Fig. 5
Post-glycated matrices induce a contractile phenotype. Primary human normal lung fibroblasts cultured within three-dimensional glycated DMEM matrices with 10 % of serum were analyzed to determine the level of alpha-smooth muscle actin (α-SMA) gene expression at the 7th, 14th and 21st day of culture. α-SMA gene expression was observed in the glycated matrices prepared with 5 mM, 15 mM ribose (R) and in the non-glycated matrices (controls) on the 21st day (only statistically significant (p < 0.05) for 5 mM). This phenomenon corresponded to the occurrence of gel contraction. In contrast, α-SMA gene expression and gels contraction were not observed in the 30 mM R glycated matrices on the 21st day. Interestingly, a progressive increase of α-SMA gene expression was observed with a gradual increase of R on day 7th, suggesting that the differentiation of fibroblasts to a contractile phenotype depends not only on time but also on the ribose concentration, which is associated with the extent of collagen cross-linking. The data are presented as percentages respect to the values on the 1st day. The experiments were repeated three times, with similar results obtained. * p-value < 0.05