Gene-selective modulation by a synthetic oxysterol ligand of the liver X receptor.
Liver X receptors (LXRs) play key roles in the regulation of cholesterol homeostasis by limiting cholesterol accumulation in macrophages within arterial wall lesion sites by a mechanism that includes the upregulation of ATP binding cassette transporters. These atheroprotective properties distinguish LXRs as potential targets for pharmaceutical intervention in cardiovascular disease. Their associated activity for promoting lipogenesis and triglyceride accretion through the activation of sterol-response element binding protein 1c (SREBP-1c) expression, however, represents a potential proatherogenic liability. A newly characterized synthetic oxysterol, N,N-dimethyl-3beta-hydroxycholenamide (DMHCA), represents a gene-selective LXR modulator that mediates potent transcriptional activation of ABCA1 gene expression while exhibiting minimal effects on SREBP-1c both in vitro and in vivo in mice. DMHCA has the potential to stimulate cholesterol transport through the upregulation of LXR target genes, including ABCA1, in liver, small intestine, and peritoneal macrophages. Compared with known nonsteroidal LXR agonists, however, DMHCA exhibits only limited activity for increasing hepatic SREBP-1c mRNA and does not alter circulating plasma triglycerides. Cell-based studies also indicate that DMHCA enhances cholesterol efflux in macrophages and suggest a mechanism whereby this selective modulator can potentially inhibit cholesterol accumulation. DMHCA and related gene-selective ligands of LXR may have application to the study and treatment of atherosclerosis.
Quinet
Elaine M
EM
Departments of Cardiovascular/Metabolic Diseases, Wyeth Research, Collegeville, PA 19246, USA. quinete@wyeth.com
Savio
Dawn A
DA
Halpern
Anita R
AR
Chen
Liang
L
Miller
Christopher P
CP
Nambi
Ponnal
P
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000818:Animals; D001161:Arteriosclerosis / Q000188:drug therapy; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000378:metabolism; D002793:Cholic Acids / Q000494:pharmacology*; D004268:DNA-Binding Proteins / Q000235:genetics; D022781:Hepatocytes; D006801:Humans; D006888:Hydroxycholesterols / Q000494:pharmacology; D008024:Ligands; D000071518:Liver X Receptors; D017737:Macrophages, Peritoneal / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects / Q000235:genetics*; D011987:Receptors, Steroid / Q000187:drug effects / Q000235:genetics; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors / Q000235:genetics; D015533:Transcriptional Activation / Q000187:drug effects*; D014280:Triglycerides / Q000097:blood; D000098825:Oxysterol Binding Proteins
C577836:ABCA1 protein, human; D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D022762:CCAAT-Enhancer-Binding Proteins; D002793:Cholic Acids; D004268:DNA-Binding Proteins; D006888:Hydroxycholesterols; D008024:Ligands; D000071518:Liver X Receptors; C413890:N,N-dimethyl-3-hydroxy-5-cholenamide; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; C497387:SREBF1 protein, human; C497388:Srebf1 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; D014280:Triglycerides; D000098825:Oxysterol Binding Proteins; D002784:Cholesterol