Abnormal balance between proliferation and apoptotic cell death in fibroblasts derived from keloid lesions

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.

Selective therapy (cryo or scalpel) combined with multimodal therapy for treating keloids

Background

Keloids are less responsive to any single treatment modality; hence, there is a need for combination therapy that can yield satisfactory outcomes.

Objective

The present study assessed efficacy and safety of combination therapy-surgical excision or cryotherapy and intralesional corticosteroids along with 5-fluorouracil [IL (S + 5-FU)] injection, followed by silicone gel sheet (SGS) under compression therapy in the treatment of keloids.

Materials and Methods

This was a retrospective, observational study comprising 21 clinically diagnosed keloid patients. All patients were treated with the stated combination therapy. Data about demographic, lesions, procedural characteristics, and treatment outcomes were reported.

Results

Of 21, 11 (52.4%) patients were treated with liquid nitrogen (LN2) cryotherapy, and 10 (47.6%) patients were treated with surgical excision. Mean age was 30.8 ± 7.6 (range: 14-44) years with slight male (52.4%) predominance. A mean surface area of keloid lesion was 96.8 ± 170.5 cm3. The most frequently involved site was auricle (8 [38.1%] patients). Patients received the following types of treatments: intralesional LN2 cryotherapy (6 [28.6%]), intralesional excisional surgery (6 [28.6%]), surface LN2 cryotherapy (5 [23.8%]), and extralesional excisional surgery (4 [19.0%]). Complications of recurrence (2 [9.5%]), secondary infections (2 [9.5%]), persistent postinflammatory hypopigmentation (1 [4.8%]), and atrophic scarring with postinflammatory hyperpigmentation (1 [4.8%]) were reported. After a study period of 2.5 years, 100% cure rate was achieved.

Conclusion

Combination therapy of surgical excision or cryotherapy and IL (S + 5-FU), followed by SGS under compression, was safe and effective in treating keloids.

Parecoxib decreases cellular growth and Bcl-2 protein levels in primary cultures of keloid fibroblasts

Keloids seem to overexpress cyclo-oxygenase-2 (COX-2), suggesting a role in its deregulated pathway in inducing an altered epithelial-mesenchymal interaction, which may be responsible for the overgrowth of dermal components resulting in scars or keloid lesions. This study aimed to evaluate the effect of Parecoxib, a COX-2 inhibitor, on cell growth in fibroblast primary cultures obtained from human keloid tissues. Tissue explants were obtained from patients who underwent intralesional excision of untreated keloids; central fractions were isolated from keloid tissues and used for establishing distinct primary cultures. Appropriate aliquots of Parecoxib, a COX-2 inhibitor were diluted to obtain the concentration used in the experimental protocols in vitro (1, 10 or 100 μM). Treatment with Parecoxib (at all concentrations) caused a significant decrease in cellular growth from 24 hours onwards, and with a maximum at 72 hours (P < .02). Moreover, at 72 hours Parecoxib significantly reduced cellular vitality. Parecoxib treatment also induced an increase in fragmented nuclei with a maximum effect at 100 μM and a significant decrease in Bcl-2 and an increase in activated caspase-3 protein levels at 72 hours compared with control untreated cultures. Our findings suggest a potential use of the COX-2 inhibitor, Parecoxib, as the therapy for keloids.

Discovering and Validating Cuproptosis-Associated Marker Genes for Accurate Keloid Diagnosis Through Multiple Machine Learning Models

Background

Keloid is a common condition characterized by abnormal scarring of the skin, affecting a significant number of individuals worldwide.

Objective

The occurrence of keloids may be related to the reduction of cell death. Recently, a new cell death mode that relies on copper ions has been discovered. This study aimed to identify novel cuproptosis-related genes that are associated with keloid diagnosis.

Methods

We utilized several gene expression datasets, including GSE44270 and GSE145725 as the training group, and GSE7890, GSE92566, and GSE121618 as the testing group. We integrated machine learning models (SVM, RF, GLM, and XGB) to identify 10 cuproptosis-related genes (CRGs) for keloid diagnosis in the training group. The diagnostic capability of the identified CRGs was validated using independent datasets, RT-qPCR, Western blotting, and IHC analysis.

Results

Our study successfully categorized keloid samples into two clusters based on the expression of cuproptosis-related genes. Utilizing WGCNA analysis, we identified 110 candidate genes associated with cuproptosis. Subsequent functional enrichment analysis results revealed that these genes may play a regulatory role in cell growth within keloid tissue through the MAPK pathway. By integrating machine learning models, we identified CRGs that can be used for diagnosing keloid. The diagnostic efficacy of CRGs was confirmed using independent datasets, RT-qPCR, Western blotting, and IHC analysis. GSVA analysis indicated that high expression of CRGs influenced the gene set related to ECM receptor interaction.

Conclusion

This study identified 10 cuproptosis-related genes that provide insights into the molecular mechanisms underlying keloid development and may have implications for the development of targeted therapies.

Piezoelectric and Triboelectric Nanogenerators for Enhanced Wound Healing

Wound healing is a highly orchestrated biological process characterized by sequential phases involving inflammation, proliferation, and tissue remodeling, and the role of endogenous electrical signals in regulating these phases has been highlighted. Recently, external electrostimulation has been shown to enhance these processes by promoting cell migration, extracellular matrix formation, and growth factor release while suppressing pro-inflammatory signals and reducing the risk of infection. Among the innovative approaches, piezoelectric and triboelectric nanogenerators have emerged as the next generation of flexible and wireless electronics designed for energy harvesting and efficiently converting mechanical energy into electrical power. In this review, we discuss recent advances in the emerging field of nanogenerators for harnessing electrical stimulation to accelerate wound healing. We elucidate the fundamental mechanisms of wound healing and relevant bioelectric physiology, as well as the principles underlying each nanogenerator technology, and review their preclinical applications. In addition, we address the prominent challenges and outline the future prospects for this emerging era of electrical wound-healing devices.

Triple Therapy Protocol for Primary and Secondary Auricular Keloids: A Prospective Outcome Evaluation

BACKGROUND

Ear keloid lesions present a significant challenge to the aesthetic surgeon. Keloids are known to recur and can cause severe cosmetic, functional, and psychological impairments. Several adjuvants to surgical removal have been promoted, with varying recurrence rates.

OBJECTIVE

To evaluate the effectiveness of triple therapy to treat secondary (and large primary) auricular keloids.

MATERIALS AND METHODS

Patients with secondary or large primary auricular keloids undergoing triple therapy were prospectively studied. Keloids were excised intramarginally under magnification and repeated triamcinolone acetonide 40 mg/mL injections were administered, followed by the application of a custom-made acrylate pressure device. Recurrent keloid formation and adverse events were monitored during a minimum of 6 months of follow-up.

RESULTS

Sixteen auricular keloid lesions (3 large primary and 13 secondary) were subjected to the proposed technique with a mean follow-up of 28 months. All cases that adhered to the protocol were free of keloid after triple therapy. Side effects were limited to 1 case of lobular atrophy and slight hypopigmentation. All patients were satisfied with the results.

CONCLUSION

The triple therapy protocol is highly effective in primary and secondary auricular keloid as long as patients remain compliant.

Evidence of inter- and intra-keloid heterogeneity through analysis of dermal fibroblasts: A new insight in deciphering keloid physiopathology

Keloid scars are hypertrophic and proliferating pathological scars extending beyond the initial lesion and without tendency to regression. Usually, keloids are considered and treated as a single entity but clinical observations suggest heterogeneity in keloid morphologies with distinction of superficial/extensive and nodular entities. Within a keloid, heterogeneity could also be detected between superficial and deep dermis or centre and periphery. Focusing on fibroblasts as main actors of keloid formation, we aimed at evaluating intra- and inter-keloid fibroblast heterogeneity by analysing their gene expression and functional capacities (proliferation, migration, traction forces), in order to improve our understanding of keloid pathogenesis. Fibroblasts were obtained from centre, periphery, papillary and reticular dermis from extensive or nodular keloids and were compared to control fibroblasts from healthy skin. Transcriptional profiling of fibroblasts identified a total of 834 differentially expressed genes between nodular and extensive keloids. Quantification of ECM-associated gene expression by RT-qPCR brought evidence that central reticular fibroblasts of nodular keloids are the population which synthesize higher levels of mature collagens, TGFβ, HIF1α and αSMA as compared to control skin, suggesting that this central deep region is the nucleus of ECM production with a centrifuge extension in keloids. Although no significant variations were found for basal proliferation, migration of peripheral fibroblasts from extensive keloids was higher than that of central ones and from nodular cells. Moreover, these peripheral fibroblasts from extensive keloids exhibited higher traction forces than central cells, control fibroblasts and nodular ones. Altogether, studying fibroblast features demonstrate keloid heterogeneity, leading to a better understanding of keloid pathophysiology and treatment adaptation.

Multimodal Management of Facial Keloid with Tissue Expansion, Excision, and Injection of 5-FU and Triamcinolone

Keloids are benign, fibroproliferative dermal growths that occur in response to injury of the skin. These hypertrophic scars can cause pain and discomfort and have been associated with negative effects on social well-being, prompting physicians to seek effective treatment modalities with minimal risk of recurrence. Although surgical excision of the keloid initially removes the scar tissue, surgery alone triggers a fibroproliferative response similar to the initial insult, resulting in a high recurrence rate. Thus, a multimodal approach may be most appropriate when surgery is indicated to limit recurrence. We present the successful treatment of recalcitrant keloid formation of the face that was treated with tissue expansion, excision, and intralesional triamcinolone and 5-flurouracil injections.

Molecular Response of Keloids to Ionizing Radiation: Targeting FOXO1 Radiosensitizes Keloids

PURPOSE

Keloids are benign dermal tumors that arise from abnormal wound healing processes following skin lesions. Surgical excision followed by radiotherapy plays an important role in the treatment of keloids. Nevertheless, radioresistance remains a serious impediment to treatment efficacy. Investigation of the molecular response of keloids to radiation may contribute to radiosensitizing strategies.

MATERIALS AND METHODS

Primary keloid fibroblasts from human keloids were isolated and irradiated with X-ray. The expression profiles of messenger RNA (mRNA) in nonradiated and irradiated primary keloid fibroblasts were measured by mRNA sequencing analysis. Then, we identified common motifs and corresponding transcription factors of dysregulated mRNAs by using bioinformatic analysis of the proximal promoters. Whereafter, GO and KEGG were used to analyse the functional enrichment of the differentially expressed genes.

RESULTS

We found that radiation not only suppressed proliferation but also increased cell senescence of primary keloid fibroblasts. There were 184 mRNAs and 204 mRNAs that showed significant changes in 4 and 8 Gy irradiated primary keloid fibroblasts, respectively. Among them, 8 upregulated and 30 downregulated mRNAs showed consistent alterations in 4 and 8 Gy irradiated primary keloid fibroblasts. More importantly, the forkhead box O1 (FOXO1) signaling pathway was involved in the irradiation response. Pretreatment with the FOXO1 signaling inhibitor AS1842856 significantly promoted LDH release, apoptosis and senescence of primary keloid fibroblasts following irradiation.

CONCLUSION

Our findings illustrated the molecular changes in human keloid fibroblasts in response to radiation, and FOXO1 pathway inhibition is expected to provide a novel strategy for the radiosensitization of keloids.

Activation of the NFκB signaling pathway in IL6+CSF3+ vascular endothelial cells promotes the formation of keloids

Background: Keloid is a disease caused by abnormal proliferation of skin fibres, the causative mechanism of which remains unclear.

Method: In this study, endothelial cells of keloids were studied using scRNAseq combined with bulk-RNAseq data from keloids. The master regulators driving keloid development were identified by transcription factor enrichment analysis. The pattern of changes in vascular endothelial cells during keloid development was explored by inferring endothelial cell differentiation trajectories. Deconvolution of bulkRNAseq by CIBERSORTX verified the pattern of keloidogenesis. Immunohistochemistry for verification of the lesion process in keloid endothelial cells.

Results: The endothelial cells of keloids consist of four main cell populations (MMP1+ Endo0, FOS + JUN + Endo1, IL6+CSF3+Endo2, CXCL12 + Endo3). Endo3 is an endothelial progenitor cell, Endo1 is an endothelial cell in the resting state, Endo2 is an endothelial cell in the activated state and Endo0 is an endothelial cell in the terminally differentiated state. Activation of the NFΚB signaling pathway is a typical feature of Endo2 and represents the early skin state of keloids.

Conclusion: We have identified patterns of vascular endothelial cell lesions during keloidogenesis and development, and have found that activation of the NFΚB signaling pathway is an essential feature of keloid formation. These findings are expected to contribute to the understanding of the pathogenesis of keloids and to the development of new targeted therapeutic agents for the lesional characteristics of vascular endothelial cells.

A Signature of Genes Featuring FGF11 Revealed Aberrant Fibroblast Activation and Immune Infiltration Properties in Keloid Tissue

Keloid is a fibroproliferative disorder in the skin, which manifested with extensive deposition of collagen and extracellular matrix. Its etiology remains a mystery and its recurrence rate remains high despite combinative treatment regimens. Current hypotheses of its pathogenesis centered on the role of inflammatory processes as well as immune infiltration in the microenvironment. However, there are a lot of discrepancies when it comes to the verification of certain well-recognized pathways involved in the dysfunctional fibroblast. Further exploration and characterization are required to reveal the driving force and even leading genes responsible for keloid formation. In this study, we provided supportive evidence of the immunologic nature of keloids distinct from normal fibroblasts and physiological scars by incorporating multiple available expressional profiles in the Gene Expression Omnibus (GEO). Through differential analyses and functional analyses, we identified a set of genes that successfully captures the dissimilarities between keloid lesions and nonlesions. They were differentially regulated in keloid samples and had opposite behavior in exposure to hydrocortisone. A key signature of six genes featuring FGF11 not only was highly correlated with significantly dysregulated fibroblast activation but also reflected various levels of immune cell infiltration. FGF11, in particular, revealed the heterogenous immunologic nature of keloid lesions. This study further supported that aberrant fibroblast was one of the main contributing factors and shed some light on investigating immune properties in future studies.

The role of altered fatty acid in pathological scars and their dermal fibroblasts

PURPOSE

The proposed pathological mechanism for scar formation is controversial, and increased attention has been paid to the fatty acids (FAs) in the formation of pathological scars. Notably, FAs are known to be important in inflammation and mechanotransduction, which is closely related to scar formation. Therefore, it is necessary to clarify the roles of FA in scar formation.

METHODS

Hypertrophic scar and keloid formed for more than a year and without other treatment, as well as normal skin samples were obtained from patients who underwent plastic surgery. Finally, keloids (n = 10), hypertrophic scars (n = 10), and normal skin samples (n = 10) were collected under informed consent. Primary dermal fibroblasts were isolated and cultured. The amount and variety of FAs were detected by lipid chromatography-mass spectrometry. Immunohistochemistry, real-time PCR, and western blotting were used to verify the expression of sterol regulatory element-binding protein-1 (SREBP1) and fatty acid synthase (FASN) in the samples and their fibroblasts. Student's t-test, ANOVA, and orthogonal partial least square discriminant analysis were performed for statistical analysis (∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001).

RESULTS

Compared with full-thickness normal skin, there were 27 differential FAs in keloids and 15 differential FAs in hypertrophic scars (∗p < 0.05 and variable influence on projection >1.0). The expression of SREBP1 and FASN was lower in pathological scars both at mRNA and protein levels (all ∗p < 0.05). However, the mRNA levels of SREBP1 (∗∗∗p = 0.0002) and FASN (∗∗∗p = 0.0021) in keloid-derived fibroblasts were higher than that in normal skin fibroblasts (NFBs), while the expression in hypertrophic scar-derived fibroblasts was lower than that in NFBs (both ∗p < 0.05). Whereas there was no significant difference in FASN protein expression between keloid-derived fibroblasts and NFBs (p > 0.05).

CONCLUSION

FAs involved in pathological scars are abnormally changed in scar formation. Thus, fatty acid-derived inflammation and de novo synthesis pathway of FA may play a key role in the formation of pathological scars.

A Review of Hypertrophic Scar and Keloid Treatment and Prevention in the Pediatric Population: Where Are We Now?

Significance: This body of work gives a concise and comprehensive overview for the clinician and scientist on the latest treatment modalities for hypertrophic scars (HTS) and keloids in the pediatric population, as well as the most promising methods of prevention currently being investigated. This review will serve as a guide to the clinician for treatment selection and as an efficient tool for the scientist to achieve a comprehensive overview of the scientific literature to guide their future experiments aimed at pathologic scar prevention. Recent Advances: Current studies in the literature suggest carbon dioxide (CO₂) laser and E-light (bipolar radiofrequency, intense pulsed light, and cooling) are two of the most effective treatment modalities for HTS, while surgical excision+CO₂ laser+triamcinolone injection was one of the most successful treatments for keloids. In animal models, drug impregnated electrospun nanofiber dressings offer encouraging results for HTS prevention, while Kelulut honey showed promising results for keloid prevention. Critical Issues: Treatment outcome reproducibility is hindered by small cohorts of patients, inadequate-follow up, and variability in assessment tools. Prevention studies show multiple ways of achieving the same result, yet fall short of complete prevention. Furthermore, some studies that have purported full prevention have not been validated. Future Directions: To establish a standard of care, large clinical trials of the most successful modalities in small cohorts are needed. The key for prevention will be validation in animal models of the most successful methods, followed by translational and clinical studies.

The Efficacy of CT-Based Conformal Electron Beam Radiation Therapy After Keloid Excision

BACKGROUND

Adjuvant computed tomography-based conformal electron beam radiation therapy (RT) for patients with keloids enables radiation oncologists to customize the target volume with precision and deliver the maximal prescription dose while sparing normal surrounding tissues.

OBJECTIVE

To report treatment and cosmetic outcomes by the patient's self-assessment survey.

METHODS

Medical records of patients with keloids, who were treated with postoperative electron beam RT between January 2015 and December 2020, were reviewed. A total of 85 consecutive patients with 136 keloids were included in this study. Subjective cosmetic outcomes were scored by each patient using a 5-point Likert scale survey.

RESULTS

The median follow-up time was 29.0 months (range, 12.1-77.9 months), and local recurrence was observed in 10 lesions (7.4%). The recurrence rate of keloids occurring in the ear was 5.4%, whereas the recurrence rate of keloids occurring at other body sites was 11.4%. Among the patients who responded to the questionnaire about the cosmetic outcome, 70.2% of patients declared being either very satisfied (44.7%) or satisfied (25.5%).

CONCLUSION

Surgical excision, followed by CT-based conformal electron beam RT, for patients with keloids ensures a high degree of local control resulting in good cosmetic outcomes.

Construction of a HOXA11-AS-Interact Ed Network in Keloid Fibroblasts Using Integrated Bioinformatic Analysis and in Vitro Validation

Background: Expression of the long noncoding RNA (lncRNA) HOXA11-AS significantly increased in keloids by unclarified molecular regulation mechanisms.

Methods: Using successfully primary cultured keloid-derived fibroblasts from central region of chronic keloid tissues (sample 0), small interfering RNAs were designed and transfected into two keloid fibroblast samples (samples 1 and 2) to knockdown HOXA11-AS. One nonspecific transfection control (sample 3) and one blank control (sample 4) were used to remove nonspecific overlap from the studied group. The lncRNAs, messenger RNAs (mRNAs), and microRNAs (miRNAs) of five samples were sequenced to identify differentially expressed (DE) profiles in HOXA11-AS-knockdown keloid fibroblasts in samples 1 and 2 (by intersection), which facilitated removal of overlap with the nonspecific controls (samples 3 and 4, by union). Using stepwise bioinformatic analysis, a HOXA11-AS-interacted competing endogenous network (ceRNA) was screened based on three DE profiles.

Results: Keloid fibroblasts with or without HOXA11-AS as well as with or without nonspecific interferences were successfully constructed respectively. A total of 1,396 mRNAs and 39 lncRNAs were significantly changed in keloid fibroblast with HOXA11-AS knockdown. Simultaneously, 1,626 mRNAs and 99 lncRNAs were significantly changed in keloid fibroblast with nonspecific interference. With removal of nonspecific overlap, a lncRNA–mRNA interactive network characterized by close natural/intronic antisense relationship was initially constructed in keloid fibroblast with HOXA11-AS knockdown. Based on this network, a lncRNA–mRNA–protein interaction network was extended by integration of the human protein–protein interaction network. Significant functional genes were screened using PageRank algorithm in the extended network. Three genes, including SNED1, NIPAL3, and VTN, were validated by real-time PCR in HOXA11-AS-knockdown keloid fibroblasts. Only NIPAL3 was predicted to be a target gene for HOXA11-AS via three competing endogenous miRNAs (hsa-miRNA-19a-3p, hsa-miR-141-3p, and hsa-miR-140-5p).

Conclusion: An interactive network of HOXA11-AS–three miRNAs–NIPAL3 was predicted in keloid fibroblasts by integrative bioinformatic analysis and in vitro validation.

To Explore Ideas From the Altered Metabolites: The Metabolomics of Pathological Scar

BACKGROUND

Pathological scars are dermal fibroproliferative disorders due to rapid inflammatory response after dermal injury. The altered metabolites could reflect pathophysiological changes directly. However, it has not cleared how the metabolites change scars.

OBJECTIVE

To explore new ideas of pathological scars from the altered metabolites by using ultra-performance liquid chromatography coupled to tandem mass spectrometry and identifying the key genes.

METHODS

Keloid (KS, n = 10), hypertrophic scar (HS, n = 10), and normal skin (NS, n = 10) were collected. Ultra-performance liquid chromatography coupled to tandem mass spectrometry was used to identify and characterize metabolites. Differential metabolites were analyzed by orthogonal partial least square discriminant analysis and Student t test. The key pathways were analyzed via Kyoto Encyclopedia of Genes and Genomes, and the related enzymes were verified by real-time Polymerase Chain Reaction, both in tissues and their dermal fibroblasts.

RESULTS

Two hundred fourteen metabolites were detected in total, mostly were fatty acids and amino acids. In the KS and NS groups, 65 different metabolites were screened (P < 0.05), and the polyunsaturated fatty acids (PUFAs) metabolism and butyric acid in keloid should be concerned. The messenger Ribonucleic Acid expression of fatty acid desaturase 1 and fatty acid desaturase 2, which are the key enzyme of PUFA metabolism, were lower in KS and keloid-derived fibroblasts, P < 0.05. In HS group, 17 metabolites were significantly different and branched chain amino acids degradation was the key pathway. Moreover, branched chain keto acid dehydrogenase E1 subunit alpha was lower expressed in HS and their fibroblasts compared with NS, P < 0.05.

CONCLUSIONS

Polyunsaturated fatty acids and butyric acid may be associated with the generation of keloids. The pathogenesis of hypertrophic scars may be involved in branched chain amino acids degradation, which is worth paying attention to.

Lnc-H19 enhances anaerobic glycolysis of keloid fibroblasts by targeting the miR-214-5p/FGF2 axis

Long non-coding RNA (lncRNA) H19 has been demonstrated as vital regulator in tumors. However, whether lnc-H19 mediated the development of keloid fibroblasts (KD) was unknown, this study was aimed to clarify the role and molecular mechanisms of lnc-H19 in KD. We have investigated the expression levels of lnc-H19, miR-214-5p and fibroblast growth factor 2 (FGF2) in KD skin samples and normal skin tissues as well as matched cells by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The glycolysis ability of keloid fibroblasts was assessed by measuring glucose consumption, lactate production, and ATP level. The western blot assay was used to assay the expression levels of FGF2 and hexokinase 2 (HK2). Migration and invasion were analyzed by transwell in keloid fibroblasts. The bioinformatics database and dual-luciferase reporter assay were used to search and identify the target of miR-214-5p and lnc-H19. Lnc-H19 was overexpressed in KD tissues and keloid fibroblasts than normal skin tissues and normal fibroblasts, respectively. Small interfering RNA of lnc-H19 treatment markedly inhibited glycolysis, migration and invasion of keloid fibroblasts exposed to hypoxia, which was reserved by silencing of miR-214-5p or upregulation of FGF2. Mechanistically, lnc-H19 regulated KD development by regulation of miR-214-5p/FGF2 axis. In summary, lnc-H19 may exert regulatory functions in KD by targeting miR-214-5p/FGF2 axis, further regulated glycolysis, migration and invasion in keloid fibroblasts exposed to hypoxia, which might be a potential marker of KD diagnosis or progression.

Adjuvant Radiotherapy after Surgical Excision in Keloids

Keloids are a benign fibroproliferative disease with a high tendency of recurrence. Keloids cause functional impairment, disfigurement, pruritus, and low quality of life. Many therapeutic options have been used for keloids. However, the high recurrence rates have led to the use of adjuvant therapy after surgical keloid excision. There are different radiotherapy regimens available, and the advantages and disadvantages of each are still unclear. The aim of this review is to explain the appropriate radiotherapy regimen for keloids as well as discuss the recent reports on keloid management with radiotherapy. Adjuvant radiotherapy after surgical excision for keloids yields excellent local control with tolerable side effects. Hypofractionated radiotherapy with a BED of more than 28 Gy (α/β value of 10) after excision is recommended in the light of its biologic background.

Metformin Inhibits Transforming Growth Factor β-Induced Fibrogenic Response of Human Dermal Fibroblasts and Suppresses Fibrosis in Keloid Spheroids

ABSTRACT

Accumulation of excessive extracellular matrix (ECM) and aberrant transforming growth factor β (TGF-β) signaling pathway function can be potential therapeutic targets for keloid treatment. In this study, we examined the antifibrotic effect of metformin as a suppressor of TGF-β signaling pathways in human dermal fibroblasts (HDFs) and keloid spheroids. Human dermal fibroblasts were stimulated with TGF-β (10 ng/mL) and treated with metformin (10 mM). The mRNA and protein expression of ECM components were evaluated by quantitative polymerase chain reaction, western blot, and immunofluorescence assay. In addition, we immunohistochemically examined the expression levels of ECM proteins in keloid spheroids. After addition of metformin (10 mM), collagen types I and III and elastin mRNA levels were significantly decreased in HDFs, and collagen type I protein level was significantly decreased. In addition, the expression levels of collagen types I and III, fibronectin, and elastin were significantly reduced in keloid spheroids after treatment with metformin (100 mM). Collagen types I and III and p-Smad2/3 complex proteins were decreased in metformin-treated keloid spheroids. These findings indicated that metformin inhibits the expression of ECM components in TGF-β-stimulated HDFs and keloid spheroids. Therefore, we suggest the potential of metformin as an effective agent for the treatment of keloids.

A prospective comparative study of radiotherapy effect upon scar quality

INTRODUCTION

The effect of radiation on uncomplicated postoperative scars is unclear. This study aimed to analyze irradiated and non-irradiated scars in patients with unilateral breast cancer, who underwent oncoplastic breast reduction surgery and radiation therapy (RT), to identify how postoperative scar changes with radiation.

METHODS

Twenty breast scars in 10 patients were analyzed after unilateral breast-conserving surgery, oncoplastic breast reduction, and RT. Scars were assessed using the Vancouver scar scale (VSS) by two independent blinded observers and three-dimensional scar analysis camera. Paired t-test between irradiated and non-irradiated scars in each patient and correlation of scar score differences with potential contributing factors were analyzed.

RESULTS

The VSS was significantly lower for the irradiated scar than that for the non-irradiated contralateral scar (1.40 vs. 4.05, p = 0.001), although time interval from the last radiation to scar assessment had a negative correlation with paired differences of VSS (Spearman's correlation coefficient: -0.637, p = 0.048). Compared with the non-irradiated scar, the irradiated scar showed a significantly high level of hemoglobin (1.04 vs. 1.26, p = 0.017) and melanin (0.55 vs. 0.63, p = 0.03).

CONCLUSIONS

Postoperative scars with radiation showed better results in objective and subjective assessments than scars without radiation. These findings suggest that radiation has a positive effect on general scar maturation.

CD26 upregulates proliferation and invasion in keloid fibroblasts through an IGF-1-induced PI3K/AKT/mTOR pathway

Background

Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion. These pathological behaviours may be related to the heterogeneity of keloid fibroblasts (KFs); however, because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism. Our previous studies revealed that the expansion of CD26⁺ KFs was responsible for increased keloid proliferation and invasion capabilities; the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation. The aim of this study was to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities, and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.

Methods

Flow cytometry was performed to isolate CD26⁺/CD26⁻ fibroblasts from KFs and normal fibroblasts. To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor (IGF-1R), lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection. Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay. Scratching assay and transwell assay were used to assess cell migration and invasion abilities. To further quantify the regulatory role of CD26 expression in the relevant signalling pathway, RT-qPCR, western blot, ELISA, PI3K activity assay and immunofluorescence were used.

Results

Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs. Furthermore, the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion. The PI3K/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.

Conclusions

CD26 can be the effective biomarker for KFs, and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway. This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.

Treatment of keloids with a single dose of low-energy superficial X-ray radiation to prevent recurrence after surgical excision: An in vitro and in vivo study

BACKGROUND

Although keloids have been empirically treated with steroids and radiation, evidence-based radiation parameters for keloid therapy are lacking.

OBJECTIVE

To determine evidence-based radiation parameters for blocking keloid fibroblast proliferation in vitro and apply them to patients.

METHODS

The effects of various radiation parameters and steroids on cell proliferation, cell death, and collagen production in keloid explants and fibroblasts were evaluated with standard assays. Effective radiation parameters were then tested on patients.

RESULTS

No differences were observed between the effects of 50 and 320 kV radiation or between single and fractionated radiation doses on keloid fibroblasts. A 3 Gy, 50 kV dose inhibited keloid fibroblast proliferation in culture, whereas 9 Gy completely blocked their outgrowth from explants by inducing multiple cell death pathways and reducing collagen levels. Thirteen of 14 keloids treated with a single 8 Gy, 50 kV dose of radiation did not recur, although 4 patients with 6 keloids were lost to follow-up.

LIMITATIONS

Seventy-five percent of patients received steroids for pruritus, whereas approximately 25% of patients were lost to follow-up.

CONCLUSIONS

A single 8 Gy dose of superficial 50 kV radiation delivered an average of 34 days after keloid excision maybe sufficient to minimize recurrence, including in individuals resistant to steroids. Higher radiation energies, doses, or fractions may be unnecessary for keloid therapy.

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.

Combined surgical excision and electron external beam radiation improves the treatment of keloids: A descriptive study

Keloids are firm, fibrous nodules that form on an individual's skin and are associated with difficult symptoms as well as high recurrence rates. This study aims to improve the surgical techniques that reduce local tension after surgical excision of keloids as well as applying adjuvant radiotherapy to suppress scar formation. A total of 58 patients aged between 21 and 76 years received surgical incision of keloid and immediate postoperation low-dose radiotherapy. All patient follow-ups were performed at the out-patient department. Any sign of a keloid at the incision site was defined as treatment failure or keloid recurrence, regardless of the size. At a median follow-up of 22 months, the overall recurrence for all lesions was 8.6%, which is improved compared with previous study. In addition, all incisions performed during surgeries were healed and no signs of necrosis or the development of ulcers was observed. Our study suggests that this combined therapy provides excellent local control of keloids and shows promise for future therapy.

Keloid and Hypertrophic Scar Formation, Prevention, and Management: Standard Review of Abnormal Scarring in Orthopaedic Surgery

Keloid and hypertrophic scar formation after orthopaedic surgical closure is a complex issue. The nature and location of procedures maximize wound tension, leave foreign bodies, and diminish dermal supply, all potentiating keloid formation. There is little discussion regarding the pathophysiology and management of this recurrent problem in orthopaedic literature. Keloid formation is a fibroproliferative disorder resulting in extensive production of extracellular matrix and collagen, but prevention and treatment is poorly understood. Patient and surgical factors contributing to the development of this condition are discussed. The treatments include both medical and surgical therapies that work at a biologic level and attempt to produce a cosmetic and complication-free management strategy. Medical options that have been investigated include combinations of intralesional steroid therapy, laser therapy, and biologics. Preventive surgical closure and excision remain mainstays of treatment. Radiation therapy has also been used in refractory cases with mixed results. Despite medical therapies and surgical excision aimed at treating the resulting scar, recurrence rate is very high for all modalities that have been studied to this point. Future work is being done to better understand the pathophysiology leading to keloid and hypertrophic scar formation in an effort to find preventive methods as compared to treatment strategies.

Histopathology and immunohistochemical analysis of 5-fluorouracil and triamcinolone treated keloids in double-blinded randomized controlled trial

Keloids are a major complication related to surgical wound healing and very challenging condition to treat. Many treatment options are available, but the efficacy of the treatment is poor in most of cases and some keloids do not respond to the treatment at all. We compared the efficacy of intralesional 5-fluorouracil (5-FU) and triamcinolone (TAC) injections in a double-blind randomized controlled trial (RCT). Forty-three patients with 50 keloid scars were treated with either intralesional TAC or 5-FU-injections over 6 months. We wanted to find out whether biological features (cell density, cell proliferation rate, vascular density, myofibroblast numbers, steroid hormone receptor expression) in keloids could be used to predict the response to therapy and define the biological changes that take place in patients receiving a response. As there was no statistically significant difference in the remission rate between TAC and 5-FU treatments, all patients were combined and analyzed as responders and nonresponders. Although responders have slightly more myofibroblasts than the nonresponders in their keloids in the pretreatment biopsy samples, we could not identify a single predictive factor that could identify those patients that respond to drug injections. The good clinical response to therapy is associated with the simultaneous reduction of myofibroblasts in the keloid. This study demonstrates that myofibroblasts are reduced in number in those keloids that were responsive to therapy, and that both 5-FU and TAC injections are useful for keloid treatment.

lncRNA-H19/miR-29a axis affected the viability and apoptosis of keloid fibroblasts through acting upon COL1A1 signaling

This study was intended to clarify the potential of applying the long-chain noncoding RNA H19/miR-29a axis in keloid treatment by elucidating its correlation with the activity of fibroblasts. In this study, 80 keloid tissues, 63 normal fibrous tissues, and 91 normal skin tissues were collected in advance, and concurrently, fibroblasts separated from the tissues were cultured. Besides this, the si-H19, pcDNA3.1-H19, miR-29a mimic, and miR-29a inhibitor were transfected to keloid fibroblasts, whose proliferation, apoptosis, and metastasis were appraised by employing the colony formation assay, flow cytometry, and transwell assay. In addition, the luciferase reporter gene assay was carried out to determine whether targeted regulation was present between H19 and miR-29a, as well as between miR-29a and COL1A1. The study results demonstrated that keloid tissues and fibroblasts exhibited observably upregulated H19 expression and downregulated miR-29a expression, relative to normal skin tissues and fibroblasts (P < .05). Also observed was a negative correlation between H19 expression and miR-29a expression among the gathered keloid tissues (r_s  = -.267, P = .017). Furthermore, in vitro transfection of pcDNA3.1-H19 or miR-29a inhibitor could intensify viability, proliferation, migration, and invasion of the fibroblasts (P < .05), while silencing of H19 and overexpression of miR-29a hindered both metastasis and multiplication of the fibroblasts significantly (P < .05). In addition, H19 was capable of altering miR-29a expression within fibroblasts by directly sponging it, and overexpression of COL1A1 could deter the impact of miR-29a on viability, proliferation, migration, and invasion of fibroblasts (P < .05). In conclusion, H19 might facilitate proliferation and metastasis of fibroblasts by modifying downstream miR-29a and COL1A1, which was expected to allow for development of keloid-targeted treatments.

Expression profile and bioinformatics analyses of circular RNAs in keloid and normal dermal fibroblasts

Increasing evidence indicates that circular RNAs (circRNAs) play a crucial regulatory role in the pathogenesis of multiple diseases. However, no study has examined the potential biological function and expression profile of circRNAs in keloid dermal fibroblasts (KDFs). Therefore, the aim of this study to investigate the expression profile of circRNAs and analyze their role in KDFs. Bioinformatic analyses and high-throughput RNA sequencing technology were applied to explore the expression profile of circRNAs in 3 human KDFs and normal dermal fibroblasts (NDFs). The differentially expressed circRNAs were verified by reverse transcription PCR (RT-PCR), quantitative real-time-PCR (qRT-PCR) and Sanger sequencing. A circRNA-microRNA (miRNA)-mRNA interaction network was created using bioinformatics tools. Hsa_circ_0008259, was selected to confirm its function by qRT-PCR and Western blot. Collectively, 411 circRNAs, of which 206 were upregulated and 205 decreased, were found to be differentially expressed in KDFs and could bind to 2532 miRNA response elements (MREs). GO and KEGG pathways enrichment analyses showed that differentially expressed circRNAs were mainly involved in apoptosis, focal adhesion, PI3K-Akt and metabolic pathway, and may regulate the pathogenesis and development of keloid. Two candidate circRNAs (hsa_circRNA_0008259, hsa_circRNA_0005480) were verified to be significantly reduced in KDFs, and one candidate circRNA (hsa_circRNA_0002198) was significantly elevated in accordance with RNA-Seq data analysis. Overexpression of hsa_circRNA_0008259 inhibited type I and Ⅲ collagen expression. Taken together, our study demonstrates for the first time that circRNAs exhibits differential expression in KDFs, and may be key players in the pathogenesis of keloid, or act as biomarkers of keloid.

The effect of 5α-oleandrin on keloid fibroblast activities

Background

Keloids develop due to hyperactivity of keloid fibroblast (KF) in proliferation, migration, and collagen deposition along with low rates of collagen degradation. These are a result of the Wnt/β catenin signaling pathways under stimulation of TGF-β. 5α-oleandrin can suppress Wnt-targeted genes of osteosarcoma cells. We aimed to evaluate the anti-fibrotic effects of 5α-oleandrin on KF activities.

Methods

We collected the core of keloid materials from six patients who underwent keloid debulking surgery. Passage 4 of KF cells were then treated with mitomycin-C, 5α-oleandrin, and dilution medium as the negative control. To determine the effective dose of 5α-oleandrin, we diluted 5α-oleandrin into various concentrations. The incubation periods were 24 h, 48 h, and 72 h. The anti-proliferation and anti-fibrotic properties were measured using standard assay.

Results

Both the mitomycin-C and 5α-oleandrin treated groups indicated decrease in proliferation index (86.16 ± 4.20% and 73.76 ± 4.94%, respectively), collagen deposition index (90.26 ± 1.72% and 71.35 ± 4.26%, respectively), and migration capacity (33.51 ± 1.50% and 28.57 ± 1.58%, respectively). These were significant changes (p ≤ 0.05) compared to the non-treated group. Antifibrotic activities of 5α-oleandrin in cellular proliferation and collagen deposition were better than mitomycin-C.

Conclusions

The 5α-oleandrin has good antifibrotic effect in keloid fibroblast activities.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

In Vitro and Ex Vivo Models for Functional Testing of Therapeutic Anti-scarring Drug Targets in Keloids

Significance: Keloids are benign fibro-proliferative raised dermal lesions that spread beyond the original borders of the wound, continue to grow, rarely regress, and are the most common in pigmented individuals after an abnormal wound healing response. The current treatment failure and respective challenges involved highlighting the underlying issue that the etiopathogenesis of keloids is still not well understood. Disease models are required to better understand the disease pathogenesis. It is not possible to establish keloids in animals because of the uniqueness of this disease to human skin. To address this challenge, along these lines, non-animal reproducible models are vital in investigating molecular mechanisms of keloid pathogenesis and therapeutics development. Recent Advances: Various non-animal models have been developed to better understand the molecular mechanisms involved in keloid scarring and aid in identifying and evaluating the therapeutic potential of novel drug candidates. In this scenario, the current review aims at describing in vitro monocultures, co-cultures, organotypic cultures, and ex vivo whole skin keloid tissue organ culture models. Critical Issues and Future Directions: Current treatment options for keloids are far from securing a cure or preventing disease recurrence. Identifying universally accepted effective therapy for keloids has been hampered by the absence of appropriate disease model systems. Animal models do not accurately mimic the disease, thus non-animal model systems are pivotal in keloid research. The use of these models is essential not only for a better understanding of disease biology but also for identifying and evaluating novel drug targets.

Antifibrotic Effects of High-Mobility Group Box 1 Protein Inhibitor (Glycyrrhizin) on Keloid Fibroblasts and Keloid Spheroids through Reduction of Autophagy and Induction of Apoptosis

Overabundance of extracellular matrix resulting from hyperproliferation of keloid fibroblasts (KFs) and dysregulation of apoptosis represents the main pathophysiology underlying keloids. High-mobility group box 1 (HMGB1) plays important roles in the regulation of cellular death. Suppression of HMGB1 inhibits autophagy while increasing apoptosis. Suppression of HMGB1 with glycyrrhizin has therapeutic benefits in fibrotic diseases. In this study, we explored the possible involvement of autophagy and HMGB1 as a cell death regulator in keloid pathogenesis. We have highlighted the potential utility of glycyrrhizin as an antifibrotic agent via regulation of the aberrant balance between autophagy and apoptosis in keloids. Higher HMGB1 expression and enhanced autophagy were observed in keloids. The proliferation of KFs was decreased following glycyrrhizin treatment. While apoptosis was enhanced in keloids after glycyrrhizin treatment, autophagy was significantly reduced. The expressions of ERK1/2, Akt, and NF-κB, were enhanced in HMGB1-teated fibroblasts, but decreased following glycyrrhizin treatment. The expression of extracellular matrix (ECM) components was reduced in glycyrrhizin-treated keloids. TGF-β, Smad2/3, ERK1/2, and HMGB1 were decreased in glycyrrhizin-treated keloids. Treatment with the autophagy inhibitor 3-MA resulted in a decrease of autophagy markers and collagen in the TGF-β-treated fibroblasts. The results indicated that autophagy plays an important role in the pathogenesis of keloids. Because glycyrrhizin appears to reduce ECM and downregulate autophagy in keloids, its potential use for treatment of keloids is indicated.

Understanding Keloid Pathobiology From a Quasi-Neoplastic Perspective: Less of a Scar and More of a Chronic Inflammatory Disease With Cancer-Like Tendencies

Keloids are considered as benign fibroproliferative skin tumors growing beyond the site of the original dermal injury. Although traditionally viewed as a form of skin scarring, keloids display many cancer-like characteristics such as progressive uncontrolled growth, lack of spontaneous regression and extremely high rates of recurrence. Phenotypically, keloids are consistent with non-malignant dermal tumors that are due to the excessive overproduction of collagen which never metastasize. Within the remit of keloid pathobiology, there is increasing evidence for the various interplay of neoplastic-promoting and suppressing factors, which may explain its aggressive clinical behavior. Amongst the most compelling parallels between keloids and cancer are their shared cellular bioenergetics, epigenetic methylation profiles and epithelial-to-mesenchymal transition amongst other disease biological (genotypic and phenotypic) behaviors. This review explores the quasi-neoplastic or cancer-like properties of keloids and highlights areas for future study.

Expression Profiles of lncRNAs and circRNAs in Keloid

Supplemental Digital Content is available in the text.

Background:

We hypothesized that crosstalk between noncoding RNAs, including microRNA (miRNA), lncRNA, and circRNA, might play a critical role in keloids development and physiology. To reveal the molecular mechanisms involved in the pathogenesis of keloids, we compared their gene expression profiles and differential expressions in keloid and normal skin tissues.

Methods:

Expression profiles of mRNAs and lncRNAs and circRNAs in 2 pairs (identification set) of keloid and matched normal skin tissues were analyzed through sequencing. Real-time quantitative PCR was performed to validate the sequencing results using 5 pairs (validation set) of keloid and matched normal skin tissues. Presumed targets of differentially expressed lncRNAs and circRNAs were functionally annotated by bioinformatics approaches.

Results:

The differential expression of mRNAs in keloid and normal skin by high-throughput sequencing was 2,528, of which 1,271 were downregulated, whereas 1,257 were upregulated. In the meantime, sequencing identified 2,227 differentially expressed lncRNAs, including 1,224 upregulated and 1,003 downregulated in keloid tissue compared with normal skin tissue. Additionally, 154 differentially expressed circRNAs were identified, including 81 upregulated and 73 downregulated in keloid tissue compared with normal skin tissue. Functional annotations of differentially expressed circRNA targets revealed their enrichment in several signaling pathways important for scar wound healing.

Conclusions:

Expression profiles of mRNAs, lncRNAs, and circRNAs were altered in keloid tissue, which may partly contribute to the etiology of keloids by affecting several signaling pathways relevant to scar wound healing. A better understanding of keloids pathogenesis may identify new therapeutic targets for keloids.

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.

Retrospective study of immediate postoperative electron radiotherapy for therapy-resistant earlobe keloids

Keloid resection followed by adjuvant radiotherapy is the most efficacious treatment for keloids. However, for earlobe keloids, an optimal protocol for the total dose and fractions of adjuvant radiation has not yet been established. We retrospectively analyzed the efficacy and safety of immediate three-fraction electron radiotherapy after operation for resistant earlobe keloids. From 2011 to 2017, three-fraction electron radiotherapy with single dose of 5 Gy was given postoperatively to 23 patients with 30 keloids in our hospital. The first fraction of adjuvant radiotherapy was administered within 2 h of surgery, and the other two sessions were completed within the next day or two. Five (16.7%) primary keloids and 25 (83.3%) recurrent keloids were examined in this study. The primary endpoint was the local control rate, which was 86.7% after a median follow-up of 26 months (14–93 months). Secondary endpoints were acute and late procedure-related complications, and no severe complications were observed after combination therapy. Our results suggest that three-fraction electron radiotherapy after excision within 2 days of surgery is a safe and effective protocol for the prevention of earlobe keloid recurrence that can also improve patient compliance and comfort.

Intralesional excision as a surgical strategy to manage keloid scars: what's the evidence?

INTRODUCTION

Keloid scars are a particularly challenging clinical entity and a variety of management approaches have been described in the literature including intralesional surgery. The current literature lacks a summative review to ascertain the evidence base behind this surgical approach.

METHODS

A comprehensive English literature database search was performed using PubMed Medline, EMBASE and Web of Science from their individual dates of inception to March 2018. We present the different rationales proposed for the use of this technique, the clinical outcomes reported in the literature as well as the scientific basis for intralesional excision of keloid scars.

DISCUSSION

A number of arguments have been proposed to support intralesional excision including avoiding injury to neighbouring non-keloidal skin and the deep layer of the dermis, removal of the most proliferative fibroblastic group as well as debulking to facilitate the administration of injectable steroid. The most current literature does not provide sufficient support for the adoption of intralesional excisions based on data emerging from basic science as well as clinical outcome studies.

CONCLUSION

Emerging evidence supports the extralesional excision of keloid scars based on current mechanobiological, histological as well as clinical outcome data. Further trials comparing extralesional and intralesional surgical practices are eagerly awaited to ascertain the role of intralesional excisions in the keloid management arena.

Reconstructed human keloid models show heterogeneity within keloid scars

Keloid scars are often described as having an actively growing peripheral margin with a regressing centre. The aim of this study was to examine the possible heterogeneity within keloids and the involvement of different regions within and around keloid scars in the pathogenesis, using an in vitro keloid scar model. In vitro skin models were constructed from keratinocytes and fibroblasts from normal skin and different regions within and around keloid scars: periphery, centre, and (adjacent) surrounding-normal-skin regions. Additionally, fibroblasts were isolated from the superficial-central and deep-central regions of the keloid and combined with central keratinocytes. All keloid regions showed increased contraction compared to normal skin models, particularly in central regions. Myofibroblasts were present in all keloid regions but were more abundant in models containing central-deep keloid fibroblasts. Secretion of anti-fibrotic HGF and extracellular matrix collagen IV gene expression was reduced in the central deep keloid compared to normal skin. No significant differences between peripheral and central regions within keloids were observed for inflammatory cytokine CCL20, CCL27, CXCL8, IL-6 and IL-18 secretion. Parameters for surrounding-normal-skin showed similarities to both non-lesional normal skin and keloids. In conclusion, a simple but elegant method of culturing keloid-derived keratinocytes and fibroblasts in an organotypic 3D scar model was developed, for the dual purpose of studying the underlying pathology and ultimately testing new therapeutics. In this study, these tissue engineered scar models show that the central keloid region shows a more aggressive keloid scar phenotype than the periphery and that the surrounding-normal-skin also shares certain abnormalities characteristic for keloids.

MiR-21 regulates the apoptosis of keloid fibroblasts by caspase-8 and the mitochondria-mediated apoptotic signaling pathway via targeting FasL

MicroRNA-21 (miR-21) has been found to be upregulated in keloid tissue and to affect the proliferation and apoptosis of keloid fibroblasts; however, the possible mechanisms remain unclear. In this study, we aimed to evaluate the role of miR-21 in FasL-induced caspase-8 activation and the mitochondria-mediated apoptotic signaling pathway in keloid fibroblasts. Our study found that the protein level of FasL was decreased by miR-21 over-expression, while being enhanced by miR-21 inhibition in keloid fibroblasts. Subsequently, the mitochondria-mediated apoptosis of keloid fibroblasts was restrained by miR-21 over-expression, as evidenced by enhanced mitochondrial membrane potential and decreased production of mitochondrial ROS. Moreover, over-expression of miR-21 inhibited the activation of the caspase-8 and the mitochondria-mediated apoptotic signaling pathway. As expected, inhibition of miR-21 had the opposite effects. Finally, silencing of FasL suppressed miR-21 inhibition-induced apoptosis by inactivation of caspase-8 and the mitochondria-mediated apoptotic signaling pathway, which was comparable to Z-IETD-FMK, a caspase-8 inhibitor. Taken together, these results suggest that miR-21 regulates the apoptosis of keloid fibroblasts via targeting FasL, and caspase-8 and the mitochondria-mediated apoptotic signaling pathway is involved in this process. Our findings provide evidence that miR-21 may be considered to be a therapeutic target for keloids.

Complete excision of proliferating core in auricular keloids significantly reduces local recurrence: A prospective study

Keloids are mysterious soft‐tissue tumors that are characterized by excessive reparative processes composed of collagen‐forming fibroblasts and inflammatory cells. Generally, complete tumor excision regardless of sufficient margin is considered as a first‐line treatment because they are considered reactive rather than a neoplastic condition. Recently, a specific part of the keloids is being highlighted as an important microstructure for local recurrence, but there has been very little evidence. We conducted a prospective study to evaluate the relationship of recurrence and several clinicopathological parameters with specific focus on surgical resection margin. A total 87 cases of auricular keloids from 71 patients were included. The resection margins were carefully evaluated by an exhaustive grossing method and thorough microstructural assessment. During up to 48.8 months of the follow‐up period, local recurrence has been monitored and documented. The clinicopathological data including symptoms, bilaterality, size, location, prior treatment and operation history, gross type and etiology were collected and analyzed. Positive margin status was significantly related to tumor recurrence (P < 0.0001). Complete excision warrants a lower recurrence of auricular keloids in an Asian population. The most reasonable explanation for this seems to be remnant “proliferating core”, which may serve a key role in local recurrence.

Up-regulation of α1-adrenoceptors in burn and keloid scars

Stimulation of α₁-adrenoceptors evokes inflammatory cytokine production, boosts neurogenic inflammation and pain, and influences cellular migration and proliferation. Hence, these receptors may play a role both in normal and abnormal wound healing. To investigate this, the distribution of α₁-adrenoceptors in skin biopsies of burn scars (N=17), keloid scars (N=12) and unscarred skin (N=17) was assessed using immunohistochemistry. Staining intensity was greater on vascular smooth muscle in burn scars than in unscarred tissue, consistent with heightened expression of α₁-adrenoceptors. In addition, expression of α₁-adrenoceptors was greater on dermal nerve fibres, blood vessels and fibroblasts in keloid scars than in either burn scars or unscarred skin. These findings suggest that increased vascular expression of α₁-adrenoceptors could alter circulatory dynamics both in burn and keloid scars. In addition, the augmented expression of α₁-adrenoceptors in keloid tissue may contribute to processes that produce or maintain keloid scars, and might be a source of the uncomfortable sensations often associated with these scars.

Mortalin deficiency suppresses fibrosis and induces apoptosis in keloid spheroids

Mortalin (Mot) is a mitochondrial chaperone of the heat shock protein 70 family and it’s pro-proliferative and anti-apoptosis functions could be associated with keloid pathogenesis, and blocking of mortalin and its interaction with p53 might be a potential novel target for the treatment of keloid. Therefore, we generated mortalin-specific small hairpin (sh) RNAs (dE1-RGD/GFP/shMot) and introduced into keloid spheroids for examination of its apoptotic and anti-fibrotic effect. On keloid tissues, mortalin expression was higher than adjacent normal tissues and it’s protein expressions were activated keloid fibroblasts (KFs). After primary keloid spheroid were transduced with dE1-RGD/GFP/shMot for knockdown of mortalin, expression of type I, III collagen, fibronectin, and elastin was significantly reduced and transforming growth factor-β1, epidermal growth factor receptor (EGFR), Extracellular Signal-Regulated Kinases 1 and 2 (Erk 1/2), and Smad 2/3 complex protein expression were decreased. In addition, increased TUNEL activities and cytochrome C were observed. Further, for examine of mortalin and p53 interaction, we performed immunofluorescence analysis. Knockdown of mortalin relocated p53 to the cell nucleus in primary keloid spheroids by dE1-RGD/GFP/shMot transduction. These results support the utility of knockdown of mortalin to induce apoptosis and reduce ECMs expression in keloid spheroid, which may be highly beneficial in treating keloids.

Treating Scars in the Auricle Region

This article provides a review of the surgical and nonsurgical options available to manage a variety of auricular scars. The basics of wound healing are discussed in addition to the etiology of keloids and the cauliflower ear. Many auricular scars can be revised with scar excision techniques, but separate discussions for the treatment of keloids and the cauliflower ear are provided. The management plan for auricular scarring requires appropriate patient counseling regarding the risk of recurrence in keloids, regrowth of scar tissue in cauliflower ears, scar hypertrophy at the line of closure, widening of the scar, and persisting ear contour deformities.

Upregulation of microRNA-205 suppresses vascular endothelial growth factor expression-mediated PI3K/Akt signaling transduction in human keloid fibroblasts

Keloid is one of the most frustrating problems related to wounding healing and presents a great challenge in clinic. MicroRNAs (miRs) have shown their potential as a novel therapy for the prevention and treatment of keloid. Vascular endothelial growth factor (VEGF) plays a critical role in the regulation of scar development. In the current study, it was hypothesized that miR-205-5p was capable of suppressing keloid formation by inhibiting the VEGF-mediated wound healing cascade. The expression statuses of miR-205-5p and VEGF in clinical keloid tissues and keloid cell line human keloid fibroblasts (HKF) were detected. Then the direct action of miR-205-5p on VEGF gene was assessed using dual-luciferase assay. Thereafter, orchestrated administrations on HKF with miR-205-5p mimic, specific VEGF siRNA, PI3K agonist (740 Y-P), and PI3K inhibitor (LY294002) were performed to reveal the roles of miR-205-5p and VEGF in keloid formation and further explain the mechanism through which miR-205-5p affected the VEGF-mediated signaling transductions. Our results showed that there was significant low expression of miR-205-5p in keloid tissue specimens and the cell line while the expression of VEGF in keloid tissues was augmented. Moreover, miR-205-5p overexpression dramatically impaired the cell viability, induced the cell apoptosis, and inhibited the cell invasion and migration ability in HKF. Based on the detection of dual luciferase assay and detection at protein level, miR-205-5p antagonized the keloids by directly targeting VEGF expression and subsequently inhibiting PI3K/Akt pathway. The current study is the first one demonstrating that miR-205-5p inhibits the pathogenesis of keloids, indicating the potential of miR-205-5p in the development of therapies for prevention and treatment of keloids.

Brachytherapy in the adjuvant management of keloid scars: literature review

INTRODUCTION

Radiation therapy is a well-recognised modality for the adjuvant treatment of keloid scars. It can be conventionally delivered as external beam using a large apparatus at a distance from the lesion or as brachytherapy with specialised equipment to enable the delivery of treatment in the immediate vicinity of the keloidal tissue.

METHODS

An English literature review was performed with keywords 'brachytherapy' and 'keloid' using the databases PubMed, Embase and Web of Science from their individual dates of inception until June 2017. Studies pertinent to the field are presented in a chronological manner to depict the evolution of different brachytherapy strategies over the last decades. We also discuss considerations relating to the risk of secondary carcinogenesis, which are relevant to shared decision-making in the clinical setting.

DISCUSSION

Low dose rate interstitial brachytherapy was first introduced in the English literature in 1976 and currently appears to have been superseded by more modern approaches, including high dose rate interstitial brachytherapy. This modality compares favourably to more traditional modes of radiotherapy in terms of recurrence as well as rates of symptomatic relief from keloidal symptoms. Superficial brachytherapy was introduced more recently in the relevant literature and appears to be associated with favourable therapeutic outcomes compared to external beam radiation therapy.

CONCLUSION

Brachytherapy is a valid modality of radiotherapy for the adjuvant treatment of keloid scars, with high dose rate interstitial and surface regimens gaining in popularity over recent years. Further research needs to focus on randomised controlled trials to further establish the role of different radiotherapy modalities in keloid scar management.

Functional analysis of keratinocyte and fibroblast gene expression in skin and keloid scar tissue based on deviation analysis of dynamic capabilities

The aim of the present study was to select key genes that are associated with fibroblasts and keratinocytes during keloid scar progression and development. The gene expression profile of GSE44270, which includes 32 samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) in case samples compared with control samples were screened using the Limma R package followed by hierarchical clustering analysis. Protein-protein interaction (PPI) networks of the total selected DEGs were constructed using Cytoscape. Moreover, the Gene Ontology biological processes and significant Kyoto Encyclopedia of Genes and Genomes pathways of the total selected DEGs were enriched using the Database for Annotation, Visualization and Integrated Discovery. Significant pathways that may be associated with keloid scar were analyzed using deviation analysis of dynamic capabilities. There were 658 DEGs in fibroblast keloid vs. normal, 112 DEGs in fibroblast non-lesion vs. normal, 439 DEGs in fibroblast keloid vs. non-lesion, 523 DEGs in keratocyte keloid vs. normal, 186 DEGs in keratocyte non-lesion vs. normal, and 963 DEGs in keratocyte keloid vs. non-lesion groups. HOXA9, BMP4, CDKN1A and SMAD2 in fibroblasts, and HOXA7, MCM8, PSMA4 and PSMB2 in keratinocytes were key genes in the PPI networks. Moreover, the amino sugar and nucleotide sugar metabolism pathway, cell cycle, and extracellular matrix (ECM)-receptor interaction pathway were significant pathways. This study suggests that several key genes (BMP4, HOXA9, SMAD2, CDKN1A, HOXA7, PSMA4 and PSMB2) that participate in some significant pathways (cell cycle and ECM-receptor interaction pathways) may be potential therapeutic targets for keloid scars.

Tanshinone IIA Inhibits Proliferation and Induces Apoptosis Through the Downregulation of Survivin in Keloid Fibroblasts

Keloids are considered benign dermal fibroproliferative tumors. Keloid fibroblasts (KFs) persistently proliferate and fail to undergo apoptosis, and no treatment is completely effective against these lesions. Tanshinone IIA induces apoptosis and inhibits the proliferation of various tumor cell types. In this study, we investigated the effect of tanshinone IIA on the regulation of proliferation, cell cycle, and apoptosis in KFs, and investigated potential mechanisms involved in the effects. First, KFs and normal skin fibroblasts (NSFs) were treated with various concentrations of tanshinone IIA. Cell counting kit-8 (CCK-8) was used to assess the proliferative activity of KFs and NSFs, and flow cytometry was used to investigate the cell cycle and apoptosis in KFs. We found that the proliferation of all tanshinone IIA-treated KFs was significantly decreased after treatment for 72 hours (P < 0.001). Also, NSFs treated with tanshinone IIA did not exhibit noticeable effects compared with KFs. In addition, the percentages of G0/G1 cells in all tanshinone IIA-treated KFs were significantly increased after treatment for 72 hours (P < 0.001). And the percentages of cells undergoing early apoptosis in all tanshinone IIA-treated KFs were significantly increased after treatment for 120 hours (P < 0.001). Furthermore, the apoptosis antibody array kit and Western blot analysis revealed that tanshinone IIA decreased survivin expression in KFs (P < 0.001). In conclusion, tanshinone IIA downregulates survivin and deactivates KFs, thus suggesting that tanshinone IIA could serve as a potential clinical keloid treatment.