1
|
Mauriac SA, Peineau T, Zuberi A, Lutz C, Géléoc GSG. Loss of Pex1 in Inner Ear Hair Cells Contributes to Cochlear Synaptopathy and Hearing Loss. Cells 2022; 11:cells11243982. [PMID: 36552747 PMCID: PMC9777190 DOI: 10.3390/cells11243982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/04/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Peroxisome Biogenesis Disorders (PBD) and Zellweger syndrome spectrum disorders (ZSD) are rare genetic multisystem disorders that include hearing impairment and are associated with defects in peroxisome assembly, function, or both. Mutations in 13 peroxin (PEX) genes have been found to cause PBD-ZSD with ~70% of patients harboring mutations in PEX1. Limited research has focused on the impact of peroxisomal disorders on auditory function. As sensory hair cells are particularly vulnerable to metabolic changes, we hypothesize that mutations in PEX1 lead to oxidative stress affecting hair cells of the inner ear, subsequently resulting in hair cell degeneration and hearing loss. Global deletion of the Pex1 gene is neonatal lethal in mice, impairing any postnatal studies. To overcome this limitation, we created conditional knockout mice (cKO) using Gfi1Creor VGlut3Cre expressing mice crossed to floxed Pex1 mice to allow for selective deletion of Pex1 in the hair cells of the inner ear. We find that Pex1 excision in inner hair cells (IHCs) leads to progressive hearing loss associated with significant decrease in auditory brainstem responses (ABR), specifically ABR wave I amplitude, indicative of synaptic defects. Analysis of IHC synapses in cKO mice reveals a decrease in ribbon synapse volume and functional alterations in exocytosis. Concomitantly, we observe a decrease in peroxisomal number, indicative of oxidative stress imbalance. Taken together, these results suggest a critical function of Pex1 in development and maturation of IHC-spiral ganglion synapses and auditory function.
Collapse
Affiliation(s)
- Stephanie A. Mauriac
- Department of Otolaryngology, Boston Children’s Hospital, Boston, MA 02115, USA
- Kirby Neurobiology Center, Harvard Medical School, Boston, MA 02115, USA
| | - Thibault Peineau
- Department of Otolaryngology, Boston Children’s Hospital, Boston, MA 02115, USA
- Kirby Neurobiology Center, Harvard Medical School, Boston, MA 02115, USA
| | - Aamir Zuberi
- Rare Disease Translational Center, The Jackson Laboratory, Bar Harbor, ME 04609, USA
- Technology Evaluation and Development Research Laboratory, The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Cathleen Lutz
- Rare Disease Translational Center, The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Gwénaëlle S. G. Géléoc
- Department of Otolaryngology, Boston Children’s Hospital, Boston, MA 02115, USA
- Kirby Neurobiology Center, Harvard Medical School, Boston, MA 02115, USA
- Correspondence: ; Tel.: +1-617-919-4061
| |
Collapse
|
2
|
Wangler MF, Hubert L, Donti TR, Ventura MJ, Miller MJ, Braverman N, Gawron K, Bose M, Moser AB, Jones RO, Rizzo WB, Sutton VR, Sun Q, Kennedy AD, Elsea SH. A metabolomic map of Zellweger spectrum disorders reveals novel disease biomarkers. Genet Med 2018; 20:1274-1283. [PMID: 29419819 PMCID: PMC7605708 DOI: 10.1038/gim.2017.262] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/12/2017] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Peroxisome biogenesis disorders-Zellweger spectrum disorders (PBD-ZSD) are metabolic diseases with multisystem manifestations. Individuals with PBD-ZSD exhibit impaired peroxisomal biochemical functions and have abnormal levels of peroxisomal metabolites, but the broader metabolic impact of peroxisomal dysfunction and the utility of metabolomic methods is unknown. METHODS We studied 19 individuals with clinically and molecularly characterized PBD-ZSD. We performed both quantitative peroxisomal biochemical diagnostic studies in parallel with untargeted small molecule metabolomic profiling in plasma samples with detection of >650 named compounds. RESULTS The cohort represented intermediate to mild PBD-ZSD subjects with peroxisomal biochemical alterations on targeted analysis. Untargeted metabolomic profiling of these samples revealed elevations in pipecolic acid and long-chain lysophosphatidylcholines, as well as an unanticipated reduction in multiple sphingomyelin species. These sphingomyelin reductions observed were consistent across the PBD-ZSD samples and were rare in a population of >1,000 clinical samples. Interestingly, the pattern or "PBD-ZSD metabolome" was more pronounced in younger subjects suggesting studies earlier in life reveal larger biochemical changes. CONCLUSION Untargeted metabolomics is effective in detecting mild to intermediate cases of PBD-ZSD. Surprisingly, dramatic reductions in plasma sphingomyelin are a consistent feature of the PBD-ZSD metabolome. The use of metabolomics in PBD-ZSD can provide insight into novel biomarkers of disease.
Collapse
Affiliation(s)
- Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
- Texas Children's Hospital, Houston, Texas, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA.
- Developmental Biology Program, Baylor College of Medicine, Houston, Texas, USA.
| | - Leroy Hubert
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Taraka R Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | | | - Marcus J Miller
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Nancy Braverman
- Research Institute of the McGill University Health Center, Montreal, Quebec, Canada
| | - Kelly Gawron
- Department of Nutrition and Food Studies, Montclair State University, Montclair, New Jersey, USA
| | - Mousumi Bose
- Department of Nutrition and Food Studies, Montclair State University, Montclair, New Jersey, USA
| | - Ann B Moser
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Richard O Jones
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | | | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Qin Sun
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | | | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
| |
Collapse
|