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

Abstract

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

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

“…Since its discovery as a new metabolic hormone, several clinical studies have been conducted to establish a correlation of asprosin levels with obesity, diabetes mellitus, insulin resistance, metabolic syndrome, or diabetic nephropathy 4,6 (Supplementary Table S1). Pathologically elevated asprosin levels were reported in patients with obesity 7,16 , insulin resistance 23,24 , and diabetes mellitus type 1 25 and type 2 [26][27][28] .…”

“…Due to its proposed crucial metabolic function, several clinical studies have been conducted to establish a correlation of asprosin levels with obesity, diabetes mellitus type 1 and 2, insulin resistance, metabolic syndrome, and physical exercise [4][5][6] . However, reported measurements of asprosin in clinical samples showed considerable variations across studies raising serious concerns about the reliability of the applied ELISA detection approaches 5 .…”

Association Between Serum Asprosin and Diabetic Nephropathy in Patients with Type 2 Diabetes Mellitus in the Community: A Cross-Sectional Study

“…Asprosin is a recently discovered fasting-induced protein hormone mainly secreted by the white adipose tissue and recruited by the liver and brain. 1 , 2 Plasma asprosin levels can be modulated by physical activity, where anaerobic exercises increase their level, while aerobic exercises decrease it. 2 When reaching the liver, asprosin exerts a glucogenic effect through an olfactory G-protein-coupled receptor (OR4M1), and upon crossing the blood–brain barrier, it stimulates appetite-modulating neurons in the arcuate nucleus of the hypothalamus.…”

“… 1 , 2 Plasma asprosin levels can be modulated by physical activity, where anaerobic exercises increase their level, while aerobic exercises decrease it. 2 When reaching the liver, asprosin exerts a glucogenic effect through an olfactory G-protein-coupled receptor (OR4M1), and upon crossing the blood–brain barrier, it stimulates appetite-modulating neurons in the arcuate nucleus of the hypothalamus. 3 Recent experimental and clinical studies have shown that serum asprosin concentration is higher in subjects with metabolic syndrome and T2DM compared to controls.…”

Evaluation of serum asprosin levels in women with metabolic syndrome in Duhok City-Kurdistan Region/Iraq

“…16 In this study, it was elucidated that women with metabolic syndrome were had markedly elevated serum asprosin concentrations, similarly to a finding conducted from newly established study done in patients with T2DM. [17][18][19] However, the exact causes for an excessive production of asprosin in this condition is uncertain. 20 Nevertheless, data from previous studies show that pathologically elevated serum asprosin concentrations were be found in mice and humans with IR, in addition improving in insulin resistant and reduction in serum asprosin levels were be seen in mice treated by asprosin-specific monoclonal antibody.…”