| Autor: |
Georgiadou, Eleni, Muralidharan, Charanya, Martinez, Michelle, Chabosseau, Pauline, Tomas, Alejandra, Su Wern, Fiona Yong, Stylianides, Theodoros, Rothery, Stephen M., Di Gregorio, Aida, Leclerc, Isabelle, Ali, Yusuf, Linnemann, Amelia K., Rodriguez, Tristan A., Rutter, Guy A. |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| DOI: |
10.1101/2020.04.22.055384 |
| Popis: |
Background and aims Mitochondria are highly dynamic organelles, fundamental to cellular energy homeostasis. Mitochondrial metabolism of glucose is essential for the initiation of insulin release from pancreatic beta cells. Whether mitochondrial ultra-structure, and the proteins controlling fission and fusion, are important for glucose recognition are unclear. Mitochondrial fusion is supported by proteins including mitofusin 1 (MFN1), mitofusin 2 (MFN2) and optic atrophy (OPA1), and fission by dynamin-related protein 1 (DRP1). Here, we generated mice with beta cell-selective, adult-restricted deletion of Mfn1 and Mfn2 (β Mfn1/2 -KO), and explored the impact on insulin secretion and glucose homeostasis in vivo and in vitro. Materials and methods C57BL/6J mice bearing Mfn1 and Mfn2 alleles with lox P sites, were crossed to animals carrying an inducible Cre recombinase at the Pdx1 locus ( Pdx CreERT ). Isolated islets were used for live beta cell fluorescence imaging of cytosolic (Cal-520) or mitochondrial (Pericam) free Ca 2+ concentration and membrane potential (TMRE). Mitochondrial network characteristics were quantified using super resolution fluorescence and transmission electron microscopy. Beta cell-beta cell connectivity was assessed using the Pearson (R) analysis and Monte Carlo simulation in intact mouse islets. Intravital imaging was performed in mice injected with an adeno-associated virus to express the cytosolic Ca 2+ sensor GCaMP6s selectively in beta cells and TMRM to visualise mitochondria using multiphoton microscopy. Results βMfn1/2 -KO mice displayed higher fasting glycaemia than control littermates at 14 weeks (8.6 vs 6.4 mmol/L, p>0.05) and a >five-fold decrease in plasma insulin post-intraperitoneal glucose injection (5-15 min, p |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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