Splice variants VEGF121 and VEGF165 of the angiogenic peptide vascular endothelial cell growth factor are expressed in the synovial tissue of patients with rheumatoid arthritis
T. Pufe et al., Splice variants VEGF121 and VEGF165 of the angiogenic peptide vascular endothelial cell growth factor are expressed in the synovial tissue of patients with rheumatoid arthritis, J RHEUMATOL, 28(7), 2001, pp. 1482-1485
Objective. To determine the expression of the angiogenic peptide vascular e
ndothelial growth factor (VEGF also known as vascular permeability factor,
VPF) in the synovium of patients with rheumatoid arthritis IRA).
Methods. Expression of VEGF protein from the synovial tissue of 10 patients
with RA was monitored by ELISA and visualized by immunocytochemistry, and
by double-staining with the VEGFR-1/flt-1. VEGF mRNA and its splice variant
s were determined by reverse transcriptase polymerase chain reaction (RT-PC
R).
Results. VEGF protein was strongly increased in rheumatoid synovium and loc
alized at the synovial surface, whereas the VEGF receptor flt-1 (VEGFR-1) w
as visualized on microvessels in close vicinity. In synovial tissues from a
ll 10 patients with RA. VEGF(121) and VEGF(165) were identified at the mRNA
level as the only VEGF splice forms expressed.
Conclusion. Since VEGF(165) and VEGF(121) are differently diffusible due to
their opposite heparan sulfate-binding properties, they act at different d
istances. The presence of VEGF(121) may explain induction of the VEGFR-1 on
infiltrating blood vessels near the synovial surface.