Search

• Interbreed differences in hormonal adipokine profiles in plasma and pituitary. • Adipokine variability across estrous cycle phases. • Correlation analysis of adipokines with metabolic and reproductive parameters. • Importance of breed-dependent correlations between Large White and Meishan pigs. • The potential impact of adipokines on metabolic and reproductive processes in swine. Adipokines play crucial roles in both reproductive and energy metabolic processes. This study aimed to compare the hormonal plasma profile of adiponectin, apelin, vaspin, chemerin, resistin, visfatin, and adipolin, and the expression of their receptors in the anterior pituitary (AP) between normal-weight Large White (LW) and fat Meishan (MS) pigs during different phases of the estrous cycle. We measured adipokine levels in the plasma and assessed their gene expression in the AP. We used Pearson's correlation analysis to examine potential links between adipokines levels, their receptors, and metabolic parameters (body weight; backfat thickness) and reproductive parameters (pituitary weight; age at puberty; levels of gonadotropins, steroid hormones; and gene expression of gonadotropin-releasing hormone receptor and gonadotropins in AP). The plasma levels of the evaluated adipokines fluctuated with phase and breed, except for visfatin and adipolin. Moreover, adipokine expression in AP varied significantly between breeds and estrous cycle phases, except for resistin receptor CAP1. Notably, we observed a positive correlation between plasma levels of adiponectin and its transcript in the AP only in MS pigs. Apelin gene expression correlated negatively with its receptor in MS, while we observed a breed-dependent correlation between chemerin gene expression and its receptor CMKLR1. We identified significant positive or negative correlations between adipokines or their receptor levels in plasma and AP as well as metabolic or reproductive parameters, depending on the breed. In conclusion, we have demonstrated breed-specific and estrous cycle-dependent regulation of adipokines in AP, underscoring their potential impact on metabolic and reproductive processes in swine. [ABSTRACT FROM AUTHOR]

Spexin (SPX) is a newly identified neuropeptide, a natural ligand for the galanin receptors (GALR) 2/3, which is involved in maintaining physiological functions including female reproduction. One of the most common endocrine disorder in reproductive system is polycystic ovary syndrome (PCOS), however the role of SPX in PCOS is still unknown. The objective of this study was to determine the expression of mRNA and peptide levels of SPX and its receptors GALR2/3 in the hypothalamus and ovary (by real time PCR and Western blot) as well as plasma levels of SPX (ELISA) in letrozole - induced PCOS rats. We observed that SPX plasma level does not change in PCOS rats. In the hypothalamus transcript level of Spx and Galr3 were significantly higher in PCOS rats compared to the control, while mRNA of Galr2 and protein expression of GALR2/3 were lower. Moreover, expression of Spx and Galr2/ 3 mRNA as well as GALR2/3 peptide production were lower in the ovary of PCOS rats. In summary, while our results did not show differences in plasma SPX levels, we observed tissue-dependent significant differences in the SPX/GALR2/3 levels between PCOS and control rats, what indicates possible new mechanisms of PCOS neuroendocrinology. • SPX plasma level does not change in PCOS rats. • Hypothalami mRNA of Spx and Galr3 were higher in PCOS rats. • Ovarian expression of Spx and Galr2/ 3 mRNA and GALR2/3 protein were lower in the PCOS rats. [ABSTRACT FROM AUTHOR]

• LEP, RARRES2 and RETN protein levels in plasma and WAT are higher in MS than LW sows. • ADIPOQ and ITLN1 protein levels in plasma and WAT are lower in MS than LW sows. • Plasma LEP and RARRES2 are positively associated with the BFT in MS and LW sows. • Plasma LEP and RARRES2 are negatively associated with the puberty age in MS and LW. • Plasma ADIPOQ is negatively linked to BFT and positively to the puberty age in MS and LW. In pig, backfat deposition is strongly related to the growth and reproductive performance. However, the molecular regulatory mechanisms of adipose tissue are not clearly understood. Adipose tissue is now recognized as an important endocrine organ that secretes a variety of factors including adipokines. However, the regulation of expression pattern of these adipokines in both plasma and visceral white adipose tissue (WAT) in lean and fat pig is unclear. In the present study, we used two representative porcine breeds (Large White, LW; Meishan, MS) with contrasting backfat thickness and sexual maturity age. Using specific ELISA assays, we determined the plasma profile of eight adipokines, leptin, adiponectin, visfatin, apelin, chemerin, resistin, omentin and vaspin in LW and MS sows. By RT-qPCR and western-blot we also investigated the mRNA and protein levels of these adipokines and their cognate receptors (LEPR, ADIPOR1, ADIPOR2, CMKLR1, CCRL2, GPR1, APLNR, TLR4, ROR1, CAP1 and HSPA5) in the peri renal WAT, respectively. At both plasma and peri renal WAT level, we found that the amounts of leptin, chemerin, resistin and vaspin were higher whereas those of adiponectin and omentin were lower in MS than LW sows. Plasma and adipose tissue visfatin and apelin levels were not different between the two breeds. Moreover, we noted that the variations of peri renal WAT adipokines observed between MS and LW were similar at the protein and mRNA level except for chemerin and apelin suggesting post-transcriptional modifications for these two adipokines. Finally, among the eight adipokines studied, we showed that only the plasma concentrations of leptin and chemerin were positively and those of adiponectin, negatively associated with the thickness of fat and opposite correlation was found for the onset of puberty in both LW and MS animals. Taken together, these results support a potential involvement of adipokines in WAT regulation and its link with the onset of the puberty in sows. [ABSTRACT FROM AUTHOR]