Apoptotic body engulfment by a human stellate cell line is profibrogenic

Ali Canbay, Pavel Taimr, Natalie Torok, Hajime Higuchi, Scott Friedman, Gregory J. Gores

Research output: Contribution to journalArticlepeer-review

294 Scopus citations

Abstract

Hepatocyte apoptosis and stellate cell activation are both features of chronic liver diseases, but a relationship between these events has not been explored. In macrophages, engulfment of apoptotic bodies induces expression of transforming growth factor-β (TGF-β), a profibrogenic cytokine. We examined whether a similar response occurs in stellate cells. Fluorescently labeled hepatocyte apoptotic bodies were added to cultures of primary and immortalized human stellate cells. Stellate cells, but not hepatocytes, readily engulfed apoptotic bodies in a time-dependent manner as assessed by confocal microscopy. The activation of primary and immortalized human stellate cells after incubation with apoptotic bodies, as well as their fibrogenic activity, was indicated by an increase in α-smooth muscle actin (primary cells), TGF-β1, and collagen α1(I) mRNA (primary and immortalized cells). The profibrogenic response was dependent upon apoptotic body engulfment, because nocodazole, a microtubule-inhibiting agent, blocked both the engulfment and the increase of TGF-β1 and collagen α1(I) mRNA. As described in primary rodent stellate cells, up-regulation of collagen α1(I) mRNA was inhibited by a PI-3K inhibitor (LY294002) and a p38 mitogen-activated protein kinase inhibitor (SB203580) in LX-1 cells. In conclusion, these data support a model in which engulfment of hepatocyte apoptotic bodies by stellate cells leads to a fibrogenic response by eliciting a kinase-signaling pathway.

Original languageEnglish (US)
Pages (from-to)655-663
Number of pages9
JournalLaboratory Investigation
Volume83
Issue number5
DOIs
StatePublished - May 1 2003

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Molecular Biology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Apoptotic body engulfment by a human stellate cell line is profibrogenic'. Together they form a unique fingerprint.

Cite this