In studying a mouse model for Batten disease, we report the presence of an autoantibody to glutamic acid decarboxylase (GAD65) in cln3-knockout mice serum that associates with brain tissue but is not present in sera or brain of normal mice.
Juvenile neuronal ceroid lipofuscinosis (JNCL) is a lysosomal storage disease caused by autosomal recessive mutations in ceroid lipofuscinosis 3 (CLN3).
Batten disease (juvenile-onset neuronal ceroid lipofuscinosis [JNCL]) is an autosomal recessive condition characterized by accumulation of lipopigments (lipofuscin and ceroid) in neurons and other cell types.
Juvenile neuronal ceroid lipofuscinosis (JNCL) is characterized by severe visual impairment with onset around age 4-8 years, and a developmental course that includes blindness, epilepsy, speech problems, dementia, motor coordination problems, and emotional reactions.
Initial work has revealed disturbed metabolic pathways in several NCL disorders and most analyses have utilized the infantile (INCL/CLN1) and juvenile (JNCL/CLN3) disease modeling and utilized mainly human and mouse samples.
To identify candidate biomarkers, we analyzed autopsy brain and matching CSF samples from controls and three genetically distinct NCLs due to deficiencies in palmitoyl protein thioesterase 1 (CLN1 disease), tripeptidyl peptidase 1 (CLN2 disease), and CLN3 protein (CLN3 disease).
We propose that defective transport at the lysosomal membrane caused by an absence of functional CLN3 is the primary biochemical defect that results in Batten disease.
caspase-dependent/independent apoptosis and autophagy occur caspase-dependent pathways initiate autophagy Golgi fragmentation results from apoptosis ceramide elevation is independent of caspases, and CLN3 blocks all cell death, prevents Golgi fragmentation and elevation of ceramide in JNCL.
This suggests that the yhc3 delta mutant is a good model to investigate the biological function of human CLN3 gene in mammalian cells and to understand the pathophysiology of juvenile Batten disease.
Accumulating autofluorescent lysosomal storage material in CLN3 disease, consisting of dolichols, lipids, biometals, and a protein that normally resides in the mitochondria, subunit c of the mitochondrial ATPase, provides evidence that autophagosomal-lysosomal turnover of cellular components is disrupted upon loss of CLN3 protein function.
Mitochondrial damage results in a reversible increase in lysosomal storage material in lymphoblasts from patients with juvenile neuronal ceroid-lipofuscinosis (Batten Disease).