Figure 5.

β-catenin deletion in Lgr5⁺ and K15⁺ stem cells inhibits their differentiation into sebocytes

(A) Representative images of Lgr5:mTmG and Lgr5: mTmG:β-catenin^flox/flox mice at the second telogen.

(B and C) Lineage tracing of Lgr5⁺ SCs in Lgr5:mTmG and Lgr5: mTmG:β-catenin^flox/flox mice. The inhibition of β-catenin signaling in Lgr5⁺ cells blocked their differentiation into SG cells (B); mGFP⁺ cells within the SGs were counted (A–C), Data are represented as mean ± SEM, ∗∗∗p < 0.005, t-test, n = 3).

(D) Representative images of K15:mTmG and K15: mTmG:β-catenin^flox/flox mice at the second telogen.

(E and F) Lineage tracing of K15⁺ SCs in K15:mTmG and K15: mTmG:β-catenin^flox/flox mice showed a decrease in the number of mGFP-labeled cells within the SGs upon β-catenin deletion (E–F, Data are represented as mean ± SEM, ∗p < 0.05, ∗∗∗p < 0.005, t-test, n = 3).

(G and H) Representative images of HFs close to wounds in Lgr5:mTmG and Lgr5:mTmG:β-catenin^flox/flox mice (G) Tracing of Gli1-expressing cells in Gli1:mTmG:β-catenin^flox/flox mice (8W) at 15 days post-injections of TAM. (H) Quantitation of mGFP⁺ cells within the SGs in Gli1:mTmG and Gli1:mTmG: β-catenin^flox/flox mice (G-H), Data are represented as mean ± SEM, ∗p < 0.05, ∗∗∗p < 0.005, t-test, n = 3).

(I) Schematic illustrations of the fate of Gli1⁺ SCs during normal hair cycle in wild-type mice, and in Gli1:mTmG: β-catenin^flox/flox mice with loss of β-catenin expression (J and k) and K15:mTmG and K15:mTmG:β-catenin^flox/flox mice (K) at 20 days post-wounding.

(L) Quantitation of mGFP⁺ cells within SGs in Lgr5:mTmG, Lgr5:mTmG:β-catenin^flox/flox, K15:mTmG, and K15:mTmG:β-catenin^flox/flox mice adjacent to wounds (J–L), Data are represented as mean ± SEM ∗p < 0.05 and ∗∗∗p < 0.005, n = 3). Bu, bulge; DP, dermal papilla; IFN, infundibulum; IS, isthmus; SG, sebaceous gland. Scale bars: 2 cm in A and D; 50 μm in B, E, G, and H.