Plasmalogenase is elevated in early demyelinating lesions

Area of Science:

• Biochemistry
• Neuroscience
• Cell Biology

Background:

• Plasmalogenase hydrolyzes ethanolamine plasmalogens, with activity paralleling myelination during development.
• The enzyme is concentrated in oligodendroglial cells, not myelin, and may be involved in lipid metabolism for white matter.
• Plasmalogens are precursors for thromboxane and prostaglandin synthesis.

Purpose of the Study:

• To investigate the role and activity of plasmalogenase in demyelinating conditions of the central nervous system (CNS).
• To determine if elevated plasmalogenase activity is an early indicator of demyelination.
• To explore the potential involvement of plasmalogenase in oligodendrocyte damage.

Main Methods:

• Assaying plasmalogenase activity in CNS tissues, including those affected by distemper virus, anti-myelin antibodies, and ischemia.
• Comparing plasmalogenase activity with lysosomal enzyme activities (beta-glucuronidase, acid proteinase, neutral proteinase).
• Evaluating phospholipase activities acting on phosphatidyl ethanolamine.

Main Results:

• Plasmalogenase activity was significantly elevated (4.9-fold) in early demyelinating lesions caused by distemper virus.
• Elevated plasmalogenase activity preceded cellular invasion and lysosomal enzyme activation.
• Other phospholipases acting on phosphatidyl ethanolamine were not activated and showed lower activity than plasmalogenase in control tissues.
• Plasmalogenase activity also increased after anti-myelin antibody injection and ischemia.

Conclusions:

• Elevated plasmalogenase activity is an early event in CNS demyelination.
• Plasmalogenase may contribute to oligodendrocyte necrosis, a key process in demyelination.
• The enzyme's specificity for plasmalogens suggests a role in lipid metabolism disruption during demyelination.