Electrophoretic analysis of various urinary proteins in Japanese patients with Dent disease

Patients with Dent disease excrete high amounts of urinary α1-microglobulin (α1-m), β2-microglobulin (β2-m), and retinol-binding protein (RBP). We found that the levels of α1-m, β2-m, and RBP in patients with Dent disease were higher than those in healthy subjects by 20 times, 130 times, and 200 times, respectively. These results confirmed the results of previous studies. The cellulose acetate membrane electrophoresis (CAE) showed that the characteristics of the urinary protein fraction in patients with Dent disease included appearance of pre-albumin, low albumin value, equal α1-globulin (α1-G) and α2-globulin (α2-G) values, disappearance of β-globulin (β-G), and appearance of slow α2-G (RBP) and slow β-G (β2-m). Urinary albumin (ALB), α1-m, β2-m, and RBP of patients with Dent disease 1 (mutation of CLCN 5) and Dent disease 2 (mutation of OCRL 1) and of healthy subjects were identified using western blot analysis after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Six bands from 84 kDa to 130 kDa were detected in addition to a main band of ALB (67 kDa). Seven bands from 51 kDa to 92 kDa were detected in addition to a main band of α1-m (34 kDa). A 17-kDa band was detected in addition to a main band of β2-m (14 kDa). RBP was detected only in the main band (17 kDa). The ALB and α1-m bands, which were in the high molecular weight range in addition to the main band, were densely stained in Dent disease 2.