Upregulation of Bax protein and increased DNA degradation in ALS spinal cord motor neurons.

OBJECTIVES: To investigate if degeneration of motor neurons in amyotrophic lateral sclerosis (ALS) is related to altered levels of the apoptosis regulating proteins Bcl-2 and Bax. In addition, immunoreactivity of the cysteine protease ICH-IL and detection of motor neurons with DNA fragmentation, indicative of apoptosis, was also studied.
MATERIAL AND METHODS: The immunoreactivity of Bcl-2, Bax and ICH-1L were compared in ALS and control spinal cord motor neurons by immunohistochemical analysis and motor neurons with DNA fragmentation were identified by the TUNEL-method.
RESULTS: The results demonstrate an increased expression of Bax in the ALS material as compared to controls but no change in Bcl-2 and ICH-1L expressions. Moreover, a larger proportion of motor neurons stained positive for TUNEL in ALS spinal cords.
CONCLUSION: Present study suggest an upregulation of the cell death promoting protein Bax and increased DNA degradation, indicative of apoptosis, in spinal motor neurons of ALS patients.