Abnormal accumulation of galactosylceramide in the kidney of twitcher mouse

doi:10.1016/0006-291X(83)91053-7

Biochemical and Biophysical Research Communications

Volume 110, Issue 3, 10 February 1983, Pages 940-944

https://doi.org/10.1016/0006-291X(83)91053-7 Get rights and content

Abstract

The kidney tissue of the twitcher mice, a neurological mutant caused by a genetic deficiency of galactosylceramidase, contains enormously increased amounts, up to 50 times normal, of galactosylceramide. The finding is in sharp contrast with those in the enzymatically equivalent human disease, globoid cell leukodystrophy (Krabbe disease), in which no specific abnormal accumulation of galactosylceramide occurs despite the same genetic block in the catabolic pathway. This indicates that the same genetic defect can result in entirely different consequences in different species. Caution must be exercised even when “authentic animal models” are utilized for studies of human diseases.

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Cited by (28)

A novel brain-penetrant oral UGT8 inhibitor decreases in vivo galactosphingolipid biosynthesis in murine Krabbe disease
2022, Biomedicine and Pharmacotherapy
Citation Excerpt :
The agent significantly reduced NFA-galactosylceramide in kidney of twitcher mice and OH-GalCer in kidney of all genotypes; it significantly increased renal OH-glucosylceramide in tissue of all genotypes. Unlike the brain in the latter stages of Krabbe disease, when galactosylceramides are reduced with extensive demyelination and white matter loss, in the kidney of twitcher mice total galactosylceramides are elevated: these are accompanied by a 5–10-fold increase in the NFA GalCer and up to 100-fold elevation of the hydroxylated component compared with wild type mice [66,67]. In the brain, the UGT8 inhibitor modestly increased NFA-GlcCer but unexpectedly, OH-GlcCer was markedly reduced by this treatment.
Krabbe disease is a rare, inherited neurodegenerative disease due to impaired lysosomal β-galactosylceramidase (GALC) activity and formation of neurotoxic β-galactosylsphingosine (‘psychosine’). We investigated substrate reduction therapy with a novel brain-penetrant inhibitor of galactosylceramide biosynthesis, RA 5557, in twitcher mice that lack GALC activity and model Krabbe disease. This thienopyridine derivative selectively inhibits uridine diphosphate-galactose glycosyltransferase 8 (UGT8), the final step in the generation of galactosylceramides which are precursors of sulphatide and, in the pathological lysosome, the immediate source of psychosine. Administration of RA 5557, reduced pathologically elevated psychosine concentrations (72–86%) in the midbrain and cerebral cortex in twitcher mice: the inhibitor decreased galactosylceramides by about 70% in midbrain and cerebral cortex in mutant and wild type animals. Exposure to the inhibitor significantly decreased several characteristic inflammatory response markers without causing apparent toxicity to myelin-producing cells in wild type and mutant mice; transcript abundance of oligodendrocyte markers MBP (myelin basic protein) and murine UGT8 was unchanged. Administration of the inhibitor before conception and during several breeding cycles to mice did not impair fertility and gave rise to healthy offspring. Nevertheless, given the unchanged lifespan, it appears that GALC has critical functions in the nervous system beyond the hydrolysis of galactosylceramide and galactosylsphingosine. Our findings support further therapeutic exploration of orally active UGT8 inhibitors in Krabbe disease and related galactosphingolipid disorders. The potent thienopyridine derivative with effective target engagement here studied appears to have an acceptable safety profile in vivo; judicious dose optimization will be needed to ensure efficacious clinical translation.
Dependence of reversibility and progression of mouse neuronopathic Gaucher disease on acid β-glucosidase residual activity levels
2008, Molecular Genetics and Metabolism
Genetic and chemically induced neuronopathic mouse models of Gaucher disease were developed to facilitate understanding of the reversibility and/or progression of CNS involvement. The lethality of the skin permeability barrier defect of the complete gene knock out [gba, (glucocerebrosidase) GCase] was avoided by conditional reactivation of a low activity allele (D409H) in keratinocytes (kn-9H). In kn-9H mice, progressive CNS disease and massive glucosylceramide storage in tissues led to death from CNS involvement by the age of 14 days. Conduritol B epoxide (CBE, a covalent inhibitor of GCase) treatment (for 8–12 days) of wild type, D409H, D409V or V394L homozygotes recapitulated the CNS phenotype of the kn-9H mice with seizures, tail arching, shaking, tremor, quadriparesis, extensive neuronal degeneration loss and apoptosis, and death by the age of 14 days. Minor CNS abnormalities occurred after daily CBE injections of 100 mg/kg/day for 6 doses, but neuronal degeneration was progressive and glucosylceramide storage persisted in D409V homozygotes in the 2 to 5 months after CBE cessation; wild type and D409H mice had persistent neurological damage without progression. The persistent CNS deterioration, histologic abnormalities, and glucosylceramide storage in the CBE-treated D409V mice revealed a threshold level of GCase activity necessary for the prevention of progression of CNS involvement.
Gaucher disease mouse models: Point mutations at the acid β-glucosidase locus combined with low-level prosaposin expression lead to disease variants
2005, Journal of Lipid Research
Citation Excerpt :
Samples were then subjected to alkaline methanolysis (33) and desalted. Relative proportions of lipids from these tissue samples were determined by thin-layer chromatography with borate-impregnated plates (10 cm2 Merck HPTLC silica gel 60; 200 μm) (34). Plates were developed in chloroform-methanol-water (65:25:4, v/v/v).
Gaucher disease is a common lysosomal storage disease caused by a defect of acid β-glucosidase (GCase). The optimal in vitro hydrolase activity of GCase requires saposin C, an activator protein that derives from a precursor, prosaposin. To develop additional models of Gaucher disease and to test in vivo effects of saposin deficiencies, mice expressing low levels (4–45% of wild type) of prosaposin and saposins (PS-NA) were backcrossed into mice with specific point mutations (V394L/V394L or D409H/D409H) of GCase. The resultant mice were designated 4L/PS-NA and 9H/PS-NA, respectively. In contrast to PS-NA mice, the 4L/PS-NA and 9H/PS-NA mice displayed large numbers of engorged macrophages and nearly exclusive glucosylceramide (GC) accumulation in the liver, lung, spleen, thymus, and brain. Electron microscopy of the storage cells showed the characteristic tubular storage material of Gaucher cells. Compared with V394L/V394L mice, 4L/PS-NA mice that expressed 4–6% of wild-type prosaposin levels had ∼25–75% decreases in GCase activity and protein in liver, spleen, and fibroblasts.
These results imply that reduced saposin levels increased the instability of V394L or D409H GCases and that these additional decreases led to large accumulations of GC in all tissues. These models mimic a more severe Gaucher disease phenotype and could be useful for therapeutic intervention studies.
Models of Krabbe Disease
2004, Myelin Biology and Disorders
Globoid cell leukodystrophy, GLD is classical form of human Krabbe disease. It is caused by genetic deficiency of galactosylceramidase activity. Galactosylceramidase cDNA is cloned and disease-causing mutations have been identified in mouse, West Highland and Cairn terriers, and the Rhesus monkey. These models have been extensively utilized for studies of the pathogenesis and treatment of GLD. This chapter emphasizes on the mouse models and refers to other models, as appropriate. It discusses the twitcher mutant, its clinical manifestations, pathology, and biochemistry. In addition to the naturally occurring twitcher mutant, a new experimental model of GLD because of genetic galactosylceramidase deficiency and an entirely new, genetically distinct mouse model of GLD are also described. They provide varying advantages and disadvantages as animal models because of their different sizes and life spans. It is noted that GLD identified by its unique neuropathology has also been described in other mammalian species and some other strain of dogs.
Viable Mouse Models of Acid β-Glucosidase Deficiency: The Defect in Gaucher Disease
2003, American Journal of Pathology
Citation Excerpt :
These samples were subjected to alkaline methanolysis36 and desalted. Relative proportions of lipids from ∼100 mg (wet weight) of tissue samples were determined by thin-layer chromatography with borate impregnated plates37 (TLC, 10 cm2 Merck HPTLC silica gel 60, 200 μm). Plates were developed in chloroform/methanol/water (65/25/4, v/v/v).
Gaucher disease is an autosomal recessively inherited disease caused by mutations at the acid β-glucosidase (GCase) locus (GBA). To develop viable models of Gaucher disease, point mutations (pmuts), encoding N370S, V394L, D409H, or D409V were introduced into the mouse GCase (gba) locus. DNA sequencing verified each unique pmut. Mutant GCase mRNAs were near wild-type (WT) levels. GCase activities were reduced to 2 to 25% of WT in liver, lung, spleen, and cultured fibroblasts from pmut/pmut or pmut/null mice. The corresponding brain GCase activities were ∼25% of WT. N370S homozygosity was lethal in the neonatal period. For the other pmut mice, a few storage cells appeared in the spleen at ≥7 months (D409H or D409V homozygotes) or ≥1 year (V394L homozygotes). V394L/null, D409H/null, or D409V/null mice showed scattered storage cells in spleen at ∼3 to 4 months. Occasional storage cells (sinusoidal cells) were present in liver. In D409V/null mice, large numbers of Mac-3-positive storage cells (ie, macrophages) accumulated in the lung. Glycosphingolipid analyses showed varying rates of progressive glucosylceramide accumulation in visceral organs of pmut/pmut or pmut/null mice, but not in brain. These GCase-deficient mice provide tools for gaining insight into the pathophysiology of Gaucher disease and developing improved therapies.
Myelination in the absence of galactocerebroside and sulfatide: Normal structure with abnormal function and regional instability
1996, Cell
The vertebrate nervous system is characterized by ensheathment of axons with myelin, a multilamellar membrane greatly enriched in the galactolipid galactocerebroside (GalC) and its sulfated derivative sulfatide. We have generated mice lacking the enzyme UDP-galactose:ceramide galactosyltransferase (CGT), which is required for GalC synthesis. CGT-deficient mice do not synthesize GalC or sulfatide but surprisingly form myelin containing glucocerebroside, a lipid not previously identified in myelin. Microscopic and morphometric analyses revealed myelin of normal ultrastructural appearance, except for slightly thinner sheaths in the ventral region of the spinal cord. Nevertheless, these mice exhibit severe generalized tremoring and mild ataxia, and electrophysiological analysis showed conduction deficits consistent with reduced insulative capacity of the myelin sheath. Moreover, with age, CGT-deficient mice develop progressive hindlimb paralysis and extensive vacuolation of the ventral region of the spinal cord. These results indicate that GalC and sulfatide play important roles in myelin function and stability.

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Abnormal accumulation of galactosylceramide in the kidney of twitcher mouse

Abstract

J. Lipid Res

Brain Res

Biochem. Med

J. Biol. Chem

J. Chromatogr

J. Biol. Chem