The orphan nuclear receptor small heterodimer partner as a novel coregulator of nuclear factor-kappa B in oxidized low density lipoprotein-treated macrophage cell line RAW 264.7
Ys. Kim et al., The orphan nuclear receptor small heterodimer partner as a novel coregulator of nuclear factor-kappa B in oxidized low density lipoprotein-treated macrophage cell line RAW 264.7, J BIOL CHEM, 276(36), 2001, pp. 33736-33740
Small heterodimer partner (SHP), specifically expressed in liver and a limi
ted number of other tissues, is an unusual orphan nuclear receptor that lac
ks the conventional DNA binding domain. In this work, we found that SHP exp
ression is abundant in murine macrophage cell line RAW 264.7 but was suppre
ssed by oxidized low density lipoprotein (oxLDL) and its constituent 13-hyd
roxyoctadecadienoic acid, a ligand for peroxisome proliferator-activated re
ceptor gamma. Furthermore, SHP acted as a transcription coactivator of nucl
ear factor-kappaB (NF kappaB) and was essential for the previously describe
d NF kappaB transactivation by palmitoyl lysophosphaticlylcholine, one of t
he oxLDL constituents. Accordingly NF kappaB, which was transcriptionally a
ctive in the beginning, became progressively inert in oxLDL-treated RAW 264
.7 cells as oxLDL decreased the SHP expression. Thus, SBP appears to be an
important modulatory component to regulate the transcriptional activities o
f NF kappaB in oxLDL-treated, resting macrophage cells.