Dolichol and dolichyl phosphate in the neuronal ceroid-lipofuscinoses and other diseases

Although, compared to age-matched control samples, nonphosphorylated dolichols are significantly increased in the cerebral cortex of children with the late infantile and juvenile types of neuronal ceroid-lipofuscinosis (NCL), dolichyl phosphates are increased to a much greater extent in infantile, late infantile, and juvenile forms of this disease group. Dolichyl phosphates in the cerebral cortex, expressed as a percentage of the combined nonphosphorylated and phosphorylated compounds, ranged from 59 to 85 (mean 71) in NCL, whereas in the non-NCL disease group the range is 18-36 (mean 25). This marked proportional increase in dolichyl phosphates is not unique to NCL but is also found in the brain of GM1-gangliosidosis and Tay-Sachs disease patients. In the liver from NCL patients, dolichyl phosphates are not a major proportion of the total dolichol compounds (1-9%). However, in the kidney and heart, dolichyl phosphates are again markedly increased, and this is associated with large storage of ceroid. Although to a lesser extent than in NCL, dolichols and dolichyl phosphates are significantly increased over levels in age-matched control samples in the temporal cortex in Alzheimer disease. Our interpretation of these results is that storage in secondary in secondary lysosomes in NCL and the gangliosidoses leads to a decrease in the catabolism of dolichyl phosphate compounds in the Golgi saccules or primary lysosomes.