t-PA expression and gelatinase activity in IT of the human Das.

<p><b>(A)</b> Quantitative RT-PCR shows higher <i>PLAT</i> mRNA expression in IT of the human DAs compared to the tunica media (Patients 1–5). n = 5, *<i>p</i> < 0.05. <b>(B)</b> Upper panels: Immunohistochemistry detected a positive immunoreaction for t-PA proteins in ECs and in the IT area in human DAs (Patients 1–3; brown color). Middle panels: Immunohistochemistry for MMP-2 in the human DAs. Lower panels: elastica van Gieson staining of the IT area in human DAs. Black boxes indicate the areas of the upper panels. Scale bars, 100 μm (upper panels) and 500 μm (lower panels). <b>(C)</b> <i>In situ</i> gelatin zymography demonstrates high gelatinase activity in the IEL and IT of the human DA (Patient 6). The green color indicates gelatinase activity (middle panel). Gelatinase activity was inhibited by EDTA supplementation (right panel). Profiles of Patients 1–6 are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190871#pone.0190871.s004" target="_blank">S1 Table</a>. Arrows indicate IEL. The blue color in zymography indicates nuclei. Scale bars, 200 μm.