Tunneling nanotube-driven complete regeneration of murine fetal skin.

This study investigated the three-dimensional (3D) cellular interactions and tunneling nanotubes (TNTs) during fetal mouse skin regeneration on embryonic days 13 (E13) and 15 (E15). We aimed to understand spatial relationships among cell types involved in skin regeneration and assess the potential role of TNTs. Full-thickness skin incisions were performed in E13 and E15 embryos. Wound sites were collected, embedded in epoxy resin, processed for 3D reconstruction (1 µm thickness sections), and subjected to whole-mount immunostaining. We conducted in vitro co-culture experiments with fetal macrophages and fibroblasts to observe TNT formation. To assess the effect of TNTs on skin regeneration, an inhibiting agent (cytochalasin B) was administered to amniotic fluid. Results revealed that E13 epidermal keratinocytes interacted with dermal fibroblasts and macrophages, facilitating skin regrowth. TNT structures were observed at the E13-cell wound sites, among macrophages, and between macrophages and fibroblasts, confirmed through in vitro co-culture experiments. In vitro and utero cytochalasin B administration hindered those formation and inefficient skin texture regeneration at E13 wound sites. This emphasizes the necessity of 3D cellular interactions between epidermal and dermal cells during skin regeneration in mouse embryos at E13. The prevalence of TNT structures indicated their involvement in achieving complete skin texture restoration.

Salicylate induces epithelial actin reorganization via activation of the AMP-activated protein kinase and promotes wound healing and contraction in mice.

Wounds that occur in adults form scars due to fibrosis, whereas those in embryos regenerate. If wound healing in embryos is mimicked in adults, scarring can be reduced. We found that mouse fetuses could regenerate tissues up to embryonic day (E) 13, but visible scars remained thereafter. This regeneration pattern requires actin cable formation at the epithelial wound margin via activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK). Here, we investigated whether the AMPK-activating effect of salicylate, an anti-inflammatory drug, promotes regenerative wound healing. Salicylate administration resulted in actin cable formation and complete wound regeneration in E14 fetuses, in which scarring should have normally occurred, and promoted contraction of the panniculus carnosus muscle, resulting in complete wound regeneration. In vitro, salicylate further induced actin remodeling in mouse epidermal keratinocytes in a manner dependent on cell and substrate target-specific AMPK activation and subsequent regulation of Rac1 signaling. Furthermore, salicylate promoted epithelialization, enhanced panniculus carnosus muscle contraction, and inhibited scar formation in adult mice. Administration of salicylates to wounds immediately after injury may be a novel method for preventing scarring by promoting a wound healing pattern similar to that of embryonic wounds.

The Prospective Natural History Study of Patients with Intractable Venous Malformation and Klippel-Trenaunay Syndrome to Guide Designing a Proof-of-Concept Clinical Trial for Novel Therapeutic Intervention.

Background: The natural history of venous malformation (VM) and Klippel-Trenaunay Syndrome (KTS) has not been quantitatively studied. To obtain benchmarks to guide designing clinical trials to assess safety and efficacy of novel drug candidates, the clinical course of the patients was followed for 6 months. Methods and Results: This is a multicenter prospective observational study evaluating the change rate in lesion volume from baseline with magnetic resonance images, as the primary endpoint. In addition, disease severities, performance status (PS), pain visual analog scale (VAS) score, quality of life (QoL), infections, and coagulation markers were also evaluated. Thirty-four patients (VM = 17, KTS = 17, 1-53 of age; median 15.9 years) with measurable lesion volume were analyzed. There was no statistically significant difference in the lesion volume between baseline and day 180, and the mean change rate (standard deviation) was 1.06 (0.28). There were no baseline characteristics that affected the change in lesion volume over 6 months. However, there were patients who showed more than 20% volume change and it was suggested that the lesion volume was largely impacted by local infection. There were no statistically significant changes in pain VAS score, severity, PS, QoL score, D-dimer, and platelet count over 6 months within all patients analyzed. Conclusion: The results showed the representative natural course of VM and KTS for a 6-month period with objective change of lesion volume and other factors, suggesting that it is scientifically reasonable to conduct a Phase 2 proof-of-concept study without a placebo arm, using the results of this study as the control. Clinical Trial Registration: NCT04285723, NCT04589650.

Additional Wide Resection of Infantile Dermatofibrosarcoma Protuberans after Unplanned Excision: A Case Report.

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive intermediate soft tissue neoplasm that occurs in the dermis. DFSP generally occurs in young to middle-aged adults and rarely in infancy. Because of its extreme rarity, DFSP is difficult to diagnose and treat, especially when it occurs in infancy. In this paper, we reported a case of infantile DFSP in which we performed additional wide resection with a 3-cm horizontal margin for a mass that had previously undergone unplanned excision. No tumor recurrence has been seen for 3 years postoperatively. We suggest that the possibility of DFSP should always be considered when an enlarging superficial mass is identified on the trunk, even in an infant. Additionally, radical local treatment is as important for DFSP in infancy as it is for DFSP in adults, even after unplanned excision.

Fetal Fibroblast Transplantation via Ablative Fractional Laser Irradiation Reduces Scarring.

Scar treatments include fractional laser treatment, cell transplantation, surgery, skin needling, and dermal fillers. Fractional laser treatments are used to reduce scarring and blurring. Cell transplantation is promising, with mature fibroblasts and adipose-derived stem cells being used clinically, while embryonic fibroblasts are used experimentally. Herein, we developed a combination of ablative CO2 (carbon dioxide) fractional laser and cell transplantation for the treatment of scars. Eight-week-old male C57Bl/6 mice were used to create a full-layer skin defect in the back skin and create scars. The scar was then irradiated using a CO2 fractional laser. The cells were then transplanted onto the scar surface and sealed with a film agent. The transplanted cells were GFP-positive murine fetal fibroblasts (FB), fetal fibroblasts with a long-term sphere-forming culture (LS), and fetal skin with a short-term sphere-forming culture (SS). After transplantation, green fluorescent protein (GFP)-positive cells were scattered in the dermal papillary layer and subcutis in all the groups. LS significantly reduced the degree of scarring, which was closest to normal skin. In conclusion, the combination of ablative fractional laser irradiation and fetal fibroblast transplantation allowed us to develop new methods for scar treatment.

Effect of All-trans Retinoic Acid on Panniculus Carnosus Muscle Regeneration in Fetal Mouse Wound Healing.

The dermal panniculus carnosus (PC) muscle is critical for wound contraction in lower mammals and is a useful model of muscle regeneration owing to its high cellular metabolic turnover. During wound healing in mice, skin structures, including PC, are completely regenerated up to embryonic day (E) 13, but PC is only partially regenerated in fetuses or adult animals after E14. Nevertheless, the mechanisms underlying wound repair for complete regeneration in PC have not been fully elucidated. We hypothesized that retinoic acid (RA) signaling, which is involved in muscle differentiation, regulates PC regeneration. Methods: Surgical injury was induced in ICR mice on E13 and E14. RA receptor alpha (RARα) expression in tissue samples from embryos was evaluated using immunohistochemistry and reverse transcription-quantitative polymerase chain reaction. To evaluate the effects of RA on PC regeneration, beads soaked in all-trans RA (ATRA) were implanted in E13 wounds, and tissues were observed. The effects of RA on myoblast migration were evaluated using a cell migration assay. Results: During wound healing, RARα expression was enhanced at the cut surface in PCs of E13 wounds but was attenuated at the cut edge of E14 PCs. Implantation of ATRA-containing beads inhibited PC regeneration on E13 in a concentration-dependent manner. Treatment of myoblasts with ATRA inhibited cell migration. Conclusions: ATRA inhibits PC regeneration, and decreased RARα expression in wounds after E14 inhibits myoblast migration. Our findings may contribute to the development of therapies to promote complete wound regeneration, even in the muscle.

The protective effects of blueberry honey from Canada against H2O2-induced cytotoxicity in human buccal mucosal cells.

OBJECTIVES: Several clinical trials have been conducted worldwide to evaluate the efficacy of honey against stomatitis. However, it is unclear which types of honey are effective at preventing and/or treating stomatitis. This study aimed to evaluate the potencies of several types of honey in preventing and/or curing aphthous stomatitis in in vitro studies. METHODS: The following experiments were performed: H2O2-induced cytotoxicity and mucosal cell migration in a scratch assay using buccal mucosa squamous carcinoma (HO-1-N-1) cells and the cellular expression of heme oxygenase-1 (HO-1) mRNA encoding an enzyme involved in protection against oxidative stress by real-time RT-PCR analysis, and liquid-liquid extraction and UHPLC analysis in order to examine the active components of honey. RESULTS: Of the 13 types of honey used, Canadian blueberry honey exhibited the protective effect on H2O2-induced cytotoxicity and enhanced cell migration. In addition, blueberry honey increased the expression of HO-1 mRNA with and without cotreatment with H2O2. With regard to active components of blueberry honey, the water-soluble components with a mass of >10 kDa showed a cytoprotective effect, but they have not been identified. CONCLUSION: Canadian blueberry honey, but not the other types of honey, prevents H2O2-induced oxidation of cells, probably through activation of the antioxidant and cytoprotective enzyme HO-1. Blueberry honey also enhanced cell migration, which may be relevant to wound healing. The results of this study suggest the possibility of prophylactic and therapeutic effects of Canadian blueberry honey on human stomatitis that could complement existing treatments.

Single-Cell RNA-seq Analysis Reveals Cellular Functional Heterogeneity in Dermis Between Fibrotic and Regenerative Wound Healing Fates.

Background: Fibrotic scars are common in both human and mouse skin wounds. However, wound-induced hair neogenesis in the murine wounding models often results in regenerative repair response. Herein, we aimed to uncover cellular functional heterogeneity in dermis between fibrotic and regenerative wound healing fates. Methods: The expression matrix of single-cell RNA sequencing (scRNA-seq) data of fibrotic and regenerative wound dermal cells was filtered, normalized, and scaled; underwent principal components analysis; and further analyzed by Uniform Manifold Approximation and Projection (UMAP) for dimension reduction with the Seurat package. Cell types were annotated, and cell-cell communications were analyzed. The core cell population myofibroblast was identified and the biological functions of ligand and receptor genes between myofibroblast and macrophage were evaluated. Specific genes between fibrotic and regenerative myofibroblast and macrophage were identified. Temporal dynamics of myofibroblast and macrophage were reconstructed with the Monocle tool. Results: Across dermal cells, there were six cell types, namely, EN1-negative myofibroblasts, EN1-positive myofibroblasts, hematopoietic cells, macrophages, pericytes, and endothelial cells. Ligand and receptor genes between myofibroblasts and macrophages mainly modulated cell proliferation and migration, tube development, and the TGF-ß pathway. Specific genes that were differentially expressed in fibrotic compared to regenerative myofibroblasts or macrophages were separately identified. Specific genes between fibrotic and regenerative myofibroblasts were involved in the mRNA metabolic process and organelle organization. Specific genes between fibrotic and regenerative macrophages participated in regulating immunity and phagocytosis. We then observed the underlying evolution of myofibroblasts or macrophages. Conclusion: Collectively, our findings reveal that myofibroblasts and macrophages may alter the skin wound healing fate through modulating critical signaling pathways.

Decorin Inhibits Dermal Mesenchymal Cell Migration and Induces Scar Formation.

Background: Variations in skin healing capacities are observed during different murine embryonic developmental stages. Through embryonic day 16 (E16), embryos are able to regenerate dermal architecture following flank skin wounding; however, after E17, wounds heal incompletely, inducing scar formation. The regenerative ability of the E16 fetal dermis depends on the migration of dermal mesenchymal cells. Decorin is a small molecule known to affect tissue tensile strength, cell phenotype, and tissue repair, including skin wound healing. In the current study, we evaluated the expression and roles of decorin in wound healing. Methods: Surgical injury was induced at E16 and E17 in ICR mouse embryos. Decorin expression was evaluated in tissue samples from these embryos using immunohistochemistry and reverse transcription quantitative polymerase chain reaction. Cell migration assays were used to evaluate wound healing capability of separated dermal and fascial tissues. Results: Our results showed that decorin exhibited distinct expression patterns during wound healing at E16 versus E17. Additionally, decorin expression altered cell migration in vitro. Dermal and fascial mesenchymal cells were found to exhibit distinct migration patterns concomitant with altered decorin expression. Specifically, decorin inhibited migration and favored scar formation. Conclusion: Decorin expression may contribute to scar formation in the late stage of mouse embryos by inhibiting the migration of dermal mesenchymal cells.

Screening of Autophagy-Related Prognostic Genes in Metastatic Skin Melanoma.

Cutaneous melanoma refers to a common skin tumor that is dangerous to health with a great risk of metastasis. Previous researches reported that autophagy is associated with the progression of cutaneous melanoma. Nevertheless, the role played by genes with a relation to autophagy (ARG) in the prediction of the course of metastatic cutaneous melanoma is still largely unknown. We observed that thirteen ARGs showed relations to overall survival (OS) in the Cox regression investigation based on a single variate. We developed 2-gene signature, which stratified metastatic cutaneous melanoma cases to groups at great and small risks. Cases suffering from metastatic cutaneous melanoma in the group at great risks had power OS compared with cases at small risks. The risk score, T phase, N phase, and age were proved to be individual factors in terms of the prediction of OS. Besides, the risk scores identified by the two ARGs were significantly correlated with metastatic cutaneous melanoma. Receiver operating characteristic (ROC) curve analysis demonstrated accurate predicting performance exhibited by the 2-gene signature. We also found that the immunization and stromal scores achieved by the group based on large risks were higher compared with those achieved by the group based on small risks. The metastatic cutaneous melanoma cases achieving the score based on small risks acquired greater expression of immune checkpoint molecules as compared with the high-risk group. In conclusion, the 2-ARG gene signature indicated a novel prognostic indicator for prognosis prediction of metastatic cutaneous melanoma, which served as an important tool for guiding the clinical treatment of cutaneous melanoma.

Clinical Analysis of Cultured Epidermal Autograft (JACE) Transplantation for Giant Congenital Melanocytic Nevus.

BACKGROUND: Cultured epidermal transplantation (JACE) is performed for giant congenital melanocytic nevus (GCMN), but there are few reports on its postoperative course and surgical content or indications. We aimed to investigate the postoperative course of GCMN patients undergoing cultured epidermal autograft transplantation and compare the outcomes between 2 nevus tissue resection methods. METHODS: Twelve GCMN patients aged 0 months to 8 years and 9 months were included in this single-center case series study. Cultured epidermal autograft transplantation was performed at 19 sites of the patients' extremities and trunks, after excision of the nevus either by using an electric dermatome, which we initially used in 2017, or by curettage with a sharp spoon and use of a hydrosurgery system (Versajet), which we started performing in 2018. Univariate and multivariate analyses were performed for factors associated with postoperative hypertrophic scar formation. RESULTS: In all cases, >90% of the grafts survived, and the dark brown color of the nevus was reduced. Average postoperative observation period was 16.5 months. Hypertrophic scar formation was observed postoperatively at 9 wound sites out of the 12 sites with GCMN removed with a dermatome and at only 1 site with GCMN removed by curettage with use of a hydrosurgery system. In the univariate and multivariate analyses, hypertrophic scar formation was associated with age at surgery. CONCLUSION: In cultured epidermal autograft transplantation for GCMN, nevus tissue removal at an early age by curettage with use of a hydrosurgery system can provide good results while reducing complications, including recurrence and hypertrophic scar formation.

Treatment of Deliberate Self-harm Scars with Rotated Thin-skin Graft and Minced-skin Graft.

Scars developing after wrist cutting (a deliberate action of self-harm) have various patterns and are difficult to treat. In addition, they can occur at anatomically prominent sites and are easily recognized as caused by self-harm; thus, scars can cause lifelong regrets. However, there are no standard treatment guidelines for wounds inflicted through self-harm. This study aimed to evaluate the effectiveness of our novel technique using 90-degree rotated skin grafts, which were thinly collected at a thickness of 250 µm from a wound site, together with minced-skin grafts. METHODS: Five regions on the forearm of 5 Japanese women (age, 19-29 years) were treated from July 2011 to April 2012. The skin at the scar site was cut with an electric dermatome at a thickness of 250 µm. The scar contained therein was excised, and the skin was rotated 90 degree and transplanted. The scar remaining in the dermis of the wound was resected and resurfaced. At the site where the skin graft was insufficient, the skin was processed into a minced shape and then transplanted (minced-skin graft). RESULTS: In all cases, skin grafting was performed. The scar was successfully camouflaged and transformed into a socially acceptable appearance. At the wound site, the skin texture was reproduced. Following skin grafting, nodules, pigmentation, and redness around the graft transiently occurred, which then disappeared over time. No scar contractures were observed. CONCLUSION: A combination of thin-skin graft rotated 90 degrees and minced-skin graft is useful in camouflaging a wide variety of deliberate self-harm scars.

Correction of Diastasis Rectus Abdominis with Tacking the Rectus Sheath and Resection of Excess Skin for Cosmesis.

INTRODUCTION: We report a case of diastasis rectus abdominis (DRA), in which the improvement of the appearance was obtained by performing extra skin resection. Case Report. A 30-year-old woman presented persistent abdominal bulging after her second delivery. She was diagnosed as DRA by computed tomography. We underwent a surgery that tacking the anterior layer of the rectus sheath and resecting excess skin. RESULTS: There has been no clinical evidence of recurrence, and the patient satisfies her abdominal appearance. CONCLUSION: Because DRA is not a true hernia, surgery for DRA should be performed in understanding how patients want to improve their aesthetic appearance.

Fibro-adipose vascular anomaly (FAVA): three case reports with an emphasis on the mammalian target of rapamycin (mTOR) pathway.

BACKGROUND: Fibro-adipose vascular anomaly (FAVA) is a new entity of vascular anomalies with somatic and mosaic gain-of-function mutations of the phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA). PIK3CA mutation excessively activates mammalian target of rapamycin (mTOR) pathway, which promotes angiogenesis and lymphangiogenesis. Histologically, FAVA is composed of intramuscular fibrous and adipose tissues with venous malformation (VM). Although sirolimus known as a mTOR inhibitor has good response to FAVA, expression pattern of the mTOR pathway was still unclear. Herein, we immunohistochemically investigated three novel FAVA patients with an emphasis on the mTOR pathway (p-S6K1, p-4EBP1 and p-AKT). CASE PRESENTATION: Case 1: A 10-year-old female had complained of pain in the left thigh since she was 6-year-old. Under the clinical diagnosis of VM, she underwent surgical resection for the lesion. Case 2: A 29-year-old female patient had complained of discomfort and mild pain in the left shoulder since she was 18-year-old. After childbirth, she had severe ongoing pain and contracture of the shoulder. Under clinical diagnosis of VM, surgical resection was performed. Case 3: A 53-year-old female had complained of pain and knee restriction after surgical treatment of a knee tumor at the age of 31. Under the clinical diagnosis of atypical lipomatous tumor or high grade liposarcoma, surgical resection was performed. Histologically, all three patients presented with characteristic features of fibrous and adipose tissues with abnormal vessels within the skeletal muscle, leading to diagnosis of FAVA. Although VM has been reported as an important finding in FAVA, immunohistological findings demonstrated that abnormal vessels comprised complex of VM and lymphatic malformation (LM) in all cases. Furthermore, besides vascular malformation, abnormal fibrous and adipose tissues of FAVA expressed mTOR pathway components. CONCLUSIONS: We presented three new cases of FAVA. Histological and immunohistochemical analyses revealed that VM and LM complex was an important finding in FAVA, and that the mTOR pathway components were expressed in abnormal fibrous tissue, adipose tissue and vascular malformation. These findings suggested that FAVA might be a mesenchymal malformation caused by PI3K/AKT/mTOR pathway.

Diagnosis and Treatment of Keloids and Hypertrophic Scars-Japan Scar Workshop Consensus Document 2018.

There has been a long-standing need for guidelines on the diagnosis and treatment of keloids and hypertrophic scars that are based on an understanding of the pathomechanisms that underlie these skin fibrotic diseases. This is particularly true for clinicians who deal with Asian and African patients because these ethnicities are highly prone to these diseases. By contrast, Caucasians are less likely to develop keloids and hypertrophic scars, and if they do, the scars tend not to be severe. This ethnic disparity also means that countries vary in terms of their differential diagnostic algorithms. The lack of clear treatment guidelines also means that primary care physicians are currently applying a hotchpotch of treatments, with uneven outcomes. To overcome these issues, the Japan Scar Workshop (JSW) has created a tool that allows clinicians to objectively diagnose and distinguish between keloids, hypertrophic scars, and mature scars. This tool is called the JSW Scar Scale (JSS) and it involves scoring the risk factors of the individual patients and the affected areas. The tool is simple and easy to use. As a result, even physicians who are not accustomed to keloids and hypertrophic scars can easily diagnose them and judge their severity. The JSW has also established a committee that, in cooperation with outside experts in various fields, has prepared a Consensus Document on keloid and hypertrophic scar treatment guidelines. These guidelines are simple and will allow even inexperienced clinicians to choose the most appropriate treatment strategy. The Consensus Document is provided in this article. It describes (1) the diagnostic algorithm for pathological scars and how to differentiate them from clinically similar benign and malignant tumors, (2) the general treatment algorithms for keloids and hypertrophic scars at different medical facilities, (3) the rationale behind each treatment for keloids and hypertrophic scars, and (4) the body site-specific treatment protocols for these scars. We believe that this Consensus Document will be helpful for physicians from all over the world who treat keloids and hypertrophic scars.

Labial Adhesions Causing Recurrent Urinary-Tract Infections in an Elderly Woman.

A 91-year-old postmenopausal woman with a prior history of two labial-adhesion separations suffered from recurrent urinary-tract infections. We were able to successfully treat her labial adhesions using surgery.

Selective Inhibition of ADAM28 Suppresses Lung Carcinoma Cell Growth and Metastasis.

ADAM28 (a disintegrin and metalloproteinase 28) is overexpressed by carcinoma cells in non-small cell lung carcinomas (NSCLC) and plays an important role in cancer cell proliferation and metastasis by reactivation of insulin-like growth factor-1 (IGF-1) and escaping from von Willebrand factor (VWF)-induced apoptosis through digestion of IGF-binding protein-3 and VWF, respectively. To aim for new target therapy of NSCLC patients, we developed human neutralizing antibodies 211-12 and 211-14 against ADAM28, which showed IC50 values of 62.4 and 37.5 nmol/L, respectively. Antibody 211-14 recognized the junctional region between cysteine-rich domain and secreted-specific domain and showed a KD value of 94.7 pmol/L for the epitope-containing peptide. This antibody detected monkey and human secreted-form ADAM28s, although it was not reactive with mouse membrane-anchored ADAM28m. Antibody 211-14 effectively inhibited IGF-1-stimulated cell proliferation of lung adenocarcinoma cell lines with ADAM28 expression, including PC-9 cells, and promoted VWF-induced cell death in these cell lines. In lung metastasis models, antibody 211-14 significantly reduced tumor growth and metastases of PC-9 cells and prolonged survivals in the antibody-treated mice compared with the control IgG-treated ones. Combination therapy of the antibody and docetaxel was more effective than that of bevacizumab and docetaxel and showed further elongation of survival time compared with monotherapy. No adverse effects were observed even after administration of 10-fold more than effective dose of anti-ADAM28 antibody to normal mice. Our data demonstrate that antibody 211-14 is a neutralizing antibody specific to ADAM28s and suggest that this antibody may be a useful treatment remedy for NSCLC patients. Mol Cancer Ther; 17(11); 2427-38. ©2018 AACR.

Stromal Versican Regulates Tumor Growth by Promoting Angiogenesis.

The proteoglycan versican is implicated in growth and metastases of several cancers. Here we investigated a potential contribution of stromal versican to tumor growth and angiogenesis. We initially determined versican expression by several cancer cell lines. Among these, MDA-MB231 and B16F10 had none to minimal expression in contrast to Lewis lung carcinoma (LLC). Notably, tumors arising from these cell lines had higher versican levels than the cell lines themselves suggesting a contribution from the host-derived tumor stroma. In LLC-derived tumors, both the tumor and stroma expressed versican at high levels. Thus, tumor stroma can make a significant contribution to tumor versican content. Versican localized preferentially to the vicinity of tumor vasculature and macrophages in the tumor. However, an ADAMTS protease-generated versican fragment uniquely localized to vascular endothelium. To specifically determine the impact of host/stroma-derived versican we therefore compared growth of tumors from B16F10 cells, which produced littleversican, in Vcan hdf/+ mice and wild-type littermates. Tumors in Vcan hdf/+ mice had reduced growth with a lower capillary density and accumulation of capillaries at the tumor periphery. These findings illustrate the variability of tumor cell line expression of versican, and demonstrate that versican is consistently contributed by the stromal tissue, where it contributes to tumor angiogenesis.

Relationship between Keloid Formation and YAP/TAZ Signaling.

YAP (yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif) are part of a classical pathway that controls contact inhibition in the Hippo pathway. YAP and TAZ were recently reported to act as nuclear relays of mechanical signals that communicate extracellular matrix rigidity and cell shape. However, the role of YAP/TAZ signaling in keloid formation is unclear. Here, we used immunohistochemistry to investigate YAP/TAZ expression in keloid and nonaffected lesions. YAP/TAZ expression in keloid fibroblasts had a greater tendency to localize to the nucleus relative to that seen in fibroblasts from unaffected tissues. Meanwhile, keratinocytes or endothelial cells from either keloid or unaffected tissues showed no significant differences in YAP/TAZ expression patterns. These results suggest that YAP/TAZ nuclear localization in keloid fibroblasts might activate Hippo signaling and may play an important role in gene expression that affects keloid formation and stiffness.

Management of chronic expanding haematoma using triamcinolone after latissimus dorsi flap harvesting.

Chronic expanding haematoma (CEH) is a rare type of haematoma that enlarges slowly and continuously without coagulation. It can occur following surgery because of shear stress-induced bleeding in the scar tissue between the subcutaneous fat and fascia. We present three cases of large chronic CEH that were successfully treated with triamcinolone injections. Three female patients developed large chronic CEH at 9 months, 5 years, and 6 years, respectively, after latissimus dorsi flap harvesting for breast reconstruction. Although the condition did not improve after multiple sessions of haematoma aspiration in the first two patients, it resolved following a single 40-mg triamcinolone injection along with appropriate compression dressing for several weeks. In the third patient, triamcinolone was injected immediately after the initial aspiration of the haematoma, and the condition improved considerably. There were no side effects in any of the patients. To the best of our knowledge, this is the first report of successful treatment of large CEH using triamcinolone. Therefore, we suggest that triamcinolone injections be considered for the treatment of CEH.