INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Endonuclear lipids have a high proportion of neutral lipids
Autor/es:
LAYERENZA, JUAN PABLO; TRICERRI, ALEJANDRA M.; GARCÍA DE BRAVO, MARGARITA M.; POLO, MÓNICA; VES-LOSADA, ANA
Lugar:
Carlos Paz, Córdoba
Reunión:
Congreso; XLIV Reunión anual de SAIB; 2008
Institución organizadora:
SAIB
Resumen:
Nuclear lipids are mostly found in the double nuclear membrane, and in a minor proportion they are associated to chromatin and to the nuclear matrix (Mx). Composition and physico-chemical properties of these lipid pools are very important as they are the sources of nuclear signal transduction system of PI, PC and SM as well FA involved in genetic regulation. The aim of this work was to analyze nuclear neutral lipids composition (NL), their location and nuclear fluidity (GP: Generalized polarization). Thus, whole nuclei and nuclear double membrane–depleted nuclei (Mx) were isolated from rat liver cells. Purity of nuclear fractions was determined by electronic microscopy and marker proteins. Nuclei lipids mainly contain 84% and 16% of PL an NL, respectively, as follows: PC>PE>TAG>PI>Cho>SM/PS>>CE. Endonuclear lipids (Mx) are mainly constituted of 57% PL and 43% NL, as follows: TAG³PC>PE³Cho>SM/PI/PS/CE. Thus, the mayor lipid pool in nuclei is PC, while TAG and PC are mainly found inside nuclei. Mx were analized by Laurdan GP (espectrofluorometric and 2 Foton microscopy), presenting less fluidity than nuclei. In conclusion, endonuclear lipids are enriched in NL (TAG, Cho, CE). Despite the minor amount of PL, these are enriched in SM and PS. TAG and PC were found to be the major lipids inside the nuclei, and they may be alternative sources of FA with different properties and regulation.