Figure 3

RCMV increases expression of matrix metalloproteinases and decreases collagen deposition in the aortic allografts. (A) Cross sections of RCMV-infected and uninfected allografts (controls) at 2 and 8 weeks post transplantation, stained with Masson's trichrome to identify collagen deposits. Blue, collagen; red, muscle fibers; black, nuclei; I, intima; M, media; A, adventitia. Bar chart shows the collagen deposits in the allografts of RCMV-infected and uninfected allografts at 2 and 8 weeks post transplantation presented as the size (μm²) of positive blue immunostained area per cross section. *p < 0.05 vs.uninfected controls 8 weeks after transplantation. At 8 weeks, infected allografts had significantly less collagen. (B) Cross sections of RCMV-infected and uninfected allografts (controls) stained to identify MMP-2. Brown indicates positivity for MMP-2. I, intima; M, media; A, adventitia. Bar chart shows percentage of positive areas for MMP-2 in infected and uninfected allografts at 2 and 8 weeks post transplantation determined as the percentage of positive area of the total cross section area. ***p < 0.001 vs.uninfected controls at 8 weeks. (C) Cross sections of RCMV-infected and uninfected allografts (controls) stained to identify MMP-9. Brown indicates positivity for MMP-9. I, intima; M, media; A, adventitia. Bar chart shows percentage of positive areas for MMP-9 in infected and uninfected allografts at 2 and 8 weeks post transplantation. Early after transplantation both MMP-2 and MMP-9 after confined mainly to the adventitia.