Figure 2.
Tissue Damage Activates a Transient Zone of Stress Resilience within the Repairing Epithelium
(A–E) Wounding triggers the epithelium to become more resistant to UV-induced cell damage and death (schematic, A). Naive unwounded tissue is sensitive to UV-A (B–E), with targeted cells (asterisks) rapidly rounding up and delaminating (B; magenta nuclei, His2Av-mRFP; green cell outlines, dE-cadherin-GFP), with increased ROS (blue DHE in C), γH2AvD puncta (arrowheads, yellow in D), and AnnexinV staining (arrowheads, blue, E and E′).
(F and G) Wounded epithelium (magenta nuclei, His2Av-mRFP; green cell outlines, dE-cadherin-GFP) initially sensitive to UV-A (F) with targeted cells (asterisks) delaminating from epithelium (arrowheads, F′–F″″) as in controls. Wounded epithelium more resistant to UV-induced stress 90 min post-wounding (G) with targeted cells (asterisk) remaining in epithelium (arrowheads, G′–G″″).
(H–K) The induction of UV resistance is temporary (quantified in H), displays a typical dose-response behavior (quantified in I), and fades with increasing distance from the wound edge (J and K).
Wound edge represented by dashed yellow outlines in (F) and (G); UV-targeted cells indicated by dashed white line in (B), (C), (E), (F′)–(F″″), (G′)–(G″″), and (K)–(K″). pw, post-wounding. Scale bars represent 10 μm in (F) and (G) and 5 μm in (B)–(E), (F′)–(F″″), (G′)–(G″″), and (K)–(K″).