ININFA   02677
INSTITUTO DE INVESTIGACIONES FARMACOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Potentiation of Histamine H1 receptor calcium response by rational designed GRK2 inhibitors
Autor/es:
ECHEVERRIA E; CABRERA M; MONCZOR F; DAVIO C; LORENZANO-MENNA P; FERNANDEZ N; JURITZ E; SHAYO C
Reunión:
Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigaciones Clínicas; 2016
Resumen:
G protein-coupled receptors (GPCRs) are the largest family of cell-surface receptors and regulate most biological processes. Because approximately 30% of therapeutic drugs directly target GPCRs, it is of paramount importance to understand the mechanisms that regulate their function. GPCR kinase 2 (GRK2) plays a major role mediating desensitization through phosphorylation dependent and independent mechanisms and has been associated to the progression of several pathologies.Our aim was to obtain GRK2 inhibitors based on a rational drug design approach. Using the crystallographic image of GRK2, 13 compounds were chosen by virtual screening (VS) according to their docking energy and purchased to the supplier.Considering that histamine H1 receptor (H1R) desensitization depends on GRK2 activity, we evaluated the ability of the selected compounds to block H1R desensitization. Histamine-stimulated intracellular calcium release was tested in A549 cells endogenously expressing H1R using Fura2AM dye. 40 minutes incubation with 100nM of 3 of the selected compounds potentiated calcium response. Moreover, the incubation with these compounds reverted H1R desensitization induced by 10 minutes histamine pretreatment.To mitigate the risk of a future failure of the compounds due to a potential toxic effect in late phases of drug development, cytotoxicity was evaluated by trypan blue exclusion on hepatic HEPG2 and hematopoietic derived U937 cells after 48hs of treatment. Concentration response assays showed that the compounds that displayed cytotoxicity presented a CC50 value greater that 10uM. These results indicate that at concentrations used for calcium assay the compounds display no cytotoxicity though they inhibited GRK2 mediated H1R desensitization. Based on these observations, 3 of the candidates obtained by VS are promissory inhibitors for the treatment of pathologies where GRK2 mediated desensitization of GPCRs takes place.