Severe white matter astrocytopathy in CADASIL.

Area of Science:

• Neuroscience
• Pathology
• Cell Biology

Background:

• Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic disorder.
• It is characterized by white matter hyperintensities, lacunar infarcts, and arteriolosclerosis on MRI.
• The gliovascular unit's role in CADASIL is not fully understood.

Purpose of the Study:

• To investigate astrocyte damage in the deep white matter of CADASIL subjects.
• To determine if astrocytes undergo autophagy-like cell death in CADASIL.
• To assess the integrity of the gliovascular unit in CADASIL.

Main Methods:

• Post-mortem brain tissue evaluation from CADASIL and control subjects.
• Immunohistochemical and immunofluorescent staining for astrocytes, microvessels, and autophagy markers.
• Unbiased stereological methods to quantify cellular changes and marker distribution.

Main Results:

• CADASIL subjects showed increased clasmatodendritic astrocytes and decreased normal astrocytes in deep white matter.
• The anterior temporal pole exhibited abundant clasmatodendritic astrocytes with displaced aquaporin 4.
• Autophagy markers (LC3, p62) and Caspase-3 were localized in GFAP-positive clasmatodendritic cells, especially perivascularly.

Conclusions:

• Astrocytes in CADASIL undergo autophagy-like cell death, progressing through distinct morphological types.
• The anterior temporal pole is particularly vulnerable to this astrocyte damage.
• These findings suggest a severely impaired gliovascular unit in the deep white matter of CADASIL patients.