Pyruvate Kinase M2 Accelerates Cutaneous Wound Healing via Glycolysis and Wnt/ß-Catenin Signaling.

Cutaneous wound healing is a complex and dynamic process with high energy demand. The activation of glycolysis is essential for restoring the structure and function of injured tissues in wounds. Pyruvate kinase M2 (PKM2) is an enzyme that plays a crucial role in the last step of glycolysis. PKM2-mediated glycolysis is known to play an important role in diseases related to regeneration and inflammation. However, the role of PKM2 in wound healing has not been fully elucidated. In this study, we found that PKM2 expression and pyruvate kinase (PK) activity were increased with the activation of Wnt/ß-catenin signaling during wound healing in mice. TEPP-46, an allosteric activator of PKM2, enhanced HaCaT human keratinocyte migration and cutaneous wound healing with an increment of PK activity. Moreover, we confirmed the effect of co-treatment with TEPP-46 and KY19382, a Wnt/ß-catenin signaling activator through the interference with the CXXC-type zinc finger protein 5 (CXXC5) Dishevelled interaction, on wound healing. The combination treatment significantly accelerated wound healing, which was confirmed by the expression level of PCNA, keratin 14, and α-SMA. Furthermore, co-treatment induced angiogenesis in the wound beds. Overall, activation of both glycolysis and Wnt/ß-catenin signaling has the potential to be used as a therapeutic approach for wound healing.

Inhibiting the cytosolic function of CXXC5 accelerates diabetic wound healing by enhancing angiogenesis and skin repair.

Diabetic wound healing, including diabetic foot ulcer (DFU), is a serious complication of diabetes. Considering the complexity of DFU development, the identification of a factor that mediates multiple pathogeneses is important for treatment. In this study, we found that CXXC-type zinc finger protein 5 (CXXC5), a negative regulator of the Wnt/ß-catenin pathway, was overexpressed with suppression of the Wnt/ß-catenin pathway and its target genes involved in wound healing and angiogenesis in the wound tissues of DFU patients and diabetes-induced model mice. KY19334, a small molecule that activates the Wnt/ß-catenin pathway by inhibiting the CXXC5-Dvl interaction, accelerated wound healing in diabetic mice. The enhancement of diabetic wound healing could be achieved by restoring the suppressed Wnt/ß-catenin signaling and subsequently inducing its target genes. Moreover, KY19334 induced angiogenesis in hindlimb ischemia model mice. Overall, these findings revealed that restorative activation of Wnt/ß-catenin signaling by inhibiting the function of cytosolic CXXC5 could be a therapeutic approach for treating DFUs.

CXXC5 Mediates DHT-Induced Androgenetic Alopecia via PGD2.

The number of people suffering from hair loss is increasing, and hair loss occurs not only in older men but also in women and young people. Prostaglandin D2 (PGD2) is a well-known alopecia inducer. However, the mechanism by which PGD2 induces alopecia is poorly understood. In this study, we characterized CXXC5, a negative regulator of the Wnt/ß-catenin pathway, as a mediator for hair loss by PGD2. The hair loss by PGD2 was restored by Cxxc5 knock-out or treatment of protein transduction domain-Dishevelled binding motif (PTD-DBM), a peptide activating the Wnt/ß-catenin pathway via interference with the Dishevelled (Dvl) binding function of CXXC5. In addition, suppression of neogenic hair growth by PGD2 was also overcome by PTD-DBM treatment or Cxxc5 knock-out as shown by the wound-induced hair neogenesis (WIHN) model. Moreover, we found that CXXC5 also mediates DHT-induced hair loss via PGD2. DHT-induced hair loss was alleviated by inhibition of both GSK-3ß and CXXC5 functions. Overall, CXXC5 mediates the hair loss by the DHT-PGD2 axis through suppression of Wnt/ß-catenin signaling.

Adhesive Hydrogel Patch-Mediated Combination Drug Therapy Induces Regenerative Wound Healing through Reconstruction of Regenerative Microenvironment.

Regenerative wound healing involves the scarless wound healing as observed in fetal skin. Multiple features of regenerative wound healing have been well studied; however, the practical application of pro-regenerative materials to recapitulate the regenerative wound healing in adult skins has not yet been achieved. In this study, the authors identified that their novel pro-regenerative material, pyrogallol-functionalized hyaluronic acid (HA-PG) patches in combination with protein transduction domain-fused Dishevelled (Dvl)-binding motif (PTD-DBM), a peptide inhibiting the CXXC-type zinc finger protein 5 (CXXC5)-Dvl interaction, promoted regenerative wound healing in mice. The HA-PG patches loaded with this competitor peptide and valproic acid (VPA), a glycogen synthase kinase 3ß (GSK3ß) inhibitor, significantly inhibited scar formation during wound healing. The HA-PG patches with PTD-DBM and/or VPA inhibit the expression of differentiated cell markers such as α-smooth muscle actin (α-SMA) while inducing the expression of stem cell markers such as CD105 and Nestin. Moreover, Collagen III, an important factor for regenerative healing, is critically induced by the HA-PG patches with PTD-DBM and/or VPA, as also seen in VPA-treated Cxxc5-/- mouse fibroblasts. Overall, these findings suggest that the novel regeneration-promoting material can be utilized as a potential therapeutic agent to promote both wound healing and scar attenuation.

Pyruvate Kinase M2 Promotes Hair Regeneration by Connecting Metabolic and Wnt/ß-Catenin Signaling.

Hair follicle stem cells (HFSCs) utilize glycolytic metabolism during their activation and anagen induction. However, the role of pyruvate kinase M2 (PKM2), which catalyzes the final step of glycolysis, in hair regeneration has not been elucidated. In this study, we investigated the expression pattern and activity of PKM2 during the depilation-induced anagen progression in mice. We found that TEPP-46, a selective activator of PKM2, enhanced hair re-growth and proliferation of HFSCs. PKM2 expression was increased via up-regulation of Wnt/ß-catenin signaling, which is involved in hair regeneration. Moreover, a combined treatment with KY19382, a small molecule that activates Wnt/ß-catenin signaling, and TEPP-46 significantly enhanced hair re-growth and wound-induced hair follicle neogenesis (WIHN). These results indicate that simultaneous activation of the PKM2 and Wnt/ß-catenin signaling could be a potential strategy for treating alopecia patients.

Wnt/ß-catenin signaling activator restores hair regeneration suppressed by diabetes mellitus.

Diabetes mellitus is one of the most prevalent diseases in modern society. Many complicationssuch as hepatic cirrhosis, neuropathy, cardiac infarction, and so on are associated with diabetes. Although a relationship between diabetes and hair loss has been recently reported, the treatment of diabetic hair loss by Wnt/ß-catenin activators has not been achieved yet. In this study, we found that the depilation-induced anagen phase was delayed in both db/db mice and high-fat diet (HFD) and streptozotocin (STZ)-induced diabetic mice. In diabetic mice, both hair regrowth and wound-induced hair follicle neogenesis (WIHN) were reduced because of suppression of Wnt/ß-catenin signaling and decreased proliferation of hair follicle cells. We identified that KY19382, a small molecule that activates Wnt/ß-catenin signaling, restored the capabilities of regrowth and WIHN in diabetic mice. The Wnt/ß-catenin signaling activator also increased the length of the human hair follicle which was decreased under high glucose culture conditions. Overall, the diabetic condition reduced both hair regrowth and regeneration with suppression of the Wnt/ß-catenin signaling pathway. Consequently, the usage of Wnt/ß-catenin signaling activators could be a potential strategy to treat diabetes-induced alopecia patients. [BMB Reports 2022; 55(11): 559-564].

KY19382, a novel activator of Wnt/ß-catenin signalling, promotes hair regrowth and hair follicle neogenesis.

BACKGROUND AND PURPOSE: The promotion of hair regeneration and growth heavily depends on the activation of Wnt/ß-catenin signalling in the hair follicle, including dermal papilla (DP). KY19382, one of the newly synthesized analogues of indirubin-3'-monoxime (I3O), was identified as a Wnt/ß-catenin signalling activator via inhibition of the interaction between CXXC-type zinc finger protein 5 (CXXC5) and dishevelled (Dvl). Given the close relationship between the Wnt/ß-catenin signalling and hair regeneration, we investigated the effect of KY19382 on hair regrowth and hair follicle neogenesis. EXPERIMENTAL APPROACH: In vitro hair induction effects of KY19382 were performed in human DP cells. The hair elongation effects of KY19382 were confirmed through the human hair follicle and vibrissa culture system. In vivo hair regeneration abilities of KY19382 were identified in three models: hair regrowth, wound-induced hair follicle neogenesis (WIHN) and hair patch assays using C57BL/6 mice. The hair regeneration abilities were analysed by immunoblotting, alkaline phosphatase (ALP) and immunohistochemical staining. KEY RESULTS: KY19382 activated Wnt/ß-catenin signalling and elevated expression of ALP and the proliferation marker PCNA in DP cells. KY19382 also increased hair length in ex vivo-cultured mouse vibrissa and human hair follicles and induced hair regrowth in mice. Moreover, KY19382 significantly promoted the generation of de novo hair follicles as shown by WIHN and hair patch assays. CONCLUSION AND IMPLICATIONS: These results indicate that KY19382 is a potential therapeutic drug that exhibits effective hair regeneration ability via activation of the Wnt/ß-catenin signalling for alopecia treatments.