Factors influencing the measurement of lysosomal enzymes activity in human cerebrospinal fluid.

Measurements of the activities of lysosomal enzymes in cerebrospinal fluid have recently been proposed as putative biomarkers for Parkinson's disease and other synucleinopathies. To define the operating procedures useful for ensuring the reliability of these measurements, we analyzed several pre-analytical factors that may influence the activity of ß-glucocerebrosidase, α-mannosidase, ß-mannosidase, ß-galactosidase, α-fucosidase, ß-hexosaminidase, cathepsin D and cathepsin E in cerebrospinal fluid. Lysosomal enzyme activities were measured by well-established fluorimetric assays in a consecutive series of patients (n = 28) with different neurological conditions, including Parkinson's disease. The precision, pre-storage and storage conditions, and freeze/thaw cycles were evaluated. All of the assays showed within- and between-run variabilities below 10%. At -20°C, only cathepsin D was stable up to 40 weeks. At -80°C, the cathepsin D, cathepsin E, and ß-mannosidase activities did not change significantly up to 40 weeks, while ß-glucocerebrosidase activity was stable up to 32 weeks. The ß-galactosidase and α-fucosidase activities significantly increased (+54.9±38.08% after 4 weeks and +88.94±36.19% after 16 weeks, respectively). Up to four freeze/thaw cycles did not significantly affect the activities of cathepsins D and E. The ß-glucocerebrosidase activity showed a slight decrease (-14.6%) after two freeze/thaw cycles. The measurement of lysosomal enzyme activities in cerebrospinal fluid is reliable and reproducible if pre-analytical factors are accurately taken into consideration. Therefore, the analytical recommendations that ensue from this study may contribute to the establishment of actual values for the activities of cerebrospinal fluid lysosomal enzymes as putative biomarkers for Parkinson's disease and other neurodegenerative disorders.

Spinal cord edema, 5-hydroxytryptamine, lipid peroxidation, and lysosomal enzyme release after acute contusion and compression injury in primates.

Physical and biochemical changes in the spinal cord of monkeys at 1/2, 2, and 4 hours following 200 g cm contusion injury and 50 g of compression injury and 2 hours of decompression following 4 hours of compression were studied. The pathophysiologic changes were milder in compression compared to contusion injury. Following contusion injury, at 1/2 and 2 hours there was significant increase in % water content, lipid peroxidation, and alpha-L-fucosidase. alpha-D-Mannosidase was significantly increased at all time periods, and beta-D-hexosaminidase was increased at 1/2 and 4 hours. At 4 hours following injury, serotonin (5 HT) and 5-hydroxyindole-3-acetic acid (5-HIAA) showed a significant increase. From 10 minutes to 2 hours there was increased platelet aggregation. In compression injury, a significant increase in water content and 5 HT was observed only at 1/2 hour. Lipid peroxidation had increased at all time periods, whereas B-D-hexosaminidase, beta-D-galactosidase, and 5-HIAA were increased at 2 hours. alpha-D-Mannosidase had increased at 1/2 and 2 hours, and alpha-L-fucosidase had increased at 4 hours. After 2 hours decompression following 4 hours compression, water content, beta-D-galactosidase, and alpha-D-Mannosidase were significantly increased. An attempt was made to correlate the findings and to understand the sequential pathophysiologic changes in the first 4 hours following spinal cord trauma, providing a baseline for evaluation of the efficacy of any therapeutic maneuvers.

Acid glycosidase and arylsulfatase activities of human cerebrospinal fluid as measured by concanavalin A-sepharose affinity chromatography.

An affinity chromatographic method using concanavalin A-Sepharose is described for the determination of N-acetyl-beta-D-glucosaminidase, arylsulfatase. alpha-L-Fucosidase and alpha-D-mannosidase activities in the human cerebrospinal fluid. By this method (starting with 12 to 20 ml samples of cerebrospinal fluid) the above enzymes could be obtained in a concentrated form and their activities could be determined within incubation periods of 30 min to 1 h under the assay conditions described. The pH optima of the enzymes were in the range of pH 4 to 5. About 80% of the total cerebrospinal fluid N-acetyl-beta-D-glucosaminidase was found to be the A form by DEAE-Sephadex A-50 chromatography. About 60% of the total arylsulfatase was also found to be the A form. Determination of these enzyme activities in a few samples of human cerebrospinal fluid indicated a rough proportionality between the enzyme activities and the protein concentration in the cerebrospinal fluid.