👤 R L Boriack

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a severe autosomal recessive neurodegenerative disorder resulting from mutations in the CLN3 gene. The gene product is a 438-amino acid hydrophobic peptide of unknown function containing five transmembrane domains. In order to study the tissue distribution of the peptide, polyclonal antibodies were raised in rabbits to three epitopes and were affinity purified before use. All three antibodies were used together for immunocytochemical staining of human pancreas. This staining showed localization in pancreatic islet cells. Double labelling of the tissue indicated that cells staining for the CLN3 protein were also positive for somatostatin. Show less

Juvenile neuronal ceroid lipofuscinosis (Batten disease) is a progressive neurologic disorder which results from mutations in the CLN3 gene, which normally produces a 48-kDa polypeptide of unknown function. To help characterize the CLN3 protein, we have studied its tissue distribution and subcellular localization in human tissues using three epitope-specific polyclonal antibodies to human CLN3 by immunoblot, immunocytochemical, and immunoelectron microscopic analysis. The most abundant CLN3 protein expression was in the gray matter of the brain, where it was localized to astrocytes, capillary endothelium, and neurons. CLN3 was also evident in peripheral nerve, in pancreatic islet cells, and within the seminiferous tubules in the testis. Staining was generally diffuse within the cytoplasm with some nuclear reactivity. Subcellular localization identified the CLN3 protein within the nucleus and along cell membranes. These results were contrasted with the cellular distribution of palmitoyl-protein thioesterase (PPT), the enzyme whose deficiency is responsible for infantile neuronal ceroid lipofuscinosis (CLN1). PPT was most abundant in brain and visceral macrophages where it displayed a coarse granular staining pattern typical of lysosomal distribution. Immunoelectron microscopy confirmed that PPT immunoreactivity was limited to lysosomes. Show less

We have studied the effects of polyunsaturated fatty acid (PUFA) supplementation in utero and throughout life in mnd mutant mice, a proposed model for juvenile neuronal ceroid lipofuscinosis (CLN-3). Unlike our earlier in-vitro studies in humans with CLN-3, and in-vitro studies in CLN-3 lymphoblasts, we saw no beneficial effects in electroretinographic, electron microscopic or clinical studies in the mnd mice. Electron microscopy of brain revealed a pattern which was not consistent with the characteristic ceroid patterns in CLN-3. Our data suggest that the mnd mouse is not responsive to PUFA supplementation and may not be an appropriate animal model for CLN-3. Show less