Galactosialidosis: historic aspects and overview of investigated and emerging treatment options

May combine two claims.

Human PPCA has strong sequence similarity to serine carboxypeptidases, and Ser196, His475, and Asp418 were proposed to make up the catalytic triad of an active PPCA enzyme.

“Analysis of the primary structure of human PPCA revealed strong sequence similarity to serine carboxypeptidases, suggesting that the protein had an intrinsic enzymatic activity.”

• Also stated in: § 4. PPCA - a serine carboxypeptidase identical to cathepsin A · hedged

  “It was postulated that this histidine and the aspartic acid at position 418 activate the serine in the active site of the protein; hence, the three amino-acids, Ser196, His475 and Asp418, were proposed to make up the catalytic triad of an active PPCA enzyme 29,31.”

• cites [29] sourcePartly supported

  The paper describes PPCA as a serine carboxypeptidase and reports about 30% sequence identity with wheat serine carboxypeptidase (Abstract), supporting the similarity and enzymatic-activity point. The Fig. 1 caption identifies a catalytic triad, but the passages in our copy do not name Ser196, His475, and Asp418 as its members. Page numbers are not available in the indexed passages. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [31] sourcePartly supported

  The Biological implications section reports 30% sequence identity between HPP and wheat and yeast serine carboxypeptidases, and says maturation releases carboxypeptidase activity. The Results and discussion section identifies an HPP catalytic triad, but numbers its residues Ser150, His429 and Asp372—not Ser196, His475 and Asp418 as in the claim. No page numbers are available in our copy. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

May combine two claims.

In the absence of functional PPCA, NEU1 is retained in the endosomal compartment while the pool of β-GAL reaching lysosomes is rapidly degraded; formation of the PPCA/NEU1/β-GAL complex has a reciprocal advantage for the three enzymes, which acquire active and stable conformation in lysosomes.

“In absence of functional PPCA, NEU1 is retained in the endosomal compartment while the pool of β-GAL reaching the lysosomes is rapidly degraded 36.”

• Also stated in: § 5. PPCA, a pleiotropic enzyme · plain

  “Formation of the PPCA/NEU1/β-GAL complex 5,6,37–41 has a reciprocal advantage for the three enzymes that in such configuration acquire their active and stable conformation in lysosomes 36.”

• cites [36] sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [5] sourceNot checked — no full text of the source
• cites [6] sourceNot checked — no full text of the source
• cites [37] Hoogeveen AT, 1983, J Biol Chem sourceNot checked — no full text of the source
• cites [38] sourceNot checked — no full text of the source
• cites [39] sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [40] sourceNot checked — no full text of the source
• cites [41] sourceNot checked — no full text of the source

May combine two claims.

PPCA functions as an indispensable chaperone/auxiliary transport protein, especially for NEU1, which is catalytically inert without PPCA, and PPCA prevents self-aggregation of NEU1 molecules.

“It is nonetheless genetically and biochemically proven that PPCA functions as an indispensable chaperone/auxiliary transport protein, especially for NEU1, that is catalytically inert without PPCA.”

• Also stated in: § 5. PPCA, a pleiotropic enzyme · hedged

  “Thus, it appears that PPCA prevents self-aggregation of NEU1 molecules, suggesting that heterodimerization between NEU1 and PPCA helps them to acquire the most suitable conformation for proper intra-organellar routing and full activation/stability in lysosomes 42.”

• cites [42] sourcePartly supported

  The paper describes PPCA as a crucial chaperone and transport protein for NEU1 and says it promotes NEU1’s lysosomal localization while preventing its clustering (introduction; Complex Formation between PPCA and NEU1; page numbers unavailable). The Results say NEU1 gains full catalytic activity through association with PPCA, but do not establish the stronger claim that NEU1 is completely catalytically inert without it. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

May combine two claims.

The most heterogeneous pool of CTSA mutations has been found in patients with the severe, early infantile form of GS, although some recurrent mutations point to a founder effect in specific ethnic groups.

“As foreseeable, the most heterogeneous pool of CTSA mutations have been found in patients with the severe, early infantile form of GS, although some recurrent mutations seem to point to a founder effect in specific ethnic groups 20–23.”

• cites [20] sourceNot checked — no full text of the source
• cites [21] sourcePartly supported

  The Results and Discussion (pages not provided) identify multiple mutations and describe a common SpDEx7 mutation in Japanese patients, alongside mutations observed in patients of other ancestries. They do not establish that early-infantile patients have the most heterogeneous mutation pool or attribute recurrent mutations to a founder effect. (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites [22] sourcePartly supported

  The Abstract and discussion passages report the same mutation in five Japanese patients with adult-onset galactosialidosis, supporting the recurrent-mutation aspect. The discussion does not establish a founder effect and explicitly says the authors had no information on mutations in early-onset galactosialidosis; it cannot support the claim that early infantile cases have the most heterogeneous mutations. Page numbers were not available in our copy. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [23] sourcePartly supported

  The Abstract (Results) reports several novel CTSA changes in infantile GS and suggests an Italian founder effect for the recurrent c.114delG mutation; the Discussion also describes that founder-effect hypothesis. The Results table lists multiple mutations associated with early-infantile disease, but the paper does not establish that this form has the most heterogeneous mutation pool compared with other forms. (LLM, conf=0.82)

  Experimental — accuracy not yet measured

May combine two claims.

The majority of CTSA mutations reported in the literature have been identified in Japanese patients, who share a common single base substitution at the donor splice site of intron 7 causing skipping of exon 7 (SpDEx7), and this mutation apparently segregates with the juvenile/adult type.

“By far, the majority of CTSA mutations reported in the literature have been identified in Japanese patients 8,20,21.”

• Also stated in: § 2.4 Disease-causing CTSA Mutations · plain

  “These patients share a common single base substitution at the donor splice site of intron 7, causing aberrant splicing of the pre-mRNA and the skipping of exon 7 (SpDEx7) 22.”

• Also stated in: § 2.4 Disease-causing CTSA Mutations · hedged

  “This mutation apparently segregates with the juvenile/adult type of the disease.”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

• cites [20] sourceNot checked — no full text of the source
• cites [21] sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [22] sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

In the endosomal/lysosomal compartment, the inactive 54 kDa PPCA precursor undergoes endoproteolytic cleavage to a 34- and 20-kDa inactive two-chain intermediate, followed by removal of a 2-kDa linker/excision peptide to give the mature fully active two-chain enzyme of 32- and 20-kDa covalently linked by disulfide bridges.

“In the endosomal/lysosomal compartment the inactive 54 kDa precursor undergoes an initial endoproteolytic cleavage that generates a 34- and 20-kDa inactive, two-chain intermediate.”

• Also stated in: § 3. PPCA biosynthesis · plain

  “This proteolytic step is followed by the removal of a 2-kDa “linker” or “excision” peptide from the C-terminus of the large chain, which ultimately gives rise to the mature and fully active, two-chain enzyme of 32- and 20-kDa, covalently linked by disulfide bridges 30.”

• cites [30] sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

No adverse side effects have been identified and no difference in heart and lung morphology has been observed.

“No adverse side effects have been identified and no difference in heart and lung morphology has been observed.”

• cites [60] sourceSupported

May combine two claims. The quote only partly states this claim.

Increased levels of cathepsin A induced upregulation of cathepsin B, D, and Z and downregulation of numerous protease inhibitors and antioxidative stress proteins in the murine cardiac proteome, and inhibition of cathepsin A activity has cardioprotective properties.

“Interestingly, increased levels of cathepsin A induced the upregulation of cathepsin B, D and Z, and the downregulation of numerous protease inhibitors, as well as several antioxidative stress proteins 49.”

• Also stated in: § 5. PPCA, a pleiotropic enzyme · boosted

  “The same group has further demonstrated that inhibition of cathepsin A activity has cardioprotective properties and proposed the use of this approach for the treatment of heart failure after myocardial infarction 50.”

• cites [49] sourceNot checked — no full text of the source
• cites [50] sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

Transplantation of Ppca−/− mice with transgenic bone marrow led to complete reversal of their systemic pathology, normalization of urinary oligosaccharides, and increased cathepsin A and Neu1 activities.

“Transplantation of Ppca−/− mice with the transgenic bone marrow led to complete reversal of their systemic pathology, normalization of urinary oligosaccharides and increased cathepsin A and Neu1 activities, although correction of the CNS pathology was only partial 53.”

• cites [53] sourcePartly supported

  The ‘Rescue of the galactosialidosis phenotype’ section reports normal urinary sialyloligosaccharide levels and complete reversal of the gross diseased phenotype after transplantation; the discussion describes complete reversal of lesions in visceral organs with transgenic marrow. However, the enzyme-activity increases in Table 3 were measured in deficient human fibroblasts exposed to transgenic-mouse serum or bone-marrow-conditioned medium, not in the transplanted mice. The histopathology section also notes residual storage in some autonomic ganglia, so ‘complete reversal’ is too broad for all systemic pathology. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

May combine two claims.

Mice injected with intermediate or high dose of rAAV showed normal PPCA expression in the choroid plexus, accompanied by clearance of lysosomal storage.

“Remarkably, mice injected with intermediate or high dose of rAAV showed normal PPCA expression in the choroid plexus, accompanied by clearance of lysosomal storage 60.”

• cites [60] sourcePartly supported

  The Results report that choroid-plexus vacuolization was fully reversed in intermediate- and high-dose-treated mice. But the Discussion says PPCA was not detectable in brain tissue or specific brain regions; it proposes that circulating PPCA below the detection limit was taken up by choroid-plexus cells. The claim of normal PPCA expression there is not supported. (LLM, conf=0.91)

  Experimental — accuracy not yet measured

May combine two claims.

Ppca−/− mice have a clinical and pathological presentation that closely recapitulates early onset forms of GS, with no cathepsin A activity, severe secondary Neu1 deficiency, and β-Gal partially reduced only in some cell types.

“These mice have a clinical and pathological presentation that closely recapitulates the early onset forms of GS (Figure 2).”

• Also stated in: § 6.1 PPCA−/− animal model · plain

  “Tissues and cells isolated from mutant mice have no cathepsin A activity and severe secondary deficiency of Neu1, while β-Gal is partially reduced only in some cell types 53,54.”

• cites [53] sourceSupported
• cites [54] sourceNot checked — no full text of the source

May combine two claims.

PPCA co-purified with LAMP2a in lysosomal preparations from rat liver, indicating that cathepsin A alone or in complex controls LAMP2a turnover, and PPCA-deficient fibroblasts show reduced LAMP2a degradation and increased chaperone-mediated autophagy.

“It was shown that in lysosomal preparations isolated from rat liver PPCA co-purified with LAMP2a, indicating that cathepsin A alone or in complex controls the turnover of LAMP2a 51.”

• Also stated in: § 5. PPCA, a pleiotropic enzyme · boosted

  “In fact, a reduction in the rate of LAMP2a degradation was demonstrated in both human and mouse PPCA-deficient fibroblasts, which in contrast displayed increased levels of CMA 51.”

• cites [51] sourceSupported

May combine two claims.

Regardless of viral dose used, rAAV-treated Ppca−/− mice appeared indistinguishable from WT mice; they had normal fur, coordination and gait, moved actively and were no longer edematous.

“Regardless of the viral dose used, treated mice appeared indistinguishable from WT mice; they had normal fur, coordination and gait, moved actively and were no longer edematous.”

• cites [60] sourceSupported

May combine two claims.

A total of 27 mutations have been identified in the CTSA gene, including small deletions/insertions, missense mutations, splicing variants, and only one nonsense mutation.

“Using genomic DNA, cDNA, or whole-exome sequencing a total of 27 mutations have been identified in the CTSA gene, including small deletions/insertions, missense mutations, splicing variants and only one nonsense mutation (refer to http://www.hgmd.cf.ac.uk/ac/index.php and http://www.ncbi.nlm.nih.gov/clinvar) (Table 1).”

• cites http://www.hgmd.cf.ac.uk/ac/index.phpNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites http://www.ncbi.nlm.nih.gov/clinvarNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

A small pool of phosphorylated PPCA precursor can be recovered extracellularly, but this secreted form can be re-internalized via mannose-6-phosphate receptor-mediated endocytosis and routed to lysosomes where it becomes catalytically active.

“A small pool of phosphorylated precursor can also be recovered extracellularly, but this secreted form can be re-internalized by cells via mannose-6-phosphate receptor-mediated endocytosis and routed to the lysosomes where it becomes catalytically active as the de novo synthesized enzyme 5,6.”

• cites [5] sourceNot checked — no full text of the source
• cites [6] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Galactosialidosis is caused by mutations in the CTSA gene, which encodes lysosomal protective protein/cathepsin A (PPCA).

“Galactosialidosis is a glycoprotein storage disease caused by mutations in the CTSA gene, encoding lysosomal protective protein/cathepsin A (PPCA).”

May combine two claims.

The 54-kDa precursor was the extracellular form that, once taken up by GS cells, restored NEU1 and β-GAL activities and their lysosomal stability.

“The 54-kDa precursor was also the form present extracellularly that once taken up by GS cells restored NEU1 and β-GAL activities and their lysosomal stability.”

• cites [5] sourceNot checked — no full text of the source

May combine two claims.

PPCA mutants with substitution of Ser196 or His475 lose cathepsin A activity but retain the ability to interact with and protect NEU1 and β-GAL when taken up by GS fibroblasts.

“PPCA mutants generated by substitution of the Ser196 or His475 active site residues loose cathepsin A activity but still retain their ability to interact and “protect” NEU1 and β-GAL when taken up by GS fibroblasts 35.”

• cites [35] Galjart NJ, 1991, J Biol Chem sourceNot checked — no full text of the source

May combine two claims.

GS primarily affects cells of the reticuloendothelial system and can be suspected in children with features typical of a lysosomal disorder, such as coarse facies, macular cherry-red spots, vertebral changes, foam cells in the bone marrow, and vacuolated lymphocytes in peripheral blood.

“GS primarily affects cells of the reticuloendothelial system and can be suspected in children with features typical of a lysosomal disorder, such as coarse facies, macular cherry-red spots, vertebral changes, foam cells in the bone marrow, and vacuolated lymphocytes in peripheral blood 8.”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

In the PPCA/NEU1/β-GAL complex, the two glycosidases acquire their full activity and stability in lysosomes.

“In this configuration the two glycosidases acquire their full activity and stability in lysosomes.”

May combine two claims.

Aside from cathepsin A activity at acidic pH, PPCA also functions as deamidase and esterase at neutral pH, and all enzymatic activities of PPCA were drastically reduced in lymphoblastoid cells and fibroblasts from numerous GS patients of Japanese origin.

“Aside from its cathepsin A activity at acidic pH, PPCA also functions as deamidase and esterase at neutral pH.”

• Also stated in: § 5. PPCA, a pleiotropic enzyme · boosted

  “All enzymatic activities of PPCA were shown to be drastically reduced in lymphoblastoid cells and fibroblasts from numerous GS patients of Japanese origin 45.”

• cites [45] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

After removal of the signal peptide, the PPCA precursor is N-linked glycosylated at Asn163 and Asn351, forms a homodimer soon after synthesis in the endoplasmic reticulum, and acquires the mannose-6-phosphate recognition marker on the Asn117 oligosaccharide chain for correct routing and lysosomal localization.

“After removal of the signal peptide, the precursor is N-linked glycosylated at sites Asn163 and Asn351, and forms a homodimer soon after synthesis in the endoplasmic reticulum.”

• Also stated in: § 3. PPCA biosynthesis · plain

  “The acquisition of the mannose-6-phosphate recognition marker on the Asn117 oligosaccharide chain allows for the correct routing and lysosomal localization of the PPCA precursor.”

May combine two claims.

The three proteins were products of a single gene, and the 54-kDa polypeptide was the uncleaved precursor of the 32- and 20-kDa proteins.

“It was soon apparent that the three proteins were the products of a single gene and that the 54-kDa polypeptide was in fact the uncleaved precursor of the 32- and 20-kDa proteins 5.”

• cites [5] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

GS is a prototypical lysosomal storage disease of glycoprotein catabolism, inherited as an autosomal recessive trait.

“GS is a prototypical lysosomal storage disease (LSD) of glycoprotein catabolism, which is inherited as an autosomal recessive trait.”

Probably not a substantial claim: may not pass S3 (load-bearing).

PPCA's catalytic activity is distinct from its protective function towards β-galactosidase (β-GAL) and neuraminidase 1 (NEU1).

“The enzyme’s catalytic activity is distinct from its protective function towards β-galactosidase (β-GAL) and neuraminidase 1 (NEU1), with which PPCA forms a complex.”

May combine two claims.

Sialyloligosacchariduria is diagnostic of GS but is indistinguishable from that observed in patients with sialidosis caused by isolated NEU1 deficiency.

“Sialyloligosacchariduria is diagnostic of the disease but it is indistinguishable from that observed in patients with sialidosis, caused by an isolated deficiency of NEU1 (sialidase).”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

May combine two claims.

Some early onset cases of GS lacked protective protein mRNA, and the protective protein has homology with serine proteases.

“After the cloning of the protective protein cDNA, Galjart et al. 6 demonstrated that some of the early onset cases of GS lacked the protective protein mRNA and identified the homology of the protein with serine proteases.”

• cites Galjart et al. 6Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Patients with GS are usually classified into three clinical types based on age of onset and severity of symptoms.

“Based on the age of onset and the severity of the symptoms, patients with GS are usually classified into three clinical types.”

May combine two claims.

Mouse PPCA is 87% identical at the amino-acid level to human PPCA, shares similar biochemical and kinetic properties, and can substitute for the human enzyme in correcting both NEU1 and β-GAL activities when taken up by patients' fibroblasts.

“Mouse PPCA 32 is 87% identical at the amino-acid level to the human counterpart, and shares similar biochemical and kinetic properties.”

• Also stated in: § 3. PPCA biosynthesis · plain

  “In fact, murine PPCA can substitute for the human enzyme in correcting both NEU1 and β-GAL activities when taken up by patients’ fibroblasts 32.”

• cites [32] Galjart NJ, 1990, J Biol Chem sourceNot checked — no full text of the source

May combine two claims.

Early infantile GS presents with signs between birth and 3 months of age, including non-immune hydrops fetalis, neonatal edema, coarse facies, inguinal hernias, proteinuria, and telangectasias.

“The early infantile type of GS presents with signs of the disease between birth and 3-months of age; these include non-immune hydrops fetalis, neonatal edema, coarse facies, inguinal hernias, proteinuria and telangectasias.”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

• cites [11] sourceNot checked — no full text of the source

May combine two claims.

Deficiency of a protective protein secondarily affects both glycosidases, and the three proteins physically associate to form a multienzyme complex.

“These findings gave the first proof that deficiency of a “protective protein” secondarily affected both glycosidases, and reinforced the biochemical evidence that the three proteins physically associate to form a multienzyme complex.”

May combine two claims.

Very severe early infantile GS patients die within the first year of life, likely because of heart and kidney failure.

“These very severe patients die within the first year of life likely because of heart and kidney failure 8.”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

May combine two claims.

PPCA and cathepsin A have the same identity, and an antibody against human PPCA immunoprecipitated a cathepsin A activity that was less than 1% of control values in GS fibroblasts.

“It was soon demonstrated that indeed PPCA and cathepsin A had the same identity and that an antibody against human PPCA immunoprecipitated a cathepsin A activity that was less than 1% of the control values in GS fibroblasts.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Human PPCA is synthesized as a 480-amino acid pre-proform containing a canonical hydrophobic signal peptide of ~46 residues and nine cysteines.

“Human PPCA is synthesized as a 480-amino acid pre-proform containing a canonical hydrophobic signal peptide of ~46 residues and nine cysteines.”

May combine two claims.

The secondary severe loss of NEU1 activity probably accounts for most overt clinical manifestations and for the disease pathogenesis in GS.

“However, the secondary severe loss of NEU1 activity probably accounts for most of the overt clinical manifestations seen in patients and for the disease pathogenesis.”

May combine two claims.

The majority of GS patients belong to the juvenile/adult type, are mostly of Japanese origin, and have severe neurologic manifestations including myoclonus, cerebellar ataxia, generalized seizures, progressive cognitive impairment, and mental retardation, with absence of visceromegaly, angiokeratoma, and long survival frequently observed.

“The majority of GS patients belong to the juvenile/adult type.”

• Also stated in: § 2.3 Juvenile/Adult · plain

  “They are mostly of Japanese origin.”

• Also stated in: § 2.3 Juvenile/Adult · plain

  “Besides characteristic features such as coarse facies, vertebral changes, cherry-red spots and corneal clouding, patients develop severe neurologic manifestations, including myoclonus, cerebellar ataxia, generalized seizures, progressive cognitive impairment and mental retardation.”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

• cites [13] sourceNot checked — no full text of the source
• cites [14] sourceNot checked — no full text of the source
• cites [15] Usui T, 1993, Metab Pediatr Syst Ophthalmol (1985)Not checked — no full text of the source
• cites [16] d’Azzo A, 2009Not checked yet

  Not checked in the free run.

May combine two claims.

Late infantile GS comprises a distinct group characterized by mild or absent cognitive disability, with symptoms usually presenting within the first 2 years of life and slow progression into adulthood; many such patients survive into adulthood.

“The late infantile type of GS comprises a distinct group of patients characterized by mild or absent cognitive disability.”

• Also stated in: § 2.2 Late Infantile GS · plain

  “Patients usually present with phenotypic alterations and symptoms within the first 2 years of life and they slowly progress into adulthood.”

• Also stated in: § 2.2 Late Infantile GS · plain

  “Many of the patients diagnosed with the late infantile phenotype survive into adulthood and are still alive.”

• cites [8] d’Azzo A, 2013Not checked yet

  Not checked in the free run.

• cites [12] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

The availability of a faithful animal model for GS has been instrumental for testing investigative therapies that have been overall very successful in correcting the clinical manifestations characteristic of the disease in patients, including partial reversal of the brain pathology.

“The availability of a faithful animal model for GS has been instrumental for testing investigative therapies that have been overall very successful in correcting the clinical manifestations characteristic of the disease in patients, including partial reversal of the brain pathology.”

May combine two claims.

CathAS190A-Neo mice display drastically reduced Neu1 activity in most tissues due to destabilization of Ppca mRNA by the Neo cassette, but are vital, fertile, develop normally, and have a normal lifespan, suggesting that 10% NEU1 activity is sufficient to promote normal development and growth.

“Although the mutation targeted the Ppca locus, the CathAS190A-Neo mice displayed a drastically reduced activity of Neu1 in most tissues, due to destabilization of Ppca mRNA by the Neo cassette.”

• Also stated in: § 6.2 CathAS190A-Neo animal model · hedged

  “Contrary to the Ppca−/− mice, the CathAS190A-Neo mice are apparently vital and fertile, develop normally and have a normal lifespan, suggesting that 10% NEU1 activity is sufficient to promote normal development and growth.”

• cites [47] sourceNot checked — no full text of the source

May combine two claims.

PPCA has pleiotropic activities that may go beyond its lysosomal functions and may contribute to the complex phenotype of GS patients.

“All together, these data suggest that PPCA has pleiotropic activities that may go beyond its lysosomal functions and, if so, may contribute to the complex phenotype of GS patients.”

May combine two claims.

Treated mice showed delayed loss of cerebellar Purkinje cells and enhanced motor coordination.

“In addition, treated mice showed delayed loss of cerebellar Purkinje cells and, in turn, enhanced motor coordination 58.”

• cites [58] sourceNot checked — no full text of the source

May combine two claims.

CathAS190A mice have an isolated deficiency of cathepsin A with intact protective properties toward NEU1 and normal Neu1 activity, show abnormalities in elastin-rich tissues such as skin, arteries, and lung with impaired deposition of insoluble elastin, and have significantly higher diastolic and systolic blood pressure than wild-type siblings.

“Upon removal of the Neo cassette from intron 7, the same authors successfully generated mice (CathAS190A) with an isolated deficiency of cathepsin A, but with intact protective properties toward NEU1; CathAS190A mice have normal Neu1 activity.”

• Also stated in: § 6.2 CathAS190A-Neo animal model · plain

  “At the histopathological level these mice show abnormalities in elastin-rich tissues, such as skin, arteries, and lung, and their skin fibroblasts have impaired deposition of insoluble elastin 47.”

• Also stated in: § 6.2 CathAS190A-Neo animal model · plain

  “In addition, CathAS190A mice have significantly higher levels of both diastolic and systolic blood pressure than their wild-type siblings.”

• cites [47] sourceNot checked — no full text of the source

May combine two claims.

In the brain, this therapeutic approach resulted in general improvement of brain architecture with significant reduction of the number of neural cells containing storage material.

“In the brain, this therapeutic approach resulted in a general improvement of the brain architecture with significant reduction of the number of neural cells containing storage material.”

• cites [58] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

The biochemical characteristics of PPCA, its long half life as secreted inactive precursor (zymogen) in circulation, its efficient internalization from cells at multiple sites and its scalable purification make it an extremely versatile therapeutic product.

“In addition, the biochemical characteristics of PPCA, its long half life as secreted inactive precursor (zymogen) in circulation, its efficient internalization from cells at multiple sites and its scalable purification make it an extremely versatile therapeutic product.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

PPCA is an unusual lysosomal enzyme, which functions as a molecular chaperone for NEU1 and β-GAL, while maintaining an intrinsic carboxypeptidase/deamidase/esterase activity towards a selected number of bioactive peptides.

“PPCA is an unusual lysosomal enzyme, which functions as a molecular chaperone for NEU1 and β-GAL, while maintaining an intrinsic carboxypeptidase/deamidase/esterase activity towards a selected number of bioactive peptides.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

PPCA's differential tissue distribution and level of expression in different cell types likely reflect the physiological need for the protein to either complex with the two glycosidases or to remain a free dimer, depending on the range and type of substrates to be degraded or processed.

“Its differential tissue distribution and level of expression in different cell types likely reflect the physiological need for the protein to either complex with the two glycosidases or to remain a free dimer, depending on the range and type of substrates to be degraded or processed.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

The availability of pools of free and assembled enzymes that are committed to diverse functions and potentially be differentially regulated creates a highly dynamic degradative/processing system.

“Obviously, the availability of pools of free and assembled enzymes that are committed to diverse functions and potentially be differentially regulated creates a highly dynamic degradative/processing system.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The higher blood pressure phenotype in CathAS190A mice could result from impaired processing of endothelin-1 due to loss of cathepsin A activity.

“The latter phenotype could be the results of impaired processing of endothelin-1, a potent vasoconstrictive peptide, due to loss of cathepsin A activity.”

May combine two claims.

All investigative and preclinical therapeutic approaches applied to the GS mouse model have been extremely successful and have encouraged the development of an AAV-mediated gene therapy for the treatment of the mild late infantile group of GS patients with no neuropathic signs.

“So far, all investigative and preclinical therapeutic approaches applied to the GS mouse model have been extremely successful and have encouraged the development of an AAV-mediated gene therapy for the treatment of the mild late infantile group of GS patients with no neuropathic signs.”

May combine two claims.

This was accompanied by marked reduction of disease pathology in all visceral organs and resolution of the edematous phenotype.

“Transplanted mice showed sustained and long-term expression (up to 10 months) of the transgene, which was accompanied by a marked reduction of disease pathology in all visceral organs (Figure 4) and resolution of the edematous phenotype characteristic of the disease.”

• cites [58] sourceNot checked — no full text of the source

May combine two claims.

Ppca−/− mice present with severe early-onset nephropathy associated with edema and proteinuria, oligosacchariduria, time-dependent splenomegaly, heart involvement, infertility due to structural changes in the blood-epididymal barrier, and a reduced lifespan of ~6-9 months.

“Similarly to patients with the severe form of the disease, mutant mice present with severe early-onset nephropathy, associated with edema and proteinuria, in addition to oligosacchariduria.”

• Also stated in: § 6.1 PPCA−/− animal model · plain

  “Time-dependent splenomegaly and heart involvement are also characteristic features of the disease.”

• Also stated in: § 6.1 PPCA−/− animal model · plain

  “Homozygous knockouts are infertile, because of structural changes in the blood-epididymal barrier, resulting in altered sperm motility 55, and have a reduced lifespan of ~6–9 months, although gender differences have been documented.”

• cites [55] sourceNot checked — no full text of the source

May combine two claims.

Cathepsin A plays an important role in blood pressure regulation and development of elastic fibers.

“These results demonstrate that cathepsin A plays an important role in blood pressure regulation and development of the elastic fibers which may influence the complex phenotype observed both in the GS mouse model and GS patients.”

May combine two claims.

Early in life Ppca−/− mice acquire acute and progressive ataxia associated with regional loss of cerebellar Purkinje cells and impaired motor coordination, a phenotype not observed in Neu1−/− mice at least not until the end of their lifespan (5-7 months).

“The most overt difference is seen in the cerebellum; early in life Ppca−/− mice acquire acute and progressive ataxia that is associated with regional loss of cerebellar Purkinje cells and impaired motor coordination (Figure 3) 56.”

• Also stated in: § 6.1 PPCA−/− animal model · plain

  “This phenotype is not observed in the Neu1−/− mice at least not until the end of their lifespan (5–7 months).”

• cites [56] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

The possibility remains that some of the patients' clinical symptoms and complications are related to the loss of cathepsin A activity.

“Although, based on current evidence, it is the PPCA’s protective function, not its enzymatic activity, at the basis of lysosomal dysfunction in GS patients, the possibility remains that some of the patients’ clinical symptoms and complications are related to the loss of cathepsin A activity.”

Probably not a substantial claim: may not pass S2 (checkable).

The favorable outcome of these preclinical studies supports the notion that glycoprotein storage diseases, like GS, are particularly responsive to different types of treatment from ERT to gene therapy.

“The favorable outcome of these preclinical studies supports the notion that glycoprotein storage diseases, like GS, are particularly responsive to different types of treatment from ERT to gene therapy.”

May combine two claims.

Two weeks after ERT, treated mice showed normalized cathepsin A activity in many systemic organs and reduction of lysosomal storage.

“Two weeks after ERT, treated mice showed normalized cathepsin A activity in many of the systemic organs and reduction of lysosomal storage (Figure 5) 59.”

• cites [59] sourceNot checked — no full text of the source

May combine two claims.

Cultured embryonic brain cells isolated from CathAS190A mice secrete higher levels of endothelin-1 and have reduced degradation rate of endothelin-1 in blood and tissues.

“In fact, cultured embryonic brain cells isolated from CathAS190A mice secrete higher levels of endothelin-1 and have reduced degradation rate of endothelin-1 in blood and tissues 47.”

• cites [47] sourceNot checked — no full text of the source