Activation of SOCS-3 by resistin

The influence of chronic periodontitis and type 2 diabetes mellitus on resistin levels of gingival crevicular fluid- a systematic review and meta-analysis

Aim

Chronic periodontitis (CP), a prevalent inflammatory dental disease, has been linked to systemic conditions like Type 2 Diabetes Mellitus (T2DM). This systematic review and meta-analysis aimed to evaluate resistin levels in the Gingival Crevicular Fluid (GCF) of CP individuals with T2DM. The objective was to determine if resistin could be a potential biomarker for periodontal disease in T2DM individuals.

Methods

The review included data from seventeen clinical studies that investigated resistin levels in GCF of individuals diagnosed with CP and T2DM. Data were sourced from PubMed, Scopus, and EBSCOhost, selected for their extensive coverage of medical and dental research, ensuring thorough retrieval of relevant studies. From the initial seventeen studies, five complied with the strict inclusion criteria for meta-analysis.

Results

Using a comprehensive meta-analysis, the significance of GCF Resistin levels in individuals with CP and T2DM relative to the healthy groups was examined. In addition, a meta-analysis was carried out to look into the relationship between periodontal probing depth (PPD) and CP and T2DM. The results indicated that individuals with T2DM and CP had significantly higher GCF resistin levels than the other groups. Furthermore, the PPD in T2DM with CP was significantly greater than in the other groups.

Conclusion

The present review highlights the potential role of resistin as a biomarker to diagnose individuals with chronic periodontitis and T2DM.

Clinical significance

The significantly elevated levels of resistin suggest that resistin could serve as a potential biomarker for T2DM in individuals with CP. This could lead to improved methods of early diagnosis and treatment, which could enhance individual outcomes and quality of life.

Prospero registration

The registration number CRD42023467186.

White adipose tissue in type 2 diabetes and the effect of antidiabetic drugs

White adipose tissue (WAT) is highly flexible and was previously considered a passive location for energy storage. Its endocrine function has been established for several years, earning it the title of an "endocrine organ" due to its ability to secrete many adipokines that regulate metabolism. WAT is one of the core tissues that influence insulin sensitivity. Its dysfunction enhances insulin resistance and type 2 diabetes (T2D) progression. However, T2D may cause WAT dysfunction, including changes in distribution, metabolism, adipocyte hypertrophy, inflammation, aging, and adipokines and free fatty acid levels, which may exacerbate insulin resistance. This review used PubMed to search WAT dysfunction in T2D and the effects of these changes on insulin resistance. Additionally, we described and discussed the effects of antidiabetic drugs, including insulin therapy, sulfonylureas, metformin, glucose-like peptide-1 receptor agonists, thiazolidinediones, and sodium-dependent glucose transporters-2 inhibitors, on WAT parameters under T2D conditions.

Deciphering endocrine function of adipose tissue and its significant influences in obesity-related diseases caused by its dysfunction

Current research has found that adipose tissue is not only involved in energy metabolism, but also a highly active endocrine organ that secretes various adipokines, including adiponectin, leptin, resistin and apelin, which are involved in the regulation of physiology and pathology of tissues and organs throughout the body. With the yearly increasing incidence, obesity has become a risk factor for a variety of pathological changes, including inflammation and metabolic syndrome in various system (endocrine, circulatory, locomotor and central nervous system). Thus these symptoms lead to multi-organ dysfunctions, including the heart, liver, kidneys, brain and joints. An in-depth summary of the roles of adipokines in the regulation of other tissues and organs can help to provide more effective therapeutic strategies for obesity-related diseases and explore potential therapeutic targets. Therefore, this review has retrospected the endocrine function of adipose tissue under obesity and the role of dysregulated adipokine secretion in related diseases and the underlying mechanisms, in order to provide a theoretical basis for targeting adipokine-mediated systemic dysregulation.

Changes in Cells Associated with Insulin Resistance

Insulin is a polypeptide hormone synthesized and secreted by pancreatic β-cells. It plays an important role as a metabolic hormone. Insulin influences the metabolism of glucose, regulating plasma glucose levels and stimulating glucose storage in organs such as the liver, muscles and adipose tissue. It is involved in fat metabolism, increasing the storage of triglycerides and decreasing lipolysis. Ketone body metabolism also depends on insulin action, as insulin reduces ketone body concentrations and influences protein metabolism. It increases nitrogen retention, facilitates the transport of amino acids into cells and increases the synthesis of proteins. Insulin also inhibits protein breakdown and is involved in cellular growth and proliferation. On the other hand, defects in the intracellular signaling pathways of insulin may cause several disturbances in human metabolism, resulting in several chronic diseases. Insulin resistance, also known as impaired insulin sensitivity, is due to the decreased reaction of insulin signaling for glucose levels, seen when glucose use in response to an adequate concentration of insulin is impaired. Insulin resistance may cause, for example, increased plasma insulin levels. That state, called hyperinsulinemia, impairs metabolic processes and is observed in patients with type 2 diabetes mellitus and obesity. Hyperinsulinemia may increase the risk of initiation, progression and metastasis of several cancers and may cause poor cancer outcomes. Insulin resistance is a health problem worldwide; therefore, mechanisms of insulin resistance, causes and types of insulin resistance and strategies against insulin resistance are described in this review. Attention is also paid to factors that are associated with the development of insulin resistance, the main and characteristic symptoms of particular syndromes, plus other aspects of severe insulin resistance. This review mainly focuses on the description and analysis of changes in cells due to insulin resistance.

The Role of Adipokines in the Control of Pituitary Functions

The pituitary gland is a key endocrine gland in all classes of vertebrates, including mammals. The pituitary gland is an important component of hypothalamus-pituitary-target organ hormonal regulatory axes and forms a functional link between the nervous system and the endocrine system. In response to hypothalamic stimuli, the pituitary gland secretes a number of hormones involved in the regulation of metabolism, stress reactions and environmental adaptation, growth and development, as well as reproductive processes and lactation. In turn, hormones secreted by target organs at the lowest levels of the hormonal regulatory axes regulate the functions of the pituitary gland in the process of hormonal feedback. The pituitary also responds to other peripheral signals, including adipose-tissue-derived factors. These substances are a broad group of peptides known as adipocytokines or adipokines that act as endocrine hormones mainly involved in energy homeostasis. Adipokines, including adiponectin, resistin, apelin, chemerin, visfatin, and irisin, are also expressed in the pituitary gland, and they influence the secretory functions of this gland. This review is an overview of the existing knowledge of the relationship between chosen adipose-derived factors and endocrine functions of the pituitary gland, with an emphasis on the pituitary control of reproductive processes.

Diabetes mellitus: Classification, mediators, and complications; A gate to identify potential targets for the development of new effective treatments

Nowadays, diabetes mellitus has emerged as a significant global public health concern with a remarkable increase in its prevalence. This review article focuses on the definition of diabetes mellitus and its classification into different types, including type 1 diabetes (idiopathic and fulminant), type 2 diabetes, gestational diabetes, hybrid forms, slowly evolving immune-mediated diabetes, ketosis-prone type 2 diabetes, and other special types. Diagnostic criteria for diabetes mellitus are also discussed. The role of inflammation in both type 1 and type 2 diabetes is explored, along with the mediators and potential anti-inflammatory treatments. Furthermore, the involvement of various organs in diabetes mellitus is highlighted, such as the role of adipose tissue and obesity, gut microbiota, and pancreatic β-cells. The manifestation of pancreatic Langerhans β-cell islet inflammation, oxidative stress, and impaired insulin production and secretion are addressed. Additionally, the impact of diabetes mellitus on liver cirrhosis, acute kidney injury, immune system complications, and other diabetic complications like retinopathy and neuropathy is examined. Therefore, further research is required to enhance diagnosis, prevent chronic complications, and identify potential therapeutic targets for the management of diabetes mellitus and its associated dysfunctions.

Adipokines and Bacterial Metabolites: A Pivotal Molecular Bridge Linking Obesity and Gut Microbiota Dysbiosis to Target

Adipokines are essential mediators produced by adipose tissue and exert multiple biological functions. In particular, adiponectin, leptin, resistin, IL-6, MCP-1 and PAI-1 play specific roles in the crosstalk between adipose tissue and other organs involved in metabolic, immune and vascular health. During obesity, adipokine imbalance occurs and leads to a low-grade pro-inflammatory status, promoting insulin resistance-related diabetes and its vascular complications. A causal link between obesity and gut microbiota dysbiosis has been demonstrated. The deregulation of gut bacteria communities characterizing this dysbiosis influences the synthesis of bacterial substances including lipopolysaccharides and specific metabolites, generated via the degradation of dietary components, such as short-chain fatty acids, trimethylamine metabolized into trimethylamine-oxide in the liver and indole derivatives. Emerging evidence suggests that these bacterial metabolites modulate signaling pathways involved in adipokine production and action. This review summarizes the current knowledge about the molecular links between gut bacteria-derived metabolites and adipokine imbalance in obesity, and emphasizes their roles in key pathological mechanisms related to oxidative stress, inflammation, insulin resistance and vascular disorder. Given this interaction between adipokines and bacterial metabolites, the review highlights their relevance (i) as complementary clinical biomarkers to better explore the metabolic, inflammatory and vascular complications during obesity and gut microbiota dysbiosis, and (ii) as targets for new antioxidant, anti-inflammatory and prebiotic triple action strategies.

Association of resistin (rs3138167) gene polymorphism with metabolic response after a hypocaloric Mediterranean diet

BACKGROUND

the single nucleotide polymorphism (SNP) (rs3138167) of resistin (RETN) gene is a polymorphism that has been associated with metabolic disorder in obese subjects and its effect on the metabolic response after a dietary intervention has not been evaluated.

OBJECTIVE

our aim was to analyze the effects of the rs3138167 RETN gene polymorphism on metabolic changes secondary to weight loss with a hypocaloric diet with a Mediterranean pattern.

METHOD

one thousand and eight Caucasian obese patients were evaluated. Before and after 12 weeks on a hypocaloric diet with Mediterranean pattern, an anthropometric evaluation and a biochemical analysis were performed. The statistical analysis was performed as a dominant model (CC vs CT + TT).

RESULTS

the values of insulin, HOMA-IR and resistin were higher in T allele carriers than non-T allele carriers in pre- and post-intervention time. In non-T allele carriers, resistin, insulin, HOMA-IR, triglycerides and C-reactive protein levels decreased. The improvement was statistically superior in non-T allele carriers; resistin (-1.2 ± 0.2 ng/dl; p = 0.02), triglycerides (-18.3 ± 4.3 mg/dl; p = 0.02), C-reactive protein (-2.6 ± 0.3 mg/dl; p = 0.02), insulin -4.4 ± 1.9 mUI/l; p = 0.02) and HOMA-IR (-2.1 ± 0.7; p = 0.03).

CONCLUSION

we report an association of rs3138167 with a worse metabolic response (insulin, HOMA-IR, triglyceride and C-reactive protein) in T allele carriers after weight loss with a hypocaloric diet with Mediterranean pattern.

Resistin stimulates PC-3 prostate cancer cell growth through stimulation of SOCS3 and SOCS5 genes

Resistin and suppressors of cytokine signaling (SOCSs) have been reported to regulate prostate cancer (PCa) cell proliferation and survival, respectively. Whether any of the SOCS molecules mediate the mitogenic effect of resistin on PCa cells is unknown. Using PC-3 human PCa cells, we found that resistin upregulates the expression of SOCS3 and SOCS5 mRNA, but not SOCS7 mRNA, in a dose- and time-dependent manner. The resistin-induced increases in SOCS3 and SOCS5 expression and cell proliferation were prevented by pretreatment with specific inhibitors of the TLR4, ERK, p38 MAPK, JNK, PI3K, and JAK2 proteins. However, pretreatment with a TLR2 inhibitor had no effect on resistin-mediated SOCS3 and SOCS5 expression. In addition, the effects of resistin on SOCS3, SOCS5, and SOCS7 mRNA levels were cell type-specific. Overexpression of either SOCS3 or SOCS5 enhanced further resistin-stimulated growth of PC-3 cells, whereas silencing SOCS3 or SOCS5 antagonized resistin-increased cell growth. Further PCa tissue analysis demonstrated higher levels of RETN, TLR4, SOCS3, and SOCS5 mRNAs in cancer tissues than benign prostate hyperplasia and indicated positive correlations among RETN, TLR4, and SOCS5. These data suggest that SOCS5, TLR4, and, to a lesser extent, SOCS3 can mediate the mitogenic effect of resistin on PC-3 PCa cells.

Insulin signaling and its application

The discovery of insulin in 1921 introduced a new branch of research into insulin activity and insulin resistance. Many discoveries in this field have been applied to diagnosing and treating diseases related to insulin resistance. In this mini-review, the authors attempt to synthesize the updated discoveries to unravel the related mechanisms and inform the development of novel applications. Firstly, we depict the insulin signaling pathway to explain the physiology of insulin action starting at the receptor sites of insulin and downstream the signaling of the insulin signaling pathway. Based on this, the next part will analyze the mechanisms of insulin resistance with two major provenances: the defects caused by receptors and the defects due to extra-receptor causes, but in this study, we focus on post-receptor causes. Finally, we discuss the recent applications including the diseases related to insulin resistance (obesity, cardiovascular disease, Alzheimer's disease, and cancer) and the potential treatment of those based on insulin resistance mechanisms.

Relationship of resistin gene polymorphism (rs7139228) with resistin levels and metabolic syndrome risk in obese subjects

Introduction

Background: despite the relationship of resistin with metabolic syndrome (MS), the relationship of the 5'UTR intron C/T variant SNP rs7139228 of the RETN gene with the presence of MS has not been evaluated. Objective: the objective of this study is to evaluate the influence of SNP rs7139228 of the RETN gene on circulating resistin levels, as well as on MS in obese subjects. Material and Methods: a Caucasian population of 1003 obese subjects was enrolled. An anthropometric evaluation (weight, waist circumference, fat mass), evaluation of nutritional intake, biochemical study (glucose, insulin, C-reactive protein, lipid profile, insulin, HOMA-IR, resistin) and rs7139228 genotype was carried out. Results: genotype distribution was: 852 subjects with GG (84.9 %), 147 subjects with GA (14.7 %) and 4 subjects with AA (0.4 %). The allelic frequency was G (0.92) and A (0.08). Serum levels of resistin (delta: 1.7 ± 0.2 ng/ml; p = 0.01), insulin (delta: 4.2 ± 0.4 IU/L; p = 0.01) and HOMA-IR (delta: 1.9 ± 0.2 units; p = 0.03) were higher in patients carrying the A allele than in non-carriers. The overall prevalence of MS was 48.1 %. A logistic regression analysis showed a high percentage of hyperglycemia (OR = 1.60, 95 % CI = 1.08-2.96; p = 0.02) and metabolic syndrome (OR = 1.33, 95 % CI = 1.07-3.39, p = 0.02) in carriers of the A allele after adjusting for resistin levels, sex, BMI and age. Conclusions: the A allele of the genetic variant rs7139228 is associated with higher levels of resistin, basal insulin, insulin resistance, and prevalence of metabolic syndrome in obese subjects.

Resistin/uric acid index as a marker of metabolic syndrome in females with obesity

BACKGROUND

The resistin/uric index has been considered a prognostic factor for identifying young people with obesity. Obesity and Metabolic Syndrome (MS) are an important health problem in females.

AIMS

The objective of this work was to evaluate the relationship of resistin/acid uric index with Metabolic Syndrome on Caucasian females with obesity.

METHODS

We conducted a cross sectional study in 571 females with obesity. Measurements of anthropometric parameters, blood pressure, fasting blood glucose, insulin concentration, insulin resistance (HOMA-IR), lipid profile, C reactive protein, uric acid, resistin and prevalence of Metabolic Syndrome were determined. The resistin/uric acid index was calculated.

RESULTS

In total, 249 subjects had MS (43.6%). We detected higher levels in the following parameters (Delta; p values); waist circumference (3.1 ± 0.5 cm; p = 0.04), systolic blood pressure (5.3 ± 3.6 mmHg; p = 0.01), diastolic blood pressure (2.3 ± 0.4 mmHg; p = 0.02), glucose levels (7.5 ± 0.9 mg/dL; p = 0.01), insulin levels (2.5 ± 0.3 UI/L; p = 0.02), HOMA-IR (0.7 ± 0.2 units; p = 0.03), uric acid levels (0.9 ± 0.2 mg/dl; p = 0.01), resistin levels (4.1 ± 0.4 ng/dl; p = 0.01) and resistin/uric acid index (0.61 ± 0.01 mg/dl; p = 0.02) in subjects of the high resistin/uric acid index group than low index group. Logistic regression analysis reported a high percentage of hyperglycemia (OR = 1.77, 95% CI = 1.10-2.92; p = 0.02), hypertension (OR = 1.91, 95% CI = 1.36-3.01; p = 0.01), central obesity (OR = 1.48, 95% CI = 1.15-1.84; p = 0.03) and metabolic syndrome percentage (OR = 1.71, 95% CI = 1.22-2.69; p = 0.02) in high resistin/uric acid index group.

CONCLUSIONS

Resistin/uric acid index is related with Metabolic syndrome (MS) risk and criteria of it in a population of Caucasian females with obesity and this index is a correlated with glucose levels, insulin levels and insulin resistance (HOMA-IR).

Role of resistin (rs7139228) gene polymorphism with metabolic response after a hypocaloric mediterranean diet

BACKGROUND

The SNP (rs7139228) of the RETN gene is a polymorphism that has been associated with metabolic disorder in subjects with obesity, and its effect on metabolic response after dietary intervention has not been evaluated.

OBJECTIVE

Our objective was to analyse the effects of the polymorphism of the RETN gene rs7139228 on metabolic changes secondary to weight loss with a hypocaloric Mediterranean diet.

DESIGN

1000 obese Caucasian patients were evaluated. An anthropometric evaluation and a biochemical analysis were performed before and after 12 weeks of a hypocaloric Mediterranean diet. The statistical analysis was performed as a dominant model (GG vs GA+AA).

RESULTS

Improvements in anthropometric parameters, leptin levels and systolic blood pressure were similar in both genotype groups. In non- A allele carriers, levels of resistin, insulin, HOMA-IR, triglycerides and C-reactive protein decreased. The improvements were statistically significant in this group; resistin (-1.3+0.1ng/dL: p=0.02), triglycerides (-22.9+4.9mg/dl: p=0.02), CRP (-2.7+0 0.4mg/dl: p=0.02), insulin -6.5+1.8 mIU/L: p=0.02) and HOMA-IR (-2.2+0.8: p=0, 03). In addition, insulin, HOMA-IR and resistin levels were higher in A allele carriers than in non-carriers. Finally, the prevalence of metabolic syndrome and hyperglycaemia were higher in A allele carriers, and these percentages only decreased after intervention in non-A allele carriers.

CONCLUSION

The A rs7139228 allele is associated with a worse metabolic response (insulin, HOMA-IR, triglycerides and CRP) after weight loss with a hypocaloric Mediterranean diet. A non-significant decrease in the prevalence of metabolic syndrome and hyperglycaemia were detected in A allele carriers.

Alterations of SOCS1 and SOCS3 transcript levels, but not promoter methylation levels in subcutaneous adipose tissues in obese women

BACKGROUND

Animal model studies suggest that change in the members of the suppressor of the cytokine signaling (SOCS) family (mainly SOCS1 and SOCS3) is linked to the pathogenesis of obesity-related metabolic disorders. Moreover, epigenetic modification is involved in the transcriptional regulation of the SOCS gene family. Here, we aimed to evaluate the mRNA expression as well as gene promoter methylation of SOCS1 and SOCS3 in subcutaneous adipose tissue (SAT) from obese women compared to normal-weight subjects. We also intend to identify the possible association of SOCS1 and SOCS3 transcript levels with metabolic parameters in the context of obesity.

METHODS

This study was conducted on women with obesity (n = 24) [body mass index (BMI) ≥ 30 kg/m ²] and women with normal-weight (n = 22) (BMI < 25 kg/m ²). Transcript levels of SOCS1 and SOCS3 were evaluated by real-time PCR in SAT from all participants. After bisulfite treatment of DNA, methylation-specific PCR was used to assess the putative methylation of 10 CpG sites in the promoter of SOCS1 and 13 CpG sites in SOCS3 in SAT from women with obesity and normal weight.

RESULTS

It was found that unlike SOCS3, which disclosed an elevating expression pattern, the expression level of SOCS1 was lower in the women with obesity as compared with their non-obese counterparts (P-value = 0.03 for SOCS1 transcript level and P-value = 0.011 for SOCS3 transcript level). As for the analysis of promoter methylation, it was found that SOCS1 and SOCS3 methylation were not significantly different between the individuals with obesity and normal weight (P-value = 0.45 and P-value = 0.89). Correlation analysis indicated that the transcript level of SOCS1 mRNA expression had an inverse correlation with BMI, hs-CRP levels, HOMA-IR, and insulin levels. However, the SOCS3 transcript level showed a positive correlation with BMI, waist-to-height ratio, waist circumference, hip circumference, hs-CRP, HOMA-IR, insulin, fasting blood glucose, and total cholesterol. Interestingly, HOMA-IR is the predictor of the transcript level of SOCS1 (β =  - 0.448, P-value = 0.003) and SOCS3 (β = 0.465, P-value = 0.002) in SAT of all participants.

CONCLUSIONS

Our findings point to alterations of SOCS1 and SOCS3 transcript levels, but not promoter methylation levels in subcutaneous adipose tissues from women with obesity. Moreover, mRNA expression of SOCS1 and SOCS3 in SAT was associated with known obesity indices, insulin resistance, and hs-CRP, suggesting the contribution of SOCS1 and SOCS3 in the pathogenesis of obesity-related metabolic abnormalities. However, further studies are required to establish this concept.

Adipokines from white adipose tissue in regulation of whole body energy homeostasis

Diseases originating from altered energy homeostasis including obesity, and type 2 diabetes are rapidly increasing worldwide. Research in the last few decades on animal models and humans demonstrates that the white adipose tissue (WAT) is critical for energy balance and more than just an energy storage site. WAT orchestrates the whole-body metabolism through inter-organ crosstalk primarily mediated by cytokines named "Adipokines". The adipokines influence metabolism and fuel selection of the skeletal muscle and liver thereby fine-tuning the load on WAT itself in physiological conditions like starvation, exercise and cold. In addition, adipokine secretion is influenced by various pathological conditions like obesity, inflammation and diabetes. In this review, we have surveyed the current state of knowledge on important adipokines and their significance in regulating energy balance and metabolic diseases. Furthermore, we have summarized the interplay of pro-inflammatory and anti-inflammatory adipokines in the modulation of pathological conditions.

Increased growth hormone secretagogue receptor-1a (GHSR-1a) in hypothalamus during olanzapine treatment in rats

Weight gain is the one of the most important factors which increases global burden of psychiatric disorder. Second-generation antipsychotics, olanzapine (Olz) and valproic acid (Vpa) in particular, are held responsible for weight gain. However, it is still uncertain how these drugs cause this. Thus, the rats selected for the experiment were randomly divided into 3 groups. The 1st group received only 0.5 ml saline solution intraperitoneally (n = 20, control group); the second group was given 200 mg / kg Vpa intraperitoneally (n = 20, Vpa group) and 2 mg / kg Olz was given intraperitoneally to the 3rd group (n = 20, Olz group) between 8 and 10 am for 30 days. We examined serum leptin, adiponectin, resistin, TNF-α, IL-6, ghrelin level and, the amount of ghrelin secreting cells in the stomach and growth hormone secretagogue receptor-1a (GHSR-1a, ghrelin receptor) expression in the hypothalamus. The hypothalamic GHS-1a receptor index was significantly higher in the Olz group compared with the control group and Vpa group (p = 0.036 and p = 0.016 respectively). Ghrelin immune positive cell index in stomach was statistically significantly lower in the Vpa group compared with the control and Olz groups (p = 0.028 and p = 0.013 respectively) There was no difference between the groups in terms of serum leptin, resistin, IL-6 and ghrelin levels. In the Vpa group, a statistically significant increase was found in serum adiponectin level compared with both the control group and the Olz group (p = 0009 and p = 0024 respectively) and, significant decrease was found in serum TNF-α level compared to Olz group (p = 0007). In conclusion, we found that the main cause of weight gain in Olz use was the increase in the number of hypothalamic ghrelin receptors. Investigating the mechanism by which Olz increases the number of ghrelin receptors may help to develop effective treatment strategies in preventing obesity in psychiatric patients.

Adipokines in Non-Alcoholic Fatty Liver Disease: Are We on the Road toward New Biomarkers and Therapeutic Targets?

Simple Summary

Non-alcoholic fatty liver disease (NAFLD) is an unmet medical need due to its increasingly high incidence, severe clinical consequences, and the absence of feasible diagnostic tools and effective drugs. This review summarizes the preclinical and clinical data on adipokines, cytokine-like hormones secreted by adipose tissue, and NAFLD. The aim is to establish the potential of adipokines as diagnostic and prognostic biomarkers, as well as their potential as therapeutic targets for NAFLD. The limitations of current research are also discussed, and future perspectives are outlined.

Abstract

Non-alcoholic fatty liver disease (NAFLD) has become the major cause of chronic hepatic illness and the leading indication for liver transplantation in the future decades. NAFLD is also commonly associated with other high-incident non-communicable diseases, such as cardiovascular complications, type 2 diabetes, and chronic kidney disease. Aggravating the socio-economic impact of this complex pathology, routinely feasible diagnostic methodologies and effective drugs for NAFLD management are unavailable. The pathophysiology of NAFLD, recently defined as metabolic associated fatty liver disease (MAFLD), is correlated with abnormal adipose tissue–liver axis communication because obesity-associated white adipose tissue (WAT) inflammation and metabolic dysfunction prompt hepatic insulin resistance (IR), lipid accumulation (steatosis), non-alcoholic steatohepatitis (NASH), and fibrosis. Accumulating evidence links adipokines, cytokine-like hormones secreted by adipose tissue that have immunometabolic activity, with NAFLD pathogenesis and progression; however, much uncertainty still exists. Here, the current knowledge on the roles of leptin, adiponectin, ghrelin, resistin, retinol-binding protein 4 (RBP4), visfatin, chemerin, and adipocyte fatty-acid-binding protein (AFABP) in NAFLD, taken from preclinical to clinical studies, is overviewed. The effect of therapeutic interventions on adipokines’ circulating levels are also covered. Finally, future directions to address the potential of adipokines as therapeutic targets and disease biomarkers for NAFLD are discussed.

Quercetin for managing type 2 diabetes and its complications, an insight into multitarget therapy

BACKGROUND

Quercetin, a bioflavonoid abundant in grapefruit, onion, berries, etc., has vast therapeutic potential, especially against Type 2 diabetes and its complications. Quercetin showed similar effects as that of metformin, (widely prescribed antidiabetic drug) in cell lines models (Sajan et al., 2010; Dhanya et al., 2017). In vivo findings also showcase it as a promising agent against diabetes and its pathophysiological complications.

SCOPE AND APPROACH

Quercetin can be produced on a large scale through a novel fermentation-based glycosylation strategy from cheap substrates and can be utilized as a dietary supplement. The review focuses on the mounting evidence pointing to Quercetin as a promising candidate for managing type 2 diabetes and its oxidative stress mediated pathophysiological complications.

CONCLUSION

Quercetin acts on multiple targets of diabetes and regulates key signalling pathways which improve the symptoms as well as the complications of Type 2 diabetes. However further studies are needed to improve the bioavailability and to establish a dosing regimen for Quercetin.

The Impact of Dysmetabolic Sarcopenia Among Insulin Sensitive Tissues: A Narrative Review

Sarcopenia is a common muscular affection among elderly individuals. More recently, it has been recognized as the skeletal muscle (SM) expression of the metabolic syndrome. The prevalence of sarcopenia is increasing along with visceral obesity, to which it is tightly associated. Nonetheless, it is a still underreported entity by clinicians, despite the worsening in disease burden and reduced patient quality of life. Recognition of sarcopenia is clinically challenging, and variability in study populations and diagnostic methods across the clinical studies makes it hard to reach a strong evidence. Impaired insulin activity in SM is responsible for the altered molecular pathways and clinical manifestations of sarcopenia, which is morphologically expressed by myosteatosis. Lipotoxicity, oxidative stress and adipose tissue-derived inflammation lead to both alterations in glucose disposal and protein synthesis in SM, with raising insulin resistance (IR) and SM atrophy. In particular, hyperleptinemia and leptin resistance interfere directly with SM activity, but also with the release of Growth Hormone from the hypohysis, leading to a lack in its anabolic effect on SM. Moreover, sarcopenia is independently associated to liver fibrosis in Non-Alcoholic Fatty Liver Disease (NAFLD), which in turn worsens SM functionality through the secretion of proinflammatory heptokines. The cross-talk between the liver and SM in the IR setting is of crucial relevance, given the high prevalence of NAFLD and the reciprocal impact of insulin-sensitive tissues on the overall disease burden. Along with the efforts of non-invasive diagnostic approaches, irisin and myostatin are two myokines currently evaluated as potential biomarkers for diagnosis and prognostication. Decreased irisin levels seem to be potentially associated to sarcopenia, whereas increased myostatin has shown to negatively impact on sarcopenia in pre-clinical studies. Gene variants in irisin have been explored with regard to the impact on the liver disease phenotype, with conflicting results. The gut-muscle axis has gain relevance with the evidence that insulin resistance-derived gut dysbiosis is responsible for increased endotoxemia and reduction in short-chain free fatty acids, directly affecting and predisposing to sarcopenia. Based on the current evidence, more efforts are needed to increase awareness and improve the management of sarcopenic patients.

Resistin Expression in Epithelial Ovarian Cancer promotes the Proliferation and Migration of Ovarian Cancer Cells to Worsen Prognosis

Background: Epithelial ovarian cancer (EOC) is the most common gynecological cancer in women. Resistin, an inflammatory adipocytokine, is associated with obesity, insulin resistance, and various cancer types.

Materials and Methods: We investigated resistin expression in tissues and its association with the clinicopathological characteristics and prognosis of patients with EOC. The SKOV3 and CAOV3 cell lines were treated with exogenous resistin and rapamycin (resistin inhibitor), and the expression of mTOR in SKOV3 and CAOV3 cells was measured. Cell proliferation was measured using the CCK-8 assay. Western blotting analysis was performed to examine the phosphorylation of P70S6K and mTOR. Wound healing and Transwell analyses were conducted to examine the effect of resistin on the migration of SKOV3 and CAOV3 cells.

Results: High resistin expression was positively correlated with the pathological grade (P = 0.017) and lymph node metastasis (P = 0.045). However, resistin expression was not correlated with age, FIGO stage, or residual tumor after initial laparotomy (P > 0.05). Cox multivariate analysis showed that resistin expression was an independent factor for determining disease-free survival, whereas lymph node metastasis, resistin expression, and age (≥55 years) were independent factors affecting overall survival. Exogenous resistin induced ovarian cancer cell proliferation, whereas rapamycin had the opposite effect. Resistin promoted the proliferation of ovarian cancer cells via the mTOR signaling pathway and was associated with phosphorylating P70S6K. Furthermore, resistin promoted the migration of ovarian cancer cells.

Conclusions: Resistin may promote the occurrence of ovarian cancer and is related to the prognosis of patients. This protein may also affect the proliferation of EOC cells through the mTOR signaling pathway. Therefore, resistin shows potential as a molecular therapeutic target in ovarian cancer.

Salivary resistin level and its association with insulin resistance in obese individuals

The escalating global burden of type 2 diabetes mellitus necessitates the implementation of strategies that are both more reliable and faster in order to improve the early identification of insulin resistance (IR) in high-risk groups, including overweight and obese individuals. The use of salivary biomarkers offers a promising alternative to serum collection because it is safer, more comfortable, and less painful to obtain saliva samples. As obesity is the foremost contributory factor in IR development, the adipocytokines such as leptin, adiponectin, resistin, and visfatin secreted from the adipose tissue have been studied as potential reliable biomarkers for IR. Measurement of salivary adipokines as predictors for IR has attracted widespread attention because of the strong correlation between their blood and salivary concentrations. One of the adipokines that is closely related to IR is resistin. However, there are conflicting findings on resistin's potential role as an etiological link between obesity and IR and the reliability of measuring salivary resistin as a biomarker for IR. Hence this study reviewed the available evidence on the potential use of salivary resistin as a biomarker for IR in order to attempt to gain a better understanding of the role of resistin in the development of IR in obese individuals.

Age and Sex: Impact on adipose tissue metabolism and inflammation

Age associated chronic inflammation is a major contributor to diseases with advancing age. Adipose tissue function is at the nexus of processes contributing to age-related metabolic disease and mediating longevity. Hormonal fluctuations in aging potentially regulate age-associated visceral adiposity and metabolic dysfunction. Visceral adiposity in aging is linked to aberrant adipogenesis, insulin resistance, lipotoxicity and altered adipokine secretion. Age-related inflammatory phenomena depict sex differences in macrophage polarization, changes in T and B cell numbers, and types of dendritic cells. Sex differences are also observed in adipose tissue remodeling and cellular senescence suggesting a role for sex steroid hormones in the regulation of the adipose tissue microenvironment. It is crucial to investigate sex differences in aging clinical outcomes to identify and better understand physiology in at-risk individuals. Early interventions aimed at targets involved in adipose tissue adipogenesis, remodeling and inflammation in aging could facilitate a profound impact on health span and overcome age-related functional decline.

The Inflammatory Profile of Obesity and the Role on Pulmonary Bacterial and Viral Infections

Obesity is a globally increasing health problem, entailing diverse comorbidities such as infectious diseases. An obese weight status has marked effects on lung function that can be attributed to mechanical dysfunctions. Moreover, the alterations of adipocyte-derived signal mediators strongly influence the regulation of inflammation, resulting in chronic low-grade inflammation. Our review summarizes the known effects regarding pulmonary bacterial and viral infections. For this, we discuss model systems that allow mechanistic investigation of the interplay between obesity and lung infections. Overall, obesity gives rise to a higher susceptibility to infectious pathogens, but the pathogenetic process is not clearly defined. Whereas, viral infections often show a more severe course in obese patients, the same patients seem to have a survival benefit during bacterial infections. In particular, we summarize the main mechanical impairments in the pulmonary tract caused by obesity. Moreover, we outline the main secretory changes within the expanded adipose tissue mass, resulting in chronic low-grade inflammation. Finally, we connect these altered host factors to the influence of obesity on the development of lung infection by summarizing observations from clinical and experimental data.

The complex role of adipokines in obesity, inflammation, and autoimmunity

The global obesity epidemic is a major contributor to chronic disease and disability in the world today. Since the discovery of leptin in 1994, a multitude of studies have characterized the pathological changes that occur within adipose tissue in the obese state. One significant change is the dysregulation of adipokine production. Adipokines are an indispensable link between metabolism and optimal immune system function; however, their dysregulation in obesity contributes to chronic low-grade inflammation and disease pathology. Herein, I will highlight current knowledge on adipokine structure and physiological function, and focus on the known roles of these factors in the modulation of the immune response. I will also discuss adipokines in rheumatic and autoimmune diseases.

Association of Adipose Tissue and Adipokines with Development of Obesity-Induced Liver Cancer

Obesity is rapidly dispersing all around the world and is closely associated with a high risk of metabolic diseases such as insulin resistance, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD), leading to carcinogenesis, especially hepatocellular carcinoma (HCC). It results from an imbalance between food intake and energy expenditure, leading to an excessive accumulation of adipose tissue (AT). Adipocytes play a substantial role in the tumor microenvironment through the secretion of several adipokines, affecting cancer progression, metastasis, and chemoresistance via diverse signaling pathways. AT is considered an endocrine organ owing to its ability to secrete adipokines, such as leptin, adiponectin, resistin, and a plethora of inflammatory cytokines, which modulate insulin sensitivity and trigger chronic low-grade inflammation in different organs. Even though the precise mechanisms are still unfolding, it is now established that the dysregulated secretion of adipokines by AT contributes to the development of obesity-related metabolic disorders. This review focuses on several obesity-associated adipokines and their impact on obesity-related metabolic diseases, subsequent metabolic complications, and progression to HCC, as well as their role as potential therapeutic targets. The field is rapidly developing, and further research is still required to fully understand the underlying mechanisms for the metabolic actions of adipokines and their role in obesity-associated HCC.

Factors Affecting Metabolic Outcomes Post Bariatric Surgery: Role of Adipose Tissue

Obesity is an ever-growing public health crisis, and bariatric surgery (BS) has become a valuable tool in ameliorating obesity, along with comorbid conditions such as diabetes, dyslipidemia and hypertension. BS techniques have come a long way, leading to impressive improvements in the health of the majority of patients. Unfortunately, not every patient responds optimally to BS and there is no method that is sufficient to pre-operatively predict who will receive maximum benefit from this surgical intervention. This review focuses on the adipose tissue characteristics and related parameters that may affect outcomes, as well as the potential influences of insulin resistance, BMI, age, psychologic and genetic factors. Understanding the role of these factors may help predict who will benefit the most from BS.

Prominent and emerging anti-diabetic molecular targets

Diabetes is on the rise across the globe affecting more than 463 million people and crucially increasing morbidities of diabetes-associated diseases. Urgent and immense actions are needed to improve diabetes prevention and treatment. Regarding the correlation of diabetes with many associated diseases, inhibition of the disease progression is more crucial than controlling symptoms. Currently, anti-diabetic drugs are accompanied by undesirable side-effects and target confined types of biomolecules. Thus, extensive research is demanding to identify novel disease mechanisms and molecular targets as probable candidates for effective treatment of diabetes. This review discusses the conventional molecule targets that have been applied for their therapeutic rationale in treatment of diabetes. Further, the emerging and prospective molecular targets for the future focus of library screenings are presented.

Adipose tissue in health and disease

Adipose, or fat, tissue (AT) was once considered an inert tissue that primarily existed to store lipids, and was not historically recognized as an important organ in the regulation and maintenance of health. With the rise of obesity and more rigorous research, AT is now recognized as a highly complex metabolic organ involved in a host of important physiological functions, including glucose homeostasis and a multitude of endocrine capabilities. AT dysfunction has been implicated in several disease states, most notably obesity, metabolic syndrome and type 2 diabetes. The study of AT has provided useful insight in developing strategies to combat these highly prevalent metabolic diseases. This review highlights the major functions of adipose tissue and the consequences that can occur when disruption of these functions leads to systemic metabolic dysfunction.

Potential Benefits of Acupuncture and Herbs for Obesity-Related Chronic Inflammation by Adipokines

The adipose tissue is an organ that stores energy in the form of fats. It also has been known as an endocrine playing an integral role in metabolic homeostasis by secreting various adipokines. In obesity, the adipokine components and secretion patterns are altered toward proinflammation with weight gain, causing low chronic inflammation, which is closely linked to various metabolic diseases. Acupuncture and herbs are used for the management of obesity and its comorbidities, and it has been observed that these therapies affect the amount of expression and concentration of adipokines with improved metabolic phenotypes in both animal and human metabolic diseases. In this review, we discuss the role of adipokines and summarize beneficial effects of the treatments such as electroacupuncture, pharmacopuncture, catgut embedding acupuncture, and single and multiple medicinal herbs on obesity and its relations to adipokine composition. It will provide a new insight for applying adipokines as surrogate markers in complementary and alternative medicine practice.

Roles of leptin and resistin in metabolism, reproduction, and leptin resistance

Increased adipose mass can cause insulin resistance and type 2 diabetes mellitus. This phenomenon is related to adipocyte-secreted signaling molecules that affect glucose balance, such as fatty acids, adiponectin, leptin, interleukin-6, tumor necrosis factor-α, and resistin. Among these hormones, leptin and resistin play important roles in regulating weight and glucose metabolism. Leptin and resistin work in both similar and opposite ways, and they interact with each other. Circulating concentrations of leptin and resistin are elevated in models of obesity and rodents fed a high-fat diet. In addition, leptin and resistin are similarly regulated by nutritional status: they are reduced by fasting and increased by feeding. This effect is mediated partially through insulin receptors and glucose transporters. Our latest data provided the first indication that in sheep, intravenous infusion of resistin increases the mean circulating concentrations of leptin and decreases luteinizing hormone in a dose-dependent manner during both the long-day (LD) and short-day seasons. Furthermore, exogenous resistin increased suppressor of cytokine signaling (SOCS)-3 mRNA expression only during the LD season, when the leptin resistance/insensitivity phenomenon was observed in the arcuate nucleus, preoptic area, and anterior pituitary. We concluded that one factor contributing to central leptin resistance is autosuppression, via which leptin and resistin stimulate the expression of SOCS-3, which inhibits leptin signaling. The increased expression of SOCS-3 in response to leptin and resistin may be a pivotal cause of leptin resistance/insensitivity, a pathological situation in obese individuals and a physiological occurrence in sheep during the LD season.

Effect of weight loss induced by laparoscopic sleeve gastrectomy on liver histology and serum adipokine levels

BACKGROUND & AIM

Bariatric surgery is a valid treatment option for persons with non-alcoholic fatty liver disease. This study prospectively examined the impact of laparoscopic sleeve gastrectomy (LSG) on liver histopathology, and blood levels of adiponectin, leptin, resistin, and pre-B cell enhancing factor/Nampt/visfatin.

PATIENTS & METHODS

In 81 patients with non-alcoholic fatty liver disease who underwent LSG, paired liver biopsies and blood specimens were obtained before and 18 months after LSG. Differences between preoperative and 18 months postoperative data were tested by paired Student's t-test or Wilcoxon rank test as appropriate.

RESULTS

At follow up, there was a significant improvement in biochemical markers for glucose homeostasis, including fasting glucose, HbA1c, insulin levels, and homeostatic model assessment index. Postoperative liver function tests, namely serum alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transpeptidase level, showed a significant improvement compared to before weight loss. The number of patients who had definite, borderline, or no non-alcoholic steatohepatitis was 43 (53%), 27 (33%), and 11 (14%), respectively, at baseline, and 9 (11%), 32 (40%), and 40 (49%) at 18-month post-surgery follow up. A significant reduction in steatosis, liver fibrosis, lobular inflammation, and hepatocyte ballooning was observed in the postoperative biopsies (P < 0.001 each). In addition, at the follow-up assessment, there was a significant increase in serum adiponectin levels and significant decline in serum levels of leptin, resisitin, and pre-B cell enhancing factor/Nampt/visfatin.

CONCLUSION

Weight loss after sleeve gastrectomy was associated with a significant improvement in several metabolic parameters, liver enzyme levels, liver histopathology, and changes in serum adipokine levels towards antidiabetic and anti-inflammatory profiles.

Associations of iron status with apolipoproteins and lipid ratios: a cross-sectional study from the China Health and Nutrition Survey

Background

Iron overload has been found to be related with various cardiometabolic disorders, like dyslipidemia, metabolic syndrome, and diabetes. The disturbance of the iron status and lipid metabolism can contribute to organ damage such as atherosclerotic plaque growth and instability. An assessment on the associations of iron status with apolipoproteins and lipid ratios would be informative for maintenance of metabolic homeostasis and hinderance of disease progression. Hence, this study aims to establish the relationships of iron status with apolipoproteins and lipid ratios.

Methods

A cross-sectional study of 7540 adult participants from the China Health and Nutrition Survey 2009 was conducted. Logistic regression analyses were used to investigate the relationships between indicators of iron status and the prevalence of unfavorable apolipoprotein profiles. Multivariate linear regression models were constructed to assess the dose-response correlations between serum ferritin and lipid parameters.

Results

After adjustment for confounding factors, in both sexes, the subjects in the top quartile of ferritin had the highest prevalence of an elevated apolipoprotein B (men: odds ratio (OR) 1.97, 95% confidence interval (CI) 1.50–2.62; women: OR 2.13, 95% CI 1.53–2.97) and an elevated apolipoprotein B/apolipoprotein A1 ratio (men: OR 2.00, 95% CI 1.50–2.66; women: OR 1.41, 95% CI 1.04–1.92) when compared with individuals in the lowest quartile. Hemoglobin were also independently associated with unfavorable apolipoprotein B and apolipoprotein B/apolipoprotein A1 ratio both in men and women. However, transferrin (men: OR 0.74, 95% CI 0.56–0.99; women: OR 0.73, 95% CI 0.56–0.95) and soluble transferrin receptor (men: OR 0.75, 95% CI 0.57–0.99; women: OR 0.71, 95% CI 0.55–0.91) were found to be negatively associated with a decreased apolipoprotein A1. Moreover, after controlling for potential confounders, the ferritin concentrations were significantly associated with the levels of lipid ratios including TG/HDL-C, non-HDL-C/HDL-C, TC/HDL-C, apoB/apoA1, and LDL-C/HDL-C ratio in men (β coefficient = 0.147, 0.061, 0.043, 0.038, 0.032, respectively, all P values < 0.001) and in women (β coefficient = 0.074, 0.034, 0.025, 0.020, 0.018, respectively, all P values < 0.05).

Conclusions

The indicators of iron status are significantly associated with unfavorable apolipoprotein profiles. Serum ferritin concentrations are positively correlated with the levels of lipid ratios. The management on the modifiable iron status and lipid metabolism has a clinical significance. The atherosclerotic lipid profiles of the patients with iron overload deserve special clinical concerns.

Altered adipose tissue and adipocyte function in the pathogenesis of metabolic syndrome

Over the past decade, great progress has been made in understanding the complexity of adipose tissue biology and its role in metabolism. This includes new insights into the multiple layers of adipose tissue heterogeneity, not only differences between white and brown adipocytes, but also differences in white adipose tissue at the depot level and even heterogeneity of white adipocytes within a single depot. These inter- and intra-depot differences in adipocytes are developmentally programmed and contribute to the wide range of effects observed in disorders with fat excess (overweight/obesity) or fat loss (lipodystrophy). Recent studies also highlight the underappreciated dynamic nature of adipose tissue, including potential to undergo rapid turnover and dedifferentiation and as a source of stem cells. Finally, we explore the rapidly expanding field of adipose tissue as an endocrine organ, and how adipose tissue communicates with other tissues to regulate systemic metabolism both centrally and peripherally through secretion of adipocyte-derived peptide hormones, inflammatory mediators, signaling lipids, and miRNAs packaged in exosomes. Together these attributes and complexities create a robust, multidimensional signaling network that is central to metabolic homeostasis.

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

BACKGROUND AND AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

CHINESE CLINICAL TRIAL REGISTRATION

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

Circulating Resistin Is Associated with Plasma Glucagon-Like Peptide-1 in Cirrhotic Patients with Hepatitis C Virus Genotype-4 Infection

Purpose: Limited and contradictory data on the circulating levels of glucagon-like peptide (GLP-1) and resistin in hepatitis C virus genotype-4 (HCV-4) cirrhotic patients are present. Thus, this study aimed to evaluate their concentrations and to investigate the association between total GLP-1, resistin, and insulin resistance in those patients.Materials and Methods: Non-diabetic HCV-4 cirrhotic patients (n = 80; 40 with Child-Pugh A, 20 with Child-Pugh B, and 20 with Child-Pugh C), and 25 healthy subjects were enrolled in this study. The basal circulating levels of total GLP-1 and resistin along with serum insulin, glucose, total cholesterol, and triglycerides were measured.Results: Plasma GLP-1 and serum resistin levels were significantly higher in cirrhotic patients than controls (P < . 001). Moreover, circulating GLP-1 and resistin levels increased in a stepwise fashion in line with increasing grade of liver damage. According to Spearman's rank correlation, both GLP-1 and resisitin correlated positively with each other, insulin, homeostatic model assessment of insulin resistance, alanine aminotransferase (ALT), total bilirubin, and international normalized ratio while they correlated negatively with albumin (P < .001). Multiple stepwise regression analysis showed that ALT, serum resistin and Child-Pugh score independently influenced the GLP-1 levels in cirrhotic patients.Conclusions: Circulating levels of GLP-1 and resistin were elevated in cirrhotic patients with HCV-4. Further, the severity of liver cirrhosis and serum resistin were the determinant factors explaining the variability of GLP-1 levels by about 84%. In addition, a positive relation was found between insulin resistance and both GLP-1 and resistin levels.

Nutritional status and follicular-derived thyroid cancer: An update

The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase. They include modified iodine intake, lifestyle-associated risk factors, exposure to various toxic compounds, pollutants and xenobiotics, nutritional deficiencies, eating habits and comorbidities. Foremost, nutritional patterns have gained high interest as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this narrative review is to focus on the relationship between thyroid cancer and nutritional factors, dietary habits and obesity. Low iodine intake has been associated to increased risk of thyroid cancer, favoring the development of more aggressive histotypes. Moreover, correction of iodine deficiency can shift thyroid cancer subtypes toward less aggressive forms, without affecting the overall risk for cancer. Actually, evidence regarding the association between selenium and vitamin D deficiency and thyroid cancer is very limited, despite their well-known anti-cancer potentials, and the clinical usefulness of their supplementation is still uncertain in this setting. Albeit the relationship between single foods and thyroid cancer is difficult to examine, fish and iodine-rich foods, vegetables, and fruits might exert protective effects on thyroid cancer risk. Conversely, no clear association has been found for other foods to date. Lastly, a clear association between obesity and the risk of thyroid cancer, with more aggressive behavior, seems to emerge from most studies, likely involving variations in thyroid function and chronic inflammation mediated by cytokines, insulin, leptin and adiponectins. Although no definite association between dietary factors and thyroid cancer has been firmly established so far, some nutritional patterns, together with excessive weight, seem to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. These effects may play an additive role to the well-established one exerted by environmental carcinogens, such as pollutants and radiation exposure.

Antihyperglycemic Effects and Mode of Actions of Musa paradisiaca Leaf and Fruit Peel Hydroethanolic Extracts in Nicotinamide/Streptozotocin-Induced Diabetic Rats

The present study aimed to evaluate the antihyperglycemic effects of Musa paradisiaca (M. paradisiaca) leaf and fruit peel hydroethanolic extracts and to suggest their probable mode of actions in nicotinamide (NA)/streptozotocin (STZ)-induced diabetic rats. The leaf and fruit peel hydroethanolic extracts were analyzed by GC-MS that indicated the presence of phytol, octadecatrienoic acid, hexadecanoic acid, and octadecadienoic acid as major components in the leaf extract and vitamin E, octadecenamide, β-sitosterol, and stigmasterol as major phytochemicals in the fruit peel extract. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (60 mg/kg body weight) dissolved in citrate buffer (pH 4.5), 15 minutes after intraperitoneal injection of NA (120 mg/kg body weight). The NA/STZ-induced diabetic rats were, respectively, treated with M. paradisiaca leaf and fruit peel hydroethanolic extracts at a dose of 100 mg/kg body weight/day by oral administration for 28 days. The treatment of NA/STZ-induced diabetic rats with leaf and fruit peel extracts significantly improved the impaired oral glucose tolerance and significantly increased the lowered serum insulin and C-peptide levels. The HOMA-IR (as the index of insulin resistance) and QUICKI (as a marker for insulin sensitivity), as well as HOMA-β cell function were significantly alleviated as a result of treatment of diabetic rats with leaf and fruit peel extracts. In association, the elevated serum-free fatty acids, TNF-α, and IL-6 levels were significantly decreased. In addition, the suppressed adipose tissue PPARγ, GLUT4, adiponectin, and insulin receptor β-subunit mRNA expressions were upregulated while the elevated adipose tissue resistin expression was downregulated in diabetic rats as a result of treatment with the leaf and peel extract. Based on these results, it can be concluded that M. paradisiaca leaf and fruit peel hydroethanolic extracts have antihyperglycemic effects which may be mediated via their insulinotropic and insulin-sensitizing effects.

Resistin Is Increased in Periodontal Cells and Tissues: In Vitro and In Vivo Studies

Resistin, a proinflammatory adipokine, is elevated in many inflammatory diseases. However, little is known about its performance in periodontitis. The present study is aimed at evaluating resistin expression and synthesis in periodontal cells and tissues under inflammatory/microbial stress in addition to its effects on the periodontium. In vivo, 24 male rats were randomly divided into two groups: control and ligature-induced periodontal disease. After 6 and 12 days, animals were sacrificed to analyze gene expression of adipokines, bone loss, inflammation, and resistin synthesis. In vitro, human periodontal ligament (PDL) fibroblasts were used to evaluate the expression of resistin after inflammatory stimuli. In addition, PDL fibroblasts were exposed to resistin to evaluate its role on soft and hard tissue metabolism markers. The periodontitis group demonstrated significant bone loss, an increase in the number of inflammatory cells and vascular structures, an increase in resistin expression and synthesis, and a decrease in the expression of adiponectin, leptin, and its functional receptor. PDL fibroblasts showed a significant increase in resistin expression and synthesis in response to the inflammatory stimulus by IL-1β. Resistin induced an increase in cytokine expression and a decrease in the regulation of some hard tissue and matrix formation genes in PDL fibroblasts. These data indicate that resistin is produced by periodontal cells and tissues, and this effect is enhanced by inflammatory stimuli. Moreover, resistin seems to interfere with soft and hard tissue metabolism during periodontitis by reducing markers related to matrix formation and bone tissue.

Relation of Circulating Resistin to Insulin Resistance in Type 2 Diabetes and Obesity: A Systematic Review and Meta-Analysis

Background: Resistin, a cysteine-rich polypeptide encoded by the RETN gene, which plays an important role in many mechanisms in rodent studies, including lipid metabolism, inflammation and insulin resistance. Nevertheless, the relationship between resistin and insulin resistance in humans is under debate. The present study was designed to clarify the correlation between resistin and insulin resistance. Methods: A systematic literature search was performed using PubMed, Embase and Cochrane Library until March 3, 2019 with the keywords "resistin" and "insulin resistance." Funnel plots and Egger's test were used to detect publication bias. A random-effects model was used to calculate the pooled effect size. Subgroup analysis and meta regression was performed to identify the sources of heterogeneity. Results: Fifteen studies were included in our systematic review. Among them, 10 studies with Pearson coefficients were used for meta-analysis. We found resistin levels were weakly correlated with insulin resistance in those with T2DM and obesity (r = 0.21, 95% CI: 0.06-0.35, I 2 = 59.7%, P = 0.003). Nevertheless, subgroup analysis suggested that circulating resistin levels were significantly positively correlated with insulin resistance in individuals with hyperresistinemia (≥14.8 ng/ml) (r = 0.52, 95% CI: 0.35-0.68, I 2 = 0.0%, P = 0.513). And there was no relationship between circulating resistin and insulin resistance in those with normal circulating resistin levels (<14.8 ng/ml) (r = 0.08, 95% CI: -0.01-0.18, I 2 = 0.0%, P = 0.455). Publication bias was insignificant (Egger's test P = 0.592). Conclusion: In T2DM and obese individuals, resistin levels were positively correlated with insulin resistance in those with hyperresistinemia, but not in those with normal circulating resistin levels.

Hypothalamic-Pituitary and Adipose Tissue Responses to the Effect of Resistin in Sheep: The Integration of Leptin and Resistin Signaling Involving a Suppressor of Cytokine Signaling 3 and the Long Form of the Leptin Receptor

We hypothesized that resistin is engaged in the development of leptin central insensitivity/resistance in sheep, which is a unique animal model to explore reversible leptin resistance. Thirty Polish Longwool ewes, which were ovariectomized with estrogen replacement, were used. Treatments consisted of the intravenous injection of control (saline) or recombinant bovine resistin (rbresistin): control (Control; n = 10), a low dose of rbresistin (R1; 1.0 μg/kg body weight (BW); n = 10), and a high dose of rbresistin (R2; 10.0 μg/kg BW; n = 10). The studies were performed during short-day (SD) and long-day (LD) photoperiods. Leptin and resistin concentrations were determined. Expression levels of a suppressor of cytokine signaling (SOCS)-3 and the long form of the leptin receptor (LeptRb) were determined in selected brain regions, including in the anterior pituitary (AP), hypothalamic arcuate nucleus (ARC), preoptic area (POA), and ventro- and dorsomedial nuclei (VMH/DMH). The results indicate that resistin induced a consistent decrease in LeptRb (except in POA) and an increase in SOCS-3 expression during the LD photoperiod in all selected brain regions. In conclusion, the results demonstrate that the action of resistin appears to be strongly associated with photoperiod-driven changes in the leptin signaling pathway, which may underlie the phenomenon of central leptin resistance.

In vitro effects of resistin on epithelial to mesenchymal transition (EMT) in MCF-7 and MDA-MB-231 breast cancer cells - qRT-PCR and Westen blot analyses data

Resistin is an adipokine produced by the white adipocytes and adipose-derived macrophages, which mediates inflammation and insulin resistance Huang et al., 1997 and Renehan et al., 2008 Feb. Here, we provide data on the effect of resistin on epithelial to mesenchymal transition (EMT) in breast cancer cells in vitro. As model systems, we used human MCF-7 (low-metastatic) and MDA-MB-231 (high-metastatic) breast cancer cell lines. To optimize experimental conditions, we treated the cells with various concentrations of resistin (12.5, 25 and 50 ng/ml) for different time intervals (6 and 24 hours), and measured SOCS3 mRNA expression by using qRT-PCR analysis. Further, we used qRT-PCR and Western blot analyses to measure the expression of various epithelial (E-cadherin, claudin-1) and mesenchymal (SNAIL, SLUG, ZEB1, TWIST1, fibronectin, and vimentin) markers after resistin treatment. This data article is part of a study Avtanski et al., 2019 May, where detailed interpretation and discussion can be found.

Oral contraceptive use increases risk of inflammatory and coagulatory disorders in women with Polycystic Ovarian Syndrome: An observational study

Polycystic ovarian syndrome (PCOS) is a multispectral disorder requiring lifelong management. Its pathophysiology is still being explored which makes its treatment options restrained. Present study explores impact of oral contraceptive mode of treatment on metabolic, hormonal, inflammation and coagulation profile of PCOS women. 50 subjects diagnosed with Rotterdam criteria receiving no drug treatment served as controls whereas 50 subjects receiving only OCPs (Ethinyl estradiol 0.03 mg, Levonorgestrel 0.15 mg) as a mode of treatment at least for six-months served as cases. Ferriman-Gallwey score and hormonal profile improved on OCP treatment. However, parameters like weight, Body mass index, waist-hip ratio, Oral glucose tolerance test, lipid profile, insulin, HOMA-IR, adiponectin, interleukin1β, visfatin, resistin, tissue factor, PT and APTT showed considerable derangements in OCP group. All above parameters are associated with the risk of diabetes mellitus, dyslipidemia, coronary vascular disease, cancers, hypercoagulable state, venous thromboembolism and thrombotic events. Long-term use of OCPs needs to be considered carefully for PCOS patients who are already burdened with associated risk factors. This study was conducted in a region where women do not have much access to high-end screening and diagnostic facilities that further exacerbates their clinical outcomes. Large scale, long-term studies need to be designed to further evaluate safety use of OCPs in PCOS women.

Adipose Tissue-Derived Signatures for Obesity and Type 2 Diabetes: Adipokines, Batokines and MicroRNAs

: Obesity is one of the main risk factors for type 2 diabetes mellitus (T2DM). It is closely related to metabolic disturbances in the adipose tissue that primarily functions as a fat reservoir. For this reason, adipose tissue is considered as the primary site for initiation and aggravation of obesity and T2DM. As a key endocrine organ, the adipose tissue communicates with other organs, such as the brain, liver, muscle, and pancreas, for the maintenance of energy homeostasis. Two different types of adipose tissues-the white adipose tissue (WAT) and brown adipose tissue (BAT)-secrete bioactive peptides and proteins, known as "adipokines" and "batokines," respectively. Some of them have beneficial anti-inflammatory effects, while others have harmful inflammatory effects. Recently, "exosomal microRNAs (miRNAs)" were identified as novel adipokines, as adipose tissue-derived exosomal miRNAs can affect other organs. In the present review, we discuss the role of adipose-derived secretory factors-adipokines, batokines, and exosomal miRNA-in obesity and T2DM. It will provide new insights into the pathophysiological mechanisms involved in disturbances of adipose-derived factors and will support the development of adipose-derived factors as potential therapeutic targets for obesity and T2DM.

Cynometra cauliflora Linn. Attenuates metabolic abnormalities in high-fat diet-induced obese mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cynometra cauliflora Linn. belongs to the Fabaceae family and is known locally in Malaysia as nam-nam. Traditionally, a decoction of the C. cauliflora leaves is used for treating hyperlipidemia and diabetes.

AIM OF THE STUDY

This study aims to investigate the anti-obesity and lipid lowering effects of ethanolic extract of C. cauliflora leaves and its major compound (vitexin) in C57BL/6 obese mice induced by high-fat diet (HFD), as well as to further identify the molecular mechanism underlying this action.

METHODS AND MATERIAL

Male C57BL/6 mice were fed with HFD (60% fat) for 16 weeks to become obese. The treatment started during the last 8 weeks of HFD feeding and the obese mice were treated with C. cauliflora leaf extract at 200 and 400 mg/kg/day, orlistat (10 mg/kg) and vitexin (10 mg/kg).

RESULTS

The oral administration of C. cauliflora (400 and 200 mg/kg) and vitexin significantly reduced body weight, adipose tissue and liver weight and lipid accumulation in the liver compared to control HFD group. Both doses of C. cauliflora also significantly (P ≤ 0.05) decreased serum triglyceride, LDL, lipase, IL-6, peptide YY, resistin levels, hyperglycemia, hyperinsulinemia, and hyperleptinemia compared to the control HFD group. Moreover, C. cauliflora significantly up-regulated the expression of adiponectin, Glut4, Mtor, IRS-1 and InsR genes, and significantly decreased the expression of Lepr in white adipose tissue. Furthermore, C. cauliflora significantly up-regulated the expression of hypothalamus Glut4, Mtor and NF-kB genes. GC-MS analysis of C. cauliflora leaves detected the presence of phytol, vitamin E and β-sitosterol. Besides, the phytochemical evaluation of C. cauliflora leaves showed the presence of flavonoid, saponin and phenolic compounds.

CONCLUSION

This study shows interesting outcomes of C. cauliflora against HFD-induced obesity and associated metabolic abnormalities. Therefore, the C. cauliflora extract could be a potentially effective agent for obesity management and its related metabolic disorders such as insulin resistance and hyperlipidemia.

Mechanisms of obesity-induced metabolic and vascular dysfunctions

Obesity has reached epidemic proportions and its prevalence is climbing. Obesity is characterized by hypertrophied adipocytes with a dysregulated adipokine secretion profile, increased recruitment of inflammatory cells, and impaired metabolic homeostasis that eventually results in the development of systemic insulin resistance, a phenotype of type 2 diabetes. Nitric oxide synthase (NOS) is an enzyme that converts L-arginine to nitric oxide (NO), which functions to maintain vascular and adipocyte homeostasis. Arginase is a ureohydrolase enzyme that competes with NOS for L-arginine. Arginase activity/expression is upregulated in obesity, which results in diminished bioavailability of NO, impairing both adipocyte and vascular endothelial cell function. Given the emerging role of NO in the regulation of adipocyte physiology and metabolic capacity, this review explores the interplay between arginase and NO, and their effect on the development of metabolic disorders, cardiovascular diseases, and mitochondrial dysfunction in obesity. A comprehensive understanding of the mechanisms involved in the development of obesity-induced metabolic and vascular dysfunction is necessary for the identification of more effective and tailored therapeutic avenues for their prevention and treatment.