Problem: In our previous study, we have been reported that calpain, a calcium-dependent cysteine protease, activated by increasing intracellular calcium-ion concentration in endometrial cell, cause endometrial dysfunction for implantation. In this study, we investigated the existence and contribution of calpains, their endogenous inhibitor calpastatin, and their substrate such as integrin β3 and α-fodrin in deciduas of patients with recurrent miscarriage.
Method of Study: Deciduas were surgically collected from 31 patients with recurrent miscarriage and 23 healthy women with informed consent. Immunohistochemistry, SDS-PAGE and western blot analysis were performed using antibodies against calpain, calpastatin, integrin β3 and α-fodrin.
Results: Staining of μ-calpain, m-calpain, capastatin, integrin β3 and α-fodrin were observed in the cytoplasm of stromal and epithelial cells in deciduas using immunohistochemistry. No significant differences were observed in staining patterns. Western blot analysis shows no significant differences in m-calpain, calpastatin and α-fodrin, while μ-calpain was significantly higher and integrin β3 was lower in subject.
Conclusions: The result provided that cleavage of integrin β3 by μ-calpain may cause adverse effect in the mechanism of early pregnancy.