Anti-Thy-1 antibody-induced neurite outgrowth in cultured dorsal root ganglionic neurons is mediated by the c-Src-MEK signaling pathway.
Our previous study has shown that anti-Thy-1 antibody promotes neurite outgrowth of cultured dorsal root ganglion (DRG) neurons in a protein kinase A (PKA)-dependent manner. The present study provided another intracellular signaling pathway for the neurotrophic effect of anti-Thy-1 antibody. In DMSO-treated control cells, Thy-1 was enriched in microdomain-like structures on cell membranes by immunofluorescence observation. Treatment of DRG neurons with anti-Thy-1 antibody not only stimulated neurite outgrowth, but also increased the branching complexity of the neurites in both small and large neurons. We have previously shown that anti-Thy-1 antibody causes a time-dependent activation of mitogen-activated protein kinase (MEK) and of cyclic AMP response-element binding protein (CREB). Here, anti-Thy-1 antibody elicited a transient activation of c-Src kinase, and the activation of c-Src kinase appeared occurring upstream of the activation of MEK and CREB, since pretreatment with the Src kinase inhibitor, PP2, effectively abolished the anti-Thy-1 antibody-induced neurite outgrowth and the phosphorylation of MEK and CREB. CREB phosphorylation might result in upregulation of certain neurite outgrowth-related proteins. We therefore conclude that anti-Thy-1 antibody activates the c-Src kinase-MEK-CREB cascade and overcomes the inhibitory effect of Thy-1 on neurite outgrowth in DRG neurons.
Yang
Shih-Hung
SH
Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.
Chen
Yi-Jen
YJ
Tung
Po-Yuan
PY
Lai
Wei-Ling
WL
Chen
Ying
Y
Jeng
Chung-Jiuan
CJ
Wang
Seu-Mei
SM
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004789:Enzyme Activation; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology / Q000201:enzymology* / Q000276:immunology; D020935:MAP Kinase Signaling System; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016501:Neurites / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018800:Thy-1 Antigens / Q000276:immunology*
D000906:Antibodies; D017362:Cyclic AMP Response Element-Binding Protein; D047428:Protein Kinase Inhibitors; D018800:Thy-1 Antigens; D016392:Proto-Oncogene Proteins pp60(c-src); D020929:Mitogen-Activated Protein Kinase Kinases