Apoptosis, bcl-2 expression, and proliferative activity in human endometrial stroma and endometrial granulated lymphocytes.
Human endometrial leukocytes undergo regular cyclical changes during the menstrual cycle, with a striking increase in the phenotypically unusual population of CD56+ CD16- endometrial granulated lymphocytes (eGLs) in the late secretory phase and early pregnancy. The factors that regulate this increase in eGL numbers are unclear; their unusual morphology, however, has led to the suggestion that they undergo apoptosis at the end of the menstrual cycle. Apoptosis, bcl-2 expression, and proliferative activity were examined in the stroma of normal cycling, progesterone-treated, and early-pregnancy endometrium. The expression of bcl-2 and the Ki67 proliferation marker by highly purified (> 98% CD56+) eGLs from endometrium during the menstrual cycle and from first-trimester decidua was also studied. Apoptotic cells were rarely observed in the endometrial stroma of any of the samples examined. Stromal bcl-2 expression, however, increased from the proliferative to the premenstrual phase, and double immunohistochemical labeling demonstrated large numbers of bcl-2+ CD56+ eGLs. In contrast, Ki67 expression was high in the endometrial stroma during the proliferative phase, fell during the secretory phase, and rose again premenstrually, because of expression by eGLs. Isolated CD56+ eGLs also showed high bcl-2 and Ki67 expression at the end of the menstrual cycle. Unlike premenstrual endometrium, progesterone-treated endometrium and first-trimester decidua contained few proliferating cells, expressed high levels of bcl-2, and showed no evidence of apoptosis. Thus, eGLs do not undergo apoptosis in premenstrual endometrium, and their regulatory mechanisms remain to be clarified.
Jones
R K
RK
Department of Immunology, University of Newcastle, Newcastle-upon-Tyne, United Kingdom. 101552.3635@compuserve.com
Searle
R F
RF
Stewart
J A
JA
Turner
S
S
Bulmer
J N
JN
D017209:Apoptosis; D019002:CD56 Antigen / Q000032:analysis; D002455:Cell Division; D004717:Endometrium / Q000166:cytology* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D019254:Genes, bcl-2 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008214:Lymphocytes / Q000166:cytology* / Q000378:metabolism; D008597:Menstrual Cycle; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology; D017154:Stromal Cells / Q000166:cytology* / Q000378:metabolism
D019002:CD56 Antigen; D019394:Ki-67 Antigen; D011374:Progesterone