Identification and expression of AMPK in Echinococcus sp.: conserved signal transduction in cestode.

LOOS JULIA A; CUMINO ANDREA C

Mar del Plata

Congreso; LVI Reunión Científica Anual de la Sociedad Argentina de Investigaciones Clínicas; 2011

Sociedad Argentina de Investigaciones Clínicas

Glucose and glycogen are the main energy source in both larval and adult of the cestode. In helminthes, the carbohidrate metabolism is known target to be affected by a number of anthelmintic agents (benzimidazole derivates, praziquantel, and genistein). Here, we investigated the effects of metformin (biguanide) in the viability of protoscoleces and metacestode of Echinocuccus granulosus, causative agent of the cystic hydatid disease. Metformin inhibit gluconeogenesis and mitochondrial respiratory chain complex I, and activates the AMP-activated kinase (AMPK) in insulin-sensitive tissues. The drug reduced the vitality of protoscoleces in a dose-dependent manner and induces the deleterious effect on germinal layer of intact cysts determined by confocal and SEM. As metformin sensitivity is the major criterion used to detect AMP kinase, we identified in silico ortologous in E. granulosus genome. In this work, we analyzed encoding genes for α, β and γ subunits of Eg-AMPK and carry out expression studies of regulatory genes (β and γ). The primary and quaternary structures are highly conserved in Echinococcus sp: Eg-AMPKα, belongs to the protein kinases C superfamily and contains a kinase domain (with conserved T176, possible phosphorylation and activation site) and an βγ interaction domain; Eg-AMPKβ contains glycogen-binding domain (GBD) and αγ interaction domains; and finally Eg-AMPKγ (CBS superfamily) show typical CBS motifs (Bateman domains) of AMP and ATP interaction. Also, transcriptional expression studies were conducted to evaluate the metformin effect on the levels of key transcripts, demonstrated reduction level of pepck, g6p and mdh expression in protoscolices. Finally, we showed an increase in type II fermentation due to the reduction of glycogen and increased α-amylase and LDH activities. These preliminary results will let us continue subsequent studies that may improve the outline for further identification of downstream target proteins, a promising target for chemotherapy of cystic echinococcosis.