Instituto de Biología Molecular y Celular de Rosario (IBR- CONICET) Ocampo y Esmeralda, Predio CONICET and Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, 2000, Argentina.
INIBIBB-UNS-CONICET, Camino La Carrindanga KM 7, Bahía Blanca, 8000, Argentina.
Mol Neurobiol. 2016 Nov;53(9):6316-6331. doi: 10.1007/s12035-015-9528-0. Epub 2015 Nov 14.
Neuronal differentiation plays a key role during embryogenesis. However, based on the capacity of neuronal stem cells to either generate or regenerate neurons and because differentiation stops aberrant neuroblasts proliferation, neuronal differentiation is crucial during neuropathological conditions. Although phosphatidylcholine (PtdCho) has been proposed as an important molecule for neurite growth and neuronal regeneration, the identity of the molecular target has remained elusive. This study originally describes that lysophosphatidylcholine (LPtdCho), either exogenously supplied or generated by the imbalance of PtdCho metabolism through the enzymatic action of cytosolic phospholipase A, acts as a neurotrophic-like factor. We demonstrated that LPtdCho induces neuronal differentiation by activation of the small G protein Ras followed by the Raf/MEK/ERK signaling pathway. Accordingly, LPtdCho redirects neuroblasts gene expression leading to the generation of functional mature neurons expressing βIII-tubulin and having increased acetylcholinesterase activity and membrane biosynthesis required for neuritogenesis. These findings provide mechanistic details of the role of cytidine-5-diphosphocholine (CDP-choline) and PtdCho as neuroprotectors. Furthermore, as LPtdCho recapitulates the effect of the therapeutic agent retinoic acid, these results open new avenues for drug discovery for the treatment of neuropathological conditions.
神经元分化在胚胎发生过程中起着关键作用。然而,基于神经元干细胞产生或再生神经元的能力,并且由于分化停止异常神经母细胞的增殖,神经元分化在神经病理学条件下是至关重要的。尽管磷脂酰胆碱(PtdCho)已被提议作为神经突生长和神经元再生的重要分子,但分子靶标的身份仍然难以捉摸。本研究最初描述了溶血磷脂酰胆碱(LPtdCho),无论是通过细胞质磷脂酶 A 的酶促作用从外源性供应还是从 PtdCho 代谢的失衡中产生,都作为一种神经营养样因子发挥作用。我们证明 LPtdCho 通过激活小 G 蛋白 Ras 诱导神经元分化,随后是 Raf/MEK/ERK 信号通路。因此,LPtdCho 重新定向神经母细胞基因表达,导致生成功能性成熟神经元,表达 βIII-微管蛋白,并增加乙酰胆碱酯酶活性和膜生物合成,这是神经突发生所必需的。这些发现提供了胞苷-5-二磷酸胆碱(CDP-胆碱)和 PtdCho 作为神经保护剂的作用的机制细节。此外,由于 LPtdCho 再现了治疗剂维甲酸的作用,这些结果为治疗神经病理学条件的药物发现开辟了新途径。