Table 2.

Adipokine expression dynamics and roles in modulating adipose tissue (AT) lipolysis in transition 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]