Sango Kazunori, Yanagisawa Hiroko, Komuta Yukari, Si Yang, Kawano Hitoshi
Division of Neural Development and Regeneration, Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan.
Histochem Cell Biol. 2008 Oct;130(4):669-79. doi: 10.1007/s00418-008-0484-x. Epub 2008 Aug 5.
We observed that recombinant ciliary neurotrophic factor (CNTF) enhanced survival and neurite outgrowth of cultured adult rat dorsal root ganglion (DRG) neurons. Among other neurotrophic factors (NGF and GDNF) and interleukin (IL)-6 cytokine members [IL-6, LIF, cardiotrophin-1, and oncostatin M (OSM)] at the same concentration (50 ng/ml), CNTF, as well as LIF and OSM, displayed high efficacy for the promotion of the number of viable neurons and neurite-bearing cells. CNTF enhanced the number of neurite-bearing cells in both small neurons (soma diameter <30 microm) and large neurons (soma diameter > or =30 microm), whereas NGF and GDNF promoted that in only small neurons. Western blot analysis revealed that CNTF induced phosphorylation of STAT3, Akt, and ERK1/2 in the neurons. Furthermore, the neurite outgrowth-promoting activity of CNTF was diminished by co-treatment with Janus kinase (JAK) 2 inhibitor, AG490; STAT3 inhibitor, STA-21; phosphatidyl inositol-3'-phosphate-kinase (PI3K) inhibitor, LY294002; and mitogen-activated protein kinase kinase (MEK) inhibitor, PD98059, in a concentration-dependent manner. Its survival-promoting activity was also affected by AG490, STA-21, and LY294002 at higher concentrations, but not by PD98059. These findings suggest the involvement of JAK2/STAT3, PI3K/Akt, and MEK/ERK signaling pathways in CNTF-induced neurite outgrowth, where the former two pathways are thought to play major roles in mediating the survival response of neurons to CNTF.
我们观察到重组睫状神经营养因子（CNTF）可提高培养的成年大鼠背根神经节（DRG）神经元的存活率并促进其神经突生长。在相同浓度（50 ng/ml）的其他神经营养因子（NGF和GDNF）以及白细胞介素（IL）-6细胞因子家族成员[IL-6、LIF、心肌营养因子-1和制瘤素M（OSM）]中，CNTF以及LIF和OSM在促进存活神经元和有神经突细胞数量方面表现出高效能。CNTF可增加小神经元（胞体直径<30微米）和大神经元（胞体直径≥30微米）中有神经突细胞的数量，而NGF和GDNF仅促进小神经元中有神经突细胞数量的增加。蛋白质印迹分析显示，CNTF可诱导神经元中STAT3、Akt和ERK1/2的磷酸化。此外，与Janus激酶（JAK）2抑制剂AG490、STAT3抑制剂STA-21、磷脂酰肌醇-3'-磷酸激酶（PI3K）抑制剂LY294002以及丝裂原活化蛋白激酶激酶（MEK）抑制剂PD98059共同处理时，CNTF促进神经突生长的活性以浓度依赖性方式降低。其促进存活的活性在较高浓度下也受到AG490、STA-21和LY294002的影响，但不受PD98059的影响。这些发现表明JAK2/STAT3、PI3K/Akt和MEK/ERK信号通路参与了CNTF诱导的神经突生长，其中前两条通路被认为在介导神经元对CNTF的存活反应中起主要作用。
