Targeted disruption of the arylsulfatase B gene results in mice resembling the phenotype of mucopolysaccharidosis VI.

Abstract

Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disease with autosomal recessive inheritance caused by a deficiency of the enzyme arylsulfatase B (ASB), which is involved in degradation of dermatan sulfate and chondroitin 4-sulfate. A MATERIALS AND METHODSIsolation of a Genomic Clone and Targeting Vector Construction. A 758-bp partial murine ASB cDNA clone (pCABM750) was isolated from a Agtll brain cDNA library (Clontech) by homology screening with a full-length human ASB cDNA probe (4). The nucleotide sequence of pCABM750 was deposited in the GenBank/EMBL data base (accession no. X92096). pCABM750 exhibits 81.8% sequence identity with the human ASB cDNA (4) on nucleotide and 83.1% on deduced amino acid level (data not shown). In EcoRI digested genomic liver DNA of 129/SvJ mice a 9-kbp and a 1.6-kbp DNA fragment are hybridizing with pCABM750. A subgenomic DNA library was constructed by ligation of 8-to 10-kbp EcoRI DNA fragments from genomic liver DNA of 129/SvJ with X-EMBL4 arms and subsequent packaging according to the instructions of the supplier (Stratagene). A 9-kbp genomic clone (pmAB9E, see Fig. la) was isolated from the library by hybridization with pCABM750. For construction of a targeting vector the 6-kbp BamHI DNA fragment from pmAB9E was subcloned into pBlueskript SK-. A linker fragment from the BamHI site to the Sall site of the plasmid vector pUC18 was ligated to the XhoI site at the 5' end of the neomycin (neo) expression cassette of pMClneo poly(A) (ref.13; Stratagene); the neo cassette in pMClneo poly(A) contains a BamHI site at its 3' end. The neo cassette was inserted into the BglII site in exon 5 of the 6-kbp BamHI subclone described above as a BamHI-BamHI restriction fragment resulting in the targeting vector pAB6Bneo (see Fig. la). The insertion of the neo cassette introduces a premature translational stop codon

Systemic inflammation and neurodegeneration in a mouse model of multiple sulfatase deficiency

“…Some of them represent spontaneous mutants, whereas others were generated as KO mice. The latter are available for five diseases due to individual sulfatase deficiencies, namely metachromatic leukodystrophy, and MPSs (i.e., MPSII, MPSIIIA, MPSIVA, and MPSVI) (11)(12)(13)(14)(15)(16). In all instances the biochemical abnormalities in the mouse models replicated those observed in the corresponding human disease.…”

“…Hind limb clasping, head tremor, and seizures were also detected starting at 1 month of age, indicating neurological involvement (data not shown). All these features are important components of the phenotype observed in patients with MSD (8) and in human patients and murine models of MPSs (5)(6)(7)(11)(12)(13)(14)(15)(16).…”

“…Joint deformities were also evident in most mice. All these features are important components of the phenotype of LSDs and are observed in patients with MSD (8) and of both human patients and murine models of MPSs (5,(12)(13)(14)(15)(16). In addition, bone histological analysis of Sumf1 Ϫ/Ϫ mice showed clear signs of defective osteogenesis (C.S., unpublished data).…”

Cardiac and Ocular Pathologies in a Mouse Model of Mucopolysaccharidosis Type VI

“…The phenotype of ASB-deficient mice is highly reminiscent of the pathologic characteristics of MPS VI (18). The functional inactivation of the ASB gene results in facial dysmorphy, pelvic and costal abnormalities and shortening of long bones.…”

“…This is a major drawback in attempts to develop gene therapy strategies for which many parameters need to be optimized (17). Thus, in previous work the mouse ASB gene has been disrupted by homologous recombination to obtain an MPS VI mouse model (18).…”