Biomaterial Database

Phospholipase A2 plays an important role in myelin breakdown and phagocytosis during Wallerian degeneration. 2003

Susna De, and Marcelino Avilés Trigueros, and Athena Kalyvas, and Samuel David

Centre for Research in Neuroscience, McGill University, Montreal General Hospital Research Institute, 1650 Cedar Avenue, Montreal, Quebec, Canada H3G 1A4.

Phospholipase A(2) (PLA(2)) hydrolyzes phosphatidylcholine to lysophosphatidylcholine and arachidonic acid. The former can induce myelin breakdown and the latter, via eicosanoids, can stimulate inflammatory responses. Immunohistochemical analysis of secreted (sPLA(2)) and cytosolic (cPLA(2)) forms of the enzyme was assessed in the injured adult rat sciatic and optic nerves. sPLA(2) and cPLA(2) are expressed in the first 2 weeks in the injured sciatic nerve, which correlates with rapid Wallerian degeneration in peripheral nerves. In contrast, both forms of PLA(2) were not expressed in the optic nerve for the first 3 weeks after crush injury, which correlates with slow Wallerian degeneration in the central nervous system (CNS). In addition, PLA(2) is not expressed in the lesioned sciatic nerve of C57BL/Wld(s) mutant mice in which Wallerian degeneration is severely retarded. Blocking cPLA(2) in the transected sciatic nerve of C57BL/6 mice, which have a naturally occurring null mutation for the major from of sPLA(2), resulted in a marked slowing of myelin and axonal degradation and phagocytosis in the distal nerve segment. These results provide direct evidence of an important role for cPLA(2) in Wallerian degeneration.

UI	MeSH Term	Description	Entries
D008810	Mice, Inbred C57BL	One of the first INBRED MOUSE STRAINS to be sequenced. This strain is commonly used as genetic background for transgenic mouse models. Refractory to many tumors, this strain is also preferred model for studying role of genetic variations in development of diseases.	Mice, C57BL,Mouse, C57BL,Mouse, Inbred C57BL,C57BL Mice,C57BL Mice, Inbred,C57BL Mouse,C57BL Mouse, Inbred,Inbred C57BL Mice,Inbred C57BL Mouse
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009186	Myelin Sheath	The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.	Myelin,Myelin Sheaths,Sheath, Myelin,Sheaths, Myelin
D010587	Phagocytosis	The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).	Phagocytoses
D010741	Phospholipases A	Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001095	Arachidonic Acids		Eicosatetraenoic Acids,Acids, Arachidonic,Acids, Eicosatetraenoic