Entamoeba histolytica: proteinase secretion induced by collagen type I is dependent on cytoskeleton integrity

Abstract

Proteolytic activities of the protozoan parasite Entamoeba histolytica strain HM1:IMSS and the cytochalasin D-resistant mutant BG-3 were analyzed following stimulation with collagen type I and Ca2+, which induces electron-dense associated collagenase secretion. The mutant BG-3 had a protease activity of 73 kDa and secretion of total protease activity was not stimulated by collagen type I and Ca2+, which produced, in contrast, a 2-fold increase in protease secretion by the parental strain. This collagen-stimulated protease secretion was inhibited by cytochalasin D at a concentration of 1 microgram/ml. Cytochalasin D did not have any effect on the protease activity released by the mutant BG-3. These findings suggest that cytoskeleton integrity is necessary for collagen-induced protease secretion.

Host-Parasite Interaction: Parasite-Derived and -Induced Proteases That Degrade Human Extracellular Matrix

“…Collagen type I incubation not only promotes collagenase activity but also increases the secretion of other proteases (mainly CP) [59], and, together with Ca 2+ , is able to induce the activation of several amoebic genes related to certain virulence factors, such as amoebapore C and cysteine protease 5, along with the stress-induced protein HSP70 and the ribosomal protein L27a [60]. In a recent study, Chávez Munguia et al [35] demonstrated that electron-dense granules contain multiple cysteine protease activities.…”

Pathogenesis of Intestinal Amebiasis: From Molecules to Disease

“…In vitro, incubation of trophozoites on collagen-coated wells induces the formation and release of electron-dense granules (EDGs) through a cytoskeleton-driven, Ca 2ϩ -calmodulin-dependent mechanism (87,102,146). In addition to a collagenolytic activity, EDGs seem to contain at least 25 polypeptides with acidic pIs (6.06 to 6.59), 9 gelatinase activities, actin, small molecules including inorganic phosphate (P i ) and pyrophosphate (PP i ), and several ions.…”

Entamoeba histolytica: focal adhesion kinase and Erk phosphorylation are altered in the cytoskeleton mutant BG-3

“…Trophozoite adherence to human collagen type I The BG-3 strain showed low collagenolytic activity and a low capacity to produce liver lesions in the hamster model, as compared with the parenteral strain HM1:IMSS (Flores-Romo et al 1997;Serrano et al 1994Serrano et al , 1996. This observation encouraged us to quantify the adherence of both strains to human collagen type I.…”