Hepatic stellate cell (vitamin A-storing cell) and its relative--past, present and future.
HSCs (hepatic stellate cells) (also called vitamin A-storing cells, lipocytes, interstitial cells, fat-storing cells or Ito cells) exist in the space between parenchymal cells and liver sinusoidal endothelial cells of the hepatic lobule and store 50-80% of vitamin A in the whole body as retinyl palmitate in lipid droplets in the cytoplasm. In physiological conditions, these cells play pivotal roles in the regulation of vitamin A homoeostasis. In pathological conditions, such as hepatic fibrosis or liver cirrhosis, HSCs lose vitamin A and synthesize a large amount of extracellular matrix components including collagen, proteoglycan, glycosaminoglycan and adhesive glycoproteins. Morphology of these cells also changes from the star-shaped SCs (stellate cells) to that of fibroblasts or myofibroblasts. The hepatic SCs are now considered to be targets of therapy of hepatic fibrosis or liver cirrhosis. HSCs are activated by adhering to the parenchymal cells and lose stored vitamin A during hepatic regeneration. Vitamin A-storing cells exist in extrahepatic organs such as the pancreas, lungs, kidneys and intestines. Vitamin A-storing cells in the liver and extrahepatic organs form a cellular system. The research of the vitamin A-storing cells has developed and expanded vigorously. The past, present and future of the research of the vitamin A-storing cells (SCs) will be summarized and discussed in this review.
Departments of Cell Biology and Morphology, Akita University Graduate School of Medicine, 111 Hondo, Akita City, Akita 0108543, Japan. senoo@ipc.akita-u.ac.jp
Haruki
H
Senoo
Kiwamu
K
Yoshikawa
Mayako
M
Morii
Mitsutaka
M
Miura
Katsuyuki
K
Imai
Yoshihiro
Y
Mezaki
D000818:Animals; D003585:Cell Biology / Q000639:trends*; D055166:Hepatic Stellate Cells / Q000145:classification / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D022781:Hepatocytes / Q000166:cytology / Q000502:physiology; D006801:Humans; D008099:Liver / Q000166:cytology* / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D008954:Models, Biological; D009626:Terminology as Topic; D014801:Vitamin A / Q000378:metabolism
D014801:Vitamin A