Extracellular‐Regulated Kinases and Phosphatidylinositol 3‐Kinase Are Involved in Brain‐Derived Neurotrophic Factor‐Mediated Survival and neuritogenesis of the Neuroblastoma Cell Line SH‐SY5Y

Abstract

Retinoic acid (RA) induces the differentiation of many cell lines, including those derived from neuroblastoma. RA treatment of SH-SY5Y cells induces the appearance of functional Trk B and Trk C receptors. Acute stimulation of RA-predifferentiated SH-SY5Y cells with brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), or neurotrophin 4/5 (NT-4/5), but not nerve growth factor (NGF), induces Trk autophosphorylation, followed by phosphorylation of Akt and the extracellular signalregulated kinases (ERKs) 1 and 2. In addition, BDNF, NT-3, or NT-4/5, but not NGF, promotes cell survival and neurite outgrowth in serum-free medium. The mitogenactivated protein kinase and ERK kinase (MEK) inhibitor PD98059 blocks BDNF-induced neurite outgrowth and growth-associated protein-43 expression but has no effects on cell survival. On the other hand, the phosphatidylinositol 3-kinase inhibitor LY249002 reverses the survival response elicited by BDNF, leading to a cell death with morphological features of apoptosis.

Altered Expression and Uptake Activity of Spinal Glutamate Transporters after Nerve Injury Contribute to the Pathogenesis of Neuropathic Pain in Rats

“…The above time course experiment revealed an initial GT upregulation after CCI (see Results). Because Trk receptors and MAPK have been shown to modulate GT expression (Danbolt, 2001), the effect of blocking Trk receptors and MAPK on GT expression and its relation to the induction of neuropathic pain behaviors were examined in CCI rats by using intrathecal K252a, a nonselective Trk receptor inhibitor, or PD98059, an inhibitor primarily for the extracellular signal-regulated kinase (ERK) members of MAPK (Encinas et al, 1999;Pascual et al, 2001;Troller et al, 2001). Five groups of rats (n ϭ 6 -8/group) were used, which included (1) CCI ϩ vehicle, (2) CCI ϩ K252a (0.5 g/10 l), (3 and 4) CCI ϩ PD98059 (1 g/10 l), and (5) sham ϩ vehicle.…”

“…Five groups of rats (n ϭ 6 -8/group) were used, which included (1) CCI ϩ vehicle, (2) CCI ϩ K252a (0.5 g/10 l), (3 and 4) CCI ϩ PD98059 (1 g/10 l), and (5) sham ϩ vehicle. The doses for K252a and PD98059 were based on previous and our pilot studies that showed reliable inhibition of Trk receptors and MAPK (Encinas et al, 1999;Pascual et al, 2001;Troller et al, 2001). Each treatment was given intrathecally twice a day for postoperative days 1-4 (groups 1, 2, 3, 5) or postoperative days 1-2 (group 4 -PD98059), beginning immediately after the operation.…”

“…Expression of neurotrophic factors in the dorsal root ganglion and spinal cord is upregulated dramatically under pathological conditions (Coffey et al, 1997;Li et al, 1999;Oyesiku et al, 1999;Ha et al, 2001), and such neurotrophic factors can be released into the spinal cord after peripheral nerve injury (Deng et al, 2000;Walker et al, 2001). Activation of Trk receptors in turn initiates downstream cascades, including activation of MAPK (Encinas et al, 1999;Hagemann and Blank, 2001). Activation of MAPK enhances gene expression for a variety of protein elements (Gegelashvili et al, 1997;Hagemann and Blank, 2001;Williams et al, 2001;Ji et al, 2002) and indeed has been shown to induce the expression of both GLT-1 mRNA and protein in astrocytes (Gegelashvili et al, 2000;Zelenaia et al, 2000).…”

Bcl-2 is a key regulator for the retinoic acid-induced apoptotic cell death in neuroblastoma

“…Recent works offer insights into the molecular mechanisms by which ATRA exerts its biological effects on neuroblastomas. All-trans-retinoic acid activates phosphatidylinositol 3 0 -kinase-Akt pathway that plays an important role in neuronal differentiation (Encinas et al, 1999;Lopez-Carballo et al, 2002), and it reduces the expression levels of MYCN (Thiele et al, 1985) and upregulates the cyclin-dependent kinase (CDK) inhibitor p27 KIP1 in association with the ATRA-induced cell cycle arrest in neuroblastoma cells (Lee et al, 1996;Nakamura et al, 2003). In addition, certain neuroblastoma cells underwent apoptosis in response to ATRA (Piacentini et al, 1992;Takada et al, 2001;Nagai et al, 2004).…”

Notch activation induces neurite remodeling and functional modifications in SH‐SY5Y neuronal cells

“…Human SH-SY5Y neuroblastoma cells were differentiated with a sequential treatment of retinoic acid and BDNF in order to obtain a nearly pure population of human neuronal differentiated cells (Encinas et al, 1999;Ferrari-Toninelli et al, 2004;Jämsä et al, 2004). After differentiation, cells presented many of the characteristics of primary cultured neurons including arrest in the G1 phase of cell cycle; they were also stable for at least 2-3 weeks showing neither signs of cellular degeneration nor reversion of the neuronal phenotype (Encinas et al, 2000).…”