Department of Neurology, Hannover Medical School, Hannover, Germany.
PLoS One. 2012;7(5):e36946. doi: 10.1371/journal.pone.0036946. Epub 2012 May 11.
Human fetal midbrain-derived neural progenitor cells (NPCs) may deliver a tissue source for drug screening and regenerative cell therapy to treat Parkinson's disease. While glutamate and GABA(A) receptors play an important role in neurogenesis, the involvement of glycine receptors during human neurogenesis and dopaminergic differentiation as well as their molecular and functional characteristics in NPCs are largely unknown.
METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated NPCs in respect to their glycine receptor function and subunit expression using electrophysiology, calcium imaging, immunocytochemistry, and quantitative real-time PCR. Whole-cell recordings demonstrate the ability of NPCs to express functional strychnine-sensitive glycine receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular analyses indicate a predominance of glycine receptor heteromers containing α2β subunits. Intracellular calcium measurements of differentiated NPCs suggest that glycine evokes depolarisations mediated by strychnine-sensitive glycine receptors and not by D-serine-sensitive excitatory glycine receptors. Culturing NPCs with additional glycine, the glycine-receptor antagonist strychnine, or the Na(+)-K(+)-Cl(-) co-transporter 1 (NKCC1)-inhibitor bumetanide did not significantly influence cell proliferation and differentiation in vitro.
CONCLUSIONS/SIGNIFICANCE: These data indicate that NPCs derived from human fetal midbrain tissue acquire essential glycine receptor properties during neuronal maturation. However, glycine receptors seem to have a limited functional impact on neurogenesis and dopaminergic differentiation of NPCs in vitro.
人胎中脑源性神经前体细胞（NPC）可作为药物筛选和再生细胞治疗帕金森病的组织来源。尽管谷氨酸和 GABA（A）受体在神经发生中起着重要作用，但甘氨酸受体在人类神经发生和多巴胺能分化中的作用，以及它们在 NPC 中的分子和功能特性在很大程度上仍是未知的。
方法/主要发现：在此，我们通过电生理学、钙成像、免疫细胞化学和实时定量 PCR 研究了 NPC 中的甘氨酸受体功能和亚基表达。全细胞记录显示，NPC 在体外分化 3 周后能够表达功能性士的宁敏感甘氨酸受体。药理学和分子分析表明，甘氨酸受体异源体主要含有 α2β 亚基。分化后的 NPC 的细胞内钙测量表明，甘氨酸通过士的宁敏感甘氨酸受体而不是 D-丝氨酸敏感兴奋性甘氨酸受体引发去极化。在体外培养 NPC 时添加甘氨酸、甘氨酸受体拮抗剂士的宁或 Na(+)-K(+)-Cl(-)共转运蛋白 1（NKCC1）抑制剂布美他尼，并不会显著影响细胞增殖和分化。
结论/意义：这些数据表明，源自人胎中脑组织的 NPC 在神经元成熟过程中获得了必需的甘氨酸受体特性。然而，甘氨酸受体似乎对 NPC 的神经发生和多巴胺能分化的体外功能影响有限。
