Neurites from PC12 cells are connected to each other by synapse-like structures.
PC12 cells have been used as a model of sympathetic neurons. Nerve growth factor (NGF), basic fibroblast growth factor (bFGF), and cAMP induce neurite outgrowth from PC12 cells. cAMP induced a greater number of neurites than did NGF. In particular, we attempted to elucidate whether PC12 cell neurites, induced by several factors including NGF, bFGF, and cAMP, form synapses, and whether each neurite has presynaptic and postsynaptic properties. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), we observed that neurites are connected to each other. The connected regions presented dense core vesicles and a clathrin-coated membrane invagination. In addition, typical maker proteins for axon and dendrite were identified by an immuno-staining method. Tau-1, an axonal marker in neurons, was localized at a high concentration in the terminal tips of neurites from PC12 cells, which were connected to neurite processes containing MAP-2, a dendritic marker in neurons. Furthermore, neurites containing SV2 and synaptotagmin, markers of synaptic vesicles, were in contact with neurites harboring drebrin, a marker of the postsynaptic membrane, suggesting that neurites from PC12 cells induced by NGF, bFGF, and cAMP may form synapse-like structures. Tat-C3 toxin, a Rho inhibitor, augmented neurite outgrowth induced by NGF, bFGF, and cAMP. Tat-C3 toxin together with neurotrophins also exhibited synapse-like structures between neurites. However, it remains to be studied whether RhoA inhibition plays a role in the formation of synapse-like structures in PC12 cells.
Jeon
Chan-Young
CY
Department of Biochemistry, College of Medicine, Hallym University, Chuncheon, Kangwon-Do, 200-702, Republic of Korea.
Jin
Jae-Kwang
JK
Koh
Young-Ho
YH
Chun
Wook
W
Choi
Ihn-Geun
IG
Kown
Hyung-Joo
HJ
Kim
Yong-Sun
YS
Park
Jae-Bong
JB
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D000242:Cyclic AMP / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000378:metabolism; D008854:Microscopy, Electron / Q000379:methods; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D020932:Nerve Growth Factor / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016501:Neurites / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D016716:PC12 Cells / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D013569:Synapses / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D050857:Synaptotagmins / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000378:metabolism
D000911:Antibodies, Monoclonal; D004791:Enzyme Inhibitors; C489787:MAP2 protein, rat; D008562:Membrane Glycoproteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; C489618:Sv2a protein, rat; C085348:tau-1 monoclonal antibody; D016222:Fibroblast Growth Factor 2; D050857:Synaptotagmins; D020932:Nerve Growth Factor; D000242:Cyclic AMP; D020742:rhoA GTP-Binding Protein