ProNGF induces TNFalpha-dependent death of retinal ganglion cells through a p75NTR non-cell-autonomous signaling pathway.
Neurotrophin binding to the p75 neurotrophin receptor (p75(NTR)) activates neuronal apoptosis following adult central nervous system injury, but the underlying cellular mechanisms remain poorly defined. In this study, we show that the proform of nerve growth factor (proNGF) induces death of retinal ganglion cells in adult rodents via a p75(NTR)-dependent signaling mechanism. Expression of p75(NTR) in the adult retina is confined to Müller glial cells; therefore we tested the hypothesis that proNGF activates a non-cell-autonomous signaling pathway to induce retinal ganglion cell (RGC) death. Consistent with this, we show that proNGF induced robust expression of tumor necrosis factor alpha (TNFalpha) in Müller cells and that genetic or biochemical ablation of TNFalpha blocked proNGF-induced death of retinal neurons. Mice rendered null for p75(NTR), its coreceptor sortilin, or the adaptor protein NRAGE were defective in proNGF-induced glial TNFalpha production and did not undergo proNGF-induced retinal ganglion cell death. We conclude that proNGF activates a non-cell-autonomous signaling pathway that causes TNFalpha-dependent death of retinal neurons in vivo.
Department of Pathology and Cell Biology and Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montreal, Quebec H3C 3J7, Canada.
Frédéric
F
Lebrun-Julien
Mathieu J
MJ
Bertrand
Olivier
O
De Backer
David
D
Stellwagen
Carlos R
CR
Morales
Adriana
A
Di Polo
Philip A
PA
Barker
D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D020932:Nerve Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000502:physiology*; D000099183:Sortilin
D033942:Adaptor Proteins, Vesicular Transport; D020932:Nerve Growth Factor; D020800:Receptor, Nerve Growth Factor; D014409:Tumor Necrosis Factor-alpha; D000099183:Sortilin