title: Scavenger receptor B1, the HDL receptor, is expressed abundantly in liver sinusoidal endothelial cells.
abstract: Cholesterol from peripheral tissue, carried by HDL, is metabolized in the liver after uptake by the HDL receptor, SR-B1. Hepatocytes have long been considered the only liver cells expressing SR-B1; however, in this study we describe two disparate immunofluorescence (IF) experiments that suggest otherwise. Using high-resolution confocal microscopy employing ultrathin (120 nm) sections of mouse liver, improving z-axis resolution, we identified the liver sinusoidal endothelial cells (LSEC), marked by FcγRIIb, as the cell within the liver expressing abundant SR-B1. In contrast, the hepatocyte, identified with β-catenin, expressed considerably weaker levels, although optical resolution of SR-B1 was inadequate. Thus, we moved to a different IF strategy, first separating dissociated liver cells by gradient centrifugation into two portions, hepatocytes (parenchymal cells) and LSEC (non-parenchymal cells). Characterizing both portions for the cellular expression of SR-B1 by flow cytometry, we found that LSEC expressed considerable amounts of SR-B1 while in hepatocytes SR-B1 expression was barely perceptible. Assessing mRNA of SR-B1 by real time PCR we found messenger expression in LSEC to be about 5 times higher than in hepatocytes.
authors: Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, United States.
authors: Latha P
authors: LP
authors: Ganesan
authors: Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, United States.
authors: Jessica M
authors: JM
authors: Mates
authors: Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, United States.
authors: Alana M
authors: AM
authors: Cheplowitz
authors: Department of Surgery, The Ohio State University, Columbus, OH 43210, United States.
authors: Christina L
authors: CL
authors: Avila
authors: Department of Surgery, The Ohio State University, Columbus, OH 43210, United States.
authors: Jason M
authors: JM
authors: Zimmerer
authors: Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, United States.
authors: Zhili
authors: Z
authors: Yao
authors: Department of Medicine, Division of Cardiovascular Medicine, University of Maryland, Baltimore, MD 21201, United States.
authors: Andrei
authors: A
authors: Maiseyeu
authors: Department of Microbial Infection and Immunity,The Ohio State University, Columbus, OH 43210, United States.
authors: Murugesan V S
authors: MV
authors: Rajaram
authors: Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, United States.
authors: John M
authors: JM
authors: Robinson
authors: Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, United States.
authors: Clark L
authors: CL
authors: Anderson
mesh_terms: D000818:Animals; D001692:Biological Transport; D019556:COS Cells; D002460:Cell Line; D002469:Cell Separation; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008867:Microtomy; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D017452:Receptors, IgG / Q000235:genetics / Q000378:metabolism; D051122:Scavenger Receptors, Class B / Q000235:genetics* / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: C495267:CTNNB1 protein, mouse; C499172:Fcgr2b protein, mouse; D012333:RNA, Messenger; D017452:Receptors, IgG; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D051176:beta Catenin; D002784:Cholesterol