Immunolocalization of G Protein‐Coupled Estrogen Receptor in the Pig Epididymis

Abstract

The presence of estrogen in the genital ducts of different mammalian species has been extensively studied and the estrogen influence on the functional activity of the male genital tract has been hypothesized. Conversely, very few data have been reported on pig excurrent ducts: the localization of classical estrogen receptors (ERα and ERβ) is scarcely known, while the expression of the G protein-coupled receptor (GPER1), a membrane estrogen receptor, is still unknown in pig. The aim of the present study was to evaluate GPER1 expression in the different regions of the mature pig epididymis, using immunohistochemistry, western blot and RT-PCR analyses. The results showed that GPER1 is mainly expressed in the epithelial cells of the corpus epididymis compared to the caput and the cauda, while muscle cells are moderately immunostained and stromal cells are unstained. The presence of GPER1 was confirmed by Western blot and RT-PCR analyses. In our study, we have demonstrated for the first time the GPER1 expression in male porcine epididymis, revealing a new mediator of estrogen signaling at this site. In conclusion, these new data suggest that estrogen action via GPER1 may contribute to sperm maturation in the corpus and sperm protection/storage in the cauda. Interestingly, the presence of GPER1 in the muscle layer may be indicative of a possible GPER1 involvement in the estrogen regulation of duct contractility. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc.

G Protein-Coupled Estrogen Receptor (GPER) and ERs Are Modulated in the Testis–Epididymal Complex in the Normal and Cryptorchid Dog

“…The expression of ERs has been widely documented in the epididymis of several species (mice, rats, dogs, cats, and monkeys) [ 32 , 35 , 36 , 46 , 58 ] with a common observation of the presence of ER-alpha in the efferent ductules that not only provide to the reabsorption of more than 90% of the rete testis fluid but concentrate sperm for epididymal storage [ 59 ]. In addition, the very wide GPER expression in the epididymis of pigs [ 28 , 60 ], rats [ 30 ], sheep [ 61 ] and in humans’ ductuli efferents and proximal epididymis [ 29 ] suggests its involvement in sperm maturation, protection, and storage. However, GPER could play other different roles such as in the regulation of contractility, demonstrated by its presence in the muscle cells of the human ductuli efferent and proximal epididymis [ 29 , 62 ].…”

“…GPER expression was investigated in the testis of the horse [ 23 ], rat [ 24 , 25 , 26 ] and human [ 27 ], while in the epididymis, its expression was reported in pigs [ 28 ], humans [ 29 ] and rats [ 30 ]. On the contrary, in dogs, limited studies have shown its presence in testes with and without tumors [ 31 ], and no data are available for dog epididymis.…”

Function and therapeutic potential of GPCRs in epididymis

“…GPER has been detected in many male reproductive structures, such as the testes (Cassault-Meyer et al , 2014;Gautier et al , 2016;Lucas et al , 2010), spermatozoa (Arkoun et al , 2014;Cassault-Meyer et al , 2014;Gautier et al , 2016), and prostate (Rago et al , 2016). It has also been found in the efferent ductules and epididymis (Cao et al , 2017;Hess et al , 2011;Katleba et al , 2015;Krejcirova et al , 2018;Lu et al , 2016;Malivindi et al , 2018;Martinez-Traverso et al , 2015;Menad et al , 2017;Pereira et al , 2014;Rago et al , 2018), indicating that GPER may play important roles in sperm maturation, protection and storage (Table 1). For instance, in the corpus epididymis of postnatal pigs, GPER participates in sperm maturation by affecting the formation of the blood-epididymal barrier (Katlebaet al , 2015).…”

Function and therapeutic potential of G protein‐coupled receptors in epididymis

“…GPER has been detected in many male reproductive structures, such as the testes (Cassault-Meyer, Gress, Seralini, & Galeraud-Denis, 2014;Gautier et al, 2016;Lucas et al, 2010), spermatozoa (Arkoun et al, 2014;Cassault-Meyer et al, 2014;Gautier et al, 2016), and prostate (Rago, Romeo, Giordano, Ferraro, & Carpino, 2016). It has also been found in the efferent ductules and epididymis (Cao et al, 2017;Hess et al, 2011;Katleba et al, 2015;Krejcirova et al, 2018;Lu et al, 2016;Malivindi, Aquila, & Rago, 2018;Martinez-Traverso & Pearl, 2015;Menad et al, 2017;Pereira et al, 2014;Rago et al, 2018), indicating that GPER may play important roles in sperm maturation, protection and storage (Table 1). For instance, in the corpus epididymis of postnatal pigs, GPER participates in sperm maturation by affecting the formation of the blood-epididymal barrier (Katleba et al, 2015).…”