Interleukin-1β suppresses epithelial sodium channel β-subunit expression and ENaGdependent fluid absorption in human middle ear epithelial cells
Interleukin-1β suppresses epithelial sodium channel β-subunit expression and ENaGdependent fluid absorption in human middle ear epithelial cells
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DOI：
10.1016/j.ejphar.2007.04.026
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发表时间：
2007-07-12
影响因子：
5
通讯作者：
Yoon, Joo-Heon
中科院分区：
文献类型：
--
作者：
Choi, Jae Young;Choi, Yoon-Seok;Yoon, Joo-Heon
最近的报道表明，细胞因子通过抑制各种上皮细胞中的Na+通道活性来抑制液体吸收。在这项研究中，我们研究了上皮钠通道（ENaC）在正常人中车上皮细胞（NHN）液体吸收中的作用，以及白细胞介素（IL）-1 β对ENaC表达和NHN细胞液体吸收的影响。我们通过免疫细胞化学证实了ENaC α、β和γ主要表达在NH 4细胞的顶端表面。此外，阿米洛利，一个有效的ENaC阻滞剂，顶膜的NH 4+细胞的液体吸收率降低剂量依赖性的方式。用10 ng/ml IL-1 β处理24 h可抑制ENaC β表达、ENaC依赖性短路电流（Isc）和ENaC依赖性液体吸收。用磷脂酶C（PLC）抑制剂预处理NH 4细胞，（U 73122，10 μ M），蛋白激酶C（PKC）抑制剂（Calphostin C，0.1 μ M）或细胞外信号调节激酶（ERK）1/2抑制剂（PD 98059，10 μ M），IL-1 β处理的细胞中的阿米洛利敏感性电流逆转至对照水平; SB 202190（p38丝裂原活化蛋白（MAP）激酶抑制剂）或SP 600125（c-Jun N-末端激酶可逆抑制剂）未见此作用。在这项研究中，我们发现ENaC对于NH 4细胞中的液体吸收是必不可少的，并且IL-1 β通过PLC-PKC-ERK 1/2途径抑制ENaC依赖性电流。这些结果表明，IL-1 β可能通过改变电解质转运和减少中耳上皮液体吸收而导致渗出性中耳炎的液体潴留。(c)2007 Elsevier B. V.保留所有权利。
Recent reports have shown that cytokines inhibit fluid absorption by suppressing Na+ channel activity in various epithelia. In this study, we investigated the role of epithelial sodium channel (ENaC) in fluid absorption in normal human middle car epithelial (NHMEE) cells, as well as the effects of Interleukin (IL)-1 beta on ENaC expression and fluid absorption in NHMEE cells. We confirmed that ENaC alpha, beta and gamma were predominantly expressed on the apical surface of the NHMEE cells by immunocytochemistry. Addition of amiloride, a potent ENaC blocker, to apical membranes of NHMEE cells decreased the fluid absorption rate in a dose-dependent manner. Treatment with 10 ng/ml IL-1 beta for 24 h suppressed ENaC beta expression, the ENaC-dependent short-circuit current (Isc), and ENaC-dependent fluid absorption. When the NHMEE cells were pretreated with a phospholipase C (PLC)inhibitor (U73122, 10 mu M), a protein kinase C (PKC) inhibitor (Calphostin C, 0.1 mu M), or extracellular signal regulated kinase (ERK) 1/2 inhibitor (PD98059, 10 mu M), the amiloride-sensitive currents in IL-1 beta-treated cells were reversed to control levels; an effect not seen with SB202190 (an inhibitor of p38 mitogen-activated protein (MAP) kinase) or SP600125 (a reversible inhibitor of c-Jun N-terminal kinase). In this study we showed that ENaC is essential for fluid absorption in NHMEE cells and that IL-1 beta suppresses the ENaC- dependent current via the PLC-PKC-ERK1/2 pathway. These results suggest that IL-1 beta may contribute to fluid retention in otitis media with effusion by changing electrolyte transport and reducing middle ear epithelial fluid absorption. (c) 2007 Elsevier B.V. All rights reserved.