Role of genetic variants in ADIPOQ in human eating behavior

Mulberry leaf extract inhibits obesity and protects against diethylnitrosamine-induced hepatocellular carcinoma in rats

Mulberry leaf has been recognized as a traditional Chinese medicinal plant, which was distributed throughout the Asia. The aqueous extract of mulberry leaf extract (MLE) has various biologically active components such as polyphenols and flavonoids. However, the inhibitory effect of MLE in hepatocarcinogenesis is poorly understood. In this study, we determined the role of MLE supplementation in preventing hepatocarcinogenesis in a carcinogen-initiated high-fat diet (HFD)-promoted Sprague-Dawley (SD) rat model. The rats were fed an HFD to induce obesity and spontaneous hepatomas by administering 0.01% diethylnitrosamine (DEN) in their drinking water for 12 weeks (HD group), and also to fed MLE through oral ingestion at daily doses of 0.5%, 1%, or 2%. At the end of the 12-week experimental period, the liver tumors were analyzed to identify markers of oxidative stress and antioxidant enzyme activities, and their serum was analyzed to determine their nutritional status and liver function. Histopathological analysis revealed that MLE supplementation significantly suppressed the severity and incidence of hepatic tumors. Furthermore, compared with the HFD + DEN groups, the expression of protein kinase C (PKC)-α and Rac family small GTPase 1 (Rac1) was lower in the MLE groups. These findings suggest that MLE prevents obesity-enhanced, carcinogen-induced hepatocellular carcinoma development, potentially through the protein kinase C (PKC)α/Rac1 signaling pathway. MLE might be an effective chemoprevention modality for nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH)-related hepatocarcinogenesis.

Goldfish adiponectin: (I) molecular cloning, tissue distribution, recombinant protein expression, and novel function as a satiety factor in fish model

Adiponectin (AdipoQ) is an adipokine involved in glucose homeostasis and lipid metabolism. In mammals, its role in appetite control is highly controversial. To shed light on the comparative aspects of AdipoQ in lower vertebrates, goldfish was used as a model to study feeding regulation by AdipoQ in fish species. As a first step, goldfish AdipoQ was cloned and found to be ubiquitously expressed at the tissue level. Using sequence alignment, protein modeling, phylogenetic analysis and comparative synteny, goldfish AdipoQ was shown to be evolutionarily related to its fish counterparts and structurally comparable with AdipoQ in higher vertebrates. In our study, recombinant goldfish AdipoQ was expressed in E. coli, purified by IMAC, and confirmed to be bioactive via activation of AdipoQ receptors expressed in HepG2 cells. Feeding in goldfish revealed that plasma levels of AdipoQ and its transcript expression in the liver and brain areas involved in appetite control including the telencephalon, optic tectum, and hypothalamus could be elevated by food intake. In parallel studies, IP and ICV injection of recombinant goldfish AdipoQ in goldfish was effective in reducing foraging behaviors and food consumption. Meanwhile, transcript expression of orexigenic factors (NPY, AgRP, orexin, and apelin) was suppressed with parallel rises in anorexigenic factors (POMC, CART, CCK, and MCH) in the telencephalon, optic tectum and/or hypothalamus. In these brain areas, transcript signals for leptin receptor were upregulated with concurrent drops in the NPY receptor and ghrelin receptors. In the experiment with IP injection of AdipoQ, transcript expression of leptin was also elevated with a parallel drop in ghrelin mRNA in the liver. These findings suggest that AdipoQ can act as a novel satiety factor in goldfish. In this case, AdipoQ signals (both central and peripheral) can be induced by feeding and act within the brain to inhibit feeding behaviors and food intake via differential regulation of orexigenic/anorexigenic factors and their receptors. The feeding inhibition observed may also involve the hepatic action of AdipoQ by modulation of feeding regulators expressed in the liver.

Comparison of Adiponectin Levels in Anorexia Nervosa, Bulimia Nervosa, Binge-Eating Disorder, Obesity, Constitutional Thinness, and Healthy Controls: A Network Meta-Analysis

Adiponectin is a protein hormone that is produced and secreted primarily by adipose tissue. The levels of adiponectin in those with eating disorders, obesity, and healthy controls have been extensively studied. However, the general picture of the differences in adiponectin levels across the mentioned conditions is still unclear and fragmented. In this study, we pooled previous studies and performed a network meta-analysis to gain a global picture of comparisons of adiponectin levels across eating disorders, obesity, constitutional thinness, and healthy controls. Electronic databases were searched for anorexia nervosa, avoidant restrictive food intake disorder, binge-eating disorder, bulimia nervosa, healthy controls, night eating syndrome, obesity, and constitutional thinness in studies where adiponectin levels were measured. A total of 4262 participants from 50 published studies were included in the network meta-analysis. Adiponectin levels were significantly higher in participants with anorexia nervosa than in healthy controls (Hedges' g = 0.701, p < 0.001). However, adiponectin levels in constitutionally thin participants were not significantly different from those of healthy controls (Hedges' g = 0.470, p = 0.187). Obesity and binge-eating disorder were associated with significantly lower adiponectin levels compared to those of healthy controls (Hedges' g = -0.852, p < 0.001 and Hedges' g = -0.756, p = 0.024, respectively). The disorders characterized by excessive increases or decreases in BMI were associated with significant changes in adiponectin levels. These results suggest that adiponectin may be an important marker of severely disequilibrated homeostasis, especially in fat, glucose, and bone metabolisms. Nonetheless, an increase in adiponectin may not simply be associated with a decrease in BMI, as constitutional thinness is not associated with a significant increase in adiponectin.

Molecular cloning, expression and appetite regulation function of adiponectin in Siberian sturgeon (Acipenser baerii)

Adiponectin (AdipoQ) as an adipocytokine has the potential to regulate feeding behavior, but the information about adipoq in fish is limited. In this study, Siberian sturgeon adiponectin (Ssadipoq) gene was cloned encoding 264 amino acids. The amino acid identity of SsAdipoQ was low compared with that of mammals, birds, amphibians and teleost fishes. The expression of Ssadipoq in the hypothalamus was significantly decreased at 1 h and 3 h post feeding, and increased after 15-day fasting. The mature domain of AdipoQ (fAd) was inserted into expression vector pET32a and successfully expressed in Escherichia coli BL21 (DE3) after stimulated by isopropyl-β-d-thiogalactoside. Food intake at 1 h and 3 h post treatment with SsfAd protein decreased significantly (P < 0.05). The mRNA expression of pyy and cck in the valvula intestine was promoted and hypothalamic npy, agrp and pomc mRNA expression were inhibited after treatment with SsfAd protein. Furthermore, hypothalamic ampk subunits expression was associated with peripheral SsfAd treatment. In summary, present study indicate that SsfAd plays an important role in the regulation of food intake and appetite signals in Siberian sturgeon, which provides a basis for further study application of prokaryotic AdipoQ in feeding behavior regulation.

Indirect Genetic Effects of ADIPOQ Variants on Lipid Levels in a Sibling Study of a Rural Chinese Population

Variations in lipid levels are the result of combinations of genetic and environmental factors. We aim to investigate the indirect effect between siblings of the three polymorphisms of ADIPOQ on serum lipid levels in rural Chinese populations. A total of 2571 sibling pairs were enrolled as study participants. A generalized estimating equation was used to accommodate a family-based design. We used stratified analysis to detect sex combination differences in the indirect genetic effect. We found a significant association between the number of altered risk alleles of rs182052 and ego lipid levels of TG (β = 0.177, P = 0.003), TC (β = 0.140, P = 0.004) and LDL-C (β = 0.098, P = 0.014). Ego and altered genotypes of rs182052 demonstrated a joint effect on ego lipid levels of TC (β = 0.212, P = 0.019), HDL-C (β = 0.099, P = 0.002) and LDL-C (β = 0.177, P = 0.013) in recessive inheritance mode. In opposite-sex siblings, the altered GG genotype of rs182052 increased the ego lipid levels. Thus, our findings demonstrate that ADIPOQ has an indirect genetic effect on lipid levels in sibling pairs, and there are sex-combination differences in the indirect genetic effect in siblings.

Association of ADIPOQ Single-Nucleotide Polymorphisms with the Two Clinical Phenotypes Type 2 Diabetes Mellitus and Metabolic Syndrome in a Kinh Vietnamese Population

PURPOSE

Genetic factors play an important role in the development of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS). However, few genetic association studies related to these disorders have been performed with Vietnamese subjects. In this study, the potential associations of ADIPOQ single nucleotide polymorphisms (SNPs) with T2DM and MetS in a Kinh Vietnamese population were investigated.

PATIENTS AND METHODS

A study with 768 subjects was conducted to examine the associations of four ADIPOQ SNPs (rs266729, rs1501299, rs3774261, and rs822393) primarily with T2DM and secondarily with MetS. The TaqMan SNP genotyping assay was used to determine genotypes from subjects' DNA samples.

RESULTS

After statistical adjustment for age, sex, and body mass index, the ADIPOQ SNP rs266729 was found to be associated with increased risk of T2DM under multiple inheritance models: codominant (OR = 2.30, 95% CI = 1.16-4.58), recessive (OR = 2.17, 95% CI = 1.11-4.26), and log-additive (OR = 1.32, 95% CI = 1.02-1.70). However, rs1501299, rs3774261, and rs822393 were not associated with risk for T2DM. Additionally, rs266729, rs3774261, and rs822393 were statistically associated with MetS, while rs1501299 was not. Haplotype analysis showed a strong linkage disequilibrium between the SNP pairs rs266729/rs822393 and rs1501299/rs3774261, and the haplotype rs266729(G)/rs822393(T) was not statistically associated with MetS.

CONCLUSION

The results show that rs266729 is a lead candidate SNP associated with increased risk of developing T2DM and MetS in a Kinh Vietnamese population, while rs3774261 is associated with MetS only. Further functional characterization is needed to uncover the mechanism underlying the potential genotype-phenotype associations.

Genetics of eating disorders in the genome-wide era

Enabled by advances in high throughput genomic sequencing and an unprecedented level of global data sharing, molecular genetic research is beginning to unlock the biological basis of eating disorders. This invited review provides an overview of genetic discoveries in eating disorders in the genome-wide era. To date, five genome-wide association studies on eating disorders have been conducted - all on anorexia nervosa (AN). For AN, several risk loci have been detected, and ~11-17% of the heritability has been accounted for by common genetic variants. There is extensive genetic overlap between AN and psychological traits, especially obsessive-compulsive disorder, and intriguingly, with metabolic phenotypes even after adjusting for body mass index (BMI) risk variants. Furthermore, genetic risk variants predisposing to lower BMI may be causal risk factors for AN. Causal genes and biological pathways of eating disorders have yet to be elucidated and will require greater sample sizes and statistical power, and functional follow-up studies. Several studies are underway to recruit individuals with bulimia nervosa and binge-eating disorder to enable further genome-wide studies. Data collections and research labs focused on the genetics of eating disorders have joined together in a global effort with the Psychiatric Genomics Consortium. Molecular genetics research in the genome-wide era is improving knowledge about the biology behind the established heritability of eating disorders. This has the potential to offer new hope for understanding eating disorder etiology and for overcoming the therapeutic challenges that confront the eating disorder field.

The Controversial Role of Adiponectin in Appetite Regulation of Animals

Eating disorders and obesity are important health problems with a widespread global epidemic. Adiponectin (AdipoQ), the most abundant adipokine in the plasma, plays important roles in the regulation of energy homeostasis, glucose metabolism and lipid metabolism. Plasma adiponectin concentration is negatively associated with obesity and binge eating disorder. There is a growing interest in the appetite regulation function of adiponectin. However, the effect of AdipoQ on feeding behavior is controversial and closely related to nutritional status and food composition. In this review, we summarize the literatures about the discovery, structure, tissue distribution, receptors and regulation of nutritional status, and focus on the biological function of adiponectin in the regulation of food intake in the central and peripheral system.

[Current state of the obesity research: genetic aspects, the role of microbiome, and susceptibility to COVID-19]

Obesity affects over 700 million people worldwide and its prevalence keeps growing steadily. The problem is particularly relevant due to the increased risk of COVID-19 complications and mortality in obese patients. Obesity prevalence increase is often associated with the influence of environmental and behavioural factors, leading to stigmatization of people with obesity due to beliefs that their problems are caused by poor lifestyle choices. However, hereditary predisposition to obesity has been established, likely polygenic in nature. Morbid obesity can result from rare mutations having a significant effect on energy metabolism and fat deposition, but the majority of patients does not present with monogenic forms. Microbiome low diversity significantly correlates with metabolic disorders (inflammation, insulin resistance), and the success of weight loss (bariatric) surgery. However, data on the long-term consequences of bariatric surgery and changes in the microbiome composition and genetic diversity before and after surgery are currently lacking. In this review, we summarize the results of studies of the genetic characteristics of obesity patients, molecular mechanisms of obesity, contributing to the unfavourable course of coronavirus infection, and the evolution of their microbiome during bariatric surgery, elucidating the mechanisms of disease development and creating opportunities to identify potential new treatment targets and design effective personalized approaches for the diagnosis, management, and prevention of obesity.

Adiponectin Gene Variant rs3774261, Effects on Lipid Profile and Adiponectin Levels after a High Polyunsaturated Fat Hypocaloric Diet with Mediterranean Pattern

The role of ADIPOQ gene variants on metabolic improvements after weight change secondary to different hypocaloric diets remained unclear. We evaluate the effect of rs3774261 of ADIPOQ gene polymorphism on biochemical improvements and weight change after high polyunsaturated fat hypocaloric diet with a Mediterranean dietary pattern for 12 weeks. A population of 361 obese subjects was enrolled in an intervention trial with a calorie restriction of 500 calories over the usual intake and 45.7% of carbohydrates, 34.4% of fats, and 19.9% of proteins. The percentages of different fats was; 21.8% of monounsaturated fats, 55.5% of saturated fats, and 22.7% of polyunsaturated fats. Before and after intervention, an anthropometric study, an evaluation of nutritional intake and a biochemical evaluation were realized. All patients lost weight regardless of genotype and diet used. After 12 weeks with a similar improvement in weight loss (AA vs. AG vs. GG); total cholesterol (delta: −28.1 ± 2.1 mg/dL vs. −14.2 ± 4.1 mg/dL vs. −11.0 ± 3.9 mg/dL; p = 0.02), LDL cholesterol (delta: −17.1 ± 2.1 mg/dL vs. −6.1 ± 1.9 mg/dL vs. −6.0 ± 2.3 mg/dL; p = 0.01), triglyceride levels (delta: −35.0 ± 3.6 mg/dL vs. 10.1 ± 3.2 mg/dL vs. −9.7 ± 3.1 mg/dL; p = 0.02), C reactive protein (CRP) (delta: −2.3 ± 0.1 mg/dL vs. −0.2 ± 0.1 mg/dL vs. −0.2 ± 0.1 mg/dL; p = 0.02), serum adiponectin (delta: 11.6 ± 2.9 ng/dL vs. 2.1 ± 1.3 ng/dL vs. 3.3 ± 1.1 ng/dL; p = 0.02) and adiponectin/leptin ratio (delta: 1.5 ± 0.1 ng/dL vs. 0.3 ± 0.2 ng/dL vs. 0.4 ± 0.3 ng/dL; p = 0.03), improved only in AA group. AA genotype of ADIPOQ variant (rs3774261) is related with a significant increase in serum levels of adiponectin and ratio adiponectin/leptin and decrease on lipid profile and C-reactive protein (CRP).

Eating behaviour in contrasting adiposity phenotypes: Monogenic obesity and congenital generalized lipodystrophy

Most known types of nonsyndromic monogenic obesity are caused by rare mutations in genes of the leptin-melanocortin pathway controlling appetite and adiposity. In contrast, congenital generalized lipodystrophy represents the most extreme form of leanness in humans caused by recessive mutations in four genes involved in phospholipid/triglyceride synthesis and lipid droplet/caveolae structure. In this disease, the inability to store triglyceride in adipocytes results in hypoleptinemia and ectopic hepatic and muscle fat accumulation leading to fatty liver, hypertriglyceridemia and severe insulin resistance. As a result of hypoleptinemia, patients with lipodystrophy show alterations in eating behaviour characterized by constant increased energy intake. As it occurs in obesity caused by genetic leptin deficiency, exogenous leptin rapidly reduces hunger scores in patients with congenital generalized lipodystrophy, with additional beneficial effects on glucose homeostasis and metabolic profile normalization. The melanocortin-4 receptor agonist setmelanotide has been used in the treatment of monogenic obesities. There is only one report on the effect of setmelanotide in a patient with partial lipodystrophy resulting in mild reductions in hunger scores, with no improvements in metabolic status. The assessment of contrasting phenotypes of obesity/leanness represents an adequate strategy to understand the pathophysiology and altered eating behaviour associated with adipose tissue excessive accumulation/paucity.

Serum Lipid and Adiponectin Improvements after a Mediterranean Dietary Pattern in Non-G-Allele Carriers of the Variant rs3774261

BACKGROUND

The role of adiponectin (ADIPOQ) polymorphisms in weight loss and serum lipid changes following different dietary interventions remain unclear. The Mediterranean dietary pattern has been associated with improved cardiovascular risk factors in different studies.

OBJECTIVE

Our aim was to analyze the effects of a hypocaloric diet with a Mediterranean dietary pattern on the metabolic response and adiposity parameters, taking into account the 712 G/A rs3774261 polymorphisms in ADIPOQ.

DESIGN

A population of 135 obese patients was enrolled. Anthropometric and serum parameters (lipid profile, insulin, homeostasis model assessment for insulin resistance [HOMA-IR], glucose, C-reactive protein [CRP], adiponectin, resistin, and leptin levels) were measured before and after the dietary intervention (12 weeks). All of the patients were genotyped for the rs3774261 polymorphism.

RESULTS

The genotype distribution of this population was 36 patients with AA (26.7%), 68 patients with AG (50.4%), and 31 patients with GG (22.9%). After the dietary intervention and in both genotypes, BMI, weight, fat mass, systolic blood pressure, waist circumference, glucose, insulin, HOMA-IR, and leptin levels all decreased. After the dietary intervention with secondary weight loss and in non-G-allele carriers (AA vs. AG+GG), total cholesterol (Δ = -15.7 ± 3.9 vs. -4.9 ± 2.9 mg/dL; p = 0.02), LDL cholesterol (Δ = -15.3 ± 3.8 vs. -1.7 ± 1.9 mg/dL; p = 0.01), triglyceride levels (Δ = -23.4 ± 5.6 vs. 2.3 ± 2.3 mg/dL; p = 0.01), and CRP (Δ = -1.1 ± 0.1 vs. -0.4 ± 0.2 mg/dL; p = 0.01) decreased. Adiponectin levels (Δ = 7.2 ± 2.1 vs. -0.4 ± 0.3 ng/dL; p = 0.02) increased. Notably, G-allele carriers did not show this improvement.

CONCLUSION

Non-G-allele carriers of the ADIPOQ variant (rs3774261) showed significant improvement in serum levels of adiponectin, lipid profiles, and CRP in response to a hypocaloric diet with a Mediterranean dietary pattern.

Regulatory Functions of Fatty Acids with Different Chain Lengths on the Intestinal Health in Pigs and Relative Signaling Pathways

Intestines are not only major organs for nutrient digestion and absorption, but are also the largest immune organ in pigs. They are essential for maintaining the health and growth of piglets. Fatty acids, including short-chain fatty acids, medium-chain fatty acids, and long-chain polyunsaturated fatty acids, are important nutrients; they are a major energy source, important components of the cell membrane, metabolic substrates in many biochemical pathways, cell-signaling molecules, and play role as immune modulators. Research has shown that fatty acids exert beneficial effects on intestinal health in animal models and clinical trials. The objective of this review is to give a clear understanding of the regulatory effects of fatty acids of different chain lengths on intestinal health in pigs and their signaling pathways, providing scientific reference for developing a feeding technique to apply fatty acids to piglet diets.

Adiponectin and human eating behaviour: a Mendelian randomization study

Background

Adiponectin plays key roles in regulating appetite and food intake. Altered circulating adiponectin levels have been observed in human eating disorders such as anorexia nervosa, bulimia nervosa or binge eating. In addition, an association between circulating adiponectin levels and human eating behaviour (EB) has been reported. Interestingly, a disturbance in eating behaviour is the defining characteristic of human eating disorders. However, it is unknown whether adiponectin is causally implicated in human EB. We therefore aimed to investigate the causal effect of adiponectin on EB.

Results

Mendelian randomization (MR) analysis estimated the influence of blood adiponectin on EB by combining data on the association of adiponectin gene (ADIPOQ) variants with adiponectin levels and with three EB factors involving disinhibition, restraint and hunger. Using inverse-variance weighted (IVW) regression method and other complementary MR techniques (weighted median regression, MR Egger and weighted modal regression), the MR analysis revealed a broadly consistent evidence that higher blood adiponectin concentration was significantly associated with increased EB factor disinhibition (beta coefficient for IVW regression [βIVW], 3.05; 95% confidence interval [CI] 1.10, 5.00) but non-significantly associated with increased EB factor restraint (βIVW, 0.17; 95% CI − 1.85, 2.18), and increased EB factor hunger (βIVW, 1.63; 95% CI − 0.75, 4.01).

Conclusions

Overall, our findings indicate a causal role of adiponectin levels in eating disinhibition but not in eating restraint and hunger.

Expression of the key metabolic regulators in the white adipose tissue of rats; the role of high-fat diet and aerobic training

Lipid metabolism, especially in the white adipose tissue as an active metabolic organ, is tightly regulated by the key transcription factors, such as the sterol regulatory element binding protein 1c (SREBP-1c) and the Farnesoid X Receptor (FXR). We have studied the expression of these genes in the white adipose tissue to see how a high fat diet (HFD) and two intensities of aerobic training change the lipogenic and lipolytic pathways. 44 male Wistar rats randomly divided into the normal (12% calories from fat) and HFD (56% calories from fat) groups. Each group included control (n=6), moderate trained (n=8, ~65% Vo2max) and high intensity trained (n=8, ~75% Vo2max) rats. After 8 weeks of training, the weight changes, plasma insulin and lipid profile levels and the relative gene expression of SREBP-1c and FXR in the adipose tissue was measured. Data were analysed by 2-way ANOVA (P<0.05). HFD fed rats showed higher levels of insulin and dyslipidemia that was correlated with the higher weight gain. Also, the adipose expression of SREBP-1c was higher in the HFD fed rats that it was strongly correlated with the lower FXR expression. Trained rats independent of the intensity of the training showed lower SREBP-1c and higher FXR expression, but no change was observed in the lipid profile levels. HFD-induced dyslipidemia could occur via SREBP-1c activation in the adipose tissue while the aerobic training activates FXR and inhibits the lipogenic pathways. Despite the activation of lipolytic pathways in the trained rats, it seems that diet has more effect on the lipid profile than the aerobic training.

Genetic association of ADIPOQ gene variants (-3971A>G and +276G>T) with obesity and metabolic syndrome in North Indian Punjabi population

BACKGROUND AND AIMS

At present obesity and metabolic syndrome (MetS) in India are the most challenging health problems. It is also well accepted that obesity is a significant risk factor for the development of metabolic syndrome and other degenerative diseases. Many studies have reported that single-nucleotide polymorphisms (SNPs) of the adiponectin (ADIPOQ) gene have been associated with obesity and its related disorders. Here, we aimed to investigate the association of two intronic variants in ADIPOQ gene, -3971A>G (rs822396) and +276G>T (rs1501299) with obesity and metabolic syndrome.

METHODS

Biochemical and anthropometric measurements were obtained from a total of 550 unrelated subjects (obese = 250 and non-obese = 300) of North Indian Punjabi population. Genotyping for the intron variants were performed by polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP) methods. After genotyping, as a quality control measure 10% of the samples for each polymorphism were confirmed by Sanger Sequencing method. The distributions of genotypic and allelic frequencies among obese and non-obese groups were compared by chi-square test and the corresponding risk was calculated using binary logistic regression. The effects of multiple testing were controlled by applying Bonferroni corrections.

RESULTS

All the anthropometric and biochemical parameters except triglycerides (TG) and very low-density lipoproteins cholesterol (VLDL-C) have shown significant association with both GG and TT genotypes of -3971A>G (rs822396) and +276G>T (rs1501299) polymorphisms respectively. The frequencies of GG (-3971A>G) and TT (+276G>T) genotypes were higher among obese cases (p = 0.008 and p = 0.035 respectively). However, no significant association was found between allelic frequencies of ADIPOQ rs822396 and obesity, whereas the association of ADIPOQ rs1501299 attenuated and became marginally significant after Bonferroni correction (p>0.025). Both the variant genotypes of ADIPOQ gene polymorphisms (-3971GG and +276TT) significantly increased the risk of development of obesity (OR: 1.52, p = 0.03; OR: 1.58, p = 0.04 respectively) and MetS (OR: 1.42, p = 0.03; OR: 1.57, p = 0.01 respectively) in the present population, after adjusting the various covariates. The G-T haplotype model (possessing -3971G and +276T alleles) was shown toprovide ~ 3 fold risk towards the obesity susceptibility (OR: 2.69, p = 0.009) and MetS risk (OR: 2.73, p = 0.009) and the association persisted after adjusting for different confounding variables.

CONCLUSION

The present study has confirmed that ADIPOQ -3971A>G (rs822396) and +276G>T (rs1501299) polymorphism may be clinically helpful to estimate obesity and MetS risk in North Indian Punjabi population.

The role of eating behavior traits in mediating genetic susceptibility to obesity

Background

Genome-wide association studies (GWASs) have identified several genes associated with obesity. The mechanisms through which these genes affect body weight are not fully characterized. Recent studies suggest that eating behavior (EB) traits could be involved, but only a few EB traits were investigated.

Objective

This study aimed to investigate whether genetic susceptibility to obesity is mediated by EB traits (cognitive restraint, disinhibition, hunger) and their subscales. We hypothesized that EB traits, and their subscales, partly mediate this association.

Design

Adult individuals (n = 768) who participated in the Quebec Family Study were included in this cross-sectional study. A genetic risk score (GRS) of obesity was calculated based on the 97 genetic variants recently identified in a GWAS meta-analysis of body mass index (BMI). EB traits and their subscales were assessed with the use of the Three-Factor Eating Questionnaire. Regression analyses with age and sex as covariates were used to investigate the associations between GRS, EB traits, BMI, and WC and whether the association between GRS and obesity is mediated by EB traits, which represents the indirect effect of GRS on obesity.

Results

The GRS of obesity was positively associated with BMI (β = 0.19 ± 0.04, P < 0.0001) and WC (β = 0.46 ± 0.10, P < 0.0001). Regression analyses also revealed that the association between GRS of obesity and BMI was partly mediated by disinhibition and susceptibility to hunger (βindirect = 0.09 ± 0.03, P = 0.0007, and βindirect = 0.04 ± 0.02, P = 0.02, respectively). Habitual and situational susceptibility to disinhibition (βindirect = 0.08 ± 0.03, P = 0.002 and βindirect = 0.05 ± 0.02, P = 0.003, respectively) as well as internal and external locus of hunger (βindirect = 0.03 ± 0.02, P = 0.03 for both) were also found to mediate the association between GRS of obesity and BMI. The same trends were observed with WC.

Conclusions

The results of this study indicate that the genetic susceptibility to obesity is partly mediated through undesirable EB traits, which suggests that they could be targeted in obesity treatment and prevention. This trial was registered at clinicaltrials.gov as NCT03355729.

Relationship Between 12 Adipocytokines and Distinct Components of the Metabolic Syndrome

OBJECTIVE

Adipose tissue-derived signals potentially link obesity and adipose tissue dysfunction with metabolic and cardiovascular diseases. Although some adipocytokines have been closely related to metabolic and cardiovascular traits, it is unknown which adipocytokine or adipocytokine clusters serve as meaningful markers of metabolic syndrome (MS) components. Therefore, this study investigated the associations of 12 adipocytokines with components of the MS to identify the most relevant cytokines potentially related to specific metabolic profiles.

RESEARCH DESIGN AND METHODS

Twelve cytokines [adiponectin, adipocyte fatty acid-binding protein (AFABP), angiopoietin-related growth factor, chemerin, fibroblast growth factor (FGF) 19, FGF21, FGF23, insulin-like growth factor-1, interleukin 10, irisin, progranulin, and vaspin] were quantified in a cross-sectional cohort of 1046 subjects. Hypothesis-free cluster analysis, multivariate regression analyses with parameters of the MS, and discriminant analysis were performed to assess associations and the relative importance of each cytokine for reflecting MS and its components.

RESULTS

Among the studied adipocytokines, adiponectin, AFABP, chemerin, and FGF21 showed the strongest associations with MS and several MS components in discriminant analyses and multiple regression models. For certain metabolic components, these adipocytokines were better discriminators than routine metabolic markers. Other cytokines investigated in the present cohort are less able to distinguish between metabolically healthy and unhealthy subjects.

CONCLUSIONS

Adiponectin, AFABP, chemerin, and FGF21 showed the strongest associations with MS components in a general population, suggesting that adverse adipose tissue function is a major contributor to these metabolic abnormalities. Future prospective studies should address the question whether these adipocytokines can predict the development of metabolic disease states.

Elevated total plasma-adiponectin is stable over time in young women with bulimia nervosa

Background

Bulimia nervosa (BN) is characterized by dysregulated eating behaviour and present data suggest adipokines may regulate food intake. We investigated a possible association between BN and adipokine levels and hypothesized that plasma (P)-adiponectin would be elevated and P-leptin and P-leptin-adiponectin-ratio would be reduced in women with BN.

Methods

The study was designed as a cross-sectional study with a longitudinal arm for patients with BN. Plasma-adiponectin and leptin was measured in 148 female patients seeking psychiatric ambulatory care and 45 female controls. Fifteen patients were diagnosed with BN and the remaining with other affective and anxiety disorders. P-adiponectin and P-leptin levels were compared between patients with BN, patients without BN and controls. At follow-up 1–2 years later, adipokines were reassessed in patients with BN and the Eating Disorder Examination Questionnaire was used to assess symptom severity.

Results

P-adiponectin was elevated in patients with BN at baseline and at follow-up when compared to patients without BN and controls (P < 0.004 and < 0.008 respectively). The difference remained significant after controlling for body mass index. P-adiponectin was correlated to symptom severity at follow-up in patients with BN without morbid obesity (ρ = 0.72, P < 0.04). P-leptin-adiponectin-ratio was significantly lower in patients with BN compared to controls (P < 0.04) and P-leptin non-significantly lower.

Conclusions

Findings indicate a stable elevation of P-adiponectin in women with BN. P-adiponectin at follow-up correlates to eating disorder symptom severity in patients without morbid obesity, indicating that P-adiponectin should be further investigated as a possible potential prognostic biomarker for BN.

Genetic Variations of Circulating Adiponectin Levels Modulate Changes in Appetite in Response to Weight-Loss Diets

CONTEXT

Adiponectin plays key roles in regulating appetite and food intake.

OBJECTIVE

To investigate interactions between the genetic risk score (GRS) for adiponectin levels and weight-loss diets varying in macronutrient intake on long-term changes in appetite and adiponectin levels.

DESIGN, SETTING, AND PARTICIPANTS

A GRS was calculated based on 5 adiponectin-associated variants in 692 overweight adults from the 2-year Preventing Overweight Using Novel Dietary Strategies trial.

MAIN OUTCOME MEASURES

Repeated measurements of plasma adiponectin levels and appetite-related traits, including cravings, fullness, prospective consumption, and hunger.

RESULTS

Dietary fat showed nominally significant interactions with the adiponectin GRS on changes in appetite score and prospective consumption from baseline to 6 months (P for interaction = 0.014 and 0.017, respectively) after adjusting for age, sex, ethnicity, baseline body mass index, and baseline respective outcome values. The GRS for lower adiponectin levels was associated with a greater decrease in appetite (P < 0.001) and prospective consumption (P = 0.008) among participants consuming a high-fat diet, whereas no significant associations were observed in the low-fat group. Additionally, a significant interaction was observed between the GRS and dietary fat on 6-month changes in adiponectin levels (P for interaction = 0.021). The lower GRS was associated with a greater increase in adiponectin in the low-fat group (P = 0.02), but it was not associated with adiponectin changes in the high-fat group (P = 0.31).

CONCLUSIONS

Our findings suggest that individuals with varying genetic architecture of circulating adiponectin may respond divergently in appetite and adiponectin levels to weight-loss diets varying in fat intake.

Whole-genome single-nucleotide polymorphism (SNP) marker discovery and association analysis with the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content in Larimichthys crocea

Whole-genome single-nucleotide polymorphism (SNP) markers are valuable genetic resources for the association and conservation studies. Genome-wide SNP development in many teleost species are still challenging because of the genome complexity and the cost of re-sequencing. Genotyping-By-Sequencing (GBS) provided an efficient reduced representative method to squeeze cost for SNP detection; however, most of recent GBS applications were reported on plant organisms. In this work, we used an EcoRI-NlaIII based GBS protocol to teleost large yellow croaker, an important commercial fish in China and East-Asia, and reported the first whole-genome SNP development for the species. 69,845 high quality SNP markers that evenly distributed along genome were detected in at least 80% of 500 individuals. Nearly 95% randomly selected genotypes were successfully validated by Sequenom MassARRAY assay. The association studies with the muscle eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content discovered 39 significant SNP markers, contributing as high up to ∼63% genetic variance that explained by all markers. Functional genes that involved in fat digestion and absorption pathway were identified, such as APOB, CRAT and OSBPL10. Notably, PPT2 Gene, previously identified in the association study of the plasma n-3 and n-6 polyunsaturated fatty acid level in human, was re-discovered in large yellow croaker. Our study verified that EcoRI-NlaIII based GBS could produce quality SNP markers in a cost-efficient manner in teleost genome. The developed SNP markers and the EPA and DHA associated SNP loci provided invaluable resources for the population structure, conservation genetics and genomic selection of large yellow croaker and other fish organisms.

The use of animal models to decipher physiological and neurobiological alterations of anorexia nervosa patients

Extensive studies were performed to decipher the mechanisms regulating feeding due to the worldwide obesity pandemy and its complications. The data obtained might be adapted to another disorder related to alteration of food intake, the restrictive anorexia nervosa. This multifactorial disease with a complex and unknown etiology is considered as an awful eating disorder since the chronic refusal to eat leads to severe, and sometimes, irreversible complications for the whole organism, until death. There is an urgent need to better understand the different aspects of the disease to develop novel approaches complementary to the usual psychological therapies. For this purpose, the use of pertinent animal models becomes a necessity. We present here the various rodent models described in the literature that might be used to dissect central and peripheral mechanisms involved in the adaptation to deficient energy supplies and/or the maintenance of physiological alterations on the long term. Data obtained from the spontaneous or engineered genetic models permit to better apprehend the implication of one signaling system (hormone, neuropeptide, neurotransmitter) in the development of several symptoms observed in anorexia nervosa. As example, mutations in the ghrelin, serotonin, dopamine pathways lead to alterations that mimic the phenotype, but compensatory mechanisms often occur rendering necessary the use of more selective gene strategies. Until now, environmental animal models based on one or several inducing factors like diet restriction, stress, or physical activity mimicked more extensively central and peripheral alterations decribed in anorexia nervosa. They bring significant data on feeding behavior, energy expenditure, and central circuit alterations. Animal models are described and criticized on the basis of the criteria of validity for anorexia nervosa.