title: The role of retinoic acid receptors in activated hepatic stellate cells.
abstract: Hepatic stellate cells (HSCs), also known as Ito cells, fat-storing cells, vitamin A-storing cells or lipocytes, reside in the spaces between hepatocytes and liver sinusoids. Vitamin A storage within the HSCs is achieved through the cooperative action of two proteins, cellular retinol-binding protein (CRBP) I and lecithin:retinol acyltransferase (LRAT). After the discovery that HSCs are responsible not only for the storage of vitamin A, but also for the development of liver fibrosis and subsequent liver cirrhosis, HSCs have been considered a therapeutic target for prevention or reversal of liver fibrogenesis. We have reported that HSCs acquire retinoid responsiveness after in vitro activation by post-transcriptional upregulation of retinoic acid receptor α gene expression. Here we extend this observation in relation to the functions of CRBP I and LRAT, and propose a hypothesis that increased retinoid signaling in activated HSCs forms a feedback loop toward vitamin A restoration in the liver.
authors.affiliation: Department of Cell Biology and Morphology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan. mezaki@gipc.akita-u.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Mezaki
authors.forename: Mayako
authors.initials: M
authors.lastname: Morii
authors.forename: Taku
authors.initials: T
authors.lastname: Hebiguchi
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Noriko
authors.initials: N
authors.lastname: Yamaguchi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yoshino
authors.forename: Haruki
authors.initials: H
authors.lastname: Senoo
mesh_terms: D055166:Hepatic Stellate Cells / Q000502:physiology*; D006801:Humans; D018168:Receptors, Retinoic Acid / Q000502:physiology*
chemical_list: D018168:Receptors, Retinoic Acid