Immunolocalization of the hyaluronan receptor CD44 in the reproductive tract of the mare

• Published in: Theriogenology Vol. 75; no. 2; pp. 276 - 286
• Main Authors: Rodriguez Hurtado, I., Stewart, A.J., Wolfe, D.F., Caldwell, F.J., Harrie, M., Whitley, E.M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.01.2011; [Oxford]: Butterworth-Heinemann; [New York]: Elsevier Science
• Subjects: Animals; biochemical pathways; CD44; cell adhesion; epithelial cells; Epithelium - metabolism; Female; female reproductive system; Fibrosis; Genital Diseases, Female - metabolism; Genital Diseases, Female - pathology; Genitalia, Female - immunology; Genitalia, Female - metabolism; Genitalia, Female - pathology; glycoproteins; glycosaminoglycans; Horse; Horse Diseases - metabolism; Horse Diseases - pathology; Horses - metabolism; Hyaluronan receptor; hyaluronan receptor CD44; Hyaluronan Receptors - metabolism; Hyaluronic Acid - metabolism; Immunohistochemistry; immunolocalization; inflammation; Inflammation - metabolism; Inflammation - pathology; Lymphocytes - metabolism; Lymphocytes - pathology; mares; Ovary; Oviduct; receptors; reproductive disorders; Signal Transduction - immunology; Signal Transduction - physiology; Uterus; Ovary; Oviduct; Uterus; CD44; Hyaluronan receptor; Horse
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2010.08.014

Hyaluronan (HA), a glycosaminoglycan, is a major component of the pericellular matrix which envelopes mammalian cells. Binding of hyaluronan to one of its specific receptors, CD44, modulates transduction of intracellular signals which direct a variety of processes, including embryogenesis, wound healing, inflammation, and neoplasia. Since regulation of these processes is critical to equine reproductive success, localization of constitutive CD44 expression was evaluated by immunohistochemical methods in ovarian, oviductal, and uterine tissues from healthy mares. Ovarian stroma contained thecal cells with varying CD44 immunopositivity. Follicular and granulosa cells of some antral and atretic follicles were positive for CD44. In the oviduct, the luminal epithelium was variably positive for CD44, with overall decreasing intensity of immunostaining from the infundibulum to the isthmus. The CD44 molecule was expressed strongly by surface epithelial cells of the uterine endometrium, but was present only rarely among cells of uterine glands. In addition, CD44 was expressed by smooth muscle cells of vascular walls, oviduct, and uterus. Since CD44 is known to modulate cell movement and differentiation, and was present at multiple sites in the reproductive tract of normal mares, we inferred there may be an important role for the HA-CD44 signaling pathway in reproductive function and inflammation.