Extended Data Fig. 8: Pharmaceutical inhibition of MAPK/ERK suppresses IR induced premature skin aging.

a, Left diagram: Experimental design for pharmaceutical intervention of LIR phenotypes using sch772984 (+sch) or Solvent control (+S) by Oral Gavage. Right panel: Backskin photographs of WT C57BL/6 mice at A2 analysis point that were LIR treated (LIR) or untreated (Ctrl), and were +sch or +S intervened. Scale bar: 1 cm. b,FACS profiles of HFSC abundance of +S/+ T LIR treated mice at A1 time. c, Comparative Pharmacological kinetics (PK) analysis of plasma drug concentration after one time same dosage Trametinib administration by Oral or Topical method. Horizon axis: hours post administration. n = 3 mice. d, Day 6 backskin exoplant cultures from A1 time backskins of mice in Fig. 6i and MK area quantification (n = 5 exoplants separated from 3 mice). Scale bars: 100 μm. e, SG size quantification in Fig. 6f. n = 5 HFs. f, Photos and quantification (n = 5) of backskin full-thickness wound healing of mice in Fig. 6i at A1 time. Scale bars: 5 mm. P values are for Rad+T vs Rad+S, n = 3 mice. g, FACS profiles and quantification (n = 3 mice) of HFSC abundance in Fig. 6i at A1 time. h, IF images of backskin sections of the Fig. 6j mice after +T or +S administration for 3 times without waxing and radiation. DAPI is in blue. Scale bars: 50μm. For all relevant figures, data are represented as mean ± SEM. P values were calculated with two tail t-test.