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 regu lating proteins Bcl-2 and Bax. In addition, immunoreactivity of the cystein e protease ICH-1(L) and detection of motor neurons with DNA fragmentation, indicative of apoptosis, was also studied. Material and methods - The immun oreactivity of Bcl-2, Bax and ICH-1(L) were compared in ALS and control spi nal cord motor neurons by immunohistochemical analysis and motor neurons wi th DNA fragmentation were identified by the TUNEL-method. Results - The res ults demonstrate an increased expression of Bax in the ALS material as comp ared to controls but no change in Bcl-2 and ICH-1(L) expressions. Moreover, a larger proportion of motor neurons stained positive for TUNEL in ALS spi nal cords. Conclusion - Present study suggest an upregulation of the cell d eath promoting protein Pax and increased DNA degradation, indicative of apo ptosis, in spinal motor neurons of ALS patients.