Upregulation of proinflammatory genes in skin lesions may be the cause of keloid formation (Review)

Targeting the Epigenome Reduces Keloid Fibroblast Cell Proliferation, Migration and Invasion

Keloids are pathological fibroproliferative scars resulting from abnormal collagen deposition within and beyond the margins of the initial cutaneous insult. Keloids negatively impact quality of life functionally and cosmetically, with current treatment modalities unsatisfactory. Recent studies indicate that epigenetic dysregulation is central to the development and progression of keloids. Here we evaluate the functional significance of epigenetic targeting strategies in vitro using patient-derived keloid fibroblasts treated with small molecule inhibitors of HDACs, LSD1, CoREST and p300, as potential therapies for keloids. We find that both the dual-acting CoREST inhibitor, corin, and the HDAC inhibitor, entinostat, reduce fibroblast proliferation more than the LSD1 inhibitor, GSK-LSD1; additionally, corin was the most effective inhibitor of migration and invasion across keloid fibroblasts. RNA-seq analysis of keloid fibroblasts treated with corin demonstrates coordinate upregulation of many genes including key mediators of cell adhesion such as claudins. Corin also downregulates gene sets involved in cell cycle progression, including reduced expression of cyclins A1 and B2 compared to DMSO. These results highlight a significant role for epigenetic regulation of pathologic mediators of keloidal scarring and suggest that inhibitors of the epigenetic CoREST repressor complex may prove beneficial in the prevention and/or treatment of keloidal scarring in patients.

Natural products - Dawn of keloid treatment

Keloids are prevalent pathological scars, often leading to cosmetic deformities and hindering joint mobility.They cause discomfort, including burning and itching, while gradually expanding and potentially posing a risk of cancer.Developing effective drugs and treatments for keloids has been a persistent challenge in the medical field. Natural products are an important source of innovative drugs and a breakthrough for many knotty disease.Herein, keywords of "natural, plant, compound, extract" were combined with "keloid" and searched in PubMed and Google Scholar, respectively. A total of 32 natural products as well as 9 extracts possessing the potential for treating keloids were ultimately identified.Current research in this field faces a significant challenge due to the lack of suitable animal models, resulting in a predominant reliance on in vitro studies.In vivo and clinical studies are notably scarce as a result.Moreover, there is a notable deficiency in research focusing on the role of nutrients in keloid formation and treatment.The appropriate dosage form (oral, topical, injectable) is crucial for the development of natural product drugs. Finally, the conclusion was hereby made that natural products, when used as adjuncts to other treatments, hold significant potential in the management of keloids.By summarizing the natural products and elucidating their mechanisms in keloid treatment, the present study aims to stimulate further discoveries and research in drug development for effectively addressing this challenging condition.

Postoperative Scar Management Protocol for Asian Patients

BACKGROUND

Postoperative scar formation remains a morbidity for patients even with the advent of minimally invasive techniques. Furthermore, the significant difference between the Asian and Caucasian skin results in poorer postoperative scar outcomes in Asians, supporting the need for an evidence-based scar management protocol.

METHODS

Following a literature review of the PubMed and the Cochrane databases over the past 10 years, we constructed a novel postoperative scar management protocol for the Asian skin, utilized in a Singaporean tertiary healthcare institution.

RESULTS

We describe a timeline-based scar protocol from the point of skin closure to a minimum of 1 year of follow-up. We support the use of intraoperative botulinum toxin for selected high-risk individuals upon skin closure with a follow-up regimen in the postoperative setting. For recalcitrant keloids, we have described a multimodal therapy comprising elements of intralesional steroids, botulinum toxin, lasers, surgery, and radiotherapy.

CONCLUSIONS

A consolidated postoperative scar management protocol provides the necessary guidance for improved scar outcomes in the Asian skin. There is inherent potential in expanding the protocol to include post-traumatic and burn wounds or support other skin types including the Caucasian skin.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Scarring Skin: Mechanisms and Therapies

Skin injury always results in fibrotic, non-functional scars in adults. Although multiple factors are well-known contributors to scar formation, the precise underlying mechanisms remain elusive. This review aims to elucidate the intricacies of the wound healing process, summarize the known factors driving skin cells in wounds toward a scarring fate, and particularly to discuss the impact of fibroblast heterogeneity on scar formation. To the end, we explore potential therapeutic interventions used in the treatment of scarring wounds.

[Principle and clinical application of keloid core excision technique]

Objective

To review the research progress of the principle and clinical application of keloid core excision technique.

Methods

The literature on keloid core excision technique at home and abroad in recent years was extensively reviewed, and the principle, development history, indications, advantages and disadvantages of this technique were summarized, and the existing controversies were analyzed.

Results

Keloid core excision is a technique to remove the inner fibrous core from the keloid and cover the defect with the keloidal flap. It reduces the wound tension, yields good aesthetic results in the treatment of ear keloids, and reduces the recurrence rate of keloids combining with adjuvant therapies.

Conclusion

The keloid core excision technique has specific advantages, yet its overall efficacy remains controversial. Further studies are imperative to explore the mechanisms regarding keloid recurrence and the vascular supply principles of the keloidal flap. It is also necessary to define appropriate surgical indications and safety protocols of this technique.

The Communication from Immune Cells to the Fibroblasts in Keloids: Implications for Immunotherapy

Keloids are a type of fibrotic disease characterized by excessive collagen production and extracellular matrix (ECM) deposition. The symptoms of pain and itching and frequent recurrence after treatment significantly impact the quality of life and mental health of patients. A deeper understanding of the pathogenesis of keloids is crucial for the development of an effective therapeutic approach. Fibroblasts play a central role in the pathogenesis of keloids by producing large amounts of collagen fibers. Recent evidence indicates that keloids exhibit high immune cell infiltration, and these cells secrete cytokines or growth factors to support keloid fibroblast proliferation. This article provides an update on the knowledge regarding the keloid microenvironment based on recent single-cell sequencing literature. Many inflammatory cells gathered in keloid lesions, such as macrophages, mast cells, and T lymphocytes, indicate that keloids may be an inflammatory skin disease. In this review, we focus on the communication from immune cells to the fibroblasts and the potential of immunotherapy for keloids. We hope that this review will trigger interest in investigating keloids as an inflammatory disease, which may open up new avenues for drug development by targeting immune mediators.

Characterization of the skin keloid microenvironment

Keloids are a fibroproliferative skin disorder that develops in people of all ages. Keloids exhibit some cancer-like behaviors, with similar genetic and epigenetic modifications in the keloid microenvironment. The keloid microenvironment is composed of keratinocytes, fibroblasts, myofibroblasts, vascular endothelial cells, immune cells, stem cells and collagen fibers. Recent advances in the study of keloids have led to novel insights into cellular communication among components of the keloid microenvironment as well as potential therapeutic targets for treating keloids. In this review, we summarized the nature of genetic and epigenetic regulation in keloid-derived fibroblasts, epithelial-to-mesenchymal transition of keratinocytes, immune cell infiltration into keloids, the differentiation of keloid-derived stem cells, endothelial-to-mesenchymal transition of vascular endothelial cells, extracellular matrix synthesis and remodeling, and uncontrolled angiogenesis in keloids with the aim of identifying new targets for therapeutic benefit. Video Abstract.

Genome-wide analysis of dysregulated RNA-binding proteins and alternative splicing genes in keloid

Introduction: The pathogenesis of keloids remains unclear. Methods: In this study, we analyzed RNA-Seq data (GSE113619) of the local skin tissue of 8 keloid-prone individuals (KPI) and 6 healthy controls (HC) before and 42 days after trauma from the gene expression omnibus (GEO) database. The differential alternative splicing (AS) events associated with trauma healing between KPIs and HCs were identifified, and their functional differences were analyzed by gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) pathways. The co-expression relationship of differentially alternative splicing genes and differentially expressed RNA binding proteins (RBPs) was established subsequently. Results: A total of 674 differential AS events between the KD42 and the KD0 and 378 differential AS events between the HD42 and the HD0 were discovered. Notably, most of the differential genes related to keloids are enriched in actin, microtubule cells, and cortical actin cytoskeletal tissue pathway. We observed a signifificant association between AS genes (EPB41, TPM1, NF2, PARD3) and trauma healing in KPIs and HCs. We also found that the differential expression of healthy controls-specifific trauma healing-related RBPs (TKT, FDPS, SAMHD1) may affect the response of HCs to trauma healing by regulating the AS of downstream trauma healing-related genes such as DCN and DST. In contrast, KPIs also has specifific differential expression of trauma healing related RBPs (S100A9, HspB1, LIMA1, FBL), which may affect the healing response of KPIs to trauma by regulating the AS of downstream trauma healing-related genes such as FN1 and TPM1. Discussion: Our results were innovative in revealing early wound healing-related genes (EPB41, TPM1, NF2, PARD3) in KPI from the perspective of AS regulated by RBPs.

The JAK-STAT pathway in keloid pathogenesis: a systematic review with qualitative synthesis

Keloid tissues contain inflammatory cells and upregulated pro-inflammatory cytokines. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway mediate cellular responses to these cytokines. We performed a systematic review on the role of the JAK-STAT pathway in keloid pathogenesis and the evidence for JAK-STAT inhibitors in keloid treatment. The search combined the terms (1) keloid and (2) JAK or TYK or STAT and included MeSH terms and synonyms. Two reviewers screened the articles and assessed the full texts on eligibility. Data were collected on the tested drugs and molecules, the type of cells and tissues used in the experiments, and study findings on the association between the JAK-STAT pathway and keloid cells and tissues. A total of twenty preclinical studies were included. Eleven preclinical studies proved that STAT3 expression and phosphorylation are enhanced in keloid tissue and keloid fibroblasts. Thirteen different JAK and/or STAT inhibitors were investigated. Tested drugs inhibited keloid progression as demonstrated by different processes, including reduced collagen production, cell proliferation and migration, increased cell cycle arrest and apoptosis, enhanced antioxidant responses, decreased (paracrine) signalling, and decreased profibrotic gene expression. No clinical studies have been published to date. Preclinical studies indicate a role for the JAK-STAT pathway in keloid pathogenesis and a potential role for JAK-STAT inhibitors in keloid treatment. The effect of these drugs should be further investigated on relevant biomarkers in a human keloid skin model, preferably including immune cells besides keloid fibroblasts and keratinocytes and in clinical studies.

Vascular and Collagen Target: A Rational Approach to Hypertrophic Scar Management

Significance: Hypertrophic scarring is a challenging issue for patients and clinicians. The prevalence of hypertrophic scarring can be up to 70% after burns, and patients suffer from pain, itching, and loss of joint mobility. To date, the exact mechanisms underlying hypertrophic scar formation are unclear, and clinical options remain limited. Recent Advances: Several studies have demonstrated that pathological scars are a type of hyperactive vascular response to wounding. Scar regression has been found to be accompanied by microvessel occlusion, which causes severe hypoxia, malnutrition, and endothelial dysfunction, suggesting the essential roles of microvessels in scar regression. Therefore, interventions that target the vasculature, such as intense pulsed light, pulsed dye lasers, vascular endothelial growth factor antibodies, and Endostar, represent potential treatments. In addition, the mass of scar-associated collagen is usually not considered by current treatments. However, collagen-targeted therapies such as fractional CO₂ laser and collagenase have shown promising outcomes in scar treatment. Critical Issues: Traditional modalities used in current clinical practice only partially target scar-associated microvessels or collagen. As a result, the effectiveness of current treatments is limited and is too often accompanied by undesirable side effects. The formation of scars in the early stage is mainly affected by microvessels, whereas the scars in later stages are mostly composed of residual collagen. Traditional therapies do not utilize specific targets for scars at different stages. Therefore, more precise treatment strategies are needed. Future Directions: Scars should be classified as either "vascular-dominant" or "collagen-dominant" before selecting a treatment. In this way, strategies that are vascular-targeted, collagen-targeted, or a combination thereof could be recommended to treat scars at different stages.

Skin fibrosis associated with keloid, scleroderma and Jorge Lobo's disease (lacaziosis): An immuno-histochemical study

Fibrosis is a common pathophysiological response of many tissues and organs subjected to chronic injury. Despite the diverse aetiology of keloid, lacaziosis and localized scleroderma, the process of fibrosis is present in the pathogenesis of all of these three entities beyond other individual clinical and histological distinct characteristics. Fibrosis was studied in 20 samples each of these three chronic cutaneous inflammatory diseases. An immunohistochemical study was carried out to explore the presence of α-smooth muscle actin (α-SMA) and vimentin cytoskeleton antigens, CD31, CD34, Ki67, p16; CD105, CD163, CD206 and FOXP3 antigens; and the central fibrotic cytokine TGF-β. Higher expression of vimentin in comparison to α-SMA in all three lesion types was found. CD31- and CD34-positive blood vessel endothelial cells were observed throughout the reticular dermis. Ki67 expression was low and almost absent in scleroderma. p16-positive levels were higher than ki67 and observed in reticular dermis of keloidal collagen in keloids, in collagen bundles in scleroderma and in the external layers of the granulomas in lacaziosis. The presence of α-actin positive cells and rarely CD34 positive cells, observed primarily in keloids, may be related to higher p16 antigen expression, a measure of cell senescence. Low FOXP3 expression was observed in all lesion types. CD105-positive cells were mainly found in perivascular tissue in close contact with the adventitia in keloids and scleroderma, while, in lacaziosis, these cells were chiefly observed in conjunction with collagen deposition in the external granuloma layer. We did not find high involvement of CD163 or CD206-positive cells in the fibrotic process. TGF-β was notable only in keloid and lacaziosis lesions. In conclusion, we have suggested vimentin to be the main myofibroblast general marker of the fibrotic process in all three studied diseases, while endothelial-to-mesenchymal transition (EndoMT) and mesenchymal stem cells (MSCs) and M2 macrophages may not play an important role.

Identification of nanoparticle-mediated siRNA-ASPN as a key gene target in the treatment of keloids

Background: Keloid, also known as connective tissue hyperplasia, is a benign proliferative disorder with a global distribution. The available therapeutic interventions are steroid injections, surgical removal of keloids, radiotherapy, compression therapy, the application of cryosurgery, and many other methods.

Objectives: Existing treatments or approaches for keloids may lead to similar or even larger lesions at the site of keloid excision, leading to a high recurrence rate. Therefore, this study aims at identifying a new gene-based therapy for the treatment of keloids.

Methods: An ASPN-siRNA/nanoparticle combination (si-ASPN) and a negative siRNA/nanoparticle complex (NC) was developed on the basis of bioinformatics studies and used in vitro and in vivo experiments.

Results: The results showed a strong correlation between the development of keloids and high expression of ASPN protein. With the expression of ASPN protein greatly reduced in keloid fibroblasts and nude mice allografts after treatment with si-ASPN, the collagen and fibroblasts were also uniform, thinner, parallel and regular.

Conclusion: All the above experimental results suggest that keloid and ASPN are closely related and both fibroblast growth and metabolism of keloid are inhibited after silencing ASPN. Therefore, ASPN-siRNA delivered via nanoparticles can serve as a novel intervention therapy for the treatment of keloids.

Adipose-Derived Stromal/Stem Cell Response to Tumors and Wounds: Evaluation of Patient Age

Tumors were characterized as nonhealing wounds by Virchow in 1858 and Dvorak in 1986. Since then, researchers have analyzed tumors from a new perspective. The parallels between tumorigenesis and physiological wound healing can provide a new framework for developing antitumor therapeutics. One commonality between tumors and wounds is the involvement of the stromal environment, particularly adipose stromal/stem cells (ASCs). ASCs exhibit dual functions, in which they stimulate tumor progression and assist in tissue repair and regeneration. Numerous studies have focused on the role of ASCs in cancer and wound healing, but none to date has linked age, cancer, and wound healing. Furthermore, very few studies have focused on the role of donor-specific characteristics of ASCs, such as age and their role in facilitating ASC behavior in cancer and wound healing. This review article is designed to provide important insights into the impact of donor age on ASC tumor and wound response and their role in facilitating ASC behavior in cancer and wound healing.

Effect of Mortalin on Scar Formation in Human Dermal Fibroblasts and a Rat Incisional Scar Model

Wound healing is a complicated cascading process; disequilibrium among reparative processes leads to the formation of pathologic scars. Herein, we explored the role of mortalin in scar formation and its association with the interleukin-1α receptor using in vitro and in vivo models. To investigate the effects of mortalin, we performed an MTT cell viability assay, qRT-PCR, and Western blot analyses, in addition to immunofluorescence and immunoprecipitation studies using cultured fibroblasts. A rat incisional wound model was used to evaluate the effect of a mortalin-specific shRNA (dE1-RGD/GFP/shMot) Ad vector in scar tissue. In vitro, the mortalin-treated human dermal fibroblast displayed a significant increase in proliferation of type I collagen, α-smooth muscle actin, transforming growth factor-β, phospho-Smad2/3-complex, and NF-κB levels. Immunofluorescence staining revealed markedly increased mortalin and interleukin-1α receptor protein in keloid tissue compared to those in normal tissue, suggesting that the association between mortalin and IL-1α receptor was responsible for the fibrogenic effect. In vivo, mortalin-specific shRNA-expressing Ad vectors significantly decreased the scar size and type-I-collagen, α-SMA, and phospho-Smad2/3-complex expression in rat incisional scar tissue. Thus, dE1-RGD/GEP/shMot can inhibit the TGF-β/α-SMA axis and NF-κB signal pathways in scar formation, and blocking endogenous mortalin could be a potential therapeutic target for keloids.

Single-Cell RNA-Sequencing Reveals the Cellular and Genetic Heterogeneity of Skin Scar to Verify the Therapeutic Effects and Mechanism of Action of Dispel-Scar Ointment in Hypertrophic Scar Inhibition

Hypertrophic scarring (HS), caused by excessive fibrosis of injured skin, imposes a psychological burden and creates a source of distress that impairs the quality of life of affected individuals. However, the gold standard for HS treatment has not yet been determined due to the complicated and difficult nature of the routines and procedures involved. Previous studies have indicated that the topical application of certain active components found in traditional Chinese medicines shows potential as a therapeutic alternative for scars. Here, single-cell RNA-sequencing was performed to determine cellular heterogeneity and identify marker genes and mechanisms associated with HS. It was found that fibroblasts comprise the largest proportion of HS cell types. The marker genes that were highly expressed in fibroblasts were extracellular matrix (ECM)-related, whereas ECM-receptor interactions and the transforming growth factor (TGF)-β signalling pathway were also found to be active. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry, which was applied to identify the molecular compounds of Dispel-Scar Ointment (DSO), revealed 74 effective chemical components belonging to 14 types of constituents, such as flavonoids, tanshinones, salvianolic acids, glycosides, and phthalides. Furthermore, in vivo studies using rat scar models showed that the topical application of Salvia miltiorrhiza, Ligusticum chuanxiong, peach kernel, safflower, and motherwort exerted beneficial effects on fibroblasts. DSO promoted scar maturation and reduced scar areas, its efficacy being similar to that of topically applied silicone. Functional studies using immunofluorescence staining, western blotting, and quantitative real-time polymerase chain reaction demonstrated that DSO may target the TGF-β/Smad pathway to inhibit collagen synthesis and promote ECM remodelling. However, further in vitro mechanistic research and single-drug prescription studies may be required to identify the specific effective compound or active ingredient of DSO, which would provide more substantial evidence regarding the potential therapeutic value of traditional herbs in HS.

Downregulated cytotoxic CD8+ T-cell identifies with the NKG2A-soluble HLA-E axis as a predictive biomarker and potential therapeutic target in keloids

Keloids are an abnormal fibroproliferative wound-healing disease with a poorly understood pathogenesis, making it difficult to predict and prevent this disease in clinical settings. Identifying disease-specific signatures at the molecular and cellular levels in both the blood circulation and primary lesions is urgently needed to develop novel biomarkers for risk assessment and therapeutic targets for recurrence-free treatment. There is mounting evidence of immune cell dysregulation in keloid scarring. In this study, we aimed to profile keloid scar tissues and blood cells and found that downregulation of cytotoxic CD8+ T cells is a keloid signature in the peripheral blood and keloid lesions. Single-cell RNA sequencing revealed that the NKG2A/CD94 complex was specifically upregulated, which might contribute to the significant reduction in CTLs within the scar tissue boundary. In addition, the NKG2A/CD94 complex was associated with high serum levels of soluble human leukocyte antigen-E (sHLA-E). We subsequently measured sHLA-E in our hospital-based study cohort, consisting of 104 keloid patients, 512 healthy donors, and 100 patients with an interfering disease. The sensitivity and specificity of sHLA-E were 83.69% (87/104) and 92.16% (564/612), respectively, and hypertrophic scars and other unrelated diseases exhibited minimal interference with the test results. Furthermore, intralesional therapy with triamcinolone combined with 5-fluorouracil drastically decreased the sHLA-E levels in keloid patients with better prognostic outcomes, while an incomplete reduction in the sHLA-E levels in patient serum was associated with higher recurrence. sHLA-E may effectively serve as a diagnostic marker for assessing the risk of keloid formation and a prognostic marker for the clinical outcomes of intralesional treatment.

Study of Interleukin-1Beta Expression in Acne Vulgaris and Acne Scars

BACKGROUND

Acne vulgaris is a multifactorial disease that mostly heals by scarring. Interleukin-1 beta (IL-1β) is a proinflammatory cytokine, suggested to play a key role in acne pathogenesis.

OBJECTIVE

To study the immunohistochemical (IHC) expression of IL1β in acne vulgaris and acne scars to evaluate its possible role in their pathogenesis and to study the relation between expression of IL1β and the clinicopathological parameters.

PATIENTS AND METHODS

This study was conducted on sixty subjects (twenty patients with acne vulgaris and twenty patients with acne scars), and twenty healthy volunteers as controls. Skin biopsies were taken from patients and controls for routine histopathological examination with Hematoxylin and Eosin (H&E) stain and IHC staining of IL-1β.

RESULTS

There was a statistically significant increase in expression of IL-1β in acne vulgaris compared to post-acne scars and controls, (p<0.001) for both. IL-1β expression was significantly positively correlated with both clinical severity of acne vulgaris (p=0.022) and severity of histopathological inflammation (p=0.011).

CONCLUSION

IL-1β expression was associated with acne vulgaris and post acne scars with significant positive correlation to clinical and histopathological severity of acne vulgaris. Thus IL-1β could be a key player cytokine in acne pathogenesis, its severity and development of post acne scars.

Use of Adipose Stem Cells Against Hypertrophic Scarring or Keloid

Hypertrophic scars or keloid form as part of the wound healing reaction process, and its formation mechanism is complex and diverse, involving multi-stage synergistic action of multiple cells and factors. Adipose stem cells (ASCs) have become an emerging approach for the treatment of many diseases, including hypertrophic scarring or keloid, owing to their various advantages and potential. Herein, we analyzed the molecular mechanism of hypertrophic scar or keloid formation and explored the role and prospects of stem cell therapy, in the treatment of this condition.

Early Application of Quaternized Chitin Derivatives Inhibits Hypertrophic Scar Formation

Various treatments for hypertrophic scars (HS) are applied after wound re-epithelialization. However, the lack of early intervention within the wound bed leads to poor HS treatment outcomes. In this study, quaternized chitin (QC) derivatives with different degrees of deacetylation (7.4% and 78.9%) are synthesized and their effects on HS formation are evaluated in a rabbit ear scar model. Early application of QC alleviates scar hypertrophy without delayed wound healing. Fibroblast count, collagen content, and α-smooth muscle actin expression are decreased, while matrix metalloproteinase-1 is upregulated on day 35 in the QC treatment group. QC suppresses inflammatory cell infiltration and IL-6 expression. A subsequent reduction in transforming growth factor β1 expression is also observed. The inhibitory effect of QC on HS formation is eliminated through the administration of exogenous IL-6. Taken together, early application of QC inhibits HS formation by downregulating IL-6 expression, and QC with a low degree of deacetylation tends to be more effective. Considering its potential for accelerating wound healing, inhibiting HS formation, and its antibacterial activity, QC may be used as an effective dressing in clinical wound management.

Emerging insights into the immunological aspects of keloids

A special kind of scar, keloid, sometimes grows huge, disturbing patients in different ways. We discussed the pathogenesis of keloids and found researches about fibroblasts and collagen disorders, with little emphasis on immunity. Coupled with few effective treatments in keloid at present, we have focused on the immunological mechanisms of keloids with an aim to unravel some new therapeutic approaches in the future. In this review, the immunological processes are separately illustrated by the classification of different immune cells. In addition, we also discuss possible reasons for the repeated recurrence of keloids, the phenomenon of cell talks, and inflammation-related signal pathways involved in the pathogenesis of keloids.

Risk of cancer development in patients with keloids

Keloid is a skin disease characterized by exaggerated scar formation, excessive fibroblast proliferation, and excessive collagen deposition. Cancers commonly arise from a fibrotic microenvironment; e.g., hepatoma arises from liver cirrhosis, and oral cancers arise from submucosal fibrosis. As keloids are a prototypic fibroproliferative disease, this study investigated whether patients with keloids have an increased cancer risk. In a matched, population-based study, first 17,401 patients treated for keloids during 1998–2010 with 69,604 controls without keloids at a ratio of 1:4 were evaluated. The association between keloids and risk of cancer was estimated by logistic regression or Cox proportional hazard regression models after adjustment of covariates. In total, 893 first-time cases of cancer were identified in the 17,401 patients with keloids. The overall cancer risk was 1.49-fold higher in the keloids group compared to controls. Regarding specific cancers, the keloids group, had a significantly higher risk of skin cancer compared to controls (Relative risk = 1.73). The relative risk for skin cancer was even higher for males with keloids (Relative risk = 2.16). Further stratified analyses also revealed a significantly higher risk of developing pancreatic cancer in female patients with keloids compared to controls (Relative risk = 2.19) after adjustment for known pancreatic cancer risk factors. This study indicates that patients with keloids have a higher than normal risk for several cancer types, especially skin cancers (both genders) and pancreatic cancer (females). Therefore, patients with keloids should undergo regular skin examinations, and females with keloids should regularly undergo abdominal ultrasonography.

Increased sensitivity to TNF-α promotes keloid fibroblast hyperproliferation by activating the NF-κB, JNK and p38 MAPK pathways

Hyperproliferation of fibroblasts is the main cause of keloid formation. However, the pathogenesis of keloids has yet to be fully elucidated. Tumor necrosis factor (TNF)-α may play an important role in the formation and proliferation of keloids, as it is implicated in the pathogenesis of various fibrous disorders. In the present study, the expression level of TNF-α and its receptors, soluble TNF receptor (sTNFR)1 and sTNFR2, in the peripheral blood and skin tissues was detected by ELISA, reverse transcription-quantitative PCR or immunohistochemistry. There was no statistically significant difference in the expression of TNF-α and sTNFR2 in the peripheral blood and skin tissues between patients with keloids and healthy participants (P>0.05), while the sTNFR1 mRNA level in fibroblasts cultured in vitro and its protein level in keloid skin samples were significantly higher compared with those in normal skin (P<0.05). Subsequently, TNF-α recombinant protein was used to treat keloid-derived and normal skin fibroblasts, and it was observed that TNF-α promoted the proliferation of keloid fibroblasts (KFs), but had little effect on normal skin fibroblasts. Furthermore, it was observed that TNF-α stimulation led to the activation of the nuclear factor (NF)-κB, c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) pathways in KFs. In conclusion, KFs exhibited increased expression of sTNFR1, which may contribute to the increased sensitivity to TNF-α, resulting in low concentrations of TNF-α activating the NF-κB, JNK and p38 MAPK pathways, thereby promoting the sustained and excessive proliferation of KFs.

Adiponectin, but Not TGF-β1, CTGF, IL-6 or TNF-α, May Be a Potential Anti-Inflammation and Anti-Fibrosis Factor in Keloid

INTRODUCTION

Numerous studies have elucidated adiponectin as a negative impact on inflammation and tissue fibrosis. However, little is known about the relevance between adiponectin and inflammatory factors in keloid.

METHODS

To clarify whether adiponectin plays a role in the inflammation and fibrosis of keloid, 50 patients with keloid and 50 healthy subjects were enrolled, We examined the serum and mRNA expression levels of adiponectin, TGF-β1, CTGF, IL-6 and TNF-α in normal skin tissues and keloid tissues by ELISA and qPCR, respectively. Correlation analysis between serum concentration of adiponectin with Vancouver Scar Scale (VSS) scores and the age of patients with keloid was evaluated, and the adiponectin concentrations in patients with keloid between different genders were measured. We further examined the effects of adiponectin on TGF-β1 mediated expression of collagen I, FN and MMP-1 in normal fibroblasts (NFs) and keloid fibroblasts (KFs).

RESULTS

We discovered that lower serum concentration and mRNA expression of adiponectin, but higher TGF-β1, CTGF, IL-6 and TNF-α levels were measured in patients with keloid compared with those in normal controls. Furthermore, there was a strong inverse correlation between the serum adiponectin levels and VSS scores in patients with keloid, but not in ages, and there was no statistically difference between different genders. Moreover, adiponectin attenuated TGF-β1 mediated expression of collagen I and FN, and upregulated the expression level of MMP-1 in KFs, but not in NFs. In addition, the inhibitory effect of adiponectin on TGF-β1 was attenuated by AMPK inhibitor Compound C, but not PI3K/Akt inhibitor LY294002.

DISCUSSION

Adiponectin may exert an anti-inflammation and anti-fibrosis role in the development of keloid. One of the underlying mechanisms may be the activation of the AMPK signaling pathway.

A retrospective study of hypofractionated radiotherapy for keloids in 100 cases

At present, the consensus on the best treatment for keloids is the combination of clinical and surgical therapies, if necessary, associated with adjuvant radiotherapy like brachytherapy. Whereas, the uniform scheme of radiotherapy in keloids is unclear. Here, we conducting a retrospective analysis to assess the efficacy and safety of a specific treatment regimen (20 Gy in 5 fractions) in keloid patients. We retrospectively analysed the medical records of keloid patients receiving auxiliary postoperative radiotherapy (PORT) treatment from 2009 to 2019. The patients were treated with the hypofractionation method of 20 Gy in 5 fractions. We compared the local control rate and complications, using the chi-square test and logistic regression analyses. After screening, we identified 100 keloid patients in this study, with a median follow-up of 59 months. In this study, the overall local control rate of keloid lesions was 84.8%. After multivariate analyses (primary keloid or not, family history, interval from surgery to irradiation and site), our research showed that primary keloid, site and interval from surgery to irradiation were significantly related to recurrence. Acute radiation injury and late radiation injury accounted for 3% (erythema) and 1% (skin sclerosis) of the total cases, respectively. Our results indicate that a postoperative hypofractionation with radiation dose of 20 Gy in 5 fractions may be effective, easy to accept and safe for keloid patients.

IL-17 Induced Stromal Cell-Derived Factor-1 and Profibrotic Factor in Keloid-Derived Skin Fibroblasts via the STAT3 Pathway

The pathogenesis of keloids has not been elucidated, and the disease is thought to be caused by abnormal secretion of proinflammatory mediators and irregular responses to other inflammatory signals mediated by keloid fibroblasts (KFs). In this study, we investigated whether a local increase in interleukin IL-17 in keloid tissues stimulates the production of stromal cell–derived factor-1 (SDF-1) in KFs causing further recruitment of IL-17-producing T helper 17 (Th17) cells, which subsequently creates a positive feedback loop. Histological assessment was performed and the change in the expression of IL-17, IL-1β, IL-6, and TNF-α which of fibrosis and inflammation associated markers was examined. In addition, fibroblasts were treated with IL-17 in the presence or absence of STAT3 inhibitor STA-21; SDF-1 levels and fibrosis genes were measured. Our results showed that fibrotic reaction and expression of proinflammatory cytokines including IL-17 were most prominent in the growing margin (perilesional area) of keloid tissue and Th17 cells significantly infiltrated the perilesional area. In addition, IL-17 upregulated the expression of SDF-1, collagen, and α-SMA in KFs. Finally, STA-21 decreased SDF-1α expression and the expression of fibrosis genes in KFs even after IL-17 stimulation. Our study demonstrated that a local increase in IL-17 in keloid tissues stimulates the production of SDF-1 in KFs causing further recruitment of IL-17-producing T helper 17 (Th17) cells, which subsequently creates a positive feedback loop. These findings suggest that STAT3 inhibition can be used to treat keloid scars by reversing the vicious cycle between Th17 cells and KFs.

Downregulation of CR6-interacting factor 1 suppresses keloid fibroblast growth via the TGF-β/Smad signaling pathway

Keloids are a type of aberrant skin scarring characterized by excessive accumulation of collagen and extracellular matrix (ECM), arising from uncontrolled wound healing responses. While typically non-pathogenic, keloids are occasionally regarded as a form of benign tumor. CR6-interacting factor 1 (CRIF1) is a well-known CR6/GADD45-interacting protein, that has both nuclear and mitochondrial functions, and also exerts regulatory effects on cell growth and apoptosis. In this study, cell proliferation, cell migration, collagen production and TGF-β signaling was compared between normal fibroblasts (NFs) and keloid fibroblasts (KFs). Subsequently, the effects of CRIF1 deficiency were investigated in both NFs and KFs. Cell proliferation, cell migration, collagen production and protein expressions of TGF-β, phosphorylation of Smad2 and Smad3 were all found to be higher in KFs compared to NFs. CRIF1 deficiency in NFs and KFs inhibited cell proliferation, migration, and collagen production. In addition, phosphorylation of Smad2 and Smad3, which are transcription factors of collagen, was decreased. In contrast, mRNA expression levels of Smad7 and SMURF2, two important inhibitory proteins of Smad2/3, were increased, suggesting that CRIF1 may regulate collagen production. CRIF1 deficiency decreases the proliferation and migration of KFs, thereby inhibiting their overgrowth via the transforming growth factor-β (TGF-β)/Smad pathway. CRIF1 may therefore represent a potential therapeutic target in keloid pathogenesis.

The association between keloid and osteoporosis: real-world evidence

Background

Keloids are characterized by disturbance of fibroblast proliferation and apoptosis, deposition of collagen, and upregulation of dermal inflammation cells. This benign dermal fibro-proliferative scarring condition is a recognized skin inflammation disorder. Chronic inflammation is a well-known contributor to bone loss and its sequelae, osteoporosis. They both shared a similar pathogenesis through chronic inflammation. We assessed whether keloids increase osteoporosis risk through using National Health Insurance Research Database.

Methods

The 42,985 enrolled patients included 8597 patients with keloids but no history of osteoporosis; 34,388 controls without keloids were identified from the general population and matched at a one-to-four ratio by age, gender. Kaplan-Meier method was applied to determine cumulative incidence of osteoporosis. Cox proportional hazard regression analysis was performed after adjustment of covariates to estimate the effect of keloids on osteoporosis risk.

Results

Of the 8597 patients with keloids, 178 (2.07%) patients were diagnosed with osteoporosis while in the 34,388 controls, 587 (1.71%) were diagnosed with osteoporosis. That is, the keloids patients had 2.64-fold higher risk of osteoporosis compared to controls after adjustment for age, gender, Charlson Comorbidity Index and related comorbidities. The association between keloids and osteoporosis was strongest in patients younger than 50 years (hazard ratio = 7.06%) and in patients without comorbidities (hazard ratio = 4.98%). In the keloids patients, a high incidence of osteoporosis was also associated with advanced age, high Charlson Comorbidity Index score, hyperlipidemia, chronic liver disease, stroke, and depression.

Conclusions

Osteoporosis risk was higher in patients with keloids compared to controls, especially in young subjects and subjects without comorbidities.

RNA Sequencing Keloid Transcriptome Associates Keloids With Th2, Th1, Th17/Th22, and JAK3-Skewing

Keloids are disfiguring, fibroproliferative growths and their pathogenesis remains unclear, inhibiting therapeutic development. Available treatment options have limited efficacy and harbor safety concerns. Thus, there is a great need to clarify keloid pathomechanisms that may lead to novel treatments. In this study, we aimed to elucidate the profile of lesional and non-lesional keloid skin compared to normal skin. We performed gene (RNAseq, qRT-PCR) and protein (immunohistochemistry) expression analyses on biopsy specimens obtained from lesional and non-lesional skin of African American (AA) keloid patients compared to healthy skin from AA controls. Fold-change≥2 and false-discovery rate (FDR)<0.05 was used to define significance. We found that lesional versus normal skin showed significant up-regulation of markers of T-cell activation/migration (ICOS, CCR7), Th2- (IL-4R, CCL11, TNFSF4/OX40L), Th1- (CXCL9/CXCL10/CXCL11), Th17/Th22- (CCL20, S100As) pathways, and JAK/STAT-signaling (JAK3) (false-discovery rate [FDR]<0.05). Non-lesional skin also exhibited similar trends. We observed increased cellular infiltrates in keloid tissues, including T-cells, dendritic cells, mast cells, as well as greater IL-4rα⁺, CCR9⁺, and periostin⁺ immunostaining. In sum, comprehensive molecular profiling demonstrated that both lesional and non-lesional skin show significant immune alternations, and particularly Th2 and JAK3 expression. This advocates for the investigation of novel treatments targeting the Th2 axis and/or JAK/STAT-signaling in keloid patients.

The Keloid Disorder: Heterogeneity, Histopathology, Mechanisms and Models

Keloids constitute an abnormal fibroproliferative wound healing response in which raised scar tissue grows excessively and invasively beyond the original wound borders. This review provides a comprehensive overview of several important themes in keloid research: namely keloid histopathology, heterogeneity, pathogenesis, and model systems. Although keloidal collagen versus nodules and α-SMA-immunoreactivity have been considered pathognomonic for keloids versus hypertrophic scars, conflicting results have been reported which will be discussed together with other histopathological keloid characteristics. Importantly, histopathological keloid abnormalities are also present in the keloid epidermis. Heterogeneity between and within keloids exists which is often not considered when interpreting results and may explain discrepancies between studies. At least two distinct keloid phenotypes exist, the superficial-spreading/flat keloids and the bulging/raised keloids. Within keloids, the periphery is often seen as the actively growing margin compared to the more quiescent center, although the opposite has also been reported. Interestingly, the normal skin directly surrounding keloids also shows partial keloid characteristics. Keloids are most likely to occur after an inciting stimulus such as (minor and disproportionate) dermal injury or an inflammatory process (environmental factors) at a keloid-prone anatomical site (topological factors) in a genetically predisposed individual (patient-related factors). The specific cellular abnormalities these various patient, topological and environmental factors generate to ultimately result in keloid scar formation are discussed. Existing keloid models can largely be divided into in vivo and in vitro systems including a number of subdivisions: human/animal, explant/culture, homotypic/heterotypic culture, direct/indirect co-culture, and 3D/monolayer culture. As skin physiology, immunology and wound healing is markedly different in animals and since keloids are exclusive to humans, there is a need for relevant human in vitro models. Of these, the direct co-culture systems that generate full thickness keloid equivalents appear the most promising and will be key to further advance keloid research on its pathogenesis and thereby ultimately advance keloid treatment. Finally, the recent change in keloid nomenclature will be discussed, which has moved away from identifying keloids solely as abnormal scars with a purely cosmetic association toward understanding keloids for the fibroproliferative disorder that they are.

Long-wave Ultraviolet Ray Promotes Inflammation in Keloid-derived Fibroblasts by Activating P38-NFκB1 Signaling Pathway

One of the main mechanisms of keloid formation is the persistent chronic inflammation, which initiates the activation of keloid-derived fibroblasts (KFs) and boosts the production of extracellular matrix. Meanwhile, 95% of the ultraviolet rays that reach the earth are long-wave ultraviolet (UVA). However, the effect of UVA on keloids is currently unclear. The objective of our research is to investigate UVA's impact on keloids. Cell viability assay, migration assay, and cell cycle analysis were conducted. UVA's impacts on gene expressions were detected by real-time quantitative polymerase chain reaction, western blot analysis, enzyme-linked immunosorbent assay, and immunofluorescence. Our results indicated that UVA inhibited the proliferation and migration of KFs. In addition, after UVA irradiation, the expressions of matrix metallopeptidase 1 and matrix metallopeptidase 2 markedly increased in KFs. Moreover, the expression of α-smooth muscle actin and collagen I decreased. Furthermore, KFs with UVA irradiation secreted more interleukin-6 and interleukin-8 in the culture medium. And it was confirmed that the protein expressions of inflammation-related factors, including P38, CK2A, NFκB1, and P65, increased observably in KFs with UVA irradiation. The protein expression of IKBα, also known as NFκB inhibitor α, decreased. All these observations suggested that UVA irradiation could inhibit cellular activity and collagen production in KFs while promoting inflammation by activating P38-NFκB1 signal pathway.

Orf Virus IL-10 and VEGF-E Act Synergistically to Enhance Healing of Cutaneous Wounds in Mice

Orf virus (OV) is a zoonotic parapoxvirus that causes highly proliferative skin lesions which resolve with minimal inflammation and scarring. OV encodes two immunomodulators, vascular endothelial growth factor (VEGF)-E and interleukin-10 (ovIL-10), which individually modulate skin repair and inflammation. This study examined the effects of the VEGF-E and ovIL-10 combination on healing processes in a murine wound model. Treatments with viral proteins, individually and in combination, were compared to a mammalian VEGF-A and IL-10 combination. Wound biopsies were harvested to measure re-epithelialisation and scarring (histology), inflammation, fibrosis and angiogenesis (immunofluorescence), and gene expression (quantitative polymerase chain reaction). VEGF-E and ovIL-10 showed additive effects on wound closure and re-epithelialisation, and suppressed M1 macrophage and myofibroblast infiltration, while allowing M2 macrophage recruitment. The viral combination also increased endothelial cell density and pericyte coverage, and improved collagen deposition while reducing the scar area. The mammalian combination showed equivalent effects on wound closure, re-epithelialisation and fibrosis, but did not promote blood vessel stabilisation or collagen remodeling. The combination treatments also differentially altered the expression of transforming growth factor beta isoforms, Tgfβ1 and Tgfβ3. These findings show that the OV proteins synergistically enhance skin repair, and act in a complimentary fashion to improve scar quality.

Effects of hyperbaric oxygen therapy on the expression levels of the inflammatory factors interleukin-12p40, macrophage inflammatory protein-1β, platelet-derived growth factor-BB, and interleukin-1 receptor antagonist in keloids

BACKGROUND

Our study aimed to screen and explore the expression of inflammatory factors in keloid patients and to investigate how hyperbaric oxygen (HBO) therapy affects the expression levels of interleukin-12p40 (IL-12p40), macrophage inflammatory protein-1β (MIP-1β), platelet-derived growth factor-BB (PDGF-BB), and interleukin-1 receptor antagonist (IL-1Ra).

OBJECTIVE

30 patients were randomly selected and divided into the following 3 groups: keloid samples from keloid patients treated with HBO therapy (A), keloid samples from keloid patients treated without HBO therapy (B), and normal control skin samples derived from individuals who had no clear scarring (C). Each group included 10 samples.

METHODS

Inflammatory factors in the keloid tissues were measured with the MILLIPLEX multiplexed Luminex system. Hematoxylin and eosin staining, immunohistochemical staining, and Western blotting were used to observe the morphological differences in different tissues and the expression levels.

RESULTS

The expression levels of inflammatory mediators, including IL-12p40, MIP-1β, PDGF-BB, and IL-1Ra, in keloid tissues were significantly different from those in samples of normal skin. Hematoxylin and eosin staining showed significantly greater inflammatory infiltration in keloid tissue. Significantly different expression levels were observed in group A, B, and C.

CONCLUSION

Significantly altered levels of inflammatory factors in the samples from keloid patients were observed, suggesting that formation of a keloid is potentially related to inflammatory responses. HBO therapy could significantly affect the expression levels of IL-12p40, MIP-1β, PDGF-BB, and IL-1Ra, indicating that the effects of HBO therapy are associated with the attenuation of inflammatory responses.

Antibiotics Affect ROS Production and Fibroblast Migration in an In-vitro Model of Sinonasal Wound Healing

Introduction: Antibiotics are often administered to patients perioperatively and have been shown to affect ROS production of nasal cells in vitro, but their effect in the setting of active wound healing remains unclear. Reactive oxygen species (ROS) are known to play a significant role in wound healing. This study analyzed a broad array of antibiotics used after sinus surgery to assess their effect on wound healing and ROS production in vitro. It was hypothesized that ROS production would be affected by these antibiotics and there would be a negative relationship between ROS activity and cell migration speed. Methods: Monolayers of primary human nasal epithelial cells (HNEC) and primary fibroblasts were disrupted with a linear wound, treated with 10 different antibiotics or a ROS inhibitor and observed over 36 h in a controlled environment using confocal microscopy. ROS activity and migration speed of the wound edge were measured at regular intervals. The relationship between the two parameters was analyzed using mixed linear modeling. Results: Performing a linear scratch over the cell monolayers produced an immediate increase in ROS production of ~35% compared to unscratched controls in both cell types. Incubation with mitoquinone and the oxazolidinone antibiotic linezolid inhibited ROS activity in both fibroblasts and HNEC in association with slowed fibroblast cell migration (p < 0.05). Fibroblast cell migration was also reduced in the presence of clarithromycin and mupirocin (p < 0.05). A significant correlation was seen between ROS suppression and cell migration rate in fibroblasts for mitoquinone and all antibiotics except for azithromycin and doxycycline, where no clear relationship was seen. Treatments that slowed fibroblast cell migration compared to untreated controls showed a significant correlation with ROS suppression (p < 0.05). Conclusion: Increased ROS production in freshly wounded HNEC and fibroblast cell monolayers was suppressed in the presence of antibiotics, in correlation with reduced fibroblast cell migration. In contrast, HNEC cell migration was not significantly affected by any of the antibiotics tested. This differential effect of antibiotics on fibroblast and HNEC migration might have clinical relevance by reducing adhesion formation without affecting epithelial healing in the postoperative setting.

Pirfenidone inhibits epithelial-mesenchymal transition in keloid keratinocytes

Background

Keloids are benign fibroproliferative skin lesions that are difficult to treat and become a lifetime predicament for patients. Several treatment modalities have been put forth, but as yet no satisfactory approach to the prevention or treatment of keloids has been identified. The process of epithelial-to-mesenchymal transition (EMT) has been implicated in keloid scarring, as keloid keratinocytes display an EMT-like phenotype. This study investigated the potential of pirfenidone, an antifibrotic agent, to counteract EMT-like alterations in keloid keratinocytes, including gene expression, cell migratory and proliferative functions.

Methods

Normal and keloid keratinocytes were isolated from discarded normal skin tissues and from resected keloid tissues, respectively. Cells were quiesced for 24 h without epidermal growth factor DS-Qi1MCDigital and were exposed to transforming growth factor-beta1 (TGF-β1; 10 ng/mL), with or without pirfenidone (400 μg/mL), for an additional 24 h. The effects of pirfenidone on cytotoxicity, cell migration, cell proliferation, and on expression of genes and proteins involved in EMT were assayed. Statistical significance was determined by two-way ANOVA using Sigma Plot.

Results

We found that pirfenidone did not elicit any cytotoxic effect at concentrations up to 1000 μg/mL. A statistically significant dose-dependent decrease in basal cell proliferation rate was noted in both normal and keloid keratinocytes when exposed to pirfenidone at concentrations ranging from 200 to 1000 μg/mL. Pirfenidone significantly decreased basal cell migration in both normal and keloid keratinocytes, but a significant decrease in TGF-β1-induced cell migration was seen only in keloid keratinocytes. Significant inhibition of the expression of TGF-β1-induced core EMT genes, namely hyaluronan synthase 2, vimentin, cadherin-11, and wingless-type MMTV integration site family, member 5A along with fibronectin-1, was observed in both normal and keloid keratinocytes treated with pirfenidone. In addition, the protein levels of vimentin and fibronectin were significantly reduced by pirfenidone (400 μg/mL) in both normal and keloid keratinocytes.

Conclusions

For the first time, this study shows the efficacy of pirfenidone in inhibiting the EMT-like phenotype in keratinocytes derived from keloids, suggesting that pirfenidone may counteract a critical contributor of keloid progression and recurrence.

Keloid treatment: what about adjuvant radiotherapy?

Background: Keloids are debilitating fibrous skin proliferations with a high recurrence rate after surgical treatment. Postoperative radiotherapy (PORT) is a well-tolerated adjuvant treatment to reduce the risk of recurrence, but the optimal regimen for this combined treatment remains unknown. The aim of this study is to evaluate the efficacy of combining surgical excision and immediate PORT.

Methods: We retrospectively reviewed the records of patients with keloid lesions treated with adjuvant PORT in the period 2005–2014 at Geneva University Hospitals. Main outcomes were the rates of complications and recurrence in patients with a minimal follow-up of 1 year, including the Patient and Observer Scar Assessment Scale satisfaction scores.

Results: 10 patients with 16 keloids were eligible (mean follow-up, 37 months). Only one recurrence was reported (6%). In 12.5% of cases, mild erythema appeared in the early postoperative period. No major complications were observed. The overall patient and observer satisfaction rate was excellent.

Conclusion: Surgical excision combined with immediate PORT is an effective and easy treatment with good esthetic results and an acceptable recurrence rate. It should be considered for patients with persistent keloid formation after failure of other treatments and those at high risk of relapse.

Improving the anti-keloid outcomes through liposomes loading paclitaxel-cholesterol complexes

Background

Keloids represent benign fibroproliferative tumors which result from elevated expression of inflammation. Paclitaxel (PTX) was an effective chemotherapeutic agent and has been reported to have anti-fibrotic effects, but the strong hydrophobicity brings a challenge for its clinical application.

Purpose

The objective of this study was to improve the water solubility of PTX and investigate its anti-keloid effects.

Methods

We prepared a PTX-cholesterol-loaded liposomes (PTXL) by thin film evaporation fashion and characterized their physicochemical properties. We also investigated the effects of PTX on proliferation, invasion and fibrosis of keloid fibroblasts in vitro and in vivo.

Results

The prepared PTXL have a spherical appearance, a particle size of 101.43 nm and a zeta potential of −41.63 mV. PTXL possessed a high drug entrapment efficiency of 95.63% and exhibited a good stability within 30 days. The drugs in PTXL were released in a slow and sustained mode. The PTXL could be effectively uptaken into human keloids fibroblast (HKFs) in a time-dependent manner. In vitro, PTXL showed better ability on inhibiting cell proliferation, migration and invasion, and effectively on promoting apoptosis and arresting cell cycle in G₂/M phase compared to PTX. Meanwhile, in vivo studies indicated that the PTXL had better performance on inhibiting the keloids growth compared to the PTX in keloid-bearing BALB/c nude mice model. Finally, we found PTX treatment suppressed the production of tumor necrosis factor alpah (TNF-α), interleukin 6 (IL-6) and transforming growth factor beta (TGF-β) and inhibited the expression of alpha smooth muscle actin (α-SMA) and collagen I in HKFs. The activation of protein kinase B (AKT)/glycogen synthase kinase 3 beta (GSK3β) signaling pathway also blocked by PTX in cultured HKFs and keloid tissues. LY294002, a PI3K (phosphatidylinositol 3-kinase)/AKT inhibitor, also suppressed the expression of TNF-α, IL-6 and TGF-β, and simultaneously, reduced the production of α-SMA and collagen I in HKFs. The inhibition of AKT/GSK3β signaling pathway contribute to inhibit the generation of fibrogenic cytokines by PTXL on ameliorating fibrosis progress in keloids.

Conclusion

Our results suggested that the developed PTXL would become a promising therapeutic agent in the field of anti-keloid therapy.

Deferiprone has anti-inflammatory properties and reduces fibroblast migration in vitro

Normal wound healing is a highly regulated and coordinated process. However, tissue injury often results in inflammation with excessive scar tissue formation after 40-70% of operations. Here, we evaluated the effect of the iron chelator deferiprone on inflammation and the migration of primary nasal fibroblasts and primary human nasal epithelial cells (HNECs) in vitro. The cytotoxicity of deferiprone was examined by the lactate dehydrogenase assay on primary nasal fibroblasts and air-liquid interface (ALI) cultures of HNECs. Wound closure was observed in scratch assays by using time-lapse confocal scanning laser microscopy. Interleukin-6 (IL-6) and type I and III collagen protein levels were determined by ELISA. Intracellular Reactive Oxygen Species (ROS) activity was measured by utilizing the fluorescent probe H2DCFDA. Deferiprone at 10 mM concentration was non-toxic to primary fibroblasts and HNECs for up to 48 hours application. Deferiprone had significant dose-dependent inhibitory effects on the migration, secreted collagen production and ROS release by primary nasal fibroblasts. Deferiprone blocked Poly (I:C)-induced IL-6 production by HNECs but did not alter their migration in scratch assays. Deferiprone has the potential to limit scar tissue formation and should be considered in future clinical applications.

Hyperbaric oxygen therapy improves the effect of keloid surgery and radiotherapy by reducing the recurrence rate

OBJECTIVE

Keloids are exuberant cutaneous scars that form due to abnormal growth of fibrous tissue following an injury. The primary aim of this study was to assess the efficacy and mechanism of hyperbaric oxygen therapy (HBOT) to reduce the keloid recurrence rate after surgical excision and radiotherapy.

METHODS

(1) A total of 240 patients were randomly divided into two groups. Patients in the HBOT group (O group) received HBOT after surgical excision and radiotherapy. Patients in the other group were treated with only surgical excision and radiotherapy (K group). (2) Scar tissue from recurrent patients was collected after a second operation. Hematoxylin and eosin (H&E) staining was used to observe keloid morphology. Certain inflammatory factors (interleukin-6 (IL-6), hypoxia-inducible factor-1α (HIF-1α), tumor necrosis factor-α (TNF-α), nuclear factor κB (NF-κB), and vascular endothelial growth factor (VEGF)) were measured using immunohistochemical staining.

RESULTS

(1) The recurrence rate of the O group (5.97%) was significantly lower than that of the K group (14.15%), P<0.05. Moreover, patients in the O group reported greater satisfaction than those in the K group (P<0.05). (2) Compared with the recurrent scar tissue of the K group, the expression levels of the inflammatory factors were lower in the recurrent scar tissue of the O group.

CONCLUSIONS

Adjunctive HBOT effectively reduces the keloid recurrence rate after surgical excision and radiotherapy by improving the oxygen level of the tissue and alleviating the inflammatory process.

Correlation between Serum 25-Hydroxyvitamin D Levels with Keloid Severity

BACKGROUND

Keloids are dermal fibroproliferative tumours characterised by excessive deposition of extra cellular matrix components. The active form of vitamin D is known to inhibit the proliferation of keloid fibroblasts by inhibiting extracellular matrix production induced by transforming growth factor ß (TGF-β) and increasing matrix metalloproteinase (MMP) activity. Vitamin D derivatives are thought to be an early preventive treatment strategy for keloid.

AIM

To determine the correlation between serum 25-hydroxyvitamin D level with keloid severity.

METHODS

This is a cross-sectional analytic study involving 32 keloid patients. Keloid patients were diagnosed by history and clinical examinations. Then an assessment of the severity was conducted using the Vancouver Scar Scale (VSS). We conducted blood sampling and measurement of serum 25-hydroxyvitamin D level to the patients. This study has been approved by the Health Research Ethics Commission of the Faculty of Medicine, Universitas Sumatera Utara, H. Adam Malik General Hospital Medan.

RESULTS

There is negative correlation between serum 25-hydroxyvitamin D level with severity in keloid patients (p = 0.0001; r = -0.737). There is no significant correlation between serum 25-hydroxyvitamin D level with gender (p = 0.271), age (p = 0.201; r = -0.232), duration of keloid (p = 0.505; r = -0.122) and family history (p = 0.262).

CONCLUSION

Lower level of plasma 25-hydroxyvitamin D, the severity of keloid became an increasingly heavy. There is no significant difference between serum 25-hydroxyvitamin D level with gender, age, duration of keloid and family history in keloid patients.

High in situ mRNA levels of IL-22, TFG-β, and ARG-1 in keloid scars

Keloid scars are currently considered a chronic inflammatory process and no longer a benign skin tumor. Keloids are defined as highly inflamed, hyperproliferative pathological scars. Growth factors and cytokines have important functions in the keloid inflammatory etiopathogenesis. The aim of this study was to analyze the in situ expression of cytokines and growth factors in keloid scars in comparison with that in normal scars. Among them, we specifically assessed TGF-β, FGF, IL-33, IL-22, ARG-1, ARG-2, iNOS, VIP, VIP-R1, TAC, and TAC-R1. A total of 98 biopsies were evaluated, including of 53 keloid and 45 normal scars. The age of patients with keloids ranged from 11 to 73 years, with a mean age of 28 years and predominance of the female gender (58.5% of the total patients). Around 64.15% of the patients belonged to the black ethnic group. Evaluated keloids were most commonly located in the earlobe because of ear piercing, representing 73.6% of the cases. We found significantly greater expression of TGF-β, IL-22, and ARG-1 in keloids when compared with that in normal scars. As for IL-33, ARG-2, and VIP-R1, despite the higher number of mRNA copies found in keloids, this difference was not significant. Furthermore, FGF, iNOS, VIP, TAC, and TAC-R1 mRNA levels were not detectable, and therefore these results were inconclusive in this study. Considering these results, understanding the cellular and molecular mechanisms that control the inflammatory response during cutaneous healing may promote the development of strategies to improve the treatment of patients with keloids.

Tumor necrosis factor α-308 G/A and interleukin 1 β-511 C/T gene polymorphisms in patients with scarring acne

BACKGROUND

Acne is a chronic inflammatory skin disorder which may heal with scarring. Tumor necrosis factor alpha (TNF α) and interleukin 1 β (IL-1β) are considered as the main responsible proinflammatory mediators of acne pathogenesis. Oversecretion of these cytokines was found to be associated with TNF α-308 G>A and IL-1β-511 C<T polymorphisms.

AIM

To evaluate the association of TNF α-308 and IL-1β-511 gene polymorphisms with acne and postacne scarring susceptibility and acne severity.

METHODS

Study subjects included 90 patients with acne vulgaris (31 males, 59 females; mean age: 19.6 ± 3.7 years) and 30 healthy controls (11 males, 19 females; mean age: 19.2 ± 5.1 years). Patients were sub-grouped on the basis of acne severity into mild, moderate, and severe acne groups and on the presence postacne scarring into scarring acne and nonscarring acne groups. Peripheral venous blood samples were obtained for performing real-time PCR analysis for detecting TNF α-308 and IL-1β-511 genotypic variants.

RESULTS

Among patients, 21.7% (n = 26) had mild, 22.5% (n = 27) had moderate, 30.8% (n = 37) had severe, and 30% (n = 36) had scarring acne. Genotypic variants of TNF α-308 and IL-1β-511 did not statistically differ between acne patients and controls (P values: .245 and .466). When compared in terms of acne severity and the presence of postacne scarring, no statistical significance was observed regarding frequencies of genotypic variants related to the both TNF α-308 and IL-1β polymorphisms (P > .05).

CONCLUSION

TNF α-308 and IL-1β polymorphic variants are not associated with acne and postacne scarring susceptibility and acne severity.

Ginsenoside Rg3 inhibits keloid fibroblast proliferation, angiogenesis and collagen synthesis in vitro via the TGF‑β/Smad and ERK signaling pathways

A wide range of therapeutic options exists for the treatment of keloids, all of which have their own strengths; however, a high risk of side-effects and frequent recurrence remains. Therefore, the present study aimed to identify improved therapeutic approaches or drugs for the treatment of keloids. Ginsenoside Rg3 (Rg3) has been reported to exert numerous antitumor effects, thus indicating that Rg3 may be a potential therapeutic agent that targets keloids. The present study determined the effects of Rg3 on human keloid fibroblasts (KFs) in vitro, and further explored the associated molecular and cellular mechanisms. Keloid scar specimens were obtained from patients, aged between 22 and 35 years, without systemic diseases and primary cells were isolated from keloid tissues. In each assay, KFs were divided into three groups and were cultured in medium with or without various concentrations of Rg3 (50 or 100 μg/ml). Cell viability assay, flow cytometry, quantitative polymerase chain reaction, cell migration assay, immunofluorescence staining, western blot analysis, Transwell cell invasion assay and immunohistochemical analysis were used to analyze the KFs and keloid explant cultures. The results of the present study demonstrated that Rg3 was able to exert an inhibitory effect on the transforming growth factor-β/Smad and extracellular signal-regulated kinase signaling pathways in KFs. The proliferation, migration, invasion, angiogenesis and collagen synthesis of KFs were markedly suppressed following treatment with Rg3. Furthermore, the results of an ex vivo assay indicated that Rg3 inhibited angiogenesis and reduced collagen accumulation in keloids. Significant statistical differences existed between the control and Rg3-treated groups (P<0.05). All of these experimental results suggested that Rg3 may serve as a reliable drug for the treatment of patients with keloids.

Expression of HIF-1α in keloids and its correlation with inflammatory responses and apoptosis

The aim of this study was to investigate the expression of hypoxia-inducible factor-1α (HIF-1α) in keloids and its correlation with inflammatory responses and apoptosis. The keloid specimens resected in our hospital from November 2015 to February 2017 were selected as the pathological group, and the normal skin tissues from our hospital during the same period were selected as the control group. The expression of HIF-1α, inflammatory response cytokines, and apoptotic molecules in the tissues of two groups were detected. The messenger RNA (mRNA) expression of HIF-1α in the keloids in the pathological group was significantly higher than that in the control group, and the mRNA expression of interleukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α in the pathological group was significantly higher than those in the control group. The mRNA expression of Bax in the pathological group was significantly higher than that in the control group. The mRNA expression of Bcl-2, livin, and hPEBP4 in the pathological group was significantly lower than that in the control group. Pearson test showed that there was a positive correlation between the mRNA expression of HIF-1α and inflammatory cytokines including IL-1β, IL-2, IL-6, and TNF-α. There were also a positive correlation between the mRNA expression of HIF-1α and Bax and a negative correlation between the mRNA expression of HIF-1α and Bcl-2, livin, and hPEBP4. In conclusion, HIF-1α was highly expressed in keloids and closely related to inflammatory response cytokines and apoptosis molecules. Increased expression of HIF-1α in keloids may be an important factor in inflammatory responses and increased apoptosis in skin tissues.

Macrophages in keloid are potent at promoting the differentiation and function of regulatory T cells

The mechanistic details of keloid formation are still not understood. Given that the immune system is engaged in skin lesion repair, we examined the CD14⁺ macrophages and CD3⁺ T cells in keloid tissues and in the normal skin. Compared to the normal skin, keloid tissues presented significantly elevated infiltration by CD14⁺ macrophages. Moreover, the transcription and protein expression of iNOS, IL-12, IL-10, and TGF-β were significantly higher in keloid macrophages than in normal skin macrophages, in which the expression of M2-associated genes were further elevated compared to M1-associated genes in keloid. We also observed that keloid tissues presented higher infiltration by CD3⁺ T cells, of which the majority was CD4⁺ T cells. Notably, the frequency of Foxp3⁺ regulatory T cells (Tregs) in keloid tissues was significantly higher compared to that in the peripheral blood. Furthermore, macrophages from keloid tissues possessed potent capacity to induce Foxp3 expression in circulating CD3⁺ T cells. Together, this study suggested that macrophages in keloid tissues presented high activation status and were polarized toward the M2 subtype; moreover, these macrophages could promote Treg differentiation by upregulating Foxp3 expression.

Adiponectin Is Involved in Connective Tissue Growth Factor-Induced Proliferation, Migration and Overproduction of the Extracellular Matrix in Keloid Fibroblasts

Adiponectin, an adipocyte-derived hormone, exerts pleiotropic biological effects on metabolism, inflammation, vascular homeostasis, apoptosis and immunity. Recently, adiponectin has been suggested to attenuate the progression of human dermal fibrosis. Connective tissue growth factor (CTGF) is induced in keloids and is thought to be participated in the formation of keloid fibrosis. However, the roles played by adiponectin in keloids remain unclear. In this study, we explored the effects of adiponectin on CTGF-induced cell proliferation, migration and the deposition of extracellular matrix (ECM) and their associated intracellular signalling pathways in keloid fibroblasts (KFs). We also explored possible mechanisms of keloid pathogenesis. Primary fibroblast cultures were established from foreskin biopsies and skin biopsies from patients with keloids. The expression of adiponectin and adiponectin receptors (adipoRs) was evaluated by reverse transcription-PCR (RT-PCR), quantitative real-time RT-PCR, immunofluorescence staining, and immunohistochemical analysis. Next, KFs and normal dermal fibroblasts (NFs) were treated with CTGF in the presence or absence of adiponectin. A cell counting kit-8 (CCK-8) and the Transwell assay were used to examine cell proliferation and migration. The level of the collagen I, fibronectin (FN) and α-smooth muscle actin (α-SMA) mRNAs and proteins were determined by quantitative real-time RT-PCR and western blotting. The effects of RNA interference (RNAi) targeting the adipoR genes were detected. Phosphorylation of adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase-protein kinase (PI3K-Akt) were examined by western blotting to further investigate the signalling pathways. Furthermore, inhibitors of signal transduction pathways were investigated. The expression levels of adiponectin and adipoRs were significantly decreased in keloids compared with those in normal skin tissue. Adiponectin suppressed the CTGF-induced KFs, but not NFs, proliferation, migration and ECM production. Moreover, adiponectin inhibited the phosphorylation of AMPK, p38 and extracellular-regulated kinase (ERK), but not that of Jun N-terminal kinase (JNK) or Akt, in CTGF-treated KFs. The activity of adiponectin-mediated signalling pathways was attenuated by small interfering RNAs (siRNAs) targeting adipoR1 (but not siRNAs targeting adipoR2, T-cadherin or calreticulin), AMPK (Compound C), p38 (SB203580) inhibitors, and mitogen-activated protein kinase kinase (MEK) inhibitor (PD98059). Based on our results, adiponectin suppresses CTGF-induced KFs proliferation, migration and ECM overproduction. One of the underlying mechanisms is the activation of the adipoR1, AMPK, p38, and ERK signalling pathways. Therefore, adiponectin may play an important role in the progression of keloids, suggesting a potential novel target for keloid treatment.

Keloid and Hypertrophic Scars Are the Result of Chronic Inflammation in the Reticular Dermis

Keloids and hypertrophic scars are caused by cutaneous injury and irritation, including trauma, insect bite, burn, surgery, vaccination, skin piercing, acne, folliculitis, chicken pox, and herpes zoster infection. Notably, superficial injuries that do not reach the reticular dermis never cause keloidal and hypertrophic scarring. This suggests that these pathological scars are due to injury to this skin layer and the subsequent aberrant wound healing therein. The latter is characterized by continuous and histologically localized inflammation. As a result, the reticular layer of keloids and hypertrophic scars contains inflammatory cells, increased numbers of fibroblasts, newly formed blood vessels, and collagen deposits. Moreover, proinflammatory factors, such as interleukin (IL)-1α, IL-1β, IL-6, and tumor necrosis factor-α are upregulated in keloid tissues, which suggests that, in patients with keloids, proinflammatory genes in the skin are sensitive to trauma. This may promote chronic inflammation, which in turn may cause the invasive growth of keloids. In addition, the upregulation of proinflammatory factors in pathological scars suggests that, rather than being skin tumors, keloids and hypertrophic scars are inflammatory disorders of skin, specifically inflammatory disorders of the reticular dermis. Various external and internal post-wounding stimuli may promote reticular inflammation. The nature of these stimuli most likely shapes the characteristics, quantity, and course of keloids and hypertrophic scars. Specifically, it is likely that the intensity, frequency, and duration of these stimuli determine how quickly the scars appear, the direction and speed of growth, and the intensity of symptoms. These proinflammatory stimuli include a variety of local, systemic, and genetic factors. These observations together suggest that the clinical differences between keloids and hypertrophic scars merely reflect differences in the intensity, frequency, and duration of the inflammation of the reticular dermis. At present, physicians cannot (or at least find it very difficult to) control systemic and genetic risk factors of keloids and hypertrophic scars. However, they can use a number of treatment modalities that all, interestingly, act by reducing inflammation. They include corticosteroid injection/tape/ointment, radiotherapy, cryotherapy, compression therapy, stabilization therapy, 5-fluorouracil (5-FU) therapy, and surgical methods that reduce skin tension.

Site-specific gene expression profiling as a novel strategy for unravelling keloid disease pathobiology

Keloid disease (KD) is a fibroproliferative cutaneous tumour characterised by heterogeneity, excess collagen deposition and aggressive local invasion. Lack of a validated animal model and resistance to a multitude of current therapies has resulted in unsatisfactory clinical outcomes of KD management. In order to address KD from a new perspective, we applied for the first time a site-specific in situ microdissection and gene expression profiling approach, through combined laser capture microdissection and transcriptomic array. The aim here was to analyse the utility of this approach compared with established methods of investigation, including whole tissue biopsy and monolayer cell culture techniques. This study was designed to approach KD from a hypothesis-free and compartment-specific angle, using state-of-the-art microdissection and gene expression profiling technology. We sought to characterise expression differences between specific keloid lesional sites and elucidate potential contributions of significantly dysregulated genes to mechanisms underlying keloid pathobiology, thus informing future explorative research into KD. Here, we highlight the advantages of our in situ microdissection strategy in generating expression data with improved sensitivity and accuracy over traditional methods. This methodological approach supports an active role for the epidermis in the pathogenesis of KD through identification of genes and upstream regulators implicated in epithelial-mesenchymal transition, inflammation and immune modulation. We describe dermal expression patterns crucial to collagen deposition that are associated with TGFβ-mediated signalling, which have not previously been examined in KD. Additionally, this study supports the previously proposed presence of a cancer-like stem cell population in KD and explores the possible contribution of gene dysregulation to the resistance of KD to conventional therapy. Through this innovative in situ microdissection gene profiling approach, we provide better-defined gene signatures of distinct KD regions, thereby addressing KD heterogeneity, facilitating differential diagnosis with other cutaneous fibroses via transcriptional fingerprinting, and highlighting key areas for future KD research.