Microvascular destruction identifies murine allografts that cannot be rescued from airway fibrosis
J. Clin. Invest. Ashok N. Babu, et al. 117:3774 doi:10.1172/JCI32311 [Go to this article.]

Figure 3
Both allogeneic and syngeneic grafts reperfuse by day 6 via connections of recipient vessels to the preexisting donor vascular network at the anastomosis. (A) At day 2, both allografts and syngrafts have a CD31⁺ vascular network (red) but no perfusion. Reperfusion of both allografts and syngeneic grafts begins at day 4 and is complete by day 6. (B and C) Mean fluorescent intensity and percent area of FITC⁺ vessels. *P < 0.05 versus both groups at day 2 and day 4. (D) Schematic of transplanted trachea. Black ovals represent sutures at anastomosis site. Light blue represents the cartilage rings. Red colors the membranous trachea in the transplanted graft, and blue represents that of the recipient ends. (E–G) Vessel origin experiment was conducted in allografts (BALB/c→FVB [Tie2 / β-galactosidase]) and syngrafts (FVB→FVB [Tie2 / β-galactosidase]). Prior to tissue harvest, these animals were perfused with red india ink via the aorta to opacify perfused vessels in red. (E) Graft vessels are exclusively red in color (i.e., donor origin). (F) Cutout at anastomosis with suture demonstrating recipient vessels, which connect to donor vessels. Blue-staining cells are noted outside of vessels. (G) Higher magnification at anastomosis. (H) Double stain for β-galactosidase and CD31 on axial sectioning of day 6 allograft demonstrating that the blue dots are neither part of the CD31 vascular network nor express CD31. (I and J) Serial sections of day 6 allograft independently stained for β-galactosidase (I) and CD31 (J) to demonstrate that β-galactosidase–expressing cells do not express CD31 (n = 3–4 for all groups). Original magnification, ×20 (E, F, I, and J); ×40 (G and H).