Can novel adipokines, asprosin and meteorin-like, be biomarkers for malignant mesothelioma?

The Function and Mechanism of Anti-Inflammatory Factor Metrnl Prevents the Progression of Inflammatory-Mediated Pathological Bone Osteolytic Diseases

Metrnl, recently identified as an adipokine, is a secreted protein notably expressed in white adipose tissue, barrier tissues, and activated macrophages. This adipokine plays a pivotal role in counteracting obesity-induced insulin resistance. It enhances adipose tissue functionality by promoting adipocyte differentiation, activating metabolic pathways, and exerting anti-inflammatory effects. Extensive research has identified Metrnl as a key player in modulating inflammatory responses and as an integral regulator of muscle regeneration. These findings position Metrnl as a promising biomarker and potential therapeutic target in treating inflammation-associated pathologies. Despite this, the specific anti-inflammatory mechanisms of Metrnl in immune-mediated osteolysis and arthritis remain elusive, warranting further investigation. In this review, we will briefly elaborate on the role of Metrnl in anti-inflammation function in inflammation-related osteolysis, arthritis, and pathological bone resorption, which could facilitate Metrnl's clinical application as a novel therapeutic strategy to prevent bone loss. While the pathogenesis of elbow stiffness remains elusive, current literature suggests that Metrnl likely exerts a pivotal role in its development.

Elevated Asprosin Levels in Breast Cancer: Insights from a Comparative Study

Background: Breast cancer (BC) is the most common type of cancer in women. Diagnosis in the early stage is very important for cancer treatment. There is no good biomarker to diagnose BC in T1-T2 or N0 stage. This study aimed to evaluate asprosin (ASP) levels of BC compared with non-cancer. Materials and Methods: An enzyme-linked immunosorbent assay was used to evaluate serum ASP levels in 40 patients with BC and 40 healthy women. The cancer group included T1-T4, N1-N3, and M0-M1 patients. T stages were divided into groups as T1-T2 and T3-T4. N stages were divided into groups as N (0) and N (+). Results: ASP showed good discrimination (area under the curve = 0.767, 95% confidence interval: 0.657-0.878) between the BC group and the healthy group and acceptable discriminating ability (sensitivity = 0.825; specificity = 0.750) at the optimal cutoff value of 1.82 ng/mL. ASP indicated no difference for T, N, and M stages (p = 0.919, p = 0.859, and p = 0.225, respectively). There was a significant difference between grades within cancer patients in terms of ASP (p = 0.025). Conclusions: These findings provide evidence of a potential association between elevated ASP levels and the presence of BC. The observed higher levels of ASP in women with BC compared with healthy individuals suggest that ASP could potentially serve as a biomarker for distinguishing between the two groups. These results may contribute to our understanding of the potential role of ASP in BC detection and highlight its potential as a diagnostic marker. Further studies are required to establish whether ASP can be used to diagnose BC.

Role of asprosin and meteorin-like peptide in progression of actinic keratosis to squamous cell carcinoma

Squamous cell carcinoma (SCC) often develops from an underlying premalignant lesion. Factors that affect the progression of actinic keratosis (AK) to invasive SCC are not fully known. Asprosin (ASP) and meteorin-like peptide (METRNL) are adipokines that are involved primarily in glucose metabolism. We investigated the expression of ASP and METRNL in AK and SCC to evaluate the role of these adipokines in the development of SCC. We used 15 SCC specimens, 12 AK specimens and 12 healthy control skin specimens. ASP and METRNL protein expression in tumor and surrounding tissue was evaluated using immunohistochemistry. ASP expression in tumor tissue was significantly greater in the SCC group than in the control and AK groups, but it did not differ significantly between the AK and control groups. A positive correlation was observed for both ASP and METRNL expressions between tumor tissue and adjacent epidermis, hair follicles, sebaceous gland, eccrine gland, inflammatory cells and vascular structures. ASP and METRNL may exert pro-tumor effects toward development of invasive SCC. The expression intensity of ASP and METRNL can be used as a biomarker of risk of progression to SCC.

The Role of Meteorin-Like Peptide and Asprosin in Colon Carcinoma

INTRODUCTION

 Colon cancer is one of the most frequent gastrointestinal system cancers on a global scale. Common colonoscopy tests have reduced the incidence of colorectal cancer (CRC). Although nutrition, microorganisms, and their metabolites are related to colon cancer, the exact mechanism of CRC is still not clear. For this reason, it is of great importance to elucidate the molecular mechanisms of colon oncogenesis.

METHODS

This study was conducted retrospectively with samples obtained from the laboratory of Firat University Faculty of Medicine, Department of Pathology. A total of 30 patient samples were used. The control group consisted of healthy colon tissues from the same patients, and the other group consisted of colon carcinoma tissues from the same patients. Tissue samples of both groups were evaluated immunohistochemically with meteorin-like (METRNL) peptide and Asprosin.

RESULTS

The immunoreactivity of METRNL was found to be lower in colon carcinoma tissues than in healthy colon tissues (0.2 ± 0.06 and 0.08 ± 0.03, respectively). Asprosin immunoreactivity was found to be higher in colon carcinoma tissues than in healthy colon tissues (0.4 ± 0.07 and 1.08 ± 0.15, respectively).

CONCLUSION

As a result of this study, it was observed that there was a significant difference between healthy colon tissue and colon carcinoma tissue in terms of METRNL and Asprosin expression. Both proteins might be involved in the molecular mechanism of colon carcinoma. This situation is important in terms of diagnosis.

The protective effects of humanin in rats with experimental myocardial infarction: The role of asprosin and spexin

Objective

In this study, by applying humanin (HN) before myocardial infarction (MI) in rats, its protection in MI and the possible roles in asprosin and spexin were investigated.

Materials and methods

The rats were divided into 7 groups each with 6 rats (group I (control), group II (HN 48th hour), group III (HN 7th day), group IV (MI 48th hour), group V (MI 7th day), group VI (MI + HN 48th hour), group VII (MI + HN 7th day). To create MI, 200 mg/kg isoproterenol (ISO) was administered subcutaneously to the rats. 2 mg/kg HN was given intraperitoneally (ip) to rats alone and before MI. Molecular parameters asprosin and spexin were examined by immunohistochemical in heart tissue. Biochemical parameters (aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), Troponin I) were studied in serum by enzyme-linked immunosorbent assay (ELISA) method.

Results

It was found in the study that the levels of spexin elevated especially towards the 7th day after MI and decreased more significantly towards the 7th day, after HN application before MI. Asprosin elevated significantly towards the 7th day after MI and decreased especially on the 7th day after HN application before MI. Also, serum AST, LDH, CK-MB, and Troponin I levels tended to decrease and a significant decrease was detected in congested veins in the heart tissue at the 48th hour of MI and erythrocyte extravasation, congested veins and necrotic muscle fibers at the 7th day of MI in rats given HN before MI.

Conclusion

It was concluded that HN has a cardioprotective effect in MI and asprosin and spexin might mediate this effect.

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.

Use of asprosin and subfatin for differential diagnosis of serous ovarian tumors

Asprosin (ASP) and subfatin are hormones that regulate glucose metabolism. The role of ASP and subfatin in serous ovarian tumors has not been investigated. We investigated the expression of subfatin and asprosin in 30 serous benign, 30 serous borderline, 30 malignant and 30 control ovarian tissues. We investigated ASP and subfatin immunoreactivity and quantification was achieved using an ELISA method. ASP and subfatin were localized in the epithelial parts of normal ovarian tissues; however, in cancer tissues, immunoreactivity was detected in the parenchymal areas. Biochemical analysis of ovarian tissues revealed significantly decreased ASP and subfatin compared to the control. We propose that ASP and subfatin are promising candidates for biomarkers to distinguish serous benign, serous borderline and malignant ovarian cancers.

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.

Meteorin-like/Metrnl, a novel secreted protein implicated in inflammation, immunology, and metabolism: A comprehensive review of preclinical and clinical studies

Meteorin-like, also known as Metrnl, Meteorin-β, Subfatin, and Cometin, is a novel secreted protein exerting pleiotropic effects on inflammation, immunology, and metabolism. Earlier research on this hormone focused on regulating energy expenditure and glucose homeostasis. Consequently, several studies attempted to characterize the molecule mechanism of Metrnl in glucose metabolism and obesity-related disorders but reported contradictory clinical results. Recent studies gradually noticed its multiple protective functions in inflammatory immune regulations and cardiometabolic diseases, such as inducing macrophage activation, angiogenesis, tissue remodeling, bone formation, and preventing dyslipidemias. A comprehensive understanding of this novel protein is essential to identify its significance as a potential therapeutic drug or a biomarker of certain diseases. In this review, we present the current knowledge on the physiology of Metrnl and its roles in inflammation, immunology, and metabolism, including animal/cell interventional preclinical studies and human clinical studies. We also describe controversies regarding the data of circulation Metrnl in different disease states to determine its clinical application better.

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, 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.

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.

A pancancer overview of FBN1, asprosin and its cognate receptor OR4M1 with detailed expression profiling in ovarian cancer

Ovarian cancer affects >295,000 women worldwide and is the most lethal of gynaecological malignancies. Often diagnosed at a late stage, current research efforts seek to further the molecular understanding of its aetiopathogenesis and the development of novel biomarkers. The present study investigated the expression levels of the glucogenic hormone asprosin [encoded by fibrillin-1 (FBN1)], and its cognate receptor, olfactory receptor 4M1 (OR4M1), in ovarian cancer. A blend of in silico open access The Cancer Genome Atlas data, as well as in vitro reverse transcription-quantitative PCR (RT-qPCR), immunohistochemistry and immunofluorescence data were used. RT-qPCR revealed expression levels of OR4M1 and FBN1 in clinical samples and in ovarian cancer cell lines (SKOV-3, PEO1, PEO4 and MDAH-2774), as well as the normal human ovarian surface epithelial cell line (HOSEpiC). Immunohistochemical staining of a tissue microarray was used to identify the expression levels of OR4M1 and asprosin in ovarian cancer samples of varying histological subtype and grade, including clear cell carcinoma, serous ovarian cancer and mucinous adenocarcinoma. Immunofluorescence analysis revealed asprosin expression in SKOV-3 and HOSEpiC cells. These results demonstrated the expression of both asprosin and OR4M1 in normal and malignant human ovarian tissues. This research invokes further investigation to advance the understanding of the role of asprosin and OR4M1 within the ovarian tumour microenvironment.

Asprosin is associated with anorexia and body fat mass in cancer patients

PURPOSE

Increasing evidence suggests that many adipokines are involved in cancer-related anorexia and cachexia syndrome (CACS), although the underlying mechanism remains to be clarify. Asprosin is a new peptide hormone mainly secreted by white adipose tissues that can increase appetite and body weight. In this cross-sectional study, we tested whether asprosin may intervene in the development of CACS.

METHODS

The fasting plasma asprosin levels were determined via enzyme-linked immune-sorbent assay. Anorexia was determined using the anorexia/cachexia subscale (A/CS) of the functional assessment of anorexia/cachexia therapy (FAACT) questionnaire. The body composition was assessed using bioelectrical impedance analysis. The association of plasma asprosin with anorexia, cachexia, and nutritional status was analyzed.

RESULTS

One hundred twenty treatment-naïve patients with pathological confirmed gastrointestinal or lung cancer and 14 mild gastritis patients were recruited. We found no significant difference in asprosin levels between subgroups of patients by age, sex, cancer types or stage. Correlation analysis suggested that asprosin levels were positively associated with body fat mass (r = 0.248, p = 0.043). No correlations were found between asprosin levels and hemoglobin, white blood cell count, blood platelet count, albumin, C-reactive protein, glucose, cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, body mass index, body fat percentage, protein, skeletal muscle, muscle mass, lean body mass, and basal metabolic rate. Furthermore, asprosin levels were not significantly different between patients with or without cachexia. However, patients with anorexia had significantly lower asprosin levels compared with patients without anorexia. No significant difference in asprosin levels between gastritis and gastric cancer patients. Similarly, no significant change of asprosin levels occurred postoperatively in 10 gastric cancer patients.

CONCLUSIONS

Patients with anorexia had significantly lower asprosin levels compared with patients without anorexia. We therefore speculated that asprosin might intervene in the development of cancer anorexia and serve as a potential therapeutic target.

Expression of asprosin in rat hepatic, renal, heart, gastric, testicular and brain tissues and its changes in a streptozotocin-induced diabetes mellitus model

In this study, we aimed to investigate the presence of asprosin (ASP) in the liver, kidneys, heart, stomach, testicles and brain and to determine the serum and tissue asprosin levels in diabetic rats. A total of 14 male Wistar Albino rats were divided into two groups, each containing 7 rats: (I) control group and (II) experimental diabetes group. Control rats received no treatment and the rats in the experiment group received single-dose of streptozotocin (STZ) (50 mg/kg) dissolved in 0.1 M sodium citrate buffer (pH: 4.5) intraperitoneally. Serum levels of asprosin were measured using ELISA method. The presence of asprosin in hepatic, renal, cardiac, gastric, testicular and brain tissues was investigated using immunohistochemical staining. Asprosin was detected in hepatocytes in the liver, cortical distal tubule cells in the kidney, cardiomyocytes in heart, surface epithelial cells of stomach fundus, interstitial Leydig cells in testes and cortical neurons of the brain. Compared to control group, it was found that diabetic rats had decreased asprosin levels in liver, kidney and heart tissues, increased levels in gastric and testicular tissues and no significant changes in brain tissue. Serum asprosin levels of diabetic rats were found to be decreased compared to the control group. This is the first study in the literature that reports the presence of asprosin in liver, kidney, heart, stomach, testis and brain tissues in rats. The aim of the study is to determine the presence of ASP, a newly discovered adipokine, in various tissues and to examine tissue and serum level changes in STZ-induced diabetes.