[P1-175] Autophagy dysfunction as emerging mechanism of Krabbe disease is alleviated by gene therapy
Krabbe disease is also known as Globoid cell leukodystrophy (GLD) is caused by GALC mutations leading to galactocerebrosidase (GALC) deficiency and psychosine accumulation in CNS and PNS. Toxicity of accumulated psychosine results in apoptosis and disrupted lipid rafts in oligodendrocytes and myelinating glia leading to broad demyelination. Affected infants with GLD manifest with rapid deterioration and premature death.
In vitro study using MO3.13 human oligodendrocytes incubated with psychosine overnight, we observed significantly increased levels of both P62 and LC3-II/LC3-I ratio and intracellular accumulation of p62, which were further elevated in MO3.13 cells targeted with hGALC shRNA. Furthermore, spinal cords from untreated Twitcher mice, a murine model of GLD, showed significant elevated levels of LC3 ratio, p62 , Lamp2, and Parkin, and a remarkable intracellular accumulation of p62, lamp1 and beclin in CNS in comparison with that from wild-type mice, suggesting the autophagy dysfunction as a pathomechanism of GLD.
The efficacy of AAV-mediated gene therapy was determined via direct injection of AAV-GALC vectors in CNS of neonatal Twitcher mice. Of note, GALC expression was intensive distributed throughout the CNS and spinal cord of AAV-treated Twitcher mice, which showed normal autophagy pathway and were avoid of amyloid neuronal inclusions, demyelination and neuroinflammation in the CNS in comparison with the untreated twitcher mice.
Collectively, autophagy dysfunction caused from psychosine accumulation plays an import role in the pathomechanism of GLD. Whereas AAV-mediated gene therapy efficiently corrects autophagy dysfunction and neuropathology in GLD, constituting a proof of principle for the treatment of lysosomal neurodegenerative disorders.
In vitro study using MO3.13 human oligodendrocytes incubated with psychosine overnight, we observed significantly increased levels of both P62 and LC3-II/LC3-I ratio and intracellular accumulation of p62, which were further elevated in MO3.13 cells targeted with hGALC shRNA. Furthermore, spinal cords from untreated Twitcher mice, a murine model of GLD, showed significant elevated levels of LC3 ratio, p62 , Lamp2, and Parkin, and a remarkable intracellular accumulation of p62, lamp1 and beclin in CNS in comparison with that from wild-type mice, suggesting the autophagy dysfunction as a pathomechanism of GLD.
The efficacy of AAV-mediated gene therapy was determined via direct injection of AAV-GALC vectors in CNS of neonatal Twitcher mice. Of note, GALC expression was intensive distributed throughout the CNS and spinal cord of AAV-treated Twitcher mice, which showed normal autophagy pathway and were avoid of amyloid neuronal inclusions, demyelination and neuroinflammation in the CNS in comparison with the untreated twitcher mice.
Collectively, autophagy dysfunction caused from psychosine accumulation plays an import role in the pathomechanism of GLD. Whereas AAV-mediated gene therapy efficiently corrects autophagy dysfunction and neuropathology in GLD, constituting a proof of principle for the treatment of lysosomal neurodegenerative disorders.