Alternative splicing products of the tenascin gene distinguish rat liver fat storing cells from arterial smooth muscle cells and skin fibroblasts.
Fat storing-(Ito-)cells (FSC) transform into a myofibroblast-like cell type during liver fibrogenesis. A similar development can be observed in cell culture. At the moment, a definite marker to differentiate transformed FSC from smooth muscle cells (SMC) is not available. We recently found that FSC, SMC and skin fibroblasts (SF) synthesize tenascin, a novel matrix protein. As it is reported that various tissues express different tenascin forms by the mechanism of alternative pre-mRNA splicing, we analyzed the tenascin transcripts in these cell types. Total RNA extracted from cultured FSC, SMC and SF, analyzed by Northern blot hybridization, showed a 7.2 kb transcript in FSC, a 8.7 kb mRNA in SMC, whereas SF produced both messages. As the splicing pattern of FSC in primary culture did not change after passaging, this differential expression of tenascin mRNA might provide a tool to identify myofibroblast-like cells derived from FSC. The important fibrogenic mediator transforming growth factor-beta (TGF-beta) increased tenascin gene expression in each cell type. In SMC, TGF-beta additionally induced the production of the 7.2 kb transcript. Determination of tenascin transcripts will allow to examine the purity of FSC cultures and facilitate a better identification of the cells involved in liver fibrosis.
Schwögler
S
S
I. Dept. of Internal Medicine, University of Mainz, FRG.
Odenthal
M
M
Meyer zum Büschenfelde
K H
KH
Ramadori
G
G
D000273:Adipose Tissue / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics*; D002454:Cell Differentiation; D003598:Cytoskeletal Proteins / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005347:Fibroblasts / Q000502:physiology*; D005353:Fibronectins / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000502:physiology*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D019063:Tenascin; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D015816:Cell Adhesion Molecules, Neuronal; D003598:Cytoskeletal Proteins; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D019063:Tenascin; D016212:Transforming Growth Factor beta