Regulation of transforming growth factor-beta, basic fibroblast growth factor, and vascular endothelial cell growth factor mRNA in peripheral blood leukocytes in patients with diabetic retinopathy

In the present study, we examined the effect of glucose concentration on th e expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor-beta (TGF-beta) mRNA using reverse transcriptase-polymerase chain reaction (RT-PCR) in normal he althy leukocytes in vitro and in leukocytes from patients with type 1 diabe tes mellitus. In vitro, the level of TGF-beta mRNA was altered in response to the glucose concentration (maximum at 10 mmol/L), while bFGF mRNA remain ed relatively constant and VEGF mRNA varied with no clear correlation with the glucose concentration. Leukocytes from type 1 patients showed no differ ence in bFGF or TGF-beta mRNA levels compared with age-matched healthy cont rols. However, VEGF mRNA was significantly lower in type 1 patients compare d with controls (P < .05). When the patients were subtyped according to the severity of retinopathy, the level of TGF-beta mRNA was elevated selective ly in patients with evidence of active new retinal vessels (P < .01) and VE GF(121) mRNA was reduced in patients with mild to moderate retinopathy. Thu s, leukocyte growth factor mRNAs respond to acute changes in the glucose co ncentration in vitro, and are differentially expressed in type 1 diabetic p atients during the course of the disease. Copyright(C) 1999 by W.B. Saunder s Company.