Adiponectin, an Unlocking Adipocytokine

Abstract

A large number of studies revealed that adiponectin, a protein secreted specifically by adipose tissue, exhibits antiinflammatory, antiatherogenic, and antidiabetic properties. This 247‐amino acid protein contains four differentiable domains and exists in five different configurations, which binds three kinds of receptors. The plasma adiponectin concentration is at amazing microgram level and the gender difference is very clear. Obese subjects showed decreased plasma level of adiponectin while exercise seems to restore it. Many researchers demonstrated that it could be a reliable biomarker for multiple diseases. However, there is controversy about its role in inflammation since its plasma concentration decreases in some inflammatory diseases and increases under some other inflammatory conditions. The signal transduction pathway is still not very clear yet. Could adiponectin be a promising drug target?

TNF‐α, a potent lipid metabolism regulator

“…This concentration is about 3 orders of magnitude higher than leptin and about 6 orders of magnitude higher than IL-6, which measured in ng mL À1 and pg mL À1 , respectively; (2) adiponectin exists in six forms in vivo: the gAPN (globular adiponectin), fAPN (full-length adiponectin), LMW (low molecular weight adiponectin), MMW (middle molecular weight adiponectin), HMW (high molecular weight adiponectin), and Alb-LMW (serum albumin bounded form adiponectin). 105 Its multiple beneficial effects in obesity, atherosclerosis, and metabolic syndrome 104,106 strongly supports its potential role in lipid metabolism regulation. Similar to leptin, regulation of adiponectin expression and secretion by TNF-a was well documented: Neutralization of TNF-a and anti-TNF-a therapy reduced ConA-induced liver damage in mice and improve endothelial dysfunction in patients with RA, respectively.…”

Hemoglobin is Associated with Serum High Molecular Weight Adiponectin in Japanese Community-Dwelling Persons

“…A large number of studies have demonstrated that adiponectin exhibits anti-inflammatory, anti-diabetic, anti-atherogenic, anti-thrombotic, lipidoxidation enhancing, and vasodilatory properties [2][3][4][5] . Moreover, it has been recently demonstrated that adiponectin forms multimers and is present in the serum as a trimer, hexamer, or as a HMW form, which is the most active form of this protein 6) .…”

Serum High Molecular Weight Adiponectin is Associated with Mild Renal Dysfunction in Japanese Adults

“…Adiponectin, a recently discovered circulating 247-amino acid protein secreted specifically by adipose tissue, contains four differentiable domains, is present at concentrations of 5 − 30 g/mL in healthy humans, and is considered to exhibit anti-inflammatory, antiatherogenic, and antidiabetic properties [1][2][3][4] . tion with an eGFR ≥ 60 mL/min/1.73 m 2 10) .…”