2026-08-09 | Phenotypic and Genetic Characterization of 64 Egyptian Children With Neuronal Ceroid Lipofuscinosis.
Neuronal ceroid lipofuscinoses (NCLs) are the most common neurodegenerative diseases in childhood. This study aimed to investigate the phenotypic and genetic spectrum of NCLs in Egypt. This descriptive study involved children with NCLs diagnosed and managed at five Egyptian centers between 2019 and 2024. Demographic, clinical, brain imaging, and genetic data were systematically evaluated. Identified variants in NCL-related genes were classified following the American College of Medical Genetics and Genomics guidelines. The cohort included 64 Egyptian children (from 57 families) with eight NCL types. The most commonly identified genotype was CLN2 (17/64, 27%), followed by CLN1 and CLN7 (12/64, 19% each). Patients generally exhibited the classic manifestations of NCLs, particularly motor regression (64/64, 100%), cognitive decline (64/64, 100%), language impairment (64/64, 100%), epilepsy (57/64, 89%), and vision loss (47/64, 73%). Notably, developmental regression (12/17, 71%) was the predominant presenting symptom for CLN2. Brain imaging generally showed typical cerebral and cerebellar atrophy in 95% (61/64) and 84% (54/64) of cases, respectively. Nevertheless, thalamic abnormalities were observed in only 16% (10/64) of cases. A total of 46 distinct variants were identified across eight NCL-related genes, including 23 novel ones, with the majority (33/46, 72%) being private. There was a median diagnostic delay of 2 years, and none of the patients received specific therapy. This study reports the largest cohort of children with NCLs from Egypt, including 12 patients with the less-commonly reported CLN7 subtype, which expands the demographic, clinical, and molecular spectrum of these diseases.
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2026-07-20 | Chronic oral cannabidiol delays seizure onset and reduces seizure burden in a mouse model of CLN2 disease.
A growing body of literature describes the anti-inflammatory, neuroprotective, and anti-epileptic properties of the cannabis sativa constituent cannabidiol, suggesting that it might play a useful role in the treatment of neurodegenerative diseases. Late infantile neuronal ceroid lipofuscinosis (CLN2 disease) is a rare pediatric neurodegenerative disorder resulting from an inherited dysfunction of the lysosome. CLN2 disease, and its representative animal models, display neuroimmune response, neuroinflammation, neurodegeneration, and epileptic seizures, and these symptoms are all touted as potential targets of cannabidiol therapeutic benefit. Here, we treated a valid model of CLN2 disease with long-term daily cannabidiol (300 mg/kg) from 1 month of age until disease end stage and evaluated epileptic seizures, lifespan, and markers of neuroimmune response. Chronic cannabidiol treatment significantly delayed or fully eliminated seizures in CLN2 model mice compared to those treated with vehicle only, and the treatment led to a non-significant extension of lifespan. These effects occurred in the absence of any therapeutic benefit to physiological markers of disease such as GFAP, CD68, and cytokine/chemokine reactivity. Taken together, we show that chronic treatment with cannabidiol confers significant anti-seizure benefit to the mouse model of CLN2 disease, and that it does not appear to do so by altering the inflammatory and neuroimmune markers traditionally used to track CLN2 disease progression.
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2026-06-18 | Thapsigargin-induced autophagic flux impairment and inflammation are potentiated by CLN3 deficiency and alleviated by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) in human ARPE-19 cells.
Juvenile neuronal lipofuscinosis (JNCL) is a rare disease caused by mutations in the CLN3 gene. It leads to early vision loss mediated by retinal degeneration. Impaired autophagosomal-lysosomal degradation is a major hallmark of JNCL pathology, and neuroinflammation has also been postulated to play a role in its pathogenesis. Thapsigargin, a selective inhibitor of sarco/endoplasmic reticulum Ca2+-ATPase, inhibits autophagy, leading to an accumulation of autophagosomes/autophagophores in cells. Cells with defective CLN3 protein function have been found to be particularly sensitive to the anti-autophagic effects of thapsigargin. Here, we characterized the effects of thapsigargin on inflammatory cytokines and autophagic markers in ARPE-19 cells using ELISA and western blotting. We further examined these effects in cells deficient in CLN3 function by exposing the cells to CLN3 siRNA and testing whether the effects of thapsigargin could be modulated by the well-known autophagy activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR). Thapsigargin induced the accumulation of LC3 and p62/SQSTM1, consistent with impaired autophagic flux in ARPE-19 cells. Additionally, we observed that thapsigargin possessed pro-inflammatory potential, as it induced the release of IL-6 in ARPE-19 cells, no inflammasome activation was detected. Both effects were enhanced by CLN3 siRNA and alleviated by AICAR. In conclusion, thapsigargin-induced impaired autophagic flux and the accompanying inflammatory response are more pronounced in CLN3-deficient ARPE-19 cells, indicating that loss of CLN3 function affects both autophagy and inflammatory signaling.
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2026-06-17 | TGFb signaling promotes astroglial activation and TDP-43 proteinopathy in organoid models of frontotemporal lobar degeneration.
Dominant mutations in Progranulin (GRN) gene cause frontotemporal lobar degeneration (FTLD-GRN), whereas homozygous GRN mutations lead to neuronal ceroid lipofuscinosis, a childhood neurodegenerative disorder. While recent transcriptomic studies reveal profound glial and neuronal pathology in FTLD-GRN at the disease end stage, the mechanism that disrupts glia-neuron homeostasis remains unclear. Using induced pluripotent stem cell (iPSC)-derived cortical organoids, we showed that GRN-/- and GRNR493X mutations lead to precocious astrogliosis that promotes neuronal stress and synaptic loss. Single-cell transcriptomics and histopathology analyses revealed a robust activation in TGFb signaling pathway in GRN-/- and GRNR493X/R493X astrocytes, which was accompanied by features of immune activation, loss of synaptic support, and abundant pTDP-43+ fibrils in astroglial cytoplasm, a feature characteristic of FTLD-GRN. Intriguingly, blocking TGFb signaling mitigated astroglial activation and pTDP-43 proteinopathy in GRN-/- organoids. Together, these results provide new insights into the cell-autonomous role of astroglial activation in neurodegeneration caused by Progranulin deficiency.
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2026-05-28 | Cellular and molecular characterisation of MFSD8 mutations associated with the variant late-infantile NCL CLN7
Batten disease (BD), also known as neuronal ceroid lipofuscinoses (NCLs), is a collective group of inherited neurodegenerative disorders. NCLs are the most prevalent cause of dementia in children, and they are distinguished by a common symptomatology that includes epileptic seizures, visual impairment, and a progressive decline in cognitive and physical function that results in early mortality. There are currently 12 different NCLs genetically identified in humans (CLN1-CLN8, CLN10-CLN13), with four newly identified genes (CLN9, CLN14, CLCN6, and SGSH). This study specifically focused on the variant late-infantile NCL (vLINCL) CLN7, which is caused primarily by homozygous mutations in CLN7/MFSD8, a major facilitator superfamily gene. MFSD8 encodes a multispanning integral lysosomal membrane protein with 12 transmembrane domains and has recently been described as a potential chloride channel on endosomes and lysosomes. However, there is still no cure or treatment available for CLN7 disease. Additionally, there is strong evidence demonstrating that MFSD8 is involved in the pathogenesis and pathobiology of other adult dementias, such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), as well as maculopathies and retinopathies, which share common disease-causing mutations in a heterozygosity manner. Considering the emerging relevance of the use of induced pluripotent stem cells (iPSCs) as a model for the investigation of neurodegenerative diseases, in this thesis, I studied CLN7 disease employing CLN7 patient-derived iPSCs. Specifically, two iPS cell lines were utilised, which were derived from a female patient diagnosed at the age of 2.5 years, who exhibited homozygosity for the common missense mutation p.T294K and a male patient diagnosed at the age of 4.5 years, who was also homozygous for a more severe missense mutation corresponding to p.R465W. These iPS cell lines were further differentiated into Neural Progenitor Cells (NPCs), constituting a novel approach to study the variant late-infantile NCL CLN7 and providing an opportunity to examine the disease using cell types that could more closely resemble those affected in vivo. In light of previous proteomic studies conducted in CLN7 patient-derived NPCs by our group, resulting in a downregulation of several nuclear proteins and, consistent with the observation of other studies, we identify the localisation of MFSD8 in the nucleus. These findings provide evidence of the potential existence of several co-existing MFSD8 variants within the cells, suggesting that MFSD8 might exert different functions depending on the different isoform expressed and its localisation. Additionally, this work also reveals an impairment in the autophagy-lysosomal pathway and mitochondria produced by disease-causing mutations in NPCs and the improvement of these phenotypes with the use of existing compounds. Furthermore, through the study of the post-translational modifications of MFSD8 and different protein stability assays, this work also provides more evidence of the intricacy of this protein. Therefore, further studies on the potential protein binding partners of MFSD8 were conducted to gain a deeper understanding of novel signalling pathways or molecular mechanisms in which MFSD8 might be involved. In summary, this thesis provides significant insights into the cellular and molecular biology of MFSD8 through the use of a clinically relevant model, which sheds new light on future directions for the study of CLN7 disease. These findings can contribute to the development of significant therapeutic strategies to ameliorate CLN7 disease and, as a consequence, improve other adult neurodegenerative diseases which share the same disease-causing mutations as CLN7 disease.
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