An insult can trigger a protective response or even cell death depending on different factors that include the duration and magnitude of the event and the ability of the cell to activate protective intracellular signals, including inflammatory cytokines. Our previous work showed that the treatment of Lister Hooded rat retinal cell cultures with 50 ng/mL phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, increases the survival of retinal ganglion cells (RGCs) kept in culture for 48 h after axotomy. Here we aim to analyze how PMA modulates the levels of TNF-α and IL-1β (both key inflammatory mediators) and the impact of this modulation on RGCs survival. We hypothesize that the increase in RGCs survival mediated by PMA treatment depends upon modulation of the levels of IL-1β and TNF-α. The effect of PMA treatment was assayed on cell viability, caspase 3 activation, TNF-α and IL-1β release and TNF receptor type I (TNFRI) and TNF receptor type II (TNFRII) levels. PMA treatment increases IL-1β and TNF-α levels in 15 min in culture and increases the release of both cytokines after 30 min and 24 h, respectively. Both IL-1β and TNF-α levels decrease after 48 h of PMA treatment. PMA treatment also induces an increase in TNFRII levels while decreasing TNFRI after 24 h. PMA also inhibited caspase-3 activation, and decreased ROS production and EthD-1/calcein ratio in retinal cell cultures leading to an increase in cell viability. The neutralization of IL-1β (anti-IL1β 0,1ng/mL), the neutralization of TNF-α (anti-TNF-α 0,1ng/mL) and the TNF-α inhibition using a recombinant soluble TNFRII abolished PMA effect on RGCs survival. These data suggest that PMA treatment induces IL1β and TNF-α release and modulation of TNFRI/TNFRII expression promoting RGCs survival after axotomy.

损伤可以触发保护性反应甚至细胞死亡，这取决于不同的因素，包括事件的持续时间和幅度以及细胞激活保护性细胞内信号（包括炎性细胞因子）的能力。我们之前的工作表明，用 50 ng/mL 佛波醇 12-肉豆蔻酸酯 13-乙酸 (PMA)（一种蛋白激酶 C 激活剂）处理 Lister Hooded 大鼠视网膜细胞培养物，可提高培养中视网膜神经节细胞 (RGC) 的存活率。轴切术后 48 小时。在这里，我们旨在分析 PMA 如何调节 TNF-α 和 IL-1β（两者都是关键的炎症介质）的水平以及这种调节对 RGC 存活的影响。我们假设 PMA 治疗介导的 RGC 存活率的增加取决于 IL-1β 和 TNF-α 水平的调节。测定 PMA 处理对细胞活力、半胱天冬酶 3 活化、TNF-α 和 IL-1β 释放以及 TNF I 型受体 (TNFRI) 和 TNF 受体 II 型 (TNFRII) 水平的影响。PMA 处理在培养 15 分钟内增加 IL-1β 和 TNF-α 水平，并分别在 30 分钟和 24 小时后增加两种细胞因子的释放。PMA 处理 48 小时后，IL-1β 和 TNF-α 水平均下降。PMA 处理还诱导 TNFRII 水平增加，同时在 24 小时后降低 TNFRI。PMA 还抑制 caspase-3 活化，并降低视网膜细胞培养物中的 ROS 产生和 EthD-1/钙黄绿素比率，从而提高细胞活力。中和 IL-1β（抗 IL1β 0.1ng/mL）、中和 TNF-α（抗 TNF-α 0.1ng/mL）和使用重组可溶性 TNFRII 的 TNF-α 抑制消除了 PMA 对RGC 存活。