Hyperbaric oxygen therapy can ameliorate the EMT phenomenon in keloid tissue

EW-7197, transforming growth factor β inhibitor, combined with irreversible electroporation for improving skin wound in a rat excisional model

To evaluate the safety and efficacy of combining EW-7197 with irreversible electroporation (IRE) for improving wound healing, 16 male Sprague-Dawley rats were randomly divided into four groups of four rats each after dorsal excisional wound induction: sham control group; oral administration of EW-7197 for 7 days group; one-time application of IRE group; and one-time application of IRE followed by oral administration of EW-7197 for 7 days group. Measurement of wound closure rate, laser Doppler scanning, histological staining (hematoxylin and eosin and Masson's trichrome), and immunohistochemical analyses (Ki-67 and α-SMA) were performed to evaluate the efficacy. Fifteen of 16 rats survived throughout the study. Statistically significant differences in wound closure rates were observed between the combination therapy group and the other three groups (all P < 0.05). The degrees of inflammation, α-SMA, and Ki-67 were reduced in the EW-7197 and IRE monotherapy groups; however, not statistically significant. The fibrosis score exhibited significant reduction in all three treatment groups, with the most prominent being in the combination therapy group. This study concludes that oral administration of EW-7197 combined with IRE demonstrated effectiveness in improving skin wound in a rat excisional model and may serve as a potential alternative for promoting healing outcomes.

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.

The Mechanisms of Action of Hyperbaric Oxygen in Restoring Host Homeostasis during Sepsis

The perception of sepsis has shifted over time; however, it remains a leading cause of death worldwide. Sepsis is now recognized as an imbalance in host cellular functions triggered by the invading pathogens, both related to immune cells, endothelial function, glucose and oxygen metabolism, tissue repair and restoration. Many of these key mechanisms in sepsis are also targets of hyperbaric oxygen (HBO2) treatment. HBO2 treatment has been shown to improve survival in clinical studies on patients with necrotizing soft tissue infections as well as experimental sepsis models. High tissue oxygen tension during HBO2 treatment may affect oxidative phosphorylation in mitochondria. Oxygen is converted to energy, and, as a natural byproduct, reactive oxygen species are produced. Reactive oxygen species can act as mediators, and both these and the HBO2-mediated increase in oxygen supply have the potential to influence the cellular processes involved in sepsis. The pathophysiology of sepsis can be explained comprehensively through resistance and tolerance to infection. We argue that HBO2 treatment may protect the host from collateral tissue damage during resistance by reducing neutrophil extracellular traps, inhibiting neutrophil adhesion to vascular endothelium, reducing proinflammatory cytokines, and halting the Warburg effect, while also assisting the host in tolerance to infection by reducing iron-mediated injury and upregulating anti-inflammatory measures. Finally, we show how inflammation and oxygen-sensing pathways are connected on the cellular level in a self-reinforcing and detrimental manner in inflammatory conditions, and with support from a substantial body of studies from the literature, we conclude by demonstrating that HBO2 treatment can intervene to maintain homeostasis.

Epithelial-Mesenchymal Plasticity and Endothelial-Mesenchymal Transition in Cutaneous Wound Healing

Epithelial and endothelial cells possess the inherent plasticity to undergo morphological, cellular, and molecular changes leading to their resemblance of mesenchymal cells. A prevailing notion has been that cutaneous wound reepithelialization involves partial epithelial-to-mesenchymal transition (EMT) of wound-edge epidermal cells to enable their transition from a stationary state to a migratory state. In this review, we reflect on past findings that led to this notion and discuss recent studies that suggest a refined view, focusing predominantly on in vivo results using mammalian excisional wound models. We highlight the concept of epithelial-mesenchymal plasticity (EMP), which emphasizes a reversible conversion of epithelial cells across multiple intermediate states within the epithelial-mesenchymal spectrum, and discuss the critical importance of restricting EMT for effective wound reepithelialization. We also outline the current state of knowledge on EMP in pathological wound healing, and on endothelial-to-mesenchymal transition (EndMT), a process similar to EMT, as a possible mechanism contributing to wound fibrosis and scar formation. Harnessing epithelial/endothelial-mesenchymal plasticity may unravel opportunities for developing new therapeutics to treat human wound healing pathologies.

Hyperbaric Oxygen Therapy in Plastic, Aesthetic, and Reconstructive Surgery: Systematic Review

Introduction: Hyperbaric oxygen therapy (HBOT) has been used over the past six decades to treat multiple conditions. This systematic review aims to identify and evaluate the clinical outcomes of hyperbaric oxygen therapy in the field of plastic, reconstructive, and aesthetic surgery, found in the literature from the year 2000 to the present. Methods: A systematic review of the literature focused on the conceptual and methodological aspects of the PRISMA Declaration. The search for clinical trials focused on the results of hyperbaric therapy in plastic, reconstructive, and cosmetic surgery. The Newcastle–Ottawa scale suggested by the Cochrane manual was applied to each study. The study was carried out with a defined protocol and was registered in PROSPERO, with code CRD42022301261. Results: From the 170 articles identified, 6 were selected. Five of them showed that hyperbaric oxygen therapy favored the reduction of the size of skin ulcers and increased the formation of granulation tissue (two trials; p < 0.05), increased the partial pressure of transcutaneous oxygen in patients with free flaps (one trial; p < 0.001), reduced perfusion in keloid scarring disorder (one trial; p < 0.01), and accelerated both the fading of melanin pigmentation and the decrease in age spot size (one trial; p < 0.05). The methodological quality was moderate in all cases because there was no blinding method reported. One study failed to find differences in flap survival, time to resolution of venous congestion, resolution of edema, and postoperative recovery period (p > 0.05). Conclusions: Hyperbaric oxygen therapy has been increasingly used in the field of plastic and reconstructive surgery, and has shown potential benefits in promoting wound healing, reducing the risk of infection, and improving the survival of tissues used in reconstructive procedures. Further research with more rigorous clinical trials is needed to fully understand the efficacy and optimal use of this therapy in the field of plastic and reconstructive surgery.

Could hyperbaric oxygen be an effective therapy option for pathological scars? A systematic review and meta-analysis

BACKGROUND

Hyperbaric oxygen (HBO) therapy involves breathing pure oxygen or a high oxygen concentration above atmospheric (ATM) pressure in an enclosed chamber. Studies on pathological scars have demonstrated that HBO can inhibit the formation of pathological scars.

OBJECTIVE

To evaluate the efficacy of HBO in the treatment of pathological scars via meta-analysis.

METHODS

Searches were run on various databases, including the Cochrane, Embase, PubMed, Web of Science, and CNKI databases. A comparative study was conducted on patients with pathological scars treated with or without HBO. We used RevMan 5.4 software to determine the recurrence rate, treatment satisfaction, and Vancouver Scar Scale(VSS) score in the pathological scar.

RESULTS

A total of 543 publications were identified; after screening, four were selected for review, including one randomized controlled trial (RCT), one controlled clinical trial (CCT), and two retrospective cohort studies. Meta-analysis results showed that HBO treatment reduced the pathological scar recurrence rate after surgery and radiotherapy (OR = 0.26, 95% CI: 0.13-0.52, p = 0.0001). Patients had higher satisfaction after HBO therapy (OR = 4.45, 95% CI: 1.49-13.30, p = 0.007). The Vancouver scar scale (VSS) score of patients with pathological scars was significantly improved in the HBO group (SMD: -3.82, 95% CI: -6.07to -0.49, p = 0.02).

CONCLUSIONS

HBO treatment decreased the recurrence rate of pathological scars after surgery and radiotherapy, increased patient satisfaction, and reduced the VSS score, thus providing a new way to treat pathological scar hyperplasia. However, evaluation of the longer-term effects of HBO treatment requires further comprehensive studies, including more RCTs.

Role of HIF-1α in pathogenic mechanisms of keloids

BACKGROUDS AND OBJECTIVE

Keloids are defined as overrepairing products that develop after skin lesions. Keloids are characterized by the proliferation of fibroblasts and the overaccumulation of extracellular matrix components (mainly collagen), leading to a locally hypoxic microenvironment. Hence, this article was aimed to review hypoxia in pathogenesis of keloids.

METHODS

We reviewed and summarized the relevant published studies.

RESULTS

Hypoxia results in the accumulation of hypoxia-inducible factor 1α (HIF-1α) in keloids, contributing to overactivation of the fibrotic signaling pathway, epithelial-mesenchymal transition, and changes in metabolism, eventually leading to aggravated fibrosis, infiltrative growth, and radiotherapy resistance.

CONCLUSION

It is, therefore, essential to understand the role of HIF-1α in the pathogenic mechanisms of keloids in order to develop new therapeutic approaches.

Advances in the pathogenesis and clinical application prospects of tumor biomolecules in keloid

Keloid scarring is a kind of pathological healing manifestation after skin injury and possesses various tumor properties, such as the Warburg effect, epithelial-mesenchymal transition (EMT), expression imbalances of apoptosis-related genes and the presence of stem cells. Abnormal expression of tumor signatures is critical to the initiation and operation of these effects. Although previous experimental studies have recognized the potential value of a single or several tumor biomolecules in keloids, a comprehensive evaluation system for multiple tumor signatures in keloid scarring is still lacking. This paper aims to summarize tumor biomolecules in keloids from the perspectives of liquid biopsy, genetics, proteomics and epigenetics and to investigate their mechanisms of action and feasibility from bench to bedside. Liquid biopsy is suitable for the early screening of people with keloids due to its noninvasive and accurate performance. Epigenetic biomarkers do not require changes in the gene sequence and their reversibility and tissue specificity make them ideal therapeutic targets. Nonetheless, given the ethnic specificity and genetic predisposition of keloids, more large-sample multicenter studies are indispensable for determining the prevalence of these signatures and for establishing diagnostic criteria and therapeutic efficacy estimations based on these molecules.

Epithelial-mesenchymal transition in organ fibrosis development: current understanding and treatment strategies

Organ fibrosis is a process in which cellular homeostasis is disrupted and extracellular matrix is excessively deposited. Fibrosis can lead to vital organ failure and there are no effective treatments yet. Although epithelial–mesenchymal transition (EMT) may be one of the key cellular mechanisms, the underlying mechanisms of fibrosis remain largely unknown. EMT is a cell phenotypic process in which epithelial cells lose their cell-to-cell adhesion and polarization, after which they acquire mesenchymal features such as infiltration and migration ability. Upon injurious stimulation in different organs, EMT can be triggered by multiple signaling pathways and is also regulated by epigenetic mechanisms. This narrative review summarizes the current understanding of the underlying mechanisms of EMT in fibrogenesis and discusses potential strategies for attenuating EMT to prevent and/or inhibit fibrosis. Despite better understanding the role of EMT in fibrosis development, targeting EMT and beyond in developing therapeutics to tackle fibrosis is challenging but likely feasible.

Hyperbaric oxygen treatment on keloid tumor immune gene expression

Background:

Hyperbaric oxygen treatment (HBOT) has been demonstrated to influence the keloid recurrence rate after surgery and to relieve keloid symptoms and other pathological processes in keloids. To explore the mechanism of the effect of HBOT on keloids, tumor immune gene expression and immune cell infiltration were studied in this work.

Methods:

From February 2021 to April 2021, HBOT was carried out on keloid patients four times before surgery. Keloid tissue samples were collected and divided into an HBOT group (keloid with HBOT before surgery [HK] group, n = 6) and a non-HBOT group (K group, n = 6). Tumor gene expression was analyzed with an Oncomine Immune Response Research Assay kit. Data were mined with R package. The differentially expressed genes between the groups were compared. Hub genes between the groups were determined and verified with Quantitative Real-time PCR. Immune cell infiltration was analyzed based on CIBERSORT deconvolution algorithm analysis of gene expression and verified with immunohistochemistry (IHC).

Results:

Inflammatory cell infiltration was reduced in the HK group. There were 178 upregulated genes and 217 downregulated genes. Ten hub genes were identified, including Integrin Subunit Alpha M (ITGAM), interleukin (IL)-4, IL-6, IL-2, Protein Tyrosine Phosphatase Receptor Type C (PTPRC), CD86, transforming growth factor (TGF), CD80, CTLA4, and IL-10. CD80, ITGAM, IL-4, and PTPRC with significantly downregulated expression were identified. IL-10 and IL-2 were upregulated in the HK group but without a significant difference. Infiltration differences of CD8 lymphocyte T cells, CD4 lymphocyte T-activated memory cells, and dendritic resting cells were identified with gene CIBERSORT deconvolution algorithm analysis. Infiltration levels of CD4 lymphocyte T cell in the HK group were significantly higher than those of the K group in IHC verification.

Conclusion:

HBOT affected tumor gene expression and immune cell infiltration in keloids. CD4 lymphocyte T cell, especially activated memory CD4⁺T, might be the key regulatory immune cell, and its related gene expression needs further study.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pirfenidone inhibits epithelial-mesenchymal transition in keloid keratinocytes

Background

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

Methods

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

Results

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

Conclusions

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

Hyperbaric oxygen therapy relieved pruritus and pain of keloid patients

Objective: Keloid patients usually have local pruritus and pain. In our clinical work, we have found keloid patients after receiving hyperbaric oxygen (HBO) therapy reflect less pruritus and pain. The hypothesis was that patients with keloid and a history of HBO therapy would have less pruritus and pain than patients without HBO therapy, and the pruritus or pain-related factors were detected in keloid with/without HBO therapy and normal skin. Methods: Three groups of samples were established: keloid samples from patients with HBO therapy for two weeks before and after surgery (H group); keloid samples from patients without HBO therapy (G group); normal skin samples from patients without obvious scar (N group). Hematoxylin and eosin (H&E) staining was used to observe morphological changes. Pruritus/pain related factors: Tryptophan Hydroxylase1 (TPH1), connexin-43 (Cx43) and transient receptor potential vanilloid type 1 (TRPV1) were detected by immunofluorescence and western blot technology. The expression of these factors' mRNA was also measured by the real-time quantitative polymerase chain reaction (RT-qPCR). Results: Among three groups, G group presented significantly highest expression levels of TPH1, Cx43 and TRPV1, conversely, N group presented significantly lowest expression levels of TPH1, Cx43 and TRPV1. Conclusion: TPH1, Cx43 and TRPV1 were overexpressed in the samples of keloid patients, indicating that the pruritus and pain of keloid might be related to these factors. Furthermore, TPH1, Cx43 and TRPV1 were expressed highest in keloid patients without HBO therapy, indicating that HBO therapy might relief pruritus of keloid patients by regulating these factors.

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

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