1. A knock-in rat model unravels acute and chronic renal toxicity in glutaric aciduria type I
- Author
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Margherita Ruoppolo, Johannes A. Mayr, Marianna Caterino, Frédéric Barbey, Diana Ballhausen, Olivier Braissant, Gilles Allenbach, John O. Prior, Andrea Orlando Fontana, Mary Gonzalez Melo, David Viertl, Samuel Rotman, René G. Feichtinger, Michele Costanzo, Gonzalez Melo, M, Fontana, Ao, Viertl, D, Allenbach, G, Prior, Jo, Rotman, S, Feichtinger, Rg, Mayr, Ja, Costanzo, M, Caterino, M, Ruoppolo, M, Braissant, O, Barbey, F, and Ballhausen, D
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Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Renal function ,Mitochondrion ,Kidney ,Biochemistry ,Oxidative Phosphorylation ,Glutarates ,Neonatal Screening ,Endocrinology ,Tubulopathy ,Internal medicine ,Genetics ,medicine ,Animals ,Humans ,Gene Knock-In Techniques ,Protein Interaction Maps ,Young adult ,Ga EDTA ,Molecular Biology ,Newborn screening ,Glutaryl-CoA Dehydrogenase ,business.industry ,Glutaric aciduria ,Infant, Newborn ,Computational Biology ,Glutaric aciduria type I ,medicine.disease ,Rats ,Disease Models, Animal ,Inborn error of metabolism ,Vacuoles ,Renal toxicity ,Toxicity ,Organic aciduria ,Female ,business ,Metabolism, Inborn Errors ,Glomerular Filtration Rate - Abstract
Glutaric aciduria type I (GA-I, OMIM # 231670 ) is an autosomal recessive inborn error of metabolism caused by deficiency of the mitochondrial enzyme glutaryl-CoA dehydrogenase (GCDH). The principal clinical manifestation in GA-I patients is striatal injury most often triggered by catabolic stress. Early diagnosis by newborn screening programs improved survival and reduced striatal damage in GA-I patients. However, the clinical phenotype is still evolving in the aging patient population. Evaluation of long-term outcome in GA-I patients recently identified glomerular filtration rate (GFR) decline with increasing age. We recently created the first knock-in rat model for GA-I harboring the mutation p.R411W (c.1231 C>T), corresponding to the most frequent GCDH human mutation p.R402W. In this study, we evaluated the effect of an acute metabolic stress in form of high lysine diet (HLD) on young Gcdhki/ki rats. We further studied the chronic effect of GCDH deficiency on kidney function in a longitudinal study on a cohort of Gcdhki/ki rats by repetitive 68Ga-EDTA positron emission tomography (PET) renography, biochemical and histological analyses. In young Gcdhki/ki rats exposed to HLD, we observed a GFR decline and biochemical signs of a tubulopathy. Histological analyses revealed lipophilic vacuoles, thinning of apical brush border membranes and increased numbers of mitochondria in proximal tubular (PT) cells. HLD also altered OXPHOS activities and proteome in kidneys of Gcdhki/ki rats. In the longitudinal cohort, we showed a progressive GFR decline in Gcdhki/ki rats starting at young adult age and a decline of renal clearance. Histopathological analyses in aged Gcdhki/ki rats revealed tubular dilatation, protein accumulation in PT cells and mononuclear infiltrations. These observations confirm that GA-I leads to acute and chronic renal damage. This raises questions on indication for follow-up on kidney function in GA-I patients and possible therapeutic interventions to avoid renal damage.
- Published
- 2021
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