Targeting multiple genetic defects of mitochondrial diseases with a single bacterial lipoate protein ligase

Metabolic disorders caused by defects in energy metabolism can lead to many life-threatening diseases; their therapy remains elusive in most cases. Conventional gene therapy relies on the "one gene for one genetic defect" strategy. Here, we demonstrate a more efficient strategy to target multiple genetic defects with a single gene intervention. Specifically, we used a bacterial lipoate protein ligase involved in protein lipoylation to rescue mitochondrial dysfunctions in human lipoylation pathway (<i>LIPT2</i>, <i>LIAS</i>, and <i>LIPT1</i>), lipoyl precursor supply (<i>MECR</i>), and sulfur insertion accessary partner (<i>FDX1</i>). The efficacy and safety of <i>Escherichia coli</i>-derived LplA or <i>Bacillus subtilis</i>-derived LplJ were validated in human cells and mouse models. <i>LplA</i> knock-in mice exhibited normal health with enhanced energy expenditure. Overexpressing LplA through a mating strategy rescued embryonic lethality in <i>Lipt1</i>^-/- mutants, yielding viable offspring with normal body weight, energy expenditure, tissue morphology, and biochemical profile. Our work highlights how evolutionary differences in biosynthetic pathways between humans and bacteria can be leveraged for cross-species therapeutic innovations.