INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
L-FABP stimulates endonuclear arachidonic acid mobilization
Autor/es:
LAYERENZA, JUAN PABLO; MATÉ, SABINA M.; VES-LOSADA, ANA
Lugar:
Mar del Plata
Reunión:
Congreso; XLIII Reunión Anual de SAIB; 2007
Institución organizadora:
SAIB
Resumen:
We have already shown that endonuclear lipid pools have a more active metabolism than that in whole nuclei. Thus endonuclear arachidonic acid (20:4n-6) pools could provide an endogenous source of PPARá ligands and/or be metabolized to prostaglandins or leukotrienes. Taking into account that the nucleus is considered a control site for 20:4n-6 incorporation and subcellular redistribution; the aim of the present work was to determine if L-FABP is involved in endonuclear 20:4n-6 mobilization and release. With this purpose, endonuclear 20:4n-6 pools were labeled by in vitro incubation of isolated nuclear matrix (Mx: membrane depleted nuclei) with [1-14C]20:4n-6, ATP and CoA. [14C]Mx was reincubated without 20:4n-6, plus ATP, CoA and delipidized L-FABP. We observed that increasing concentrations of L-FABP determined a dose-dependent release of 20:4n-6 to the incubation mixture, and an increase of 20:4n-6 in PL and a decrease in FFA from endonuclear lipids. In conclusion, we showed that L-FABP stimulates endonuclear 20:4n-6 mobilization. L-FABP delivers 20:4n-6 to an acyl-CoA synthetase located in the nuclear matrix, and then to those enzymes (acyl-tranferases) responsible for its esterification in PL. In the same time frame, L-FABP would deliver 20:4n-6 to another fate, by promoting fatty acid release from endonuclear pools to different cellular compartments.