Characterization of apoptosis in a motor neuron cell line

Serum withdrawal was introduced to a spinal cord motor neuron cell line to investigate the mode of cell death.

To characterize the death of motor neurons in culture, to gain insight into mechanisms that could be important in spinal cord diseases.

Normal reduction of cell number during central nervous system development is brought about by programmed cell death. These same apoptotic processes probably play a role in a variety of central nervous system disorders, including traumatic injury. Although certain proteolytic processes are involved, the molecular details involved in the apoptotic induction have not been fully elucidated.

To identify apoptosis, several criteria were used, including analysis of chromatin condensation with DNA-specific stains (propidium iodide and Hoechst 33342); in situ end-labeling of DNA fragments in apoptotic nuclei with terminal deoxynucleotidyl transferase; fragmentation of DNA separated on agarose gel electrophoresis; and cleavage of a characteristic substrate for apoptotic proteases, alpha-fodrin, into signature cleavage fragments.

The NSC19 cell line exhibited motor neuron characteristics morphologically, with typical cellular structure, and biochemically, by synthesizing choline acetyl transferase. Under various treatments including serum withdrawal (loss of trophic factors), cell loss occurred through an apoptotic cell death pathway.

A murine motor neuron cell line, NSC19, has been used to investigate apoptosis in this in vitro system. Cell death occurs by apoptosis, suggesting that this cell line may provide a useful model for studying apoptotic mechanisms in spinal cord degeneration and injury.