MRC Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh Medical School, Edinburgh, Scotland, UK.
Eur J Immunol. 2010 Apr;40(4):1127-38. doi: 10.1002/eji.200939664.
Successful resolution of inflammation requires inflammatory cells such as neutrophils to undergo apoptosis prior to non-inflammatory phagocytosis by professional phagocytes. Recently, cyclin-dependent kinase (CDK) inhibitors (e.g. R-roscovitine) have been shown to induce neutrophil apoptosis and enhance the resolution of inflammation. Interestingly, NF-kappaB and MAPK pathways and key endogenous survival proteins (typified by Mcl-1) are involved in the regulation of neutrophil apoptosis and, in cancer-cell lines, have been implicated as possible targets of CDK inhibitors. Here, we demonstrate that R-roscovitine over-rides TNF-alpha and LPS-induced survival (determined by morphological examination and binding of fluorescently labelled annexin-V) of isolated peripheral blood neutrophils. This effect did not appear to be mediated via effects on early markers of neutrophil activation (e.g. surface marker expression, shape change, aggregation and superoxide anion generation), by direct inhibition of NF-kappaB activation (assessed by cytoplasmic IkappaBalpha proteolysis and NF-kappaB p65 subunit translocation) and ERK activation (determined by specific ERK phosphorylation) but due to down-regulation (at protein and mRNA level) of the survival protein Mcl-1 but not the pro-apoptotic bcl-2 homologue Bim. These findings suggest that key endogenous survival proteins may be the targets of CDK inhibitors and consequently may be of critical importance in the resolution of inflammation.
成功解决炎症需要炎症细胞（如中性粒细胞）在被专业吞噬细胞进行非炎症性吞噬之前发生细胞凋亡。最近，细胞周期蛋白依赖性激酶（CDK）抑制剂（如 R-罗司维亭）已被证明可诱导中性粒细胞凋亡并增强炎症的消退。有趣的是，NF-κB 和 MAPK 途径以及关键的内源性生存蛋白（以 Mcl-1 为代表）参与了中性粒细胞凋亡的调节，并且在癌细胞系中，被认为是 CDK 抑制剂的可能靶点。在这里，我们证明 R-罗司维亭可以逆转 TNF-α和 LPS 诱导的外周血中性粒细胞的存活（通过形态学检查和荧光标记的膜联蛋白-V 的结合来确定）。这种作用似乎不是通过对中性粒细胞活化的早期标志物（例如表面标志物表达、形状变化、聚集和超氧阴离子生成）的影响来介导的，也不是通过直接抑制 NF-κB 活化（通过细胞质 IkappaBalpha 蛋白水解和 NF-κB p65 亚基易位来评估）和 ERK 活化（通过特异性 ERK 磷酸化来确定），而是由于生存蛋白 Mcl-1 的下调（在蛋白和 mRNA 水平上），而不是促凋亡 bcl-2 同源物 Bim。这些发现表明，关键的内源性生存蛋白可能是 CDK 抑制剂的靶点，因此在炎症消退中可能具有至关重要的意义。
