Human laminin-332 degradation by Candida proteinases

Background:  Human laminin-332 (Lm-332) degradation by 12 Candida strains and effects of synthetic proteinase inhibitors Ilomastat (ILM), EDTA, chemically modified tetracycline-3(CMT-3), CMT-308, synthetic peptide CTT-2, and Pefabloc] were studied.
Materials and methods:  Laminin-332 was incubated with sonicated cell fractions and 10 times concentrated cell-free fractions of reference and clinical strains of C. albicans, C. dubliniensis , C. guilliermondii , C. glabrata, C. krusei , and C. tropicalis . Proteolysis, pH effects, and inhibitors were analyzed by fluorography and zymography.
Results:  Cell fractions of all species except C. guilliermondii and cell-free fractions of C. albicans , and C. dubliniensis showed 20–70 kDa gelatinases at pH 5.0 and 6.0. At pH 7.6, C. glabrata , C. krusei , and C. tropicalis cell fractions and C. tropicalis cell-free fractions showed 55–70 kDa gelatinases. CMT-3, CMT-308, and CTT-2 inhibited Candida gelatinases slightly better than Pefabloc, ILM, and EDTA. No Candida fractions degraded Lm-332 at pH 7.6, but at pH 5.0, 100 kDa bands were generated by cell fractions of C. dubliniensis and C. tropicalis ; C. albicans and C. glabrata clinical strains; and C. guilliermondii reference strain. C. krusei reference strain yielded three 100–130 kDa bands. C. albicans , C. dubliniensis , and C. tropicalis reference and clinical strain's cell-free fractions generated 100 kDa band .
Conclusions:  Laminin-332 degradation is pH-dependent and differences exist between studied Candida strains. Lm-332 degradation can exert functional disturbances on basement membrane integrity, possibly aiding Candida cell invasion into tissues. Certain synthetic matrix metalloproteinase inhibitors (CMTs, CTT) can inhibit Candida proteinases and may be therapeutically useful in future.