Hypoxia-inducible factor 1 alpha and vascular endothelial growth factor overexpression in ischemic colitis.
OBJECTIVE
To examine the etiology and pathophysiology in human ischemic colitis from the viewpoint of ischemic factors such as hypoxia-inducible factor 1 alpha (HIF-1 alpha and vascular endothelial growth factor (VEGF).


METHODS
Thirteen patients with ischemic colitis and 21 normal controls underwent colonoscopy. The follow-up colonoscopy was performed in 8 patients at 7 to 10 d after the occurrence of ischemic colitis. Biopsy samples were subjected to real-time RT-PCR and immunohistochemistry to detect the expression of HIF-1 alpha and VEGF.


RESULTS
HIF-1 alpha and VEGF expression were found in the normal colon tissues by RT-PCR and immunohistochemistry. HIF-1 alpha and VEGF were overexpressed in the lesions of ischemic colitis. Overexpressed HIF-1 alpha and VEGF RNA quickly decreased to the normal level in the scar regions at 7 to 10 d after the occurrence of ischemic colitis.


CONCLUSIONS
Constant expression of HIF-1 alpha and VEGF in normal human colon tissue suggested that HIF-1 alpha and VEGF play an important role in maintaining tissue integrity. We confirmed the ischemic crisis in ischemic colitis at the molecular level, demonstrating overexpression of HIF-1 alpha and VEGF in ischemic lesions. These ischemic factors may play an important role in the pathophysiology of ischemic colitis.
Okuda
Tomoyuki
T
Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Matsuoka-cho, Yoshida-gun, Fukui 9101193, Japan.
Azuma
Takeshi
T
Ohtani
Masahiro
M
Masaki
Ryuho
R
Ito
Yoshiyuki
Y
Yamazaki
Yukinao
Y
Ito
Shigeji
S
Kuriyama
Masaru
M
D016022:Case-Control Studies; D017091:Colitis, Ischemic / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A