title: Protease-resistant modified human β-hexosaminidase B ameliorates symptoms in GM2 gangliosidosis model.
abstract: GM2 gangliosidoses, including Tay-Sachs and Sandhoff diseases, are neurodegenerative lysosomal storage diseases that are caused by deficiency of β-hexosaminidase A, which comprises an αβ heterodimer. There are no effective treatments for these diseases; however, various strategies aimed at restoring β-hexosaminidase A have been explored. Here, we produced a modified human hexosaminidase subunit β (HexB), which we have termed mod2B, composed of homodimeric β subunits that contain amino acid sequences from the α subunit that confer GM2 ganglioside-degrading activity and protease resistance. We also developed fluorescent probes that allow visualization of endocytosis of mod2B via mannose 6-phosphate receptors and delivery of mod2B to lysosomes in GM2 gangliosidosis models. In addition, we applied imaging mass spectrometry to monitor efficacy of this approach in Sandhoff disease model mice. Following i.c.v. administration, mod2B was widely distributed and reduced accumulation of GM2, asialo-GM2, and bis(monoacylglycero)phosphate in brain regions including the hypothalamus, hippocampus, and cerebellum. Moreover, mod2B administration markedly improved motor dysfunction and a prolonged lifespan in Sandhoff disease mice. Together, the results of our study indicate that mod2B has potential for intracerebrospinal fluid enzyme replacement therapy and should be further explored as a gene therapy for GM2 gangliosidoses.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kitakaze
authors.forename: Yasumichi
authors.initials: Y
authors.lastname: Mizutani
authors.forename: Eiji
authors.initials: E
authors.lastname: Sugiyama
authors.forename: Chikako
authors.initials: C
authors.lastname: Tasaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsuji
authors.forename: Nobuo
authors.initials: N
authors.lastname: Maita
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Hirokawa
authors.forename: Daisuke
authors.initials: D
authors.lastname: Asanuma
authors.forename: Mako
authors.initials: M
authors.lastname: Kamiya
authors.forename: Kohei
authors.initials: K
authors.lastname: Sato
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Setou
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Urano
authors.forename: Tadayasu
authors.initials: T
authors.lastname: Togawa
authors.forename: Akira
authors.initials: A
authors.lastname: Otaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakuraba
authors.forename: Kohji
authors.initials: K
authors.lastname: Itoh
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D004195:Disease Models, Animal; D020143:Gangliosidoses, GM2 / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D020125:Mutation, Missense; D010447:Peptide Hydrolases / Q000737:chemistry; D059748:Proteolysis; D054821:beta-Hexosaminidase beta Chain / Q000235:genetics / Q000494:pharmacology
chemical_list: C513386:HEXB protein, human; D054821:beta-Hexosaminidase beta Chain; D010447:Peptide Hydrolases