The expression of chemerin and its receptors (CMKLR1, GPR1, CCRL2) in the porcine uterus during the oestrous cycle and early pregnancy and in trophoblasts and conceptuses

Abstract

Recent research has demonstrated that chemerin may take part in the regulation of reproduction. The aim of this study was to determine the expression of chemerin system – chemerin and its receptors, chemokine-like receptor 1 (CMKLR1), G protein-coupled receptor 1 (GPR1) and C-C chemokine receptor-like 2 (CCRL2) – in the porcine uterus during the oestrous cycle and early pregnancy, and in trophoblasts and conceptuses by real-time PCR and western blotting. Chemerin concentrations in uterine luminal flushings (ULF) were determined using ELISA test. In the endometrium, the highest expression of chemerin and GPR1 proteins was observed during the mid-luteal phase; CMKLR1, during the late luteal phase; and CCRL2, during the follicular phase of the cycle. In the myometrium, chemerin protein expression was enhanced during the early luteal phase, and chemerin receptor proteins were highly expressed during the follicular phase. In the endometrium of pregnant pigs, the highest expression of chemerin and CCRL2 protein was observed during implantation; CMKLR1, during placentation; and GPR1, during embryo migration. In the myometrium, chemerin and CCRL2 protein expression increased at the end of implantation, and the expression of CMKLR1 and GPR1 protein was enhanced during implantation. In the conceptuses and trophoblasts, the highest expression of chemerin system proteins was observed during placentation, with the exception of GPR1 protein in the trophoblasts. The highest concentrations of the analysed adipokine were observed in ULF during the luteal phase of the cycle and during maternal recognition of pregnancy. This is the first study to demonstrate that the expression of the chemerin system in the porcine uterus, conceptuses and trophoblasts, and chemerin concentrations in ULF are influenced by the hormonal milieu in different stages of the oestrous cycle and in early pregnancy. The present results also suggest that chemerin is implicated in the regulation of reproductive functions in pigs.

Genomic Analysis of IgG Antibody Response to Common Pathogens in Commercial Sows in Health-Challenged Herds

“…These genes are most related to cytokine-cytokine receptor interactions. Of those, CCRL2 has recently been implicated in the regulation of reproductive functions in pigs (Gudelska et al, 2020). The region on SSC 4 (63 Mb) has also previously been associated with number of piglets mummified in a large White population (Wu et al, 2019).…”

The In Vitro Effect of Prostaglandin E2 and F2α on the Chemerin System in the Porcine Endometrium during Gestation

“…The expression of the chemerin system in the porcine reproductive tract during the estrous cycle and early gestation has been reported previously [ 23 ]. Chemerin, CMKLR1, GPR1, and CCRL2 have been detected in both the endometrium and the myometrium.…”

“…During this time, the direction of PGF 2α secretion is altered from endocrine to exocrine, and PGE 2 production is stimulated, which promotes the secretory functions of the corpus luteum and ensures the proper course of gestation [ 36 , 37 ]. During our previous study we indicated the changes of chemerin system protein expression across early gestation which may be caused by a number of factors present in the uterine microenvironment [ 23 ]. The analysis of the results presented herein indicates many similarities between the basal and PG-stimulated chemerin system expression patterns on the corresponding days of gestation.…”

“…The expression of chemerin and its receptors in the porcine hypothalamic structures responsible for gonadoliberin (GnRH) production, as well as in the pituitary gonadotrophs suggests the potential involvement of the adipokine in the regulation of the reproductive functions [ 14 , 15 ]. Chemerin system expression was observed in the human uterus [ 18 , 19 ], in human and rat placenta [ 1 , 20 ], in the ovaries of women and rodents [ 1 , 21 , 22 ], and in porcine ovaries, uteri, trophoblasts, and conceptuses [ 23 , 24 ]. The expression of the chemerin system components in the endometrium, trophoblasts, placentas, and conceptuses suggests that the adipokine may play an important role in the foeto–maternal crosstalk during early pregnancy, as well as, through the placenta, across the whole gestation period.…”

“…Our previous research revealed changes in the expression of the chemerin system in porcine uterine and ovarian tissues and demonstrated changes in serum chemerin concentrations during the estrous cycle and early gestation. These findings suggest that chemerin system expression may be dependent on the hormonal milieu [ 14 , 23 , 24 ]. Similar observations were made by Yang et al, [ 26 ] who reported that chemerin and GPR1 expression in the ovaries of mice varied during the estrous cycle.…”