title: Non-redundant roles for LXRalpha and LXRbeta in atherosclerosis susceptibility in low density lipoprotein receptor knockout mice.
abstract: The liver X receptors LXRalpha and LXRbeta play critical roles in maintaining lipid homeostasis by functioning as transcription factors that regulate genetic networks controlling the transport, catabolism, and excretion of cholesterol. The studies described in this report examine the individual anti-atherogenic activity of LXRalpha and LXRbeta and determine the ability of each subtype to mediate the biological response to LXR agonists. Utilizing individual knockouts of LXRalpha and LXRbeta in the Ldlr(-/-) background, we demonstrate that LXRalpha has a dominant role in limiting atherosclerosis in vivo. Functional studies in macrophages indicate that LXRalpha is required for a robust response to LXR ligands, whereas LXRbeta functions more strongly as a repressor. Furthermore, selective knockout of LXRalpha in hematopoietic cells and rescue experiments indicate that the anti-atherogenic activity of this LXR subtype is not restricted to macrophages. These studies indicate that LXRalpha plays a selective role in limiting atherosclerosis in response to hyperlipidemia.
authors.affiliation: Exelixis, Inc., San Diego, CA, USA.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Bischoff
authors.forename: Chris L
authors.initials: CL
authors.lastname: Daige
authors.forename: Mary
authors.initials: M
authors.lastname: Petrowski
authors.forename: Harry
authors.initials: H
authors.lastname: Dedman
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pattison
authors.forename: Joseph
authors.initials: J
authors.lastname: Juliano
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Li
authors.forename: Ira G
authors.initials: IG
authors.lastname: Schulman
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000378:metabolism; D004198:Disease Susceptibility / Q000378:metabolism; D005786:Gene Expression Regulation; D055786:Gene Knockout Techniques; D000071518:Liver X Receptors; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D057093:Orphan Nuclear Receptors / Q000819:agonists / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011973:Receptors, LDL / Q000172:deficiency* / Q000235:genetics*
chemical_list: D000071518:Liver X Receptors; C000605214:Nr1h3 protein, mouse; D057093:Orphan Nuclear Receptors; D011973:Receptors, LDL
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