Extended Data Fig. 4: Structure and mechanics of the skin.
From: Matrix-producing neutrophils populate and shield the skin
a, Second harmonic generation (SHG) in the ear skin to determine average fibre width using CT-FIRE (see Methods). b, Measure of fibre “vesselness” to detect potential changes in fibre structure using the Frangi score (coloured as shown in the scale). More signal in the control group (Cre-negative Rosa26iDTR littermates) shows loss of fibrous matrix structure in the iDTR and TgfbrΔN mice, as shown in the quantifications below. The number of replicates is indicated in the plot. P-value determined by two-sided multiple t-test. c, Experimental design and schematics of the tensile tester used to measure the passive force of tissues at defined strains (see Methods). d, Skin stiffness at different times of day (ZT), which display marked circadian variations; the numbers of replicates (n) are displayed in the figure; p-value was calculated using the amplitude vs. zero test22. e,f, Neutrophil depletion using anti-Ly6G antibody (1A8) (e) caused loss of diurnal variations in skin stiffness (f) measured at the trough and peak times (ZT9 and ZT17). The number of replicates for each group is displayed in the figure. P-value determined by one-way ANOVA with multiple comparison test (e,f). Box plots show median ± interquartile; whiskers show the range from minimum to maximum.
