When an anti-human BMP antibody was added to cells of an immortalized human mesangial cell line cultured in the presence of human BMP, the anti-human BMP antibody significantly suppressed the production of type IV collagen in mesangial cells. A number of signaling pathways are involved in abnormal proliferation of type IV collagen. It was therefore completely unpredictable whether merely blocking the BMP signal would indeed suppress the abnormal proliferation of type IV collagen. However, for the first time, the present inventors demonstrated that anti-BMP antibodies are very effective in suppressing the abnormal proliferation of type IV collagen. Thus, anti-BMP antibodies can be used as novel therapeutic agents for kidney diseases associated with abnormal proliferation of the mesangial matrix.
