Expression pattern of peptidylarginine deiminase in rat and human Schwann cells.
The peptidylarginine deiminase (PAD) family of enzymes are responsible for conversion of protein-bound arginine to citrulline in most tissues of the body and are garnering increased interest for their physiological and pathological roles. Although it has been shown that oligodendrocytes of the CNS express the PAD isoenzyme type 2, nothing is presently known about PAD expression in Schwann cells, the myelinating cells of the PNS. To evaluate PAD expression in the PNS, cultivated rat and human Schwann cells and slices of fetal, juvenile, and normal and regenerated adult sciatic nerves were examined with RT-PCR, Western blot, and immunohistochemical analysis. Samples from cerebellar cultures and skin served as positive controls. One of the principle findings was that cultivated Schwann cells expressed significant levels of mRNA and protein for the PAD isoenzymes 2 and 3. PAD1 and PAD4, however, were not expressed in any types of Schwann cells. Using double immunofluorescence, the majority of PAD2 staining was localized in immature cell stages. Moreover, increased amounts of PAD2, PAD3, and peptidyl-citrulline were also found in human fetal and rat juvenile and regenerated sciatic nerves as compared to similar normal adult specimens. Neuronal and inducible nitric oxide synthases, enzymes that convert free arginine to citrulline, were also expressed in Schwann cells; however, their massive induction by LPS/K(+), was not reflected in an enhanced peptidyl-citrulline immunosignal. These data suggest that, similar to the CNS, citrullination of proteins may also exert a specific role in thecourse of PNS development and repair.
Keilhoff
Gerburg
G
Institute of Medical Neurobiology, University of Magdeburg, Magdeburg, Germany. gerburg.keilhoff@med.ovgu.de
Prell
Tino
T
Langnaese
Kristina
K
Mawrin
Christian
C
Simon
Michel
M
Fansa
Hisham
H
Nicholas
Anthony P
AP
D000328:Adult; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D005333:Fetus; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D006867:Hydrolases / Q000378:metabolism*; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D000080064:Protein-Arginine Deiminase Type 2; D000076342:Protein-Arginine Deiminases; D051381:Rats; D017208:Rats, Wistar; D012583:Schwann Cells / Q000201:enzymology*; D012584:Sciatic Nerve / Q000166:cytology / Q000378:metabolism*
D007527:Isoenzymes; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D019001:Nitric Oxide Synthase; D006867:Hydrolases; C000620352:PADI2 protein, human; C461539:Padi2 protein, rat; D000080064:Protein-Arginine Deiminase Type 2; D000076342:Protein-Arginine Deiminases