Inhibition of the CoREST Repressor Complex Promotes Wound Re-Epithelialization through the Regulation of Keratinocyte Migration.

Wound healing is a complex process involving phases of hemostasis, inflammation, proliferation, and remodeling. The regenerative process in the skin requires coordination between many regulators, including signaling molecules, transcription factors, and the epigenetic machinery. In this study, we show that chromatin regulators HDAC1 and LSD1, key components of the CoREST repressor complex, are upregulated in the regenerating epidermis during wound repair. We also show that corin, a synthetic dual inhibitor of the CoREST complex and HDAC1/LSD1 activities, significantly accelerates wound closure through enhanced re-epithelialization in a mouse tail wound model. Acetylated H3K9 (methylation of histone H3 at lysine 9) expression, a histone modification targeted by HDAC1, is increased in keratinocytes after topical treatment with 100 nM and 1 µM of corin. In vitro experiments demonstrate that corin promotes migration and inhibits the proliferation of human keratinocytes. Furthermore, expression levels of genes promoting keratinocyte migration, such as AREG, CD24, EPHB2, ITGAX, PTGS, SCT1, SERPINB2, SERPINE1, SLPI, SNAI2, and TWIST, increased in keratinocytes treated with corin. These data demonstrate that dual inhibition of class I histone deacetylases and LSD1 by corin may serve as a new approach for promoting wound re-epithelialization and provide a platform for further applications of corin for the treatment of chronic wounds.

A case of markedly impaired wound repair with angiostatic pazopanib in a patient who had Mohs surgery for a basal cell carcinoma.

This case report highlights the adverse effects of pazopanib, a vascular endothelial growth factor receptor inhibitor, on wound healing after Mohs surgery. A 79-year-old male with metastatic renal cell carcinoma of the lung, on 600 mg daily pazopanib, underwent Mohs surgery for a nodular basal cell carcinoma on his right leg. Despite multiple wound care strategies, his wound deteriorated over 4 months. Discontinuing pazopanib resulted in rapid wound closure within 2 months. However, metastatic lung nodules grew, prompting treatment with immune checkpoint inhibitors, nivolumab, and ipilimumab, which were discontinued due to complications. Near-complete wound healing was observed prior to reintroducing pazopanib (6 months after initial discontinuation), which again led to wound deterioration. Pazopanib negatively impacts wound repair by inhibiting cell proliferation and angiogenesis. Depending on the malignancy or tumor, cessation of pazopanib, or switching to a course of immune checkpoint inhibitors may be warranted perioperatively.

Chronic wounds.

Chronic wounds are characterized by their inability to heal within an expected time frame and have emerged as an increasingly important clinical problem over the past several decades, owing to their increasing incidence and greater recognition of associated morbidity and socio-economic burden. Even up to a few years ago, the management of chronic wounds relied on standards of care that were outdated. However, the approach to these chronic conditions has improved, with better prevention, diagnosis and treatment. Such improvements are due to major advances in understanding of cellular and molecular aspects of basic science, in innovative and technological breakthroughs in treatment modalities from biomedical engineering, and in our ability to conduct well-controlled and reliable clinical research. The evidence-based approaches resulting from these advances have become the new standard of care. At the same time, these improvements are tempered by the recognition that persistent gaps exist in scientific knowledge of impaired healing and the ability of clinicians to reduce morbidity, loss of limb and mortality. Therefore, taking stock of what is known and what is needed to improve understanding of chronic wounds and their associated failure to heal is crucial to ensuring better treatments and outcomes.

Autologous Cultured Bone Marrow-Derived Mesenchymal Stem Cells in a Fibrin Spray to Treat Venous Ulcers: A Randomized Controlled Double-Blind Pilot Study.

We treated a small cohort of venous ulcers that were very unresponsive to standard and advanced therapies with autologous cultured bone marrow-derived mesenchymal stem cells (MSCs). This pilot clinical trial was randomized, controlled, and double-blinded. Subjects were treated with either normal saline (Group A), fibrin spray alone (Group B), or MSCs in fibrin (1 million cells/cm2 of wound bed surface) (Group C). The control and test materials were applied to the wound using a double-barreled syringe with thrombin and fibrinogen (with or without MSCs) in each barrel, or saline alone in both barrels. The MSCs were separated, cultured in vitro, and expanded in a dedicated Good Manufacturing Practice (GMP) facility from 30-50 ml of bone marrow aspirate obtained from the iliac crest in Group C subjects. To ensure that the study remained controlled and blinded, subjects who were randomized to one of the two control arms (saline or fibrin) underwent sham bone marrow aspiration performed by a hematologist who anesthetized the iliac crest area down to and pushing against the periosteum, but without penetrating the bone marrow. Therefore, both the clinician who evaluated wound progress and the study subjects had no knowledge of whether bone aspiration was actually performed and what treatment had been applied to the wound. The study was performed after full FDA investigational new drug (IND) approval. The primary endpoint was the rate of healing (wound closure as linear healing from the wound margins in cm/week), as measured by the Gilman equation. One-way ANOVA was used to calculate the statistical significance of differences between the mean healing rates of each of the 3 treatment groups every 4 weeks and over the 24 weeks of treatment. Overall, treatment with MSCs accelerated the healing rate by about 10-fold compared to those in the saline and fibrin control groups. Although the total number of patients in this pilot study was small (n=11), the statistical significance was surprisingly promising: p<0.01 and f-ratio of 15.9358. No serious adverse events were noted. This small but carefully performed prospective, controlled, randomized, and double-blinded pilot study in a rare population of totally unresponsive patients adds to previous reports showing the promise of MSCs in the treatment of chronic wounds and provides proof of principle for how to approach this type of very demanding clinical and translational research.

Dermal Fibroblasts from Chronic Wounds Exhibit Paradoxically Enhanced Proliferative and Migratory Activities that May be Related to the Non-Canonical Wnt Signaling Pathway.

It is generally thought that dermal fibroblasts from chronic wounds are in a state of senescence, which contributes to the failure to heal. This assumption, based on limited experimental evidence, has led to the widespread use of therapeutic approaches focused on delivering new fibroblasts and/or increasing resident fibroblast activity to promote healing. In this study, we decided to re-visit the evidence for the relative inactivity of resident chronic wound fibroblasts. We therefore evaluated the proliferative and migratory activities of matching, patient-derived dermal fibroblasts from a chronic wound (wound dermal fibroblasts, or WDF), ipsilateral thigh newly created acute wound dermal fibroblasts (ADF, Day-3 after wounding the normal thigh skin), and ipsilateral thigh normal dermal skin fibroblasts (NDF). This approach was used in each of 10 consecutive non-selected individual patients with a venous leg ulcer, and allowed us to determine whether WDF are intrinsically less active than NDF and AWD. Cell migration and proliferation were quantified by a live-cell analysis system and MTT assay, respectively, in low (0.5%) or high (10%) levels of fetal bovine serum (FBS). In addition, the ability of patient-derived fibroblasts to modulate wound re-epithelialization in vivo was analyzed by transplantation in a mouse tail full-thickness wound model. Wnt5a mRNA, its ROR1 co-receptors, and ROR2 mRNA levels were determined by qRT-PCR. We report that WDF had increased -SMA and increased levels of Wnt5a. Moreover, using live-cell imaging in a scratch assay monolayer model, WDF showed baseline migratory activity similar to those of NDF and ADF, and such activity was not stimulated by FBS. WDF showed the same capacity to increase wound re-epithelialization as NDF and ADF. Together, these results suggest that WDF are not actually less "active" than NDF and ADF. This enhanced activity of chronic wound fibroblasts may lead to high energy requirements that contribute to a failure to heal. The findings may represent a new paradigm for wound chronicity, impaired healing, and high recurrence rates.

Principles of Wound Dressings: A Review.

Dressing is an essential element of standard wound care. The main purpose of wound dressing is: a) provide a temporary protective physical barrier, b) absorb wound drainage, and c) provide the moisture necessary to optimize re-epithelialization. The choice of dressing depends on the anatomical and pathophysiological characteristics of the wound. Contemporary wound dressings provide additional benefits, such as antimicrobial properties and pain relief. In this concise review, we discuss the principles of wound dressing, highlight the features of basic and advanced types of dressings, and offer some practical tips on the choice and application of dressings.

Research Techniques Made Simple: Animal Models of Wound Healing.

Animal models have been developed to study the complex cellular and biochemical processes of wound repair and to evaluate the efficacy and safety of potential therapeutic agents. Several factors can influence wound healing. These include aging, infection, medications, nutrition, obesity, diabetes, venous insufficiency, and peripheral arterial disease. Lack of optimal preclinical models that are capable of properly recapitulating human wounds remains a significant translational challenge. Animal models should strive for reproducibility, quantitative interpretation, clinical relevance, and successful translation into clinical use. In this concise review, we discuss animal models used in wound experiments including mouse, rat, rabbit, pig, and zebrafish, with a special emphasis on impaired wound healing models.

Research Techniques Made Simple: Analysis of Collective Cell Migration Using the Wound Healing Assay.

Collective cell migration is a hallmark of wound repair, cancer invasion and metastasis, immune responses, angiogenesis, and embryonic morphogenesis. Wound healing is a complex cellular and biochemical process necessary to restore structurally damaged tissue. It involves dynamic interactions and crosstalk between various cell types, interaction with extracellular matrix molecules, and regulated production of soluble mediators and cytokines. In cutaneous wound healing, skin cells migrate from the wound edges into the wound to restore skin integrity. Analysis of cell migration in vitro is a useful assay to quantify alterations in cell migratory capacity in response to experimental manipulations. Although several methods exist to study cell migration (such as Boyden chamber assay, barrier assays, and microfluidics-based assays), in this short report we will explain the wound healing assay, also known as the "in vitro scratch assay" as a simple, versatile, and cost-effective method to study collective cell migration and wound healing.

An in vitro priming step increases the expression of numerous epidermal growth and migration mediators in a tissue-engineering construct.

An FDA-approved, prototypic, living, bilayered skin construct (BSC) has been used for non-healing wounds. Using this particular construct as proof of principle, we hypothesized that an in vitro 'priming' step may enhance its repertoire of expression of key mediators and genes. The priming step used here was incubation in Dulbecco's modified Eagle's medium (DMEM) for 24 h at 37°C and 5% CO2 , with or without construct meshing. Microarray and ingenuity pathway analysis (IPA) showed that >1000 genes were overexpressed by the priming step, including interleukin 6 (IL-6), which plays important roles in wound healing. Genes highly overexpressed by priming were those involved in epidermal proliferation and migration. Quantitative real-time PCR (qRT-PCR), immunostaining and western blots verified the results. An epiboly assay (epidermal migration over dermis) showed that BSC epiboly was inhibited by IL-6 neutralizing antibody. Back wounds of nude mice were treated with primed or control BSCs for 3 days prior to harvesting; primed BSCs showed a significantly (p = 0.006) greater level of epidermal migration vs unprimed. Our study demonstrates that an in vitro priming step induces wound healing-related genes in the BSC, leading to a construct that could prove more effective in stimulating wound healing. Copyright © 2014 John Wiley & Sons, Ltd.

Cryofibrinogenemia-Induced Cutaneous Ulcers: A Review and Diagnostic Criteria.

Chronic skin ulcers are frequently encountered in clinical practice and are often due to very heterogeneous etiologies. Cryofibrinogenemia is an unusual cause of non-healing skin ulcers. It is a small-vessel occlusive vascular disorder that results from the precipitation of cryofibrinogens in plasma. The lack of definitive diagnostic criteria means cryofibrinogenemia remains an under-diagnosed entity that causes significant morbidity. One of the most common manifestations of cryofibrinogenemia is skin ulceration. The presence of non-healing ulcers in otherwise healthy patients with no evidence of large-vessel disease should raise the suspicion of essential cryofibrinogenemia. An important clinical feature is the presence of microlivedo, which represents short hyperpigmented linear streaks around the ulcer or even distally about the foot. Histopathologic findings are microthrombi in the dermis and not confined exclusively to the ulcerated area. Cryofibrinogenemia can be secondary to an underlying disorder, so careful investigation to exclude other etiologies is always necessary.

Novel Stem Cell Therapies for Applications to Wound Healing and Tissue Repair.

The number of individuals with chronic cutaneous wounds has been increasing worldwide due to an aging population, diabetes, obesity, and cardiovascular disease. In the United States, almost seven million Americans have chronic skin ulcers. Many therapeutic approaches have been used. However, the treatment outcomes are not always ideal because of failure to achieve complete wound closure in around 60% of cases, scarring, and high rate of recurrence. Therefore, there is a need for more effective therapies. Stem cells offer promising possibilities. Pre-clinical studies have shown that bone- or adipose tissue-derived mesenchymal stem cells (MSCs) have a competitive advantage over other types of stem cells due to their better defined multipotent differentiating potential, paracrine effects, immunomodulatory properties, and safety. However, large controlled clinical trials are needed to examine the capabilities of MSCs in humans and to assess their safety profile. In this review, we highlight emerging treatments in tissue regeneration and repair and provide some perspectives on how to translate current knowledge about stem cells-both multipotent and pluripotent-into viable clinical approaches for treating patients with difficult to heal wounds.

Optimizing Technology Use for Chronic Lower-Extremity Wound Healing: A Consensus Document.

Innovations in technology are used in managing chronic wounds. Despite the wide range of technologies available, healing of chronic wounds remains variable. In this paper, the authors offer an evidence based approach to the use of technology for diagnosis and management based on the concept of standardised care.

Mesenchymal Stem Cells in Chronic Wounds: The Spectrum from Basic to Advanced Therapy.

Significance: Almost 7 million Americans have chronic cutaneous wounds and billions of dollars are spent on their treatment. The number of patients with nonhealing wounds keeps increasing worldwide due to an ever-aging population, increasing number of obese and diabetic patients, and cardiovascular disease. Recent Advances: Advanced treatments for difficult wounds are needed. Therapy with mesenchymal stem cells (MSCs) is attractive due to their differentiating potential, their immunomodulating properties, and their paracrine effects. Critical Issues: New technologies (including growth factors and skin substitutes) are now widely used for stimulating wound healing. However, in spite of these advances, the percentage of complete wound closure in most clinical situations is around 50-60%. Moreover, there is a high rate of wound recurrence. Future Directions: Recently, it has been demonstrated that MSCs speed up wound healing by decreasing inflammation, by promoting angiogenesis, and by decreasing scarring. However, there are some potential limitations to successful MSC therapy. These limitations include the need to improve cell delivery methods, cell viability, heterogeneity in MSC preparations, and suboptimal wound bed preparation. Further large, controlled clinical trials are needed to establish the safety of MSCs before widespread clinical application.

Serratia marcescens Bullous Cellulitis in a Splenectomized Patient: A Case Report and Review of the Literature.

Serratia marcescens is a Gram-negative bacillus belonging to the Enterobacteriaceae family. Cutaneous infection with Serratia is rare, and usually occurs in immunocompromised individuals. Primary cutaneous infections are uncommon, but they are typically severe and are associated with significant morbidity and mortality. The pathogenetic factors leading to S. marcescens infection are not fully understood, but contributing virulence factors include proteases, secreted exotoxins, and the formation of biofilm. We report a case of cellulitis occurring in a splenectomized patient, which led to multiple wound debridements and a transmetatarsal amputation. This dramatic case led us to review the published literature on soft tissue infections caused by S. marcescens.

Transforming growth factor beta (TGF-ß) isoforms in wound healing and fibrosis.

Scar formation, with persistent alteration of the normal tissue structure, is an undesirable and significant result of both wound healing and fibrosing disorders. There are few strategies to prevent or to treat scarring. The transforming growth factor beta (TGF-ß) superfamily is an important mediator of tissue repair. Each TGF-ß isoform may exert a different effect on wound healing, which may be context-dependent. In particular, TGF-ß1 may mediate fibrosis in adults' wounds, while TGF-ß3 may promote scarless healing in the fetus and reduced scarring in adults. Thus, TGF-ß3 may offer a scar-reducing therapy for acute and chronic wounds and fibrosing disorders.

Chronic wound repair and healing in older adults: current status and future research.

Older adults are more likely to have chronic wounds than younger people, and the effect of chronic wounds on quality of life is particularly profound in this population. Wound healing slows with age, but the basic biology underlying chronic wounds and the influence of age-associated changes on wound healing are poorly understood. Most studies have used in vitro approaches and various animal models, but observed changes translate poorly to human healing conditions. The effect of age and accompanying multimorbidity on the effectiveness of existing and emerging treatment approaches for chronic wounds is also unknown, and older adults tend to be excluded from randomized clinical trials. Poorly defined outcomes and variables; lack of standardization in data collection; and variations in the definition, measurement, and treatment of wounds also hamper clinical studies. The Association of Specialty Professors, in conjunction with the National Institute on Aging and the Wound Healing Society, held a workshop, summarized in this article, to explore the current state of knowledge and research challenges, engage investigators across disciplines, and identify research questions to guide future study of age-associated changes in chronic wound healing.

Liver enzymes and lipid levels in patients with lipodermatosclerosis and venous ulcers treated with a prototypic anabolic steroid (stanozolol): a prospective, randomized, double-blinded, placebo-controlled trial.

Anabolic steroids have been used to treat lower extremity ulcerations, including venous and cryofibrinogenemic ulcers and lipodermatosclerosis (LDS). Yet there have been no studies to determine the severity and reversibility of side effects of anabolic steroids on liver enzymes and lipid profiles in elderly patients. We therefore evaluated, in a prospective, randomized, double-blinded, placebo-controlled trial, the extent and reversibility of abnormal liver enzymes and lipid profiles in patients with LDS and venous leg ulcers treated with stanozolol at 2 mg twice daily for up to 6 months. Follow-up laboratory testing was done for 2 months after cessation of treatment. A total of 44 patients with LDS and venous ulcers were enrolled and treated with either leg compression alone (placebo) or leg compression plus oral stanozolol 2 mg twice daily (active). Baseline and follow-up laboratory testing of liver enzymes and lipid profiles were obtained. A total of 21 active and 23 placebo patients were treated and evaluated. We measured liver enzymes (aspartate aminotransferase [AST/SGOT], alanine aminotransferase [ALT/SGPT], γ-glutamyl transferase [GGT]) and lipid profile components (high-density lipoprotein [HDL], low-density lipoprotein [LDL], total cholesterol) before, during, and after the treatment period. We found that AST/SGOT and ALT/SGPT became significantly elevated in 29% (P = .0415 at 2 months) and 33% (P = .0182 at 1 month) of patients treated with stanozolol or placebo, respectively, with return to baseline in the posttreatment period. Unexpectedly, 91% of patients on stanozolol developed a significant (P < .0001) decrease in HDL levels, by as much as 37 U/L. All patients remained asymptomatic and levels returned to baseline after discontinuation of the drug. We conclude that low-dose stanozolol, 2 mg twice daily, produces asymptomatic and temporary elevation of liver transaminases and depression of the HDL level in a significant proportion of patients.

Chronic wound repair and healing in older adults: current status and future research.

The incidence of chronic wounds is increased among older adults, and the impact of chronic wounds on quality of life is particularly profound in this population. It is well established that wound healing slows with age. However, the basic biology underlying chronic wounds and the influence of age-associated changes on wound healing are poorly understood. Most studies have used in vitro approaches and various animal models, but observed changes translate poorly to human healing conditions. The impact of age and accompanying multi-morbidity on the effectiveness of existing and emerging treatment approaches for chronic wounds is also unknown, and older adults tend to be excluded from randomized clinical trials. Poorly defined outcomes and variables, lack of standardization in data collection, and variations in the definition, measurement, and treatment of wounds also hamper clinical studies. The Association of Specialty Professors, in conjunction with the National Institute on Aging and the Wound Healing Society, held a workshop, summarized in this paper, to explore the current state of knowledge and research challenges, engage investigators across disciplines, and identify key research questions to guide future study of age-associated changes in chronic wound healing.