A zymographic study of metalloproteinase activities in whole cell extracts and extracellular secretions of Leishmania (L.) , L. major and L. infantum from Iran.

Abstract

Leishmaniosis encompasses a group of diseases that is transmitted by sand flies and caused by different species of Leishmania. The skin is the initial organ to be infected by the Leishmania in cutaneous, mucocutaneous and visceral forms of leishmaniosis. The matrix metalloproteinases (MMPs) are capable of degrading all kinds of extracellular matrix (ECM) proteins. The aim of this study was to investigate the protease activity through zymography in cell extracts and extracellular secretions of L. major, L. tropica and L. infantum as three prevalent Leishmania spp. in Iran. The three Leishmania spp. were cultured in RPMI-1640 medium supplemented with fetal calf serum. Promastigotes and axenic amastigotes were harvested and lysed at various phases, and extracellular secretions and cell extracts were collected. Leishmania spp. were proved by targeting kDNA gene. Enzymes were characterized according to gelatin zymography and sensitivity to distinct proteinase inhibitors. We observed proteinase bands with molecular weights (MWs) between 66 to 180 kDa in cellular extracts of axenic amastigotes of L. infantum, L. tropica, and L. major, and from 66 to 92 kDa in extracellular secretions of L. infantum. No proteinase activities were observed in extracellular secretions of axenic amastigotes and in cellular extracts of promastigotes in logarithmic and stationary phases of L. major and L. tropica. Using specific inhibitors, we determined that these proteolytic activities are due to metalloproteases. Our study demonstrated that amastigotes of all three Leishmania spp. have distinct amounts of proteinase activities and therefore can cause various types of lesions and outcomes of the disease.