Circulating asprosin concentrations are increased in type 2 diabetes mellitus and independently associated with fasting glucose and triglyceride

Asprosin: its function as a novel endocrine factor in metabolic-related diseases

BACKGROUND AND PURPOSE

Asprosin was discovered as a new endocrine hormone originating from fibrillin-1 cleavage that plays a crucial role in various metabolic-related diseases, such as obesity, nonalcoholic fatty liver disease (NAFLD), diabetes, polycystic ovary syndrome (PCOS), and cardiovascular diseases. The purpose of this review is to describe the recent advancements of asprosin.

METHOD

Narrative review.

RESULT

This comprehensive review explores its tissue-specific functions, focusing on white adipose tissue, liver, hypothalamus, testis, ovary, heart, pancreas, skeletal muscle, and kidney.

CONCLUSION

Asprosin is a multifaceted protein with tissue-specific roles in various physiological and pathological processes. Further research is needed to fully understand the mechanisms and potential of asprosin as a therapeutic target. These insights could provide new directions for treatments targeting metabolic-related diseases.

Asprosin: the potential player in combined double diabetes and hypothyroidism

BACKGROUND

Double diabetes is a term used to describe people with type 1 diabetes who are overweight, show signs of insulin resistance, or have a family history of type 2 diabetes. Asprosin is a novel glucogenic adipokine; Asprosin regulates appetite and glucose metabolism. The study aimed to investigate the level of asprosin in people with double diabetes with and without hypothyroidism and its association with markers of insulin resistance.

SUBJECTS AND METHODS

This case-control study was conducted in Iraq between March 2022 and January 2023. One hundred sixty participants were enrolled; the selected participants were classified into three age and sex-matched groups. The first group consisted of eighty healthy controls served as the control group. Of eighty participants with newly discovered DD, half (40) have DD alone, and 40 have both DD and hypothyroidism. Serum asprosin, insulin, thyroid, lipid profile, glucose, and glycated hemoglobin were measured. The estimated glucose disposal rate, triglyceride-glucose index, and HOMA-IR were calculated.

RESULTS

Participants with double diabetes had significantly (p ≤ 0.001) greater circulation asprosin levels than subjects in the control group. Comparatively, to double diabetes participants without hypothyroidism, asprosin levels were also higher in double diabetes subjects with hypothyroidism (p ≤ 0.001), and the insulin resistance markers increased in a stepwise way across the asprosin quartiles (p ≤ 0.001). Asprosin significantly correlated with insulin resistance markers, eGDR, plasma glucose, HbA1C, triglycerides, HDL-C, and LDL-C.

CONCLUSION

Elevated asprosin levels might be a potential biomarker for the alteration in glucose metabolism, insulin resistance, and double diabetes. It may be the missing link between metabolic and endocrine disorders.

Leptin, Ghrelin, Irisin, Asprosin and Subfatin Changes in Obese Women: Effect of Exercise and Different Nutrition Types

Background and Objectives: In this study, the effects of a six-week training program and various diets on subfatin, asprosin, irisin, leptin, ghrelin and the lipid profile were investigated in overweight women. Materials and Methods: A total of 78 women voluntarily participated in the study. Groups: The study was divided into eight groups: Healthy Control, Obese Control, Obese + Vegetarian, Obese + Ketogenic, Obese + Intermittent Fasting, Obese + Exercise + Vegetarian, Obese + Exercise + Ketogenic and Obese + Exercise + Intermittent Fasting. While there was no intervention in the healthy and obese control groups, the other groups followed predetermined exercise and diet programs for 6 weeks. Blood samples were taken from the participants in the research group twice (before and after the interventions). An autoanalyzer was used to determine the lipid profile in the blood samples taken, and the ELISA method was used to analyze other parameters. Results: Overall, a significant difference was found in the values of weight, BMI, subfatin, ghrelin, leptin, cholesterol, triglyceride, HDL and LDL as a result of the exercise and diet interventions (p < 0.05). There was no significant difference in asprosin and irisin values (p > 0.05). Conclusions: In conclusion, regular exercise and dietary interventions in obese women can regulate lipid profile, ghrelin, leptin and asprosin levels, and increasing irisin with exercise can activate lipid metabolism and support positive changes in lean mass.

Asprosin contributes to pathogenesis of obesity by adipocyte mitophagy induction to inhibit white adipose browning in mice

BACKGROUND

Asprosin (ASP) is a newly discovered adipokine secreted by white adipose tissue (WAT), which can regulate the homeostasis of glucose and lipid metabolism. However, it is not clear whether it can regulate the browning of WAT and mitophagy during the browning process. Accordingly, this study aims to investigate the effects and possible mechanisms of ASP on the browning of WAT and mitophagy in vivo and in vitro.

METHODS

In in vivo experiments, some mouse models were used including adipose tissue ASP-specific deficiency (ASP-/-), high fat diet (HFD)-induced obesity and white adipose browning; in in vitro experiments, some cell models were also established and used, including ASP-deficient 3T3-L1 preadipocyte (ASP-/-) and CL-316243 (CL, 1 µM)-induced browning. Based on these models, the browning of WAT and mitophagy were evaluated by morphology, functionality and molecular markers.

RESULTS

Our in vivo data show that adipose tissue-specific deletion of ASP contributes to weight loss in mice; supplementation of ASP inhibits the expressions of browning-related proteins including UCP1, PRDM16 and PGC1ɑ during the cold exposure-induced browning, and promotes the expressions of mitophagy-related proteins including PINK1 and Parkin under the conditions of whether normal diet (ND) or HFD. Similarly, our in vitro data also show that the deletion of ASP in 3T3-L1 cells significantly increases the expressions of the browning-related proteins and decreases the expressions of the mitophagy-related proteins.

CONCLUSIONS

These data demonstrate that ASP deletion can facilitate the browning and inhibit mitophagy in WAT. The findings will lay an experimental foundation for the development of new drugs targeting ASP and the clinical treatment of metabolic diseases related to obesity.

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.

The role of asprosin in regulating ovarian granulosa- and theca-cell steroidogenesis: a review with comparisons to other adipokines

Adipose tissues produce a variety of biologically active compounds, including cytokines, growth factors and adipokines. Adipokines are important as they function as endocrine hormones that are related to various metabolic and reproductive diseases. The goal of this review was to summarise the role of asprosin, a recently discovered adipokine, and compare its role in ovarian steroidogenesis with that of other adipokines including adiponectin, leptin, resistin, apelin, visfatin, chemerin, irisin, and gremlin 1. The summary of concentrations of these adipokines in humans, rats and other animals will help researchers identify appropriate doses to test in future studies. Review of the literature indicated that asprosin increases androstenedione production in theca cells (Tc), and when cotreated with FSH increases oestradiol production in granulosa cells (Gc). In comparison, other adipokines (1) stimulate Gc oestradiol production but inhibit Tc androgen production (adiponectin), (2) inhibit Gc oestradiol production and Tc androstenedione production (leptin and chemerin), (3) inhibit Gc steroidogenesis with no effect on Tc (resistin), (4) inhibit Gc oestradiol production but stimulate Tc androgen production (gremlin 1), and (5) increase steroid secretion by Gc, with unknown effects on Tc steroidogenesis (apelin and visfatin). Irisin has direct effects on Gc but its precise role (inhibitory or stimulatory) may be species dependent and its effects on Tc will require additional research. Thus, most adipokines have direct effects (either positive or negative) on steroid production in ovarian cells, but how they all work together to create a cumulative effect or disease will require further research.

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.

Comparison of the effects of empagliflozin and sitagliptin, as add-on to metformin, on serum levels of asprosin and metabolic parameters in patients with type 2 diabetes mellitus

The effect of sitagliptin and empagliflozin on serum levels of asprosin and metabolic parameters in patients with type 2 diabetes mellitus (T2DM) was assessed in a non-randomized, prospective observational study. Seventy-nine T2DM patients, without adequate glycemic control with metformin monotherapy, were included in the study. In addition to the ongoing metformin treatment, patients received sitagliptin 100 mg and empagliflozin 10 mg once daily for 12 weeks. Anthropometric parameters, lipid and glycemic profile, insulin resistance (homeostasis model assessment of insulin resistance index [HOMA-IR]), and asprosin serum levels were assessed at baseline and after 12 weeks of therapy. Both empagliflozin and sitagliptin treatments led to similar, significant improvement in fasting blood glucose (FBG) and hemoglobin A1C (HbA1C). Compared to baseline, triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) were improved with both treatments, but empagliflozin led to the more improvement. No significant change of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were observed in either group. Insulin resistance was significantly attenuated in both groups, but to a greater degree with empagliflozin treatment. The reduction in serum asprosin levels from baseline was significantly higher in patients taking empagliflozin compared to those receiving sitagliptin. Additionally, individuals on empagliflozin exhibited a more decrease in body mass index (BMI) and body weight compared to those on sitagliptin. According to our findings, the addition of empagliflozin to metformin appeared to offer greater benefits compared to the addition of sitagliptin in terms of decreasing asprosin levels and improving certain metabolic parameters in T2DM patients.

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.

Asprosin aggravates atherosclerosis via regulating the phenotype transformation of vascular smooth muscle cells

Phenotype transformation of vascular smooth muscle cells (VSMCs) plays an important role in the development of atherosclerosis. Asprosin is a newly discovered adipokine, which is critical in regulating metabolism. However, the relationship between asprosin and phenotype transformation of VSMCs in atherosclerosis remains unclear. The aim of this study is to investigate whether asprosin affects the progression of atherosclerosis by inducing phenotype transformation of VSMCs. We established an atherosclerosis model in ApoE-/- mice and administered asprosin recombinant protein and asprosin antibody to mice. Knocking down asprosin was also as an intervention. Interestingly, we found a correlation between asprosin levels and atherosclerosis. Asprosin promoted plaque formation and phenotype transformation of VSMCs. While, AspKD or asprosin antibody reduced the plaque lesion and suppressed vascular stiffness in ApoE-/- mice. Mechanistically, asprosin induced phenotype transformation of MOVAs by binding to GPR54, leading to Gαq/11 recruitment and activation of the PLC-PKC-ERK1/2-STAT3 signaling pathway. Si GPR54 or GPR54 antagonist partially inhibited the action of asprosin in MOVAs. Mutant GPR54-(267, 307) residue cancelled the binding of asprosin and GPR54. In summary, this study confirmed asprosin activated GPR54/Gαq/11-dependent ERK1/2-STAT3 signaling pathway, thereby promoting VSMCs phenotype transformation and aggravating atherosclerosis, thus providing a new target for the treatment of atherosclerosis.

Increased serum asprosin is correlated with diabetes mellitus-induced erectile dysfunction

OBJECTIVE

Asprosin, a newly identified adipokine, is pathologically increased in type 2 diabetes. The aim of this study is to see whether serum asprosin concentrations are linked to diabetes mellitus-induced erectile dysfunction (DMED).

METHODS

90 male patients with type 2 diabetes were included. According to the International Index of Erectile Function (IIEF-5) score, they were classified into two groups: 45 type 2 diabetes patients without erectile dysfunction (DM group) (IIEF-5 > 21),45 patients with diabetes induced erectile dysfunction (DMED group) (IIEF-5 ≤ 21)0.45 healthy male volunteers with normal blood glucose, IIEF-5 score > 21 points, and age matched with the DMED group were included as the control group. Anthropometric and biochemical variables were determined in all participants.

RESULTS

When compared to the controls, T2DM ( Type 2 Diabetes Mellitus)patients had higher serum asprosin levels. The DMED group had significantly higher serum asprosin than the T2DM groups(p < 0.001). After adjusting for multiple variables considered traditional risk factors for ED(erectile dysfunction), Asprosin can still be used as an independent risk factor for ED; The ROC(Receive Operating Characteristic Curve) indicates that asprosin has good sensitivity (97.8%) and specificity (62.2%) in predicting ED, with an area under the curve of 0.843.Correlation analysis shows that asprosin is negatively correlated with SOD(superoxide dismutase ) and positively correlated with MDA (malondialdehyde).

CONCLUSION

Serum asprosin concentrations are increased in patients with DMED. Also, asprosin is correlated with oxidative stress indexes (MDA, SOD).

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.

Exercise-induced effects on asprosin and indices of atherogenicity and insulin resistance in males with metabolic syndrome: a randomized controlled trial

Metabolic syndrome (MetS) development is associated with insulin resistance and obesity, with the progression of visceral adipose tissue playing a crucial role. Excessive adipose tissue is accompanied by an increase in the asprosin (ASP), which is responsible for carbohydrate metabolism and the regulation of hunger and satiety. Exercise affects the release of ASP, which may regulate metabolism accordingly. Due to the inconclusive results of the effect of exercise on ASP concentration in men with MetS, 12-week interventions were carried out in the following groups: EG1-aerobic training (n = 21, age: 34.21 ± 6.06, WC; waist circumference: 114.7 ± 10.93) and EG2-a combination of aerobic and resistance training (n = 21, age: 37.37 ± 7.08, WC: 114.8 ± 11.64) and compared with a control group (CG) of men with MetS without any intervention (n = 20, age: 38.26 ± 7.43, WC: 115.3 ± 10.54). Body composition, indicators of carbohydrate-lipid metabolism, and ASP were assessed four times: before the intervention, at 6 and 12 weeks of training, and 4 weeks after the training sessions. A comparison of the intervention influence on changes in the analyzed variables between the groups was performed using ANOVA test for dependent groups with post-hoc comparison. The effect size (ES) was also assessed using squared eta (η2). The implementation of aerobic training resulted in a decrease in ASP concentration (p = 0.03) within 6 weeks of the intervention, while in the CG a gradual increase in ASP was confirmed (p < 0.001). Aerobic-resistance training did not induce significant changes in ASP concentration but resulted in an increase in fat-free mass/fat mass (FFM/FM) ratio (p < 0.001), and a decrease (p = 0.04) in Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Changes in the visceral adipose tissue level indicate a gradual decrease in both the EG1 (p = 0.01) and EG2 (p = 0.04) groups. Both aerobic and aerobic-resistance exercises may have a regulatory effect, mainly by reducing visceral adipose tissue, on the improvement of metabolic disorders.

Association of serum Asprosin concentrations with heart failure

BACKGROUND

To analyze the association of serum Asprosin concentrations with heart failure (HF).

METHODS

A total of 103 patients with HF were included in the HF group, and 103 patients with health checkups were included in the non-HF group. The serum Asprosin levels of the two groups were measured, and relevant clinical data were collected for statistical analysis.

RESULTS

Compared with the non-HF group, the serum Asprosin concentration was significantly higher in the HF group, and the difference was statistically significant (P < 0.001). According to the serum Asprosin levels, we divided all the subjects into three quartiles. We found that the prevalence of HF increased with increasing serum Asprosin levels in the three groups (P < 0.001). Serum Asprosin levels were positively correlated with NT-ProBNP (P < 0.05) and negatively correlated with LVEF (P < 0.001). Dichotomous logistic regression analysis found Asprosin and age to be independent risk factors for HF (OR = 1.010, 95% CI: 1.003-1.018; OR = 1.058, 95% CI:1.004-1.665, respectively). Combining Asprosin and NT-proBNP indicators to draw ROC curves can improve the specificity and sensitivity of HF diagnosis.

CONCLUSIONS

Serum Asprosin levels were significantly elevated in HF patients. The serum Asprosin level is an independent risk factor for HF, and the combined detection of Asprosin and NT-proBNP levels can improve the accuracy of HF diagnosis.

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.

Association Between Plasma Asprosin Levels and Gestational Diabetes Mellitus

Purpose

This study sought to investigate whether asprosin can be used in the diagnosis of GDM or for diagnostic purposes in high-risk pregnancies, along with a review of other parameters that may be associated with serum asprosin levels.

Patients and Methods

The study investigated the association between gestational diabetes mellitus (GDM) and asprosin levels. A total of 93 participants; 30 patients with GDM, 33 healthy pregnant women with normal glucose tolerance (NGT), and 30 healthy non-diabetic women (control group) at the Endocrinology and Metabolic Diseases outpatient clinic of a tertiary care university hospital were enrolled in the study. Patients with GDM and NGT were examined in terms of GDM between the 24th and 28th week of pregnancy (2nd trimester). Patient data were collected during routine examinations, and asprosin levels were measured using the ELISA method. All participants underwent testing for measurements of serum hemoglobin, insulin, C-peptide, fasting plasma glucose, and glycated hemoglobin (HbA1c) levels following a fasting period of at least eight hours.

Results

Asprosin levels were higher in pregnant women with NGT and with GDM versus controls (Control-NGT asprosin, p = 0.001; Control-GDM asprosin, p = 0.001). Pregnant women with GDM had higher asprosin levels than those with NGT (p = 0.001). In detecting GDM in pregnant women, an asprosin cutoff value of >31.709 ng/mL yielded a sensitivity of 93.3%, specificity of 90.9%, positive predictive value of 90.3%, and negative predictive value of 93.75% (p < 0.001).

Conclusion

Serum asprosin levels can potentially be used as a marker in the diagnosis of GDM.

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.

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.

Correlation of Serum Asprosin Levels With Normalized Protein Catabolic Rate in Patients Receiving Peritoneal Dialysis Treatment

Background Peritoneal dialysis patients are malnourished due to loss of protein in the dialysate and inadequate dialysis, although they take additional calories every day during treatment. Many parameters are used to assess nutritional status, with normalized protein catabolic rate (nPCR) being one of the most common. Asprosin, a novel adipokine secreted by adipose tissue, peaks during fasting and induces hepatic glucose release through the activation of the G-protein-cAMP-PKA pathway, which has been indicated to have a curative effect on chronic inflammation. In this study, we aimed to investigate the relationship between asprosin levels and nutritional parameters in patients receiving peritoneal dialysis treatment as well as to investigate the applicability of more practical tests. Methodology A total of 70 peritoneal dialysis patients, 35 female (59%) and 24 male (41%), were included in the study. The mean age of the patients was 53 ± 14 years (range = 18-80 years), and the median peritoneal dialysis duration was 31.5 months (range = 20-56.2 months). The most common etiologic cause was hypertension (37%). Patients over 18 years of age who had been receiving peritoneal dialysis treatment for at least 24 months were included in the study. The correlation between patients' nPCR levels and serum asprosin, body mass index, and lipids was evaluated. Results The correlation between the level of nPCR and the serum asprosin level, body mass index, and lipids was evaluated. Patients with nPCR <0.815 were considered malnourished, and factors affecting malnutrition were determined by univariate analysis. Among the factors affecting malnutrition according to univariate analysis, those with p-value <0.05 were analyzed by multivariate analysis. Low asprosin level was one of the independent factors affecting malnutrition in patients (Exp(B) = 0.944, 95% confidence interval (CI) = 0.896-0.994). Other independent factors affecting malnutrition were Kt/V (Exp(B) = 0.018, 95% CI = 0.001-0.550) and residual renal function (Exp(B) = -0.004, 95% CI = 0.993-0.999). Conclusions There is a need for more accessible tests and reliable parameters to evaluate dialysis and nutritional deficiency in peritoneal dialysis patients. One possible hormone that could serve as a guide is asprosin.

Betatrophin, elabela, asprosin, glucagon and subfatin peptides in breast tissue, blood and milk in gestational diabetes

We investigated the presence of asprosin (ASP), betatrophin, elabela (ELA), glucagon and subfatin (SUB) in the milk of mothers with gestational diabetes mellitus (GDM) and compared their levels with blood levels. We also investigated whether these peptides are synthesized by the breast. We investigated 12 volunteer mothers with GDM and 14 pregnant non-GDM control mothers. The peptides were measured using ELISA and their tissue localization was determined using immunohistochemistry. Breast milk contains ASP, betatrophin, ELA, glucagon and SUB. The amount of the peptides ranged from highest to the lowest in colostrum, transitional milk and mature milk. The amount of peptides in the milk was greater than for blood. The peptides, except for ELA, were increased in milk and blood by GDM. Betatrophin and ELA are synthesized in the connective tissue of the breast. ASP, glucagon and SUB are synthesized in the alveolar tissue of the breast. These peptides in breast milk may contribute to the development of the gastrointestinal tract of newborns and infants.

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 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.

Asprosin, irisin, and meteorin-like protein immunoreactivity in different stages of colorectal adenocarcinoma

OBJECTIVE

In this study, we aimed to investigate the immunoreactivity of asprosin, irisin, and meteorin-like protein (METRNL) in different stages of colorectal adenocarcinoma, which is the most common malignancy of the gastrointestinal tract.

MATERIALS AND METHODS

Overall, 60 patients with colorectal adenocarcinoma, including 20 well (Group 1), moderately (Group 2), and poorly differentiated (Group 3) cases, respectively, and 20 with normal colonic mucosa, were examined using light microscopy for immunohistochemical staining of asprosin, METRNL, and irisin.

RESULTS

Compared with the control group, a significant increase in irisin and asprosin immunoreactivity was found in the grade 1 and 2 colorectal adenocarcinoma groups. Moreover, compared with the grade 1 and 2 groups, this immunoreactivity was significantly decreased in the grade 3 colorectal adenocarcinoma group. Although there was no significant difference in METRNL immunoreactivity between the grade 1 and control groups, a statistically significant increase in this immunoreactivity was found in the grade 2 group. In contrast, METRNL immunoreactivity was significantly decreased in the grade 3 group compared with the grade 2 group.

CONCLUSION

We found that in early-stage colorectal adenocarcinoma there was an increase in the immunoreactivity of asprosin and irisin, but in the advanced stage there was a decrease in immunoreactivity. Although METRNL immunoreactivity did not change in the control and grade 1 groups, it was found to increase significantly in the grade 2 group and decrease in the grade 3 group.

Asprosin aggravates vascular endothelial dysfunction via disturbing mitochondrial dynamics in obesity models

OBJECTIVE

The aim of the study was to investigate the contribution of asprosin (ASP), a fasting-induced hormone involved in metabolic disorders, to vascular endothelial dysfunction in obesity models.

METHODS

Primary rat thoracic aortic endothelial cells treated with palmitic acid and mice fed with a high-fat diet (HFD) were used as the obesity models. The role and mechanism of ASP in endothelial dysfunction were investigated by the means of morphologic, functional, and genetic analysis.

RESULTS

ASP aggravated the endothelial dysfunction induced by either palmitic acid in vitro or an HFD in vivo, characterized as the impairment of endothelium-dependent vasodilation, reduction of nitric oxide levels, elevation of malondialdehyde levels, and inhibition of phosphoinositide 3-kinase-AKT-endothelial nitric oxide synthase signaling. However, adipose conditional knockout of ASP or ASP neutralization significantly alleviated the endothelial dysfunction induced by an HFD. Mechanistically, ASP enhanced mitochondrial fission, and inhibition of the fission through knockdown of dynamin-related protein 1 (a fission-hallmark factor) rescued the endothelial dysfunction and the disturbance to mitochondrial dynamics induced by ASP.

CONCLUSIONS

The findings demonstrate that ASP causes and even exacerbates vascular endothelial dysfunction through promoting mitochondrial fission in obesity, suggesting that ASP can act as an early predictive marker of blood vessel dysfunction and become a novel potential therapeutic target for obesity-related cardiovascular diseases.

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.

Cytokines and regulation of glucose and lipid metabolism in the obesity

The article presents data of the influence of cytokines of different directions of glucose and lipid metabolism in obesity. A change of the basic paradigm regarding adipose tissue has contributed to a number of recent discoveries. This concerns such basic concepts as healthy and diseased adipocytes, and, as a consequence, changes of their metabolism under the influence of cytokins. Distinguishing the concept of organokines demonstrates that despite the common features of cytokine regulation, each organ has its own specifics features of cytokine regulation, each organ has its own specific an important section of this concept is the idea of the heterogeneity of adipose tissue. Knowledge of the function of adipose tissue localized in different compartments of the body is expanding. There are date about the possibility of transition of one type of adipose tissue to another. A possible mechanism linking adipose tissue inflammation and the formation of insulin resistance (IR) is presented in this paper. The mechanism of IR development is closely connected with to proinflammatory cytokins disordering the insulin signal, accompanied by a decrease of the work of glucose transporters. A decrease of the income of glucose into cells leads to a change of glycolysis level to an increase of the fatty acids oxidation. Cytokins are able to participate in the process of the collaboration of some cells with others, that occurs both during physiological and pathological process.

Assessment of asprosin level and some of physiological variables in patients with cardiovascular diseases in Kirkuk city, Iraq

Introduction and Aim: Asprosin is a novel fasting-induced glucogenic adipokine, which stimulates the liver to release glucose into the blood stream. The aim of this study was to examine the role of asprosin as well as various physiological and oxidative stress factors in atherosclerosis and myocardial infarction patients in comparison to healthy controls in Kirkuk city, in order to clarify whether asprosin helps in protecting heart and preventing heart disease.   Materials and Methods: This study included blood samples collected from patients (n=70) and normal healthy controls (n=20), aged between 45-65 years from the Kirkuk General Hospital and external specialized clinical between December 2021 to February 2022. The samples were divided into three groups which included healthy controls (n=20), patients suffering from atherosclerosis (n=40) and myocardial infarction (n=30) respectively. Individuals in all groups were tested for their blood ASP, CPK-BM Tnt and lipid profile levels. Blood serum was also tested for concentration of FBS, INS, HbA1c, MDA and GSH.   Results: The asprosin, CPK-BM, Cardiac troponin (TNt) and INS levels was observed to be significantly elevated in atherosclerosis patients in comparison to healthy controls. However, in myocardial infarction patients significant increase levels was seen only for CPK-BM and INS levels. Lipid profiling showed that except for HDL levels, significant increased levels for TC, TG, LDL and VLDL in both atherosclerosis and MI patients as compared to healthy individuals. The concentration of FBS was seen elevated in blood serum of atherosclerosis and MI patients in comparison to controls.  No significant increase was observed for HbA1c and oxidative stress hormones MDA and GSH).   Conclusion: Changes in asprosin levels in patients with cardiovascular disease could be considered as a biochemical marker to estimate the severity of injury in heart and heart muscles.

Effects of GLP-1 receptor agonists on asprosin levels in normal weight or overweight/obesity patients with type 2 diabetes mellitus

Asprosin is a newly identified adipokine with glucose-raising and appetite-enhancing effects which acts differently from the known hepatic glucose utilization pathway. This study investigated changes in serum asprosin levels in normal weight or overweight/obese liraglutide-treated patients with type 2 diabetes (T2DM). This study is a non-randomized, prospective observational study. The metabolic parameters and asprosin levels were compared between 90 people with T2DM and 66 people who had normal glucose tolerance (NGT). During the treatment phase, only T2DM patients were given liraglutide at doses of 0.6 mg/d for the first 2 weeks, 1.2 mg/d for the subsequent 4 weeks, and 1.8 mg/d for the following 16 weeks. T2DM patients were separated into a normal weight group and an overweight/obesity group to compare changes in asprosin and parameters pre- and post-treatment. The T2DM group had significantly higher fasting asprosin and 2h-postprandial asprosin levels than the NGT group (all P < .001). Fasting asprosin and postprandial asprosin positively correlated with BMI, 2hPG, HbA1c, TG, and HOMA-IR, and negatively correlated with HDL-C in both the T2DM and NGT groups. Asprosin levels decreased after liraglutide treatment in both normal and overweight/obesity T2DM groups (all P < .001), with significantly reduced body weight and BMI in overweight/obese T2DM patients (all P < .001). Fasting and postprandial serum asprosin concentrations are higher in T2DM patients compared to normal glucose controls. Fasting and postprandial asprosin positively correlated with BMI, 2hPG, HbA1c, TG, and HOMA-IR and negatively correlated with HDL-C in all participants. Liraglutide lowers asprosin levels in T2DM patients and can reduce weight and BMI in overweight or obese type 2 diabetics.

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.

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.

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.

Ameliorative Effect of Oxytocin on FBN1 and PEPCK Gene Expression, and Behavioral Patterns in Rats' Obesity-Induced Diabetes

Amelioration of hyperinsulinemia and insulin resistance associated with obesity is a cardinal target for therapeutics. Therefore, we investigated the relation of Fibrilln-1 (FBN1) mRNA expression and hepatic phosphoenolpyruvate caboxykinase (PEPCK) enzyme to the ameliorative impact of oxytocin on obesity-induced diabetes, suggesting glycogenolysis markers in diabetic models. Four groups of forty male Wistar rats were formed (n = 10): a control group fed basal diet and intraperitoneal injections of saline; an oxytocin-injected group; a diet-induced obese group fed a high-fat/high-sugar diet and injected with saline; a diet-induced obese group injected with oxytocin. Depending on blood glucose levels, obese groups were further sub-grouped into prediabetic, and diabetic rats, with 5 rats each, at the ninth and the 16th week of the feeding period, respectively. FBN1 expression and PEPCK activity were determined using the qPCR technique and some biochemical parameters (glycemic, lipid profile, kidney, and liver functions) were determined using kits. Obese groups showed an elevation of brain FBN1 expression, high serum lipid profile, high glucose level, and a deleterious impact on liver and kidney functions. Obese groups showed the stimulator effect of the PEPCK enzyme and time-dependent pathological changes in renal and hepatic tissues. The motor activities were negatively correlated with FBN1 gene expression in prediabetic and diabetic rats. In addition to our previous review of the crucial role of asprosin, here we showed that oxytocin could ameliorate obesity-induced diabetes and decrease FBN1 gene expression centrally to block appetite. Oxytocin caused decreases in PEPCK enzyme activity as well as glycogenolysis in the liver. Therefore, oxytocin has a potential effect on FBN1 expression and PEPCK enzyme activity in the obesity-induced diabetic-rat model.

Serum Asprosin Concentrations in Children with Prader-Willi Syndrome: Correlations with Metabolic Parameters

Children with Prader–Willi syndrome (PWS) are characterized by severe obesity. Asprosin is a newly discovered protein hormone produced by the white adipose tissue and is correlated with insulin resistance. The aim of our study was to describe the concentrations of serum asprosin in children with PWS compared to those with overweight/obesity and normal weight, and to explore the postprandial change in asprosin concentrations in participants with PWS and BMI-z matched controls. We enrolled 52 children, 23 with PWS, 8 with overweight/obesity, and 21 with normal weight. Fasting levels of asprosin, glucose, and insulin were collected in all children, and postprandial asprosin and fasting levels of acyl ghrelin (AG) and leptin were also determined in a subsample of participants. There were no significant differences among groups in fasting levels of asprosin, glucose, insulin, and HOMA-IR. Fasting serum asprosin and 1-h post-meal serum asprosin did not differ in children with PWS nor in BMI-z matched controls. Fasting asprosin showed an adjusted positive correlation with glucose in children with obesity (r = 0.93, p = 0.007) but not in children with PWS nor children with normal weight. Circulating asprosin might be a predictor of early alterations in glucose metabolism in children with obesity. More research is needed to further explain the association between asprosin, food intake, metabolism, and obesity in PWS.

Protein tyrosine phosphatase receptor δ serves as the orexigenic asprosin receptor

Asprosin is a fasting-induced glucogenic and centrally acting orexigenic hormone. The olfactory receptor Olfr734 is known to be the hepatic receptor for asprosin that mediates its effects on glucose production, but the receptor for asprosin's orexigenic function has been unclear. Here, we have identified protein tyrosine phosphatase receptor δ (Ptprd) as the orexigenic receptor for asprosin. Asprosin functions as a high-affinity Ptprd ligand in hypothalamic AgRP neurons, regulating the activity of this circuit in a cell-autonomous manner. Genetic ablation of Ptprd results in a strong loss of appetite, leanness, and an inability to respond to the orexigenic effects of asprosin. Ablation of Ptprd specifically in AgRP neurons causes resistance to diet-induced obesity. Introduction of the soluble Ptprd ligand-binding domain in the circulation of mice suppresses appetite and blood glucose levels by sequestering plasma asprosin. Identification of Ptprd as the orexigenic asprosin receptor creates a new avenue for the development of anti-obesity therapeutics.

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 relationship of asprosin with β-hydroxybutyric acid and postpartum disorders in cows

The aim of the present study was to determine asprosin levels in cows, the relationship of this hormone with postpartum disorders and β-hydroxybutyric acid, and also the potential of asprosin to be a marker for postpartum diseases. The study was designed as a two-stage trial. In the first stage, blood asprosin and β-hydroxybutyric acid levels of 20 healthy Simmental cows aged 3-4 years were measured at the time of calving, and on days 3, 6, 9, 12 and 15 postpartum. In the second stage, 200 cows were divided into two groups: (1) healthy (n = 100) and (2) diseased (placental retention, hypocalcaemia, metritis, lameness, abomasal displacement, mastitis; n = 100); asprosin and β-hydroxybutyric acid concentrations of the blood were assessed on day 15 postpartum. In conclusion, the asprosin level was found to be at measurable levels in cows, and a negative correlation with β-hydroxybutyric acid was found. According to these findings, the data obtained from this study could be used for the prevention, control and treatment of some postpartum disorders associated with ketosis and for developing novel hypotheses concerning the actions of this hormone. It was concluded that further studies are required to reveal the associations between asprosin and postpartum disorders.

A potential role of fibrillin-1 (FBN1) mRNA and asprosin in follicular development in water buffalo

Fibrillin-1 (FBN1) functions as a structural protein in the ovary, while the role of its protein product asprosin remains unknown. Both proteins are encoded by the FBN1 gene and when it is cleaved at the C-terminal end, asprosin is produced. Asprosin is associated with various metabolic parameters and sex-related hormones in women. One goal of this research was to quantify FBN1 and the presumed asprosin receptor, olfactory receptor family 4 subfamily M member 1 (OR4M1) mRNA in water buffalo granulosa cells and correlate them to aromatase (CYP19A1) gene expression. A second goal was to determine the effect of asprosin on follicular growth in vivo. In Exp. 1, ovaries were collected from a local slaughterhouse, follicular fluid and granulosa cells from small (<6 mm) and large (6-13 mm) follicles were aspirated, cellular RNA extracted for gene expression analysis, data analyzed using ANOVA, and Pearson correlation coefficients were calculated among FBN1, OR4M1, and CYP19A1 gene expression. In Exp. 2, an intra-follicular injection of asprosin (600 ng of asprosin/194 μL of PBS) or vehicle (200 μL of PBS; Controls) was given via the theca layer of the dominant follicle of synchronized cows (n = 5/group) 1 day after injection of PGF2α, follicle sizes were measured daily via transrectal ultrasonography for 3 days, a two-way repeated measures ANOVA was used to determine the effect of asprosin on growth rate of follicles from day 0-2, and Chi-square analysis for the percentage of cows ovulated 2 days following asprosin injections. In Exp. 1, FBN1 mRNA abundance was 1.9-fold greater in cells of follicular aspirates from small than large follicles (P < 0.05), but abundance of OR4M1 and CYP19A1 mRNA did not differ (P > 0.10) between the two sizes of follicles. Abundance of FBN1 mRNA was positively correlated with CYP19A1 (r = 0.55, P < 0.05) and OR4M1 mRNA (r = 0.50, P < 0.06) across follicle sizes. In Exp. 2, cows treated with asprosin revealed a greater follicle growth rate from day 0-2 (63.4% increase in diameter) than placebo cows (36.8% increase in diameter) post-injection, and more follicles from asprosin treatment vs. control group (100% vs. 20%; P < 0.05) ovulated within 2 days. These findings suggest that FBN1 may be developmentally regulated in follicular cells, and that asprosin may induce follicular growth in buffaloes, but further studies will be required to determine if asprosin directly regulates estradiol production during follicle development.

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.

Crosstalk Communications Between Islets Cells and Insulin Target Tissue: The Hidden Face of Iceberg

The regulation of insulin secretion is under control of a complex inter-organ/cells crosstalk involving various metabolites and/or physical connections. In this review, we try to illustrate with current knowledge how β-cells communicate with other cell types and organs in physiological and pathological contexts. Moreover, this review will provide a better understanding of the microenvironment and of the context in which β-cells exist and how this can influence their survival and function. Recent studies showed that β-cell insulin secretion is regulated also by a direct and indirect inter-organ/inter-cellular communication involving various factors, illustrating the idea of "the hidden face of the iceberg". Moreover, any disruption on the physiological communication between β-cells and other cells or organs can participate on diabetes onset. Therefore, for new anti-diabetic treatments' development, it is necessary to consider the entire network of cells and organs involved in the regulation of β-cellular function and no longer just β-cell or pancreatic islet alone. In this context, we discuss here the intra-islet communication, the β-cell/skeletal muscle, β-cell/adipose tissue and β-cell/liver cross talk.

New Discovered Adipokines Associated with the Pathogenesis of Obesity and Type 2 Diabetes

Obesity is defined as abnormal or excessive accumulation of adipose tissue, closely associated with the increased risk of various comorbidities, especially type 2 diabetes mellitus (T2DM). Adipose tissue is a complex structure responsible for not only fat storage but also releasing adipokines which may play roles in the pathogenesis and could be developed into biomarkers for diagnosis, treatment and prognosis of obesity-related metabolic diseases. This review aims to summarize several adipokines discovered recently that have promising functions in obesity and T2DM. Among them, the levels of FSTL1, WISP1 and Asprosin in subjects with obesity or diabetes are commonly higher than in normal controls, suggesting that they may be pathogenic. Inversely, SFRP5, Metrnl, NRG4 and FAM19A5 may serve as the protective factors.

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.