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Mature pig oligodendrocytes rapidly process human recombinant pro‐nerve growth factor and do not undergo cell death
Author(s) -
Althaus Hans H.,
Klöppner Sabine
Publication year - 2006
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2006.03891.x
Subject(s) - nerve growth factor , tropomyosin receptor kinase a , trk receptor , oligodendrocyte , neurotrophin , biology , low affinity nerve growth factor receptor , mapk/erk pathway , microbiology and biotechnology , programmed cell death , axotomy , receptor , chemistry , apoptosis , biochemistry , signal transduction , endocrinology , central nervous system , regeneration (biology) , myelin
The neurotrophin family with its first member, nerve growth factor (NGF), binds two classes of receptors, more specifically to Trk receptors and to a shared p75 NTR receptor. It has been shown that proNGF rather than NGF is predominant in the mature central nervous system. A recent finding indicated that a furin‐resistant proNGF preferentially binds to p75 NTR , initiating a pro‐apoptotic cascade even in the presence of TrkA. In this context, rodent oligodendrocytes were reported to undergo cell death when exposed to proNGF. We have investigated the effect of a non‐mutated 32 kDa human recombinant proNGF (rhproNGF) on cultured pig oligodendrocytes which express TrkA, p75 NTR and sortilin. Pig oligodendrocytes respond to rhproNGF (50 ng/mL) with an enhanced regeneration of their processes as already observed for NGF. Activity of mitogen‐activated protein kinase (MAPK), which plays an important role in oligodendroglial process formation, was increased even when rhproNGF processing was inhibited by the furin inhibitor Decanoyl‐RVKR‐CMK. Similarly, a cleavage‐resistant proNGF (R‐1G) activated MAPK and promoted oligodendroglial process regeneration. High concentrations of rhproNGF (300 ng/mL) did not induce cell death. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis and Western blotting revealed that oligodendrocytes process rhproNGF to NGF. NGF was detected in Western blots of oligodendroglial lysates already 10 min after rhproNGF exposure, followed by a release of NGF into the culture medium. Indirect evidence indicates that rhproNGF processing occurs via an endocytotic route.