Bruckmeier Martin, Kuehnl Andreas, Culmes Mihaela, Pelisek Jaroslav, Eckstein Hans-Henning
Clinic for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany.
Cell Physiol Biochem. 2012;30(1):199-209. doi: 10.1159/000339044. Epub 2012 Jun 15.
The C-type natriuretic peptide (CNP) has anti-inflammatory, anti-proliferative, and anti-migratory properties. The purpose of this study was to investigate the occurrence of CNP and its receptors (NPR2 and NPR3) in a human monocytic cell line (THP-1 cells) as well as in peripheral blood monocytic cells (PBMC). Impact of both, LPS and human oxLDL on expression pattern of CNP and its receptors shall be studied.
Cells were cultured in standard medium with or without LPS or oxLDL. Expression levels of CNP, NPR2, NPR3, TNF-α, IL-1β, IL-6, CD14 and CD68 were measured at baseline, 24h, and 48h.
Baseline expression of all analysed genes was significantly higher in PBMC compared to THP-1 cells (all p<0.05). Expression levels of CNP, IL-1β, IL-6, and CD14 were significantly increased in PBMC following stimulation with LPS. In contrast, in THP-1 cells stimulated by LPS, significant increase in expression was found only for IL-6 (p=0.007). In THP-1 cells, oxLDL increased the expression levels of NPR3, TNF-α, IL-1β, IL-6, CD14, and CD68 significantly. In contrast, expression level of NPR2 was diminished by oxLDL (p=0.007). In PBMC NPR3 was significantly down-regulated (p=0.002). Treatment with oxLDL for 48h increased NPR2/3-ratio significantly in PBMC (22.5 vs. 4.8, p=0.010). In contrast, in THP-1 cells, NPR2/3-ratio was lowered significantly by oxLDL (0.31 vs. 17.0, p=0.008).
Treatment with LPS or oxLDL leads to diverging changes in gene expression PBMC and THP-1 cells. With respect to CNP and its receptors, data gained from THP-1 cells should be further validated using naive human peripheral blood monocytes. However, THP-1 cells can serve as a negative control for e.g. future signalling pathway studies related to oxLDL effect on CNP system in monocytes/macrophages.
C型利钠肽（CNP）具有抗炎、抗增殖和抗迁移特性。本研究旨在调查CNP及其受体（NPR2和NPR3）在人单核细胞系（THP-1细胞）以及外周血单核细胞（PBMC）中的表达情况。同时研究脂多糖（LPS）和人氧化低密度脂蛋白（oxLDL）对CNP及其受体表达模式的影响。
细胞在添加或不添加LPS或oxLDL的标准培养基中培养。在基线、24小时和48小时测量CNP、NPR2、NPR3、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）、CD14和CD68的表达水平。
与THP-1细胞相比，所有分析基因的基线表达在PBMC中显著更高（所有p<0.05）。LPS刺激后，PBMC中CNP、IL-1β、IL-6和CD14的表达水平显著增加。相反，在LPS刺激的THP-1细胞中，仅发现IL-6的表达显著增加（p=0.007）。在THP-1细胞中，oxLDL显著增加了NPR3、TNF-α、IL-1β、IL-6、CD14和CD68的表达水平。相反，oxLDL使NPR2的表达水平降低（p=0.007）。在PBMC中，NPR3显著下调（p=0.002）。oxLDL处理48小时后，PBMC中NPR2/3比值显著增加（22.5对4.8，p=0.010）。相反，在THP-1细胞中，oxLDL使NPR2/3比值显著降低（0.31对17.0，p=0.008）。
LPS或oxLDL处理导致PBMC和THP-1细胞基因表达出现不同变化。关于CNP及其受体，从THP-1细胞获得的数据应使用未处理的人外周血单核细胞进一步验证。然而，THP-1细胞可作为例如未来与oxLDL对单核细胞/巨噬细胞中CNP系统影响相关的信号通路研究的阴性对照。
