title: Study of mitochondrial respiratory defects on reprogramming to human induced pluripotent stem cells.
abstract: Reprogramming of somatic cells into a pluripotent state is known to be accompanied by extensive restructuring of mitochondria and switch in metabolic requirements. Here we utilized Leber's hereditary optic neuropathy (LHON) as a mitochondrial disease model to study the effects of homoplasmic mtDNA mutations and subsequent oxidative phosphorylation (OXPHOS) defects in reprogramming. We obtained fibroblasts from a total of 6 LHON patients and control subjects, and showed a significant defect in complex I respiration in LHON fibroblasts by high-resolution respiratory analysis. Using episomal vector reprogramming, our results indicated that human induced pluripotent stem cell (hiPSC) generation is feasible in LHON fibroblasts. In particular, LHON-specific OXPHOS defects in fibroblasts only caused a mild reduction and did not significantly affect reprogramming efficiency, suggesting that hiPSC reprogramming can tolerate a certain degree of OXPHOS defects. Our results highlighted the induction of genes involved in mitochondrial biogenesis (TFAM, NRF1), mitochondrial fusion (MFN1, MFN2) and glycine production (GCAT) during reprogramming. However, LHON-associated OXPHOS defects did not alter the kinetics or expression levels of these genes during reprogramming. Together, our study provides new insights into the effects of mtDNA mutation and OXPHOS defects in reprogramming and genes associated with various aspects of mitochondrial biology.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Sandy S C
authors.initials: SS
authors.lastname: Hung
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Van Bergen
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Stacey
authors.initials: S
authors.lastname: Jackson
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Helena
authors.initials: H
authors.lastname: Liang
authors.affiliation: Lions Eye Institute and University of Western Australia, Nedlands, Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
authors.affiliation: O'Brien Institute Department, St Vincent's Institute of Medical Research, Fitzroy, Australia.
authors.forename: Damián
authors.initials: D
authors.lastname: Hernández
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.|O'Brien Institute Department, St Vincent's Institute of Medical Research, Fitzroy, Australia.
authors.forename: Shiang Y
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.|School of Medicine, Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia.
authors.forename: Alex W
authors.initials: AW
authors.lastname: Hewitt
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Trounce
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Alice
authors.initials: A
authors.lastname: Pébay
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital and Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Raymond C B
authors.initials: RC
authors.lastname: Wong
mesh_terms: D065150:Cellular Reprogramming; D004272:DNA, Mitochondrial; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D029242:Optic Atrophy, Hereditary, Leber / Q000378:metabolism*; D001678:Organelle Biogenesis; D010085:Oxidative Phosphorylation
chemical_list: D004272:DNA, Mitochondrial
keywords: Leber's hereditary optic neuropathy; cellular reprogramming; induced pluripotent stem cells; mitochondria; oxidative phosphorylation