Combined extrinsic and intrinsic manipulations exert complementary neuronal enrichment in embryonic rat neural precursor cultures: An in vitro and in vivo analysis

摘要: Dysregulation of GABAergic signaling resulting in hyperexcitability is implicated a number CNS disorders, including epilepsy, basal ganglia movement disorders and neuropathic pain (Galvan Wichmann, 2007; Kleppner Tobin, 2001; Scholz et al., 2005). Most current therapeutic strategies for treating these involve the systemic administration drugs that compensate loss inhibitory signaling, sometimes producing undesirable cognitive behavioral side effects. Cell transplantation could potentially supplement deficient cell populations deliver focal, physiologically specific therapy. The cells has been shown to produce recovery animal models neurological (Bosch 2004; Carlson 2003; Eaton Gernert 2002). Endogenous spinal dorsal horn play major role inhibiting incoming nociceptive signals from periphery. endogenous cells, as well GAD expression, reported decrease animals with peripheral central injuries (Eaton 1998; Ibuki 1997; Moore 2002). Reversal mechanical allodynia after intrathecal injections GABA receptor agonists (Hao 1992; Hwang Yaksh, von Heijne 2001) or into lumbar cord 1999; 2007) suggests there may be close relationship between presence behaviors. Prospectively, replacement therapy can used treat caused by neurons injury 2003). However, requires considerable per graft, often several graft sites (Wolfe 2007). A renewable source such neural stem precursor provide adequate numbers numerous transplants over time (Caldwell 2001), immature neuronal exhibit enhanced viability integration host tissue (Alvarez-Dolado 2006). limitation this strategy majority multipotent rat (NPC) survive tend differentiate astrocytes (Cao particularly traumatically- ischemically-injured (Benton 2005; Cao This species-related some extent, human neurosphere grafts have express phenotypes injured (Akesson Astrocytes are thought they exacerbating chronic symptoms following nerve (Ji 2006) creating an impediment axonal regrowth (McKeon 1991). Transplantation undifferentiated (Hofstetter Macias Promising outcomes using more fully differentiated precursors (Lee pre-differentiated embryonic (Hendricks 2006), directed differentiation neurogenin-2 transduction suppress astrocytic 2005). Extracellular bring about changes gene expression control NPCs decision whether not differentiate, subsequently take on glial fate. Since default fate precursors, manipulating extrinsic intrinsic mechanisms lead yield enriched, self-renewing amenable vivo use. Thus, goal work advantage known molecular environmental enrich treatment injury-induced pain. FGF-2 promotes proliferation (Gritti 1996) represses through upregulation Notch (Faux Yoon 2004). Downregulating antineurogenic effectors FGF depriving exogenous FGF-2 appears important promoting neurogenesis gliogenesis vitro. It influenced undergo at expense vitro when concentration diminished (Qian 1997). Indeed, many protocols employ withdrawal their methodologies Ito Su 2007). In transgenic kinase-deficient receptors, developing nervous system results proneuronal basic helix-loop-helix (bHLH) transcription factor MATH1 (Jukkola 2006; Shin 2004) related member family, mammalian achaete-scute homolog 1 (MASH1), plays during early differentiation. MASH1 was first discovered crest (Guillemot 1993; Lo 1991) found involved forebrain interneuron development (Reviewed (Schuurmans Guillemot, held check effector HES1 multiple (Kageyama Sriuranpong 2002) until conditions allow proceed. neurogenic potential overexpression demonstrated cultured even postnatal (Berninger 2007a; Berninger 2007b; Farah 2000; Hamada Ikeda 2004). Thus, propagating overexpressing successive passages supply enriched population transplantable therapeutically desirable phenotype. study examined effects manipulation (FGF-2 deprivation) genetic (MASH1 overexpression), either independently concert, also survival adult rats. Preliminary findings presented abstract form (Furmanski 2008; Lee 2001).