Thymic atrophy via estrogen-induced apoptosis is related to Fas/FasL pathway.
A convincing body of evidence indicates that estrogen has significant immunomodulatory properties, including induction of thymic involution. However, it is unclear whether or not estrogen induces thymic involution by triggering apoptosis depended on Fas-FasL interactions. In the present study, estradiol-17beta (E(2)) was used to treat rats by gavages at 10, 1, 0.1, 0.01, and 0 ng/kg/day, respectively. Atrophy of thymus was determined by in situ morphological examination. Apoptotic cells were identified by terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labeling (TUNEL) assay. A semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method was used to analyze Fas and FasL mRNA levels. The results showed that E(2) induced thymic atrophy, increased the rates of apoptotic death, and enhanced the Fas/FasL mRNA levels. These findings suggested that Fas/FasL-mediated apoptosis involved in the induction of thymic atrophy by E(2).
Immunology and Reproduction Biology Lab, Medical School and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, China.
Genhong
G
Yao
Yayi
Y
Hou
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001284:Atrophy; D004958:Estradiol / Q000494:pharmacology*; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013950:Thymus Gland / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism*
D053222:Fas Ligand Protein; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D019014:fas Receptor; D004958:Estradiol