Repressed SIRT1/PGC-1alpha pathway and mitochondrial disintegration in iPSC-derived RPE disease model of age-related macular degeneration.
Repressed SIRT1/PGC-1alpha pathway and mitochondrial disintegration in iPSC-derived RPE disease model of age-related macular degeneration.
- 2016
Available online through MWHC library: 2003 - present
BACKGROUND: Study of age related macular degeneration (AMD) has been hampered by lack of human models that represent the complexity of the disease. Here we have developed a human in vitro disease model of AMD to investigate the underlying AMD disease mechanisms. CONCLUSIONS: Our studies suggest SIRT1/PGC-1alpha as underlying pathways contributing to AMD pathophysiology, and open new avenues for development of targeted drugs for treatment of this devastating neurodegenerative disease of the visual system. METHODS: Generation of iPSCs from retinal pigment epithelium (RPE) of AMD donors, age-matched normal donors, skin fibroblasts of a dry AMD patient, and differentiation of iPSCs into RPE (AMD RPE-iPSC-RPE, normal RPE-iPSC-RPE and AMD Skin-iPSC-RPE, respectively). Immunostaining, cell viability assay and reactive oxygen species (ROS) production under oxidative stress conditions, electron microscopy (EM) imaging, ATP production and glycogen concentration assays, quantitative real time PCR, western blot, karyotyping. RESULTS: The AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE present functional impairment and exhibit distinct disease phenotypes compared to RPE-iPSC-RPE generated from normal donors (Normal RPE-iPSC-RPE). The AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE show increased susceptibility to oxidative stress and produced higher levels of reactive oxygen species (ROS) under stress in accordance with recent reports. The susceptibility to oxidative stress-induced cell death in AMD RPE-iPSC-RPE and Skin-iPSC-RPE was consistent with inability of the AMD RPE-iPSC-RPE and Skin-iPSC-RPE to increase SOD2 expression under oxidative stress. Phenotypic analysis revealed disintegrated mitochondria, accumulation of autophagosomes and lipid droplets in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE. Mitochondrial activity was significantly lower in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE compared to normal cells and glycogen concentration was significantly increased in the diseased cells. Furthermore, Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1alpha), a regulator of mitochondrial biogenesis and function was repressed, and lower expression levels of NAD-dependent deacetylase sirtuin1 (SIRT1) were found in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE as compared to normal RPE-iPSC-RPE.
English
1479-5876
*Induced Pluripotent Stem Cells/pa [Pathology]
*Macular Degeneration/me [Metabolism]
*Macular Degeneration/pa [Pathology]
*Mitochondria/me [Metabolism]
*Models, Biological
*Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/me [Metabolism]
*Retinal Pigment Epithelium/pa [Pathology]
*Sirtuin 1/me [Metabolism]
Aged
Aged, 80 and over
Cell Differentiation
Female
Humans
Induced Pluripotent Stem Cells/me [Metabolism]
Induced Pluripotent Stem Cells/ul [Ultrastructure]
Male
Middle Aged
Oxidative Stress
Phagocytosis
Phenotype
Reactive Oxygen Species/me [Metabolism]
Retinal Pigment Epithelium/ul [Ultrastructure]
Signal Transduction
Skin/pa [Pathology]
Superoxide Dismutase/me [Metabolism]
MedStar Washington Hospital Center
Ophthalmology
Journal Article
Available online through MWHC library: 2003 - present
BACKGROUND: Study of age related macular degeneration (AMD) has been hampered by lack of human models that represent the complexity of the disease. Here we have developed a human in vitro disease model of AMD to investigate the underlying AMD disease mechanisms. CONCLUSIONS: Our studies suggest SIRT1/PGC-1alpha as underlying pathways contributing to AMD pathophysiology, and open new avenues for development of targeted drugs for treatment of this devastating neurodegenerative disease of the visual system. METHODS: Generation of iPSCs from retinal pigment epithelium (RPE) of AMD donors, age-matched normal donors, skin fibroblasts of a dry AMD patient, and differentiation of iPSCs into RPE (AMD RPE-iPSC-RPE, normal RPE-iPSC-RPE and AMD Skin-iPSC-RPE, respectively). Immunostaining, cell viability assay and reactive oxygen species (ROS) production under oxidative stress conditions, electron microscopy (EM) imaging, ATP production and glycogen concentration assays, quantitative real time PCR, western blot, karyotyping. RESULTS: The AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE present functional impairment and exhibit distinct disease phenotypes compared to RPE-iPSC-RPE generated from normal donors (Normal RPE-iPSC-RPE). The AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE show increased susceptibility to oxidative stress and produced higher levels of reactive oxygen species (ROS) under stress in accordance with recent reports. The susceptibility to oxidative stress-induced cell death in AMD RPE-iPSC-RPE and Skin-iPSC-RPE was consistent with inability of the AMD RPE-iPSC-RPE and Skin-iPSC-RPE to increase SOD2 expression under oxidative stress. Phenotypic analysis revealed disintegrated mitochondria, accumulation of autophagosomes and lipid droplets in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE. Mitochondrial activity was significantly lower in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE compared to normal cells and glycogen concentration was significantly increased in the diseased cells. Furthermore, Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1alpha), a regulator of mitochondrial biogenesis and function was repressed, and lower expression levels of NAD-dependent deacetylase sirtuin1 (SIRT1) were found in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE as compared to normal RPE-iPSC-RPE.
English
1479-5876
*Induced Pluripotent Stem Cells/pa [Pathology]
*Macular Degeneration/me [Metabolism]
*Macular Degeneration/pa [Pathology]
*Mitochondria/me [Metabolism]
*Models, Biological
*Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/me [Metabolism]
*Retinal Pigment Epithelium/pa [Pathology]
*Sirtuin 1/me [Metabolism]
Aged
Aged, 80 and over
Cell Differentiation
Female
Humans
Induced Pluripotent Stem Cells/me [Metabolism]
Induced Pluripotent Stem Cells/ul [Ultrastructure]
Male
Middle Aged
Oxidative Stress
Phagocytosis
Phenotype
Reactive Oxygen Species/me [Metabolism]
Retinal Pigment Epithelium/ul [Ultrastructure]
Signal Transduction
Skin/pa [Pathology]
Superoxide Dismutase/me [Metabolism]
MedStar Washington Hospital Center
Ophthalmology
Journal Article