Developmental stage - induced carboxyle sterase isozymes in the parasitic trematode Fasciola hepatica .

MIRANDA - MIRANDA ESTEFAN; COSSÍO - BAYÚGAR RAQUEL; PEDROZA - GÓMEZ YARETZI JAQUELINE; PÉREZ - DE LA ROSA JUAN DIEGO; SCARCELLA SILVANA; SOLANA HUGO DANIEL

Congreso; 13 th INTERNATIONAL CONGRESS OF PARASITOLOGY; 2014

BACKGROUND: Steroid hormone like molecules exert control on developmental changes of helminthes into fully reproductive adults. All invertebrates exhibit a very delicate balance of circulating steroids and the ubiquitous enzymes carboxylesterases are necessary for hydrolyzing excess hormone levels or completely depleting it for the  final transition into adulthood. The liver fluke Fasciola hepatica exhibit abundance of carboxylesterase activity already reported in the literature, however very little scientific information is available on this enzyme role on controlling the parasites development. METHODS: Closed cycle laboratory-cultured Fasciola hepatica anthelmintic-susceptible reference strain was used as the source of carboxylesterases. In vitro excysed metacercariae, parenchyma migratory larvae and adult developmental stages were analyzed by PAGE carboxylesterase zymograms.RESULTS: A 90 kDa. band containing most of the enzyme activity (2500 6000 enzyme units/mg of protein by Gomori assay) was found in all developmental stages under denaturing SDS -PAGE, however when the proteins were sorted by charge under non denaturing PAGE, the 90 kDa band split into seven different isozymes each exhibiting a different electrophoretic retention factor (Rf), which combined showed a distinctive zymogram pattern for each developmental stage. CONCLUSIONS: Our results suggest that F. hepatica controls its developmental molting process by the catalytic action of seven different 90 kDa carboxylesterases isozymes. Our study also suggests that controlling the action of different carboxylesterases isozymes may tamper the liver flukes biological cycle.