Figure 1 - available via license: CC BY
Content may be subject to copyright.
Domains and structure of adiponectin. The primary structure of adiponectin, which consist of 244 amino acids, has an N-terminal signal sequence, a variable region with attached O-glycoside side chains, a collagenous domain, and a C-terminal sequence of a globular domain.
Source publication
Adiponectin is the richest adipokine in human plasma, and it is mainly secreted from white adipose tissue. Adiponectin circulates in blood as high-molecular, middle-molecular, and low-molecular weight isoforms. Numerous studies have demonstrated its insulin-sensitizing, anti-atherogenic, and anti-inflammatory effects. Additionally, decreased serum...
Context in source publication
Context 1
... human adiponectin gene contains three exons with the start codon in exon 2 and stop codon in exon 3 [7]. As shown in Figure 1, full length human adiponectin, has 244 amino acids, and consists of four regions including signal sequence at the N-terminus of 18 amino acids, a variable region of 24 amino acids, a collagenous domain of 65 amino acids, and a C-terminal globular domain of 137 amino acids [8,11]. After synthesis, it undergoes post-translational modification by glycosylation and hydroxylation. ...
Similar publications
Background
Premature/low-birth-weight infants are at significant risk of metabolic diseases in adulthood, which may be related to the levels of fetal adipokine. Here, we investigated the differences in the levels of umbilical cord blood adiponectin, leptin, insulin, and ghrelin in preterm and term infants and sought to elucidate the link between th...
Citations
... [42,44,45] These changes are particularly relevant as adiponectin is associated with improved insulin sensitivity and reduced inflammation, while elevated C-reactive protein levels are linked to metabolic dysfunction. [63,64] The underlying mechanism for the observed improvements in metabolic markers could be attributed to the distinct neuromuscular necessities of BGT. [52] The higher motor unit recruitment and metabolic demand may lead to the mobilization of fat reserves. ...
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.
... Larger adipocytes show reduced insulin sensitivity, as indicated by impaired insulin-stimulated glucose uptake, which can result in diabetes [48]. Additionally, high serum levels of adiponectin, MCP-1, TNF-α, TBARS, and BUN are primary contributors to obesity-related inflammation in db/db mice [18,49]. The current study suggests that 42 days of MLP treatment can reduce pro-inflammatory cytokines, improve adipocyte insulin sensitivity, and decrease body weight. ...
... The results showed an increased protein expression of the lipogenic transcription factor SREBP1 in db/db CON mice ( Figure 5), stimulating FAS and ACC, thereby enhancing lipogenesis and adipogenesis, leading to increased liver TG and TC levels [58,59]. Elevated SREBP-1 expression can disrupt lipid metabolism in the liver by influencing the glucose/lipid balance [49]. According to Fang et al. [22], SREBP-1 activity is regulated by AMPK expression, and its inhibition may have an anti-hepatic steatosis effect in obese 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.
... Studies have shown that adiponectin levels tend to be greater in male and female UC patients compared to healthy controls, and elevated levels of adiponectin are observed in the serum of patients with CD (37,38). Adiponectin levels vary in autoimmune and chronic inflammatory diseases such as rheumatoid arthritis (RA), chronic kidney disease (CKD), and IBD, exhibiting both pro-and anti-inflammatory properties relying on the specific tissue and signaling pathways involved (39). ...
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.
... Some of these adipokines, such as leptin, resistin (RES), and adiponectin, seem to be altered in IBD patients and are related to disease severity [11]. Remarkably, IBD patients usually show lower levels of leptin and higher levels of adiponectin and RES in their blood [13]. In particular, RES is a cysteinerich adipokine produced in humans by adipocytes as well as by immune cells and macrophages and can be considered a promising inflammatory marker due to the significant connections between adipose tissues and inflammatory response. ...
Inflammatory bowel disease (IBD) is a clinical condition of the gastrointestinal tract that has significant incidence in childhood. Major symptoms include abdominal pain, dyspepsia, delayed gastric emptying, anorexia, diarrhea and weight loss. IBD etiopathogenesis is multifactorial, with a proven involvement of cytokines. In this regard, cytokines like resistin and adiponectin produced by adipose tissue play a crucial role in inflammation. Particularly, resistin seems related to IBD severity and is considered a promising marker of disease occurrence and progression. Unraveling its mechanism of action and downstream effectors is mandatory when designing novel therapies. This preclinical study aims to further elucidate the action of resistin in causing functional gastrointestinal alterations, comparing it with the well-defined effect of adiponectin. To this end, we carried out electrophysiological analysis on murine gastric fundus. We found that resistin, similarly to adiponectin, increases smooth muscle cell (SMC) capacitance, indicative of cell surface remodeling, which is consistent with relaxation. However, contrary to adiponectin, resistin unalters membrane potential and inward Ca2+ entry and scarcely affects outward current, suggesting its inefficacy in markedly modifying electrical phenomena on the SMC membrane. This outcome, supporting the role of resistin in gastrointestinal distention, as observed in IBD, rules out a strikingly direct effect on SMCs.
... Unexpectedly, there were more patients with hypertension and cardiovascular disease in the moderate COVID-19 cohort than in the severe COVID-19 cohort for an unknown reason, and this is a limitation of our study. Serum adiponectin is low in patients with obesity, hypertension, diabetes, and cardiovascular disease [5,8,14,63]. Such differences were not observed in our patient cohorts. ...
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.
... 62,63 Macrophages have two phenotypes, M1 and M2, with M1 having pro-inflammatory and M2 anti-inflammatory effects. 64,65 Obesity can contribute to the conversion of M2 to M1 phenotype, 65,66 which causes an increase in pro-inflammatory factors (eg, TNF-α, IL-6, etc.) and leads to an increased production of intracellular reactive oxygen species (ROS). It in turn causes cellular injury and oxidative stress. ...
... 93,94 Adiponectin has both anti-inflammatory and pro-inflammatory effects, which is one of the mechanisms that cause the development of various diseases. 64,95 The reduced secretion of adiponectin in people with obesity may be related to the suppression of adiponectin transcription due to the persistent chronic inflammatory state of the body caused by obesity. 64,96 Adiponectin exerts its function by interacting with adiponectin receptors (Figure 3). ...
... 64,95 The reduced secretion of adiponectin in people with obesity may be related to the suppression of adiponectin transcription due to the persistent chronic inflammatory state of the body caused by obesity. 64,96 Adiponectin exerts its function by interacting with adiponectin receptors (Figure 3). ...
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.
... It is also an insulinsensitizing hormone, which plays a pivotal role in the regulation of energy homeostasis, inflammation, and cell proliferation [2,3]. Previous investigations have suggested that the low serum adiponectin concentration was associated with the incidence of various chronic diseases such as cardiovascular diseases (CVDs), diabetes, cancers, and chronic kidney disease [3][4][5]. Adiponectin levels in humans can be increased through indirect methods such as weight loss or physical activity [6,7]. Therefore, improving the level of adiponectin is one of the important goals of health systems. ...
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.
... Activation of BAT leads to an increased release of FGF21. FGF21, in turn, reduces brain oxidative stress and neuroinflammation by enhancing antioxidant activity and diminishing proinflammatory cytokines such as TNF-α and IL-6, critical factors in Alzheimer's Disease pathogenesis [227] . Hormones produced by BAT, including adiponectin and leptin, contribute to neuroprotective effects by inhibiting proinflammatory cytokines and suppressing Aβ production, thereby attenuating tau phosphorylation [228,229] , providing additional evidence of BAT's involvement in Alzheimer's Disease. ...
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.
... Adiponectin and angiopoietin-like protein 2 (ANGPTL2) are two proteins secreted by adipocytes, and both take part in inflammation. While large quantities of (ANGPTL2) are produced in response to inflammation, adiponectin ameliorates inflammatory response by modulating different signaling pathways [157,158]. BBR significantly downregulated the synthesis of pro-inflammatory proteins and cytokines by decreasing the expression of adipocyte macrophage-derived Angptl2 signaling pathway NAFLD-induced rats [95]. ...
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.
... AdipoQ is initially produced in monomeric form, and once circulating, undergoes a multimerization process, that Francesca Simoncelli and Francesca Mercati have contributed equally to the work. is essential for the biological actions of the molecule. The monomeric form is modified into multiple isoforms: lowmolecular weight (LMW) (trimer), middle-molecular weight (MMW) (hexamer), and high-molecular weight (HMW) (multimer); the latter is the most biologically active form (Caminos et al. 2008;Choi et al. 2020). To perform its functions, AdipoQ needs the bind with its two receptors, AdipoR1 and AdipoR2, first characterized by Yamauchi et al. (2003). ...
In all vertebrates, reproductive strategies are achieved by modulation of the neuroendocrine system in a similar manner and with minor variations among the different classes. Most of the available information on amphibian testicular cycles derive from anurans, and among these, water frogs have been extensively studied in terms of reproductive mechanisms and sex steroid correlation. Adiponectin (AdipoQ) and its receptors—AdipoR1 and AdipoR2—are essential for most of the normal testicular and sperm functions. In this study, the identification of AdipoQ and its two receptors was carried out by immunohistochemistry in the testis of adult males of Pelophylax bergeri. The AdipoQ system was observed in the frog spermatogenic cysts, in both germinal and Sertoli cells, as well as in the rete testis. AdipoQ and AdipoR1 were localized in germ-line cells, from spermatogonia to round spermatids, while AdipoR2 was detected in the elongated spermatids, spermatozoa, and Sertoli cells. AdipoR1 was also observed in the intratesticular canals of the rete testis. This preliminary study shows the AdipoQ system’s presence in the anurans’ testis. The results obtained could be a starting point for future functional studies aimed at defining the physiological role of the AdipoQ system in frog testicular functions.
