Roles of p300 and cyclic adenosine monophosphate response element binding protein in high glucose-induced hypoxia-inducible factor 1α inactivation under hypoxic conditions.
OBJECTIVE
Given the high prevalence of diabetes and burn injuries worldwide, it is essential to dissect the underlying mechanism of delayed burn wound healing in diabetes patients, especially the high glucose-induced hypoxia-inducible factor 1 (HIF-1)-mediated transcription defects.


METHODS
Human umbilical vein endothelial cells were cultured with low or high concentrations of glucose. HIF-1α-induced vascular endothelial growth factor (VEGF) transcription was measured by luciferase assay. Immunofluorescence staining was carried out to visualize cyclic adenosine monophosphate response element binding protein (CREB) localization. Immunoprecipitation was carried out to characterize the association between HIF-1α/p300/CREB. To test whether p300, CREB or p300+CREB co-overexpression was sufficient to rescue the HIF-1-mediated transcription defect after high glucose exposure, p300, CREB or p300+CREB co-overexpression were engineered, and VEGF expression was quantified. Finally, in vitro angiogenesis assay was carried out to test whether the high glucose-induced angiogenesis defect is rescuable by p300 and CREB co-overexpression.


RESULTS
Chronic high glucose treatment resulted in impaired HIF-1-induced VEGF transcription and CREB exclusion from the nucleus. P300 or CREB overexpression alone cannot rescue high glucose-induced HIF-1α transcription defects. In contrast, co-overexpression of p300 and CREB dramatically ameliorated high glucose-induced impairment of HIF-1-mediated VEGF transcription, as well as in vitro angiogenesis. Finally, we showed that co-overexpression of p300 and CREB rectifies the dissociation of HIF-1α-p300-CREB protein complex in chronic high glucose-treated cells.


CONCLUSIONS
Both p300 and CREB are required for the function integrity of HIF-1α transcription machinery and subsequent angiogenesis, suggesting future studies to improve burn wound healing might be directed to optimization of the interaction between p300, CREB and HIF-1α.
Department of Burn and Plastic Surgery, The Third Affiliated Hospital of Nantong University, Wuxi, Jiangsu Province, China.|Department of Plastic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
Lingtao
L
Ding
Department of Burn and Plastic Surgery, The Third Affiliated Hospital of Nantong University, Wuxi, Jiangsu Province, China.
Minlie
M
Yang
Department of Plastic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
Tianlan
T
Zhao
Department of Burn and Plastic Surgery, The Third Affiliated Hospital of Nantong University, Wuxi, Jiangsu Province, China.
Guozhong
G
Lv
D002056:Burns / Q000378:metabolism*; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000378:metabolism*; D050881:E1A-Associated p300 Protein / Q000378:metabolism*; D005947:Glucose / Q000008:administration & dosage; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D009389:Neovascularization, Pathologic; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D017362:Cyclic AMP Response Element-Binding Protein; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; D005947:Glucose
Cyclic adenosine monophosphate response element binding protein; Diabetic burn wound healing; P300