Metabolomics Analysis of Skeletal Muscles from FKRP-Deficient Mice Indicates Improvement After Gene Replacement Therapy

Charles Harvey Vannoy,Qi Long Lu,Katarzyna Broniowska,Victoria Leroy

doi:10.1038/s41598-019-46431-1

Charles Harvey Vannoy, Qi Long Lu + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-46431-1

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Abstract

Muscular dystrophy-dystroglycanopathies comprise a heterogeneous and complex group of disorders caused by loss-of-function mutations in a multitude of genes that disrupt the glycobiology of α-dystroglycan, thereby affecting its ability to function as a receptor for extracellular matrix proteins. Of the various genes involved, FKRP codes for a protein that plays a critical role in the maturation of a novel glycan found only on α-dystroglycan. Yet despite knowing the genetic cause of FKRP-related dystroglycanopathies, the molecular pathogenesis of disease and metabolic response to therapeutic intervention has not been fully elucidated. To address these challenges, we utilized mass spectrometry-based metabolomics to generate comprehensive metabolite profiles of skeletal muscle across diseased, treated, and normal states. Notably, FKRP-deficient mice elicit diverse metabolic abnormalities in biomarkers of extracellular matrix remodeling and/or aging, pentoses/pentitols, glycolytic intermediates, and lipid metabolism. More importantly, the restoration of FKRP protein activity following AAV-mediated gene therapy induced a substantial correction of these metabolic impairments. While interconnections of the affected molecular mechanisms remain unclear, our datasets support the notion that global metabolic profiling can be valuable for determining the involvement of previously unsuspected regulatory or pathological pathways as well as identifying potential targets for drug discovery and diagnostics.

Highlights

Metabolic Pathway Amino Acid Peptide Carbohydrate Energy Lipid Nucleotide Cofactor/Vitamin Xenobiotic Total Downregulated Upregulated predictive molecular biomarkers becomes critical
Our results demonstrate the feasibility of the metabolomics-based approach and provide a deeper understanding of FKRP-related dystroglycanopathies that can be helpful in identifying biomarkers of disease progression, distinguishing molecular markers and targets for therapeutic intervention, as well as predicting long-term, treatment-related side effects
This high-throughput metabolomics study across diseased, treated, and normal states is an extension of our previous assessment of protein/gene expression, histopathology, skeletal muscle function, and cardiorespiratory function performed over a 52-week observation period using the same mouse cohorts[17]

Summary

Introduction

Metabolic Pathway Amino Acid Peptide Carbohydrate Energy Lipid Nucleotide Cofactor/Vitamin Xenobiotic Total Downregulated Upregulated predictive molecular biomarkers becomes critical. The use of analytical tools such as ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) can be employed to generate global metabolite profiles that reveal the entirety of low-molecular-weight molecules (e.g., amino acids, carbohydrates, and fatty acids) that are essential components of multiple mammalian systems and are required for energy generation, the biosynthesis of important macromolecules, and maintaining metabolic homeostasis[19] This strategy has already been evaluated in skeletal/cardiac tissue and serum from animal models and patients exhibiting similar physiological disorders, including Duchenne, Becker, facioscapulohumeral, and other limb-girdle muscular dystrophies[20,21,22,23]. Our results demonstrate the feasibility of the metabolomics-based approach and provide a deeper understanding of FKRP-related dystroglycanopathies that can be helpful in identifying biomarkers of disease progression, distinguishing molecular markers and targets for therapeutic intervention, as well as predicting long-term, treatment-related side effects

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