Neurite Outgrowth Mediated by Translation Elongation Factor eEF1A1: A Target for Antiplatelet Agent Cilostazol

Abstract

Cilostazol, a type-3 phosphodiesterase (PDE3) inhibitor, has become widely used as an antiplatelet drug worldwide. A recent second Cilostazol Stroke Prevention Study demonstrated that cilostazol is superior to aspirin for prevention of stroke after an ischemic stroke. However, its precise mechanisms of action remain to be determined. Here, we report that cilostazol, but not the PDE3 inhibitors cilostamide and milrinone, significantly potentiated nerve growth factor (NGF)-induced neurite outgrowth in PC12 cells. Furthermore, specific inhibitors for the endoplasmic reticulum protein inositol 1,4,5-triphosphate (IP3) receptors and several common signaling pathways (PLC-γ, PI3K, Akt, p38 MAPK, and c-Jun N-terminal kinase (JNK), and the Ras/Raf/ERK/MAPK) significantly blocked the potentiation of NGF-induced neurite outgrowth by cilostazol. Using a proteomics analysis, we identified that levels of eukaryotic translation elongation factor eEF1A1 protein were significantly increased by treatment with cilostazol, but not cilostamide, in PC12 cells. Moreover, the potentiating effects of cilostazol on NGF-induced neurite outgrowth were significantly antagonized by treatment with eEF1A1 RNAi, but not the negative control of eEF1A1. These findings suggest that eEF1A1 and several common cellular signaling pathways might play a role in the mechanism of cilostazol-induced neurite outgrowth. Therefore, agents that can increase the eEF1A1 protein may have therapeutic relevance in diverse conditions with altered neurite outgrowth.

Differential regulation of proliferation and neuronal differentiation in adult rat spinal cord neural stem/progenitors by ERK1/2, Akt, and PLCγ

“…Previous studies on PC12, adult rat dorsal root ganglion neurons, and corticospinal motor neurons have reported that neurite outgrowth involves growth factor-mediated ERK1/2 activation (Hollis et al, 2009; Hashimoto and Ishima, 2011). To investigate whether the MEK/ERK1/2 pathway, as well as the PI3K/Akt and PLCγ signaling pathways played a role in neurite outgrowth, both neurite branching and the average length of the longest neurite of MAP2+ neurons were quantified in cultures treated with the corresponding inhibitors and vehicle control (Figures 5A,B).…”

Neurite outgrowth mediated by the heat shock protein Hsp90α: a novel target for the antipsychotic drug aripiprazole

“…15, 16, 17, 18 PC12 cells, a cell line derived from a pheochromocytoma of the rat adrenal medulla, are widely used as a model system for nerve growth factor (NGF)-induced neurite outgrowth. 19, 20, 21, 22, 23, 24, 25 It is reported that atypical antipsychotic drugs such as olanzapine, quetiapine and clozapine could enhance neurite outgrowth in PC12 cells. 15 A number of signaling molecules, including phospholipase C-γ (PLC-γ), phosphatidylinositol-3 kinase (PI3K), the mammalian target of rapamycin (mTOR), p38 MAPK, c-Jun N-terminal kinase (JNK), Akt and the Ras/Raf/ERK/MAPK pathways plays a role in the NGF-induced neurite outgrowth in PC12 cells.…”

“…15 A number of signaling molecules, including phospholipase C-γ (PLC-γ), phosphatidylinositol-3 kinase (PI3K), the mammalian target of rapamycin (mTOR), p38 MAPK, c-Jun N-terminal kinase (JNK), Akt and the Ras/Raf/ERK/MAPK pathways plays a role in the NGF-induced neurite outgrowth in PC12 cells. 19, 20, 21, 22, 23, 24, 25 To date, there are no reports on precisely how aripiprazole induces neurite outgrowth, although it is reported that this drug protects rat cortical neurons against glutamate toxicity. 26 …”

“…Second, we examined the role of intracellular Ca 2+ and the endoplasmic reticulum (ER) protein inositol 1,4,5-triphosphate (IP 3 ) receptors, on the potentiation of NGF-induced neurite outgrowth by aripiprazole, since Ca 2+ signaling via IP 3 receptors plays an important role in NGF-induced neurite outgrowth. 19, 20, 21, 22, 23, 24, 25 Third, we investigated the role of cellular signaling pathways on aripiprazole potentiation of NGF-induced neurite outgrowth. Finally, using proteomic analysis, we observed significantly increased levels of heat shock protein Hsp90α, one of the most abundant proteins in cells, 27, 28, 29, 30, 31, 32, 33, 34 after treatment with aripiprazole and speculate that this protein may promote NGF-induced neurite outgrowth.…”

Novel Interactive Partners of Neuroligin 3: New Aspects for Pathogenesis of Autism

“…EEF1A1 interacts with calcium/CaM and the binding site potentially located at a less flexible region from Asn311 to Gly327 (Kanibolotsky et al 2008). Hashimoto and Ishima reported that EEF1A1 might contribute to neurite outgrowth as a target of cilostazo, a selective inhibitor of 3-type phosphodiesterase (PDE3) (Hashimoto and Ishima 2011).…”