The role of TGFβ in wound healing pathologies

Zn@TA assisted dual cross-linked 3D printable glycol grafted chitosan hydrogels for robust antibiofilm and wound healing

Rapid regeneration of the injured tissue or organs is necessary to achieve the usual functionalities of the damaged parts. However, bacterial infections delay the regeneration process, a severe challenge in the personalized healthcare sector. To overcome these challenges, 3D-printable multifunctional hydrogels of Zn/tannic acid-reinforced glycol functionalized chitosan for rapid wound healing were developed. Polyphenol strengthened intermolecular connections, while glutaraldehyde stabilized 3D-printed structures. The hydrogel exhibited enhanced viscoelasticity (G'; 1.96 × 104 Pa) and adhesiveness (210 kPa). The dual-crosslinked scaffolds showed remarkable antibacterial activity against Bacillus subtilis (∼81 %) and Escherichia coli (92.75 %). The hydrogels showed no adverse effects on human dermal fibroblasts (HDFs) and macrophages (RAW 264.7), indicating their superior biocompatibility. The Zn/TA-reinforced hydrogels accelerate M2 polarization of macrophages through the activation of anti-inflammatory transcription factors (Arg-1, VEGF, CD163, and IL-10), suggesting better immunomodulatory effects, which is favorable for rapid wound regeneration. Higher collagen deposition and rapid re-epithelialization occurred in scaffold-treated rat groups vis-à-vis controls, demonstrating superior wound healing. Taken together, the developed multifunctional hydrogels have great potential for rapidly regenerating bacteria-infected wounds in the personalized healthcare sector.

Helminth protein enhances wound healing by inhibiting fibrosis and promoting tissue regeneration

Skin wound healing due to full thickness wounds typically results in fibrosis and scarring, where parenchyma tissue is replaced with connective tissue. A major advance in wound healing research would be to instead promote tissue regeneration. Helminth parasites express excretory/secretory (ES) molecules, which can modulate mammalian host responses. One recently discovered ES protein, TGF-β mimic (TGM), binds the TGF-β receptor, though likely has other activities. Here, we demonstrate that topical administration of TGM under a Tegaderm bandage enhanced wound healing and tissue regeneration in an in vivo wound biopsy model. Increased restoration of normal tissue structure in the wound beds of TGM-treated mice was observed during mid- to late-stage wound healing. Both accelerated re-epithelialization and hair follicle regeneration were observed. Further analysis showed differential expansion of myeloid populations at different wound healing stages, suggesting recruitment and reprogramming of specific macrophage subsets. This study indicates a role for TGM as a potential therapeutic option for enhanced wound healing.

The stress-responsive gene ATF3 drives fibroblast activation and collagen production through transcriptionally activating TGF-β receptor Ⅱ in skin wound healing

Skin wound is an emerging health challenge on account of the high-frequency trauma, surgery and chronic refractory ulcer. Further study on the disease biology will help to develop new effective approaches for wound healing. Here, we identified a wound-stress responsive gene, activating transcription factor 3 (ATF3), and then investigated its biological action and mechanism in wound healing. In the full-thickness skin wound model, ATF3 was found to promote fibroblast activation and collagen production, resulted in accelerated wound healing. Mechanically, ATF3 transcriptionally activated TGF-β receptor Ⅱ via directly binding to its specific promoter motif, followed by the enhanced TGF-β/Smad pathway in fibroblasts. Moreover, the increased ATF3 upon skin injury was partly resulted from hypoxia stimulation with Hif-1α dependent manner. Altogether, this work gives novel insights into the biology and mechanism of stress-responsive gene ATF3 in wound healing, and provides a potential therapeutic target for treatment.

S100A12 inhibits Streptococcus pneumoniae and aids in wound healing of corneal epithelial cells both in vitro and in vivo

Streptococcus pneumoniae, a leading cause of corneal infections worldwide, are extremely aggressive despite antibiotic sensitivity and exhibit increased resistance towards antibiotics. Antimicrobial peptides are often considered as potent alternatives against antibiotic resistance and here we have investigated the possible roles of S100A12, a host defense peptide, in wound healing and S. pneumoniae infection. S100A12 significantly inhibited growth of S. pneumoniae by disruption of membrane integrity along with increased generation of reactive oxygen species. Additionally, S100A12 accelerated cell migration and wound closure in human corneal epithelial cells and in a murine corneal wound model by activation of EGFR and MAPK signaling pathways.

45S5 Bioactive Glass-Ointment Positively Effects on Wound Healing in Rats by Regulating TNFα, Il-10, VEGF, and TGFβ

AIM

This study aimed to investigate the effects of 45S5 bioactive glass-ointment (BG) on cutaneous wound healing in rats at the molecular, biochemical, and histopathological levels.

MATERIALS AND METHODS

Thirty-two rats were divided into four groups (n = 8): Control, Sham, BG, and DEX (Dexpanthenol). While no wound treatment was applied to the CONTROL, a wound model was created in the Sham, and no treatment was applied. A wound model was created for other groups, and BG and DEX were applied locally for 21 days. During the 21-day experiment period, feed and water consumption and weight changes were observed. Wound areas were calculated on days 0, 3, 7, 4, and 21. Following treatment, the rats were euthanized and tissues from the wound area and blood samples were collected. While the expression levels of tumor necrosis factor-alpha (TNFα), Interleukin 6 (IL6), Interleukin 10 (IL10), transforming growth factor-beta (TGFβ), and vascular endothelial growth factor (VEGF) genes were determined by qPCR, the levels of TNFα, IL6, and IL10 proteins were measured by ELISA.

RESULTS

It was observed that the BG group showed anti-inflammatory activity by suppressing TNFα levels and stimulating IL-10. In addition, it was determined that BG increased fibroblast activity and vascularization.

CONCLUSION

Current findings showed that topical application of BG has anti-inflammatory effects, while also accelerating healing by increasing vascularity and making positive contributions to tissue healing.

Pathogenic mechanisms in genetically defined Ehlers-Danlos syndromes

The Ehlers-Danlos syndromes (EDS) are a group of rare heritable connective tissue disorders, common hallmarks of which are skin hyperextensibility, joint hypermobility, and generalized connective tissue fragility. Currently, 13 EDS types are recognized, caused by defects in 20 genes which consequently alter biosynthesis, organization, and/or supramolecular assembly of collagen fibrils in the extracellular matrix (ECM). Molecular analyses on patient samples (mostly dermal fibroblast cultures), combined with studies on animal models, have highlighted that part of EDS pathogenesis can be attributed to impaired cellular dynamics. Although our understanding of the full extent of (extra)cellular consequences is still limited, this narrative review aims to provide a comprehensive overview of our current knowledge on the extracellular, pericellular, and intracellular alterations implicated in EDS pathogenesis.

MiR-494-3p regulates skin fibroblast activities by mediating fibromodulin production

Skin wound healing is a well-coordinated process in which various cells and factors participate, during which fibroblast exhibits a critical role by exerting its multiple activities, including proliferation, migration, invasion, and differentiation. Previous studies have identified that fibromodulin (FMOD) could enhance dermal wound healing by promoting skin fibroblast activities, but little is known about its upstream regulator. We occasionally found that FMOD expression was downregulated in skin fibroblast by transforming growth factor-β1 treatment. It was hypothesized that microRNAs (miRNA) in skin fibroblast could downregulate FMOD production and blocking them would increase FMOD expression, as well as promote skin wound healing. Here, by utilizing combined analysis of miRNA microarray from the Gene Expression Omnibus database and miRNA targets prediction, we successfully identified a miRNA, termed miR-494-3p, could regulate FMOD production in human skin fibroblast (BJ fibroblast). The functional analysis revealed that miR-494-3p mimics could inhibit BJ fibroblast migration and invasion but not proliferation and differentiation, while miR-494-3p inhibition markedly promotes migration, invasion, and differentiation of BJ fibroblast. Moreover, we established FMOD overexpression (OE) and knockout BJ fibroblast. We found that FMOD OE could rescue the inhibitory effects of miR-494-3p mimics on the migration and invasion of BJ fibroblast. In contrast, the miR-494-3p inhibitor transfection could not enhance migration, invasion, and differentiation of FMOD KO BJ fibroblast. Together, our results suggest that miR-494-3p may be a potential target for skin wound management via regulating FMOD production.

The Potential of Fish Oil Components and Manuka Honey in Tackling Chronic Wound Treatment

Chronic wounds are becoming an increasing burden on healthcare services, as they have extended healing times and are susceptible to infection, with many failing to heal, which can lead ultimately to amputation. Due to the additional rise in antimicrobial resistance and emergence of difficult-to-treat Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. (ESKAPE pathogens), novel treatments will soon be required asides from traditional antibiotics. Many natural substances have been identified as having the potential to aid in both preventing infection and increasing the speed of wound closure processes. Manuka honey is already in some cases used as a topical treatment in the form of ointments, which in conjunction with dressings and fish skin grafts are an existing US Food and Drug Administration-approved treatment option. These existing treatment options indicate that fatty acids from fish oil and manuka honey are well tolerated by the body, and if the active components of the treatments were better understood, they could make valuable additions to topical treatment options. This review considers two prominent natural substances with established manufacturing and global distribution-marine based fatty acids (including their metabolites) and manuka honey-their function as antimicrobials and how they can aid in wound repair, two important aspects leading to resolution of chronic wounds.

Serum deprivation protein response intervenes in the proliferation, motility, and extracellular matrix production in keloid fibroblasts by blocking the amplification of TGF-β1/SMAD signal cascade via ERK1/2

Keloid formation has been linked to abnormal fibroblast function, such as excessive proliferation and extracellular matrix (ECM) production. Serum deprivation protein response (SDPR) is a crucial regulator of cellular function under diverse pathological conditions, yet its role in keloid formation remains unknown. The current work investigated the function of SDPR in regulating the proliferation, motility, and ECM production of keloid fibroblasts (KFs), as well as to decipher the mechanisms involved. Analysis of RNA sequencing data from the GEO database demonstrated significant down-regulation of SDPR in KF compared to normal fibroblasts (NFs). This down-regulation was also observed in clinical keloid specimens and isolated KFs. Overexpression of SDPR suppressed the proliferation, motility, and ECM production of KFs, while depletion of SDPR exacerbated the enhancing impact of TGF-β1 on the proliferation, motility, and ECM production of NFs. Mechanistic studies revealed that SDPR overexpression repressed TGF-β/Smad signal cascade activation in KFs along with decreased levels of phosphorylated Samd2/3, while SDPR depletion exacerbated TGF-β/Smad activation in TGF-β1-stimulated NFs. SDPR overexpression also repressed ERK1/2 activation in KFs, while SDPR depletion exacerbated ERK1/2 activation in TGF-β1-stimulated NFs. Inhibition of ERK1/2 abolished SDPR-depletion-induced TGF-β1/Smad activation, cell proliferation, motility, and ECM production in NFs. In conclusion, SDPR represses the proliferation, motility, and ECM production in KFs by blocking the TGF-β1/Smad pathway in an ERK1/2-dependent manner. The findings highlight the role of SDPR in regulating abnormal behaviors of fibroblasts associated with keloid formation and suggest it as a potential target for anti-keloid therapy development.

Lipid-based nanosystems for wound healing

INTRODUCTION

Wounds, resulting from traumas, surgery, burns or diabetes, are important medical problems due to the complexity of wound healing process regarding healing times and healthcare costs. Nanosystems have emerged as promising candidates in this field thank to their properties and versatile applications in drugs delivery.

AREAS COVERED

Lipid-based nanosystems (LBN) are described for wound treatment, highlighting their different behaviors when interacting with the cutaneous tissue. The role of nanosystems in delivering mostly natural compounds on skin as well as the technological and engineering strategies to increase their efficiency in wound healing effect are reviewed. Finally, in vitro, ex-vivo and in vivo studies are reported.

EXPERT OPINION

LBN have shown promise in addressing the challenges of wound healing as they can improve the stability of drugs used in wound therapy, leading to higher efficacy and fewer adverse effects as compared to traditional formulations. LBNs being involved in the inflammatory and proliferation stages of the wound healing process, enable the modification of wound healing through multiple ways. In addition, the use of new technologies, including 3D bioprinting and photobiomodulation, may lead to potential breakthroughs in wound healing. This would provide clinicians with more potent forms of therapy for wound healing.

Isorhamnetin inhibits hypertrophic scar formation through TGF-β1/Smad and TGF-β1/CREB3L1 signaling pathways

Background

Hypertrophic scar (HS) is a common fibrotic skin disease that occurs secondary to burns or injuries. The activation of the TGF-β signaling pathway contributes immensely to HS formation. Isorhamnetin (ISO) is a type of flavonoid compound that exerts an antifibrotic effect via TGF-β signaling suppression. However, whether ISO can inhibit HS formation via TGF-β signaling is yet to be elucidated. This study aimed to examine the influence of ISO on HS pathogenesis and TGF-β signaling, especially the downstream molecules and networks of TGF-β signaling that facilitate HS formation.

Methods

Hypertrophic scar fibroblasts (HSFBs) were isolated from human HS tissues. The in vitro proliferation, migration, contractile ability, cell cycle, and apoptosis of HSFBs after ISO treatment were determined using cell viability assay, EdU staining, wound healing assay, collagen gel contraction assay, and flow cytometry. The expressions of genes and proteins involved in TGF-β signaling and its downstream molecules in ISO-treated HSFBs were determined using quantitative PCR (qPCR), immunofluorescence, and western blotting. In vivo, a rabbit HS model was established, and the effects of ISO on rabbit HS formation were investigated using histological analysis, immunohistochemical staining, and qPCR.

Results

In vitro studies indicated that ISO treatment suppressed the proliferation, migration, and contractile ability of HSFBs; attenuated the expressions of COL Ⅰ, COL Ⅲ, and α-SMA; and inhibited TGF-β1 signaling-induced activation of HSFBs by decreasing the levels of phosphorylated Smad2/3 and cleaved CREB3L1 in a dose-dependent manner. Furthermore, ISO augmented apoptosis and G2 phase cell cycle arrest of HSFBs by upregulating the expressions of the proapoptotic proteins Bax and cleaved caspase-3 and downregulating the expression of the antiapoptotic protein Bcl-2. In vivo studies revealed that ISO ameliorated HS formation in the rabbit ear by lowering the scar elevation index, attenuating the collagen density, facilitating the regular arrangement of collagen fibers, and downregulating the expressions of TGF-β1, CREB3L1, COL Ⅰ, COL Ⅲ, and α-SMA.

Conclusions

ISO suppressed HS pathogenesis by dampening TGF-β1/Smad and TGF-β1/CREB3L1 signaling pathways, which suggests that it may serve as a candidate inhibitor of TGF-β1 signaling and a promising anti-HS drug with a high therapeutic potential.

Advances in skin gene therapy: utilizing innovative dressing scaffolds for wound healing, a comprehensive review

The skin, serving as the body's outermost layer, boasts a vast area and intricate structure, functioning as the primary barrier against external threats. Disruptions in the composition and functionality of the skin can lead to a diverse array of skin conditions, such as wounds, burns, and diabetic ulcers, along with inflammatory disorders, infections, and various types of skin cancer. These disorders not only exacerbate concerns regarding skin health and beauty but also have a significant impact on mental well-being. Due to the complexity of these disorders, conventional treatments often prove insufficient, necessitating the exploration of new therapeutic approaches. Researchers develop new therapies by deciphering these intricacies and gaining a thorough understanding of the protein networks and molecular processes in skin. A new window of opportunity has opened up for improving wound healing processes because of recent advancements in skin gene therapy. To enhance skin regeneration and healing, this extensive review investigates the use of novel dressing scaffolds in conjunction with gene therapy approaches. Scaffolds that do double duty as wound protectors and vectors for therapeutic gene delivery are being developed using innovative biomaterials. To improve cellular responses and speed healing, these state-of-the-art scaffolds allow for the targeted delivery and sustained release of genetic material. The most recent developments in gene therapy techniques include RNA interference, CRISPR-based gene editing, and the utilization of viral and non-viral vectors in conjunction with scaffolds, which were reviewed here to overcome skin disorders and wound complications. In the future, there will be rare chances to develop custom methods for skin health care thanks to the combination of modern technology and collaboration among disciplines.

IL-17 in wound repair: bridging acute and chronic responses

Chronic wounds, resulting from persistent inflammation, can trigger a cascade of detrimental effects including exacerbating inflammatory cytokines, compromised blood circulation at the wound site, elevation of white blood cell count, increased reactive oxygen species, and the potential risk of bacterial infection. The interleukin-17 (IL-17) signaling pathway, which plays a crucial role in regulating immune responses, has been identified as a promising target for treating inflammatory skin diseases. This review aims to delve deeper into the potential pathological role and molecular mechanisms of the IL-17 family and its pathways in wound repair. The intricate interactions between IL-17 and other cytokines will be discussed in detail, along with the activation of various signaling pathways, to provide a comprehensive understanding of IL-17's involvement in chronic wound inflammation and repair.

Microplastics in aquaculture - Potential impacts on inflammatory processes in Nile tilapia

Aquaculture is essential for meeting the growing global demand for fish consumption. However, the widespread use of plastic and the presence of microplastics in aquaculture systems raise concerns about their impact on fish health and the safety of aquaculture products. This study focused on the Nile tilapia (Oreochromis niloticus), one of the most important aquaculture fish species globally. The aim of this study was to investigate the effects of dietary exposure to a mixture of four conventional fossil fuel-based polymers (microplastics) on the health of adult and juvenile Nile tilapia. Two experiments were conducted, with 36 juvenile tilapia (10-40 g weight) exposed for 30 days and 24 adult tilapia (600-1000 g) exposed for 7 days, the former including a natural particle (kaolin) treatment. In the adult tilapia experiment, no significant effects on intestinal health (Ussing chamber method), oxidative stress, or inflammatory pathways (enzymatic and genetic biomarkers) were observed after exposure to the microplastic mixture. However, in the juvenile tilapia experiment, significant alterations in inflammatory pathways were observed following 30 days of exposure to the microplastic mixture, indicating potential adverse effects on fish health. These results highlight the potential negative impacts of microplastics on fish health and the economics and safety of aquaculture.

Genome-wide analysis of early vascular tunic repair and regeneration for Botrylloides digenesis reveals striking similarities to human wound healing

The early stages of regeneration after injury are similar to those of wound healing. The ascidian Botrylloides diegensis can regenerate an entire adult from a small fragment of vascular tunic following the removal of all zooids in an injury-induced regeneration model. We investigated the molecular and cellular changes following injury to determine the differences between the healing process and the initiation of whole-body regeneration (WBR). We conducted transcriptome analysis at specific time points during regeneration and wound healing to identify differentially expressed genes (DEGs) and the unique biological processes associated with each state. Our findings revealed 296 DEGs at 10 h post-injury (hpi), with 71 highly expressed in healed tissue and 225 expressed during the WBR process. These DEGs were predicted to play roles in tissue reorganization, integrin signaling, extracellular matrix organization, and the innate immune system. Pathway analysis of the upregulated genes in the healed tunic indicated functional enrichment related to tissue repair, as has been observed in other species. Additionally, we examined the cell types in the tunic and ampullae in both tissue states using histology and in situ hybridization for six genes identified by transcriptome analysis. We observed strong mRNA expression in cells within the WBR tunic, and in small RNA-positive granules near the tunic edge. We hypothesized that many of these genes function in the compaction of the ampullae tunic, which is a pivotal process for WBR and dormancy in B. diegensis, and in an immune response. These findings establish surprising similarities between ascidian regeneration and human wound healing, emphasizing the potential for future investigations into human regenerative and repair mechanisms. This study provides valuable insights into the gene sets specifically activated during regeneration compared to wound healing, shedding light on the divergent activities of these processes.

Substance P promotes transforming growth factor-β-induced collagen synthesis in human corneal fibroblasts

Corneal fibroblasts maintain homeostasis of the corneal stroma by mediating the synthesis and degradation of extracellular collagen, and these actions are promoted by transforming growth factor-β (TGF-β) and interleukin-1β (IL-1β), respectively. The cornea is densely innervated with sensory nerve fibers that are not only responsible for sensation but also required for physiological processes such as tear secretion and wound healing. Loss or dysfunction of corneal nerves thus impairs corneal epithelial wound healing and can lead to neurotrophic keratopathy. The sensory neurotransmitter substance P (SP) promotes corneal epithelial wound healing by enhancing the stimulatory effects of growth factors and fibronectin. We have now investigated the role of SP in collagen metabolism mediated by human corneal fibroblasts in culture. Although SP alone had no effect on collagen synthesis or degradation by these cells, it promoted the stimulatory effect of TGF-β on collagen type I synthesis without affecting that of IL-1β on the expression of matrix metalloproteinase-1. This effect of SP on TGF-β-induced collagen synthesis was accompanied by activation of p38 mitogen-activated protein kinase (MAPK) signaling and was attenuated by pharmacological inhibition of p38 or of the neurokinin-1 receptor. Our results thus implicate SP as a modulator of TGF-β-induced collagen type I synthesis by human corneal fibroblasts, and they suggest that loss of this function may contribute to the development of neurotrophic keratopathy.NEW & NOTEWORTHY This study investigates the role of substance P (SP) in collagen metabolism mediated by human corneal fibroblasts in culture. We found that, although SP alone had no effect on collagen synthesis or degradation by corneal fibroblasts, it promoted the stimulatory effect of transforming growth factor-β on collagen type I synthesis without affecting that of interleukin-1β on the expression of matrix metalloproteinase-1.

Acne-induced pathological scars: pathophysiology and current treatments

Acne is a common chronic inflammatory dermatosis that can lead to pathological scars (PSs, divided into hypertrophic scars and keloids). These kinds of abnormal scars seriously reduce the quality of life of patients. However, their mechanism is still unclear, resulting in difficult clinical prevention, unstable treatment effects and a high risk of recurrence. Available evidence supports inflammatory changes caused by infection as one of the keys to abnormal proliferation of skin fibroblasts. In acne-induced PSs, increasing knowledge of the immunopathology indicates that inflammatory cells directly secrete growth factors to activate fibroblasts and release pro-inflammatory factors to promote the formation of PSs. T helper cells contribute to PSs via the secretion of interleukin (IL)-4 and IL-13, the pro-inflammatory factors; while regulatory T cells have anti-inflammatory effects, secrete IL-10 and prostaglandin E2, and suppress fibrosis production. Several treatments are available, but there is a lack of combination regimens to target different aspects of acne-induced PSs. Overall, this review indicates that the joint involvement of inflammatory response and fibrosis plays a crucial role in acne-induced PSs, and also analyzes the interaction of current treatments for acne and PS.

Epigenetic regulation of TGF-β pathway and its role in radiation response

PURPOSE

Transforming growth factor (TGF-β) plays a dual role in tumor progression as well as a pivotal role in radiation response. TGF-β-related epigenetic regulations, including DNA methylation, histone modifications (including methylation, acetylation, phosphorylation, ubiquitination), chromatin remodeling and non-coding RNA regulation, have been found to affect the occurrence and development of tumors as well as their radiation response in multiple dimensions. Due to the significance of radiotherapy in tumor treatment and the essential roles of TGF-β signaling in radiation response, it is important to better understand the role of epigenetic regulation mechanisms mediated by TGF-β signaling pathways in radiation-induced targeted and non-targeted effects.

CONCLUSIONS

By revealing the epigenetic mechanism related to TGF-β-mediated radiation response, summarizing the existing relevant adjuvant strategies for radiotherapy based on TGF-β signaling, and discovering potential therapeutic targets, we hope to provide a new perspective for improving clinical treatment.

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.

Alternative viewpoint against diabetic wound based on stem cell secretome that can mediated angiogenesis and reduce inflammation

Diabetes mellitus, as an important metabolic disorder, affects the health of millions of people worldwide. A diabetic wound is one of the complications of diabetes. The stem cell secretome can particularly affect the wound healing process in diabetic wounds. The present study aimed to investigate the effects of Adipose-derived stem cells (ASCs) secretome on the skin wound healing process, angiogenesis, and inflammation in diabetic rats. For this purpose, ASCs were extracted from Adipose tissue and confirmed by flow cytometry and cell differentiation. Secretome was prepared. 27 rats were divided into three groups, non-diabetic, diabetic (treated with phosphate-buffered saline), and diabetics treated with secretome. The levels of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) were examined by the enzyme-linked immunosorbent assay (ELISA) was performed in the skin tissues of all groups. Hematoxylin and eosin (H&E) staining was performed. The level of VEGF was higher in the diabetic group treated with secretome as compared to the other two groups, while the level of TGF-β was lower in this group, compared to the diabetic group. Based on the results of H&E staining, the epidermal thickness and angiogenesis were higher in the diabetic group treated with secretome, whereas edema, number of inflammatory cells, and epidermal damage were lower in this group, compared to the diabetic group. Subcutaneous injection of secretome can lead to diabetic wound healing by increasing growth factors associated with angiogenesis such as VEGF, increasing angiogenesis, regulating TGF-β levels, reducing inflammatory cells.

Continuum of care in hard-to-heal wounds by copper dressings: a case series

OBJECTIVE

The quest for an ideal wound dressing has been a longstanding challenge due to the complex nature of wound healing, including stages of haemostasis, inflammation, maturation and remodelling, with overlapping timelines. This makes it difficult to find a single dressing that optimally supports all phases of wound healing. In addition, the ideal wound dressing should possess antibacterial properties and be capable of effectively debriding and lysing necrotic tissue. Copper is an essential trace element that participates in many of the key physiological wound healing processes.

METHOD

Copper stimulates secretion of various cytokines and growth factors, thus promoting angiogenesis, granulation tissue formation, extracellular matrix proteins secretion and re-epithelialisation. Harnessing this knowledge, we have used copper oxide-impregnated wound dressings in numerous cases and observed their benefits throughout the entire wound healing process.

RESULTS

This led us to postulate the 'continuum of care' hypothesis of copper dressings. In this study we describe four cases of hard-to-heal wounds of various aetiologies, in which we applied copper dressings consistently across all stages of wound healing, with rapid uneventful healing.

CONCLUSION

We believe we have successfully implemented the continuum of care principle.

Extracellular vesicles modulate key signalling pathways in refractory wound healing

Chronic wounds are wounds that cannot heal properly due to various factors, such as underlying diseases, infection or reinjury, and improper healing of skin wounds and ulcers can cause a serious economic burden. Numerous studies have shown that extracellular vesicles (EVs) derived from stem/progenitor cells promote wound healing, reduce scar formation and have significant advantages over traditional treatment methods. EVs are membranous particles that carry various bioactive molecules from their cellular origins, such as cytokines, nucleic acids, enzymes, lipids and proteins. EVs can mediate cell-to-cell communication and modulate various physiological processes, such as cell differentiation, angiogenesis, immune response and tissue remodelling. In this review, we summarize the recent advances in EV-based wound healing, focusing on the signalling pathways that are regulated by EVs and their cargos. We discuss how EVs derived from different types of stem/progenitor cells can promote wound healing and reduce scar formation by modulating the Wnt/β-catenin, phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin, vascular endothelial growth factor, transforming growth factor β and JAK-STAT pathways. Moreover, we also highlight the challenges and opportunities for engineering or modifying EVs to enhance their efficacy and specificity for wound healing.

A role for vitamin D and the vitamin D receptor in keloid disorder

Keloids are disfiguring fibroproliferative lesions that can occur in susceptible individuals following any skin injury. They are extremely challenging to treat, with relatively low response rates to current therapies and high rates of recurrence after treatment. Although several distinct genetic loci have been associated with keloid formation in different populations, there has been no single causative gene yet identified and the molecular mechanisms guiding keloid development are incompletely understood. Further, although it is well known that keloids are more commonly observed in populations with dark skin pigmentation, the basis for increased keloid risk in skin of colour is not yet known. Because individuals with dark skin pigmentation are at higher risk for vitamin D deficiency, the role of vitamin D in keloid pathology has gained interest in the keloid research community. A limited number of studies have found lower serum vitamin D levels in patients with keloids, and reduced expression of the vitamin D receptor (VDR) in keloid lesions compared with uninjured skin. Vitamin D has documented anti-inflammatory, anti-proliferative and pro-differentiation activities, suggesting it may have a therapeutic role in suppression of keloid fibrosis. Here we review the evidence supporting a role for vitamin D and VDR in keloid pathology.

Therapeutic Potential of Nanocarrier-Mediated Delivery of Phytoconstituents for Wound Healing: Their Current Status and Future Perspective

The treatment of wounds is a serious problem all over the world and imposes a huge financial burden on each and every nation. For a long time, researchers have explored wound dressing that speeds up wound healing. Traditional wound dressing does not respond effectively to the wound-healing process as expected. Therapeutic active derived from plant extracts and extracted bioactive components have been employed in various regions of the globe since ancient times for the purpose of illness, prevention, and therapy. About 200 years ago, most medical treatments were based on herbal remedies. Especially in the West, the usage of herbal treatments began to wane in the 1960s as a result of the rise of allopathic medicine. In recent years, however, there has been a resurgence of interest in and demand for herbal medicines for a number of reasons, including claims about their efficacy, shifting consumer preferences toward natural medicines, high costs and negative side effects of modern medicines, and advancements in herbal medicines brought about by scientific research and technological innovation. The exploration of medicinal plants and their typical uses could potentially result in advanced pharmaceuticals that exhibit reduced adverse effects. This review aims to present an overview of the utilization of nanocarriers in plant-based therapeutics, including its current status, recent advancements, challenges, and future prospects. The objective is to equip researchers with a comprehensive understanding of the historical background, current state, and potential future developments in this emerging field. In light of this, the advantages of nanocarriers based delivery of natural wound healing treatments have been discussed, with a focus on nanofibers, nanoparticles, nano-emulsion, and nanogels.

Role of NADPH Oxidase 4 in Corneal Endothelial Cells Is Mediated by Endoplasmic Reticulum Stress and Autophagy

Human corneal-endothelial cells (hCEnCs) are located on the inner layer of the cornea. Injury to CEnCs leads to permanent corneal edema, requiring corneal transplantation. NADPH oxidase 4 (NOX4) has been reported to be implicated in the pathogenesis of CEnCs diseases. Thus, we investigated the role of NOX4 in CEnCs in this study. In an animal study, siRNA for NOX4 (siNOX4) or plasmid for NOX4 (pNOX4) was introduced into the corneal endothelium of rats by electroporation, using a square-wave electroporator (ECM830, Havard apparatus) to decrease or increase the expression of NOX4, respectively, and the rat corneas were cryoinjured through contact with a metal rod of 3 mm diameter frozen in liquid nitrogen for 10 min. The immunofluorescence staining of NOX4 and 8-OHdG showed that the levels of NOX4 and 8-OHdG were decreased in the siNOX4 group compared to the siControl, and increased in the pNOX4 group compared to the pControl at one week after treatment. Without cryoinjury, corneal opacity was more severe, and the density of CEnCs was lower, in pNOX4-treated rats compared to pControl. After cryoinjury, the corneas were more transparent, and the CEnC density was higher, in siNOX4-treated rats. The hCEnCs were cultured and transfected with siNOX4 and pNOX4. The silencing of NOX4 in hCEnCs resulted in a normal cell shape, higher viability, and higher proliferation rate than those transfected with the siControl, while NOX4 overexpression had the opposite effect. NOX4 overexpression increased the number of senescent cells and intracellular oxidative stress levels. NOX4 overexpression increased ATF4 and ATF6 levels, and nuclear translocation of XBP-1, which is the endoplasmic reticulum (ER) stress marker, while the silencing of NOX4 had the opposite effect. Additionally, the mitochondrial membrane potential was hyperpolarized by the silencing of NOX4, and depolarized by NOX4 overexpression. The LC3II levels, a marker of autophagy, were decreased by the silencing of NOX4, and increased by NOX4 overexpression. In conclusion, NOX4 plays a pivotal role in the wound-healing and senescence of hCEnCs, by modulating oxidative stress, ER stress, and autophagy. The regulation of NOX4 may be a potential therapeutic strategy for regulating the homeostasis of CEnCs, and treating corneal-endothelial diseases.

Natural exosome-like nanoparticles derived from ancient medicinal insect Periplaneta americana L. as a novel diabetic wound healing accelerator

Along with the recognized therapeutic outcomes of regenerative medicine, extracellular vesicles and their exosome subsets have become an alternative option for wound healing. Periplaneta americana L. (PA), an ancient and traditional medicinal insect, has been around for 300 million years, and displays magic formidable vitality and environmental adaptive ability. The linkage between intrinsic amputation regeneration feature and the acknowledged wound healing medicinal benefit of PA has never been revealed. Herein, inspired by the ability of exosomes to participate in the interkingdom communication, we explored whether this effect was ascribed to PA derived exosome-like nanoparticles (PA-ELNs). PA-ELNs were extracted by differential velocity centrifugation approach and characterized by DLS, NTA and TEM. Their cargoes were analyzed by LC-MS/MS proteomics and small RNA-seq analysis. The wound healing activity was verified in vivo and in vitro. PA-ELNs with a concentration of 2.33x10⁹±6.35x10⁷ particles/mL exhibited a lipid bilayer-bound membrane structure with an average size of 104.7 nm. Furthermore, the miRNA cargoes in PA-ELNs participate in some wound healing related signal pathways such as TGF-beta, mTOR, and autophagy. As expected, the in vitro tests indicated that PA-ELNs were apt to be internalized in HUVECs, L929 and RAW 264.7 cells and contributed to cell proliferation and migration. Most importantly, we demonstrated that the topical administration of PA-ELNs could remarkably accelerate wound healing in a diabetic mouse model, and was involved in anti-inflammatory, re-epithelialization and autophagy regulation. This study provides clear evidence for the first time that PA-ELNs, as diabetic wound healing accelerators, are the "bioactive code" of this ancient medicinal insect.

Our experience of using Losartan for esophageal stenosis in children with dystrophic form of congenital epidermolysis bullosa

INTRODUCTION

Dystrophic epidermolysis bullosa (DEB) is one of the most severe forms of congenital epidermolysis bullosa and characterized by the formation of many surgical complications. Esophageal stenosis is a common complication of DEB and occurs in almost 76% of cases. Balloon dilatation (BD) under X-ray control is the main therapeutic technique, however conservative treatment is necessary to prevent restenosis. The use of the drug losartan is promising due to its antifibrotic effect through the suppression of transforming growth factor-β1 (TGF-β1).

PURPOSE

To evaluate the efficacy of losartan in the prevention of restenosis after BD of esophageal stenosis in children with DEB.

MATERIALS AND METHODS

The study included 19 children from 2 to 16 years old (mean age 9.2 ± 3.58 years) with DEB and X-ray confirmed esophageal stenosis. All children underwent BD. In the main group 9 children after BD have received losartan, in the control group of 10 children - only standard therapy. The observation period was 12 months.

RESULTS

In the main group, 1 child (11.1%) required repeated dilatation, in the control group - 4 children (40%). Indicators of nutritional deficiency (THINC scale) and the disease severity index (EBDASI) were significantly lower in the group of children treated with losartan. No undesirable actions of the drug were recorded.

CONCLUSIONS

In this study losartan showed its safety, contributed to a decrease in the restenosis frequency and an improvement in the nutritional status of children with DEB after BD. However, further studies are required to confirm its effectiveness.

LEVEL OF EVIDENCE

IV.

Jellyfishes—Significant Marine Resources with Potential in the Wound-Healing Process: A Review

The wound-healing process is a significant area of interest in the medical field, and it is influenced by both external and patient-specific factors. The aim of this review paper is to highlight the proven wound-healing potential of the biocompounds found in jellyfish (such as polysaccharide compounds, collagen, collagen peptides and amino acids). There are aspects of the wound-healing process that can benefit from polysaccharides (JSPs) and collagen-based materials, as these materials have been shown to limit exposure to bacteria and promote tissue regeneration. A second demonstrated benefit of jellyfish-derived biocompounds is their immunostimulatory effects on growth factors such as (TNF-α), (IFN-γ) and (TGF), which are involved in wound healing. A third benefit of collagens and polysaccharides (JSP) is their antioxidant action. Aspects related to chronic wound care are specifically addressed, and within this general theme, molecular pathways related to tissue regeneration are explored in depth. Only distinct varieties of jellyfish that are specifically enriched in the biocompounds involved in these pathways and live in European marine habitats are presented. The advantages of jellyfish collagens over mammalian collagens are highlighted by the fact that jellyfish collagens are not considered transmitters of diseases (spongiform encephalopathy) or various allergic reactions. Jellyfish collagen extracts stimulate an immune response in vivo without inducing allergic complications. More studies are needed to explore more varieties of jellyfish that can be exploited for their biocomponents, which may be useful in wound healing.

Perioperative Medication Management in Elective Plastic Surgery Procedures

BACKGROUND

Perioperative medication management is vital to maintain patient safety while under anesthesia, as well as to avoid postoperative complications. Plastic surgeons make daily decisions on whether to ask a patient to stop taking medication before their surgery. These important decisions can affect bleeding risk, wound healing, and interactions with anesthetics, which can range from minor to life-threatening. Current plastic surgery literature lacks a comprehensive review of perioperative medication management, with existing reports focusing on specific procedures and specific medication classes.

METHODS

A PubMed database search was conducted for articles through July 2021. The bibliographies of included studies were also examined for articles not acquired in the initial search queries. The authors included studies on medication usage and perioperative guidance in patients undergoing elective plastic surgery procedures. The authors excluded studies unrelated to plastic surgery and studies where the medications were used as an intervention. Abstracts, animal studies, studies involving the pediatric population, and book chapters were also excluded, as well as articles not published in English.

RESULTS

A total of 801 papers were identified by our search terms. After title and abstract screening, 35 papers were selected for full-text review. After full-text review, 20 papers were selected for inclusion, with an additional 6 papers from cited references added. Of the 26 papers, 6 papers discussed psychotropic drugs, 6 papers discussed medications affecting hemostasis, 4 papers discussed hormone-containing medications, 3 papers discussed antilipid medications, 2 papers discussed antihypertensive medications, 2 papers discussed herbal supplements, 1 paper discussed both psychotropic and herbal supplements, 1 paper discussed medications affecting wound healing, and 1 paper discussed rheumatologic medications. A summary of those recommendations was then compiled together.

CONCLUSIONS

The perioperative medication management in elective plastic surgery procedures remains a complex and multidisciplinary process. It is important to manage these patients in a case-by-case manner and to consult a specialist when necessary. Careful medication reconciliation is essential to decrease the likelihood of adverse outcomes and interactions with perioperative anesthetics.

Elucidating the Focal Immunomodulatory Clues Influencing Mesenchymal Stem Cells in the Milieu of Intervertebral Disc Degeneration

The intervertebral discs (IVDs) are a relatively mobile joint that interconnects vertebrae of the spine. Intervertebral disc degeneration (IVDD) is one of the leading causes of low back pain, which is most often related to patient morbidity as well as high medical costs. Patients with chronic IVDD often need surgery that may sometimes lead to biomechanical complications as well as augmented degeneration of the adjacent segments. Moreover, treatment modalities like rigid intervertebral fusion, dynamic instrumentation, as well as other surgical interventions are still controversial. Mesenchymal stem cells (MSCs) have exhibited to have immunomodulatory functions and the ability to differentiate into cartilage, making these cells possibly an epitome for IVD regeneration. Transplanted MSCs were able to repair IVDD back to the normal disc milieu via the activation of the generation of extracellular matrix (ECM) proteins such as aggrecan, proteoglycans and collagen types I and II. IVD milieu clues like, periostin, cluster of differentiation, tumor necrosis factor alpha, interleukins, chemokines, transforming growth factor beta, reactive oxygen species, toll-like receptors, tyrosine protein kinase receptor and disialoganglioside, exosomes are capable of influencing the MSCs during treatment of IVDD. ECM microenvironment clues above have potentials as biomarkers as well as accurate molecular targets for therapeutic intervention in IVDD.

Ginseng-derived nanoparticles induce skin cell proliferation and promote wound healing

Background

Past studies suggested that ginseng extracts and ginseng-derived molecules exerted significant regulatory effects on skin. However, no reports have described the effects of ginseng-derived nanoparticles (GDNPs) on skin cell proliferation and wound healing. In this study, we investigated whether GDNPs regulate the proliferation of skin cells and promote wound healing in a mouse model.

Methods

GDNPs were separated and purified via differential centrifugation and sucrose/D2O gradient ultracentrifugation. GDNP uptake, cell proliferation and cell cycle progression were measured by confocal microscopy, CCK-8 assay and flow cytometry, respectively. Cell migration and angiogenic effects were assessed by the wound scratch assay and tube formation assay, respectively. ELISA was used to detect extracellular matrix secretion. The relevant signaling pathway was confirmed by western blotting. The effects of GDNPs on skin wound healing were assessed by wound observation, HE staining, and western blotting.

Results

GDNPs possessed the essential features of exosomes, and they were accumulated by skin cells. Treatment with GDNPs notably enhanced the proliferation of HaCaT, BJ and HUVECs. GDNPs also enhanced the migration in HaCaT cells and HUVECs and angiogenesis in HUVECs. GDNPs increased the secretion of MMP-1, fibronectin-1, elastin-1, and COL1A1 in all three cell lines. GDNPs regulated cell proliferation through the ERK and AKT/ mTOR pathways. Furthermore, GDNPs facilitated skin wound healing and decreased inflammation in a mouse skin wound model.

Conclusion

GDNPs can promote skin wound healing through the ERK and AKT/mTOR pathways. GDNPs thus represent an alternative treatment for chronic skin wounds.

Smurf2 Regulates Inflammation and Collagen Processing in Cutaneous Wound Healing through Transforming Growth Factor-β/Smad3 Signaling

Wound healing is a highly conserved process that restores the integrity and functionality of injured tissues. Transforming growth factor (TGF)-β is a master regulator of wound healing, whose signaling is attenuated by the E3 ubiquitin ligase Smurf2. Herein, the roles of Smurf2 in cutaneous wound healing were examined using a murine incisional cutaneous model. Loss of Smurf2 increased early inflammation in the wounds and led to narrower wounds with greater breaking strength. Loss of Smurf2 also led to more linearized collagen bundles in normal and wounded skin. Gene expression analyses by real-time quantitative PCR indicated that Smurf2-deficient fibroblasts had increased levels of TGF-β/Smad3 signaling and changes in expression profile of genes related to matrix turnover. The effect of Smurf2 loss on wound healing and collagen bundling was attenuated by the heterozygous loss of Smad3. Together, these results show that Smurf2 affects inflammation and collagen processing in cutaneous wounds by down-regulating TGF-β/Smad3 signaling.

Tiny tots for a big-league in wound repair: Tools for tissue regeneration by nanotechniques of today

Overall, chronic injuries place considerable burden on patients and health systems. The skin injuries are exposed to inflammatory bacteria and hinder the healing process. The skin being the biggest tissue of the whole body ensures protection against microbial invasion, dehydration, and against chemical, thermal, bright radiations and mechanical agents. When injured, the skin loses its defensive purpose and the attack of bacterial types arises with the loss of protein, water, and electrolytes. Improved wound closure therapy helps to restore normal skin function by managing wounds with the help of a suitable skin replacement. According to the type of wound and its healing ability, an appropriate skin replacement system must be identified. Nanofibrous layers because of their permeable structure, their large superficial reach and their similarity with the local extracellular network serve as cutaneous substitution for dealing with deep and superficial injuries. By a diminished microbial load without infestation, scab formation and infiltration of defense cells in the initial phase, acute injuries are usually characterized. Here recovery is related with epithelialization, angiogenesis and relocation of fibroblasts. The wound becomes obstinate when microbial biofilms are developed while the immune system does not manage to eliminate the infection. Increased inflammatory process, lower deep tissue oxygenation, fibrin cuffs, fibroblastic senescence, altered angiogenesis, stalled re-epithelialization and chronic infection have been visualized. Conventional wound mending treatments for the most part falling flat to supply a great clinical result, either basically like wound epithelialization and regulation of fluid loss or practically like histological highlights that decide versatility, strength, affectability, etc. Conventional wound therapies commonly fail to offer a better medical output, like wound epithelialization and regulation of fluid reduction or physiologically like cellular features that determine durability, sensitivity, elasticity, etc. Nanotechnology may be a dependable investigation space for wound-healing treatments through their versatile physicochemical properties. Advancing nano platforms with novel solutions for curing chronicdiabetic wounds are discussed in detail that can guide further research in this sector.

Loureirin A Exerts Antikeloid Activity by Antagonizing the TGF-β1/Smad Signalling Pathway

It has been recently shown that loureirin A (LA), a major active component of resina draconis, might be effective in the prevention and treatment of liver fibrosis. We examined whether LA could inhibit the formation of keloids. To investigate the pharmacological effects of loureirin A on keloid formation and the underlying mechanisms. CellTiter-Blue viability assays were used to examine the proliferation of keloid fibroblasts (KFs) that were treated with LA. Fibroblast migration was evaluated using a cell migration assay. Immunofluorescence staining was used to measure the expression of α-SMA in KFs. RT-qPCR was used to evaluate the mRNA expression of Col-I, Col-III, α-SMA, Bax, and Caspase-3, while Western blotting was used to evaluate the protein expression of Col-I, Col-III, α-SMA, Bax, Caspase-3, p-Smad2, and p-Smad3. LA inhibited the proliferation of KFs and suppressed the migration and TGF-β1-induced myofibroblast differentiation of KFs. In addition, LA downregulated the mRNA and protein levels of Col-I, Col-III, and α-SMA while promoting the mRNA and protein levels of Bax and Caspase-3. Moreover, LA downregulated the protein levels of p-Smad2 and p-Smad3 in cultured TGF-β1-treated KFs ex vivo. These results show that LA has an antikeloid effect on KFs by suppressing the TGF-β1/Smad signalling pathway. Our findings suggest that LA may be a potential candidate drug for the prevention and treatment of keloids.

Investigation of the In Vivo, In Vitro, and In Silico Wound Healing Potential of Pinctada martensii Purified Peptides

Previous studies found that both oral and topical administration of enzymatic digestion products < 3 K Da ultrafiltration fractions of Pinctada martensii mantle (PMPs) had pro-healing effects. Thus, we further purified them by Sephadex-G25 and screened them by cellular assays to obtain Pinctada martensii purified peptides (PMPPs). In this study, we explored the mechanism of PMPPs on wound healing by in vivo, in vitro, and in silico experiments. LC-MS/MS results showed that PMPPs consisted of 33 peptides with molecular weights ranging from 758.43 to 2014.04 Da, and the characteristic peptide was Leu-Asp. The results of cellular assays showed that PMPPs promoted the proliferation of human skin fibroblasts (HSF) (135%) and human immortalized keratinocyte (HaCaT) cells (125%) very significantly at 12.5 μg/mL. The in vivo results showed that PMPPs could achieve scarless healing by inhibiting the inflammatory response, accelerating the epithelialization process, and regulating collagen I/III ratio. The optimal peptide sequence FAFQAEIAQLMS of PMPPs was screened for key protein receptors in wound healing (EGFR1, FGFR1, and MMP-1) with the help of molecular docking technique, which also showed to be the key pro-healing active peptide sequence. Therefore, it may provide a therapeutic strategy with great potential for wound healing.

The emerging therapeutic targets for scar management: genetic and epigenetic landscapes

Background

Wound healing is a complex process including hemostasis, inflammation, proliferation, and remodeling during which an orchestrated array of biological and molecular events occurs to promote skin regeneration. Abnormalities in each step of the wound healing process lead to reparative rather than regenerative responses, thereby driving the formation of cutaneous scar. Patients suffering from scars represent serious health problems such as contractures, functional and esthetic concerns as well as painful, thick, and itchy complications, which generally decrease the quality of life and impose high medical costs. Therefore, therapies reducing cutaneous scarring are necessary to improve patients' rehabilitation.

Summary

Current approaches to remove scars, including surgical and nonsurgical methods, are not efficient enough, which is in principle due to our limited knowledge about underlying mechanisms of pathological as well as the physiological wound healing process. Thus, therapeutic interventions focused on basic science including genetic and epigenetic knowledge are recently taken into consideration as promising approaches for scar management since they have the potential to provide targeted therapies and improve the conventional treatments as well as present opportunities for combination therapy. In this review, we highlight the recent advances in skin regenerative medicine through genetic and epigenetic approaches to achieve novel insights for the development of safe, efficient, and reproducible therapies and discuss promising approaches for scar management.

Key Message

Genetic and epigenetic regulatory switches are promising targets for scar management, provided the associated challenges are to be addressed.

Polydopamine Decorated Microneedles with Fe-MSC-Derived Nanovesicles Encapsulation for Wound Healing

Wound dressing with the capacities of antioxidation, antiinflammation, and efficient angiogenesis induction is expected for effectively promoting wound healing. Herein, a novel core-shell hyaluronic acid (HA) microneedle (MN) patch with ferrum-mesenchymal stem cell-derived artificial nanovesicles (Fe-MSC-NVs) and polydopamine nanoparticles (PDA NPs) encapsulated in the needle tips is presented for wound healing. Fe-MSC-NVs containing multifunctional therapeutic cytokines are encapsulated in the inner HA core of the MN tips for accelerating angiogenesis. The PDA NPs are encapsulated in the outer methacrylated hyaluronic acid (HAMA) shell of the MN tips to overcome the adverse impacts from reactive oxygen species (ROS)-derived oxidative stress. With the gradual degradation of HAMA patch tips in the skin, the PDA NPs are sustainably released at the lesion to suppress the ROS-induced inflammation reaction, while the Fe-MSC-NVs significantly increase the migration, proliferation, and tube formation of human umbilical vein endothelial cells (HUVEC). More attractively, the combination of PDA NPs and Fe-MSC-NVs further promotes M2 macrophage polarization, thereby suppressing wound inflammation. Through in vivo experiment, the Fe-MSC-NVs/PDA MN patch shows an excellent effect for diabetic wound healing. These features of antioxidation, antiinflammation, and pro-angiogenesis indicate the proposed composite core-shell MN patch is valuable for clinical wound healing applications.

Molecular alterations due to Col5a1 haploinsufficiency in a mouse model of classic Ehlers-Danlos syndrome

Type V collagen is a regulatory fibrillar collagen essential for type I collagen fibril nucleation and organization and its deficiency leads to structurally abnormal extracellular matrix (ECM). Haploinsufficiency of the Col5a1 gene encoding α(1) chain of type V collagen is the primary cause of classic Ehlers-Danlos syndrome (EDS). The mechanisms by which this initial insult leads to the spectrum of clinical presentation are not fully understood. Using transcriptome analysis of skin and Achilles tendons from Col5a1 haploinsufficient (Col5a1+/-) mice, we recognized molecular alterations associated with the tissue phenotypes. We identified dysregulation of ECM components including thrombospondin-1, lysyl oxidase, and lumican in the skin of Col5a1+/- mice when compared with control. We also identified upregulation of transforming growth factor β1 (Tgf-β) in serum and increased expression of pSmad2 in skin from Col5a1+/- mice, suggesting Tgf-β dysregulation is a contributor to abnormal wound healing and atrophic scarring seen in classic EDS. Together, these findings support altered matrix to cell signaling as a component of the pathogenesis of the tissue phenotype in classic EDS and point out potential downstream signaling pathways that may be targeted for the treatment of this disease.

Effects of Adipose-Derived Stem Cells and Their Conditioned Medium in a Human Ex Vivo Wound Model

Adult stem cells have been extensively investigated for tissue repair therapies. Adipose-derived stem cells (ASCs) were shown to improve wound healing by promoting re-epithelialization and vascularization as well as modulating the inflammatory immune response. In this study, we used ex vivo human skin cultured in a six-well plate with trans-well inserts as a model for superficial wounds. Standardized wounds were created and treated with allogeneic ASCs, ASCs conditioned medium (ASC-CM), or cell culture medium (DMEM) supplemented with fetal calf serum (FCS). Skin viability (XTT test), histology (hematoxylin and eosin, H and E), β-catenin expression as well as inflammatory mediators and growth factors were monitored over 12 days of skin culture. We observed only a moderate time-dependent decrease in skin metabolic activity while skin morphology was preserved, and re-epithelialization occurred at the wound edges. An increase in β-catenin expression was observed in the newly formed epithelia, especially in the samples treated with ASC-CM. In general, increased growth factors and inflammatory mediators, e.g., hepatocytes growth factor (HGF), platelet-derived growth factor subunit AA (PDGF-AA), IL-1α, IL-7, TNF-α, and IL-10, were observed over the incubation time. Interestingly, different expression profiles were observed for the different treatments. Samples treated with ASC-CM significantly increased the levels of inflammatory cytokines and PDGF-AA with respect to control, whereas the treatment with ASCs in DMEM with 10% FCS resulted in significantly increased levels of fibroblast growth factor-basic (FGF-basic) and moderate increases of immunomodulatory cytokines. These results confirm that the wound microenvironment can influence the type of mediators secreted by ASCs and the mode as to how they improve the wound healing process. Comparative investigations with pre-activated ASCs will elucidate further aspects of the wound healing mechanism and improve the protocols of ACS application.

Role of Betaglycan in TGF-β Signaling and Wound Healing in Human Endometriotic Epithelial Cells and in Endometriosis

Endometriosis is characterized by the presence of ectopic endometrium most often in the pelvis. The transforming growth factor-beta (TGF-β) superfamily is also involved in the pathogenesis; however, betaglycan (BG, syn. TGF-β type III receptor) as an important co-receptor was not studied. We analyzed mainly BG ectodomain shedding because released soluble BG (sBG) often antagonizes TGF-β signaling. Furthermore, we studied the role of TGF-βs and BG in wound healing and evaluated the suitability of BG measurements in serum and endocervical mucus for non-invasive diagnosis of endometriosis. Evaluation of the BG shedding and signaling pathways involved as well as wound healing was performed with enzyme-linked immune assays (ELISAs), reverse transcription-quantitative polymerase chain reaction (RT-qPCR), small interfering RNA (siRNA) knockdown, and scratch assays with human endometriotic epithelial cells. TGF-β1/2 stimulation resulted in a significant dose-dependent reduction in BG shedding in endometriotic cells, which was TGF-β/activin receptor-like kinase-5 (ALK-5)/mother against decapentaplegic homolog3 (SMAD3)- but not SMAD2-dependent. Inhibition of matrix metalloproteinases (MMPs) using the pan-MMP inhibitor GM6001 and tissue inhibitor of MMPs (TIMP3) equally attenuated BG shedding, signifying the involvement of MMPs in shedding. Likewise, recombinant BG moderately reduced the secretion of TGF-β1/2 and wound healing of endometriotic cells. TGF-β1 significantly enhanced the secretion of MMP2 and MMP3 and moderately promoted wound healing. In order to evaluate the role of BG in endometriosis, serum (n = 238) and mucus samples (n = 182) were analyzed. Intriguingly, a significant reduction in the levels of sBG in endocervical mucus but not in the serum of endometriosis patients compared to controls was observed. Collectively, these observations support a novel role for BG in the pathophysiology of endometriosis.

The Interplay Between TGF-β Signaling and Cell Metabolism

The transforming growth factor-β (TGF-β) signaling plays a critical role in the development and tissue homeostasis in metazoans, and deregulation of TGF-β signaling leads to many pathological conditions. Mounting evidence suggests that TGF-β signaling can actively alter metabolism in diverse cell types. Furthermore, metabolic pathways, beyond simply regarded as biochemical reactions, are closely intertwined with signal transduction. Here, we discuss the role of TGF-β in glucose, lipid, amino acid, redox and polyamine metabolism with an emphasis on how TGF-β can act as a metabolic modulator and how metabolic changes can influence TGF-β signaling. We also describe how interplay between TGF-β signaling and cell metabolism regulates cellular homeostasis as well as the progression of multiple diseases, including cancer.

Lipoaspirate Shows In Vitro Potential for Wound Healing

Mesenchymal stem cells (MSCs) are a promising therapy in wound healing, although extensive time and manipulation are necessary for their use. In our previous study on cartilage regeneration, we demonstrated that lipoaspirate acts as a natural scaffold for MSCs and gives rise to their spontaneous outgrowth, together with a paracrine effect on resident cells that overcome the limitations connected to MSC use. In this study, we aimed to investigate in vitro whether the microfragmented adipose tissue (lipoaspirate), obtained with Lipogems^® technology, could promote and accelerate wound healing. We showed the ability of resident cells to outgrow from the clusters of lipoaspirate encapsulated in a 3D collagen substrate as capability of repopulating a culture of human skin. Moreover, we demonstrated that the in vitro lipoaspirate paracrine effect on fibroblasts and keratinocytes proliferation, migration, and contraction rate is mediated by the release of trophic/reparative proteins. Finally, an analysis of the paracrine antibacterial effect of lipoaspirate proved its ability to secrete antibacterial factors and its ability to modulate their secretion in culture media based on a bacterial stimulus. The results suggest that lipoaspirate may be a promising approach in wound healing showing in vitro regenerative and antibacterial activities that could improve current therapeutic strategies.

Decellularized Tissues for Wound Healing: Towards Closing the Gap Between Scaffold Design and Effective Extracellular Matrix Remodeling

The absence or damage of a tissue is the main cause of most acute or chronic diseases and are one of the appealing challenges that novel therapeutic alternatives have, in order to recover lost functions through tissue regeneration. Chronic cutaneous lesions are the most frequent cause of wounds, being a massive area of regenerative medicine and tissue engineering to have efforts to develop new bioactive medical products that not only allow an appropriate and rapid healing, but also avoid severe complications such as bacterial infections. In tissue repair and regeneration processes, there are several overlapping stages that involve the synergy of cells, the extracellular matrix (ECM) and biomolecules, which coordinate processes of ECM remodeling as well as cell proliferation and differentiation. Although these three components play a crucial role in the wound healing process, the ECM has the function of acting as a biological platform to permit the correct interaction between them. In particular, ECM is a mixture of crosslinked proteins that contain bioactive domains that cells recognize in order to promote migration, proliferation and differentiation. Currently, tissue engineering has employed several synthetic polymers to design bioactive scaffolds to mimic the native ECM, by combining biopolymers with growth factors including collagen and fibrinogen. Among these, decellularized tissues have been proposed as an alternative for reconstructing cutaneous lesions since they maintain the complex protein conformation, providing the required functional domains for cell differentiation. In this review, we present an in-depth discussion of different natural matrixes recently employed for designing novel therapeutic alternatives for treating cutaneous injuries, and overview some future perspectives in this area.

Polyphosphate in Chronic Wound Healing: Restoration of Impaired Metabolic Energy State

Many pathological conditions are characterized by a deficiency of metabolic energy. A prominent example is nonhealing or difficult-to-heal chronic wounds. Because of their unique ability to serve as a source of metabolic energy, inorganic polyphosphates (polyP) offer the opportunity to develop novel strategies to treat such wounds. The basis is the generation of ATP from the polymer through the joint action of two extracellular or plasma membrane-bound enzymes alkaline phosphatase and adenylate kinase, which enable the transfer of energy-rich phosphate from polyP to AMP with the formation of ADP and finally ATP. Building on these findings, it was possible to develop novel regeneratively active materials for wound therapy, which have already been successfully evaluated in first studies on patients.

Acceleration of chronic wound healing by bio-inorganic polyphosphate: In vitro studies and first clinical applications

The healing of chronic wounds is impaired by a lack of metabolic energy. In previous studies, we showed that physiological inorganic polyphosphate (polyP) is a generator of metabolic energy by forming ATP as a result of the enzymatic cleavage of the high-energy phosphoanhydride bonds of this polymer. Therefore, in the present study, we investigated whether the administration of polyP can substitute for the energy deficiency in chronic wound healing. Methods: PolyP was incorporated into collagen mats and applied in vitro and to patients in vivo. Results: (i) In vitro studies: Keratinocytes grown in vitro onto the polyP/collagen mats formed long microvilli to guide them to a favorable environment. HUVEC cells responded to polyP/collagen mats with an increased adhesion and migration propensity as well as penetration into the mats. (ii) In vivo - human clinical studies: In a "bench to bedside" process these promising in vitro results were translated from the laboratory into the clinic. In the proof-of-concept application, the engineered polyP/collagen mats were applied to chronic wounds in patients. Those mats impressively accelerated the re-epithelialization rate, with a reduction of the wound area to 65% after 3 weeks and to 36.6% and 22.5% after 6 and 9 weeks, respectively. Complete healing was achieved and no further treatment was necessary. Biopsy samples from the regenerating wound area showed predominantly myofibroblasts. The wound healing process was supported by the use of a polyP containing moisturizing solution. Conclusion: The results strongly recommend polyP as a beneficial component in mats for a substantial healing of chronic wounds.

Local Application of Transcutaneous Carbon Dioxide Paste Decreases Inflammation and Accelerates Wound Healing

INTRODUCTION

 Delayed wound healing after surgery lowers the long-term quality of a patient's life and leads to discomfort and pain. However, treatments for wound healing are often difficult and have not yet been fully established. In this study, we investigated the effect of a special paste that can be administered transdermally and holds a non-gaseous carbon dioxide (CO₂) source in its carrier, which can be applied to the head and neck region for wound healing in a rat skin defect model.

METHODS

Forty-eight Sprague Dawley rats were randomized into control and CO₂ groups. We punched a 6.2-mm wound on the back of each rat. The control rats were left untreated, whereas rats in the CO₂ group were treated with the CO₂ paste every day after surgery. We evaluated wound healing 3, 7, 14, and 21 days after wounding by analyzing the diameter of the wound, gene expression of inflammatory markers vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β, hypoxia-inducible factor (HIF)-1α, interleukin (IL)-1β, and IL-6 using quantitative real-time polymerase chain reaction, hematoxylin and eosin, and immunohistochemical staining patterns.

RESULTS

Rats in the CO₂ group showed accelerated wound healing compared to those in the control group. Furthermore, VEGF and TGF-β were overexpressed, whereas HIF-1α, IL-1β, and IL-6 were downregulated in the rats treated with CO₂. Immunohistochemical analysis also revealed similar patterns of expression.

CONCLUSION

Taken together, the CO₂ paste promoted wound healing by regulating the hypoxic environment, reducing inflammation, and accelerating angiogenesis.

Effect of Skeletal Paracrine Signals on the Proliferation of Interzone Cells

OBJECTIVE

Articular cartilage in mammals has limited intrinsic capacity to repair structural defects, a fact that contributes to the chronic and progressive nature of osteoarthritis. In contrast, Mexican axolotl salamanders have demonstrated the remarkable ability to spontaneously and completely repair large joint cartilage lesions, a healing process that involves interzone cells in the intraarticular space. Furthermore, interzone tissue transplanted into skeletal defects in the axolotl salamander demonstrates a multi-differentiation potential. Cellular and molecular mechanisms of this repair process remain unclear. The objective of this study was to examine whether paracrine mitogenic signals are an important variable in the interaction between interzone cells and the skeletal microenvironment.

DESIGN

The paracrine regulation of the proliferation of equine interzone cells was evaluated in an in vitro co-culture system. Cell viability and proliferation were measured in equine fetal interzone cells after exposure to conditioned medium from skeletal and nonskeletal primary cell lines. Steady-state expression was determined for genes encoding 37 putative mitogens secreted by cells that generated the conditioned medium.

RESULTS

All experimental groups of conditioned media elicited a mitogenic response in interzone cells. Fetal anlage chondrocytes (P < 0.0001) and dermal fibroblasts (P < 0.0001) conditioned medium showed a significantly higher mitogenic potential compared with interzone cells. Conditioned medium from bone marrow-derived cells elicited a significantly higher proliferative response relative to that from young adult articular chondrocytes (P < 0.0001) or dermal fibroblasts (P < 0.0001). Sixteen genes had expression patterns consistent with the functional proliferation assays.

CONCLUSIONS

The results indicate a mitogenic effect of skeletal paracrine signals on interzone cells.

Resveratrol against Cardiac Fibrosis: Research Progress in Experimental Animal Models

Cardiac fibrosis is a heterogeneous disease, which is characterized by abundant proliferation of interstitial collagen, disordered arrangement, collagen network reconstruction, increased cardiac stiffness, and decreased systolic and diastolic functions, consequently developing into cardiac insufficiency. With several factors participating in and regulating the occurrence and development of cardiac fibrosis, a complex molecular mechanism underlies the disease. Moreover, cardiac fibrosis is closely related to hypertension, myocardial infarction, viral myocarditis, atherosclerosis, and diabetes, which can lead to serious complications such as heart failure, arrhythmia, and sudden cardiac death, thus seriously threatening human life and health. Resveratrol, with the chemical name 3,5,4'-trihydroxy-trans-stilbene, is a polyphenol abundantly present in grapes and red wine. It is known to prevent the occurrence and development of cardiovascular diseases. In addition, it may resist cardiac fibrosis through a variety of growth factors, cytokines, and several cell signaling pathways, thus exerting a protective effect on the heart.