Apoptosis and Bcl-2 protein expression in human placenta over the course of normal pregnancy.
Apoptosis plays a central role in organ development, homeostasis and immune defence in multicellular organisms and is strictly controlled in part by members of Bcl-2 family. The Bcl-2 is a pro-survival molecule identified through its involvement in B-cell lymphomas. The aim of the study was to evaluate the incidence of apoptosis in the human placenta at different stages of pregnancy and to correlate it further with Bcl-2 expression. A total of 96 placental samples from first trimester, mid-trimester and uncomplicated term pregnancies were collected (n = 32 + 32 + 32). M30 cyto death monoclonal antibody was used to identify apoptotic cells. The apoptosis index of first trimester placentae was 2.33 ± 1.70, mid- trimester was 1.77 ± 1.36 and term placenta was 1.15 ± 0.21. Bcl-2 protein was found immunolocalized in the cytoplasm of syncytiotrophoblast. Apoptosis index was significantly reduced in term cases as compared with first trimester (P < 0.002) and mid-trimester placentae (P = 0.01). On the contrary, Bcl-2 expression was significantly higher at term cases than in first trimester (P < 0.0001) and mid-trimester cases (P < 0.001). The present study divulges the importance of apoptosis in permitting normal physiological turnover of villous trophoblast and also exhibits the contribution of bcl-2 in maintaining syncytial integrity throughout normal pregnancy.
Soni
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Department of Anatomy, Vardhman Mahavir Medical College & Safdarjung Hospital, New Delhi, India.
Rath
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Prasad
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CP
Salhan
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Saxena
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Jain
A K
AK
D000328:Adult; D017209:Apoptosis; D005260:Female; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy / Q000378:metabolism*; D011261:Pregnancy Trimester, First / Q000378:metabolism; D011262:Pregnancy Trimester, Second / Q000378:metabolism; D011263:Pregnancy Trimester, Third; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism; D055815:Young Adult
D019253:Proto-Oncogene Proteins c-bcl-2