Modelling of Neuronal Ceroid Lipofuscinosis Type 2 in Dictyostelium discoideum Suggests That Cytopathological Outcomes Result from Altered TOR Signalling

The neuronal ceroid lipofuscinoses comprise a group of neurodegenerative disorders with similar clinical manifestations whose precise mechanisms of disease are presently unknown. We created multiple cell lines each with different levels of reduction of expression of the gene coding for the type 2 variant of the disease, Tripeptidyl peptidase (Tpp1), in the cellular slime mould Dictyostelium discoideum. Knocking down Tpp1 in Dictyostelium resulted in the accumulation of autofluorescent material, a characteristic trait of Batten disease. Phenotypic characterisation of the mutants revealed phenotypic deficiencies in growth and development, whilst endocytic uptake of nutrients was enhanced. Furthermore, the severity of the phenotypes correlated with the expression levels of Tpp1. We propose that the phenotypic defects are due to altered Target of Rapamycin (TOR) signalling. We show that treatment of wild type Dictyostelium cells with rapamycin (a specific TOR complex inhibitor) or antisense inhibition of expression of Rheb (Ras homologue enriched in the brain) (an upstream TOR complex activator) phenocopied the Tpp1 mutants. We also show that overexpression of Rheb rescued the defects caused by antisense inhibition of Tpp1. These results suggest that the TOR signalling pathway is responsible for the cytopathological outcomes in the Dictyostelium Tpp1 model of Batten disease.

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Aggregation chimeras provide evidence of in vivo intercellular correction in ovine CLN6 neuronal ceroid lipofuscinosis (Batten disease)

10.1101/2021.12.06.471461 ◽

2021 ◽

Author(s):

Lucy A. Barry ◽

Graham W. Kay ◽

Nadia L. Mitchell ◽

Samantha J. Murray ◽

Nigel P. Jay ◽

...

Keyword(s):

Vision Loss ◽

Inflammatory Responses ◽

Neuronal Ceroid Lipofuscinosis ◽

Batten Disease ◽

Brain Regions ◽

Glial Activation ◽

Neuronal Ceroid Lipofuscinoses ◽

Lysosomal Storage ◽

Storage Body

AbstractThe neuronal ceroid lipofuscinoses (NCLs; Batten disease) are fatal, mainly childhood, inherited neurodegenerative lysosomal storage diseases. Sheep affected with a CLN6 form display progressive regionally defined glial activation and subsequent neurodegeneration, indicating that neuroinflammation may be causative of pathogenesis. In this study, aggregation chimeras were generated from homozygous unaffected normal and CLN6 affected sheep embryos, resulting in seven chimeric animals with varied proportions of normal to affected cells. These sheep were classified as affected-like, recovering-like or normal-like, based on their cell-genotype ratios and their clinical and neuropathological profiles.Neuropathological examination of the affected-like animals revealed intense glial activation, prominent storage body accumulation and severe neurodegeneration within all cortical brain regions, along with vision loss and decreasing intracranial volumes and cortical thicknesses consistent with ovine CLN6 disease. In contrast, intercellular communication affecting pathology was evident at both the gross and histological level in the normal-like and recovering-like chimeras, resulting in a lack of glial activation and rare storage body accumulation in only a few cells. Initial intracranial volumes of the recovering-like chimeras were below normal but progressively recovered to about normal by two years of age. All had normal cortical thicknesses, and none went blind. Extended neurogenesis was evident in the brains of all the chimeras.This study indicates that although CLN6 is a membrane bound protein, the consequent defect is not cell intrinsic. The lack of glial activation and inflammatory responses in the normal-like and recovering-like chimeras indicate that newly generated cells are borne into a microenvironment conducive to maturation and survival.

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Neuronal Ceroid Lipofuscinosis Type 6 (CLN6) clinical findings and molecular diagnosis: Costa Rica’s experience

Orphanet Journal of Rare Diseases ◽

10.1186/s13023-021-02162-z ◽

2022 ◽

Vol 17 (1) ◽

Author(s):

R. Badilla-Porras ◽

A. Echeverri-McCandless ◽

J. M. Weimer ◽

A. Ulate-Campos ◽

A. Soto-Rodríguez ◽

...

Keyword(s):

Clinical Diagnosis ◽

Clinical Characteristics ◽

Clinical Manifestations ◽

Cerebellar Atrophy ◽

Batten Disease ◽

Costa Rican ◽

Common Element ◽

Neuronal Ceroid Lipofuscinoses ◽

Molecular Testing ◽

Homozygous Mutation

Abstract Background Commonly known as Batten disease, the neuronal ceroid lipofuscinoses (NCLs) are a genetically heterogeneous group of rare pediatric lysosomal storage disorders characterized by the intracellular accumulation of autofluorescent material (known as lipofuscin), progressive neurodegeneration, and neurological symptoms. In 2002, a disease-causing NCL mutation in the CLN6 gene was identified (c.214G > T) in the Costa Rican population, but the frequency of this mutation among local Batten disease patients remains incompletely characterized, as do clinical and demographic attributes for this rare patient population. Objective To describe the main sociodemographic and clinical characteristics of patients with a clinical diagnosis for Batten Disease treated at the National Children's Hospital in Costa Rica and to characterize via molecular testing their causative mutations. Methods DNA extracted from buccal swabs was used for CLN6 gene sequencing. Participants’ sociodemographic and clinical characteristics were also obtained from their medical records. Results Nine patients with a clinical diagnosis of Batten disease were identified. Genetic sequencing determined the presence of the previously described Costa Rican homozygous mutation in 8 of 9 cases. One patient did not have mutations in the CLN6 gene. In all cases where the Costa Rican CLN6 mutation was present, it was accompanied by a substitution in intron 2. Patients were born in 4 of the 7 Costa Rican provinces, with an average onset of symptoms close to 4 years of age. No parental consanguinity was present in pedigrees. Initial clinical manifestations varied between patients but generally included: gait disturbances, language problems, visual impairment, seizures and psychomotor regression. Cortical and cerebellar atrophy was a constant finding when neuroimaging was performed. Seizure medication was a common element of treatment regimens. Conclusions This investigation supports that the previously characterized c.214G > T mutation is the most common causative NCL mutation in the Costa Rican population. This mutation is geographically widespread among Costa Rican NCL patients and yields a clinical presentation similar to that observed for CLN6 NCL patients in other geographies.

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Recent Insights into NCL Protein Function Using the Model Organism Dictyostelium discoideum

Cells ◽

10.3390/cells8020115 ◽

2019 ◽

Vol 8 (2) ◽

pp. 115 ◽

Cited By ~ 11

Author(s):

Meagan McLaren ◽

Sabateeshan Mathavarajah ◽

Robert Huber

Keyword(s):

Dictyostelium Discoideum ◽

Neurological Disorders ◽

Protein Function ◽

Model Organism ◽

Batten Disease ◽

Neuronal Ceroid Lipofuscinoses ◽

Biomedical Model ◽

The Social ◽

Wide Range ◽

Poor Understanding

The neuronal ceroid lipofuscinoses (NCLs) are a group of devastating neurological disorders that have a global distribution and affect people of all ages. Commonly known as Batten disease, this form of neurodegeneration is linked to mutations in 13 genetically distinct genes. The precise mechanisms underlying the disease are unknown, in large part due to our poor understanding of the functions of NCL proteins. The social amoeba Dictyostelium discoideum has proven to be an exceptional model organism for studying a wide range of neurological disorders, including the NCLs. The Dictyostelium genome contains homologs of 11 of the 13 NCL genes. Its life cycle, comprised of both single-cell and multicellular phases, provides an excellent system for studying the effects of NCL gene deficiency on conserved cellular and developmental processes. In this review, we highlight recent advances in NCL research using Dictyostelium as a biomedical model.

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Molecular networking in the neuronal ceroid lipofuscinoses: insights from mammalian models and the social amoeba Dictyostelium discoideum

Journal of Biomedical Science ◽

10.1186/s12929-020-00653-y ◽

2020 ◽

Vol 27 (1) ◽

Cited By ~ 1

Author(s):

Robert J. Huber

Keyword(s):

Dictyostelium Discoideum ◽

Mammalian Cells ◽

Batten Disease ◽

Neuronal Ceroid Lipofuscinoses ◽

Common Disease ◽

Cellular Mechanisms ◽

Molecular Networking ◽

Social Amoeba ◽

Cellular Models ◽

The Social

Abstract The neuronal ceroid lipofuscinoses (NCLs), commonly known as Batten disease, belong to a family of neurological disorders that cause blindness, seizures, loss of motor function and cognitive ability, and premature death. There are 13 different subtypes of NCL that are associated with mutations in 13 genetically distinct genes (CLN1-CLN8, CLN10-CLN14). Similar clinical and pathological profiles of the different NCL subtypes suggest that common disease mechanisms may be involved. As a result, there have been many efforts to determine how NCL proteins are connected at the cellular level. A main driving force for NCL research has been the utilization of mammalian and non-mammalian cellular models to study the mechanisms underlying the disease. One non-mammalian model that has provided significant insight into NCL protein function is the social amoeba Dictyostelium discoideum. Accumulated data from Dictyostelium and mammalian cells show that NCL proteins display similar localizations, have common binding partners, and regulate the expression and activities of one another. In addition, genetic models of NCL display similar phenotypes. This review integrates findings from Dictyostelium and mammalian models of NCL to highlight our understanding of the molecular networking of NCL proteins. The goal here is to help set the stage for future work to reveal the cellular mechanisms underlying the NCLs.

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Neuronal Ceroid Lipofuscinosis Type 6 (CLN6) Clinical Findings and Molecular Diagnosis: Costa Rica´s Experience

10.21203/rs.3.rs-860956/v1 ◽

2021 ◽

Author(s):

Ramses Badilla-Porras ◽

Ann Echeverri-McCandless ◽

Jill Weiner ◽

Adriana Ulate-Campos ◽

Andrés Soto-Rodríguez ◽

...

Keyword(s):

Costa Rica ◽

Clinical Diagnosis ◽

Clinical Characteristics ◽

Clinical Manifestations ◽

Cerebellar Atrophy ◽

Batten Disease ◽

Costa Rican ◽

Common Element ◽

Neuronal Ceroid Lipofuscinoses ◽

Homozygous Mutation

Abstract Background: Commonly known as Batten disease, the neuronal ceroid lipofuscinoses (NCLs) are a genetically heterogeneous group of rare pediatric lysosomal storage disorders characterized by the intracellular accumulation of autofluorescent material (known as lipofuscin), progressive neurodegeneration, and neurological symptoms. In 2002, a disease-causing NCL mutation in the CLN6 gene was identified (c.214G>T) in the Costa Rican population, but the frequency of this mutation among local Batten disease patients remains incompletely characterized, as do clinical and demographic attributes for this rare patient population.Objective: To describe the main sociodemographic and clinical characteristics of patients with a clinical diagnosis for Batten Disease treated at the National Children's Hospital in Costa Rica and to genetically characterize their causative mutations.Methods: CLN6 gene sequences were determined from DNA extracted from patient buccal swabs. Participants’ sociodemographic and clinical characteristics were also obtained from their medical records.Results: Nine patients with a clinical diagnosis of Batten disease were identified. Genetic sequencing determined the presence of the previously-described Costa Rican homozygous mutation in 8 of 9 cases. One patient did not have mutations in the CLN6 gene. In all cases where the Costa Rican CLN6 mutation was present, it was accompanied by a substitution in intron 2. Patients were born in 4 of the 7 Costa Rican provinces, with an average onset of symptoms close to 4 years of age. No parental consanguinity was present in pedigrees. Initial clinical manifestations varied between patients but generally included: gait disturbances, language problems, visual impairment, seizures and psychomotor regression. Cortical and cerebellar atrophy was a constant finding when neuroimaging was performed. Seizure medication was a common element of treatment regimens.Conclusions: This investigation supports that the previously characterized c.214G>T mutation is the most common causative NCL mutation in the Costa Rican population. This mutation is geographically widespread among Costa Rican NCL patients and yields a clinical presentation similar to that observed for CLN6 NCL patients in other geographies.

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Patient-Derived Induced Pluripotent Stem Cell Models for Phenotypic Screening in the Neuronal Ceroid Lipofuscinoses

Molecules ◽

10.3390/molecules26206235 ◽

2021 ◽

Vol 26 (20) ◽

pp. 6235

Author(s):

Ahmed Morsy ◽

Angelica V. Carmona ◽

Paul C. Trippier

Keyword(s):

Neuronal Ceroid Lipofuscinosis ◽

Batten Disease ◽

Induced Pluripotent Stem Cell ◽

Epileptic Seizures ◽

Premature Death ◽

Model Systems ◽

Neuronal Ceroid Lipofuscinoses ◽

Phenotypic Screening ◽

Lysosomal Storage ◽

Induced Pluripotent

Batten disease or neuronal ceroid lipofuscinosis (NCL) is a group of rare, fatal, inherited neurodegenerative lysosomal storage disorders. Numerous genes (CLN1–CLN8, CLN10–CLN14) were identified in which mutations can lead to NCL; however, the underlying pathophysiology remains elusive. Despite this, the NCLs share some of the same features and symptoms but vary in respect to severity and onset of symptoms by age. Some common symptoms include the progressive loss of vision, mental and motor deterioration, epileptic seizures, premature death, and in the rare adult-onset, dementia. Currently, all forms of NCL are fatal, and no curative treatments are available. Induced pluripotent stem cells (iPSCs) can differentiate into any cell type of the human body. Cells reprogrammed from a patient have the advantage of acquiring disease pathogenesis along with recapitulation of disease-associated phenotypes. They serve as practical model systems to shed new light on disease mechanisms and provide a phenotypic screening platform to enable drug discovery. Herein, we provide an overview of available iPSC models for a number of different NCLs. More specifically, we highlight findings in these models that may spur target identification and drug development.

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Clinical - genetic characteristics of neuronal ceroid lipofuscinosis type 2

Neuroscience and Neurological Surgery ◽

10.31579/2578-8868/129 ◽

2020 ◽

Vol 6 (4) ◽

pp. 01-08

Author(s):

Khachatryan L.G

Keyword(s):

Neuronal Ceroid Lipofuscinosis ◽

Fatal Outcome ◽

Clinical Manifestations ◽

Scientific Data ◽

Psychomotor Development ◽

Main Function ◽

Genetic Characteristics ◽

Ceroid Lipofuscinosis ◽

Wide Range

The article is devoted to the issues of diagnosis and therapy of one of the most severe degenerative diseases in children - neuronal ceroid lipofuscinosis (NCL). This is a group of inherited neurodegenerative diseases related to lysosomal storage diseases characterized by regression of psychomotor development, resistant epileptic seizures, vision failure up to amaurosis. The morphological basis of NCL types is the accumulation of autofluorescence material in tissues (particularly in the brain), similar in structure to ceroids and lipofuscin, which are related to the “aging” and “wear-and-tear” pigments. To date, we know 14 variants of diseases associated with mutations in 13 genes (PPT1, TPP1, CLN3, CLN5, CLN6, MFSD8, CLN8, KPUR, DNAJC5, CTSF, ATP13A2, CTD7).The most common and deeply studied types of NCL are types 1,2,3. According to scientific data, neuronal ceroid lipofuscinosis is the most common neurodegenerative disease associated with epilepsy and an early fatal outcome. The article demonstrates a unique family case with this disease, reports a discussion of issues related to preclinical diagnosis through genetic verification and suggests a necessity for etiopathogenetic therapy. Here we present two children, from one family, a brother and sister. At the time of diagnosis the sister already had a complete clinical picture of the disease and was genetically verified as having NCL type 2. This fact enabled to identify the same disease in her younger brother at preclinical level and to begin his pathogenetic therapy in time. Currently, the treatment of these patients is conducted with the expensive preparation of Cerliponase - alpha (brineura), which is a purified human enzyme obtained through recombinant DNA technology. Brineura is a recombinant human tripeptidyl peptidase-1 (rhTPP1), the main function of which is the cleavage of the N-terminal tripeptides of a wide range of protein substrates. With the example of this family, the dynamics of clinical manifestations in a child with NCL has been demonstrated in detail, and the algorithm of the medical action aimed at leveling off the serious neurological deficit has been shown.

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Mitochondrial collapse links PFKFB3-promoted glycolysis with CLN7/MFSD8 neuronal ceroid lipofuscinosis pathogenesis

10.1101/2020.10.20.345314 ◽

2020 ◽

Author(s):

Irene Lopez-Fabuel ◽

Marina Garcia-Macia ◽

Costantina Buondelmonte ◽

Olga Burmistrova ◽

Nicolo Bonora ◽

...

Keyword(s):

Clinical Symptoms ◽

Neuronal Ceroid Lipofuscinosis ◽

Batten Disease ◽

Glycolytic Enzyme ◽

Neuronal Ceroid Lipofuscinoses ◽

Loss Of Function ◽

Biochemical Processes ◽

Lysosomal Accumulation ◽

Lysosomal Membrane Glycoprotein

The neuronal ceroid lipofuscinoses (NCLs) are a family of monogenic life-limiting pediatric neurodegenerative disorders collectively known as Batten disease1. Although genetically heterogeneous2, NCLs share several clinical symptoms and pathological hallmarks such as lysosomal accumulation of lipofuscin and astrogliosis2,3. CLN7 disease belongs to a group of NCLs that present in late infancy4–6 and, whereas CLN7/MFSD8 gene is known to encode a lysosomal membrane glycoprotein4,7–9, the biochemical processes affected by CLN7-loss of function are unexplored thus preventing development of potential treatments1,10. Here, we found in the Cln7Δex2 mouse model11 of CLN7 disease that failure in the autophagy-lysosomal pathway causes accumulation of structurally and bioenergetically impaired, reactive oxygen species (ROS)-producing neuronal mitochondria that contribute to CLN7 pathogenesis. Cln7Δex2 neurons exhibit a metabolic shift mediated by pro-glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3). PFKFB3 inhibition in Cln7Δex2 mice in vivo and in CLN7 patients-derived cells rectified key disease hallmarks. Thus, specifically targeting glycolysis may alleviate CLN7 pathogenesis.

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A clinical case of neuronal ceroid lipofuscinosis type 2

Bulletin of Siberian Medicine ◽

10.20538/1682-0363-2019-4-244-248 ◽

2020 ◽

Vol 18 (4) ◽

pp. 244-248

Author(s):

L. S. Kraeva ◽

E. S. Koroleva ◽

V. M. Alifirova ◽

A. V. Kuzmina

Keyword(s):

Neurodegenerative Diseases ◽

Clinical Case ◽

Neuronal Ceroid Lipofuscinosis ◽

Molecular Genetic ◽

Genetic Research ◽

Batten Disease ◽

Neuronal Ceroid Lipofuscinoses ◽

Blood Leukocytes ◽

Progressive Myoclonus Epilepsy ◽

Age Related

Neuronal ceroid lipofuscinoses (NCL, Batten disease) are a group of inherited neurodegenerative diseases characterized by age-related onset, progressive myoclonus epilepsy, visual impairment and progressive intellectual and motor disorders. In all forms of NCL, the pathological autofluorescent lipopigment accumulates in the brain and other tissues. The diagnosis is made following determination of the activity of specific enzymes in blood leukocytes or cell culture of skin fibroblasts and investigation of biopsy specimens with electron microscopy as well as molecular genetic research. The article presents a patient with the onset of the disease at the age of 3 with epileptic tonic-clonic seizures, with further progression of the disease in the form of myoclonic seizures, motor pyramidal and cerebellar disorders, as well as intellectual, mnestic and speech disturbances. The presented clinical case demonstrates difficulties in the diagnosis of neurodegenerative diseases at onset, as well as the absence of pathognomonic signs of the disease during neurophysiological and neuroimaging examinations, which makes it necessary to conduct additional molecular and genetic research

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