FSP1: a liver cirrhosis marker which is not one
(Vienna/San Diego/Washington, 21 Dec. 2010) Christoph Österreicher from the Institute of Pharmacology at MedUni Vienna and his co-authors, including from the University of California, San Diego School of Medicine, have now “done away” with a previously established opinion with the publication in the Proceedings of the National Academy of Sciences (PNAS): that scarring of the liver comes from cells which have the marker FSP1.
Liver fibrosis and liver cirrhosis, the increasing scarring of the vital organ, are a frequent consequence of chronic liver damage. Connective tissue cells (fibroblasts) are responsible for this. It was also thought that the causes here included conversion of epithelial cells into fibroblasts, a “transition” from epithelial (e.g. skin cells) into mesenchymal cells (cells to which connective tissue also belongs), which was usually demonstrated with the marker FSP1.
Österreicher explains: “The fibroblast-specific protein 1 (FSP1) was considered an important marker for identifying connective tissue cells in scarred organs. It was thought that this could provide proof of such fibrotic processes. There are more than 19,000 entries on this subject in the databases on the corresponding scientific literature."
But this is clearly not the case at all with chronic liver diseases. The scientist explains: “We have discovered that liver fibroblasts never form this protein. In the damaged liver tissue and also in other organs it is clear that only certain pro-inflammatory macrophages (note: eating cells) do this.” After refuting this previous dogma the scientists now want to clarify what the cells which form FSP1 really do.
» Fibroblast-specific protein 1 identifies an inflammatory subpopulation of macrophages in the liver
Christoph H. Österreicher, Melitta Penz-Österreicher, Sergei I. Grivennikov, Monica Guma, Ekaterina K. Koltsova, Christian Datz, Roman Sasik, Gary Hardiman, Michael Karin, and David A. Brenner