Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA.
Am J Physiol Cell Physiol. 2013 May 15;304(10):C966-75. doi: 10.1152/ajpcell.00261.2012. Epub 2013 Mar 13.
Epithelial morphogenesis is dependent upon a variety of factors, many of which involve complex interactions between cells and their surrounding environments. We analyzed the patterns of differential gene expression associated with Madin-Darby canine kidney (MDCK) renal epithelial cells grown within a collagen gel in three-dimensional (3D) culture compared with those grown atop a collagen gel in two-dimensional (2D) culture. Under these conditions, MDCK cells spontaneously formed either hollow spherical cysts or flat monolayer sheets, respectively. Microarray analysis of gene expression revealed a twofold or greater expression difference in 732 gene sets from MDCK cysts compared with monolayers (false discovery rate or FDR-adjusted P values <0.05). Interleukin-8 (IL-8) was reproducibly found to be among the genes whose expression was most dramatically upregulated, and this behavior was verified through real-time PCR analysis. The level of IL-8 protein expression was significantly increased in 3D MDCK cultures compared with that detected in cells in 2D culture. Hepatocyte growth factor (HGF) induces MDCK cells in 3D culture to form linear tubule-like structures. We found that HGF stimulation caused MDCK cells in 3D culture to decrease the expression of IL-8 at both the mRNA and protein levels. Furthermore, the addition of recombinant IL-8 to HGF-stimulated 3D MDCK cultures was sufficient to partially reverse the tubulogenic effects of HGF, resulting in the formation of cystic structures. These data suggest that IL-8 participates in the formation of cystic structures by MDCK cells in 3D culture and that HGF may stimulate tubulogenesis through the suppression of IL-8.
上皮形态发生依赖于多种因素，其中许多涉及细胞与其周围环境之间的复杂相互作用。我们分析了与在三维（3D）培养中的胶原凝胶中生长的犬肾（MDCK）上皮细胞相关的差异基因表达模式，与在二维（2D）培养中的胶原凝胶上生长的细胞相比。在这些条件下，MDCK 细胞分别自发形成空心球形囊肿或平的单层片。基因表达的微阵列分析显示，与单层相比，MDCK 囊肿中的 732 个基因集的表达差异增加了两倍或更多（错误发现率或 FDR 调整的 P 值<0.05）。白细胞介素 8（IL-8）被反复发现是表达上调最显著的基因之一，并且通过实时 PCR 分析验证了这种行为。与在 2D 培养中的细胞相比，3D MDCK 培养物中 IL-8 蛋白表达水平显著增加。肝细胞生长因子（HGF）诱导 3D 培养中的 MDCK 细胞形成线性管状结构。我们发现，HGF 刺激导致 3D 培养中的 MDCK 细胞在 mRNA 和蛋白质水平上降低 IL-8 的表达。此外，向 HGF 刺激的 3D MDCK 培养物中添加重组 IL-8 足以部分逆转 HGF 的管状发生作用，导致形成囊肿结构。这些数据表明，IL-8 参与了 3D 培养中的 MDCK 细胞形成囊肿结构，HGF 可能通过抑制 IL-8 来刺激管状发生。
