Proteoglycans and cutaneous vascular defense and repair

Selective adhesion inhibition and hyaluronan envelope reduction of dermal tumor cells by cold plasma-activated medium

The sensitivity to cold plasma is specific to tumor cells while leaving normal tissue cells unaffected. This is the desired challenge in cancer therapy. Therefore, the focus of this work was a comparative study concerning the plasma sensitivity of dermal tumor cells (A-431) versus non-tumorigenic dermal cells (HaCaT) regarding their adhesion capacity. We found a selective inhibiting effect of plasma-activated medium on the adhesion of tumor cells while hardly affecting normal cells. We attributed this to a lower basal gene expression for the adhesion-relevant components CD44, hyaluronan synthase 2 (HAS2), HAS3, and the hyaluronidases in A431. Noteworthy, after plasma exposure, we revealed a significantly higher expression and synthesis of the hyaluronan envelope, the HAS3 gene, and the transmembrane adhesion receptors in non-tumorigenic HaCaTs.

Interplay between Cell-Surface Receptors and Extracellular Matrix in Skin

Skin consists of the epidermis and dermis, which are connected by a specialized basement membrane-the epidermal basement membrane. Both the epidermal basement membrane and the underlying interstitial extracellular matrix (ECM) created by dermal fibroblasts contain distinct network-forming macromolecules. These matrices play various roles in order to maintain skin homeostasis and integrity. Within this complex interplay of cells and matrices, cell surface receptors play essential roles not only for inside-out and outside-in signaling, but also for establishing mechanical and biochemical properties of skin. Already minor modulations of this multifactorial cross-talk can lead to severe and systemic diseases. In this review, major epidermal and dermal cell surface receptors will be addressed with respect to their interactions with matrix components as well as their roles in fibrotic, inflammatory or tumorigenic skin diseases.

Limiting angiogenesis to modulate scar formation

Angiogenesis, the process of new blood vessel formation from existing blood vessels, is a key aspect of virtually every repair process. During wound healing an extensive, but immature and leaky vascular plexus forms which is subsequently reduced by regression of non-functional vessels. More recent studies indicate that uncontrolled vessel growth or impaired vessel regression as a consequence of an excessive inflammatory response can impair wound healing, resulting in scarring and dysfunction. However, in order to elucidate targetable factors to promote functional tissue regeneration we need to understand the molecular and cellular underpinnings of physiological angiogenesis, ranging from induction to resolution of blood vessels. Especially for avascular tissues (e.g. cornea, tendon, ligament, cartilage, etc.), limiting rather than boosting vessel growth during wound repair potentially is beneficial to restore full tissue function and may result in favourable long-term healing outcomes.

Expression of heparanase in basal cell carcinoma and squamous cell carcinoma

Background

Heparanase is an enzyme that cleaves heparan sulfate chains. Oligosaccharides generated by heparanase induce tumor progression. Basal cell carcinoma and squamous cell carcinoma comprise types of nonmelanoma skin cancer.

Objectives

Evaluate the glycosaminoglycans profile and expression of heparanase in two human cell lines established in culture, immortalized skin keratinocyte (HaCaT) and squamous cell carcinoma (A431) and also investigate the expression of heparanase in basal cell carcinoma, squamous cell carcinoma and eyelid skin of individuals not affected by the disease (control).

Methods

Glycosaminoglycans were quantified by electrophoresis and indirect ELISA method. The heparanase expression was analyzed by quantitative RT-PCR (qRTPCR).

Results

The A431 strain showed significant increase in the sulfated glycosaminoglycans, increased heparanase expression and decreased hyaluronic acid, comparing to the HaCaT lineage. The mRNA expression of heparanase was significantly higher in Basal cell carcinoma and squamous cell carcinoma compared with control skin samples. It was also observed increased heparanase expression in squamous cell carcinoma compared to the Basal cell carcinoma.

Conclusion

The glycosaminoglycans profile, as well as heparanase expression are different between HaCaT and A431 cell lines. The increased expression of heparanase in Basal cell carcinoma and squamous cell carcinoma suggests that this enzyme could be a marker for the diagnosis of such types of non-melanoma cancers, and may be useful as a target molecule for future alternative treatment.

Effects of C-xylopyranoside derivative on epithelial regeneration in an in vitro 3D oral mucosa model

Identifying substandard tissue-engineered oral mucosa grafts with a poor epithelium before clinical use is critical to ensure quality assurance/control in regenerative medicine, leading to success of grafting. This study investigated the effects of one of the C-xylopyranoside derivatives, β-D-xylopyranoside-n-propane-2-one (XPP), on oral epithelial regeneration. Using a three-dimensional oral mucosa model, we analyzed changes of the epithelial structure, glycosaminoglycan (GAG) synthesis, the expression levels of basement membrane zone markers, and substrates of Akt/mTOR signaling. Compared with the control, 2 mM XPP treatment increased the mean and minimal epithelial thickness, and reduced the variation of epithelial thickness. It also stimulated expressions of decorin and syndecan-1 with change of GAG amount and/or composition, and enhanced the expressions of integrin α6, CD44, and Akt/mTOR signaling substrates. These findings suggest that XPP supplementation contributes to consistent epithelial regeneration. Moreover, upregulation of those markers may play a role in increasing the quality of the oral mucosal epithelium.

A primer on wound healing in colorectal surgery in the age of bioprosthetic materials

Wound healing is a complex, dynamic process that is vital for closure of cutaneous injuries, restoration of abdominal wall integrity after laparotomy closure, and to prevent anastomotic dehiscence after bowel surgery. Derangements in healing have been described in multiple processes including diabetes mellitus, corticosteroid use, irradiation for malignancy, and inflammatory bowel disease. A thorough understanding of the process of healing is necessary for clinical decision making and knowledge of the current state of the science may lead future researchers in developing methods to enable our ability to modulate healing, ultimately improving outcomes. An exciting example of this ability is the use of bioprosthetic materials used for abdominal wall surgery (hernia repair/reconstruction). These bioprosthetic meshes are able to regenerate and remodel from an allograft or xenograft collagen matrix into site-specific tissue; ultimately being degraded and minimizing the risk of long-term complications seen with synthetic materials. The purpose of this article is to review healing as it relates to cutaneous and intestinal trauma and surgery, factors that impact wound healing, and wound healing as it pertains to bioprosthetic materials.

The role of the extracellular matrix components in cutaneous wound healing

Wound healing is the physiologic response to tissue trauma proceeding as a complex pathway of biochemical reactions and cellular events, secreted growth factors, and cytokines. Extracellular matrix constituents are essential components of the wound repair phenomenon. Firstly, they create a provisional matrix, providing a structural integrity of matrix during each stage of healing process. Secondly, matrix molecules regulate cellular functions, mediate the cell-cell and cell-matrix interactions, and serve as a reservoir and modulator of cytokines and growth factors' action. Currently known mechanisms, by which extracellular matrix components modulate each stage of the process of soft tissue remodeling after injury, have been discussed.

Host defense peptides in wound healing

Host defense peptides are effector molecules of the innate immune system. They show broad antimicrobial action against gram-positive and -negative bacteria, and they likely play a key role in activating and mediating the innate as well as adaptive immune response in infection and inflammation. These features make them of high interest for wound healing research. Non-healing and infected wounds are a major problem in patient care and health care spending. Increasing infection rates, growing bacterial resistance to common antibiotics, and the lack of effective therapeutic options for the treatment of problematic wounds emphasize the need for new approaches in therapy and pathophysiologic understanding. This review focuses on the current knowledge of host defense peptides affecting wound healing and infection. We discuss the current data and highlight the potential future developments in this field of research.

Antimicrobial peptides

Antimicrobial peptides (AMPs) are small molecular weight proteins with broad spectrum antimicrobial activity against bacteria, viruses, and fungi. These evolutionarily conserved peptides are usually positively charged and have both a hydrophobic and hydrophilic side that enables the molecule to be soluble in aqueous environments yet also enter lipid-rich membranes. Once in a target microbial membrane, the peptide kills target cells through diverse mechanisms. Cathelicidins and defensins are major groups of epidermal AMPs. Decreased levels of these peptides have been noted for patients with atopic dermatitis and Kostmann's syndrome, a congenital neutropenia. In addition to important antimicrobial properties, growing evidence indicates that AMPs alter the host immune response through receptor-dependent interactions. AMPs have been shown to be important in such diverse functions as angiogenesis, wound healing, and chemotaxis. As our knowledge of AMP biology expands, the precise role and relevance of these peptides will be better elucidated.

Normal cutaneous wound healing: clinical correlation with cellular and molecular events

BACKGROUND

Cutaneous wound healing is a normal physiologic function, observed and described for centuries by those afflicted with wounds and by those caring for them. Recently, tremendous progress has been made in discovering the cellular and molecular mechanisms responsible for wound healing. Counseling patients appropriately and planning future therapeutic interventions in delayed or abnormal wound healing may be improved by a thorough understanding of the relationship between clinical, cellular, and subcellular events occurring during the normal healing process.

MATERIALS AND METHODS

A review of the wound healing literature from the past several decades, with a focus on the past 5 to 10 years in particular, along with illustrative case examples from our clinical practice over the past decade.

RESULTS

Traditional clinical stages of wounding healing are still relevant, but more overlap between stages is likely a more accurate depiction of events. The role of cells such as platelets, macrophages, leukocytes, fibroblasts, endothelial cells, and keratinocytes is much better known, particularly during the inflammatory and proliferation stages of healing. Molecules such as interferon, integrins, proteoglycans and glycosaminoglycans, matrix metalloproteinases, and other regulatory cytokines play a critical role in the regulation of healing mechanisms.

CONCLUSION

Cutaneous wound healing in normal hosts follows an orderly clinical process. The scientific underpinnings for healing are better understood than ever, although much remains to be discovered. Eventually, such improved understanding of cellular and subcellular physiology may lead to new or better forms of therapy for patients with acute, chronic, and surgical skin wounds.

Normal cutaneous wound healing: clinical correlation with cellular and molecular events

BACKGROUND

Cutaneous wound healing is a normal physiologic function, observed and described for centuries by those afflicted with wounds and by those caring for them. Recently, tremendous progress has been made in discovering the cellular and molecular mechanisms responsible for wound healing. Counseling patients appropriately and planning future therapeutic interventions in delayed or abnormal wound healing may be improved by a thorough understanding of the relationship between clinical, cellular, and subcellular events occurring during the normal healing process.

MATERIALS AND METHODS

A review of the wound healing literature from the past several decades, with a focus on the past 5 to 10 years in particular, along with illustrative case examples from our clinical practice over the past decade.

RESULTS

Traditional clinical stages of wounding healing are still relevant, but more overlap between stages is likely a more accurate depiction of events. The role of cells such as platelets, macrophages, leukocytes, fibroblasts, endothelial cells, and keratinocytes is much better known, particularly during the inflammatory and proliferation stages of healing. Molecules such as interferon, integrins, proteoglycans and glycosaminoglycans, matrix metalloproteinases, and other regulatory cytokines play a critical role in the regulation of healing mechanisms.

CONCLUSION

Cutaneous wound healing in normal hosts follows an orderly clinical process. The scientific underpinnings for healing are better understood than ever, although much remains to be discovered. Eventually, such improved understanding of cellular and subcellular physiology may lead to new or better forms of therapy for patients with acute, chronic, and surgical skin wounds.

Microarray analysis of gene expression in murine skin exposed to sulfur mustard

The chemical warfare agent sulfur mustard [bis-(2-chloroethyl)-sulfide; SM] produces a delayed inflammatory response followed by blister formation in skin of exposed individuals. Studies are underway evaluating the efficacy of pharmacological compounds to protect against SM skin injury. Microarray analysis provides the opportunity to identify multiple transcriptional biomarkers associated with SM exposure. This study examined SM-induced changes in gene expression in skin from mice cutaneously exposed to SM using cDNA microarrays. Ear skin from five mice, paired as SM-exposed right ear and dichloromethane vehicle-exposed left ear at six dose levels (0.005, 0.01, 0.02, 0.04, 0.08, and 0.16 mg; 6 mM to 195 mM range), was harvested at 24 h post-exposure. SM-induced gene expression was analyzed using cDNA microarrays that included 1,176 genes. Genes were selected on the basis of all mice (N=5) in the same dose group demonstrating a > or =2-fold increase or decrease in gene expression for the SM-exposed tissue compared to the dichloromethane vehicle control ear tissue at all six SM doses. When skin exposed to all six concentrations of SM was compared to controls, a total of 19 genes within apoptosis, transcription factors, cell cycle, inflammation, and oncogenes and tumor suppressors categories were found to be upregulated; no genes were observed to be downregulated. Differences in the number and category of genes that were up- or down-regulated in skin exposed to low (0.005-0.01 mg) and high (0.08-0.16 mg) doses of SM were also observed. The results of this study provide a further understanding of the molecular responses to cutaneous SM exposure, and enable the identification of potential diagnostic markers and therapeutic targets for treating SM injury.

Chronic delayed-type hypersensitivity reaction as a means to treat alopecia areata

The acute phase of alopecia areata (AA) is characterized by an increase in CD44v3+ and CD44v10+ skin-infiltrating leucocytes (SkIL). Induction of a contact eczema, one of the therapeutic options in AA, can be mitigated strongly by a blockade of CD44v10. The observation that induction of a delayed type hypersensitivity (DTH) reaction abrogates an autoimmune reaction, where both responses apparently use similar effector mechanisms, is surprising and prompted us to search for the underlying mechanisms. AA-affected C3H/HeJ mice were treated with the contact sensitizer SADBE (squaric acid dibutylester) and leucocyte subpopulations and their activation state was evaluated in SkIL and draining lymph nodes. AA-affected mice exhibited an increased number of SkIL with a predominance of T lymphocytes. After treatment with the contact sensitizer SADBE recovery of SkIL was reduced and monocytes predominated. However, a significantly increased number of leucocytes was recovered from draining lymph nodes. Draining lymph node cells from untreated and treated AA mice exhibited all signs of recent activation with high-level expression of co-stimulatory and accessory molecules and an increased percentage of CD44v3+ and CD44v10+ leucocytes. In contrast, SkIL of SADBE-treated AA mice contained relatively few activated T cells and reduced numbers of CD44v3+ and CD44v10+ cells. Thus, the activation state and the distribution of leucocyte subsets in SADBE-treated AA mice are consistent with a blockade of leucocyte extravasation. Accordingly, the therapeutic effect of long-term SADBE treatment may rely on impaired leucocyte traffic.

Manipulation of cell surface macromolecules by flaviviruses

Cell surface macromolecules play a crucial role in the biology and pathobiology of flaviviruses, both as receptors for virus entry and as signaling molecules for cell–cell interactions in the processes of vascular permeability and inflammation. This review examines the cell tropism and pathogenesis of flaviviruses from the standpoint of cell surface molecules, which have been implicated as receptors in both virus–cell as well as cell–cell interactions. The emerging picture is one that encompasses extensive regulation and interplay among the invading virus, viral immune complexes, Fc receptors, major histocompatibility complex antigens, and adhesion molecules.

Extracellular matrix metabolites as potential biomarkers of disease activity in wound fluid: lessons learned from other inflammatory diseases?

The new era of pharmacogenetics has identified a potential for individuals to receive customized treatments for a variety of disease states. For such individualized treatments to fulfil their potential, it will be essential for clinicians to be able to monitor disease activity, ideally in a rapid, noninvasive fashion. The accessibility of the skin offers much potential to develop noninvasive tests of metabolic and disease activity for clinical use. Impaired human wound healing in the skin is a chronic inflammatory disorder in which the development of such tests has considerable potential, aiding clinical decision making and monitoring responses to treatment. This review article discusses how studies in other human diseases have highlighted potential biochemical markers (biomarkers) of disease activity in secreted biofluids, as aids to determining disease and metabolic activity within tissues. Using, as examples, lessons learned in the study of disease activity and prognosis of other chronic inflammatory conditions, such as osteoarthritis and periodontal disease, this review highlights the potential of dermal extracellular matrix (ECM) components (collagens, proteoglycans, hyaluronan and glycoproteins) for such uses. The limitations of currently utilized techniques and the concept that analysis of ECM components in wound fluid may represent useful biomarkers of disease activity are also discussed.

Fibronectin and adhesion molecules on canine scarred vocal folds

OBJECTIVE

To examine the expressions of fibronectin and other adhesion molecules on the scarred vocal folds in a short- and long-term animal model.

STUDY DESIGN

Animal model.

METHODS

Six beagles' vocal folds were stripped unilaterally and left untreated. After wounding the vocal folds were harvested from three dogs at 2 months and three dogs at 6 months. The untouched vocal fold was used as a control, and the stripped vocal fold as scarred. Subsequently, the expressions of fibronectin, cadherin, syndecan-1 and syndecan-4 on both vocal folds were examined by immunohistochemical and image analysis.

RESULTS

Compared with the control vocal folds, fibronectin significantly increased in the superficial layer of the lamina propria on the scarred vocal folds at both 2 and 6 months. Co-deposition of collagen was observed only at 6 months. Syndecan-4 was significantly overexpressed at the basal layer cells of the epithelium at both 2 and 6 months. No significant expression of either cadherin or syndecan-1 was detected.

CONCLUSIONS

Scar characteristics at 2 and 6 months are not identical, suggesting that a 2-month period may not be a sufficient to study vocal fold scarring. Adhesion molecules are important in reorganization of extracellular matrix during wound healing because of their binding and adhesion characteristics. The results indicate that fibronectin might be important in providing a scaffold for the deposition of other proteins such as collagen, and the binding characteristics might affect the stiffness of the scarred vocal fold. Prolonged expression of syndecan-4 may reflect the role of focal adhesion during the assembly of scar structure. Ultimately, better understanding of the histological features of the scarred vocal fold might lead to new approaches to treatment.

Why do some cavity wounds treated with honey or sugar paste heal without scarring?

As well as having antimicrobial properties, honey and sugar paste are associated with scarless healing in some cavity wounds. This article uses evidence to suggest why these products can modify excessive collagen production to prevent scarring.