A role for schwann cells in the neuroregenerative effects of a non-immunosuppressive fk506 derivative, jnj460.
FK506 and its non-immunosuppressive derivatives represent a class of pharmacological agents referred to as immunophilin ligands that have been reported to promote neuroregeneration and survival in several experimental models; however their cellular and molecular mechanisms of action have not been well established. Here we characterize a new immunophilin ligand that interacts with both FK506 binding protein 12 (FKBP12) and FKBP52, and demonstrate that JNJ460 induces neurite outgrowth from freshly explanted dorsal root ganglia (DRG) in a Schwann cell-dependent manner. Purified cultures of neurons fail to respond to these drugs, but cultures containing Schwann cells and neurons respond with neurite outgrowth, as do neurons grown in conditioned medium from JNJ460-treated Schwann cells. Using microarray analysis and a transcription reporter assay, we show that JNJ460 induces a series of transcriptional changes that occur in a temporal cascade. Among the Schwann cell-expressed genes upregulated following JNJ460 treatment is the POU transcription factor SCIP, which has been shown to regulate Schwann cell gene transcription and differentiation. JNJ460 potentiated transforming growth factor beta (TGF-beta)-induced transcriptional activation and SCIP induction in Schwann cells, by altering the interaction between FKBP12 and the TGF-beta type I receptor, TbetaR1. Finally, to test whether JNJ460 enhances neurite regeneration in vivo, we treated animals with JNJ460 for 30 days following mechanical transection of the sciatic nerve and demonstrated myelin and axonal hypertrophy at the ultrastructural level. Collectively, these data suggest that Schwann cells play an important role in the biological effects of immunophilin ligands by affecting neuron-glial signaling during regeneration.


CONCLUSIONS
The cellular and molecular mechanisms responsible for the regenerative effects of immunophilin ligands are not well understood. Here we show that the neuritogenic effects of JNJ460 in a DRG model depend on interactions between neurons and Schwann cells. Treatment of purified Schwann cells with JNJ460 alters Schwann cell gene expression, and promotes the generation of factors that act on neurons. These data indicate that Schwann cells play an important role in the actions of immunophilin ligands.
Laboratory of Molecular Oncology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. birgera@umdnj.edu
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RB
Birge
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Wadsworth
R
R
Akakura
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Abeysinghe
R
R
Kanojia
M
M
MacIelag
J
J
Desbarats
M
M
Escalante
K
K
Singh
S
S
Sundarababu
K
K
Parris
G
G
Childs
A
A
August
J
J
Siekierka
D E
DE
Weinstein
D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000187:drug effects / Q000648:ultrastructure; D015152:Blotting, Northern / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D002478:Cells, Cultured; D018920:Coculture Techniques / Q000379:methods; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004790:Enzyme Induction; D005455:Fluorescent Antibody Technique / Q000379:methods; D005727:Ganglia, Spinal / Q000166:cytology*; D020104:Immunophilins / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron / Q000379:methods; D008958:Models, Molecular; D020932:Nerve Growth Factor / Q000494:pharmacology; D009416:Nerve Regeneration / Q000187:drug effects*; D050816:Octamer Transcription Factor-6; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012583:Schwann Cells / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D020426:Sciatic Neuropathy / Q000188:drug therapy; D016559:Tacrolimus / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000627:therapeutic use; D022021:Tacrolimus Binding Proteins / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection / Q000379:methods; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism
D017077:Culture Media, Conditioned; D007166:Immunosuppressive Agents; C485833:JNJ460; C494180:Pou3f1 protein, mouse; C494179:Pou3f1 protein, rat; D012333:RNA, Messenger; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D050816:Octamer Transcription Factor-6; D014364:Tryptophan; D020932:Nerve Growth Factor; D022021:Tacrolimus Binding Proteins; C403485:tacrolimus binding protein 4; D020104:Immunophilins; D016559:Tacrolimus