Journal: Science Advances

Article Title: Wnt signaling modulates mechanotransduction in the epidermis to drive hair follicle regeneration

doi: 10.1126/sciadv.adq0638

Figure Lengend Snippet: ( A ) Representative images of phalloidin (green) and E-cadherin (red) staining in CHIR-treated human keratinocytes. Increased expression of membrane E-cadherin (white arrowheads) after CHIR treatment. Scale bars, 20 μm. ( B ) Representative images of β-catenin (green) staining in CHIR-treated human keratinocytes. Increased membrane β-catenin (arrowheads) after CHIR treatment. Scale bars, 20 μm. ( C ) Capillary electrophoresis immunoblots for β-catenin expression in cytoplasmic and membrane fractions of CHIR-treated human keratinocytes. Cytoplasmic loading control, GAPDH. Membrane loading control, Na/K-ATPase (NKA). Two bands for NKA correspond to intact form (150 kDa) and α1 subunit (100 kDa) of NKA , and the ratio reflects the sum of both bands. After CHIR treatment, membrane β-catenin expression was increased. ( D and E ) qPCR assessment for CDH1 and CDH3 of CHIR-treated human keratinocytes. (D) Linear regression analysis revealed a strong, linear relationship between CDH1 and LEF1 expression. LEF1 induced by CHIR in a dose-dependent manner, with (E) a corresponding decrease in CDH3 in the same set of samples. n = 3 to 4 dishes per group. Data represented as means ± SEM. * P < 0.05 and ** P < 0.01. Unprocessed blots are provided.

Article Snippet: The fixed cells were incubated overnight in 4°C using antibodies against E-cadherin (1:400, Rabbit mAb no. 3195, Cell Signaling Technology), β-catenin (1:500, Mouse mAb catalog no. 13-8400, Invitrogen), or desmogleins 1/3 (Px44, a gift from A. Payne and X. Mao).

Techniques: Staining, Expressing, Membrane, Electrophoresis, Western Blot, Control

Journal: Science Advances

Article Title: Wnt signaling modulates mechanotransduction in the epidermis to drive hair follicle regeneration

doi: 10.1126/sciadv.adq0638

Figure Lengend Snippet: ( A ) Wnt signaling optimizes tissue mechanics to amplify the regenerative capacity of a wound. During WIHN, PZHR (area with optimal tissue E ) emerges in the wound’s center region after re-epithelialization to define the zone capable of hair regeneration. Wnt signaling, which precedes scab detachment by 2 to 3 days, expands the PZHR area severalfold to greatly amplify the regenerative capacity of the wound. ( B to D ) Summary of the Wnt-mediated mechanoregulatory axis. (B) Mechanobiological response of keratinocytes to Wnt. β-Catenin serves a dual role as the main downstream effector of Wnt signaling and an essential component of AJs. Increased cytoplasmic β-catenin enhances the formation of AJs, which anchor actin filaments at cell-cell junctions. This triggers a massive shift in intracellular actin architecture to render a “hollowed-out” appearance: sparse in the center and rich in the periphery (i.e., cell-cell junctions), where junctional actin filaments become highly organized. As a result, the entire cell becomes less rigid. However, the drop in rigidity is less pronounced in cell-cell junctions ( E jcn ) compared to other cellular compartments (e.g., cytoplasmic rigidity, E cyto ). In the nucleus, Wnt agonist treatment promotes chromatin decondensation, a state that is conducive to transcription of Wnt target genes. This leads to a steep decline in nuclear rigidity ( E nuc ). (C) Unlike keratinocytes, fibroblasts lack a robust network of AJs. Thus, Wnt-induced actin remodeling—which is AJ dependent—attenuates mechanotransduction and the substrate rigidity response in epidermal keratinocytes but not dermal fibroblasts. (D) Wnt signaling generates a mechanical syncytium—a cohesive contractile unit with augmented mechanical cooperativity. The Wnt-driven increase in cell-cell adhesion is counterbalanced by higher cell-ECM forces, which becomes concentrated around the rim of multicellular colonies. Increased cadherin-based adhesions, supported by organized junctional actin filaments, enhance collective durotaxis by promoting synchrony between cells over speed.

Article Snippet: The fixed cells were incubated overnight in 4°C using antibodies against E-cadherin (1:400, Rabbit mAb no. 3195, Cell Signaling Technology), β-catenin (1:500, Mouse mAb catalog no. 13-8400, Invitrogen), or desmogleins 1/3 (Px44, a gift from A. Payne and X. Mao).

Techniques: