Department of Nephrology, Skåne University Hospital, Malmö, Sweden.
Nephrol Dial Transplant. 2011 Jul;26(7):2195-201. doi: 10.1093/ndt/gfq673. Epub 2010 Nov 2.
Neutrophils from patients with chronic kidney disease (CKD) are dysfunctional and thus a contributing factor to the risk of infections. The mechanisms for leucocyte dysfunction in CKD are not fully understood. It is known that lipopolysaccharide (LPS) activates transcription of several genes encoding proinflammatory cytokines. We therefore aimed to study the effect of LPS on neutrophil expression of genes related to the inflammatory response to address the hypothesis that LPS-induced gene transcriptions are altered in CKD patients.
We analysed gene expression of LPS-stimulated neutrophils from 30 patients with CKD and 15 healthy controls. Superoxide dismutase-2 (SOD2), IL1A, IL-1R1, IL-1R2 and IL8RA gene expression from both neutrophils and differentiated HL60 cells were measured by quantitative polymerase chain reaction. Differentiated HL60 cells were stimulated with phorbol-12-myristate-7-acetate (PMA) after inhibition of SOD2 by small interfering RNA followed by respiratory burst assessment using flow cytometry.
LPS stimulation induced a significant mobilization of CD11b on neutrophils from CKD and healthy controls. Upregulation of SOD2, IL1A, IL-1R1 and IL-1R2 gene expression in neutrophils from healthy controls after LPS stimulation was contrasted by no change in gene transcription (IL-1R1 and IL-1R2) or even a downregulation in patients with CKD (SOD2 and IL1A). Inhibition of SOD2 reduced the PMA-induced respiratory burst and IL1A, IL-1R1, IL-1R2 and IL8RA gene expression in neutrophil-differentiated HL60 cells.
Because of the critical role of SOD2 in the generation of hydrogen peroxide during phagocytosis, downregulation of SOD2 gene expression after LPS stimulation in neutrophils from patients with CKD indicates a potential mechanism for neutrophil dysfunction and cytokine dysregulation in these patients.
慢性肾脏病 (CKD) 患者的中性粒细胞功能失调，是导致感染风险的一个因素。CKD 患者白细胞功能障碍的机制尚不完全清楚。已知脂多糖 (LPS) 可激活编码促炎细胞因子的几个基因的转录。因此，我们旨在研究 LPS 对中性粒细胞炎症反应相关基因表达的影响，以验证 LPS 诱导的基因转录在 CKD 患者中发生改变的假设。
我们分析了 30 例 CKD 患者和 15 例健康对照者 LPS 刺激后的中性粒细胞基因表达。通过定量聚合酶链反应测量来自中性粒细胞和分化的 HL60 细胞的超氧化物歧化酶 2 (SOD2)、IL1A、IL-1R1、IL-1R2 和 IL8RA 基因表达。用小干扰 RNA 抑制 SOD2 后，用佛波醇 12-肉豆蔻酸 7-乙酸酯 (PMA) 刺激分化的 HL60 细胞，然后用流式细胞术评估呼吸爆发。
LPS 刺激诱导 CKD 和健康对照者的中性粒细胞 CD11b 明显动员。与 LPS 刺激后健康对照组中性粒细胞中 SOD2、IL1A、IL-1R1 和 IL-1R2 基因表达的上调相反，CKD 患者的基因转录没有变化（IL-1R1 和 IL-1R2）甚至下调（SOD2 和 IL1A）。SOD2 抑制降低了 PMA 诱导的呼吸爆发和分化的 HL60 细胞中的 IL1A、IL-1R1、IL-1R2 和 IL8RA 基因表达。
由于 SOD2 在吞噬作用中产生活性氧的关键作用，CKD 患者中性粒细胞中 LPS 刺激后 SOD2 基因表达的下调表明了这些患者中性粒细胞功能障碍和细胞因子失调的潜在机制。
