HIF1A and diabetes mellitus: To provide further support for our data revealing that the association of HIF-1α with the VEGF promoter is impaired as a function of diabetes, a plasmid expressing the reporter gene luciferase under the control of a fragment of the human VEGF promoter containing the HRE was transiently transfected into control and diabetic SIECs, and then these cells were incubated with MB-cAMP for 24 hours.