Cleavage of integrin by mu-calpain during hypoxia in human endometrial cells

Problem:  The distribution and activation of μ-calpain and possible cleavage of integrin in human endometrial cells under hypoxic condition were investigated. Method of study:  Human endometrial epithelial and stromal cells were subjected to hypoxia, and subsequently used for immunostaining and western blot analysis. Results:  The proform of μ-calpain was detected in the cytoplasm of normal cells, and displayed a substantial decrease after hypoxia. Conversely, the active form of μ-calpain was not detected in normal cells, but was abundant after hypoxia. The cytoplasmic domain of integrin β3 was also detected in the cytoplasm of endometrial cells. Western blot analysis confirmed that both the proform of μ-calpain and the integrin β3 cytoplasmic domain decreased during hypoxia. Conclusions: μ-Calpain is activated in human endometrial cells during hypoxia and that subsequent cleavage of the integrin β3 cytoplasmic domain may give some adverse effects to the function of human endometrium.