Evaluation of N-nonyl-deoxygalactonojirimycin as a pharmacological chaperone for human GM1 gangliosidosis leads to identification of a feline model suitable for testing enzyme enhancement therapy

Abstract

Deficiencies of lysosomal β-D-galactosidase can result in GM1 gangliosidosis, a severe neurodegenerative disease characterized by massive neuronal storage of GM1 ganglioside in the brain. Currently there are no available therapies that can even slow the progression of this disease. Enzyme enhancement therapy utilizes small molecules that can often cross the blood brain barrier, but are also often competitive inhibitors of their target enzyme. It is a promising new approach for treating diseases, often caused by missense mutations, associated with dramatically reduced levels of functionally folded enzyme. Despite a number of positive reports based on assays performed with patient cells, skepticism persists that an inhibitor-based treatment can increase mutant enzyme activity in vivo. To date no appropriate animal model, i.e., one that recapitulates a responsive human genotype and clinical phenotype, has been reported that could be used to validate enzyme enhancement therapy. In this report, we identify a novel enzyme enhancementagent, N-nonyl-deoxygalactonojirimycin, that enhances the mutant β-galactosidase activity in the lysosomes of a number of patient cell lines containing a variety of missense mutations. We then demonstrate that treatment of cells from a previously described, naturally occurring feline model (that biochemically, clinically and molecularly closely mimics GM1 gangliosidosis in humans) with this molecule, results in a robust enhancement of their mutant lysosomal β-galactosidase activity. These data indicate that the feline model could be used to validate this therapeutic

Morquio‐B disease: Clinical and genetic characteristics of a distinct GLB1‐related dysostosis multiplex

“…Several pharmacological chaperones acting on β‐galactosidase including galactose, N‐octyl‐4‐epi‐beta‐valienamine (NOEV), alkylated or fluorinated derivates of desoxynojirimycine (DGJ), and (5aR)‐5a‐C‐Pentyl‐4‐epiisofagomine have been tested against numerous GLB1 mutant enzymes …”

N‐Alkyl‐, 1‐C‐Alkyl‐, and 5‐C‐Alkyl‐1,5‐dideoxy‐1,5‐imino‐(l)‐ribitols as Galactosidase Inhibitors

“…Chaperone assays:T he fibroblast cell lines derived from GM1-gangliosidosis patients GM02439 and GM03251 were obtained from Coriell Institute (Camden, NJ, USA). The chaperone assays were conducted by following the method described by Rigat et al [30] Fibroblasts were cultured in 25 cm 2 flasks placed in ah umidified incubator (37 8Ca nd 5% CO 2 )u sing DMEM complete (DMEM-c) made from DMEM supplemented with nonessential amino acids, penicillin, streptomycin and 10 %f etal calf serum (Invitrogen Ther-moFisher Scientific). For the chaperone assays, cells were harvested by trypsinization, seeded in triplicates at 210 4 cells per well of 24-well plates in 2mLD MEM-c with the adequate compound concentrations.…”

Candidate Molecules for Chemical Chaperone Therapy of G M1 -Gangliosidosis

“…Chaperone candidates for human b-gal were also explored in the derivatives of DGJ (taBle 2) [48][49][50]. Recently, Rigat et al reported that N-nonyl-DGJ (NN-DGJ) enhanced mutant b-gal activity in feline G M1 -gangliosidosis fibroblasts.…”

“…Recently, Rigat et al reported that N-nonyl-DGJ (NN-DGJ) enhanced mutant b-gal activity in feline G M1 -gangliosidosis fibroblasts. This naturally occurring feline G M1 -gangliosidosis is likely to be a good model of human juvenile form and is a suitable model for the evaluation of in vivo chaperone effect in the future study [50]. There is compelling evidence indicating that drug repositioning or repurposing could accelerate drug discovery including chaperones for LSDs [51][52][53][54][55].…”

“…Chaperones for Gaucher and Pompe diseases have also been tested in preclinical studies. In addition, synergetic effect of Yes (model mice) [32][33][34][35][36][38][39][40] DGJ, NB-DGJ R201C, R201H, R457Q ND [32] Galactose R442Q ND [72] DLHex-DGJ R201C, R201H, C230R, G428E ND [48] Fluorous iminoalditols R148S, R201C, D332N ND [49] NN-DNJ R201H, W509C, R483P (feline GLB1) ND [50] 6S-NBI-DGJ (MTD118) 24 out of 88 missense mutations (including I51T, R201C, G438E)…”