Molecular mechanism of cerebral ischemia through Jak-Stat signaling

Jak-Stat信号传导脑缺血的分子机制

• 批准号: 16591444
• 负责人: HATA Ryuji
• 金额: $ 2.24万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16591444/
• 关键词: cerebral ischemia; cytokine; Stat3; Neuronal death; apoptosis

Introduction :Cerebral ischemia induces the expression of a number of growth factors and cytokines that can protect neurons against ischemic brain injury. For example, ciliary neurotrophic factor (CNTF), epidermal growth factor (EGF) and interleukin-6 (IL-6) have been shown to promote Stat3 activation. These growth factors and cytokines can activate Janus protein tyrosine kinases (Jaks)/signal transducers and activators of transcription (Stat) pathways. Recently, we reported that Stat3 was activated following cerebral ischemia in mouse [1]. However, little is known about the function of activated Stat3 in the ischemic brain. Here we demonstrate the increased expression of activated Stat3 promotes cell death in cultured astrocyres.Methods & Results :Astrocytes from the forebrains of newborn rats were cultured. Recombinant adenovirus expressing Stat3 wild type (St3.Wt), Stat3 dominant negative type (St3.DN) and LacZ were constructed as described previously [2]. Astocytes were exposed to … More adenovirus vector expressing Stat3.Wt, Stat3.DN or LacZ (multiplicity of infection 10) for 2h and incubated with a virus free fresh medium up to 72h. Three days later, inoculation with the virus vectors expressing St3.wt and St3.DN remarkably induced Stat3 protein compared with the control (LacZ). Western blots also revealed that Ad.St3.wt remarkably induced p-Stat3(Tyr-705) while Ad.St3.DN and Ad.LacZ did not. These results demonstrated that both Ad.St3.Wt and Ad.St3.DN induced Stat3 protein in cultured astrocytes and that only Ad.St3.Wt could phosphorylate Stat3 at Tyr-705 site and activate Stat3. LDH assay revealed that overexpression of St3.wt promoted cell death while overexpression of St3.DN and LacZ did not. In addition, caspase-3 like activity of the St3.Wt treated group was significantly increased than that of the St3.DN group at 2d after virus inoculation.Conclusion :We have shown that over-expression of Stat3 promotes cell death in cultured astrocytes, and activation of caspase-3 activity may be involved in this cell death mechanism. These data have revealed that activation of Stat3 can play a crucial role in the mechanism of ischemic cell death.References :[1]Wen et al. ; Neurosci Lett, 303:153-156, (2001)[2]Nakajima et al. ; EMBO J, 15:3651-58 (1996) Less

前言：脑缺血可诱导多种生长因子和细胞因子的表达，从而保护神经元免受缺血性脑损伤。例如，睫状神经营养因子(CNTF)、表皮生长因子(EGF)和白介素6(IL-6)被证明可以促进STAT3的激活。这些生长因子和细胞因子可以激活Janus蛋白酪氨酸激酶(JAKs)/信号转导和转录激活因子(Stat)通路。最近，我们报道了小鼠脑缺血后STAT3被激活[1]。然而，人们对激活的STAT3在脑缺血中的作用知之甚少。在这里，我们证明了在培养的星形胶质细胞中，激活的STAT3的表达增加促进了细胞死亡。方法与结果：培养新生大鼠前脑的星形胶质细胞。如前所述，构建了表达STAT3野生型(St3.Wt)、STAT3显性阴性型(St3.dN)和LacZ的重组腺病毒。星形胶质细胞暴露于…更多的表达Stat3、Wt、Stat3、Dn或LacZ(感染复数为10)的腺病毒载体，在无病毒的新鲜培养液中孵育至72小时。3天后，表达St3.wt和St3.Dn的病毒载体与对照(LacZ)相比，显著诱导了STAT3蛋白的表达。Western blotting还表明，Ad.St3.wt能显著诱导p-STAT3(Tyr-705)，而Ad.St3.dN和Ad.LacZ则不能。这些结果表明，Ad.St3.Wt和Ad.St3.Dn均能诱导培养的星形胶质细胞中STAT3蛋白的表达，并且只有Ad.St3.Wt能磷酸化Tyr-705位点的STAT3并激活STAT3。乳酸脱氢酶检测显示，St3.wt过表达促进细胞死亡，而St3.dN和LacZ过表达不促进细胞死亡。结论：STAT3的过度表达促进了星形胶质细胞的死亡，caspase-3活性的激活可能参与了这一细胞死亡机制。这些数据表明，STAT3的激活在缺血性细胞死亡的机制中起着至关重要的作用。参考文献：[1]文等。Nurosci Lett，303：153-156，(2001)[2]Nakajima等.《EMBO J》，15：3651-58(1996)少

项目成果

Identification of hippocampus-related candidate genes for Alzheimer's disease

• DOI: 10.1002/ana.20433
• 发表时间: 2005-04-01
• 期刊: ANNALS OF NEUROLOGY
• 影响因子: 11.2
• 作者: Taguchi, K;Yamagata, HD;Miki, T
• 通讯作者: Miki, T

Suppression of Stat3 promotes neurogenesis in cultured neural star cells.

抑制 Stat3 可促进培养的神经星细胞中的神经发生。

• 发表时间: 2005
• 期刊: J Neurosci Res. 86
• 作者: Gu F;Hata R;Ma YJ;Tanaka J;Mitsuda N;Kumon Y;Hanakawa Y;Hashimoto K;Nakajima K;Sakanaka M.
• 通讯作者: Sakanaka M.

Protective effect of vitamin E against focal brain ischemia and neuronal death through induction of target genes of hypoxia-inducible factor-1.

维生素 E 通过诱导缺氧诱导因子 1 的靶基因对局灶性脑缺血和神经元死亡发挥保护作用。

• 发表时间: 2004
• 期刊: Neuroscience 126
• 作者: Zhang;B.;Tanaka;J.;Yang;L.;Yang;L.;Sakanaka;M.;Hata;R.;Maeda;N.;Mitsuda;N.
• 通讯作者: N.

Suppression of Stat3 promotes neurogenesis in cultured neural stem cells

• DOI: 10.1002/jnr.20561
• 发表时间: 2005-07-15
• 期刊: JOURNAL OF NEUROSCIENCE RESEARCH
• 影响因子: 4.2
• 作者: Gu, F;Hata, R;Sakanaka, M
• 通讯作者: Sakanaka, M

Possible inhibition of focal cerebral ischemia by angiotensin 11 type 2 receptor stimulation

血管紧张素 11 2 型受体刺激可能抑制局灶性脑缺血

• 发表时间: 2004
• 期刊: Circulation 110
• 作者: Iwai;M.;Liu H.W.;Chen R.;Ide A.;Okamoto S.;Hata R.;Sakanaka M.;Shiuchi T.;Horiuchi M.
• 通讯作者: Horiuchi M.