Figure 5

Differential expression of MMP1 in un-treated and inflammatory mediator-treated HUVECs isolated from 29 separate individuals. (a) Quantitative RT-PCR measuring MMP1 abundance in un-treated (UT) and inflammatory mediator-treated (IM) conditions identified two distinct populations; HUVECs isolated from seven individuals had low MMP1 mRNA abundance regardless of UT or IM culture conditions (labelled as Basal Low Expressers), while HUVECs isolated from the other 22 individuals had relatively higher MMP1 mRNA abundance regardless of UT or IM culture conditions (labelled as Basal High Expressers) (P < 0.0001, Mann Whitney non parametric test). (b) To illustrate the regulation of MMP1 mRNA abundance by inflammatory mediator-treatment, the fold change in MMP1 abundance in IM -vs- UT conditions is shown. In six out of the seven Basal Low Expressers MMP1 abundance was increased in response to IM treatment. In contrast, in 19 out of the 22 Basal High Expressers MMP1 abundance either did not change significantly or fell slightly in response to IM treatment. Both the difference in mRNA abundance between the untreated and the inflammatory mediator treated conditions and the differential response between the high and low basal expressers to inflammatory mediator treatment showed statistical significance (Paired t-test, P < 0.0001 and Mann Whitney nonparametric test, P = 0.002 respectively). (c) Total MMP1 enzymatic activity was measured in a subset of the HUVEC isolates. In general low basal expressers have lower enzyme activity than high basal expressers.