Murine Cathepsin F Deficiency Causes Neuronal Lipofuscinosis and Late-Onset Neurological Disease

ABSTRACT Cathepsin F (cat F) is a widely expressed lysosomal cysteine protease whose in vivo role is unknown. To address this issue, mice deficient in cat F were generated via homologous recombination. Although cat F−/− mice appeared healthy and reproduced normally, they developed progressive hind leg weakness and decline in motor coordination at 12 to 16 months of age, followed by significant weight loss and death within 6 months. cat F was found to be expressed throughout the central nervous system (CNS). cat F−/− neurons accumulated eosinophilic granules that had features typical of lysosomal lipofuscin by electron microscopy. Large amounts of autofluorescent lipofuscin, characteristic of the neurodegenerative disease neuronal ceroid lipofuscinosis (NCL), accumulated throughout the CNS but not in visceral organs, beginning as early as 6 weeks of age. Pronounced gliosis, an indicator of neuronal stress and neurodegeneration, was also apparent in older cat F−/− mice. cat F is the only cysteine cathepsin whose inactivation alone causes a lysosomal storage defect and progressive neurological features in mice. The late onset suggests that this gene may be a candidate for adult-onset NCL.

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GFAP hyperpalmitoylation exacerbates astrogliosis and neurodegenerative pathology in PPT1-deficient mice

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2022261118 ◽

2021 ◽

Vol 118 (13) ◽

pp. e2022261118

Author(s):

Wei Yuan ◽

Liaoxun Lu ◽

Muding Rao ◽

Yang Huang ◽

Chun-e Liu ◽

...

Keyword(s):

Neuronal Ceroid Lipofuscinosis ◽

Astrocyte Proliferation ◽

Infantile Neuronal Ceroid Lipofuscinosis ◽

Protein Palmitoylation ◽

Neurodegenerative Pathology ◽

The Central Nervous System ◽

Proliferation In Vitro ◽

The Brain

The homeostasis of protein palmitoylation and depalmitoylation is essential for proper physiological functions in various tissues, in particular the central nervous system (CNS). The dysfunction of PPT1 (PPT1-KI, infantile neuronal ceroid lipofuscinosis [INCL] mouse model), which catalyze the depalmitoylation process, results in serious neurodegeneration accompanied by severe astrogliosis in the brain. Endeavoring to determine critical factors that might account for the pathogenesis in CNS by palm-proteomics, glial fibrillary acidic protein (GFAP) was spotted, indicating that GFAP is probably palmitoylated. Questions concerning if GFAP is indeed palmitoylated in vivo and how palmitoylation of GFAP might participate in neural pathology remain unexplored and are waiting to be investigated. Here we show that GFAP is readily palmitoylated in vitro and in vivo; specifically, cysteine-291 is the unique palmitoylated residue in GFAP. Interestingly, it was found that palmitoylated GFAP promotes astrocyte proliferation in vitro. Furthermore, we showed that PPT1 depalmitoylates GFAP, and the level of palmitoylated GFAP is overwhelmingly up-regulated in PPT1-knockin mice, which lead us to speculate that the elevated level of palmitoylated GFAP might accelerate astrocyte proliferation in vivo and ultimately led to astrogliosis in INCL. Indeed, blocking palmitoylation by mutating cysteine-291 into alanine in GFAP attenuate astrogliosis, and remarkably, the concurrent neurodegenerative pathology in PPT1-knockin mice. Together, these findings demonstrate that hyperpalmitoylated GFAP plays critical roles in regulating the pathogenesis of astrogliosis and neurodegeneration in the CNS, and most importantly, pinpointing that cysteine-291 in GFAP might be a valuable pharmaceutical target for treating INCL and other potential neurodegenerative diseases.

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VALPROIC ACID EXTENDS LIFESPAN OF THE ZEBRAFISH MODEL OF CLN2 DISEASE (LATE INFANTILE NEURONAL CEROID LIPOFUSCINOSIS)

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2015-312379.61 ◽

2015 ◽

Vol 86 (11) ◽

pp. e4.153-e4

Author(s):

Fahad Mahmood ◽

Anselm Zdebik ◽

Alexandra Au ◽

Jennifer Cooke ◽

Claire Russell

Keyword(s):

Seizure Activity ◽

Neuronal Ceroid Lipofuscinosis ◽

Epileptiform Activity ◽

Intractable Epilepsy ◽

Premature Death ◽

Neuronal Ceroid Lipofuscinoses ◽

Lysosomal Storage ◽

Zebrafish Model ◽

Lysosomal Protease

CLN2 disease is a subtype of the neuronal ceroid lipofuscinoses (NCLs), a group of lysosomal storage disorders causing progressive, untreatable, neurodegeneration, intractable epilepsy and premature death in children. We have developed a permanent genetic zebrafish model of CLN2 disease due to a mutation in tpp1 encoding the lysosomal protease Tripeptidyl-peptidase-1 that replicates the neurodegenerative and storage phenotype. We hypothesize that CLN2 zebrafish display electrical and behavioural evidence of seizure activity that responds to established anti-convulsants and can further be used to develop novel therapeutic approaches.To validate the presence of seizures we performed single electrode electroencephalography showing CLN2 zebrafish had increased spiking activity vs wildtype with Fast-Fourier transform showing significantly increased amplitude about 2–4Hz. This was attenuated by Valproate (p=0.049), but not pentobarbitone. We also demonstrate that Valproate significantly reduces seizure-related movement bouts, thereby correlating movements and epileptiform activity. Lastly, we show exposure to Valproate significantly extends the lifespan of our zebrafish model with mortality between 3–6 days post-fertilization 8.33% in treated vs 33.3% in controls (p=0.01).The CLN2 zebrafish model thus displays electrical and behavioural seizure activity that can be attenuated by Valproate, with associated prolongation in survival. Moreover this model can utilize high-throughput in vivo screening assays to develop novel anti-convulsants.

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Differential Expression of miRNAs and Behavioral Change in the Cuprizone-Induced Demyelination Mouse Model

International Journal of Molecular Sciences ◽

10.3390/ijms21020646 ◽

2020 ◽

Vol 21 (2) ◽

pp. 646 ◽

Cited By ~ 1

Author(s):

Han ◽

Kang ◽

Jeon ◽

Lee ◽

Park ◽

...

Keyword(s):

Mouse Model ◽

Mirna Expression ◽

Motor Coordination ◽

Field Tests ◽

Treated Group ◽

Demyelinating Diseases ◽

The Central Nervous System ◽

Mirna Expression Profiling ◽

And Behavior

The demyelinating diseases of the central nervous system involve myelin abnormalities, oligodendrocyte damage, and consequent glia activation. Neurotoxicant cuprizone (CPZ) was used to establish a mouse model of demyelination. However, the effects of CPZ on microRNA (miRNA) expression and behavior have not been clearly reported. We analyzed the behavior of mice administered a diet containing 0.2% CPZ for 6 weeks, followed by 6 weeks of recovery. Rotarod analysis demonstrated that the treated group had poorer motor coordination than control animals. This effect was reversed after 6 weeks of CPZ withdrawal. Open-field tests showed that CPZ-treated mice exhibited significantly increased anxiety and decreased exploratory behavior. CPZ-induced demyelination was observed to be alleviated after 4 weeks of CPZ treatment, according to luxol fast blue (LFB) staining and myelin basic protein (MBP) expression. miRNA expression profiling showed that the expression of 240 miRNAs was significantly changed in CPZ-fed mice compared with controls. Furthermore, miR-155-5p and miR-20a-5p upregulations enhanced NgR induction through Smad 2 and Smad 4 suppression in demyelination. Taken together, our results demonstrate that CPZ-mediated demyelination induces behavioral deficits with apparent alterations in miRNA expression, suggesting that differences in miRNA expression in vivo may be new potential therapeutic targets for remyelination.

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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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Glial contribution to cyclodextrin-mediated reversal of cholesterol accumulation in murine NPC1-deficient neurons in vivo

10.1101/2021.04.08.438990 ◽

2021 ◽

Author(s):

Amélie Barthelemy ◽

Valérie Demais ◽

Izabela-Cristina Stancu ◽

Eugeniu Vasile ◽

Tom Houben ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Glial Cells ◽

Animal Studies ◽

Lysosomal Storage ◽

Genes Encoding ◽

The Central Nervous System ◽

Lysosomal System ◽

Niemann Pick

AbstractNiemann-Pick type C (NPC) disease is a rare and fatal lysosomal storage disorder presenting severe neurovisceral symptoms. Disease-causing mutations in genes encoding either NPC1 or NPC2 protein provoke accumulation of cholesterol and other lipids in specific structures of the endosomal-lysosomal system and degeneration of specific cells, notably neurons in the central nervous system (CNS). 2-hydroxypropyl-beta-cyclodextrin (CD) emerged as potential therapeutic approach based on animal studies and clinical data, but the mechanism of action on neurons has remained unclear. To address this topic in vivo, we took advantage of the retina as highly accessible part of the (CNS) and intravitreal injections as mode of drug administration. We find that CD enters the endosomal-lysosomal system of neurons and enables the release of lipid-laden lamellar inclusions, which are then removed from the extracellular space by specific types of glial cells. Thus, CD triggers a concerted action of neurons and glial cells to restore lipid homeostasis in the central nervous system.

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Transmembrane Batten disease proteins interact with a shared network of vesicle sorting proteins to regulate synaptic composition and function.

10.1101/2021.09.16.460691 ◽

2021 ◽

Author(s):

Mitchell J. Rechtzigel ◽

Brandon L Meyerink ◽

Hannah Leppert ◽

Tyler B Johnson ◽

Jacob T. Cain ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Batten Disease ◽

Lysosomal Storage ◽

Associated Proteins ◽

The Central Nervous System ◽

And Function ◽

Shared Network ◽

Storage Disorders

Batten disease is unique among lysosomal storage disorders for the early and profound manifestation in the central nervous system, but little is known regarding potential neuron-specific roles for the disease-associated proteins. We demonstrate substantial overlap in the protein interactomes of three transmembrane Batten proteins (CLN3, CLN6, and CLN8), and that their absence leads to synaptic depletion of key partners (i.e. SNAREs and tethers) and aberrant synaptic SNARE dynamics in vivo, demonstrating a novel shared etiology.

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Response to Steroids in IQSEC2-Related Encephalopathy Presenting with Rett-Like Phenotype and Infantile Spasms

Journal of Pediatric Genetics ◽

10.1055/s-0040-1721371 ◽

2020 ◽

Author(s):

Divya Nagabushana ◽

Aparajita Chatterjee ◽

Raghavendra Kenchaiah ◽

Ajay Asranna ◽

Gautham Arunachal ◽

...

Keyword(s):

Late Onset ◽

Neurodevelopmental Disorder ◽

Epileptic Encephalopathy ◽

Infantile Spasms ◽

The Past ◽

Resource Limited ◽

The Central Nervous System ◽

Motor Milestone ◽

Behavior And Cognition ◽

Atypical Rett Syndrome

Abstract Introduction IQSEC2-related encephalopathy is an X-linked childhood neurodevelopmental disorder with intellectual disability, epilepsy, and autism. This disorder is caused by a mutation in the IQSEC2 gene, the product of which plays an important role in the development of the central nervous system. Case Report We describe the symptomatology, clinical course, and management of a 17-month-old male child with a novel IQSEC2 mutation. He presented with an atypical Rett syndrome phenotype with developmental delay, autistic features, midline stereotypies, microcephaly, hypotonia and epilepsy with multiple seizure types including late-onset infantile spasms. Spasms were followed by worsening of behavior and cognition, and regression of acquired milestones. Treatment with steroids led to control of spasms and improved attention, behavior and recovery of lost motor milestone. In the past 10 months following steroid therapy, child lags in development, remains autistic with no further seizure recurrence. Conclusion IQSEC2-related encephalopathy may present with atypical Rett phenotype and childhood spasms. In resource-limited settings, steroids may be considered for spasm remission in IQSEC2-related epileptic encephalopathy.

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Physical exercise protects dynamic balance and motor coordination of rats treated with vincristine

Revista Brasileira de Fisiologia do Exercício ◽

10.33233/rbfex.v19i5.4220 ◽

2020 ◽

Vol 19 (5) ◽

pp. 336

Author(s):

Luiza Minato Sagrillo ◽

Viviane Nogueira De Zorzi ◽

Luiz Fernando Freire Royes ◽

Michele Rechia Fighera ◽

Beatriz Da Silva Rosa Bonadiman ◽

...

Keyword(s):

Oxidative Stress ◽

Locomotor Activity ◽

Physical Exercise ◽

Motor Coordination ◽

Dynamic Balance ◽

Exercise Group ◽

Adult Rats ◽

The Central Nervous System ◽

Stress Damage ◽

Training Protocol

Physical exercise has been shown to be an important modulator of the antioxidant system and neuroprotective in several diseases and treatments that affect the central nervous system. In this sense, the present study aimed to evaluate the effect of physical exercise in dynamic balance, motor coordination, exploratory locomotor activity and in the oxidative and immunological balance of rats treated with vincristine (VCR). For that, 40 adult rats were divided into two groups: exercise group (6 weeks of swimming, 1h/day, 5 days/week, with overload of 5% of body weight) and sedentary group. After training, rats were treated with 0.5 mg/kg of vincristine sulfate for two weeks or with the same dose of 0.9% NaCl. The behavioral tests were conducted 1 and 7 days after each dose of VCR. On day 15 we carried out the biochemical analyzes of the cerebellum. The physical exercise was able to protect against the loss of dynamic balance and motor coordination and, had effect per se in the exploratory locomotor activity, and neutralize oxidative stress, damage DNA and immune damage caused by VCR up to 15 days after the end of the training protocol. In conclusion, we observed that previous physical training protects of the damage motor induced by vincristine.Key-words: exercise, oxidative stress, neuroprotection, cerebellum.

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