[The relationship between abnormal apoptosis and Fas expression of thymocytes from patients with myasthenia gravis].
OBJECTIVE
To explore the roles of abnormalities of thymocytic abnormal apoptosis and its Fas expression in patients with myasthenia gravis (MG) in generation of autoimmune response.


METHODS
The thymocytes were isolated and thymus extractive was prepared from fresh thymic tissue excised from MG patients. The proliferation of thymocyes was evaluated by MTT colorimetry. The apoptosis of thymocytes were examined by DNA electrophoresis. Expression of Fas was analyzed by a FACScan flow cytometry. Transcription and mutation of Fas gene were detected by RT-PCR and single-stranded conformation polymorphism ( SSCP) analysis.


RESULTS
Thymus extractive could inhibit proliferation of normal thymocytes, while had no influence on the thymocytic proliferation of MG patients. The proliferation of thymocytes of both normal persons and MG patients could be inhibited by thymus extractive in the presence of dexamethasone. The inhibition rates were 58. 33% and 54. 26% respectively. The cocultured thymocytes with dexamethasone showed characteristic apoptosis pattern and the DNA electrophoresis exhibited 'ladder' appearance. The abnormal bands in Fas mRNA of partial MG patients' thymocytes were found by RT-PCR-SSCP analysis.


CONCLUSIONS
Abnormalities of apoptosis and Fas gene expression of MG patients' thymocytes, and Fas gene mutation may be related to the pathogenesis and progression of MG.
Du
Ying
Y
Department of Microbiology and Immunology, Zhengzhou University, Zhengzhou 450052, China. duyingde@hotmail.com
Zhang
Qing-yong
QY
Ruan
Li-rong
LR
Liang
Chang-chun
CC
Li
Qian-ru
QR
He
Wei
W
D000293:Adolescent; D017209:Apoptosis; D002648:Child; D002675:Child, Preschool; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D009157:Myasthenia Gravis / Q000276:immunology* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000737:chemistry* / Q000473:pathology; D013949:Thymus Extracts / Q000494:pharmacology; D019014:fas Receptor / Q000032:analysis* / Q000235:genetics
D012333:RNA, Messenger; D013949:Thymus Extracts; D019014:fas Receptor; D003907:Dexamethasone