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Acute hyperglycemia regulates transcription and posttranscriptional stability of PKCβII mRNA in vascular smooth muscle cells
Author(s) -
PATEL NIKETA A.,
CHALFANT CHARLES E.,
YAMAMOTO MAYUMI,
WATSON JAMES E.,
EICHLER DUANE C.,
COOPER DENISE R.
Publication year - 1999
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.13.1.103
Subject(s) - protein kinase c , vascular smooth muscle , transfection , messenger rna , gene expression , microbiology and biotechnology , biology , western blot , cytosol , reporter gene , cell culture , medicine , endocrinology , gene , signal transduction , enzyme , biochemistry , smooth muscle , genetics
Acute hyperglycemia may contribute to the progression of atherosclerosis by regulating protein kinase C (PKC) isozymes and by accelerating vascular smooth muscle cell (VSMC) proliferation. We investigated acute glucose regulation of PKCβ gene expression in A10 cells, a rat aortic smooth muscle cell line. Western blot analysis showed that PKCβII protein levels decreased with high glucose (25 mM) compared to normal glucose (5.5 mM), whereas PKCβI levels were unaltered. PKCβ mRNA levels were depleted by 60–75% in hyperglycemic conditions. To elucidate whether high glucose regulated PKCβ expression via the common promoter for PKCβI and PKCβII, deletion constructs of the PKCβ promoter ligated to CAT as reporter gene were transfected into A10 cells. Construct D (−411 to + 179CAT) showed quenching in high glucose (25 mM) and suggested the involvement of a carbohydrate response element in the 5′ promoter region of the PKCβ gene. In actinomycin D‐treated A10 cells, a 60% decrease in PKCβ mRNA with high glucose treatment indicated that posttranscriptional destabilization by glucose was also occurring. We have demonstrated that glucose‐induced posttranscriptional destabilization of PKCβII message is mediated via a nuclease activity present in the cytosol. The specificity of glucose to post‐transcriptionally destabilize PKCβII mRNA, but not the PKCβI mRNA, was confirmed in both A10 cells and primary cultures from human aorta.—Patel, N. A., Chalfant, C. E., Yamamoto, M., Watson, J. E., Eichler, D. C., Cooper, D. R. Acute hyperglycemia regulates transcription and posttranscriptional stability of PKCβII mRNA in vascular smooth muscle cells. FASEB J. 13, 103–113 (1999)