Increase in nuclear calcium in smooth muscle cells exposed to oxidized lowdensity lipoprotein

Vascular smooth muscle cells respond with an increase in intracellular Ca2 within seconds after exposure to oxidized low density lipoprotein (oxLDL). This has been suggested to represent a signaling response that may have im plications for gene expression. If so, oxLDL may induce increases in nuclea r Ca2+ in smooth muscle cells in response to oxLDL. Aortic smooth muscle ce lls were exposed to 100 mug/ml oxLDL. Large, rapid increases in [Ca2+](i) w ere observed using fluo-3 as an indicator dye to detect intracellular Ca2on the stage of a confocal microscope. This was also confirmed using ratiom etric imaging of indo signals. These elevations appeared to be localized to the nuclear region of the cell. DNA staining of the cells confirmed its lo calization to the nuclear/perinuclear region of the cell. Our data demonstr ate that oxLDL induces a nuclear localized elevation in Ca(2+)i that may ha ve important implications for nuclear function.