Asprosin attenuates insulin signaling pathway through PKCδ‐activated ER stress and inflammation in skeletal muscle

Asprosin contributes to vascular remodeling in hypertensive rats via superoxide signaling

OBJECTIVE

Proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to vascular remodeling. Asprosin, a newly discovered protein hormone, is involved in metabolic diseases. Little is known about the roles of asprosin in cardiovascular diseases. This study focused on the role and mechanism of asprosin on VSMC proliferation and migration, and vascular remodeling in a rat model of hypertension.

METHODS AND RESULTS

VSMCs were obtained from the aortic media of 8-week-old male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Asprosin was upregulated in the VSMCs of SHR. For in vitro studies, asprosin promoted VSMC proliferation and migration of WKY and SHR, and increased Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity, NOX1/2/4 protein expressions and superoxide production. Knockdown of asprosin inhibited the proliferation, migration, NOX activity, NOX1/2 expressions and superoxide production in the VSMCs of SHR. The roles of asprosin in promoting VSMC proliferation and migration were not affected by hydrogen peroxide scavenger, but attenuated by superoxide scavenger, selective NOX1 or NOX2 inhibitor. Toll-like receptor 4 (TLR4) was upregulated in SHR, TLR4 knockdown inhibited asprosin overexpression-induced proliferation, migration and oxidative stress in VSMCs of WKY and SHR. Asprosin was upregulated in arteries of SHR, and knockdown of asprosin in vivo not only attenuated oxidative stress and vascular remodeling in aorta and mesentery artery, but also caused a subsequent persistent antihypertensive effect in SHR.

CONCLUSIONS

Asprosin promotes VSMC proliferation and migration via NOX-mediated superoxide production. Inhibition of endogenous asprosin expression attenuates VSMC proliferation and migration, and vascular remodeling of SHR.

Circulating asprosin concentrations in individuals with new-onset type 2 diabetes and prediabetes

AIMS

This research aimed to clarify the relationship between serum asprosin levels and the occurrence of type 2 diabetes mellitus (T2DM) in light of mixed findings about the role of asprosin in T2DM and the lack of studies on its effects on prediabetic conditions.

METHODS

In this observational analysis the cohort included 252 adults aged22-69 recruitedfromJinan Central Hospital were categorized into three groups, normal glucose tolerance (NGT), impaired glucose regulation (IGR) and T2DM groups. Serum asprosin levels were measured using enzyme linked immunosorbent assay (ELISA). Additionally, all participants underwent assessments of various anthropometric and biochemical markers.

RESULTS

Analysis revealed a notable increase in serum asprosin levels among individuals with newly diagnosed T2DM, with IGR subjects also demonstrating slightly elevated asprosin levels compared to the healthy group. Further stratification by quartiles of asprosin levels revealed a progressive increase in the proportions of IGR + T2DM patients, highlighting a potential association between elevated asprosin and increased T2DM risk. The Receiver Operating Characteristic (ROC) curve analysis for the efficacy of asprosin in identifying IGR + T2DM yielded an area under curve (AUC) of 0.853 (95 % CI: 0.808-0.899), pointing a threshold value of 4.95 ng/ml for asprosin.

CONCLUSIONS

This investigation revealed that individuals with prediabetes and those newly diagnosed with T2DM exhibit increased serum asprosin levels, suggesting that elevated asprosin concentrations are linked to early disturbances in glucose homeostasis.

Effects of atypical antipsychotics on serum asprosin level and other metabolic parameters in patients with schizophrenia

BACKGROUND

In this cross-sectional study, we compared fasting serum asprosin levels and metabolic parameters between patients receiving one of three atypical antipsychotics (olanzapine, risperidone, or aripiprazole) and healthy subjects.

METHODS

The study population included 62 adult outpatients with schizophrenia and 22 healthy controls, matched for age and gender. Patients were in remission and had been on stable monotherapy with one of these atypical antipsychotics for over 6 months. Body Mass Index (BMI) and fasting serum levels of asprosin, glucose, HA1c, insulin, and lipid profile were compared across the investigated groups. Additionally, the number of participants meeting the insulin resistance criterion, defined as homeostasis model assessment for insulin resistance (HOMA-IR) >2.5, as well as the number of participants with elevated BMI levels (men >27 kg/m2, women >25 kg/m2) were compared among the groups.

RESULTS

We observed statistically significant differences in BMI and fasting serum levels of glucose, HA1c, insulin, triglyceride (TG), high-density lipoprotein cholesterol, and asprosin among patients receiving olanzapine or risperidone, as compared to those receiving aripiprazole and healthy subjects. Patients on aripiprazole exhibited values comparable to healthy subjects, whereas those on risperidone or olanzapine showed significantly higher values, with the highest observed in the olanzapine group. Additionally, the prevalence of participants meeting the insulin resistance criterion and those with elevated BMI was also greater in individuals receiving olanzapine or risperidone compared to those on aripiprazole and healthy subjects. Serum asprosin levels showed a significant positive correlation with BMI and several metabolic parameters, including HbA1c, fasting insulin, HOMA-IR, and TG. No significant differences were observed among the investigated groups in terms of serum levels of total cholesterol and low-density lipoprotein cholesterol.

CONCLUSIONS

Our cross-sectional study highlights the association between elevated asprosin levels, weight gain, and metabolic disorders in patients treated with olanzapine and risperidone. Given the bidirectional nature of the relationship between serum asprosin levels and these metabolic disturbances, further research is warranted to elucidate potential causative pathways.

Plasma Asprosin Concentrations are Associated with Progression of Diabetic Kidney Disease

Purpose

To explore the expression of asprosin in subjects with pre-DKD and DKD and to analyze its relationship with kidney injury, inflammation, and glucose and lipid metabolism.

Methods

Based on urine albumin:creatinine ratio (UACr), participants were divided into DM, pre-DKD, and DKD groups. Relevant human physiological and biochemical parameters were detected in the three groups.

Results

We found relatively higher levels of asprosin in both pre-DKD and DKD groups than the DM group. Moreover, data from the Nephroseq database support increased gene expression of asprosin in kidney tissue from DKD patients. Further correlation analysis revealed that the plasma asprosin level was positively correlated with age, waist circumference, waist:hip ratio, systolic blood pressure, creatinine, UACr, triglycerides, HDL-c, fasting insulin, HOMA-IR, and the inflammatory marker G3P and negatively associated with eGFR. Multiple logistical regression analysis showed that asprosin concentration was significantly associated with pre-DKD and DKD after adjusting for sex, age, BMI, WHR, and HOMA-IR, while this correlation was lost after controlling for G3P.

Conclusion

Plasma asprosin is associated with kidney injury in diabetic conditions, and this association might be connected through inflammatory response. Further studies are needed to assess the role and mechanism of asprosin in DKD.

Comparison of HIIT and MICT and further detraining on metabolic syndrome and asprosin signaling pathway in metabolic syndrome model of rats

Physical activity promotes various metabolic benefits by balancing pro and anti-inflammatory adipokines. Recent studies suggest that asprosin might be involved in progression of metabolic syndrome (MetS), however, the underlying mechanisms have not been understood yet. This study aimed to evaluate the effects of high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and further detraining on MetS indices, insulin resistance, serum and the liver levels of asprosin, and AMP-activated protein kinase (AMPK) pathway in menopause-induced MetS model of rats. A total of 64 Wistar rats were used in this study and divided into eight groups: Sham1, OVX1 (ovariectomized), Sham2, OVX2, OVX + HIIT, OVX + MICT, OVX + HIIT + Det (detraining), and OVX + MICT + Det. Animals performed the protocols, and then serum concentrations of asprosin, TNF-α, insulin, fasting blood glucose, and lipid profiles (TC, LDL, TG, and HDL) were assessed. Additionally, the liver expression of asprosin, AMPK, and P-AMPK was measured by western blotting. Both HIIT and MICT caused a significant decrease in weight, waist circumference, BMI (P = 0.001), and serum levels of glucose, insulin, asprosin (P = 0.001), triglyceride, total cholesterol, low-density lipoprotein (LDL), and TNF-α (P = 0.001), but an increase in the liver AMPK, P-AMPK, and P-AMPK/AMPK (P = 0.001), compared with OVX2 noexercised group. MICT was superior to HIIT in reducing serum asprosin, TNF-a, TG, LDL (P = 0.001), insulin, fasting blood glucose, HOMA-IR, and QUEKI index (P = 0.001), but an increase in the liver AMPK, and p-AMPK (P = 0.001). Although after two months of de-training almost all indices returned to the pre exercise values (P < 0.05). The findings suggest that MICT effectively alleviates MetS induced by menopause, at least partly through the activation of liver signaling of P-AMPK and the reduction of asprosin and TNF-α. These results have practical implications for the development of exercise interventions targeting MetS in menopausal individuals, emphasizing the potential benefits of MICT in mitigating MetS-related complications.

Association of serum asprosin with metabolic dysfunction-associated fatty liver disease in older adult type 2 diabetic patients: a cross-sectional study

BACKGROUND

To explore the association of serum asprosin levels with metabolic dysfunction-associated fatty liver disease (MAFLD) in older adults with type 2 diabetes mellitus (T2DM).

METHODS

The cross-sectional study enrolled patients ≥ 65 years old diagnosed with T2DM at two community health service centers between November 2019 and July 2021. Logistic regression was applied to analyze the influencing factors of MAFLD.

RESULTS

Totally 219 cases were included. Compared with diabetic individuals without MAFLD (n = 105), diabetics with MAFLD (n = 114) had younger ages, higher body mass index values, shorter time from T2DM diagnosis, increased waist-to-hip ratios, elevated triglycerides, reduced high-density lipoprotein cholesterol (HDL-C), elevated alanine aminotransferase (ALT), elevated γ-glutaryl transferase, elevated fasting insulin, and elevated HOMA-IR (all P < 0.05). Serum asprosin levels were elevated in diabetics with MAFLD in comparison with the non-MAFLD group (291.71 ± 73.69 vs. 255.24 ± 82.52 pg/ml, P = 0.001). Multivariable analysis revealed, after adjusted for age, time from T2DM diagnosis, HDL-C, and ALT, serum asprosin level (OR = 1.006, 95%CI: 1.001-1.010, P = 0.014) were independently associated with MAFLD in T2DM.

CONCLUSIONS

High asprosin level are associated with MAFLD in older patients with T2DM, after adjusted for age, time from T2DM diagnosis, WHR, TG, HDL-C, ALT, GGT, FINS, and HOMA-IR.

Salivary and serum asprosin hormone levels in the 2018 EFP/AAP classification of periodontitis stages and body mass index status: a case-control study

OBJECTIVES

A newly discovered adipokine known asprosin in serum and saliva in patients with periodontitis has not been explored. The aim of this study was to determine the relationship between serum and saliva asprosin levels and periodontitis by grouping it according to body mass index (BMI).

MATERIALS AND METHODS

The study was conducted on 65 systemically healthy patients (35 patients with periodontitis (periodontitis group), 30 periodontally healthy patients (control group)). In each patient, age, BMI, and clinical periodontal parameters (plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL)) were evaluated. Statistical analyses were conducted utilizing the Student t-test, ANOVA, and Pearson correlation analysis. For the significance level of the tests, p<0.05 were accepted.

RESULTS

The serum and saliva were collected to assess asprosin levels. Both the serum and saliva asprosin levels were statistically significantly higher in the periodontitis group than in the control group (p<0.001). Saliva and serum asprosin levels were directly proportional to the severity of the periodontal disease (p<0.05). Asprosin levels were higher in patients with a higher BMI (p<0.05).

CONCLUSION

Asprosin levels were increased in periodontitis, and even a high BMI status apparently affected the levels of this hormone. It is thought that asprosin may be a useful biomarker in evaluating the relationship between periodontal status and BMI.

CLINICAL RELEVANCE

Asprosin may be a useful parameter as a biomarker of periodontal disease progression. However, BMI status should be considered when evaluating asprosin levels in patients with periodontitis.

Myricetin attenuates hypoxia-induced inflammation in human adipocytes

BACKGROUND

Adipose tissue hypoxia plays a crucial role in the development of chronic low-grade systemic inflammation which has been associated with the pathogenesis of obesity-related diseases. Myricetin is a natural compound present in numerous plant-based foods with presumed anti-inflammatory and beneficial health effects. The impact of this flavonoid on hypoxia-induced expression of inflammatory adipokines and hypoxia-regulated pathways is unknown so far and has been addressed in the present study.

METHODS

Differentiated human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were cultured with or without myricetin under normoxic and hypoxic conditions for varying time periods. The effect of hypoxia and myricetin on the expression of the investigated adipokines was measured by real-time RT-PCR. Western blot analysis was used for the detection of transcription factors involved in hypoxia-regulated pathways.

RESULTS

Myricetin interfered in the hypoxia-induced regulation of adipokines and the underlying pathways, which are involved in transmitting the inflammatory response. It strongly repressed hypoxia-induced expression of apelin, leptin, chemerin, asprosin, and DPP-4 and HIF-1α accumulation in the nucleus was diminished. Furthermore, the activation of the key regulators in the inflammatory response NF-κB, Akt, and CREB was suppressed by myricetin under hypoxic conditions. Myricetin also decreased hypoxia-induced accumulation of the pro-tumorigenic transcription factors Snail and Slug in the nucleus.

CONCLUSION

Taken together, our results indicated that myricetin regulated hypoxia-induced expression of adipokines and hypoxia-regulated pathways in human adipocytes. Our study therefore provided evidence of the anti-inflammatory effects of myricetin in hypoxia-treated human adipocytes.

Increased RBP4 and Asprosin Are Novel Contributors in Inflammation Process of Periodontitis in Obese Rats

There is a significant comorbidity between obesity and periodontitis, while adipokines are pivotal in the immunoinflammatory process, which may play a role in this special relationship. We aimed to assess the effect of adipokines as mediators in the progression of periodontitis in obese Sprague Dawley rats. Rats were divided into four groups: normal body weight with and without periodontitis and obesity with and without periodontitis. Experimental obesity and periodontitis were induced by a high-fat diet or ligaturing, and the effect was measured using metabolic and micro-computed tomography analysis and histological staining. Compared with the other three groups, the group of periodontitis with obesity (OP) had the heaviest alveolar bone absorption, the largest increase in osteoclasts, the utmost inflammatory cell infiltration and the highest expressions of pro-inflammatory cytokines and nuclear factor-kappa B ligand (RANKL); meanwhile, its expression of the osteogenesis-related gene was the lowest among the four groups. The expressions of leptin, visfatin, resistin, retinol-binding protein 4 (RBP4) and asprosin were upregulated, while adiponectin was decreased significantly in OP. The strong positive associations between the periodontal or circulating levels of RBP4 (or asprosin) and the degree of alveolar resorption in experimental periodontitis and obese rats were revealed. The upregulated expression of inflammation biomarkers, the corresponding degradation in connective tissue and the generation of osteoclasts in periodontitis were activated and exacerbated in obesity. The elevated level of RBP4/asprosin may contribute to a more severe periodontal inflammatory state in obese rats.

Asprosin, a novel glucogenic adipokine implicated in type 2 diabetes mellitus

Asprosin, encoded by penultimate two exons (exon 65 and exon 66) of the gene Fibrillin 1 (FBN1), has been recently discovered to be a novel hormone secreted by white adipose tissues during fasting. The glucose metabolism disorders are often accompanied by increased asprosin level. Previous research suggests that asprosin may contribute to the development of diabetes by regulating glucose homeostasis, appetite, insulin secretion, and insulin sensitivity. In this review, we summarize the recent findings from studies on asprosin and its association with Type 2 diabetes mellitus, and discusses its mechanisms from various aspects, so as to provide clinical diagnosis and treatment ideas for T2DM.

Whole-Body Cryotherapy Improves Asprosin Secretion and Insulin Sensitivity in Postmenopausal Women-Perspectives in the Management of Type 2 Diabetes

Type 2 diabetes (T2DM) is a global problem. The effect of whole-body cryotherapy (WBC) on metabolism in humans is postulated. The aim of this study was to determine the effect of WBC on asprosin concentrations, glucose homeostasis and insulin resistance in postmenopausal women with T2DM. Changes in fasting blood glucose (FBG), glycated haemoglobin (HbA1c), insulin, asprosin, insulin-resistance indices (HOMA-IR, Quicki), the triglyceride-glucose index (TyG) and C-reactive protein (CRP) were determined. Determination was carried out after 30 WBCs (3 min, -120 °C), applied in six series of five treatments, with 2-day breaks in postmenopausal women with T2DM and the results were compared to changes in postmenopausal women without T2DM (CON). Blood was collected before 1 WBC (T0), after 30 WBCs (T1) and 2 weeks after their completion (T2). In the T2DM group, there was a significant decrease in FBG and HbA1c in T1 and T2, as well as a significant decrease in insulin, HOMA-IR and CRP, and an increase in the Quicki index in T2. In the CON group, the concentration of asprosin at T2 was significantly lower than at T0. There was a significantly positive correlation between asprosin and FBG and HOMA-IR, and a trend towards a decrease of asprosin concentration in T2 in postmenopausal women with T2DM.

Asprosin, a novel glucogenic adipokine: a potential therapeutic implication in diabetes mellitus

OBJECTIVES

We aimed to investigate the effects of asprosin on diabetes with a focus on serum glucose, irisin, ghrelin, leptin levels and hepatic levels of triglycerides (TG), cholesterol, low-density lipoprotein (LDL).

METHODS

Asprosin (10 µg/kg) was administered intraperitoneally four times at 3-day intervals and then blood and hepatic parameters above mentioned were investigated in control and diabetic mice.

RESULTS

The administration of asprosin increased blood glucose level in healthy animals (p = .05) whereas it did not change blood glucose level in diabetic animals. In addition, while asprosin decreased irisin level and increased ghrelin level, it did not change leptin level in diabetic mice. Therewithal, asprosin decreased the increasing levels in hepatic TG, cholesterol, and LDL in diabetic mice.

CONCLUSIONS

Our novel findings implicate that asprosin may be a target molecule in preventing the development and complications of diabetes.

Can the new adipokine asprosin be a metabolic troublemaker for cardiovascular diseases? A state-of-the-art review

Adipokines play a significant role in cardiometabolic diseases. Asprosin, a newly discovered adipokine, was first identified as a glucose-raising protein hormone. Asprosin also stimulates appetite and regulates glucose and lipid metabolism. Its identified receptors so far include Olfr734 and Ptprd. Clinical studies have found that asprosin may be associated with cardiometabolic diseases. Asprosin may have diagnostic and therapeutic potential in obesity, diabetes, metabolic syndrome and atherosclerotic cardiovascular diseases. Herein, the structure, receptors, and functions of asprosin and its relationship with cardiometabolic diseases are summarized based on recent findings.

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.

Serum Asprosin Correlates with Indirect Insulin Resistance Indices

BACKGROUND AND OBJECTIVES

Insulin resistance is a major contributor to the development of type 2 diabetes and can be assessed using indirect indicators calculated from non-invasive tests. Asprosin is a recently discovered adipokine with a postulated effect on glycemic regulation. This study aimed to investigate the correlation between serum asprosin levels and insulin resistance indices. The correlation between circulating asprosin and obesity indices was also investigated.

MATERIALS AND METHODS

A total of 50 non-diabetic patients with obesity and 50 healthy volunteers were studied. Laboratory data, including circulating asprosin and anthropometric data, were collected. The following insulin resistance indices were calculated: triglyceride-glucose index (TyG), TyG-neck circumference (TyG-NC), TyG-neck circumference to height ratio (TyG-NHtR), TyG-waist circumference (TyG-WC), TyG-waist to height ratio (TyG-WHtR), TyG-body mass index (TyG-BMI), and the ratio between triglycerides and high-density cholesterol (TG/HDLc). The obtained data were analyzed separately for males and females.

RESULTS

Asprosin concentrations were significantly higher in obese patients (p < 0.001). Asprosin concentrations positively correlated with body mass index (p < 0.001, r = 0.8 in females and r = 0.8 in males), waist circumference (p < 0.001, r = 0.73 in females and r = 0.81 in males), and all tested indices of insulin resistance. The strongest correlation was observed for TyG-BMI (p < 0.001, r = 0.78 in females and r = 0.81 in males). Circulating asprosin was higher in females (p < 0.001).

CONCLUSIONS

Asprosin can be considered a marker of obesity and insulin resistance.

Circulating Asprosin Concentrations in Patients with Obesity and Carbohydrate Disturbances

Asprosin is a fasting-induced glucogenic hormone, secreted by white adipose tissue in response to starvation. The aim of the current study was to determine the levels of asprosin in subjects from the entire spectrum of the carbohydrate metabolism. A total of 153 Causcasian subjects participated in this study: group 1, healthy volunteers; group 2, obese subjects without glycemic disturbances; group 3, subjects with prediabetes and group 4, patients with newly identified type 2 diabetes. Subject with body mass index≥30 kg/m2 and dysglycemia (prediabetes and diabetes) showed significantly high levels of asprosin (1.40 ng/ml [IQR=0.98-1.94]; 1.27 ng/ml [IQR=0.86-2.12]; 1.09 ng/ml [IQR=0.89-1.58]) compared to the control group (0.71 ng/ml [IQR=0.54-0.92]; p<0.001). Correlation analysis showed that serum asprosin also had significant positive associations with some anthropometric parameters, liver enzymes, fasting and post load glucose and insulin, LDL and triglycerides. Furthermore, we estimated a marked relationship between asprosin concentrations and intima media thickness of the common carotid artery as well as neuropathy disability and vibration sensitivity. The circulating asprosin levels for differentiating subjects with carbohydrate disturbances and those with obesity were determined by ROC analysis. The AUC for disturbances of the glucose metabolism was 0.672 (p<0.001; 95% CI=0.581-0.751) and for obesity AUC was 0.849 (p<0.001; 95% CI=0.785-0.919). Circulating asprosin could be used as a predictive factor for early carbohydrate disorders and might be a potential new therapeutic target for the treatment of dysglycemia and obesity. Further prospective studies are needed to confirm this observation.

Asprosin Exacerbates Endothelium Inflammation Induced by Hyperlipidemia Through Activating IKKβ-NF-κBp65 Pathway

Vascular endothelium dysfunction caused by endothelium inflammation is a trigger of numerous cardiovascular diseases. Vascular endothelium inflammation often occurs in patients with obesity. Asprosin (ASP) derived from white adipose tissue plays important roles in maintaining glucose homeostasis. However, effect of ASP on the vascular endothelium inflammation induced by hyperlipidemia and its underlying mechanism remains largely unclear. In this study, models of vascular endothelium inflammation were established to investigate the effect of ASP on the endothelium inflammation both in vivo and in vitro. Our data in vivo showed that recombinant ASP or high-fat diet (HFD) significantly increased the circulating levels of IL-6 and TNF-α and enhanced the adhesion of macrophages to endothelia characterized by the expression increase of CD68, ICAM-1, and VCAM-1 in rats. However, neutralization of ASP with an ASP specific antibody (AASP) significantly antagonized the changes induced by HFD. Similarly, our data in vitro also showed that ASP treatment elevated the expressions of IL-6, TNF-α, and ICAM-1 as well as VCAM-1. More important, our data revealed that the pro-inflammation effect of ASP was achieved by activating the IKKβ-NF-κBp65 pathway other than the oxidative stress pathway both in vivo and in vitro. In conclusion, our results demonstrate that ASP is a pro-inflammation player in the obesity-associated endothelium dysfunction. The findings would provide a novel target for the prevention and treatment of obesity-related cardiovascular diseases.

Asprosin Enhances Cytokine Production by a Co-Culture of Fully Differentiated Mature Adipocytes and Macrophages Leading to the Exacerbation of the Condition Typical of Obesity-Related Inflammation

Asprosin, a fasting-induced, glucogenic, and orexigenic adipokine, has gained popularity in recent years as a potential target in the fight against obesity and its complications. However, the contribution of asprosin to the development of moderate obesity-related inflammation remains still unknown. The present study aimed to evaluate the effect of asprosin on the inflammatory activation of adipocyte–macrophage co-cultures at various stages of differentiation. The study was performed on co-cultures of the murine 3T3L1 adipocyte and the RAW264.7 macrophage cell lines treated with asprosin before, during, and after 3T3L1 cell differentiation, with or without lipopolysaccharide (LPS) stimulation. Cell viability, overall cell activity, and the expression and release of key inflammatory cytokines were analyzed. In the concentration range of 50–100 nM, asprosin increased the pro-inflammatory activity in the mature co-culture and enhanced the expression and release of tumor necrosis factor α (TNF-α), high-mobility group box protein 1 (HMGB1), and interleukin 6 (IL-6). Macrophage migration was also increased, which could be related to the upregulated expression and release of monocyte chemoattractant protein-1 (MCP-1) by the adipocytes. In summary, asprosin exerted a pro-inflammatory effect on the mature adipocyte–macrophage co-culture and may contribute to the spread of moderate obesity-associated inflammation. Nevertheless, further research is needed to fully elucidate this process.

Selenium Protects Mouse Hypothalamic Cells from Glucocorticoid-Induced Endoplasmic Reticulum Stress Vulnerability and Insulin Signaling Impairment

The use of glucocorticoid medications is known to cause metabolic side effects such as overeating, excess weight gain, and insulin resistance. The hypothalamus, a central regulator of feeding behavior and energy expenditure, is highly responsive to glucocorticoids, and it has been proposed that it plays a role in glucocorticoid-induced metabolic defects. Glucocorticoids can alter the expression and activity of antioxidant enzymes and promote the accumulation of reactive oxygen species. Recent evidence indicates that selenium can counter the effects of glucocorticoids, and selenium is critical for proper hypothalamic function. This study sought to determine whether selenium is capable of protecting hypothalamic cells from dysfunction caused by glucocorticoid exposure. We treated mHypoE-44 mouse hypothalamic cells with corticosterone to study the effects on cellular physiology and the involvement of selenium. We found that corticosterone administration rendered cells more vulnerable to endoplasmic reticulum stress and the subsequent impairment of insulin signaling. Supplementing the cell culture media with additional selenium alleviated endoplasmic reticulum stress and promoted insulin signaling. These findings implicate a protective role of selenium against chronic glucocorticoid-induced hypothalamic dysfunction.

Asprosin in health and disease, a new glucose sensor with central and peripheral metabolic effects

Adipose tissue malfunction leads to altered adipokine secretion which might consequently contribute to an array of metabolic diseases spectrum including obesity, diabetes mellitus, and cardiovascular disorders. Asprosin is a novel diabetogenic adipokine classified as a caudamin hormone protein. This adipokine is released from white adipose tissue during fasting and elicits glucogenic and orexigenic effects. Although white adipose tissue is the dominant source for this multitask adipokine, other tissues also may produce asprosin such as salivary glands, pancreatic B-cells, and cartilage. Significantly, plasma asprosin levels link to glucose metabolism, lipid profile, insulin resistance (IR), and β-cell function. Indeed, asprosin exhibits a potent role in the metabolic process, induces hepatic glucose production, and influences appetite behavior. Clinical and preclinical research showed dysregulated levels of circulating asprosin in several metabolic diseases including obesity, type 2 diabetes mellitus (T2DM), polycystic ovarian syndrome (PCOS), non-alcoholic fatty liver (NAFLD), and several types of cancer. This review provides a comprehensive overview of the asprosin role in the etiology and pathophysiological manifestations of these conditions. Asprosin could be a promising candidate for both novel pharmacological treatment strategies and diagnostic tools, although developing a better understanding of its function and signaling pathways is still needed.

Fibrillin-1 and asprosin, novel players in metabolic syndrome

Fibrillin-1 is a major component of the extracellular microfibrils, where it interacts with other extracellular matrix proteins to provide elasticity to connective tissues, and regulates the bioavailability of TGFβ family members. A peptide consisting of the C-terminal 140 amino acids of fibrillin-1 has recently been identified as a glucogenic hormone, secreted from adipose tissue during fasting and targeting the liver to release glucose. This fragment, called asprosin, also signals in the hypothalamus to stimulate appetite. Asprosin levels are correlated with many of the pathologies indicative of metabolic syndrome, including insulin resistance and obesity. Previous studies and reviews have addressed the therapeutic potential of asprosin as a target in obesity, diabetes and related conditions without considering mechanisms underlying the relationship between generation of asprosin and expression of the much larger fibrillin-1 protein. Profibrillin-1 undergoes obligatory cleavage at the cell surface as part of its assembly into microfibrils, producing the asprosin peptide as well as mature fibrillin-1. Patterns of FBN1 mRNA expression are inconsistent with the necessity for regulated release of asprosin. The asprosin peptide may be protected from degradation in adipose tissue. We present evidence for an alternative possibility, that asprosin mRNA is generated independently from an internal promoter within the 3' end of the FBN1 gene, which would allow for regulation independent of fibrillin-synthesis and is more economical of cellular resources. The discovery of asprosin opened exciting possibilities for treatment of metabolic syndrome related conditions, but there is much to be understood before such therapies could be introduced into the clinic.

Asprosin Exerts Pro-Inflammatory Effects in THP-1 Macrophages Mediated via the Toll-like Receptor 4 (TLR4) Pathway

Adipose tissue is a dynamic endocrine organ, secreting a plethora of adipokines which play a key role in regulating metabolic homeostasis and other physiological processes. An altered adipokine secretion profile from adipose tissue depots has been associated with obesity and related cardio-metabolic diseases. Asprosin is a recently described adipokine that is released in response to fasting and can elicit orexigenic and glucogenic effects. Circulating asprosin levels are elevated in a number of cardio-metabolic diseases, including obesity and type 2 diabetes. In vitro studies have reported pro-inflammatory effects of asprosin in a variety of tissues. The present study aimed to further elucidate the role of asprosin in inflammation by exploring its potential effect(s) in THP-1 macrophages. THP-1 monocytes were differentiated to macrophages by 48 h treatment with dihydroxyvitamin D3. Macrophages were treated with 100 nM recombinant human asprosin, 100 ng/mL lipopolysaccharide (LPS), and 10 μM caffeic acid phenethyl ester (CAPE; an inhibitor of NFκB activation) or 1 µM TAK-242 (a Toll-like receptor 4, TLR4, inhibitor). The expression and secretion of pertinent pro-inflammatory mediators were measured by qPCR, Western blot, ELISA and Bioplex. Asprosin stimulation significantly upregulated the expression and secretion of the pro-inflammatory cytokines: tumour necrosis factor α (TNFα), interleukin-1β (IL-1β), IL-8 and IL-12 in vitro. This pro-inflammatory response in THP-1 macrophages was partly attenuated by the treatments with CAPE and was significantly inhibited by TAK-242 treatment. Asprosin-induced inflammation is significantly counteracted by TLR4 inhibition in THP-1 macrophages, suggesting that asprosin exerts its pro-inflammatory effects, at least in part, via the TLR4 signalling pathway.

Stachydrine alleviates lipid-induced skeletal muscle insulin resistance via AMPK/HO-1-mediated suppression of inflammation and endoplasmic reticulum stress

OBJECTIVE

Insulin resistance develops due to skeletal muscle inflammation and endoplasmic reticulum (ER) stress. Stachydrine (STA), extracted from Leonurus heterophyllus, has been shown to suppress proliferation and induce apoptosis in breast cancer cells and exert anti-inflammatory properties in the brain, heart, and liver. However, the roles of STA in insulin signaling in skeletal muscle remain unclear. Herein, we examined the impacts of STA on insulin signaling in skeletal muscle under hyperlipidemic conditions and its related molecular mechanisms.

METHODS

Various protein expression levels were determined by Western blotting. Levels of mouse serum cytokines were measured by ELISA.

RESULTS

We found that STA-ameliorated inflammation and ER stress, leading to attenuation of insulin resistance in palmitate-treated C2C12 myocytes. STA dose-dependently enhanced AMPK phosphorylation and HO-1 expression. Administration of STA attenuated not only insulin resistance but also inflammation and ER stress in the skeletal muscle of high-fat diet (HFD)-fed mice. Additionally, STA-ameliorated glucose tolerance and insulin sensitivity, as well as serum TNFα and MCP-1, in mice fed a HFD. Small interfering (si) RNA-associated suppression of AMPK or HO-1 expression abolished the effects of STA in C2C12 myocytes.

CONCLUSIONS

These results suggest that STA activates AMPK/HO-1 signaling, resulting in reduced inflammation and ER stress, thereby improving skeletal muscle insulin resistance. Using STA as a natural ingredient, this research successfully treated insulin resistance and type 2 diabetes.

Effect of Carica papaya on IRS-1/Akt Signaling Mechanisms in High-Fat-Diet-Streptozotocin-Induced Type 2 Diabetic Experimental Rats: A Mechanistic Approach

Despite rigorous endeavors, existing attempts to handle type 2 diabetes (T2DM) are still a long way off, as a substantial number of patients do not meet therapeutic targets. Insulin resistance in skeletal muscle is discerned as a forerunner in the pathogenesis of T2DM and can be detected years before its progress. Studies have revealed the antidiabetic properties of Carica papaya (C. papaya), but its molecular mechanism on insulin receptor substrate-1 (IRS-1)/Akt signaling mechanisms is not yet known. The present study aimed to evaluate the role of C. papaya on IRS1 and Akt in high-fat-diet-streptozotocin-induced type 2 diabetic rats and also to analyze the bioactive compounds of C. papaya against IRS-1 and Akt via in silico analysis. Ethanolic extract of the leaves of C. papaya (600 mg/kg of body weight) was given daily for 45 days postinduction of T2DM up to the end of the study. Gluconeogenic enzymes, glycolytic enzymes, gene expression, and immunohistochemical analysis of IRS-1 and Akt in skeletal muscle were evaluated. C. papaya treatment regulated the levels of gluconeogenic and glycolytic enzymes and the levels of IRS-1 and Akt in skeletal muscle of type 2 diabetic animals. In silico studies showed that trans-ferulic acid had the greatest hit rate against the protein targets IRS-1 and Akt. C. papaya restored the normoglycemic effect in diabetic skeletal muscle by accelerating the expression of IRS-1 and Akt.

Apelin-13 and Asprosin in Adolescents with Anorexia Nervosa and Their Association with Psychometric and Metabolic Variables

Anorexia nervosa (AN) is a widespread, metabo-psychiatric disorder with high relapse rates, comorbidity, and mortality. Many regulatory proteins and neurohormones studied to date play essential roles in the etiopathogenesis of eating disorders and the maintenance of psychopathological symptoms. Nevertheless, the regulatory and pathophysiological mechanisms of AN are still poorly understood. In the presented study, the plasma levels of apelin-13 (APE-13) and asprosin (ASP), as well as carbohydrate metabolism parameters and psychometric parameters, were evaluated in low-weight adolescent female patients with AN (AN1), after partial weight normalization (AN2) and in an age-matched healthy control group (CG) were evaluated. APE-13 levels were higher in the AN1 group than in the post-realimentation and the CG group. APE-13 levels were independent of insulin and glucose levels. Plasma ASP levels increased with increasing body weight in patients with AN, correlating with the severity of eating disorder symptoms in emaciation. The presented data suggest that APE-13 and ASP may be AN’s biomarkers-regulation of eating behavior by APE-13 and ASP, the close relationship between them and emotional behavior, and changes in neurohormone levels in patients with eating and affective disorders seem to support these hypotheses. Moreover, their plasma levels seem to be related to the severity of psychopathological symptoms of eating disorders.

Diet and exercise interventions reduce serum asprosin and the corresponding hypothalamic– pituitary–gonad-axis dysfunction in obese men

Background: Asprosin (ASP) is a recently discovered adipocyte factor that participates in glucose metabolism and inflammatory reactions. Recent findings suggest that it may be involved in the regulation of sex hormone secretion in the hypothalamic-pituitary-gonad (HPG) axis, but no studies have been reported in related populations. The purpose of this study was to evaluate the changes in serum ASP levels in healthy men and obese men, as well as before and after exercise weight loss, and to investigate male hypogonadism, insulin resistance, inflammatory response, and relationships induced by ASP and obesity.

Methods: Thirty-eight young male volunteers were recruited and divided into a normal group (n = 20) and an obese group (n = 18) according to their body mass index. Fourteen of the obese men underwent a 14-week exercise and diet intervention (first 8 weeks of aerobic exercise at 60%–70% HR_max for 30–50 min/4 days a week). Beginning at week 9, the intensity was increased to 75% HR_max. Participants in the obese groups maintained a calorie-restricted diet throughout the study period.

Results: Serum ASP levels in the obese group were significantly higher than those in the normal group, and serum gonadotropin-releasing hormone (GnRh), luteinizing hormone (LH), and testosterone (T) levels were decreased. After 14 weeks of exercise and diet intervention, serum ASP decreased significantly, the levels of body weight, lean body weight, body fat rate, fasting insulin (FINS), homeostatic model assessment for insulin resistance, TNF-α, IL-6, and IL-1β decreased significantly, and the serum GnRH, LH, and T levels increased significantly. ASP was positively correlated with body weight, body fat percentage, FINS, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β and negatively correlated with relative lean body weight and serum LH and T levels.

Conclusion: The serum ASP levels were increased in obese men compared with those of normal weight individuals, resulting in a chronic inflammatory reaction, high serum insulin, and HPG axis injury. Fourteen weeks of exercise and diet intervention effectively alleviated this phenomenon. It has been speculated that ASP might regulate male reproductive function by regulating the inflammatory response and insulin sensitivity.

Association between circulating asprosin levels and carotid atherosclerotic plaque in patients with type 2 diabetes

BACKGROUND

Carotid plaque is one of the typical manifestations and precursors of diabetic cardiovascular complications. As a new adipokine, asprosin participates in the development of diabetes and cardiovascular diseases, and is considered to be closely related to insulin resistance and glucolipid metabolism. This study aimed to analyze the relationship between serum asprosin level and carotid plaque in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 180 patients with T2DM were selected. The basic parameters and biochemical indexes of the subjects were measured, and the serum asprosin concentration of the subjects was detected by ELISA. The carotid plaque was evaluated by color Doppler ultrasound.

RESULTS

The level of serum asprosin in the T2DM with carotid plaque group was significantly higher than that in T2DM without carotid plaque group [2.53(1.73-3.21) vs 1.72(1.23-2.34) ng/mL, P < 0.05]. The incidence of carotid plaque in the low, middle and high quartiles was 31.7 %, 48.3 % and 70 % respectively. Correlation analysis showed that serum asprosin was positively correlated with BMI, WHR, SBP, DBP, FIns, LDL-C, HOMA-IR, and HOMA-β (P < 0.05). Linear regression analysis showed that WHR, DBP, FIns, and LDL-C were independent influencing factors of asprosin. Logistic regression analysis showed that serum asprosin was still significantly correlated with carotid plaque in T2DM patients after adjusting for multiple confounding factors. The area under receiver-operating curve (ROC) of asprosin predicting carotid plaque was 0.701 (0.625-0.777) in T2DM.

CONCLUSION

The level of serum asprosin in T2DM patients with carotid plaques is significantly higher, suggesting that asprosin may play a role in the occurrence and development of carotid plaques in T2DM. Detection of this index can provide new clinical evidence for the prevention and treatment of diabetic cardiovascular disease.

Asprosin inhibits macrophage lipid accumulation and reduces atherosclerotic burden by up-regulating ABCA1 and ABCG1 expression via the p38/Elk-1 pathway

Background

Asprosin, a newly discovered adipokine, is a C-terminal cleavage product of profibrillin. Asprosin has been reported to participate in lipid metabolism and cardiovascular disease, but its role in atherogenesis remains elusive.

Methods

Asprosin was overexpressed in THP-1 macrophage-derived foam cells and apoE^−/− mice using the lentiviral vector. The expression of relevant molecules was determined by qRT-PCR and/or western blot. The intracellular lipid accumulation was evaluated by high-performance liquid chromatography and Oil red O staining. HE and Oil red O staining was employed to assess plaque burden in vivo. Reverse cholesterol transport (RCT) efficiency was measured using [³H]-labeled cholesterol.

Results

Exposure of THP-1 macrophages to oxidized low-density lipoprotein down-regulated asprosin expression. Lentivirus-mediated overexpression of asprosin promoted cholesterol efflux and inhibited lipid accumulation in THP-1 macrophage-derived foam cells. Mechanistic analysis revealed that asprosin overexpression activated p38 and stimulated the phosphorylation of ETS-like transcription factor (Elk-1) at Ser383, leading to Elk-1 nuclear translocation and the transcriptional activation of ATP binding cassette transporters A1 (ABCA1) and ABCG1. Injection of lentiviral vector expressing asprosin diminished atherosclerotic lesion area, increased plaque stability, improved plasma lipid profiles and facilitated RCT in apoE^−/− mice. Asprosin overexpression also increased the phosphorylation of p38 and Elk-1 as well as up-regulated the expression of ABCA1 and ABCG1 in the aortas.

Conclusion

Asprosin inhibits lipid accumulation in macrophages and decreases atherosclerotic burden in apoE^−/− mice by up-regulating ABCA1 and ABCG1 expression via activation of the p38/Elk-1 signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03542-0.

The Effects of Asprosin on Exercise-Intervention in Metabolic Diseases

Fibrillin is the major constituent of extracellular microfibrils, which are distributed throughout connective tissues. Asprosin is derived from the C-terminal region of the FBN1 gene, which encodes profibrillin that undergoes cleavage by furin protein. In response to fasting with low dietary glucose, asprosin is released as a secreted factor from white adipose tissue, and is transported to the liver for the mediation of glucose release into the blood circulation. Through binding to OLFR734, an olfactory G-protein-coupled receptor in liver cells, asprosin induces a glucogenic effect to regulate glucose homeostasis. Bioinformatics analyses revealed that the FBN1 gene is abundantly expressed in human skeletal muscle-derived mesoangioblasts, osteoblast-like cells, and mesenchymal stem cells, indicating that the musculoskeletal system might play a role in the regulation of asprosin expression. Interestingly, recent studies suggest that asprosin is regulated by exercise. This timely review discusses the role of asprosin in metabolism, its receptor signalling, as well as the exercise regulation of asprosin. Collectively, asprosin may have a vital regulatory effect on the improvement of metabolic disorders such as diabetes mellitus and obesity via exercise.

The modulatory effects of irisin on asprosin, leptin, glucose levels and lipid profile in healthy and obese male and female rats

OBJECTIVES

The main aim of this study was to investigate the effects of irisin on asprosin, leptin, glucose levels and lipid profile in healthy and obese male and female rats.

METHODS

Irisin was subcutaneously administered with osmotic minipumps at the dose of 100 ng/kg/day for 28 days and then, the serum levels of asprosin, leptin, glucose and lipid profile were investigated.

RESULTS

Irisin infusion increased asprosin levels in male rats (p = .02) but not in female rats. Irisin inhibited obesity-induced high glucose, low-density lipoprotein (LDL), triglyceride (TG) and leptin levels in all groups; however, it did not lead to any change in asprosin levels in both obese female and male rats.

CONCLUSIONS

It was determined that irisin increased serum asprosin levels and decreased LDL, TG, glucose and leptin levels, and this could indicate a protective role of irisin against obesity development.

Association of cord blood asprosin concentration with atherogenic lipid profile and anthropometric indices

BACKGROUND

Elevated lipids in umbilical cord blood affect fetal programming, leading to a higher risk of developing cardiovascular disease in later life. However, the causes of changes in the lipid profile of umbilical cord blood are not clear yet. This study aimed for the first time to determine the association of asprosin concentration with TAG, TC, HDL-C, LDL-C concentrations and TAG/HDL-C, TC/HDL-C, LDL-C/HDL-C and non-HDL-C/HDL-C ratio in umbilical cord blood as well as newborn anthropometric indices. This cross-sectional study was based on 450 mother- newborn pairs of a birth cohort study in Sabzevar, Iran. Multiple linear regression was used to estimate the association of lipid concentration and lipid ratios as well as birth weight (BW), birth length (BL), head circumference (HC) and chest circumference (CC) with asprosin in cord blood samples controlled for the relevant covariates.

RESULT

In fully adjusted models, each 1 ng/mL increase in asprosin was associated with 0.19 (95% CI 0.06, 0.31, P < 0.01), 0.19 (95% CI 0.10, 0.29, P < 0.01), 0.17 (95% CI 0.09, 0.25, P < 0.01), 0.17 (95% CI 0.09, 0.25, P < 0.01), 0.01 (95% CI 0.00, 0.013, P < 0.01), 0.01 (95% CI 0.01, 0.01, P < 0.01), 0.01 (95% CI 0.01, 0.01, P < 0.01) and 0.01 (95% CI 0.01, 0.01, P < 0.01) increase in TAG, TC, LDL-C, TAG/HDL-C, TC/HDL-C, LDL-C/HDL-C and non-HDL-C/HDL-C ratio respectively. Moreover, higher asprosin levels was positively associated with newborn BW, BL, HC and CC; however, these associations were not statistically significant.

CONCLUSION

Overall, our findings support the positive association between cord asprosin concentration and the development of atherogenic lipid profile in newborns. Further studies are needed to confirm the findings of this study in other populations.

Asprosin, a C-Terminal Cleavage Product of Fibrillin 1 Encoded by the FBN1 Gene, in Health and Disease

BACKGROUND

Asprosin is a novel fasting-induced, glucogenic, and orexigenic protein hormone that is discovered with the help of genetic studies in patients with neonatal progeroid syndrome. Asprosin is encoded by the penultimate 2 exons (65 and 66) of the fibrillin 1 (FBN1) gene. Profibrillin 1 is the unprocessed protein product of FBN1 and undergoes a proteolytic cleavage by furin enzyme to produce mature fibrillin 1 and asprosin. The main organ responsible for the asprosin production seems to be white adipose tissue.

SUMMARY

Asprosin promotes hepatic glucose release in the liver and appetite stimulation in the hypothalamus through activation of the cAMP signaling circuitry through interacting with its G protein-coupled receptor, called OR4M1. Increasing mass of evidence suggests that asprosin is involved in the development and progression of various clinical conditions including diabetes, obesity, cardiomyopathy, cancer, and polycystic ovarian syndrome. It regulates various cellular and physiological processes such as appetite stimulation, glucose release, insulin secretion, apoptotic cell death, and inflammatory response. In this review, we discuss the current literature on asprosin and try to shed light on the yet undiscovered functions of asprosin.

KEY MESSAGE

Asprosin is a key regulatory factor for preserving the homeostasis of energy metabolism.

Correlation of metabolic characteristics with maternal, fetal and placental asprosin in human pregnancy

OBJECTIVE

Asprosin is a recently discovered hormone associated with obesity and diabetes mellitus. Little is known about asprosin's role during pregnancy, but a contribution of asprosin to pregnancy complications resulting from maternal obesity and gestational diabetes mellitus (GDM) is conceivable. We assessed the potential effects of obesity, GDM and other clinical parameters on maternal and fetal umbilical plasma asprosin concentrations and placental asprosin expression.

DESIGN

The Cologne-Placenta Cohort Study comprises 247 female patients, from whom blood and placentas were collected at the University Hospital Cologne.

METHODS

We studied the maternal and fetal umbilical plasma and placentas of pregnant women with an elective, primary section. Sandwich ELISA measurements of maternal and fetal umbilical plasma and immunohistochemical stainings of placental tissue were performed to determine the asprosin levels. Also, the relation between asprosin levels and clinical blood parameters was studied.

RESULTS

There was a strong correlation between the maternal and fetal plasma asprosin levels and both increased with GDM in normal-weight and obese women. Asprosin immunoreactivity was measured in cultivated placental cells and placental tissue. BMI and GDM were not but pre-pregnancy exercise and smoking were correlated with maternal and/or fetal asprosin levels. Placental asprosin levels were associated with maternal but not with fetal plasma asprosin levels and with BMI but not with GDM. Placental asprosin was related to maternal insulin levels and increased upon insulin treatment in GDM patients.

CONCLUSIONS

Asprosin could potentially act as a biomarker and contribute to the clinical manifestation of pregnancy complications associated with maternal obesity.

Asprosin induces vascular endothelial-to-mesenchymal transition in diabetic lower extremity peripheral artery disease

Background

Altered adipokine secretion in dysfunctional adipose tissue facilitates the development of atherosclerotic diseases including lower extremity peripheral artery disease (PAD). Asprosin is a recently identified adipokine and displays potent regulatory role in metabolism, but the relationship between asprosin and lower extremity PAD remains uninvestigated.

Methods

33 type 2 diabetes mellitus (T2DM) patients (DM), 51 T2DM patients with PAD (DM + PAD) and 30 healthy normal control (NC) volunteers were recruited and the blood samples were collected for detecting the circulatory asprosin level and metabolomic screening. RNA sequencing was performed using the aorta tissues from the type 2 diabetic db/db mice and human umbilical vein endothelial cells (HUVECs) were treated with asprosin to determine its impact on the endothelial-to-mesenchymal transition (EndMT).

Results

The circulating levels of asprosin in DM + PAD group were significantly higher than that of NC group and the DM group. Circulating asprosin level was remarkably negatively correlated with ankle-brachial index (ABI), even after adjusting for age, sex, body mass index (BMI) and other traditional risk factors of PAD. Logistic regression analysis revealed that asprosin is an independent risk factor for PAD and receiver-operator characteristic (ROC) curve determined a good sensitivity (74.5%) and specificity (74.6%) of asprosin to distinguish PAD. Data from metabolomics displayed a typical characteristics of de novo amino acid synthesis in collagen protein production by myofibroblasts in patients with PAD and activation of TGF-β signaling pathway appeared in the aortic tissue of db/db mice. Asprosin directly induces EndMT in HUVECs in a TGF-β-dependent manner as TGF-β signaling pathway inhibitor SB431542 erased the promotional effect of asprosin on EndMT.

Conclusions

Elevated circulatory asprosin level is an independent risk factor of lower extremity PAD and might serve as a diagnostic marker. Mechanistically, asprosin directly induces EndMT that participates in vascular injury via activation of TGF-β signaling pathway.

Trial registration This trial was registered at clinicaltrials.gov as NCT05068895

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01457-0.

Sensitive asprosin detection in clinical samples reveals serum/saliva correlation and indicates cartilage as source for serum asprosin

The C-terminal pro-fibrillin-1 propeptide asprosin is described as white adipose tissue derived hormone that stimulates rapid hepatic glucose release and activates hunger-promoting hypothalamic neurons. Numerous studies proposed correlations of asprosin levels with clinical parameters. However, the enormous variability of reported serum and plasma asprosin levels illustrates the need for sensitive and reliable detection methods in clinical samples. Here we report on newly developed biochemical methods for asprosin concentration and detection in several body fluids including serum, plasma, saliva, breast milk, and urine. Since we found that glycosylation impacts human asprosin detection we analyzed its glycosylation profile. Employing a new sandwich ELISA revealed that serum and saliva asprosin correlate strongly, depend on biological sex, and feeding status. To investigate the contribution of connective tissue-derived asprosin to serum levels we screened two cohorts with described cartilage turnover. Serum asprosin correlated with COMP, a marker for cartilage degradation upon running exercise and after total hip replacement surgery. This together with our finding that asprosin is produced by primary human chondrocytes and expressed in human cartilage suggests a contribution of cartilage to serum asprosin. Furthermore, we determined asprosin levels in breast milk, and urine, for the first time, and propose saliva asprosin as an accessible clinical marker for future studies.

The Roles and Associated Mechanisms of Adipokines in Development of Metabolic Syndrome

Metabolic syndrome is a cluster of metabolic indicators that increase the risk of diabetes and cardiovascular diseases. Visceral obesity and factors derived from altered adipose tissue, adipokines, play critical roles in the development of metabolic syndrome. Although the adipokines leptin and adiponectin improve insulin sensitivity, others contribute to the development of glucose intolerance, including visfatin, fetuin-A, resistin, and plasminogen activator inhibitor-1 (PAI-1). Leptin and adiponectin increase fatty acid oxidation, prevent foam cell formation, and improve lipid metabolism, while visfatin, fetuin-A, PAI-1, and resistin have pro-atherogenic properties. In this review, we briefly summarize the role of various adipokines in the development of metabolic syndrome, focusing on glucose homeostasis and lipid metabolism.

Sex-Specific Effects of Maternal and Post-Weaning High-Fat Diet on Adipose Tissue Remodeling and Asprosin Expression in Mice Offspring

SCOPE

Perinatal high-fat diet (HFD) increases risk of metabolic disorders in offspring. Adipose tissue remodeling is associated with metabolic syndrome. The current study characterizes the profile of maternal HFD-induced changes in adipose tissue remodeling and adipokines expression in mice offspring.

METHODS AND RESULTS

Female C57BL/6 mice are fed with CHOW or HFD for 2 weeks before mating, throughout gestation and lactation. At weaning, pups are randomly fed with CHOW or HFD, resulting in eight groups according to sex and maternal diet: Male CHOW-CHOW (MCC), Male CHOW-HFD (MCH), Male HFD-CHOW (MHC), Male HFD-HFD (MHH), Female CHOW-CHOW (FCC), Female CHOW-HFD (FCH), Female HFD-CHOW (FHC), and Female HFD-HFD (FHH). Increased body weight, impaired glucose tolerance, increased adipose tissue mass and hypertrophy, and decreased circulating asprosin level are only observed in male offspring exposure to maternal HFD. Serum asprosin level negatively correlates with fasting blood glucose, serum cholesterol (CHO), and high-density lipoprotein (HDL) levels, while positively correlates with serum low-density lipoprotein (LDL) and glutamate-oxaloacetate transaminase (GOT) levels in male offspring. A combination of genetic and biochemical analyses of adipokines shows the depot- and sex-specific changes in response to maternal and/or post-weaning HFD.

CONCLUSION

This study's results reveal the differential metabolic changes in response to maternal and/or post-weaning HFD in male and female offspring. The effect of maternal HFD on metabolic phonotype is more obvious in male offspring, supporting the notion that males are more susceptible to HFD-induced metabolic disorders.

Caudamins, a new subclass of protein hormones

Hormones have traditionally been classified by their mode of biosynthetic origin. We postulate a mode of hormone biosynthesis that leads to a new subclass of protein hormones. Members of this class are derived from a cleavage event that also generates a much larger, functionally unrelated, nonhormonal protein. Here, we examine four representative members of this group: endostatin, endotrophin, asprosin, and placensin. We have named this subclass of protein hormones caudamins, from the Latin word cauda meaning 'tail'. These four caudamins have shown promise in understanding and treating diseases like metabolic syndrome and cancer. Identification of the rest of the caudamins will likely provide a plethora of drug targets for a variety of diseases.

Nordic Walking at Maximal Fat Oxidation Intensity Decreases Circulating Asprosin and Visceral Obesity in Women With Metabolic Disorders

Objective

Excess visceral adipose tissue is associated with insulin resistance and other metabolic disorders, including deregulation of adipokine secretion, which may be corrected by aerobic exercise training. Asprosin is a novel adipokine responsible for the regulation of appetite and the release of glucose from the liver, and its levels are pathologically elevated in obesity. The aim of the study was to evaluate the effects of 8-week Nordic walking (NW) training at maximal fat oxidation intensity (FAT_max) on changes in body mass, as well as those in insulin resistance and asprosin levels among young women with visceral obesity and metabolic disorders.

Materials and Methods

The study was completed by 14 women (30.14 ± 3.63 years) representing low levels of physical activity, visceral obesity (waist circumference 105.50 ± 14.87 cm, BMI 33.85 ± 5.48 kg/m²) and with metabolic disorders, who for 8 weeks (three times a week, 60 min), participated in NW training at the FAT_max intensity (61.92 ± 6.71% HR_max, 42.33 ± 8.69% VO_2max) controlled on the basis of heart rate (114.21 ± 14.10 bpm).

Results

After 4 and 8 weeks of NW training, a significant decrease in the concentration of asprosin, waist and hip circumference (HC), waist-to-height ratio and body adiposity index (BAI) (p < 0.05, large effect size) were found.

Conclusion

The 8-week NW training at an FAT_max intensity decreases the concentration of asprosin in the blood as well as visceral obesity in young women with metabolic disorders.

Serum levels of Asprosin in patients diagnosed with coronary artery disease (CAD): a case-control study

Background

Coronary artery disease (CAD) is considered as a multi-faceted chronic inflammatory disease involving reduced blood supply to the myocardium as a result of accumulating lipids in the atrial walls. Visceral adiposity with disrupted release of adipokines play a key role in its pathogenesis. Asprosin is a newly identified fasting-induced glucogenic adipokine that has been related with metabolic disorders such as type II diabetes mellitus and polycystic ovary syndrome. The preset study sought to assess circulating asprosin in context of CAD.

Methods

In this study, serum levels of asprosin were determined in 88 CAD patients and 88 non-CAD healthy controls. Serum IL-6, TNF-α, asprosin and adiponectin were assessed using ELISA kits.

Results: Serum asprosin was found to be higher in CAD patients when compared to non-CAD subjects (7.84 ± 2.08 versus 5.02 ± 1.29 μg/mL, p <  0.001). Similarly, serum TNF-α, and IL-6 elevated in CAD group significantly (p <  0.001). However, circulating adiponectin diminished in CAD group when compared with non-CAD subjects (p < 0.001). Moreover, serum asprosin levels directly correlated with BMI, FBG, HOMA-IR, TG and TC. Logistic regression analyses showed that asprosin levels were associated with increased risk of developing CAD (odds ratio: 3.01, 95% CI: 2.16, 4.20 and p < 0.001), after adjusting for potential confounders (age, sex and BMI).

Conclusions

The present study findings suggested a possible relation of serum asprosin with the pathogenesis of CAD, in particular through insulin resistance and dyslipidemia.

Circulating levels of asprosin and its association with insulin resistance and renal function in patients with type 2 diabetes mellitus and diabetic nephropathy

INTRODUCTION

Adipokines play an important role in the development of type 2 diabetes mellitus (T2DM) and its complications like nephropathy. Asprosin is a newly discovered adipokine involved in glucose metabolism and inflammation process. The present study aimed to evaluate asprosin levels in patients with T2DM and T2DM + nephropathy (NP) compared to control subjects as well as investigating its relationship with insulin resistance, inflammation, and renal function markers.

METHODS

Serum levels of asprosin, adiponectin, IL-6, and TNF-α were measured in 55 control subjects, 54 T2DM, and 55 T2DM + NP patients using ELISA kits.

RESULTS

Asprosin was found to be higher in the T2DM (6.73 ± 1.67) and T2DM + NP (7.11 ± 1.54) patients compared to the controls (4.81 ± 1.09) (p < 0.001), while adiponectin indicated a lower concentration in both patient groups compared to the control group. Moreover, IL-6 and TNF-α indicated higher levels in the two patients group compared to the control group. Asprosin was observed to have a positive correlation with HbA1c, FBG, TC, LDL-C, IL-6, and TNF-α in the T2DM group. In the patients with T2DM + NP, asprosin was found to be positively correlated with BMI, HbA1c, insulin, HOMA-IR, Cr, UAE, IL-6, and TNF-α, and it was inversely correlated with eGFR.

CONCLUSION

Higher concentrations of asprosin in the T2DM and T2DM + NP groups and its relationship with glucose and lipid metabolism and markers of renal function and inflammation suggested a possible role for this adipokine in the pathogenesis of both T2DM and nephropathy.

Asprosin, a novel pleiotropic adipokine implicated in fasting and obesity-related cardio-metabolic disease: Comprehensive review of preclinical and clinical evidence

White adipose tissue is a dynamic endocrine organ that releases an array of adipokines, which play a key role in regulating metabolic homeostasis and multiple other physiological processes. An altered adipokine secretion profile from adipose tissue depots frequently characterizes obesity and related cardio-metabolic diseases. Asprosin is a recently discovered adipokine that is released in response to fasting. Following secretion, asprosin acts - via an olfactory G-protein coupled receptor and potentially via other unknown receptor(s) - on hepatocytes and agouti-related peptide-expressing neurons in the central nervous system to stimulate glucose secretion and promote appetite, respectively. A growing body of both in vitro and in vivo studies have shown asprosin to exert a number of effects on different metabolic tissues. Indeed, asprosin can attenuate insulin signalling and promote insulin resistance in skeletal muscle by increasing inflammation and endoplasmic reticulum stress. Interestingly, asprosin may also play a protective role in cardiomyocytes that are exposed to hypoxic conditions. Moreover, clinical studies have reported elevated circulating asprosin levels in obesity, type 2 diabetes and other obesity-related cardio-metabolic diseases, with significant associations to clinically relevant parameters. Understanding the spectrum of the effects of this novel adipokine is essential in order to determine its physiologic role and its significance as a potential therapeutic target and/or a biomarker of cardio-metabolic disease. The present review offers a comprehensive overview of the published literature on asprosin, including both clinical and preclinical studies, focusing on its role in metabolism and cardio-metabolic disease.

Novel adipokine asprosin modulates browning and adipogenesis in white adipose tissue

Obesity is an increasingly serious epidemic worldwide characterized by an increase in the number and size of adipocytes. Adipose tissue maintains the balance between lipid storage and energy utilization. Therefore, adipose metabolism is of great significance for the prevention, treatment and intervention of obesity. Asprosin, a novel adipokine, is a circulating hormone mainly secreted by white adipose tissue. Previous studies have shown that asprosin plays a role in fasting-induced homeostasis, insulin resistance, and glucose tolerance. However, whether it can regulate the metabolism of adipose tissue itself has not been studied. This study intended to examine the roles and potential mechanisms of asprosin in adipose regulation. We first demonstrated that the expression level of asprosin was significantly downregulated in subcutaneous white adipose tissue (scWAT) of high-fat diet (HFD)-fed or cold-stimulated mice. Overexpression of asprosin in scWAT reduced heat production, decreased expression of the browning marker uncoupling protein 1 (UCP1) and other browning-related genes, along with upregulation of adipogenic gene expression. Mechanistically, we found that Nrf2 was activated upon cold exposure, but this activation was suppressed after asprosin overexpression. In primary cultured adipocytes, adenovirusmediated asprosin overexpression inhibited adipose browning and aggravated lipid deposition, while Nrf2 agonist oltipraz could reverse these changes. Our findings suggest that novel adipokine asprosin negatively regulated browning and elevate lipid deposition in adipose tissue via a Nrf2-mediated mechanism. Asprosin may be a promising target for the prevention and treatment of obesity and other metabolic diseases.

Increased serum asprosin is correlated with diabetic nephropathy

OBJECTIVE

The adipokine asprosin, which was recently discovered, facilitates hepatic glucose production. The aim of this study is to see whether serum asprosin concentrations are linked to diabetic nephropathy (DN).

METHODS

We performed this investigation in a group of 212 type 2 diabetes (T2DM) patients. These patients were classified into three subgroups: DN0 group (normal to mildly increased), DN1 group (moderately increased), and DN2 group (severely increased) on the basis of urine albumin-to-creatinine ratio (ACR).

RESULTS

When compared to the controls, T2DM patients had higher serum asprosin levels. The DN2 group had significantly higher serum asprosin than the DN0 and DN1 groups. Furthermore, the DN1 group had higher serum asprosin than the DN0 group. Serum asprosin was linked to a higher risk of T2DM and DN in a logistic regression analysis. Serum asprosin was found to be positively related with disease duration, systolic blood pressure, blood urea nitrogen, creatinine, uric acid, ACR, calcium channel blockers, and angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker therapy, but negatively related with glomerular filtration rate, metformin, and acarbose therapy.

CONCLUSION

Serum asprosin increase with the progression of DN. Serum asprosin is correlated with renal function and ACR.

Old Paradoxes and New Opportunities for Appetite Control in Obesity

Human obesity is accompanied by alterations in the blood concentrations of multiple circulating appetite regulators. Paradoxically, most of the appetite-inhibitory hormones are elevated in nonsyndromic obesity, while most of the appetite stimulatory hormones are reduced, perhaps reflecting vain attempts of regulation by inefficient feedback circuitries. In this context, it is important to understand which appetite regulators exhibit a convergent rather than paradoxical behavior and hence are likely to contribute to the maintenance of the obese state. Pharmacological interventions in obesity should preferentially consist of the supplementation of deficient appetite inhibitors or the neutralization of excessive appetite stimulators. Here, we critically analyze the current literature on appetite-regulatory peptide hormones. We propose a short-list of appetite modulators that may constitute the best candidates for therapeutic interventions.

Asprosin serum levels and glucose homeostasis in children with obesity

PURPOSE

Asprosin is a novel adipokine involved in glucose homeostasis, food intake regulation and energy homeostasis. However, the role of asprosin in glucose homeostasis regulation remains still controversial, especially in pediatrics. Aims of the study were to compare fasting serum asprosin levels between obese children and controls and to investigate the relationships of asprosin with body mass index (BMI) and biochemical markers of insulin resistance, insulin sensitivity, β-cell function and cardio-metabolic risk in obese non-diabetic children.

METHODS

This cross-sectional, case-controlled, study included 43 obese children and 24 lean matched controls consecutively recruited. Children underwent clinical and biochemical assessments, including oral glucose tolerance test. Fasting asprosin serum levels were measured using an enzyme-linked immunosorbentassay (ELISA). Homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of β-cell function (HOMA-B), Matsuda-index, Insulinogenic-index, Areas Under the Curves for glucose and insulin were calculated. Successively, asprosin variable was dichotomized according to mean value in order to create two ordered classes of values.

RESULTS

Fasting asprosin concentration was significantly lower in obese children compared to controls (331.9 ± 120.5 vs 358.1 ± 74.1 pg/ml; p = 0.013). Asprosin was lower in boys than in girls (313.7 ± 59.5 vs 361.1 ± 127.2 pg/ml; p = 0.044), while BMI standard deviation score (SDS) was higher in boys compared to girls (p = 0.024). Asprosin was negatively correlated with BMI (p = 0.024), BMI SDS (p = 0.044) and male sex (p = 0.043) in the entire cohort. No significant differences in asprosin levels were demonstrated between insulin resistant and non-insulin resistant obese children. Logistic regression models documented a significant negative association between BMI SDS and dichotomized asprosin. In particular, higher BMI SDS values were associated to lower asprosin serum levels class. A receiver operating characteristic (ROC) analysis showed existence of the best cut-off for BMI SDS (+2.7 SDS) variable into discriminating patients belonging to two asprosin classes in our cohort.

CONCLUSIONS

In conclusion, asprosin serum levels were significantly lower in obese children compared to control. Fasting asprosin decreased with increasing BMI, but it was not significantly affected by IR.

Asprosin-A Fasting-Induced, Glucogenic, and Orexigenic Adipokine as a New Promising Player. Will It Be a New Factor in the Treatment of Obesity, Diabetes, or Infertility? A Review of the Literature

Asprosin is a recently discovered protein released during fasting conditions mainly by adipocytes from white adipose tissue. As a glucogenic peptide, it stimulates the release of glucose from hepatic cells by binding to the OLFR734 receptor and leading to the activation of the G protein-cAMP-PKA pathway. As it crosses the blood–brain barrier, it also acts as an orexigenic peptide that stimulates food intake through activation of AgRP neurons in the hypothalamus; thus, asprosin participates in maintaining the body’s energy homeostasis. Moreover, studies have shown that asprosin levels are pathologically elevated in obesity and related diseases. However, the administration of anti-asprosin antibodies can both normalize its concentration and reduce food intake in obese mice, which makes it an interesting factor to combat obesity and related diseases. Current research also draws attention to the relationship between asprosin and fertility, especially in men. Asprosin improves age- and obesity-related decrease in fertility potential by improving sperm motility. It should also be mentioned that plasma asprosin levels can be differentially modulated by physical activity; intense anaerobic exercise increases asprosin level, while aerobic exercise decreases it. However, further research is necessary to confirm the exact mechanisms of asprosin activity and its potential as a therapeutic target.

Association of serum asprosin concentrations with obstructive sleep apnea syndrome

OBJECTIVE

Asprosin, a recently discovered adipokine, stimulates the release of hepatic glucose. The purpose of the current research was to determine the relation between serum asprosin and obstructive sleep apnea syndrome (OSAS).

METHODS

The current investigation enrolled 152 patients with OSAS and 97 control subjects. Serum asprosin concentrations were measured and analyzed.

RESULTS

Higher serum asprosin concentrations were found in patients with OSAS than in the controls. Logistic regression analysis demonstrated that serum asprosin concentrations were associated with an increased risk of OSAS. Patients with severe OSAS had significantly increased asprosin compared to mild and moderate groups. The group with moderate OSAS showed higher serum asprosin levels than the group with mild OSAS. Pearson correlation analysis demonstrated a positive relation between serum asprosin and disease severity. Simple linear regression analyses showed a significant correlation between serum asprosin with body mass index (BMI), fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), and apnea-hypopnea index (AHI), and negatively correlated with high-density lipoprotein cholesterol (HDL-C). Multiple linear regression analysis revealed a significant correlation between serum asprosin with BMI, FPG, HOMA-IR, TG, AHI, and HDL-C.

CONCLUSION

There is a significant correlation between serum asprosin with the presence and severity of OSAS.

High Serum Asprosin Levels Are Associated with Presence of Metabolic Syndrome

OBJECTIVE

Asprosin, a new adipocytokine, has reportedly been associated with glucose release, dyslipidemia, and insulin resistance (IR). However, the relationship of asprosin with metabolic syndrome (MetS) remains unknown. This study aimed to investigate serum asprosin levels in MetS as well as their association with various metabolic parameters in humans.

METHODS

A total of 131 consecutive patients with MetS, and 162 age-matched, healthy subjects were recruited for this study. Serum asprosin concentrations were determined using the enzyme-linked immunosorbent assay. Lipid profile, glucose, insulin, and inflammatory markers were also measured.

RESULTS

Serum asprosin levels were higher in subjects with MetS (23.52 [16.70, 32.05] ng/mL) than in controls (16.70 [12.87, 22.38] ng/mL; P < 0.01), and they showed an increasing trend with increasing numbers of metabolic components (P for trend < 0.01). In all studied subjects, serum asprosin levels were positively correlated with body mass index, waist circumference, triglycerides, fasting plasma glucose, 2-hour plasma glucose, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR) index, interleukin-6, and monocyte chemoattractant protein-1 and negatively correlated with high-density lipoprotein cholesterol (P < 0.05). In multiple linear regression, asprosin was independently and positively correlated with triglyceride and HOMA-IR (P < 0.05). Binary logistic regression revealed that asprosin was independently and positively correlated with the occurrence of MetS and IR, even after controlling for anthropometric variables, lipid profiles, and inflammatory markers.

CONCLUSION

Asprosin is a potential metabolic-related adipokine and may be related to IR and MetS. This trial was registered with ChiCTR, ChiCTR1800018347.