Ahdieh M, Vandenbos T, Youakim A
Department of Biomolecular Screening, Immunex Corporation, Seattle, Washington 98101, USA.
Am J Physiol Cell Physiol. 2001 Dec;281(6):C2029-38. doi: 10.1152/ajpcell.2001.281.6.C2029.
To understand the effects of cytokines on epithelial cells in asthma, we have investigated the effects of interleukin (IL)-4, IL-13, and interferon (IFN)-gamma on barrier function and wound healing in Calu-3 human lung epithelial cells. IL-4 and IL-13 treatment of Calu-3 cells grown on Transwell filters resulted in a 70-75% decrease in barrier function as assessed by electrophysiological and [(14)C]mannitol flux measurements. In contrast, IFN-gamma enhanced barrier function threefold using these same parameters. Cells treated concurrently with IFN-gamma and IL-4 or IL-13 showed an initial decline in barrier function that was reversed within 2 days, resulting in barrier levels comparable to control cells. Analysis of the tight junction-associated proteins ZO-1 and occludin showed that IL-4 and IL-13 significantly reduced ZO-1 expression and modestly decreased occludin expression compared with controls. IFN-gamma, quite unexpectedly given its enhancing effect on barrier function, reduced expression of ZO-1 and occludin to almost undetectable levels compared with controls. In wound-healing assays of cells grown on collagen I, IL-4 and IL-13 decreased migration, whereas IFN-gamma treatment enhanced migration, compared with control cells. Addition of IFN-gamma, in combination with IL-4 or IL-13, restored migration of cells to control levels. Migration differences observed between the various cytokine treatments was correlated with expression of the collagen I-binding alpha(2)beta(1)-integrin at the leading edge of cells at the wound front; alpha(2)beta(1)-integrin expression was decreased in IFN-gamma-treated cells compared with controls, whereas it was highest in IL-4- and IL-13-treated cells. These results demonstrate that IL-4 and IL-13 diminish the capacity of Calu-3 cells to maintain barrier function and repair wounds, whereas IFN-gamma promotes epithelial restitution by enhancing barrier function and wound healing.
为了解细胞因子对哮喘中上皮细胞的影响，我们研究了白细胞介素（IL）-4、IL-13和干扰素（IFN）-γ对Calu-3人肺上皮细胞屏障功能和伤口愈合的影响。用IL-4和IL-13处理接种于Transwell小室滤膜上生长的Calu-3细胞，通过电生理学和[¹⁴C]甘露醇通量测量评估，结果显示屏障功能下降了70%-75%。相比之下，使用相同参数，IFN-γ使屏障功能增强了三倍。同时用IFN-γ与IL-4或IL-13处理的细胞，其屏障功能最初下降，但在2天内逆转，最终屏障水平与对照细胞相当。对紧密连接相关蛋白ZO-1和闭合蛋白的分析表明，与对照相比，IL-4和IL-13显著降低了ZO-1的表达，并适度降低了闭合蛋白的表达。鉴于IFN-γ对屏障功能具有增强作用，但其却将ZO-1和闭合蛋白的表达降低至与对照相比几乎检测不到的水平，这相当出乎意料。在I型胶原上生长的细胞进行伤口愈合试验时，与对照细胞相比，IL-4和IL-13降低了细胞迁移，而IFN-γ处理则增强了细胞迁移。添加IFN-γ与IL-4或IL-13联合使用，可使细胞迁移恢复到对照水平。在不同细胞因子处理之间观察到的迁移差异与伤口前沿细胞前缘处I型胶原结合α₂β₁整合素的表达相关；与对照相比，IFN-γ处理的细胞中α₂β₁整合素表达降低，而在IL-4和IL-13处理的细胞中表达最高。这些结果表明，IL-4和IL-13降低了Calu-3细胞维持屏障功能和修复伤口的能力，而IFN-γ通过增强屏障功能和伤口愈合促进上皮修复。
