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CELLULAR AND MOLECULAR
Department of Human Genetics, Mount Sinai School of Medicine, New York, New York (S.I., H.-H.C., J.-Q.F.); Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan (S.I., A.T.); and Faculty of Medicine, Oita University, Oita, Japan (H.Y., T.S., K.M., Y.H.)
Fabry disease is an inborn error of glycosphingolipid metabolism caused by deficiency of
-galactosidase A (
-Gal A) activity. It has been shown that protein misfolding is primarily responsible for the enzyme deficiency in a large proportion of mutations identified in Fabry patients with residual enzyme activity, and 1-deoxygalactonojirimycin (DGJ) can effectively increase the residual enzyme activity in cultured patient's cells. Herein, we demonstrate the preclinical efficacy and safety of DGJ in transgenic mice that express human mutant
-Gal A activity.
-Gal A activity in heart, kidney, spleen, and liver was increased dose- and time-dependently. The mutant
-Gal A was increased in cardiomyocytes and distal convoluted tubules of the transgenic mice in a null background after 2 weeks of DGJ treatment. Globotriaosylceramide storage was remarkably reduced in kidney of mice after a 4-week treatment at a dosage of approximately 3 mg/kg body weight/day. The half-life of DGJ was less than 1 day in all major issues and that of the enzyme synthesized during the DGJ treatment period was approximately 4 days. No abnormality of blood chemistry and pathological tissue damage was found in mice treated with DGJ at
30 mg/kg body weight/day for 9 weeks. Furthermore, no change was observed in appearance, growth, fertility, and life span in mice during a 2-year period of continuous administration of DGJ at the effective dosage. These preclinical results indicate that DGJ is effective in restoring mutant enzyme activity in tissues and reversing substrate storage in kidney and is well tolerated in mice.
Address correspondence to: Dr. Jian-Qiang Fan, Mount Sinai School of Medicine, Department of Human Genetics, 5th Avenue at 100th Street, New York, NY 10029. E-mail: jian-qiang.fan{at}mssm.edu