Upregulation of vascular endothelial growth factor isoform VEGF-164 and receptors (VEGFR-2, Npn-1, and Npn-2) in rats with cyclophosphamide-induced cystitis

Departments of 1 Neurology and 2 Anatomy, University of Vermont College of Medicine, Burlington, Vermont Submitted 13 May 2008 ; accepted in final form 11 July 2008 Regulation of the VEGF-VEGF receptor system was examined in the urinary bladder after acute (2–48 h) and chronic (10 days) cyclophosphamide (CYP)-induced cystitis. ELISAs demonstrated significant ( P 0.01) upregulation of VEGF in whole urinary bladder with acute and chronic CYP-induced cystitis; however, the magnitude of increase was greater after acute (2–4 h) cystitis. Immunohistochemistry for VEGF immunoreactivity revealed a significant ( P 0.05) increase in VEGF immunoreactivity in the urothelium, suburothelial vasculature, and detrusor smooth muscle with acute (4 and 48 h) CYP treatment. RT-PCR identified the isoform VEGF-164, the VEGF receptor VEGFR-2, and the VEGF co-receptors neuropilin (Npn)-1 and Npn-2 in the urinary bladder. Quantitative PCR demonstrated upregulation of VEGF-164 transcript with acute and chronic CYP-induced cystitis, but VEGFR-2, Npn-1, and Npn-2 transcripts were upregulated ( P 0.01) in whole bladder only with chronic CYP-induced cystitis. Additional studies demonstrated regulation of VEGF transcript expression in the urinary bladder by nerve growth factor (NGF) in a novel line of NGF-overexpressing mice. These studies demonstrated that urinary bladder inflammation and NGF regulate the VEGF-VEGF receptor system in the urinary bladder. Functional role(s) for the VEGF-VEGF receptor system in urinary bladder inflammation remain to be determined. urothelium; quantitative polymerase chain reaction; immunohistochemistry; detrusor smooth muscle; vasculature; nerve growth factor Address for reprint requests and other correspondence: M. A. Vizzard, Dept. of Neurology, Univ. of Vermont College of Medicine, D415A Given Research Bldg., Burlington, VT 05405 (e-mail: margaret.vizzard{at}uvm.edu )