Abe Yumiko, Akeda Koji, An Howard S, Aoki Yasuchika, Pichika Rajeswari, Muehleman Carol, Kimura Tomoatsu, Masuda Koichi
Department of Orthopedic Surgery, Rush Medical College at Rush University Medical Center, Chicago IL, USA.
Spine (Phila Pa 1976). 2007 Mar 15;32(6):635-42. doi: 10.1097/01.brs.0000257556.90850.53.
In vitro studies of the effects of proinflammatory cytokines on the production of nerve growth factor (NGF) by human intervertebral disc (IVD) cells.
To determine the constitutive expression and production of NGF and the effect of cytokines on the expression of NGF by human IVD cells.
NGF may play a role in the collateral sprouting of sensory axons, neural survival, and regulation of nociceptive sensory neurons. NGF is known to be up-regulated by proinflammatory cytokines.
The presence of NGF protein was analyzed by immunohistochemistry using human IVD cells obtained from cadaveric human spines with no known disc disease (MRI Thompson grades 2-4). The effects of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) on NGF production and mRNA expression of NGF by IVD cells were examined. The expression of NGF receptors, trkA and p75, was also assessed immunohistochemically.
Cadaveric anulus fibrosus (AF) and nucleus pulposus (NP) cells cultured in vitro in monolayer and in alginate beads positively stained with an anti-NGF antibody. The constitutive production of NGF protein in IVD cells was low (NP) or not detectable (AF). The expression of NGF mRNA was detectable in both cell types. IL-1beta and TNF-alpha up-regulated the NGF mRNA expression and the secretion of NGF protein into the media. TrkA was immunolocalized in AF and NP cells.
Our results demonstrate, for the first time, that human AF and NP cells constitutively express NGF protein and mRNA, and that the proinflammatory cytokines IL-1beta and TNF-alpha stimulate the production of NGF. The precise role of NGF produced by IVD cells in the generation of discogenic pain or on the metabolism of IVD cells, especially under certain physiologic conditions in which cytokines are up-regulated, needs to be clarified in future experimentation.
关于促炎细胞因子对人椎间盘（IVD）细胞产生神经生长因子（NGF）影响的体外研究。
确定人IVD细胞中NGF的组成性表达和产生情况，以及细胞因子对人IVD细胞中NGF表达的影响。
NGF可能在感觉轴突的侧支发芽、神经存活以及伤害性感觉神经元的调节中起作用。已知促炎细胞因子可上调NGF。
使用从无已知椎间盘疾病（MRI汤普森分级2 - 4级）的尸体人脊柱获取的人IVD细胞，通过免疫组织化学分析NGF蛋白的存在情况。检测白细胞介素 - 1β（IL - 1β）和肿瘤坏死因子 - α（TNF - α）对IVD细胞中NGF产生及NGF mRNA表达的影响。还通过免疫组织化学评估NGF受体trkA和p75的表达。
体外单层培养和在藻酸盐珠中培养的尸体纤维环（AF）和髓核（NP）细胞用抗NGF抗体呈阳性染色。IVD细胞中NGF蛋白的组成性产生较低（NP）或无法检测到（AF）。两种细胞类型中均能检测到NGF mRNA的表达。IL - 1β和TNF - α上调了NGF mRNA表达以及NGF蛋白向培养基中的分泌。TrkA免疫定位在AF和NP细胞中。
我们的结果首次证明，人AF和NP细胞组成性表达NGF蛋白和mRNA，并且促炎细胞因子IL - 1β和TNF - α刺激NGF的产生。IVD细胞产生的NGF在椎间盘源性疼痛的产生或IVD细胞代谢中的精确作用，尤其是在细胞因子上调的某些生理条件下，需要在未来的实验中加以阐明。
