Hoffman M P, Kibbey M C, Letterio J J, Kleinman H K
Cell Biology Section, National Institute for Dental Research, National Institutes of Health, Bethesda, MD 20892-4370, USA.
J Cell Sci. 1996 Aug;109 ( Pt 8):2013-21. doi: 10.1242/jcs.109.8.2013.
Previous studies show that culturing an immortalized human submandibular gland cell line (HSG) on Matrigel, a basement membrane extract, induces cytodifferentiation. We have further defined this model system and identified factors involved in HSG cell acinar development and cyto-differentiation. Acinar development is marked by cell migration into multi-cellular spherical structures, cell proliferation and apoptosis of the centrally localized cells. In addition, functional differentiation was determined by indirect immunofluorescence and immunoblot analysis for cystatin, a salivary gland acinar cell-specific protein found to be produced by differentiated HSG cells. Matrigel contains multiple extracellular matrix proteins, however, laminin-1 was identified as the major matrix component that induced HSG cell acinar development and cytodifferentiation. Antibodies against specific components of Matrigel and against cell surface adhesion molecules were added to cells in culture to identify components important for HSG cell acinar differentiation. Immunostaining of HSG cell acini identified TGF-beta 2 and beta 3 as the predominant isoforms within the cells. Neutralizing antibodies directed against TGF-beta 3 significantly decreased (P < or = 0.0002) the size of acini formed. These results indicate that multiple components, including laminin-1 and TGF-beta 3, contribute to HSG cell acinar development. This model system will be useful to study acinar differentiation and salivary gland-specific protein expression in vitro.
先前的研究表明，在基底膜提取物基质胶上培养永生化的人下颌下腺细胞系（HSG）可诱导细胞分化。我们进一步明确了该模型系统，并确定了参与HSG细胞腺泡发育和细胞分化的因素。腺泡发育的标志是细胞迁移到多细胞球形结构中、细胞增殖以及中央定位细胞的凋亡。此外，通过间接免疫荧光和免疫印迹分析来确定功能分化，检测对象为胱抑素，这是一种唾液腺腺泡细胞特异性蛋白，发现分化的HSG细胞可产生该蛋白。基质胶包含多种细胞外基质蛋白，然而，层粘连蛋白-1被确定为诱导HSG细胞腺泡发育和细胞分化的主要基质成分。将针对基质胶特定成分和细胞表面黏附分子的抗体添加到培养的细胞中，以确定对HSG细胞腺泡分化重要的成分。HSG细胞腺泡的免疫染色确定TGF-β2和β3是细胞内的主要亚型。针对TGF-β3的中和抗体显著减小了（P≤0.0002）所形成腺泡的大小。这些结果表明，包括层粘连蛋白-1和TGF-β3在内的多种成分有助于HSG细胞腺泡的发育。该模型系统将有助于体外研究腺泡分化和唾液腺特异性蛋白表达。
