Hydrogen Peroxide‐Induced VEGF Transcription in C2C12 Myoblasts is Dependent on the Oxygen Environment

Abstract

This study investigates the transcriptional regulation of vascular endothelial growth factor (VEGF) in skeletal myoblasts exposed to low Po2 and hydrogen peroxide (H2O2). In order to measure VEGF transcription in skeletal myoblasts, cells were cotransfected with a full length mouse VEGF promoter/firefly luciferase reporter construct and the TK promoter/renilla luciferase (internal control). Transfected, proliferating myoblasts were then exposed to 21% O2 or 0.5–1% O2 and treated with 200μM H2O2, 400μM H2O2 or no treatment for 8 hours. VEGF transcription was assayed by measuring firefly and renilla luciferase activities in lysed cells. No difference in VEGF transcription was detected in C2C12 cells treated with H2O2 when cultured in 21% O2. Myoblasts treated with 400μM H2O2 and cultured in a 0.5–1.0% O2 environment revealed a 2 fold increase in luciferase activity compared to non-treated myoblasts. Furthermore, a change in oxygen concentration from 21 to 0.5–1.0% in the absence of H2O2 treatment did not alter VEGF transcription levels. These results indicate that oxygen tension plays a role in mediating the transcriptional response of VEGF to H2O2 in skeletal myoblasts. Supported by: NIH RO1 HL084281-01