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Mitogen crosstalk accompanying urokinase receptor expression in stimulated vascular smooth muscle cells
Author(s) -
Reuning Ute,
Dixon Eric P.,
Little Sheila P.,
Bang Nils U.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00797-1
Subject(s) - urokinase receptor , basic fibroblast growth factor , thrombin , messenger rna , plasminogen activator , receptor , endocrinology , medicine , biology , growth factor , thrombin receptor , vascular smooth muscle , chemistry , microbiology and biotechnology , platelet , immunology , biochemistry , smooth muscle , gene
Thrombin and other mitogens regulate the expression of the urokinase‐type plasminogen activator receptor (uPAR) protein and mRNA levels in bovine vascular smooth muscle cells (SMC). We investigated interactions between mitogens capable of increasing uPAR mRNA levels in SMC. Up‐regulation of uPAR mRNA upon thrombin and basic fibroblast growth factor (bFGF) stimulation was preceded by a 2–3‐fold transient increase in bFGF mRNA within 1 h. TGF‐ β 1 did not result in a significant change in bFGF mRNA levels. Platelet‐derived growth factor (PDGF) while substantially enhancing uPAR mRNA levels, diminished bFGF mRNA levels by 3–4‐fold. Both thrombin and bFGF induced the message for bFGF‐R 2–3‐fold. Thrombin also provoked a 3–4‐fold rise in TGF‐ β 1 mRNA levels within 30 min. In summary, on the mRNA level, we demonstrated both positive as well as negative feed‐back mechanisms between different mitogens, among them bFGF revealing in addition to autoinduction also up‐regulation of the transcript concentration of its own receptor. Thus, cooperation and possible amplification of mitogenic effects might be implicated in the fine‐tuned regulation of uPAR mRNA in stimulated bovine aorta SMC.