Establishment of immortalized Schwann cells from Fabry mice and their low uptake of recombinant alpha-galactosidase

J Hum Genet. 2007;52(12):1018-1025. doi: 10.1007/s10038-007-0210-x. Epub 2007 Oct 27.

Abstract

Peripheral neuropathy is one of the important manifestations of Fabry disease. Enzyme replacement therapy with presently available recombinant alpha-galactosidases does not always improve the Fabry neuropathy. But the reason has not been determined yet. We established a Schwann cell line from Fabry mice, characterized it, and then examined the uptake of alpha-galactosidase by cells and its effect on the degradation of accumulated substrate. The cells exhibited a distinct Schwann cell morphology and biochemical phenotype (alpha-Galactosidase activity was deficient, and numerous cytoplasmic inclusion bodies were present in the cells). A recombinant alpha-galactosidase added to the culture medium was incorporated into the cultured Fabry Schwann cells dose dependently. But the increase in cell-associated enzyme activity was less than that in the cases of human and mouse Fabry fibroblasts. The administration of a high dose of the enzyme improved the pathological changes in cells, although a low dose of it did not. Cellular uptake of the enzyme was strongly inhibited in the presence of mannose 6-phosphate. This suggests that the enzyme is incorporated via cation-independent mannose 6-phosphate receptors in Schwann cells. The low expression of cation-independent mannose 6-phosphate receptors in Schwann cells must be one of the reasons their uptake of the present enzymes was low. The administration of a high dose of the enzyme or the development of an enzyme containing many mannose 6-phosphate residues is required to improve Fabry neuropathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport
  • Dose-Response Relationship, Drug
  • Fabry Disease / drug therapy*
  • Fabry Disease / enzymology
  • Fabry Disease / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Receptor, IGF Type 2
  • Recombinant Proteins
  • Schwann Cells / drug effects
  • Schwann Cells / metabolism*
  • alpha-Galactosidase / antagonists & inhibitors
  • alpha-Galactosidase / pharmacokinetics*

Substances

  • Receptor, IGF Type 2
  • Recombinant Proteins
  • alpha-Galactosidase