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Our retrospective study (2010-2020) examined treatment patterns, outcomes, and healthcare resource utilization in Finnish acute myeloid leukemia (AML) patients. Data covered 153 patients diagnosed at Hospital District of Southwest Finland (HDSF) and 107 from other districts who underwent allogeneic stem cell transplantation (aSCT) at HDSF. Of the 153 patients, 56.2% received intensive chemotherapy (IC), while 43.8% deemed ineligible for IC received low-intensity therapies or best supportive care (BSC). Median overall survival for IC patients was 31.2 months, compared to 5.3 months for those under azacytidine and 1.2 months on BSC. Majority (57.5%) of patients over 60 with intermediate/high European leukemia network risk had poor outcomes with IC and couldn't proceed to aSCT. These patients carried the highest costs and hospital resource use per patient month. Most common reasons for transplant ineligibility after IC were refractory disease and infection. Our data provides a comprehensive view on AML treatment landscape from a period when the latest treatment advancements were not yet accessible. The data describes patient groups with poor prognosis and increased healthcare burden, emphasizing the need to improve treatment practices and identify better ways to get more patients to transplant, in a rapidly evolving treatment landscape.
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Registros Electrónicos de Salud , Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Humanos , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/epidemiología , Finlandia/epidemiología , Estudios Retrospectivos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Adulto , Resultado del Tratamiento , Pronóstico , Adulto Joven , Adolescente , Manejo de la Enfermedad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Terapia Combinada , Anciano de 80 o más AñosRESUMEN
Background: The rapid development of multiple myeloma (MM) management underscores the value of real-world data. In our study we examined 509 adult MM patients treated with immunochemotherapy (ICT) with/without stem cell transplantation (SCT) from 2013 to 2019 in the Hospital District of Helsinki and Uusimaa, Finland. Materials & methods: Our study was based on computational analyses of data integrated into the hospital data lake. Results: After 2017, treatment pattern diversity increased with improved access to novel treatments. 5-year survivals were 74.4% (95% CI: 65.5-84.5) in SCT-eligible and 44.0% (95% CI: 37.6-51.4) in non-SCT subgroups. In the SCT-eligible subgroup, high first-year hospitalization costs were followed by stable resource requirements. Conclusion: Hospital data lakes can be adapted to carry out complex analysis of large MM cohorts.
To better understand how multiple myeloma (a type of blood cancer) is clinically managed, we examined 509 adult patients using advanced computer analysis and data stored in the Hospital District of Helsinki and Uusimaa information system. Our study found that after 2017, there was more variety in treatments due to better access to new therapies. Compared with a nontransplant group (44.0%), patients eligible for stem cell transplantation had a better 5-year survival rate (74.4%) and used higher levels of healthcare resources. Our study highlights the potential of hospital data systems to study large groups of multiple myeloma patients and inform strategies to tackle the burden associated with the treatment costs of multiple myeloma.
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Trasplante de Células Madre Hematopoyéticas , Mieloma Múltiple , Adulto , Humanos , Mieloma Múltiple/diagnóstico , Mieloma Múltiple/epidemiología , Mieloma Múltiple/terapia , Finlandia/epidemiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre , Hospitales , Estudios RetrospectivosRESUMEN
Genital warts (GWs) caused by the human papilloma virus (HPV) are a significant health problem due to high prevalence and rate of recurrence. Bivalent vaccine has been used since the start of the national vaccination program in 2013, making it feasible to study the GW burden in Finland. There is no national and up-to-date information available on the prevalence and the burden of GWs in the various healthcare sectors in Finland. The present study investigated the prevalence, healthcare resource use, and direct medical costs of the treatment of GWs in Finland in 2018 using data in national healthcare registers. GW cases were identified based on diagnoses in public healthcare and GW-related prescription medications. Cost analysis included public healthcare contacts, procedures in private care, and medications. The study showed that approximately 12,000 GWs cases were treated in Finland in 2018. Since less than half of GW diagnoses were recorded in public healthcare registers, determining the exact costs was challenging. The estimated direct treatment costs in 2018 were 2.6 M, which is higher than the previous estimation in Finland, yet still likely an underestimation of the true burden. These results provide information for the management of the GW burden in Finland.
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Background: Autosomal recessive Gaucher disease (GD) is likely underdiagnosed in many countries. Because the number of diagnosed GD patients in Finland is relatively low, and the true prevalence is currently not known, it was hypothesized that undiagnosed GD patients may exist in Finland. Our previous study demonstrated the applicability of Gaucher Earlier Diagnosis Consensus point-scoring system (GED-C PSS; Mehta et al., 2019) and Finnish biobank data and specimens in the automated point scoring of large populations. An indicative point-score range for Finnish GD patients was determined, but undiagnosed patients were not identified partly due to high number of high-score subjects in combination with a lack of suitable samples for diagnostics in the assessed biobank population. The current study extended the screening to another biobank and evaluated the feasibility of utilising the automated GED-C PSS in conjunction with small nucleotide polymorphism (SNP) chip genotype data from the FinnGen study of biobank sample donors in the identification of undiagnosed GD patients in Finland. Furthermore, the applicability of FFPE tissues and DNA restoration in the next-generation sequencing (NGS) of the GBA gene were tested. Methods: Previously diagnosed Finnish GD patients eligible to the study, and up to 45,100 sample donors in Helsinki Biobank (HBB) were point scored. The GED-C point scoring, adjusted to local data, was automated, but also partly manually verified for GD patients. The SNP chip genotype data for rare GBA variants was visually assessed. FFPE tissues of GD patients were obtained from HBB and Biobank Borealis of Northern Finland (BB). Results: Three previously diagnosed GD patients and one patient previously treated for GD-related features were included. A genetic diagnosis was confirmed for the patient treated for GD-related features. The GED-C point score of the GD patients was 12.5-22.5 in the current study. The score in eight Finnish GD patients of the previous and the current study is thus 6-22.5 points per patient. In the automated point scoring of the HBB subpopulation (N ≈ 45,100), the overall scores ranged from 0 to 17.5, with 0.77% (346/45,100) of the subjects having ≥10 points. The analysis of SNP chip genotype data was able to identify the diagnosed GD patients, but potential undiagnosed patients with the GED-C score and/or the GBA genotype indicative of GD were not discovered. Restoration of the FFPE tissue DNA improved the quality of the GBA NGS, and pathogenic GBA variants were confirmed in five out of six unrestored and in all four restored FFPE DNA samples. Discussion: These findings imply that the prevalence of diagnosed patients (~1:325,000) may indeed correspond the true prevalence of GD in Finland. The SNP chip genotype data is a valuable tool that complements the screening with the GED-C PSS, especially if the genotyping pipeline is tuned for rare variants. These proof-of-concept biobank tools can be adapted to other rare genetic diseases.
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Background: Real-world data on diffuse large B-cell lymphoma (DLBCL) has remained incomplete. In Finland, health record data originally recorded in different hospital data record systems are collectively available via data lake technology, enabling efficient extraction and analysis of large data sets. The usability of Finnish data lake data in the assessment of DLBCL was evaluated. Methods: Adult DLBCL patients diagnosed between 2010 and 2019, home municipality in the Hospital District of Southwest Finland and data available in respective data lake were included. Results: The algorithmic determination of treatment lines and respective survival was successful. Patient characterization was feasible, albeit partly incomplete because of limited data content/availability and coverage. Stage, International Prognostic Index and cell of origin were available for 63.0, 68.3 and 28.4% of patients, respectively. Genetic aberrations were not structurally available or feasible to extract without a manual chart review. Conclusion: Finnish data lakes represent an efficient way to analyze large DLBCL data sets. The current study provides a tool for developing recording practices in routine care.
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Antineoplásicos/uso terapéutico , Linfoma de Células B Grandes Difuso/epidemiología , Sistema de Registros , Anciano , Anciano de 80 o más Años , Algoritmos , Registros Electrónicos de Salud , Femenino , Finlandia/epidemiología , Hospitales , Humanos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/mortalidad , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
BACKGROUND: Gaucher disease (GD) is a rare inherited multiorgan disorder, yet a diagnosis can be significantly delayed due to a broad spectrum of symptoms and lack of disease awareness. Recently, the prototype of a GD point-scoring system (PSS) was established by the Gaucher Earlier Diagnosis Consensus (GED-C) initiative, and more recently, validated in Gaucher patients in UK. In our study, the original GED-C PSS was tested in Finnish GD patients. Furthermore, the feasibility of point scoring large electronic health record (EHR) data set by data mining to identify potential undiagnosed GD cases was evaluated. METHODS: This biobank study was conducted in collaboration with two Finnish biobanks. Five previously diagnosed Finnish GD patients and ~ 170,000 adult biobank subjects were included in the study. The original PSS was locally adjusted due to data availability issues and applied to the Finnish EHR data representing special health care recordings. RESULTS: All GD patients had high levels of the biomarker lyso-Gb1 and deleterious GBA mutations. One patient was a compound heterozygote with a novel variant, potentially pathogenic mutation. Finnish EHR data allowed the retrospective assessment of 27-30 of the 32 original GED-C signs/co-variables. Total point scores of GD patients were high but variable, 6-18.5 points per patient (based on the available data on 28-29 signs/co-variables per patient). All GD patients had been recorded with anaemia while only three patients had a record of splenomegaly. 0.72% of biobank subjects were assigned at least 6 points but none of these potential "GD suspects" had a point score as high as 18.5. Splenomegaly had been recorded for 0.25% of biobank subjects and was associated with variable point score distribution and co-occurring ICD-10 diagnoses. DISCUSSION: This study provides an indicative GED-C PSS score range for confirmed GD patients, also representing potential mild cases, and demonstrates the feasibility of scoring Finnish EHR data by data mining in order to screen for undiagnosed GD patients. Further prioritisation of the "GD suspects" with more developed algorithms and data-mining approaches is needed. FUNDING: This study was funded by Shire (now part of Takeda).
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Neuronal ceroid lipofuscinoses (NCLs) are autosomal recessive progressive encephalopathies caused by mutations in at least 14 different genes. Despite extensive studies performed in different NCL animal models, the molecular mechanisms underlying neurodegeneration in NCLs remain poorly understood. To model NCL in human cells, we generated induced pluripotent stem cells (iPSCs) by reprogramming skin fibroblasts from a patient with CLN5 (ceroid lipofuscinosis, neuronal, 5) disease, the late infantile variant form of NCL. These CLN5 patient-derived iPSCs (CLN5Y392X iPSCs) harbouring the most common CLN5 mutation, c.1175_1176delAT (p.Tyr392X), were further differentiated into neural lineage cells, the most affected cell type in NCLs. The CLN5Y392X iPSC-derived neural lineage cells showed accumulation of autofluorescent storage material and subunit C of the mitochondrial ATP synthase, both representing the hallmarks of many forms of NCLs, including CLN5 disease. In addition, we detected abnormalities in the intracellular organelles and aberrations in neuronal sphingolipid transportation, verifying the previous findings obtained from Cln5-deficient mouse macrophages. Therefore, patient-derived iPSCs provide a suitable model to study the mechanisms of NCL diseases.
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Células Madre Pluripotentes Inducidas/citología , Proteínas de la Membrana/genética , Lipofuscinosis Ceroideas Neuronales/genética , Fenotipo , Diferenciación Celular , Linaje de la Célula , Células Cultivadas , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Proteínas de Membrana de los Lisosomas , Mutación , Lipofuscinosis Ceroideas Neuronales/patologíaRESUMEN
Mitochondrial disorders are among the most prevalent inborn errors of metabolism but largely lack treatments and have poor outcomes. High-fat, low-carbohydrate ketogenic diets (KDs) have shown beneficial effects in mouse models of mitochondrial myopathies, with induction of mitochondrial biogenesis as the suggested main mechanism. We fed KD to mice with respiratory chain complex III (CIII) deficiency and progressive hepatopathy due to mutated BCS1L, a CIII assembly factor. The mutant mice became persistently ketotic and tolerated the KD for up to 11 weeks. Liver disease progression was attenuated by KD as shown by delayed fibrosis, reduced cell death, inhibition of hepatic progenitor cell response and stellate cell activation, and normalization of liver enzyme activities. Despite no clear signs of increased mitochondrial biogenesis in the liver, CIII assembly and activity were improved and mitochondrial morphology in hepatocytes normalized. Induction of hepatic glutathione transferase genes and elevated total glutathione level were normalized by KD. Histological findings and transcriptome changes indicated modulation of liver macrophage populations by the mutation and the diet. These results reveal a striking beneficial hepatic response to KD in mice with mitochondrial hepatopathy and warrant further investigations of dietary modification in the management of these conditions in patients.
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ATPasas Asociadas con Actividades Celulares Diversas/genética , Complejo III de Transporte de Electrones/deficiencia , Hepatopatías/dietoterapia , Miopatías Mitocondriales/complicaciones , Mutación , Animales , Células Cultivadas , Dieta Cetogénica , Modelos Animales de Enfermedad , Complejo III de Transporte de Electrones/genética , Células Estrelladas Hepáticas/citología , Humanos , Hepatopatías/etiología , Ratones , Miopatías Mitocondriales/genética , Resultado del TratamientoRESUMEN
Neuronal ceroid lipofuscinoses (NCL) are the most commonly inherited progressive encephalopathies of childhood. Pathologically, they are characterized by endolysosomal storage with different ultrastructural features and biochemical compositions. The molecular mechanisms causing progressive neurodegeneration and common molecular pathways linking expression of different NCL genes are largely unknown. We analyzed proteome alterations in the brains of a mouse model of human infantile CLN1 disease-palmitoyl-protein thioesterase 1 (Ppt1) gene knockout and its wild-type age-matched counterpart at different stages: pre-symptomatic, symptomatic and advanced. For this purpose, we utilized a combination of laser capture microdissection-based quantitative liquid chromatography tandem mass spectrometry (MS) and matrix-assisted laser desorption/ionization time-of-flight MS imaging to quantify/visualize the changes in protein expression in disease-affected brain thalamus and cerebral cortex tissue slices, respectively. Proteomic profiling of the pre-symptomatic stage thalamus revealed alterations mostly in metabolic processes and inhibition of various neuronal functions, i.e., neuritogenesis. Down-regulation in dynamics associated with growth of plasma projections and cellular protrusions was further corroborated by findings from RNA sequencing of CLN1 patients' fibroblasts. Changes detected at the symptomatic stage included: mitochondrial functions, synaptic vesicle transport, myelin proteome and signaling cascades, such as RhoA signaling. Considerable dysregulation of processes related to mitochondrial cell death, RhoA/Huntington's disease signaling and myelin sheath breakdown were observed at the advanced stage of the disease. The identified changes in protein levels were further substantiated by bioinformatics and network approaches, immunohistochemistry on brain tissues and literature knowledge, thus identifying various functional modules affected in the CLN1 childhood encephalopathy.
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Corteza Cerebral/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Lipofuscinosis Ceroideas Neuronales/metabolismo , Proteómica , Tálamo/metabolismo , Animales , Células Cultivadas , Corteza Cerebral/patología , Corteza Cerebral/fisiopatología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Fibroblastos/metabolismo , Perfilación de la Expresión Génica , Humanos , Captura por Microdisección con Láser , Masculino , Ratones , Mitocondrias , Modelos Neurológicos , Vaina de Mielina/patología , Proteínas del Tejido Nervioso/genética , Neuritas/patología , Lipofuscinosis Ceroideas Neuronales/genética , Lipofuscinosis Ceroideas Neuronales/patología , Lipofuscinosis Ceroideas Neuronales/fisiopatología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Tálamo/patología , Tálamo/fisiopatología , Tioléster Hidrolasas/deficiencia , Tioléster Hidrolasas/genéticaRESUMEN
Mutations in the CLN1 gene that encodes Palmitoyl protein thioesterase 1 (PPT1) or CLN1, cause Infantile NCL (INCL, MIM#256730). PPT1 removes long fatty acid chains such as palmitate from modified cysteine residues of proteins. The data shown here result from isolated protein complexes from PPT1-expressing SH-SY5Y stable cells that were subjected to single step affinity purification coupled to mass spectrometry (AP-MS). Prior to the MS analysis, we utilised a modified filter-aided sample preparation (FASP) protocol. Based on label free quantitative analysis of the data by SAINT, 23 PPT1 interacting partners (IP) were identified. A dense connectivity in PPT1 network was further revealed by functional coupling and extended network analyses, linking it to mitochondrial ATP synthesis coupled protein transport and thioester biosynthetic process. Moreover, the terms: inhibition of organismal death, movement disorders and concentration of lipid were predicted to be altered in the PPT1 network. Data presented here are related to Scifo et al. (J. Proteomics, 123 (2015) 42-53).
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Neuronal ceroid lipofuscinoses (NCL) are a group of inherited progressive childhood disorders, characterized by early accumulation of autofluorescent storage material in lysosomes of neurons or other cells. Clinical symptoms of NCL include: progressive loss of vision, mental and motor deterioration, epileptic seizures and premature death. CLN1 disease (MIM#256730) is caused by mutations in the CLN1 gene, which encodes palmitoyl protein thioesterase 1 (PPT1). In this study, we utilised single step affinity purification coupled to mass spectrometry (AP-MS) to unravel the in vivo substrates of human PPT1 in the brain neuronal cells. Protein complexes were isolated from human PPT1 expressing SH-SY5Y stable cells, subjected to filter-aided sample preparation (FASP) and analysed on a Q Exactive Hybrid Quadrupole-Orbitrap mass spectrometer. A total of 23 PPT1 interacting partners (IP) were identified from label free quantitation of the MS data by SAINT platform. Three of the identified PPT1 IP, namely CRMP1, DBH, and MAP1B are predicted to be palmitoylated. Our proteomic analysis confirmed previously suggested roles of PPT1 in axon guidance and lipid metabolism, yet implicates the enzyme in novel roles including: involvement in neuronal migration and dopamine receptor mediated signalling pathway. BIOLOGICAL SIGNIFICANCE: The significance of this work lies in the unravelling of putative in vivo substrates of human CLN1 or PPT1 in brain neuronal cells. Moreover, the PPT1 IP implicate the enzyme in novel roles including: involvement in neuronal migration and dopamine receptor mediated signalling pathway.
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Regulación Neoplásica de la Expresión Génica , Proteínas de la Membrana/metabolismo , Neuroblastoma/metabolismo , Proteómica/métodos , Axones/metabolismo , Encéfalo/metabolismo , Línea Celular Tumoral , Movimiento Celular , Metabolismo Energético , Glicosilación , Células HEK293 , Humanos , Lisosomas/metabolismo , Espectrometría de Masas , Proteínas de la Membrana/genética , Microscopía Fluorescente , Mitocondrias/fisiología , Mutación , Lipofuscinosis Ceroideas Neuronales/metabolismo , Neuronas/metabolismo , Sistemas de Lectura Abierta , Transducción de Señal , Tioléster HidrolasasRESUMEN
Neuronal ceroid lipofuscinoses (NCL) are the most common inherited progressive encephalopathies of childhood. One of the most prevalent forms of NCL, Juvenile neuronal ceroid lipofuscinosis (JNCL) or CLN3 disease (OMIM: 204200), is caused by mutations in the CLN3 gene on chromosome 16p12.1. Despite progress in the NCL field, the primary function of ceroid-lipofuscinosis neuronal protein 3 (CLN3) remains elusive. In this study, we aimed to clarify the role of human CLN3 in the brain by identifying CLN3-associated proteins using a Tandem Affinity Purification coupled to Mass Spectrometry (TAP-MS) strategy combined with Significance Analysis of Interactome (SAINT). Human SH-SY5Y-NTAP-CLN3 stable cells were used to isolate native protein complexes for subsequent TAP-MS. Bioinformatic analyses of isolated complexes yielded 58 CLN3 interacting partners (IP) including 42 novel CLN3 IP, as well as 16 CLN3 high confidence interacting partners (HCIP) previously identified in another high-throughput study by Behrends et al., 2010. Moreover, 31 IP of ceroid-lipofuscinosis neuronal protein 5 (CLN5) were identified (18 of which were in common with the CLN3 bait). Our findings support previously suggested involvement of CLN3 in transmembrane transport, lipid homeostasis and neuronal excitability, as well as link it to G-protein signaling and protein folding/sorting in the ER.
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Glicoproteínas de Membrana/metabolismo , Chaperonas Moleculares/metabolismo , Mapas de Interacción de Proteínas , Proteoma/metabolismo , Línea Celular Tumoral , Cromatografía de Afinidad , Células HEK293 , Humanos , Inmunoprecipitación , Anotación de Secuencia Molecular , Neuroblastoma , Lipofuscinosis Ceroideas Neuronales/metabolismo , Mapeo de Interacción de Proteínas/métodos , Transporte de Proteínas , Proteoma/aislamiento & purificación , Proteómica , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en TándemRESUMEN
Neuronal ceroid lipofuscinoses (NCL) comprise a group of inherited lysosomal disorders with variable age of onset, characterized by lysosomal accumulation of autofluorescent ceroid lipopigments, neuroinflammation, photoreceptor- and neurodegeneration. Most of the NCL-related genes encode soluble and transmembrane proteins which localize to the endoplasmic reticulum or to the endosomal/lysosomal compartment and directly or indirectly regulate lysosomal function. Recently, exome sequencing led to the identification of four novel gene defects in NCL patients and a new NCL nomenclature currently comprising CLN1 through CLN14. Although the precise function of most of the NCL proteins remains elusive, comprehensive analyses of model organisms, particularly mouse models, provided new insight into pathogenic mechanisms of NCL diseases and roles of mutant NCL proteins in cellular/subcellular protein and lipid homeostasis, as well as their adaptive/compensatorial regulation at the transcriptional level. This review summarizes the current knowledge on the expression, function and regulation of NCL proteins and their impact on lysosomal integrity. This article is part of a Special Issue entitled: The Neuronal Ceroid Lipofuscinoses or Batten Disease.
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Proteínas de la Membrana/metabolismo , Lipofuscinosis Ceroideas Neuronales/metabolismo , Lipofuscinosis Ceroideas Neuronales/patología , Tioléster Hidrolasas/metabolismo , Animales , Humanos , RatonesRESUMEN
CLN3 is an endosomal/lysosomal transmembrane protein mutated in classical juvenile onset neuronal ceroid lipofuscinosis, a fatal inherited neurodegenerative lysosomal storage disorder. The function of CLN3 in endosomal/lysosomal events has remained elusive due to poor understanding of its interactions in these compartments. It has previously been shown that the localisation of late endosomal/lysosomal compartments is disturbed in cells expressing the most common disease-associated CLN3 mutant, CLN3∆ex7-8 (c.462-677del). We report here that a protracted disease causing mutant, CLN3E295K, affects the properties of late endocytic compartments, since over-expression of the CLN3E295K mutant protein in HeLa cells induced relocalisation of Rab7 and a perinuclear clustering of late endosomes/lysosomes. In addition to the previously reported disturbances in the endocytic pathway, we now show that the anterograde transport of late endosomal/lysosomal compartments is affected in CLN3 deficiency. CLN3 interacted with motor components driving both plus and minus end microtubular trafficking: tubulin, dynactin, dynein and kinesin-2. Most importantly, CLN3 was found to interact directly with active, guanosine-5'-triphosphate (GTP)-bound Rab7 and with the Rab7-interacting lysosomal protein (RILP) that anchors the dynein motor. The data presented in this study provide novel insights into the role of CLN3 in late endosomal/lysosomal membrane transport.
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Endosomas/metabolismo , Glicoproteínas de Membrana/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas Motoras Moleculares/metabolismo , Lipofuscinosis Ceroideas Neuronales/metabolismo , Células HeLa , Humanos , Lisosomas/metabolismo , Glicoproteínas de Membrana/genética , Chaperonas Moleculares/genética , Mutación , Proteínas de Unión al GTP rab/metabolismo , Proteínas de Unión a GTP rab7RESUMEN
Juvenile neuronal ceroid lipofuscinosis (JNCL, Batten disease) is the most common progressive neurodegenerative disorder of childhood. CLN3, the transmembrane protein underlying JNCL, is proposed to participate in multiple cellular events including membrane trafficking and cytoskeletal functions. We demonstrate here that CLN3 interacts with the plasma membrane-associated cytoskeletal and endocytic fodrin and the associated Na(+), K(+) ATPase. The ion pumping activity of Na(+), K(+) ATPase was unchanged in Cln3(-/-) mouse primary neurons. However, the immunostaining pattern of fodrin appeared abnormal in JNCL fibroblasts and Cln3(-/-) mouse brains suggesting disturbances in the fodrin cytoskeleton. Furthermore, the basal subcellular distribution as well as ouabain-induced endocytosis of neuron-specific Na(+), K(+) ATPase were remarkably affected in Cln3(-/-) mouse primary neurons. These data suggest that CLN3 is involved in the regulation of plasma membrane fodrin cytoskeleton and consequently, the plasma membrane association of Na(+), K(+) ATPase. Most of the processes regulated by multifunctional fodrin and Na(+), K(+) ATPase are also affected in JNCL and Cln3-deficiency implicating that dysregulation of fodrin cytoskeleton and non-pumping functions of Na(+), K(+) ATPase may play a role in the neuronal degeneration in JNCL.
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Proteínas Portadoras/metabolismo , Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Microfilamentos/metabolismo , Chaperonas Moleculares/metabolismo , Lipofuscinosis Ceroideas Neuronales/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Células Cultivadas , Endocitosis/fisiología , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Iones/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Complejos Multiproteicos/metabolismo , Degeneración Nerviosa/genética , Degeneración Nerviosa/metabolismo , Lipofuscinosis Ceroideas Neuronales/genética , Neuronas/metabolismo , Neuronas/patologíaRESUMEN
Infantile neuronal ceroid lipofuscinosis (INCL) is a severe neurodegenerative disease caused by deficiency of palmitoyl protein thioesterase 1 (PPT1). INCL results in dramatic loss of thalamocortical neurons, but the disease mechanism has remained elusive. In the present work we describe the first interaction partner of PPT1, the F(1)-complex of the mitochondrial ATP synthase, by co-purification and in vitro-binding assays. In addition to mitochondria, subunits of F(1)-complex have been reported to localize in the plasma membrane, and to be capable of acting as receptors for various ligands such as apolipoprotein A-1. We verified here the plasma membrane localization of F(1)-subunits on mouse primary neurons and fibroblasts by cell surface biotinylation and TIRF-microscopy. To gain further insight into the Ppt1-mediated properties of the F(1)-complex, we utilized the Ppt1-deficient Ppt1(Delta ex4) mice. While no changes in the mitochondrial function could be detected in the brain of the Ppt1(Delta ex4) mice, the levels of F(1)-subunits alpha and beta on the plasma membrane were specifically increased in the Ppt1(Delta ex4) neurons. Significant changes were also detected in the apolipoprotein A-I uptake by the Ppt1(Delta ex4) neurons and the serum lipid composition in the Ppt1(Delta ex4) mice. These data indicate neuron-specific changes for F(1)-complex in the Ppt1-deficient cells and give clues for a possible link between lipid metabolism and neurodegeneration in INCL.