Induction of calponin-h1 by transforming growth factor-beta1 in cultured human ito cells, LI90.
We investigated the effect of transforming growth factor-beta1 (TGF-beta1) on the expression of calponin-h1, alpha-smooth muscle actin (alpha-SMA), and extracellular matrix (ECM) components in a cultured human Ito cell line, LI90. The TGF-beta1 treatment stimulated productions of hyaluronic acid and laminin, and significantly decreased the secretion of hepatocyte growth factor in LI90 cells. The functional characteristics of LI90 cells were compatible with those of human-activated Ito cells that are known as pericyte-like mesenchymal liver cells. TGF-beta1 induced a slight growth-inhibition of LI90 cells. TGF-beta1 enhanced the expressions of both alpha-SMA and calponin-h1 at the protein level, while tumor necrosis factor-alpha and interleukin-1alpha did not affect the expressions of these cytoskeletal proteins on LI90 cells. The addition of TGF-beta1 to LI90 cells resulted in a significant increase of calponin-h1 mRNA levels, but not calponin-h2. These data suggest that the expression of calponin-h1 is controlled at the level of mRNA under the coordinate regulation together with alpha-SMA as the process of perpetuation of activated Ito cells promoted by TGF-beta1. The identification of smooth muscle features promoted by TGF-beta1 support the hypothesis that the activation of Ito cells coincides with their contractile behavior, indicating that these cells may be important in vasoregulation during liver injury and fibrosis.
Ueki
N
N
Third Department of Internal Medicine, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya, Hyogo 663, Japan.
Ohkawa
T
T
Yamamura
H
H
Takahashi
K
K
Tsutsui
T
T
Kawai
Y
Y
Yokoyama
Y
Y
Amuro
Y
Y
Hada
T
T
Higashino
K
K
D000199:Actins / Q000187:drug effects / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000187:drug effects* / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D015870:Gene Expression / Q000187:drug effects / Q000235:genetics; D005786:Gene Expression Regulation; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism; D007797:Laminin / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008840:Microfilament Proteins; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D000096985:Calponins
D000199:Actins; D002135:Calcium-Binding Proteins; D017228:Hepatocyte Growth Factor; D006820:Hyaluronic Acid; D007797:Laminin; D008840:Microfilament Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D000096985:Calponins