The impact of metabolic stressors on mitochondrial homeostasis in a renal epithelial cell model of methylmalonic aciduria
Methylmalonic aciduria (MMA-uria) is caused by deficiency of the mitochondrial enzyme methylmalonyl-CoA mutase (MUT). MUT deficiency hampers energy generation from specific amino acids, odd-chain fatty acids and cholesterol. Chronic kidney disease (CKD) is a well-known long-term complication. We exp...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
11 May 2023
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| In: |
Scientific reports
Year: 2023, Volume: 13, Pages: 1-15 |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-023-34373-8 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1038/s41598-023-34373-8 Verlag, kostenfrei, Volltext: https://www.nature.com/articles/s41598-023-34373-8 
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| Author Notes: | Anke Schumann, Marion Brutsche, Monique Havermans, Sarah C. Grünert, Stefan Kölker, Olaf Groß, Luciana Hannibal & Ute Spiekerkoetter |
| Summary: | Methylmalonic aciduria (MMA-uria) is caused by deficiency of the mitochondrial enzyme methylmalonyl-CoA mutase (MUT). MUT deficiency hampers energy generation from specific amino acids, odd-chain fatty acids and cholesterol. Chronic kidney disease (CKD) is a well-known long-term complication. We exposed human renal epithelial cells from healthy controls and MMA-uria patients to different culture conditions (normal treatment (NT), high protein (HP) and isoleucine/valine (I/V)) to test the effect of metabolic stressors on renal mitochondrial energy metabolism. Creatinine levels were increased and antioxidant stress defense was severely comprised in MMA-uria cells. Alterations in mitochondrial homeostasis were observed. Changes in tricarboxylic acid cycle metabolites and impaired energy generation from fatty acid oxidation were detected. Methylcitrate as potentially toxic, disease-specific metabolite was increased by HP and I/V load. Mitophagy was disabled in MMA-uria cells, while autophagy was highly active particularly under HP and I/V conditions. Mitochondrial dynamics were shifted towards fission. Sirtuin1, a stress-resistance protein, was down-regulated by HP and I/V exposure in MMA-uria cells. Taken together, both interventions aggravated metabolic fingerprints observed in MMA-uria cells at baseline. The results point to protein toxicity in MMA-uria and lead to a better understanding, how the accumulating, potentially toxic organic acids might trigger CKD. |
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| Item Description: | Gesehen am 28.06.2023 |
| Physical Description: | Online Resource |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-023-34373-8 |