载脂蛋白嵌合模拟肽通过NF-κB途径抑制ox-LDL诱导的巨噬细胞炎症反应

目的：探讨载脂蛋白嵌合模拟肽Ac-hE-18A-NH2对氧化型低密度脂蛋白(oxidized LDL，ox-LDL)刺激下巨噬细
胞肿瘤坏死因子-α(tumor necrosis factor-α，TNF-α)表达的影响及其作用机制。方法：Ox-LDL刺激RAW264.7巨噬细胞，
给予不同浓度的模拟肽Ac-hE-18A-NH2(1~100 μg/mL)干预，收集细胞，测定巨噬细胞TNF-α的分泌和mRNA表达水平。
Western印迹检测ATP结合盒转运蛋白A1(ATP-binding cassette transporter A1，ABCA1)及P-IκB蛋白浓度。EMSA检测核因
子-κB(nuclear factor-κB，NF-κB)活性。结果：Ox-LDL刺激使RAW264.7巨噬细胞TNF-α 分泌和mRNA表达明显增强，细
胞内胆固醇蓄积，促进IκB磷酸化，并激活NF-κB。Ac-hE-18A-NH2浓度依赖性地降低TNF-α 分泌及mRNA表达，上调
ABCA1 mRNA和蛋白的表达，减少细胞内胆固醇含量，抑制NF-κB活化，并抑制IκB磷酸化。相同的实验条件下及作
用浓度，D-4F对于TNF-α 分泌的抑制作用不如Ac-hE-18A-NH2。结论：Ac-hE-18A-NH2能抑制ox-LDL诱导的RAW264.7
巨噬细胞TNF-α分泌和mRNA表达，IκB/NF-κB-TNF-α信号通路是其中作用途径之一。Ac-hE-18A-NH2的抗炎作用优于
apoA-I模拟肽D-4F。

Ac-hE-18A-NH2 inhibits the inflammatory response inducedby ox-LDL via inhibiting NF-κB activation in RAW264.7macrophages

Objective: To evaluate the effect of Ac-hE-18A-NH2 on TNF-α secretion and mRNA expression in
ox-LDL-stimulated RAW264.7 macrophages and to elucidate the possible mechanisms.
Methods: Macrophages were incubated in the medium containing various concentrations of Ac-hE18A-NH2 (1-50 μg/mL) with ox-LDL (50 μg/mL) stimulated. The TNF-α level
and intracellular cholesterol content were measured by commercially available quantitation
kits following the manufacturer’s instructions. TNF-α and ATP-binding cassette transporter
A1 (ABCA1) mRNA expression were detected by real-time PCR. ABCA1 and IκB protein
-expression in the macrophages were determined by Western blot. NF-κB activity was evaluated by
electrophoretic mobility shift assay (EMSA).
Results: Ox-LDL stimulation induced a significant increase in TNF-α secretion, mRNA expression,
cholesterol accumulation and nuclear factor-κB (NF-κB) activity in RAW264.7 macrophages.
Ac-hE-18A-NH2 reduced TNF-α secretion and mRNA expression, up-regulated the ABCA1
mRNA and protein expression, reduced the intracellular cholesterol content, and inhibited NF-
κB activation in a dose-dependent manner. Under the same condition and the same concentration,
Ac-hE-18A-NH2 was more efficient than D-4F (apoA-I mimetic peptide) in inhibiting the
inflammatory response induced by ox-LDL in the macrophages.
Conclusion: Ac-hE-18A-NH2 may suppress TNF-α secretion and mRNA expression in ox-LDLstimulated
RAW264.7 macrophages via IκB-NF-κB signaling pathway. The anti-inflammatory effect
of Ac-hE-18A-NH2 is better than that of apoA-I mimic peptide D-4F.