Morphological and functional differentiation of HSG cells: role of extracellular matrix and XXXX .

@entity1 @entity5941 @entity7012 @entity460
A @entity1 salivary intercalated duct cell line (HSG) is capable of morphological change to acinar-type cells, and of salivary amylase ( @entity5941 ) 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 @entity5941 expression. To investigate the role of intracellular @entity460 in amylase expression, a pcDNA3.1-TRPC1alpha construct was used to overexpress htrp1alpha, which mediates the store-operated @entity460 entry in HSG cells. Expression of the @entity5941 , 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 @entity5941 or @entity7012 . HSG cells cultured on higher concentration BME (17.5 or 16.4 mg/ml) formed reticular networks. @entity5941 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 @entity5941 upregulation. Overall, the higher protein concentration BME favors amylase expression in HSG cells, whereas the lower concentration causes marked morphological changes.
