Rat liver ferritin selectively inhibits expression of alpha-smooth muscle actin in cultured rat lipocytes.

Abstract

The role of ferritin in lipocyte activation is unknown. This study examined the effect of rat liver ferritin (RLF), human recombinant H-ferritin (HrHF), human recombinant L-ferritin (HrLF), apo-ferritin (apo-RLF), and hemin on lipocyte activation. Lipocytes were cultured on uncoated plastic and were incubated with these agents for 7 days, at concentrations ranging from 10(-14) to 10(-7) M (0.5 to 50 microM for hemin). Collagen/noncollagen protein production and lipocyte proliferation were determined by [3H]proline and [3H]thymidine incorporation, respectively, and the expression of alpha-smooth muscle actin (alpha-SMA) and desmin was determined by Western blot. RLF, at concentrations ranging from 10(-10) to 10(-7) M, decreased alpha-SMA expression by 65-88%. Apo-RLF, HrHF, and HrLF decreased alpha-SMA by 17-45% at 10(-7) and 10(-8) M. Hemin (10 or 50 microM) inhibited alpha-SMA by 37 and 54%, respectively. Desmin expression was not altered by ferritin or hemin. Collagen and noncollagen protein production were not altered by either RLF or apo-RLF. Lipocyte proliferation was decreased by 54, 32, and 40%, by 10(-7) M RLF, HrHF, and HrLF, respectively, whereas apo-RLF had no effect. Thus RLF inhibited lipocyte alpha-SMA expression, which may be due to an effect of sequestered iron, since neither apo-RLF, HrHF, nor HrLF had a potent effect on alpha-SMA expression and all are essentially iron-free. The inhibitory effect of iron-loaded RLF on alpha-SMA expression suggests that tissue ferritin does not initiate lipocyte activation in iron overload, but rather may have a suppressive action on this process.

Statistics

0100200'01'03'05'07'09'11'13'15'17
Citations per Year

176 Citations

Semantic Scholar estimates that this publication has 176 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Ramm1996RatLF, title={Rat liver ferritin selectively inhibits expression of alpha-smooth muscle actin in cultured rat lipocytes.}, author={Grant A Ramm and Robert S. Britton and Rosemary O'neill and Hubertus Kohn and Bruce R. Bacon}, journal={The American journal of physiology}, year={1996}, volume={270 2 Pt 1}, pages={G370-5} }