Altered lipid profile and reduced neuronal support in <scp>human induced pluripotent stem cell</scp>‐derived astrocytes from adrenoleukodystrophy patients

X-linked adrenoleukodystrophy (ALD) is a peroxisomal disorder resulting from pathogenic variants in the ABCD1 gene that primarily affects the nervous system and is characterized by progressive axonal degeneration in the spinal cord and peripheral nerves and leukodystrophy. Dysfunction of peroxisomal very long-chain fatty acid (VLCFA) degradation has been implicated in ALD pathology, but the impact on astrocytes, which critically support neuronal function, remains poorly understood. Fibroblasts from four ALD patients were reprogrammed to generate human-induced pluripotent stem cells (hiPSC). hiPSC-derived astrocytes were generated to study the impact of ALD on astrocytic fatty acid homeostasis. Our study reveals significant changes in the lipidome of ALD hiPSC-derived astrocytes, characterized by an enrichment of VLCFAs across multiple lipid classes, including triacylglycerols, cholesteryl esters, and phosphatidylcholines. Importantly, ALD hiPSC-derived astrocytes not only exhibit intrinsic lipid dysregulation but also affect the dendritic tree complexity of neurons in co-culture systems. These findings highlight the cell-autonomous effects of pathogenic variants in the ABCD1 protein on astrocytes and their microenvironment, shed light on potential mechanisms underlying ALD neuropathology, and underscore the critical role of astrocytes in neuronal health.