Complement C3 is expressed by mast cells in cutaneous vasculitis and is degraded by chymase
详细信息    查看全文
文摘
The complement factor C3 and chymase released from tryptase+, chymase+ mast cells may be involved in the pathogenesis of cutaneous leukocytoclastic vasculitis. To study whether mast cells contain C3 in vasculitis and whether chymase interacts with C3, cryosections from vasculitis biopsies were double-stained histochemically for C3c in tryptase+ mast cells, as well as for chymase and vessel wall C3c, or they were treated with 5 µg/ml rh-chymase for 24 h followed by immunofluorescence (IF) analysis of C3c, IgG, IgM and IgA. The effect of rh-chymase on purified human C3, C3a and IgG was studied using SDS-PAGE electrophoresis and LAD2 mast cell cultures. The results show that 34.2 ± 17.9, 37.4 ± 15.5 and 43.4 ± 18.6 % (mean ± SD) of the mast cells express C3c immunoreactivity in the healthy skin, initial petechial (IP) and palpable purpura (PP) lesions, respectively. About 9.4–12.1 % of the chymase+ mast cells were in apparent contact with C3c+ vessels in IP and PP. The treatment of cryosections with rh-chymase decreased the IF staining of C3c, but not that of immunoglobulins. In SDS-PAGE, 1–10 µg/ml rh-chymase degraded the alpha- and beta-chains of C3, but did not degrade IgG. Unexpectedly, the rh-chymase treatment of C3 produced fragments that resulted in the release of tryptase and histamine from LAD2 cells. However, rh-chymase degraded C3a and consequently inhibited C3a activity on LAD2. In conclusion, mast cells can be one source for C3 in the early and late phases of vasculitis pathogenesis. However, rh-chymase degraded native C3, vessel wall C3c, and biologically active C3a. Therefore, chymase may control C3-related pathology.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700