Multifaceted Physiological Roles of Adiponectin in Inflammation and Diseases

Enhancing adipose tissue functionality in obesity: senotherapeutics, autophagy and cellular senescence as a target

Obesity, a global health crisis, disrupts multiple systemic processes, contributing to a cascade of metabolic dysfunctions by promoting the pathological expansion of visceral adipose tissue (VAT). This expansion is characterized by impaired differentiation of pre-adipocytes and an increase in senescent cells, leading to a pro-inflammatory state and exacerbated oxidative stress. Particularly, the senescence-associated secretory phenotype (SASP) and adipose tissue hypoxia further impair cellular function, promoting chronic disease development. This review delves into the potential of autophagy modulation and the therapeutic application of senolytics and senomorphics as novel strategies to mitigate adipose tissue senescence. By exploring the intricate mechanisms underlying adipocyte dysfunction and the emerging role of natural compounds in senescence modulation, we underscore the promising horizon of senotherapeutics in restoring adipose health. This approach not only offers a pathway to combat the metabolic complications of obesity, but also opens new avenues for enhancing life quality and managing the global burden of obesity-related conditions. Our analysis aims to bridge the gap between current scientific progress and clinical application, offering new perspectives on preventing and treating obesity-induced adipose dysfunction.

Key Players in the Complex Pathophysiology of Obesity: A Cross-Talk Between the Obesogenic Genes and Unraveling the Metabolic Pathway of Action of Capsaicin and Orange Peel

Obesity is a widespread prevailing health concern with multifactorial causes. Among the various defined molecular targets associated with obesity, peroxisome proliferator activated receptor gamma, leptin, ghrelin, and adiponectin play crucial roles in fundamental processes including energy balance, adipose tissue biology, and metabolic health, making them particularly significant in the study of obesity.Capsaicin and orange peel exhibit promising anti-obesity properties through their thermogenic, metabolic, and anti-inflammatory effects. Potential pathways for therapeutic approaches in the management of obesity are provided by these targets. The lipid-lowering and anti-obesity benefits of specific plant species have been highlighted in Asian medicine. Due to the potential anti-obesity qualities, capsaicin, which is derived from chilli peppers, and orange peel extract has been focused in this review. Capsaicin causes apoptosis in preadipocytes and adipocytes and suppresses adipogenesis. Citrus fruits are a significant source of bioactive substances, primarily flavonoids. Due to their ability to reduce adipocyte development and cellular lipid content, citrus polyphenols are helpful in the control of obesity. This extensive analysis offers insights into new treatment approaches for the prevention and management of obesity and metabolic syndrome by examining the interactions of molecular variables in obesity as well as the possible anti-obesity advantages of capsaicin and orange peel extract.

Effect of tannic acid on adiponectin and gonads in male Brandt's voles (Lasiopodomys brandtii)

Adiponectin regulates steroid production and influences gonadal development. This study examined the effects of tannic acid (TA) on the adiponectin levels and gonads of male Brandt's voles. Male Brandt's voles aged 90 d were randomly separated into three groups: a control group (provided distilled water), a group given 600 mg∙kg-1 TA, and a group that received 1200 mg∙kg-1 TA (continuous gavage for 18 d). In this study, we examined the effects of TA on the adiponectin, antioxidant, and inflammatory levels in the testes. Furthermore, we examined the expression of important regulatory elements that influence adiponectin expression and glucose utilisation. In addition, the body weight, reproductive organ weight, and testicular shape were assessed. Our study observed that TA treatment increased serum adiponectin levels, DsbA-L and Ero1-Lα transcription levels, and AdipoR1, AMPK, GLUT1, and MCT4 expression levels in testicular tissue. TA enhanced pyruvate and lactic acid levels in the testicular tissue, boosted catalase activity, and reduced MDA concentrations. TA reduced the release of inflammatory factors in the testicular tissues of male Brandt's voles. TA increased the inner diameter of the seminiferous tubules. In conclusion, TA appears to stimulate adiponectin secretion and gonadal growth in male Brandt's voles while acting as an antioxidant and anti-inflammatory agent.

Role of leptin and adiponectin in the pathogenesis of post-transplant diabetes mellitus

Solid organ transplantation is a life-saving treatment for patients with end-stage organ failure, but it poses unique challenges due to metabolic and immunological changes in recipients. One significant complication is post-transplant diabetes mellitus (PTDM), which affects a variety of solid organ recipients. Leptin, a hormone produced by adipose tissue, regulates appetite and affects glucose metabolism. High leptin levels are associated with the development of PTDM, especially in kidney transplant recipients. Adiponectin, another adipokine, increases insulin sensitivity and has anti-diabetic properties. Low adiponectin levels are associated with insulin resistance and increase the risk of PTDM. As the incidence of PTDM increases due to the increased life expectancy among transplant patients, understanding the role of adipokines such as leptin and adiponectin becomes crucial for early detection and treatment. Additional studies on other adipokines may also provide valuable information on the pathogenesis of PTDM.

Adipokines-A Cohort Prospective Study in Children with Severe Burns

Burns generate every year an important burden of morbidity, being a major global public health problem through prolonged hospitalization, complications, and increased mortality. This study's purpose was to evaluate the serum levels of three adipokines and to establish significant correlations with other circulating molecules and with some clinical parameters. We evaluated 32 children with severe burns (over 25% total burned surface area-TBSA) at 48 h, day 10, and day 21 post burn, and 21 controls. The serum levels of adiponectin, resistin, leptin, tumor necrosis factor-α (TNF-α), plasminogen activator inhibitor-1 (PAI-1), and C-reactive protein (CRP) (among nine other biochemical parameters) were detected by Multiplex technique. Significant statistical differences were obtained for resistin and leptin compared to the control group, in different moments of measurements. Adiponectin serum levels presented statistically significant correlations with hot liquid mechanism of burn, the Revised Baux score, TBSA, resistin, PAI-1, CRP, TNF-α, and triglycerides (TGLs) serum levels. Resistin serum levels presented statistically significant correlations with adiponectin, CRP, PAI-1, leptin, and TNF-α. Additionally, we found statistically significant correlations between leptin serum levels and length of hospitalization, TNF-α, resistin, adiponectin, and PAI-1 serum levels. In severely burned children, adiponectin, resistin, and leptin specifically correlate with clinical parameters and with proteins involved in the systemic inflammatory response and the hypermetabolic response.

Exploring the multifaceted role of obesity in breast cancer progression

Obesity is a multifaceted metabolic disorder characterized by excessive accumulation of adipose tissue. It is a well-established risk factor for the development and progression of breast cancer. Adipose tissue, which was once regarded solely as a passive energy storage depot, is now acknowledged as an active endocrine organ producing a plethora of bioactive molecules known as adipokines that contribute to the elevation of proinflammatory cytokines and estrogen production due to enhanced aromatase activity. In the context of breast cancer, the crosstalk between adipocytes and cancer cells within the adipose microenvironment exerts profound effects on tumor initiation, progression, and therapeutic resistance. Moreover, adipocytes can engage in direct interactions with breast cancer cells through physical contact and paracrine signaling, thereby facilitating cancer cell survival and invasion. This review endeavors to summarize the current understanding of the intricate interplay between adipocyte-associated factors and breast cancer progression. Furthermore, by discussing the different aspects of breast cancer that can be adversely affected by obesity, this review aims to shed light on potential avenues for new and novel therapeutic interventions.

Overlapping action of melatonin and female reproductive hormones-Understand the impact in pregnancy and menopause

Melatonin is an indolamine secreted to circulation by the pineal gland according to a circadian rhythm. Melatonin levels are higher during nighttime, and the principal function of this hormone is to organize the temporal night and day distribution of physiological adaptive processes. Besides hormonal pineal production, melatonin is synthesized in various organs and tissues like the ovaries or the placenta for local utilization. In addition to its function as a circadian messenger, melatonin is also associated with many physiological functions. For example, melatonin has antioxidant properties and is involved in the regulation of energy and bone metabolism, and reproduction. Melatonin impacts several stages of reproduction and the action across the hypothalamus-pituitary-gonadal axis is well described. However, it is not well understood how those actions impact the female reproductive hormones secretion nor the consequent physiological outcomes. Thus, the first part of this chapter describes the regulation of female reproductive hormone synthesis by melatonin. Moreover, melatonin and female reproductive hormones have coincident physiological functions. Life stages like pregnancy or menopause are characterized by alterations in the reproductive hormones secretion that may be associated with certain physiological stages. Therefore, the second part discusses whether melatonin fluctuations could have an overlapping role with reproductive hormones in contributing to clinical outcomes associated with pregnancy and menopause.

What is the disease burden from childhood and adolescent obesity?: a narrative review

The prevalence of childhood and adolescent obesity has increased and exacerbated during the coronavirus disease 2019 pandemic, both in Korea and globally. Childhood and adolescent obesity poses significant risks for premature morbidity and mortality. The development of serious comorbidities depends not only on the duration of obesity but also on the age of onset. Obesity in children and adolescents affects almost all organ systems, including the endocrine, cardiovascular, gastrointestinal, reproductive, nervous, and immune systems. Obesity in children and adolescents affects growth, cognitive function, and psychosocial interactions during development, in addition to aggravating known adult comorbidities such as type 2 diabetes mellitus, hypertension, dyslipidemia, nonalcoholic fatty liver disease, obstructive sleep apnea, and cancer. Childhood and adolescent obesity are highly associated with increased cardiometabolic risk factors and prevalence of metabolic syndrome. The risk of cardiovascular and metabolic diseases in later life can be considerably decreased by even a small weight loss before the onset of puberty. Childhood and adolescent obesity is a disease that requires treatment and is associated with many comorbidities and disease burdens. Therefore, early detection and therapeutic intervention are crucial.

Bioactive Peptides from Meretrix lusoria Enzymatic Hydrolysate as a Potential Treatment for Obesity in db/db Mice

Obesity is acknowledged as a significant risk factor for cardiovascular disease, often accompanied by increased inflammation and diabetes. Bioactive peptides derived from marine animal proteins show promise as safe and effective anti-obesity agents by regulating adipocyte differentiation through the AMPK signaling pathway. Therefore, this study aims to investigate the anti-obesity and anti-diabetic effects of bioactive compounds derived from a Meretrix lusoria Protamex enzymatic hydrolysate (MLP) fraction (≤1 kDa) through a 6-week treatment (150 mg/kg or 300 mg/kg, administered once daily) in leptin receptor-deficient db/db mice. The MLP treatment significantly decreased the body weight, serum total cholesterol, triglycerides, and LDL-cholesterol levels while also exhibiting a beneficial effect on hepatic and serum marker parameters in db/db mice. A histological analysis revealed a reduction in hepatic steatosis and epididymal fat following MLP treatment. Furthermore, poor glucose tolerance was improved, and hepatic antioxidant enzyme activities were elevated in MLP-treated mice compared to db/db control mice. Western blot analysis showed an increased expression of the AMPK protein after MLP treatment. In addition, the expression of lipogenic genes decreased in db/db mice. These findings indicate that bioactive peptides, which are known to regulate blood glucose levels, lipid metabolism, and adipogenesis, could be beneficial functional food additives and pharmaceuticals.

Mendelian randomization study and mediation analysis about the relation of inflammatory bowel disease and diabetic retinopathy: the further exploration of gut-retina axis

Background

The concept of the gut-retinal axis proposed by previous scholars primarily focused on the relationship between intestinal microbiota and retinal diseases, and few further expanded the relationship between intestinal diseases and retinal diseases. To further substantiate the concept of the gut-retinal axis, we analyzed inflammatory bowel disease (IBD) and diabetic retinopathy (DR) using Mendelian randomization (MR), and use mediation analysis to further explore the potential substances that influence this causal relationship.

Methods

The genome-wide association study's (GWAS) summary statistics for genetic variations were utilized in a Mendelian randomization (MR) investigation. GWAS data on IBD (including ulcerative colitis (UC), Crohn's disease (CD), and IBD) for non-Finnish Europeans (NFE) were sourced from published articles. In contrast, data on DR (including DR and diabetic maculopathy (DMP)) were obtained from FinnGen R9. The causal relationship has been investigated using inverse variance weighted (IVW), MR-Egger, and weighted median and sensitivity analysis was applied to verify the stability of the results. In addition, we applied mediation analysis to investigate whether circulating inflammatory proteins and plasma lipids played a mediating role, and calculated its effect ratio.

Results

The causal relationship between IBD and DR was discovered by employing the inverse variance weighted (IVW) method and weighted median method. In forward MR, UC was significantly associated with lower risk of DR (IVW: OR=0.874; 95%CI= 0.835-0.916; P value= 1.28E-08) (Weighted median: OR=0.893; 95%CI= 0.837-0.954; P value= 7.40E-04). In reverse MR, it was shown that DR (IVW: OR=0.870; 95%CI= 0.828-0.914; P value= 2.79E-08)(Weighted median: OR=0.857; 95%CI= 0.801-0.916; P value= 6.40E-06) and DMP (IVW: OR=0.900; 95%CI= 0.865-0.937; P value= 3.34E-07)(Weighted median: OR=0.882; 95%CI= 0.841-0.924; P value= 1.82E-07) could reduce the risk of CD. What's more, DR is associated with a lower risk of IBD according to genetic prediction (IVW: OR=0.922; 95%CI= 0.873-0.972; P value= 0.002) (Weighted median: OR=0.924; 95%CI= 0.861-0.992; P value= 0.029). Fibroblast growth factor 21 (FGF21), phosphatidylcholine (PC), and triacylglycerol (TG) serve as mediators in these relationships.

Conclusions

Our research offers novel insights and sources for investigating the gut-retina axis in the genetic relationship between IBD and DR. We discover four mediators and more about the association between the intestine and retinal disorders and provide more evidence for the gut-retinal axis theory.

The mysterious association between adiponectin and endometriosis

Adiponectin is a pleiotropic cytokine predominantly derived from adipose tissue. In addition to its role in regulating energy metabolism, adiponectin may also be related to estrogen-dependent diseases, and many studies have confirmed its involvement in mediating diverse biological processes, including apoptosis, autophagy, inflammation, angiogenesis, and fibrosis, all of which are related to the pathogenesis of endometriosis. Although many researchers have reported low levels of adiponectin in patients with endometriosis and suggested that it may serve as a protective factor against the development of the disease. Therefore, the purpose of this review was to provide an up-to-date summary of the roles of adiponectin and its downstream cytokines and signaling pathways in the aforementioned biological processes. Further systematic studies on the molecular and cellular mechanisms of action of adiponectin may provide novel insights into the pathophysiology of endometriosis as well as potential therapeutic targets.

A novel blood-based bioassay to monitor adiponectin signaling

The diverse beneficial effects of adiponectin-receptor signaling, including its impact on the regulation of inflammatory processes in vivo, have resulted in development of adiponectin receptor agonists as a treatment for metabolic disorders. However, there are no established non-invasive bioassays for detection of adiponectin target engagement in humans or animal models. Here, we designed an assay using small amounts of blood to assess adiponectin action. Specifically, we tested effects of the small 10-amino acid peptide adiponectin receptor agonist, ALY688, in a sublethal LPS endotoxemia model in mice. LPS-induced pro-inflammatory cytokine levels in serum were significantly reduced in mice treated with ALY688, assessed via multiplex ELISA in flow cytometry. Furthermore, ALY688 alone significantly induced TGF-β release in serum 1 h after treatment and was elevated for up to 24 h. Additionally, using a flow-cytometry panel for detection of changes in circulating immune cell phenotypes, we observed a significant increase in absolute T cell counts in mice after ALY688 treatment. To assess changes in intracellular signaling effectors downstream of adiponectin, phospho-flow cytometry was conducted. There was a significant increase in phosphorylation of AMPK and p38-MAPK in mice after ALY688 treatment. We then used human donor immune cells (PBMCs) treated with ALY688 ex vivo and observed elevation of AMPK and p38-MAPK phosphorylation from baseline in response to ALY688. Together, these results indicate we can detect adiponectin action on immune cells in vivo by assessing adiponectin signaling pathway for AMPK and p38-MAPK, as well as pro-inflammatory cytokine levels. This new approach provides a blood-based bioassay for screening adiponectin action.

Serum Adiponectin Predicts COVID-19 Severity

Adiponectin is primarily known for its protective role in metabolic diseases, and it also possesses immunoregulatory properties. Elevated levels of adiponectin have been observed in various inflammatory diseases. However, studies investigating adiponectin levels in the serum of COVID-19 patients have yielded conflicting results. This study aimed to assess serum adiponectin levels in 26 healthy controls, as well as in 64 patients with moderate and 60 patients with severe COVID-19, to determine a potential association between serum adiponectin and the severity of COVID-19. Serum adiponectin levels in severe COVID-19 patients were significantly lower than in those with moderate disease and healthy controls, who exhibited similar serum adiponectin levels. Among patients with moderate disease, positive correlations were observed between serum adiponectin and C-reactive protein levels. Of note, serum adiponectin levels of severe COVID-19 cases were comparable between patients with and without dialysis or vasopressor therapy. Superinfection with bacteria did not exert a notable influence on serum adiponectin levels in patients with severe disease. Patients who were diagnosed with severe COVID-19 and vancomycin-resistant enterococci bacteremia showed a significant reduction in their serum adiponectin levels. An analysis conducted on the entire cohort, including both moderate and severe COVID-19 patients, showed that individuals who did not survive had lower serum adiponectin levels when compared to those who survived. In summary, this study highlights a decrease in serum adiponectin levels in severe COVID-19 cases, indicating the potential utility of adiponectin as an additional biomarker for monitoring disease severity in COVID-19 or critical illnesses in general.

The New Challenge of Obesity - Obesity-Associated Nephropathy

In recent years, obesity has become one of the major diseases that affect human health and consume human health resources, especially when it causes comorbidities such as hypertension, diabetes, cardiovascular disease and kidney disease. Many studies have demonstrated that obesity is associated with the development of chronic kidney disease and can exacerbate the progression of end-stage renal disease. This review described the mechanisms associated with the development of obesity-associated nephropathy and the current relevant therapeutic modalities, with the aim of finding new therapeutic targets for obesity-associated nephropathy. The mechanisms of obesity-induced renal injury include, in addition to the traditional alterations in renal hemodynamics, the involvement of various mechanisms such as macrophage infiltration in adipose tissue, alterations in adipokines (leptin and adiponectin), and ectopic deposition of lipids. At present, there is no "point-to-point" treatment for obesity-induced kidney injury. The renin-angiotensin-aldosterone system (RAAS) inhibitors, sodium-dependent glucose transporter 2 (SGLT-2) inhibitors and bariatric surgery described in this review can reduce urinary protein to varying degrees and delay the progression of kidney disease. In addition, recent studies on the therapeutic effects of intestinal flora on obesity may reduce the incidence of obesity-related kidney disease from the perspective of primary prevention. Both of these interventions have their own advantages and disadvantages, so the continuous search for the mechanism of obesity-induced related kidney disease will be extremely helpful for the future treatment of obesity-related kidney disease.

Berberine Effects in Pre-Fibrotic Stages of Non-Alcoholic Fatty Liver Disease-Clinical and Pre-Clinical Overview and Systematic Review of the Literature

Non-alcoholic fatty liver disease (NAFLD) is the predominant cause of chronic liver conditions, and its progression is marked by evolution to non-alcoholic steatosis, steatohepatitis, cirrhosis related to non-alcoholic steatohepatitis, and the potential occurrence of hepatocellular carcinoma. In our systematic review, we searched two databases, Medline (via Pubmed Central) and Scopus, from inception to 5 February 2024, and included 73 types of research (nine clinical studies and 64 pre-clinical studies) from 2854 published papers. Our extensive research highlights the impact of Berberine on NAFLD pathophysiology mechanisms, such as Adenosine Monophosphate-Activated Protein Kinase (AMPK), gut dysbiosis, peroxisome proliferator-activated receptor (PPAR), Sirtuins, and inflammasome. Studies involving human subjects showed a measurable reduction of liver fat in addition to improved profiles of serum lipids and hepatic enzymes. While current drugs for NAFLD treatment are either scarce or still in development or launch phases, Berberine presents a promising profile. However, improvements in its formulation are necessary to enhance the bioavailability of this natural substance.

Nanomodulator-Mediated Restructuring of Adipose Tissue Immune Microenvironments for Antiobesity Treatment

In obesity, the interactions between proinflammatory macrophages and adipocytes in white adipose tissues are known to play a crucial role in disease progression by providing inflammatory microenvironments. Here, we report that the functional nanoparticle-mediated modulation of crosstalk between adipocytes and macrophages can remodel adipocyte immune microenvironments. As a functional nanomodulator, we designed antivascular cell adhesion molecule (VCAM)-1 antibody-conjugated and amlexanox-loaded polydopamine nanoparticles (VAPN). Amlexanox was used as a model drug to increase energy expenditure. Compared to nanoparticles lacking antibody modification or amlexanox, VAPN showed significantly greater binding to VCAM-1-expressing adipocytes and lowered the interaction of adipocytes with macrophages. In high fat diet-fed mice, repeated subcutaneous administration of VAPN increased the populations of beige adipocytes and ameliorated inflammation in white adipose tissues. Moreover, the localized application of VAPN in vivo exerted a systemic metabolic effect and reduced metabolic disorders, including insulin tolerance and liver steatosis. These findings suggested that VAPN had potential to modulate the immune microenvironments of adipose tissues for the immunologic treatment of obesity. Although we used amlexanox as a model drug and anti-VCAM-1 antibody in VAPN, the concept of immune nanomodulators can be widely applied to the immunological treatment of obesity.

The role of brown adipose tissue in mediating healthful longevity

There are two major subtypes of adipose tissue, i.e., white adipose tissue (WAT) and brown adipose tissue (BAT). It has been known for a long time that WAT mediates obesity and impairs healthful longevity. More recently, interest has focused on BAT, which, unlike WAT, actually augments healthful aging. The goal of this review is to examine the role of BAT in mediating healthful longevity. A major role for BAT and its related beige adipose tissue is thermogenesis, as a mechanism to maintain body temperature by producing heat through uncoupling protein 1 (UCP1) or through UCP1-independent thermogenic pathways. Our hypothesis is that healthful longevity is, in part, mediated by BAT. BAT protects against the major causes of impaired healthful longevity, i.e., obesity, diabetes, cardiovascular disorders, cancer, Alzheimer's disease, reduced exercise tolerance, and impaired blood flow. Several genetically engineered mouse models have shown that BAT enhances healthful aging and that their BAT is more potent than wild-type (WT) BAT. For example, when BAT, which increases longevity and exercise performance in mice with disruption of the regulator of G protein signaling 14 (RGS14), is transplanted to WT mice, their exercise capacity is enhanced at 3 days after BAT transplantation, whereas BAT transplantation from WT to WT mice also resulted in increased exercise performance, but only at 8 weeks after transplantation. In view of the ability of BAT to mediate healthful longevity, it is likely that a pharmaceutical analog of BAT will become a novel therapeutic modality.

Soy Supplementation Does Not Affect Serum Adiponectin Levels in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Numerous studies have indicated that low levels of serum adiponectin are linked with the development of various chronic diseases. While some recent research has suggested that soy has a positive impact on serum adiponectin levels, the results are inconsistent. Therefore, we aim to conduct a thorough systematic review and meta-analysis of randomized controlled trials (RCTs) that investigate the effects of soy on serum adiponectin levels in adults. The search was conducted until March 2024 on PubMed, Scopus, Web of Science, and Cochrane Library databases to identify RCTs that studied the effects of soy supplementation on serum adiponectin levels. A random-effects model was used to pool the weighted mean differences (WMDs). Ten and nine RCTs were selected for the systematic review and meta-analysis, respectively. After analyzing data from 9 eligible RCTs, it was found that soy supplementation did not significantly impact the concentrations of adiponectin (WMD = -0.24 μg/mL; 95% confidence interval, -1.56 to 1.09; p = 0.72). However, there was significant heterogeneity between the studies (I2 = 89.8%, p < 0.001). Sensitivity analysis showed that overall estimates were not affected by the elimination of any study. We did not observe any evidence regarding publication bias. In conclusion, soy supplementation did not have a significant effect on adiponectin levels in adults. However, further RCTs are needed with longer intervention duration, higher doses, and studies conducted in different countries.

Effectiveness of backward gait training on body composition, cardiopulmonary fitness, inflammation, and metabolic marker in adults: A systematic review and meta-analysis

Walking is a fundamental physical activity with significant health implications. Backward gait training (BGT) has emerged as a novel approach with potential benefits, yet its effects in comparison to traditional forward gait training (FGT) remain uncertain. This systematic review and meta-analysis aimed to evaluate the effects of BGT on body composition, cardiopulmonary fitness, and inflammatory and metabolic markers in adults. A comprehensive search across electronic databases was conducted following the Preferred Publishing Items for Systematic Reviews and Meta-Analyses guidelines. Randomized clinical trials (RCTs) comparing BGT with FGT in adults were included. Methodological quality was assessed using the Cochrane risk-of-bias tool. The certainty of evidence was evaluated using the Grading of Recommendation, Assessment, Development, and Evaluation approach. The analysis included a total of 379 male participants across the studies. The meta-analysis demonstrated significant changes in body composition and inflammatory marker outcomes, which included waist-to-height ratio (standardized mean difference [SMD]-1.18, 95% confidence interval [CI]-1.89-0.48, I2 = 83%, P < 0.01), body mass index (SMD-0.55, 95% CI-0.77-0.32, I2= 0%, P < 0.01), and C-reactive protein (SMD-0.98, 95% CI-1.28-0.70, I2= 0%, P < 0.01). In addition, the qualitative review revealed potential enhancements in cardiopulmonary fitness and metabolic markers following BGT. While the results suggest potential benefits of BGT on body composition and inflammatory markers, the evidence remains limited and heterogeneous. Further robust research with diverse populations, longer intervention periods, and comprehensive outcome assessments is essential to elucidate the true impact of BGT and its utility for promoting overall health and well-being in adults.

Consequences of COVID-19 on Adipose Tissue Signatures

Since the emergence of coronavirus disease-19 (COVID-19) in 2019, it has been crucial to investigate the causes of severe cases, particularly the higher rates of hospitalization and mortality in individuals with obesity. Previous findings suggest that adipocytes may play a role in adverse COVID-19 outcomes in people with obesity. The impact of COVID-19 vaccination and infection on adipose tissue (AT) is currently unclear. We therefore analyzed 27 paired biopsies of visceral and subcutaneous AT from donors of the Leipzig Obesity BioBank that have been categorized into three groups (1: no infection/no vaccination; 2: no infection but vaccinated; 3: infected and vaccinated) based on COVID-19 antibodies to spike (indicating vaccination) and/or nucleocapsid proteins. We provide additional insights into the impact of COVID-19 on AT biology through a comprehensive histological transcriptome and serum proteome analysis. This study demonstrates that COVID-19 infection is associated with smaller average adipocyte size. The impact of infection on gene expression was significantly more pronounced in subcutaneous than in visceral AT and mainly due to immune system-related processes. Serum proteome analysis revealed the effects of the infection on circulating adiponectin, interleukin 6 (IL-6), and carbonic anhydrase 5A (CA5A), which are all related to obesity and blood glucose abnormalities.

Structural analysis of polysaccharide from Inonotus obliquus and investigate combined impact on the sex hormones, intestinal microbiota and metabolism in SPF male mice

The dysregulation of sex hormone levels is associated with metabolic disorders such as obesity. Inonotus obliquus polysaccharide (IOP) exhibits a promising therapeutic effect on conditions like obesity and diabetes, potentially linked to its influence on intestinal microbiota and metabolism. The exact cause and mechanisms that link sex hormones, gut microbiota and metabolism are still unknown. In this research, we examined the molecular weight, monosaccharide composition, and glycosidic bond type of IOP. We found that IOP mostly consists of alpha-structured 6‑carbon glucopyranose, with a predominant (1 → 4) linkage to monosaccharides and a uniform distribution. Following this, we administered two different concentrations of IOP to mice through gavage. The results of the enzyme-linked immunosorbent assay (ELISA) demonstrated a significant increase in testosterone (T) levels in the IOP group as compared to the control group. Additionally, the results of tissue immunofluorescence indicated that increased IOP led to a decrease in adiponectin content and an increase in SET protein expression. The study also revealed changes in the intestinal microbiota and metabolic changes in mice through 16S rRNA data and non-targeted LC-MS data, respectively. The study also found that IOP mainly affects pathways linked to glycerophospholipid metabolism. In addition, it has been observed that there is an increase in the number of beneficial bacteria, such as the Eubacterium coprostanoligenes group and g.Lachnospiraceae NK4A136 group, while the levels of metabolites that are linked to obesity or diabetes, such as 1,5-anhydrosorbitol, are reduced. Furthermore, biomarker screening has revealed that the main microorganism responsible for the differences between the three groups is g.Erysipelatoclostridiaceae. In summary, these findings suggest that IOP exerts its therapeutic effects through a synergistic interplay between sex hormones, gut microbiome composition, and metabolic processes.

Adipose tissue as a therapeutic target for vascular damage in Alzheimer's disease

Adipose tissue has recently been recognized as an important endocrine organ that plays a crucial role in energy metabolism and in the immune response in many metabolic tissues. With this regard, emerging evidence indicates that an important crosstalk exists between the adipose tissue and the brain. However, the contribution of adipose tissue to the development of age-related diseases, including Alzheimer's disease, remains poorly defined. New studies suggest that the adipose tissue modulates brain function through a range of endogenous biologically active factors known as adipokines, which can cross the blood-brain barrier to reach the target areas in the brain or to regulate the function of the blood-brain barrier. In this review, we discuss the effects of several adipokines on the physiology of the blood-brain barrier, their contribution to the development of Alzheimer's disease and their therapeutic potential. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.

Long-term exposure to ambient air pollution and inflammatory response in the KORA study

Previous studies consistently showed an association between fine atmospheric particulate matter (PM2.5) and cardiovascular diseases. Concerns about adverse health effects of ultrafine particles (UFP) are growing but long-term studies are still scarce. In this study, we examined the association between long-term exposure to ambient air pollutants and blood biomarkers of inflammation and coagulation, including fibrinogen, high-sensitivity C-reactive protein (hs-CRP), serum amyloid A (SAA) adiponectin and interleukin-6 (IL-6), measured in the German KORA-S4 cohort study (1999-2001). IL-6 was available for older participants only, who were therefore considered as a subsample. Annual mean concentrations of UFP (as particle number concentration), particulate matter in different particles sizes (PM10, PMcoarse, PM2.5, PM2.5 absorbance), ozone (O3), and nitrogen oxides (NO2, NOX) were estimated by land-use regression models and assigned to participants' home addresses. We performed a multiple linear regression between each pollutant and each biomarker with adjustment for confounders. Per 1 interquartile range (IQR, 1945 particles/cm3) increase of UFP, fibrinogen increased by 0.70 % (0.04; 1.37) and hs-CRP increased by 3.16 % (-0.52; 6.98). Adiponectin decreased by -2.53 % (-4.78; -0.24) per 1 IQR (1.4 μg/m3) increase of PM2.5. Besides, PM2.5 was associated with increased IL-6 in the subsample. In conclusion, we observed that long-term exposure to air pollutants, including both fine and ultrafine particles, was associated with higher concentrations of pro-inflammatory and lower concentrations of an anti-inflammatory blood biomarkers, which is consistent with an increased risk for cardiovascular disease observed for long-term exposure to air pollutants.

Adiponectin protects against myocardial ischemia-reperfusion injury: a systematic review and meta-analysis of preclinical animal studies

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is widespread in the treatment of ischemic heart disease, and its treatment options are currently limited. Adiponectin (APN) is an adipocytokine with cardioprotective properties; however, the mechanisms of APN in MIRI are unclear. Therefore, based on preclinical (animal model) evidence, the cardioprotective effects of APN and the underlying mechanisms were explored.

METHODS

The literature was searched for the protective effect of APN on MIRI in six databases until 16 November 2023, and data were extracted according to selection criteria. The outcomes were the size of the myocardial necrosis area and hemodynamics. Markers of oxidation, apoptosis, and inflammation were secondary outcome indicators. The quality evaluation was performed using the animal study evaluation scale recommended by the Systematic Review Center for Laboratory animal Experimentation statement. Stata/MP 14.0 software was used for the summary analysis.

RESULTS

In total, 20 papers with 426 animals were included in this study. The pooled analysis revealed that APN significantly reduced myocardial infarct size [weighted mean difference (WMD) = 16.67 (95% confidence interval (CI) = 13.18 to 20.16, P < 0.001)] and improved hemodynamics compared to the MIRI group [Left ventricular end-diastolic pressure: WMD = 5.96 (95% CI = 4.23 to 7.70, P < 0.001); + dP/dtmax: WMD = 1393.59 (95% CI = 972.57 to 1814.60, P < 0.001); -dP/dtmax: WMD = 850.06 (95% CI = 541.22 to 1158.90, P < 0.001); Left ventricular ejection fraction: WMD = 9.96 (95% CI = 7.29 to 12.63, P < 0.001)]. Apoptosis indicators [caspase-3: standardized mean difference (SMD) = 3.86 (95% CI = 2.97 to 4.76, P < 0.001); TUNEL-positive cells: WMD = 13.10 (95% CI = 8.15 to 18.05, P < 0.001)], inflammatory factor levels [TNF-α: SMD = 4.23 (95% CI = 2.48 to 5.98, P < 0.001)], oxidative stress indicators [Superoxide production: SMD = 4.53 (95% CI = 2.39 to 6.67, P < 0.001)], and lactate dehydrogenase levels [SMD = 2.82 (95% CI = 1.60 to 4.04, P < 0.001)] were significantly reduced. However, the superoxide dismutase content was significantly increased [SMD = 1.91 (95% CI = 1.17 to 2.65, P < 0.001)].

CONCLUSION

APN protects against MIRI via anti-inflammatory, antiapoptotic, and antioxidant effects, and this effect is achieved by activating different signaling pathways.

Preliminary Report on the Influence of Acute Inflammation on Adiponectin Levels in Older Inpatients with Different Nutritional Status

Inflammation can be triggered by a variety of factors, including pathogens, damaged cells, and toxic compounds. It is a biological response of the immune system, which can be successfully assessed in clinical practice using some molecular substances. Because adiponectin, a hormone released by adipose tissue, influences the development of inflammation, its evaluation as a potential measure of inflammation in clinical practice is justified. In the present contribution, statistical comparison of adiponectin concentration and selected molecular substances recognized in clinical practice as measures of inflammation were utilized to demonstrate whether adipose tissue hormones, as exemplified by adiponectin, have the potential to act as a measure of rapidly changing inflammation when monitoring older hospitalized patients in the course of bacterial infection. The study showed no statistically significant differences in adiponectin levels depending on the rapidly changing inflammatory response in its early stage. Interestingly, the concentration of adiponectin is statistically significantly higher in malnourished patients than in people with normal nutritional levels, assessed based on the MNA. According to the results obtained, adiponectin is not an effective measure of acute inflammation in clinical practice. However, it may serve as a biomarker of malnutrition in senile individuals.

Associating Liver Enzymes and Their Interactions with Metabolic Syndrome Prevalence in a Japanese Working Population

Background: Serum gamma-glutamyltransferase (γ-GT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels often increase in metabolic diseases. Objective: This study was conducted to determine which liver enzymes are strongly associated with metabolic syndrome (MetS), how they interact to produce different probability estimates, and what cutoff levels should be used to guide clinical decision-making. Methods: The researchers examined the insurance-based medical checkup data of 293,610 employees ≥35 years years of age, who underwent medical checkups between April 1, 2016, and March 31, 2017. Liver enzyme levels were grouped into quartiles. The association and interaction of liver enzymes with MetS were examined using logistic regression, and receiver operating characteristic (ROC) analyses were used to determine the optimal cutoff values for each liver enzyme in detecting the prevalence of MetS. Results: High levels of γ-GT and ALT were more strongly associated with MetS than AST. At various levels, the tested liver enzymes were found interactive, and associated with the likelihood of MetS prevalence. ROC analysis underscored the significance of all liver enzymes in predicting the development of MetS. The cutoff values for each liver enzyme were determined. Conclusion: This findings of this study directly support the identification of MetS risks within the population, prioritize prevention strategies, and potentially inform policy formulation.

The association between adipokines and pulmonary diseases: a mendelian randomization study

BACKGROUND

The role of adipokines in the development of lung diseases is significant, yet their specific relationship with different lung diseases remains unclear.

METHODS

In our research, we analyzed genetic variations associated with adipokines and various lung conditions such as interstitial lung disease, chronic obstructive pulmonary disease, asthma, lung cancer, sleep apnea, pneumonia, and tuberculosis, using data from public genome-wide studies. We employed Mendelian randomization techniques, including inverse variance weighting, weighted median, and MR-Egger regression methods, and conducted sensitivity checks to validate our findings.

RESULTS

A study using the FinnGen database, which included 198,955 participants, identified 13 SNPs associated with adiponectin. Notably, adiponectin was found to significantly reduce the risk of interstitial lung disease and idiopathic pulmonary fibrosis. However, little evidence was found to establish a direct cause-effect relationship between the six adipokines and several other lung conditions, including sarcoidosis, asthma, chronic obstructive pulmonary disease, lung cancer, tuberculosis, pneumonia, and sleep apnea syndrome.

CONCLUSION

This study reveals a reverse link between adiponectin levels and the likelihood of interstitial lung disease, including idiopathic pulmonary fibrosis.

Therapeutic potential of adiponectin in prediabetes: strategies, challenges, and future directions

Adiponectin, an adipose-derived hormone, plays a pivotal role in glucose regulation and lipid metabolism, with a decrease in circulating adiponectin levels being linked to insulin resistance and prediabetes. This review examines the therapeutic potential of adiponectin in managing prediabetes, elucidating on multiple aspects including its role in glucose and lipid metabolism, influence on insulin sensitivity, and anti-inflammatory properties. Moreover, the paper highlights the latest strategies to augment adiponectin levels, such as gene therapy, pharmacological interventions, dietary modifications, and lifestyle changes. It also addresses the challenges encountered in translating preclinical findings into clinical practice, primarily related to drug delivery, safety, and efficacy. Lastly, the review proposes future directions, underlining the need for large-scale human trials, novel adiponectin analogs, and personalized treatment strategies to harness adiponectin's full therapeutic potential in preventing the transition from prediabetes to diabetes.

Activated Human Adipose Tissue Transplantation Promotes Sensorimotor Recovery after Acute Spinal Cord Contusion in Rats

Traumatic spinal cord injuries (SCIs) often result in sensory, motor, and vegetative function loss below the injury site. Although preclinical results have been promising, significant solutions for SCI patients have not been achieved through translating repair strategies to clinical trials. In this study, we investigated the effective potential of mechanically activated lipoaspirated adipose tissue when transplanted into the epicenter of a thoracic spinal contusion. Male Sprague Dawley rats were divided into three experimental groups: SHAM (uninjured and untreated), NaCl (spinal cord contusion with NaCl application), and AF (spinal cord contusion with transplanted activated human fat). Pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) were measured to assess endogenous inflammation levels 14 days after injury. Sensorimotor recovery was monitored weekly for 12 weeks, and gait and electrophysiological analyses were performed at the end of this observational period. The results indicated that AF reduced endogenous inflammation post-SCI and there was a significant improvement in sensorimotor recovery. Moreover, activated adipose tissue also reinstated the segmental sensorimotor loop and the communication between supra- and sub-lesional spinal cord regions. This investigation highlights the efficacy of activated adipose tissue grafting in acute SCI, suggesting it is a promising therapeutic approach for spinal cord repair after traumatic contusion in humans.

Predictive value of adipokines for the severity of acute pancreatitis: a meta-analysis

BACKGROUND

Severe acute pancreatitis (SAP) is a dangerous condition with a high mortality rate. Many studies have found an association between adipokines and the development of SAP, but the results are controversial. Therefore, we performed a meta-analysis of the association of inflammatory adipokines with SAP.

METHODS

We screened PubMed, EMBASE, Web of Science and Cochrane Library for articles on adipokines and SAP published before July 20, 2023. The quality of the literature was assessed using QUADAS criteria. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated to assess the combined effect. Subgroup analysis, sensitivity analysis and publication bias tests were also performed on the information obtained.

RESULT

Fifteen eligible studies included 1332 patients with acute pancreatitis (AP). Pooled analysis showed that patients with SAP had significantly higher serum levels of resistin (SMD = 0.78, 95% CI:0.37 to 1.19, z = 3.75, P = 0.000). The difference in leptin and adiponectin levels between SAP and mild acute pancreatitis (MAP) patients were not significant (SMD = 0.30, 95% CI: -0.08 to 0.68, z = 1.53, P = 0.127 and SMD = 0.11, 95% CI: -0.17 to 0.40, z = 0.80, P = 0.425, respectively). In patients with SAP, visfatin levels were not significantly different from that in patients with MAP (SMD = 1.20, 95% CI: -0.48 to 2.88, z = 1.40, P = 0.162).

CONCLUSION

Elevated levels of resistin are associated with the development of SAP. Resistin may serve as biomarker for SAP and has promise as therapeutic target.

What Is New in Metabolic Dysfunction-Associated Steatotic Liver Disease in Lean Individuals: From Bench to Bedside

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects more than 30% of the world's adult population. While it is associated with obesity and metabolic syndrome, emerging evidence has shown that a substantial number of MASLD patients have a normal body mass index ("lean individuals with MASLD"). In this article, we provide an overview of the definition, epidemiology, pathogenesis, and clinical outcomes associated with lean individuals with MASLD and updates on current management.

Antidiabetic features of AdipoAI, a novel AdipoR agonist

Adiponectin is an antidiabetic endogenous adipokine that plays a protective role against the unfavorable metabolic sequelae of obesity. Recent evidence suggests a sinister link between hypoadiponectinemia and development of insulin resistance/type 2 diabetes (T2D). Adiponectin's insulin-sensitizing property is mediated through the specific adiponectin receptors R1 and R2, which activate the AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR) α pathways. AdipoAI is a novel synthetic analogue of endogenous adiponectin with possibly similar pharmacological effects. Thus, there is a need of orally active small molecules that activate Adipoq subunits, and their downstream signaling, which could ameliorate obesity related type 2 diabetes. In the study we aim to investigate the effects of AdipoAI on obesity and T2D. Through in-vitro and in-vivo analyses, we investigated the antidiabetic potentials of AdipoAI and compared it with AdipoRON, another orally active adiponectin receptors agonist. Our results showed that in-vitro treatment of AdipoAI (0-5 µM) increased adiponectin receptor subunits AdipoR1/R2 with increase in AMPK and APPL1 protein expression in C2C12 myotubes. Similarly, in-vivo, oral administration of AdipoAI (25 mg/kg) observed similar effects as that of AdipoRON (50 mg/kg) with improved control of blood glucose and insulin sensitivity in diet-induced obesity (DIO) mice models. Further, AdipoAI significantly reduced epididymal fat content with decrease in inflammatory markers and increase in PPAR-α and AMPK levels and exhibited hepatoprotective effects in liver. Further, AdipoAI and AdipoRON also observed similar results in adipose tissue. Thus, our results suggest that low doses of orally active small molecule agonist of adiponectin AdipoAI can be a promising therapeutic target for obesity and T2D.

What Does Sarcopenia Have to Do with Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. As the second stage of developing steatosis, nonalcoholic hepatitis (NASH) carries the risk of fibrosis, cirrhosis, and hepatocellular carcinoma. Sarcopenia is defined as a condition characterized by a decrease in muscle mass and functional decline. Both NAFLD and sarcopenia are global problems. The pathophysiological mechanisms that link the two entities of the disease are insulin resistance, inflammation, nutritional deficiencies, impairment of myostatin and adiponectin, or physical inactivity. Furthermore, disorders of the gut-liver axis appear to induce the process of developing NAFLD and sarcopenia. The correlations between NAFLD and sarcopenia appear to be bidirectional, so the main objective of the review was to determine the cause-and-effect relationship between the two diseases.

Lactiplantibacillus plantarum NKK20 Increases Intestinal Butyrate Production and Inhibits Type 2 Diabetic Kidney Injury through PI3K/Akt Pathway

Nephropathy injury is a prevalent complication observed in individuals with diabetes, serving as a prominent contributor to end-stage renal disease, and the advanced glycation products (AGEs) are important factors that induce kidney injury in patients with diabetes. Addressing this condition remains a challenging aspect in clinical practice. The aim of this study was to explore the effects of Lactiplantibacillus plantarum NKK20 strain (NKK20) which protects against diabetic kidney disease (DKD) based on animal and cell models. The results showed that the NKK20 can significantly reduce renal inflammatory response, serum oxidative stress response, and AGE concentration in diabetic mice. After treatment with NKK20, the kidney damage of diabetic mice was significantly improved, and more importantly, the concentration of butyrate, a specific anti-inflammatory metabolite of intestinal flora in the stool of diabetic mice, was significantly increased. In addition, nontargeted metabolomics analysis showed a significant difference between the metabolites in the mouse serum contents of the NKK20 administration group and those in the nephropathy injury group, in which a total of 24 different metabolites that were significantly affected by NKK20 were observed, and these metabolites were mainly involved in glycerophospholipid metabolism and arachidonic acid metabolism. Also, the administration of butyrate to human kidney- (HK-) 2 cells that were stimulated by AGEs resulted in a significant upregulation of ZO-1, Occludin, and E-cadherin gene expressions and downregulation of α-SMA gene expression. This means that butyrate can maintain the tight junction structure of HK-2 cells and inhibit fibrosis. Butyrate also significantly inhibited the activation of PI3K/Akt pathway. These results indicate that NKK20 can treat kidney injury in diabetic mice by reducing blood glucose and AGE concentration and increasing butyrate production in the intestine. By inhibiting PI3K pathway activation in HK-2 cells, butyrate maintains a tight junction structure of renal tubule epithelial cells and inhibits renal tissue fibrosis. These results suggest that NKK20 is helpful to prevent and treat the occurrence and aggravation of diabetic kidney injury.

The Antiviral Potential of AdipoRon, an Adiponectin Receptor Agonist, Reveals the Ability of Zika Virus to Deregulate Adiponectin Receptor Expression

Zika virus (ZIKV) is a pathogenic member of the flavivirus family, with several unique characteristics. Unlike any other arbovirus, ZIKV can be transmitted sexually and maternally, and thus produce congenital syndromes (CZS) due to its neurotropism. This challenges the search for safe active molecules that can protect pregnant women and their fetuses. In this context, and in the absence of any existing treatment, it seemed worthwhile to test whether the known cytoprotective properties of adiponectin and its pharmacological analog, AdipoRon, could influence the outcome of ZIKV infection. We showed that both AdipoRon and adiponectin could significantly reduce the in vitro infection of A549 epithelial cells, a well-known cell model for flavivirus infection studies. This effect was particularly observed when a pre-treatment was carried out. Conversely, ZIKV revealed an ability to downregulate adiponectin receptor expression and thereby limit adiponectin signaling.

Comparative Evaluation of Adipokine Metrics for the Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the most common medical disorders in pregnancy. Adipokines, predominantly secreted by adipose tissue, are involved in numerous metabolic processes. The exact role of adipokines in the pathogenesis of GDM is still not well known, and numerous adipokines have been analysed throughout pregnancy and proposed as biomarkers of GDM. This study aimed to evaluate serum adiponectin, chemerin, lipocalin and apelin levels in GDM and non-GDM women, to assess them as clinically useful biomarkers of the occurrence of GDM and to demonstrate the correlation between the levels of the above adipokines in the blood serum and the increased risk of the development of GDM. The role of these adipokines in the pathogenesis of GDM was also analysed. The statistically significant differences between the levels of adiponectin (7234.6 vs. 9837.5 ng/mL, p < 0.0001), chemerin (264.0 vs. 206.7 ng/mL, p < 0.0001) and lipocalin (39.5 vs. 19.4 ng/mL, p < 0.0001) were observed between pregnant women with GDM and healthy ones. The diagnostic usefulness of the tested adipokines in detecting GDM was also assessed. The research results confirm the hypothesis on the significance of adiponectin, chemerin, lipocalin and apelin in the pathophysiological mechanisms of GDM. We speculate that these adipokines could potentially be established as novel biomarkers for the prediction and early diagnosis of GDM.

Obesity and COVID-19 Pandemics: Epidemiology, Mechanisms, and Management

Obesity is a principle causative factor of various metabolic dysfunctions, chronic inflammation, and multi-organ impairment. The global epidemic of obesity has constituted the greatest threat to global health. Emerging evidence has associated obesity with an increased risk of severe infection and poor outcomes from coronavirus disease 2019 (COVID-19). During current COVID-19 pandemic, the interaction between COVID-19 and obesity has exaggerated the disease burden of obesity more than ever before. Thus, there is an urgent need for consideration of universal measures to reduce the risk of complications and severe illness from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in obesity population. In this review, we first summarized the clinical evidence on the effect of obesity on susceptibility, severity, and prognosis of COVID-19. Then we discussed and the underlying mechanisms, including respiratory pathophysiology of obesity, dysregulated inflammation, upregulated angiotensin-converting enzyme 2 (ACE2) expression, hyperglycemia, and adipokines. Finally, we proposed recommendations on how to reduce the spread and pandemic of SARS-CoV-2 infection by prevention and treatment of obesity.

GPR84-mediated signal transduction affects metabolic function by promoting brown adipocyte activity

The G protein-coupled receptor 84 (GPR84), a medium-chain fatty acid receptor, has garnered attention because of its potential involvement in a range of metabolic conditions. However, the precise mechanisms underlying this effect remain elusive. Our study has shed light on the pivotal role of GPR84, revealing its robust expression and functional significance within brown adipose tissue (BAT). Mice lacking GPR84 exhibited increased lipid accumulation in BAT, rendering them more susceptible to cold exposure and displaying reduced BAT activity compared with their WT counterparts. Our in vitro experiments with primary brown adipocytes from GPR84-KO mice revealed diminished expression of thermogenic genes and reduced O2 consumption. Furthermore, the application of the GPR84 agonist 6-n-octylaminouracil (6-OAU) counteracted these effects, effectively reinstating the brown adipocyte activity. These compelling in vivo and in vitro findings converge to highlight mitochondrial dysfunction as the primary cause of BAT anomalies in GPR84-KO mice. The activation of GPR84 induced an increase in intracellular Ca2+ levels, which intricately influenced mitochondrial respiration. By modulating mitochondrial Ca2+ levels and respiration, GPR84 acts as a potent molecule involved in BAT activity. These findings suggest that GPR84 is a potential therapeutic target for invigorating BAT and ameliorating metabolic disorders.

Adipose Tissue, Non-Communicable Diseases, and Physical Exercise: An Imperfect Triangle

The study of adipose tissue has received considerable attention due to its importance not just in maintaining body energy homeostasis but also in playing a role in a number of other physiological processes. Beyond storing energy, adipose tissue is important in endocrine, immunological, and neuromodulatory functions, secreting hormones that participate in the regulation of energy homeostasis. An imbalance of these functions will generate structural and functional changes in the adipose tissue, favoring the secretion of deleterious adipocytokines that induce a pro-inflammatory state, allowing the development of metabolic and cardiovascular diseases and even some types of cancer. A common theme worldwide has been the development of professional guidelines for the control and treatment of obesity, with emphasis on hypocaloric diets and exercise. The aim of this review is to examine the pathophysiological mechanisms of obesity, considering the relationship among adipose tissue and two aspects that contribute positively or negatively to keeping a healthy body homeostasis, namely, exercise and noninfectious diseases. We conclude that the relationship of these aspects does not have homogeneous effects among individuals. Nevertheless, it is possible to establish some common mechanisms, like a decrease in pro-inflammatory markers in the case of exercise, and an increase in chronic inflammation in non-communicable diseases. An accurate diagnosis might consider the particular variables of a patient, namely their molecular profile and how it affects its metabolism, routines, and lifestyle; their underling health conditions; and probably even the constitution of their microbiome. We foresee that the development and accessibility of omics approaches and precision medicine will greatly improve the diagnosis, treatment, and successful outcomes for obese patients.

Adiponectin inhibits LPS-induced nucleus pulposus cell pyroptosis through the miR-135a-5p/TXNIP signaling pathway

Pyroptosis, a newly discovered programmed cell death process, is characterized by NLRP3 inflammasome activation and pro-inflammatory mediator release. Nucleus pulposus (NP) cell pyroptosis is an important cause of intervertebral disc degeneration (IDD). Adiponectin (APN) is an adipokine and has an anti-inflammatory effect. However, whether and how APN protects against NP cell pyroptosis remains unexplored. Our results showed that human degenerated NP tissue displayed a significant increase in the protein levels of NLRP3, caspase-1 and GSDMD-N. APN expression was down-regulated in human degenerated NP tissue and NP cells challenged with lipopolysaccharide (LPS). Lentivirus-mediated overexpression of APN increased miR-135a-5p levels, decreased thioredoxin-interacting protein (TXNIP) expression and its interaction with NLRP3, and inhibited pyroptosis in human NP cells stimulated with LPS. TXNIP was identified as a direct target of miR-135a-5p. The inhibitory effects of APN on pyroptosis were reversed by pretreatment with miR-135a-5p inhibitor or lentiviral vector expressing TXNIP in LPS-treated human NP cells. In summary, these data suggest that APN restrains LPS-induced pyroptosis through the miR-135a-5p/TXNIP signaling pathway in human NP cells. Increasing APN levels could be a new approach to retard IDD.

Chinese herbal compound Huangqin Qingrechubi capsule reduces lipid metabolism disorder and inflammatory response in gouty arthritis via the LncRNA H19/APN/PI3K/AKT cascade

CONTEXT

Gouty arthritis (GA) is a characteristically inflammatory disease often associated with lipid metabolism disorder. Huangqin Qingrechubi capsule (HQC) has been used for the treatment of GA.

OBJECTIVE

To explore the mechanism of HQC in the treatment of GA.

MATERIALS AND METHODS

A total of 30 GA patients (GA group) and 30 healthy subjects [normal control (NC) group] were recruited. The GA group was treated with HQC (3.6 g/d) for 10 days. Lipid metabolism and inflammation indexes were detected. Five herbal names of HQC, or 'gouty arthritis', 'hyperlipidemia' and 'inflammation' were used as key words to search related databases for network pharmacological analysis. Subsequently, GA-fibroblast-like synoviocytes (FLSs) were stimulated with GA-peripheral blood mononuclear cells (PBMCs) (3:1) and treated with HQC drug-containing serum (20%). RT-qPCR, Western blot, and ELISA were conducted to further explore the mechanism of HQC in improving GA.

RESULTS

In clinical observation, HQC decreased the expression of lncRNA H19 and IL-1β, and increased the expression of adiponectin (APN) and IL-4 in the GA group (about half). Through network pharmacology, the PI3K/AKT signaling pathway was identified. Cell experiments showed that HQC treatment reduced the viability of GA-FLSs (49.61%), up-regulated the expression of IL-4 (155.18%), IL-10 (165.13%), and APN (31.24%), and down-regulated the expression of lncRNA H19 (33.70%), IL-1β (64.70%), TNF-α (78.32%), p-PI3K (48.80%), and p-AKT (53.48%).

DISCUSSION AND CONCLUSIONS

HQC improved lipid metabolism disorder and inflammatory response of GA by regulating the lncRNA H19/APN/PI3K/AKT. Maintaining the stability of lipid metabolism may be an effective way to alleviate GA.

Influence of birth-related maternal and neonatal factors on the levels of energy metabolism mediators in infants born at 32 or fewer weeks of gestation

BACKGROUND

Energy metabolism mediators, which include the adipokines (leptin, adiponectin, ghrelin) and insulin-like growth factor 1 [IGF-1], are hormone-like proteins, produced and expressed in the placenta and fetal membranes, with properties featuring metabolic adaptation and inflammatory processes. Due to the complexity of the metabolic adaptation of preterm neonates during the transition to extrauterine life, it becomes essential to recognize the factors that influence the alteration of the adipokines and IGF-1 levels in the early postpartum stage.This study assessed the significance of maternal-fetal-neonatal factors in predicting the levels of leptin, adiponectin, ghrelin, and IGF-1 in preterm infants born at 32 or fewer weeks of gestation, during the early stage of postnatal adaptation.

METHODS

Energy metabolism mediator levels were measured in urine samples obtained from extremely (less than 28 weeks) and very (28-32 weeks) preterm infants, within 48 h after their birth, and before the initiation of enteral nutrition. The urine samples were analyzed using enzyme-linked immunosorbent assay (ELISA) kits. The collected data included all birth-related maternal and neonatal factors such as maternal age, race/ethnicity, hypertensive disorders of pregnancy, diabetes, gravidity, parity, type of pregnancy, mode of delivery, and antenatal use of corticosteroids, antibiotics, magnesium sulfate, Apgar scores at 1 and 5 min, gestational age, and birth weight. We investigated the correlation between the levels of the tested mediators, the significance of the differences in their average levels based on the dichotomized maternal and neonatal factors, and the effect of the selected factors, in multiple regression models. Data from the regression models constructed for leptin, adiponectin, ghrelin, and IGF-1 are presented as regression coefficient β with Standard Error (SE) of β, coefficient of determination (R2), and adjusted R2. Before including the factor in regression models, we tested for the multicollinearity effect. Two-sided P values <0.05 were considered statistically significant.

RESULTS

Among the 70 studied infants, 47.1% were male, 40.6% were white, 28.6% were extremely preterm, and 18.6% were born with a weight <750 grams. Except for a mild interplay between the adiponectin and IGF-1 levels, there was no correlation between the levels of the other studied mediators. Up to 20% variation in the tested energy metabolism mediator levels was dependent on some of the birth-related maternal and neonatal characteristics. For instance, leptin levels were reduced in association with male gender (-0.493 [0.190], p < 0.02) and increased in infants born to primigravids (0.562 [0.215], p < 0.02). Adiponectin levels were increased in infants born to nulliparous as compared to multiparous women (0.400 [0.171], p < 0.03). Ghrelin levels were reduced in males (-0.057 [0.026], p < 0.04). IGF-1 levels were increased in the urine of extremely preterm neonates (0.357 [0.111], p < 0.01) and preterm infants born with an Apgar less than three at 1 min (0. 340 [p < 0.153], p < 0.04).

CONCLUSIONS

Nearly one-fifth of the variation in the urinary levels of the adipokines (leptin, adiponectin, ghrelin) and IGF-1 during the early postnatal stage in infants born at 32 or fewer weeks of gestation was predicated on one or more of the maternal and neonatal factors such as the infant's sex, extreme preterm gestation, a low Apgar score at 1 min, or birth to nulliparous women or primigravida mothers. Further studies will be required to explain the role of energy metabolism mediators in the postnatal adaptation of preterm-born infants.

AdipoRon and ADP355, adiponectin receptor agonists, in Metabolic-associated Fatty Liver Disease (MAFLD) and Nonalcoholic Steatohepatitis (NASH): A systematic review

Adiponectin replacement therapy holds the potential to benefit numerous human diseases, and ongoing research applies particular interest in how adiponectin acts against Metabolic-associated Fatty Liver Disease (MAFLD) and Nonalcoholic Steatohepatitis (NASH). However, the pharmacological limitations of the intact protein have prompted a focus on alternative options, specifically peptidic and small molecule agonists targeting the adiponectin receptor. AdipoRon is an extensively researched non-peptidic drug candidate in adiponectin replacement therapy. In turn, ADP355 is an adiponectin-based active short peptide. They have garnered significant attention due to their potential as substitutes for adiponectin. Researchers have studied AdipoRon's and ADP355's efficacy and therapeutic applications in various disease conditions. However, the effects of AdipoRon and ADP355 against NAFLD and NASH models advanced more, and no systematic review explored this area before. This systematic review was conceived to address the deficiency mentioned above and consider the lack of clinical evidence. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized. To assess the risk of bias in systematic review, The Joanna Briggs Institute (JBI) Critical Appraisal Checklist was employed. Results from pre-clinical evidence show that AdipoRon and ADP355 represent promising effects in NAFLD and NASH-related models, including reducing hepatic steatosis, modulating inflammation, improving insulin sensitivity, enhancing mitochondrial function, and protecting against liver fibrosis. While AdipoRon and ADP355 exhibit promise in pre-clinical studies and experimental models, additional clinical trials are necessary to assess their effectiveness, safety, and potential translational therapeutic potential uses in NAFLD and NASH human cases.

Adiponectin - stratification biomarker in diastolic cardiac dysfunction

This study does not propose to elucidate how adiponectin secretion is regulated, but how its adiponectin concentration is an indicator of heart disease. About adiponectin, it is not known whether it is functionally an enzyme, or very likely a cytokine/chemokine/hormone, secreted by fat cells/adipocytes in the abdomen. Abdominal fat secretes 67 hormones, and all of which cause disease. For example, adiponectin generates diabetes and ischaemic heart disease via dyslipidemia. Based on clinical symptoms, electrocardiographic and echocardiographic parameters, a group of 208 patients with diastolic cardiac dysfunction with or without preserved systolic function, developed on a background of painful chronic ischaemic heart disease, stable angina on exertion, was constituted. The serum levels of adiponectin, total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides were measured. Using the identified values, it was appreciated whether adiponectin correlates with the type of any of the two conditions, so that it can be recognised as a diagnostic and risk stratification marker.

Intermittent fasting favorably modulates adipokines and potentially attenuates atherosclerosis

Adipose tissue is now recognized as an endocrine organ that secretes bioactive molecules called adipokines. These biomolecules regulate key physiological functions, including insulin sensitivity, energy metabolism, appetite regulation, endothelial function and immunity. Dysregulated secretion of adipokines is intimately associated with obesity, and translates into increased risk of obesity-related cardiovasculo-metabolic diseases. In particular, emerging evidence suggests that adipokine imbalance contributes to the pathogenesis of atherosclerosis. One of the promising diet regimens that is beneficial in the fight against obesity and cardiometabolic disorders is intermittent fasting (IF). Indeed, IF robustly suppresses inflammation, meditates weight loss and mitigates many aspects of the cardiometabolic syndrome. In this paper, we review the main adipokines and their role in atherosclerosis, which remains a major contributor to cardiovascular-associated morbidity and mortality. We further discuss how IF can be employed as an effective management modality for obesity-associated atherosclerosis. By exploring a plethora of the beneficial effects of IF, particularly on inflammatory markers, we present IF as a possible intervention to help prevent atherosclerosis.

Adipokines in Rheumatoid Arthritis: Emerging Biomarkers and Therapeutic Targets

Rheumatoid arthritis (RA) is a chronic inflammatory disease manifested by joint involvement, extra-articular manifestations, and general symptoms. Adipose tissue, previously perceived as an inert energy storage organ, has been recognised as a significant contributor to RA pathophysiology. Adipokines modulate immune responses, inflammation, and metabolic pathways in RA. Although most adipokines have a pro-inflammatory and aggravating effect on RA, some could counteract this pathological process. The coexistence of RA and sarcopenic obesity (SO) has gained attention due to its impact on disease severity and outcomes. Sarcopenic obesity further contributes to the inflammatory milieu and metabolic disturbances. Recent research has highlighted the intricate crosstalk between adipose tissue and skeletal muscle, suggesting potential interactions between these tissues in RA. This review summarizes the roles of adipokines in RA, particularly in inflammation, immune modulation, and joint destruction. In addition, it explores the emerging role of adipomyokines, specifically irisin and myostatin, in the pathogenesis of RA and their potential as therapeutic targets. We discuss the therapeutic implications of targeting adipokines and adipomyokines in RA management and highlight the challenges and future directions for research in this field.

Isthmin-1 attenuates allergic Asthma by stimulating adiponectin expression and alveolar macrophage efferocytosis in mice

BACKGROUND

Allergic asthma is a common respiratory disease that significantly impacts human health. Through in silico analysis of human lung RNASeq, we found that asthmatic lungs display lower levels of Isthmin-1 (ISM1) expression than healthy lungs. ISM1 is an endogenous anti-inflammatory protein that is highly expressed in mouse lungs and bronchial epithelial cells, playing a crucial role in maintaining lung homeostasis. However, how ISM1 influences asthma remains unclear. This study aims to investigate the potential involvement of ISM1 in allergic airway inflammation and uncover the underlying mechanisms.

METHODS

We investigated the pivotal role of ISM1 in airway inflammation using an ISM1 knockout mouse line (ISM1-/-) and challenged them with house dust mite (HDM) extract to induce allergic-like airway/lung inflammation. To examine the impact of ISM1 deficiency, we analyzed the infiltration of immune cells into the lungs and cytokine levels in bronchoalveolar lavage fluid (BALF) using flow cytometry and multiplex ELISA, respectively. Furthermore, we examined the therapeutic potential of ISM1 by administering recombinant ISM1 (rISM1) via the intratracheal route to rescue the effects of ISM1 reduction in HDM-challenged mice. RNA-Seq, western blot, and fluorescence microscopy techniques were subsequently used to elucidate the underlying mechanisms.

RESULTS

ISM1-/- mice showed a pronounced worsening of allergic airway inflammation and hyperresponsiveness upon HDM challenge. The heightened inflammation in ISM1-/- mice correlated with enhanced lung cell necroptosis, as indicated by higher pMLKL expression. Intratracheal delivery of rISM1 significantly reduced the number of eosinophils in BALF and goblet cell hyperplasia. Mechanistically, ISM1 stimulates adiponectin secretion by type 2 alveolar epithelial cells partially through the GRP78 receptor and enhances adiponectin-facilitated apoptotic cell clearance via alveolar macrophage efferocytosis. Reduced adiponectin expression under ISM1 deficiency also contributed to intensified necroptosis, prolonged inflammation, and heightened severity of airway hyperresponsiveness.

CONCLUSIONS

This study revealed for the first time that ISM1 functions to restrain airway hyperresponsiveness to HDM-triggered allergic-like airway/lung inflammation in mice, consistent with its persistent downregulation in human asthma. Direct administration of rISM1 into the airway alleviates airway inflammation and promotes immune cell clearance, likely by stimulating airway adiponectin production. These findings suggest that ISM1 has therapeutic potential for allergic asthma.

Fibroblast Growth Factor 21 in Gestational Diabetes Mellitus and Type 2 Diabetes Mellitus

Objective

Women who develop GDM present a metabolic condition similar to that found in type 2 diabetes, characterized by impaired insulin response. Due to similar pathophysiologic mechanisms found between type 2DM and GDM, there is a great interest in finding markers that will lead to the understanding of a possible common origin to both diseases. The aim of this study was to determine serum FGF21 levels in 2DM and GDM and its correlation with selected metabolic parameters.

Method

The study included 54 2DM patients and 52 nondiabetic individuals (control group 1) as well as 74 GDM women and 32 healthy pregnant controls (control group 2). Serum FGF21 was determined by enzyme-linked immunosorbent assay (ELISA), in all groups, and correlated with biochemical parameters of glucose metabolism and insulin resistance (HbA1c, HOMA index, TG, and HDL cholesterol).

Results

FGF21 concentration was significantly higher in 2DM as compared with control group 1 (p < 0.01). In the 2DM group, FGF21 was positively correlated with HOMA index (p = 0.022, R = 0.398). In the GDM group, the positive relationships with FGF21 were observed with glucose (p = 0.020, R = 0.264) and TG (p = 0.013, R = 0.283) while HDL-C levels were correlated negatively (p = 0.004, R = -0.326).

Conclusion

Serum FGF21 levels were significantly higher in 2DM patients than those without diabetes. Moreover, serum FGF21 levels were associated with selected metabolic parameters, suggesting that it may play acrolein glucose and lipid metabolism.

Increased Expression of Adipokines in Patients With Frozen Shoulder

BACKGROUND

Adipokines represent a spectrum of bioactive molecules that could modulate fibroblastic and inflammatory processes. The role of adipokines in the pathogenesis of frozen shoulder (FS), a common musculoskeletal disorder characterized by chronic inflammation, remains obscure.

PURPOSE

To evaluate whether adipokines contribute to the pathogenic mechanisms of FS and to evaluate any potential correlation of adipokines with patients' symptoms.

STUDY DESIGN

Controlled laboratory study.

METHODS

Shoulder capsule specimens were obtained from 10 patients with FS and 10 patients with shoulder instability (control group). The specimens were dyed using hematoxylin and eosin and immunohistochemically assessed with antibodies targeting adipokines, collagen I, collagen III, and tumor necrosis factor α. Immunoreactivity was graded from "no" to "strong" in a blinded manner. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) analysis was conducted. Before the surgery, patient-reported frequency of pain, severity of pain, stiffness, and shoulder range of motion were documented.

RESULTS

In comparison with the control group, patients with FS had significantly greater pain frequency, pain severity, and stiffness and more limited shoulder range of motion (P < .001). Hematoxylin and eosin- and Masson trichrome-stained samples from the FS group displayed hypercellularity and increased collagen fibers. Immunohistochemistry and RT-qPCR analyses indicated that expression of adipokines was significantly increased in FS capsules compared with the control group. The expression of collagen I, collagen III, and tumor necrosis factor α was also increased in FS capsules. No significant correlation was noted between adipokine expression and patient-reported outcomes in the control group, whereas in patients with FS, adiponectin expression was correlated with pain frequency (r = 0.78; P = .01) and stiffness (r = 0.73; P = .02). Visfatin was also correlated with pain frequency (r = 0.70; P = .02).

CONCLUSION/CLINICAL RELEVANCE

This study indicated a potential role for adipokines in the pathogenesis of FS and demonstrated a correlation between adipokine expression and patients' pain and stiffness.

Omentum provides a special cell microenvironment for ovarian cancer

BACKGROUND

Ovarian cancer seriously threatens women's health because of its poor prognosis and high mortality. Due to the lack of efficient early detection and screening methods, when patients seek doctors' help with complaints of abdominal distension, back pain and other nonspecific signs, the clinical results always hint at the widespread metastasis of disease. When referring to the metastasis of this disease, the omentum always takes precedence.

RECENT FINDINGS

The distinguishing feature of the omentum is adipose tissue, which satisfies the energy demand of cancer cells and supplies a more aggressive environment for ovarian cancer cells. In this review, we mainly focus on three important cell types: adipocytes, macrophages, and mesenchymal stem cells. Besides, several mechanisms underlying cancer-associated adipocytes (CAA)-facilitated ovarian cancer cell development have been revealed, including their capacities for storing lipids and endocrine function, and the release of hormones, growth factors, and adipokines. Blocking the reciprocity among cancer cells and various cells located on the omentum might contribute to ovarian cancer therapy. The inhibition of hormones, growth factors and adipokines produced by adipocytes will be a novel therapeutic strategy. However, a sufficient number of trials has not been performed. In spite of this, the therapeutic potential of metformin and the roles of exercise in ovarian cancer will be worth mentioning.

CONCLUSION

It is almost impossible to overcome completely ovarian cancer at the moment. What we can do is trying our best to improve these patients' prognoses. In this process, adipocytes may bring promising future for the therapy of ovarian cancer.