Fig. 5

Disrupted GMT of Plp1-lineage cells attenuates bone regeneration in aged mice. a Experimental strategy for aged mice lineage tracing and jaw bone healing model. b Representative images of μCT reconstruction of the alveolar bone regeneration at day 7 post tooth extraction from young/old mice and quantitative analyses (n = 5). c Representative images of Shh immunostaining in healing sockets at day 7 post tooth extraction and the quantification (n = 5). Scale bar: 100 μm. d Representative images of tdTomato⁺ cells and Gli1 immunostaining in healing sockets at day 7 post tooth extraction and relative quantification per socket (n = 5). Scale bar: 100 μm. e Representative images of CD31 and EMCN immunostaining and quantification of CD31⁺EMCN⁺ type H vessels per socket (n = 5). Scale bar: 100 μm. f Western blot images of CD105, Gli1, MAG, and Shh expression of FACS-sorted tdTomato⁺ cells from young/old mice tooth extraction sockets at day 0 and 7 post tooth extraction. g RT-qPCR data of Shh mRNA expression of SCs from young/old mice (n = 3). h NAD⁺ was measured in serum and supernatant medium of SCs from young and old mice (n = 5). Y, young mice. O, old mice. i RT-qPCR analysis of mRNA levels of Sirt1-7 in SCs (n = 3). j Western blot analysis of the knockdown efficiency of siRNAs for SIRT1, SIRT2, SIRT3, SIRT6, and relevant Shh expression. k Representative images of tdTomato⁺ cells and SIRT6 immunostaining in TES at day 7 post tooth extraction and the relative quantification (n = 5). Scale bar: 100 μm. l Western blot showing SIRT6, c-Jun, Shh, Ptch1, and Gli1 in SCs with aging or SIRT6 knockdown/overexpression. Data were presented as mean ± SD; *P < 0.05, **P < 0.01, ***P < 0.001