GLUCOSE-INDUCED GENES IN BOVINE AORTIC SMOOTH-MUSCLE CELLS IDENTIFIED BY MESSENGER-RNA DIFFERENTIAL DISPLAY

Hyperglycemia is postulated to cause chronic changes in the vasculature of diabetic patients, suggesting structural or genetic alterations. We have characterized the glucose induced alterations of gene expression in cultured bovine aortic smooth muscle cells using the recently developed mRNA differential display method. After five days of incubation with either 5.5 or 22 mM glucose, RNA preparations were isolated from confluent cells and probed with 10 candidate clones identified after screening up to 3000 mRNA species. Among these, three clones (2A, 2C, 3) showed significant changes in expression by Northern blot analysis. Elevated glucose levels decreased the mRNA expression of clones 2A and 3 to 51 +/- 7% (P < .01) and 59 +/- 10% (P < .05) (mean% of control +/- SEM), respectively. Expression of clone 2C was increased in 22 mM glucose condition to 221 +/- 23% (P < .05). Nucleotide sequence analysis showed that clone 3 had 77% homology to the 3'-noncoding region of human elongation factor 2, a member of the GTPase family which is essential for polypeptide synthesis. Clones 2A and 2C do show no homology to known nucleotide sequences. These results indicate that physiologically attainable high glucose conditions can significantly effect gene expression in aortic smooth muscle cells. Furthermore, mRNA differential display can be used in metabolic studies to identify new genes regulated by nutrients such as glucose.