Adiponectin Signaling Pathway Research Articles

Transcription and post-translational mechanisms: dual regulation of adiponectin-mediated Occludin expression in diabetes

BackgroundOccludin, a crucial component of tight junctions, has emerged as a promising biomarker for the diagnosis of acute ischemic disease, highlighting its significant potential in clinical applications. In the diabetes, Occludin serves as a downstream target gene intricately regulated by the adiponectin (APN) signaling pathway. However, the specific mechanism by which adiponectin regulates Occludin expression remains unclear.Methods and resultsEndothelial-specific Ocln knockdown reduced APN-mediated blood flow recovery after femoral artery ligation and nullified APN's protection against high-fat diet (HFD)-triggered apoptosis and angiogenesis inhibition in vivo. Mechanically, we have meticulously elucidated APN's regulatory role in Occludin expression through a comprehensive analysis spanning transcriptional and post-translational dimensions. Foxo1 has been elucidated as a crucial transcriptional regulator of Occludin that is modulated by the APN/APPL1 signaling axis, as evidenced by validation through ChIP-qPCR assays and Western blot analysis. APN hindered Occludin degradation via the ubiquitin–proteasome pathway. Mass spectrometry analysis has recently uncovered a novel phosphorylation site, Tyr467, on Occludin. This site responds to APN, playing a crucial role in inhibiting Occludin ubiquitination by APN. The anti-apoptotic and pro-angiogenic effects of APN were attenuated in vitro and in vivo following Foxo1 knockdown or expression of a non-phosphorylatable mutant, OccludinY467A. Clinically, elevated plasma concentrations of Occludin were observed in patients with diabetes. A significant negative correlation was found between Occludin levels and APN concentrations.ConclusionOur study proposes that APN modulates Occludin expression through mechanisms involving both transcriptional and post-translational interactions, thereby conferring a protective effect on endothelial integrity within diabetic vasculature.Graphical abstract

Effect of goose-derived adiponectin peptide gADP3 on LPS-induced inflammatory injury in goose liver

ABSTRACT 1. This study evaluated the effects and mechanisms of action of the peptide gADP3 on hepatic inflammatory injury induced by lipopolysaccharide (LPS). 2. Hepatic inflammatory injury was induced in geese by intraperitoneal injection of LPS and gADP3, and the adiponectin receptor agonist AdipoRon (positive control) was used for potential amelioration. Serum inflammatory factor levels, liver function-related biochemical indicators and oxidative stress-related biochemical parameters in the liver tissues were determined. The expression levels of adiponectin and its receptors, inflammation and oxidative stress-related genes and key signalling molecules involved in adiponectin, inflammation and oxidative stress signalling pathways in liver tissues were detected. 3. The peptide gADP3 alleviated inflammatory cell infiltration and hepatic inflammatory changes, reversed the decrease in serum albumin (ALB), total protein (TP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) content or activity induced by LPS and increased the activity of the antioxidant enzymes CAT (catalase), SOD (superoxide dismutase) and GSH-Px (glutathione peroxidase). 4. The peptide gADP3 upregulated the expression of antioxidant enzyme-related genes GCLC, HO-1 and NQO1 in liver tissues, decreased the levels of inflammatory factors like TNF-α, IL-1β, IL-6, IFN-γ and TGF-β and reduced mRNA expression levels of inflammatory-related genes TNF-α, IL-1β, iNOS and TGF-β. Additionally, it increased the mRNA and protein expression levels of adiponectin and its receptors, as well as key molecules in the adiponectin signalling pathway like AMPK and PPARα. In addition, gADP3 reversed the changes in mRNA or protein expression of inflammatory and oxidative stress signalling pathway-related genes P38MAPK, NF-κBP65, TLR4 and Nrf2 in liver tissues caused by LPS treatment. 5. In conclusion, goose-derived adiponectin peptide gADP3, similar to the adiponectin receptor agonist AdipoRon, attenuated LPS-induced hepatic inflammatory injury in geese.

Regulation of placental amino acid transport in health and disease.

Abnormal fetal growth, i.e., intrauterine growth restriction (IUGR) or fetal growth restriction (FGR) and fetal overgrowth, is associated with increased perinatal morbidity and mortality and is strongly linked to the development of metabolic and cardiovascular disease in childhood and later in life. Emerging evidence suggests that changes in placental amino acid transport may contribute to abnormal fetal growth. This review is focused on amino acid transport in the human placenta, however, relevant animal models will be discussed to add mechanistic insights. At least 25 distinct amino acid transporters with different characteristics and substrate preferences have been identified in the human placenta. Of these, System A, transporting neutral nonessential amino acids, and System L, mediating the transport of essential amino acids, have been studied in some detail. Importantly, decreased placental Systems A and L transporter activity is strongly associated with IUGR and increased placental activity of these two amino acid transporters has been linked to fetal overgrowth in human pregnancy. An array of factors in the maternal circulation, including insulin, IGF-1, and adiponectin, and placental signaling pathways such as mTOR, have been identified as key regulators of placental Systems A and L. Studies using trophoblast-specific gene targeting in mice have provided compelling evidence that changes in placental Systems A and L are mechanistically linked to altered fetal growth. It is possible that targeting specific placental amino acid transporters or their upstream regulators represents a novel intervention to alleviate the short- and long-term consequences of abnormal fetal growth in the future.

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.

Osteocalcin activates lipophagy via the ADPN-AMPK/PPARα-mTOR signaling pathway in chicken embryonic hepatocyte

Fatty liver hemorrhage syndrome (FLHS) is the leading cause of noninfectious mortality in caged layers worldwide. Osteocalcin (OCN) is a protein secreted by osteoblasts, and its undercarboxylated form (ucOCN) acts as a multifunctional hormone that protects laying hens from FLHS. Lipophagy is a form of selective autophagy that breaks down lipid droplets (LDs) through lysosomes, and defective lipophagy is associated with FLHS. The aim of this study was to investigate the effects of ucOCN on the lipophagy of chicken embryonic hepatocytes and associated the function of the adiponectin (ADPN) signaling pathway. In this study, chicken embryonic hepatocytes were divided into 5 groups: control (CONT), fat emulsion (FE, 10% FE, v/v), FE with ucOCN at 1 ng/mL (FE-LOCN), 3 ng/mL (FE-MOCN), and 9 ng/mL (FE-HOCN). In addition, 4 μM AdipoRon, an adiponectin receptor agonist, was used to investigate the function of ADPN. The results showed that compared with CONT group, FE promoted the levels of phosphorylation of mammalian target of rapamycin (p-mTOR) (P < 0.05) and decreased the mRNA expression of ADNP receptors (AdipoR1 and AdipoR2). Compared with FE group, 3 and 9 ng/mL ucOCN inhibited the levels of autophagy adaptor p62 and p-mTOR (P < 0.05), increased the ratios of LC3-II/LC3-I (P < 0.05) and phosphorylated adenosine 5'-monophosphate-activated protein kinase (p-AMPK)/AMPK (P < 0.05), as well as the levels of peroxisome proliferator-activated receptor α (PPAR-α) and ADPN (P < 0.05). In addition, ucOCN at the tested concentrations increased the colocalization of LC3 and LDs in fatty hepatocytes. Administrated 4 μM AdipoRon activated AdipoR1 and AidpoR2 mRNA expression (P < 0.05), decreased the concentrations of triglyceride (P < 0.05), without effects on cell viability (P > 0.05). AdipoRon also increased the LC3-II/LC3-I ratio (P < 0.05) and the levels of p-AMPK/AMPK and PPAR-α (P < 0.05). In conclusion, the results reveal that ucOCN regulates lipid metabolism by activating lipophagy via the ADPN-AMPK/PPARα-mTOR signaling pathway in chicken embryonic hepatocytes. The results may provide new insights for controlling FLHS in laying hens.

Linking Adiponectin and Its Receptors to Age-Related Macular Degeneration (AMD).

In recent years, there has been a captivating focus of interest in elucidating the intricate crosstalk between adiponectin (APN), a versatile fat-associated adipokine and ocular pathologies. Unveiling the intricate relationship between adipocytokine APN and its receptors (AdipoRs) with aging eye disorders has emerged as a fascinating frontier in medical research. This review article delves into this connection, illuminating the hidden influence of APN on retinal health. This comprehensive review critically examines the latest findings and breakthroughs that underscore the pivotal roles of APN/AdipoRs signaling in maintaining ocular homeostasis and protecting against eye ailments. Here, we meticulously explore the intriguing mechanisms by which APN protein influences retinal function and overall visual acuity. Drawing from an extensive array of cutting-edge studies, the article highlights APN's multifaceted functions, ranging from anti-inflammatory properties and oxidative stress reduction to angiogenic regulation within retinal and macula tissues. The involvement of APN/AdipoRs in mediating these effects opens up novel avenues for potential therapeutic interventions targeting prevalent aging eye conditions. Moreover, this review unravels the interplay between APN signaling pathways and age-related macular degeneration (AMD). The single-cell RNA-seq results validate the expression of both the receptor isoforms (AdipoR1/R2) in retinal cells. The transcriptomic analysis showed lower expression of AdipoR1/2 in dry AMD pathogenesis compared to healthy subjects. The inhibitory adiponectin peptide (APN1) demonstrated over 75% suppression of CNV, whereas the control peptide did not exert any inhibitory effect on choroidal neovascularization (CNV). The elucidation of these relationships fosters a deeper understanding of adipose tissue's profound influence on ocular health, presenting new prospects for personalized treatments and preventative measures. Because APN1 inhibits CNV and leakage, it can be used to treat human AMD, although the possibility to treat human AMD is in the early stage and more clinical research is needed. In conclusion, this review provides a captivating journey into the enthralling world of APN, intertwining the realms of adipose biology and ophthalmology in aging.

Adiponectin reverses β-Cell damage and impaired insulin secretion induced by obesity.

Obesity significantly decreases life expectancy and increases the incidence of age-related dysfunctions, including β-cell dysregulation leading to inadequate insulin secretion. Here, we show that diluted plasma from obese human donors acutely impairs β-cell integrity and insulin secretion relative to plasma from lean subjects. Similar results were observed with diluted sera from obese rats fed ad libitum, when compared to sera from lean, calorically restricted, animals. The damaging effects of obese circulating factors on β-cells occurs in the absence of nutrient overload, and mechanistically involves mitochondrial dysfunction, limiting glucose-supported oxidative phosphorylation and ATP production. We demonstrate that increased levels of adiponectin, as found in lean plasma, are the protective characteristic preserving β-cell function; indeed, sera from adiponectin knockout mice limits β-cell metabolic fluxes relative to controls. Furthermore, oxidative phosphorylation and glucose-sensitive insulin secretion, which are completely abrogated in the absence of this hormone, are restored by the presence of adiponectin alone, surprisingly even in the absence of other serological components, for both the insulin-secreting INS1 cell line and primary islets. The addition of adiponectin to cells treated with plasma from obese donors completely restored β-cell functional integrity, indicating the lack of this hormone was causative of the dysfunction. Overall, our results demonstrate that low circulating adiponectin is a key damaging element for β-cells, and suggest strong therapeutic potential for the modulation of the adiponectin signaling pathway in the prevention of age-related β-cell dysfunction.

New insights into effects of Kaixin Powder on depression via lipid metabolism related adiponectin signaling pathway

ObjectiveTo clarify the anti-depressive potential mechanisms of Kaixin Powder (KP), a drug that helps to prevent and treat depression and other mentaldiseases, from genome-wide transcriptome profiling. MethodsTranscriptome and KEGG pathway analysis were conducted on the hippocampus of depressed rats, then the differentially expressed genes were validated and serum concentration of lipid parameters were identified by enzymatic assays. Furthermore, high-fat diets induced depression-like behaviors in Syrian golden hamsters were conducted to verify the predicted molecular mechanisms acquired from the transcriptome analysis. ResultsTranscriptome results revealed that the 24 differentially expressed genes (DEGs) in chronic mild stress (CMS) rats could be reversed after two weeks of KP treatment. The mechanisms of KP in treating depression firstly involved the regulation of several pathology modules, including lipid metabolism, synapse function and inflammation. KP could regulate imbalances of lipid homeostasis in high-fat diet induced depressive symptoms. Furthermore, it was validated that cholesterol metabolism dysfunction can be ameliorated by KP, which was correlated with upregulation of the AdipoR1-BDNF (brain-derived neurotrophic factor) co-regulatory pathway. ConclusionTaken together, our results demonstrated that KP not only alleviates depression via traditional mental illness targets, but it may also simulates the cholesterol metabolism and adiponectin signaling with multi-target characteristics.

The Mef2c/AdipoR1 axis is responsible for myogenic differentiation and is regulated by resistin in skeletal muscles

Previous studies have shown that accumulated lipid and insulin resistance emerges in skeletal muscle after the onset of obesity and diabetes. We have previously shown that resistin significantly increases lipid contents in C2C12 cells. However, studies evaluating the effects of resistin on skeletal muscle cells and tissues are limited; despite that, an understanding of resistin action and function on lipid alteration in skeletal muscle tissues is critical for understanding obesity-related diseases. In this study, we document that resistin increases lipid deposition both in vitro and in vivo. Further, resistin promotes fiber type transformation, decreases enzyme activities, inhibits myogenic differentiation, and decreases muscle grip and excise endurance. In addition, adiponectin signaling is activated during myocyte differentiation, but it is inhibited at elevated resistin concentrations. Mechanistic investigation revealed that mef2c is responsible for adiponectin signaling pathway inhibition by inhibiting adipoR1 expression at the transcriptional level. In conclusion, this is the first study to document that resistin increases ectopic lipid deposition in skeletal muscles via a mef2c-adipoR1 signaling pathway, which reveals for the first time the presence of crosstalk between resistin and adiponectin in skeletal muscles.

Dietary n-3 and n-6 polyunsaturated fatty acids differentially modulate the adiponectin and leptinmediated major signaling pathways in visceral and subcutaneous white adipose tissue in high fat diet induced obesity in Wistar rats

Obesity is a chronic metabolic disease that involves excessive accumulation of fat in white adipose tissue (WAT). Apart from storing excess fats, WAT also serves as an important endocrine organ secreting adipocytokines such as adiponectin and leptin. Adiponectin and leptin bind to their transmembrane receptors adiponectin receptor 1 (AdipoR1)/adiponectin receptor 2 (AdipoR2) and Ob-R, respectively, and mediate their effect on metabolism by regulating multiple downstream targets. Dietary fat is considered the main culprit behind obesity development. Numerous preclinical studies have highlighted role of essential polyunsaturated fatty acids (PUFAs), particularly n-3 PUFAs, in prevention of obesity. Despite emerging data, there still is no clear understanding of the mechanism of action of n-3 PUFAs and n-6 PUFAs on adipose tissue function in two functionally and anatomically different depots of WAT: visceral and subcutaneous. We designed this study using a high fat diet (HFD) fed rodent model of obesity to test our hypothesis that n-3 and n-6 PUFAs possibly differentially modulate adipokine secretion and downstream metabolic pathways such as peroxisome proliferator-activated receptor-γ (PPAR-γ), protein kinase B (AKT)-forkhead box O1 (FOXO1), and Janus kinase-signal transducer and activator of transcription in obesity. The results of the current study showed that n-3 PUFAs upregulate the expression of AdipoR1/R2 and ameliorate the effects of HFD by modulating adipogenesis via PPAR-γ and by improving glucose tolerance and lipid metabolism via AKT-FOXO1 axis in fish oil fed rats. However, n-6 PUFAs did not show any remarkable change compared with HFD fed animals. Our study highlights that n-3 PUFAs modulate expression of various targets in adiponectin and leptin signaling cascade, bringing about an overall reduction in obesity and improvement in adipose tissue function in HFD induced obesity.

Integration of bioassay and non-target metabolite analysis of tomato reveals that β-carotene and lycopene activate the adiponectin signaling pathway, including AMPK phosphorylation.

Adiponectin, an adipokine, regulates glucose metabolism and insulin sensitivity through the adiponectin receptor (AdipoR). In this study, we searched for metabolites that activate the adiponectin signaling pathway from tomato (Solanum lycopersicu). Metabolites of mature tomato were separated into 55 fractions by liquid chromatography, and then each fraction was examined using the phosphorylation assay of AMP-protein kinase (AMPK) in C2C12 myotubes and in AdipoR-knockdown cells by small interfering RNA (siRNA). Several fractions showed AMPK phosphorylation in C2C12 myotubes and siRNA-mediated abrogation of the effect. Non-targeted metabolite analysis revealed the presence of 721 diverse metabolites in tomato. By integrating the activity of fractions on AMPK phosphorylation and the 721 metabolites based on their retention times of liquid chromatography, we performed a comprehensive screen for metabolites that possess adiponectin-like activity. As the screening suggested that the active fractions contained four carotenoids, we further analyzed β-carotene and lycopene, the major carotenoids of food. They induced AMPK phosphorylation via the AdipoR, Ca2+/calmodulin-dependent protein kinase kinase and Ca2+ influx, in addition to activating glucose uptake via AdipoR in C2C12 myotubes. All these events were characteristic adiponectin actions. These results indicated that the food-derived carotenoids, β-carotene and lycopene, activate the adiponectin signaling pathway, including AMPK phosphorylation.

Metformin Treatment Regulates the Expression of Molecules Involved in Adiponectin and Insulin Signaling Pathways in Endometria from Women with Obesity-Associated Insulin Resistance and PCOS.

Polycystic ovary syndrome (PCOS) is an endocrine/metabolic disorder associated with insulin resistance (IR) and obesity. Endometria from women with PCOS present failures in insulin action, glucose uptake and signaling of insulin-sensitizing molecules, such as adiponectin, with consequences for reproduction. Metformin (MTF) treatment improves insulin signaling in endometrial tissues, but its mechanism is not fully understood. This study addresses the MTF effect, as well as adiponectin agonist action, on levels of molecules associated with insulin and adiponectin signaling pathways in endometrial tissue and cells, as assessed by immunohistochemistry and immunocytochemistry, respectively. Endometrial tissues were obtained from women and divided into five groups: Normal Weight (control); Obesity + IR; Obesity + IR + PCOS; Obesity + IR + MTF; Obesity + IR + PCOS + MTF. Endometrial cells stimulated with TNFα (as obesity-marker) were also used to partially emulate an obesity environment. The results showed low levels of insulin/adiponectin signaling in the endometria from women with obesity, IR and PCOS compared with the control group. MTF re-established these levels, independently of PCOS. TNFα-associated molecules were elevated in pathologic endometria, whereas MTF diminished these levels. The low levels of insulin/adiponectin molecules in endometrial cells treated with TNFα were reverted by MTF, similar to what was observed in the case of the adiponectin agonist. Therefore, independently of PCOS, MTF can re-establish levels of molecules involved in insulin/adiponectin signaling in endometrial cells, suggesting an improvement in insulin action and reproductive failures observed in endometria from women with obesity/PCOS.

6-Gingerol ameliorates adipose tissue insulin resistance in aging rats

This study investigated the effects and mechanisms of 6-gingerol on adipose tissue insulin resistance in naturally aging rats with glycolipid metabolism disorders. Twenty-seven aging male SD rats were randomly divided into a model group(aged, n=9) and two groups treated with 6-gingerol at 0.05 mg·kg~(-1)(G-L, n=9) and 0.2 mg·kg~(-1)(G-H, n=9). Six young rats were randomly assigned to a normal control group(NC). Rats were treated for seven weeks by gavage. Non-esterified fatty acid(NEFA) and insulin content was determined by enzyme-linked immunosorbent assay(ELISA), and adipose tissue insulin resistance index(Adipo-IR) was calculated. HE staining was used to observe the size of adipocytes in epididymal white adipose tissue(eWAT). The gene and protein expression levels of adiponectin receptor 1(AdipoR1), AMP-activated protein kinase α(AMPKα), phosphorylated AMPK(p-AMPKα~(Thr172)), peroxisome proliferator-activated receptor-γ coactivator-1α(PGC-1α), phosphatidylinositol 3-kinase(PI3 K), protein kinase B(Akt), phosphorylated Akt(p-Akt~(Ser473)), tumor necrosis factor-α(TNF-α), c-Jun N-terminal kinase 1/2(JNK1/2), phosphorylated JNK1/2(p-JNK~(Thr183/Tyr185)), interleukin-1β(IL-1β), and interleukin-6(IL-6) in adiponectin(APN), insulin, and inflammatory factor signaling pathways were detected by Western blot and real-time RCR, respectively. The results showed that 6-gingerol at a high dose could significantly decrease the fasting plasma content of NEFA and insulin and reduce Adipo-IR. Additionally, 6-gingerol at a high dose significantly increased the protein and mRNA expression of APN, AdipoR1, PGC-1α, and PI3 K in eWAT, elevated the relative expression of p-AMPK~(Thr172) and p-Akt~(Ser 473), reduced the protein and mRNA expression of TNF-α, IL-1, and IL-6 in eWAT, and decreased the relative expression of p-JNK1 and p-JNK2. This study reveals that 6-gingerol can improve insulin sensitivity of adipose tissues in aging rats with glycolipid metabolism disorders, and this effect is presumedly achieved by enhancing the PI3 K/Akt signaling pathway, inhibiting adipose tissue inflammation, increasing APN synthesis, enhancing AdipoR1 expression, and activating its downstream AMPK/PGC-1α signaling pathway.

Effects of berberine on LPS /NF-κB and MAPK signaling pathways in PCOS model rats

Objective: To investigate the effects of berberine on glucose and lipid metabolism, sex hormone binding protein, adiponectin (LPS), NF-κB and MAPK signaling pathways in polycystic ovary syndrome (PCOS) model rats. Methods: Female SD rats were randomly divided into control group, PCOS model group, berberine (0.216 g/kg) group, metformin (0.135 g/kg) group and Dyne-35 (0.18 mg/kg) group, 10 rats in each group. The rats in PCOS model group were treated with letrozole 1 mg.kg-1 by ig for 3 weeks. After 28 days of drug intervention, the body constitution, ovarian and uterine indexes of the rats were detected, and the changes in the number of ovarian follicles were observed by HE staining. The levels of serum sex hormone, glucose and insulin, triglyceride and cholesterol, sex hormone-binding protein and adiponectin were determined by ELISA, and the protein expressions of p38-MAPK, C-Jun and NF-κB in ovarian tissues were determined by Western blot. Results: Compared with control group, body weight of model group was increased (P＜0.05), and uterine index was decreased (P＜0.05); The number of follicles was increased (P＜0.05). Serum levels of luteinizing hormone (LH), testosterone (T) and LH/FSH ratio were increased (P＜0.05), follicular estrogen (FSH) level was decreased (P＜0.05), total cholesterol (TC), triglyceride (TG), fasting insulin and insulin index (HOMA) were increased (P＜ 0.05). The content of sex hormone binding protein (SHBG) was decreased and the content of adiponectin (LPS) was increased (P＜0.05). The protein expressions of p38-MAPK, c-Jun and NF-κB in ovarian tissue were up-regulated (P＜0.05). Compared with model group, in berberine group, the uterine index and the number of secondary follicles were increased(P＜0.05), the serum levels of luteinizing hormone (LH) , testosterone (T) and the ratio of LH/FSH were decreased (P＜0.05), and the protein expression levels of p38-MAPK and NF-κB in ovarian tissue were down-regulated (P＜0.05), which were similar to those of Dyne-35 group. Berberine significantly decreased serum triglyceride (TG), insulin level and insulin index (P＜0.05), increased serum SHBG level and decreased serum LPS level (P＜0.05), which were similar to those of metformin. Conclusion: Berberine can regulate sex hormone disorder and insulin resistance (IR) in PCOS rats by down-regulating the expressions of p38-MAPK and NF-κB protein in ovarian tissues and decreasing the serum content of LPS.

Abstract ES7-1: Harnessing Lifestyle Interventions via Diet and Exercise for Cancer Risk Reduction

Abstract A growing body of evidence indicates the importance of maintaining optimal metabolic health to reduce the risk of developing cancer and to improve outcomes after cancer diagnosis. Classical and normal weight obesity are states of metabolic dysfunction, and highly prevalent risk factors for the development and growth of several cancers. Classical obesity (defined as a body mass index (BMI) ≥ 30) is a risk factor for at least 13 different types of cancer. Recent data indicate that up to one third of normal weight individuals have metabolic obesity and, subsequently, increased risk for several cancers including breast and colon. Methods to risk-stratify metabolic health and subsequent cancer risk beyond traditional anthropometric metrics such as BMI could improve the efficacy of lifestyle interventions aimed at reducing cancer risk and improving cancer outcomes. In this educational session, the molecular mechanisms linking classical and normal weight obesity to cancer growth will be presented. Obesity-related dysfunction can contribute to cancer pathogenesis and treatment resistance through various mechanisms, including those mediated by insulin, leptin, adiponectin, pro-inflammatory mediators, and hormone signaling pathways, particularly in women. Furthermore, adiposity-related changes can influence tumor vascularity and inflammation in the tumor microenvironment, which can support tumor development and growth. Building upon these mechanistic findings, several clinical trials testing “precision lifestyle” interventions targeted at specific biologic pathways are ongoing. Several randomized control trials testing diet, exercise, and weight loss interventions in cancer populations have demonstrated the feasibility of such interventions. Here, the next generation of lifestyle interventions, such as digital interventions, that target specific pathway dysregulation will be presented. Additionally, pharmacologic interventions that target host metabolism are under study as adjuncts to standard cancer therapy. As rates of classical and normal weight obesity continue to increase, the development of individualized and biologically rational lifestyle interventions could represent an impactful strategy to reduce the worldwide cancer burden. Citation Format: NM Iyengar. Harnessing Lifestyle Interventions via Diet and Exercise for Cancer Risk Reduction [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr ES7-1.

ALY688 elicits adiponectin-mimetic signaling and improves insulin action in skeletal muscle cells

Adiponectin is well established to mediate many beneficial metabolic effects, and this has stimulated great interest in development and validation of adiponectin receptor agonists as pharmaceutical tools. This study investigated the effects of ALY688, a peptide-based adiponectin receptor agonist, in rat L6 skeletal muscle cells. ALY688 significantly increased phosphorylation of several adiponectin downstream effectors, including AMPK, ACC, and p38MAPK, assessed by immunoblotting and immunofluorescence microscopy. Temporal analysis using cells expressing an Akt biosensor demonstrated that ALY688 enhanced insulin sensitivity. This effect was associated with increased insulin-stimulated Akt and IRS-1 phosphorylation. The functional metabolic significance of these signaling effects was examined by measuring glucose uptake in myoblasts stably overexpressing the glucose transporter GLUT4. ALY688 treatment increased basal glucose uptake and enhanced insulin-stimulated glucose uptake. In the model of high-glucose/high-insulin (HGHI)-induced insulin-resistant cells, both temporal studies using the Akt biosensor as well as immunoblotting to assess Akt and IRS-1 phosphorylation indicated that ALY688 significantly reduced insulin resistance. Importantly, we observed that ALY688 administration to high-fat high-sucrose-fed mice also improves glucose handling, validating its efficacy in vivo. In summary, these data indicate that ALY688 activates adiponectin signaling pathways in skeletal muscle, leading to improved insulin sensitivity and beneficial metabolic effects.

Ziziphus spina-christi (L.) fortified with Camellia sinensis mediates apoptosis, Notch-1 signaling, and mitigates obesity-induced non-alcoholic fatty liver.

The habit of drinking tea is highly prevalent and could be utilized to introduce more health benefits through fortification with medicinal plants. The purpose of this analysis was to assess the nutritional quality and health benefits of fortified Ziziphus tea (ZT) with green tea (GT) against obesity and non-alcoholic fatty liver disease (NAFLD). Proximate analysis and sensory evaluation were carried out on the fortified tea. In the in vivo study, 15 SD rats were used for each group. Flow cytometry was utilized for caspase 3 analysis. ELISA was used for the detection of tumor necrosis factor-alpha and adiponectin levels. Real-time PCR was used to detect Notch-1 and Hes-1 gene expression. The composition of fortified (GT+ZT) showed a significant improvement in the nutritional value represented by the increase in overall protein, crude fat, crude fiber, ash, carbohydrate, mineral contents, and antioxidant capacity. Treatment with GT+ZT restored the disturbance in body weight, lipid profile, liver function, glucose, insulin sensitivity index, and oxidative status. It reversed the changes in TNF-α and adiponectin levels. Their protective effects against NAFLD were indicated by the inhibition of hepatic caspase-3 activity, suppression of Notch-1, and Hes-1 gene expression and amelioration of high-fat diet (HFD)-induced histological alterations. Collectively, our findings, elucidate the precise mechanism of fortified ZT+GT for the attenuation of obesity-induced metabolic disorders and NAFLD via regulating lipolysis, TNF-α, adiponectin, apoptosis, and Notch-1 signaling pathways, and provide a foundation for an easily implemented healthy habit of drinking. PRACTICAL APPLICATIONS: The incorporation of bioactive compounds into functional foods is a growing market. Consumer attention in well-being has increased rapidly toward a fortified diet that provides additional health effects. The fortified (GT+ZT) tea may potentially serve as an easily implemented healthy drinking habit to prevent and manage obesity and NAFLD and reduce the risk of other diseases. Fortification with ZT improved the health-promoting functionality of GT through the enhancement of total protein, carbohydrates, antioxidant, and mineral contents. This was reflected by their synergetic therapeutic activity in ameliorating the disturbance in obesity-related disorders and NAFLD via regulating lipolysis, inflammation, oxidative stress, apoptosis, and Notch-1 signaling pathways. Therefore, (GT+ZT) could be considered functional foods which attribute to functional improvement and reduction in disease risk.

Roles of adiponectin and leptin signaling-related microRNAs in the preventive effects of calorie restriction in mammary tumor development.

Calorie restriction (CR) is suggested to prevent the development of mammary tumors (MTs); however, the mechanism remains to be clarified. We aimed to determine the microRNA (miRNA) profile in mice applied to 2 different CR protocols; chronic (CCR) and intermittent (ICR) and follow the MT development. In addition, the roles of miRNAs involved in adiponectin and/or leptin signaling pathways were investigated. Mice were divided into 3groups: ad-libitum (AL), CCR, or ICR, which comprised 3 weeks of AL feeding followed by 1 week of 60% CR in a cyclic manner. Blood and tissue collection were performed at weeks 10, 17/18, 49/50 and 81/82. Long-term CCR provided better protection compared with ICR for MT development with a delay in the MT occurrence. Adiponectin expression in mammary fat pad were significantly higher in CCR group compared with AL. Using GeneChip Array, 250 of 3195 miRNAs were differentially expressed among the dietary groups. Thirteen of 250 miRNAs were related to adiponectin and/or leptin signaling genes. Results were verified by reverse transcription polymerase chain reaction. Specifically, miR-326-3p, miR-500-3p and miR-129-5p, which are related to adiponectin and/or leptin signaling, may play important roles in the preventive effects of CR in MT development and in ageing. Thus, these miRNAs might be putative biomarkers to target for diagnostic and treatment purposes. Novelty: Type of CR and micro RNA interaction is related to ageing. miR-326-3p, miR-500-3p and miR-129-5p expression levels were differentially expressed in MT development and in ageing. The genes associated with adiponectin and/or leptin signaling pathways are regulated by certain miRNAs in the protective effects of CR.

Polymorphisms analysis for association between ADIPO signaling pathway and genetic susceptibility to T2DM in Chinese han population

ABSTRACT The aim of the present study is to explored the relationship between ADIPO signalling pathway and T2DM, to provide clues for further study of the pathogenesis of T2DM and to determine the possible drug targets. This study employed a case-control study design. Twenty-three single nucleotide polymorphisms (SNPs) of 13 genes in the selected ADIPO signalling pathway were genotyped by SNPscanTM kit. All statistical analysis was performed by SPSS 25.0, PLINK 1.07, R 2.14.2, Haploview 4.2, SNPstats, and other statistical software packages. In the association analysis based on a single SNPs, rs1044471 had statistical significance in the overdominant model without adjusting covariates. Rs1042531 had statistical significance in the overdominant model. Rs12718444 had statistical significance in the recessive model. There was a linkage disequilibrium between the loci within 9 genes, and the two loci in RXRA gene did not form blocks. Four kernel functions were used for SNPs set analysis based on ADIPO signalling pathway showed that there was no statistical significance whether covariates were added or not, P>0.05.According to our research results, it is found that some single nucleotide polymorphisms (ADIPOR2 rs1044471, PCK1 rs1042531, GLUT1 rs12718444) in the adiponectin signalling pathway may be associated with T2DM

Adiponectin Signaling and Impaired GTPase Rab5 Expression in Adipocytes of Adolescents with Obesity

Introduction: Abnormalities in adipose tissue AdipoR1; adaptor protein, phosphotyrosine interaction, PH domain, and leucine zipper containing 1 (APPL1); GTPase Rab5; adiponectin; leptin; and visfatin in adults with obesity have been associated with metabolic disturbances. Objective: The objective of this study was to examine whether pediatric obesity disrupts elements of the adiponectin signaling pathway and GTPase Rab5 in adipose tissue. Methods: Primary adipocyte cultures of subcutaneous abdominal tissue were obtained from 96 lean and 66 children and adolescents with obesity (AO). AdipoR1, APPL1, and GTPase Rab5 mRNA levels were measured by RT-PCR and their protein content by Western immunoblotting. Serum total and high-molecular-weight adiponectin, leptin, leptin soluble receptor (sOB-R), and visfatin were measured by ELISA. Results: The mRNA expression and protein content of AdipoR1 and APPL1 did not differ significantly with obesity, age, or puberty. However, GTPase Rab5 protein was increased in the adipocytes of younger prepubertal children with obesity but decreased in AO. Leptin was increased in AO compared to lean adolescents (AL) and in older prepubertal lean (OPL) children and AL compared to younger prepubertal lean and obese children. sOB-R was higher in OPL children and in the AL and AO. Serum visfatin was increased in the younger prepubertal children and AO. Conclusions: In contrast to adults, obesity did not change the expression of AdipoR1 and APPL1 in cultured adipocytes from biopsies of subcutaneous abdominal adipose tissue of children and adolescents. Similar to adipose tissue studies in adults with obesity and metabolic dysfunction, the AO in our study showed reduced adipocyte GTPase Rab5 expression.