Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig University Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany.
Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig University Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany; Center for Mind, Brain and Behavior CMBB, Philipps-Universität of Marburg & Justus-Liebig-University of Giessen, Germany.
Neuroscience. 2018 Dec 1;394:1-13. doi: 10.1016/j.neuroscience.2018.10.018. Epub 2018 Oct 18.
Primary cultures of rat dorsal root ganglia (DRG) consist of neurons, satellite glial cells and a moderate number of macrophages. Measurements of increased intracellular calcium [Ca] induced by stimuli, have revealed that about 70% of DRG neurons are capsaicin-responsive nociceptors, while 10% responded to cooling and or menthol (putative cold sensors). Cultivation of DRG in the presence of a moderate dose of lipopolysaccharide (LPS, 1 µg/ml) enhanced capsaicin-induced Ca signals. We therefore investigated further properties of DRG primary cultures stimulated with 10 µg/ml LPS for a short period. Exposure to LPS for 2 h resulted in pronounced release of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) into the supernatants of DRG cultures, increased expression of both cytokines in the DRG cells and increased TNF immunoreactivity predominantly in macrophages. We further observed an accumulation of the inflammatory transcription factors NF-IL6 and STAT3 in the nuclei of LPS-exposed DRG neurons and macrophages. In the presence of the cytotoxic agent cisplatin (5 or 10 µg/ml), the number of macrophages was decreased significantly, the growth of satellite glial cells was markedly suppressed, but the vitality and stimulus-induced Ca signals of DRG neurons were not impaired. Under these conditions the LPS-induced production and expression of TNF-α and IL-6 were blunted. Our data suggest a potential role for macrophages and satellite glial cells in the initiation of inflammatory processes that develop in sensory ganglia upon injury or exposure to pathogens.
大鼠背根神经节（DRG）的原代培养物由神经元、卫星胶质细胞和一定数量的巨噬细胞组成。对刺激引起的细胞内钙离子[Ca]增加的测量表明，约 70%的 DRG 神经元是辣椒素反应性伤害感受器，而 10%的神经元对冷却或薄荷醇（假定的冷感受器）有反应。在中等剂量脂多糖（LPS，1μg/ml）存在下培养 DRG 可增强辣椒素诱导的 Ca 信号。因此，我们进一步研究了用 10μg/ml LPS 短时间刺激 DRG 原代培养物的进一步特性。暴露于 LPS 2 小时会导致 DRG 培养物上清液中肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）的显著释放，DRG 细胞中两种细胞因子的表达增加，以及 TNF 免疫反应性主要在巨噬细胞中增加。我们还观察到 LPS 暴露的 DRG 神经元和巨噬细胞的核中炎症转录因子 NF-IL6 和 STAT3 的积累。在细胞毒性药物顺铂（5 或 10μg/ml）存在下，巨噬细胞数量显著减少，卫星胶质细胞的生长受到明显抑制，但 DRG 神经元的活力和刺激诱导的 Ca 信号不受损害。在这些条件下，LPS 诱导的 TNF-α和 IL-6 的产生和表达受到抑制。我们的数据表明，巨噬细胞和卫星胶质细胞可能在损伤或接触病原体后感觉神经节中炎症过程的启动中发挥作用。
