CLN2 Disease Research Articles

CLN2 disease (neuronal ceroid lipofuscinosis type 2): Experience in the real world with cerliponase alfa intracerebroventricular enzyme replacement therapy in a public hospital in Cordoba, Argentina

CLN2 disease (neuronal ceroid lipofuscinosis type 2): Experience in the real world with cerliponase alfa intracerebroventricular enzyme replacement therapy in a public hospital in Cordoba, Argentina

Long-term safety and efficacy of intracerebroventricular enzyme replacement therapy with cerliponase alfa in children with CLN2 disease: Two year results from an ongoing multicenter extension study

The corrosion fatigue (CF) behavior and crack tip characteristic of 316LN stainless steel in 325 °C water at different strain rates were investigated under a strain amplitude of 0.6%. With decreasing the strain rate from 0.4% s−1 to 0.0004% s−1, the CF life decreased linearly in log-log plot. More obvious reduction of CF life at low strain rate was due to the environmental damage. The morphology of cracks and the dislocation density near the crack-tip front exhibit a significant different under different strain rate conditions. The hydrogen enhanced localized plasticity mechanism is discussed to explain the micro-damage process at different strain rates in high-temperature water.

Early gait abnormalities relate to brainstem and spinal cord pathology in CLN1 disease

Dissolution trapping is one of the most important mechanisms for geological carbon storage (GCS). Recent laboratory and field experiments have shown non-equilibrium dissolution of supercritical CO2 (scCO2) and coupled scCO2 dissolution and water flow, i.e., scCO2 dissolution at local pores/pore throats creating new water-flow paths, which in turn enhance dissolution by increased advection and interfacial area. However, the impacts of pore-scale characteristics on these coupled processes have not been investigated. In this study, imbibition and dissolution experiments were conducted under 40°C and 9 MPa using a homogeneous/isotropic hexagonal micromodel, two homogeneous elliptical micromodels with low or high anisotropy, and a heterogeneous sandstone-analog micromodel. The four micromodels, initially saturated with deionized (DI)-water, were drained by injecting scCO2 to establish a stable scCO2 saturation. DI water was then injected at different rates with logCa (the capillary number) ranging from −6.56 to −4.34. Results show that bypass of scCO2 by displacing water is the dominant mechanism contributing to the residual CO2 trapping, triggered by heterogeneity in pore characteristics or pore-scale scCO2-water distribution. Bypass can be enhanced by pore heterogeneity or reduced by increasing transverse permeability, resulting in relatively low (<2% of CO2 solubility) or high (9–13% of CO2 solubility) dissolved CO2 concentration in displacing water. The overall dissolution of residual scCO2 increases with decreasing Ca, and approaches to their solubility at low Ca value with sufficient residence time. This main trend is similar to a capillary desaturation curve that represents the relationship between the residual saturation and Ca. Spatially, dissolution initiates along the boundary of bypassed scCO2 cluster(s) in a non-equilibrium manner, and the coupling of water flow and dissolution occurs which fragments the bypassed scCO2 clusters and enhance scCO2 dissolution.

Using PEDI-CAT to assess functional capabilities in CLN3 (Batten) disease

Using PEDI-CAT to assess functional capabilities in CLN3 (Batten) disease

Asymptotic neurodegeneration in CLN2 disease assessed by MRI cortical thickness histograms

Asymptotic neurodegeneration in CLN2 disease assessed by MRI cortical thickness histograms

Intracerebrovascular enzyme replacement therapy for CLN2 disease: A collaborative, multi-disciplinary approach

This chapter briefly reviews the different applications of natural circulation systems (NCSs) in various industries. Closed-loop NCSs are extensively used in solar water heaters, geothermal, fossil-fueled, and nuclear power plants. In addition, these systems are used in component-cooling applications such as transformers, electronic devices such as computer chips, and gas turbines. Although NCSs are mainly employed as heat transport devices, they can be engineered for noncooling applications such as passive controls, liquid fins, and study of low-velocity corrosion and deterministic chaos. Examples of open-loop natural circulation applications include solar chimneys, buoyancy pumps, air lift pumps, and building ventilation. The largest applications of NCSs are possibly in the chemical process industries. However, the highest power operating NCSs can be found in fossil-fueled power plants. The ESBWR (Economic Simplified Boiling Water Reactor) is the highest power (4500 MW) NCS designed so far. Mini loops with heat transport capability of the order of a few tens of Watts also can be found in the electronics industry.Some of the emerging applications of NCSs are in passive cooling of aircraft, vehicles, building ventilation, and solar thermal power plants. Due to the energy-saving potential of natural circulation, its application is increasing in various industry sectors. Natural circulation applications in electronics device cooling, solar thermal power plants, and residential buildings are expected to increase in the near future. In addition, its passive functioning without operator action or signal is important for enhanced safety and reliability of nuclear reactors, increasing their applications in the nuclear field.

Molecular basis of CLN2 disease: A review and classification of TPP1 gene variants reported worldwide

Molecular basis of CLN2 disease: A review and classification of TPP1 gene variants reported worldwide

A proposed staging system for CLN3 disease (juvenile Batten disease)

Major depression is associated with endothelial dysfunction and arterial stiffening, which may mediate development of hypertension and increased cardiovascular risk. The effect of response to antidepressant treatment on these vascular parameters has not been elucidated.We aimed to assess the net effect of antidepressant therapy on endothelial function and arterial stiffness in patients with psychotic depression.Thirty-seven patients with major psychotic depression, according to DSM-IV-TR, were treated with titrated citalopram 20–60 mg and risperidone 0.5–1 mg and were followed for 6 months. Twelve additional patients who denied treatment, or were non-compliant, were also followed for the same time period. Vascular function was assessed by flow-mediated dilatation (FMD), carotid-femoral pulse wave velocity (PWV) and augmentation index (AI), at baseline and at the end of follow-up.Aortic and peripheral blood pressure (BP), PWV, FMD and AI (p < 0.05 for all) were significantly improved in the group that received treatment. Overall, only responders to treatment (n = 24) presented significant improvements in all hemodynamic and vascular parameters (p < 0.05 for all), irrespectively of traditional cardiovascular risk factors (TRFs), vasoactive medication and BP lowering. In a secondary analysis, patients with psychotic depression presented worse endothelial function as compared to controls matched for TRFs.Non-randomized study.Patients who respond to therapy for major psychotic depression present sustained improvement in vascular function. Given that depressed patients are considered to be at high cardiovascular risk and are often non-compliant with treatment, further research to assess cardiovascular benefits of vigilant monitoring of antidepressant therapy is warranted.

Short-Term Administration of Mycophenolate Is Well-Tolerated in CLN3 Disease (Juvenile Neuronal Ceroid Lipofuscinosis).

Mycophenolate, an immunosuppressant, is commonly used off-label for autoimmune neurological conditions. In CLN3 disease, a neurodegenerative disorder of childhood, preclinical and clinical data suggest secondary autoimmunity and inflammation throughout the central nervous system are key components of pathogenesis. We tested the short-term tolerability of mycophenolate in individuals with CLN3 disease, in preparation for possible long-term efficacy trials of this drug. We conducted a randomized, double-blind, placebo-controlled, crossover study of mycophenolate in 19 ambulatory individuals with CLN3 disease to determine the safety and tolerability of short-term administration (NCT01399047). The study included two 8-week treatment periods with a 4-week intervening washout. Mycophenolate was well tolerated. 89.5% of participants completed the mycophenolate arm, on the assigned study dose (95% CI: 66.9-98.7%), and there were no significant differences in tolerability rates between mycophenolate and placebo arms (10.5%; 95% CI: -3.3-24.3%, p=0.21). All reported adverse events were mild in severity; the most common adverse events on mycophenolate were vomiting (31.6%; 95% CI: 12.6-56.6%), diarrhea (15.8%; 95% CI: 3.4-39.6%), and cough (15.8%; 95% CI: 3.4-39.6%). These did not occur at a significantly increased frequency above placebo. There were no definite effects on measured autoimmunity or clinical outcomes in the setting of short-term administration. Study of long-term exposure is needed to test the impact of mycophenolate on key clinical features and CLN3 disease trajectory.

PD49 Social Preferences In HTA: A Pilot Analysis In CLN2 Disease

Introduction:It is established that the current cost effectiveness health technology assessment (HTA) paradigm does not appropriately value rare disease technologies. Social willingness-to-pay (SWTP) has been suggested to be higher for rare disease technologies, it's inclusion into existing HTA framework could better reflect social preferences (SP) and enable a more equitable evaluation of rare disease technologies. Our study aims to estimate SP and SWTP for a rare disorder, CLN2 disease.Methods:Relevant attributes for CLN2 disease were developed and validated by literature review and focus groups with patient's primary caregivers. An elicitation survey (discrete choice experiment (DCE) WTP and relative social willingness to pay (RS-WTP)) was developed using the selected attributes and levels of each attribute. The survey instruments and attributes/levels were tested and validated in a pre-pilot survey (n = 103) and a subsequent pilot survey (n = 286) of the United Kingdom (UK) general population. Information about CLN2 disease was provided to respondents and their understanding of the disease was tested including assessment of framing effects. The main survey with the general UK population (n = 4,009) is now complete.Results:Eight hundred and twenty-six people were contacted, of which 286 completed the DCE, 113 abandoned the survey before the DCE and 92 abandoned after the DCE. There were no significant differences in characteristics of respondents completing the DCE and those starting but not completing the DCE. Median survey completion time was 20 minutes with 90 percent of participants completing in a single sitting. Median score for the understanding test was 3 (Min = 0 and Max = 4). Incoherencies in WTP estimates were analyzed enabling us introduce relevant modifications and select the most appropriate attribute levels.Conclusions:DCE and RS-WTP potentially are appropriate methods for assessment of social preferences. The selected attributes/levels for the experiment in CLN2 disease have been validated in this pilot.

Lack of specificity of antibodies raised against CLN3, the lysosomal/endosomal transmembrane protein mutated in juvenile Batten disease

Juvenile CLN3 (Batten) disease, a fatal, childhood neurodegenerative disorder, results from mutations in the CLN3 gene encoding a lysosomal/endosomal transmembrane protein. The exact physiological function of CLN3 is still unknown and it is unclear how CLN3 mutations lead to selective neurodegeneration. To study the tissue expression and subcellular localization of the CLN3 protein, a number of anti-CLN3 antibodies have been generated using either the whole CLN3 protein or short peptides from CLN3 for immunization. The specificity of these antibodies, however, has never been tested properly. Using immunoblot experiments, we show that commercially available or researcher-generated anti-CLN3 antibodies lack specificity: they detect the same protein bands in wild-type (WT) and Cln3−/− mouse brain and kidney extracts prepared with different detergents, in membrane proteins isolated from the cerebellum, cerebral hemisphere and kidney of WT and Cln3−/− mice, in cell extracts of WT and Cln3−/− mouse embryonic fibroblast cultures, and in lysates of BHK cells lacking or overexpressing human CLN3. Protein BLAST searches with sequences from peptides used to generate anti-CLN3 antibodies identified short motifs present in a number of different mouse and human proteins, providing a plausible explanation for the lack of specificity of anti-CLN3 antibodies. Our data provide evidence that immunization against a transmembrane protein with low to medium expression level does not necessarily generate specific antibodies. Because of the possible cross-reactivity to other proteins, the specificity of an antibody should always be checked using tissue samples from an appropriate knock-out animal or using knock-out cells.

Glial cells are functionally impaired in juvenile neuronal ceroid lipofuscinosis and detrimental to neurons

The neuronal ceroid lipofuscinoses (NCLs or Batten disease) are a group of inherited, fatal neurodegenerative disorders of childhood. In these disorders, glial (microglial and astrocyte) activation typically occurs early in disease progression and predicts where neuron loss subsequently occurs. We have found that in the most common juvenile form of NCL (CLN3 disease or JNCL) this glial response is less pronounced in both mouse models and human autopsy material, with the morphological transformation of both astrocytes and microglia severely attenuated or delayed. To investigate their properties, we isolated glia and neurons from Cln3-deficient mice and studied their basic biology in culture. Upon stimulation, both Cln3-deficient astrocytes and microglia also showed an attenuated ability to transform morphologically, and an altered protein secretion profile. These defects were more pronounced in astrocytes, including the reduced secretion of a range of neuroprotective factors, mitogens, chemokines and cytokines, in addition to impaired calcium signalling and glutamate clearance. Cln3-deficient neurons also displayed an abnormal organization of their neurites. Most importantly, using a co-culture system, Cln3-deficient astrocytes and microglia had a negative impact on the survival and morphology of both Cln3-deficient and wildtype neurons, but these effects were largely reversed by growing mutant neurons with healthy glia. These data provide evidence that CLN3 disease astrocytes are functionally compromised. Together with microglia, they may play an active role in neuron loss in this disorder and can be considered as potential targets for therapeutic interventions.

Proteomic Analysis of Brain and Cerebrospinal Fluid from the Three Major Forms of Neuronal Ceroid Lipofuscinosis Reveals Potential Biomarkers

Clinical trials have been conducted for the neuronal ceroid lipofuscinoses (NCLs), a group of neurodegenerative lysosomal diseases that primarily affect children. Whereas clinical rating systems will evaluate long-term efficacy, biomarkers to measure short-term response to treatment would be extremely valuable. To identify candidate biomarkers, we analyzed autopsy brain and matching CSF samples from controls and three genetically distinct NCLs due to deficiencies in palmitoyl protein thioesterase 1 (CLN1 disease), tripeptidyl peptidase 1 (CLN2 disease), and CLN3 protein (CLN3 disease). Proteomic and biochemical methods were used to analyze lysosomal proteins, and, in general, we find that changes in protein expression compared with control were most similar between CLN2 disease and CLN3 disease. This is consistent with previous observations of biochemical similarities between these diseases. We also conducted unbiased proteomic analyses of CSF and brain using isobaric labeling/quantitative mass spectrometry. Significant alterations in protein expression were identified in each NCL, including reduced STXBP1 in CLN1 disease brain. Given the confounding variable of post-mortem changes, additional validation is required, but this study provides a useful starting set of candidate NCL biomarkers for further evaluation.

The Networks of Genes Encoding Palmitoylated Proteins in Axonal and Synaptic Compartments Are Affected in PPT1 Overexpressing Neuronal-Like Cells.

CLN1 disease (OMIM #256730) is an early childhood ceroid-lipofuscinosis associated with mutated CLN1, whose product Palmitoyl-Protein Thioesterase 1 (PPT1) is a lysosomal enzyme involved in the removal of palmitate residues from S-acylated proteins. In neurons, PPT1 expression is also linked to synaptic compartments. The aim of this study was to unravel molecular signatures connected to CLN1. We utilized SH-SY5Y neuroblastoma cells overexpressing wild type CLN1 (SH-p.wtCLN1) and five selected CLN1 patients’ mutations. The cellular distribution of wtPPT1 was consistent with regular processing of endogenous protein, partially detected inside Lysosomal Associated Membrane Protein 2 (LAMP2) positive vesicles, while the mutants displayed more diffuse cytoplasmic pattern. Transcriptomic profiling revealed 802 differentially expressed genes (DEGs) in SH-p.wtCLN1 (as compared to empty-vector transfected cells), whereas the number of DEGs detected in the two mutants (p.L222P and p.M57Nfs*45) was significantly lower. Bioinformatic scrutiny linked DEGs with neurite formation and neuronal transmission. Specifically, neuritogenesis and proliferation of neuronal processes were predicted to be hampered in the wtCLN1 overexpressing cell line, and these findings were corroborated by morphological investigations. Palmitoylation survey identified 113 palmitoylated protein-encoding genes in SH-p.wtCLN1, including 25 ones simultaneously assigned to axonal growth and synaptic compartments. A remarkable decrease in the expression of palmitoylated proteins, functionally related to axonal elongation (GAP43, CRMP1 and NEFM) and of the synaptic marker SNAP25, specifically in SH-p.wtCLN1 cells was confirmed by immunoblotting. Subsequent, bioinformatic network survey of DEGs assigned to the synaptic annotations linked 81 DEGs, including 23 ones encoding for palmitoylated proteins. Results obtained in this experimental setting outlined two affected functional modules (connected to the axonal and synaptic compartments), which can be associated with an altered gene dosage of wtCLN1. Moreover, these modules were interrelated with the pathological effects associated with loss of PPT1 function, similarly as observed in the Ppt1 knockout mice and patients with CLN1 disease.

Synergistic effects of treating the spinal cord and brain in CLN1 disease

Infantile neuronal ceroid lipofuscinosis (INCL, or CLN1 disease) is an inherited neurodegenerative storage disorder caused by a deficiency of the lysosomal enzyme palmitoyl protein thioesterase 1 (PPT1). It was widely believed that the pathology associated with INCL was limited to the brain, but we have now found unexpectedly profound pathology in the human INCL spinal cord. Similar pathological changes also occur at every level of the spinal cord of PPT1-deficient (Ppt1-/- ) mice before the onset of neuropathology in the brain. Various forebrain-directed gene therapy approaches have only had limited success in Ppt1-/- mice. Targeting the spinal cord via intrathecal administration of an adeno-associated virus (AAV) gene transfer vector significantly prevented pathology and produced significant improvements in life span and motor function in Ppt1-/- mice. Surprisingly, forebrain-directed gene therapy resulted in essentially no PPT1 activity in the spinal cord, and vice versa. This leads to a reciprocal pattern of histological correction in the respective tissues when comparing intracranial with intrathecal injections. However, the characteristic pathological features of INCL were almost completely absent in both the brain and spinal cord when intracranial and intrathecal injections of the same AAV vector were combined. Targeting both the brain and spinal cord also produced dramatic and synergistic improvements in motor function with an unprecedented increase in life span. These data show that spinal cord pathology significantly contributes to the clinical progression of INCL and can be effectively targeted therapeutically. This has important implications for the delivery of therapies in INCL, and potentially in other similar disorders.

Progress toward Fulfilling the Potential of Immunomodulation in Childhood Neurodegeneration?

In this issue of Molecular Therapy, Groh and colleagues1 have provided further evidence that immunomodulatory approaches may be of value in treating two types of lysosomal storage disorder, CLN1 and CLN3 disease.1 The study builds upon their previous work in mouse models, which revealed an adaptive immune response mediated by sialoadhesin,2,3 showing low-level infiltration of the brain by predominantly CD8+ lymphocytes, and that genetically blocking this infiltration partly slowed disease progression and extended life-span moderately.

Longitudinal MRI brain volumetry in CLN3 disease: Introduction of a new sensitive and objective marker for the measurement of clinical disease outcome

Objective: A precise description of disease progression in CLN3 disease is urgently needed in order to establish an evaluation tool for future experimental treatments. This is especially challenging as CLN3 disease may present with variable clinical disease progression despite most patients harboring the same 1 kb deletion in the CLN3 gene. Gray matter atrophy due to neuronal loss is a striking feature of patients with juvenile CLN3 disease. Therefore, to develop a quantitative marker to measure brain volume outcome, we analyzed the longitudinal volumetric development of gray matter (GM), white matter (WM) and lateral ventricles and correlated those with the clinical course and with patient age. Methods: 122 MRIs of 35 patients (14 male; 21 female; age 15.3±4.8 years) with genetically confirmed CLN3 disease were performed on 1.5T scanners. A 3D T1-weighted MP- RAGE sequence was acquired. Volumetric segmentation of the brain was performed using Freesurfer Software suite. The clinical severity was assessed by the Hamburg juvenile NCL score, a disease-specific scoring system. Results: The volumes of cortical GM, cerebellar GM and WM, basal ganglia + thalami and hippocampus significantly (all P<0.0001) decreased with age, while the lateral ventricle volume increased (P<0.0001). Supratentorial WM volume correlated much poorer with age than the other observed regions (R=0.21, P=0.0094). Decrease of cortical gray matter volume showed the most uniform decrease with the strongest correlation with age (R=0.814, P<0.0001). CLN3 patients lost on average 4.6% (± 0.2 %) of cortical GM per year. In addition, a strong correlation with the Hamburg JNCL Score existed for the cortical GM (R=0.823, P=<0.0001). Conclusion: Cortical GM volume decline seems to be the most sensitive parameter for assessment of disease progression and represents a potential objective and sensitive outcome measure for evaluation of future therapies.

Intracerebroventricular cerliponase alfa for children with CLN2 disease: Interim results from an ongoing phase 2 extension study

Intracerebroventricular cerliponase alfa for children with CLN2 disease: Interim results from an ongoing phase 2 extension study

Impaired neuronal connectivity as dysregulated cellular function in CLN1 disease: A pathogenetic prediction by RNAseq analysis

Impaired neuronal connectivity as dysregulated cellular function in CLN1 disease: A pathogenetic prediction by RNAseq analysis

Detailed Clinical Phenotype and Molecular Genetic Findings in CLN3-Associated Isolated Retinal Degeneration

Mutations in genes traditionally associated with syndromic retinal disease are increasingly found to cause nonsyndromic inherited retinal degenerations. Mutations in CLN3 are classically associated with juvenile neuronal ceroid lipofuscinosis, a rare neurodegenerative disease with early retinal degeneration and progressive neurologic deterioration, but have recently also been identified in patients with nonsyndromic inherited retinal degenerations. To our knowledge, detailed clinical characterization of such cases has yet to be reported. To provide detailed clinical, electrophysiologic, structural, and molecular genetic findings in nonsyndromic inherited retinal degenerations associated with CLN3 mutations. A multi-institutional case series of 10 patients who presented with isolated nonsyndromic retinal disease and mutations in CLN3. Patient ages ranged from 16 to 70 years; duration of follow-up ranged from 3 to 29 years. Longitudinal clinical evaluation, including full ophthalmic examination, multimodal retinal imaging, perimetry, and electrophysiology. Molecular analyses were performed using whole-genome sequencing or whole-exome sequencing. Electron microscopy studies of peripheral lymphocytes and CLN3 transcript analysis with polymerase chain reaction amplification were performed in a subset of patients. There were 7 females and 3 males in this case series, with a mean (range) age at last review of 37.1 (16-70) years. Of the 10 patients, 4 had a progressive late-onset rod-cone dystrophy, with a mean (range) age at onset of 29.7 (20-40) years, and 6 had an earlier onset rod-cone dystrophy, with a mean (range) age at onset of 12.1 (7-17) years. Ophthalmoscopic examination features included macular edema, mild intraretinal pigment migration, and widespread atrophy in advanced disease. Optical coherence tomography imaging demonstrated significant photoreceptor loss except in patients with late-onset disease who had a focal preservation of the ellipsoid zone and outer nuclear layer in the fovea. Electroretinography revealed a rod-cone pattern of dysfunction in 6 patients and were completely undetectable in 2 patients. Six novel CLN3 variants were identified in molecular analyses. This report describes detailed clinical, imaging, and genetic features of CLN3-associated nonsyndromic retinal degeneration. The age at onset and natural progression of retinal disease differs greatly between syndromic and nonsyndromic CLN3 disease, which may be associated with genotypic differences.