The prevention and treatment of hypoadiponectinemia-associated human diseases by up-regulation of plasma adiponectin

J-shaped relationship between Chinese visceral adiposity index and hyperuricemia: a cross-sectional study

BACKGROUND

Recent years have seen the emergence of numerous novel indicators for visceral obesity. This study investigates the potential correlation between the Chinese visceral adiposity index (CVAI) and hyperuricemia (HUA).

METHODS

This research, derived from a 2011 cross-sectional analysis in Dalian, China, employed restricted cubic spline (RCS) plots to identify inflection points. Subsequently, one-way and multifactorial logistic regression models were utilized, with HUA as the outcome variable. Additionally, subgroup analyses and interaction tests were conducted. Eventually, receiver operating characteristic (ROC) curves were calculated to assess the effectiveness of CVAI and other body composition indices in predicting HUA.

RESULTS

The study included 10,061 individuals, with a HUA prevalence of 14.25%. Significant relationships with HUA were observed for CVAI. RCS analysis revealed a J-shaped relationship between CVAI and HUA. Compared to those in the low CVAI category, HUA was notably associated with individuals in the high CVAI category in multifactorial logistic regression (OR = 2.661, 95% CI: 2.323, 3.047). Subgroup analyses demonstrated stronger relationships in women, participants without hypertension, and participants without diabetes. Additional modeling via ROC curves suggested that the CVAI may offer effective predictive value for HUA.

CONCLUSION

This study confirmed that an elevated CVAI elevates the risk of HUA in middle-aged and elderly populations in the Dalian community. The findings advance obesity prevention strategies that mitigate HUA risk and support healthcare initiatives for China's aging population.

Adiponectin: A Promising Target for the Treatment of Diabetes and Its Complications

Diabetes mellitus, a chronic metabolic disorder characterized by hyperglycemia, presents a formidable global health challenge with its associated complications. Adiponectin, an adipocyte-derived hormone, has emerged as a significant player in glucose metabolism and insulin sensitivity. Beyond its metabolic effects, adiponectin exerts anti-inflammatory, anti-oxidative, and vasoprotective properties, making it an appealing therapeutic target for mitigating diabetic complications. The molecular mechanisms by which adiponectin impacts critical pathways implicated in diabetic nephropathy, retinopathy, neuropathy, and cardiovascular problems are thoroughly examined in this study. In addition, we explore possible treatment options for increasing adiponectin levels or improving its downstream signaling. The multifaceted protective roles of adiponectin in diabetic complications suggest its potential as a novel therapeutic avenue. However, further translational studies and clinical trials are warranted to fully harness the therapeutic potential of adiponectin in the management of diabetic complications. This review highlights adiponectin as a promising target for the treatment of diverse diabetic complications and encourages continued research in this pivotal area of diabetes therapeutics.

Effect of Manual Lymphatic Drainage on the Concentrations of Selected Adipokines, Cytokines, C-Reactive Protein and Parameters of Carbohydrate and Lipid Metabolism in Patients with Abnormal Body Mass Index: Focus on Markers of Obesity and Insulin Resistance

The aim of the study was to assess the impact of manual lymphatic drainage (MLD) on the parameters of carbohydrate metabolism, lipid metabolism and the level of selected adipokines and cytokines in people with abnormal body mass index (BMI). In addition, an attempt was made to assess the optimal cut-off values of serum concentrations of the biochemical parameters studied in identifying the risk of obesity and insulin resistance (IR). The study included 60 subjects who underwent 10 and 30 min long MLD sessions three times a week. The study group included 15 patients with a normal body mass index (group I; n = 15), overweight patients (group II; n = 15) and obese patients (group III; n = 10). The control group was IV; n = 20 subjects not undergoing MLD. Biochemical tests were carried out on all subjects at stage 0' (before MLD therapy) and at stage 1' (one month after MLD therapy). In the control group, the time between the sample collection at stage 0' and stage 1' was the same as in the study group. Our results showed that 10 MLD sessions may have a positive effect on the selected biochemical parameters, including insulin, 2h-PG, leptin and HOMA-IR values in normal weight and overweight patients. In addition, in the study group, the highest AUC_ROC values in identifying the risk of obesity were found for leptin (AUC_ROC = 82.79%; cut-off = 17.7 ng/mL; p = 0.00004), insulin (AUC_ROC = 81.51%; cut-off = 9.5 µIU/mL; p = 0.00009) and C-peptide (AUC_ROC = 80.68%; cut-off = 2.3 ng/mL; p = 0.0001) concentrations as well as for HOMA-IR values (AUC_ROC = 79.97%; cut-off = 1.8; p = 0.0002). When considering the risk of IR, we observed the highest diagnostic value for insulin (AUC_ROC = 93.05%; cut-off = 1.8 ng/mL; p = 0.053), which was followed by C-peptide (AUC_ROC = 89.35%; cut-off = 17.7 ng/mL; p = 0.000001), leptin (AUC_ROC = 79.76%; cut-off = 17.6 ng/mL; p = 0.0002) and total cholesterol (AUC_ROC = 77.31%; cut-off = 198 mg/dL; p = 0.0008). Our results indicate that MLD may have a positive effect on selected biochemical parameters, including insulin, 2h-PG, leptin and HOMA-IR, in normal weight and overweight patients. In addition, we successfully established optimal cut-off values for leptin in the assessment of obesity and insulin in the assessment of insulin resistance in patients with abnormal body mass index. Based on our findings, we hypothesize that MLD, when combined with caloric restriction and physical activity, may serve as an effective preventive intervention against the development of obesity and insulin resistance.

Mechanistic insights into the beneficial effects of curcumin on insulin resistance: opportunities and challenges

The past couple of decades in particular have seen a rapid increase in the prevalence of type 2 diabetes mellitus (T2DM), a debilitating metabolic disorder characterised by insulin resistance. The insufficient efficacy of current management strategies for insulin resistance calls for additional therapeutic options. The preponderance of evidence suggests potential beneficial effects of curcumin on insulin resistance, while modern science provides a scientific basis for its potential applications against the disease. Curcumin combats insulin resistance by increasing the levels of circulating irisin and adiponectin, activating PPARγ, suppressing Notch1 signalling, and regulating SREBP target genes, among others. In this review, we bring together the diverse areas pertaining to our current understanding of the potential benefits of curcumin on insulin resistance, associated mechanistic insights, and new therapeutic possibilities. Teaser: Current approaches to manage insulin resistance are not highly efficacious, which necessitates additional therapeutic options; curcumin combats insulin resistance by improving the levels of circulating irisin and adiponectin, upregulating and activating PPARγ, and suppressing Notch‑1 signalling.

Discovery of Pan-peroxisome Proliferator-Activated Receptor Modulators from an Endolichenic Fungus, Daldinia childiae

Adiponectin-synthesis-promoting compounds possess therapeutic potential to treat diverse metabolic diseases, including obesity and diabetes. Phenotypic screening to find adiponectin-synthesis-promoting compounds was performed using the adipogenesis model of human bone marrow mesenchymal stem cells. The extract of the endolichenic fungus Daldinia childiae 047215 significantly promoted adiponectin production. Bioactivity-guided isolation led to 13 active polyketides (1-13), which include naphthol monomers, dimers, and trimers. To the best of our knowledge, trimers of naphthol (1-4) have not been previously isolated as either natural or synthetic products. The novel naphthol trimer 3,1',3',3″-ternaphthalene-5,5',5″-trimethoxy-4,4',4″-triol (2) and a dimer, nodulisporin A (12), exhibited concentration-dependent adiponectin-synthesis-promoting activity (EC₅₀ 30.8 and 15.2 μM, respectively). Compounds 2 and 12 bound to all three peroxisome proliferator-activated receptor (PPAR) subtypes, PPARα, PPARγ, and PPARδ. In addition, compound 2 transactivated retinoid X receptor α, whereas 12 did not. Naphthol oligomers 2 and 12 represent novel pan-PPAR modulators and are potential pharmacophores for designing new therapeutic agents against hypoadiponectinemia-associated metabolic diseases.

Adiponectin: friend or foe in obesity and inflammation

Adiponectin is an adipokine predominantly produced by fat cells, circulates and exerts insulin-sensitizing, cardioprotective and anti-inflammatory effects. Dysregulation of adiponectin and/or adiponectin signaling is implicated in a number of metabolic diseases such as obesity, insulin resistance, diabetes, and cardiovascular diseases. However, while the insulin-sensitizing and cardioprotective effects of adiponectin have been widely appreciated in the field, the obesogenic and anti-inflammatory effects of adiponectin are still of much debate. Understanding the physiological function of adiponectin is critical for adiponectin-based therapeutics for the treatment of metabolic diseases.

Evaluating the effects of Juglans regia L. extract on hyperglycaemia and insulin sensitivity in experimental type 2 diabetes in rat

OBJECTIVE

The present study aimed to investigate the effects of Juglans regia (JR) extract on hyperglycaemia and insulin sensitivity.

METHODS

Forty rats were divided into 4 groups: Control (C), Diabetes Control (DC), Diabetes + Juglans regia (D + JR) and Diabetes + Metformin (D + M).

RESULTS

In the D + JR group, Fasting blood glucose (FBG) levels decreased from day 14 onwards. There was a significant decrease in plasma levels of Fibronectin Type III Domain Containing 5 (FNDC5) and adiponectin (ADP) in the DC group compared to the C group (p < .01, p < .001 respectively). In the D + JR group, there was a significant increase in plasma FNDC5 and ADP (p < .05), while the plasma Tumour necrosis factor-alpha (TNF-α) levels were decreased compared to the DC group (p < .001).

CONCLUSIONS

In conclusion, the present study found that JR and its bioactive components alleviated insulin resistance by increasing ADP and FNDC5 and decreasing FBG in a rat model of streptozotocin (STZ) + nicotinamide (NAD)-induced type 2 diabetes (T2D).HighlightsJuglans regia extract increased insulin sensitivity.Juglans regia extract significantly reduced the level of fasting blood glucose.Juglans regia extract reduced TNF-α levels in rats with type 2 diabetes.Juglans regia extract prevent weight loss in type 2 diabetes.

Endogenous Protective Factors and Potential Therapeutic Agents for Diabetes-Associated Atherosclerosis

The complications of macrovascular atherosclerosis are the leading cause of disability and mortality in patients with diabetes. It is generally believed that the pathogenesis of diabetic vascular complications is initiated by the imbalance between injury and endogenous protective factors. Multiple endogenous protective factors secreted by endothelium, liver, skeletal muscle and other tissues are recognized of their importance in combating injury factors and maintaining the homeostasis of vasculatures in diabetes. Among them, glucagon-like peptide-1 based drugs were clinically proven to be effective and recommended as the first-line medicine for the treatment of type 2 diabetic patients with high risks or established arteriosclerotic cardiovascular disease (CVD). Some molecules such as irisin and lipoxins have recently been perceived as new protective factors on diabetic atherosclerosis, while the protective role of HDL has been reinterpreted since the failure of several clinical trials to raise HDL therapy on cardiovascular events. The current review aims to summarize systemic endogenous protective factors for diabetes-associated atherosclerosis and discuss their mechanisms and potential therapeutic strategy or their analogues. In particular, we focus on the existing barriers or obstacles that need to be overcome in developing new therapeutic approaches for macrovascular complications of diabetes.

Adiponectin regulates electroacupuncture-produced analgesic effects in association with a crosstalk between the peripheral circulation and the spinal cord

Neurotransmitter-mediated acupuncture analgesia has been widely studied in nervous systems. It remains largely unclear if peripheral substances are involved the acupuncture analgesia. Adiponectin (APN), a circulating adipokine, shows analgesic effects. The study aimed to examine whether APN regulates analgesic effects of electroacupuncture (EA) in the complete Freund's adjuvant (CFA)-induced mouse model. APN wild type (WT) and knockout (KO) mouse were employed in the study. We found that EA attenuates the CFA-induced pain as demonstrated by the Hargreaves thermal test and the von Frey filament test. The deletion of APN significantly reduced the acupuncture analgesia in the CFA-treated APN KO mice while the intrathecal administration of APN mimicked the analgesic effects of EA. We further revealed that EA produced analgesic effects mainly via APN/AdipoR2-mediated AMPK pathway by the siRNA inhibitions of APN receptors (adipoR1/2) in the spinal cord. The immunofluorescence staining analysis showed that EA increased the APN accumulation in spinal cord through the blood circulation. In conclusion, the study indicates a novel mechanism that acupuncture produces analgesic effects at least partially via APN/AdipoR2-AMPK pathway in the spinal cord.

Adiponectin gene polymorphisms associated with diabetes mellitus: A descriptive review

Diabetes is currently a growing concern of the age. Prevention and treatment of diabetes is a global health priority. Adiponectin is an adipocyte derived protein hormone that enhances insulin sensitivity and ameliorates diabetes by enhancing fatty acid oxidation and glucose uptake in skeletal muscle and reducing glucose production in the liver. Low serum adiponectin concentrations are associated with diabetes, central obesity, insulin resistance and metabolic syndrome. Adiponectin gene is located on chromosome 3q27, where a locus of susceptibility to diabetes was mapped. Several cross-sectional studies showed that single nucleotide polymorphisms (SNPs) in adiponectin gene (ADIPOQ) were associated with diabetes. SNPs in ADIPOQ help in assessing the association of common variants with levels of adiponectin and the risk of diabetes. Two common SNPs, rs2241766 and rs1501299, have been linked significantly to type 1 diabetes mellitus which endow the world with a block of haplotypes. Experimental evidences also suggest that rs1501299, rs2241766, rs266729, rs17366743, rs17300539, rs182052, rs822396, rs17846866, rs3774261 and rs822393 are significantly associated with type 2 diabetes mellitus which is the predominant form of the disease. In addition, rs2241766 and rs266729 are extensively associated with gestational diabetes, a condition that develops in women during pregnancy. Therefore not a particular single mutation but a number of SNPs in adiponectin gene could be a risk factor for developing diabetes among the individuals worldwide. This study firmly suggests that adiponectin plays a crucial role in the pathogenesis of type 1, type 2 and gestational diabetes mellitus.

Predictors of HbA1c among Adipocytokine Biomarkers in African-American Men with Varied Glucose Tolerance

This study explored adipocytokine associations with acute and chronic hyperglycemia in African-American men (AAM). Fourteen adipocytokines were measured from men with normal glucose tolerance (NGT) or type 2 diabetes (T2D, drug-naïve MF(-) or using metformin MF(+)). Acute and chronic hyperglycemia were evaluated by 120 min oral glucose tolerance test (OGTT) and glycohemoglobin A1c (HbA1c). AAM with T2D (n = 21) compared to NGT (n = 20) were older, had higher BMI and slightly higher glucose and insulin. In the fasted state, TNF-α, IL-6, PAI-1, IL-13, adiponectin, adipsin, and lipocalin were lower in T2D vs. NGT. At 120 min post-glucose load, TNF-α, IL-6, IL-13, IL-8, PAI-1, adiponectin, adipsin, lipocalin, and resistin were lower in T2D vs. NGT. There were no statistical differences for GM-CSF, IL-7, IL-10, IP-10, and MCP-1. Regression analysis showed that fasting IL-8, TNF-α, adiponectin, lipocalin, resistin, adipsin, and PAI-1 were associated with HbA1c. After adjusting for age, BMI, glucose tolerance, and metformin use, only adipsin remained significantly associated with HbA1c (p = 0.021). The model including adipsin, TNF-α, age, BMI, and group designation (i.e., NGT, MF(-), MF(+)) explained 86% of HbA1c variability. The data suggested that adipsin could be associated with HbA1c in AAM with varied glucose tolerance.

Production of pharmaceutical active recombinant globular adiponectin as a secretory protein in Withania Somnifera hairy root culture

Among various in vitro plant culture systems, hairy root systems seem to be one of the most appealing methods of recombinant protein production due to their advantages in combining both whole-plant cultivation and suspension cell culture platform. This is a report on production and secretion of a recombinant pharmaceutically active protein from hairy roots cultures of Withania somnifera to improve the economic potential of this plant for the production pharmaceutical compounds. In this study, we selected and synthesized a codon-optimized globular adiponectin (gAd) gene with a calreticulin signal peptide and cloned the sequence into a plant expression binary vector containing a nptII gene as a selectable marker gene. The transgenic hairy roots were produced by Agrobacterium rhizogenes-mediated transformation protocol developed by our group. Among ten established nptII positive hairy roots lines, six colons significantly accumulated gAd protein in the biomass and extracellular medium. The presence of gAd was confirmed by western blot analysis of root extracts. The maximum level of hairy root biomass, growth rate (GR), intra- and extracellular gAd expressions were obtained after 25-26 days of culture on MS medium. The maximum level of intra- and extracellular gAd proteins were found to be 15.19 μg/gFW and 215.7 μg/L, respectively, which resulted in a significant decrease in the amount of intra- and extracellular withanolide A and withaferin A production. The addition of PVP, KNO3 and NaCl significantly increased the level of extracellular gAd by approximately 13 folds. This improvement could significantly increase the amount of intra- and extracellular withanolide A and withaferin A production, too. The recombinant gAd produced from W. somnifera is functional as proved by induction the phosphorylation of ACC in C2C12 muscle cells, as its functional amount was 5.1-fold more than gAd produced from E. coli and 45 % lower than CHO cells.

Evidence-based umbrella review of 162 peripheral biomarkers for major mental disorders

The literature on non-genetic peripheral biomarkers for major mental disorders is broad, with conflicting results. An umbrella review of meta-analyses of non-genetic peripheral biomarkers for Alzheimer's disease, autism spectrum disorder, bipolar disorder (BD), major depressive disorder, and schizophrenia, including first-episode psychosis. We included meta-analyses that compared alterations in peripheral biomarkers between participants with mental disorders to controls (i.e., between-group meta-analyses) and that assessed biomarkers after treatment (i.e., within-group meta-analyses). Evidence for association was hierarchically graded using a priori defined criteria against several biases. The Assessment of Multiple Systematic Reviews (AMSTAR) instrument was used to investigate study quality. 1161 references were screened. 110 met inclusion criteria, relating to 359 meta-analytic estimates and 733,316 measurements, on 162 different biomarkers. Only two estimates met a priori defined criteria for convincing evidence (elevated awakening cortisol levels in euthymic BD participants relative to controls and decreased pyridoxal levels in participants with schizophrenia relative to controls). Of 42 estimates which met criteria for highly suggestive evidence only five biomarker aberrations occurred in more than one disorder. Only 15 meta-analyses had a power >0.8 to detect a small effect size, and most (81.9%) meta-analyses had high heterogeneity. Although some associations met criteria for either convincing or highly suggestive evidence, overall the vast literature of peripheral biomarkers for major mental disorders is affected by bias and is underpowered. No convincing evidence supported the existence of a trans-diagnostic biomarker. Adequately powered and methodologically sound future large collaborative studies are warranted.

Icariin treatment reduces blood glucose levels in type 2 diabetic rats and protects pancreatic function

Icariin, a flavonoid isolated from traditional oriental herbal medicines, has been demonstrated to exhibit several health benefits in animal models and in humans. The aim of the present study was to investigate the effect of Icariin on hyperglycemia in type 2 diabetes mellitus (T2DM) in rats. A model of diabetes was established in 50 Sprague Dawley rats using a high-sugar and high-fat diet and peritoneal injection of streptozotocin. Diabetic rats were divided into five groups: Diabetic control; metformin; and rats treated with three different doses of Icariin, 5, 10 and 20 mg/kg. Body weight and blood glucose levels were measured, and serum adiponectin levels, expression of phospho-AMP mediated protein kinase (p-AMPK) and glucose transporter isoform 4 (GLUT-4) were measured using ELISA, Realtime PCR and western blotting, respectively. Diabetic rats without drug treatment exhibited reduced body weight, increased blood glucose levels and decreased the number of islets. In T2DM rats treated with 10 or 20 mg/kg Icariin, the blood glucose levels were reduced, whereas serum adiponectin levels were not affected. Additionally, the mRNA and protein expression levels of p-AMPK and GLUT-4 protein were increased in the T2DM rats treated with Icariin. In conclusion, in the diabetes rat model, Icariin alleviated the severity of diabetes, and the effects may be associated with reduction of hyperglycemia by activating an AMPK/GLUT-4 pathway.

Association of polymorphisms in leptin and adiponectin genes with long-term outcomes in renal transplant recipients

The effect of polymorphims in leptin and adiponectin genes on long-term outcomes of renal transplantation is unknown. In 349 renal transplant recipients (RTR), we aimed to determine associations between five SNPs in the leptin receptor (LEPR) and adiponectin (ADIPOQ) genes and these outcomes. Follow-up time ranged from 2 to 25 years (mean 10.29 ± 5.16 years). Two SNPs showed associations with long-term outcomes and their statistical significance greatly increased after 39 RTR with a history of cardiovascular events prior to transplantation were removed from the analysis. Adjusted odds ratios (OR) for LEPR rs1805094 and ADIPOQ rs1501299 and risk of graft loss were 0.35 (0.16-0.74) p = 0.006 and 2.37 (1.28-4.37) p = 0.006, respectively. The assessment of risk for global mortality revealed OR values of 0.20 (0.06-0.62), p = 0.005, and 2.43 (1.08-5.44), p = 0.031 for LEPR rs1805094 and ADIPOQ rs1501299, respectively. Our results show that polymorphism in genes involved in leptin and adiponectin function modify long-term outcomes in renal transplantation.

AMPK: a balancer of the renin-angiotensin system

The renin-angiotensin system (RAS) is undisputedly well-studied as one of the oldest and most critical regulators for arterial blood pressure, fluid volume, as well as renal function. In recent studies, RAS has also been implicated in the development of obesity, diabetes, hyperlipidemia, and other diseases, and also involved in the regulation of several signaling pathways such as proliferation, apoptosis and autophagy, and insulin resistance. AMP-activated protein kinase (AMPK), an essential cellular energy sensor, has also been discovered to be involved in these diseases and cellular pathways. This would imply a connection between the RAS and AMPK. Therefore, this review serves to draw attention to the cross-talk between RAS and AMPK, then summering the most recent literature which highlights AMPK as a point of balance between physiological and pathological functions of the RAS.

Low Degree Hyaluronic Acid Crosslinking Inducing the Release of TGF-Β1 in Conditioned Medium of Wharton's Jelly-Derived Stem Cells

BACKGROUND:

Presently, the application of stem cells and their paracrine effect for anti-ageing therapy has commenced. Wharton’s jelly-derived stem cell conditioned medium (WJSCs-CM) is renowned for increasing proliferation, migrate ageing skin fibroblasts and increase consumption of extracellular transforming growth factor-β (TGF-β). With more than 85% of frequently used dermal filler procedures are hyaluronic acid fillers (HA), a mixture of both with optimal HA crosslinking degree has not yet been identified.

AIM:

This study aimed to determine the discrepancies in the results of various HA crosslinking degree in WJSCs-CM concerning various levels of growth factors (GF).

METHODS:

Conditioned medium was obtained from mesenchymal stem cells Wharton’s jelly of the newborn umbilical cord with caesarean section procedure, fabricated with hypoxia method (HCM). HA was obtained from preparations on the market with crosslinking degrees of 3%, 4%, and 10%. GF levels were measured using sandwich ELISA method based on the protocol provided by anti-TGF-β1, platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) antibody producers (Cloud-Clone Corp®, Texas, USA).

RESULTS:

Low degree HA crosslinking (3% and 4%) elevated TGF-β1 release in WJSCs-CM. HA crosslinking did not provoke increased levels of PDGF and bFGF in WJSCs-CM, both at low and higher degrees.

CONCLUSION:

Low degree HA crosslinking induced the increase of TGF-β1 release in WJSCs-CM.

Elevation of the adiponectin/leptin ratio in women with gestational diabetes mellitus after supplementation with alpha-lipoic acid

Alpha-lipoic acid (ALA) is a short chain fatty acid and is known as a universal antioxidant. The aim of the current clinical trial study was to explore the effects of ALA supplementation on maternal circulating values of adiponectin (A), leptin (L); and A/L, L/A, adiponectin/homeostatic model assessment for insulin resistance (A/H), and malondialdehyde/total antioxidant capacity (MDA/TAC) ratios in pregnant women with gestational diabetes mellitus (GDM). Sixty women diagnosed as GDM during 24 and 28 weeks of pregnancy were randomly divided into drug (n = 30) and placebo (n = 30) groups. They consumed ALA (100 mg) and cellulose acetate (100 mg) respectively for 8 weeks, per day. The biochemical variables were evaluated before and after the trial. Maternal fasting serum values of glucose (p < .001), HOMA-IR (p < .001), MDA/TAC (p < .001), and L/A (p = .008) were decreased while values of adiponectin (p = .011), A/L (p = .001), and A/H (p < .001) were increased in the drug group after the intervention. In summary, current study had shown that after daily supplementation with 100 mg of ALA for 8 weeks in women with GDM, maternal circulating values of adiponectin, A/L, and A/H were increased while values of L/A and MDA/TAC were decreased.

Adiponectin as a Potential Therapeutic Target for Prostate Cancer

Adipokines are bioactive proteins that mediate proliferation, metabolism, inflammation, and angiogenesis. Adiponectin is an important adipokine that exerts multiple key functions via its anti-metabolic syndrome and anti-inflammatory properties. A number of adiponectin receptors, AdipoR1, AdipoR2 and T-cadherin, have been identified. Recent studies have suggested the involvement of adiponectin and receptors in several cancers, including prostate, breast, endometrial, brain, and colon cancer. Altered levels of adiponectin expression, or its interacting receptors, in cancers can lead to dysregulation of signaling pathways. Our current review describes the molecular mechanisms underlying the anti-tumorigenesis activity of adiponectin and the role of its receptors in prostate carcinogenesis, and provides perspectives of adiponectin-mediated signaling as a potential target for therapy.

Adiponectin and colon cancer: evidence for inhibitory effects on viability and migration of human colorectal cell lines

Adiponectin (Acrp30) is an adipokine widely studied for its beneficial metabolic and anti-inflammatory properties. Colorectal cancer is among the most common cancers worldwide. The aim of present study was to explore the effects of Acrp30 on both CaCo-2 and HCT116 colorectal cancer cells in terms of viability, oxidative stress, and apoptosis. In addition, since colorectal cancer represents a typical inflammation-related cancer, we investigated whether Acrp30 treatment modifies the migration and the expression of crucial proteins in the EMT transition. Finally, we analyzed the expression of cytokines in CaCo-2 cells. We found that Acrp30 reduces the survival rate of both CaCo-2 and HCT116 cells through induction of apoptosis and oxidative stress already after 24 h of treatment. In addition, wound-healing assay indicated that Acrp30 exposure statistically inhibits CaCo-2 and HCT116 cell migration. Western blot analysis performed on E-cadherin and vimentin, two EMT crucial markers in carcinogenesis, indicated that Acrp30 does not influence EMT transition. Finally, we found a reduction of mRNA levels corresponding to the anti-inflammatory IL-10 cytokine together with an increase of the pro-inflammatory IL-6 and IL-8 cytokines. This study provides new insight into Acrp30 molecular effects on colorectal cancer cells. Indeed, even if further studies are necessary to clarify the precise role of Acrp30 in colorectal cancer, our data strongly suggest that Acrp30 negatively regulates cell survival and migration in association with induction of oxidative stress and regulation of cytokines expression in both CaCo-2 and HCT116 colorectal cells.

The polymorphism of rs266729 in adiponectin gene and type 2 diabetes mellitus: A Meta-Analysis

Genome-wide association studies and meta-analyses indicate that the polymorphism of rs266729 in adiponectin gene increases the risk of type 2 diabetes mellitus (T2DM); however, these study methods have not been able to identify the underlying genetic effect on the development of T2DM. A genetic model-free approach was conducted to determine the underlying genetic model of inheritance of T2DM because of rs266729 in adiponectin gene.We searched available studies on the association between the rs266729 in adiponectin gene and T2DM in accordance with the inclusion and exclusion criteria. Based on the information extracted from the studies, generalized odds ratio value (GOR) was used to evaluate whether the rs266729 polymorphism was a risk factor for T2DM. The parameter λ was calculated to estimate the genetic model, which was defined as the quotient of natural logarithm odds ratio of GC to CC divided by the natural logarithm odds ratio of GG to CC. Finally, binary logistic regression analysis was used to calculate the genetic effect of rs266729 on T2DM.Data from 7 studies were included in this meta-analysis. The total number of subjects was 12,323, comprising 5,948 cases and 6,395 controls. Mean (standard deviation) age of cases was 59.50 (11.53), and that of the controls was 53.80 (11.65), whereas the proportion of male was 40.9 and 50.0%, respectively. GOR was 1.13 (1.02, 1.25) and λ was 0.47 (0.29, 0.64). The result of logistic regression indicated that the G allele influenced the development of T2DM in the additive model, whereas the genetic effect was 1.13 (1.06, 1.19). Sources of control populations were the cause of between-study heterogeneity; nonetheless, there was no publication bias among studies.The G allele of rs266729 in adiponectin gene increases the risk of T2DM through an additive genetic model with an effect of 1.13 (1.06, 1.19).

Adiponectin, lipids and atherosclerosis

PURPOSE OF REVIEW

Adiponectin is an adipokine with anti-inflammatory, antioxidant, antiatherogenic, pro-angiogenic, vasoprotective and insulin-sensitizing properties. Several factors may influence adiponectin levels, such as genetic polymorphisms, obesity / body fat distribution, diet and exercise as well as cardiovascular risk factors such as sleep deprivation and smoking as well as medications. Adiponectin has been proposed as a potential prognostic biomarker and a therapeutic target in patients with cardiometabolic diseases.

RECENT FINDINGS

This narrative review discusses the associations of adiponectin with obesity-related metabolic disorders (metabolic syndrome, nonalcoholic fatty liver disease, hyperuricaemia and type 2 diabetes mellitus). We also focus on the links between adiponectin and lipid disorders and with coronary heart disease and noncardiac vascular diseases (i.e. stroke, peripheral artery disease, carotid artery disease, atherosclerotic renal artery stenosis, abdominal aortic aneurysms and chronic kidney disease). Further, the effects of lifestyle interventions and drug therapy on adiponectin levels are briefly reviewed.

SUMMARY

Based on available data, adiponectin represents a multifaceted biomarker that may beneficially affect atherosclerosis, inflammation and insulin resistance pathways. However, there are conflicting results with regard to the associations between adiponectin levels and the prevalence and outcomes of cardiometabolic diseases. Further research on the potential clinical implications of adiponectin in the diagnosis and treatment of such diseases is needed.

Genetically modified mesenchymal stem/stromal cells transfected with adiponectin gene can stably secrete adiponectin

AIMS

Mesenchymal stem/stromal cells (MSCs) hold promises for the treatment of diverse diseases and regeneration of injured tissues. Genetic modification of MSCs through gene delivery might enhance their therapeutic potential. Adiponectin has been appeared as a potential biomarker for predicting various diseases. Plasma adiponectin levels are negatively correlated with various metabolic and vascular diseases and supplementation of exogenous adiponectin ameliorates the diseases. This study aims to develop adiponectin secreting genetically modified MSCs (GM-MSCs) as a potent strategic tool to complement endogenous adiponectin for the treatment of adiponectin deficiency diseases.

MAIN METHODS

Human bone marrow derived MSCs were isolated, expanded in vitro and transfected with adiponectin gene containing plasmid vector. Total RNA was extracted and cDNA was prepared by reverse transcription polymerase chain reaction (RT-PCR). The expression of adiponectin gene and protein in GM-MSCs was analyzed by PCR and Western blotting respectively. The secretion of adiponectin protein from GM-MSCs was analyzed by enzyme-linked immunosorbent assay.

KEY FINDINGS

The expression of adiponectin gene and plasmid DNA was detected in GM-MSCs but not in control group of MSCs. Adiponectin gene expression was detected in GM-MSCs at 2, 7, 14, 21 and 28days after transfection. Western blotting analysis revealed the expression of adiponectin protein only in GM-MSCs. The GM-MSCs stably secreted adiponectin protein into culture media at least for 4weeks.

SIGNIFICANCE

GM-MSCs express and secret adiponectin protein. Therefore, these adiponectin secreting GM-MSCs could be instrumental for the supplementation of adiponectin in the treatment of adiponectin deficiency related diseases.

Targeting endothelial metaflammation to counteract diabesity cardiovascular risk: Current and perspective therapeutic options

The association of obesity and diabetes, termed "diabesity", defines a combination of primarily metabolic disorders with insulin resistance as the underlying common pathophysiology. Cardiovascular disorders associated with diabesity represent the leading cause of morbidity and mortality in the Western world. This makes diabesity, with its rising impacts on both health and economics, one of the most challenging biomedical and social threats of present century. The emerging comprehension of the genes whose alteration confers inter-individual differences on risk factors for diabetes or obesity, together with the potential role of genetically determined variants on mechanisms controlling responsiveness, effectiveness and safety of anti-diabetic therapy underlines the need of additional knowledge on molecular mechanisms involved in the pathophysiology of diabesity. Endothelial cell dysfunction, resulting from the unbalanced production of endothelial-derived vascular mediators, is known to be present at the earliest stages of insulin resistance and obesity, and may precede the clinical diagnosis of diabetes by several years. Once considered as a mere consequence of metabolic abnormalities, it is now clear that endothelial dysfunctional activity may play a pivotal role in the progression of diabesity. In the vicious circle where vascular defects and metabolic disturbances worsen and reinforce each other, a low-grade, chronic, and 'cold' inflammation (metaflammation) has been suggested to serve as the pathophysiological link that binds endothelial and metabolic dysfunctions. In this paradigm, it is important to consider how traditional antidiabetic treatments (specifically addressing metabolic dysregulation) may directly impact on inflammatory processes or cardiovascular function. Indeed, not all drugs currently available to treat diabetes possess the same anti-inflammatory potential, or target endothelial cell function equally. Perspective strategies pointing at reducing metaflammation or directly addressing endothelial dysfunction may disclose beneficial consequences on metabolic regulation. This review focuses on existing and potential new approaches ameliorating endothelial dysfunction and vascular inflammation in the context of diabesity.

Cognitive deficits associated with a high-fat diet and insulin resistance are potentiated by overexpression of ecto-nucleotide pyrophosphatase phosphodiesterase-1

There is growing evidence that over consumption of high-fat foods and insulin resistance may alter hippocampal-dependent cognitive function. To study the individual contributions of diet and peripheral insulin resistance to learning and memory, we used a transgenic mouse line that overexpresses ecto-nucleotide pyrophosphatase phosphodiesterase-1 in adipocytes, which inhibits the insulin receptor. Here, we demonstrate that a model of peripheral insulin resistance exacerbates high-fat diet induced deficits in performance on the Morris Water Maze task. This finding was then reviewed in the context of the greater literature to explore potential mechanisms including triglyceride storage, adiponectin, lipid composition, insulin signaling, oxidative stress, and hippocampal signaling. Together, these findings further our understanding of the complex relationship among peripheral insulin resistance, diet and memory.

Angiotensin-(1-7) improves non-alcoholic steatohepatitis through an adiponectin-independent mechanism

AIM

Recent evidence suggests that angiotensin-(1-7) [Ang-(1-7)] could improve non-alcoholic steatohepatitis (NASH) through an adiponectin-dependent mechanism. This study aimed to investigate whether and how Ang-(1-7) influences NASH without adiponectin.

METHODS

Adiponectin knockout mice were fed with a high fat diet (HFD) or normal chow for 6 months, and were subsequently infused with Ang-(1-7) or saline for 2 weeks.

RESULTS

We found that HFD-fed mice showed obesity, hyperlipidemia, NASH, and significantly increased levels of serum Ang-(1-7). Chronic infusion of Ang-(1-7) could reduce body weight, absolute and relative liver weight, and serum levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol in HFD-fed mice. In addition, Ang-(1-7) treatment could attenuate hepatocellular inflammation, steatosis, and ballooning with activation of the hepatic AMP-activated protein kinase signaling pathway in HFD-fed knockout mice.

CONCLUSIONS

These results showed the protective role of Ang-(1-7) in the development of NASH through an adiponectin-independent mechanism, which may be partially attributed to the activation of hepatic AMP-activated protein kinase pathway.

Adiponectin-Resistance in Obesity

The decrease in adiponectin levels are negatively correlated with chronic subclinical inflammation markers in obesity. The hypertrophic adipocytes cause obesity-linked insulin resistance and metabolic syndrome. Furthermore, macrophage polarization is a key determinant regulating adiponectin receptor (AdipoR1/R2) expression and differential adiponectin-mediated macrophage inflammatory responses in obese individuals. In addition to decrease in adiponectin concentrations, the decline in AdipoR1/R2 mRNA expression leads to a decrement in adiponectin binding to cell membrane, and this turns into attenuation in the adiponectin effects. Within the receptor complex, adaptor protein-containing pleckstrin homology domain, phosphotyrosine-binding domain, and leucine zipper motif 1 (APPL1) is the intracellular binding partner of AdipoR1 and AdipoR2. The expression levels of APPL1 or APPL2 lead to an altered adiponectin activity. Despite normal or high adiponectin levels, an impaired post receptor signaling due to APPL1/APPL2 may alter adiponectin efficiency and activity. However, APPL2 blocks adiponectin signaling through AdipoR1 and AdipoR2 by competitive inhibition of APPL1. APPL1 is also an important mediator of adiponectin dependent insulin sensitization. In this context, adiponectin resistance is associated with insulin resistance and is thought to be partly due to the down-regulation of the AdipoRs in high-fat diet fed subjects. Actually, adiponectin resistance occurs very rapidly after saturated fatty acid feeding, this metabolic disturbance is not due to a decrease in AdipoR1 protein content. Intra-abdominal adipose tissue-AdipoR2 expression is reduced in obesity, whereas AdipoR1 expression is not changed. Adiponectin resistance together with insulin resistance forms a vicious cycle. The elevated adiponectin levels with adiponectin resistance is a compensatory response in the condition of an unusual discordance between insulin resistance and adiponectin unresponsiveness.Additionally, different mechanisms are involved in vascular adiponectin resistance at different stages of obesity. Nevertheless, diet-induced hyperlipidemia is the leading cause of vascular adiponectin resistance. Leptin/adiponectin imbalance may also be an important marker of the elevated risk of developing abdominal obesity-associated cardiovascular diseases.

Weight Gain Alters Adiponectin Receptor 1 Expression on Adipose Tissue-Resident Helios+ Regulatory T Cells

Adipose tissue produces multiple mediators that modulate the immune response. Adiponectin is an adipocyte-derived cytokine that exhibits metabolic and anti-inflammatory effects. Adiponectin acts through binding to adiponectin receptor 1 and 2 (AdipoR1/AdipoR2). AdipoR1 is ubiquitously expressed, whereas AdipoR2 is restricted to skeletal muscle and liver. AdipoR1 expression has been reported on a small percentage of T cells; nevertheless, it is still unknown whether Foxp3(+) regulatory T cells (Tregs) express AdipoR1. Recently, it has been shown that Tregs accumulate in adipose tissue and that they play a potential role in modulating adipose tissue inflammation. Our aim was to evaluate AdipoR1 expression in adipose tissue-resident Tregs and to evaluate the effect of weight gain on this expression. Male C57BL/6 mice were fed with a high-fat diet for 14 weeks (to develop overweight) or 21 weeks (to develop obesity). Mice on a standard diet were used as age-matched controls. Helios expression was evaluated as a marker to discriminate thymic-derived from peripherally induced Tregs. The majority of Tregs in both adipose tissue and the spleen expressed Helios. Adipose tissue Tregs expressed higher levels of AdipoR1 than Tregs in the spleen. AdipoR1 expression on adipose tissue Helios(+) Tregs was negatively correlated with epididymal fat. Overall, we show that AdipoR1 is expressed on adipose tissue-resident Tregs, mainly Helios(+) Tregs, and that this expression is dependent on weight and fat accumulation. Because both adiponectin and Tregs play roles in anti-inflammatory mechanisms, our data propose a new mechanism through which weight gain might alter immunoregulation.

Obesity shifts house dust mite-induced airway cellular infiltration from eosinophils to macrophages: effects of glucocorticoid treatment

Although classically characterized by chronic airway inflammation with eosinophil infiltration, asthma is a complex and multifactorial condition with numerous clinical phenotypes. Epidemiological studies strongly support the link between obesity and asthma and suggest that obesity precedes and promotes asthma development, increases asthma severity, and reduces steroid responsivity. Using a house dust mite (HDM) model of airway hyperresponsiveness in C57BL/6 mice, we examined the effects of diet-induced obesity on allergic airway inflammation and its treatment with dexamethasone. When compared to lean mice treated with HDM, obese-HDM mice had reduced plasma adiponectin, an anti-inflammatory adipokine, lower eosinophil and higher macrophage infiltration into the lungs and bronchoalveolar lavage (BAL) fluid, increased expression of total, M1, and M2 macrophage markers in the lungs, and enhanced Th2 and non-Th2 cytokine expression in the lungs. While Th2-associated responses in obese-HDM mice were suppressed by systemic dexamethasone, several Th2-independent responses, including total and M1 macrophage markers in the lungs, and lung CXC-motif ligand 1 (CXCL1) levels, were not improved following dexamethasone treatment. Thus, HDM combined with obesity promotes mixed localized inflammatory responses (e.g., M1, M2, Th1, and Th2) and shifts the cellular infiltration from eosinophils to macrophages, which are less sensitive to dexamethasone regulation. Because obese asthmatics exhibit more severe symptoms, lack a predominance of Th2 biomarkers, and are predicted to experience more steroid resistance when compared to lean asthmatics, this model could be used to study blunted steroid responses in obese-HDM mice and to define the macrophages found in the lungs.