Format

Send to

Choose Destination
J Biol Chem. 2010 Feb 5;285(6):3633-42. doi: 10.1074/jbc.M109.072900. Epub 2009 Dec 5.

Impairment of transforming growth factor beta signaling in caveolin-1-deficient hepatocytes: role in liver regeneration.

Author information

1
Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Arturo Duperier 4, 28029 Madrid.

Abstract

Caveolin-1 (Cav-1) is the main structural protein of caveolae and plays an important role in various cellular processes such as vesicular transport, cholesterol homeostasis, and signal transduction pathways. The expression and functional role of Cav-1 have been reported in liver and in hepatocyte cell lines, in human cirrhotic liver, and in hepatocellular carcinomas. Previous studies demonstrated that Cav-1 was dispensable for liver regeneration, because Cav-1(-/-) animals survived and fully regenerated liver function and size after partial hepatectomy. In this study, we have investigated the mechanisms by which the lack of Cav-1 accelerates liver regeneration after partial hepatectomy. The data show that transforming growth factor beta (TGF-beta) signaling is impaired in regenerating liver of Cav-1(-/-) mice and in hepatocytes derived from these animals. TGF-beta receptors I and II do not colocalize in the same membrane fraction in the hepatocytes derived from Cav-1(-/-) mice, as Smad2/3 signaling decreased in the absence of Cav-1 at the time that the transcriptional corepressor SnoN accumulates. Accordingly, the expression of TGF-beta target genes, such as plasminogen activator inhibitor-1, is decreased due to the presence of the high levels of SnoN. Moreover, hepatocyte growth factor inhibited TGF-beta signaling in the absence of Cav-1 by increasing SnoN expression. Taken together, these data might help to unravel why Cav-1-deficient mice exhibit an accelerated liver regeneration after partial hepatectomy and add new insights on the molecular mechanisms controlling the initial commitment to hepatocyte proliferation.

PMID:
19966340
PMCID:
PMC2823504
DOI:
10.1074/jbc.M109.072900
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center