Expression of a P-selectin Ligand in Zona Pellucida of Porcine Oocytes and P-selectin on Acrosomal Membrane of Porcine Sperm Cells. Potential Implications for Their Involvement in Sperm–Egg Interactions

Abstract

The selectin family of cell adhesion molecules mediates initial leukocyte adhesion to vascular endothelial cells at sites of inflammation. O-glycan structural similarities between oligosaccharides from human leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) and from zona pellucida glycoproteins of porcine oocytes indicate the possible existence of a P-selectin ligand in the zona pellucida. Here, using biochemical as well as morphological approaches, we demonstrate that a P-selectin ligand is expressed in the porcine zona pellucida. In addition, a search for a specific receptor for this ligand leads to the identification of P-selectin on the acrosomal membrane of porcine sperm cells. In vitro binding of porcine acrosome-reacted sperm cells to oocytes was found to be Ca2+ dependent and inhibitable with either P-selectin, P-selectin receptor–globulin, or leukocyte adhesion blocking antibodies against P-selectin and PSGL-1. Moreover, porcine sperm cells were found to be capable of binding to human promyeloid cell line HL-60. Taken together, our findings implicate a potential role for the oocyte P-selectin ligand and the sperm P-selectin in porcine sperm– egg interactions.

Distribution of sialoglycoconjugates in the oviductal isthmus of the horse during anoestrus, oestrus and pregnancy: a lectin histochemistry study

“…The O-linked glycans secreted by non-ciliated cells are likely to constitute the cell coat of the luminal plasmamembrane of the epithelium . Glycoproteins secreted by non-ciliated cells create an intraluminal environment able to immobilise spermatozoa (Hunter, 1995), to maintain the viability and fertilizing capability of spermatozoa (Pollard et al, 1991;Suarez et al, 1991;Chian et al, 1995) and to play a supportive role in sperm/egg interactions (Geng et al, 1997;Tulsiani et al, 1997). Differences in the production of oestrus-associated glycoproteins by oestrogen have been observed in the isthmus of baboon (Verhage and Fazleabas, 1988) and pig (Buhi et al, 1992).…”

“…The differences in the isthmus distribution of O-linked oligosaccharides during the investigated stages may be related to the existence of a cycle-specific regulation of the spermatozoa attachment to the oviductal epithelium of horse (Thomas et al, 1994). It has been proposed that, in other mammals, O-linked glycans are involved in a variety of biological phenomena including in vitro sperm capacitation (Banerjee and Chowdhry, 1994;Focarelli et al, 1995), a selective barrier to sperm transport, modulation of sperm ascent to the site of fertilization (DeSouza and Murray, 1995) and sperm-egg interaction (Geng et al, 1997;Tulsiani et al, 1997). At present, the role played by sialoglycoconjugates of the epithelium lining the isthmic oviduct of horse is not known.…”

“…Among the carbohydrates that constitute the oligosaccharide chains in glycoproteins, sialic acids are known to be a large family of nine-carbon carboxylated sugars that usually occupy the terminal position of oligosaccharide chains in a variety of glycoconjugates (Schauer, 1982) and to act as ligands in recognition phenomena (Varki, 1997) as well as in vitro sperm capacitation (Banerjee and Chowdhry, 1994;Focarelli et al, 1995) and spermegg interaction (Geng et al, 1997). In spite of their putative importance, sialoglycoconjugates have not been studied in horse.…”

“…However, non-ciliated cells are mainly involed in the synthesis and release of secretory glycoproteins that are dissolved in the oviductal fluid. Once released in the lumen, glycoproteins create an intraluminal environment able to maintain the viability and fertilizing capability of spermatozoa (Pollard et al, 1991;Suarez et al, 1991;Chian et al, 1995) and to play a supportive role in sperm/egg interactions (Geng et al, 1997;Tulsiani et al, 1997).…”

Andrographolide inhibits NF-κB activation and attenuates neointimal hyperplasia in arterial restenosis

“…The de novo synthesis of E-selectin and VCAM-1 in vascular endothelial cells is well known to be exclusively regulated by NF-κB transcription factors [9,[14][15][16][17][18][19][20]. We thus examined whether the expression of E-selectin and VCAM-1 is regulated by p50-mediated NF-κB activation in our murine models of experimental arterial restenosis.…”