Regulation of adipocytokines and insulin resistance

Induction of insulin resistance in female mice due to prolonged phenanthrene exposure: unveiling the low-dose effect and potential mechanisms

Phenanthrene (Phe) is a commonly occurring polycyclic aromatic hydrocarbon (PAH) found in various food sources and drinking water. Previous studies have shown that long-term exposure to Phe in male mice leads to insulin resistance in a dose-dependent manner. However, the effect of Phe on glucose homeostasis in female mice remains unknown. To address this knowledge gap, female Kunming mice were exposed to Phe through their drinking water at concentrations of 0.05, 0.5, and 5 ng/mL. After 270 d of exposure, we surprisingly discovered a low-dose effect of Phe on insulin resistance in female mice, which differed from the effect observed in male mice and showed sexual dimorphism. Specifically, insulin resistance was only observed in the 0.05 ng/mL treatment, and this low-dose effect was also reflected in the concentration of Phe in white adipose tissue (WAT). Differences in metabolic enzyme activities in the liver may potentially explain this effect. The observed sexual dimorphism in Phe exposure could be attributed to variations in estrogen (E2) level and estrogen receptor beta (ERβ) expression in WAT. These findings highlight the association between environmental factors and the development of insulin resistance, emphasizing the pathogenic effect of even low doses of Phe. Moreover, sex dependent-effect should be given more attention when studying the toxic effects of environmental pollutants.

Mind the Metabolic Gap: Bridging Migraine and Alzheimer's disease through Brain Insulin Resistance

Brain insulin resistance has recently been described as a metabolic abnormality of brain glucose homeostasis that has been proven to downregulate insulin receptors, both in astrocytes and neurons, triggering a reduction in glucose uptake and glycogen synthesis. This condition may generate a mismatch between brain's energy reserve and expenditure, mainly during high metabolic demand, which could be involved in the chronification of migraine and, in the long run, at least in certain subsets of patients, in the prodromic phase of Alzheimer's disease, along a putative metabolic physiopathological continuum. Indeed, the persistent disruption of glucose homeostasis and energy supply to neurons may eventually impair protein folding, an energy-requiring process, promoting pathological changes in Alzheimer's disease, such as amyloid-β deposition and tau hyperphosphorylation. Hopefully, the "neuroenergetic hypothesis" presented herein will provide further insight on there being a conceivable metabolic bridge between chronic migraine and Alzheimer's disease, elucidating novel potential targets for the prophylactic treatment of both diseases.

Importance of circulating leptin and adiponectin in the causal pathways between obesity and the development of colorectal cancer in Japanese men

BACKGROUND

The mechanistic associations between obesity and risk of colorectal cancer (CRC) remain unclear. Here, using body mass index (BMI) as an obesity indicator, we decomposed the total effects of obesity on the risk of CRC into: (1) direct effects, which are possibly mediated by unmeasured or currently unknown factors; (2) indirect effects mediated by circulating leptin and adiponectin; and (3) indirect effects that are not mediated by circulating leptin and adiponectin but by hyperinsulinemia and chronic inflammation (assessed via circulating connecting peptide and C-reactive protein, respectively).

METHODS

We adopted a causal mediation framework, using data from a large prospective cohort study of 44,271 Japanese men.

RESULTS

BMI was not associated with the risk of CRC due to direct and indirect effects that were not mediated by circulating leptin and adiponectin. By contrast, individuals with BMIs of 25.0-27.4 kg/m2 (risk ratio, 1.29; 95% confidence interval, 0.98-1.69) and ≥27.5 kg/m2 (risk ratio, 1.28; 95% confidence interval, 0.98-1.68) had a higher risk of CRC due to indirect effects of circulating leptin and adiponectin.

CONCLUSIONS

Our mediation analyses suggest that the association between BMI and CRC risk may be largely mediated by a pathway involving circulating leptin and adiponectin.

Effects of mifepristone on adipocyte differentiation in mouse 3T3-L1 cells

BACKGROUND

Both glucocorticoid receptor and peroxisome proliferator-activated receptor-γ (PPARγ) play a critical role in adipocyte differentiation. Mifepristone is not only an antagonist of the glucocorticoid receptor but also an agonist of PPARγ. Therefore, the present study investigated the effect of mifepristone on adipocyte differentiation.

METHODS

Mouse 3T3-L1 cells were used as a model for adipocyte differentiation. The lipid droplet formation was evaluated with Bodipy493/503 staining and the expression of adipocyte markers [adiponectin and adipocyte fatty acid binding protein-4 (Fabp4)] was evaluated with quantitative PCR and immunoblot analyses for indication of adipocyte differentiation. siRNA and neutralizing antibodies were used to elucidate the molecular mechanism of mifepristone-induced adipocyte differentiation. Luciferase reporter assay was used to examine the effect of mifepristone on the promoter activity of PPAR-response element (PPRE). The DNA microarray analysis was used to characterize the transcriptome of the mifepristone-induced adipocytes. In vivo adipogenic effect of mifepristone was examined in mice.

RESULTS

Mifepristone not only enhanced adipocyte differentiation induced by the conventional protocol consisting of insulin, dexamethasone and 3-isobutyl-1-methylxanthine but also induced adipocyte differentiation alone, as evidenced by lipid droplets formation and induction of the expression of adiponectin and Fabp4. These effects were inhibited by an adiponectin-neutralizing antibody and a PPARγ antagonist. Mifepristone activated the promoter activity of PPRE in a manner sensitive to PPARγ antagonist. A principal component analysis (PCA) of DNA microarray data revealed that the mifepristone-induced adipocytes represent some characteristics of the in situ adipocytes in normal adipose tissues to a greater extent than those induced by the conventional protocol. Mifepristone administration induced an increase in the weight of epididymal, perirenal and gluteofemoral adipose tissues.

CONCLUSIONS

Mifepristone alone is capable of inducing adipocyte differentiation in 3T3-L1 cells and adipogenesis in vivo. PPARγ plays a critical role in the mifepristone-induced adipocyte differentiation. Mifepristone-induced adipocytes are closer to the in situ adipocytes than those induced by the conventional protocol. The present study proposes a single treatment with mifepristone as a novel protocol to induce more physiologically relevant adipocytes in 3T3-L1 cells than the conventional protocol.

Research Advances in Fusion Protein-Based Drugs for Diabetes Treatment

Diabetes mellitus (DM) is a chronic metabolic disease characterized by elevated blood glucose levels, resulting in multi-organ dysfunction and various complications. Fusion proteins can form multifunctional complexes by combining the target proteins with partner proteins. It has significant advantages in improving the performance of the target proteins, extending their biological half-life, and enhancing patient drug compliance. Fusion protein-based drugs have emerged as promising new drugs in diabetes therapeutics. However, there has not been a systematic review of fusion protein-based drugs for diabetes therapeutics. Hence, we conducted a comprehensive review of published literature on diabetic fusion protein-based drugs for diabetes, with a primary focus on immunoglobulin G (IgG) fragment crystallizable (Fc) region, albumin, and transferrin (TF). This review aims to provide a reference for the subsequent development and clinical application of fusion protein-based drugs in diabetes therapeutics.

Recent progress in bone-repair strategies in diabetic conditions

Bone regeneration following trauma, tumor resection, infection, or congenital disease is challenging. Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia. It can result in complications affecting multiple systems including the musculoskeletal system. The increased number of diabetes-related fractures poses a great challenge to clinical specialties, particularly orthopedics and dentistry. Various pathological factors underlying DM may directly impair the process of bone regeneration, leading to delayed or even non-union of fractures. This review summarizes the mechanisms by which DM hampers bone regeneration, including immune abnormalities, inflammation, reactive oxygen species (ROS) accumulation, vascular system damage, insulin/insulin-like growth factor (IGF) deficiency, hyperglycemia, and the production of advanced glycation end products (AGEs). Based on published data, it also summarizes bone repair strategies in diabetic conditions, which include immune regulation, inhibition of inflammation, reduction of oxidative stress, promotion of angiogenesis, restoration of stem cell mobilization, and promotion of osteogenic differentiation, in addition to the challenges and future prospects of such approaches.

The serum creatinine to cystatin C to waist circumference ratios predicts risk for type 2 diabetes: A Chinese cohort study

BACKGROUND

There is a lack of research regarding the relationship between creatinine to cystatin C to waist circumference ratio (CCR/WC ratios) and the development of type 2 diabetes mellitus (T2DM). We aimed to evaluate the association between CCR/WC ratios and incident T2DM in Chinese adults.

METHODS

This prospective study was from the China Health and Retirement Longitudinal Study (2011, 2013, 2015, and 2018). The participants were divided into three groups by tertiaries of the CCR/WC ratios. Cox proportional-hazards models were used to identify the relationship between CCR/WC and T2DM.

RESULTS

Overall, 5938 participants were included for analysis, 766 of whom developed T2DM between 2011 and 2018. Risk of incident T2DM was decreased with tertiaries 2, 3 versus tertiary 1 of the CCR/WC index (adjusted hazard ratio [HR] 0.772 [95% confidence interval 0.647-0.921] and 0.724 [0.596-0.880], p for trend = .001 across tertiaries of the CCR/WC index). The results were consistent excluding participants with T2DM in the first 2 years.

CONCLUSIONS

This study demonstrated that CCR/WC was negatively correlated with the risk of T2DM in Chinese adults. Early detection is necessary to control the development of T2DM in Chinese with low CCR/WC levels.

Adipocyte Glucocorticoid Receptor Inhibits Immune Regulatory Genes to Maintain Immune Cell Homeostasis in Adipose Tissue

Glucocorticoids acting via the glucocorticoid receptors (GR) are key regulators of metabolism and the stress response. However, uncontrolled or excessive GR signaling adversely affects adipose tissue, including endocrine, immune, and metabolic functions. Inflammation of the adipose tissue promotes systemic metabolic dysfunction; however, the molecular mechanisms underlying the role of adipocyte GR in regulating genes associated with adipose tissue inflammation are poorly understood. We performed in vivo studies using adipocyte-specific GR knockout mice in conjunction with in vitro studies to understand the contribution of adipocyte GR in regulating adipose tissue immune homeostasis. Our findings show that adipocyte-specific GR signaling regulates adipokines at both mRNA and plasma levels and immune regulatory (Coch, Pdcd1, Cemip, and Cxcr2) mRNA gene expression, which affects myeloid immune cell presence in white adipose tissue. We found that, in adipocytes, GR directly influences Cxcr2. This chemokine receptor promotes immune cell migration, indirectly affecting Pdcd1 and Cemip gene expression in nonadipocyte or stromal cells. Our findings suggest that GR adipocyte signaling suppresses inflammatory signals, maintaining immune homeostasis. We also found that GR signaling in adipose tissue in response to stress is sexually dimorphic. Understanding the molecular relationship between GR signaling and adipose tissue inflammation could help develop potential targets to improve local and systemic inflammation, insulin sensitivity, and metabolic health.

Gene-diet interaction analysis using novel weighted food scores discovers the adipocytokine signaling pathway associated with the development of type 2 diabetes

Introduction

The influence of dietary patterns measured using Recommended Food Score (RFS) with foods with high amounts of antioxidant nutrients for Type 2 diabetes (T2D) was analyzed. Our analysis aims to find associations between dietary patterns and T2D and conduct a gene-diet interaction analysis related to T2D.

Methods

Data analyzed in the current study were obtained from the Korean Genome and Epidemiology Study Cohort. The dietary patterns of 46 food items were assessed using a validated food frequency questionnaire. To maximize the predictive power of the RFS, we propose two weighted food scores, namely HisCoM-RFS calculated using the novel Hierarchical Structural Component model (HisCoM) and PLSDA-RFS calculated using Partial Least Squares-Discriminant Analysis (PLS-DA) method.

Results

Both RFS (OR: 1.11; 95% CI: 1.03- 1.20; P = 0.009) and PLSDA-RFS (OR: 1.10; 95% CI: 1.02-1.19, P = 0.011) were positively associated with T2D. Mapping of SNPs (P < 0.05) from the interaction analysis between SNPs and the food scores to genes and pathways yielded some 12 genes (CACNA2D3, RELN, DOCK2, SLIT3, CTNNA2, etc.) and pathways associated with T2D. The strongest association was observed with the adipocytokine signalling pathway, highlighting 32 genes (STAT3, MAPK10, MAPK8, IRS1, AKT1-3, ADIPOR2, etc.) most likely associated with T2D. Finally, the group of the subjects in low, intermediate and high using both the food scores and a polygenic risk score found an association between diet quality groups with issues at high genetic risk of T2D.

Conclusion

A dietary pattern of poor amounts of antioxidant nutrients is associated with the risk of T2D, and diet affects pathway mechanisms involved in developing T2D.

Heat-treated foxtail millet protein delayed the development of pre-diabetes to diabetes in mice by altering gut microbiota and metabolomic profiles

Millet protein has gained much attention for its beneficial effects in mitigating metabolic diseases. However, most individuals pass through a prediabetic phase before developing full-blown diabetes, and whether millet protein has hypoglycemic effects on prediabetic mice remains unclear. In the present study, heat-treated foxtail millet protein (HMP) supplementation significantly decreased fasting blood glucose and serum insulin levels, alleviated insulin resistance, and improved impaired glucose tolerance in prediabetic mice. In addition, HMP altered the intestinal flora composition, as evidenced by the reduction in the abundance of Dubosiella and Marvinbryantia and the increase in the content of Lactobacillus, Bifidobacterium, and norank_f_Erysipelotrichaceae. Moreover, HMP supplementation dramatically regulated the levels of serum metabolites (i.e., LysoPCs, 11,14,17-eicosatrienoic acid, and sphingosine) and related metabolic pathways, such as sphingolipid metabolism and pantothenate and CoA biosynthesis. In conclusion, the improvement of gut microbiota and serum metabolic profiles was related to the hypoglycemic potential of HMP in prediabetes.

The benefits of adipocyte metabolism in bone health and regeneration

Patients suffering from musculoskeletal diseases must cope with a diminished quality of life and an increased burden on medical expenses. The interaction of immune cells and mesenchymal stromal cells during bone regeneration is one of the key requirements for the restoration of skeletal integrity. While stromal cells of the osteo-chondral lineage support bone regeneration, an excessive accumulation of cells of the adipogenic lineage is thought to promote low-grade inflammation and impair bone regeneration. Increasing evidence indicates that pro-inflammatory signaling from adipocytes is responsible for various chronic musculoskeletal diseases. This review aims to summarize the features of bone marrow adipocytes by phenotype, function, secretory features, metabolic properties and their impact on bone formation. In detail, the master regulator of adipogenesis and prominent diabetes drug target, peroxisome proliferator-activated receptor γ (PPARG), will be debated as a potential therapeutic approach to enhance bone regeneration. We will explore the possibilities of using clinically established PPARG agonists, the thiazolidinediones (TZDs), as a treatment strategy to guide the induction of a pro-regenerative, metabolically active bone marrow adipose tissue. The impact of this PPARG induced bone marrow adipose tissue type on providing the necessary metabolites to sustain osteogenic-as well as beneficial immune cells during bone fracture healing will be highlighted.

Beneficial effects of folic acid on inflammatory markers in the patients with metabolic syndrome: Meta-analysis and meta-regression of data from 511 participants in 10 randomized controlled trials

Previous clinical studies on the anti-inflammatory effects of folic acid (FA) in patients with metabolic syndrome (MetS) have shown controversial results. This study aimed to synthesize the evidence on the effect of FA on inflammatory marker levels in MetS patients. We screened PubMed, Embase, Medline, and the Cochrane Library (from inception to March 2022) to identify relevant randomized controlled trials (RCTs). DerSimonian and Laird random effects were used to estimate the pooled weighted mean difference (WMD) with 95% confidence interval (CI). Funnel plot, Egger's test, and the Begg-Mazumdar correlation test was used to assess publication bias. Subgroup analysis, meta-regression and sensitivity analysis were performed to find out possible sources of between-study heterogeneity. Ten RCTs with a total of 511 participants were included. The analysis showed that FA reduced high sensitivity C-reactive protein (hs-CRP) (WMD, -0.94; 95% CI, -1.56 to -0.32; P = 0.00), interleukin-6 (IL-6) (WMD, -0.39; 95% CI, -0.51 to -0.28; P = 0.00), and tumor necrosis factor-alpha (TNF-α) (WMD, -1.28; 95% CI, -1.88 to -0.68; P = 0.00), but did not decrease the C-reactive protein (CRP) (WMD, 0.10; 95% CI, -0.13 to 0.33; P = 0.38). Sensitivity analysis, subgroup analysis, and meta-regression showed that the effect sizes remained stable. Our findings suggest that FA supplementation could reduce inflammatory markers, such as hs-CRP, IL-6, TNF-α in patients with MetS. This study is registered with PROSPERO (CRD42021223843).

Interferon gamma mediates the reduction of adipose tissue regulatory T cells in human obesity

Decreased adipose tissue regulatory T cells contribute to insulin resistance in obese mice, however, little is known about the mechanisms regulating adipose tissue regulatory T cells numbers in humans. Here we obtain adipose tissue from obese and lean volunteers. Regulatory T cell abundance is lower in obese vs. lean visceral and subcutaneous adipose tissue and associates with reduced insulin sensitivity and altered adipocyte metabolic gene expression. Regulatory T cells numbers decline following high-fat diet induction in lean volunteers. We see alteration in major histocompatibility complex II pathway in adipocytes from obese patients and after high fat ingestion, which increases T helper 1 cell numbers and decreases regulatory T cell differentiation. We also observe increased expression of inhibitory co-receptors including programmed cell death protein 1 and OX40 in visceral adipose tissue regulatory T cells from patients with obesity. In human obesity, these global effects of interferon gamma to reduce regulatory T cells and diminish their function appear to instigate adipose inflammation and suppress adipocyte metabolism, leading to insulin resistance.

Metabolic Syndrome Predicts Response to Neoadjuvant Chemotherapy in Breast Cancer

Purpose

This research investigated the predictive role of metabolic syndrome (MetS) in breast cancer neoadjuvant chemotherapy (BCNACT) response.

Methods

One hundred fifty primary breast cancer (BC) patients who underwent neoadjuvant chemotherapy (NACT) were included retrospectively. MetS, MetS components [waist circumference (WC), fasting blood glucose (FBG), blood pressure, triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C)], serum lipid, and other MetS-related laboratory indicators within two weeks before BCNACT were evaluated. Univariate, multivariate, and subgroup analyses were performed to determine the predictors of BCNACT pathologic complete response (pCR), clinical response, and pathologic response. The effectiveness of the model was evaluated via receiver operating characteristic curve (ROC) and calibration curve. External validation was performed through 135 patients.

Results

Univariate analysis revealed that MetS before BCNACT predicted poor BCNACT response (pCR, P = 0.003; clinical response, P = 0.033; pathologic response, P < 0.001). Multivariate analysis confirmed that MetS before BCNACT predicted lower pCR rate (P = 0.041). Subgroup analysis showed that this relationship was significant in estrogen receptor (ER) (−) (RR = 0.266; 95% CI, 0.074–0.954), human epidermal growth factor 2 (HER2) (−) (RR = 0.833; 95% CI, 0.740–0.939) and TNBC (RR = 0.833; 95% CI, 0.636–0.995). Multivariate analysis of external validation confirmed that pretreatment MetS was associated with a lower pCR rate (P = 0.003), and subgroup analysis also confirmed that this relationship had significant statistical differences in ER (−), HER2 (−), and TNBC subgroups.

Conclusions

MetS before BCNACT predicted a lower pCR rate. Intervention on MetS status, especially in ER (−), HER2 (−), and TNBC subgroups, is expected to improve the response rate of BCNACT further.

Inflammation and atherogenic markers in patients with type 2 diabetes mellitus

Type two diabetes mellitus (T2DM) is characterized by a chronic inflammation status. Altered markers such as lipid concentrations are usually found in this disease. Elevated inflammation markers have been described such as cytokines (interleukin 6, tumour necrosis factor-alpha, and IL-8). However, there is a lack of information about the behaviour of the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), lipid coefficients, and atherogenic index in T2DM.

OBJECTIVE

To describe the atherogenic and inflammation parameters in a group of patients with T2DM.

MATERIALS AND METHODS

42 patients with T2DM were included, all patients were surveyed on clinic history (disease history, comorbidity, smoking, and other relevant variables), measurements of haematological, biochemical, and anthropometric parameters were taken and atherogenic coefficients and inflammation ratios were calculated.

RESULTS

Inflammation markers such as interleukin 6 and 8, necrosis tumour factor, and NLR were elevated. Of the patients, 88% were classified as high risk according to the atherogenic index. Former smokers had lower levels of IL-8 and higher NLR than non-smokers.

CONCLUSION

The atherogenic and inflammation markers such as atherogenic index, IL-8, and NLR make it possible to identify a subgroup of patients that are at risk of severe complications and mortality.

Assessment of causal effects of visceral adipose tissue on risk of cancers: a Mendelian randomization study

BACKGROUND

Despite the established association between obesity and cancer risk, it remains unclear whether visceral obesity is causally related to cancer risk and whether it is more pro-oncogenic than total body fat.

METHODS

We conducted two-sample Mendelian randomization (MR) analysis to assess the causal effects of visceral adipose tissue (VAT) on six common cancers. For exposure data, 221 genetic variants associated with the predicted volume of VAT in 325 153 Europeans from UK Biobank were used as instrumental variables. Genetic association data of six common cancers (breast, lung, colorectal, ovarian, pancreatic and prostate cancers) were obtained from large-scale consortia with an average of 19 576 cases and 43 272 controls. We performed univariable MR with five MR methods [inverse-variance weighted (IVW), MR-Egger regression, weighted median, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO) and Radial MR] and multivariable MR to estimate the effect of VAT independent of body mass index (BMI). Finally, we performed a series of sensitivity analyses as validation of primary MR results.

RESULTS

Two associations survived the false discovery rate correction for multiple testing (q-value < 0.05): in IVW, the odds ratios (95% CIs) per unit increase in genetically determined VAT were 1.65 (1.03 to 2.62) for pancreatic cancer and 1.47 (1.20 to 1.82) for lung squamous-cell carcinoma, respectively, which showed the same directions and overlapped confidence intervals with MR-Egger regression and weighted median results. There were no outlier variants identified by MR-PRESSO and no evidence supporting the presence of heterogeneity and pleiotropy in sensitivity analyses, although with wider confidence intervals that included the null, multivariable MR results for these two cancers showed the same directions and similar effect sizes as in IVW, which were independent of the effect from BMI. There was no evidence for a causal effect of VAT on the risk of other types of cancer.

CONCLUSION

Our findings suggest that lifelong exposure to elevated volumes of VAT might increase the risk of pancreatic cancer and lung squamous-cell carcinoma, highlighting the importance of revealing the underlying mechanisms for intervention targets.

Drug-like sphingolipid SH-BC-893 opposes ceramide-induced mitochondrial fission and corrects diet-induced obesity

Ceramide-induced mitochondrial fission drives high-fat diet (HFD)-induced obesity. However, molecules targeting mitochondrial dynamics have shown limited benefits in murine obesity models. Here, we reveal that these compounds are either unable to block ceramide-induced mitochondrial fission or require extended incubation periods to be effective. In contrast, targeting endolysosomal trafficking events important for mitochondrial fission rapidly and robustly prevented ceramide-induced disruptions in mitochondrial form and function. By simultaneously inhibiting ARF6- and PIKfyve-dependent trafficking events, the synthetic sphingolipid SH-BC-893 blocked palmitate- and ceramide-induced mitochondrial fission, preserved mitochondrial function, and prevented ER stress in vitro. Similar benefits were observed in the tissues of HFD-fed mice. Within 4 h of oral administration, SH-BC-893 normalized mitochondrial morphology in the livers and brains of HFD-fed mice, improved mitochondrial function in white adipose tissue, and corrected aberrant plasma leptin and adiponectin levels. As an interventional agent, SH-BC-893 restored normal body weight, glucose disposal, and hepatic lipid levels in mice consuming a HFD. In sum, the sphingolipid analog SH-BC-893 robustly and acutely blocks ceramide-induced mitochondrial dysfunction, correcting diet-induced obesity and its metabolic sequelae.

Association of circulating leptin and adiponectin levels with colorectal cancer risk: A systematic review and meta-analysis of case-control studies

PURPOSE

Leptin and adiponectin are adipokines which have been commonly implicated in carcinogenesis. As such, many studies have investigated the association of circulating leptin and adiponectin levels with colorectal cancer (CRC) risk. However, the results remained inconsistent.

METHODS

In this work, we performed a systematic review and meta-analysis to precisely examine the association between circulating levels of leptin and adiponectin and CRC risk. A systematic literature search was performed in PubMed/MEDLINE, Scopus, Web of Science, and EMBASE databases from inception until October 2020. The pooled effect size was then estimated by calculating the odds ratio (OR).

RESULTS

A total of 23 records (comprising 26 studies) were included in the meta-analysis. The overall analysis found that circulating levels of leptin and adiponectin were not significantly associated with CRC risk (P > 0.05). Interestingly, subgroup analysis revealed that a higher level of adiponectin was significantly associated with an increased CRC risk among overweight individuals (OR = 1.16; 95 % CI: 1.02, 1.32), and a decreased CRC risk among normal weight individuals (OR = 0.76; 95 % CI: 0.62, 0.92). Besides, a higher level of adiponectin was also significantly associated with a decreased risk of CRC in men (OR = 0.76; 95 % CI: 0.59, 0.98).

CONCLUSIONS

In conclusion, circulating leptin level was not associated with CRC risk, but that of adiponectin was associated with CRC risk only in specific subgroups.

-308G/A polymorphism of tumor necrosis factor alpha (TNF-α) gene and metabolic syndrome susceptibility: a meta-analysis

Many studies tried to assess the relationship between -308G/A polymorphism of tumor necrosis factor alpha (TNF-α) gene and risk of metabolic syndrome (MS), but their results were contradictory. This meta-analysis aimed to precisely evaluate this association. A systematic literature search was performed in Pubmed database and WanFang Med Online, STATA software 14.0 was used for the meta-analysis. Eleven independent studies containing 3277 cases and 3312 controls were included in our meta-analysis. In overall analysis, significant association was found between -308G/A polymorphism of TNF-α and MS in both allele model (OR 1.47, 95% CI 1.09–1.98, P 0.013) and dominant model (OR 1.77, 95% CI 1.21–2.58, P 0.003). In the subgroup analysis, the A allele was associated with increased risk of MS in Asia group (allele model: OR 1.82 95% CI 1.31–2.53, P < 0.001; dominant model: OR 2.30, 95% CI 1.64–3.21 P < 0.001; homozygous model: OR 2.29, 95% CI 1.31–4.01, P 0.004), and decreased risk of MS in Europe group (dominant model: OR 0.83, 95% CI 0.70–0.99, P < 0.001; recessive model: OR 0.51, 95% CI 0.28–0.92, P 0.025; homozygous model: OR 0.49 95% CI 0.27–0.89, P 0.02). The A allele also appeared to linked to increased risk of MS in CDS group and IDF groups. No significant association was observed in NCEPATPIII group. Our results suggested that -308G/A of TNF-α gene was a risk factor for MS, but it may played different roles in different ethnics, further studies with larger sample size and more other ethnics should be performed to confirm our conclusions.

A preliminary evaluation of the circulating leptin/adiponectin ratio in dogs with pituitary-dependent hyperadrenocorticism and concurrent diabetes mellitus

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic β-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic β-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1β, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1β concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMA_{β-cell function} was significantly lower in PDH dogs with DM than in normoglycemic PDH dogs, while HOMA_{insulin sensitivity} was significantly lower in PDH dogs with DM than in healthy dogs. These results suggest that adipokine dysregulation, a reduction in insulin sensitivity, and a further impairment in pancreatic β-cell function might predispose PDH dogs to DM. Further longitudinal study will be necessary to confirm this result.

Chronic Exposure to Environmental Level Phenanthrene Induces Non-Obesity-Dependent Insulin Resistance in Male Mice

Epidemiological evidence shows that the body burden of polycyclic aromatic hydrocarbons (PAHs) is related to the disruption of glucose homeostasis. However, the contribution of PAHs to the development of diabetes remains poorly documented. In the current work, male Kunming mice received phenanthrene (Phe) (5, 50, and 500 ng/kg) by gavage administration once every 2 days for 28 weeks. The significant elevation of homeostasis model assessment-insulin resistance (HOMA-IR) and HOMA-β cell, accompanied by hyperinsulinemia, indicated the occurrence of insulin resistance. The suppression of the insulin receptor signaling pathway in skeletal muscle might be responsible for glucose intolerance. Under the nonobese state, the serum levels of resistin, tumor necrosis factor-α, and interleukin-6 were elevated, whereas the levels of adiponectin were reduced. These changes in adipocytokine levels were consistent with their transcription in white adipose tissue. The promoter methylation levels of Retn (encoding resistin) and Adipoq (encoding adiponectin) were inversely correlated with their mRNA levels, indicating that Phe exposure could cause the disruption of adipocytokine secretion via epigenetic modification. The results would be helpful for understanding the pathogenesis in the development of T2DM caused by nonobesogenic pollutants.

Anti-Obesity and Antidiabetic Effects of Nelumbinis Semen Powder in High-Fat Diet-Induced Obese C57BL/6 Mice

Nelumbinis Semen (NS, the seeds of Nelumbo nucifera) extract is a traditional Korean medicine with anti-oxidant activity. The present study examined the anti-obesity and antidiabetic effects of NS powder in high-fat diet (HFD)-induced obese C57BL/6 mice. Mice (n = 8/group) were fed a normal diet (CON), HFD, HFD containing 5% NS powder (HFD-NS5%), or HFD containing 10% NS powder (HFD-NS10%) for 12 weeks. Food intake was relatively higher in groups HFD-NS5% and HFD-NS10%, while the food efficiency ratio was highest in group HFD (p < 0.05). HFD-NS5% reduced the body weight (-39.1%) and fat weight (-26.6%), including epididymal fat and perirenal fat, and lowered the serum triglyceride levels (-20.6%) compared with HFD. Groups HFD-NS5% and HFD-NS10% showed hepatoprotective properties, reducing the serum ALT levels (p < 0.05) and fat globules (size and number) in the liver compared with group HFD. HFD-NS5% and HFD-NS10% regulated the blood glucose, improved the glucose intolerance, and showed a 12.5% and 15.0% reduction in the area under the curve (AUC) of intraperitoneal glucose tolerance test (IPGTT), and a 26.8% and 47.3% improvement in homeostatic model assessment insulin resistance (HOMA-IR), respectively, compared with HFD (p < 0.05). Regarding the expressions of genes related to anti-obesity and antidiabetes, there was a 1.7- and 1.3-fold increase in PPAR-α protein expression, 1.4- and 1.6-fold increase in PPAR-γ protein expression, and 0.7- and 0.6-fold decrease in TNF-α protein expression, respectively, following HFD-NS5% and HFD-NS10% treatments, compared with HFD, and GLUT4 protein expression increased relative to CON (p < 0.05). These results comprehensively provide the fundamental data for NS powder's functional and health-promoting benefits associated with anti-obesity and antidiabetes.

Prognostic significance of high triglyceride and apolipoprotein B levels in patients with stage III and high-risk stage II colorectal cancer undergoing curative surgery

Although epidemiologic studies suggest that dyslipidemia increases the risk of colorectal cancer (CRC), the prognostic value of blood lipid and apolipoprotein levels in CRC remains unclear. The aim of the present study was to investigate the impact of blood lipid and apolipoprotein levels on the prognosis of patients with stage III and high-risk stage II CRC undergoing curative surgery. Preoperative levels of total cholesterol, triglycerides (TG), high-density lipoprotein, low-density lipoprotein, very-low-density lipoprotein, apolipoprotein A1 and apolipoprotein B (APO-B) in patients with CRC undergoing surgery were evaluated. The cut-off values of these factors were determined by the maximal x² method and were used to classify patients into two prognostic groups: Poor and good prognosis groups. The patients prognostic values were assessed using the Kaplan-Meier curve and Cox regression analysis. In addition, the impact of these parameters on the prognosis and their predictive accuracy were evaluated using nomograms and Harrells concordance index, respectively. In total, 246 patients were included in this evaluation. Based on the cut-off points for TG (1.53 mmol/l in men and 1.58 mmol/l in women) and APO-B (0.73 mmol/l in men and women), the present study determined that both TG and APO-B were predictors of disease-free survival (DFS) and overall survival (OS). Multivariate analysis demonstrated that high TG (men, ≥1.53 mmol/l; women, ≥1.58 mmol/l) and high APO-B (≥0.73 mmol/l) levels were significantly associated with decreased DFS and OS. Nomograms that included values for TG and APO-B levels demonstrated higher predictive accuracy compared with that of nomograms without these values. These results indicated that TG and APO-B levels may be good independent prognostic biomarkers after radical CRC surgery. Therefore, adjusting these parameters to moderate levels may be beneficial.

Cancer Biology and Prevention in Diabetes

The available evidence suggests a complex relationship between diabetes and cancer. Epidemiological data suggest a positive correlation, however, in certain types of cancer, a more complex picture emerges, such as in some site-specific cancers being specific to type I diabetes but not to type II diabetes. Reports share common and differential mechanisms which affect the relationship between diabetes and cancer. We discuss the use of antidiabetic drugs in a wide range of cancer therapy and cancer therapeutics in the development of hyperglycemia, especially antineoplastic drugs which often induce hyperglycemia by targeting insulin/IGF-1 signaling. Similarly, dipeptidyl peptidase 4 (DPP-4), a well-known target in type II diabetes mellitus, has differential effects on cancer types. Past studies suggest a protective role of DPP-4 inhibitors, but recent studies show that DPP-4 inhibition induces cancer metastasis. Moreover, molecular pathological mechanisms of cancer in diabetes are currently largely unclear. The cancer-causing mechanisms in diabetes have been shown to be complex, including excessive ROS-formation, destruction of essential biomolecules, chronic inflammation, and impaired healing phenomena, collectively leading to carcinogenesis in diabetic conditions. Diabetes-associated epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition (EndMT) contribute to cancer-associated fibroblast (CAF) formation in tumors, allowing the epithelium and endothelium to enable tumor cell extravasation. In this review, we discuss the risk of cancer associated with anti-diabetic therapies, including DPP-4 inhibitors and SGLT2 inhibitors, and the role of catechol-o-methyltransferase (COMT), AMPK, and cell-specific glucocorticoid receptors in cancer biology. We explore possible mechanistic links between diabetes and cancer biology and discuss new therapeutic approaches.

The PDK1-FoxO1 signaling in adipocytes controls systemic insulin sensitivity through the 5-lipoxygenase-leukotriene B4 axis

Although adipocytes are major targets of insulin, the influence of impaired insulin action in adipocytes on metabolic homeostasis remains unclear. We here show that adipocyte-specific PDK1 (3'-phosphoinositide-dependent kinase 1)-deficient (A-PDK1KO) mice manifest impaired metabolic actions of insulin in adipose tissue and reduction of adipose tissue mass. A-PDK1KO mice developed insulin resistance, glucose intolerance, and hepatic steatosis, and this phenotype was suppressed by additional ablation of FoxO1 specifically in adipocytes (A-PDK1/FoxO1KO mice) without an effect on adipose tissue mass. Neither circulating levels of adiponectin and leptin nor inflammatory markers in adipose tissue differed between A-PDK1KO and A-PDK1/FoxO1KO mice. Lipidomics and microarray analyses revealed that leukotriene B4 (LTB4) levels in plasma and in adipose tissue as well as the expression of 5-lipoxygenase (5-LO) in adipose tissue were increased and restored in A-PDK1KO mice and A-PDK1/FoxO1KO mice, respectively. Genetic deletion of the LTB4 receptor BLT1 as well as pharmacological intervention to 5-LO or BLT1 ameliorated insulin resistance in A-PDK1KO mice. Furthermore, insulin was found to inhibit LTB4 production through down-regulation of 5-LO expression via the PDK1-FoxO1 pathway in isolated adipocytes. Our results indicate that insulin signaling in adipocytes negatively regulates the production of LTB4 via the PDK1-FoxO1 pathway and thereby maintains systemic insulin sensitivity.

An MRM-Based Multiplexed Quantification Assay for Human Adipokines and Apolipoproteins

Adipokines and apolipoproteins are key regulators and potential biomarkers in obesity and associated diseases and their quantitative assessment is crucial for functional analyses to understand disease mechanisms. Compared to routinely used ELISAs, multiple reaction monitoring (MRM)-based mass spectrometry allows multiplexing and detection of proteins for which antibodies are not available. Thus, we established an MRM method to quantify 9 adipokines and 10 apolipoproteins in human serum. We optimized sample preparation by depleting the two most abundant serum proteins for improved detectability of low abundant proteins. Intra-day and inter-day imprecision were below 16.5%, demonstrating a high accuracy. In 50 serum samples from participants with either normal weight or obesity, we quantified 8 adipokines and 10 apolipoproteins. Significantly different abundances were observed for five adipokines (adipsin, adiponectin, chemerin, leptin, vaspin) and four apolipoproteins (apo-B100/-C2/-C4/-D) between the body mass index (BMI) groups. Additionally, we applied our MRM assay to serum samples from normal weight children and human adipocyte cell culture supernatants to proof the feasibility for large cohort studies and distinct biological matrices. In summary, this multiplexed assay facilitated the investigation of relationships between adipokines or apolipoproteins and phenotypes or clinical parameters in large cohorts, which may contribute to disease prediction approaches in the future.

Adverse Effects of Glycemia-Lowering Medications in Type 2 Diabetes

PURPOSE OF REVIEW

Treatment of patients with type 2 diabetes mellitus is focused on preventing the occurrence and delaying the development of macro- and micro-vascular complications. Glycemic control can help prevent these complications, but there is concern about the adverse effects of glycemia-lowering medications. A rational approach is to balance the desired low risk of adverse events against the unwanted higher risk of major complications resulting from suboptimal glucose control.

RECENT FINDINGS

Using the above approach, approved glucose-lowering agents have favorable benefit-to-risk profiles for use in most patients with type 2 diabetes. We first briefly review the mechanism of actions and benefits of the different commonly used classes of glycemia-lowering medications and then discuss adverse effects and safety concern associated with their use. Our overall assessment is that if used appropriately, the different classes of glycemia-lowering medications offer beneficial outcomes with relatively modest and, in some instances, preventable adverse events.

Selected adipocytokines in patients with an incidentally discovered pheochromocytoma

BACKGROUND

Adipose tissue secretes many adipokines and cytokines, which may be an additional risk factor of cardiovascular and metabolic diseases in patients with an incidentally discovered pheochromocytoma (PHEO). The aim of the study was to investigate levels of selected adipocytokines in these patients.

METHODS

This prospective study included 12 patients with an incidentally discovered PHEO and 18 healthy participants. In all participants plasma/serum concentrations of triglycerides, HDL and LDL cholesterol, insulin, glucose, adipocytokines (adiponectin, leptin, resistin, TNFα, IL6, and MCP1) were determined, hormonal tests were performed in patients.

RESULTS

Patients and controls did not differ significantly in terms of age, sex, and body mass index. Among incidentally discovered PHEO patients, adiponectin levels were lower, while TNFα concentrations higher than in controls. Concentrations of adiponectin correlated with 24-hour urinary excretion of normetanephrine in women. Significantly higher TNFα concentrations were found in hypertensive than in normotensive PHEO patients as well as in non-diabetic PHEO patients than controls. Further, resistin concentration was higher in PHEO patients with diabetes than in non-diabetic ones (P<0.001). Incidentally discovered PHEO tumor size correlated with leptin and IL6 levels. Adiponectin levels were higher, while TNFα and resistin lower among five patients re-examined after tumor resection.

CONCLUSIONS

Among patients with an incidentally discovered pheochromocytoma, lower adiponectin, and higher resistin and TNFα levels may constitute additional factors for HT and DM. In our study, for the first time, correlations between incidentally discovered PHEO tumor size and concentrations of leptin as well as IL6 were found.

Intrauterine growth restriction: the controversial role of perinatal adipocytokines in the prediction of metabolic adult disease

"Prenatal/fetal programming," implying structural/functional disorders of developing tissues/organs, consequent to an adverse intrauterine environment leading to asymmetric intrauterine growth restriction (IUGR), predisposes to metabolic syndrome and noncommunicable diseases in adulthood, in the framework of the "Developmental Origins of Health and Disease" (DOHaD) concept. DOHaD consequences are associated with adipose tissue, particularly the visceral one, occurring in relative abundance in IUGR infants. Adipose tissue secretes numerous hormones, collectively called adipocytokines, as leptin, adiponectin, ghrelin, resistin, apelin, visfatin, omentin, vaspin, preadipocyte factor-1 (Pref-1), fatty acid-binding protein-4, lipocalin-2, and others, implicated in fetal growth, body metabolism, energy homeostasis, and insulin resistance. Early identification of adipocytokines as biomarkers predicting later metabolic disorders/diseases in IUGR individuals, enabling relevant protective interventions, would be of utmost importance. Current data do not support this perspective, due to controversial results in the literature, with the eventual exception of visfatin and possibly Pref-1.

Multigenerational epigenetic inheritance: One step forward, two generations back

Modifications to DNA and histone proteins serve a critical regulatory role in the developing and adult brain, and over a decade of research has established the importance of these "epigenetic" modifications in a wide variety of brain functions across the lifespan. Epigenetic patterns orchestrate gene expression programs that establish the phenotypic diversity of various cellular classes in the central nervous system, play a key role in experience-dependent gene regulation in the adult brain, and are commonly implicated in neurodevelopmental, psychiatric, and neurodegenerative disease states. In addition to these established roles, emerging evidence indicates that epigenetic information can potentially be transmitted to offspring, giving rise to inter- and trans-generational epigenetic inheritance phenotypes. However, our understanding of the cellular events that participate in this information transfer is incomplete, and the ability of this transfer to overcome complete epigenetic reprogramming during embryonic development is highly controversial. This review explores the existing literature on multigenerational epigenetic mechanisms in the central nervous system. First, we focus on the cellular mechanisms that may perpetuate or counteract this type of information transfer, and consider how epigenetic modification in germline and somatic cells regulate important aspects of cellular and organismal development. Next, we review the potential phenotypes resulting from ancestral experiences that impact gene regulatory modifications, including how these changes may give rise to unique metabolic phenotypes. Finally, we discuss several caveats and technical limitations that influence multigenerational epigenetic effects. We argue that studies reporting multigenerational epigenetic changes impacting the central nervous system must be interpreted with caution, and provide suggestions for how epigenetic information transfer can be mechanistically disentangled from genetic and environmental influences on brain function.

Role of Endocrine-Disrupting Engineered Nanomaterials in the Pathogenesis of Type 2 Diabetes Mellitus

Nanotechnology has enabled the development of innovative technologies and products for several industrial sectors. Their unique physicochemical and size-dependent properties make the engineered nanomaterials (ENMs) superior for devising solutions for various research and development sectors, which are otherwise unachievable by their bulk forms. However, the remarkable advantages mediated by ENMs and their applications have also raised concerns regarding their possible toxicological impacts on human health. The actual issue stems from the absence of systematic data on ENM exposure-mediated health hazards. In this direction, a comprehensive exploration on the health-related consequences, especially with respect to endocrine disruption-related metabolic disorders, is largely lacking. The reasons for the rapid increase in diabetes and obesity in the modern world remain largely unclear, and epidemiological studies indicate that the increased presence of endocrine disrupting chemicals (EDCs) in the environment may influence the incidence of metabolic diseases. Functional similarities, such as mimicking natural hormonal actions, have been observed between the endocrine-disrupting chemicals (EDCs) and ENMs, which supports the view that different types of NMs may be capable of altering the physiological activity of the endocrine system. Disruption of the endocrine system leads to hormonal imbalance, which may influence the development and pathogenesis of metabolic disorders, particularly type 2 diabetes mellitus (T2DM). Evidence from many in vitro, in vivo and epidemiological studies, suggests that ENMs generally exert deleterious effects on the molecular/hormonal pathways and the organ systems involved in the pathogenesis of T2DM. However, the available data from several such studies are not congruent, especially because of discrepancies in study design, and therefore need to be carefully examined before drawing meaningful inferences. In this review, we discuss the outcomes of ENM exposure in correlation with the development of T2DM. In particular, the review focuses on the following sub-topics: (1) an overview of the sources of human exposure to NMs, (2) systems involved in the uptake of ENMs into human body, (3) endocrine disrupting engineered nanomaterials (EDENMs) and mechanisms underlying the pathogenesis of T2DM, (4) evidence of the role of EDENMs in the pathogenesis of T2DM from in vitro, in vivo and epidemiological studies, and (5) conclusions and perspectives.

Postnatal exposure to di-(2-ethylhexyl)phthalate alters cardiac insulin signaling molecules and GLUT4Ser488 phosphorylation in male rat offspring

Di-(2-ethylhexyl)phthalate (DEHP), a distinctive endocrine-disrupting chemical, is widely used as a plasticizer in a variety of consumer products. It can easily cross the placenta and enter breast milk and then it is rapidly absorbed by offspring. Since it is generally accepted that individuals are more sensitive to chemical exposure during vital developmental periods, we investigated whether DEHP exposure during lactation affects cardiac insulin signaling and glucose homeostasis in the F₁ male rat offspring at postnatal day 22 (PND22). Lactating Wistar rats were administered with DEHP (1, 10, and 100 mg/kg/d) or olive oil from lactation day 1 to 21 by oral gavage. All the male pups were perfused and killed on PND22. On the day before the killing, they were kept for fasting overnight and blood was collected. The cardiac muscle was dissected out, washed in ice-cold physiological saline repeatedly and used for the assay of various parameters. DEHP-exposed offspring had significantly lower body weight than the control. DEHP-exposed offspring showed elevated blood glucose, decreased ¹⁴ C-2-deoxyglucose uptake and ¹⁴ C-glucose oxidation in cardiac muscle at PND22. The concentration of upstream insulin signaling molecules such as insulin receptor subunit β (InsRβ) and insulin receptor substrate 1 (IRS1) were downregulated in DEHP-exposed offspring. However, no significant alterations were observed in protein kinase B (Akt) and Akt substrate of 160 kDa (AS160). Surprisingly, phosphorylation of IRS1 ^Tyr632 and Akt ^Ser473 were diminished. Low levels of glucose transporter type 4 (GLUT4) protein and increased GLUT4 ^Ser488 phosphorylation which decreases its intrinsic activity and translocation towards plasma membrane were also recorded. Lactational DEHP exposure predisposes F ₁ male offspring to cardiac glucometabolic disorders at PND22, which may impair cardiac function.

Metabolaid® Combination of Lemon Verbena and Hibiscus Flower Extract Prevents High-Fat Diet-Induced Obesity through AMP-Activated Protein Kinase Activation

Lemon verbena (Lippia citriodora) has been used as a food spice, cosmetic, and in traditional medicine formulations to treat asthma and diabetes in South America and Southern Europe. Hibiscus flower (Hibiscus sabdariffa L.) is used in traditional Chinese medicine in the form of a tea to treat hypertension and inflammation. In the present study, we examined the synergistic effects of a formula of Metabolaid^® (MetA), a combination of lemon verbena and hibiscus-flower extracts, on obesity and its complications in high-fat-diet (HFD)-induced obese mice. The results showed that MetA decreased body weight, white adipose tissue (WAT), and liver weight. Additionally, serum and hepatic lipid profiles, glucose levels, glucose tolerance, and cold-induced thermogenesis were significantly improved. Appetite-regulating hormones adiponectin and leptin were significantly increased and decreased, respectively, while the inflammatory-related factors tumor necrosis factor (TNF)-α and interleukin (IL)-6 were downregulated by MetA. Adipogenesis-activating gene expression was decreased, while increased thermogenesis-inducing genes were upregulated in the WAT, correlating with increased phosphorylation of AMPK and fatty-acid oxidation in the liver. Taken together, these results suggest that MetA decreased obesity and its complications in HFD mice. Therefore, this formula may be a candidate for the prevention and treatment of obesity and its complications.

The combination of canagliflozin and omega-3 fatty acid ameliorates insulin resistance and cardiac biomarkers via modulation of inflammatory cytokines in type 2 diabetic rats

The present study was carried out with the hypothesis that combination of canagliflozin and omega-3 fatty acid may have potential effect on insulin level, insulin resistance, cardiac biomarkers, inflammatory cytokines and histological studies in type 2 diabetes mellitus (DM). Type 2 DM was induced by injecting nicotinamide (120 mg/kg, i.p.) 15 min before STZ (60 mg/kg) injection. Canagliflozin (5 and 10 mg/kg) and omega-3 fatty acid (300 mg/kg) were given for 28 days after confirmation of diabetes. Biochemical estimations revealed elevated levels of glucose, insulin, HOMA-R and inflammatory cytokines in diabetic group. Daily dosing of alone canagliflozin and omega-3 fatty acid slightly reduced elevated levels of glucose, insulin, HOMA-R and inflammatory cytokines (IL-1β, IL-2, and TNFα), whereas canagliflozin and omega-3 fatty acid combination has reduced these biochemical parameters significantly when compared with diabetic group. Similarly in diabetic group the levels of cardiac biomarkers such as lipid profile, LDH, CKMB and troponin were significantly increased. Elevated levels of cardiac biomarkers were significantly reduced after daily dosing of alone canagliflozin and omega-3 fatty acid. Canagliflozin and omega-3 fatty acid combination has offered better improvement in cardiac biomarkers compared to alone canagliflozin and omega-3 fatty acid. Histopathological analysis also supported the above hypothesis that combination therapy (canagliflozin and omega-3 fatty acid) offered better protection against degenerative changes in β-cells of pancreas as compared to alone treatment with these drugs. Thus the present study revealed that canagliflozin and omega-3 fatty acid can be used as potential combination therapy in type 2 DM along with cardiac complication.

Adipokine and cytokine levels in non-functioning adrenal incidentalomas (NFAI)

Due to the fact that overweight or obesity is accompanied by hormonally active adrenal tumors: Cushing Syndrome-(CS) and Subclinical Cushing Syndrome (SCS), it is of high interest the correlation between different adipokines and cytokines secreted by adipose tissue, with metabolic disorders and hormonal activity in this group. Even in non-functioning adrenal incidentalomas (NFAI) elevated risk for cardiovascular disease and metabolic syndrome was demonstrated. The aim of the study was to investigate plasma adiponectin, leptin, resistin, tumor necrosis factor α (TNFα), interleukin 6 (IL6) and monocyte chemoattractant protein 1 (MCP1) levels in patients with NFAIs and healthy subjects. The study included 18 NFAI patients and 18 healthy subjects. The groups were homogeneous in terms of age, sex and body mass index (BMI). Patients with NFAI showed significantly higher circulating levels of pro-inflammatory cytokines compared to healthy controls (MCP 1: p < 0.001; TNFα p = 0.021; IL6 p = 0.012). On the other hand, adiponectin concentration was significantly lower in the NFAI group (p = 0.034). The serum leptin and resistin concentrations did not differ significantly between the two groups. Acquired results were not dependent on glucocorticoid and catecholamine secretion in NFAI patients. Also, there were no clear correlations between BMI and cytokine levels. It is possible that increased risk for cardiovascular and metabolic diseases reported in NFAI patients is at least partially dependent on adipose tissue activity.

Millettia macrophylla (Fabaceae) phenolic fraction prevents differentiation of 3T3-L1 adipocytes and the increased risks of cardiovascular diseases in ovariectomized rats

ETHNOPHARMACOLOGICAL RELEVANCE

A prolonged estrogen deficiency alters lipid metabolism and increases risks of cardiovascular diseases. Phytoestrogens, naturally occurring compounds with estrogenic properties are reported to have cardiovascular protective effects. Millettia macrophylla used in the Cameroonian traditional system to treat physiological disorders related to menopause, was previously reported to have estrogenic effects.

AIM

We, therefore, proposed evaluating the in vitro and in vivo effects of M. macrophylla phenolic fraction on some risk factors for cardiovascular diseases.

MATERIAL AND METHODS

In vitro, the ability of the M. macrophylla phenolic fraction (PF) as well as the 9 isolates to prevent the 3T3-L1 preadipocytes differentiation was assessed. Further, the preventive effects of PF on abdominal fat accumulation, body weight gain, lipid profile, nitric oxide level, superoxide dismutase (SOD) and catalase activities, reduced glutathione (GSH) and malondialdehyde (MDA) levels were assessed in a postmenopausal rat model.

RESULTS

In vitro, PF and its isolate secundiferol I inhibited lipid accumulation in 3T3-L1 cells. Moreover, all the isolates except daidzein dimethylether prevented the interleukin IL-6 production in 3T3-L1 cells. In vivo, PF prevented ovariectomy-induced abdominal fat accumulation, body weight gain, dyslipidemia, glucose intolerance and decreased atherogenic index. In addition, it induced a vasorelaxant effect by preventing the low level of nitric oxide in the aorta. PF also exhibited antioxidant effects as it increased aorta GSH level, SOD, and catalase activities and decreased MDA level.

CONCLUSIONS

Taken together, our data suggest that PF prevents the increased risks of cardiovascular diseases in ovariectomized rats.

Epigenetics and Immunometabolism in Diabetes and Aging

SIGNIFICANCE

A strong relationship between hyperglycemia, impaired insulin pathway, and cardiovascular disease in type 2 diabetes (T2D) is linked to oxidative stress and inflammation. Immunometabolic pathways link these pathogenic processes and pose important potential therapeutic targets. Recent Advances: The link between immunity and metabolism is bidirectional and includes the role of inflammation in the pathogenesis of metabolic disorders such as T2D, obesity, metabolic syndrome, and hypertension and the role of metabolic factors in regulation of immune cell functions. Low-grade inflammation, oxidative stress, balance between superoxide and nitric oxide, and the infiltration of macrophages, T cells, and B cells in insulin-sensitive tissues lead to metabolic impairment and accelerated aging.

CRITICAL ISSUES

Inflammatory infiltrate and altered immune cell phenotype precede development of metabolic disorders. Inflammatory changes are tightly linked to alterations in metabolic status and energy expenditure and are controlled by epigenetic mechanisms.

FUTURE DIRECTIONS

A better comprehension of these mechanistic insights is of utmost importance to identify novel molecular targets. In this study, we describe a complex scenario of epigenetic changes and immunometabolism linking to diabetes and aging-associated vascular disease. Antioxid. Redox Signal. 29, 257-274.

Lactobacillus acidophilus NS1 attenuates diet-induced obesity and fatty liver

Obesity is a major threat to public health, and it is strongly associated with insulin resistance and fatty liver disease. Here, we demonstrated that administration of Lactobacillus acidophilus NS1 (LNS1) significantly reduced obesity and hepatic lipid accumulation, with a concomitant improvement in insulin sensitivity, in high-fat diet (HFD)-fed mice. Furthermore, administration of LNS1 inhibited the effect of HFD feeding on the SREBP-1c and PPARα signaling pathways and reduced lipogenesis with an increase in fatty acid oxidation in ex vivo livers from HFD-fed mice. These LNS1 effects were confirmed in HepG2 cells and ex vivo livers by treatment with LNS1 culture supernatant (LNS1-CS). Interestingly, AMPK phosphorylation and activity in the liver of HFD-fed mice were increased by administration of LNS1. Consistently, chemical inhibition of AMPK with compound C, a specific inhibitor of AMPK, dramatically reduced the effect of LNS1-CS on lipid metabolism in HepG2 cells and ex vivo livers by modulating the SREBP-1c and PPARα signaling pathways. Furthermore, administration of LNS1 to HFD-fed mice significantly improved insulin resistance and increased Akt phosphorylation in the liver, white adipose tissue and skeletal muscle. Together, these data suggest that LNS1 may prevent diet-induced obesity and related metabolic disorders by improving lipid metabolism and insulin sensitivity through an AMPK→SREBP-1c/PPARα signaling pathway.

Chrysanthemum indicum L. ethanol extract reduces high-fat diet-induced obesity in mice

The present study was undertaken to investigate the mechanism behind the anti-obesity effect of the 50% ethanol extract of Chrysanthemum indicum L. flowers (CIEE) in a mouse model of high-fat diet (HFD)-induced obesity. Male C57BL/6J mice (six mice in each group) were administered CIEE (8, 40 and 200 mg/kg) for 6 weeks while being fed with a HFD. Garcinia cambogia (GC) was used as the positive control and was administered in the same manner as CIEE. Results demonstrated that oral administration of CIEE significantly reduced body weight, epididymal white adipose tissue (EWAT), liver weight and serum levels of total cholesterol and triglyceride (P<0.05). In addition, CIEE reduced serum leptin and increased adiponectin levels. CIEE significantly downregulated peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein-α and fatty acid synthase expression levels in EWAT, and upregulated the protein expression of PPARα in liver tissue of HFD-fed obese mice (P<0.05). These results suggested that Chrysanthemum indicum L. flowers may be a potentially effective therapeutic agent for obesity and its associated complications.

Chrysanthemum indicum Inhibits Adipogenesis and Activates the AMPK Pathway in High-Fat-Diet-Induced Obese Mice

Chrysanthemum indicum (CI) is widely distributed in China and many parts of the tropical world, and has been reported to have antibacterial, antiviral, anti-oxidant and immunomodulatory effects, but no information is available on its effects on high fat diet (HFD)-induced obesity. This was undertaken to investigate the mechanism responsible for the effect of ethyl acetate fraction of CI (CIEA) on adipogenesis, in vitro and in vivo models of obesity. In the in vitro study, differentiating 3T3-L1 cells were treated with media to initiate differentiation (MDI) in the presence or absence of CIEA with different concentrations, and in the in vivo study, C57BL/6 mice were fed with HFD and administered CIEA daily for six weeks. Garcinia cambogia (GC) was used as the positive control, and was administered in the same manner as CIEA. Results showed CIEA reduced HFD-induced body weight gain, epididymal white adipose tissue (eWAT), and liver weight. In addition, CIEA significantly decreased serum lipid profiles, including total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterol (LDLc) and increased high density lipoprotein cholesterol (HDLc) levels. Furthermore, CIEA also reduced leptin levels and increased adiponectin levels in serum, and significantly decreased peroxisome proliferator-activated receptor [Formula: see text] (PPAR[Formula: see text]) and CCAAT/enhancer-binding protein (C/EPBs) levels, but increased PPAR[Formula: see text] level and the phosphorylation of AMP-activated protein kinase (AMPK) in eWATs and in the liver tissues of HFD fed obese mice. Taken together, these results indicate CIEA might be beneficial for preventing obesity.

Anti-obesity effects of pectinase and cellulase enzyme‑treated Ecklonia cava extract in high‑fat diet‑fed C57BL/6N mice

The present study investigated the anti‑obesity effects of enzyme‑treated Ecklonia cava extract (EEc) in C57BL/6N mice with high‑fat diet (HFD)‑induced obesity. The EEc was separated and purified with the digestive enzymes pectinase (Rapidase X‑Press L) and cellulase (Rohament CL) and its effects on the progression of HFD‑induced obesity were examined over 10 weeks. The mice were divided into 6 groups (n=10/group) as follows: Normal diet group, HFD group, mice fed a HFD with 25 mg/kg/day Garcinia cambogia extract and mice fed a HFD with 5, 25 or 150 mg/kg/day EEc (EHD groups). Changes in body weight, fat, serum lipid levels and lipogenic enzyme levels were determined. The body weight and liver weight were increased in the HFD group compared with those in the ND group, which was significantly reduced by EEc supplementation. In addition, significant reductions in epididymal, perirenal and mesenteric white adipose tissues were present in the EHD groups and all three EHD groups exhibited decreases in insulin, leptin and glutamate pyruvate transaminase levels compared with those in the HFD group. In addition, EEc treatment significantly decreased the serum and hepatic triglyceride levels compared with those in the HFD group. However, the levels of high‑density lipoprotein cholesterol/total cholesterol ration increased significantly in EHD‑25 and ‑150 groups compared with those in the HFD group. Changes in adipogenic and lipogenic protein expression in the liver was assessed by western blot analysis. The EHD‑25 and -150 groups exhibited reduced levels of CCAAT/enhancer‑binding protein α and peroxisome proliferator activated receptor γ. However, the phosphorylation ratios of AMP‑activated protein kinase and acetyl‑CoA carboxylase were significantly increased in the liver tissue obtained from the EHD (5, ‑25 and ‑150 mg/kg/day) groups compared with those in the HFD group. EEc supplementation reduced levels of sterol regulatory element‑binding protein‑1c, adipose fatty acid‑binding protein, fatty acid synthase and leptin, while it significantly increased glucose transporter type 4 and adiponectin protein levels in the liver tissues of all three EHD groups compared with those in the HFD group. Taken together, these results suggest that EEc exerts anti‑obesity effects by reducing body weight and the serum and hepatic levels of obesity‑associated factors. Thus, EEc supplementation reduces HFD‑induced obesity in C57BL/6N mice and has the potential to prevent obesity and subsequent metabolic disorders.

Effects of 12-week circuit exercise program on obesity index, appetite regulating hormones, and insulin resistance in middle-aged obese females

[Purpose] The purpose of this study is to investigate the effects of circuit exercise on obesity index, appetite regulating hormones and insulin resistance in middle-aged obese women. [Subjects and Methods] The subjects of this study were 26 obese middle-aged women who were selected among participants in exercise class at K Region Health Promotion Center in South Korea and were randomly assigned to the exercise group (n=13; age 50.15 ± 3.82, % body fat 38.79 ± 3.28) and the control group (n=13; age 49.84 ± 2.96, % body fat 37.46 ± 2.51). Circuit exercise consisted of aerobic exercise and resistance exercise for 5 weeks and 50 minutes for 12 weeks. Before and after exercise we measured obesity index, leptin, ghrelin, fasting blood glucose, insulin, and insulin resistance in all subjects. A repeated-measured two-way of variance was performed for comparison of the treatment effects between the exercise and control groups. [Results] Body weight, BMI, and body fat percentage of obese index decreased significantly. Leptin of dietary regulation hormone was significantly decreased and ghrelin was significantly increased. Insulin and insulin resistance was significantly decreased. [Conclusion] Circuit exercise can be viewed as an effective exercise program to induce changes in appetite regulating hormones and to improve insulin resistance by mechanisms of energy homeostasis by weight loss.

Low molecular weight galactomannans-based standardized fenugreek seed extract ameliorates high-fat diet-induced obesity in miceviamodulation of FASn, IL-6, leptin, and TRIP-Br2

Background: Obesity is a complex, chronic metabolic disorder and its prevalence is increasing throughout most of the world. Low molecular weight galactomannans-based standardized fenugreek seed extract (LMWGAL-TF) has previously shown anti-diabetic and anti-hyperlipidemic potential. Aim: To evaluate the efficacy and mechanism of action of LMWGAL-TF in treating high fat diet (HFD)-induced obesity and hyperlipidemia in mice. Materials and methods: Male C57BL/6 mice were fed the HFD for 12 weeks and were co-administered with LMWGAL-TF (10, 30 and 100 mg kg⁻¹, p.o.). Variables measured were behavioral, biochemical, molecular and histopathological. In a separate in vitro experiment, copper-ascorbate (Cu-As)-induced mitochondrial oxidative damage was evaluated. Results: The HFD-induced increase (p < 0.001) in body weight, fat mass, lean mass, adipose tissue (brown, mesenteric, epididymal and retroperitoneal) and liver weight was significantly attenuated (p < 0.001) by LMWGAL-TF (30 and 100 mg kg⁻¹). The HFD-induced elevated levels of serum lipid, interleukins (ILs)-6 and leptin were significantly decreased (p < 0.001) by LMWGAL-TF (30 and 100 mg kg⁻¹). Elevated fatty acid synthase (FASn), IL-6, leptin and transcriptional regulator interacting with the PHD-bromodomain 2 (TRIP-Br2) mRNA expression in brown adipose tissue (BAT), liver, and epididymal fat were significantly down-regulated (p < 0.001) by LMWGAL-TF (30 and 100 mg kg⁻¹). Additionally, HFD-induced histological alterations in skeletal muscle, liver, white adipose tissue (WAT) and BAT were also reduced by LMWGAL-TF. Furthermore, the Cu-As-induced alteration in mitochondria oxidative stress (lipid peroxidation, protein carbonylation, glutathione, glutathione reductase, glutathione peroxidase, isocitrate dehydrogenase and α-ketoglutarate dehydrogenase) in skeletal muscle and BAT was significantly (p < 0.001) ameliorated by LMWGAL-TF (2, 4 and 6 mg mL⁻¹) treatment. It also reduced the Cu-As-induced mitochondrial swelling. Conclusion: LMWGAL-TF showed its beneficial effect in reducing HFD-induced obesity via down-regulation of FASn, IL-6, leptin, and TRIP-Br2 in mice.

Obesity is a complex, chronic metabolic disorder and its prevalence is increasing throughout most of the world.

L:A ratio, Insulin resistance and metabolic risk in women with polycystic ovarian syndrome

BACKGROUND AND AIMS

The plasma leptin-adiponectin ratio (L:A) has been suggested as a one of the potentially independent predictor of metabolic risk and Insulin resistance in women with polycystic ovarian syndrome (PCOS).

METHODS

This is a case-control study, total 439 female subjects, comprises in to two group 223 cases (PCOS) and 216 control (non-PCOS women) according to their clinical characteristics. Further both case and control group were sub-grouped in PCOS and non-PCOS with metabolic syndrome (wMetS) and without metabolic syndrome (woMetS) as per National Cholesterol Education Program Treatment Panel (NCEPATP) guidelines. Anthropometrical measurements and biochemical analysis were done. Leptin and adiponectin level were estimated by enzyme-linked immunosorbent assay.

RESULTS

Results indicated that SAD, WHR, BMI, BP, lipid profile, FPG, fasting plasma insulin, IR (HOMA-IR), leptin and L:A ratio were significantly higher (p=<0.001) in PCOS women compare to non PCOS. Furthermore anthropometrical values and level of FPG, TC, TG, Insulin, IR (HOMA-IR) and L:A ratio were significantly high (p=<0.001) in PCOS wMetS compare woMetS, however HDL (p=<0.001) and adiponectin level (p=<0.001) were significantly low. The same trend was also found in comparison between with and without MetS among non-PCOS women. The correlation between L:A Ratio with different metabolic risk markers, L:A ratio was positively significant with SAD (r=0.97, p <0.001), FPG (r=0.96, p<0.001), TC (r=0.44, p<0.001), insulin (r=0.98, p<0.001), IR (r=0.97, p<0.001), Adiponectin (r=0.21, p<0.01) and negatively significant with HDL(r=-0.42, p<0.001) in PCOS wMetS whereas L:A ratio was also positively correlated with SAD, BMI, TG in PCOS woMetS.

CONCLUSIONS

Study concluded L:A ratio may be one of the potential biomarker for metabolic syndrome and insulin resistance which is independent for presence of PCOS disease.