Table 1.
Main characteristics of novel organokines involved in the pathophysiology of obesity.
| Organokine | Putative Role in Obesity and Obesity-Related Disturbances | Change | Reference |
|---|---|---|---|
| Adipokines | |||
| Chemerin | Mediation of obesity-associated low-grade inflammation; Negative correlation with HDL-linked antioxidant paraoxonase-1 enzyme; Strong correlation with the markers of dyslipidemia including lipoprotein subfractions; Biomarker for obesity and insulin resistance; Mechanistic influence on systolic blood pressure and hypertension. |
↑ | [23,26,28,32] |
| PAI-1 | Thrombotic effects and inflammation; Biomarker for obesity, insulin resistance and T2DM; Associations with the markers of atherogenic dyslipidemia (correlations with HDL subfractions and ApoAI; PAI-1 release stimulated by small-sized HDL in adipocytes; VLDL was capable of increasing the PAI-1 level in endothelial cells). |
↑ | [33,35,36,41] |
| LCN-2 | Biomarker for early renal injury; Biomarker for insulin resistance; Biomarker for hypertension; High LCN-2 levels negatively affect muscle physiology. |
↑ | [45,46,49,51] |
| PEDF | Anti-angiogenic properties by direct effects on endothelial cells; Role in lipid metabolism by the binding of adipose triglyceride lipase; PEDF expression may be upregulated by a compensatory mechanism; Biomarker for obesity, T2DM and MetS. |
↑ | [55,56,59] |
| PGRN | Growth factor in epithelial cells, fibroblasts and adipocytes; Direct binding to TNFR inhibiting neutrophil activation; Contradictory results in the progression of insulin resistance and inflammation; PGRN expression may be upregulated by a compensatory mechanism; Change of PGRN negatively correlated with the improvement of current perception threshold after 6-month alpha-lipoic treatment in T2DM patients with peripheral neuropathy. |
↑↓ | [60,61,63,65,68] |
| Vaspin | Insulin-sensitizing and anti-inflammatory agent via a compensatory mechanism; Involvement in hypertension; Involvement in lipid metabolism; Biomarker for obesity, T2DM and NAFLD. |
↑↓ | [71,72,75,76] |
| Omentin-1 | Insulin sensitizing and anti-inflammatory agent; Biomarker for MetS, hypertension, T2DM and diabetic complications; Involvement in lipid metabolism |
↓ | [77,79,80,81] |
| Metrnl | Involvement in thermogenesis in brown/beige adipocytes; Insulin sensitizing and anti-inflammatory effects; Putative involvement in lipid metabolism. |
↑↓ | [85,86,89] |
| Hepatokines | |||
| Afamin | Association with adiposity, markers of MetS and NAFLD; Biomarker for the prevalence and incidence of T2DM and gestational diabetes; Biomarker for unstable atherosclerotic plaque; Involvement in HDL metabolism. |
↑ | [96,97,99,101] |
| RBP4 | Strong correlation with the markers of dyslipidemia including lipoprotein subfractions and ApoAI; Association with adiposity, insulin resistance, MetS and T2DM. |
↑↓ | [103,105,106,109] |
| Fetuin-A | Strong correlation with the markers of dyslipidemia including lipoprotein subfractions; Putative association to HDL proteome; Biomarker for obesity, MetS and T2DM; Biomarker for subclinical atherosclerosis. |
↑↓ | [109,113,115,117,123] |
| FGF21 | Insulin-sensitizing effects; Regulator of thermogenesis and lipolysis in the brown adipose tissue; FGF21 expression may be upregulated by a compensatory mechanism in obesity, T2DM and hypertension; Short term moderately intensive physical activity improved FGF21 levels in T2DM patients with peripheral neuropathy. |
↑↓ | [127,128,133,134,135] |
| Gut hormones | |||
| Obestatin | Anorexigenic and insulin-sensitizing effects; Involvement in the pathophysiology of obesity, insulin resistance and T2DM; Involvement in the regulation of lipid metabolism including VLDL and HDL subfractions, correlation with mean LDL size. |
↓ | [139,142,145] |
| Ghrelin | Orexigenic effects, stimulating gastric motility and hepatic glucose secretion and reducing insulin secretion; Inducing growth hormone and glucocorticoid secretion; Ghrelin expression is markedly decreased in obese individuals independently of gender. |
↓ | [147,152,203] |
| Myokines | |||
| Irisin | Insulin sensitizing hormone; Involvement in lipid metabolism; Biomarker for MetS, T2DM and cardiovascular diseases; Increased levels after physical activity; Decreased levels after weight loss due to bariatric surgery. |
↑↓ | [171,178,185,187] |
| Myostatin | Negative regulator of skeletal muscle growth; Levels are decreasing with age and exercise; Related to systemic inflammation and sarcopenic obesity. |
↑↓ | [191,193,195] |
| Follistatin | Promoting muscle mass and function; Potential therapeutic use for the treatment of muscle wasting in cachexic conditions; Involvement in beige and brown adipose tissue differentiation. |
↑↓ | [197,202] |
Abbreviations: ↑ increased; ↓ decreased; ApoAI, apolipoprotein AI; FGF21, Fibroblast growth factor 21; HDL, high-density lipoprotein; LCN-2, lipocalin-2; LDL, low-density lipoprotein; Metrnl, Meteorin-like; MetS, metabolic syndrome; NAFLD, non-alcoholic fatty liver disease; PAI-1, plasminogen-activator inhibitor-1; PEDF, pigment epithelium derived factor; PGRN, progranulin; RBP4, Retinol-binding protein 4; TNFR, tumor necrosis factor alpha receptor; T2DM, type 2 diabetes mellitus; VLDL, very low-density lipoprotein.