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Updated: Jul 10, 2025
Mouse Models of Periventricular Leukomalacia
Published on: May 18, 2010
A novel mouse model of cerebral adrenoleukodystrophy highlights NLRP3 activity in lesion pathogenesis
Ezzat Hashemi1, Isha Narain Srivastava1, Alejandro Aguirre1
1Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA.
Objective:
We sought to create and characterize a mouse model of the inflammatory, cerebral demyelinating phenotype of X-linked adrenoleukodystrophy (ALD) that would facilitate the study of disease pathogenesis and therapy development. We also sought to cross-validate potential therapeutic targets such as fibrin, oxidative stress, and the NLRP3 inflammasome, in post-mortem human and murine brain tissues.
Background:
ALD is caused by mutations in the gene ABCD1 encoding a peroxisomal transporter. More than half of males with an ABCD1 mutation develop the cerebral phenotype (cALD). Incomplete penetrance and absence of a genotype-phenotype correlation imply a role for environmental triggers. Mechanistic studies have been limited by the absence of a cALD phenotype in the Abcd1-null mouse.
Methods:
We generated a cALD phenotype in 8-week-old, male Abcd1-null mice by deploying a two-hit method that combines cuprizone (CPZ) and experimental autoimmune encephalomyelitis (EAE) models. We employed in vivo MRI and post-mortem immunohistochemistry to evaluate myelin loss, astrogliosis, blood-brain barrier (BBB) disruption, immune cell infiltration, fibrin deposition, oxidative stress, and Nlrp3 inflammasome activation in mice. We used bead-based immunoassay and immunohistochemistry to evaluate IL-18 in CSF and post-mortem human cALD brain tissue.
Results:
MRI studies revealed T2 hyperintensities and post-gadolinium enhancement in the medial corpus callosum of cALD mice, similar to human cALD lesions. Both human and mouse cALD lesions shared common histologic features of myelin phagocytosis, myelin loss, abundant microglial activation, T and B-cell infiltration, and astrogliosis. Compared to wild-type controls, Abcd1-null mice had more severe cerebral inflammation, demyelination, fibrin deposition, oxidative stress, and IL-18 activation. IL-18 immunoreactivity co-localized with macrophages/microglia in the perivascular region of both human and mouse brain tissue.
Interpretation:
This novel mouse model of cALD suggests loss of Abcd1 function predisposes to more severe cerebral inflammation, oxidative stress, fibrin deposition, and Nlrp3 pathway activation, which parallels the findings seen in humans with cALD. We expect this model to enable long-sought investigations into cALD mechanisms and accelerate development of candidate therapies for lesion prevention, cessation, and remyelination.
Insights
A new mouse model mimics cerebral X-linked adrenoleukodystrophy (cALD), showing increased inflammation and demyelination. This model aids research into cALD pathogenesis and therapeutic target development for this rare neurological disease.
Area of Science:
- Neuroscience
- Genetics
- Immunology
Background:
- X-linked adrenoleukodystrophy (ALD) is a genetic disorder caused by ABCD1 gene mutations, leading to cerebral demyelination (cALD) in over half of affected males.
- The exact mechanisms driving cALD and the role of environmental factors remain unclear due to the lack of suitable animal models.
- Current research is limited by the absence of a reproducible cALD phenotype in existing Abcd1-null mouse models.
Approach:
- A novel two-hit method combining cuprizone and experimental autoimmune encephalomyelitis models was used to induce a cALD phenotype in Abcd1-null mice.
- In vivo MRI and post-mortem immunohistochemistry were employed to assess demyelination, neuroinflammation, blood-brain barrier integrity, and key molecular pathways.
- Human cALD brain tissues and CSF were analyzed alongside murine tissues to cross-validate findings and therapeutic targets.
Key Points:
- The developed mouse model exhibits T2 hyperintensities and contrast enhancement in the corpus callosum, mirroring human cALD lesions.
- Histological analysis revealed shared features between human and mouse cALD, including myelin loss, microglial activation, immune cell infiltration, and astrogliosis.
- Abcd1-null mice showed exacerbated cerebral inflammation, demyelination, fibrin deposition, oxidative stress, and IL-18 pathway activation compared to controls.
Conclusions:
- This validated mouse model recapitulates key aspects of human cALD, facilitating the study of disease mechanisms.
- Findings suggest that ABCD1 deficiency predisposes to heightened inflammatory responses, oxidative stress, and fibrin deposition in the brain.
- The model is expected to accelerate the development of novel therapies aimed at preventing, halting, or reversing cALD lesions.
