Schuger L, Skubitz A P, Gilbride K, Mandel R, He L
Department of Pathology and Laboratory Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
Dev Biol. 1996 Oct 10;179(1):264-73. doi: 10.1006/dbio.1996.0256.
The extracellular matrix and in particular the basement membrane (BM) play an important role in the induction of organotypic rearrangement of cells in culture. This process involves cell aggregation, sorting into epithelial and mesenchymal components, epithelial cell polarization, and lumen formation. In this study, a combination of laminin (LM) and heparan sulfate proteoglycan (HSPG), two major BM constituents, induced organotypic rearrangement of embryonic mouse lung cells. In the absence of LM/HSPG supplementation, the cells sorted into epithelial and mesenchymal compartments but epithelial cell polarization and lumen formation did not occur. Neither LM nor HSPG alone could trigger this process. Synthetic peptide F-9, representing an amino acid sequence from the inner globular region of the laminin beta1 chain (RYVVLPRPVCFEKGMNYTVR) induced organotypic cell rearrangement when substituted for LM. Exogenous LM as well as peptide F-9 were localized at the epithelial-mesenchymal interface of organotypic cultures, where a BM-like structure is formed de novo. Organotypic cell rearrangement was blocked by heparin, heparan sulfate, or antibodies against peptide F-9. Binding assays indicated that peptide F-9 interacts with HSPG but not with LM or type IV collagen. Preincubation of embryonic lung cells with peptide F-9 resulted in a significant increase in cell attachment to HSPG but not to other major BM constituents. These findings suggest that the interaction between LM and BM HSPG is critical for the development of epithelial cell polarization and lumen formation. This interaction occurs at the epithelial-mesenchymal interface and is mediated by a site in the LM molecule represented by peptide F-9 and the heparan sulfate groups of HSPG.
细胞外基质，尤其是基底膜（BM），在培养细胞的器官型重排诱导过程中发挥着重要作用。这一过程涉及细胞聚集、分选成上皮和间充质成分、上皮细胞极化以及管腔形成。在本研究中，层粘连蛋白（LM）和硫酸乙酰肝素蛋白聚糖（HSPG）这两种主要的基底膜成分相结合，诱导了胚胎小鼠肺细胞的器官型重排。在不补充LM/HSPG的情况下，细胞分选成上皮和间充质区室，但上皮细胞极化和管腔形成并未发生。单独的LM或HSPG都无法触发这一过程。合成肽F-9，代表层粘连蛋白β1链内部球状区域的氨基酸序列（RYVVLPRPVCFEKGMNYTVR），在替代LM时诱导了器官型细胞重排。外源性LM以及肽F-9定位于器官型培养物的上皮-间充质界面，在那里从头形成了类似基底膜的结构。器官型细胞重排被肝素、硫酸乙酰肝素或抗肽F-9抗体阻断。结合试验表明，肽F-9与HSPG相互作用，但不与LM或IV型胶原相互作用。用肽F-9预孵育胚胎肺细胞导致细胞与HSPG的附着显著增加，但与其他主要基底膜成分的附着没有增加。这些发现表明，LM与基底膜HSPG之间的相互作用对于上皮细胞极化和管腔形成的发展至关重要。这种相互作用发生在上皮-间充质界面，由肽F-9代表的LM分子中的一个位点和HSPG的硫酸乙酰肝素基团介导。
