Vag Janos, Byrne Elaine M, Hughes Deirdre H, Hoffman Matthew, Ambudkar Indu, Maguire Paula, O'Connell Brian C
Department of Restorative Dentistry and Periodontology, Dublin Dental School and Hospital, Trinity College, Dublin, Ireland.
J Cell Physiol. 2007 Aug;212(2):416-23. doi: 10.1002/jcp.21035.
A human salivary intercalated duct cell line (HSG) is capable of morphological change to acinar-type cells, and of salivary amylase (AMY1) expression, by culturing on basement membrane extracts (BME). The aim of this study was to determine the critical conditions for functional and morphological differentiation of HSG cells and to establish if the processes are related. Cells were grown on BMEs that had different protein concentrations and growth factor content, and then examined with respect to morphology and AMY1 expression. To investigate the role of intracellular calcium in amylase expression, a pcDNA3.1-TRPC1alpha construct was used to overexpress htrp1alpha, which mediates the store-operated calcium entry in HSG cells. Expression of the AMY1, TRPC1alpha and beta genes was quantified by means of real time RT-PCR. Growth factor-reduced BME (12.8 mg/ml) induced multicellular acinar structures with lumen formation but without stimulation of either AMY1 or TRPC1. HSG cells cultured on higher concentration BME (17.5 or 16.4 mg/ml) formed reticular networks. AMY1 expression increased both on growth factor-reduced BME (17.5 mg/ml: 3.0-fold, P < 0.001) and on regular BME (16.4 mg/ml: 3.7-fold, P < 0.001) accompanied by a slight increase in expression of TRPC1alpha and TRPC1beta. Overexpression of htrp1alpha did not cause any significant changes in AMY expression, though it attenuated the BME (17.5 mg/ml)-induced AMY1 upregulation. Overall, the higher protein concentration BME favors amylase expression in HSG cells, whereas the lower concentration causes marked morphological changes.
人唾液闰管细胞系（HSG）通过在基底膜提取物（BME）上培养，能够发生形态变化成为腺泡样细胞，并表达唾液淀粉酶（AMY1）。本研究的目的是确定HSG细胞功能和形态分化的关键条件，并确定这些过程是否相关。将细胞接种在具有不同蛋白质浓度和生长因子含量的BME上，然后检查其形态和AMY1表达。为了研究细胞内钙在淀粉酶表达中的作用，使用pcDNA3.1-TRPC1α构建体过表达htrp1α，其介导HSG细胞中的储存-操纵性钙内流。通过实时RT-PCR定量AMY1、TRPC1α和β基因的表达。生长因子降低的BME（12.8 mg/ml）诱导形成具有管腔形成的多细胞腺泡结构，但不刺激AMY1或TRPC1。在较高浓度BME（17.5或16.4 mg/ml）上培养的HSG细胞形成网状网络。在生长因子降低的BME（17.5 mg/ml：3.0倍，P < 0.001）和常规BME（16.4 mg/ml：3.7倍，P < 0.001）上，AMY1表达均增加，同时TRPC1α和TRPC1β的表达略有增加。htrp1α的过表达虽然减弱了BME（17.5 mg/ml）诱导的AMY1上调，但未引起AMY表达的任何显著变化。总体而言，较高蛋白质浓度的BME有利于HSG细胞中淀粉酶的表达，而较低浓度则导致明显的形态变化。
