Dichloroacetate improves mitochondrial function, physiology, and morphology in FBXL4 disease models

JCI Insight. 2022 Aug 22;7(16):e156346. doi: 10.1172/jci.insight.156346.

Abstract

Pathogenic variants in the human F-box and leucine-rich repeat protein 4 (FBXL4) gene result in an autosomal recessive, multisystemic, mitochondrial disorder involving variable mitochondrial depletion and respiratory chain complex deficiencies with lactic acidemia. As no FDA-approved effective therapies for this disease exist, we sought to characterize translational C. elegans and zebrafish animal models, as well as human fibroblasts, to study FBXL4-/- disease mechanisms and identify preclinical therapeutic leads. Developmental delay, impaired fecundity and neurologic and/or muscular activity, mitochondrial dysfunction, and altered lactate metabolism were identified in fbxl-1(ok3741) C. elegans. Detailed studies of a PDHc activator, dichloroacetate (DCA), in fbxl-1(ok3741) C. elegans demonstrated its beneficial effects on fecundity, neuromotor activity, and mitochondrial function. Validation studies were performed in fbxl4sa12470 zebrafish larvae and in FBXL4-/- human fibroblasts; they showed DCA efficacy in preventing brain death, impairment of neurologic and/or muscular function, mitochondrial biochemical dysfunction, and stress-induced morphologic and ultrastructural mitochondrial defects. These data demonstrate that fbxl-1(ok3741) C. elegans and fbxl4sa12470 zebrafish provide robust translational models to study mechanisms and identify preclinical therapeutic candidates for FBXL4-/- disease. Furthermore, DCA is a lead therapeutic candidate with therapeutic benefit on diverse aspects of survival, neurologic and/or muscular function, and mitochondrial physiology that warrants rigorous clinical trial study in humans with FBXL4-/- disease.

Keywords: Drug therapy; Genetic diseases; Genetics; Metabolism; Mitochondria.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Dichloroacetic Acid*
  • F-Box Proteins* / genetics
  • F-Box Proteins* / metabolism
  • Humans
  • Mitochondria / metabolism
  • Mitochondrial Diseases* / drug therapy
  • Mitochondrial Diseases* / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Zebrafish

Substances

  • F-Box Proteins
  • Dichloroacetic Acid
  • Ubiquitin-Protein Ligases
  • FbxL4 protein, human