Blocking the MIR155HG/miR-155 axis reduces CTGF-induced inflammatory cytokine production and α-SMA expression via upregulating AZGP1 in hypertrophic scar fibroblasts

Hypertrophic scarring (HS) is a pathological condition characterized by excessive fibrosis and inflammation, resulting in excessive extracellular matrix formation in the skin. MIR155HG, a long non-coding RNA, is abnormally upregulated in fibrotic tissues; however, its underlying mechanism is poorly understood. Using single-cell sequencing data, we analyzed connective tissue growth factor (CTGF) expression in various cell types in HS and normal skin tissues and MIR155HG expression in clinical samples. To investigate the mechanism of fibrosis, an in vitro model using CTGF-treated hypertrophic scar fibroblasts (HSFBs) was established and qRT-PCR, western blotting and ELISA assays were performed to investigate the expression of interleukin (IL)-1β, IL-6, and mesenchymal markers α-smooth muscle actin (α-SMA). CTGF stimulates MIR155HG level through phosphorylated STAT3 binding to the MIR155HG promoter. We analyzed the methylation of MIR155HG, assessed the levels of miR-155-5p/-3p in CTGF-treated HSFBs and identified differentially expressed genes among HS and NS samples using the Gene Expression Omnibus RNA sequencing data. The binding between miR-155-5p/-3p and AZGP1 was confirmed using a dual-luciferase assay and inflammatory cytokine production and α-SMA expression were investigated in rescue experiments. The findings revealed that CTGF elevated inflammatory cytokine production, α-SMA and MIR155HG expression in HSFBs. MIR155HG is upregulated in HS tissues due to low DNA methylation. Mechanistically, miR-155-5p/-3p was directly bound to MIR155HG 3'UTR. MIR155HG silencing inhibited cytokine production and α-SMA expression by repressing the generation of miR-155-5p/-3p in CTGF-treated HSFBs. Bioinformatics analysis and luciferase reporter assays revealed that miR-155-5p/-3p targets AZGP1. In addition, transfection with plasmids carrying AZGP1 cDNA significantly inhibited the signaling activity of miR-155-5p/-3 p-overexpressing HSFBs. Our findings highlight the importance of the MIR155HG/miR-155/AZGP1 axis in regulating cytokine production and α-SMA in HS.

Update on Hypertrophic Scar Management in Burn Patients

Hypertrophic scars arise from burn injuries because of persistent inflammation in the reticular dermis. Several risk factors promote this chronic inflammation. One is tension on the burn wound/scar due to surrounding skin tightness and bodily movements. High estrogen levels and hypertension are also important systemic risk factors. Thus, to prevent burn wounds from developing into hypertrophic scars, it is important to focus on quickly resolving the reticular dermal inflammation. If conservative treatments are not effective and the hypertrophic scar transitions to scar contracture, surgical methods such as Z-plasty, full-thickness skin grafting, and local flaps are often used.

Management of the Sequelae of Skin Grafting: Pruritis, Folliculitis, Pigmentation Changes, and More

Scars commonly give rise to unpredictable, potentially irritating, cutaneous complications including pruritis, folliculitis, and pigment changes. These problems can be self-limiting and are prevalent in many burn cases, although their expression varies among individuals. A better understanding of the presentation, risk factors, and pathophysiology of these long-term sequelae allows for more comprehensive care of burn survivors.

Minimally invasive surgical approach to model hypertrophic scarring in the rabbit ear

BACKGROUND

Current strategies for hypertrophic scar prevention and treatment are limited.

OBJECTIVE

To facilitate these efforts, a minimally invasive hypertrophic scar model was created in a rabbit ear for the first time based on previous methods used to induce ischemia.

METHODS

Six New Zealand white rabbits (12 ears total) were studied. First, ischemia was achieved by ligating the cranial artery, cranial vein and central artery, while preserving the caudal artery, caudal vein and central vein, respectively. The relative level of ischemia induced at time of surgery, both baseline and maximum perfusion, was assessed with a fluorescent light-assisted angiography and demonstrated lower rates of perfusion in the ischemic ears. Following vascular injury, a 2-cm full thickness linear wound was created on the ventral ear and closed with 4 - 0 Nylon sutures under high tension. For each rabbit, one ear received a combination of ischemia and wounding with suture tension (n = 6), while the other ear was non-ischemic with wounding and suture tension alone (n = 6).

RESULTS

Four weeks post-operatively, ischemic ears developed scar hypertrophy (histological scar thickness: 1.1 ± 0.2 mm versus 0.5 ± 0.1 mm, p < 0.05).

CONCLUSION

Herein, we describe a novel, prototypical minimally invasive rabbit ear model of hypertrophic scar formation that can allow investigation of new drugs for scar prevention.

CD248 interacts with ECM to promote hypertrophic scar formation and development

Hypertrophic scar (HS) presents a significant clinical challenge, frequently arising as a fibrotic sequela of burn injuries and trauma. Characterized by the aberrant activation and proliferation of myofibroblasts, HS lacks a targeted therapeutic approach to effectively reduce this dysregulation. This study offers novel evidence of upregulated expression of CD248 in HS tissues compared to normal skin (NS) tissues. Specifically, the expression of CD248 was predominantly localized to α-SMA+-myofibroblasts in the dermis. To explain the functional role of CD248 in dermal myofibroblast activity, we employed a targeted anti-CD248 antibody, IgG78. Both CD248 intervention and IgG78 treatment effectively suppressed the proliferative, migratory, and ECM-synthesizing activities of myofibroblasts isolated from HS dermis. In addition, IgG78 administration significantly attenuated HS formation in an in vivo rabbit ear model. The LC/MS analysis coupled with co-immunoprecipitation of HS tissues indicated a direct interaction between CD248 and the ECM components Fibronectin (FN) and Collagen I (COL I). These findings collectively suggest that CD248 may function as a pro-fibrotic factor in HS development through its interaction with ECM constituents. The utilization of an anti-CD248 antibody, such as IgG78, represents a promising novel therapeutic strategy for the treatment of HS.

Exploring the potential mechanism of WuFuYin against hypertrophic scar using network pharmacology and molecular docking

BACKGROUND

Hypertrophic scar (HTS) is dermal fibroproliferative disorder, which may cause physiological and psychological problems. Currently, the potential mechanism of WuFuYin (WFY) in the treatment of HTS remained to be elucidated.

AIM

To explore the potential mechanism of WFY in treating HTS.

METHODS

Active components and corresponding targets were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. HTS-related genes were obtained from the GeneCards, DisGeNET, and National Center for Biotechnology Information. The function of targets was analyzed by performing Gene Ontology and Kyoto Encyclopaedia of Genes and Genome (KEGG) enrichment analysis. A protein + IBM-protein interaction (PPI) network was developed using STRING database and Cytoscape. To confirm the high affinity between compounds and targets, molecular docking was performed.

RESULTS

A total of 65 core genes, which were both related to compounds and HTS, were selected from multiple databases. PPI analysis showed that CKD2, ABCC1, MMP2, MMP9, glycogen synthase kinase 3 beta (GSK3B), PRARG, MMP3, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma (PIK3CG) were the hub targets and MOL004941, MOL004935, MOL004866, MOL004993, and MOL004989 were the key compounds of WFY against HTS. The results of KEGG enrichment analysis demonstrated that the function of most genes were enriched in the PI3K-Akt pathway. Moreover, by performing molecular docking, we confirmed that GSK3B and 8-prenylated eriodictyol shared the highest affinity.

CONCLUSION

The current findings showed that the GSK3B and cyclin dependent kinase 2 were the potential targets and MOL004941, MOL004989, and MOL004993 were the main compounds of WFY in HTS treatment.

CILP2 promotes hypertrophic scar through Snail acetylation by interaction with ACLY

BACKGROUND & AIMS

Hypertrophic scar (HS) is a skin fibroproliferative disorder occurring after burns, surgeries or traumatic injuries, and it has caused a tremendous economic and medical burden. Its molecular mechanism is associated with the abnormal proliferation and transition of fibroblasts and excessive deposition of extracellular matrix. Cartilage intermediate layer protein 2 (CILP2), highly homologous to cartilage intermediate layer protein 1 (CILP1), is mainly secreted predominantly from chondrocytes in the middle/deeper layers of articular cartilage. Recent reports indicate that CILP2 is involved in the development of fibrotic diseases. We investigated the role of CILP2 in the progression of HS.

METHODS AND RESULTS

It was found in this study that CILP2 expression was significantly higher in HS than in normal skin, especially in myofibroblasts. In a clinical cohort, we discovered that CILP2 was more abundant in the serum of patients with HS, especially in the early stage of HS. In vitro studies indicated that knockdown of CILP2 suppressed proliferation, migration, myofibroblast activation and collagen synthesis of hypertrophic scar fibroblasts (HSFs). Further, we revealed that CILP2 interacts with ATP citrate lyase (ACLY), in which CILP2 stabilizes the expression of ACLY by reducing the ubiquitination of ACLY, therefore prompting Snail acetylation and avoiding reduced expression of Snail. In vivo studies indicated that knockdown of CILP2 or ACLY inhibitor, SB-204990, significantly alleviated HS formation.

CONCLUSION

CILP2 exerts a vital role in hypertrophic scar formation and might be a detectable biomarker reflecting the progression of hypertrophic scar and a therapeutic target for hypertrophic scar.

The role of circulating metabolites and gut microbiome in hypertrophic scar: a two-sample Mendelian randomization study

Hypertrophic scarring is a fibro-proliferative disorder caused by abnormal cutaneous wound healing. Circulating metabolites and the gut microbiome may be involved in the formation of these scars, but high-quality evidence of causality is lacking. To assess whether circulating metabolites and the gut microbiome contain genetically predicted modifiable risk factors for hypertrophic scar formation. Two-sample Mendelian randomization (MR) was performed using MR-Egger, inverse-variance weighting (IVW), Mendelian Randomization Pleiotropy RESidual Sum and Outlier, maximum likelihood, and weighted median methods. Based on the genome-wide significance level, genetically predicted uridine (P = 0.015, odds ratio [OR] = 1903.514, 95% confidence interval [CI] 4.280-846,616.433) and isovalerylcarnitine (P = 0.039, OR = 7.765, 95% CI 1.106-54.512) were positively correlated with hypertrophic scar risk, while N-acetylalanine (P = 0.013, OR = 7.98E-10, 95% CI 5.19E-17-0.012) and glycochenodeoxycholate (P = 0.021, OR = 0.021 95% CI 0.003-0.628) were negatively correlated. Gastranaerophilales and two unknown gut microbe species (P = 0.031, OR = 0.378, 95% CI 0.156-0.914) were associated with an decreased risk of hypertrophic scarring. Circulating metabolites and gut microbiome components may have either positive or negative causal effects on hypertrophic scar formation. The study provides new insights into strategies for diagnosing and limiting hypertrophic scarring.

Shape-fixing hydrogel promotes scarless healing of wounds under tension

The healing of a wound under tension (hereafter, "tension wound") often coincides with the development of hypertrophic scars in clinical settings. Currently, compress bandages offer a potential alternative for the healing of tension wounds; however, their application in surgery is limited due to their prefabricated patch form. To overcome this, a tension-shielding hydrogel system was designed using photocurable catechol-grafted hyaluronic acid and tannic-acid silver nanoparticles (hereafter, "HTA system"). The hydrogel exhibited tension-shielding capacity, reducing wound tension via shape-fixation and ultimately reducing scar formation. The HTA hydrogel exhibited superior photothermal antibacterial efficacy, self-healing properties, and effective dissipation of energy, thereby promoting tissue regeneration. The hydrogel significantly inhibited the mechanotransduction pathway, thus preventing Engrailed-1 activation and reducing the fibrotic response. The HTA hydrogel system, therefore, provides a treatment strategy for tension wounds, burn wounds and other wounds that are prone to form hypertrophic scars via creating a tension-free local environment. STATEMENT OF SIGNIFICANCE: In our study, we presented a wound-dressing hydrogel system (HTA) that exhibit shape-fixing capacity in tension wound model. Here, we designed and modified a tension regulator, applied it to mice, and furthermore, established a tension wound model in mice with adjustable tension. Outcomes showed that the HTA hydrogel system can effectively form a shape-fixed environment on tension wounds and dynamic wounds, thus promoting scarless healing. Additionally, HTA performs injectability, rapid crosslinking, biocompatibility, wet adhesion, hemostasis and photothermal antibacterial properties. We believe this research has various potential clinical applications, including scarless-healing in tension wounds, treatment of acute bleeding, treatment of infected wounds, and even internal organ repair.

mir-182-5p regulates all three phases of inflammation, proliferation, and remodeling during cutaneous wound healing

Wound healing is a highly programmed process, in which any abnormalities result in scar formation. MicroRNAs are potent regulators affecting wound repair and scarification. However, the function of microRNAs in wound healing is not fully understood. Here, we analyzed the expression and function of microRNAs in patients with cutaneous wounds. Cutaneous wound biopsies from patients with either hypertrophic scarring or normal wound repair were collected during inflammation, proliferation, and remodeling phases. Fourteen candidate microRNAs were selected for expression analysis by qRT-PCR. The expression of genes involved in inflammation, angiogenesis, proliferation, and migration were measured using qRT-PCR. Cell cycle and scratch assays were used to explore the proliferation and migration rates. Flow cytometry analysis was employed to examine TGF-β, αSMA and collagen-I expression. Target gene suggestion was performed using Enrichr tool. The results showed that miR-16-5p, miR-152-3p, miR-125b-5p, miR-34c-5p, and miR-182-5p were revealed to be differentially expressed between scarring and non-scarring wounds. Based on the expression patterns obtained, miR-182-5p was selected for functional studies. miR-182-5p induced RELA expression synergistically upon IL-6 induction in keratinocytes and promoted angiogenesis. miR-182-5p prevented keratinocyte migration, while overexpressed TGF-β3 following induction of inflammation. Moreover, miR-182-5p enhanced fibroblast proliferation, migration, differentiation, and collagen-1 expression. FoxO1 and FoxO3 were found to potentially serve as putative gene targets of miR-182-5p. In conclusion, miR-182-5p is differentially expressed between scarring and non-scarring wounds and affect the behavior of cells involved in cutaneous wound healing. Deregulated expression of miR-182-5p adversely affects the proper transition of wound healing phases, resulting in scar formation.

miR-125b-5p delivered by adipose-derived stem cell exosomes alleviates hypertrophic scarring by suppressing Smad2

Background

Hypertrophic scarring is the most serious and unmet challenge following burn and trauma injury and often leads to pain, itching and even loss of function. However, the demand for ideal scar prevention and treatment is difficult to satisfy. We aimed to discover the effects and mechanisms of adipose-derived stem cell (ADSC) exosomes in hypertrophic scarring.

Methods

ADSC exosomes were isolated from the culture supernatant of ADSCs and identified by nanoparticle tracking analysis, transmission electron microscopy and western blotting. The effect of ADSC exosomes on wound healing and scar formation was detected by the wound model of BALB/c mice. We isolated myofibroblasts from hypertrophic scar tissue and detected the cell viability, proliferation and migration of myofibroblasts. In addition, collagen formation and fibrosis-related molecules were also detected. To further disclose the mechanism of ADSC exosomes on fibrosis in myofibroblasts, we detected the expression of Smad2 in hypertrophic scar tissue and normal skin and the regulatory mechanism of ADSC exosomes on Smad2. Injection of bleomycin was performed in male BALB/c mice to establish an in vivo fibrosis model while ADSC exosomes were administered to observe their protective effect. The tissue injury of mice was observed via hematoxylin and eosin and Masson staining and related testing.

Results

In this study, we found that ADSC exosomes could not only speed up wound healing and improve healing quality but also prevent scar formation. ADSC exosomes inhibited expression of fibrosis-related molecules such as α-smooth muscle actin, collagen I (COL1) and COL3 and inhibited the transdifferentiation of myofibroblasts. In addition, we verified that Smad2 is highly expressed in both hypertrophic scar tissue and hypertrophic fibroblasts, while ADSC exosomes downregulated the expression of Smad2 in hypertrophic fibroblasts. Further regulatory mechanism analysis revealed that microRNA-125b-5p (miR-125b-5p) is highly expressed in ADSC exosomes and binds to the 3' untranslated region of Smad2, thus inhibiting its expression. In vivo experiments also revealed that ADSC exosomes could alleviate bleomycin-induced skin fibrosis and downregulate the expression of Smad2.

Conclusions

We found that ADSC exosomes could alleviate hypertrophic scars via the suppression of Smad2 by the specific delivery of miR-125b-5p.

Fabrication of controlled porous and ultrafast dissolution porous microneedles by organic-solvent-free ice templating method

Porous Microneedles (PMNs) have been widely used in drug delivery and medical diagnosis owing to their abundant interconnected pores. However, the mechanical strength, the use of organic solvent, and drug loading capacity have long been challenging. Herein, a novel strategy of PMNs fabrication based on the Ice Templating Method is proposed that is suitable for insoluble, soluble, and nanosystem drug loading. The preparation process simplifies the traditional microneedle preparation process with a shorter preparation time. It endows the highly tunable porous morphology, enhanced mechanical strength, and rapid dissolution performance. Micro-CT three-dimensional reconstruction was used to better quantify the internal structures of PMNs, and we further established the equivalent pore network model to statistically analyze the internal pore structure parameters of PMNs. In particular, the mechanical strength is mainly negatively correlated with the surface porosity, while the dissolution velocity is mainly positively correlated with the permeability coefficient by the correlation heatmap. The poorly water-soluble Asiatic acid was encapsulated in PMNs in nanostructured lipid carriers, showing prominent hypertrophic scar healing trends. This work offers a quick and easy way of preparation that may be used to expand PMNs function and be introduced in industrial manufacturing development.

Global proteomic analysis reveals lysine succinylation is involved in the pathogenesis of hypertrophic scar

Lysine succinylation (Ksucc) is a recently identified posttranslational modification that is involved in many diseases. This study examined the role of Ksucc in the pathogenesis of hypertrophic scar (HS). The presence of Ksucc in human skin was measured by immunoblotting. Ksucc occurs in many skin proteins ranging from 25 to 250 kDa, and higher levels of Ksucc are found in HS skin than in normal skin. An immunoaffinity approach coupled with LC-MS/MS was used to characterize the first succinylome of human skin, and 159 Ksucc sites in 79 proteins were identified. Among these, there were 38 increased succinylated sites in 29 proteins but no decreased succinylated sites in HS compared with normal skin. A parallel reaction monitoring assay was performed to validate the results of the succinylome and showed that the levels of Ksucc in decorin and collagens, which are involved in the pathogenesis of HS, were increased in HS than in normal skin. In addition, increasing the level of Ksucc enhanced cell proliferation and upregulated the expression of fibrosis markers (α-SMA, COL1, and COL3) in human skin fibroblasts. Our results provide global insights into the functional role of Ksucc in hypertrophic scarring.

Application and effect of tension-reducing suture in surgical treatment of hypertrophic scar

PURPOSE

To investigate the application and effectiveness of tension-reducing suture in the repair of hypertrophic scars.

METHODS

A retrospective analysis of clinical data was conducted on 82 patients with hypertrophic scars treated at the Department of Burns and Plastic Surgery of Nanjing Drum Tower Hospital from September 2021 to December 2022. Patients were operated with combination of heart-shaped tension-reducing suturing technique and looped, broad, and deep buried (LBD) suturing technique or conventional suture method. Outcomes of surgical treatment were assessed before and 6 months after surgery using the Patient and Observer Scar Assessment Scale (POSAS) and the Vancouver Scar Scale (VSS).

RESULTS

Improvements were achieved on scar quality compared to that preoperatively, with a reduction in scar width (1.7 ± 0.6 cm vs. 0.7 ± 0.2 cm, P < 0.001). Assessment using the POSAS and VSS scales showed significant improvements in each single parameter and total score compared to preoperative values (P < 0.05). The Combination method group achieved better score in total score of VSS scale, in color, stiffness, thickness and overall opinion of PSAS scale, and in vascularity, thickness, pliability and overall opinion of OSAS scale.

CONCLUSION

The amalgamation of the heart-shaped tension-reducing suturing technique and the LBD suturing technique has shown promising outcomes, garnering notably high levels of patient satisfaction in the context of hypertrophic scar repair. Patients have exhibited favorable postoperative recoveries, underscoring the clinical merit and the prospective broader applicability of this approach in the realm of hypertrophic scar management.

The regulatory role of the apelin/APJ axis in scarring: Identification of upstream and downstream mechanisms

Scarring, a prevalent issue in clinical settings, is characterized by the excessive generation of extracellular matrix within the skin tissue. Among the numerous regulatory factors implicated in fibrosis across various organs, the apelin/APJ axis has emerged as a potential regulator of fibrosis. Given the shared attribute of heightened extracellular matrix production between organ fibrosis and scarring, we hypothesize that the apelin/APJ axis also plays a regulatory role in scar development. In this study, we examined the expression of apelin and APJ in scar tissue, normal skin, and fibroblasts derived from these tissues. We investigated the impact of the hypoxic microenvironment in scars on apelin/APJ expression to identify the transcription factors influencing apelin/APJ expression. Through overexpressing or knocking down apelin/APJ expression, we observed their effects on fibroblast secretion of extracellular matrix proteins. We further validated these effects in animal experiments while exploring the underlying mechanisms. Our findings demonstrated that the apelin/APJ axis is expressed in fibroblasts from keloid, hypertrophic scar, and normal skin. The regulation of apelin/APJ expression by the hypoxic environment in scars plays a significant role in hypertrophic scar and keloid development. This regulation promotes extracellular matrix secretion through upregulation of TGF-β1 expression via the PI3K/Akt/CREB1 pathway.

Advances in photodynamic therapy of pathologic scar

Pathologic scars include keloids and hypertrophic scars due to abnormal wound healing. Both cause symptoms of itching and pain; they also affect one's appearance and may even constrain movement. Such scars place a heavy burden on the individual's physical and mental health; moreover, treatment with surgery alone is highly likely to leave more scarring. Therefore, there is an urgent need for a treatment that is both minimally invasive and convenient. Photodynamic therapy (PDT) is an emerging safe and noninvasive technology wherein photosensitizers and specific light sources are used to treat malignant tumors and skin diseases. Research on PDT from both the laboratory and clinic has been reported. These findings on the treatment of pathologic scars using photosensitizers, light sources, and other mechanisms are reviewed in the present article.

Accuracy of remote burn scar evaluation via live video-conferencing technology

OBJECTIVE

Telemedicine in outpatient burn care, particularly in burn scar management, may provide cost-effective care and comes highly rated by patients. However, an effective scar scale using both video and photographic elements has not been validated. The purpose of this study is to test the reliability of the Patient and Observer Scar Assessment Scale (POSAS) using live video-conferencing.

METHODS

A prospective study was conducted with individuals with healed burn scars in Kathmandu, Nepal. Three independent observers assessed 85 burn scars from 17 subjects, using the Observer portion to evaluate vascularity, pigmentation, thickness, relief, pliability, surface area, and overall opinion. The on-site observer was physically present with the subjects and used a live videoconferencing application to show the scars to two remote observers in the United States. Subjects used the Patient portion to evaluate the scar that they believed appeared the worst appearance and had the greatest impact on function.

RESULTS

The single-rater reliability of the Observer scale was acceptable (ICC>0.70) in overall opinion, thickness, pliability, and surface area. The average-rater reliability for three observers was acceptable (ICC>0.70) for all parameters except for vascularity. When comparing Patients' and Observers' overall opinion scores, patients consistently reported worse opinion.

CONCLUSIONS

Evaluation of burn scars using the Patient and Observer Scar Assessment Scale can be accurately performed via live videoconferencing and presents an opportunity to expand access to burn care to rural communities, particularly in low- and middle-income countries, where patients face significant access barriers to appropriate follow-up care.

Benzbromarone Induces Targeted Degradation of HSP47 Protein and Improves Hypertrophic Scar Formation

Fibrotic diseases are characterized by the abnormal accumulation of collagen in the extracellular matrix, leading to the functional impairment of various organs. In the skin, excessive collagen deposition manifests as hypertrophic scars and keloids, placing a substantial burden on patients and the healthcare system worldwide. HSP47 is essential for proper collagen assembly and contributes to fibrosis. However, identifying clinically applicable HSP47 inhibitors has been a major pharmaceutical challenge. In this study, we identified benzbromarone (BBR) as an HSP47 inhibitor for hypertrophic scarring treatment. BBR inhibited collagen production and secretion in fibroblasts from patients with keloid by binding to HSP47 and inhibiting the interaction between HSP47 and collagen. Interestingly, BBR not only inhibits HSP47 but also acts as a molecular glue degrader that promotes its proteasome-dependent degradation. Through these molecular mechanisms, BBR effectively reduced hypertrophic scarring in mini pigs and rats with burns and/or excisional skin damage. Thus, these findings suggest that BBR can be used to clinically treat hypertrophic scars and, more generally, fibrotic diseases.

Identification and validation of CRLF1 and NRG1 as immune-related signatures in hypertrophic scar

BACKGROUND

Hypertrophic scar (HTS) is a prevalent chronic inflammatory skin disorder characterized by abnormal proliferation and extracellular matrix deposition and the precise mechanisms underlying HTS remain elusive. This study aimed to identify and validate potential immune-related genes associated with hypertrophic scar formation.

METHODS

Skin samples from normal (n = 12) and hypertrophic scar tissues (n = 12) were subjected to RNA-seq analysis. Differentially expressed genes (DEGs) and significant modular genes in Weighted gene Co-expression Network Analysis (WGCNA) were identified. Subsequently, functional enrichment analysis was performed on the intersecting genes. Additionally, eight immune-related genes were matched from the ImmPort database. Validation of NRG1 and CRLF1 was carried out using an external cohort (GSE136906). Furthermore, the association between these two genes and immune cells was assessed by Spearman correlation analysis. Finally, RNA was extracted from normal and hypertrophic scar samples, and RT-qPCR, Immunohistochemistry staining and Western Blot were employed to validate the expression of characteristic genes.

RESULTS

A total of 940 DEGs were identified between HTS and normal samples, and 288 key module genes were uncovered via WGCNA. Enrichment analysis in key module revealed involvement in many immune-related pathways, such as Th17 cell differentiation, antigen processing and presentation and B cell receptor signaling pathway. The eight immune-related genes (IFI30, NR2F2, NRG1, ESM1, NFATC2, CRLF1, COLEC12 and IL6) were identified by matching from the ImmPort database. Notably, we observed that activated mast cell positively correlated with CRLF1 expression, while CD8 T cells exhibited a positive correlation with NRG1. The expression of NRG1 and CRLF1 was further validated in clinical samples.

CONCLUSION

In this study, two key immune-related genes (CRLF1 and NRG1) were identified as characteristic genes associated with HTS. These findings provide valuable insights into the immune-related mechanisms underlying hypertrophic scar formation.

PTEN hinders the formation of scars by regulating the levels of proteins in the extracellular matrix and promoting the apoptosis of dermal fibroblasts through Bcl-xL

Hypertrophic scar (HS) is a dermatological condition characterized by an excessive accumulation of proteins in the extracellular matrix (ECM) and an elevated cell count. The development of HS is thought to be linked to the disruption of dermal fibroblast proliferation and apoptosis. The processes of cell proliferation and apoptosis are notably influenced by PTEN. However, the precise mechanisms by which PTEN regulates hypertrophic scar fibroblasts (HSFs) and its overall role in scar formation are still not fully understood. The objective of this study was to investigate the influence of PTEN on hypertrophic scars(HS) and its function in the regulation of scar formation, with the aim of identifying a pivotal molecular target for scar treatment. Our results demonstrate that the overexpression of PTEN (AdPTEN) significantly suppressed the expression of type I collagen (Col I), type III collagen (Col III), and alpha smooth muscle actin (α-SMA) in HSFs. Furthermore, it was observed that the introduction of AdPTEN resulted in the suppression of Bcl-xL expression, which consequently led to an increase in the apoptosis of HSFs. Similarly, in the inhibition of collagens expression and subsequent increase in HSF apoptosis were also observed upon silencing Bcl-xL (sibcl-xL). Additionally, the in vitro model demonstrated that both AdPTEN and sibcl-xL were effective in reducing the contraction of FPCL. The findings of our study provide validation for the role of PTEN in inhibiting the development of hypertrophic scars (HS) by modulating the expression of extracellular matrix (ECM) proteins and promoting apoptosis in hypertrophic scar fibroblasts (HSFs) via Bcl-xL. These results indicate that PTEN and Bcl-xL may hold promise as potential molecular targets for therapeutic interventions aimed at managing hypertrophic scars.

Early intervention of carbon dioxide fractional laser in hypertrophic scar through TGFβ-1/ Smad3 signaling pathway

Hypertrophic scars are usually the result of surgical trauma or burn,and more common in individuals with a darker skin color. They appear as red and raised lesions around the wound that continually expand over a period of weeks or months, causing itching, pain, burning sensation and discomfort. Severe scarring affects interpersonal and social relationships, and decreases the quality of life of the patients.The aim of this study was to evaluate the effect of carbon dioxide fractional laser as an early intervention against hypertrophic scars using a rabbit ear scar model, and explore the role of the TGFβ-1/ Smad3 signaling pathway in scar hyperplasia. Four wounds were made into each ear of rabbits, and divided into the untreated control and three laser-treatment groups. The experimental groups received laser intervention once, twice and thrice respectively. laser treatment significantly inhibited the formation of hypertrophic scars, and maximum benefits were seen in the wounds that received three laser treatments. Immunohistochemical staining showed that the in situ expression of TGFβ-1 and Smad3 in the scars decreased by varying degrees after laser intervention, and was most obvious after three laser interventions. Furthermore, the expression levels were the lowest at the end of 6 months after modeling. Therefore, we can assume that early intervention with carbon dioxide fractional laser can prevent formation of hypertrophic scars by regulating the TGF-β1/Smad3 pathway.

The efficacy, satisfaction, and safety of carbon dioxide (CO2) fractional laser in combination with pulsed dye laser (PDL) versus each one alone in the treatment of hypertrophic burn scars: a single-blinded randomized controlled trial

The tendency to use less-invasive laser-based methods with far more obvious effectiveness has been taken into consideration today for improvement of burning scars. The present study thus aimed to assess the efficacy of two laser-based techniques including pulsed dye laser (PDL) and ablative fractional CO2 laser (AFCL) and its combination on improving different aspects of burning scars regardless of the types of scar as hypertrophic or keloid scars. This randomized single-blinded clinical trial was performed on patients suffering hypertrophic or keloid burning scars. The patients were randomly assigned into three groups scheduling for treatment with PDL alone, AFCL alone, or its combination. All patients were visited before and 40 days after the last treatment session, and their scars were assessed. In all groups, significant improvement was revealed in the Vancouver scar scale (VSS) score, the color of scar, vascular bed in the scar, the and height of scar and its pliability; however, the improvement in each item was more highlighted in the group receiving a combination therapy with PDL and AFCL techniques. In this regard, the highest improvement was found in vascular bed and pliability in the combination therapy group as compared to other groups. Although the superiority of the combined group was not statistically significant, due to the high percentage of improvement in total VSS and most of its indicators, it can be clinically significant. The efficacy of the treatment protocols was different considering subgroups of mature and immature scars (less than 1 year), so that more improvement in pliability of scar, vascularity, and color of scar was found in the group scheduling for PDL + AFCL as compared to those who were treated with PDL alone in immature scar group but not in mature scar group. Combined treatment can be much more effective in improving the appearance and pathological characteristics of scars than each individual treatment. This effectiveness can be seen mainly in immature scars.

CLC-3 regulates TGF-β/smad signaling pathway to inhibit the process of fibrosis in hypertrophic scar

Objective

To study the role and mechanism of chloride channel-3 (ClC-3) in the formation of hypertrophic scar by constructing ClC-3 interference vectors and examining their effects on human hypertrophic scar fibroblasts (HSFB).

Methods

Human HSFB and human normal skin fibroblasts (NSFB) were used in this study, and ClC-3 interference vectors were constructed to transfect cells. ClC-3 inhibitors NPPB and Tamoxifen were used to treat cells. Cell migration and the expression of TGF-β/Smad, CollagenⅠ,CollagenⅢ were examined to explore the role of ClC-3 in the formation of hypertrophic scar.

Results

Compared with the normal skin tissue, the positive expression of ClC-3 and TGF-β in the scar tissue was significantly increased. The relative expression of ClC-3 and TGF-β1 in HSFB cells was higher than that in NSFB cells. Interfering with the expression of CLC-3 can inhibit the migration of HSFB cells and the expression of TGF- β/Smad, CollagenⅠ/Ⅲ. The experiment of HSFB cells treated by CLC-3 inhibitors can also obtain similar results.

Conclusion

Inhibiting CLC-3 can reduce the formation of hypertrophic scars.

The Comparison of Efficacy and Safety Between General and Topical Anesthesia on Micro-Plasma Radiofrequency Treatment for Hypertrophic Scar: A Retrospective Cohort Study

BACKGROUND

While micro-plasma radiofrequency (MPR) treatment has a significant impact on hypertrophic scars, patients often require anesthesia to alleviate substantial discomfort. Currently, patients with similar degrees of scarring may choose surface anesthesia or general anesthesia based on their personal preferences. Nevertheless, the effectiveness and safety of different anesthesia modalities remain uncertain.

OBJECTIVE

To assess the effectiveness and safety of both general and surface anesthesia in MPR treatment for hypertrophic scars.

METHODS

We conducted a retrospective cohort study involving 101 patients diagnosed with hypertrophic scars who underwent MPR with different anesthesia methods. The primary measures of efficacy included the Vancouver Scar Scale (VSS) scores assessed before the first treatment and six months after the final treatment. Pain relief was evaluated using Visual Analog Scale (VAS) scores. Safety was assessed by comparing the incidence of adverse reactions between the two groups.

RESULTS

Patients in the general anesthesia group showed a significant difference in scar pigmentation 6 months after the treatment and lower pain level than those in the surface anesthesia group in the treatment of MPR. The difference in safety was not statistically significant. After adjusting for confounding factors and propensity score matching, the outcome of VSS and VAS scores was stable.

CONCLUSION

General anesthesia, as opposed to surface anesthesia, appears to enhance both the effectiveness and safety of MPR while reducing postoperative pain in the treatment of hypertrophic scars. For patients with heightened pain sensitivity, general anesthesia may be the preferred treatment option.

LEVEL OF EVIDENCE II

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Manufacture and use of transparent facial orthotic masks for treating facial burn scars: A systematic review

BACKGROUND

Custom-made transparent facial orthoses (TFOs) (face masks) are used to improve facial burn scars. We conducted a systematic literature review on TFO manufacture and use.

METHODS

Pubmed and Cochrane databases were searched without restrictions for relevant articles. TFO manufacture details and use according to international recommendations (20-32 mmHg pressure, TFO worn 20-23 h/day for ≥2 months) were extracted.

RESULTS

Of 279 retrieved articles, 11 published over the last 41 years (four in the last 5 years) discussed TFO manufacture/use. There were five technical notes, five case reports, and a patient-cohort study (total patients in the studies=21). TFO-manufacture methods could be categorized as classical, digital, or mixed classical-digital. Relative clinical efficacies and cost advantages were unclear. The plastics used, harness materials, harness-point number, and silicone-interface use differed from study to study. Target pressure, actual pressure, expected daily wearing time, and treatment duration ranged widely and often did not meet current guidelines. Actual wearing time and treatment duration were never measured.

CONCLUSIONS

Although TFOs play an important global role in burn care, there is a grave paucity of research. Further research is needed to promote the standardization of TFO-related practices and thereby improve the outcomes of facial-burn patients.