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Moos WH, Faller DV, Glavas IP, Harpp DN, Kanara I, Mavrakis AN, Pernokas J, Pernokas M, Pinkert CA, Powers WR, Sampani K, Steliou K, Vavvas DG, Zamboni RJ, Kodukula K, Chen X. Klotho Pathways, Myelination Disorders, Neurodegenerative Diseases, and Epigenetic Drugs. Biores Open Access 2020; 9:94-105. [PMID: 32257625 PMCID: PMC7133426 DOI: 10.1089/biores.2020.0004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.
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Affiliation(s)
- Walter H. Moos
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, San Francisco, California
- ShangPharma Innovation, Inc., South San Francisco, California
| | - Douglas V. Faller
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts
| | - Ioannis P. Glavas
- Department of Ophthalmology, New York University School of Medicine, New York, New York
| | - David N. Harpp
- Department of Chemistry, McGill University, Montreal, Canada
| | | | - Anastasios N. Mavrakis
- Department of Medicine, Tufts University School of Medicine, St. Elizabeth's Medical Center, Boston, Massachusetts
| | - Julie Pernokas
- Advanced Dental Associates of New England, Woburn, Massachusetts
| | - Mark Pernokas
- Advanced Dental Associates of New England, Woburn, Massachusetts
| | - Carl A. Pinkert
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama
| | - Whitney R. Powers
- Department of Health Sciences, Boston University, Boston, Massachusetts
- Department of Anatomy, Boston University School of Medicine, Boston, Massachusetts
| | - Konstantina Sampani
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
| | - Kosta Steliou
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts
- PhenoMatriX, Inc., Natick, Massachusetts
| | - Demetrios G. Vavvas
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | | | | | - Xiaohong Chen
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
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Pioglitazone and Deoxyribonucleoside Combination Treatment Increases Mitochondrial Respiratory Capacity in m.3243A>G MELAS Cybrid Cells. Int J Mol Sci 2020; 21:ijms21062139. [PMID: 32244971 PMCID: PMC7139379 DOI: 10.3390/ijms21062139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/17/2020] [Accepted: 03/17/2020] [Indexed: 01/05/2023] Open
Abstract
The lack of effective treatments for mitochondrial disease has seen the development of new approaches, including those that aim to stimulate mitochondrial biogenesis to boost ATP generation above a critical disease threshold. Here, we examine the effects of the peroxisome proliferator-activated receptor γ (PPARγ) activator pioglitazone (PioG), in combination with deoxyribonucleosides (dNs), on mitochondrial biogenesis in cybrid cells containing >90% of the m.3243A>G mutation associated with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). PioG + dNs combination treatment increased mtDNA copy number and mitochondrial mass in both control (CON) and m.3243A>G (MUT) cybrids, with no adverse effects on cell proliferation. PioG + dNs also increased mtDNA-encoded transcripts in CON cybrids, but had the opposite effect in MUT cybrids, reducing the already elevated transcript levels. Steady-state levels of mature oxidative phosphorylation (OXPHOS) protein complexes were increased by PioG + dNs treatment in CON cybrids, but were unchanged in MUT cybrids. However, treatment was able to significantly increase maximal mitochondrial oxygen consumption rates and cell respiratory control ratios in both CON and MUT cybrids. Overall, these findings highlight the ability of PioG + dNs to improve mitochondrial respiratory function in cybrid cells containing the m.3243A>G MELAS mutation, as well as their potential for development into novel therapies to treat mitochondrial disease.
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The NRF2 Signaling Network Defines Clinical Biomarkers and Therapeutic Opportunity in Friedreich's Ataxia. Int J Mol Sci 2020; 21:ijms21030916. [PMID: 32019240 PMCID: PMC7037688 DOI: 10.3390/ijms21030916] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 02/06/2023] Open
Abstract
Friedreich’s ataxia (FA) is a trinucleotide repeats expansion neurodegenerative disorder, for which no cure or approved therapies are present. In most cases, GAA trinucleotide repetitions in the first intron of the FXN gene are the genetic trigger of FA, determining a strong reduction of frataxin, a mitochondrial protein involved in iron homeostasis. Frataxin depletion impairs iron–sulfur cluster biosynthesis and determines iron accumulation in the mitochondria. Mounting evidence suggests that these defects increase oxidative stress susceptibility and reactive oxygen species production in FA, where the pathologic picture is worsened by a defective regulation of the expression and signaling pathway modulation of the transcription factor NF-E2 p45-related factor 2 (NRF2), one of the fundamental mediators of the cellular antioxidant response. NRF2 protein downregulation and impairment of its nuclear translocation can compromise the adequate cellular response to the frataxin depletion-dependent redox imbalance. As NRF2 stability, expression, and activation can be modulated by diverse natural and synthetic compounds, efforts have been made in recent years to understand if regulating NRF2 signaling might ameliorate the pathologic defects in FA. Here we provide an analysis of the pharmaceutical interventions aimed at restoring the NRF2 signaling network in FA, elucidating specific biomarkers useful for monitoring therapeutic effectiveness, and developing new therapeutic tools.
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