Fig. 6. Muted transcriptional response to irradiation in the aged thymic stroma linked to aaTEC disruption of trophic signals.

a, Differential expression after damage within stromal cell subsets of key thymopoietic and epithelial growth factors in 2-mo or 18-mo female C57BL/6 mice at days 4 and 7 after TBI (compared to day 1). b, Differential expression of cTECs associated genes at days 4 and 7 after TBI in 2-mo and 18-mo mice. c, Expression of receptors for epithelial growth factors across stromal cell subsets. d, Chord diagram interaction analysis of FGF and BMP signaling pathways in 2-mo or 18-mo mice at baseline and at day 7 after TBI. e, CD45⁻ nonhematopoietic stromal cells were isolated from 18-mo female mice and incubated for 5 min with KGF (100 ng ml⁻¹) when cells were stained for phosphorylated AKT by flow cytometry (n = 6 thymuses isolated from individual mice). Summary data represent mean ± s.e.m. and each dot represents an individual biological replicate. Statistics were generated using a two-tailed paired t-test.