ABSTRACT
Objective To investigate the effects of Calpain inhibitor Ⅰ on glucocorticoid receptor and its transcript activation ability. Methods Raw-264.7 cells were treated respectively with Calpain inhibitor Ⅰ and dexamethasone or both for 24 h. The changes of glucocorticoid receptor were observed. COS-7 cells were co-transfected with PRsh-GR? and pMAMneo-CAT vectors, and then the effects of Calpain inhibitor Ⅰ on glucocorticoid receptor and its transcript activation ability were detected. Results The glucocorticoid receptors was decreased after Raw-264.7 cells were treated with dexamethasone for 24 h. Calpain inhibitor Ⅰ could inhibit this effect to some extent. Co-transfection experiment revealed that Calpain inhibitor Ⅰ could also promote glucocorticoid receptor transcript activation ability. Conclusion Calpain inhibitor Ⅰ can inhibit the down-regulation of dexamethasone on glucocorticoid receptor, but promote glucocorticoid receptor transcript activation ability.