CYCLIN-DEPENDENT KINASE-5 IS ASSOCIATED WITH LIPOFUSCIN IN MOTOR-NEURONS IN AMYOTROPHIC-LATERAL-SCLEROSIS

We have studied the distribution of cyclin dependent kinase-5 (cdk-5) within spinal cord in sporadic and two superoxide dismutase type 1 (SO D1) familial cases of amyotrophic lateral sclerosis (ALS). Although mo st neurofilament accumulations in ALS motor neurones did not appear to contain high levels of cdk-5, intense cdk-5 immunoreactivity was obse rved in perikarya of degenerating neurones in many ALS cases. Here, cd k-5 co-localised with lipofuscin. Co-localisation of cdk-5 with lipofu scin was also observed in some aged non-affected controls although thi s labelling was less intense than the ALS cases. The biogenesis of lip ofuscin is believed to be linked to oxidative stress and oxidative str ess and free radical damage have been suggested to be part of the path ogenic process of ALS, possibly involving apoptotic mechanisms, cdk-5 has recently been associated with apoptosis, These observations sugges t a role for cdk-5 in the pathogenesis of ALS. (C) 1998 Elsevier Scien ce Ireland Ltd.