Mitochondrial complex I subunit deficiency promotes pancreatic α-cell proliferation

Objective: There is strong evidence that mitochondrial DNA mutations and mitochondrial dysfunction play a role in diabetes pathogenesis. The homozygous knock-in mtDNA mutator mouse is a model of premature aging due to the accumulation of mitochondrial DNA mutations. We used this mouse model to inves...

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Bibliographic Details
Main Authors: Xuefei Yu, Catherine Arden, Rolando Berlinguer-Palmini, Chun Chen, Carla Bradshaw, Anna LM Smith, Julia Whitehall, Michael White, Scott Anderson, Nicole Kattner, James Shaw, Doug Turnbull, Laura C Greaves, Mark Walker
Format: Article
Language:English
Published: Elsevier 2022-06-01
Series:Molecular Metabolism
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Online Access:http://www.sciencedirect.com/science/article/pii/S2212877822000588
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Summary:Objective: There is strong evidence that mitochondrial DNA mutations and mitochondrial dysfunction play a role in diabetes pathogenesis. The homozygous knock-in mtDNA mutator mouse is a model of premature aging due to the accumulation of mitochondrial DNA mutations. We used this mouse model to investigate the relationship between mitochondrial subunit expression and pancreatic islet cell composition. Methods: Quadruple immunofluorescence was used to quantify mitochondrial subunit expression (complex I and IV) and cell composition in pancreatic islets from mitochondrial DNA mutator mice (PolgAmut/mut) and control C57BL/6 mice at 12 and 44 weeks of age. Results: Mitochondrial complex I subunit expression was decreased in islets from 12 week PolgAmut/mut mice. This complex I deficiency persisted with age and was associated with decreased insulin staining intensity at 44 weeks. Complex I deficiency was greater in α-cells compared with β-cells in islets from 44 week PolgAmut/mut mice. Islet cell composition was normal in 12 week PolgAmut/mut mice, but the β: α cell ratio was decreased in islets from 44 week PolgAmut/mut mice. This was due to an increase in α-cell number linked to an increase in α-cell proliferation. Conclusion: Complex I deficiency promotes α-cell proliferation and alters islet cell composition.
ISSN:2212-8778