Keloid pathophysiology: fibroblast or inflammatory disorders?

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.

Blockade of Sialylation with Decrease in Polysialic Acid Levels Counteracts Transforming Growth Factor β1-Induced Skin Fibroblast-to-Myofibroblast Transition

Aberrant sialylation with overexpression of the homopolymeric glycan polysialic acid (polySia) was recently reported in fibroblasts from fibrotic skin lesions. Yet, whether such a rise in polySia levels or sialylation in general may be functionally implicated in profibrotic activation of fibroblasts and their transition to myofibroblasts remains unknown. Therefore, we herein explored whether inhibition of sialylation could interfere with the process of skin fibroblast-to-myofibroblast transition induced by the master profibrotic mediator transforming growth factor β1 (TGFβ1). Adult human skin fibroblasts were pretreated with the competitive pan-sialyltransferase inhibitor 3-Fax-peracetyl-Neu5Ac (3-Fax) before stimulation with recombinant human TGFβ1, and then analyzed for polySia expression, cell viability, proliferation, migratory ability, and acquisition of myofibroblast-like morphofunctional features. Skin fibroblast stimulation with TGFβ1 resulted in overexpression of polySia, which was effectively blunted by 3-Fax pre-administration. Pretreatment with 3-Fax efficiently lessened TGFβ1-induced skin fibroblast proliferation, migration, changes in cell morphology, and phenotypic and functional differentiation into myofibroblasts, as testified by a significant reduction in FAP, ACTA2, COL1A1, COL1A2, and FN1 gene expression, and α-smooth muscle actin, N-cadherin, COL1A1, and FN-EDA protein levels, as well as a reduced contractile capability. Moreover, skin fibroblasts pre-administered with 3-Fax displayed a significant decrease in Smad3-dependent canonical TGFβ1 signaling. Collectively, our in vitro findings demonstrate for the first time that aberrant sialylation with increased polySia levels has a functional role in skin fibroblast-to-myofibroblast transition and suggest that competitive sialyltransferase inhibition might offer new therapeutic opportunities against skin fibrosis.

A Comprehensive Review of Non-Surgical Treatments for Hypertrophic and Keloid Scars in Skin of Color

Hypertrophic and keloid scars are fibroproliferative growths resulting from aberrant wound healing. Individuals with Fitzpatrick skin types (FSTs) IV-VI are particularly predisposed to hypertrophic and keloid scarring, yet specific guidelines for these populations are still lacking within the literature. Therefore, this comprehensive review provides a list of various treatments and considerations for hypertrophic and keloid scarring in patients with skin of color. We constructed a comprehensive PubMed search term and performed quadruple-blinded screening on all resulting studies to achieve this objective. Our findings demonstrate 1) the lack of efficacious treatments for raised scars within this population and 2) the need to empirically investigate individualized and multimodal therapeutic options for those with skin of color.

Can Electrical Stimulation Prevent Recurrence of Keloid Scars: A Scoping Review

OBJECTIVE

Keloids represent a symptomatic, aberrant healing process that is difficult to treat with high recurrence rates spanning from 55-100% if treated via excision without adjuvant therapy. Electrical stimulation (ES) has demonstrated findings that suggest it could reduce the recurrence rate of keloids after resection. Therefore, the aim of this study is to conduct a scoping review to investigate ES as an adjuvant therapy for decreasing keloid recurrence after excision.

APPROACH

A scoping review was performed using PubMed and Web of Science databases. The search strategy encompassed terms linking keloids and various aspects of electrical stimulation.

RESULTS

Our search yielded 2229 articles. 115 articles were analyzed as full text. 1 article met inclusion criteria. Despite this, ES has demonstrated other evidence that suggests its utility. ES has been shown to counter keloidic features by reducing mast cell counts, shifting wound composition from M2 to M1 macrophages, promoting angiogenesis, and, controlling fibroblast orientation and location. An alternating current will orient fibroblasts perpendicular to the current without unintended migration.

INNOVATION

Our study indicates that, based on a compilation of clinical and preclinical in vitro data, the optimal scenario for ES in the role of keloid treatment is after excision with a biphasic pulsed application and square waveform.

CONCLUSIONS

ES could serve as a multifaceted, adjuvant treatment after keloid excision, steering the healing process away from keloid-associated characteristics. Its cost-effectiveness means it could be adopted globally, providing a strategy to mitigate the burden of keloids irrespective of other available treatments or economic conditions.

Development and validation of novel keloid-derived immortalized fibroblast cell lines

Keloids are a common connective tissue disorder with an ill-understood etiopathogenesis and no effective treatment. This is exacerbated because of the absence of an animal model. Patient-derived primary keloid cells are insufficient as they age through passaging and have a limited supply. Therefore, there is an unmet need for development of a cellular model that can consistently and faithfully represent keloid's pathognomic features. In view of this, we developed keloid-derived immortalized fibroblast (KDIF) cell lines from primary keloid fibroblasts (PKF) by transfecting the human telomerase reverse transcriptase (hTERT) gene. The TERT gene encodes the catalytic subunit of the telomerase enzyme, which is responsible for maintaining the cellular replicative potential (cellular immortalization). Primary fibroblasts from keloid-specific lesional (peripheral, middle, and top) as well as extralesional sites were isolated and evaluated for cell line development and comparative cellular characteristics by employing qRT-PCR and immunofluorescence staining. Moreover, the immortalized behavior of KDIF cell lines was evaluated by comparing with cutaneous fibrosarcoma and dermatofibrosarcoma protuberans cell lines. Stable KDIF cell lines with elevated expression of hTERT exhibited the cellular characteristics of site-specific keloid fibroblasts. Histochemical staining for β-galactosidase revealed a significantly lower number of β-gal-positive cells in all three KDIF cell lines compared with that in PKFs. The cell growth curve pattern was studied over 10 passages for all three KDIF cell lines and was compared with the control groups. The results showed that all three KDIF cell lines grew significantly faster and obtained a fast growing characteristic as compared to primary keloid and normal fibroblasts. Phenotypic behavior in growth potential is an indication of hTERT-mediated immortalized transformation. Cell migration analysis revealed that the top and middle KDIF cell lines exhibited similar migration trend as site-specific PKFs. Notably, peripheral KDIF cell line showed significantly enhanced cell migration in comparison to the primary peripheral fibroblasts. All KDIF cell lines expressed Collagen I protein as a keloid-associated fibrotic marker. Functional testing with triamcinolone inhibited cell migration in KDIF. ATCC short tandem repeat profiling validated the KDIF as keloid representative cell line. In summary, we provide the first novel KDIF cell lines. These cell lines overcome the limitations related to primary cell passaging and tissue supply due to immortalized features and present an accessible and consistent experimental model for keloid research.

Intralesional 5-Fluorouracil for Keloids: A Systematic Review

Keloids are benign, fibroproliferative dermal tumours, often arising after trauma, that are more common in darker skin types. Numerous therapeutic options have been employed for the treatment of keloids; however, there is no one gold standard approach. Five-fluorouracil, a potent chemotherapeutic agent, has emerged as a promising therapeutic option. Therefore, this systematic review, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, focused on providing a broad overview of the use of 5-fluorouracil for the management of keloids. Forty studies (2325 patients) met inclusion criteria and investigated 5-fluorouracil for keloid management, with 19 studies (1043 patients) including a 5-fluorouracil monotherapy group. Five-fluorouracil monotherapy demonstrated consistent keloid improvement with >254 keloids injected across various anatomical regions. Five-fluorouracil monotherapy was most often compared to intralesional triamcinolone acetonide, utilizing the Patient and Observer Scar Assessment Scale and the Vancouver Scar Scale. The most common keloid parameters assessed were height, size, volume, width, length, induration, pruritus, and erythema. Five-fluorouracil monotherapy exhibited substantial improvements, with weight averages of 73% of patients experiencing >25% improvement and 67% achieving >50% improvement. Relapse rate was 16% at 27 weeks after 5-fluorouracil monotherapy treatment. Limitations included potential selection bias, language restrictions, and heterogenous data analysis among studies. Overall, our findings underscore the potential effectiveness of 5-fluorouracil monotherapy in the management of keloids, with an encouraging safety profile. Larger prospective trials are needed to determine optimal therapy or combination therapy for the management of keloids. This detailed compilation of treatment protocols, outcomes, and relapse rates stand as a valuable resource for further research and clinical applications.

Profibrotic Inflammatory Cytokines and Growth Factors Are Predicted as the Key Targets of Uncaria gambir (Hunter) Roxb. in Keloids: An Epistatic and Molecular Simulation Approach

Keloid is characterized as the fibrotic tissue resulting from the increase of fibroblast activity. Uncaria gambir (Hunter) Roxb. possesses bioactive compounds that have potential as antifibrotic agents, while the mechanism of action in keloid has not yet been elucidated. The aim of this study was to investigate the interaction of gambir bioactive compounds with keloid target proteins using an epistatic and molecular simulation approach. The known bioactive compounds of gambir targets and keloid-related protein targets were screened using databases. The network was constructed and analyzed to obtain the core protein targets. The targets were enriched to describe the Gene Ontology (GO) and pathway related to the proteins. Eleven targets were defined as the main targets of gambir bioactive compounds related to keloid disease. Gambiriin C, Isogambirine, and Procyanidin B1 were identified as the most promising compounds with the highest binding energy to transforming growth factor beta 1 (TGFβ1), AKT serine/threonine kinase 1 (AKT1), and matrix metallopeptidase 1 (MMP1) as the target proteins. GO enrichment and pathway analysis found that gambir bioactive compounds may act on keloid-related target proteins to regulate cell proliferation, migration, transcription, and signal transduction activity via profibrotic cytokine and growth factor signaling pathways. This study provides a reference for potential targets, compounds, and pathways to explain the mechanism of gambir against keloid.

Angiotensin (1-7) Inhibits Transforming Growth Factor-Β1-Induced Epithelial-Mesenchymal Transition of Human Keratinocyte Hacat Cells in vitro

Introduction

Angiotensin (1-7) (Ang-(1-7)) is an emerging component of the renin-angiotensin system (RAS) with effective anti-fibrosis properties and has been shown to interfere with epithelial-mesenchymal transition (EMT) by numerous studies. In recent years, EMT has been proposed as a new therapeutic target for skin fibrotic diseases such as keloids. However, the effect of Ang-(1-7) on EMT in skin is still unclear. Hence, the purpose of this study was to explore the effect of Ang-(1-7) on Transforming growth factor-β1(TGF-β1)-induced EMT of human immortalized keratinocytes HaCaT in vitro.

Methods

The study involved the use of the human immortalized keratinocyte cell line (HaCaT). The cells were cultured in high-glucose DMEM medium with 10% fetal bovine serum and 1% penicillin-streptomycin. Four groups were created for experimentation: control group (Group C), TGF-β1-treated group (Group T), Ang-(1-7)-treated group (Group A), and a group treated with both TGF-β1 and Ang-(1-7) (Group A + T). Various assays were conducted, including a cell proliferation assay using CCK-8 solution, a scratch wound healing assay to evaluate cell migration, and Western blotting to detect protein expressions related to cell characteristics. Additionally, quantitative real-time polymerase chain reaction (PCR) was performed to analyze epithelial-mesenchymal transition (EMT) related gene expression levels. The study aimed to investigate the effects of TGF-β1 and Ang-(1-7) on HaCaT cells.

Results

We found that Ang-(1-7) not only reduced the migration of HaCaT cells induced by TGF-β1 in vitro but also reduced the expression of α-SMA and vimentin, and restored the protein expression of E-cadherin and claudin-1. Mechanistically, Ang-(1-7) inhibits the phosphorylation levels of Smad2 and Smad3 in the TGF-β1 canonical pathway, and suppresses the expression of EMT-related transcription factors (EMT-TFs) such as SNAI2, TWIST1, and ZEB1.

Discussion

Taken together, our findings suggest that Ang-(1-7) inhibits TGF-β1-induced EMT in HaCaT cells in vitro by disrupting the TGF-β1-Smad canonical signaling pathway. These results may be helpful in the treatment of EMT in skin fibrotic diseases such as keloids.

Management of Keloid-Associated Pruritus With Topical Crisaborole 2% Ointment: A Case Report

Introduction

The pathophysiology of keloid formation is poorly understood, and current treatments, including intralesional corticosteroids, cryotherapy, and surgery, are often associated with high resistance to treatment and recurrence. The multifactorial pathogenesis of keloid formation suggests that aberrant inflammatory cytokine signaling associated with keratinocyte dysregulation may contribute to keloid-associated pruritus.

Case Presentation

In this paper, we report 2 cases of keloid-associated pruritus that were successfully treated with topical crisaborole 2% ointment, a phosphodiesterase 4 (PDE4) inhibitor. Both patients had previously undergone multiple unsuccessful treatments before being treated with crisaborole 2% ointment. In both cases, the patients experienced complete relief of pruritus with no significant change in keloid size, thickness, or appearance.

Conclusion

We propose that PDE4 inhibitors, such as crisaborole, may be an effective therapy for keloid- associated pruritus.

Wound healing, scarring and management

Understanding wound healing is imperative for the dermatological physician to optimize surgical outcomes. Poor healing may result in negative functional, cosmetic and psychological sequelae. This review briefly outlines the physiology of wound healing, with a view to improving the management of wounds and scars, and minimizing the long-term scarring complications.

Demographics, clinical characteristics, and treatment patterns among keloid patients: United States Electronic Health Records (EHR) Database Study

INTRODUCTION

There is limited epidemiologic evidence on keloids using real-world data, especially in the United States (US) across race and ethnicity.

METHODS

We conducted a retrospective cohort study using Cerner Real-World Data, between 2015 and 2021, to describe the demographic and clinical characteristics of US adults with keloids. Keloids were identified using a combination of ICD-10 and (Systemized Nomenclature of Medicine-Clinical Terms [SNOMED] codes). Demographics (including race and ethnicity), clinical characteristics, treatment patterns, and healthcare utilization were compared across keloid and non-keloid populations.

RESULTS

Among 5,457 keloid patients identified in the study, the majority were female (61.8%) with a mean age of 34.2 years and of non-Hispanic Black, Hispanic, and Asian descent (P < 0.001). Relative to non-keloid cohorts, patients with keloids had significantly higher rates of integumentary, cardiorespiratory, general, auditory, and ocular surgeries and burns (all P < 0.05). Patients with keloids were also more likely to have comorbidities like obesity, hypertension, hyperlipidemia, and diabetes (P < 0.05) when compared to those with no keloids. A large proportion of keloids were untreated; among those treated, the most common keloid treatments were medication therapy (51.5%) and surgical excision (10.6%). Non-Hispanic Black and Hispanic keloid patients were significantly more likely to receive medication therapy and surgical excision (P < 0.001) compared to keloid patients of other races or ethnicities.

CONCLUSIONS

This study provided real-world insights into the keloid population in the US. Our findings emphasize the high burden of keloids and its substantial impact on ethnic minorities. Given high keloid recurrence rates and limited standardized treatments for keloids, further research into keloids is crucial to the development of keloid-specific therapeutic options.

Identification of a potential bioinformatics-based biomarker in keloids and its correlation with immune infiltration

Keloid formation is a pathological consequence resulting from cutaneous irritation and injury, primarily attributed to excessive collagen matrix deposition and fibrous tissue proliferation. Chronic inflammation, left uncontrolled over an extended period, also stands as a substantial contributing factor. The precise mechanisms underlying keloid formation remain unclear. Therefore, this study aimed to identify key genes for diagnostic purposes. To achieve this, we used two Gene Expression Omnibus (GEO) data sets to identify differentially expressed genes. We identified one particular gene, homeobox C9 (HOXC9), using a thorough strategy involving two algorithms (least absolute shrinkage and selection operator and support vector machine-recursive feature elimination) and weighted gene co-expression network analysis. We then assessed its expression in normal and keloid tissues. In addition, we explored its temporal expression patterns via Mfuzz time clustering analysis. In our comprehensive analysis, we observed that immune infiltration, as well as cell proliferation, are crucial to keloid formation. Thus, we investigated immune cell infiltration in the keloid and normal groups, as well as the correlation between HOXC9 and these immune cells. It was found that HOXC9 was closely associated with the immune microenvironment of keloids. This shows that HOXC9 can serve as a potential biomarker and therapeutic target for keloids.

Inhibition of ALA dehydratase activity in heme biosynthesis reduces cytoglobin expression which is related to the proliferation and viability of keloid fibroblasts

The aim of this study was to analyze the effect of heme synthesis inhibition on cytoglobin expression and its correlation with keloid fibroblast viability and proliferation. The study was conducted on primary culture of keloid fibroblasts. Heme synthesis in keloid fibroblasts was inhibited using succinyl acetone. We measured amino levulinic acid dehydratase (ALAD) enzyme activity using a colorimetric method; cytoglobin mRNA expression using qRT-PCR, cytoglobin protein expression using ELISA and immunocytochemistry, fibroblast viability using the MTT test; and fibroblast proliferation using BrdU test. The results showed that the ALAD enzyme activity level was lower in the keloid fibroblasts treated with succinyl-acetone (SA, 1, 2.5, and 5 mM) than in the control. The cytoglobin mRNA and protein expressions level were significantly lower in the keloid fibroblasts cultured with 2.5 mM and 5 mM SA than in the control and 1 mM SA. The viability and proliferation of the keloid fibroblasts decreased when the SA concentration was increased. In conclusion, the use of succinyl acetone at a concentration of 1; 2.5; and 5 mM caused decrease ALAD enzyme activity which indicated the inhibition of the heme synthesis. Inhibition of heme synthesis can affect cytoglobin expression, which correlates with the viability and proliferation of keloid fibroblasts.

Keloidal Collagen May Be Produced Directly by αSMA-positive Cells: Morphological Analysis and Protein Shotgun Analysis

Keloids are fibroproliferative lesions caused by abnormal dermal wound healing. Keloidal collagen (KC) is a pathognomic feature of keloids, but the mechanism by which it forms is unknown. This study aimed to evaluate the histopathology of KC and thereby gain clues into how it forms.

Methods

The cross-sectional study cohort consisted of a convenience series of patients with keloids who underwent surgical excision. Skin pieces (3 mm²) were collected from the keloid center and nearby control skin. Histopathology was conducted with light and electron microscopy and immunohistochemistry. KC composition was analyzed with protein shotgun analysis.

Results

Microscopic analyses revealed the ubiquitous close association between KC and αSMA-positive spindle-shaped cells that closely resembled myofibroblasts. Neither KC nor the spindle-shaped cells were observed in the control tissues. Compared with control skin, the collagen fibers in the KC were overall thinner, their diameter varied more, and their spacing was irregular. These features were particularly pronounced in the collagens in the vicinity of the spindle-shaped cells. Protein shotgun analysis did not reveal a specific collagen in KC but showed abnormally high abundance of collagens I, III, VI, XII, and XIV.

Conclusions

These findings suggest that KC may be produced directly by myofibroblasts rather than simply being denatured collagen fibers. Because collagens VI and XII associate with myofibroblast differentiation, and collagen XIV associates with local mechanical stress, these collagens may reflect, and perhaps contribute to, the keloid-specific local conditions that lead to the formation of KC.

Is Your Kid Actin Out? A Series of Six Patients With Inherited Actin-Related Protein 2/3 Complex Subunit 1B Deficiency and Review of the Literature

BACKGROUND

Hereditary actin-related protein 2/3 complex subunit 1B deficiency is characterized clinically by ear, skin, and lung infections, bleeding, eczema, food allergy, asthma, skin vasculitis, colitis, arthritis, short stature, and lymphadenopathy.

OBJECTIVE

We aimed to describe the clinical, laboratory, and genetic features of six patients from four Mexican families.

METHODS

We performed exome sequencing in patients of four families with suspected actinopathy, collected their data from medical records, and reviewed the literature for reports of other patients with actin-related protein 2/3 complex subunit 1B deficiency.

RESULTS

Six patients from four families were included. All had recurrent infections, mainly bacterial pneumonia, and cellulitis. A total of 67% had eczema whereas 50% had food allergies, failure to thrive, hepatomegaly, and bleeding. Eosinophilia was found in all; 84% had thrombocytopenia, 67% had abnormal-size platelets and anemia. Serum levels of IgG, IgA, and IgE were highly increased in most; IgM was normal or low. T cells were decreased in 67% of patients, whereas B and NK cells were increased in half of patients. Two of the four probands had compound heterozygous variants. One patient was successfully transplanted. We identified 28 other patients whose most prevalent features were eczema, recurrent infections, failure to thrive, bleeding, diarrhea, allergies, vasculitis, eosinophilia, platelet abnormalities, high IgE/IgA, low T cells, and high B cells.

CONCLUSION

Actin-related protein 2/3 complex subunit 1B deficiency has a variable and heterogeneous clinical spectrum, expanded by these cases to include keloid scars and Epstein-Barr virus chronic hepatitis. A novel deletion in exon 8 was shared by three unrelated families and might be the result of a founder effect.

Endothelial-mesenchymal transition as a novel mechanism for generating myofibroblasts during wound healing and scarring

BACKGROUND

The endothelial-mesenchymal transition (EndMT) is an important mechanism in tissue regeneration and the development of organ fibrosis. Whether EndMT occurs in wound healing and scarring remains unknown.

MATERIALS AND METHODS

The isolated cells from the normal dermal tissue and the wound tissue of mouse with full-thickness skin wound, and human scar tissue sections were performed with CD31/factorVII and α-SMA immunohistochemical staining and H and E staining. The ratio of factor VII or CD31/α-SMA double-positive cells in factor VII-positive cells was assessed in the isolated cells and in scar tissues.

RESULTS

In this study, we found that approximately 27-60% of ECs coexpressed VII factor and α-SMA in the isolated cells from the wound tissues of mice, which was significantly higher than that of normal dermal tissue cells. Accordingly, the number of CD31/α-SMA double-positive cells in mouse wound tissue sections was also significantly more than that in normal dermal tissue sections. In scar tissues, in addition to high-density microvessels, a large number of proliferative ECs in scar strama and CD31/α-SMA double-positive cells were also found. Approximately 46.82 to 84.11% of ECs and 68.77 to 95.25% of myofibroblasts coexpressed VII factor and α-SMA, and these two values in hypertrophic scars were significantly higher than those in keloids.

CONCLUSION

These results confirmed that ECs might contribute to the emergence of myofibroblasts in the wound and scar tissue via the process of EndMT.

Penile Keloid Successfully Cured in a Keloid High-Tendency Patient

Keloid scars are a relatively common condition but extremely rare in the penis. This case aims to be added to the previous 34 cases of penile keloid reported in the literature. We present the case of a 15-year-old patient with a high keloid-forming tendency who was successfully cured of penile keloid scarring with excision alone and without any adjuvant therapy. No recurrence was reported over eight years of follow-up. In contrast, at the same time, recurrence is frequently observed in other body parts after excision, making this particular part of the body an area of less keloid occurrence and recurrence.

Do Mesenchymal Stem Cells Influence Keloid Recurrence?

Introduction

Mesenchymal stem cells (MSCs) have been postulated by a number of authors to be the precursor cells of fibroblasts and myofibroblasts in keloids. They have been seen as a regenerative pool that ensures a steady supply of cells. The objective of our study was to determine MSCs in keloids and normal skin as a determinant of keloid recurrence.

Methods

This was a longitudinal prospective study in which patients with keloid excisions of their specimens analyzed for MSC. A control group of patients matched for age, sex, and body-mass index (BMI) with no history of keloids admitted for elective surgical procedures had their skin samples taken and also analyzed for MSCs. Data collected were analyzed and compared using Student's t, x ², and Fisher's exact t tests.

Results

A total of 61 patients with keloids and a control group of 32 patients were recruited. The male:female ratio was 1:2 and mean age 29.5 and 29.7 years for keloids and controls, respectively. Patients with recurrent keloids had a mean density of 841.4 MSCs/g compared to 578 MSCs/g of tissue for those with no recurrence and 580 MSCs/g for patients with normal skin. Recurrent keloids had a significantly higher percentage of MSCs than those without.

Conclusion

Keloids compared to normal skin had a higher percentage of MSCs, with recurrent keloids demonstrating an even higher count, a possible indicator that MSCs might correlate with severity of keloid disease and recurrence.

Lesion Site Is the Key Prognostic Factor for Keloid Patients Receiving Surgery With Adjuvant Radiotherapy

BACKGROUND

Keloid is a benign tumor with high recurrence rate; accordingly, complete surgical excision with adjuvant radiotherapy is one of the most effective treatments. This study reviewed outcomes of keloid patients receiving surgery and adjuvant radiotherapy in Kaohsiung Medical University Hospital.

MATERIALS AND METHODS

All patients received radiation dose with 15 Gy, with their first radiotherapy within 24 hours after surgical excision. The end points were recurrence rate and local recurrence-free interval (LRFI), defined clinically as palpable gross tumor over the treatment site and duration from the last day of radiotherapy to disease recurrence.

RESULTS

From May 2017 to July 2020, 32 patients with 40 keloid lesions were included. The mean age for these patients was 37.6 years, and the median follow-up time was 15.3 months. The overall recurrence rate was 52.5%, and the median LRFI was 9.7 months. Recurrence rates for males and females were 46.7% and 56% ( P = 0.567), respectively; for head and ear, chest, shoulder and upper extremities, and abdomen and back were 12.5%, 61.5%, 63.6%, and 62.5% ( P = 0.093); for lesions over 20 cm 2 and below 20 cm 2 were 62.5% and 50% ( P = 0.527); and for megavoltage electron beam and kilovoltage photon beam were 56.7% and 40% ( P = 0.361), respectively. Patients were further classified into 2 groups by lesion sites, which showed lower recurrence rate ( P = 0.011) and longer LRFI ( P = 0.028) with lesions over the head and ear than other sites.

CONCLUSIONS

We found that lesion site might be a prognostic factor for keloid recurrence. Adjuvant radiation dose escalation for high-recurrence risk areas (other than the head and ear) might be required.

Efficacy and safety of the innovative cold atmospheric-pressure plasma technology in the treatment of keloid: A randomized controlled trial

BACKGROUND

Keloid (KD) treatment is challenging for both physicians and patients. It can be functional debilitating and psychologically distressing. Available current therapeutics modalities give inconsistently effective results.

OBJECTIVES

To evaluate the efficacy and safety of innovative cold atmospheric plasma (CAP) technology in the treatment of keloid.

METHODS

This prospective, randomized control trial, the assessor-blinded trial, includes 18 patients with keloids. The keloid lesion was divided into two halves. One side was randomly treated with CAP technology biweekly on the same treated side for five sessions with a follow-up 30 days after finishing the final treatment. Another half was left untreated as a control. Efficacy assessment using POSAS, VSS, Patients' satisfaction scale, Antera 3D® skin imaging system. The safety assessment using VAS and adverse effects monitoring was completed.

RESULTS

Objective assessment using Antera 3D® skin imaging system (Miravex, Dublin, Ireland) showed statistically significant improvement (p-value <0.05) on the treated side compared with the untreated side in all parameters, color, melanin, hemoglobin, texture, except for volume. POSAS, patient, and observer overall opinion score, and patient and observer total score in the summary of all rated characteristics, comparing the treated and untreated areas, showed a statistically significant reduction in all parameters after two treatments (*p-value <0.05). VSS showed statistically significant improvement after the second treatment and continued to the last follow-up. Most patients rated satisfaction scales up to 72.2% as moderate improvement, 11.1% as great improvement, 11.1% as slight improvement, and 5.6% as no change. The adverse effect was only a small scab in one patient.

CONCLUSION

CAP technology could be considered an alternative treatment for keloid offering mild-to-moderate improvement with minimal side effects.

Mast Cells Are Activated in the Giant Earlobe Keloids: A Case Series

Mast cells and inflammatory cells are abundant in keloid and hypertrophic scar tissues. Even if the cause of physical injury is similar, such as piercing or scratching with hands, clinical findings show differences in the size of keloids in the same area. Hence, we performed histological studies on giant keloids larger than the earlobe, and other smaller keloids. We also examined the risk factors associated with the formation of giant lesions. No statistically significant differences in the association of the risk factors were observed. However, histological observations clearly showed a high number of degranulated or active mast cells with a trend towards a greater number of degranulated mast cells in the giant keloid tissues. Collagen production also tended to increase. Two patients with giant keloids were severely obese, suggesting that the persistent inflammatory state of obesity may also be involved in the growth of keloid lesions.

Decorin mediated biomimetic PCL-gelatin nano-framework to impede scarring

Scars occur as a result of fibrosis after tissue damage or surgery and reports suggest that excessive Transforming growth factor-β (TGF-β) activity during the process of wound healing leads to progressive fibrosis. Decorin is an extracellular matrix (ECM) protein which regulates collagen fibrillogenesis. However, targeted delivery and effective protein therapy remains a challenge owing to degradation byproteases. Hence, we aimed to deliver Decorin in a sustainable mode for the reduction of TGF-β levels and subsequent scar formation. Herein, we have fabricated PCL-Gelatin bio-mimetic scaffolds to optimize the bio-activity and provide localized delivery of recombinant Decorin. The degradation and drug release patterns reveals that this biomaterial is biodegradable and offers sustained release of the recombinant Decorin. Decorin loaded nanofiber displayed lower adhesion and proliferation rates in in-vitro conditions. Moreover, Decorin loaded scaffolds demonstrated morphological changes in cells, specifically targeting the myofibroblast. The expression of TGF-β was also scrutinized to understand the effect of Decorin loaded nanofibers. Besides, in the in-vitro fibrotic model, Decorin loaded nanofibers efficiently reduced the expression of ECM related proteins. Therefore, we report the sustained delivery of the recombinant Decorin from nanofiber dressing to potentially obstruct scar formation during the process of wound healing.

Effect of the combination of photobiomodulation therapy and the intralesional administration of corticoid in the preoperative and postoperative periods of keloid surgery: A randomized, controlled, double-blind trial protocol study

Keloid scars are characterized by the excessive proliferation of fibroblasts and an imbalance between the production and degradation of collagen, leading to its buildup in the dermis. There is no “gold standard” treatment for this condition, and the recurrence is frequent after surgical procedures removal. In vitro studies have demonstrated that photobiomodulation (PBM) using the blue wavelength reduces the proliferation speed and the number of fibroblasts as well as the expression of TGF-β. There are no protocols studied and established for the treatment of keloids with blue LED. Therefore, the purpose of this study is to determine the effects of the combination of PBM with blue light and the intralesional administration of the corticoid triamcinolone hexacetonide on the quality of the remaining scar by Vancouver Scar Scale in the postoperative period of keloid surgery. A randomized, controlled, double-blind, clinical trial will be conducted involving two groups: 1) Sham (n = 29): intralesional administration of corticoid (IAC) and sham PBM in the preoperative and postoperative periods of keloid removal surgery; and 2) active PBM combined with IAC (n = 29) in the preoperative and postoperative periods of keloid removal surgery. Transcutaneous PBM will be performed on the keloid region in the preoperative period and on the remaining scar in the postoperative period using blue LED (470 nm, 400 mW, 4J per point on 10 linear points). The patients will answer two questionnaires: one for the assessment of quality of life (Qualifibro-UNIFESP) and one for the assessment of satisfaction with the scar (PSAQ). The team of five plastic surgeons will answer the Vancouver Scar Scale (VSS). All questionnaires will be administered one, three, six, and twelve months postoperatively. The keloids will be molded in silicone prior to the onset of treatment and prior to excision to assess pre-treatment and post-treatment size. The same will be performed for the remaining scar at one, three, six, and twelve months postoperatively. The removed keloid will be submitted to histopathological analysis for the determination of the quantity of fibroblasts, the organization and distribution of collagen (picrosirius staining), and the genic expression of TGF-β (qPCR). All data will be submitted to statistical analysis.

Trial registration: This study is registered in ClinicalTrials.gov (ID: NCT04824612).

Dermal Fibroblast Heterogeneity and Its Contribution to the Skin Repair and Regeneration

Significance: Dermal fibroblasts are the major cell type in the skin's dermal layer. These cells originate from distinct locations of the embryo and reside in unique niches in the dermis. Different dermal fibroblasts exhibit distinct roles in skin development, homeostasis, and wound healing. Therefore, these cells are becoming attractive candidates for cell-based therapies in wound healing. Recent Advances: Human skin dermis comprises multiple fibroblast subtypes, including papillary, reticular, and hair follicle-associated fibroblasts, and myofibroblasts after wounding. Recent studies reveal that these cells play distinct roles in wound healing and contribute to diverse healing outcomes, including nonhealing chronic wound or excessive scar formation, such as hypertrophic scars (HTS) and keloids, with papillary fibroblasts having antiscarring and reticular fibroblast scar-forming properties. Critical Issues: The identities and functions of dermal fibroblast subpopulations in many respects remain unknown. In this review, we summarize the current understanding of dermal fibroblast heterogeneity, including their defined cell markers and dermal niches, dynamic changes, and contributions to skin wound healing, with the emphasis on scarless healing, healing with excessive scars (HTS and keloids), chronic wounds, and the potential application of this heterogeneity for developing cell-based therapies that allow wounds to heal faster with less scarring. Future Directions: Heterogeneous dermal fibroblast populations and their functions are poorly characterized. Refining and advancing our understanding of dermal fibroblast heterogeneity and their participation in skin homeostasis and wound healing may create potential therapeutic applications for nonhealing chronic wounds or wounds that heal with excessive scarring.

Activity of keloids evaluated by multimodal photoacoustic/ultrasonic imaging system

Multiple objective assessments have been used to assess the activity of keloids to compare different therapeutic regimens and facilitate the best individual treatment choice for patients, but none of them are standardized. A multimodal photoacoustic/ultrasonic (PA/US) imaging system, including photoacoustic imaging, elastography, ultra-micro-angiography, and conventional US technologies (gray scale US, color Doppler US, and power Doppler US), was applied to evaluate keloids by a radiologist. Growing stages were defined by patients, and Vancouver Scar Scale (VSS) was assessed by a plastic surgeon. A comprehensive model based on multimodal ultrasound parameters (poor-echo pattern, high vascular density, decreased elasticity, and low SO₂ within the keloid) and VSS might be a potential indicator of active keloids, comparing with VSS alone. The multimodal PA/US imaging system could be a promising technique for keloids assessment.

Targeted inhibition of YAP/TAZ alters the biological behaviours of keloid fibroblasts

Abnormal activation of fibroblasts plays a crucial role in keloid development. However, the mechanism of fibroblast activation remains to be determined. YAP/TAZ are key molecules in the Hippo signalling pathway that promote cell proliferation and inhibit apoptosis. Here, we show that keloid fibroblasts have higher levels of YAP/TAZ mRNA and proteins on primary culture. Targeted knockdown of endogenous YAP or TAZ significantly inhibited cell proliferation, reduced cell migration, induced cell apoptosis and down-regulated collagen1a1 production by keloid fibroblasts. Moreover, we demonstrate that verteporfin, an inhibitor of YAP/TAZ, has similar but stronger inhibitory effects on fibroblasts compared to YAP/TAZ knockdown. Our study provides evidence that YAP/TAZ may be involved in the pathogenesis of keloids. Targeted inhibition of YAP/TAZ could change the biological behaviours of fibroblasts and can potentially be used as therapy for keloids.

A Neglected Acne Scar Type: Papular Acne Scars and Their Correlations With Keloid Scars

BACKGROUND

Acne scarring can be divided into 2 types: atrophic and hypertrophic scars. Papular acne scars are commonly encountered, skin-colored papules on the chin and back.

OBJECTIVE

This study aimed to estimate the prevalence of each acne scar type and to investigate the clinical manifestations of papular acne scars.

METHODS

This retrospective study included 416 patients with acne scars. Dermatologists classified the scars into 3 types (atrophic, papular, and keloid type) based on clinical photographs and analyzed the clinical and histologic features of papular acne scars.

RESULTS

Among 416 patients with acne scars, 410 patients (98.56%) had atrophic scars, 53 patients (12.74%) had keloid scars, and 46 patients (11.06%) had papular acne scars. Twenty patients (4.81%) had both papular and keloid acne scars. Histologic analysis showed fibrotic tissue in both keloid and papular acne scars. Fibrosis of the papular scar was limited to the upper dermis.

CONCLUSION

Papular acne scars were significantly more prevalent in patients with keloid scars than in those without keloid scars. These results provide a basis for understanding papular acne scars, which have been under-recognized. The association between papular and keloid acne scars can suggest the decision for scar treatment.

Does Keloid Histology Influence Recurrence?

ABSTRACT

Keloids are fibroproliferative disorders characterized by high recurrence rates, with few factors known to influence the same. We conducted a study to determine whether keloid histology influences recurrence. This was a prospective longitudinal study to determine whether histopathological parameters of keloid influence recurrence. Patients with keloids managed by surgical excision were followed up at Kenyatta National Hospital between August 2018 and July 2020. The excised keloids were processed for histology using hematoxylin,/eosin, Masson, and trichrome stains. The slides were analyzed for inflammatory cells, fibroblasts, and capillary density using the hot spot technique and correlated to keloid recurrence. Postoperative follow-up was for a minimum of 1 year. A total of 90 patients with 104 keloids were recruited in the study. Overall keloid recurrence rate was 28.6%. There was a correlation between the absolute count of more than 50 per High power field of lymphocytes, fibroblasts, and macrophages with recurrence of the disease. The sensitivity and specificity for the above parameters were lymphocytes 48% and 81%, macrophages 57% and 83%, mast cells 32% and 33%, and fibroblasts 41% and 91%, respectively. There was no correlation between mast cells and vascularity status with recurrence. Routine histology should, therefore, be performed to determine these parameters. Close monitoring and second-line therapy should be considered for patients with elevated macrophages and/or lymphocytes so as to reduce the risk of recurrence.

Multi-Antigen Imaging Reveals Inflammatory DC, ADAM17 and Neprilysin as Effectors in Keloid Formation

Keloid is an aberrant scarring process of the skin, characterized by excessive extracellular matrix synthesis and deposition. The pathogenesis of this prevalent cutaneous disorder is not fully understood; however, a persistent inflammatory process is observed. To obtain more insight into this process, we analyzed lesional, perilesional and healthy tissue using multi-antigen-analysis (MAA) in conjunction with a data mining approach. Here, we demonstrate that monocyte-derived inflammatory dendritic cells (CD1a+, CD11c+, CD14+) and activated CD4+ T lymphocytes (CD45 RO+) dominated the immune infiltration in keloids while associating with fibroblasts. In perilesional tissue, precursor immune cells were dominant in the perivascular area, suggesting that they were attracted by an immune process, potentially in the lesional area. Supporting this hypothesis, only in keloid lesions, high levels of ADAM10/17 and Neprilysin (CD10) were observed in both fibroblasts and leukocytes. The spatial proximity of these two cell types, which could be confirmed by image analysis only in lesional tissue, could be a potential factor leading to the activation of fibroblasts. Our findings provide new insight into the pathogenesis of keloid formation and reveal metalloproteinases as a target for therapeutical intervention.

Myofibroblasts: Function, Formation, and Scope of Molecular Therapies for Skin Fibrosis

Myofibroblasts are contractile, α-smooth muscle actin-positive cells with multiple roles in pathophysiological processes. Myofibroblasts mediate wound contractions, but their persistent presence in tissues is central to driving fibrosis, making them attractive cell targets for the development of therapeutic treatments. However, due to shared cellular markers with several other phenotypes, the specific targeting of myofibroblasts has long presented a scientific and clinical challenge. In recent years, myofibroblasts have drawn much attention among scientific research communities from multiple disciplines and specialisations. As further research uncovers the characterisations of myofibroblast formation, function, and regulation, the realisation of novel interventional routes for myofibroblasts within pathologies has emerged. The research community is approaching the means to finally target these cells, to prevent fibrosis, accelerate scarless wound healing, and attenuate associated disease-processes in clinical settings. This comprehensive review article describes the myofibroblast cell phenotype, their origins, and their diverse physiological and pathological functionality. Special attention has been given to mechanisms and molecular pathways governing myofibroblast differentiation, and updates in molecular interventions.

Single-cell RNA-seq reveals lineage-specific regulatory changes of fibroblasts and vascular endothelial cells in keloids

Keloids are a benign dermal fibrotic disorder with features similar to malignant tumors. keloids remain a therapeutic challenge and lack medical therapies, which is partially due to the incomplete understanding of the pathogenesis mechanism. We performed single-cell RNA-seq of 28,064 cells from keloid skin tissue and adjacent relatively normal tissue. Unbiased clustering revealed substantial cellular heterogeneity of keloid tissue, which included 21 clusters assigned to 11 cell lineages. We observed significant expansion of fibroblast and vascular endothelial cell subpopulations in keloids, reflecting their strong association with keloid pathogenesis. Comparative analyses were performed to identify the dysregulated pathways, regulators and ligand-receptor interactions in keloid fibroblasts and vascular endothelial cells. Our results highlight the roles of transforming growth factor beta and Eph-ephrin signaling pathways in both the aberrant fibrogenesis and angiogenesis of keloids. Critical regulators probably involved in the fibrogenesis of keloid fibroblasts, such as TWIST1, FOXO3 and SMAD3, were identified. TWIST1 inhibitor harmine could significantly suppress the fibrogenesis of keloid fibroblasts. In addition, tumor-related pathways were activated in keloid fibroblasts and vascular endothelial cells, which may be responsible for the malignant features of keloids. Our study put insights into the pathogenesis of keloids and provides potential targets for medical therapies.

Multiple Cytokines Elevated in Patients with Keloids: Is It an Indication of Auto-Inflammatory Disease?

BACKGROUND

Inflammation seems to play a major role in the pathophysiology of keloids. However, the role of cytokines in keloid pathophysiology has not been fully evaluated with only a few cytokines studied. We undertook this study to compare various cytokines in patients with keloids and a control group of patients without keloids nor family history of keloids so as to determine which cytokines are elevated and could thus be critical in keloid formation.

METHODS

This was a cross-sectional study of patients with keloids and a control group of those without. Patients in both groups were matched for age, sex and body mass index. Their plasma was analyzed for both inflammatory and anti-inflammatory cytokines using the Bio-flex ElisaTM method. Comparisons of cytokines means in both groups were done using Student's t-test.

RESULTS

A total of 84 participants with 42 participants in each group were followed during the study. Male to female ratio was 1:2. Age ranges were similar with a mean of 29.6 years. A total of 28 cytokines were assayed. Statistically significant differences were noted in 15 of the 28 cytokines assayed with 11 being elevated more in keloid patients with only four in the non-keloid forming group. Among elevated cytokines in keloid patients were granulocyte colony-stimulating factors, granulocyte-monocyte-colony-stimulating factors, interleukins 4, 6 and 13.

CONCLUSION

Patients with keloids have significantly higher cytokines compared with non-keloid forming patients. This finding suggests that keloid formation could be influenced by multiple inflammatory cytokines, an indication that the patient's immune system could play a role in keloid formation akin to auto-inflammatory disease.

LINC01116 regulates proliferation, migration, and apoptosis of keloid fibroblasts by the TGF-β1/SMAD3 signaling via targeting miR-3141

BACKGROUND

Keloids are benign fibroproliferative skin tumors. Long non-coding RNAs (lncRNAs) have been implicated in the pathogenesis of keloid formation. In this paper, we explored the precise actions of LINC01116 in keloid formation.

METHODS

The targeted relationship between microRNA (miR)-3141 and LINC01116 or transforming growth factor β1 (TGF-β1) was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. The expression levels of LINC01116, miR-3141, TGF-β1, and SMAD family member 3 (SMAD3) were gauged by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Cell proliferation, migration, and apoptosis were assessed by the Cell Counting Kit-8 (CCK-8) assay, wound-healing assay, and flow cytometry, respectively. Animal studies were used to assess the role of LINC01116 in the subcutaneous keloid growth in vivo.

RESULTS

Our data showed that LINC01116 targeted miR-3141 by directly binding to miR-3141. LINC01116 was up-regulated and miR-3141 was down-regulated in human keloid tissues and fibroblasts. LINC01116 knockdown or miR-3141 overexpression suppressed keloid fibroblast proliferation, migration, and promoted cell apoptosis. Moreover, miR-3141 was a downstream mediator of LINC01116 function. MiR-3141 regulated the TGF-β1/SMAD3 signaling by directly targeting TGF-β1. Furthermore, TGF-β1 was identified as a direct and functional target of miR-3141. LINC01116 regulated the TGF-β1/SMAD3 signaling through miR-3141. Additionally, LINC01116 knockdown diminished the subcutaneous keloid growth in vivo.

CONCLUSION

Our findings demonstrated a novel mechanism, the miR-3141/TGF-β1/SMAD3 regulatory pathway, at least partially for the oncogenic role of LINC01116 in keloid formation.

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.

Bioinformatic Analysis of Key Genes and Pathways Related to Keloids

Background

The pathophysiology of keloids is complex, and the treatment for keloids is still an unmet medical need. Our study is aimed at identifying the hub genes among the differentially expressed genes (DEGs) between normal skin tissue and keloids and key pathways in the development of keloids.

Materials and Methods

We downloaded the GSE92566 and GSE90051 microarray data, which contain normal skin tissue and keloid gene expression data. GSE92566 was treated as a discovery dataset for summarizing the significantly DEGs, and GSE90051 served as a validation dataset. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway, Reactome enrichment analysis, gene set enrichment analysis, and gene set variation analysis were performed for the key functions and pathways enriched in DEGs. Moreover, we also validated the hub genes identified from the protein-protein interaction network and predicted miRNA-hub gene interactions.

Results

117 downregulated DEGs and 204 upregulated DEGs in GSE92566 were identified. Extracellular and collagen-related pathways were prominent in upregulated DEGs, while the keratinization-related pathway was associated with downregulated DEGs. The hub genes included COL5A1, COL5A2, and SERPINH1, which were also validated in GSE90051.

Conclusion

This study identified several hub genes and provided insights for the underlying pathways and miRNA-hub gene interactions for keloid development through bioinformatic analysis of two microarray datasets. Additionally, our results would support the development of future therapeutic strategies.

Strontium-90 brachytherapy following intralesional triamcinolone and 5-fluorouracil injections for keloid treatment: A randomized controlled trial

Background

Keloid disease is hard to fully eradicate. Recurrence and other unsatisfactory results were found in many patients. No current therapeutic modality has been determined to be most effective for treating keloid scars. Intralesional corticosteroid injections is most commonly recommended for primary management of small and young keloids as well as hypertrophic scars. However, it’s difficult for patients to adhere to long-term triamcinolone acetonide injection therapy because of the pain, inconvenience or complications including hormonal imbalance or irregular menstruation.

Objective

We aimed to determine whether and how Strontium-90 brachytherapy as an adjuvant radiation could affect keloid recurrence after intralesional triamcinolone and 5-fluorouracil injections.

Methods

We included keloid patients from March 2019 to September 2019 and randomly allocated them to two groups after 3 intralesional triamcinolone and 5-fluorouracil injections at 3 weeks interval. The experimental group received Strontium-90 brachytherapy at a total dose of 15-20Gy, while the control group didn’t receive any adjuvant treatment. We performed both Vancouver Scar Scale scoring and Color Doppler ultrasound examination to monitor and evaluate lesions regularly. A one-year follow-up was completed for each patient.

Results

31 patients who had 42 keloids in total were recruited. We found intralesional triamcinolone and 5-fluorouracil injections could effectively reduce the thickness and modify the hardness of small and young keloids. Strontium-90 brachytherapy reduced the one-year recurrence rate from 85.7 percent to 44.4 percent after 3 intralesional triamcinolone and 5-fluorouracil injections. The lesions’ thickness or elasticity was not affected by Strontium-90 brachytherapy.

Conclusion

Strontium-90 brachytherapy as an adjuvant radiation could effectively reduce small sized keloids recurrence after intralesional triamcinolone and 5-fluorouracil injections. It worked by enhancing the lesions’ stability post-injection.

Trial registration

The clinical trial registration number: ChiCTR2000030141.

Name of trial registry: Chinese Clinical Trial Registry (http://www.chictr.org.cn/)

Keloid disorder: Fibroblast differentiation and gene expression profile in fibrotic skin diseases

Keloid disorder, a group of fibroproliferative skin diseases, is characterized by unremitting accumulation of the extracellular matrix (ECM) of connective tissue, primarily collagen, to develop cutaneous tumors on the predilection sites of skin. There is a strong genetic predisposition for keloid formation, and individuals of African and Asian ancestry are particularly prone. The principal cell type responsible for ECM accumulation is the myofibroblast derived from quiescent resident skin fibroblasts either through trans-differentiation or from keloid progenitor stem cells with capacity for multi-lineage differentiation and self-renewal. The biosynthetic pathways leading to ECM accumulation are activated by several cytokines, but particularly by TGF-β signalling. The mechanical properties of the cellular microenvironment also play a critical role in the cell's response to TGF-β, as demonstrated by culturing of fibroblasts derived from keloids and control skin on substrata with different degrees of stiffness. These studies also demonstrated that culturing of fibroblasts on tissue culture plastic in vitro does not reflect their biosynthetic capacity in vivo. Collectively, our current understanding of the pathogenesis of keloids suggests a complex network of interacting cellular, molecular and mechanical factors, with distinct pathways leading to myofibroblast differentiation and activation. Keloids can serve as a model system of fibrotic diseases, a group of currently intractable disorders, and deciphering of the critical pathogenetic steps leading to ECM accumulation is expected to identify targets for pharmacologic intervention, not only for keloids but also for a number of other, both genetic and acquired, fibrotic diseases.

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.