Figure 2.

Senescent human lung fibroblasts infiltration and engraftment in mice lungs. (A) Images of lung sections showing IHC staining for CDKN1A/p21^Cip1/Waf1 (left panel) and HuNu (right panel) from mice injected with SEN-IMR90 or control. Engraftment of senescent cells (arrows) in mice sacrificed after 3 and 48 hours post-transplantation. Positive cells were confirmed using histology at low magnification (20×, scale bar 100 μm), and high magnification (40×, orange box). (B) RT–PCR expression of CDKN1A/p21^Cip1/Waf1 was measured relative to murine Actin-b to demonstrate the engraftment of SEN-IMR90 in the lungs of nude mice after 48 hours post-transplantation, and their presence at later endpoints compared to control; n = 3 each group. Statistical significance was assessed by the one-way ANOVA with Tukey test: ^***p < 0.001. (C) Serial section and staining with antibodies against human CDKN1A/p21^Cip1/Waf1 and Phospho-H2AX (γ-H2AX) to demonstrate senescence state of the engrafted cells. For further explanations, see text.