--- _id: '12174' abstract: - lang: eng text: "Vacuolar-type H+-ATPase (V-ATPase) is a multimeric complex present in a variety of cellular membranes that acts as an ATP-dependent proton pump and plays a key role in pH homeostasis and intracellular signalling pathways. In humans, 22 autosomal genes encode for a redundant set of subunits allowing the composition of diverse V-ATPase complexes with specific properties and expression. Sixteen subunits have been linked to human disease.\r\nHere we describe 26 patients harbouring 20 distinct pathogenic de novo missense ATP6V1A variants, mainly clustering within the ATP synthase α/β family-nucleotide-binding domain. At a mean age of 7 years (extremes: 6 weeks, youngest deceased patient to 22 years, oldest patient) clinical pictures included early lethal encephalopathies with rapidly progressive massive brain atrophy, severe developmental epileptic encephalopathies and static intellectual disability with epilepsy. The first clinical manifestation was early hypotonia, in 70%; 81% developed epilepsy, manifested as developmental epileptic encephalopathies in 58% of the cohort and with infantile spasms in 62%; 63% of developmental epileptic encephalopathies failed to achieve any developmental, communicative or motor skills. Less severe outcomes were observed in 23% of patients who, at a mean age of 10 years and 6 months, exhibited moderate intellectual disability, with independent walking and variable epilepsy. None of the patients developed communicative language. Microcephaly (38%) and amelogenesis imperfecta/enamel dysplasia (42%) were additional clinical features. Brain MRI demonstrated hypomyelination and generalized atrophy in 68%. Atrophy was progressive in all eight individuals undergoing repeated MRIs.\r\n \ Fibroblasts of two patients with developmental epileptic encephalopathies showed decreased LAMP1 expression, Lysotracker staining and increased organelle pH, consistent with lysosomal impairment and loss of V-ATPase function. Fibroblasts of two patients with milder disease, exhibited a different phenotype with increased Lysotracker staining, decreased organelle pH and no significant modification in LAMP1 expression. Quantification of substrates for lysosomal enzymes in cellular extracts from four patients revealed discrete accumulation. Transmission electron microscopy of fibroblasts of four patients with variable severity and of induced pluripotent stem cell-derived neurons from two patients with developmental epileptic encephalopathies showed electron-dense inclusions, lipid droplets, osmiophilic material and lamellated membrane structures resembling phospholipids. Quantitative assessment in induced pluripotent stem cell-derived neurons identified significantly smaller lysosomes.\r\nATP6V1A-related encephalopathy represents a new paradigm among lysosomal disorders. It results from a dysfunctional endo-lysosomal membrane protein causing altered pH homeostasis. Its pathophysiology implies intracellular accumulation of substrates whose composition remains unclear, and a combination of developmental brain abnormalities and neurodegenerative changes established during prenatal and early postanal development, whose severity is variably determined by specific pathogenic variants." acknowledged_ssus: - _id: EM-Fac - _id: LifeSc acknowledgement: "We thank all patients and family members for their participation in this study. We thank Melanie Pieraks and Eva Reinthaler (Neurolentech, Austria) for generating the human iPSC lines and\r\nfor performing quality checks. We thank Vanessa Zheden and Daniel Gütl for their excellent technical support in the specimen preparation for transmission electron microscopy and Flavia Leite for preparing the lentiviruses. The support from Electron Microscopy Facility and Molecular Biology Services at IST Austria is greatly acknowledged. We would like to thank Doctors Jane Hurst and Richard Scott for their help in retrieving the detailed clinical information of Patient 17. The research team acknowledges the support of the National Institute for Health Research, through the Comprehensive Clinical Research Network. See Supplementary Material for Undiagnosed Disease Network consortium details. Genetic information on Patient 23 was made available through access to the data and findings generated by the 100 000 Genomes\r\nProject; www.genomicsengland.co.uk (to K.L.). \r\nThis work was supported by the EU 7th Framework Programme (FP7) under the project DESIRE grant N602531 (to R.G.); the Regione Toscana under the Call for Health 2018 (grant\r\nDECODE-EE) (to R.G.); the ‘Brain Project’ by Fondazione Cassa di Risparmio di Firenze (to R.G.); IRCCS Ospedale Policlinico San Martino 5×1000 and Ricerca Corrente (to A.F. and F.B.). The European Reference Network (ERN) for rare and complex epilepsies (EpiCARE) provided financial support for meetings organization. The DDD study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between Wellcome and the Department of Health, and the Wellcome Sanger Institute (grant number WT098051). The views expressed in this publication\r\nare those of the author(s) and not necessarily those of Wellcome or the Department of Health. The study has UK Research Ethics Committee approval (10/H0305/83, granted by the Cambridge South REC, and GEN/284/12 granted by the Republic of Ireland REC). This study makes use of DECIPHER (https://www.deciphergenomics.org), which is funded by Wellcome. K.K.-S. was supported by the ISTplus fellowship. " article_processing_charge: No article_type: original author: - first_name: Renzo full_name: Guerrini, Renzo last_name: Guerrini - first_name: Davide full_name: Mei, Davide last_name: Mei - first_name: Margit Katalin full_name: Szigeti, Margit Katalin id: 44F4BDC0-F248-11E8-B48F-1D18A9856A87 last_name: Szigeti orcid: 0000-0001-9500-8758 - first_name: Sara full_name: Pepe, Sara last_name: Pepe - first_name: Mary Kay full_name: Koenig, Mary Kay last_name: Koenig - first_name: Gretchen full_name: Von Allmen, Gretchen last_name: Von Allmen - first_name: Megan T full_name: Cho, Megan T last_name: Cho - first_name: Kimberly full_name: McDonald, Kimberly last_name: McDonald - first_name: Janice full_name: Baker, Janice last_name: Baker - first_name: Vikas full_name: Bhambhani, Vikas last_name: Bhambhani - first_name: Zöe full_name: Powis, Zöe last_name: Powis - first_name: Lance full_name: Rodan, Lance last_name: Rodan - first_name: Rima full_name: Nabbout, Rima last_name: Nabbout - first_name: Giulia full_name: Barcia, Giulia last_name: Barcia - first_name: Jill A full_name: Rosenfeld, Jill A last_name: Rosenfeld - first_name: Carlos A full_name: Bacino, Carlos A last_name: Bacino - first_name: Cyril full_name: Mignot, Cyril last_name: Mignot - first_name: Lillian H full_name: Power, Lillian H last_name: Power - first_name: Catharine J full_name: Harris, Catharine J last_name: Harris - first_name: Dragan full_name: Marjanovic, Dragan last_name: Marjanovic - first_name: Rikke S full_name: Møller, Rikke S last_name: Møller - first_name: Trine B full_name: Hammer, Trine B last_name: Hammer - first_name: Riikka full_name: Keski Filppula, Riikka last_name: Keski Filppula - first_name: Päivi full_name: Vieira, Päivi last_name: Vieira - first_name: Clara full_name: Hildebrandt, Clara last_name: Hildebrandt - first_name: Stephanie full_name: Sacharow, Stephanie last_name: Sacharow - first_name: Luca full_name: Maragliano, Luca last_name: Maragliano - first_name: Fabio full_name: Benfenati, Fabio last_name: Benfenati - first_name: Katherine full_name: Lachlan, Katherine last_name: Lachlan - first_name: Andreas full_name: Benneche, Andreas last_name: Benneche - first_name: Florence full_name: Petit, Florence last_name: Petit - first_name: Jean Madeleine full_name: de Sainte Agathe, Jean Madeleine last_name: de Sainte Agathe - first_name: Barbara full_name: Hallinan, Barbara last_name: Hallinan - first_name: Yue full_name: Si, Yue last_name: Si - first_name: Ingrid M full_name: Wentzensen, Ingrid M last_name: Wentzensen - first_name: Fanggeng full_name: Zou, Fanggeng last_name: Zou - first_name: Vinodh full_name: Narayanan, Vinodh last_name: Narayanan - first_name: Naomichi full_name: Matsumoto, Naomichi last_name: Matsumoto - first_name: Alessandra full_name: Boncristiano, Alessandra last_name: Boncristiano - first_name: Giancarlo full_name: la Marca, Giancarlo last_name: la Marca - first_name: Mitsuhiro full_name: Kato, Mitsuhiro last_name: Kato - first_name: Kristin full_name: Anderson, Kristin last_name: Anderson - first_name: Carmen full_name: Barba, Carmen last_name: Barba - first_name: Luisa full_name: Sturiale, Luisa last_name: Sturiale - first_name: Domenico full_name: Garozzo, Domenico last_name: Garozzo - first_name: Roberto full_name: Bei, Roberto last_name: Bei - first_name: Laura full_name: Masuelli, Laura last_name: Masuelli - first_name: Valerio full_name: Conti, Valerio last_name: Conti - first_name: Gaia full_name: Novarino, Gaia id: 3E57A680-F248-11E8-B48F-1D18A9856A87 last_name: Novarino orcid: 0000-0002-7673-7178 - first_name: Anna full_name: Fassio, Anna last_name: Fassio citation: ama: 'Guerrini R, Mei D, Szigeti MK, et al. Phenotypic and genetic spectrum of ATP6V1A encephalopathy: A disorder of lysosomal homeostasis. Brain. 2022;145(8):2687-2703. doi:10.1093/brain/awac145' apa: 'Guerrini, R., Mei, D., Szigeti, M. K., Pepe, S., Koenig, M. K., Von Allmen, G., … Fassio, A. (2022). Phenotypic and genetic spectrum of ATP6V1A encephalopathy: A disorder of lysosomal homeostasis. Brain. Oxford University Press. https://doi.org/10.1093/brain/awac145' chicago: 'Guerrini, Renzo, Davide Mei, Margit Katalin Szigeti, Sara Pepe, Mary Kay Koenig, Gretchen Von Allmen, Megan T Cho, et al. “Phenotypic and Genetic Spectrum of ATP6V1A Encephalopathy: A Disorder of Lysosomal Homeostasis.” Brain. Oxford University Press, 2022. https://doi.org/10.1093/brain/awac145.' ieee: 'R. Guerrini et al., “Phenotypic and genetic spectrum of ATP6V1A encephalopathy: A disorder of lysosomal homeostasis,” Brain, vol. 145, no. 8. Oxford University Press, pp. 2687–2703, 2022.' ista: 'Guerrini R, Mei D, Szigeti MK, Pepe S, Koenig MK, Von Allmen G, Cho MT, McDonald K, Baker J, Bhambhani V, Powis Z, Rodan L, Nabbout R, Barcia G, Rosenfeld JA, Bacino CA, Mignot C, Power LH, Harris CJ, Marjanovic D, Møller RS, Hammer TB, Keski Filppula R, Vieira P, Hildebrandt C, Sacharow S, Maragliano L, Benfenati F, Lachlan K, Benneche A, Petit F, de Sainte Agathe JM, Hallinan B, Si Y, Wentzensen IM, Zou F, Narayanan V, Matsumoto N, Boncristiano A, la Marca G, Kato M, Anderson K, Barba C, Sturiale L, Garozzo D, Bei R, Masuelli L, Conti V, Novarino G, Fassio A. 2022. Phenotypic and genetic spectrum of ATP6V1A encephalopathy: A disorder of lysosomal homeostasis. Brain. 145(8), 2687–2703.' mla: 'Guerrini, Renzo, et al. “Phenotypic and Genetic Spectrum of ATP6V1A Encephalopathy: A Disorder of Lysosomal Homeostasis.” Brain, vol. 145, no. 8, Oxford University Press, 2022, pp. 2687–703, doi:10.1093/brain/awac145.' short: R. Guerrini, D. Mei, M.K. Szigeti, S. Pepe, M.K. Koenig, G. Von Allmen, M.T. Cho, K. McDonald, J. Baker, V. Bhambhani, Z. Powis, L. Rodan, R. Nabbout, G. Barcia, J.A. Rosenfeld, C.A. Bacino, C. Mignot, L.H. Power, C.J. Harris, D. Marjanovic, R.S. Møller, T.B. Hammer, R. Keski Filppula, P. Vieira, C. Hildebrandt, S. Sacharow, L. Maragliano, F. Benfenati, K. Lachlan, A. Benneche, F. Petit, J.M. de Sainte Agathe, B. Hallinan, Y. Si, I.M. Wentzensen, F. Zou, V. Narayanan, N. Matsumoto, A. Boncristiano, G. la Marca, M. Kato, K. Anderson, C. Barba, L. Sturiale, D. Garozzo, R. Bei, L. Masuelli, V. Conti, G. Novarino, A. Fassio, Brain 145 (2022) 2687–2703. date_created: 2023-01-12T12:11:45Z date_published: 2022-08-01T00:00:00Z date_updated: 2023-08-04T09:13:08Z day: '01' department: - _id: GaNo doi: 10.1093/brain/awac145 ec_funded: 1 external_id: isi: - '000807770000001' intvolume: ' 145' isi: 1 issue: '8' keyword: - Neurology (clinical) language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1093/brain/awac145 month: '08' oa: 1 oa_version: Published Version page: 2687-2703 project: - _id: 260C2330-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '754411' name: ISTplus - Postdoctoral Fellowships publication: Brain publication_identifier: eissn: - 1460-2156 issn: - 0006-8950 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'Phenotypic and genetic spectrum of ATP6V1A encephalopathy: A disorder of lysosomal homeostasis' type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 145 year: '2022' ... --- _id: '6470' abstract: - lang: eng text: 'Investigating neuronal activity using genetically encoded Ca2+ indicators in behaving animals is hampered by inaccuracies in spike inference from fluorescent tracers. Here we combine two‐photon [Ca2+] imaging with cell‐attached recordings, followed by post hoc determination of the expression level of GCaMP6f, to explore how it affects the amplitude, kinetics and temporal summation of somatic [Ca2+] transients in mouse hippocampal pyramidal cells (PCs). The amplitude of unitary [Ca2+] transients (evoked by a single action potential) negatively correlates with GCaMP6f expression, but displays large variability even among PCs with similarly low expression levels. The summation of fluorescence signals is frequency‐dependent, supralinear and also shows remarkable cell‐to‐cell variability. We performed experimental data‐based simulations and found that spike inference error rates using MLspike depend strongly on unitary peak amplitudes and GCaMP6f expression levels. We provide simple methods for estimating the unitary [Ca2+] transients in individual weakly GCaMP6f‐expressing PCs, with which we achieve spike inference error rates of ∼5%. ' article_processing_charge: No article_type: original author: - first_name: Tímea full_name: Éltes, Tímea last_name: Éltes - first_name: Miklos full_name: Szoboszlay, Miklos last_name: Szoboszlay - first_name: Margit Katalin full_name: Szigeti, Margit Katalin id: 44F4BDC0-F248-11E8-B48F-1D18A9856A87 last_name: Szigeti orcid: 0000-0001-9500-8758 - first_name: Zoltan full_name: Nusser, Zoltan last_name: Nusser citation: ama: Éltes T, Szoboszlay M, Szigeti MK, Nusser Z. Improved spike inference accuracy by estimating the peak amplitude of unitary [Ca2+] transients in weakly GCaMP6f-expressing hippocampal pyramidal cells. Journal of Physiology. 2019;597(11):2925–2947. doi:10.1113/JP277681 apa: Éltes, T., Szoboszlay, M., Szigeti, M. K., & Nusser, Z. (2019). Improved spike inference accuracy by estimating the peak amplitude of unitary [Ca2+] transients in weakly GCaMP6f-expressing hippocampal pyramidal cells. Journal of Physiology. Wiley. https://doi.org/10.1113/JP277681 chicago: Éltes, Tímea, Miklos Szoboszlay, Margit Katalin Szigeti, and Zoltan Nusser. “Improved Spike Inference Accuracy by Estimating the Peak Amplitude of Unitary [Ca2+] Transients in Weakly GCaMP6f-Expressing Hippocampal Pyramidal Cells.” Journal of Physiology. Wiley, 2019. https://doi.org/10.1113/JP277681. ieee: T. Éltes, M. Szoboszlay, M. K. Szigeti, and Z. Nusser, “Improved spike inference accuracy by estimating the peak amplitude of unitary [Ca2+] transients in weakly GCaMP6f-expressing hippocampal pyramidal cells,” Journal of Physiology, vol. 597, no. 11. Wiley, pp. 2925–2947, 2019. ista: Éltes T, Szoboszlay M, Szigeti MK, Nusser Z. 2019. Improved spike inference accuracy by estimating the peak amplitude of unitary [Ca2+] transients in weakly GCaMP6f-expressing hippocampal pyramidal cells. Journal of Physiology. 597(11), 2925–2947. mla: Éltes, Tímea, et al. “Improved Spike Inference Accuracy by Estimating the Peak Amplitude of Unitary [Ca2+] Transients in Weakly GCaMP6f-Expressing Hippocampal Pyramidal Cells.” Journal of Physiology, vol. 597, no. 11, Wiley, 2019, pp. 2925–2947, doi:10.1113/JP277681. short: T. Éltes, M. Szoboszlay, M.K. Szigeti, Z. Nusser, Journal of Physiology 597 (2019) 2925–2947. date_created: 2019-05-19T21:59:17Z date_published: 2019-06-01T00:00:00Z date_updated: 2023-08-25T10:34:15Z day: '01' department: - _id: GaNo doi: 10.1113/JP277681 external_id: isi: - '000470780400013' pmid: - '31006863' intvolume: ' 597' isi: 1 issue: '11' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1113/JP277681 month: '06' oa: 1 oa_version: Published Version page: 2925–2947 pmid: 1 publication: Journal of Physiology publication_identifier: eissn: - '14697793' issn: - '00223751' publication_status: published publisher: Wiley quality_controlled: '1' scopus_import: '1' status: public title: Improved spike inference accuracy by estimating the peak amplitude of unitary [Ca2+] transients in weakly GCaMP6f-expressing hippocampal pyramidal cells type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 597 year: '2019' ...