(E)-N-[(3,4-dimethoxyphenethyl)]-N-methyl-3-(3-pyridyl)-2-propenamide (TJN-331) inhibits mesangial expansion in experimental IgA nephropathy in ddY mice

Background: TJN-331 is an inhibitor of transforming growth factor β1 (TGF-β1) production that has similar structural features to the natural product acteoside. This study was performed to examine the antinephritic effects of TJN-331 in a mouse model of experimental IgA nephropathy.

Materials and methods: IgA nephropathy was induced in ddY mice by oral administration of bovine γ globulin, followed by reticuloendothelial blocking by colloidal carbon injection and heminephrectomy. Effects of TJN-331 were examined over oral administration periods from 10 to 15 weeks after the third colloidal carbon injection. Intravenous administration of a TGF-β1-neutralizing antibody was used to investigate the role of TGF-β1 in IgA nephropathy.

Results: Administration of TJN-331 or captopril prevented elevation of serum creatinine. Histopathological examination after both experimental periods showed that TJN-331 inhibited increases in the mesangial matrix index and the number of nuclei per glomerular cross-section, compared with in untreated ddY mice with IgA nephropathy. TJN-331 prevented increase in glomerular TGF-β1 staining without affecting IgA. In the in vitro study, TJN-331 prevented total TGF-β1 production from splenocytes stimulated with concanavalin A. A neutralizing antibody against TGF-β1 prevented increase in the mesangial matrix index and the number of glomerular cells per cross-sectional area.

Conclusion: These results suggest that TJN-331 is effective against IgA nephropathy in ddY mice and acts via suppression of TGF-β1 production in glomeruli.