Angiotensin II (All) was found to upregulate tissue inhibitor of metalloproteineses-1 (TIMP-1) gene expression in rat heart endothelial cells in a dose and time-dependent manner. The maximal stimulation of TIMP-1 mRNA was achieved by 2 h after the addition of All. This effect was blocked by losartan, an AT1 receptor antagonist and by calphostin C, a protein kinase C inhibitor. Addition of cycloheximide superinduced and actinomycin D abolished the induction. These results suggest that All stimulates TIMP-1 production by a protein kinase C dependent pathway which is dependent upon de novo RNA synthesis. Immunoprecipitation experiment showed an enhanced band of 28 kDa from the conditioned medium of All-treated cultures. Immunoblot analysis revealed that TIMP-1 was detectable in the conditioned medium 4 h after All stimulation. Since endothelial cells line the blood vessels and sense the rise in All associated with hypertension, the TIMP-1 released by these cells may provide an initial trigger leading to cardiac fibrosis in angiotensin-renin dependent hypertension.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14089 |
| Date | 28 May 1996 |
| Creators | Chua, Chu Chang, Hamdy, Ronald C., Chua, Balvin H.L. |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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