BDNF及其受体Trk B在低氧预适应小鼠中的表达变化和作用
|
摘要
目的探究BDNF、TrkB受体及BDNF/TrkB信号通路在急性低氧与低氧预适应小鼠中的表达变化及作用,进一步完善低氧预适应神经保护的分子机制,为低氧预适应的临床应用提供理论依据。方法以ICR小鼠为对象,分别构建急性低氧与低氧预适应小鼠模型,模型构建完成0～4 d后,通过Western blot、real-time PCR技术,检测小鼠海马脑区BDNF、TrkB受体在早期相和晚期相的表达及BDNF/TrkB信号通路活性的变化。结果研究发现随着小鼠低氧次数的增加,耐受时间明显增加(P<0. 05);较对照组,急性低氧和低氧预适应组BDNF及全长型TrkB受体表达有增加的趋势,在低氧预适应早期相BDNF蛋白水平表达显著增加(P<0. 05)。较对照组,截短型TrkB受体表达则有降低的趋势,在低氧预适应中、晚期相其mRNA表达显著降低(P<0. 05);较对照组,急性低氧组BDNF/TrkB信号通路活性被抑制,而低氧预适应组BDNF/TrkB信号通路活性有增加的趋势,且在晚期相差异有显著性(P<0. 05)。结论低氧预适应可能是通过上调BDNF表达并增加其与TrkB受体的结合,以及下调截短型TrkB受体表达,减少异二聚体形成,从而共同激活BDNF/TrkB信号通路,最终对小鼠产生神经保护作用。
Objective To explore the expression and mechanism of BDNF and TrkB receptors under acute hypoxia and hypoxic preconditioning, and to provide a reference for the study and clinical application of hypoxic preconditioning. Methods A model of acute hypoxia and hypoxic preconditioning was generated in ICR mice. After 0-4 days,the hippocampus was isolated from the brains of hypoxic mice,and the protein and gene expressions of BDNF and itsreceptor TrkB were detected by Western blot and real-time PCR. Results The study found that the tolerance time was increased significantly with the increased amount of hypoxia in mice( P < 0. 05). Compared with the control group,the expression of BDNF and the full-length TrkB receptor in the hypoxia group was increased,and the expression of BDNF protein was significantly increased in the early phase of hypoxic preconditioning( P < 0. 05). Compared with the control group,the expression of the truncated TrkB receptor was decreased,and the expression of mRNA was significantly decreased in the middle and late phase of hypoxic preconditioning( P<0. 05). Compared with the control group,the activity of the BDNF/TrkB signaling pathway was inhibited in the acute hypoxia group and increased in the hypoxic preconditioning group. The activity of the BDNF/TrkB signaling pathway was significantly increased in the late phase( P < 0. 05).Conclusions Hypoxic preconditioning may be mediated by upregulating the binding between BDNF and TrkB,downregulating the expression of truncated TrkB,reducing the formation of heterodimers,and co-activating the BDNF/TrkB signaling pathway,which ultimately has a neuroprotective effect in mice.
Objective To explore the expression and mechanism of BDNF and TrkB receptors under acute hypoxia and hypoxic preconditioning, and to provide a reference for the study and clinical application of hypoxic preconditioning. Methods A model of acute hypoxia and hypoxic preconditioning was generated in ICR mice. After 0-4 days,the hippocampus was isolated from the brains of hypoxic mice,and the protein and gene expressions of BDNF and itsreceptor TrkB were detected by Western blot and real-time PCR. Results The study found that the tolerance time was increased significantly with the increased amount of hypoxia in mice( P < 0. 05). Compared with the control group,the expression of BDNF and the full-length TrkB receptor in the hypoxia group was increased,and the expression of BDNF protein was significantly increased in the early phase of hypoxic preconditioning( P < 0. 05). Compared with the control group,the expression of the truncated TrkB receptor was decreased,and the expression of mRNA was significantly decreased in the middle and late phase of hypoxic preconditioning( P<0. 05). Compared with the control group,the activity of the BDNF/TrkB signaling pathway was inhibited in the acute hypoxia group and increased in the hypoxic preconditioning group. The activity of the BDNF/TrkB signaling pathway was significantly increased in the late phase( P < 0. 05).Conclusions Hypoxic preconditioning may be mediated by upregulating the binding between BDNF and TrkB,downregulating the expression of truncated TrkB,reducing the formation of heterodimers,and co-activating the BDNF/TrkB signaling pathway,which ultimately has a neuroprotective effect in mice.
引文
[1] Fu S,Dong S,Zhu M,et al. VEGF as a trophic factor for Müller glia in hypoxic retinal diseases[J]. Adv Exp Med Biol,2018,1(4):473-478.
[2] Falck M, Osredkar D, Maes E, et al. Hypothermia is neuroprotective after severe hypoxic-ischaemic brain injury in neonatal rats pre-exposed to PAM3CSK4[J]. Dev Neurosci,2018,6(1):1-9.
[3] Cho Y,Shin J E,Ewan E E,et al. Activating injury-responsive genes with hypoxia enhances axon regeneration through neuronal HIF-1α[J]. Neuron,2015,88(4):720-734.
[4]侯林,许晟迪,张柱霞,等. Hamartin在低氧/缺血耐受中的作用[J].中国比较医学杂志,2017,27(8):85-88.
[5] Wang W,Wang Y,Deng G,et al. Transplantation of hypoxicpreconditioned bone mesenchymal stem cells retards intervertebral disc degeneration via enhancing implanted cell survival and migration in rats[J]. Stem Cells Int,2018,2018(2):41-59.
[6] Miller JK,Mcdougal S,Thomas S,et al. The impact of the brain-derived neurotrophic factor gene on trauma and spatial processing[J]. J Clin Med,2017,6(12):108-119.
[7] Ye X,Yu L,Zuo D,et al. Activated m GluR5 protects BV2 cells against OGD/R induced cytotoxicity by modulating BDNF-TrkB pathway[J]. Neurosci Lett,2017,654:70-79.
[8] Namazi H,Ghiasi P,Namazi I,et al. Exosomes secreted by normoxic and hypoxic cardiosphere-derived cells have antiapoptotic effect[J] Iran J Pharm Res,2017,17(1):58-69.
[9] Zhong J B,Li X,Zhong S M,et al. Knockdown of long noncoding antisense RNA brain-derived neurotrophic factor attenuates hypoxia/reoxygenation-induced nerve cell apoptosis through the BDNF-TrkB-PI3K/Akt signaling pathway[J].Neuroreport,2017,28(14):910-921.
[10] Yu H,Yang Z,Pan S,et al. Hypoxic preconditioning promotes the translocation of protein kinase Cbinding with caveolin-3 at cell membrane not mitochondrial in rat heart[J]. Cell Cycle,2015,14(22):3557-3565.
[11] Lavezzi AM, Ferrero S, Lattuada D, et al. Pathobiological expression of the brain-derived neurotrophic factor(BDNF)in cerebellar cortex of sudden fetal and infant death victims[J]. Int J Dev Neurosci,2017,23(66):9-17.
[12] Sciesielski LK, Paliege A, Martinka P, et al. Enhanced pulmonary expression of the TrkB neurotrophin receptor in hypoxic rats is associated with increased acetylcholine-induced airway contractility[J]. Acta Physiol(Oxf),2009,197(3):253-264.
[13] Lima-Ojeda JM, Mallien AS, Brandwein C, et al. Altered prepulse inhibition of the acoustic startle response in BDNFdeficient mice in a model of early postnatal hypoxia:implications for schizophrenia[J]. Eur Arch Psychiatry Clin Neurosci,2018,1(1):1-9.
[14] Sui WH,Huang SH,Wang J,et al. Myosin Va mediates BDNFinduced postendocytic recycling of full-length TrkB and its translocation into dendritic spines[J]. J Cell Sci,2015,128(6):1108-1122.
[15] Luo J,Zheng H,Zhang L,et al. High-frequency repetitive transcranial magnetic stimulation(r TMS)improves functional recovery by enhancing neurogenesis and activating BDNF/TrkB signaling in ischemic rats[J]. Int J Mol Sc,2017,18(2):455-467.
[16] Tian X,Hua F,Sandhu H,et al. Effect ofδ-opioid receptor activation on BDNF-TrkB vs. TNF-αin the mouse cortex exposed to prolonged hypoxia[J]. Int J Mol Sci,2013,14(8):59-76.
[17] Narumiya S,Ohno M,Tanaka N,et al. Enhanced expression of full-length TrkB receptors in young rat brain with hypoxic/ischemic injury[J]. Brain Research,2017,797(2):278-286.
[2] Falck M, Osredkar D, Maes E, et al. Hypothermia is neuroprotective after severe hypoxic-ischaemic brain injury in neonatal rats pre-exposed to PAM3CSK4[J]. Dev Neurosci,2018,6(1):1-9.
[3] Cho Y,Shin J E,Ewan E E,et al. Activating injury-responsive genes with hypoxia enhances axon regeneration through neuronal HIF-1α[J]. Neuron,2015,88(4):720-734.
[4]侯林,许晟迪,张柱霞,等. Hamartin在低氧/缺血耐受中的作用[J].中国比较医学杂志,2017,27(8):85-88.
[5] Wang W,Wang Y,Deng G,et al. Transplantation of hypoxicpreconditioned bone mesenchymal stem cells retards intervertebral disc degeneration via enhancing implanted cell survival and migration in rats[J]. Stem Cells Int,2018,2018(2):41-59.
[6] Miller JK,Mcdougal S,Thomas S,et al. The impact of the brain-derived neurotrophic factor gene on trauma and spatial processing[J]. J Clin Med,2017,6(12):108-119.
[7] Ye X,Yu L,Zuo D,et al. Activated m GluR5 protects BV2 cells against OGD/R induced cytotoxicity by modulating BDNF-TrkB pathway[J]. Neurosci Lett,2017,654:70-79.
[8] Namazi H,Ghiasi P,Namazi I,et al. Exosomes secreted by normoxic and hypoxic cardiosphere-derived cells have antiapoptotic effect[J] Iran J Pharm Res,2017,17(1):58-69.
[9] Zhong J B,Li X,Zhong S M,et al. Knockdown of long noncoding antisense RNA brain-derived neurotrophic factor attenuates hypoxia/reoxygenation-induced nerve cell apoptosis through the BDNF-TrkB-PI3K/Akt signaling pathway[J].Neuroreport,2017,28(14):910-921.
[10] Yu H,Yang Z,Pan S,et al. Hypoxic preconditioning promotes the translocation of protein kinase Cbinding with caveolin-3 at cell membrane not mitochondrial in rat heart[J]. Cell Cycle,2015,14(22):3557-3565.
[11] Lavezzi AM, Ferrero S, Lattuada D, et al. Pathobiological expression of the brain-derived neurotrophic factor(BDNF)in cerebellar cortex of sudden fetal and infant death victims[J]. Int J Dev Neurosci,2017,23(66):9-17.
[12] Sciesielski LK, Paliege A, Martinka P, et al. Enhanced pulmonary expression of the TrkB neurotrophin receptor in hypoxic rats is associated with increased acetylcholine-induced airway contractility[J]. Acta Physiol(Oxf),2009,197(3):253-264.
[13] Lima-Ojeda JM, Mallien AS, Brandwein C, et al. Altered prepulse inhibition of the acoustic startle response in BDNFdeficient mice in a model of early postnatal hypoxia:implications for schizophrenia[J]. Eur Arch Psychiatry Clin Neurosci,2018,1(1):1-9.
[14] Sui WH,Huang SH,Wang J,et al. Myosin Va mediates BDNFinduced postendocytic recycling of full-length TrkB and its translocation into dendritic spines[J]. J Cell Sci,2015,128(6):1108-1122.
[15] Luo J,Zheng H,Zhang L,et al. High-frequency repetitive transcranial magnetic stimulation(r TMS)improves functional recovery by enhancing neurogenesis and activating BDNF/TrkB signaling in ischemic rats[J]. Int J Mol Sc,2017,18(2):455-467.
[16] Tian X,Hua F,Sandhu H,et al. Effect ofδ-opioid receptor activation on BDNF-TrkB vs. TNF-αin the mouse cortex exposed to prolonged hypoxia[J]. Int J Mol Sci,2013,14(8):59-76.
[17] Narumiya S,Ohno M,Tanaka N,et al. Enhanced expression of full-length TrkB receptors in young rat brain with hypoxic/ischemic injury[J]. Brain Research,2017,797(2):278-286.