CHARACTERIZATION OF A NEW SEROTONERGIC G-PROTEIN COUPLED RECEPTOR FROM CESTODES: NEW POTENTIAL TARGET FOR DRUGS AGAINST NEGLECTED TROPICAL DISEASES

CAMICIA, F.; WOODHOUSE, KRISTEN; ROSENZVIT, MARA C.; PARK, SANG KYU; CELENTANO, ANA M.; MARCHANT, JONATHAN S.; VACA, HUGO R.; LOPEZ AVETRANI, MARÍA A.

Buenos aires

Congreso; Reunión Conjunta SAIC SAI SAFIS 2019; 2019

Sociedad Argentina de investigacion clinica (SAIC)

Echinococcus canadensis is a platyhelminth parasite that belongs to the class Cestoda and is the etiological agent of the Hydatid disease, a neglected disease that affects public health and the economy in Argentina and worldwide. Currently, the treatment for echinococcosis in humans relies on benzimidazoles. However, the emergence of resistant parasites, makes the discovery of new anthelmintic drugs an imperative need. To tackle this problem, we propose to characterize G-protein coupled receptors from cestodes as new pharmacological targets. In our previous work (1), we found that serotonergic GPCRs (5-HT GPCRs) are of major importance in cestode movement and showed distinctive pharmacology. The aim of this work was to study the function of a new 5-HT GPCR from Echinococcus canadensis. Similar sequences were also found in another cestode species. Bioinformatics analyses suggest the existence of genes encoding for 5-HT GPCRs and this information was used for the design of primers. New cDNA was synthesized using RNA extracted from protoscoleces of pig origin as a template for PCR reactions. The amplificated cDNA coding for the serotonergic gene was cloned, sequenced and finally used for transient transfections in HEK293 cells. Calcium levels were measured using a fluorescent imaging plate reader (FLIPR) assay (2). When the cell line was transfected with a gene encoding for the cestode receptor, the calcium levels increased only in the presence of serotonin but not with of other ligands like tryptamine, tyramine, octopamine, acetylcholine, histidine or dopamine. The dataset confirms the bioinformatics analyses showing that the cloned gene encodes for a new 5-HT GPCR conserved in cestodes. The cloning strategy followed by sequencing and expression in HEK cells revealed a new 5-HT GPCR. The results obtained confirm bioinformatics predictions and will be tested as a target for cestocidal drugs. References 1. Camicia F, et al. PLoS Negl Trop Dis. 2018; 12(2): e0006267. 2. Harvey JH, van Rijn RM, Whistler JL. Methods Mol Biol. 2013; 995: 43-54.Acknowledgments We especially thank to Dr. Gabriel Lichtenstein (IMPAM-UBA-CONICET) for the bioinformatical assistance.