D. Kunz et al., TRANSFORMING GROWTH FACTOR-BETA(2) INHIBITS INTERLEUKIN 1-BETA-INDUCED EXPRESSION OF INDUCIBLE NITRIC-OXIDE SYNTHASE IN RAT RENAL MESANGIALCELLS, Inflammation research, 46(9), 1997, pp. 327-331
Objective and Design: We have investigated whether transforming growth
factor beta(2) (TGF-beta(2)) influences the expression of inducible n
itric oxide synthase (iNOS). Material: Rat renal mesangial cells expos
ed to the inflammatory cytokine interleukin 1 beta (IL-1 beta). Result
s: Addition of TGF-beta(2) dose-dependently suppresses IL-1 beta-induc
ed nitrite formation. Western and Northern blot analyses of mesangial
cell extracts reveal that the inhibition of IL-1 beta-induced nitrite
formation by TGF-beta(2) is due to decreased iNOS protein and iNOS mRN
A steady state levels. Reduction of iNOS mRNA levels is due to decreas
ed transcriptional activity of the iNOS gene under the action of TGF-b
eta(2) as shown by nuclear run on experiments. Conclusions: TGF-beta(2
) is a potent inhibitor of iNOS expression acting by reducing the tran
scriptional activity of the iNOS gene.