Table 2.
Main characteristics of some adipokines, myokines, osteokines, and hepatokines involved in the pathogenesis of MAFLD.
| Classification | Organokine | Production | Action | Role in MAFLD | Ref. |
|---|---|---|---|---|---|
| Adiponectin | Adipose tissue | Anti-inflammatory: Secretion of cytokines, such as IL-10; blocking NF-κβ activation; inhibition of the release of TNF-α and IL-6 Antisteatostatic Antifibrotic weight loss: Inhibition of hepatic glycogenesis |
Protective adiponectin, its levels are inversely proportional to insulin resistance | [69,137,147] | |
| Leptin | Adipose tissue | Pro-inflammatory: Secretion of IL-6 and TNF-α MAFLD progression Reduces adiponectin concentration Reduces adipose tissue lipolysis |
Related to insulin resistance or failure of the antisteatotic effect | [69,137,147,168] | |
| ADIPOKINE | Omentin | Increases peripheral sensitivity to insulin and glucose absorption Protection against atherosclerosis and liver implications |
Inversely related to obesity, hyperglycemia, inflammation, and insulin resistance | [145,147] | |
| Resistin | Adipose tissue macrophages and monocytes | Reduces the number of mitochondria Elevates lipid accumulation |
Expressed abundantly by patients with MAFLD | [147,168] | |
| Vaspin | Visceral dipole tissue | Increased insulin sensitivity: Inhibitory action of kallikrein 7 protease, responsible for insulin degradation Anti-inflammatory: Reduced production of pro-inflammatory cytokines |
Protects vascular tissue from possible damage due to fat accumulation | [147] | |
| Visfatin | Macrophages and adipocytes of adipose tissue and hepatocytes and neutrophils | Helps in the storage of triacylglycerols: Dysfunction of pancreatic beta cells Production and release of TNF-α, VCAM-1, and IL-6 |
Related to a pro-inflammatory scenario | [145,147,171] | |
| MIOKINE | Irisin | Adipose tissue | Differentiation of white adipose tissue (WAT) into brown adipose tissue (BAT) Suppresses lipogenesis and cholesterol synthesis: Optimization of lipid oxidation |
Improves lipid homeostasis | [163,168] |
| Myostatin e Mionectin | Pro-inflammatory Inhibits antioxidant compounds |
Progression of lipid uptake and deposition in the liver | [163] | ||
| OSTEOKINE | BMP-4 | Adipocytes | Regulation of metabolic processes: Adipogenesis, targeting preadipocytes toward the brown phenotype | In obesity, pre-adipocytes are resistant to this subtype of BMP, which may contribute to diseases related to this condition | [69,180] |
| Osteocalcin | Osteoblasts | Stimulation of glucose and fatty acid consumption: Expression of fatty acid transporters | Anti-inflammatory scenario that contributes to a reduction in visceral fat | [168] | |
| HEPATOKINE | ANGPTL-4 | Liver | Inhibition of pancreatic lipases | Related to less fat absorption, and in obese patients, there is a decrease in their liver levels | [168,178] |
| LECT-2 | Neutrophil chemotaxis Weight gain Detects the development of hepatic steatosis |
Associated with metabolic stress; it compromises insulin signal transduction in addition to increasing the secretion of inflammatory cytokines | [166,178] | ||
| SHBG | Liver | Transport of sex steroids Overexpression protects against the development of MAFLD: Inhibition of hepatic lipogenesis by control of lipogenic enzymes |
Decreased rate in patients with hepatic steatosis. Fat accumulation reduces SHBG production by increasing hepatic lipogenesis and exacerbating the development of MAFLD | [169,171,178] |
ANGPTL-4: Angiopoietin-Like 4; BMP: Bone Morphogenetic Protein; IL: Interleukin; MAFLD: metabolic-associated fatty liver disease; LECT 2: Leukocyte Cell-Derived Chemotaxin; NF-κβ: Nuclear Factor κβ; SHBG: Sexual Hormone-Binding Globulin; TNF-α: Tumor Necrosis Factor-α; VCAM: Vascular cell adhesion protein 1.