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The death receptor antagonist FAIM promotes neurite outgrowth by a mechanism that depends on ERK and NF-kapp B signaling.

Sole C, Dolcet X, Segura MF, Gutierrez H, Diaz-Meco MT, Gozzelino R, Sanchis D, Bayascas JR, Gallego C, Moscat J, Davies AM, Comella JX - J. Cell Biol. (2004)

Bottom Line: Whereas FAIM overexpression greatly enhanced neurite outgrowth from PC12 cells and sympathetic neurons grown with nerve growth factor (NGF), reduction of endogenous FAIM levels by RNAi decreased neurite outgrowth in these cells.The effect of FAIM on neurite outgrowth was also blocked by inhibition of the Ras-ERK pathway.These results reveal a new function of FAIM in promoting neurite outgrowth by a mechanism involving activation of the Ras-ERK pathway and NF-kappa B.

View Article: PubMed Central - PubMed

Affiliation: Group Cell Signalling and Apoptosis, Department of Basic Medical Sciences, Universitat de Lleida, 25008 Lleida, Spain.

ABSTRACT
Fas apoptosis inhibitory molecule (FAIM) is a protein identified as an antagonist of Fas-induced cell death. We show that FAIM overexpression fails to rescue neurons from trophic factor deprivation, but exerts a marked neurite growth-promoting action in different neuronal systems. Whereas FAIM overexpression greatly enhanced neurite outgrowth from PC12 cells and sympathetic neurons grown with nerve growth factor (NGF), reduction of endogenous FAIM levels by RNAi decreased neurite outgrowth in these cells. FAIM overexpression promoted NF-kappa B activation, and blocking this activation by using a super-repressor I kappa B alpha or by carrying out experiments using cortical neurons from mice that lack the p65 NF-kappa B subunit prevented FAIM-induced neurite outgrowth. The effect of FAIM on neurite outgrowth was also blocked by inhibition of the Ras-ERK pathway. Finally, we show that FAIM interacts with both Trk and p75 neurotrophin receptor NGF receptors in a ligand-dependent manner. These results reveal a new function of FAIM in promoting neurite outgrowth by a mechanism involving activation of the Ras-ERK pathway and NF-kappa B.

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FAIM interacts with TrkA and p75NTR receptors in an NGF-dependent manner. Wild-type PC12 cells were electroporated with FLAG-tagged FAIM-S and either TrkA-HA (A) or p75NTR-HA (B). After 48 h, the cells were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. TrkA-HA (A) or FAIM-FLAG (B) were immunoprecipitated from 1 mg of cell lysate followed by Western blotting with either FLAG or HA antibody. An IP with myc antibody was used as a negative IP control in B. A fraction of the lysate was blotted with FLAG, HA, or phospho-ERKs antibody (top). (C) Wild-type PC12 cells were electroporated with FLAG-FAIM-S and were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. FLAG-FAIM-S was immunoprecipitated from 1 mg of cell lysate with the FLAG antibody, and Western blotting was used to detect endogenous Trk with anti-Trk antibody 203 in the precipitates. A fraction of the lysate was blotted with FLAG or phospho-ERKs antibody (top).
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fig9: FAIM interacts with TrkA and p75NTR receptors in an NGF-dependent manner. Wild-type PC12 cells were electroporated with FLAG-tagged FAIM-S and either TrkA-HA (A) or p75NTR-HA (B). After 48 h, the cells were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. TrkA-HA (A) or FAIM-FLAG (B) were immunoprecipitated from 1 mg of cell lysate followed by Western blotting with either FLAG or HA antibody. An IP with myc antibody was used as a negative IP control in B. A fraction of the lysate was blotted with FLAG, HA, or phospho-ERKs antibody (top). (C) Wild-type PC12 cells were electroporated with FLAG-FAIM-S and were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. FLAG-FAIM-S was immunoprecipitated from 1 mg of cell lysate with the FLAG antibody, and Western blotting was used to detect endogenous Trk with anti-Trk antibody 203 in the precipitates. A fraction of the lysate was blotted with FLAG or phospho-ERKs antibody (top).

Mentions: NF-κB activation after NGF stimulation has been described to be mediated by TrkA and p75NTR (Carter et al., 1996; Hamanoue et al., 1999; Foehr et al., 2000; Wooten et al., 2001). To examine the possibility that FAIM interacts with the NGF receptors TrkA or p75, we performed immunoprecipitation experiments. Fig. 9 shows that FLAG-tagged FAIM is able to coimmunoprecipitate with both HA-tagged TrkA (Fig. 9 A) and HA-tagged p75 (Fig. 9 B) receptors upon NGF stimulation when these molecules are transfected in PC12 cells. Lysates from cells that were not stimulated with NGF failed to show any interaction, indicating that this interaction requires NGF receptor activation. We also used immunoprecipitation to investigate whether FAIM is able to interact with endogenous TrkA and whether this interaction is dependent on ligand binding. PC12 cells were transfected with FLAG-tagged FAIM and stimulated with and without NGF. Fig. 9 C shows that FLAG-tagged FAIM was able to coimmunoprecipitate with endogenous Trk but only when the cells had been stimulated with NGF. These data raise the possibility that FAIM influences NGF-induced neurite outgrowth by modulating activation of intracellular signaling pathways downstream of TrkA and p75.


The death receptor antagonist FAIM promotes neurite outgrowth by a mechanism that depends on ERK and NF-kapp B signaling.

Sole C, Dolcet X, Segura MF, Gutierrez H, Diaz-Meco MT, Gozzelino R, Sanchis D, Bayascas JR, Gallego C, Moscat J, Davies AM, Comella JX - J. Cell Biol. (2004)

FAIM interacts with TrkA and p75NTR receptors in an NGF-dependent manner. Wild-type PC12 cells were electroporated with FLAG-tagged FAIM-S and either TrkA-HA (A) or p75NTR-HA (B). After 48 h, the cells were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. TrkA-HA (A) or FAIM-FLAG (B) were immunoprecipitated from 1 mg of cell lysate followed by Western blotting with either FLAG or HA antibody. An IP with myc antibody was used as a negative IP control in B. A fraction of the lysate was blotted with FLAG, HA, or phospho-ERKs antibody (top). (C) Wild-type PC12 cells were electroporated with FLAG-FAIM-S and were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. FLAG-FAIM-S was immunoprecipitated from 1 mg of cell lysate with the FLAG antibody, and Western blotting was used to detect endogenous Trk with anti-Trk antibody 203 in the precipitates. A fraction of the lysate was blotted with FLAG or phospho-ERKs antibody (top).
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fig9: FAIM interacts with TrkA and p75NTR receptors in an NGF-dependent manner. Wild-type PC12 cells were electroporated with FLAG-tagged FAIM-S and either TrkA-HA (A) or p75NTR-HA (B). After 48 h, the cells were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. TrkA-HA (A) or FAIM-FLAG (B) were immunoprecipitated from 1 mg of cell lysate followed by Western blotting with either FLAG or HA antibody. An IP with myc antibody was used as a negative IP control in B. A fraction of the lysate was blotted with FLAG, HA, or phospho-ERKs antibody (top). (C) Wild-type PC12 cells were electroporated with FLAG-FAIM-S and were stimulated (+) or not (−) with 100 ng/ml NGF for 15 min. FLAG-FAIM-S was immunoprecipitated from 1 mg of cell lysate with the FLAG antibody, and Western blotting was used to detect endogenous Trk with anti-Trk antibody 203 in the precipitates. A fraction of the lysate was blotted with FLAG or phospho-ERKs antibody (top).
Mentions: NF-κB activation after NGF stimulation has been described to be mediated by TrkA and p75NTR (Carter et al., 1996; Hamanoue et al., 1999; Foehr et al., 2000; Wooten et al., 2001). To examine the possibility that FAIM interacts with the NGF receptors TrkA or p75, we performed immunoprecipitation experiments. Fig. 9 shows that FLAG-tagged FAIM is able to coimmunoprecipitate with both HA-tagged TrkA (Fig. 9 A) and HA-tagged p75 (Fig. 9 B) receptors upon NGF stimulation when these molecules are transfected in PC12 cells. Lysates from cells that were not stimulated with NGF failed to show any interaction, indicating that this interaction requires NGF receptor activation. We also used immunoprecipitation to investigate whether FAIM is able to interact with endogenous TrkA and whether this interaction is dependent on ligand binding. PC12 cells were transfected with FLAG-tagged FAIM and stimulated with and without NGF. Fig. 9 C shows that FLAG-tagged FAIM was able to coimmunoprecipitate with endogenous Trk but only when the cells had been stimulated with NGF. These data raise the possibility that FAIM influences NGF-induced neurite outgrowth by modulating activation of intracellular signaling pathways downstream of TrkA and p75.

Bottom Line: Whereas FAIM overexpression greatly enhanced neurite outgrowth from PC12 cells and sympathetic neurons grown with nerve growth factor (NGF), reduction of endogenous FAIM levels by RNAi decreased neurite outgrowth in these cells.The effect of FAIM on neurite outgrowth was also blocked by inhibition of the Ras-ERK pathway.These results reveal a new function of FAIM in promoting neurite outgrowth by a mechanism involving activation of the Ras-ERK pathway and NF-kappa B.

View Article: PubMed Central - PubMed

Affiliation: Group Cell Signalling and Apoptosis, Department of Basic Medical Sciences, Universitat de Lleida, 25008 Lleida, Spain.

ABSTRACT
Fas apoptosis inhibitory molecule (FAIM) is a protein identified as an antagonist of Fas-induced cell death. We show that FAIM overexpression fails to rescue neurons from trophic factor deprivation, but exerts a marked neurite growth-promoting action in different neuronal systems. Whereas FAIM overexpression greatly enhanced neurite outgrowth from PC12 cells and sympathetic neurons grown with nerve growth factor (NGF), reduction of endogenous FAIM levels by RNAi decreased neurite outgrowth in these cells. FAIM overexpression promoted NF-kappa B activation, and blocking this activation by using a super-repressor I kappa B alpha or by carrying out experiments using cortical neurons from mice that lack the p65 NF-kappa B subunit prevented FAIM-induced neurite outgrowth. The effect of FAIM on neurite outgrowth was also blocked by inhibition of the Ras-ERK pathway. Finally, we show that FAIM interacts with both Trk and p75 neurotrophin receptor NGF receptors in a ligand-dependent manner. These results reveal a new function of FAIM in promoting neurite outgrowth by a mechanism involving activation of the Ras-ERK pathway and NF-kappa B.

Show MeSH
Related in: MedlinePlus