Adipokines - removing road blocks to obesity and diabetes therapy

snRNA-seq of adipose tissues reveals the potential cellular and molecular mechanisms of cold and disease resistance in Mongolian cattle

BACKGROUND

Mongolian cattle are local breeds in northern China with excellent adaptability to harsh environmental conditions. Adipose tissues play essential roles in tolerance to cold and disease, but the associated cellular and molecular mechanisms are unclear.

METHODS

Single-nucleus RNA sequencing (snRNA-seq) was performed on the adipose tissues from the subcutaneous (SAT), greater omentum (OAT) and perirenal (PAT) of 3 healthy cattle. The adipogenic trajectory was analyzed, and the functional roles of gene of interest were verified in vitro.

RESULTS

There were different cell subpopulations in adipose tissues. The lipid-deposition adipocytes identified by the PTGER3 marker exhibited outstanding characteristics in SAT. In PAT and OAT, aldosterone was expressed to provide clues for the differential brown adipocytes. Among the DEGs by comparing OAT with SAT and PAT with OAT, C3 was significantly expressed in most of the cell populations in SAT. G0S2, LIPE, LPIN1, PTGER3 and RGCC took part in the adipogenic trajectory from preadipocyte commitment to mature adipocytes. S100A4 expression affected Ca2+ signaling and the expression of UCP1 ~ 3, FABP4 and PTGER3.

CONCLUSION

The cell heterogeneity and genes expressed in adipose tissues of Mongolian cattle not only determine the endocrine and energy storage, but contribute to adapt to cold and disease resistance.

NPTX1 Mediates the Facilitating Effects of Hypoxia-Stimulated Human Adipocytes on Adipose-Derived Stem Cell Activation and Autologous Adipose Graft Survival Rate

BACKGROUND

Autologous adipose tissue is an ideal material for soft tissue filling and transplantation; however, high volumes of fat absorption over time lead to a relatively low overall survival percentage. The survival and differentiation of adipose-derived stem cells (ADSCs) in the transplanted microenvironment might improve adipose graft survival. Adipocytes have been reported to affect ADSC activation. However, its underlying mechanisms remain unclear.

METHODS

Human ADSCs were incubated in a culture medium supplemented with hypoxic or normoxic conditioned culture medium (CM) derived from human adipocytes. Neuronal Pentraxin 1 (NPTX1) was overexpressed or knocked down in human adipocytes using an overexpression vector (NPTX1 OE) or small interfering RNA (siRNA) transfection, respectively. ADSC differentiation and paracrine secretion were assessed. Nude mice were implanted with human adipocytes and ADSCs. The adipose tissue was subsequently evaluated by histological analysis.

RESULTS

CM from hypoxic-stimulated human adipocytes significantly facilitated the differentiation ability and paracrine levels of ADSCs. NPTX1 was significantly up-regulated in human adipocytes exposed to hypoxic conditions. In vitro, CM derived from hypoxia-stimulated human adipocytes or NPTX1-overexpressing human adipocytes exposed to normoxia promoted ADSC differentiation and paracrine; after silencing NPTX1, the facilitating effects of hypoxia-treated human adipocytes on ADSC activation were eliminated. Similarly, in vivo, the NPTX1 OE + normoxia-CM group saw improved histological morphology and fat integrity, less fibrosis and inflammation, and increased vessel numbers compared with the OE NC + normoxia-CM group; the adipocyte grafts of the si-NC + hypoxia-CM group yielded the most improved histological morphology, fat integrity, and the most vessel numbers. However, these enhancements of ADSC activation and adipose graft survival were partially abolished by NPTX1 knockdown in human adipocytes.

CONCLUSION

NPTX1 might mediate the facilitating effects of hypoxia-stimulated human adipocytes on ADSC activation, thereby improving adipose tissue survival rate after autologous fat transplantation and the effectiveness of autologous fat transplantation through promoting ADSC activation.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Adipokine-Enriched Adipose Extract Restores Skin Barrier and Ameliorates Inflammatory Dysregulation in Atopic Dermatitis Mice

BACKGROUND

Atopic dermatitis (AD) is a chronic dermatosis with high incidence worldwide characterized by skin barrier abnormalities and immune dysregulation. Conventional therapies are usually limited by side effects and high cost. Given the antiinflammatory and repairing properties, adipokines are increasingly considered as promising therapeutic agents for dermatoses. Adipose collagen fragments (ACF), a novel adipokine-enriched product, may alleviate AD through modulating immune microenvironment and restoring skin barrier.

METHODS

ACF was extracted from adipose tissue by means of high-speed homogenization (10,000 rpm/min for 1 minute) and centrifugation (3000 g for 3 minutes). Ovalbumin-induced AD female BALB/c mice (6-week-old) were intradermally injected with 0.2 mL of ACF or phosphate-buffered saline (negative control), with normal mice being set as normal control ( n = 6). Dermatitis severity, inflammatory metrics (epidermal thickness, infiltrated mast cells, T helper cell [Th]-type cytokine expression), and skin barrier-related metrics (transepidermal water loss, skin barrier-related proteins expression) were evaluated after the AD induction period (day 50). ACF-derived bioactive components were also evaluated using proteomic analysis.

RESULTS

ACF-derived adipokines contained antiinflammatory, skin barrier- and lipid biosynthesis-related components. ACF treatment decreased dermatitis severity (6.2 ± 1.8 [ P < 0.0001]), epidermal thickness (25.7 ± 12.8 μm [ P = 0.0045]), infiltrated mast cells (31.3 ± 12.4 cells/field [ P = 0.0475]), and expression of Th-type cytokines (interferon-γ, tumor necrosis factor-α, interleukin [IL]-4, IL-4R, IL-13, and IL-17A [ P < 0.05]) in AD skins. Transepidermal water loss (29.8 ± 13.8 g/m 2 per hour [ P = 0.0306]) and skin barrier-related protein expression (filaggrin, 14,258 ± 4375 [ P = 0.0162]; loricrin, 6037 ± 1728 [ P = 0.0010]; claudin-1, 20,043 ± 6406 [ P = 0.0420]; and zonula occludens-1, 4494 ± 1114 [ P = 0.0134]) were also improved.

CONCLUSIONS

ACF improved AD in a murine model by ameliorating inflammatory dysregulation and skin barrier defects. Further validation is needed in more advanced animal models.

CLINICAL RELEVANCE STATEMENT

ACF is an injectable, adipose-derived collagen scaffold prepared from autologous harvested fat using fast and simple mechanical methods. ACF may reduce the limitations associated with health care regulatory issues and serve as a promising autologous therapeutic agent for skin disorders in clinics.

Molecular Mechanisms behind Obesity and Their Potential Exploitation in Current and Future Therapy

Obesity is a chronic disease caused primarily by the imbalance between the amount of calories supplied to the body and energy expenditure. Not only does it deteriorate the quality of life, but most importantly it increases the risk of cardiovascular diseases and the development of type 2 diabetes mellitus, leading to reduced life expectancy. In this review, we would like to present the molecular pathomechanisms underlying obesity, which constitute the target points for the action of anti-obesity medications. These include the central nervous system, brain-gut-microbiome axis, gastrointestinal motility, and energy expenditure. A significant part of this article is dedicated to incretin-based drugs such as GLP-1 receptor agonists (e.g., liraglutide and semaglutide), as well as the brand new dual GLP-1 and GIP receptor agonist tirzepatide, all of which have become "block-buster" drugs due to their effectiveness in reducing body weight and beneficial effects on the patient's metabolic profile. Finally, this review article highlights newly designed molecules with the potential for future obesity management that are the subject of ongoing clinical trials.

Endocrine Aspects of Pain Pathophysiology: Focus on Adipose Tissue

BACKGROUND

Multiple factors, including neurobiological, hormonal, psychological, and social/cultural norms, influence the manner in which individuals experience pain. Adipose tissue, once considered solely an energy storage site, has been recognized as a significant endocrine organ that produces and releases a range of hormones and cytokines. In recent years, research has highlighted the role of adipose tissue and its endocrine factors in the pathophysiology of pain.

SUMMARY

This narrative review aimed to provide a comprehensive overview of the current knowledge on the endocrine aspects of pain pathophysiology, with a specific focus on adipose tissue. We examine the role of adipokines released by adipose tissue, such as leptin, adiponectin, resistin, visfatin, asprosin in pain perception and response. We also explore the clinical implications of these findings, including the potential for personalized pain management based on endocrine factors and adipose tissue.

KEY MESSAGES

Overall, given this background, this review intended to highlight the importance of understanding the endocrine aspects of pain pathophysiology, particularly focusing on the role of adipose tissue, in the development of chronic pain and adipokines. Better understanding the role of adipokines in pain modulation might have therapeutic implications by providing novel targets for addressing underlying mechanism rather than directly focusing on symptoms for chronic pain, particularly in obese individuals.

Childhood Obesity: Insight into Kidney Involvement

This review examines the impact of childhood obesity on the kidney from an epidemiological, pathogenetic, clinical, and pathological perspective, with the aim of providing pediatricians and nephrologists with the most current data on this topic. The prevalence of childhood obesity and chronic kidney disease (CKD) is steadily increasing worldwide, reaching epidemic proportions. While the impact of obesity in children with CKD is less pronounced than in adults, recent studies suggest a similar trend in the child population. This is likely due to the significant association between obesity and the two leading causes of end-stage renal disease (ESRD): diabetes mellitus (DM) and hypertension. Obesity is a complex, systemic disease that reflects interactions between environmental and genetic factors. A key mechanism of kidney damage is related to metabolic syndrome and insulin resistance. Therefore, we can speculate about an adipose tissue-kidney axis in which neurohormonal and immunological mechanisms exacerbate complications resulting from obesity. Adipose tissue, now recognized as an endocrine organ, secretes cytokines called adipokines that may induce adaptive or maladaptive responses in renal cells, leading to kidney fibrosis. The impact of obesity on kidney transplant-related outcomes for both donors and recipients is also significant, making stringent preventive measures critical in the pre- and post-transplant phases. The challenge lies in identifying renal involvement as early as possible, as it is often completely asymptomatic and not detectable through common markers of kidney function. Ongoing research into innovative technologies, such as proteomics and metabolomics, aims to identify new biomarkers and is constantly evolving. Many aspects of pediatric disease progression in the population of children with obesity still require clarification. However, the latest scientific evidence in the field of nephrology offers glimpses into various new perspectives, such as genetic factors, comorbidities, and novel biomarkers. Investigating these aspects early could potentially improve the prognosis of these young patients through new diagnostic and therapeutic strategies. Hence, the aim of this review is to provide a comprehensive exploration of the pathogenetic mechanisms and prevalent pathological patterns of kidney damage observed in children with obesity.

Potential of dietary hemp and cannabinoids to modulate immune response to enhance health and performance in animals: opportunities and challenges

Cannabinoids are a group of bioactive compounds abundantly present in Cannabis sativa plant. The active components of cannabis with therapeutic potential are known as cannabinoids. Cannabinoids are divided into three groups: plant-derived cannabinoids (phytocannabinoids), endogenous cannabinoids (endocannabinoids), and synthetic cannabinoids. These compounds play a crucial role in the regulation various physiological processes including the immune modulation by interacting with the endocannabinoid system (A complex cell-signaling system). Cannabinoid receptor type 1 (CB1) stimulates the binding of orexigenic peptides and inhibits the attachment of anorexigenic proteins to hypothalamic neurons in mammals, increasing food intake. Digestibility is unaffected by the presence of any cannabinoids in hemp stubble. Endogenous cannabinoids are also important for the peripheral control of lipid processing in adipose tissue, in addition to their role in the hypothalamus regulation of food intake. Regardless of the kind of synaptic connection or the length of the transmission, endocannabinoids play a crucial role in inhibiting synaptic transmission through a number of mechanisms. Cannabidiol (CBD) mainly influences redox equilibrium through intrinsic mechanisms. Useful effects of cannabinoids in animals have been mentioned e.g., for disorders of the cardiovascular system, pain treatment, disorders of the respiratory system or metabolic disorders. Dietary supplementation of cannabinoids has shown positive effects on health, growth and production performance of small and large animals. Animal fed diet supplemented with hemp seeds (180 g/day) or hemp seed cake (143 g/kg DM) had achieved batter performance without any detrimental effects. But the higher level of hemp or cannabinoid supplementation suppress immune functions and reduce productive performance. With an emphasis on the poultry and ruminants, this review aims to highlight the properties of cannabinoids and their derivatives as well as their significance as a potential feed additive in their diets to improve the immune status and health performance of animals.

The effects of exercise training on serum concentrations of chemerin in individuals with overweight and obesity: a systematic review, meta-analysis, and meta-regression of 43 clinical trials

CONTEXT

Elevated serum concentrations of chemerin is a significant factor in the development of metabolic disorders in individuals with overweight and obesity.

OBJECTIVE

This systematic review, meta-analysis, and meta-regression evaluated the effects of exercise training on serum concentrations of chemerin in individuals with overweight and/or obesity.

METHODS

Studies published up to January 2021 were identified through four databases. Forty-three studies including 1271 participants were included and analysed using a random-effects model to calculate weighted mean differences with 95% confidence intervals.

RESULTS

Results indicated that exercise training significantly decreased serum concentrations of chemerin in individuals with overweight and/or obesity. Subgroup analysis showed that all types of exercise (aerobic, resistance, and combined training) interventions but not high-intensity interval training decreased serum concentrations of chemerin. Subgroup analysis based on baseline body mass index (BMI), gender, and intervention duration showed significant declines in serum concentrations of chemerin. Meta-regression analysis indicated a linear relationship between changes in body fat percentage (BFP) with serum concentrations of chemerin.

CONCLUSION

Exercise training may decrease serum concentrations of chemerin in individuals with overweight and/or obesity. The chemerin-lowering effects of exercise might be related to declines in BFP. Further studies are needed to confirm these findings.

Plasma IL-6, TREM1, uPAR, and IL6/IL8 biomarkers increment further witnessing the chronic inflammation in type 2 diabetes

OBJECTIVES

Type 2 diabetes (T2D) is known to be associated with chronic inflammation, but the inflammatory regulators/markers are not exactly defined and the link between them remains undetermined. The objective of this study is to identify these markers by testing traditional (IL6 & IL8) and non-traditional (TREM1 & uPAR) inflammatory markers.

METHODS

Data and blood samples were obtained from 114 T2D and 74 non-diabetic Kuwaiti subjects attending health facilities in Kuwait. Chemical analyzers were used to measure glycemic and lipid profiles, while ELISA was used to measure plasma levels of insulin and several inflammatory markers.

RESULTS

Showed that the IL-6 and TREM1 were significantly higher in T2D compared to non-diabetic controls, and the uPAR level was borderline higher in T2D but significantly correlated with IL-6 levels. Unexpectedly, IL8 was significantly below normal in T2D and IL6/IL8 ratio was significantly higher in T2D patients. Unlike other tested markers, uPAR was in addition strongly correlated with insulin levels and HOMA-IR index.

CONCLUSIONS

Raised levels of IL6, TREMI, IL6/IL8 ratio, and the strong positive correlation of plasma levels of uPAR with IL-6, insulin, and HOMA-IR index, are reliable spectators of chronic inflammation in T2D patients. The reduced level of IL-8 in T2D was a peculiar observation that needs further explanation. Finally, the consequences and impact of the sustained rise of these inflammatory regulators in diabetic tissues need to be meticulously explored.

The Level of Inflammatory Markers and Their Relationship with Fat Tissue Distribution in Children with Obesity and Type 2 Diabetes Mellitus

OBJECTIVE

This study aimed to determine the changes in proinflammatory and anti-inflam- matory markers in children aged 10-18, who were not diagnosed with type 2 diabetes mel- litus, were obese/overweight, and children with type 2 diabetes mellitus. In addition, we aimed to investigate whether these markers were associated with clinical and laboratory parame- ters, subcutaneous adipose tissue, preperitoneal adipose tissue, visceral adipose tissue, and hepatosteatosis.

MATERIALS AND METHODS

Children between the ages of 10 and 18, obese/overweight, with type 2 diabetes mellitus, and with a normal body mass index were included. Fat tissue thick- ness was measured. Tumor necrosis factor-α, interleukin-1β, interleukin-6, interleukin-18, and interferon-γ as proinflammatory markers and transforming growth factor-β and interleukin-10 levels as anti-inflammatory markers were studied.

RESULTS

Twenty-eight (31.8%) controls, 44 (50%) obese/overweight, and 16 (18.2%) patients with type 2 diabetes mellitus were included in our study. Age, sex, and puberty were similar between the groups. In the type 2 diabetes mellitus group, the subcutaneous fat tissue thick- ness was higher than that in the obese group, and the preperitoneal and visceral fat tissue thicknesses were similar to those in the obese group. Proinflammatory markers and interleu- kin-10 levels were similar in the obese/overweight, type 2 diabetes mellitus, and control groups. Transforming growth factor-β levels were significantly lower in the type 2 diabetes mellitus group than in the control group (P = .039). Transforming growth factor-β levels and other labo- ratory variables did not differ significantly in the type 2 diabetes mellitus group.

CONCLUSION

While there was no change in all markers in the obese/overweight group com- pared with the control group, proinflammatory markers in the type 2 diabetes mellitus group were similar to those in the obese/overweight and control groups, and transforming growth factor-β level, an anti-inflammatory marker, was lower in the type 2 diabetes mellitus group than in the control group.

Supplementation with spinach-derived thylakoid augments the benefits of high intensity training on adipokines, insulin resistance and lipid profiles in males with obesity

Introduction

This study investigated the effects of 12 weeks of high-intensity functional training (HIFT) combined with spinach-derived thylakoid supplementation on some selected Adipokines and insulin resistance in males with obesity.

Method

Sixty-eight participants (mean age: 27.6 ± 8.4 yrs.; mean height: 168.4 ± 2.6 cm; mean weight: 95.7 ± 3.8 kg, mean BMI: 32.6 ± 2.6 kg/m2) were randomly divided into four groups of 17 per group: Control group (CG), Supplement group (SG), Training group (TG), and Training + supplement group (TSG). Following baseline measurements, the two training groups (TG and TSG) started the 12 weeks of exercise training program (3 sessions per week). A total of 36 sessions lasting up to 60 min were included in the HIFT program using the CrossFit program. The eligible participants received 5 g/day of thylakoid-rich spinach extract or matching placebo as 5 g/day of raw corn starch (one sachet, 30 min before lunch) for 12 weeks. Baseline assessments were obtained 48 hours before the start of the training protocols and 48 hours after the last training session in all groups.

Results

There were significant interactions (p<0.001 for all) between exercise and time for adiponectin (ES:0.48), leptin (ES:0.46), resistin (ES:0.3), omentin (ES:0.65), vaspin (ES:0.46), visfatin (ES:0.62), apelin (ES:0.42), RBP4 (ES:0.63), chemrin (0.36) and semaphorin3c (ES: 0.5). Plasma levels of semaphorin3c were significantly correlated (p<0.05) with body weight (r= 0.57), BMI (r= 0.43), FFM (r= -0.612), FAT (r= 0.768), VO2peak (r=-0.53), insulin (r= 0.756), glucose (r= 0.623), and HOMA-IR (r= 0.727). There were also significant group differences in insulin (ES: 0.77), glucose (ES: 0.21), and HOM-IR (ES: 0.44) (p<0.05).

Discussion

Our findings indicate that 12 weeks of HIFT supplemented with spinach-derived thylakoid reduced levels of leptin, resistin, vaspin, visfatin, apelin, RBP4, chemrin, semaphorin3c and insulin resistance while increasing adiponectin and omentin levels in men with obesity.

Cafeteria Diet-Induced Obesity Worsens Experimental CKD

Obesity is a significant risk factor for chronic kidney disease (CKD). This study aimed to evaluate the impact of obesity on the development of kidney fibrosis in a model of cafeteria diet rats undergoing 5/6th nephrectomy (SNx). Collagen 1, 3, and 4 expression, adipocyte size, macrophage number, and the expression of 30 adipokines were determined. Collagen 1 expression in kidney tissue was increased in Standard-SNx and Cafeteria-SNx (7.1 ± 0.6% and 8.9 ± 0.9 tissue area, respectively). Renal expression of collagen 3 and 4 was significantly increased (p < 0.05) in Cafeteria-SNx (8.6 ± 1.5 and 10.9 ± 1.9% tissue area, respectively) compared to Cafeteria (5.2 ± 0.5 and 6.3 ± 0.6% tissue area, respectively). Adipocyte size in eWAT was significantly increased by the cafeteria diet. In Cafeteria-SNx, we observed a significant increase in macrophage number in the kidney (p = 0.01) and a consistent tendency in eWAT. The adipokine level was higher in the Cafeteria groups. Interleukin 11, dipeptidyl peptidase 4, and serpin 1 were increased in Cafeteria-SNx. In the kidney, collagen 3 and 4 expressions and the number of macrophages were increased in Cafeteria-SNx, suggesting an exacerbation by preexisting obesity of CKD-induced renal inflammation and fibrosis. IL11, DPP4, and serpin 1 can act directly on fibrosis and participate in the observed worsening CKD.

Adipokines regulate mesenchymal stem cell osteogenic differentiation

Mesenchymal stem cells (MSCs) can differentiate into various tissue cell types including bone, adipose, cartilage, and muscle. Among those, osteogenic differentiation of MSCs has been widely explored in many bone tissue engineering studies. Moreover, the conditions and methods of inducing osteogenic differentiation of MSCs are continuously advancing. Recently, with the gradual recognition of adipokines, the research on their involvement in different pathophysiological processes of the body is also deepening including lipid metabolism, inflammation, immune regulation, energy disorders, and bone homeostasis. At the same time, the role of adipokines in the osteogenic differentiation of MSCs has been gradually described more completely. Therefore, this paper reviewed the evidence of the role of adipokines in the osteogenic differentiation of MSCs, emphasizing bone formation and bone regeneration.

Tanshinone IIA and Cryptotanshinone Counteract Inflammation by Regulating Gene and miRNA Expression in Human SGBS Adipocytes

Inflammation of the adipose tissue contributes to the onset and progression of several chronic obesity-related diseases. The two most important lipophilic diterpenoid compounds found in the root of Salvia milthorrhiza Bunge (also called Danshen), tanshinone IIA (TIIA) and cryptotanshinone (CRY), have many favorable pharmacological effects. However, their roles in obesity-associated adipocyte inflammation and related sub-networks have not been fully elucidated. In the present study, we investigated the gene, miRNAs and protein expression profile of prototypical obesity-associated dysfunction markers in inflamed human adipocytes treated with TIIA and CRY. The results showed that TIIA and CRY prevented tumor necrosis factor (TNF)-α induced inflammatory response in adipocytes, by counter-regulating the pattern of secreted cytokines/chemokines associated with adipocyte inflammation (CCL2/MCP-1, CXCL10/IP-10, CCL5/RANTES, CXCL1/GRO-α, IL-6, IL-8, MIF and PAI-1/Serpin E1) via the modulation of gene expression (as demonstrated for CCL2/MCP-1, CXCL10/IP-10, CCL5/RANTES, CXCL1/GRO-α, and IL-8), as well as related miRNA expression (miR-126-3p, miR-223-3p, miR-124-3p, miR-155-5p, and miR-132-3p), and by attenuating monocyte recruitment. This is the first demonstration of a beneficial effect by TIIA and CRY on adipocyte dysfunction associated with obesity development and complications, offering a new outlook for the prevention and/or treatment of metabolic diseases.

State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus

Obesity and type-2 diabetes mellitus (T2DM) are metabolic disorders. Obesity increases the risk of T2DM, and as obesity is becoming increasingly common, more individuals suffer from T2DM, which poses a considerable burden on health systems. Traditionally, pharmaceutical therapy together with lifestyle changes is used to treat obesity and T2DM to decrease the incidence of comorbidities and all-cause mortality and to increase life expectancy. Bariatric surgery is increasingly replacing other forms of treatment of morbid obesity, especially in patients with refractory obesity, owing to its many benefits including good long-term outcomes and almost no weight regain. The bariatric surgery options have markedly changed recently, and laparoscopic sleeve gastrectomy (LSG) is gradually gaining popularity. LSG has become an effective and safe treatment for type-2 diabetes and morbid obesity, with a high cost-benefit ratio. Here, we review the me-chanism associated with LSG treatment of T2DM, and we discuss clinical studies and animal experiments with regard to gastrointestinal hormones, gut microbiota, bile acids, and adipokines to clarify current treatment modalities for patients with obesity and T2DM.

Insight into continuous glucose monitoring: from medical basics to commercialized devices

According to the latest statistics, more than 537 million people around the world struggle with diabetes and its adverse consequences. As well as acute risks of hypo- or hyper- glycemia, long-term vascular complications may occur, including coronary heart disease or stroke, as well as diabetic nephropathy leading to end-stage disease, neuropathy or retinopathy. Therefore, there is an urgent need to improve diabetes management to reduce the risk of complications but also to improve patient's quality life. The impact of continuous glucose monitoring (CGM) is well recognized, in this regard. The current review aims at introducing the basic principles of glucose sensing, including electrochemical and optical detection, summarizing CGM technology, its requirements, advantages, and disadvantages. The role of CGM systems in the clinical diagnostics/personal testing, difficulties in their utilization, and recommendations are also discussed. In the end, challenges and prospects in future CGM systems are discussed and non-invasive, wearable glucose biosensors are introduced. Though the scope of this review is CGMs and provides information about medical issues and analytical principles, consideration of broader use will be critical in future if the right systems are to be selected for effective diabetes management.

Hepatic Glucose Metabolism Disorder Induced by Adipose Tissue-Derived miR-548ag via DPP4 Upregulation

The present study aimed to explore the molecular mechanism underlying the regulation of glucose metabolism by miR-548ag. For the first time, we found that miR-548ag expression was elevated in the abdominal adipose tissue and serum of subjects with obesity and type 2 diabetes mellitus (T2DM). The conditional knockout of adipose tissue Dicer notably reduced the expression and content of miR-548ag in mouse adipose tissue, serum, and liver tissue. The combined use of RNAseq, an miRNA target gene prediction software, and the dual luciferase reporter assay confirmed that miR-548ag exerts a targeted regulatory effect on DNMT3B and DPP4. miR-548ag and DPP4 expression was increased in the adipose tissue, serum, and liver tissue of diet-induced obese mice, while DNMT3B expression was decreased. It was subsequently confirmed both in vitro and in vivo that adipose tissue-derived miR-548ag impaired glucose tolerance and insulin sensitivity by inhibiting DNMT3B and upregulating DPP4. Moreover, miR-548ag inhibitors significantly improved the adverse metabolic phenotype in both obese mice and db/db mice. These results revealed that the expression of the adipose tissue-derived miR-548ag increased in obese subjects, and that this could upregulate the expression of DPP4 by targeting DNMT3B, ultimately leading to glucose metabolism disorder. Therefore, miR-548ag could be utilized as a potential target in the treatment of T2DM.

Role of ACSL5 in fatty acid metabolism

Free fatty acids (FFAs) are essential energy sources for most body tissues. A fatty acid must be converted to fatty acyl-CoA to oxidize or be incorporated into new lipids. Acyl-CoA synthetase long-chain family member 5 (ACSL5) is localized in the endoplasmic reticulum and mitochondrial outer membrane, where it catalyzes the formation of fatty acyl-CoAs from long-chain fatty acids (C16-C20). Fatty acyl-CoAs are then used in lipid synthesis or β-oxidation mediated pathways. ACSL5 plays a pleiotropic role in lipid metabolism depending on substrate preferences, subcellular localization and tissue specificity. Here, we review the role of ACSL5 in fatty acid metabolism in multiple metabolic tissues, including the liver, small intestine, adipose tissue, and skeletal muscle. Given the increasing number of studies suggesting the role of ACSL5 in glucose and lipid metabolism, we also summarized the effects of ACSL5 on circulating lipids and insulin resistance.

The risk for chronic kidney disease in metabolically healthy obese patients: A systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is associated with obesity and metabolic syndrome. Nevertheless, the association of CKD with phenotype referred as metabolically healthy obese or overweight is unclear. In this this systematic review and meta-analysis, we investigate the relationships between obesity and CKD independent of metabolic syndrome by appraising published evidence in studies focusing on metabolically healthy obese people.

MATERIALS AND METHODS

We performed a literature search through three databases Embase (Elsevier), the Cochrane Central Register of Controlled Trials (Wiley) and PubMed/Medline Web of Science up to March 2022 with the following terms: "chronic kidney disease", "kidney function", "obesity", "metabolic syndrome", "metabolically healthy obesity", "metabolically healthy overweight". Metabolically unhealthy was defined an individual having at least 3 of the following: abdominal obesity, high blood pressure, hypertriglyceridemia, low HDL cholesterol and hyperglycaemia. We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for reporting. Prospective, retrospective, randomized and nonrandomized studies fitting the search criteria were included in our results.

RESULTS

Our final analysis included 16 studies with a total number of 4.965.285 participants. There is considerable heterogeneity in terms of study design, participant characteristics and number of participants across individual studies. In comparison to healthy normal weight patients, the risk was progressively higher in overweight (RR 1.29, 95% CI 1.27 to 1.32, p < 0.001) and obese patients (RR 1.47, 95% CI 1.31 to 1.65, p < 0.001).

CONCLUSION

Metabolically healthy overweight and obese individuals have higher risk of CKD compared to individuals without weight excess.

Regulatory Networks, Management Approaches, and Emerging Treatments of Nonalcoholic Fatty Liver Disease

The pathogenesis of NAFLD is complex and diverse, involving multiple signaling pathways and cytokines from various organs. Hepatokines, stellakines, adipokines, and myokines secreted by hepatocytes, hepatic stellate cells, adipose tissue, and myocytes play an important role in the occurrence and development of nonalcoholic fatty liver disease (NAFLD). The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) contributes to the progression of NAFLD by mediating liver inflammation, immune response, hepatocyte death, and later compensatory proliferation. In this review, we first discuss the crosstalk and interaction between hepatokines, stellakines, adipokines, and myokines and NF-κB in NAFLD. The characterization of the crosstalk of NF-κB with these factors will provide a better understanding of the molecular mechanisms involved in the progression of NAFLD. In addition, we examine new expert management opinions for NAFLD and explore the therapeutic potential of silymarin in NAFLD/NASH.

Nutritional activities of luteolin in obesity and associated metabolic diseases: an eye on adipose tissues

Obesity is characterized by excessive body fat accumulation and is a high-risk factor for metabolic comorbidities, including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular disease. In lean individuals, adipose tissue (AT) is not only an important regulatory organ for energy storage and metabolism, but also an indispensable immune and endocrine organ. The sustained energy imbalance induces adipocyte hypotrophy and hyperplasia as well as AT remodeling, accompanied by chronic low-grade inflammation and adipocytes dysfunction in AT, ultimately leading to systemic insulin resistance and ectopic lipid deposition. Luteolin is a natural flavonoid widely distributed in fruits and vegetables and possesses multifold biological activities, such as antioxidant, anticancer, and anti-inflammatory activities. Diet supplementation of this flavonoid has been reported to inhibit AT lipogenesis and inflammation as well as the ectopic lipid deposition, increase AT thermogenesis and systemic energy expenditure, and finally improve obesity and associated metabolic diseases. The purpose of this review is to reveal the nutritional activities of luteolin in obesity and its complications with emphasis on its action on AT energy metabolism, immunoregulation, and endocrine intervention.

Role of adiponectin in osteoarthritis

Osteoarthritis (OA) is a widespread and most common joint disease which leads to social cost increasing accompany with aging population. Surgery is often the final treatment option. The major progression of OA includes cartilage degradation caused by chondrocytes metabolism imbalance. So, the molecular mechanisms of action in chondrocytes may provide insights into treatment methods for OA. Adiponectin is an adipokine with many biological functions in the cell metabolism. Numerous studies have illustrated that adiponectin has diverse biological effects, such as inhibition of cell apoptosis. It regulates various functions in different organs, including muscle, adipose tissue, brain, and bone, and regulates skeletal homeostasis. However, the relationship between adiponectin and cell death in the progression of OA needs further investigation. We elaborate the structure and function and the effect of adiponectin and state the correlation and intersection between adiponectin, autophagy, inflammation, and OA. From the perspective of oxidative stress, apoptosis, pyroptosis, and autophagy, we discuss the possible association between adiponectin, chondrocyte metabolism, and inflammatory factor efforts in OA. What’s more, we summarize the possible treatment methods, including the use of adiponectin as a drug target, and highlight the potential future mechanistic research. In this review, we summarize the molecular pathways and mechanisms of action of adiponectin in chondrocyte inflammation and death and the pathogenesis of OA. We also review the research on adiponectin as a target for treating OA. These studies provide a novel perspective to explore more effective treatment options considering the complex interrelationship between inflammation and metabolism in OA.

A brief overview about the adipokine: Isthmin-1

Isthmin-1 is a secreted protein with multiple capability; however, it truly attracts our attention since the definition as an adipokine in 2021, which exerts indispensable roles in various pathophysiological processes through the endocrine or autocrine manners. In this review, we summarize recent knowledge of isthmin-1, including its distribution, structure, receptor and potential function.

Contribution of organokines in the development of NAFLD/NASH associated hepatocellular carcinoma

Globally the incidence of hepatocellular carcinoma (HCC) is on an upsurge. Evidence is accumulating that liver disorders like nonalcoholic fatty liver disease (NAFLD) and its more progressive form nonalcoholic steatohepatitis (NASH) are associated with increased risk of developing HCC. NAFLD has a prevalence of about 25% and 50%-90% in obese population. With the growing burden of obesity epidemic worldwide, HCC presents a major healthcare burden. While cirrhosis is one of the major risk factors of HCC, available literature suggests that NAFLD/NASH associated HCC also develops in minimum or noncirrhotic livers. Therefore, there is an urgent need to understand the pathogenesis and risk factors associated with NAFLD and NASH related HCC that would help in early diagnosis and favorable prognosis of HCC secondary to NAFLD. Adipokines, hepatokines and myokines are factors secreted by adipocytes, hepatocytes and myocytes, respectively, playing essential roles in cellular homeostasis, energy balance and metabolism with autocrine, paracrine and endocrine effects. In this review, we endeavor to focus on the role of these organokines in the pathogenesis of NAFLD/NASH and its progression to HCC to augment the understanding of the factors stimulating hepatocytes to acquire a malignant phenotype. This shall aid in the development of novel therapeutic strategies and tools for early diagnosis of NAFLD/NASH and HCC.

A randomized diet-induced weight-loss intervention reduces plasma complement C3: Possible implication for endothelial dysfunction

OBJECTIVE

Complement C3 and other components of the alternative pathway are higher in individuals with obesity. Moreover, C3 has been identified as a risk factor for cardiovascular disease. This study investigated whether, and how, a weight-loss intervention reduced plasma C3, activated C3 (C3a), and factor D and explored potential biological effects of such a reduction.

METHODS

The study measured plasma C3, C3a, and factor D by ELISA and measured visceral adipose tissue, subcutaneous adipose tissue, and intrahepatic lipid by magnetic resonance imaging in lean men (n = 25) and men with abdominal obesity (n = 52). The men with obesity were randomized to habitual diet or an 8-week dietary weight-loss intervention.

RESULTS

The intervention significantly reduced C3 (-0.15 g/L [95% CI: -0.23 to -0.07]), but not C3a or factor D. The C3 reduction was mainly explained by reduction in visceral adipose tissue but not subcutaneous adipose tissue or intrahepatic lipid. This reduction in C3 explained a part of the weight-loss-induced improvement of markers of endothelial dysfunction, particularly the reduction in soluble endothelial selectin and soluble intercellular adhesion molecule.

CONCLUSIONS

Diet-induced weight loss in men with abdominal obesity could be a way to lower plasma C3 and thereby improve endothelial dysfunction. C3 reduction may be part of the mechanism via which diet-induced weight loss could ameliorate the risk of cardiovascular disease in men with abdominal obesity.

Anti-adipogenic and Pro-lipolytic Effects on 3T3-L1 Preadipocytes by CX-4945, an Inhibitor of Casein Kinase 2

Casein kinase 2 (CK2) is a ubiquitously expressed serine/threonine kinase and is upregulated in human obesity. CX-4945 (Silmitasertib) is a CK2 inhibitor with anti-cancerous and anti-adipogenic activities. However, the anti-adipogenic and pro-lipolytic effects and the mode of action of CX-4945 in (pre)adipocytes remain elusive. Here, we explored the effects of CX-4945 on adipogenesis and lipolysis in differentiating and differentiated 3T3-L1 cells, a murine preadipocyte cell line. CX-4945 at 15 μM strongly reduced lipid droplet (LD) accumulation and triglyceride (TG) content in differentiating 3T3-L1 cells, indicating the drug’s anti-adipogenic effect. Mechanistically, CX-4945 reduced the expression levels of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and perilipin A in differentiating 3T3-L1 cells. Strikingly, CX-4945 further increased the phosphorylation levels of cAMP-activated protein kinase (AMPK) and liver kinase B-1 (LKB-1) while decreasing the intracellular ATP content in differentiating 3T3-L1 cells. In differentiated 3T3-L1 cells, CX-4945 had abilities to stimulate glycerol release and elevate the phosphorylation levels of hormone-sensitive lipase (HSL), pointing to the drug’s pro-lipolytic effect. In addition, CX-4945 induced the activation of extracellular signal-regulated kinase-1/2 (ERK-1/2), and PD98059, an inhibitor of ERK-1/2, attenuated the CX4945-induced glycerol release and HSL phosphorylation in differentiated 3T3-L1 cells, indicating the drug’s ERK-1/2-dependent lipolysis. In summary, this investigation shows that CX-4945 has strong anti-adipogenic and pro-lipolytic effects on differentiating and differentiated 3T3-L1 cells, mediated by control of the expression and phosphorylation levels of CK2, C/EBP-α, PPAR-γ, FAS, ACC, perilipin A, AMPK, LKB-1, ERK-1/2, and HSL.

The role of the androgen receptor in the pathogenesis of obesity and its utility as a target for obesity treatments

Obesity is associated with hypothalamic-pituitary-testicular axis dysregulation in males. Here, we summarize recent evidence derived from clinical trials and studies in preclinical animal models regarding the role of androgen receptor (AR) signaling in the pathophysiology of males with obesity. We also discuss therapeutic strategies targeting the AR for the treatment of obesity and their limitations and provide insight into the future research necessary to advance this field.

Novel Noninvasive Approaches to the Treatment of Obesity: From Pharmacotherapy to Gene Therapy

Recent insights into the pathophysiologic underlying mechanisms of obesity have led to the discovery of several promising drug targets and novel therapeutic strategies to address the global obesity epidemic and its comorbidities. Current pharmacologic options for obesity management are largely limited in number and of modest efficacy/safety profile. Therefore, the need for safe and more efficacious new agents is urgent. Drugs that are currently under investigation modulate targets across a broad range of systems and tissues, including the central nervous system, gastrointestinal hormones, adipose tissue, kidney, liver, and skeletal muscle. Beyond pharmacotherapeutics, other potential antiobesity strategies are being explored, including novel drug delivery systems, vaccines, modulation of the gut microbiome, and gene therapy. The present review summarizes the pathophysiology of energy homeostasis and highlights pathways being explored in the effort to develop novel antiobesity medications and interventions but does not cover devices and bariatric methods. Emerging pharmacologic agents and alternative approaches targeting these pathways and relevant research in both animals and humans are presented in detail. Special emphasis is given to treatment options at the end of the development pipeline and closer to the clinic (ie, compounds that have a higher chance to be added to our therapeutic armamentarium in the near future). Ultimately, advancements in our understanding of the pathophysiology and interindividual variation of obesity may lead to multimodal and personalized approaches to obesity treatment that will result in safe, effective, and sustainable weight loss until the root causes of the problem are identified and addressed.

Adipsin Serum Concentrations and Adipose Tissue Expression in People with Obesity and Type 2 Diabetes

(1) Adipsin is an adipokine that may link increased fat mass and adipose tissue dysfunction to obesity-related cardiometabolic diseases. Here, we investigated whether adipsin serum concentrations and adipose tissue (AT) adipsin mRNA expression are related to parameters of AT function, obesity and type 2 diabetes (T2D). (2) Methods: A cohort of 637 individuals with a wide range of age and body weight (Age: 18–85 years; BMI: 19–70 kg/m2) with (n = 237) or without (n = 400) T2D was analyzed for serum adipsin concentrations by ELISA and visceral (VAT) and subcutaneous (SAT) adipsin mRNA expression by RT-PCR. (3) Results: Adipsin serum concentrations were significantly higher in patients with T2D compared to normoglycemic individuals. We found significant positive univariate relationships of adipsin serum concentrations with age (r = 0.282, p < 0.001), body weight (r = 0.264, p < 0.001), fasting plasma glucose (r = 0.136, p = 0.006) and leptin serum concentrations (r = 0.362, p < 0.001). Neither VAT nor SAT adipsin mRNA expression correlated with adipsin serum concentrations after adjusting for age, sex and BMI. Independent of T2D status, we found significantly higher adipsin expression in SAT compared to VAT (4) Conclusions: Our data suggest that adipsin serum concentrations are strongly related to obesity and age. However, neither circulating adipsin nor adipsin AT expression reflects parameters of impaired glucose or lipid metabolism in patients with obesity with or without T2D.

Association of Cardiopulmonary Exercise Capacity and Adipokines in the General Population

Adipokines and cardiorespiratory fitness (CRF) are associated with the (patho)physiology of cardiometabolic diseases. Whether CRF and adipokines are related is unclear. We investigated associations of CRF with leptin, adiponectin, chemerin, resistin and vaspin. Data from the population-based Study of Health in Pomerania was used (n=1,479; median age 49 years; 51% women). Cardiopulmonary exercise testing was used to measure CRF. Circulating adipokine concentrations were measured by enzyme-linked immunosorbent assay. The association between CRF and adipokines was assessed using multivariable sex-specific quantile regression models. Higher maximum oxygen uptake was significantly associated with lower leptin (men:-0.11 ng/ml; 95%-confidence interval [CI]:-0.18 to-0.03 ng/ml; p<0.005; women:-0.17 ng/ml; 95%-CI:-0.33 to-0.02 ng/ml; p<0.05) and chemerin (men:-0.26 ng/ml; 95%-CI:-0.52 to-0.01 ng/ml; p<0.05; women:-0.41 ng/ml; 95%-CI:-0.82 to-0.01 ng/ml; p<0.05) as well as higher adiponectin concentrations (men: 0.06 µg/ml; 95%-CI: 0.02 to 0.11 µg/ml; p<0.05; women: 0.03 µg/ml; 95%-CI:-0.05 to 0.10 µg/ml; p=0.48). We found that CRF was inversely associated with leptin and chemerin in both sexes and positively associated with adiponectin only in men.

Non-alcoholic fatty liver disease and type 2 diabetes - An Update

The global prevalence of non‐alcoholic fatty liver disease (NAFLD) is rising, along with the epidemic of diabesity. NAFLD is present in >70% of individuals with type 2 diabetes. Although the mutually detrimental relationship between NAFLD and type 2 diabetes has been well established, a multitude of recent studies have further shown that type 2 diabetes is closely linked to the development of cirrhosis, hepatocellular carcinoma, liver‐related morbidity and mortality. In contrast, NAFLD also negatively impacts type 2 diabetes both in terms of its incidence and related adverse clinical outcomes, including cardiovascular and chronic kidney diseases. In response to these global health threats, clinical care pathways for NAFLD and guidelines for metabolic dysfunction‐associated fatty liver disease have been developed. Several antidiabetic agents have been evaluated for their potential hepatic benefits with promising results. Furthermore, type 2 diabetes patients are increasingly represented in clinical trials of novel therapeutics for NAFLD. However, despite the wealth of knowledge in NAFLD and type 2 diabetes, lack of awareness of the disease and the potential weight of this problem remains a major challenge, especially among clinicians who are outside the field of hepatology and gastroenterology. This review therefore aimed to provide all diabetes care providers with a summary of the latest evidence that supports NAFLD as an emerging diabetic complication of increasing importance, and to present the current recommendations, focusing on the assessment and therapeutic strategies, on the management of NAFLD among type 2 diabetes patients.

Involvement of caveolae in hyperglycemia-induced changes in adiponectin and leptin expressions in vascular smooth muscle cells

Hyperglycemia exerts various harmful effects on the vasculature. Studies have shown an association between the levels of the adipokines leptin and adiponectin (APN) and vascular complications in diabetes mellitus. The aim of our study was to investigate the molecular mechanisms mediated by APN and leptin that are involved in hyperglycemia-induced vascular remodeling, especially at the level of oxidative stress and actin cytoskeleton dynamics. Rat aorta organ culture was used to investigate the effect of hyperglycemia on APN and leptin protein expression in vascular smooth muscle cells (VSMCs) using Western blot analysis and immunohistochemistry. Hyperglycemia lead to a significant increase in APN synthesis in VSMCs, mainly through caveolae, but this increase failed to provide vascular protection because of the decreased expression of APN receptors, especially AdipoR2, which was assessed by qPCR. In addition, hyperglycemia significantly upregulated leptin expression in VSMCs through caveolae and the RhoA/ROCK pathway. These variations lead to a marked increase in reactive oxygen species (ROS) production, detected by dihydroethidium (DHE) staining, and in NADPH oxidase type 4 (Nox4) expression. Moreover, Nox4 mediated the synthesis of APN in hyperglycemia in VSMCs. Finally, hyperglycemia activated the RhoA/ROCK pathway and subsequently induced the polymerization of globular actin (G-actin) into filamentous actin (F-actin), decreasing the G/F-actin ratio. Taken together, these data show that hyperglycemia increases oxidative stress and changes actin cytoskeleton dynamics in the aorta via caveolae, favoring vascular remodeling.

The Role of Anti-Inflammatory Adipokines in Cardiometabolic Disorders: Moving beyond Adiponectin

The global burden of obesity has multiplied owing to its rapidly growing prevalence and obesity-related morbidity and mortality. In addition to the classic role of depositing extra energy, adipose tissue actively interferes with the metabolic balance by means of secreting bioactive compounds called adipokines. While most adipokines give rise to inflammatory conditions, the others with anti-inflammatory properties have been the novel focus of attention for the amelioration of cardiometabolic complications. This review compiles the current evidence on the roles of anti-inflammatory adipokines, namely, adiponectin, vaspin, the C1q/TNF-related protein (CTRP) family, secreted frizzled-related protein 5 (SFRP5), and omentin-1 on cardiometabolic health. Further investigations on the mechanism of action and prospective human trials may pave the way to their clinical application as innovative biomarkers and therapeutic targets for cardiovascular and metabolic disorders.

Association of adipocyte fatty acid-binding protein and tumor necrosis factor alpha with periodontal health and disease: A cross-sectional investigation

Background

Adipocyte fatty acid binding protein (A-FABP) is a novel biomarker of inflammation for various chronic systemic diseases. Since periodontitis is a chronic inflammatory disease, this study explores the association of A-FABP with periodontal disease parameters and tumor necrosis factor-alpha (TNF-α) levels in gingival crevicular fluid in periodontal health and disease.

Materials and Methods

This original research article describes a cross-sectional study conducted at the Department of Periodontics, M. R. Ambedkar Dental College and Hospital, Bangalore, India. This cross-sectional investigation was conducted on sixty subjects which were divided into three groups of twenty subjects each - healthy, gingivitis, and chronic periodontitis. Clinical parameters - plaque index, bleeding index, probing depth, and clinical attachment loss were recorded. Gingival crevicular fluid samples were analyzed for A-FABP and TNF-α levels using ELISA. One-way analysis of variance was used to find the significance of study parameters on a continuous scale between three groups. Pearson's correlation has been used to find the relationship between Gingival crevicular fluid concentration of markers and periodontal parameters. Multiple linear regression analysis was applied to the study. The statistical significance was considered at P < 0.05.

Results

Mean concentration of A-FABP (6.43 ± 2.51) and TNF-α (3454.82 ± 1566.44) was highest in the periodontitis group, and the difference among the groups was statistically significant (P < 0.05). A positive correlation was observed between clinical attachment loss and the two markers among all groups. The correlation between A-FABP and TNF-α in periodontitis groups was positive and statistically significant (P < 0.05). Multiple linear regression model was statistically significant (P < 0.05) indicating that there is a significant relationship between the set of predictors and the clinical attachment loss.

Conclusion

A-FABP and TNF-α levels in GCF were significantly elevated in the presence of inflammation. A-FABP has a probable stimulatory effect on TNF-α; however, its role needs to be explored. A-FABP could serve as a novel inflammatory biomarker of periodontitis and the scope of using A-FABP inhibition as a treatment modality could be investigated with interventional studies.

Metabolic syndrome and hidradenitis suppurativa: epidemiological, molecular, and therapeutic aspects

Hidradenitis suppurativa (HS) is a chronic, suppurative condition of the pilosebaceous unit. Patients suffering from HS demonstrate a molecular profile in keeping with a state of systemic inflammation and are often found to fit the criteria for a diagnosis of metabolic syndrome (MetS). In this paper, we review the literature with regards to established data on the prevalence of MetS in HS patients and revise the odds ratio of comorbid disease. Furthermore, we attempt to draw parallels between inflammatory pathways in HS and MetS and evaluate how convergences may explain the risk of comorbid disease, necessitating the need for multidisciplinary care.

Development of metabolic dysfunction in mice lacking chemerin

Chemerin, an adipocyte-secreted adipokine, is hypothesized to participate in energy homeostasis and glucoregulation. However, the physiologic effect of endogenous chemerin on glucose metabolism is unclear. The present studies tested the hypotheses that chemerin deficiency alters whole-body glucose homeostasis following switches to high-fat diet. Adult, male chemerin knockout and C57BL/6J control wild type mice were studied. During the following 4 weeks, chow- or high-fat diet maintained chemerin knockout mice showed elevated fasting glucose levels and glucose intolerance as well as insulin intolerance. Chemerin deficiency impaired adaptation to glucose and insulin challenge, leading to increased glucose levels. Moreover, the mRNA and protein levels of GLUT4 and PGC-1α expression in both skeletal muscle and adipose tissue were significantly decreased in chemerin knockout mice relative to the wild type, respectively. Taken together, the results support the hypotheses that chemerin helps adapt glucose metabolism to changes in dietary fat and modulates glucose consumption in mice by activation of PGC-1α/GLUT4 axis. Chemerin may play a significant role in elevation of glucose uptake and insulin sensitivity to promote glucose clearance.

Obesity and obesity-induced inflammatory disease contribute to atherosclerosis: a review of the pathophysiology and treatment of obesity

Two billion people worldwide older than 18 years of age, or approximately 30% of the world population, are overweight or obese. In addition, more than 43 million children under the age of 5 are overweight or obese. Among the population in the United States aged 20 and greater, 32.8 percent are overweight and 39.8 percent are obese. Blacks in the United States have the highest age-adjusted prevalence of obesity (49.6%), followed by Hispanics (44.8%), whites (42.2%) and Asians (17.4%). The impact of being overweight or obese on the US economy exceeds $1.7 trillion dollars, which is equivalent to approximately eight percent of the nation's gross domestic product. Obesity causes chronic inflammation that contributes to atherosclerosis and causes >3.4 million deaths/year. The pathophysiologic mechanisms in obesity that contribute to inflammation and atherosclerosis include activation of adipokines/cytokines and increases in aldosterone in the circulation. The adipokines leptin, resistin, IL-6, and monocyte chemoattractant protein activate and chemoattract monocytes/macrophages into adipose tissue that promote visceral adipose and systemic tissue inflammation, oxidative stress, abnormal lipid metabolism, insulin resistance, endothelial dysfunction, and hypercoagulability that contribute to atherosclerosis. In addition in obesity, the adipokines/cytokines IL-1β, IL-18, and TNF are activated and cause endothelial cell dysfunction and hyperpermeability of vascular endothelial junctions. Increased aldosterone in the circulation not only expands the blood volume but also promotes platelet aggregation, vascular endothelial dysfunction, thrombosis, and fibrosis. In order to reduce obesity and obesity-induced inflammation, therapies including diet, medications, and bariatric surgery are discussed that should be considered in patients with BMIs>35-40 kg/m2 if diet and lifestyle interventions fail to achieve weight loss. In addition, antihypertensive therapy, plasma lipid reduction and glucose lowering therapy should be prescribed in obese patients with hypertension, a 10-year CVD risk >7.5%, or prediabetes or diabetes.

From leptin to lasers: the past and present of mouse models of obesity

Introduction: Obesity is a prevalent condition that accounts for significant morbidity and mortality across the globe. Despite substantial effort, most obesity pharmacotherapies have proven unsafe or ineffective. The use of obese mouse models provides unique insight into the hormones and mechanisms that regulate appetite and metabolism. Paramount among these models are the 'obese' and 'diabetic' mice that revealed the powerful satiety hormone leptin, revolutionizing obesity research.Areas Covered: In this article, the authors discuss work on leptin therapy, and the clinical response to leptin in humans. The authors describe the use of modern mouse genetics to study targetable mechanisms for genetic forms of human obesity. Additionally, they describe mouse models of neuromodulation and their utility in unraveling neural circuits that govern appetite and metabolism.Expert opinion: Combining past and present models of obesity is required for the development of safe, effective, and impactful obesity therapy. Current research in obesity can benefit from repositories of genetically engineered mouse models to discover interactions between appetitive systems and circuits. Combining leptin therapy with other satiety signals comprising the gut-brain axis is a promising approach to induce significant enduring weight loss.

Retinol-binding protein 4 in obesity and metabolic dysfunctions

Excessive increased adipose tissue mass in obesity is associated with numerous co-morbid disorders including increased risk of type 2 diabetes, fatty liver disease, hypertension, dyslipidemia, cardiovascular diseases, dementia, airway disease and some cancers. The causal mechanisms explaining these associations are not fully understood. Adipose tissue is an active endocrine organ that secretes many adipokines, cytokines and releases metabolites. These biomolecules referred to as adipocytokines play a significant role in the regulation of whole-body energy homeostasis and metabolism by influencing and altering target tissues function. Understanding the mechanisms of adipocytokine actions represents a hot topic in obesity research. Among several secreted bioactive signalling molecules from adipose tissue and liver, retinol-binding protein 4 (RBP4) has been associated with systemic insulin resistance, dyslipidemia, type 2 diabetes and other metabolic diseases. Here, we aim to review and discuss the current knowledge on RBP4 with a focus on its role in the pathogenesis of obesity comorbid diseases.

AdipoRon: A Novel Insulin Sensitizer in Various Complications and the Underlying Mechanisms: A Review

BACKGROUND

AdipoRon is the first synthetic analog of endogenous adiponectin, an adipose tissue-derived hormone. AdipoRon possesses pharmacological properties similar to adiponectin and its ability to bind and activate the adipoR1 and adipoR2 receptors makes it a suitable candidate for the treatment of a multitude of disorders.

OBJECTIVE

In the present review, an attempt was made to compile and discuss the efficacy of adipoRon against various disorders.

RESULTS

AdipoRon is a drug that acts not only in metabolic diseases but in other conditions unrelated to energy metabolism. It is well- reported that adipoRon exhibits strong anti-obesity, anti-diabetic, anticancer, anti-depressant, anti-ischemic, anti-hypertrophic properties and also improves conditions like post-traumatic stress disorder, anxiety, and systemic sclerosis.

CONCLUSION

A lot is known about its effects in experimental systems, but the translation of this knowledge to the clinic requires studies which, for many of the potential target conditions, have yet to be carried out. The beneficial effects of AdipoRon in novel clinical conditions will suggest an underlying pathophysiological role of adiponectin and its receptors in previously unsuspected settings.

Fucoxanthin and Colorectal Cancer Prevention

Simple Summary

Colorectal cancer (CRC) is suggested to be preventable by certain food intakes. Fucoxanthin (Fx) is an anticancer agent contained abundantly in edible brown algae. However, epidemiological studies, in vivo and in vitro experiments for CRC, using Fx and Fx-rich foods, have not been fully outlined. To date, it has been reported that Fx, its metabolite of fucoxanthinol (FxOH) and Fx-rich algal extracts exerted anticancer potentials in human CRC cell lines, their cancer stem-cells-like spheroids and CRC animal models through a number of molecular mechanisms. Moreover, many in vivo experiments and interventional human trials have demonstrated that Fx, Fx-rich algal extracts and brown alga itself may improve CRC and/or certain risks, such as obesity, diabetes, metabolic syndrome, inflammation, oxidation, tumor microenvironment and/or gut microbiota. This review is the first report that summarizes the improving effects by Fx, FxOH and its rich brown algae for CRC and the risk factors.

Abstract

Colorectal cancer (CRC), which ranks among the top 10 most prevalent cancers, can obtain a good outcome with appropriate surgery and/or chemotherapy. However, the global numbers of both new cancer cases and death from CRC are expected to increase up to 2030. Diet-induced lifestyle modification is suggested to be effective in reducing the risk of human CRC; therefore, interventional studies using diets or diet-derived compounds have been conducted to explore the prevention of CRC. Fucoxanthin (Fx), a dietary carotenoid, is predominantly contained in edible brown algae, such as Undaria pinnatifida (wakame) and Himanthalia elongata (Sea spaghetti), which are consumed particularly frequently in Asian countries but also in some Western countries. Fx is responsible for a majority of the anticancer effects exerted by the lipophilic bioactive compounds in those algae. Interventional human trials have shown that Fx and brown algae mitigate certain risk factors for CRC; however, the direct mechanisms underlying the anti-CRC properties of Fx remain elusive. Fx and its deacetylated type “fucoxanthinol” (FxOH) have been reported to exert potential anticancer effects in preclinical cancer models through the suppression of many cancer-related signal pathways and the tumor microenvironment or alteration of the gut microbiota. We herein review the most recent studies on Fx as a potential candidate drug for CRC prevention.

Dapagliflozin elevates plasma high-density lipoprotein levels and influences visceral fat gene expression in streptozotocin-induced diabetes mellitus

OBJECTIVES

Dapagliflozin (Dapa) could potentially be used to treat type 1 diabetes mellitus. We tested the hypothesis that it would influence blood lipid levels and visceral fat accumulation in a rodent diabetic model.

METHODS

We used three groups of male Wistar rats: Controls, streptozotocin (STZ)-treated rats and STZ-treated orally with Dapa (STZ+Dapa), 10 mg/kg/day for six weeks. Blood glucose and serum lipids levels were determined. Plasma levels of lipases (hormone-sensitive lipase, HSL and lipoprotein lipase, LPL), adipokines (leptin and adiponectin) and proinflammatory cytokines [tumour necrosis factor-alpha (TNFα) and interleukin-6 (IL-6)] were determined by ELISA assays. mRNA levels in the perirenal fat were determined by real-time PCR.

KEY FINDINGS

Dapa suppressed STZ-related hyperglycemia by 20% (P < 0.05) and increased serum HDL when compared to the controls and the STZ-only treated rats (both P < 0.05). STZ treatment caused elevations of other serum lipids that were resistant to Dapa treatment. Dapa treatment also increased both plasma and visceral fat mRNA levels of leptin, LPL and IL-6, while decreasing plasma and fat expressions of HSL and TNFα compared to the STZ-only treated rats (all P < 0.05).

CONCLUSIONS

Our results suggest that Dapa, in addition to its antidiabetic effect, also influences the function of adipose tissue which could be beneficial in the treatment of diabetes.

Emerging Protein Biomarkers for the Diagnosis or Prediction of Gestational Diabetes-A Scoping Review

Introduction: Gestational diabetes (GDM), defined as hyperglycemia with onset or initial recognition during pregnancy, has a rising prevalence paralleling the rise in type 2 diabetes (T2DM) and obesity. GDM is associated with short-term and long-term consequences for both mother and child. Therefore, it is crucial we efficiently identify all cases and initiate early treatment, reducing fetal exposure to hyperglycemia and reducing GDM-related adverse pregnancy outcomes. For this reason, GDM screening is recommended as part of routine pregnancy care. The current screening method, the oral glucose tolerance test (OGTT), is a lengthy, cumbersome and inconvenient test with poor reproducibility. Newer biomarkers that do not necessitate a fasting sample are needed for the prompt diagnosis of GDM. The aim of this scoping review is to highlight and describe emerging protein biomarkers that fulfill these requirements for the diagnosis of GDM. Materials and Methods: This scoping review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for scoping reviews using Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing & Allied Health Literature (CINAHL), PubMed, Embase and Web of Science with a double screening and extraction process. The search included all articles published in the literature to July 2020. Results: Of the 3519 original database citations identified, 385 were eligible for full-text review. Of these, 332 (86.2%) were included in the scoping review providing a total of 589 biomarkers studied in relation to GDM diagnosis. Given the high number of biomarkers identified, three post hoc criteria were introduced to reduce the items set for discussion: we chose only protein biomarkers with at least five citations in the articles identified by our search and published in the years 2017-2020. When applied, these criteria identified a total of 15 biomarkers, which went forward for review and discussion. Conclusions: This review details protein biomarkers that have been studied to find a suitable test for GDM diagnosis with the potential to replace the OGTT used in current GDM screening protocols. Ongoing research efforts will continue to identify more accurate and practical biomarkers to take GDM screening and diagnosis into the 21st century.

Roles and mechanisms of adipokines in drug resistance of tumor cells

The drug resistance of cancer cells has become one of the biggest obstacles of effective anticancer treatments. Adipocytes produce plenty of cytokines (also known as adipokines), which remarkably affect the drug resistance exhibited by cancer cells. Different adipokines (leptin, visfatin, resistin, adiponectin, Interleukin 6, and tumor necrosis factor α) can induce drug resistance in different cancer cells by various functional mechanisms. This phenomenon is of great interest in pharmacological anti-cancer studies since it indicates that in the cancers with adipocyte-rich microenvironment, all adipokines join together to assist cancer cells to survive by facilitating drug resistance. Studies on adipokines contribute to the development of novel pharmacological strategies for cancer therapy if their roles and molecular targets are better understood. The review will elucidate the roles and the underlying mechanisms of adipokines in drug resistance, which may be of great significance for revealing new strategies for cancer treatment.

Visceral Obesity, Metabolic Syndrome, and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) represents an exemplar of obesity-associated carcinogenesis, with a progressive increase in EAC risk with increased body mass index. In this context, there is increased focus on visceral adipose tissue and associated metabolic dysfunction, including hypertension, diabetes mellitus and hyperlipidemia, or combinations of these in the metabolic syndrome. Visceral obesity (VO) may promote EAC via both directly impacting on gastro-esophageal reflux disease and Barrett's esophagus, as well as via reflux-independent effects, involving adipokines, growth factors, insulin resistance, and the microbiome. In this review these pathways are explored, including the impact of VO on the tumor microenvironment, and on cancer outcomes. The current evidence-based literature regarding the role of dietary, lifestyle, pharmacologic and surgical interventions to modulate the risk of EAC is explored.

Functions of Forkhead Box O on Glucose Metabolism in Abalone Haliotis discus hannai and Its Responses to High Levels of Dietary Lipid

The forkhead box O (FoxO) subfamily is a member of the forkhead transcription factor family. It has regulation functions in glucose metabolism in mammals and fish. In the present study, a gene of the foxo homolog in abalone Haliotis discus hannai was cloned. A conservative forkhead (FH) domain and a transactivation (FoxO-TAD) domain were identified. Abalone foxo-specific siRNA (small interfering RNA) was injected to investigate the functions of foxo on glucose metabolism. Knockdown of foxo inhibited expression of phosphoenolpyruvate carboxykinase (pepck) and significantly increased expressions of hexokinase (hk) and pyruvate kinase (pk), but it failed to inhibit the relative mRNA level of glucose-6-phosphatase (g6pase). Then, a 100-day feeding trial was conducted to investigate the response of foxo and glucose metabolism in abalone fed with 1.57% (LFD, low-fat diet), 3.82% (MFD, middle-fat diet) and 6.72% (HFD, high-fat diet) of dietary lipid, respectively. The insulin-signaling pathway (AKT) was depressed and FoxO was activated by the HFD, but it did not inhibit glycolysis (hk) or improved gluconeogenesis significantly (pepck and g6pase). At the same time, impaired hepatopancreas glycogen storage raised hemolymph glucose levels. In conclusion, abalone foxo can be regulated by dietary lipid and can regulate gluconeogenesis or glycolysis in response to changes of dietary lipid levels, in which glycogen metabolism plays an important role.

The impact of exercise training versus caloric restriction on inflammation markers: a systemic review and meta-analysis

Obesity is associated with an increased risk of chronic, low-grade systematic inflammation for which exercise training (EX) and caloric restriction (CR) are potential treatments. We therefore performed a systematic meta-analysis to compare the effect of EX vs. CR and EX + CR vs. CR on inflammation markers in overweight and obese individuals. PubMed, Scopus, Web of Science and the Cochrane were searched up to April 2020 for EX vs. CR or EX + CR vs. CR interventions studies on inflammatory makers i.e. CRP, IL-6 and TNF-α in overweight and obese individuals. Standardized mean differences and 95% confidence intervals were calculated. Thirty two articles (reporting 38 trials) involving 2108 participants were included in the meta-analysis. Based on studies that directly compared EX and CR, there were no evidence for an effect of EX on IL-6 (p = 0.20) and TNF-α (p = 0.58), when compared with a CR. However, when compared to EX, CR has a statistically greater benefit on CRP (p = 0.01). In those studies, directly comparing EX + CR and CR, EX + CR caused a larger decrease in TNF-α (p = 0.002) and IL-6 (p = 0.02) and tended to decrease CRP (p = 0.06) when compared with CR. These results suggest that a combination of EX and CR may be more effective than CR alone at reducing inflammatory cytokines and CRP in overweight and obese individuals.

Adipokines in the Skin and in Dermatological Diseases

Adipokines are the primary mediators of adipose tissue-induced and regulated systemic inflammatory diseases; however, recent findings revealed that serum levels of various adipokines correlate also with the onset and the severity of dermatological diseases. Importantly, further data confirmed that the skin serves not only as a target for adipokine signaling, but may serve as a source too. In this review, we aim to provide a complex overview on how adipokines may integrate into the (patho) physiological conditions of the skin by introducing the cell types, such as keratinocytes, fibroblasts, and sebocytes, which are known to produce adipokines as well as the signals that target them. Moreover, we discuss data from in vivo and in vitro murine and human studies as well as genetic data on how adipokines may contribute to various aspects of the homeostasis of the skin, e.g., melanogenesis, hair growth, or wound healing, just as to the pathogenesis of dermatological diseases such as psoriasis, atopic dermatitis, acne, rosacea, and melanoma.