Amelioration of Inflammation and Metabolic Blockage in GALC Deficient Mice After Enzyme Replacement Therapy via Extracellular Vesicles.

INTRODUCTION: Krabbe disease (KD) is a fatal lysosomal storage disorder caused by a deficiency in the enzyme galactosylceramidase (GALC), leading to toxic accumulation of psychosine. This results in widespread demyelination, inflammation, and neuronal damage. Early intervention is critical to mitigate disease progression and limit neurological injury. METHODS: To assess the therapeutic potential of early enzyme replacement therapy (ERT), HeLa cells were genetically engineered to overexpress GALC, and extracellular vesicles (EVs) containing GALC were isolated. A single intrathecal injection of these GALC-loaded EVs was administered to neonatal GALC-deficient twitcher mice, a well-established model of KD. RESULTS: Although the treatment did not prolong overall survival, it significantly reduced neuroinflammation. Treated mice exhibited decreased astrogliosis and microgliosis, along with a notable reduction in cortical psychosine levels. Molecular analysis of neuroinflammatory markers showed increased expression of IL-10 and TREM2 in microglial cells following treatment. DISCUSSION: This study demonstrates that early intervention with GALC-loaded EVs can temporarily alleviate central neuropathology in KD by reducing inflammation and psychosine burden. While not curative, this approach shows potential as an adjunctive strategy to delay disease progression and improve the neuroinflammatory environment prior to hematopoietic stem cell transplantation.