A suprapubic refractory skin ulcer following keloid radiotherapy: from hyper-proliferation to hypo-proliferation.

Radiation-induced skin ulcer following cancer and/or tumour is well-documented in the literature. However, radiation-induced skin ulcer following the excision of keloid is yet to be reported. Here, we report the case of a 33-year-old female patient with a suprapubic skin ulcer of five months' duration following keloid treatment with electron beam therapy at recommended dosage. Various examinations, including a skin biopsy, metagenomic sequencing, magnetic resonance imaging and immunochemistry, indicated that the skin ulcer was induced by radiotherapy. While postoperative radiotherapy has been recommended immediately following keloid excision to reduce the risk of recurrence, the present case highlights the risk of skin refractory ulcer following keloid radiotherapy.

CD74+ fibroblasts proliferate upon mechanical stretching to promote angiogenesis in keloids.

The healing of human skin wounds is susceptible to perturbation caused by excessive mechanical stretching, resulting in enlarged scars, hypertrophic scars, or even keloids in predisposed individuals. Keloids are fibro-proliferative scar tissues that extend beyond the initial wound boundary, consisting of the actively progressing periphery and the quiescent center. The stretch-associated outgrowth and enhanced angiogenesis are two features of the periphery of keloids. However, which cell population is responsible for transducing the mechanical stimulation to the progression of keloids remains unclear. Herein, through integrative analysis of single-cell RNA sequencing of keloids, we identified CD74+ fibroblasts, a previously unappreciated subset of fibroblasts with pro-angiogenic and stretch-induced proliferative capacities, as a key player in stretch-induced progression of keloids. Immunostaining of keloid cryosections depicted a predominant distribution of CD74+ fibroblasts in the periphery, interacting with the vasculature. In vitro tube formation assays on purified CD74+ fibroblasts ascertained their pro-angiogenic function. BrdU assays revealed that these cells proliferate upon stretching, through PIEZO1-mediated calcium influx and the downstream ERK and AKT signaling. Collectively, our findings propose a model wherein CD74+ fibroblasts serve as pivotal drivers of stretch-induced keloid progression, fueled by their proliferative and pro-angiogenic activities. Targeting the attributes of CD74+ fibroblasts holds promise as a therapeutic strategy for the management of keloids.

Efficacy of photodynamic therapy combined with cross-punch technique for the treatment of keloid.

OBJECTIVE: Keloids are characterized by abnormal activation of fibroblasts and excessive collagen deposition. Keloids are notoriously difficult to treat effectively due to their high recurrence rate after therapy. Our study explored the use of the punch technique in conjunction with photodynamic therapy, a novel approach that may swiftly reduce keloid volume, promote collagen remodeling, mitigate inflammation and enhance the wound healing process. METHODS: In our study, we conducted a retrospective analysis of 47 keloid patients who were treated with cross-punch technique combined with photodynamic therapy (punch+PDT group), compared them with a control group of 42 patients who received cross-punch therapy alone (punch group). The visual Analog Scale (VAS) scoring system, the Dermatology Life Quality Index (DLQI) questionnaire and the subjective scoring of patients were implemented to assess the improvement rate at baseline (month 0) and 12-month follow-up (month 12). RESULTS: The results demonstrated significant enhancements in both VAS scores and DLQI scores on month 12 when compared with those on month 0. Notably, the subjective scoring indicated a marked difference, with 93.62 % of patients in the punch+PDT group and 59.52 % in the punch group reporting good or excellent improvement. CONCLUSION: Patients in the punch+PDT group had a significant improvement rate than those in the punch group.

Activatable Near-Infrared Fluorescence Probe for Hypochlorous Acid Detection in Early Diagnosis of Keloids.

Keloids represent pathologic conditions characterized by the presence of hyalinized collagen bundles and chronic inflammatory reactions. Recently, increased ROS production and disrupted apoptosis mechanisms in keloids have been reported, although the detailed mechanisms remain unclear. Herein, we developed a specific fluorescence probe, Pro-NBS, to investigate ClO- levels in keloids. The probe demonstrated high specificity for ClO- over other ROS and exhibited a strong linear detection relationship. Based on its performance, we focused on the TGF-ß pathway in the development of keloids. ROS upregulation was observed in keloid-derived fibroblasts. Using ClO- as an intrinsic overexpression marker, our probe effectively distinguished between normal fibroblasts and keloid-derived fibroblasts both in vitro and in vivo. Furthermore, Pro-NBS showed potential for monitoring the progression and evaluating the systematic therapy of abnormal scarring or keloids.

Decoding skin mysteries: Unveiling the link between microbiota and keloid scars through a Mendelian randomization study.

The cause of keloids remains unclear, but studies suggest a link between skin microbiota and keloid formation. However, the causal relationship has not been confirmed. This study utilized Genome-Wide Association Studies (GWAS) data from 2 population-based German cohorts, comprising a total of 1656 skin samples. To bolster the reliability of our results, we incorporated GWAS data from 3 keloid cohorts, encompassing 2555 patients and 870,556 controls (GWAS ID: keloid1, ebi-a-GCST90018874; keloid2, bbj-a-131; keloid3, ebi-a-GCST90018654). Subsequently, we employed bidirectional 2-sample Mendelian randomization (MR) analysis to probe the causal relationship between the variables. The primary method employed was the inverse-variance weighted (IVW) method, supported by heterogeneity analysis, horizontal pleiotropy testing, outlier detection, and "leave-one-out" sensitivity analysis. By synthesizing the results from 3 groups of MR analyses, we discovered a negative causal association between a.ASV063 [Finegoldia (unc.)] located on the volar forearm and keloid disease (IVW (keloid1) odds ratio (OR): 0.939, 95% confidence interval (CI): 0.886-0.994, P = .032; IVW (keloid2) OR: 0.897, 95% CI: 0.813-0.990, P = .031; IVW (keloid3) OR: 0.900, 95% CI: 0.825-0.981, P = .017). Similarly, a negative causal relationship may also exist between the genus: Bacteroides from the antecubital fossa and keloid disease (IVW (keloid1) OR: 0.928, 95% CI: 0.884-0.973, P = .002; IVW (keloid2) OR: 0.891, 95% CI: 0.820-0.968, P = .007; IVW (keloid3) OR: 0.918, 95% CI: 0.849-0.992, P = .030). Additionally, no reverse causation was found, with all analyses showing no signs of horizontal pleiotropy or heterogeneity. This study offers new insights for the prevention and treatment of keloids.

[Effects of low dose skin tissue derived peptides on the function and collagen expression of keloid fibroblasts].

This study aims to investigate the effects of the skin tissue derived peptides on proliferation, apoptosis, migration and collagen expressions in keloid fibroblasts. From January 2015 to January 2017, patients with hypertrophic scar who underwent surgical excision in department of plastic surgery of Nanjing maternal and child health hospital were included in this retrospective study. Four peptides were selected from the differential peptides between human hypertrophic scar and normal skin tissue. They were named as peptide deregulated in hypertrophic scar 2-5 (PDHPS2-5). Bioinformatics and functional analysis were performed. A low dose of 10 µmol/L of four peptides were respectively added to the culture medium of human primary keloid fibroblasts for 24 h. Cell counting kit-8 (CCK-8) were used to detect the changes in cell viability. Cell apoptosis was detected by flow cytometry. Cell migration ability was checked by Transwell chamber. The protein expressions of collagen COL1A2 (Collagen type I alpha 2) and the myofibroblast marker gene ACTA2 (Actin alpha 2) were analyzed by Western blot. The results showed that bioinformatics prediction analysis revealed that peptide PDHPS4 has the longest half-life and the highest thermal stability. Compared with the control group, low dose of four peptides had no significant effect on the survival rate and apoptosis of keloid fibroblasts tested by CCK-8 assay and flowcytometry. Transwell analysis showed that one peptides (PDHPS5) can significantly inhibit the cell migration ability (The optical density value in Control is 0.81±0.11, in PDHPS5 is 0.27±0.03, t=8.61, P=0.001). Western blot analysis showed that four peptides (PDHPS2, PDHPS3, PDHPS4, PDHPS5) can significantly inhibit the protein expressions of COL1A2 (The relative protein band intensity in Control is 1.02±0.02, in PDHPS2 is 0.21±0.04, in PDHPS3 is 0.26±0.03, in PDHPS4 is 0.53±0.04, in PDHPS5 is 0.73±0.04, t=31.38, 38.54, 18.88, 11.07 respectively, all P value are less than 0.01). Three peptides (PDHPS2, PDHPS3, PDHPS5) can significantly inhibit the protein expressions of ACTA2 (The relative protein band intensity in Control is 1.02±0.02, in PDHPS2 is 0.64±0.05, in PDHPS3 is 0.77±0.06, in PDHPS5 is 0.47±0.07, t=12.08, 6.38, 14.06 respectively, all P value are less than 0.01). In conclusion, the differentially expressed peptides in human hypertrophic scar tissue can affect the function of keloid fibroblasts and collagen expressions to varying degrees. Among them, two peptides (PDHPS2,PDHPS3) significantly inhibit the protein expressions of COL1A2 and ACTA2. The peptide PDHPS5 has high stability, significantly suppresses cell migration, and reduces the protein expressions of COL1A2 and ACTA2, which may provide a new strategy for scar prevention and treatment.

New challenges in scar therapy: the novel scar therapy strategies based on nanotechnology.

The pathological mechanism of pathological scar is highly complex, encompassing the abnormalities of diverse cytokines, signaling pathways and regulatory factors. To discover more preferable scar treatment options, a variety of distinct approaches have been utilized clinically. Nevertheless, these treatments possess certain side effects and are inclined to relapse. Presently, pathological scar treatment remains a clinical conundrum, and there is an urgent demand for treatment methods that are safe, less traumatic and have lower recurrence rates. New drug delivery systems, novel therapeutic drugs and therapy strategies can enable drugs to permeate the skin effectively, decrease side effects, enhance drug efficacy and even achieve pain-free self-administration. Currently, novel nanotechnologies such as nanomicroneedles, photodynamics mediated by novel photosensitizers, bioelectrical stimulation and 3D printed dressings have been developed for the effective treatment of pathological scars. Additionally, innovative nanoscale fillers, including nano-fat and engineered exosomes, can serve as novel therapeutic agents for the efficient treatment of pathological scars. The intervention of nanomaterials can enhance drug absorption, stabilize and safeguard the active ingredients of drugs, delay or control drug release and enhance bioavailability. This article reviews these new treatment strategies for scar to explore novel approaches for efficient and safe for keloid treatment.

[Box: see text].

Dermal fibroblasts retain site-specific transcriptomic identity in keloids.

BACKGROUND: Human skin displays extensive spatial heterogeneity and maintains distinct positional identity. However, the impact of disease processes on these site-specific differences remains poorly understood, especially in keloid, a skin disorder characterized by pronounced spatial heterogeneity. OBJECTIVE: This study aimed to assess whether the spatial heterogeneity and positional identity observed in different anatomic sites persist in keloids. METHODS: Transcriptome sequencing was conducted on 139 keloid dermal tissues and 19 keloid fibroblast samples spanning seven distinct anatomic sites to identify the spatial transcriptomic heterogeneity. In addition, single-cell RNA sequencing data were utilized to elucidate the contributions of various cell types to the maintenance of positional identity. RESULTS: Keloid dermal tissues from diverse sites were categorized into three anatomic groupings: trunk and extremity, ear, and mandible regions. Enrichment analysis of differentially expressed genes unveiled that keloids across distinct regions retained unique anatomically-related gene expression profiles, reminiscent of those observed in normal skin. Notably, regional disparities consistently prevailed and surpassed inter-donor variations. Single-cell RNA sequencing further revealed that mesenchymal cells, particularly fibroblasts, made major contributions to positional identity in keloids. Moreover, gene expression profiles in primary keloid fibroblasts demonstrated a remarkable persistence of positional identity, enduring even after prolonged in vitro propagation. CONCLUSION: Taken together, these findings imply that keloids remain positional identity and developmental imprinting characteristic of normal skin. Fibroblasts predominantly contribute to the spatial heterogeneity observed in keloids.

Adipose stem cell exosomes promote mitochondrial autophagy through the PI3K/AKT/mTOR pathway to alleviate keloids.

BACKGROUND: Fibrosis with unrelieved chronic inflammation is an important pathological change in keloids. Mitochondrial autophagy plays a crucial role in reducing inflammation and inhibiting fibrosis. Adipose stem cell-derived exosomes, a product of adipose stem cell paracrine secretion, have pharmacological effects, such as anti-inflammatory and antiapoptotic effects, and mediate autophagy. Therefore, this study aims to investigate the function and mechanism of adipose stem cell exosomes in the treatment of keloids. METHOD: We isolated adipose stem cell exosomes under normoxic and hypoxic condition to detect their effects on keloid fibroblast proliferation, migration, and collagen synthesis. Meanwhile, 740YPDGFR (PI3K/AKT activator) was applied to detect the changes in autophagic flow levels and mitochondrial morphology and function in keloid fibroblasts. We constructed a human keloid mouse model by transplanting human keloid tissues into six-week-old (20-22 g; female) BALB/c nude mice, meanwhile, we applied adipose stem cell exosomes to treat the mouse model and observed the retention and effect of ADSC exosomes in vivo. RESULTS: ADSC exosomes can inhibit the PI3K/AKT/mTOR signaling pathway. The exosomes of ADSCs decreased the inflammatory level of KFs, enhanced the interaction between P62 and LC3, and restored the mitochondrial membrane potential. In the human keloid mouse model, ADSC exosomes can exist stably, promote mitochondrial autophagy in keloid tissue, improve mitochondrial morphology, reduce inflammatory reaction and fibrosis. Meanwhile, At the same time, the exosomes derived from hypoxic adipose stem cells have played a more effective role in both in vitro and in vivo experiments. CONCLUSIONS: Adipose stem cell exosomes inhibited the PI3K/AKT/mTOR pathway, activated mitochondrial autophagy, and alleviated keloid scars.

Phosphodiesterase 4 is overexpressed in keloid epidermal scars and its inhibition reduces keratinocyte fibrotic alterations.

BACKGROUND: Epidermal remodeling and hypertrophy are hallmarks of skin fibrotic disorders, and keratinocyte to mesenchymal (EMT)-like transformations drive epidermis alteration in skin fibrosis such as keloids and hypertrophic scars (HTS). While phosphodiesterase 4 (PDE4) inhibitors have shown effectiveness in various fibrotic disorders, their role in skin fibrosis is not fully understood. This study aimed to explore the specific role of PDE4B in epidermal remodeling and hypertrophy seen in skin fibrosis. METHODS: In vitro experiments examined the effects of inhibiting PDE4A-D (with Roflumilast) or PDE4B (with siRNA) on TGFß1-induced EMT differentiation and dedifferentiation in human 3D epidermis. In vivo studies investigated the impact of PDE4 inhibition on HOCl-induced skin fibrosis and epidermal hypertrophy in mice, employing both preventive and therapeutic approaches. RESULTS: The study found increased levels of PDE4B (mRNA, protein) in keloids > HTS compared to healthy epidermis, as well as in TGFß-stimulated 3D epidermis. Keloids and HTS epidermis exhibited elevated levels of collagen Iα1, fibronectin, αSMA, N-cadherin, and NOX4 mRNA, along with decreased levels of E-cadherin and ZO-1, confirming an EMT process. Inhibition of both PDE4A-D and PDE4B prevented TGFß1-induced Smad3 and ERK1/2 phosphorylation and mesenchymal differentiation in vitro. PDE4A-D inhibition also promoted mesenchymal dedifferentiation and reduced TGFß1-induced ROS and keratinocyte senescence by rescuing PPM1A, a Smad3 phosphatase. In vivo, PDE4 inhibition mitigated HOCl-induced epidermal hypertrophy in mice in both preventive and therapeutic settings. CONCLUSIONS: Overall, the study supports the potential of PDE4 inhibitors, particularly PDE4B, in treating skin fibrosis, including keloids and HTS, shedding light on their functional role in this condition.

Giant corneal keloid following Descemet stripping automated endothelial keratoplasty for the treatment of corneal decompensation secondary to trauma.

PURPOSE: This report aims to present a case of corneal keloid caused by chronic corneal insult after trauma and Descemet stripping automated endothelial keratoplasty (DSAEK). CASE PRESENTATION: A 35-year-old male with a history of vision loss in the right eye was referred to our hospital. The patient underwent Ahmed Glaucoma Valve Implantation to alleviate elevated intraocular pressure after ocular trauma to the same eye. One year following the procedure, the eye developed endothelial failure, leading to the performance of Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) with repositioning of the shunt tube. Upon initial examination, a well-circumscribed elevated white opaque lesion involving the central corneal surface of the RE was observed. Based on the patient's clinical history, slit lamp examination, and UBM findings, the diagnosis of corneal keloid was established. Superficial keratectomy was performed. Histopathological analysis confirmed the diagnosis of corneal keloid. Following the procedure, BCVA improved slightly. However, 3 months later, the patient underwent a penetrating keratoplasty for visual rehabilitation. CONCLUSION: Corneal keloids should be considered following any form of ocular trauma, particularly in cases involving ocular surgery. Diagnosing corneal keloids can sometimes be challenging due to the variety of potential differentials; however, by carefully evaluating the patient's medical history and clinical presentation, we can effectively narrow down the differential diagnosis of corneal conditions.

The diagnostic value and associated molecular mechanism study for fibroblast-related mitochondrial genes on keloid.

PURPOSE: This study aims to reveal the mechanism of fibroblast-related mitochondrial genes on keloid formation and explore promising signature genes for keloid diagnosis. METHOD: The distribution of fibroblasts between the keloid sample and control sample based on three keloid datasets, followed by the differentially expressed genes (DEGs) investigation and associated enrichment analysis. Then, hub genes were explored based on DEGs, mitochondrial genes from an online database, as well as fibroblast-related genes that were revealed by WCGNA. Subsequently, signature genes were screened through machine learning, and their diagnostic value was validated by nomogram. Moreover, the targeted drugs and related transcriptional regulation of these genes were analyzed. Finally, the verification analysis was performed on signature genes using qPCR analysis. RESULT: A total of totally 329 DEGs were revealed based on three datasets, followed by enrichment analysis. WGCNA revealed a total of 258 fibroblast-related genes, which were primarily assembled in functions like muscle tissue development. By using machine learning, we screened four signature genes (ACSF2, ALDH1B1, OCIAD2, and SIRT4) based on eight hub genes (fibroblast-related mitochondrial genes). Nomogram and validation analyses confirmed the well-diagnostic performance of these four genes in keloid. Immune infiltration and drug correlation analyses showed that SIRT4 was significantly associated with immune cell type 2 T helper cells and molecular drug cyclosporin. All these findings provided new perspectives for the clinical diagnosis and therapy of keloid. CONCLUSION: The fibroblast-related mitochondrial genes including SIRT4, OCIAD2, ALDH1B1, and ACSF2 were novel signature genes for keloid diagnosis, offering novel targets and strategies for diagnosis and therapy of keloid.

KECORT Study: An International e-Delphi Study on the Treatment of KEloids Using Intralesional CORTicosteroids in Clinical Practice.

BACKGROUND: Intralesional corticosteroid administration (ICA) is a first-line keloid treatment. However, it faces significant variability in current clinical and scientific practice, which hinders comparability of treatment results. OBJECTIVES: The aim of the study was to reach consensus on different aspects of ICA using hypodermic needles in keloids among an international group of dermatologists and plastic surgeons specialized in keloid treatment to provide consensus-based clinical treatment recommendations for all physicians treating keloids. METHODS: The keloid expert panel of 12 dermatologists and 11 plastic surgeons rated 30 statements. Two online e-Delphi rounds were held, both with a response rate of 100%. Fifteen (65%) keloid experts participated in the final consensus meetings. Consensus was defined as ≥ 75% of the participants choosing agree or strongly agree on a 7-point Likert scale. RESULTS: Consensus was reached on treatment goals, indication for ICA, triamcinolone acetonide (TAC) 40 mg/mL as the preferred corticosteroid administered at a maximum of 80 mg per month and at intervals of 4 weeks, minimizing pain during ICA, the use of 1 mL syringes and 25 or 27 Gauge needles, blanching as endpoint of successful infiltration, caution of not injecting subcutaneously, and the option of making multiple passes in very firm keloids prior to infiltration. Consensus could not be reached on TAC dosing, methods of prior local anesthesia, and location of injection. CONCLUSIONS: This e-Delphi study provides important clinical treatment recommendations on essential aspects of ICA in keloids. By implementing these recommendations, uniformity of ICA in keloid treatment will increase and better treatment results may be achieved.

The role of IL-17 and Th17 cells in keloid pathogenesis.

Keloids are characterized histologically by excessive fibroblast proliferation and connective tissue deposition, and clinically by scar tissue extending beyond the original site of skin injury. These scars can cause pruritus, pain, physical disfigurement, anxiety, and depression. As a result, keloid patients often have a diminished quality of life with a disproportionate burden on ethnic minorities. Despite advances in understanding keloid pathology, there is no effective Food and Drug Administration (FDA)-approved pharmacotherapy. Recent studies have highlighted the possible pathologic role of T helper (Th)17 cells and interleukin (IL)-17 in keloid formation, as well as their implication in other inflammatory disorders. This systematic review characterizes the role of Th17 cells and IL-17 in keloid pathogenesis, highlighting this pathway as a potential therapeutic target. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search on PubMed, Embase, MEDLINE, and Web of Science databases on June 5, 2024. The search included terms related to Th17 cells, IL-17, and keloids. Thirteen studies met the inclusion criteria, comprising basic science and bioinformatic studies focusing on Th17 cells and IL-17. Key findings include increased Th17 cell infiltration and IL-17 expression in keloids, IL-17's role in amplifying the inflammatory and fibrotic response via the promotion of IL-6 expression, and IL-17's involvement in upregulating fibrotic markers via SDF-1 and HIF-1α pathways. IL-17 also activates the transforming growth factor beta (TGF-ß)/Smad pathway in keloid fibroblasts. Th17 cells and IL-17 significantly contribute to the inflammatory and fibrotic processes in keloid pathogenesis. Therefore, targeting the IL-17 pathway offers a potential new therapeutic target to improve keloid patients' outcomes. Future research could further elucidate the role of Th17 cells and IL-17 in keloid pathogenesis and assess the safety and efficacy of targeting this pathway in human studies.

Systematic review of dupilumab safety and efficacy for treatment of keloid scars.

Keloids, characterized by excessive scar formation following dermal inflammation, pose a therapeutic challenge due to high recurrence rates. Radiation therapy, contraindicated in children, can minimize recurrence post-surgical removal. Dupilumab, which inhibits the pro-fibrotic interleukin-4/interleukin-13 axis, may effectively manage keloids when intralesional corticosteroid injections are unsuccessful. It may also prevent recurrence post-surgery in pediatric patients. This systematic review assesses the efficacy and safety of dupilumab for the treatment of keloids. Through a systematic search adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we identified and analyzed outcomes from three case reports and three case series studies, totaling 15 patients. Results indicate variable responses to treatment, including significant improvements, no clinical change, and worsening of keloid symptoms. Additional research is needed to recommend using dupilumab to treat keloids (Grade D). Treatment response variability may be linked to differences in interleukin-4/interleukin-13 activity between active and inactive keloids. Additionally, the unintended promotion of T helper 17 cell differentiation by dupilumab may worsen keloids.

Zinc-Alpha-2-Glycoprotein Peptide Downregulates Type I and III Collagen Expression via Suppression of TGF-ß and p-Smad 2/3 Pathway in Keloid Fibroblasts and Rat Incisional Model.

BACKGROUND: Keloids and hypertrophic scars result from abnormal collagen accumulation and the inhibition of its degradation. Although the pathogenesis remains unclear, excessive accumulation of the extracellular matrix (ECM) is believed to be associated with the TGF-ß/SMAD pathway. Zinc-alpha-2-glycoprotein (ZAG) inhibits TGF-ß-mediated epithelial-to-mesenchymal transdifferentiation and impacts skin barrier functions. In this study, we investigated the potential of a small ZAG-derived peptide against hypertrophic scars and keloids. METHODS: The study examined cell proliferation and mRNA expression of collagen types I and III in human dermal fibroblast (HDF) cell lines and keloid-derived fibroblasts (KF) following ZAG peptide treatment. A rat incisional wound model was used to evaluate the effect of ZAG peptide in scar tissue. RESULTS: Significantly lower mRNA levels of collagen types I and III were observed in ZAG-treated fibroblasts, whereas matrix metalloproteinase (MMP)-1 and MMP-3 mRNA levels were significantly increased in HDFs and KFs. Furthermore, ZAG peptide significantly reduced protein expression of collagen type I and III, TGF-ß1, and p-Smad2/3 complex in KFs. Rat incisional scar models treated with ZAG peptide presented narrower scar areas and reduced immature collagen deposition, along with decreased expression of collagen type I, α-SMA, and p-Smad2/3. CONCLUSION: ZAG peptide effectively suppresses the TGF-ß and p-Smad2/3 pathway and inhibits excessive cell proliferation during scar formation, suggesting its potential therapeutic implications against keloids and hypertrophic scars.

Comprehensive Insights into Keloid Pathogenesis and Advanced Therapeutic Strategies.

Keloid scars, characterized by abnormal fibroproliferation and excessive extracellular matrix (ECM) production that extends beyond the original wound, often cause pruritus, pain, and hyperpigmentation, significantly impacting the quality of life. Keloid pathogenesis is multifactorial, involving genetic predisposition, immune response dysregulation, and aberrant wound-healing processes. Central molecular pathways such as TGF-ß/Smad and JAK/STAT are important in keloid formation by sustaining fibroblast activation and ECM deposition. Conventional treatments, including surgical excision, radiation, laser therapies, and intralesional injections, yield variable success but are limited by high recurrence rates and potential adverse effects. Emerging therapies targeting specific immune pathways, small molecule inhibitors, RNA interference, and mesenchymal stem cells show promise in disrupting the underlying mechanisms of keloid pathogenesis, potentially offering more effective and lasting treatment outcomes. Despite advancements, further research is essential to fully elucidate the precise mechanisms of keloid formation and to develop targeted therapies. Ongoing clinical trials and research efforts are vital for translating these scientific insights into practical treatments that can markedly enhance the quality of life for individuals affected by keloid scars.

Safety and efficacy of intralesional bleomycin for keloids and hypertrophic scars: A systematic review and meta-analysis.

BACKGROUND: Bleomycin, originally an antitumor drug, was explored as a pathological scar treatment in the mid-1990s. However, its efficacy and safety profile varies among individuals. AIMS: This study aimed to assess topical bleomycin's efficacy and safety in treating hypertrophic scars and keloids. METHODS: We reviewed randomized controlled trials (RCTs) and controlled clinical trials (CCTs) published in English, comparing intralesional bleomycin to placebos or common intralesional scar treatments. Primary outcomes included percentage change in scar improvement, pigmentation, recurrence, atrophy, pain, telangiectasia, ulceration, patient self-assessment, and observer assessment (>50%). RESULTS: Six trials met the criteria. Bleomycin significantly improved scar reduction compared to triamcinolone (p < 0.05). There was no significant difference in pigmentation (p = 0.05) and recurrence (p = 0.21) compared to other treatments. In terms of safety, bleomycin caused less skin atrophy (p < 0.01) and telangiectasia (p < 0.01) but more pain (p = 0.03) than other treatments. CONCLUSIONS: Bleomycin was more effective than TAC, 5-FU, or TAC combined with 5-FU for treating keloids and hypertrophic scars with lower skin atrophy and telangiectasia risks. However, it may cause more pain than 5-FU or TAC. Further comprehensive studies, including RCTs, are required for objective analysis.

Phosphodiesterase 4 is overexpressed in human keloids and its inhibition reduces fibroblast activation and skin fibrosis.

There is a pressing medical need for improved treatments in skin fibrosis including keloids and hypertrophic scars (HTS). This study aimed to characterize the role of phosphodiesterase 4 (PDE4), specifically PDE4B in fibrotic skin remodeling in vitro and in vivo. In vitro, effects of PDE4A-D (Roflumilast) or PDE4B (siRNA) inhibition on TGFß1-induced myofibroblast differentiation and dedifferentiation were studied in normal (NHDF) and keloid (KF) human dermal fibroblasts. In vivo, the role of PDE4 on HOCl-induced skin fibrosis in mice was addressed in preventive and therapeutic protocols. PDE4B (mRNA, protein) was increased in Keloid > HTS compared to healthy skin and in TGFß-stimulated NHDF and KF. In Keloid > HTS, collagen Iα1, αSMA, TGFß1 and NOX4 mRNA were all elevated compared to healthy skin confirming skin fibrosis. In vitro, inhibition of PDE4A-D and PDE4B similarly prevented TGFß1-induced Smad3 and ERK1/2 phosphorylation and myofibroblast differentiation, elevated NOX4 protein and proliferation in NHDF. PDE4A-D inhibition enabled myofibroblast dedifferentiation and curbed TGFß1-induced reactive oxygen species and fibroblast senescence. In KF PDE4A-D inhibition restrained TGFß1-induced Smad3 and ERK1/2 phosphorylation, myofibroblast differentiation and senescence. Mechanistically, PDE4A-D inhibition rescued from TGFß1-induced loss in PPM1A, a Smad3 phosphatase. In vivo, PDE4 inhibition mitigated HOCl-induced skin fibrosis in mice in preventive and therapeutic protocols. The current study provides novel evidence evolving rationale for PDE4 inhibitors in skin fibrosis (including keloids and HTS) and delivered evidence for a functional role of PDE4B in this fibrotic condition.