Neuronal ceroid lipofuscinosis in the South American-Caribbean region: An epidemiological overview

Neuronal ceroid lipofuscinoses (NCLs) comprise 13 hereditary neurodegenerative pathologies of very low frequency that affect individuals of all ages around the world. All NCLs share a set of symptoms that are similar to other diseases. The exhaustive collection of data from diverse sources (clinical, genetic, neurology, ophthalmology, etc.) would allow being able in the future to define this group with greater precision for a more efficient diagnostic and therapeutic approach. Despite the large amount of information worldwide, a detailed study of the characteristics of the NCLs in South America and the Caribbean region (SA&C) has not yet been done. Here, we aim to present and analyse the multidisciplinary evidence from all the SA&C with qualitative weighting and biostatistical evaluation of the casuistry. Seventy-one publications from seven countries were reviewed, and data from 261 individuals (including 44 individuals from the Cordoba cohort) were collected. Each NCL disease, as well as phenotypical and genetic data were described and discussed in the whole group. The CLN2, CLN6, and CLN3 disorders are the most frequent in the region. Eighty-seven percent of the individuals were 10 years old or less at the onset of symptoms. Seizures were the most common symptom, both at onset (51%) and throughout the disease course, followed by language (16%), motor (15%), and visual impairments (11%). Although symptoms were similar in all NCLs, some chronological differences could be observed. Sixty DNA variants were described, ranging from single nucleotide variants to large chromosomal deletions. The diagnostic odyssey was probably substantially decreased after medical education activities promoted by the pharmaceutical industry and parent organizations in some SA&C countries. There is a statistical deviation in the data probably due to the approval of the enzyme replacement therapy for CLN2 disease, which has led to a greater interest among the medical community for the early description of this pathology. As a general conclusion, it became clear in this work that the combined bibliographical/retrospective evaluation approach allowed a general overview of the multidisciplinary components and the epidemiological tendencies of NCLs in the SA&C region.Fil: Guelbert, Guillermo Ariel. Hospital de Niños de la Santísima Trinidad; Argentina. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; ArgentinaFil: Venier, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; ArgentinaFil: Cismondi, Inés Adriana. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Becerra, Adriana Berónica. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; ArgentinaFil: Vazquez, Juan Carlos. Universidad Católica de Córdoba; ArgentinaFil: Fernandez, Elmer Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas. Universidad Católica de Córdoba. Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: de Paul, Ana Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina; ArgentinaFil: Guelbert, Norberto Bernardo. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; Argentina. Universidad Católica de Córdoba. Facultad de Medicina. Clínica Universitaria Reina Fabiola; ArgentinaFil: Noher, Rita Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Pesaola, Favio Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Provincia de Córdoba. Ministerio de Salud. Hospital de Niños de la Santísima Trinidad; Argentina. Washington University in St. Louis; Estados Unido

The neuronal ceroid lipofuscinosis-related protein CLN8 regulates endo-lysosomal dynamics and dendritic morphology

Background Information: The endo-lysosomal system (ELS) comprises a set of membranous organelles responsible for transporting intracellular and extracellular components within cells. Defects in lysosomal proteins usually affect a large variety of processes and underlie many diseases, most of them with a strong neuronal impact. Mutations in the endoplasmic reticulum-resident CLN8 protein cause CLN8 disease. This condition is one of the 14 known neuronal ceroid lipofuscinoses (NCLs), a group of inherited diseases characterised by accumulation of lipofuscin-like pigments within lysosomes. Besides mediating the transport of soluble lysosomal proteins, recent research suggested a role for CLN8 in the transport of vesicles and lipids, and autophagy. However, the consequences of CLN8 deficiency on ELS structure and activity, as well as the potential impact on neuronal development, remain poorly characterised. Therefore, we performed CLN8 knockdown in neuronal and non-neuronal cell models to analyse structural, dynamic and functional changes in the ELS and to assess the impact of CLN8 deficiency on axodendritic development. Results: CLN8 knockdown increased the size of the Golgi apparatus, the number of mobile vesicles and the speed of endo-lysosomes. Using the fluorescent fusion protein mApple-LAMP1-pHluorin, we detected significant lysosomal alkalisation in CLN8-deficient cells. In turn, experiments in primary rat hippocampal neurons showed that CLN8 deficiency decreased the complexity and size of the somatodendritic compartment. Conclusions: Our results suggest the participation of CLN8 in vesicular distribution, lysosomal pH and normal development of the dendritic tree. We speculate that the defects triggered by CLN8 deficiency on ELS structure and dynamics underlie morphological alterations in neurons, which ultimately lead to the characteristic neurodegeneration observed in this NCL. Significance: This is, to our knowledge, the first characterisation of the effects of CLN8 dysfunction on the structure and dynamics of the ELS. Moreover, our findings suggest a novel role for CLN8 in somatodendritic development, which may account at least in part for the neuropathological manifestations associated with CLN8 disease.Fil: Pesaola, Favio Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina. Hospital de Niños de Córdoba; ArgentinaFil: Quassollo Infanzon, Gonzalo Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Venier, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Hospital de Niños de Córdoba; ArgentinaFil: de Paul, Ana Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina. Centro de Microscopía Electrónica; ArgentinaFil: Noher, Rita Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Hospital de Niños de Córdoba; ArgentinaFil: Bisbal, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Instituto Universitario de Ciencias Biomédicas de Córdoba; Argentin

The neuronal ceroid lipofuscinoses program: A translational research experience in Argentina

Background: The Argentinean program was initiated more than a decade ago as the first experience of systematic translational research focused on NCL in Latin America. The aim was to overcome misdiagnoses and underdiagnoses in the region. Subjects: 216 NCL suspected individuals from 8 different countries and their direct family members. Methods: Clinical assessment, enzyme testing, electron microscopy, and DNA screening. Results and discussion: 1) The study confirmed NCL disease in 122 subjects. Phenotypic studies comprised epileptic seizures and movement disorders, ophthalmology, neurophysiology, image analysis, rating scales, enzyme testing, and electron microscopy, carried out under a consensus algorithm; 2) DNA screening and validation of mutations in genes PPT1 (CLN1), TPP1 (CLN2), CLN3, CLN5, CLN6, MFSD8 (CLN7), and CLN8: characterization of variant types, novel/known mutations and polymorphisms; 3) Progress of the epidemiological picture in Latin America; and 4) NCL-like pathology studies in progress. The Translational Research Program was highly efficient in addressing the misdiagnosis/underdiagnosis in the NCL disorders. The study of "orphan diseases" in a public administrated hospital should be adopted by the health systems, as it positively impacts upon the family's quality of life, the collection of epidemiological data, and triggers research advances. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)".Fil: Kohan, Romina. Universidad Nacional de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; ArgentinaFil: Pesaola, Favio Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Guelbert, Norberto Bernardo. Universidad Nacional de Córdoba; ArgentinaFil: Pons, Patricia. Universidad Nacional de Córdoba; ArgentinaFil: Oller Ramírez, Ana María. Universidad Nacional de Córdoba; ArgentinaFil: Rautenberg, Gisela Evelín. Universidad Nacional de Córdoba; ArgentinaFil: Becerra, Adriana Berónica. Universidad Nacional de Córdoba; ArgentinaFil: Sims, Katherine. Massachussets General Hospitall; Estados UnidosFil: Xin, Winnie. Massachussets General Hospitall; Estados UnidosFil: Cismondi, Inés Adriana. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Noher, Rita Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; Argentin