Table 2 Adipokine expression dynamics and roles in modulating adipose tissue (AT) lipolysis in transition dairy cows
From: Adipose tissue lipolysis and remodeling during the transition period of dairy cows
Protein | Encoding gene | Function(s) | Transition period dynamics |
|---|---|---|---|
Angiopoietin-like 4 (ANGPTL4) | ANGPTL4 | - Inhibits LPL activity and adipocyte fatty acid (FA) uptake [42] - Increases cAMP production and enhances PKA phosphorylation through the integration of catecholamine and corticoid signaling [43] - Regulated by PPARs [127] | - Gene expression inversely associated with NEB intensity during transition period [44] |
Adiponectin (Acrp30) | ADIPOQ | - Improves insulin sensitivity and promotes lipogenesis in adipocytes [9] - Enhances FA β-oxidation in myocytes and hepatocytes [9] - Promotes anti-inflammatory and resolving phenotypes in immune cells [54] | - Decreased gene expression immediately after calving compared to dry period - Plasma concentration peaks between 40–70 d of lactation [53, 54] - Decreased AT expression of its receptors (adipoR1 and adipoR2) during the first 3 wks after calving compared to dry period, increasing steadily to peak around 100 d of lactation [55, 56] |
Leptin | OB | - Decreases lipogenesis and increases lipolysis and FA oxidation [59] - Reduction in leptin transcription and secretion during the transition period may promote a rapid return to normal DMI [62] | - Leptinemia peaks during the dry period and decreases during the first week following calving [60, 61] - Increased AT gene expression during the dry period contrasted with minimal transcription immediately following parturition [60] |
Resistin | RETN | - Increases lipolytic rate and the transcription of ATGL and HSL in AT explants from transition cows [66] | - Increased in plasma after calving, returning to pre-partum concentration by 6 wks into lactation [66, 67] - AT transcription and secretion dynamics are similar to that of plasma resistin [66] |
Retinol binding protein 4 (RBP4) | RBP4 | - Serves as a carrier of retinol [68] - Impairs glucose uptake by adipocytes and hepatocytes by suppressing insulin signaling pathways [69] - Inhibits adipogenesis [70] | - Decreased circulating RBP4 during the first day after parturition followed by return to pre-calving levels by second week of lactation [71, 72] |