Project description:Chronic cutaneous wounds remain a persistent unmet medical need that decrease expectancy and quality of life. Here, we report that topical application of PY-60, a small molecule activator of the transcriptional coactivator YAP, promotes regenerative repair of cutaneous wounds in pig and human models. Pharmacological YAP activation enacts a reversible pro-proliferative transcriptional program in keratinocytes and dermal cells that results in accelerated re-epithelization and regranulation of the wound bed. These results demonstrate that transient topical administration of a YAP activating agent may represent a generalizable therapeutic approach to treating chronic wounds.
Project description:The aim of this experiment was measure the influence of age on cutaneous wound healing using human subjects. Increaded age has been associated with delayed wound healing in mouse models and in humans. Gene expression was compared between excisional biopsy wounds from young and old subjects.
Project description:Regeneration is the “holy grail” of tissue repair, but skin injury typically yields fibrotic, non-functional scars. Developing pro-regenerative therapies requires rigorous understanding of the molecular progression from injury to fibrosis or regeneration. Here, we report the divergent molecular events driving skin wound cells toward either scarring or regenerative fates. We profile scarring versus YAP inhibition-induced wound regeneration at the transcriptional (single-cell RNA-sequencing), protein (timsTOF proteomics), and tissue (extracellular matrix ultrastructural analysis) levels. Using cell surface barcoding, we integrate these data to reveal fibrotic and regenerative “molecular trajectories” of healing. We show that disrupting YAP mechanical signaling yields regenerative repair orchestrated by fibroblasts with activated Trps1 and Wnt signaling. Finally, by performing in vivo gene knockdown and overexpression in wounds, we identify Trps1 as a key regulatory gene that is necessary and partially sufficient for wound regeneration. Our findings serve as a multimodal map of wound regeneration and could have therapeutic implications for pathologic fibroses.
Project description:Human and murine skin wounding commonly result in fibrotic scarring but the murine wounding model Wound Induced Hair Neogenesis (WIHN) can frequently result in a regenerative repair response. Here we show in single cell RNA-seq comparisons of semi-regenerative and fibrotic WIHN wounds, increased expression of phagocytic/lysosomal genes in macrophages associated with predominance of fibrotic myofibroblasts in fibrotic wounds. Investigation revealed that macrophages in the late wound drive fibrosis by phagocytizing dermal Wnt inhibitor SFRP4 to establish persistent Wnt activity. In accordance, phagocytosis abrogation resulted in transient Wnt activity and a more regenerative healing. Phagocytosis of SFRP4 was integrin-mediated and dependent on the interaction of SFRP4 with the EDA splice variant of fibronectin. In the human skin condition Hidradenitis suppurativa, phagocytosis of SFRP4 by macrophages correlated with fibrotic wound repair. These results reveal that macrophages can modulate a key signaling pathway via phagocytosis to alter the skin wound healing fate.
Project description:YAP is a transcriptional co-activator of the hippo signaling pathway and is known for its oncogenic and regenerative activity across numerous tissue types. In particular, high YAP levels in patients with gastric cancer (GC) confer a lower survival rate and poor prognosis for these individuals. Therefore, there is a great need to develop targeted therapies against these aggressive tumors. However, the role of YAP and its underlying molecular mechanisms during gastric tumorigenesis are still poorly understood. Using genetic models, we demonstrate the oncogenic function of YAP in CLU+ gastric cells in vivo. YAP over-expression in CLU+ cells induced atrophy, metaplasia and hyperproliferation in the gastric corpus, while its deletion in a Notch activated gastric tumor model rescued metaplasia. Furthermore, we defined the YAP1 targetome in YAP activated gastric tumors, and showed that YAP1 binds to the active chromatin elements of spasmolytic polypeptide-expressing metaplasia (SPEM) related genes and activates their expressions in gastric tumors and ulcers. Together, these results reveal YAP1 as a critical regulator of metaplasia in the gastric corpus, and highlights YAP signaling as a possible therapeutic target to inhibit the progression of gastric tumors.
Project description:YAP is a transcriptional co-activator of the hippo signaling pathway and is known for its oncogenic and regenerative activity across numerous tissue types. In particular, high YAP levels in patients with gastric cancer (GC) confer a lower survival rate and poor prognosis for these individuals. Therefore, there is a great need to develop targeted therapies against these aggressive tumors. However, the role of YAP and its underlying molecular mechanisms during gastric tumorigenesis are still poorly understood. Using genetic models, we demonstrate the oncogenic function of YAP in CLU+ gastric cells in vivo. YAP over-expression in CLU+ cells induced atrophy, metaplasia and hyperproliferation in the gastric corpus, while its deletion in a Notch activated gastric tumor model rescued metaplasia. Furthermore, we defined the YAP1 targetome in YAP activated gastric tumors, and showed that YAP1 binds to the active chromatin elements of spasmolytic polypeptide-expressing metaplasia (SPEM) related genes and activates their expressions in gastric tumors and ulcers. Together, these results reveal YAP1 as a critical regulator of metaplasia in the gastric corpus, and highlights YAP signaling as a possible therapeutic target to inhibit the progression of gastric tumors.
Project description:We overexpressed YAP-S127D in DLD1 colorectal cancer cells for 21 days after sub-cutaneous (SubQ) injection into the flanks of nude mice. Mice were given dox for 21 days, sacrificed, and tumors were isolated for RNA extraction and analyzed by Affymetrix microarrays.
Project description:We have previously described the reindeer antler velvet as a highly unique mammalian model of adult skin regeneration as wounds on backskin form a raised, contractile scar devoid of appendages or pigment, whereas identical wounds in antler velvet exhibit scar-less regeneration. To ask whether regenerative capacity is inherent to cells within the velvet (and not due to factors derived from the antler environment), we transplanted full thickness velvet skin grafts onto dorsal backskin. This scRNA-Seq sample profiles cells within the ectopic velvet graft to assess their molecular resemblance to regenerative velvet or non-regenerative dorsal backskin.
Project description:Cardiomyocyte (CM) loss after injury results in adverse remodelling and fibrosis, which inevitably lead to heart failure. Neuregulin-ErbB2 and Hippo-Yap signaling pathways are key mediators of CM proliferation and regeneration although the crosstalk between these pathways is unclear. Here, we demonstrate in mice that temporal over-expression (OE) of activated ErbB2 in CMs promotes cardiac regeneration in a heart failure model. Cellularly, OE CMs present an EMT-like regenerative response involving cytoskeletal reprograming, migration, ECM turnover, and displacement. Molecularly, we identified Yap as a critical mediator of ErbB2 signaling. In OE CMs, Yap interacts with nuclear envelope and cytoskeletal components, reflective of the altered mechanic state elicited by ErbB2. Hippo-independent activating phosphorylation on Yap at S352 and S274 were enriched in OE CMs, peaking during metaphase. Viral overexpression of Yap phospho-mutants dampened the proliferative competence of OE CMs. Taken together, we demonstrate a potent ErbB2-mediated Yap mechanosensory signaling involving EMT-like characteristics, resulting in heart regeneration.