Generation of a human iPSC line from a patient with a mitochondrial encephalopathy due to mutations in the GFM1 gene

Human iPSC line GFM1SV.25 was generated from fibroblasts of a child with a severe mitochondrial encephalopathy associated with mutations in the GFM1 gene, encoding the mitochondrial translation elongation factor G1. Reprogramming factors OCT3/4, SOX2, CMYC and KLF4 were delivered using a non integrative methodology that involves the use of Sendai virus.This work was supported by grants from the “Centro de Investigación Biomédica en Red en enfermedades raras” (CIBERER) (Grant 13-717/132.05 to RG), the “Instituto de Salud Carlos III” [Fondo de Investigación Sanitaria and Regional development fund (ERDF/FEDER) funds PI10/0703 and PI13/00556 to RG and PI15/00484 to MEG], “Comunidad Autónoma de Madrid” (Grant number S2010/BMD-2402 to RG); TG receives grant support from the Universidad Autónoma de Madrid (FPI-UAM) and FZD from the Ministerio de Educación, Cultura y Deporte (Grant FPU13/00544). MEG is staff scientist at the “Centro de Investigación Biomédica en Red en Enfermedades Raras” (CIBERER

Generation of a human iPSC line from a patient with an optic atrophy ‘plus’ phenotype due to a mutation in the OPA1 gene

AbstractHuman iPSC line Oex2054SV.4 was generated from fibroblasts of a patient with an optic atrophy ‘plus’ phenotype associated with a heterozygous mutation in the OPA1 gene. Reprogramming factors OCT3/4, SOX2, CMYC and KLF4 were delivered using a non-integrative methodology that involves the use of Sendai virus

Generation of a human iPSC line from a patient with Leigh syndrome caused by a mutation in the MT-ATP6 gene

Human iPSC line L749.1 was generated from fibroblasts of a patient with Leigh syndrome associated with a heteroplasmic mutation in the MT-ATP6 gene. Reprogramming factors OCT4, SOX2, CMYC and KLF4 were delivered using retroviruses.This work was supported by grants from the “Centro de Investigación Biomédica en Red en enfermedades raras” (CIBERER) (Grant 13-717/132.05 to RG), the “Instituto de Salud Carlos III” (FIS PI10/0703 and PI13/00556 to RG and PI15/00484 to MEG cofunded by FEDER), “Comunidad Autónoma de Madrid” (grant number S2010/BMD-2402 to R.G); T.G-M. receives grant support from the Universidad Autónoma de Madrid, FPI-UAM and F.Z-D. from the Ministerio de Educación, Cultura y Deporte, grant number FPU13/00544. M.E.G. is senior staff scientist at the “Centro de Investigación Biomédica en Red en Enfermedades Raras” (CIBERER

Síndrome de Leigh : estudio fisiopatológico en neuronas y cardiomiocitos derivados de iPSc

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 21-04-2017Esta tesis tiene embargado el acceso al texto completo hasta el 21-10-201

The mutation m.13513G>A impairs cardiac function, favoring a neuroectoderm commitment, in a mutant-load dependent way

Mitochondrial disorders (MDs) arise as a result of a respiratory chain dysfunction. While some MDs can affect a single organ, many involve several organs, the brain being the most affected, followed by heart and/or muscle. Many of these diseases are associated with heteroplasmic mutations in the mitochondrial DNA (mtDNA). The proportion of mutated mtDNA must exceed a critical threshold to produce disease. Therefore, understanding how embryonic development determines the heteroplasmy level in each tissue could explain the organ susceptibility and the clinical heterogeneity observed in these patients. In this report, the dynamics of heteroplasmy and the influence in cardiac commitment of the mutational load of the m.13513G>A mutation has been analyzed. This mutation has been reported as a frequent cause of Leigh syndrome (LS) and is commonly associated with cardiac problems. In this report, induced pluripotent stem cell (iPSc) technology has been used to delve into the molecular mechanisms underlying cardiac disease in LS. When mutation m.13513G>A is above a threshold, iPSc‐derived cardiomyocytes (iPSc‐CMs) could not be obtained due to an inefficient epithelial‐mesenchymal transition. Surprisingly, these cells are redirected toward neuroectodermal lineages that would give rise to the brain. However, when mutation is below that threshold, dysfunctional CM are generated in a mutant‐load dependent way. We suggest that distribution of the m.13513G>A mutation during cardiac differentiation is not at random. We propose a possible explanation of why neuropathology is a frequent feature of MD, but cardiac involvement is not always present.The authors are very grateful to Dr. Munell for kindly providing them the patient's fibroblasts. Contract grant sponsor: Instituto de Salud Carlos III (Fondo de Investigación Sanitaria and Regional Development Fund [ERDF/FEDER]); contract grant numbers: PI10/00703, PI13/00556, and PI16/00489 to R. G. and PI15/00484 and PI18/00151 to M. E. G. Contract grant sponsor: Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER); contract grant numbers: (13–717/132.05 and ER16P3AC717 to R. G.). Contract grant sponsor: Miguel Servet Program from ISCIII; contract grant number: CP16/00046 to M. E. G

Mitochondrial dysfunction and calcium dysregulation in Leigh syndrome induced pluripotent stem cell derived neurons

This article belongs to the Special Issue Cells and Materials for Disease Modeling and Regenerative Medicine.Leigh syndrome (LS) is the most frequent infantile mitochondrial disorder (MD) and is characterized by neurodegeneration and astrogliosis in the basal ganglia or the brain stem. At present, there is no cure or treatment for this disease, partly due to scarcity of LS models. Current models generally fail to recapitulate important traits of the disease. Therefore, there is an urgent need to develop new human in vitro models. Establishment of induced pluripotent stem cells (iPSCs) followed by differentiation into neurons is a powerful tool to obtain an in vitro model for LS. Here, we describe the generation and characterization of iPSCs, neural stem cells (NSCs) and iPSC-derived neurons harboring the mtDNA mutation m.13513G>A in heteroplasmy. We have performed mitochondrial characterization, analysis of electrophysiological properties and calcium imaging of LS neurons. Here, we show a clearly compromised oxidative phosphorylation (OXPHOS) function in LS patient neurons. This is also the first report of electrophysiological studies performed on iPSC-derived neurons harboring an mtDNA mutation, which revealed that, in spite of having identical electrical properties, diseased neurons manifested mitochondrial dysfunction together with a diminished calcium buffering capacity. This could lead to an overload of cytoplasmic calcium concentration and the consequent cell death observed in patients. Importantly, our results highlight the importance of calcium homeostasis in LS pathology.This research was funded by ‘Fondo de Investigación Sanitaria, Instituto de Salud Carlos III co-funded by European Regional Development Funds’, grant number PI15/00484 and PI18/00151 to M.E.G; PI13/00556 and PI16/00789 to R.G. F.Z.-D. received grant support from the Ministerio de Educación, Cultura y Deporte (FPU13/00544). M.E.G. is supported by a ‘Miguel Servet’ contract (CP16/00046) from Instituto de Salud Carlos III and European Regional Development Funds. HA received support from the Swedish Research Council.Peer reviewe