USB1 Is a miRNA Deadenylase That Regulates Hematopoietic Development

Abstract Poikiloderma with neutropenia (PN)is an autosomal-recessive bone marrow failure (BMF) syndrome in which patients harbor homozygous or compound heterozygous mutations in the human gene C16orf57, which encodes the evolutionarily conserved RNA 3' to 5' exonuclease U6 biogenesis 1 (USB1). USB1 is required for the proper maturation of U6 and U6atac snRNAs, core components of the spliceosome, and consequently, splicing defects have been observed in yeast and zebrafish models with USB1 deficiency. However, lymphoblastoid cells from PN patients do not exhibit reduced U6 snRNA levels and have normal pre-mRNA splicing, establishing PN as a singular BMF syndrome, where the underlying genetic cause has been identified but the molecular mechanisms leading to tissue failure remain obscure. To investigate the role of USB1 in a physiological context, we utilized CRISPR/Cas9 to create human embryonic stem cells (hESCs) containing a frequently occurring c.531_del_A loss-of-function mutation in the USB1 gene (USB1_c.531_del_A hESCs). USB1_c.531_del_A hESCs have normal karyotype, normal growth rate, and retain pluripotency, indicating that clinically-relevant mutations in USB1 are not deleterious in undifferentiated hESCs. To elucidate the role of USB1 during hematopoiesis, we performed serum-free hematopoietic differentiations to derive hematopoietic progenitor cells from WT and USB1_c.531_del_A hESCs. The formation of definitive hematopoietic progenitors (CD45+) was decreased in USB1 mutant cells compared to WT cells, and definitive colony potential analysis showed compromised colony formation in USB1 mutants. These observations indicate that loss-of-function mutations in USB1 negatively influence hematopoiesis. Additionally, as PN is associated with severe non-cyclic neutropenia, we analyzed the potential of neutrophil formation in WT and USB1 mutant cells. USB1 mutants have reduced formation of CD15+/CD66b+ lineages, indicating abnormal neutrophil development. Conditional expression of WT USB1 in USB1_c.531_del_A mutant cells rescued these phenotypes, leading to normal hematopoietic development. Interestingly, USB1 mutants showed no reduction in the overall levels of U6 and U6atac snRNAs, similar to what was observed in patient cells. To identify other possible targets of USB1, we sequenced the transcriptome and miRome of WT and USB1 mutant cells in different stages of hematopoietic development. Through these analyses, we demonstrate that hematopoietic failure in USB1 mutants is caused by dysregulated miRNA levels during blood development, due to a failure to remove destabilizing 3' end oligo(A) tails added by PAPD5/7. Moreover, we demonstrate that modulation of oligoadenylation through genetic or chemical inhibition of PAPD5/7 rescues the defective hematopoiesis observed in USB1 mutants. This work indicates USB1 acts as a miRNA deadenylase and suggests PAPD5/7 inhibition as a potential therapy for PN. Disclosures Parker: Faze Therapeutics: Other: Co-founder.

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The role of the zinc transporter SLC30A2/ZnT2 in transient neonatal zinc deficiency

Metallomics ◽

10.1039/c7mt00162b ◽

2017 ◽

Vol 9 (10) ◽

pp. 1352-1366 ◽

Cited By ~ 18

Author(s):

Yarden Golan ◽

Taiho Kambe ◽

Yehuda G. Assaraf

Keyword(s):

Zinc Deficiency ◽

Molecular Mechanisms ◽

Current Knowledge ◽

Gene Mutations ◽

Zinc Transporter ◽

Loss Of Function ◽

Breastfed Infants ◽

Nursing Mothers ◽

Novel Approaches

Transient neonatal zinc deficiency (TNZD) results from loss of function mutations in theSLC30A2/ZnT2gene. Nursing mothers harboring this defective zinc transporter produce zinc-deficient milk. Consequently, their exclusively breastfed infants develop severe zinc deficiency. The present review summarizes our current knowledge onSLC30A2/ZnT2gene mutations and highlights the molecular mechanisms underlying this zinc deficiency. We further propose novel approaches for the early diagnosis and prevention of TNZD.

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Silencing of SPARC represses heterotopic ossification via inhibition of the MAPK signaling pathway

Bioscience Reports ◽

10.1042/bsr20191805 ◽

2019 ◽

Vol 39 (11) ◽

Author(s):

Qianjun Wang ◽

Qianqian Yang ◽

Ali Zhang ◽

Zhiqiang Kang ◽

Yingsheng Wang ◽

...

Keyword(s):

Heterotopic Ossification ◽

Signaling Pathway ◽

Molecular Mechanisms ◽

Mapk Signaling ◽

Mapk Signaling Pathway ◽

Mitogen Activated Protein Kinase ◽

Loss Of Function ◽

Alp Activity ◽

Mechanistic Investigation

Abstract Heterotopic ossification (HO), the pathologic formation of extraskeletal bone, can be disabling and lethal. However, the underlying molecular mechanisms were largely unknown. The present study aimed to clarify the involvement of secreted protein acidic and rich in cysteine (SPARC) and the underlying mechanism in rat model of HO. The mechanistic investigation on roles of SPARC in HO was examined through gain- and loss-of-function approaches of SPARC, with alkaline-phosphatase (ALP) activity, mineralized nodules, and osteocalcin (OCN) content measured. To further confirm the regulatory role of SPARC, levels of mitogen-activated protein kinase (MAPK) signaling pathways-related proteins (extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), p38, nuclear factor κ-B (NF-κB), and IkB kinase β (IKKβ)) were determined. Bone marrow mesenchymal stem cells were treated with pathway inhibitor to investigate the relationship among SPARC, MAPK signaling pathway, and HO. The results suggested that SPARC expression was up-regulated in Achilles tendon tissues of HO rats. Silencing of SPARC could decrease phosphorylation of ERK, JNK, p38, NF-κB, and IKKβ. Additionally, silencing of SPARC or inhibition of MAPK signaling pathway could reduce the ALP activity, the number of mineralized nodules, and OCN content, thus impeding HO. To sum up, our study identifies the inhibitory role of SPARC gene silencing in HO via the MAPK signaling pathway, suggesting SPARC presents a potential target for HO therapy.

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L1CAM promotes ovarian cancer stemness and tumor initiation via FGFR1/SRC/STAT3 signaling

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-02117-z ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Marco Giordano ◽

Alessandra Decio ◽

Chiara Battistini ◽

Micol Baronio ◽

Fabrizio Bianchi ◽

...

Keyword(s):

Molecular Mechanisms ◽

Genetic Manipulation ◽

Tumor Formation ◽

In Vitro Assays ◽

Tumor Initiation ◽

Loss Of Function ◽

Stat3 Signaling

Abstract Background Cancer stem cells (CSC) have been implicated in tumor progression. In ovarian carcinoma (OC), CSC drive tumor formation, dissemination and recurrence, as well as drug resistance, thus contributing to the high death-to-incidence ratio of this disease. However, the molecular basis of such a pathogenic role of ovarian CSC (OCSC) has been elucidated only to a limited extent. In this context, the functional contribution of the L1 cell adhesion molecule (L1CAM) to OC stemness remains elusive. Methods The expression of L1CAM was investigated in patient-derived OCSC. The genetic manipulation of L1CAM in OC cells provided gain and loss-of-function models that were then employed in cell biological assays as well as in vivo tumorigenesis experiments to assess the role of L1CAM in OC cell stemness and in OCSC-driven tumor initiation. We applied antibody-mediated neutralization to investigate L1CAM druggability. Biochemical approaches were then combined with functional in vitro assays to study the molecular mechanisms underlying the functional role of L1CAM in OCSC. Results We report that L1CAM is upregulated in patient-derived OCSC. Functional studies showed that L1CAM promotes several stemness-related properties in OC cells, including sphere formation, tumor initiation and chemoresistance. These activities were repressed by an L1CAM-neutralizing antibody, pointing to L1CAM as a druggable target. Mechanistically, L1CAM interacted with and activated fibroblast growth factor receptor-1 (FGFR1), which in turn induced the SRC-mediated activation of STAT3. The inhibition of STAT3 prevented L1CAM-dependent OC stemness and tumor initiation. Conclusions Our study implicate L1CAM in the tumorigenic function of OCSC and point to the L1CAM/FGFR1/SRC/STAT3 signaling pathway as a novel driver of OC stemness. We also provide evidence that targeting this pathway can contribute to OC eradication.

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De Novo Point Mutation of RPL31 in Diamond-Blackfan Anaemia: A Story from Patient to Zebrafish

Blood ◽

10.1182/blood-2019-129708 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 5018-5018

Author(s):

Yuanyuan Zhu ◽

Honghu Li ◽

Weiyan Zheng ◽

Shuyang Cai ◽

Yibo Wu ◽

...

Keyword(s):

Ribosomal Protein ◽

Point Mutation ◽

Molecular Mechanisms ◽

De Novo ◽

Conflicts Of Interest ◽

Bone Marrow Failure ◽

Macrocytic Anemia ◽

Loss Of Function ◽

Zebrafish Model ◽

Diamond Blackfan Anaemia

Diamond Blackfan anemia (DBA) is a rare bone marrow failure disorder that usually manifests as severe macrocytic anemia and erythroid hypoplasia ,often accompanied by various physical malformations and increased frequency of cancer. The disease are associated with known ribosomal protein gene and rarely GATA1 mutations in most of DBA cases, with the genetic etiology unclear in the remaining patients. Here, we present one patient with Diamond-Blackfan anaemia who lacked documented mutations involving known DBA genes by screening.Whole-exome sequencing (WES) was performed and we identified a single missense mutation in RPL31.The missense variant c.254G>T is predicted to give rise to a gene product with substitution p. Arg85Leu ,which is regarded as causative because the unaffected parents and sister of the patient do not possess the mutation,implying that this mutation was de novo. Previous studies showed that nearly all of the causative variants of RP genes observed in DBA are loss-of function mutations and RP haploinsufficiency accounts for most cases of DBA. Particularly, The coding region of RPL31 shares 89.6% amino acid identities with its zebrafish ortholog, which is highly conserved between these two species.All of above led us to explore the effects of RPL31 deficiency on morphology and erythropoietic status during embryonic development. Therefore, morpholino antisense oligonucleotides (MOs) targeting zebrafish rpl31, orthologs of human RPL31,was injected at a proper concentration into one-cell-stage zebrafish embryos to mimic RPL31 haploinsufficiency in DBA. The specificity of the rpl31-MO was valitated by western blot detection.Compared with wild-type embryos, rpl31 deficiency embryos showed developmental abnormalities such as pericardial edema, microcephaly ,delayed pigmentation and bent tail. We also performed haemoglobin staining at 48 hr post fertilization (48hpf) and found a significant decrease of erythrocyte production in the cardial vein of the morphants. Meanwhile,the number of lcr+red blood cells was reduced about 50% in lcr:GFP transgenic embryos at 48 hpf by fluorescence microscopy and 3dpf by flow cytometry when compared to control embryos.However,the myeloid and lymphoid lineages were preserved as analyzed by using lyz:dsRed transgenic line and by observing expression of rag1,respectively. Lots of evidence showed that many other ribosomal protein genes deficiency can up-regulate p53 network,resulting in consequent cell cycle arrest or apoptosis.so we want to investigate the connection between RPL31 and p53 signaling in erythropoiesis.However,p53 null can not completely rescue the erythroid defect phenotype when we injected rpl31-MO into p53-/- embryos,suggesting alternative pathways may be involved in this process. In summary, we reported a brand new point mutation in RPL31 gene and we phonecopied loss of function of RPL31 observed in the DBA patient in vivo by constructing a RPL31 deficiency zebrafish model,indicating preliminarily that the loss of function mutation in RPL31 is a candidate responsible for DBA.However,underlying molecular mechanisms and reasons of the specific erythroid impairments in RPL31 deficiency are still needed to be clarified.we will focused on these in the future. Disclosures No relevant conflicts of interest to declare.

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An auxin signaling network translates low-sugar-state input into compensated cell enlargement in the fugu5 cotyledon

PLoS Genetics ◽

10.1371/journal.pgen.1009674 ◽

2021 ◽

Vol 17 (8) ◽

pp. e1009674

Author(s):

Hiromitsu Tabeta ◽

Shunsuke Watanabe ◽

Keita Fukuda ◽

Shizuka Gunji ◽

Mariko Asaoka ◽

...

Keyword(s):

Atpase Activity ◽

Molecular Mechanisms ◽

Genetic Interaction ◽

Mitotic Cell ◽

Fine Tuning ◽

Auxin Signaling ◽

Cell Enlargement ◽

Loss Of Function ◽

Nutrient Reserves

In plants, the effective mobilization of seed nutrient reserves is crucial during germination and for seedling establishment. The Arabidopsis H+-PPase-loss-of-function fugu5 mutants exhibit a reduced number of cells in the cotyledons. This leads to enhanced post-mitotic cell expansion, also known as compensated cell enlargement (CCE). While decreased cell numbers have been ascribed to reduced gluconeogenesis from triacylglycerol, the molecular mechanisms underlying CCE remain ill-known. Given the role of indole 3-butyric acid (IBA) in cotyledon development, and because CCE in fugu5 is specifically and completely cancelled by ech2, which shows defective IBA-to-indoleacetic acid (IAA) conversion, IBA has emerged as a potential regulator of CCE. Here, to further illuminate the regulatory role of IBA in CCE, we used a series of high-order mutants that harbored a specific defect in IBA-to-IAA conversion, IBA efflux, IAA signaling, or vacuolar type H+-ATPase (V-ATPase) activity and analyzed the genetic interaction with fugu5–1. We found that while CCE in fugu5 was promoted by IBA, defects in IBA-to-IAA conversion, IAA response, or the V-ATPase activity alone cancelled CCE. Consistently, endogenous IAA in fugu5 reached a level 2.2-fold higher than the WT in 1-week-old seedlings. Finally, the above findings were validated in icl–2, mls–2, pck1–2 and ibr10 mutants, in which CCE was triggered by low sugar contents. This provides a scenario in which following seed germination, the low-sugar-state triggers IAA synthesis, leading to CCE through the activation of the V-ATPase. These findings illustrate how fine-tuning cell and organ size regulation depend on interplays between metabolism and IAA levels in plants.

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Overexpressing PLA2G6 mutations cause symptoms of young–onset dystonia–parkinsonism type 14 and reduction in DHA levels in zebrafish model

10.21203/rs.3.rs-25963/v1 ◽

2020 ◽

Author(s):

Tu-Hsueh Yeh ◽

Han-Fang Liu ◽

Mei-Ling Cheng ◽

Yin-Cheng Huang ◽

Ying-Zu Huang ◽

...

Keyword(s):

Risk Factors ◽

Dopaminergic Neurons ◽

Molecular Mechanisms ◽

Motor Disorder ◽

Loss Of Function ◽

Phospholipase Activity ◽

Young Onset ◽

Factors Associated ◽

Metabolomics Analysis

Abstract Background: Parkinson’s disease (PD) is the most common neurodegenerative motor disorder, which is currently incurable. Mutations in many genes have been demonstrated to be the primary risk factors associated with the familial or idiopathic PD; however, the mechanisms underlying these genetic mutations resulting in parkinsonism remains unclear. Phospholipase A2 group VI (PLA2G6) has been shown to regulate lipid metabolism and homeostasis in the nervous system. Previous studies have shown that point mutations in PLA2G6 might be the risk factors associated with the young–onset of dystonia–parkinsonism type 14 (PARK14). However, limited information is available regarding its pathogenic role and the mechanism underlying its function. Methods: To study the role of PLA2G6 mutations in zebrafish PARK14 models, we injected different mutation constructs of human PLA2G6 genes and zebrafish pla2g6 deletion constructs in the zebrafish larvae. We analyzed the locomotion behavior, performed immunohistochemistry to examine the formation of dopaminergic neurons, and identified the defective metabolites affected by PLA2G6 mutations through metabolomics analysis. Results: Injection of human PLA2G6 mutations and zebrafish pla2g6 deletion constructs induced symptoms such as motility defects and reduced number of dopaminergic neurons, and these symptoms resembled those observed in PARK14. These phenotypes could be rescued by treatment with L-dopa. Furthermore, the injection of two PLA2G6 mutation constructs, D331Y and T572I, led to a decrease in the phospholipase activity of PLA2G6 and its lipid metabolites, indicating that these two mutations are the loss-of-function mutations. We further performed metabolomics analysis to identify which lipids are majorly affected by the overexpression of PLA2G6 and PLA2G6 mutants. We found that injecting D331Y or T572I mutation constructs led to higher phospholipid and lower DHA levels. Conclusions: D331Y and T572I injections in zebrafish were sufficient to create a PD phenotypes. In addition, D331Y and T572I are loss of function mutations and cause defective phospholipase activity and reduced the level of DHA. These results have helped us elucidate the role of PLA2G6 mutations in PARK14 and further led to a deeper understanding of the molecular mechanisms underlying PD. The results of this study may also facilitate the development of therapeutic strategies for PD.

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Melanocortin-1 receptor (MC1R) genotypes do not correlate with size in two cohorts of medium-to-giant congenital melanocytic nevi

10.1101/2020.04.10.20055301 ◽

2020 ◽

Author(s):

Neus Calbet-Llopart ◽

Mirella Pascini-Garrigos ◽

Gemma Tell-Martí ◽

Miriam Potrony ◽

Vanessa Martins da Silva ◽

...

Keyword(s):

Epidemiological Studies ◽

Compound Heterozygous ◽

Control Analysis ◽

Large Set ◽

Adult Size ◽

Loss Of Function ◽

Melanocytic Nevi ◽

Pigmented Lesions ◽

Congenital Melanocytic Nevi

ABSTRACTCongenital melanocytic nevi (CMN) are cutaneous malformations whose prevalence is inversely correlated with projected adult size. CMN are caused by somatic mutations, but epidemiological studies suggest that germline genetic factors may influence CMN development. In CMN patients from the U.K., genetic variants in the MC1R gene, such as p.V92M and loss-of-function variants, have been previously associated with larger CMN. We analyzed the association of MC1R variants with CMN characteristics in 113 medium-to-giant CMN patients from Spain and from a distinct cohort of 53 patients from France, Norway, Canada and the U.S. These cohorts were similar at the clinical and phenotypical level, except for the number of nevi per patient. We found that the p.V92M or loss-of-function MC1R variants either alone or in combination did not correlate with CMN size, in contrast to the U.K. CMN patients. An additional case-control analysis with 259 unaffected Spanish individuals, showed a higher frequency of MC1R compound heterozygous or homozygous variant genotypes in Spanish CMN patients compared to the control population (15.9% vs. 9.3%; P=0.075). Altogether, this study suggests that MC1R variants are not associated with CMN size in these non-U.K. cohorts. Additional studies are required to define the potential role of MC1R as a risk factor in CMN development.SIGNIFICANCECongenital melanocytic nevi (CMN) are common pigmented lesions that originate during prenatal life, without clear evidence of a genetic predisposition. To date, limited data exist regarding the role of the MC1R gene, a key regulator of human pigmentation, in the development of the class of rarer CMN that are greater than 10 cm diameter at projected adult size and associated with increased morbidity or mortality risks. This study provides data from a large set of such CMN patients to support the hypothesis that MC1R could be involved in the development of these types of lesions, but at the same time discounting its influence on the size of CMN across distinct populations. Improving our understanding of genetic susceptibility to rare types of CMN is necessary to determine whether routine germline genotyping is relevant in clinical practice.

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RIPK1-Associated Inborn Errors of Innate Immunity

Frontiers in Immunology ◽

10.3389/fimmu.2021.676946 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jiahui Zhang ◽

Taijie Jin ◽

Ivona Aksentijevich ◽

Qing Zhou

Keyword(s):

Immune Deficiency ◽

Molecular Mechanisms ◽

Clinical Manifestations ◽

Physiological Role ◽

Model Organisms ◽

Loss Of Function ◽

Inborn Errors ◽

Post Translational Modifications ◽

Cell Death Signaling

RIPK1 (receptor-interacting serine/threonine-protein kinase 1) is a key molecule for mediating apoptosis, necroptosis, and inflammatory pathways downstream of death receptors (DRs) and pattern recognition receptors (PRRs). RIPK1 functions are regulated by multiple post-translational modifications (PTMs), including ubiquitination, phosphorylation, and the caspase-8-mediated cleavage. Dysregulation of these modifications leads to an immune deficiency or a hyperinflammatory disease in humans. Over the last decades, numerous studies on the RIPK1 function in model organisms have provided insights into the molecular mechanisms of RIPK1 role in the maintenance of immune homeostasis. However, the physiological role of RIPK1 in the regulation of cell survival and cell death signaling in humans remained elusive. Recently, RIPK1 loss-of-function (LoF) mutations and cleavage-deficient mutations have been identified in humans. This review discusses the molecular pathogenesis of RIPK1-deficiency and cleavage-resistant RIPK1 induced autoinflammatory (CRIA) disorders and summarizes the clinical manifestations of respective diseases to help with the identification of new patients.

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Mouse models of altered gonadotrophin action: insight into male reproductive disorders

Reproduction ◽

10.1530/rep-14-0302 ◽

2014 ◽

Vol 148 (4) ◽

pp. R63-R70 ◽

Cited By ~ 16

Author(s):

Kim C Jonas ◽

Olayiwola O Oduwole ◽

Hellevi Peltoketo ◽

Susana B Rulli ◽

Ilpo T Huhtaniemi

Keyword(s):

Mouse Models ◽

Molecular Mechanisms ◽

Pituitary Hormones ◽

Loss Of Function ◽

Reproductive Disorders ◽

Human Reproductive ◽

Multiple Loss ◽

The Relationship

The advent of technologies to genetically manipulate the mouse genome has revolutionised research approaches, providing a unique platform to study the causality of reproductive disorders in vivo. With the relative ease of generating genetically modified (GM) mouse models, the last two decades have yielded multiple loss-of-function and gain-of-function mutation mouse models to explore the role of gonadotrophins and their receptors in reproductive pathologies. This work has provided key insights into the molecular mechanisms underlying reproductive disorders with altered gonadotrophin action, revealing the fundamental roles of these pituitary hormones and their receptors in the hypothalamic–pituitary–gonadal axis. This review will describe GM mouse models of gonadotrophins and their receptors with enhanced or diminished actions, specifically focusing on the male. We will discuss the mechanistic insights gained from these models into male reproductive disorders, and the relationship and understanding provided into male human reproductive disorders originating from altered gonadotrophin action.

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Human INCL fibroblasts display abnormal mitochondrial and lysosomal networks and heightened susceptibility to ROS-induced cell death

10.1101/2020.09.14.295881 ◽

2020 ◽

Author(s):

Bailey Balouch ◽

Halle Nagorsky ◽

Truc Pham ◽

Thai LaGraff ◽

Quynh Chu-LaGraff

Keyword(s):

Oxidative Stress ◽

Cell Death ◽

Molecular Mechanisms ◽

Neurodegenerative Disorder ◽

Endoplasmic Reticulum Stress Response ◽

Compound Heterozygous ◽

Storage Material ◽

Cellular Environment ◽

And Oxidative Stress

AbstractInfantile Neuronal Ceroid Lipofuscinosis (INCL) is a pediatric neurodegenerative disorder characterized by progressive retinal and central nervous system deterioration during infancy. This lysosomal storage disorder results from a deficiency in the Palmitoyl Protein Thioesterase 1 (PPT1) enzyme - a lysosomal hydrolase which cleaves fatty acid chains such as palmitate from lipid-modified proteins. In the absence of PPT1 activity, these proteins fail to be degraded, leading to the accumulation of autofluorescence storage material in the lysosome. The underlying molecular mechanisms leading to INCL pathology remain poorly understood. A role for oxidative stress has been postulated, yet little evidence has been reported to support this possibility. Here we present a comprehensive cellular characterization of human PPT1-deficient fibroblast cells harboring Met1Ile and Tyr247His compound heterozygous mutations. We detected autofluorescence storage material and observed distinct organellar abnormalities of the lysosomal and mitochondrial structures, which supported previous postulations about the role of ER, mitochondria and oxidative stress in INCL. An increase in the number of lysosomal structures was found in INCL patient fibroblasts, which suggested an upregulation of lysosomal biogenesis, and an association with endoplasmic reticulum stress response. The mitochondrial network also displayed abnormal spherical punctate morphology instead of normal elongated tubules with extensive branching, supporting the involvement of mitochondrial and oxidative stress in INCL cell death. Autofluorescence accumulation and lysosomal pathologies can be mitigated in the presence of conditioned wild type media suggesting that a partial restoration via passive introduction of the enzyme into the cellular environment may be possible. We also demonstrated, for the first time, that human INCL fibroblasts have a heightened susceptibility to exogenous reactive oxygen species (ROS)-induced cell death, which suggested an elevated basal level of endogenous ROS in the mutant cell. Collectively, these findings support the role of intracellular organellar networks in INCL pathology, possibly due to oxidative stress.

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