Mio T, Liu X D, Adachi Y, Striz I, Sköld C M, Romberger D J, Spurzem J R, Illig M G, Ertl R, Rennard S I
Chest Disease Research Institute, Kyoto University, Japan.
Am J Physiol. 1998 Jan;274(1):L119-26. doi: 10.1152/ajplung.1998.274.1.L119.
Connective tissue contraction is an important aspect of both normal wound healing and fibrosis. This process may contribute to small airway narrowing associated with certain airway diseases. Fibroblast-mediated contraction of a three-dimensional collagen gel has been considered a model of tissue contraction. In this study, the ability of primary cultured human bronchial epithelial cells (HBEC) obtained by bronchial brushings to modulate fibroblast gel contraction was evaluated. Human lung fibroblasts (HFL1) were cast into type I collagen gels. The gels were floated both in dishes containing a monolayer of HBEC or in dishes without HBEC. Contraction assessed by measuring the area of gels was increased at all time points from 24 h up to 96 h of coculture. At 48 h, coculture of HBEC with fibroblasts resulted in significantly more contraction than fibroblasts alone (36.6 +/- 1.2 vs. 20.4 +/- 1.7%, P < 0.05). Lipopolysaccharide (LPS, 10 micrograms/ml) stimulation of the HBEC augmented the contraction (44.9 +/- 1.0%, P < 0.05 vs. HBEC). In the presence of indomethacin, the augmentation by LPS was increased further (52.2 +/- 4.3%, P < 0.05 vs. HBEC with LPS), suggesting that prostaglandins (PGs) are present and may inhibit contraction. Consistent with this, PGE was present in HBEC-conditioned medium. Bronchial epithelial cell conditioned medium had an effect similar to coculturing. SG-150 column chromatography revealed augmentive activity between 20 and 30 kDa and inhibitory activity between 10 and 20 kDa. Measurement by enzyme-linked immunosorbent assay confirmed the presence of the active form of transforming growth factor (TGF)-beta 2. The stimulatory activity of conditioned medium was blocked by adding anti-TGF-beta antibody. These data demonstrate that, through the release of factors including TGF-beta 2 which can augment and PGE which can inhibit, HBEC can modulate fibroblast-mediated collagen gel contraction. In this manner, HBEC may modulate fibroblast activities that determine the architecture of bronchial tissue.
结缔组织收缩是正常伤口愈合和纤维化的一个重要方面。这一过程可能导致与某些气道疾病相关的小气道狭窄。成纤维细胞介导的三维胶原凝胶收缩被认为是组织收缩的一种模型。在本研究中，评估了通过支气管刷检获得的原代培养人支气管上皮细胞（HBEC）调节成纤维细胞凝胶收缩的能力。将人肺成纤维细胞（HFL1）接种到I型胶原凝胶中。凝胶分别漂浮在含有单层HBEC的培养皿中或不含HBEC的培养皿中。通过测量凝胶面积评估的收缩在共培养24小时至96小时的所有时间点均增加。在48小时时，HBEC与成纤维细胞共培养导致的收缩明显多于单独的成纤维细胞（36.6±1.2%对20.4±1.7%，P<0.05）。脂多糖（LPS，10微克/毫升）刺激HBEC增强了收缩（44.9±1.0%，与HBEC相比P<0.05）。在吲哚美辛存在的情况下，LPS的增强作用进一步增加（52.2±4.3%，与含LPS的HBEC相比P<0.05），表明存在前列腺素（PGs）且可能抑制收缩。与此一致的是，PGE存在于HBEC条件培养基中。支气管上皮细胞条件培养基具有与共培养相似的作用。SG-150柱层析显示在20至30 kDa之间有增强活性，在10至20 kDa之间有抑制活性。通过酶联免疫吸附测定法测量证实了活性形式的转化生长因子（TGF）-β2的存在。加入抗TGF-β抗体可阻断条件培养基的刺激活性。这些数据表明，通过释放包括可增强收缩的TGF-β2和可抑制收缩的PGE等因子，HBEC可以调节成纤维细胞介导的胶原凝胶收缩。通过这种方式，HBEC可能调节决定支气管组织结构的成纤维细胞活性。
