Kidney-Related Function of Mitochondrial Protein Mitoregulin

A small protein, Mitoregulin (Mtln), localizes in mitochondria and contributes to oxidative phosphorylation and fatty acid metabolism. Mtln knockout mice develop obesity on a high-fat diet, demonstrating elevated cardiolipin damage and suboptimal creatine kinase oligomerization in muscle tissue. Kidneys heavily depend on the oxidative phosphorylation in mitochondria. Here we report kidney-related phenotypes in aged Mtln knockout mice. Similar to Mtln knockout mice muscle mitochondria, those of the kidney demonstrate a decreased respiratory complex I activity and excessive cardiolipin damage. Aged male mice carrying Mtln knockout demonstrated an increased frequency of renal proximal tubules' degeneration. At the same time, a decreased glomerular filtration rate has been more frequently detected in aged female mice devoid of Mtln. An amount of Mtln partner protein, Cyb5r3, is drastically decreased in the kidneys of Mtln knockout mice.

Automated summary

A small protein, Mitoregulin (Mtln), localized in mitochondria, plays a role in oxidative phosphorylation and fatty acid metabolism. Mtln knockout mice develop obesity and show damage to cardiolipin and creatine kinase oligomerization in muscle tissue. In this study, we investigate kidney-related phenotypes in aged Mtln knockout mice and found decreased respiratory complex I activity and excessive cardiolipin damage in kidney mitochondria similar to muscle mitochondria of Mtln knockout mice. Aged male mice with Mtln knockout exhibited increased renal proximal tubules' degeneration while aged female mice without Mtln showed a higher frequency of decreased glomerular filtration rate. Additionally, the amount of Mtln partner protein, Cyb5r3, decreased significantly in the kidneys of Mtln knockout mice.