Apoptotic genes expression in placenta of clubfoot-like fetus pregnant rats.

OBJECTIVE To investigate the apoptotic gene expression of placenta in an all-trans-retinoic acid (ATRA) induced fetus congenital clubfoot pregnant rat model. METHODS Sprague-Dawley (SD) rats were divided randomly into ATRA-exposed group and control group. On day 10 of pregnancy, a dose of 120 mg/kg ATRA dissolved in mineral oil was given intragastrically to the rats in the ATRA-exposed group and equivalent volume of mineral oil was given intragastrically to the control rats. Fetuses were delivered on day 20 of pregnancy, the placenta was collected for the pathological and biochemical analysis. RESULTS Clubfoot-like deformity fetuses were observed in the ATRA-exposed group and none with deformity was found in the control group. The pro-apoptosis in placenta of ATRA-exposed group was measured by flow cytometry. Moreover, compared with the control group, lower expression of Bcl-2 and higher expression of BAX were found in the ATRA-exposed group in both mRNA and protein level. Immunohistochemical labeling of Bcl-2 in the control group was more intense while BAX labeling in the ATRA-exposed group was more intense. Additionally, the caspase-3 activity was also significantly increased in the ATRA-exposed group than control group. CONCLUSION In our research, we found a pro-apoptosis in placenta in the ATRA-exposed pregnant rats, indicating a possible association between placental apoptosis and congenital clubfoot.