Atorvastatin inhibits proliferation and apoptosis, but induces senescence in hepatic myofibroblasts and thereby attenuates hepatic fibrosis in rats.
Hepatic myofibroblasts (MFB) show increased proliferation, migration and collagen production, which are crucial for hepatic fibrogenesis. Atorvastatin treatment inhibits proliferation, apoptosis and cytokine production of MFB in bile duct-ligated (BDL) rats in vivo. Here, we have further investigated the underlying mechanisms. Primary rat hepatic stellate cells (HSC) were isolated and culture-activated to hepatic MFB. Following 3 days of incubation with atorvastatin (10(-4), 10(-5) and 10(-6) M), transcription levels of profibrotic cytokines (transforming growth factor-β1, connective tissue growth factor and TIMP1) and procollagen Ia were analyzed by real time PCR. Proliferation was investigated by 5'-bromo-2'-deoxyuridine assays. α-Smooth muscle actin protein expression was examined by western blotting. Fluorescence-activated cell sorting analysis of Annexin V and propidium iodide were used to measure apoptosis. Furthermore, p21 western blotting and β-galactosidase staining were investigated in MFB as senescence markers. Subsequently, hepatic expression of desmin and senescence markers were analyzed in the livers of rats receiving atorvastatin (15 mg/kg*d) for 1 week starting 3 and 5 weeks after BDL. Atorvastatin inhibited the activation of HSC to MFB and decreased cytokine and collagen production in MFB in vitro. In addition, proliferation, cytokine and collagen production of MFB were reduced by atorvastatin. Atorvastatin initiated apoptosis at 10(-4) M and attenuated it at 10(-5) M. Atorvastatin induced p21 protein expression and β-galactosidase staining of MFB in vitro and in vivo. Atorvastatin elicits similiar effects on MFB as previously seen in vivo: it decreases MFB turnover and fibrogenesis. We suggest that a further mechanism explaining these effects is senescence of cells.
Department of Internal Medicine I, University of Bonn, Bonn, Germany.
Sabine
S
Klein
Jeremias
J
Klösel
Robert
R
Schierwagen
Christian
C
Körner
Michaela
M
Granzow
Sebastian
S
Huss
Irela Gretchen Reza
IG
Mazar
Susanne
S
Weber
Peter F M
PF
van den Ven
Ursula
U
Pieper-Fürst
Dieter O
DO
Fürst
Jacob
J
Nattermann
Frank
F
Lammert
Tilman
T
Sauerbruch
Jonel
J
Trebicka
D000199:Actins / Q000276:immunology / Q000378:metabolism; D000375:Aging / Q000187:drug effects*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D000069059:Atorvastatin; D049109:Cell Proliferation / Q000187:drug effects*; D003094:Collagen / Q000378:metabolism; D055513:Connective Tissue Growth Factor / Q000235:genetics / Q000378:metabolism; D003893:Desmin / Q000276:immunology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D055166:Hepatic Stellate Cells / Q000187:drug effects; D006538:Heptanoic Acids / Q000494:pharmacology*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008103:Liver Cirrhosis / Q000188:drug therapy*; D008297:Male; D058628:Myofibroblasts / Q000187:drug effects*; D011758:Pyrroles / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D001616:beta-Galactosidase / Q000032:analysis / Q000378:metabolism
D000199:Actins; D000069059:Atorvastatin; D003094:Collagen; D055513:Connective Tissue Growth Factor; D003893:Desmin; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D011758:Pyrroles; D019715:Tissue Inhibitor of Metalloproteinase-1; D053773:Transforming Growth Factor beta1; D001616:beta-Galactosidase; C498862:Acta2 protein, rat