Integrins, and relationship with infertility

Abstract

Integrins are a class of adhesion molecules that participate in cell-to-cell and cell-to-substratum interactions. All mammalian eggs express integrins at their surface, and the integrin alpha 6 beta 1 serves as a sperm receptor that mediates sperm-egg binding. Moreover, certain integrin moieties appear to be regulated within the cycling endometrium. Specifically, the expression of beta 1 integrins in the early proliferative phase is restricted to the glandular epithelium, whereas stromal cells also express beta 1 integrins in the midsecretory phase. The expression of beta 1 integrins increases at the time of implantation and remains elevated in the decidua during early pregnancy. A disruption of integrin expression is associated with certain types of infertility in women. As a result, integrins play particularly important roles in both fertilization and embryogenesis, including the process of implantation.