Increased resistance to oxysterol cytotoxicity in fibroblasts transfected with a lysosomally targeted Chromobacterium oxidase

Biotechnol Bioeng. 2012 Sep;109(9):2409-15. doi: 10.1002/bit.24506. Epub 2012 Apr 8.


7-Ketocholesterol (7KC) is a cytotoxic oxysterol that plays a role in many age-related degenerative diseases. 7KC formation and accumulation often occurs in the lysosome, which hinders enzymatic transformations that reduce its toxicity and increase the sensitivity to lysosomal membrane permeabilization. We assayed the potential to mitigate 7KC cytotoxicity and enhance cell viability by overexpressing 7KC-active enzymes in human fibroblasts. One of the enzymes tested, a cholesterol oxidase engineered for lysosomal targeting, significantly increased cell viability in the short term upon treatment with up to 50 µM 7KC relative to controls. These results suggest targeting the lysosome for optimal treatment of oxysterol-mediated cytotoxicity, and support the use of introducing novel catalytic function into the lysosome for therapeutic and research applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival / drug effects
  • Cells, Cultured
  • Cholesterol Oxidase / genetics
  • Cholesterol Oxidase / metabolism
  • Cholesterol Oxidase / pharmacology*
  • Chromobacterium / enzymology*
  • Chromobacterium / genetics
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Fibroblasts / physiology*
  • Humans
  • Ketocholesterols / toxicity*
  • Lysosomes / metabolism
  • Protective Agents / metabolism
  • Protective Agents / pharmacology*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / pharmacology


  • Ketocholesterols
  • Protective Agents
  • Recombinant Proteins
  • Cholesterol Oxidase
  • 7-ketocholesterol