BBA - Molecular Basis of Disease (v.1852, #10PB)

Special issue: Molecular basis of NCL by Romina Kohan; Sara E. Mole; Susan L. Cotman (2235-2236).

Genetics of the neuronal ceroid lipofuscinoses (Batten disease) by Sara E. Mole; Susan L. Cotman (2237-2241).
The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders that affect children and adults and are grouped together by similar clinical features and the accumulation of autofluorescent storage material. More than a dozen genes containing over 430 mutations underlying human NCLs have been identified. These genes encode lysosomal enzymes (CLN1, CLN2, CLN10, CLN13), a soluble lysosomal protein (CLN5), a protein in the secretory pathway (CLN11), two cytoplasmic proteins that also peripherally associate with membranes (CLN4, CLN14), and many transmembrane proteins with different subcellular locations (CLN3, CLN6, CLN7, CLN8, CLN12). For most NCLs, the function of the causative gene has not been fully defined. Most of the mutations in these genes are associated with a typical disease phenotype, but some result in variable disease onset, severity, and progression, including distinct clinical phenotypes. There remain disease subgroups with unknown molecular genetic backgrounds. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease).”
Keywords: Batten; CLN; Neuronal ceroid lipofuscinosis; NCL;

Cell biology of the NCL proteins: What they do and don't do by Jaime Cárcel-Trullols; Attila D. Kovács; David A. Pearce (2242-2255).
The fatal, primarily childhood neurodegenerative disorders, neuronal ceroid lipofuscinoses (NCLs), are currently associated with mutations in 13 genes. The protein products of these genes (CLN1 to CLN14) differ in their function and their intracellular localization. NCL-associated proteins have been localized mostly in lysosomes (CLN1, CLN2, CLN3, CLN5, CLN7, CLN10, CLN12 and CLN13) but also in the Endoplasmic Reticulum (CLN6 and CLN8), or in the cytosol associated to vesicular membranes (CLN4 and CLN14). Some of them such as CLN1 (palmitoyl protein thioesterase 1), CLN2 (tripeptidyl-peptidase 1), CLN5, CLN10 (cathepsin D), and CLN13 (cathepsin F), are lysosomal soluble proteins; others like CLN3, CLN7, and CLN12, have been proposed to be lysosomal transmembrane proteins. In this review, we give our views and attempt to summarize the proposed and confirmed functions of each NCL protein and describe and discuss research results published since the last review on NCL proteins. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.
Keywords: Neuronal ceroid lipofuscinoses; Batten disease; CLN1-14; NCL proteins;

Towards a new understanding of NCL pathogenesis by Jonathan D. Cooper; Marta A. Tarczyluk; Hemanth R. Nelvagal (2256-2261).
The Neuronal Ceroid Lipofuscinoses (NCLs, Batten disease) are a group of inherited neurodegenerative disorders that have been traditionally grouped together on the basis of certain shared clinical and pathological features. However, as the number of genes that appear to cause new forms of NCL continues to grow, it is timely to reassess our understanding of the pathogenesis of these disorders and what groups them together. The various NCL subtypes do indeed share features of a build-up of autofluorescent storage material, progressive neuron loss and activation of the innate immune system. The characterisation of animal models has highlighted the selective nature of neuron loss and its intimate relationship with glial activation, rather than the generalised build-up of storage material. More recent data provide evidence for the pathway-dependent nature of pathology, the contribution of glial dysfunction, and the involvement of new brain regions previously thought to be unaffected, and it is becoming apparent that pathology extends beyond the brain. These data have important implications, not just for therapy, but also for our understanding of these disorders. However, looking beneath these broadly similar pathological themes evidence emerges for marked differences in the nature and extent of these events in different forms of NCL. Indeed, given the widely different nature of the mutated gene products it is perhaps more surprising that these disorders resemble each other as much as they do. Such data raise the question whether we should rethink the collective grouping of these gene deficiencies together, or whether it would be better to consider them as separate entities. This article is part of a Special Issue entitled: Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease).
Keywords: Neuronal ceroid lipofuscinosis; Storage material accumulation; Selective neuron loss; Glial dysfunction; Pathogenesis;

Human NCL Neuropathology by Josefine Radke; Werner Stenzel; Hans H. Goebel (2262-2266).
The neuronal ceroid lipofuscinoses (NCL) currently encompass fourteen genetically different forms, CLN1 to CLN14, but are all morphologically marked by loss of nerve cells, particularly in the cerebral and cerebellar cortices, and the cerebral and extracerebral formation of lipopigments. These lipopigments show distinct ultrastructural patterns, i.e., granular, curvilinear/rectilinear and fingerprint profiles. They contain − although to a different degree among the different CLN forms − subunit C of ATP synthase, saposins A and D, and beta-amyloid proteins. Extracerebral pathology, apart from lipopigment formation, which provides diagnostic information, is scant or non-existent. The retina undergoes atrophy in all childhood forms. While many new data and findings have been obtained by immunohistochemistry in mouse and other animal models, similar findings in human NCL are largely missing, thus recommending respective studies of archived brain tissues. The newly described NCL forms, i.e., CLN 10 to CLN 14, also require further studies to provide complete neuropathology. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.
Keywords: Neuronal ceroid lipofuscinoses; Lipopigments; Fingerprint profiles; Lysosome; Ultrastructure;

The neuronal ceroid lipofuscinoses: Opportunities from model systems by Kiterie M.E. Faller; Rodrigo Gutierrez-Quintana; Alamin Mohammed; Ahad A. Rahim; Richard I. Tuxworth; Kim Wager; Michael Bond (2267-2278).
The neuronal ceroid lipofuscinoses are a group of severe and progressive neurodegenerative disorders, generally with childhood onset. Despite the fact that these diseases remain fatal, significant breakthroughs have been made in our understanding of the genetics that underpin these conditions. This understanding has allowed the development of a broad range of models to study disease processes, and to develop new therapeutic approaches. Such models have contributed significantly to our knowledge of these conditions. In this review we will focus on the advantages of each individual model, describe some of the contributions the models have made to our understanding of the broader disease biology and highlight new techniques and approaches relevant to the study and potential treatment of the neuronal ceroid lipofuscinoses. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.
Keywords: Neuronal ceroid lipofuscinosis; NCL; Neurodegeneration; Model systems;

Recent studies of ovine neuronal ceroid lipofuscinoses from BARN, the Batten Animal Research Network by David N. Palmer; Nicole J. Neverman; Jarol Z. Chen; Chia-Tien Chang; Peter J. Houweling; Lucy A. Barry; Imke Tammen; Stephanie M. Hughes; Nadia L. Mitchell (2279-2286).
Studies on naturally occurring New Zealand and Australian ovine models of the neuronal ceroid-lipofuscinoses (Batten disease, NCLs) have greatly aided our understanding of these diseases. Close collaborations between the New Zealand groups at Lincoln University and the University of Otago, Dunedin, and a group at the University of Sydney, Australia, led to the formation of BARN, the Batten Animal Research Network. This review focusses on presentations at the 14th International Conference on Neuronal Ceroid Lipofuscinoses (Batten Disease), recent relevant background work, and previews of work in preparation for publication. Themes include CLN5 and CLN6 neuronal cell culture studies, studies on tissues from affected and control animals and whole animal in vivo studies. Topics include the effect of a CLN6 mutation on endoplasmic reticulum proteins, lysosomal function and the interactions of CLN6 with other lysosomal activities and trafficking, scoping gene-based therapies, a molecular dissection of neuroinflammation, identification of differentially expressed genes in brain tissue, an attempted therapy with an anti-inflammatory drug in vivo and work towards gene therapy in ovine models of the NCLs. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)".
Keywords: Neuronal ceroid lipofuscinoses; NCLs; Batten Disease; CLN5; CLN6; Animal models; Neuroinflammation; Neurodegeneration; Gene therapy; Neural cultures; Neuroinflammatory pathway; Disease associated cardiology;

The discoveries of specific protein storage in the NCLs, particularly of subunit c of ATP synthase in most, and the sphingolipid activator proteins, SAPs or saposins A and D in CLN1, CLN10 and an unassigned form are reviewed. The subunit c stored in the relevant NCLs is the complete mature molecule including an unusual modification found only in animal species, trimethylation of its lysine-43. Because of its strongly hydrophobic and lipid-like properties subunit c is easily overlooked or incorrectly described. This is becoming more of a problem as subunit c is not detected in standard proteomic investigations. Methods are reviewed that allow its unequivocal characterisation. Subunit c storage and cellular storage body accumulation do not cause the neuropathology characteristic of these diseases. The function of the trimethyl group on lysine-43 of subunit c is considered, along with some indications of where its normal turnover may be disrupted in the NCLs.
Keywords: Neuronal ceroid lipofuscinoses; NCLs; ATP synthase; Subunit c; CLN; Storage body characterisation; Lysosomal storage disease; Protein storing disease;

Experimental therapies in the neuronal ceroid lipofuscinoses by Nicole J. Neverman; Hannah L. Best; Sandra L. Hofmann; Stephanie M. Hughes (2292-2300).
The neuronal ceroid lipofuscinoses represent a group of severe childhood lysosomal storage diseases. With at least 13 identified variants they are the most common cause of inherited neurodegeneration in children. These diseases share common pathological characteristics including motor problems, vision loss, seizures, and cognitive decline, culminating in premature death. Currently, no form of the disease can be treated or cured, with only palliative care to minimise discomfort. This review focuses on current and potentially ground-breaking clinical trials, including small molecule, enzyme replacement, stem cell, and gene therapies, in the development of effective treatments for the various disease subtypes. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.Display Omitted
Keywords: Neuronal ceroid lipofuscinosis; Batten disease; Small molecule therapy; Cell therapy; Enzyme replacement therapy; Gene therapy;

The neuronal ceroid lipofuscinoses program: A translational research experience in Argentina by Romina Kohan; Favio Pesaola; Norberto Guelbert; Patricia Pons; Ana María Oller-Ramírez; Gisela Rautenberg; Adriana Becerra; Katherine Sims; Winnie Xin; Inés Adriana Cismondi; Inés Noher de Halac (2301-2311).
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.216 NCL suspected individuals from 8 different countries and their direct family members.Clinical assessment, enzyme testing, electron microscopy, and DNA screening.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)”.
Keywords: Neuronal ceroid lipofuscinoses; Algorithm; Morphology; Enzymes; DNA variants;

Reprint of "Ethical issues with artificial nutrition of children with degenerative brain diseases" by Alfried Kohlschütter; Carolina Riga; Dolores Crespo; José Manuel Torres; Victor Penchaszadeh; Angela Schulz (2312-2315).
This report highlights viewpoints of the authors and comments from the auditory at a workshop, held during the 14th international Congress on neuronal ceroid lipofuscinoses (NCL) in Córdoba, Argentina, on ethical aspects of artificial nutrition in children with degenerative brain diseases. The discussion centers on what constitutes the best interest of a patient whose personality was immature before the onset of the disease, who has become demented during its course and is unable to communicate his/her own positions and desires. There is wide consensus that in a child with advanced disease who cannot be fed naturally, decisions to withhold nutrition or to institute or stop artificial nutrition, should only be made by parents (or their representatives) who are adequately prepared on an intellectual and emotional level. We try to show that such decisions are highly individual but can be made in a rationally and emotionally acceptable way after a careful and prolonged dialogue between families and professionals. A checklist summarizes important considerations. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.
Keywords: Childhood dementia; Inborn error of metabolism; Neurodegeneration; Vital support;

Guidelines for incorporating scientific knowledge and practice on rare diseases into higher education: neuronal ceroid lipofuscinoses as a model disorder by Inés Adriana Cismondi; Romina Kohan; Heather Adams; Mike Bond; Rachel Brown; Jonathan D. Cooper; Perla K. de Hidalgo; Sophia-Martha Kleine Holthaus; Sara E. Mole; Julia Mugnaini; Ana María Oller de Ramirez; Favio Pesaola; Gisela Rautenberg; Frances M. Platt; Inés Noher de Halac (2316-2323).
This article addresses the educational issues associated with rare diseases (RD) and in particular the Neuronal Ceroid Lipofuscinoses (NCLs, or CLN diseases) in the curricula of Health Sciences and Professional's Training Programs. Our aim is to develop guidelines for improving scientific knowledge and practice in higher education and continuous learning programs.Rare diseases (RD) are collectively common in the general population with 1 in 17 people affected by a RD in their lifetime. Inherited defects in genes involved in metabolism are the commonest group of RD with over 8000 known inborn errors of metabolism. The majority of these diseases are neurodegenerative including the NCLs. Any professional training program on NCL must take into account the medical, social and economic burdens related to RDs. To address these challenges and find solutions to them it is necessary that individuals in the government and administrative authorities, academia, teaching hospitals and medical schools, the pharmaceutical industry, investment community and patient advocacy groups all work together to achieve these goals.The logistical issues of including RD lectures in university curricula and in continuing medical education should reflect its complex nature. To evaluate the state of education in the RD field, a summary should be periodically up dated in order to assess the progress achieved in each country that signed up to the international conventions addressing RD issues in society. It is anticipated that auditing current practice will lead to higher standards and provide a framework for those educators involved in establishing RD teaching programs world-wide.
Keywords: Rare disease; Neuronal ceroid lipofuscinoses; Education; Research; Training; Advocacy;

Bridging NCL research gaps by Frank Stehr; Herman van der Putten (2324-2328).
The neuronal ceroid lipofuscinoses, collectively called NCLs, are rare and fatal lysosomal storage diseases that mainly affect children. Due to the fact that NCLs are both rare and heterogeneous (mutations in thirteen different genes) significant gaps exist in both preclinical and clinical research. Altogether, these gaps are major hurdles to bring therapies to patients while the need for new therapies is urgent to help them and their families. To define gaps and discuss solutions, a round table discussion involving teams and different stake holders took place during the 14th International Conference on Neuronal Ceroid Lipofuscinoses (Batten Disease) in Cordóba, Argentina. Topics covered by the teams and their leaders (in parentheses) included basic and translational research gaps with regard to large animal models (I. Tammen, D.N. Palmer), human NCL pathology and access to human tissue (J.D. Cooper, H.H. Goebel), rare NCLs (S. Hofman, I. Noher), links of NCLs to other diseases (F.M. Platt), gaps between clinic and clinical trials (H. Adams, A. Schulz), international collaborative efforts working towards a cure (S.E. Mole, H. Band) perspectives on palliative care from patient organizations (M. Frazier, A. West), and issues NCL researchers face when progressing to independent career in academia (M. Bond). Thoughts presented by the team leaders include previously unpublished opinions and information on the lack of understanding of disease pathomechanisms, gene function, assays for drug discovery and target validation, natural history of disease, and biomarkers for monitoring disease progression and treatment effects. This article is not intended to review the NCL literature. It includes personal opinions of the authors and it provides the reader with a summary of gaps discussed and solutions proposed by the teams. This article is part of a Special Issue entitled: Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease).
Keywords: Neuronal ceroid lipofuscinoses; Lysosomal storage disorders; Rare diseases; Research gaps; Bridging gaps;

Rare disease policies to improve care for patients in Europe by Charlotte Rodwell; Ségolène Aymé (2329-2335).
Rare diseases are those with a particularly low prevalence; in Europe, diseases are considered to be rare when they affect not more than 5 in 10 000 persons in the European Union. The specificities of rare diseases make the area a veritable public health challenge: the limited number of patients and scarcity of knowledge and expertise single rare diseases out as a distinctive domain of high European added-value. The Orphan Medicinal Product Regulation of 1999 was the first European legislative text concerning rare diseases, followed by many initiatives, including recommendations by the Council of Ministers of the European Union in 2009. These initiatives contributed to the development of rare diseases policies at European and national level aimed at improving care for patients with rare diseases. A review of the political framework at European level and in European countries is provided to demonstrate how legislation has created a dynamic that is progressively improving care for patients with rare diseases. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.
Keywords: Rare diseases; Policy; Healthcare planning; Codification; Registries; Orphan drugs;

Future perspectives: Moving towards NCL treatments by Susan L. Cotman; Sara E. Mole; Romina Kohan (2336-2338).
Clinicians, basic researchers, representatives from pharma and families from around the world met in Cordoba, Argentina in October, 2014 to discuss recent research progress at the 14th International Congress on Neuronal Ceroid Lipofuscinoses (NCLs; Batten disease), a group of clinically overlapping fatal, inherited lysosomal disorders with primarily neurodegenerative symptoms. This brief review article will provide perspectives on the anticipated future directions of NCL basic and clinical research as we move towards improved diagnosis, care and treatment of NCL patients.This article is part of a Special Issue entitled: Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease).
Keywords: Neuronal Ceroid Lipofuscinosis (NCL); Batten disease;