title: CNTF protects neurons from hypoxic injury through the activation of STAT3pTyr705.
abstract: The aim of the present study was to investigate whether ciliary neurotrophic factor (CNTF) plays its neuroprotective role following hypoxic injury through the activation of signal transducer and activator of transcription 3 (STAT3) signaling. Firstly, to determine whether CNTF exerts its effects via STAT3 following hypoxic injury, cultured neurons from the cerebral cortex of mice were prepared and a neuronal model of hypoxia was then established. The neurons exposed to hypoxia were then pre-treated with CNTF and transfected with small interference RNA (siRNA) targeting STAT3 (STAT3 siRNA) using polybrene, or with STAT3Tyr705 mutant or STAT3Ser727 mutant using an electroporation system. The survival, proliferation and neurite outgrowth of the neurons subjected to different treatments were also determined. RT-qPCR and western blot analysis were employed to examine the expression levels of STAT3, p-STAT3Tyr705 and p-STAT3Ser727 following treatment with CNTF and other treatments. Our results revealed that treatment with CNTF: i) protected neurons from hypoxic injury by promoting survival and neurite growth; ii) induced a significant increase in the levels of STAT3, STAT3pTyr705 and the STAT3pTyr705/STAT3 ratio; it did not however, significantly affect the levels of STAT3pSer727 in the hypoxic cerebral cortex neurons. Transfection of the hypoxic neurons pre-treated with CNTF with STAT3 siRNA or STAT3Tyr705 neutralized the protective effects exerted by CNTF. The findings of our study thus demonstrate that CNTF protects neurons from hypoxic injury through the activation of STAT3pTyr705.
authors.affiliation: Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
authors.forename: Ying Li
authors.initials: YL
authors.lastname: Gu
authors.affiliation: Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
authors.forename: Guan Qun
authors.initials: GQ
authors.lastname: Gao
authors.affiliation: Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.affiliation: Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
authors.forename: Lin Lin
authors.initials: LL
authors.lastname: Ye
authors.affiliation: Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
authors.forename: Li Wei
authors.initials: LW
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
authors.forename: Zhuo Bo
authors.initials: ZB
authors.lastname: Zhang
mesh_terms: D000818:Animals; D015687:Cell Hypoxia; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D020934:Ciliary Neurotrophic Factor / Q000378:metabolism* / Q000494:pharmacology; D003062:Codon; D005786:Gene Expression Regulation; D020868:Gene Silencing; D051379:Mice; D009154:Mutation; D000071446:Neuronal Outgrowth / Q000187:drug effects / Q000235:genetics; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000378:metabolism / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D050796:STAT3 Transcription Factor / Q000235:genetics* / Q000378:metabolism*; D014443:Tyrosine / Q000235:genetics
chemical_list: D020934:Ciliary Neurotrophic Factor; D003062:Codon; D018696:Neuroprotective Agents; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; D014443:Tyrosine