Activation of noncanonical Wnt signaling through WNT5A in visceral adipose tissue of obese subjects is related to inflammation

Diagnostic and prognostic significance of circulating secreted frizzled-related protein 5 in colorectal cancer

BACKGROUND

Secreted Frizzled-Related Protein 5 (SFRP5) modulates Wnt signalling pathways, affecting diverse biological processes. We assessed the diagnostic and prognostic value of circulating SFRP5 (cSFRP5) in colorectal cancer (CRC) METHODS: Plasma cSFRP5 concentrations were measured using enzyme-linked immunosorbent assay (ELISA) in healthy donors (n = 133), individuals diagnosed with CRC (n = 449), colorectal polyps (n = 85), and medical conditions in other organs including cancer, inflammation, and benign states (n = 64).

RESULTS

Patients with CRC, polyps, and other conditions showed higher cSFRP5 levels than healthy individuals (p < 0.0001). Receiver operating characteristic curves comparing healthy donors with medical conditions, polyps and CRC were 0.814 (p < 0.0001), 0.763 (p < 0.0001) and 0.762 (p < 0.0001), respectively. In CRC, cSFRP5 correlated with patient age (p < 0.0001), tumour stage (p < 0.0001), and histological differentiation (p = 0.0273). Levels, adjusted for patient age, sex, plasma age and collection institution, peaked in stage II versus I (p < 0.0001), III (p = 0.0002) and IV (p < 0.0001), were lowest in stage I versus III (p = 0.0002) and IV (p = 0.0413), with no difference between stage III and IV. Elevated cSFRP5 levels predicted longer overall survival in stages II-III CRC (univariate: HR 1.82, 95% CI: 1.02-3.26, p = 0.024; multivariable: HR 2.34, 95% CI: 1.12-4.88, p = 0.015).

CONCLUSION

This study confirms cSFRP5 levels are elevated in CRC compared to healthy control and reveals a correlation between elevated cSFRP5 and overall survival in stages II-III disease.

Phenotype-specific melanoma uptake of fatty acid from human adipocytes activates AXL and CAV1-dependent β-catenin nuclear accumulation

Phenotypic diversity of cancer cells within tumors generated through bi-directional interactions with the tumor microenvironment has emerged as a major driver of disease progression and therapy resistance. Nutrient availability plays a critical role in determining phenotype, but whether specific nutrients elicit different responses on distinct phenotypes is poorly understood. Here we show, using melanoma as a model, that only MITF Low undifferentiated cells, but not MITF High cells, are competent to drive lipolysis in human adipocytes. In contrast to MITF High melanomas, adipocyte-derived free fatty acids are taken up by undifferentiated MITF Low cells via a fatty acid transporter (FATP)-independent mechanism. Importantly, oleic acid (OA), a monounsaturated long chain fatty acid abundant in adipose tissue and lymph, reprograms MITF Low undifferentiated melanoma cells to a highly invasive state by ligand-independent activation of AXL, a receptor tyrosine kinase associated with therapy resistance in a wide range of cancers. AXL activation by OA then drives SRC-dependent formation and nuclear translocation of a β-catenin-CAV1 complex. The results highlight how a specific nutritional input drives phenotype-specific activation of a pro-metastasis program with implications for FATP-targeted therapies.

Secreted frizzled-related protein 5: A promising therapeutic target for metabolic diseases via regulation of Wnt signaling

Metabolic diseases pose a significant global health challenge, characterized by an imbalance in metabolism and resulting in various complications. Secreted frizzled-related protein 5 (SFRP5), an adipokine known for its anti-inflammatory properties, has gained attention as a promising therapeutic target for metabolic diseases. SFRP5 acts as a key regulator in the Wnt signaling pathway, exerting its influence on critical cellular functions including proliferation, differentiation, and migration. Its significance extends to the realm of adipose tissue biology, where it plays a central role in regulating inflammation, insulin resistance, adipogenesis, lipid metabolism, glucose homeostasis, and energy balance. By inhibiting Wnt signaling, SFRP5 facilitates adipocyte growth, promotes lipid accumulation, and contributes to a decrease in oxidative metabolism. Lifestyle interventions and pharmacological treatments have shown promise in increasing SFRP5 levels and protecting against metabolic abnormalities. SFRP5 is a pivotal player in metabolic diseases and presents itself as a promising therapeutic target. An overview of SFRP5 and its involvement in metabolic disorders and metabolism is provided in this comprehensive review. By elucidating these aspects, valuable insights can be gained to foster the development of effective strategies in combating metabolic diseases.

Phenotyping the obesities: reality or utopia?

In this thematic issue on phenotyping the obesities, prominent international experts offer an insightful and comprehensive collection of articles covering the current knowledge in the field. In order to actually capture all the polyhedral determinants of the diverse types of obesity, the granularity of the phenotypic information acquired must be expanded in the context of a personalized approach. Whilst the use of precision medicine has been successfully implemented in areas like cancer and other diseases, health care providers are more reluctant to embrace detailed phenotyping to guide diagnosis, treatment and prevention in obesity. Given its multiple complex layers, phenotyping necessarily needs to go beyond the multi-omics approach and incorporate all the diverse spheres that conform the reality of people living with obesity. Potential barriers, difficulties, roadblocks and opportunities together with their interaction in a syndemic context are analyzed. Plausible lacunae are also highlighted in addition to pointing to the need of redefining new conceptual frameworks. Therefore, this extraordinary collection of state-ofthe-art reviews provides useful information to both experienced clinicians and trainees as well as academics to steer clinical practice and research in the management of people living with obesity irrespective of practice setting or career stage.

Adipokines in atherosclerosis: unraveling complex roles

Adipokines are biologically active factors secreted by adipose tissue that act on local and distant tissues through autocrine, paracrine, and endocrine mechanisms. However, adipokines are believed to be involved in an increased risk of atherosclerosis. Classical adipokines include leptin, adiponectin, and ceramide, while newly identified adipokines include visceral adipose tissue-derived serpin, omentin, and asprosin. New evidence suggests that adipokines can play an essential role in atherosclerosis progression and regression. Here, we summarize the complex roles of various adipokines in atherosclerosis lesions. Representative protective adipokines include adiponectin and neuregulin 4; deteriorating adipokines include leptin, resistin, thrombospondin-1, and C1q/tumor necrosis factor-related protein 5; and adipokines with dual protective and deteriorating effects include C1q/tumor necrosis factor-related protein 1 and C1q/tumor necrosis factor-related protein 3; and adipose tissue-derived bioactive materials include sphingosine-1-phosphate, ceramide, and adipose tissue-derived exosomes. However, the role of a newly discovered adipokine, asprosin, in atherosclerosis remains unclear. This article reviews progress in the research on the effects of adipokines in atherosclerosis and how they may be regulated to halt its progression.

Signaling pathways and intervention for therapy of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) represents one of the fastest growing epidemic metabolic disorders worldwide and is a strong contributor for a broad range of comorbidities, including vascular, visual, neurological, kidney, and liver diseases. Moreover, recent data suggest a mutual interplay between T2DM and Corona Virus Disease 2019 (COVID-19). T2DM is characterized by insulin resistance (IR) and pancreatic β cell dysfunction. Pioneering discoveries throughout the past few decades have established notable links between signaling pathways and T2DM pathogenesis and therapy. Importantly, a number of signaling pathways substantially control the advancement of core pathological changes in T2DM, including IR and β cell dysfunction, as well as additional pathogenic disturbances. Accordingly, an improved understanding of these signaling pathways sheds light on tractable targets and strategies for developing and repurposing critical therapies to treat T2DM and its complications. In this review, we provide a brief overview of the history of T2DM and signaling pathways, and offer a systematic update on the role and mechanism of key signaling pathways underlying the onset, development, and progression of T2DM. In this content, we also summarize current therapeutic drugs/agents associated with signaling pathways for the treatment of T2DM and its complications, and discuss some implications and directions to the future of this field.

Is obesity-induced ECM remodeling a prelude to the development of various diseases?

Due to the increasing incidence rate of obesity worldwide and the associated complications such as type 2 diabetes and cardiovascular diseases, research on the adipose tissue physiology and the role of the extracellular matrix (ECM) has gained tremendous attention. The ECM, one of the most crucial components in body tissues, undergoes remodeling and regeneration of its constituents to guarantee normal tissue function. There is a crosstalk between fat tissue and various body organs, including but not limited to the liver, heart, kidney, skeletal muscle, and so forth. These organs respond to fat tissue signals through changes in ECM, function, and their secretory products. Obesity can cause ECM remodeling, inflammation, fibrosis, insulin resistance, and disrupted metabolism in different organs. However, the mechanisms underlying the reciprocal communication between various organs during obesity are still not fully elucidated. Gaining a profound knowledge of ECM alterations during the progression of obesity will pave the way toward developing potential strategies to either circumvent pathological conditions or open an avenue to treat complications associated with obesity.

A Wrong Fate Decision in Adipose Stem Cells upon Obesity

Progress has been made in identifying stem cell aging as a pathological manifestation of a variety of diseases, including obesity. Adipose stem cells (ASCs) play a core role in adipocyte turnover, which maintains tissue homeostasis. Given aberrant lineage determination as a feature of stem cell aging, failure in adipogenesis is a culprit of adipose hypertrophy, resulting in adiposopathy and related complications. In this review, we elucidate how ASC fails in entering adipogenic lineage, with a specific focus on extracellular signaling pathways, epigenetic drift, metabolic reprogramming, and mechanical stretch. Nonetheless, such detrimental alternations can be reversed by guiding ASCs towards adipogenesis. Considering the pathological role of ASC aging in obesity, targeting adipogenesis as an anti-obesity treatment will be a key area of future research, and a strategy to rejuvenate tissue stem cell will be capable of alleviating metabolic syndrome.

Frizzled receptors and SFRP5 in lipid metabolism: Current findings and potential applications

Lipid metabolism plays a very important role as the central metabolic process of the body. Lipid metabolism interruptions may cause many chronic diseases, for example, non-alcoholic fatty liver disease (NAFLD), diabetes, and obesity. Secreted Frizzled Related Protein 5 (SFRP5) and Frizzled receptors (FZD) are two newly discovered adipokines that are involved in lipid metabolism as well as lipogenesis. Both of these adipokines affect lipid metabolism and adipogenesis through three WNT signaling pathways (WNTSP): WNT/β-catenin, WNT/Ca²⁺, and WNT/JNK. FZD consists of 10 species, which have a cysteine-rich domain (CRD) to bind to the WNT protein for signal transduction. Depending on the type of ligand or co-receptor, they can stimulate or inhibit adipogenesis. In lipid metabolism, they play a role in recognizing fatty acids. In obesity, gene expression of the WNT/FZD receptors is significantly increased. In contrast, SFPR5 serves as an antagonist that can compete with FZD for inhibition of WNTSP. It is believed to have anti-inflammatory potential in obesity and diseases related to abnormal lipid metabolism. In these cases, the expression of SFRP5 is found to be very low leading to the promoted production of proinflammatory cytokines (PICS). Some methods that include using recombinant SFRP5 to improve non-alcoholic steatohepatitis (NASH), using secreted Ly-6/uPAR-related protein 1 (Slurp1) to regulate fat accumulation in the liver through SFRP5, and dietary and lifestyle interventions to improve overweight/obesity have been studied. However, understandings of the molecular mechanisms of these two adipokines and their interactions are very limited. Therefore, more in-depth studies are needed in the future.

Non-canonical WNT signalling in cardiovascular disease: mechanisms and therapeutic implications

WNT signalling comprises a diverse spectrum of receptor-mediated pathways activated by a large family of WNT ligands and influencing fundamental biological processes. WNT signalling includes the β-catenin canonical pathway and the non-canonical pathways, namely the planar cell polarity and the calcium-dependent pathways. Advances over the past decade have linked non-canonical WNT signalling with key mechanisms of atherosclerosis, including oxidative stress, endothelial dysfunction, macrophage activation and vascular smooth muscle cell phenotype regulation. In addition, non-canonical WNT signalling is involved in crucial aspects of myocardial biology, from fibrosis to hypertrophy and oxidative stress. Importantly, non-canonical WNT signalling activation has complex effects in adipose tissue in the context of obesity, thereby potentially linking metabolic and vascular diseases. Tissue-specific targeting of non-canonical WNT signalling might be associated with substantial risks of off-target tumorigenesis, challenging its therapeutic potential. However, novel technologies, such as monoclonal antibodies, recombinant decoy receptors, tissue-specific gene silencing with small interfering RNAs and gene editing with CRISPR-Cas9, might enable more efficient therapeutic targeting of WNT signalling in the cardiovascular system. In this Review, we summarize the components of non-canonical WNT signalling, their links with the main mechanisms of atherosclerosis, heart failure and arrhythmias, and the rationale for targeting individual components of non-canonical WNT signalling for the treatment of cardiovascular disease.

The effects of exercise training induced calories expenditure on type 2 diabetes related cardio metabolic physiological parameters and adipocytokines

Background

Recently, many studies have examined the effects of various training on pro-inflammatory and anti-inflammatory adipocytes. The results of these studies are contradictory. Some have reported positive effects and others have reported negative effects. However, there is no research to study the effect of exercise on similar energy expenditures on adipocytes. Hence the purpose of this study was the effects exercise training induced calories expenditure on type 2 diabetes related cardio metabolic physiological parameters and adipocytokines.

Methods

Sixty-eight men patients with type 2 diabetes [12 weeks] were randomized to 4 groups according to training regimens. the groups are [1] HIIT [n = 17], [2] RT[n = 17], [3] AT[n = 18], and [4] AT + RT n = 16]. For 12 weeks [4 days/week, 20–30 min/season], participants performed training sessions with 300 kcal energy expenditure. Before and after 12 weeks interventions, Anthropometric and physiological variables and Glucose, insulin, FFA, LDL, HDL, TG, TC collected and analyses. Leptin, SFRP5, LGR4 and Irisin levels in Serum were assessment by ELISA.

Results

Serum irisin concentrations were significantly higher in AT [%20.4] compared to other groups. Leptin, SFRP5 and LGR4 were significantly higher in HIIT [%-21.7, %48.1 and %30.9 respectively] compared to other groups. Serum SFRP5 concentrations were significantly increased in 4 groups[P > 0.05]. However, leptin and LGR4 were significantly decreased and increased in 3 groups expect in RT group[P > 0.05]. And irisin concentrations were significantly increased in AT group only[P > 0.05]. And many variables indicated positive and negative relationship between together [P > 0.05].

Conclusions

The findings of the present study showed that if exercised with energy expenditure equal to HIIT training, it has the greatest effect on improving inflammatory and anti-inflammatory indicators in type 2 diabetic patients, as well as glycemic and lipid-chemical variables.

Increased Secreted Frizzled-Related Protein 5 mRNA Expression in the Adipose Tissue of Women with Nonalcoholic Fatty Liver Disease Associated with Obesity

Secreted frizzled-related protein 5 (SFRP5) is an anti-inflammatory adipocytokine secreted by adipocytes that seems to be linked with nonalcoholic fatty liver disease (NAFLD). We aimed to evaluate the role of the SFRP5-wingless-MMTV integration site family member 5a (WNT5A) pathway, closely related to adipogenesis, in subcutaneous (SAT) and visceral adipose tissues (VAT) and its relationship with obesity-related NAFLD. Our cohort was composed of 60 women with morbid obesity (MO), who underwent hypocaloric diet, subclassified according to their hepatic histopathology and 15 women with normal weight. We observed increased SFRP5 mRNA expression in VAT and lower WNT5A expression in SAT in MO compared to normal weight. We found elevated SFRP5 expression in nonalcoholic steatohepatitis (NASH) in SAT and in mild simple steatosis (SS) and NASH in VAT. We observed higher WNT5A expression in SS compared to normal liver in SAT, and a peak of WNT5A expression in mild SS. To conclude, we reported increased SFRP5 mRNA expression in SAT and VAT of NAFLD-related to obesity subjects, suggesting an implication of the SFRP5-WNT5A pathway in NAFLD pathogenesis, probably due to the adipose tissue-liver axis. Since the mechanisms by which this potential interaction takes place remain elusive, more research in this field is needed.

YAP-dependent Wnt5a induction in hypertrophic adipocytes restrains adiposity

Wnt5a, a prototypic non-canonical Wnt, is an inflammatory factor elevated in the sera of obese humans and mice. In the present study, fat-specific knockout of Wnt5a (Wnt5a-FKO) prevented HFD-induced increases in serum Wnt5a levels in male C57BL/6 J mice, which suggested adipocytes are primarily responsible for obesity-induced increases in Wnt5a levels. Mouse subcutaneous white adipose tissues (WATs) more sensitively responded to HFD, in terms of cell size increases and Wnt5a levels than epididymal WATs. Furthermore, adipocyte sizes were positively correlated with Wnt5a levels in vitro and in vivo. In hypertrophic adipocytes, enlarged lipid droplets increased cell stiffness and rearranged the f-actin stress fibers from the cytoplasm to the cortical region. The activities of YAP (Yes-associated protein) and TAZ (transcriptional co-activator with PDZ-binding motif) increased in response to these mechanical changes in hypertrophic adipocytes, and inhibition or knock-down of YAP and TAZ reduced Wnt5a expression. ChIP (chromatin immunoprecipitation) analyses revealed that YAP was recruited by Wnt5a-1 gene promoter and increased Wnt5a expression. These results suggested that YAP responds to mechanical stress in hypertrophic adipocytes to induce the expression Wnt5a. When 8-week-old Wnt5a-FKO mice were fed an HFD for 20 weeks, the fat mass increased, especially in subcutaneous WATs, as compared with that observed in floxed mice, without significant changes in food intake or activity. Furthermore, Wnt5a-FKO mice showed impaired glucose tolerance regardless of diet type. Our findings show that hypertrophy/YAP/Wnt5a signaling constitutes a negative-feedback loop that retrains adipose tissue hypertrophy.

Exercise training modulates adipokines dysregulations in metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors for various metabolic diseases, and it is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance. The core component for MetS is adipose tissue, which releases adipokines and influences physical health. Adipokines consist of pro and anti-inflammatory cytokines and contribute to various physiological functions. Generally, a sedentary lifestyle promotes fat accumulation and secretion of pro-inflammatory adipokines. However, regular exercise has been known to exert various beneficial effects on metabolic and cognitive disorders. Although the mechanisms underlying exercise beneficial effects in MetS are not fully understood, changes in energy expenditure, fat accumulation, circulatory level of myokines, and adipokines might be involved. This review article focuses on some of the selected adipokines in MetS, and their responses to exercise training considering possible mechanisms.

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Adipokines are a potential link between visceral fats and complications of MetS.

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Physical inactivity increases pro-inflammatory adipokines.

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Moderate aerobic exercise increases anti-inflammatory adipokines partly via reducing adipose tissue mass.

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Physical exercise-induced myokines might mediate beneficial effects via a cross-talk with adipose tissues.

The role of Wnt pathway in obesity induced inflammation and diabetes: a review

Diabetes has become a major killer worldwide and at present, millions are affected by it. Being a chronic disease it increases the risk of other diseases ranging from pulmonary disorders to soft tissue infections. The loss of insulin-producing capacity of the pancreatic β-cells is the main reason for the development of the disease. Obesity is a major complication that can give rise to several other diseases such as cancer, diabetes, etc. Visceral adiposity is one of the major factors that play a role in the development of insulin resistance. Obesity causes a chronic low-grade inflammation in the tissues that further increases the chances of developing diabetes. Several pathways have been associated with the development of diabetes due to inflammation caused by obesity. The Wnt pathway is one such candidate pathway that is found to have a controlling effect on the development of insulin resistance. Moreover, the pathway has also been linked to obesity and inflammation. This review aims to find a connection between obesity, inflammation, and diabetes by taking the wnt pathway as the connecting link.

Serum secreted frizzled-related protein 5 in relation to insulin sensitivity and its regulation by insulin and free fatty acids

PURPOSE

Secreted frizzled-related protein 5 (SFRP5) is an adipokine, which acts as an inhibitor of noncanonical WNT signaling pathway. It has been suggested to exert anti-inflammatory and insulin-sensitizing effects, however, contradictory data has also been reported. The aim of this study was to assess serum SFRP5 concentration in a young healthy population in relation to insulin sensitivity and its regulation by hyperinsulinemia and/or serum free fatty acids (FFA) elevation.

METHODS

We examined 150 healthy subjects (83 normal-weight and 67 overweight/obese). Insulin sensitivity (M) was measured with hyperinsulinemic-euglycemic clamp. In 20 male subjects, clamp was prolonged to 6 h and after 1 week another clamp with the concurrent Intralipid/heparin infusion was performed. Independent group of 10 male subjects received infusions of Intralipid/heparin or saline in 1-week interval.

RESULTS

Baseline SFRP5 was lower in the overweight/obese group (p = 0.01) and was positively associated with M (r = 0.23, p = 0.006) and serum adiponectin (r = 0.55, p < 0.001) and negatively with BMI (r = -0.18, p = 0.03). In multiple regression analysis, adiponectin was independently associated with SFRP5. Insulin infusion resulted in a decrease in serum SFRP5, both at 120' (p = 0.02) and 360' (p = 0.031). This effect was not observed during the clamp with Intralipid/heparin as well as during Intralipid/heparin alone or saline infusions.

CONCLUSIONS

The relation between SFRP5 and insulin sensitivity is mainly dependent on adiponectin. FFA abolish a decrease in circulating SFRP5 caused by insulin, but Intralipid/heparin infusion alone does not regulate SFRP5 concentration. Insulin seems to be more important factor in the regulation of circulating SFRP5 levels than FFA.

Obesity and Pancreatic Cancer: Insight into Mechanisms

Simple Summary

Obesity is recognized as a chronic progressive disease and risk factor for many human diseases. The high and increasing number of obese people may underlie the expected increase in pancreatic cancer cases in the United States. There are several pathways discussed that link obesity with pancreatic cancer. Adipose tissue and adipose tissue-released factors may thereby play an important role. This review discusses selected mechanisms that may accelerate pancreatic cancer development in obesity.

Abstract

The prevalence of obesity in adults and children has dramatically increased over the past decades. Obesity has been declared a chronic progressive disease and is a risk factor for a number of metabolic, inflammatory, and neoplastic diseases. There is clear epidemiologic and preclinical evidence that obesity is a risk factor for pancreatic cancer. Among various potential mechanisms linking obesity with pancreatic cancer, the adipose tissue and obesity-associated adipose tissue inflammation play a central role. The current review discusses selected topics and mechanisms that attracted recent interest and that may underlie the promoting effects of obesity in pancreatic cancer. These topics include the impact of obesity on KRAS activity, the role of visceral adipose tissue, intrapancreatic fat, adipose tissue inflammation, and adipokines on pancreatic cancer development. Current research on lipocalin-2, fibroblast growth factor 21, and Wnt5a is discussed. Furthermore, the significance of obesity-associated insulin resistance with hyperinsulinemia and obesity-induced gut dysbiosis with metabolic endotoxemia is reviewed. Given the central role that is occupied by the adipose tissue in obesity-promoted pancreatic cancer development, preventive and interceptive strategies should be aimed at attenuating obesity-associated adipose tissue inflammation and/or at targeting specific molecules that mechanistically link adipose tissue with pancreatic cancer in obese patients.

The Emerging Role of Sfrp5 and Wnt5a in the Pathogenesis of Obesity: Implications for a Healthy Diet and Lifestyle

In recent decades, the prevalence of obesity has risen dramatically worldwide among all age groups. Obesity is characterized by excess fat accumulation and chronic low-grade inflammation. The adipose tissue functions as a metabolically active endocrine organ secreting adipokines. A novel duo of adipokines, the anti-inflammatory secreted frizzled-related protein 5 (Sfrp5) and the proinflammatory wingless type mouse mammary tumor virus (MMTV) integration site family member 5A (Wnt5a), signal via the non-canonical Wnt pathway. Recent evidence suggests that Sfpr5 and Wnt5a play a key role in the pathogenesis of obesity and its metabolic complications. This review summarizes the current knowledge on the novel regulatory system of anti-inflammatory Sfrp5 and pro-inflammatory Wnt5a, and their relation to obesity and obesity-related complications. Future studies are required to investigate the potential role of Sfrp5 and Wnt5a as biomarkers for monitoring the response to lifestyle interventions and for predicting the development of cardiometabolic risk factors. These adipokines may also serve as novel therapeutic targets for obesity-related disorders.

Serum Visfatin Levels in Nonalcoholic Fatty Liver Disease and Liver Fibrosis: Systematic Review and Meta-Analysis

(1) Background: Recently, adipokines, including visfatin, have been studied in nonalcoholic fatty liver disease (NAFLD). Several studies evaluated visfatin levels in NAFLD, the presence and severity of hepatic steatosis, liver fibrosis, lobar inflammation, nonalcoholic steatohepatitis (NASH), and gender differences. However, inconclusive results have been reported. Accordingly, we performed a systematic review and meta-analysis, aiming to address these gaps in evidence. (2) Methods: We performed a systematic electronic search on PubMed, EMBASE, and Cochrane Library using predefined keywords. Diagnosis of NAFLD by liver biopsy or imagistic investigations was accepted. Full articles satisfying our inclusion and exclusion criteria were included. NHLBI quality assessment tools were used to evaluate included studies. The principal summary outcome was the mean difference in visfatin levels. (3) Results: There were 21 studies involving 1923 individuals included in our qualitative assessment, while 14 studies were included in the quantitative assessment. No statistical significance was found assessing visfatin levels in NAFLD [3.361 (95% CI -0.175-6.897)], simple steatosis [7.523 (95% CI -16.221-31.267)], hepatic steatosis severity [-0.279 (95% CI -1.843-1.285)], liver fibrosis [4.133 (95% CI -3.176-11.443)], lobar inflammation [0.358 (95% CI -1.470-2.185)], NASH [-2.038 (95% CI -6.839-2.763)], and gender [(95% CI -0.554-0.556)]. (4) Conclusions: In conclusion, visfatin levels are not associated with NAFLD, presence or severity of hepatic steatosis, liver fibrosis, lobar inflammation, NASH, and gender. However, due to the limited methodological quality of the included studies, results should be interpreted with caution.

Novel insights into the pathological mechanisms of metabolic related dyslipidemia

Due to the technological advances, it has been well-established that obesity is strongly correlated with various health problems. Among these problems, dyslipidemia is one of the most important concomitant symptoms under obese status which is the main driving force behind the pathological progression of cardio-metabolic disorder diseases. Importantly, the type of dyslipidemia, arising from concerted action of obesity, has been identified as "metabolic related dyslipidemia", which is characterized by increased circulating levels of Low density lipoprotein cholesterol (LDL-C), Triglycerides (TG) accompanied by lower circulating levels of High density lipoprotein cholesterol (HDL-C). On the other hand, the metabolic related dyslipidemia is being verified as a vital link between obesity and hypertension, diabetes mellitus, and Cardiovascular disease (CVD). In this review, we summarized the current understanding of metabolic related dyslipidemia and the potential mechanisms which lead to the pathogenesis of obesity. Meanwhile, we also summarized the emerging results which focused on several novel lipid bio-markers in metabolic related dyslipidemia, such as pro-protein convertase subtilisin/kexin type 9 (PCSK9) and sphingosine-1-phosphate (S1P), and their potential use as biomarkers of metabolic related dyslipidemia.

Pathology of metabolically-related dyslipidemia

It is well established that overweight/obesity is closely associated with multiple health problems. Among these, dyslipidemia is the most important and main driving force behind pathologic development of cardio-metabolic disorders such as diabetes mellitus, atherosclerotic-related cardiovascular disease and hypertension. Notably, a subtype of dyslipidemia, metabolic related dyslipidemia, is now recognized as a vital link between obesity and multiple different cardiovascular diseases. This condition is characterized by increased low density lipoprotein cholesterol (LDL-C) and triglyceride (TG) and very low density lipoprotein cholesterol (VLDL-C) as well as decreased high density lipoprotein cholesterol (HDL-C) in serum. In this review, we summarize the current understanding of metabolic related dyslipidemia and the potential mechanisms which lead to the pathogenesis of obesity/overweight. We focus on several novel lipid biomarkers such as pro-protein convertase subtilisin/kexin type 9 (PCSK9) and sphingosine-1-phosphate (S1P) and their potential use as biomarkers of metabolic related dyslipidemia.

A Signaling View into the Inflammatory Tumor Microenvironment

The development of tumors requires an initiator event, usually exposure to DNA damaging agents that cause genetic alterations such as gene mutations or chromosomal abnormalities, leading to deregulated cell proliferation. Although the mere stochastic accumulation of further mutations may cause tumor progression, it is now clear that an inflammatory microenvironment has a major tumor-promoting influence on initiated cells, in particular when a chronic inflammatory reaction already existed before the initiated tumor cell was formed. Moreover, inflammatory cells become mobilized in response to signals emanating from tumor cells. In both cases, the microenvironment provides signals that initiated tumor cells perceive by membrane receptors and transduce via downstream kinase cascades to modulate multiple cellular processes and respond with changes in cell gene expression, metabolism, and morphology. Cytokines, chemokines, and growth factors are examples of major signals secreted by immune cells, fibroblast, and endothelial cells and mediate an intricate cell-cell crosstalk in an inflammatory microenvironment, which contributes to increased cancer cell survival, phenotypic plasticity and adaptation to surrounding tissue conditions. Eventually, consequent changes in extracellular matrix stiffness and architecture, coupled with additional genetic alterations, further fortify the malignant progression of tumor cells, priming them for invasion and metastasis. Here, we provide an overview of the current knowledge on the composition of the inflammatory tumor microenvironment, with an emphasis on the major signals and signal-transducing events mediating different aspects of stromal cell-tumor cell communication that ultimately lead to malignant progression.

Pregnancy Outcomes Post-bariatric Surgery-a Single-Centre Retrospective Study from India

BACKGROUND

Bariatric surgery presently is the best possible intervention for treatment of severe obesity and its related conditions. This study presents retrospective data on the pregnancy outcomes of Indian patients who underwent bariatric surgery before conception.

METHODOLOGY

This is a single-centre retrospective, observational study. Data on demographics, pre-surgery weight, body mass index (BMI), types of bariatric surgery, weight at conception, weight gain during pregnancy, type of delivery and the health of the baby were collected and analysed to study the weight loss pattern and pregnancy outcomes in female patients of childbearing potential.

RESULTS

The study included 34 women of childbearing potential (BMI>30 kg/m²) who underwent bariatric surgery. The study population was followed up from the time of surgery until 1-year post-delivery of the baby. The mean weight gain during the pregnancy was 14.9±5.4 kg. Twenty-three underwent LSCS, and the rest had normal delivery with mean baby weight of 2.5±0.4 kg. Six babies required neonatal intensive care. In our series, only 4 of 35 cohorts that are only 11% had substantial weight retention (range 5-13 kg) at the end of 12 months which is significantly lower than the normal cohorts who did not undergo bariatric surgery.

CONCLUSION

Bariatric surgery improves fertility with safe pregnancy and its outcomes in terms of preeclampsia, eclampsia, gestational diabetes, premature rupture of the membranes (PROM), postpartum haemorrhage (PPH) and puerperal sepsis in women with childbearing potential and safe for offspring in terms of shoulder dystocia, macrosomia, birth asphyxia and perinatal mortality. However, they should be well aware of the risks associated with bariatric surgery especially the mal-absorptive procedures.

The complex role of Wnt ligands in type 2 diabetes mellitus and related complications

Type 2 diabetes mellitus (T2DM) is one of the major chronic diseases, whose prevalence is increasing dramatically worldwide and can lead to a range of serious complications. Wnt ligands (Wnts) and their activating Wnt signalling pathways are closely involved in the regulation of various processes that are important for the occurrence and progression of T2DM and related complications. However, our understanding of their roles in these diseases is quite rudimentary due to the numerous family members of Wnts and conflicting effects via activating the canonical and/or non-canonical Wnt signalling pathways. In this review, we summarize the current findings on the expression pattern and exact role of each human Wnt in T2DM and related complications, including Wnt1, Wnt2, Wnt2b, Wnt3, Wnt3a, Wnt4, Wnt5a, Wnt5b, Wnt6, Wnt7a, Wnt7b, Wnt8a, Wnt8b, Wnt9a, Wnt9b, Wnt10a, Wnt10b, Wnt11 and Wnt16. Moreover, the role of main antagonists (sFRPs and WIF-1) and coreceptor (LRP6) of Wnts in T2DM and related complications and main challenges in designing Wnt-based therapeutic approaches for these diseases are discussed. We hope a deep understanding of the mechanistic links between Wnt signalling pathways and diabetic-related diseases will ultimately result in a better management of these diseases.

Dysmetabolic adipose tissue in obesity: morphological and functional characteristics of adipose stem cells and mature adipocytes in healthy and unhealthy obese subjects

The way by which subcutaneous adipose tissue (SAT) expands and undergoes remodeling by storing excess lipids through expansion of adipocytes (hypertrophy) or recruitment of new precursor cells (hyperplasia) impacts the risk of developing cardiometabolic and respiratory diseases. In unhealthy obese subjects, insulin resistance, type 2 diabetes, hypertension, and obstructive sleep apnoea are typically associated with pathologic SAT remodeling characterized by adipocyte hypertrophy, as well as chronic inflammation, hypoxia, increased visceral adipose tissue (VAT), and fatty liver. In contrast, metabolically healthy obese individuals are generally associated with SAT development characterized by the presence of smaller and numerous mature adipocytes, and a lower degree of VAT inflammation and ectopic fat accumulation. The remodeling of SAT and VAT is under genetic regulation and influenced by inherent depot-specific differences of adipose tissue-derived stem cells (ASCs). ASCs have multiple functions such as cell renewal, adipogenic capacity, and angiogenic properties, and secrete a variety of bioactive molecules involved in vascular and extracellular matrix remodeling. Understanding the mechanisms regulating the proliferative and adipogenic capacity of ASCs from SAT and VAT in response to excess calorie intake has become a focus of interest over recent decades. Here, we summarize current knowledge about the biological mechanisms able to foster or impair the recruitment and adipogenic differentiation of ASCs during SAT and VAT development, which regulate body fat distribution and favorable or unfavorable metabolic responses.

Polycystic ovary syndrome: Pathways and mechanisms for possible increased susceptibility to COVID-19

In 75% of women with polycystic ovary syndrome (PCOS), insulin action is impaired. In obesity, visceral adipose tissue becomes dysfunctional: Chronic inflammation is favored over storage, contributing to the development of metabolic complications. PCOS, metabolic syndrome (MetSy) and non-alcoholic fatty liver disease (NAFLD) apparently share common pathogenic factors; these include abdominal adiposity, excess body weight and insulin resistance. Alterations in the gut microbiome have been noted in women with PCOS compared to controls; these may lead to deterioration of the intestinal barrier, increased gut mucosal permeability and immune system activation, hyperinsulinemia and glucose intolerance, which hamper normal ovarian function and follicular development (all being hallmarks of PCOS). It has been proposed that PCOS may entail higher susceptibility to coronavirus disease 2019 (COVID-19) via its associated comorbidities (NAFLD, obesity, MetSy and alterations in the gut microbiome). Studies have found an association between acute respiratory distress syndrome (seen in severe cases of COVID-19) and the intestinal microbiome. Furthermore, apparently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can gain entry to the gastrointestinal tract via locally-expressed angiotensin converting enzyme type 2 receptors. Excess body weight is associated with more severe COVID-19 and increased mortality. Although robust links between SARS-CoV-2 infection and PCOS/NAFLD/gut microbiome/metabolic consequences are yet to be confirmed, it seems that strategies for adapting the intestinal microbiome could help reduce the severity of COVID-19 in women with PCOS with or without NAFLD, MetSy or obesity.

Leptin Is Associated with Poor Clinical Outcomes and Promotes Clear Cell Renal Cell Carcinoma Progression

Emerging evidence has shown the oncogenic roles of leptin in modulating cancer progression in addition to its original roles. Analyses of transcriptomic data and patients’ clinical information have revealed leptin’s prognostic significance in renal cell carcinoma (RCC). However, its biological effects on RCC progression have not yet been explored. Clinical and transcriptomic data of a RCC cohort of 603 patients were retrieved from The Cancer Genome Atlas (TCGA) and analyzed to reveal the correlation of leptin with clinical outcomes and the hierarchical clustering of gene signatures based on leptin levels. In addition, cox univariate and multivariate regression analyses, cell migration upon leptin treatment, identification of putative leptin-regulated canonical pathways via ingenuity pathway analysis (IPA), and the investigation of induction of Wnt5a, ROR2, and Jun N-terminal Kinases (JNK) phosphorylation activation were performed. We first observed a correlation of high leptin levels and poor outcomes in RCC patients. Knowledge-based analysis by IPA indicated the induction of cancer cell migration by leptin, which was manifested via direct leptin treatment in the RCC cell lines. In RCC patients with high leptin levels, the planar cell polarity (PCP)/JNK signaling pathway was shown to be activated, and genes in the axis, including CTHRC1, FZD2, FZD10, ROR2, WNT2, WNT4, WNT10B, WNT5A, WNT5B, and WNT7B, were upregulated. All of these genes were associated with unfavorable clinical outcomes. WNT5A and ROR2 are pivotal upstream regulators of PCP/JNK signaling, and their correlations with leptin expression levels were displayed by a Pearson correlation analysis. The inhibition of signal transduction by SP600125 reversed leptin-mediated cell migration properties in RCC cell lines. The results indicate the prognostic impact of leptin on RCC patients and uncover its ability to promote cell migration via PCP/JNK signaling.

The emerging role of Wnt5a in the promotion of a pro-inflammatory and immunosuppressive tumor microenvironment

Wnt5a is the prototypical activator of the non-canonical Wnt pathways, and its overexpression has been implicated in the progression of several tumor types by promoting cell motility, invasion, EMT, and metastasis. Recent evidences have revealed a novel role of Wnt5a in the phosphorylation of the NF-κB subunit p65 and the activation of the NF-κB pathway in cancer cells. In this article, we review the molecular mechanisms and mediators defining a Wnt5a/NF-κB signaling pathway and propose that the aberrant expression of Wnt5a in some tumors drives a Wnt5a/NF-κB/IL-6/STAT3 positive feedback loop that amplifies the effects of Wnt5a. The evidences discussed here suggest that Wnt5a has a double effect on the tumor microenvironment. First, it activates an autocrine ROR1/Akt/p65 pathway that promotes inflammation and chemotaxis of immune cells. Then, Wnt5a activates a TLR/MyD88/p50 pathway exclusively in myelomonocytic cells promoting the synthesis of the anti-inflammatory cytokine IL-10 and a tolerogenic phenotype. As a result of these mechanisms, Wnt5a plays a negative role on immune cell function that contributes to an immunosuppressive tumor microenvironment and would contribute to resistance to immunotherapy. Finally, we summarized the development of different strategies targeting either Wnt5a or the Wnt5a receptor ROR1 that can be helpful for cancer therapy by contributing to generate a more immunostimulatory tumor microenvironment.

Secreted Frizzled Related Proteins in Cardiovascular and Metabolic Diseases

Abnormal gene expression and secreted protein levels are accompanied by extensive pathological changes. Secreted frizzled related protein (SFRP) family members are antagonistic inhibitors of the Wnt signaling pathway, and they were recently found to be involved in the pathogenesis of a variety of metabolic diseases, which has led to extensive interest in SFRPs. Previous reports highlighted the importance of SFRPs in lipid metabolism, obesity, type 2 diabetes mellitus and cardiovascular diseases. In this review, we provide a detailed introduction of SFRPs, including their structural characteristics, receptors, inhibitors, signaling pathways and metabolic disease impacts. In addition to summarizing the pathologies and potential molecular mechanisms associated with SFRPs, this review further suggests the potential future use of SFRPs as disease biomarkers therapeutic targets.

Bariatric Surgery Outcomes in Patients with Latent Autoimmune Diabetes of the Adult

Bariatric surgery is a very effective treatment for obesity-associated type 2 diabetes. However, the benefits of bariatric surgery in patients with obesity and autoimmune diabetes, such as type 1 diabetes and latent autoimmune diabetes in adults (LADA), are controversial. We report 3 female patients with obesity and LADA who underwent laparoscopic Roux-en-Y gastric bypass >10 years ago. The patients were diagnosed with LADA both 1 and 9 years before (n = 2) or 11 years after the surgery (n = 1). Patients preoperative body mass index ranged from 36 to 47 kg/m2 and improved to 23-37 kg/m2 in the last follow-up visit, 10-15 years after surgery. Daily insulin dose also decreased from an average of 0.68 to 0.45 IU/kg in those patients treated with insulin before bariatric surgery. Only one patient developed diabetes-related target organ damage. This study shows that patients with LADA depict remarkable reduction of body weight and insulin requirements over long-term after bariatric surgery. So, LADA should not be considered a contraindication for bariatric surgery yet should only be recommended for patients with concomitant obesity with the primary aim of achieving sustained weight loss.

The Interplay of WNT and PPARγ Signaling in Vascular Calcification

Vascular calcification (VC), the ectopic deposition of calcium phosphate crystals in the vessel wall, is one of the primary contributors to cardiovascular death. The pathology of VC is determined by vascular topography, pre-existing diseases, and our genetic heritage. VC evolves from inflammation, mediated by macrophages, and from the osteochondrogenic transition of vascular smooth muscle cells (VSMC) in the atherosclerotic plaque. This pathologic transition partly resembles endochondral ossification, involving the chronologically ordered activation of the β-catenin-independent and -dependent Wingless and Int-1 (WNT) pathways and the termination of peroxisome proliferator-activated receptor γ (PPARγ) signal transduction. Several atherosclerotic plaque studies confirmed the differential activity of PPARγ and the WNT signaling pathways in VC. Notably, the actively regulated β-catenin-dependent and -independent WNT signals increase the osteochondrogenic transformation of VSMC through the up-regulation of the osteochondrogenic transcription factors SRY-box transcription factor 9 (SOX9) and runt-related transcription factor 2 (RUNX2). In addition, we have reported studies showing that WNT signaling pathways may be antagonized by PPARγ activation via the expression of different families of WNT inhibitors and through its direct interaction with β-catenin. In this review, we summarize the existing knowledge on WNT and PPARγ signaling and their interplay during the osteochondrogenic differentiation of VSMC in VC. Finally, we discuss knowledge gaps on this interplay and its possible clinical impact.

Sfrp5/Wnt5a and leptin/adiponectin levels in the serum and the periarterial adipose tissue of patients with peripheral arterial occlusive disease

BACKGROUND

Leptin, adiponectin, secreted frizzled-related protein 5 (Sfrp5) and wingless-type family member 5a (Wnt5a) are novel adipokines that are involved in insulin sensitivity and atherosclerosis. The aim of the present study was to investigate the serum and periarterial adipose tissue leptin/adiponectin and Sfrp5/Wnt5a levels in patients with peripheral arterial occlusive disease (PAOD).

METHODS

A total of 75 patients with PAOD and 39 control subjects were recruited. The serum concentrations of leptin, adiponectin, Sfrp5 and Wnt5a were measured by ELISAs, and the leptin, adiponectin, Sfrp5 and Wnt5a levels in the periarterial adipose tissue were observed by western blotting.

RESULTS

The serum Sfrp5 levels were significantly lower in the patients with PAOD than in the control subjects (p < 0.001) and Wnt5a levels were higher in the patients with PAOD (p < 0.001). The serum leptin levels were significantly higher in the patients with PAOD than in the control subjects (p < 0.001), and adiponectin levels were significantly lower in the patients with PAOD (p < 0.001). The serum Sfrp5 levels were associated with ABI (rs = 0.274; p = 0.018), Wnt5a (rs = -0.409; p < 0.001), adiponectin (rs = 0.244; p = 0.035) and Leptin/Adiponetin ratio (rs = -0.244; p = 0.037). The adiponectin and Sfrp5 protein levels were decreased in the periarterial adipose tissue of patients with PAOD compared with control subjects. The leptin and Wnt5a protein levels were increased in the periarterial adipose tissue of patients with PAOD compared with control subjects.

CONCLUSION

We demonstrated that the adiponectin and Sfrp5 levels in the serum and periarterial adipose tissue were significantly lower in the patients with PAOD than in the control subjects. The leptin and Wnt5a levels in the serum and periarterial adipose tissue were significantly higher in the patients with PAOD than in the control subjects.

PM2.5 Induces the Expression of Inflammatory Cytokines via the Wnt5a/Ror2 Pathway in Human Bronchial Epithelial Cells

Background and Purpose

Recently, fine particulate matter (PM2.5) was identified as the main exposure risk for COPD, and inflammation is central to the development of COPD. In this study, we investigated whether PM2.5 can induce the secretion of interleukin-6 (IL-6), IL-8 and IL-1β in human bronchial epithelial cells (HBECs) in vitro via the wingless-related integration site 5A (Wnt5a)/receptor tyrosine kinase-like orphan receptor 2 (Ror2) signaling.

Methods

The expression of Wnt5a and Ror2 was assessed by immunohistochemistry in motor vehicle exhaust (MVE)-induced Sprague-Dawley rats. HBECs were transfected with small interfering RNA (siRNA) targeting Wnt5a or Ror2 and subsequently stimulated with PM2.5.The secretion of IL-6, IL-8 and IL-1β was assessed by ELISAs, and the expression of Wnt5a/Ror2 signaling were assessed by RT-PCR and Western blotting.

Results

Both Wnt5a and Ror2 protein were increased in the lung of MVE-induced rats. HBECs exposed to PM2.5 for 24 h significantly upregulated Wnt5a and Ror2 expression and subsequently promoted the nuclear translocation of NF-κB, which increased the production of IL-1β, IL-6 and IL-8. Wnt5a siRNA prevented these outcomes. Wnt5a antagonist (BOX5) also prevented inflammatory effects. Furthermore, Ror2 siRNA blocked the NF-κB activity and inhibited the release of IL-6, IL-8 and IL-1β from PM2.5-exposed HBECs.

Conclusion

PM2.5 induces the secretion of IL-6, IL-8 and IL-1β in HBECs via the Wnt5a/Ror2 signaling, demonstrating a novel mechanism for PM2.5-associated airway inflammation.

Enhancing insulin sensitivity by dual PPARγ partial agonist, β-catenin inhibitor: Design, synthesis of new αphthalimido-o-toluoyl2-aminothiazole hybrids

AIMS

Partial PPARγ agonists attracted substantially heightened interest as safer thiazolidinediones alternatives. On the other hand, Wnt/β-catenin antagonists have been highlighted as promising strategy for type 2 diabetes management via up-regulating PPARγ gene expression. We aimed at synthesizing novel partial PPARγ agonists with β-catenin inhibitory activity which could enhance insulin sensitivity and avoid the side effects of full PPARγ agonists.

MAIN METHODS

We synthesized novel series of α-phthlimido-o-toluoyl-2-aminothiazoles hybrids for evaluating their antidiabetic activity and discovering its mechanistic pathway. We assessed effect of the new hybrids on PPARγ activation using a luciferase reporter assay system. Moreover, intracellular triglyceride levels, gene levels of c/EBPα, PPARγ and PPARγ targets including GLUT4, adiponectin, aP2 were measured in 3T3-L1 cells. Uptake of 2-DOG together with PPARγ and β-catenin protein levels were evaluated in 3T3-L1cells. In addition, molecular docking studies with PPARγ LBD, physicochemical properties and structure activity relationship of the novel hybrids were also studied.

KEY FINDINGS

Three of the synthesized hybrids showed partial PPARγ agonistic activity and distinct PPARγ binding pattern. These compounds modulated PPARγ gene expression and PPARγ target genes; and increased glucose uptake in 3T3-L1 and slightly induced adipogenesis compared to rosiglitazone. Moreover, these compounds reduced β-catenin protein level which reflected in increased both PPARγ gene and protein levels that leads to improved insulin sensitivity and increased GLUT4 and adiponectin gene expression.

SIGNIFICANCE

Our synthesized compounds act as novel partial PPARγ agonists and β-catenin inhibitors that have potent insulin sensitizing activity and mitigate the lipogenic side effects of TZDs.

High preoperative levels of circulating SFRP5 predict better prognosis in colorectal cancer patients

The purpose of this research was to investigate the diagnostic and prognostic value of circulating SFRP5 (cSFRP5) in colorectal cancer (CRC). We evaluated preoperative cSFRP5 levels in CRC patients and controls (n = 208). We found significantly higher cSFRP5 levels in CRC patients compared with non-CRC controls (p < 0.001). Levels of cSFRP5 were significantly lower in CRC patients with either vascular invasion (p = 0.001) or liver metastasis (p = 0.016). High cSFRP5 levels were associated with longer disease-free survival in both univariate (p = 0.024) and multivariate (p = 0.015) analyses. Analysis of an independent tissue cohort from The Cancer Genome Atlas database revealed significantly lower SFRP5 RNA expression in CRC tumor tissue compared with adjacent normal mucosa (n = 590 vs 47; p < 0.0001). Our findings confirm the role of cSFRP5 as a physiologic tumor suppressor and demonstrate its potential diagnostic and prognostic value in CRC.

Emerging functions of adipokines in linking the development of obesity and cardiovascular diseases

Increasing evidence shows that obesity is the critical factor in shaping cardio-metabolic phenotypes. However, the pathogenic mechanisms remain incompletely clarified. According to the published reports, adipose tissue communicates with several diverse organs, such as heart, lungs, and kidneys through the secretion of various cytokines named adipokines. The adipocytes isolated from obese mice or humans are dysfunctional with aberrant production of pro-inflammatory adipokines, which subsequently induce both acute and chronic inflammatory reaction and facilitate the process of cardio-metabolic disorder complications. Furthermore, the microenvironment within adipose tissue under obese status also influence the secretion of adipokines. Recently, given that several important adipokines have been completely researched and causally involved in various diseases, we could make a conclusion that adipokines play an essential role in modulating the development of cardio-metabolic disorder diseases, whereas several novel adipokines continue to be explored and elucidated. In the present review, we summarized the current knowledge of the microenvironment of adipose tissue and the published mechanisms whereby adipocytes affects obesity and cardiovascular diseases. On the other hand, we also provide the evidence to elucidate the functions of adipokines in controlling and regulating the inflammatory reactions which contribute to obesity and cardiovascular disease.

Newly Discovered Adipokines: Pathophysiological Link Between Obesity and Cardiometabolic Disorders

With the increasing prevalence of obesity, obesity-related problems such as cardiometabolic disorders (CMD), are also rapidly increasing. To prevent and alleviate the progressive course of CMD, it is important to discover the pathophysiological mechanisms between obesity and CMD. Adipose tissue is now recognized as an active endocrine organ that releases adipokines. Adipokines play a pivotal role in chronic low-grade inflammation, oxidative stress, and impaired insulin signaling, contributing to metabolic derangement and leading to CMD. Recent studies have provided substantial evidence supporting the association between adipokines and CMD. In this review, we highlight the pathophysiological action of adipokines in CMD that includes metabolic syndrome, type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular diseases. We focused on translational and clinical research of novel adipokines associated with metabolic and cardiovascular regulation. Exploration of the role of these adipokines connecting obesity and CMD may provide a perspective on adipokine-based therapeutic implications for CMD.

Adipose tissue-derived WNT5A regulates vascular redox signaling in obesity via USP17/RAC1-mediated activation of NADPH oxidases

Obesity is associated with changes in the secretome of adipose tissue (AT), which affects the vasculature through endocrine and paracrine mechanisms. Wingless-related integration site 5A (WNT5A) and secreted frizzled-related protein 5 (SFRP5), adipokines that regulate noncanonical Wnt signaling, are dysregulated in obesity. We hypothesized that WNT5A released from AT exerts endocrine and paracrine effects on the arterial wall through noncanonical RAC1-mediated Wnt signaling. In a cohort of 1004 humans with atherosclerosis, obesity was associated with increased WNT5A bioavailability in the circulation and the AT, higher expression of WNT5A receptors Frizzled 2 and Frizzled 5 in the human arterial wall, and increased vascular oxidative stress due to activation of NADPH oxidases. Plasma concentration of WNT5A was elevated in patients with coronary artery disease compared to matched controls and was independently associated with calcified coronary plaque progression. We further demonstrated that WNT5A induces arterial oxidative stress and redox-sensitive migration of vascular smooth muscle cells via Frizzled 2-mediated activation of a previously uncharacterized pathway involving the deubiquitinating enzyme ubiquitin-specific protease 17 (USP17) and the GTPase RAC1. Our study identifies WNT5A and its downstream vascular signaling as a link between obesity and vascular disease pathogenesis, with translational implications in humans.

Host Wnt5a Potentiates Microenvironmental Regulation of Ovarian Cancer Metastasis

The noncanonical Wnt ligand Wnt5a is found in high concentrations in ascites of women with ovarian cancer. In this study, we elucidated the role of Wnt5a in ovarian cancer metastasis. Wnt5a promoted ovarian tumor cell adhesion to peritoneal mesothelial cells as well as migration and invasion, leading to colonization of peritoneal explants. Host components of the ovarian tumor microenvironment, notably peritoneal mesothelial cells and visceral adipose, secreted Wnt5a. Conditional knockout of host WNT5A significantly reduced peritoneal metastatic tumor burden. Tumors formed in WNT5A knockout mice had elevated cytotoxic T cells, increased M1 macrophages, and decreased M2 macrophages, indicating that host Wnt5a promotes an immunosuppressive microenvironment. The Src family kinase Fgr was identified as a downstream effector of Wnt5a. These results highlight a previously unreported role for host-expressed Wnt5a in ovarian cancer metastasis and suggest Fgr as a novel target for inhibition of ovarian cancer metastatic progression.Significance: This study establishes host-derived Wnt5a, expressed by peritoneal mesothelial cells and adipocytes, as a primary regulator of ovarian cancer intraperitoneal metastatic dissemination and identifies Fgr kinase as novel target for inhibition of metastasis.

Research update on the association between SFRP5, an anti-inflammatory adipokine, with obesity, type 2 diabetes mellitus and coronary heart disease

Secreted frizzled-related protein 5 (SFRP5), an anti-inflammatory adipokine secreted by adipocytes, has been demonstrated to exert its anti-inflammatory effect via antagonizing the non-canonical wingless-type family member 5A (WNT5A) signalling pathways. The WNT5A protein, as a potent pro-inflammatory signalling molecule, is strongly involved in a variety of inflammatory disorders such as obesity, type 2 diabetes mellitus (T2DM) and atherosclerosis. In this review, we systematically outlined the current understanding on the roles of SFRP5 in the pathogenesis of three inflammatory diseases including obesity, T2DM and coronary heart disease (CHD). Our review might stimulate future research using SFRP5 as a promising novel therapeutic target for the treatment of obesity, T2DM and CHD.

Expression of Sfrp5/Wnt5a in human epicardial adipose tissue and their relationship with coronary artery disease

Secreted frizzled-related protein 5 (Sfrp5) primarily acts in combination with wingless-type family member 5a (Wnt5a), to inhibits chronic inflammation and repress atherosclerosis and other metabolic disorders. Epicardial adipose tissue (EAT), surrounding the heart and coronary arteries, has been found to be highly related to the progression of coronary artery disease through adipokines production. However, little is known about EAT-derived Sfrp5 and Wnt5a in humans. We aimed to investigate whether the EAT-derived Sfrp5/Wnt5a levels are altered in patients with CAD. Fifty-eight patients with CAD and 29 patients without CAD who underwent cardiac surgery were enrolled. Serum samples and paired adipose biopsies from EAT and subcutaneous adipose tissue (SAT) were collected, and Sfrp5 and Wnt5a levels were detected. Correlation and multivariate regression analyses were performed to determine the relationship between Sfrp5/Wnt5a expression and CAD and other clinical risk factors. According to the results, the CAD group had lower Sfrp5 and higher Wnt5a levels in EAT and serum (all p < 0.05). Serum Sfrp5 levels were significantly lower in CAD patients with impaired myocardial function. EAT Sfrp5 mRNA levels and serum Sfrp5 levels were both negatively associated with the presence of CAD, after adjustment for known biomarkers, EAT mRNA and serum Wnt5a levels correlated positively with the presence of CAD. Thus, we concluded that low Sfrp5 and high Wnt5a levels are associated with the presence of CAD, independent of other conventional risk factors.

Adipocyte-derived SFRP5 inhibits breast cancer cells migration and invasion through Wnt and epithelial-mesenchymal transition signaling pathways

Objective

Obesity is closely associated with metastasis in breast cancer patients. Secreted frizzled-related protein 5 (SFRP5), one of the novel adipokines with anti-inflammatory properties, is associated with obesity. This study aims to study the role of SFRP5 in the crosstalk between obesity and breast cancer metastasis and identify the underlying mechanism.

Methods

3T3-L1 pre-adipocytes were differentiated to mature adipocytes and a hypertrophic adipocyte model was induced with palmitic acid (PA). Cell motility was measured in MDA-MB-231 and MCF-7 breast cancer cells co-cultured with adipocytes conditioned medium (CM) with or without SFRP5 protein. Wnt and epithelial-mesenchymal transition (EMT) signal pathways were investigated by western blot. Circulating SFRP5 level in 218 breast cancer patients and the association with clinicopathologic characteristics of breast cancer were further determined. Online databases ENCORI and PREDICT Plus were used to exam the link between SFRP5 and prognosis.

Results

Reduced SFRP5 level was detected in the hypertrophic adipocyte model. Recombinant SFRP5 protein inhibited MDA-MB-231 and MCF-7 cells invasion and migration induced by PA-treated adipocyte CM, and SFRP5 inhibition by specific antibody reversed the effect of SFRP5. Furthermore, SFRP5 significantly inhibited Wnt and downstream EMT in breast cancer cells. Low circulating SFRP5 level correlated with body mass index (BMI), lymph node (LN) metastasis, TNM stage and high Ki67 expression in breast cancer patients. Increased SFRP5 level was associated with favorable predicted survival. Kaplan-Meier curves showed high SFRP5 level in tumor tissue was associated with better outcome of breast cancer patients.

Conclusions

Our findings demonstrated SFRP5 is a vital adipokine that mediates the crosslink between obesity and the metastatic potential of breast cancer. Promotion of SFRP5 expression in the adipose microenvironment may represent a novel approach for preventing breast cancer metastasis.

Wnt signaling mediates TLR pathway and promote unrestrained adipogenesis and metaflammation: Therapeutic targets for obesity and type 2 diabetes

Diabesity is the combination of type 2 diabetes and obesity characterized by chronic low-grade inflammation. The Wnt signaling act as an evolutionary pathway playing crucial role in regulating cellular homeostasis and energy balance from hypothalamus to metabolic organs. Aberrant activity of certain appendages in the canonical and non-canonical Wnt system deregulates metabolism and leads to adipose tissue expansion, this key event initiates metabolic stress causing metaflammation and obesity. Metaflammation induced obesity initiates abnormal development of adipocytes mediating through the non-canonical Wnt signaling inhibition of canonical Wnt pathway to fan the flames of adipogenesis. Moreover, activation of toll like receptor (TLR)-4 signaling in metabolic stress invites immune cells to release pro-inflammatory cytokines for recruitment of macrophages in adipose tissues, further causes polarization of macrophages into M1(classically activated) and M2 (alternatively activated) subtypes. These events end with chronic low-grade inflammation which interferes with insulin signaling in metabolic tissues to develop type 2 diabetes. However, there is a dearth in understanding the exact mechanism of Wnt-TLR axis during diabesity. This review dissects the molecular facets of Wnt and TLRs that modulates cellular components during diabesity and provides current progress, challenges and alternative therapeutic strategies at preclinical and clinical level.

Raloxifene inhibits adipose tissue inflammation and adipogenesis through Wnt regulation in ovariectomized rats and 3 T3-L1 cells

BACKGROUND

Loss of ovarian function, as in menopause or after ovariectomy (OVX), is closely associated with obesity and white adipose tissue (WAT) inflammation. Estrogen replacement protects against postmenopausal obesity but increases the risks of carcinogenesis. In the present study, we investigated the effects of long-term treatment of raloxifene (RAL), a selective estrogen receptor modulator, on the features of estrogen deficiency-induced obesity and explored the involvement of canonical and non-canonical Wnt regulation in vivo and in vitro.

METHODS

Adult female rats received bilateral OVX and divided into 5 groups: (1) Sham, (2) OVX, (3) OVX + E₂: OVX rats were administered with E₂ (50 μg/kg, s.c., 3 times/week), (4) OVX + RAL: OVX rats were treated with RAL (gavage, 1 mg/kg/day) suspended in 0.8% carboxymethylcellulose (CMC), (5) OVX + CMC: 0.8% CMC as vehicle control. All treatments were given for 8 weeks beginning at 1 week after OVX. In 3 T3-L1 cells, the effects of RAL on adipogenesis and lipopolysaccharide (LPS)-induced inflammation were evaluated.

RESULTS

Treatment with RAL significantly decreased body weight, visceral fat pad mass, adipocyte size and plasma levels of glucose but increased plasma adiponectin. RAL reduced the elevation of HIF-1α, VEGF-A and proinflammatory cytokines (MCP-1 and TNF-α) expression by inhibition of NF-κB p65 and JNK cascades in retroperitoneal WAT. This anti-inflammatory capacity of RAL may result from upregulation of secreted frizzle-related protein 5 (SFRP5), an adipokine that repressed Wnt5a signaling. Furthermore, RAL inhibited adipogenic factors such as PPAR-γ, C/EBP-α, and FABP4, and preserved canonical Wnt10b/β-catenin protein expression. In 3 T3-L1 adipocytes, RAL (20 μM) diminished lipid accumulation and inhibited adipogenic factors accompanied with the induction of β-catenin, which were effectively reversed by the β-catenin inhibitor IWR-1-endo. In addition, RAL reduced LPS-induced NF-κB p65 and p-IκB expression as well as TNF-α secretion. Suppression of SFRP5 by small interfering RNA significantly abrogated the anti-inflammatory effects of RAL.

CONCLUSIONS

Distinct activation of canonical β-catenin on inhibition of adipogenesis and non-canonical SFRP5 on suppression of WAT inflammation may contribute to the beneficial effects of RAL. Therefore, this study provides a rationale for the therapeutic potential of RAL for postmenopausal obesity.

Alprostadil attenuates LPS-induced cardiomyocyte injury by inhibiting the Wnt5a/JNK/NF-κB pathway

Background

Clinical research has demonstrated that alprostadil has an anti-inflammatory effect; however, to date, its molecular mechanisms remain unclear. This study aimed to examine the anti-inflammatory activity and related mechanisms of alprostadil in lipopolysaccharide (LPS)-treated H9c2 cells.

Methods

Cell morphology was observed under an inverted light microscope, while cell viability was assessed with the 3‑(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay. Enzyme-linked immunosorbent assays (ELISA) were conducted to study biochemical indicators of cellular damage, such as released lactate dehydrase (LDH) and troponin, and inflammatory cytokine levels including interleukin-1β (IL-1β), IL-6, IL-17, and tumor necrosis factor-α (TNF-α). The mRNA expression levels of Wnt5a, c‑jun N‑terminal kinase (JNK), and nuclear factor kappa B (NF-κB) were further investigated by real-time quantitative polymerase chain reaction (RT-PCR). The effects of alprostadil on the Wnt5a/JNK/NF-κB pathway in H9c2 cells was examined by Western blotting.

Results

Alprostadil increased the cell viability of LPS-stimulated H9c2 cells, reduced LDH and troponin production, and attenuated IL-1β, IL-6, IL-17, and TNF-α secretion. Moreover, alprostadil reduced the mRNA expression of Wnt5a, JNK, and NF-κB and decreased the expression of Wnt5a, NF-κB, and the ratio of p‑JNK/JNK in H9c2 cells treated with LPS. The siWnt5a or JNK inhibitor SP600125 significantly augmented the inhibitory effects of alprostadil on the Wnt5a/JNK/NF-κB pathway.

Conclusion

Our results show that alprostadil has anti-inflammatory effects and could attenuate LPS-induced injury in H9c2 cardiomyocytes via the Wnt5a/JNK/NF-κB pathway.

Sfrp5/Wnt Pathway: A Protective Regulatory System in Atherosclerotic Cardiovascular Disease

Adipose tissue stores energy and is the largest endocrine organ in the body, producing several adipokines. However, among these adipokines, few play a role in the positive metabolism that promotes good health. Secreted frizzled-related protein (Sfrp)-5, an antagonist that directly binds to Wnt, has attracted interest due to its favorable effects on atherosclerotic cardiovascular disease (ASCVD). This review focuses on Sfrp5 biology and the roles of the Sfrp5/Wnt system in ASCVD.

Sfrp5 increases glucose-stimulated insulin secretion in the rat pancreatic beta cell line INS-1E

Previous studies reported that secreted frizzled-related protein-5 (Sfrp5) decreases beta cell proliferation and increases fasting insulin levels, but studies on direct effects of Sfrp5 on insulin secretion and its underlying mechanisms are missing. This study examined effects of Sfrp5 on (i) beta cell viability and proliferation, (ii) basal and glucose-stimulated insulin secretion and (iii) canonical and non-canonical Wnt signalling pathways. We incubated rat INS-1E cells with 0.1, 1 or 5 μg/ml recombinant Sfrp5 for 24h. We measured basal and glucose-stimulated insulin secretion at glucose concentrations of 2.5 and 20 mmol/l. Phosphorylated and total protein content as well as mRNA levels of markers of cell proliferation, canonical and non-canonical Wnt signalling pathways were examined using Western blotting and real-time PCR. Differences between treatments were analysed by repeated measurement one-way ANOVA or Friedman’s test followed by correction for multiple testing using the Benjamini-Hochberg procedure. At 5 μg/ml, Sfrp5 reduced mRNA levels of cyclin-B1 by 25% (p<0.05). At 1 and 5 μg/ml, Sfrp5 increased glucose-stimulated insulin secretion by 24% and by 34% (both p<0.05), respectively, but had no impact on basal insulin secretion. Sfrp5 reduced the phosphorylation of the splicing forms p46 and p54 of JNK by 39% (p<0.01) and 49% (p<0.05), respectively. In conclusion, Sfrp5 reduced markers of cell proliferation, but increased in parallel dose-dependently glucose-stimulated insulin secretion in INS-1E cells. This effect is likely mediated by reduced JNK activity, an important component of the non-canonical Wnt signalling pathway.

Cinnamon extract combined with high-intensity endurance training alleviates metabolic syndrome via non-canonical WNT signaling

OBJECTIVES

The incidence of metabolic syndrome (MetS) in menopausal women is one of the main health care concerns. MetS clusters are related to an imbalance in pro- and anti-inflammatory adipokines such as secreted frizzled-related protein 5 (SFRP5) and wingless-type mammary tumor virus integration site family, member 5A (WNT5A). WNT5A induces an inflammatory state to induce insulin resistance and further pathologic consequences. Recent strategies to prevent progression of MetS to diabetes have focused on conservative treatments such as exercise and herbal medicine. The aim of this study was to investigate the mechanistic effects of cotreatment with cinnamon extract and 12-wk high-intensity endurance training on MetS components considering the non-canonical WNT5A signaling.

METHOD

Thirty-two female ovariectomized Wistar rats were divided into the following four groups (n = 8/group): exercise (Ova+Exe), cinnamon extract (Ova+Cin), exercise with cinnamon extract (Ova+Exe+Cin) and saline (Ova+Sal). One group of rats undergoing surgery without removal of the ovaries was considered as a sham. After 3 mo of experimental intervention, waist circumference, serum concentrations of glucose, insulin, lipid profile, tumor necrosis factor-α, WNT5A, and SFRP5 were measured.

RESULTS

Data showed a significant reduction in serum glucose, low-density lipoprotein, homeostasis model assessment estimate of insulin resistance, and tumor necrosis factor-α, but an increase in SFRP5 level in Ova+Exe, Ova+Cin and Ova +Exe+Cin groups compared with Ova+Sal group (P < 0.05). Serum WNT5A significantly was reduced only in Ova+Exe+Cin group (P = 0.02).

CONCLUSION

The present study indicated that high-endurance training combined with aqueous cinnamon extract supplementation for 12 wk more efficiently alleviated insulin resistance and metabolic dysfunctions via reduction in noncanonical WNT signaling in ovariectomized rats.