Beta-cell gene expression and functional characterisation of the @entity1 XXXX .

@entity1 @entity268 @entity9608 @entity14224 @entity35316 @entity1365 @entity413 @entity1928
@entity9608 cell lines are widely used to study physiological and pathophysiological mechanisms involved in @entity413 metabolism and to establish in vitro models for studies on beta-cells. In contrast, @entity1 @entity9608 cell lines are rarely used because of difficulties in obtaining and culturing them for long periods. The aim of our study was to investigate, under different experimental conditions, the capacity of the @entity1 @entity9608 to retain beta-cell function, particularly the expression of constitutive beta-cell genes (insulin, the @entity413 transporters @entity1365 and @entity35316 , @entity14224 ), intracellular and secreted insulin, beta-cell granules, and @entity268 content. Results showed that CM cells from an early-passage express specific beta-cell genes in response to @entity413 stimulation, in particular the insulin and GLUT genes. Such capacity is lost at later passages when cells are cultured at standard @entity413 concentrations. However, if cultured at lower @entity413 concentration (0.8 mM) for a longer time, CM cells re-acquire the capacity to respond to @entity413 stimulation, as shown by the increased expression of beta-cell genes (insulin, @entity35316 , @entity14224 ). Nonetheless, insulin secretion could not be restored under such experimental conditions despite the presence of intracellular insulin, although @entity268 response to a potent activator of adenylate cyclase, @entity1928 , was present indicating a viable system. In conclusion, these data show that the @entity1 @entity9608 , at both early-passage and late-passage, posseses a functional @entity413 -signalling pathway and insulin mRNA expression similar to normal beta-cells, representing, therefore, a good model for studies concerning the signalling and expression of beta-cells. Furthermore, we have previously shown that it is also a good model for immunological studies. In this respect it is important to note that the CM cell line is one of the very few existing @entity1 beta-cell lines in long-term culture.
