人巨噬细胞源泡沫细胞分化过程中MaxiK通道的发育转变(英文)

Developmental change of MaxiK channel during human macrophage-derived foam cell differentiation

目的:研究人巨噬细胞发育及其向泡沫细胞分化过程中MaxiK通道的表达和电生理学特征。方法:以健康人外周血单核细胞源性巨噬细胞为研究对象,采用Real time RT-PCR和Western blot技术观察MaxiK通道α亚单位mRNA及蛋白的表达;膜片钳技术分析MaxiK通道的电生理学特征。结果:在巨噬细胞发育过程中,MaxiK通道α亚单位的表达被轻度上调。同培养5 d的细胞相比,7.5 d细胞的mRNA及蛋白表达增加分别约为1.06和1.44倍,但无统计学意义。然而,30 mg/L oxLDL显著提高MaxiK通道α亚单位的表达,在其分化成泡沫细胞后,mRNA和蛋白表达分别是培养5 d细胞的2.4和7.27倍,有显著的差异(P<0.05)。在所有培养5 d、7.5 d和oxLDL组中的巨噬细胞上均能记录到典型的MaxiK电流;MaxiK通道的选择性阻断剂-paxilline(10μmol/L)抑制时间依从性电流、几乎全部的外向电导和噪声;但是,在培养5 d、7.5 d和oxLDL组中的巨噬细胞上MaxiK电流密度分别是(36±6)pA/pF、(35.9±3.5)pA/pF和(32.4±6.9)pA/pF,无明显差异。结论:在人巨噬细胞发育过程中,MaxiK通道的表达被上调,分化成泡沫细胞后尤为显著,但其介导的电流没有改变。

To study the expression and e lec trophysio log ica l character istics o fM ax Ki channels in the process o f humanm acrophage development and differentiation to foam ce lls. M ETHODS： M onocyte-der ived macrophag es w ere isolated fromhum an per ipheral b lood. T he mRNA leve l andM ax iK channel expression were detected using rea l time RT-PCR andW este rnb lot techn ique and the whole cellM ax Ki current from macrophages was m easured using pa tch clam p techn ique. RESULTS：In the deve lopm ent o fm acrophage ce lls, the express ion o fM ax iK channel w as slightly upregu lated. Compared w ith those inthe 5-day group, mRNA and pro tein expression in the 715-day group increased 1106 and 1144 tmi es, respectively （P 〉0105）. H ow ever, 30 mg /L oxLDL significantly increased the mRNA expression of M ax iK. A fter d ifferentiating into foamce lls, M ax iK mRNA and pro tein expression we re 214 and 7127 tmi es higher than those in the 5-day group （P 〈 0105）. T heM ax iK currentw as obta ined from 5 day, 715 day and oxLDL g roups. P ax illine （ 10Lm ol/L）, the se lective blocke r ofM ax Ki,inhib ited the tmie-dependent current and abolished the outward conductance and noises. In 5-day, 715-day and oxLDLg roups, the current densities did not show a sign ificant d ifference. CONCLUSION： In the deve lopm ent of hum an m acropha-ges, expression o fM ax iK channe l is upregulated. U pregulation is m ore obv ious after its differen tiation into foam cells. H ow-ever, the M ax iK current rem a ins unchanged dur ing developm ent and differentiation.