Hypoxia-inducible factor-1 modulates the expression of vascular endothelial growth factor and endothelial nitric oxide synthase induced by eccentric exercise.
The present study investigated the effects of acute and chronic eccentric exercise on the hypoxia-inducible factor (HIF)-1α activation response and the concomitant modulation of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) expression in rat skeletal muscle. Twenty-four male Wistar rats were randomly assigned to three experimental groups: rested control group, acutely exercised group after an intermittent downhill protocol for 90 min, and acutely exercise group with a previous eccentric training of 8 wk. HIF-1α activation, VEGF and eNOS gene expression, protein content, and promoter activation were assessed in vastus lateralis muscle biopsies. Acute eccentric exercise induced a marked activation of HIF-1α and resulted in increased VEGF and eNOS mRNA level and protein concentration. The binding of HIF-1α to the VEGF and eNOS promoters, measured by a chromatin immunoprecipitation assay, was undetectable in rested rats, whereas it was evident in acutely exercised animals. Acute exercise also increased myeloperoxidase, toll-like receptor-4, tumor necrosis factor-α, and interleukin-1β protein content, suggesting a contribution of proinflammatory stimuli to HIF-1α activation and VEGF overexpression. All of these effects were partially abolished by training. Moreover, training resulted in an increased capillary density. In summary, our findings indicate that eccentric exercise prompts an HIF-1α response in untrained skeletal muscle that contributes to the upregulation of VEGF and eNOS gene expression and is attenuated after an eccentric training program.
Institute of Biomedicine (IBIOMED), University of León, León, Spain.
Paula
P
Rodriguez-Miguelez
Institute of Biomedicine (IBIOMED), University of León, León, Spain.
Elena
E
Lima-Cabello
Institute of Biomedicine (IBIOMED), University of León, León, Spain.
Susana
S
Martínez-Flórez
Institute of Biomedicine (IBIOMED), University of León, León, Spain.
Mar
M
Almar
Institute of Biomedicine (IBIOMED), University of León, León, Spain.
María J
MJ
Cuevas
Institute of Biomedicine (IBIOMED), University of León, León, Spain jgonga@unileon.es.
Javier
J
González-Gallego
D000818:Animals; D015870:Gene Expression; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D011897:Random Allocation; D017208:Rats, Wistar; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse
eccentric exercise; endothelial nitric oxide synthase; hypoxia-inducible factor-1; vascular endothelial growth factor