In Vivo Evidence for a Role of Adipose Tissue SR-BI in the Nutritional and Hormonal Regulation of Adiposity and Cholesterol Homeostasis

• DOI: 10.1161/atvbaha.106.136382
• Publication Date: 2007-03-16T00:41:12Z
• Authors: Laurent Yvan-Charvet; Alexandre Bobard; Pascale Bossard; Florence Massiéra; Xavier Rousset; Gérard Ailhaud; Michèle Teboul; Pascal Ferré; Georges Dagher; Annie Quignard-Bo...
• Keywords: Male; Angiotensinogen; MESH: Eating; Eating; MESH: Cholesterol; Adipocytes; Homeostasis; Insulin; MESH: Animals; [SDV.BDD]Life Sciences [q-bio]/Development Biology; Adiposity; Liver X Receptors; Epididymis; 0303 health sciences; Angiotensin II; 3. Good health; DNA-Binding Proteins; Cholesterol; Adipose Tissue; MESH: Homeostasis; MESH: ATP-Binding Cassette Transporters; MESH: Angiotensin II; MESH: Cholesterol, HDL; MESH: Adipose Tissue; ATP Binding Cassette Transporter 1; MESH: Triglycerides; MESH: Protein Transport; MESH: Mice, Transgenic; MESH: Epididymis; MESH: Angiotensinogen; MESH: Insulin; MESH: Receptors, Cytoplasmic and Nuclear; MESH: Sterol Regulatory Element Binding Protein 1; 03 medical and health sciences; 3T3-L1 Cells; [SDV.BDD] Life Sciences [q-bio]/Development Biology; [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology; Animals; [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology; MESH: Mice; MESH: Adipocytes; MESH: RNA, Messenger; MESH: Adiposity; MESH: Lipogenesis; MESH: Transcription, Genetic; Lipogenesis; MESH: Time Factors; Cell Membrane; Cholesterol, HDL; MESH: 3T3-L1 Cells; MESH: Male; MESH: Scavenger Receptors, Class B; ATP-Binding Cassette Transporters; MESH: DNA-Binding Proteins; MESH: Cell Membrane

Objectives—

This study examines the role of insulin and angiotensin II in high-density lipoprotein (HDL) metabolism by focusing on the regulation and function of scavenger receptor type-BI (SR-BI) in adipose tissue.

Methods and Results—

Insulin or angiotensin II injection in wild-type mice induced a decrease in circulating HDL and it was associated with the translocation of SR-BI from intracellular sites to the plasma membrane of adipose tissue. Refeeding upregulated adipose HDL selective cholesteryl esters uptake and SR-BI proteins through transcriptional and posttranscriptional mechanisms. This occurred along with a decrease in serum HDL and an increase in adipose cholesterol content. Similar results were obtained with transgenic mice overexpressing locally angiotensinogen in adipose tissue. In adipose 3T3-L1 cell line, HDL induced lipogenesis by increasing liver X receptor binding activity. This mechanism was dependent of insulin and angiotensin II.

Conclusions—

Our results raise the possibility that adipose tissue SR-BI translocation might be a link between adipose tissue lipid storage and HDL clearance.