Impaired Mitochondrial Morphology and Functionality in Lonp1wt/- Mice.

Abstract

LONP1 is a nuclear-encoded mitochondrial protease crucial for organelle homeostasis; mutations of LONP1 have been associated with Cerebral, Ocular, Dental, Auricular, and Skeletal anomalies (CODAS) syndrome. To clarify the role of LONP1 in vivo, we generated a mouse model in which Lonp1 was ablated. The homozygous Lonp-/- mouse was not vital, while the heterozygous Lonp1wt/- showed similar growth rate, weight, length, life-span and histologic features as wild type. Conversely, ultrastructural analysis of heterozygous enterocytes evidenced profound morphological alterations of mitochondria, which appeared increased in number, swollen and larger, with a lower complexity. Embryonic fibroblasts (MEFs) from Lonp1wt/- mice showed a reduced expression of Lonp1 and Tfam, whose expression is regulated by LONP1. Mitochondrial DNA was also reduced, and mitochondria were swollen and larger, albeit at a lesser extent than enterocytes, with a perinuclear distribution. From the functional point of view, mitochondria from heterozygous MEF showed a lower oxygen consumption rate in basal conditions, either in the presence of glucose or galactose, and a reduced expression of mitochondrial complexes than wild type. In conclusion, the presence of one functional copy of the Lonp1 gene leads to impairment of mitochondrial ultrastructure and functions in vivo.

• Authors: Anna De Gaetano, Lara Gibellini, Elena Bianchini, Rebecca Borella, Sara De Biasi, Milena Nasi, Federica Boraldi, Andrea Cossarizza, Marcello Pinti
• Journal: Journal of clinical medicine (J Clin Med) Vol. 9 Issue 6 (Jun 08 2020) ISSN: 2077-0383 [Print] Switzerland
• PMID: 32521756 (Publication Type: Journal Article)