Endogenous BDNF augments NMDA receptor phosphorylation in the spinal cord via PLCγ, PKC, and PI3K/Akt pathways during colitis.
Endogenous BDNF augments NMDA receptor phosphorylation in the spinal cord via PLCγ, PKC, and PI3K/Akt pathways during colitis.
复制标题
DOI：
10.1186/s12974-015-0371-z
复制
发表时间：
2015-08-20
影响因子：
9.3
通讯作者：
Qiao LY
中科院分区：
文献类型：
--
作者：
Liu M;Kay JC;Shen S;Qiao LY
脊髓中枢敏化是内脏高敏感性产生和维持的重要过程。脑源性神经营养因子（BDNF）从初级传入神经元释放到脊髓有助于脊髓神经元的可塑性，并增加神经元的活性和突触功效。N-甲基-D-天冬氨酸（NMDA）受体具有离子通道特性，其活性通过其亚基（包括NMDA受体1（NR 1））的磷酸化来调节。通过单剂量结肠内滴注三硝基苯磺酸（TNBS）诱导结肠炎症。用免疫印迹和免疫组织化学方法检测BDNF对NR 1的磷酸化作用。通过直接检查和使用特异性抑制剂来研究信号转导。在结肠炎期间，L1和S1脊髓背角区域的NR 1磷酸化Ser 896水平增加;通过向结肠炎动物注射BDNF中和抗体（36 μg/kg，静脉内（i. v.））并且在用TNBS处理的BDNF+/-大鼠中也减少。细胞外信号调节激酶（ERK）的激活不参与BDNF诱导的NR 1磷酸化。相比之下，磷脂酰肌醇3-激酶（PI 3 K）/Akt途径在体内和培养中介导BDNF诱导的NR 1磷酸化;这是磷脂酶C-γ（PLCγ）和蛋白激酶C（PKC）的另一条途径，广泛认为其在Ser 896磷酸化NR 1。在脊髓培养中，PLC（U 73122），PKC（双吲哚马来酰亚胺I）和PI 3 K（LY 294002）的抑制剂，但不MEK（PD 98059）阻断BDNF诱导的NR 1磷酸化。在患有结肠炎的动物中，用LY 294002（50 μg/kg，i. v.）阻断脊髓中Akt活性以及NR 1在Ser 896处的磷酸化。BDNF通过上调NR 1丝氨酸896位磷酸化参与结肠炎诱导的脊髓中枢敏化PI 3 K/Akt通路，以及PLCγ和PKC，在结肠炎期间介导脊髓中BDNF的作用。本文的在线版本（doi：10.1186/s12974-015-0371-z）包含补充材料，可供授权用户使用。
Spinal central sensitization is an important process in the generation and maintenance of visceral hypersensitivity. The release of brain-derived neurotrophic factor (BDNF) from the primary afferent neurons to the spinal cord contributes to spinal neuronal plasticity and increases neuronal activity and synaptic efficacy. The N-Methyl-D-aspartic acid (NMDA) receptor possesses ion channel properties, and its activity is modulated by phosphorylation of its subunits including the NMDA receptor 1 (NR1). Colonic inflammation was induced by a single dose of intracolonic instillation of tri-nitrobenzene sulfonic acid (TNBS). NR1 phosphorylation by BDNF in vivo and in culture was examined by western blot and immunohistochemistry. Signal transduction was studied by direct examination and use of specific inhibitors. During colitis, the level of NR1 phospho-Ser896 was increased in the dorsal horn region of the L1 and S1 spinal cord; this increase was attenuated by injection of BDNF neutralizing antibody to colitic animals (36 μg/kg, intravenous (i.v.)) and was also reduced in BDNF+/− rat treated with TNBS. Signal transduction examination showed that the extracellular signal-regulated kinase (ERK) activation was not involved in BDNF-induced NR1 phosphorylation. In contrast, the phosphatidylinositol 3-kinase (PI3K)/Akt pathway mediated BDNF-induced NR1 phosphorylation in vivo and in culture; this is an additional pathway to the phospholipase C-gamma (PLCγ) and the protein kinase C (PKC) that was widely considered to phosphorylate NR1 at Ser896. In spinal cord culture, the inhibitors to PLC (U73122), PKC (bisindolylmaleimide I), and PI3K (LY294002), but not MEK (PD98059) blocked BDNF-induced NR1 phosphorylation. In animals with colitis, treatment with LY294002 (50 μg/kg, i.v.) blocked the Akt activity as well as NR1 phosphorylation at Ser896 in the spinal cord. BDNF participates in colitis-induced spinal central sensitization by up-regulating NR1 phosphorylation at Ser896. The PI3K/Akt pathway, in addition to PLCγ and PKC, mediates BDNF action in the spinal cord during colitis. The online version of this article (doi:10.1186/s12974-015-0371-z) contains supplementary material, which is available to authorized users.