| Autor: |
Cecile Jacovetti, Chris Donnelly, Véronique Menoud, Mara Suleiman, Cristina Cosentino, Jonathan Sobel, Kejing Wu, Karim Bouzakri, Piero Marchetti, Claudiane Guay, Bengt Kayser, Romano Regazzi |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
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| Zdroj: |
Molecular Metabolism, Vol 84, Iss , Pp 101955- (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2212-8778 |
| DOI: |
10.1016/j.molmet.2024.101955 |
| Popis: |
Objective: The contribution of the mitochondrial electron transfer system to insulin secretion involves more than just energy provision. We identified a small RNA fragment (mt-tRF-LeuTAA) derived from the cleavage of a mitochondrially-encoded tRNA that is conserved between mice and humans. The role of mitochondrially-encoded tRNA-derived fragments remains unknown. This study aimed to characterize the impact of mt-tRF-LeuTAA, on mitochondrial metabolism and pancreatic islet functions. Methods: We used antisense oligonucleotides to reduce mt-tRF-LeuTAA levels in primary rat and human islet cells, as well as in insulin-secreting cell lines. We performed a joint transcriptome and proteome analysis upon mt-tRF-LeuTAA inhibition. Additionally, we employed pull-down assays followed by mass spectrometry to identify direct interactors of the fragment. Finally, we characterized the impact of mt-tRF-LeuTAA silencing on the coupling between mitochondrial metabolism and insulin secretion using high-resolution respirometry and insulin secretion assays. Results: Our study unveils a modulation of mt-tRF-LeuTAA levels in pancreatic islets in different Type 2 diabetes models and in response to changes in nutritional status. The level of the fragment is finely tuned by the mechanistic target of rapamycin complex 1. Located within mitochondria, mt-tRF-LeuTAA interacts with core subunits and assembly factors of respiratory complexes of the electron transfer system. Silencing of mt-tRF-LeuTAA in islet cells limits the inner mitochondrial membrane potential and impairs mitochondrial oxidative phosphorylation, predominantly by affecting the Succinate (via Complex II)-linked electron transfer pathway. Lowering mt-tRF-LeuTAA impairs insulin secretion of rat and human pancreatic β-cells. Conclusions: Our findings indicate that mt-tRF-LeuTAA interacts with electron transfer system complexes and is a pivotal regulator of mitochondrial oxidative phosphorylation and its coupling to insulin secretion. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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