Apoptosis and Expression of bcl-2, bax in the Cyclic Human Endometrium. |
Chang Suk Suh, Shin Yong Moon |
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Abstract |
OBJECTIVE To understand the regulatory mechanism of apoptosis by pro- and anti-apoptotic genes in the cyclic human endometrium. METHODS: Each case of endometrial status was classified by Noyes criteria, and grouped into early proliferative(n=13), late proliferative(n=14), early secretory(n=15), and late secretory phases(n=15). Expression of bcl-2, and bax were assessed by Northern blot and immunohistochemistry in relation to apoptotic index by TUNEL. Results: Apoptotic index showed increasing tendency as progressing to the late secretory phase, which phase showed significantly higher apoptotic index compared to the other phases(p<0.05). The intensity of bcl-2 8.5kb transcript by Northern blot was highest in the late proliferative phase significantly(p<0.05), decreasing to nadir in the late secretory phase. In contrast to bcl-2 expression, bax mRNA expression was highest in the late secretory phase significantly(p<0.05). Both the relative ratio of bcl-2 8.5kb transcript and bcl-2 5.5kb trascript to bax showed that the ratio was higher in the early, and late proliferative phase, but, reversed in the late secretory phase. Both the immunoreactivity of bcl-2 and bax proteins could be detected in the basal, functional, and stromal layers of endometrium. The immunoreactivity of bcl-2 protein was more prominent in the proliferative phase, however, bax protein was more prominent in the secretory phase. CONCLUSION: This study suggests that apoptosis could be regulated by the relative dominance of bcl-2 or bax expression in the human endometrium. Thus, bcl-2 and bax expressions might be one of the possible mechanism in the regulation of normal menstruation. |
Key Words:
Apoptosis, TUNELbcl-2, bax, Northern blot, Immunohistochemistry |
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