Moss-Derived Human Recombinant GAA Provides an Optimized Enzyme Uptake in Differentiated Human Muscle Cells of Pompe Disease

Abstract

Pompe disease is an autosomal recessive lysosomal storage disorder (LSD) caused by deficiency of lysosomal acid alpha-glucosidase (GAA). The result of the GAA deficiency is a ubiquitous lysosomal and non-lysosomal accumulation of glycogen. The most affected tissues are heart, skeletal muscle, liver, and the nervous system. Replacement therapy with the currently approved enzyme relies on M6P-mediated endocytosis. However, therapeutic outcomes still leave room for improvement, especially with regard to skeletal muscles. We tested the uptake, activity, and effect on glucose metabolism of a non-phosphorylated recombinant human GAA produced in moss (moss-GAA). Three variants of moss-GAA differing in glycosylation pattern have been analyzed: two with terminal mannose residues in a paucimannosidic (Man3) or high-mannose (Man 5) configuration and one with terminal N-acetylglucosamine residues (GnGn). Compared to alglucosidase alfa the moss-GAA GnGn variant showed increased uptake in differentiated myotubes. Moreover, incubation of immortalized muscle cells of Gaa−/− mice with moss-GAA GnGn led to similarly efficient clearance of accumulated glycogen as with alglucosidase alfa. These initial data suggest that M6P-residues might not always be necessary for the cellular uptake in enzyme replacement therapy (ERT) and indicate the potential of moss-GAA GnGn as novel alternative drug for targeting skeletal muscle in Pompe patients.

Pompe Disease: New Developments in an Old Lysosomal Storage Disorder

“…The metabolome profile of the diseased muscle reflected the state of limited glucose availability and revealed a decrease in glycolysis and a shift from carbohydrate to lipids as the main energy source. Lower than normal glycolysis was also observed in human primary myoblasts from Pompe disease patients [91]. It is worth mentioning that metabolic pathways are highly conserved through evolution, and metabolic similarities between rodents and humans are very comparable despite the commonly observed differences in the phenotype of many mouse models of human diseases, including Pompe disease.…”

Stable Protein Sialylation in Physcomitrella

“…Furthermore, the clinical phase I study of the recombinantly produced candidate biopharmaceutical moss-aGal against Fabry disease was successfully completed (Reski et al, 2018; Hennermann et al, 2019). Moss-GAA and moss-aGal proved to have better overall performance compared to their variants produced in mammalian cell cultures (Hennermann et al, 2019; Hintze et al, 2020), demonstrating the potential of P. patens to produce biobetters. However, the last step in humanizing N- glycans, protein sialylation, still has to be accomplished.…”

“…Particularly, with regard to recent achievements in the production of candidate biopharmaceuticals, combined with its Good Manufacturing Practice (GMP)-compliant production capabilities, the moss P. patens serves as a competitive production platform for biopharmaceuticals (Decker and Reski, 2020). Preclinical trials of moss-derived recombinant human complement factor H were recently effectively accomplished (Häffner et al, 2017; Michelfelder et al, 2017), along with the moss-GAA (acid alpha-1,4-glucosidase) against Pompe disease (Hintze et al, 2020). Furthermore, the clinical phase I study of the recombinantly produced candidate biopharmaceutical moss-aGal against Fabry disease was successfully completed (Reski et al, 2018; Hennermann et al, 2019).…”

Stable Protein Sialylation in Physcomitrella

“…Particularly, with regard to recent achievements in the production of candidate biopharmaceuticals, combined with its Good Manufacturing Practice (GMP)-compliant production capabilities, the moss Physcomitrella serves as a competitive production platform for biopharmaceuticals (Decker and Reski, 2020). Preclinical trials of moss-derived recombinant human complement factor H were recently effectively accomplished (Häffner et al, 2017;Michelfelder et al, 2017), along with the moss-GAA (acid alpha-1,4glucosidase) against Pompe disease (Hintze et al, 2020). Furthermore, the clinical phase I study of the recombinantly produced candidate biopharmaceutical moss-aGal against Fabry disease was successfully completed (Reski et al, 2018;Hennermann et al, 2019).…”

“…Furthermore, the clinical phase I study of the recombinantly produced candidate biopharmaceutical moss-aGal against Fabry disease was successfully completed (Reski et al, 2018;Hennermann et al, 2019). Moss-GAA and moss-aGal proved to have better overall performance compared to their variants produced in mammalian cell cultures (Hennermann et al, 2019;Hintze et al, 2020), demonstrating the potential of Physcomitrella to produce biobetters. However, the last step in humanizing N-glycans, protein sialylation, still has to be accomplished.…”