CREATION AND CHARACTERIZATION OF MITOCHONDRIAL DNA-DEPLETED CELL-LINES WITH NEURONAL-LIKE PROPERTIES

Mitochondrial dysfunction and attendant bioenergetic defects are incre asingly recognized as playing an important role in neurodegenerative d isorders. The increased attention on mitochondrial involvement points to the need for developing cell lines that have neuron-like characteri stics for the genetic analysis and modeling of these diseases. We desc ribe the creation of respiratory-deficient SH-SY5Y neuroblastoma cell lines (rho(0)64/5) by selectively depleting mitochondrial DNA through prolonged exposure to ethidium bromide. Oxygen consumption in these ce lls and activities of the electron transport chain enzyme complexes I and IV that contain subunits encoded by the mitochondrial genome are e liminated. In contrast, the function of complex II, a nuclear-encoded electron transport chain component, is largely intact in these cells. The rho(0)64/5 cells retain the ability to differentiate into cells wi th neuron-like phenotypes following treatment with phorbol ester or re tinoic acid. Normal respiratory function is recovered by repopulation of rho(0)64/5 cells with exogenous human platelet mitochondria. The rh o(0)64/5 cell line serves as a valuable model for the study of neurolo gic diseases suspected of involving mitochondrial dysfunction.