Mishra Santosh K, Braun Norbert, Shukla Varsha, Füllgrabe Marc, Schomerus Christof, Korf Horst-Werner, Gachet Christian, Ikehara Yukio, Sévigny Jean, Robson Simon C, Zimmermann Herbert
Biocenter, J.W. Goethe-University, AK Neurochemistry, Frankfurt am Main, Germany.
Development. 2006 Feb;133(4):675-84. doi: 10.1242/dev.02233.
We have previously shown that the extracellular nucleoside triphosphate-hydrolyzing enzyme NTPDase2 is highly expressed in situ by stem/progenitor cells of the two neurogenic regions of the adult murine brain: the subventricular zone (type B cells) and the dentate gyrus of the hippocampus (residual radial glia). We explored the possibility that adult multipotent neural stem cells express nucleotide receptors and investigated their functional properties in vitro. Neurospheres cultured from the adult mouse SVZ in the presence of epidermal growth factor and fibroblast growth factor 2 expressed the ecto-nucleotidases NTPDase2 and the tissue non-specific isoform of alkaline phosphatase, hydrolyzing extracellular ATP to adenosine. ATP, ADP and, to a lesser extent, UTP evoked rapid Ca(2+) transients in neurospheres that were exclusively mediated by the metabotropic P2Y(1) and P2Y(2) nucleotide receptors. In addition, agonists of these receptors and low concentrations of adenosine augmented cell proliferation in the presence of growth factors. Neurosphere cell proliferation was attenuated after application of the P2Y(1)-receptor antagonist MRS2179 and in neurospheres from P2Y(1)-receptor knockout mice. In situ hybridization identified P2Y(1)-receptor mRNA in clusters of SVZ cells. Our results infer nucleotide receptor-mediated synergism that augments growth factor-mediated cell proliferation. Together with the in situ data, this supports the notion that extracellular nucleotides contribute to the control of adult neurogenesis.
我们之前已经表明，细胞外核苷三磷酸水解酶NTPDase2在成年小鼠脑两个神经发生区域的干/祖细胞中高度原位表达：脑室下区（B型细胞）和海马齿状回（残留放射状胶质细胞）。我们探讨了成年多能神经干细胞表达核苷酸受体的可能性，并在体外研究了它们的功能特性。在表皮生长因子和成纤维细胞生长因子2存在的情况下，从成年小鼠脑室下区培养的神经球表达外切核苷酸酶NTPDase2和碱性磷酸酶的组织非特异性同工型，将细胞外ATP水解为腺苷。ATP、ADP以及程度较轻的UTP在神经球中引发快速的Ca(2+)瞬变，这完全由代谢型P2Y(1)和P2Y(2)核苷酸受体介导。此外，这些受体的激动剂和低浓度的腺苷在生长因子存在的情况下增强了细胞增殖。应用P2Y(1)受体拮抗剂MRS2179后以及在来自P2Y(1)受体敲除小鼠的神经球中，神经球细胞增殖减弱。原位杂交在脑室下区细胞簇中鉴定出P2Y(1)受体mRNA。我们的结果推断核苷酸受体介导的协同作用增强了生长因子介导的细胞增殖。连同原位数据，这支持了细胞外核苷酸有助于控制成年神经发生的观点。
