Tetracyclines promote survival and fitness in mitochondrial disease models

Mitochondrial diseases (MDs) are a heterogeneous group of disorders resulting from mutations in nuclear or mitochondrial DNA genes encoding mitochondrial proteins(1,2). MDs cause pathologies with severe tissue damage and ultimately death(3,4). There are no cures for MDs and current treatments are only palliative(5-7). Here we show that tetracyclines improve fitness of cultured MD cells and ameliorate disease in a mouse model of Leigh syndrome. To identify small molecules that prevent cellular damage and death under nutrient stress conditions, we conduct a chemical high-throughput screen with cells carrying human MD mutations and discover a series of antibiotics that maintain survival of various MD cells. We subsequently show that a sub-library of tetracycline analogues, including doxycycline, rescues cell death and inflammatory signatures in mutant cells through partial and selective inhibition of mitochondrial translation, resulting in an ATF4-independent mitohormetic response. Doxycycline treatment strongly promotes fitness and survival of Ndufs4(-/-) mice, a preclinical Leigh syndrome mouse model(8). A proteomic analysis of brain tissue reveals that doxycycline treatment largely prevents neuronal death and the accumulation of neuroimmune and inflammatory proteins in Ndufs4(-/-) mice, indicating a potential causal role for these proteins in the brain pathology. Our findings suggest that tetracyclines deserve further evaluation as potential drugs for the treatment of MDs.

Automated summary

Mitochondrial diseases are a group of disorders caused by mutations in nuclear or mitochondrial DNA genes, with no current cure available. Research shows that tetracyclines may have potential therapeutic effects on MDs.