[Regulation role of superoxide dismutase coenzyme on Fas/FasL signal transduction and apoptosis in alveolar macrophages of pneumoconiosis patients].

Objective: To explore the role of superoxide dismutase (SOD) coenzyme in regulation of Fas/FasL signal transduction and apoptosis of alveolar macrophages in pneumoconiosis patients.

Methods: 50 male and Han nationality cases, including the dust exposed workers, Phase I, II pneumoconiosis patients confirmed by local pneumoconiosis diagnosis group according to GBZ 70 - 2002 diagnosis standard, who underwent whole lung lavage treatment were chosen as subjects. Their alveolar macrophages (AMs) were collected and purified. The cells were divided into three groups: the untreated group, the Fas/FasL group and the SOD group. 5 x 10(6) purified AMs were added into incubating bottles containing DMEM for 2 hours for purifying, added with SOD coenzyme and other block reagents separately, and then incubated for 24 hours in CO(2) incubation. The cells were harvested and lysed. Western-blot were used to analyze the expressions of Fas, FasL, Caspases-8 and Caspases-3. Software of Quantity One 7.0 was used to analyze the relative quantity of Fas, FasL, Caspase-8 and Caspase-3. TUNEL and DNA fragment analysis were used to analyze AMs apoptosis.

Results: The apoptosis index in SOD coenzyme group (9.50 +/- 2.76)% and Fas/FasL group (14.01 +/- 2.56)% was significantly lower than that of in untreated group (19.18 +/- 2.83)% (P < 0.05). The catachrestic DNA ladder appeared in untreated group, was looming in Fas/FasL group, and was not found in the SOD group. The expressions of Fas, FasL, Caspase-8 and Caspase-3 of phase I and II in SOD group were higher than in the other two groups (P < 0.05). There was no significant difference in the expression of Fas, FasL, Caspase-8 and Caspase-3 among different phases of pneumoconiosis (P > 0.05).

Conclusion: SOD coenzyme can effectively regulate Fas/FasL signal transduction and block AMs apoptosis.