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Analysis of the Epithelial Damage Produced by Entamoeba histolytica Infection
Published on: June 12, 2014
Expression of in vitro virulence by Entamoeba histolytica: effect of calmodulin inhibitors
S Arias-Negrete1, M de L Muñoz, F Murillo-Jasso
1Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, Gto, México.
Abstract:
The possible role of calmodulin (CaM) in functions such as cytotoxicity, phagocytosis, and amoebic growth was studied. These are important factors for the in vitro pathogenicity of Entamoeba histolytica HM1 strain. The CaM inhibitors trifluoperazine (TFP), N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (W-7) and N-(6-aminohexyl)-naphthalenesulfonamide (W-5) were used for these purposes. Cytotoxicity was determined as the ability of amoebae to kill and/or lyse nucleated mouse spleen cells. Phagocytosis by amoebae was assessed by calculating the number of endocytosed human red blood cells. Cytotoxicity by E. histolytica showed a decrease dependent upon the concentration of W-7 and TFP, whereas W-5 did not show a significant inhibiting effect. Phagocytosis was roughly sensitive to W-7; TFP and W-5 did not have any significant effect. Amoebic growth was sensitive to TFP and W-7 CaM inhibitors. These results suggest that CaM participates in the expression of in vitro cytotoxicity of E. histolytica.
Insights
Calmodulin (CaM) inhibitors reduced Entamoeba histolytica cytotoxicity and growth. These findings suggest CaM plays a role in the parasite's virulence factors, impacting amoebic pathogenicity.
Area of Science:
- Parasitology
- Molecular Biology
- Cell Biology
Background:
- Entamoeba histolytica is a significant human pathogen.
- Virulence factors like cytotoxicity and phagocytosis are crucial for E. histolytica pathogenicity.
- Calmodulin (CaM) is a calcium-binding protein involved in various cellular processes.
Purpose of the Study:
- To investigate the role of calmodulin (CaM) in the in vitro pathogenicity of Entamoeba histolytica.
- To determine the effect of CaM inhibitors on E. histolytica cytotoxicity, phagocytosis, and growth.
Main Methods:
- Utilized CaM inhibitors: trifluoperazine (TFP), W-7, and W-5.
- Assessed cytotoxicity by measuring the lysis of mouse spleen cells.
- Quantified phagocytosis by counting endocytosed human red blood cells.
- Monitored amoebic growth in the presence of CaM inhibitors.
Main Results:
- Cytotoxicity of E. histolytica decreased in a dose-dependent manner with W-7 and TFP.
- Phagocytosis was sensitive to W-7 but not significantly affected by TFP or W-5.
- Amoebic growth was inhibited by both TFP and W-7.
Conclusions:
- Calmodulin (CaM) appears to be involved in the expression of in vitro cytotoxicity in Entamoeba histolytica.
- CaM may play a role in regulating E. histolytica growth and phagocytic activity.
- Targeting CaM could be a potential strategy for controlling E. histolytica infections.
