RESUMO
Objective: To explore the expression of MMP-9 in mouse brain tissue and its significance. Methods: Cryptococcosis ssuspension alone (fungal suspension group) or combined with aprotinin (aprotinin group) was injected in to female C57 BL/6 mice via femoral vein cannulation. The expression of MMP-9 was examined immunohistochemically 8 h later. Meanwhile, the mouse brain tissue homogenate colony count (CFU) was observed and the results were compared with that of the immunohistochemical examination. Results: The expression of MMP-9 was markedly increased in the fungal suspension group compared with the normal control group (P0.05). The amount of cryptococcosis in the brain tissue was positively correlated with expression of MMP-9. Conclusion: MMP-9 is overexpressed in the brain of mice with Cryptococcal meningitis; MMP-9 might lead to increased permeability of blood brain barrier.
RESUMO
Objective: To determine the serine protease expression in Cryptococcus neoformans (C. neoformans) by cell microarray technique,so as to investigate the role of serine protease in the pathogenesis of C. neoformans. Methods: The cell microarray was constructed with tissue microarray. Thirty-six strains of C. neoformans of different sources and homologous serotypes were examined for their serine protease expression by cell microarray technique and immunohistochemistry. Results: Strong expressi on of serine protease was found in 25(67.0%) strains. The rates of strong serine protease expression in serotype A, B and D/AD strains were 46.2%(6/13), 92.3%(12/13) and 66.7%(4/6), and in environment-isolated, clinically isolated and uncapsuled strains were 55.6%(5/9),82.6%(19/23) and 25%(1/4), respectively. Serine protease expressions in serotype B and clinically-isolated strains were significantly higher than that in other group (P<0.05). Conclusion: Mic roarray of strain cells is a new method for identifying pathogenic fungus. Higher expression of serine protease in clinically-isolated strains is associated with strong virulence of clinical isolates strains, suggesting that serine protease plays a major role in the pathogenesis of C. neoformans.
RESUMO
Objective: To evaluate the activities of extracellular proteinase and serine protease secreted by Cryptococcus neoformans (C. neoformans) of different sources and serotypes and incubated under different conditions. Methods: Thirty-six C. neoformans strains of different sources and serotypes were incubated in protein agar medium at 30°C and 37°C separately. Activities of extracellular proteinase and serine protease were analyzed by determining Clearance Halos(CHs) produced by C. neoformans. Activity changes of the 2 proteases were analyzed after treated with serine protease inhibitors. The activity and the molecular weight of extracellular proteinase in the concentrated supernatant were measured using zymography assay. Results: Thirty-three of 36 C. neoformans strains produced specific Clearance Halos around the colonies, and their mean CHs at 30°C and 37°C were 0.558±0.170 and 0.575±0.169, respectively (P>0.05). The mean CHs of serotype A(n=13), B(n=13), and D/AD (n=6) strains were 0.564±0.144, 0.515±0.078 and 0.482±0.072, respectively (P>0.05); the mean CHs of clinical(n=23), environmental(n=9),and uncapsuled strains(n=4) were 0.570±0.177, 0.513±0.069, and 0.942±0.075, respectively (P<0.05). The mean CHs of control group (without protease inhibitor) and groups treated with protease inhibitor (1.2 mU and 1.6 mU) were 0.459±0.188, 0.975±0.287 and 0.733±0.252, respectively(P<0.01). Rich extracellular protease was found in the concentrated supernatant. Conclusion: The incubation temperature (30°C and 37°C) has no effect on activities of extracellular proteinase and serine protease, and the activities of clinical strains are significantly stronger than those of other 2 strains; the activities in different serotypes groups have no significant difference and can be inhibited by serine protease inhibitors.