二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）可降低脂多糖（LPS）诱导的HK-2细胞炎症反应：过氧化物酶体增殖物激活受体γ（PPAR-γ）依赖性机制的证据。

EPA and DHA reduce LPS-induced inflammation responses in HK-2 cells: evidence for a PPAR-gamma-dependent mechanism.

作者信息

Li Hang, Ruan Xiong Z, Powis Stephen H, Fernando Ray, Mon Wint Y, Wheeler David C, Moorhead John F, Varghese Zac

机构信息

Centre for Nephrology, Royal Free and University College Medical School, University College London, London, United Kingdom.

出版信息

Kidney Int. 2005 Mar;67(3):867-74. doi: 10.1111/j.1523-1755.2005.00151.x.

DOI:10.1111/j.1523-1755.2005.00151.x

PMID:15698426

Abstract

BACKGROUND

Recent studies have shown that fish oil, containing omega-3 polyunsaturated fatty acids (omega-3 PUFAs) eicosapentaenoic acid (EPA) (C20:5 omega 3), and docosahexaenoic acid (DHA) (C22:6 omega 3) retard the progression of renal disease, especially in IgA nephropathy (IgAN). Despite increasing knowledge of the beneficial effects of fish oils, little is known about the mechanisms of action of omega-3 PUFAs. It has been reported that activation of peroxisome proliferator-activated receptors (PPARs) inhibits production of proinflammatory cytokines. Both EPA and DHA have been shown to activate PPARs. The aim of this study was to examine if omega-3 PUFAs have anti-inflammatory effects via activation of PPARs in human renal tubular cells.

METHODS

An immortalized human proximal tubular cell line [human kidney-2 (HK-2) cells] was used in all experiments. Conditioned media was collected from omega-3 PUFAs- treated cells and subjected to enzyme-linked immunosorbent assay (ELISA). Total cellular RNA was isolated from the above cells for real-time quantitative polymerase chain reaction (PCR). Nuclear Extracts were prepared from the HK-2 cells for transcription factor activation assay.

RESULTS

Both EPA and DHA at 10 micromol/L and 100 micromol/L concentrations effectively decreased lipopolysaccharide (LPS)-induced nuclear factor-kappaB (NF-kappaB) activation and monocyte chemoattractant protein-1 (MCP-1) expression. EPA and DHA also increased both PPAR-gamma mRNA and protein activity (two- to threefold) in HK-2 cells. A dose of 100 micromol/L bisphenol A diglycidyl ether (BADGE) abolished the PPAR-gamma activation induced by both EPA and DHA and removed the inhibitory effect of EPA and DHA on LPS-induced NF-kappaB activation in HK-2 cells. Overexpression of PPAR-gamma further inhibited NF-kappaB activation compared to the control cells in the presence of EPA and DHA.

CONCLUSION

Our data demonstrate that both EPA and DHA down-regulate LPS-induced activation of NF-kappaB via a PPAR-gamma-dependent pathway in HK-2 cells. These results suggest that PPAR-gamma activation by EPA and DHA may be one of the underlying mechanisms for the beneficial effects of fish oil.

摘要

背景

最近的研究表明，富含ω-3多不饱和脂肪酸（ω-3 PUFAs）二十碳五烯酸（EPA）（C20:5 ω3）和二十二碳六烯酸（DHA）（C22:6 ω3）的鱼油可延缓肾脏疾病的进展，尤其是在IgA肾病（IgAN）中。尽管对鱼油有益作用的认识不断增加，但对ω-3 PUFAs的作用机制知之甚少。据报道，过氧化物酶体增殖物激活受体（PPARs）的激活可抑制促炎细胞因子的产生。EPA和DHA均已被证明可激活PPARs。本研究的目的是检验ω-3 PUFAs是否通过激活人肾小管细胞中的PPARs发挥抗炎作用。

方法

所有实验均使用永生化人近端肾小管细胞系[人肾-2（HK-2）细胞]。收集来自ω-3 PUFAs处理细胞的条件培养基，并进行酶联免疫吸附测定（ELISA）。从上述细胞中分离总细胞RNA用于实时定量聚合酶链反应（PCR）。从HK-2细胞制备核提取物用于转录因子激活测定。

结果

10 μmol/L和100 μmol/L浓度的EPA和DHA均有效降低脂多糖（LPS）诱导的核因子-κB（NF-κB）激活和单核细胞趋化蛋白-1（MCP-1）表达。EPA和DHA还使HK-2细胞中的PPAR-γ mRNA和蛋白活性增加（两到三倍）。100 μmol/L双酚A二缩水甘油醚（BADGE）的剂量消除了EPA和DHA诱导的PPAR-γ激活，并消除了EPA和DHA对HK-2细胞中LPS诱导的NF-κB激活的抑制作用。与存在EPA和DHA的对照细胞相比，PPAR-γ的过表达进一步抑制了NF-κB激活。