with Obesity-Related Traits in Canines via Gene-Set Enrichment and Pathway-Based GWAS Analysis.

Simple SummaryObesity is a serious health issue and is increasing at an alarming rate in several dog breeds, but there is limited information on the genetic mechanism underlying it. Moreover, there have been very few reports on genetic markers associated with canine obesity. These studies were limited to the use of a single breed in the association study. In this study, we have performed a GWAS and supplemented it with gene-set enrichment and pathway-based analyses to identify causative loci and genes associated with canine obesity in 18 different dog breeds. From the GWAS, the significant markers associated with obesity-related traits including body weight (CACNA1B, C22orf39, U6, MYH14, PTPN2, SEH1L) and blood sugar (PRSS55, GRIK2), were identified. Furthermore, the gene-set enrichment and pathway-based analysis (GESA) highlighted five enriched pathways (Wnt signaling pathway, adherens junction, pathways in cancer, axon guidance, and insulin secretion) and seven GO terms (fat cell differentiation, calcium ion binding, cytoplasm, nucleus, phospholipid transport, central nervous system development, and cell surface) which were found to be shared among all the traits.The present study aimed to identify causative loci and genes enriched in pathways associated with canine obesity using a genome-wide association study (GWAS). The GWAS was first performed to identify candidate single-nucleotide polymorphisms (SNPs) associated with obesity and obesity-related traits including body weight and blood sugar in 18 different breeds of 153 dogs. A total of 10 and 2 SNPs were found to be significantly (p < 3.74 × 10−7) associated with body weight and blood sugar, respectively. None of the SNPs were identified to be significantly associated with obesity trait. We subsequently followed up the GWAS analysis with gene-set enrichment and pathway analyses. A gene-set with 1057, 1409, and 1243 SNPs annotated to 449, 933 and 820 genes for obesity, body weight, and blood sugar, respectively was created by sub-setting the GWAS result at a threshold of p < 0.01 for the gene-set enrichment analysis. In total, 84 GO and 21 KEGG pathways for obesity, 114 GO and 44 KEGG pathways for blood sugar, 120 GO and 24 KEGG pathways for body weight were found to be enriched. Among the pathways and GO terms, we highlighted five enriched pathways (Wnt signaling pathway, adherens junction, pathways in cancer, axon guidance, and insulin secretion) and seven GO terms (fat cell differentiation, calcium ion binding, cytoplasm, nucleus, phospholipid transport, central nervous system development, and cell surface) that were found to be shared among all the traits. Our data provide insights into the genes and pathways associated with obesity and obesity-related traits.

Identification of Genetic Variants for Female Obesity and Evaluation of the Causal Role of Genetically Defined Obesity in Polycystic Ovarian Syndrome.

PurposeObservational studies have demonstrated an increased risk of polycystic ovarian syndrome (PCOS) in obese women. This study aimed to identify genetic variants influencing obesity in females and to evaluate the causal association between genetically defined obesity and PCOS in Korean women.MethodsTwo-stage GWAS was conducted to identify genetic variants influencing obesity traits (such as body mass index [BMI], waist–hip ratio [WHR], and waist circumference [WC]) in Korean women. Two-sample Mendelian randomization (MR) analysis was employed to evaluate the causal effect of variants as genetic instruments for female obesity on PCOS.ResultsMeta-analysis of 9953 females combining discovery (N = 4658) and replication (N = 5295) stages detected four (rs11162584, rs6760543, rs828104, rs56137030), six (rs139702234, rs2341967, rs73059848, rs5020945, rs550532151, rs61971548), and two genetic variants (rs7722169, rs7206790) suggesting a highly significant association (P < 1×10−6) with BMI, WHR, and WC, respectively. Of these, an intron variant rs56137030 in FTO achieved genome-wide significant association (P = 3.39×10−8) with BMI in females. Using variants for female obesity, their effect on PCOS in 946 cases and 976 controls was evaluated by MR analysis. MR results indicated no significant association between genetically defined obesity and PCOS in Korean women.ConclusionThis study, for the first time, revealed genetic variants for female obesity in the Korean population and reported no causal association between genetically defined obesity and PCOS in Korean women.

“Evening chronotype associates with increased triglyceride levels in young adults in two independent populations”

Evening chronotype has been linked with obesity, diabetes and metabolic syndrome (MetS) in middle-aged and older adults. However, few studies have analyzed this association in young adults. The aim of this study was to assess potential associations between individual chronotype and cardiometabolic outcomes in young adults of two independent populations from Europe and America. Total population comprised 2 223 young adults (18-29 years old), 525 from Spain (Europe) and 1 698 from Mexico (America). Anthropometric, body composition and biochemical analyses were performed. Circadian preference was determined using the Morningness-Eveningness Questionnaire (MEQ). In these two young adult populations, a higher metabolic risk was found in those individuals with evening chronotypes, whereas those with neither or morning chronotypes showed lower cardiometabolic risk. Evening chronotypes showed lipid alterations with increased levels of triglycerides in both populations, VLDL-c in Spaniards and total cholesterol and LDL-c in Mexicans. Among the Mexican population, evening chronotypes showed higher MetS risk and more obesity traits than the other two chronotypes; no significant differences for the same comparison were found among the equivalent Spanish chronotypes. Evening chronotypes showed lower carbohydrates and higher fat intake in Spaniards, while they had lower fiber intake in Mexicans. The associations between MEQ score and cardiometabolic risk were independent of the dietary characteristics. Lifestyle factors differed among chronotypes with more smokers and habitual drinkers among evening chronotypes than in neither or morning chronotypes (P<0.05). This study performed in two American and European independent populations shows that even in apparently healthy young adults, evening chronotypes have increased cardiometabolic risk and lipid alterations as compared to neither or morning chronotypes.

Diving deep-multipronged investigations into RIPK1 as a risk factor for obesity.

A recent study by Karunakaran et al. suggests that RIPK1 is important in obesity and related metabolic traits. With genetic variation associated with expression and the risk of obesity, and repression of activity leading to a favourable metabolic profile in an obesogenic model, is there evidence for a potential therapeutic role?

Variation in Normal Range Thyroid Function Affects Serum Cholesterol Levels, Blood Pressure, and Type 2 Diabetes Risk: A Mendelian Randomization Study.

Background: Observational studies have demonstrated that variation in normal range thyroid function is associated with major cardiovascular risk factors, including dyslipidemia, hypertension, type 2 diabetes (T2D), and obesity. As observational studies are prone to residual confounding, reverse causality, and selection bias, we used a Mendelian randomization (MR) approach to investigate whether these associations are causal or not. Methods: Two-sample MR analysis using data from the largest available genome-wide association studies on normal range thyrotropin (TSH) and free thyroxine (fT4) levels, serum lipid levels, blood pressure measurements, T2D, and obesity traits (body mass index [BMI] and waist/hip ratio). Results: A one standard deviation (SD) increase in genetically predicted TSH levels was associated with a 0.037 SD increase in total cholesterol levels (p = 3.0 × 10-4). After excluding pleiotropic instruments, we also observed significant associations between TSH levels and low-density lipoprotein levels (β = 0.026 SD, p = 1.9 × 10-3), pulse pressure (β = -0.477 mmHg, p = 7.5 × 10-10), and T2D risk (odds ratio = 0.95, p = 2.5 × 10-3). While we found no evidence of causal associations between TSH or fT4 levels and obesity traits, we found that a one SD increase in genetically predicted BMI was associated with a 0.075 SD decrease in fT4 levels (p = 3.6 × 10-4). Conclusions: Variation in normal range thyroid function affects serum cholesterol levels, blood pressure, and T2D risk.

Association of Candidate Gene Polymorphism with Metabolic Syndrome among Mongolian Subjects: A Case-Control Study.

Metabolic syndrome (MetS) is complex and determined by the interaction between genetic and environmental factors and their influence on obesity, insulin resistance, and related traits associated with diabetes and cardiovascular disease risk. Some dynamic markers, including adiponectin (ADIPOQ), brain-derived neurotrophic factor (BDNF), and lipoprotein lipase (LPL), are implicated in MetS; however, the influence of their genetic variants on MetS susceptibility varies in racial and ethnic groups. We investigated the association of single nucleotide polymorphism (SNP)-SNP interactions among nine SNPs in six genes with MetS’s genetic predisposition in Mongolian subjects. A total of 160 patients with MetS for the case group and 144 healthy individuals for the control group were selected to participate in this study. Regression analysis of individual SNPs showed that the ADIPOQ + 45GG (odds ratio (OR) = 2.09, p = 0.011) and P+P+ of LPL PvuII (OR = 2.10, p = 0.038) carriers had an increased risk of MetS. Conversely, G allele of LPL S447X (OR = 0.45, p = 0.036) and PGC-1α 482Ser (OR = 0.26, p = 0.001) allele were estimated as protective factors, respectively. Moreover, a haplotype containing the G-P+-G combination was related to MetS. Significant loci were also related to body mass index (BMI), systolic blood pressure (SBP), serum high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and fasting blood glucose (FBG), adipokines, and insulin as well as insulin resistance (p < 0.05). Our results confirm that ADIPOQ + 45T > G, LPL PvII, and PGC-1α Gly482Ser loci are associated with MetS in Mongolian subjects.

Identifying factors associated with obesity traits in undergraduate students: a scoping review.

This scoping review identifies factors associated with obesity traits including body mass index, weight, and body fat percentage in undergraduate students. We searched CINAHL, EMBASE, MEDLINE, and PsycINFO for original studies of undergraduate students where an obesity trait was associated with a risk factor. Two-hundred sixty-eight articles were included comprising of 251 studies: 186 cross-sectional, 50 cohort, 11 interventional, and 4 qualitative. We extracted data on risk/protective factors, obesity traits, and the direction of effect between them. We identified a variety of factors including age, sex, ethnicity, socioeconomic status, religion, diet, eating habits, physical activity, sedentary activity, sleep, stress, university campus life, alcohol use, smoking, psychiatric disorders, body image, eating attitude, eating regulation, personality, sociocultural influences, and genetics. The majority of associations were cross-sectional. For longitudinal findings, usually only one study investigated each trait. This review identifies a need for higher quality evidence to support results from cross-sectional studies and replication of findings of longitudinal studies. This review identifies gaps in the literature, generates hypotheses, guides researchers to plan future studies, and helps decision-makers design obesity-prevention programs in universities.

Fgr kinase is required for proinflammatory macrophage activation during diet-induced obesity.

Proinflammatory macrophages are key in the development of obesity. In addition, reactive oxygen species (ROS), which activate the Fgr tyrosine kinase, also contribute to obesity. Here we show that ablation of Fgr impairs proinflammatory macrophage polarization while preventing high-fat diet (HFD)-induced obesity in mice. Systemic ablation of Fgr increases lipolysis and liver fatty acid oxidation, thereby avoiding steatosis. Knockout of Fgr in bone marrow (BM)-derived cells is sufficient to protect against insulin resistance and liver steatosis following HFD feeding, while the transfer of Fgr-expressing BM-derived cells reverts protection from HFD feeding in Fgr-deficient hosts. Scavenging of mitochondrial peroxides is sufficient to prevent Fgr activation in BM-derived cells and HFD-induced obesity. Moreover, Fgr expression is higher in proinflammatory macrophages and correlates with obesity traits in both mice and humans. Thus, our findings reveal the mitochondrial ROS-Fgr kinase as a key regulatory axis in proinflammatory adipose tissue macrophage activation, diet-induced obesity, insulin resistance and liver steatosis.

The FTO Gene and Diseases: The Role of Genetic Polymorphism, Epigenetic Modifications, and Environmental Factors

The review provides information on the function of the FTO gene (known as the fat mass and obesity-associated gene) and the encoded enzyme, on the functional role of single nucleotide polymorphisms (SNPs) in coding and noncoding gene regions and the range of their competences, and on association of the FTO polymorphisms with diseases and traits. Factors that have modifying effect on the contribution of polymorphisms to the risk of disease development and trait variability are discussed. The FTO gene encodes alpha-ketoglutarate-dependent dioxygenase, which has a wide range of competences (including demethylation of RNA and single-stranded DNA), which are important for the functioning of the body. Nonsynonymous substitutions in the FTO gene lead to the development of orphan autosomal recessive disease (OMIM 612938). In the FTO noncoding regions, a wide range of variants has been detected, including those of regulatory importance (eQTL, sQTL, etc.). The competence of these variants extends to both FTO and neighboring genes (IRX3, IRX5, RPGRIP1L). Intronic polymorphisms of the FTO gene have been found to be associated with a wide range of multifactorial diseases and traits (obesity and related anthropometric traits, lipid metabolism markers, diabetes mellitus (type 2), coronary heart disease, metabolic syndrome, and other diseases). In the overwhelming majority of studies, the same allele variants are classified as risk ones; however, previously established associations of the FTO polymorphisms with diseases (traits) are demonstrated not in all populations. It is demonstrated that the effects of the FTO gene SNPs can be modified by exogenous and endogenous environmental factors, as well as lifestyle (including the type of diet, consumption of certain nutrients and medications, physical activity, etc.). Epigenetic factors (DNA methylation at CpG sites) are also important for regulating the level of FTO expression and the effects of individual SNPs. The accumulated data on the FTO structure and function, as well as the functional role of the encoded enzyme, make this gene attractive from the point of view of developing personalized approaches to healthcare.

Association of obesity and its genetic predisposition with the risk of severe COVID-19: Analysis of population-based cohort data

ObjectiveWe aimed to examine the associations of obesity-related traits (body mass index [BMI], central obesity) and their genetic predisposition with the risk of developing severe COVID-19 in a population-based data. Research design and methodsWe analyzed data from 489,769 adults enrolled in the UK Biobank—a population-based cohort study. The exposures of interest are BMI categories and central obesity (e.g., larger waist circumference). Using genome-wide genotyping data, we also computed polygenic risk scores (PRSs) that represent an individual's overall genetic risk for each obesity trait. The outcome was severe COVID-19, defined by hospitalization for laboratory-confirmed COVID-19. ResultsOf 489,769 individuals, 33% were normal weight (BMI, 18.5–24.9 kg/m2), 43% overweight (25.0–29.9 kg/m2), and 24% obese (≥30.0 kg/m2). The UK Biobank identified 641 patients with severe COVID-19. Compared to adults with normal weight, those with a higher BMI had a dose-response increases in the risk of severe COVID-19, with the following adjusted ORs: for 25.0–29.9 kg/m2, 1.40 (95%CI 1.14–1.73; P = 0.002); for 30.0–34.9 kg/m2, 1.73 (95%CI 1.36–2.20; P < 0.001); for 35.0–39.9 kg/m2, 2.82 (95%CI 2.08–3.83; P < 0.001); and for ≥40.0 kg/m2, 3.30 (95%CI 2.17–5.03; P < 0.001). Likewise, central obesity was associated with significantly higher risk of severe COVID-19 (P < 0.001). Furthermore, larger PRS for BMI was associated with higher risk of outcome (adjusted OR per BMI PRS Z-score 1.14, 95%CI 1.05–1.24; P = 0.004). ConclusionsIn this large population-based cohort, individuals with more-severe obesity, central obesity, or genetic predisposition for obesity are at higher risk of developing severe-COVID-19.

Inference of causal relationships between sleep-related traits and 1,527 phenotypes using genetic data.

Sleep is essential for both physical and mental health, and there is a growing interest in understanding how different factors shape individual variation in sleep duration, quality and patterns, or confer risk for sleep disorders. The present study aimed to identify novel inferred causal relationships between sleep-related traits and other phenotypes, using a genetics-driven hypothesis-free approach not requiring longitudinal data. We used summary-level statistics from genome-wide association studies and the latent causal variable (LCV) method to screen the phenome and infer causal relationships between seven sleep-related traits (insomnia, daytime dozing, easiness of getting up in the morning, snoring, sleep duration, napping, and morningness) and 1,527 other phenotypes. We identify 84 inferred causal relationships. Among other findings, connective tissue disorders increase insomnia risk and reduce sleep duration; depression-related traits increase insomnia and daytime dozing; insomnia, napping, and snoring are affected by obesity and cardiometabolic traits and diseases; and working with asbestos, thinner, or glues may increase insomnia risk, possibly through an increased risk of respiratory disease or socio-economic related factors. Overall, our results indicate that changes in sleep variables are predominantly the consequence, rather than the cause, of other underlying phenotypes and diseases. These insights could inform the design of future epidemiological and interventional studies in sleep medicine and research.

Gut Bacteria Selectively Altered by Sennoside A Alleviate Type 2 Diabetes and Obesity Traits

Accumulating evidences implicate that gut microbiota play an important role in the onset and prolongation of fat inflammation and diabetes. Sennoside A, the main active ingredient of Rhizoma Rhei (rhubarb), is widely used for constipation as a kind of anthranoid laxative (e.g., senna). Here, we put forward the hypothesis that the structural alteration of gut microbiota in obesity mice may be involved in the pathogenesis of type 2 diabetes (T2D) which may be ameliorated by Sennoside A. We investigated the appearance of obesity, insulin resistance, host inflammation, and leaky gut phenotype with or without Sennoside A in db/db mice. Horizontal fecal microbiota transplantation (FMT) was used to confirm the critical roles of gut microbiota in the amelioration of the indices in T2D mice after Sennoside A treatment. As a result, we found that Sennoside A administration markedly improved the indices in T2D mice and obesity-related traits including blood glucose level, body weight, lipid metabolism disorder, and insulin resistance. The gut microbiota changed quickly during the onset of T2D in db/db mice, which confirmed the hypothesis that gut microbiota was involved in the pathogenesis of T2D. Sennoside A altered gut microbial composition which might mediate the antiobesogenic effects in T2D remission. Sennoside A also reduced inflammation and increased tight junction proteins in the ileum in gene-deficient mice via gut microbiota alteration. FMT lowered the blood glucose level and improved insulin resistance, corroborating that Sennoside A perhaps exerted its antiobesogenic effects through gut microbiota alteration. Chemical Compounds Studied in This Article. Compounds studied in this article include Sennoside A (PubChem CID: 73111) and metformin hydrochloride (PubChem CID: 14219).

Association of the NEGR1 rs2815752 with obesity and related traits in Pakistani females

Introduction: The variant NEGR1 rs2815752 has recently been linked with obesity in Caucasians. However, a very limited number of studies have examined the association of the NEGR1 rs2815752 with overweight/obesity in non-Caucasians with no such study ever performed in Pakistani population. Therefore, the present study was undertaken to seek the association of the rs2815752 with overweight, obesity, and related traits in Pakistanis.Subjects and methods: The study involved 112 overweight/control pairs (total 224) and 194 obese/control pairs (total 388). Anthropometric parameters were measured by employing standard procedures. Metabolic parameters were determined by biochemical assays. Behavioral information was collected through a questionnaire. The rs2815752 was genotyped via TaqMan allelic discrimination assay. Regression analyses were employed to analyze the data in SPSS software.Results: The study revealed significant gender-specific association of the rs2815752 with obesity (OR 3.03; CI 1.19–7.72, p = 0.020) and some obesity-related anomalous anthropometric traits (weight, BMI, waist circumference, hip circumference, and abdominal and supra-iliac skinfold thicknesses) in females according to dominant model (h = 0.023). However, no association of the rs2815752 with obesity-related behavioral and metabolic parameters was observed.Conclusion: The NEGR1 rs2815752 may be associated with obese phenotype and some of the related anthropometric traits in Pakistani females.

Genetic background and diet affect brown adipose gene coexpression networks associated with metabolic phenotypes.

Adipose is a dynamic endocrine organ that is critical for regulating metabolism and is highly responsive to nutritional environment. Brown adipose tissue is an exciting potential therapeutic target; however, there are no systematic studies of gene-by-environment interactions affecting function of this organ. We leveraged a weighted gene coexpression network analysis to identify transcriptional networks in brown adipose tissue from LG/J and SM/J inbred mice fed high- or low-fat diets and correlate these networks with metabolic phenotypes. We identified eight primary gene network modules associated with variation in obesity and diabetes-related traits. Four modules were enriched for metabolically relevant processes such as immune and cytokine response, cell division, peroxisome functions, and organic molecule metabolic processes. The relative expression of genes in these modules is highly dependent on both genetic background and dietary environment. Genes in the immune/cytokine response and cell division modules are particularly highly expressed in high fat-fed SM/J mice, which show unique brown adipose-dependent remission of diabetes. The interconnectivity of genes in these modules is also heavily dependent on diet and strain, with most genes showing both higher expression and coexpression under the same context. We highlight several genes of interest, Col28a1, Cyp26b1, Bmp8b, and Ngef, that have distinct expression patterns among strain-by-diet contexts and fall under metabolic quantitative trait loci previously mapped in an F16 generation of an advanced intercross between LG/J and SM/J. Each of these genes have some connection to obesity and diabetes-related traits, but have not been studied in brown adipose tissue. Our results provide important insights into the relationship between brown adipose and systemic metabolism by being the first gene-by-environment study of brown adipose transcriptional networks.

Molecular phenomics of a high-calorie diet-induced porcine model of prepubertal obesity

As obesity incidence is alarmingly rising among young individuals, we aimed to characterize an experimental model of this situation, considering the similarity between human and porcine physiology. For this reason, we fed prepubertal (63 days old) Duroc breed females (n=21) either with a standard growth diet (3800 kcal/day) or one with a high-calorie content (5200 kcal/day) during 70 days. Computerized tomography, mass-spectrometry-based metabolomics and lipidomics, as well as peripheral blood mononuclear cell transcriptomics, were applied to define traits linked to high-calorie intake. Samples from a human cohort confirmed potential lipidomic markers. Compared to those fed a standard growth diet, pigs fed a high-calorie diet showed an increased weight gain (13%), much higher adiposity (53%), hypertriacylglyceridemia and hypercholesterolemia in parallel to insulin resistance. This diet induced marked changes in the circulating lipidome, particularly in phosphatidylethanolamine-type molecules. Also, circulating specific diacylglycerol and monoacylglycerol contents correlated with visceral fat and intrahepatic triacylglycerol concentrations. Specific lipids associated with obesity in swine (mainly belonging to glycerophospholipid, triacylglyceride and sterol classes) were also linked with obesity traits in the human cohort, reinforcing the usefulness of the chosen approach. Interestingly, no overt inflammation in plasma or adipose tissue was evident in this model. The presented model is useful as a preclinical surrogate of prepubertal obesity in order to ascertain the pathophysiology interactions between energy intake and obesity development.