title: Distinct early molecular responses to mutations causing vLINCL and JNCL presage ATP synthase subunit C accumulation in cerebellar cells.
abstract: Variant late-infantile neuronal ceroid lipofuscinosis (vLINCL), caused by CLN6 mutation, and juvenile neuronal ceroid lipofuscinosis (JNCL), caused by CLN3 mutation, share clinical and pathological features, including lysosomal accumulation of mitochondrial ATP synthase subunit c, but the unrelated CLN6 and CLN3 genes may initiate disease via similar or distinct cellular processes. To gain insight into the NCL pathways, we established murine wild-type and CbCln6(nclf/nclf) cerebellar cells and compared them to wild-type and CbCln3(Δex7/8/Δex7/8) cerebellar cells. CbCln6(nclf/nclf) cells and CbCln3(Δex7/8/Δex7/8) cells both displayed abnormally elongated mitochondria and reduced cellular ATP levels and, as cells aged to confluence, exhibited accumulation of subunit c protein in Lamp 1-positive organelles. However, at sub-confluence, endoplasmic reticulum PDI immunostain was decreased only in CbCln6(nclf/nclf) cells, while fluid-phase endocytosis and LysoTracker® labeled vesicles were decreased in both CbCln6(nclf/nclf) and CbCln3(Δex7/8/Δex7/8) cells, though only the latter cells exhibited abnormal vesicle subcellular distribution. Furthermore, unbiased gene expression analyses revealed only partial overlap in the cerebellar cell genes and pathways that were altered by the Cln3(Δex7/8) and Cln6(nclf) mutations. Thus, these data support the hypothesis that CLN6 and CLN3 mutations trigger distinct processes that converge on a shared pathway, which is responsible for proper subunit c protein turnover and neuronal cell survival.
authors.affiliation: Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cao
authors.forename: John F
authors.initials: JF
authors.lastname: Staropoli
authors.forename: Sunita
authors.initials: S
authors.lastname: Biswas
authors.forename: Janice A
authors.initials: JA
authors.lastname: Espinola
authors.forename: Marcy E
authors.initials: ME
authors.lastname: MacDonald
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Susan L
authors.initials: SL
authors.lastname: Cotman
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000235:genetics; D002478:Cells, Cultured; D002531:Cerebellum / Q000378:metabolism* / Q000473:pathology; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D046228:Microarray Analysis; D025261:Mitochondrial Proton-Translocating ATPases / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000502:physiology*; D009154:Mutation / Q000502:physiology; D009472:Neuronal Ceroid-Lipofuscinoses / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology / Q000502:physiology; D021122:Protein Subunits / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D013997:Time Factors
chemical_list: C105199:CLN3 protein, human; C447500:CLN6 protein, human; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; D021122:Protein Subunits; D025261:Mitochondrial Proton-Translocating ATPases