Effects of Protein Kinase Cα Overexpression on A7r5 Smooth Muscle Cell Proliferation and Differentiation
| Autor: | Shaoshan Wang, Richard M. Niles, Gary L. Wright, Dinakar S. Desai |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Electrophoresis
Protein Kinase C-alpha Cellular differentiation Smooth muscle cell differentiation Protein Kinase C beta Protein Kinase C-epsilon Biology Transfection PKC alpha Gene Expression Regulation Enzymologic Muscle Smooth Vascular Desmin Animals Cloning Molecular Aorta Protein Kinase C Cell growth Cell Differentiation Cell Biology Molecular biology Actins Vinculin Rats Cell biology Isoenzymes Transcription Factor AP-1 Protein Kinase C-delta Cell culture Biomarkers Cell Division |
| Zdroj: | Experimental Cell Research. 236:117-126 |
| ISSN: | 0014-4827 |
| DOI: | 10.1006/excr.1997.3714 |
| Popis: | Smooth muscle cell differentiation and proliferation are increasingly seen to be intimately tied to the etiology of atherosclerosis and hypertension. To determine the role of PKC alpha in the regulation of smooth muscle cell differentiation and proliferation, the rat embryonic smooth muscle cell line A7r5 was transfected with an expression vector containing the full-length PKC alpha cDNA. Neomycin-resistant clones which exhibited increased PKC alpha levels compared to wild-type cells were selected. The A7r5 cells overexpressing PKC alpha had altered morphology and decreased growth rates compared to wild-type cells and cells transfected only with the neomycin resistance gene. Electrophoretic mobility shift assays showed that nuclear extracts from overexpressing clones gave a different pattern of protein-DNA binding to an AP-1 consensus oligonucleotide compared to wild-type cells. In contrast to the growth characteristics of these clones, their levels of cell differentiation marker proteins such as vinculin and desmin were not affected by PKC alpha overexpression. Moreover, the smooth muscle-specific differentiation marker alpha-actin was markedly reduced, while beta-actin levels were found to remain unchanged. Northern blot analysis confirmed that alpha-actin downregulation occurred at the RNA level. Western blot analysis revealed that A7r5 cells have five different PKC isoforms and that these isoform protein levels were not changed by PKC alpha overexpression. These findings suggest that PKC alpha regulates growth and differentiation of A7r5 smooth muscle cells and that these changes might result from altered expression/function of AP-1 transcription factors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect