Extended Data Fig. 6: Physiological aging and/or the DNA damage response triggers the destabilization of cell polarity-related proteins in HFSCs.
From: Distinct types of stem cell divisions determine organ regeneration and aging in hair follicles
a, Heat map showing the log fold expression changes (logFC) of cell polarity-related genes between RU486-treated wild-type control (Cont) and aged (25mo) anagen stage HFSCs (aHFSCs) from microarray data. b, GSEA enrichment score curve of control (12 wo) versus aged (25 mo) HFSCs with the gene set for ‘CDC42RAC1 PATHWAY’ from microarray data. c, GSEA enrichment score curve of young (8 wo) versus aged (22–25 mo) HFSCs with the gene set for cell polarity-related genes from microarray data (GSE72683). d, Heat map showing the logFC of HFSC signature genes between young (8 wo) and aged (25 mo) anagen stage HFSCs (aHFSCs) from microarray data (GSE72683 from Matsumura et al. Science 2016). Aged aHFSCs had decreased expression of cell polarity-related genes. e, IF images of NUMB, CDC42 and PARD3 in the Bg area of young (8 wo) and of aged (24 mo) mice at 3 days after plucking (3d). f, Western blot hybridization analysis of COL17A1, CDC42, aPKCλ, NUMB, RAC1, PARD3 and TUBULIN in total epidermal lysates from young (8 wo) and from aged (24 mo) at 3d. Physiological aging destabilizes the cell polarity-related proteins. g,Venn diagram showing overlaps between 2> fold increased genes in cont vs aged HFSCs, 2> fold increased genes in cont vs Col17a1 cKO HFSCs, and 2> fold increased genes in cont vs aPKCλ cKO HFSCs. h, Venn diagram showing overlaps between 2> fold decreased genes in cont vs aged HFSCs, 2> fold decreased genes in cont vs Col17a1 cKO HFSCs, and 2> fold decreased genes in cont vs aPKCλ cKO HFSCs. i, IF images of ITGA6, COL17A1, NUMB and PARD3 in the bulge area of 12 mo control and of XPDTTD/TTD mutant mice. XPDTTD/TTD mutant HFSCs had decreased expression of cell polarity-related proteins. j, IF images of KRT15 and NUMB at 7 days after 10 Gy X-ray irradiation. hCOL17A1 transgenes rescued the IR-mediated instability of NUMB expression. k, IF images of KRT15 and aPKCλ in the Bg area from wild-type control or hCOL17A1 tg young (8 wo) and aged (25 mo) mice. hCOL17A1 transgenes rescued the age-associated instability of cell polarity-related proteins. l, TEM analysis of HD structure of young (8 wo), aged (25 mo) and aged (25 mo) hCOL17A1 transgenic mice. Right panels indicate magnified views of areas marked by red arrows on the left. Blue arrows indicate HDs. Small insets indicate magnified views of HDs (Red dotted lines). Bg, bulge area; HS, hair shaft. m, Quantification of HD number (8w, n = 3 HFs, n = 34 images; 25mo, n = 3 HFs, n = 16 images, 25mo tg, n = 2 HFs, n = 15 images). Expression of the hCOL17A1 transgene significantly rescued aged-associated immaturity and the reduced number of HDs. Error bars, means ± SEM; one-way ANOVA with Dunnett’s post-hoc test (m).
