miR-23b promotes cutaneous wound healing through inhibition of the inflammatory responses by targeting ASK1

MiR-23b-3p alleviates Sjögren's syndrome by targeting SOX6 and inhibiting the NF-κB signaling

OBJECTIVE

MicroRNA-23b-3p has been demonstrated to act as a safeguard against several autoimmune diseases. However, its role in Sjögren's syndrome (SS) remains unclear.

METHODS

In order to investigate its role in SS, we administered agomiR-23b-3p or agomiR-NC to non-obese diabetic (NOD) mice via tail vein weekly for 6 weeks. The study examined the saliva flow rate, histological changes in submandibular glands, and levels of autoantibodies. Additionally, the levels of several cytokines, cell apoptosis, and NF-κB signaling were evaluated. The protective effect of miR-23b-3p was confirmed in a cell model.

RESULTS

The results demonstrated that miR-23b-3p overexpression improved salivary flow rates, inhibited lymphocyte infiltration, reduced cytokine levels, and suppressed cell apoptosis in NOD mice. Moreover, NF-κB signaling was inactivated following miR-23b-3p overexpression. In a cellular model of SS, overexpression of miR-23b-3p protected submandibular gland epithelial cells exposed to IFN-γ against apoptosis and inflammation by targeting SOX6.

CONCLUSIONS

The study concludes that miR-23b-3p alleviates SS by targeting SOX6 and inhibiting the NF-κB signaling pathway. The miR-23b-3p/SOX6 axis represents a promising avenue for the development of novel therapeutic strategies for SS.

Progress in Wound-Healing Products Based on Natural Compounds, Stem Cells, and MicroRNA-Based Biopolymers in the European, USA, and Asian Markets: Opportunities, Barriers, and Regulatory Issues

Wounds are breaks in the continuity of the skin and underlying tissues, resulting from external causes such as cuts, blows, impacts, or surgical interventions. Countless individuals suffer minor to severe injuries, with unfortunate cases even leading to death. In today's scenario, several commercial products are available to facilitate the healing process of wounds, although chronic wounds still present more challenges than acute wounds. Nevertheless, the huge demand for wound-care products within the healthcare sector has given rise to a rapidly growing market, fostering continuous research and development endeavors for innovative wound-healing solutions. Today, there are many commercially available products including those based on natural biopolymers, stem cells, and microRNAs that promote healing from wounds. This article explores the recent breakthroughs in wound-healing products that harness the potential of natural biopolymers, stem cells, and microRNAs. A comprehensive exploration is undertaken, covering not only commercially available products but also those still in the research phase. Additionally, we provide a thorough examination of the opportunities, obstacles, and regulatory considerations influencing the potential commercialization of wound-healing products across the diverse markets of Europe, America, and Asia.

LncRNA H19 Inhibits Keratinocyte Cell Proliferation and Migration by Targeting miR-17-5p/RUNX1 Axis in Chronic Wounds

The migration and proliferation of keratinocytes are critical for re-epithelization during chronic wound healing. Runt-related transcription factor 1 (RUNX1) has been indicated to repress keratinocyte proliferation. Nonetheless, the potential molecular mechanism of RUNX1 in regulating keratinocyte proliferation and migration remains unclear. Cell counting kit-8 and wound-healing assays were implemented for examining keratinocyte viability and migration, respectively. Western blotting and real-time quantitative polymerase chain reaction were utilized for quantifying protein and RNA levels. Luciferase reporter assay was employed for verifying the interaction between RUNX1, miR-17-5p, and long noncoding RNA H19. The results showed that RUNX1 depletion promoted keratinocyte proliferation and migration and repressed extracellular matrix degradation. Mechanistically, H19 upregulated RUNX1 expression by competitively absorbing miR-17-5p. Rescue experiments revealed that overexpressing RUNX1 reversed H19 silencing-mediated effects on the phenotypes of keratinocytes. In conclusion, H19 knockdown promotes keratinocyte proliferation and migration and suppresses extracellular matrix degradation via the miR-17-5p/RUNX1 axis.

Extended characterization of IL-33/ST2 as a predictor for wound age determination in skin wound tissue samples of humans and mice

Interleukin (IL)-33, an important inflammatory cytokine, is highly expressed in skin wound tissue and serum of humans and mice, and plays an essential role in the process of skin wound healing (SWH) dependent on the IL-33/suppression of tumorigenicity 2 (ST2) pathway. However, whether IL-33 and ST2 themselves, as well as their interaction, can be applied for skin wound age determination in forensic practice remains incompletely characterized. Human skin samples with injured intervals of a few minutes to 24 hours (hs) and mouse skin samples with injured intervals of 1 h to 14 days (ds) were collected. Herein, the results demonstrated that IL-33 and ST2 are increased in the human skin wounds, and that in mice skin wounds, there is an increase over time, with IL-33 expression peaking at 24 hs and 10 ds, and ST2 expression peaking at 12 hs and 7 ds. Notably, the relative quantity of IL-33 and ST2 proteins < 0.35 suggested a wound age of 3 hs; their relative quantity > 1.0 suggested a wound age of 24 hs post-mouse skin wounds. In addition, immunofluorescent staining results showed that IL-33 and ST2 were consistently expressed in the cytoplasm of F4/80-positive macrophages and CD31-positive vascular endothelial cells with or without skin wounds, whereas nuclear localization of IL-33 was absent in α-SMA-positive myofibroblasts with skin wounds. Interestingly, IL-33 administration facilitated the wound area closure by increasing the proliferation of cytokeratin (K) 14 -positive keratinocytes and vimentin-positive fibroblasts. In contrast, treating with its antagonist (i.e., anti-IL-33) or receptor antagonist (e.g., anti-ST2) exacerbated the aforementioned pathological changes. Moreover, treatment with IL-33 combined with anti-IL-33 or anti-ST2 reversed the effect of IL-33 on facilitating skin wound closure, suggesting that IL-33 administration facilitated skin wound closure through the IL-33/ST2 signaling pathway. Collectively, these findings indicate that the detection of IL-33/ST2 might be a reliable biomarker for the determination of skin wound age in forensic practice.

A novel sprayable thermosensitive hydrogel coupled with zinc modified metformin promotes the healing of skin wound

A novel sprayable adhesive is established (ZnMet-PF127) by the combination of a thermosensitive hydrogel (Pluronic F127, PF127) and a coordination complex of zinc and metformin (ZnMet). Here we demonstrate that ZnMet-PF127 potently promotes the healing of traumatic skin defect and burn skin injury by promoting cell proliferation, angiogenesis, collagen formation. Furthermore, we find that ZnMet could inhibit reactive oxygen species (ROS) production through activation of autophagy, thereby protecting cell from oxidative stress induced damage and promoting healing of skin wound. ZnMet complex exerts better effects on promoting skin wound healing than ZnCl₂ or metformin alone. ZnMet complex also displays excellent antibacterial activity against Staphylococcus aureus or Escherichia coli, which could reduce the incidence of skin wound infections. Collectively, we demonstrate that sprayable PF127 could be used as a new drug delivery system for treatment of skin injury. The advantages of this sprayable system are obvious: (1) It is convenient to use; (2) The hydrogel can cover irregular skin defect sites evenly in a liquid state. In combination with this system, we establish a novel sprayable adhesive (ZnMet-PF127) and demonstrate that it is a potential clinical treatment for traumatic skin defect and burn skin injury.

Landscape of the epigenetic regulation in wound healing

Wound healing after skin injury is a dynamic and highly coordinated process involving a well-orchestrated series of phases, including hemostasis, inflammation, proliferation, and tissue remodeling. Epigenetic regulation refers to genome-wide molecular events, including DNA methylation, histone modification, and non-coding RNA regulation, represented by microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA). Epigenetic regulation is pervasively occurred in the genome and emerges as a new role in gene expression at the post-transcriptional level. Currently, it is well-recognized that epigenetic factors are determinants in regulating gene expression patterns, and may provide evolutionary mechanisms that influence the wound microenvironments and the entire healing course. Therefore, this review aims to comprehensively summarize the emerging roles and mechanisms of epigenetic remodeling in wound healing. Moreover, we also pose the challenges and future perspectives related to epigenetic modifications in wound healing, which would bring novel insights to accelerated wound healing.

Innovative Treatment Strategies to Accelerate Wound Healing: Trajectory and Recent Advancements

Wound healing is highly specialized dynamic multiple phase process for the repair of damaged/injured tissues through an intricate mechanism. Any failure in the normal wound healing process results in abnormal scar formation, and chronic state which is more susceptible to infections. Chronic wounds affect patients’ quality of life along with increased morbidity and mortality and are huge financial burden to healthcare systems worldwide, and thus requires specialized biomedical intensive treatment for its management. The clinical assessment and management of chronic wounds remains challenging despite the development of various therapeutic regimens owing to its painstakingly long-term treatment requirement and complex wound healing mechanism. Various conventional approaches such as cell therapy, gene therapy, growth factor delivery, wound dressings, and skin grafts etc., are being utilized for promoting wound healing in different types of wounds. However, all these abovementioned therapies are not satisfactory for all wound types, therefore, there is an urgent demand for the development of competitive therapies. Therefore, there is a pertinent requirement to develop newer and innovative treatment modalities for multipart therapeutic regimens for chronic wounds. Recent developments in advanced wound care technology includes nanotherapeutics, stem cells therapy, bioengineered skin grafts, and 3D bioprinting-based strategies for improving therapeutic outcomes with a focus on skin regeneration with minimal side effects. The main objective of this review is to provide an updated overview of progress in therapeutic options in chronic wounds healing and management over the years using next generation innovative approaches. Herein, we have discussed the skin function and anatomy, wounds and wound healing processes, followed by conventional treatment modalities for wound healing and skin regeneration. Furthermore, various emerging and innovative strategies for promoting quality wound healing such as nanotherapeutics, stem cells therapy, 3D bioprinted skin, extracellular matrix-based approaches, platelet-rich plasma-based approaches, and cold plasma treatment therapy have been discussed with their benefits and shortcomings. Finally, challenges of these innovative strategies are reviewed with a note on future prospects.

Anti-Inflammatory microRNAs for Treating Inflammatory Skin Diseases

Skin inflammation occurs due to immune dysregulation because of internal disorders, infections, and allergic reactions. The inflammation of the skin is a major sign of chronic autoimmune inflammatory diseases, such as psoriasis, atopic dermatitis (AD), and lupus erythematosus. Although there are many therapies for treating these cutaneous inflammation diseases, their recurrence rates are high due to incomplete resolution. MicroRNA (miRNA) plays a critical role in skin inflammation by regulating the expression of protein-coding genes at the posttranscriptional level during pathogenesis and homeostasis maintenance. Some miRNAs possess anti-inflammatory features, which are beneficial for mitigating the inflammatory response. miRNAs that are reduced in inflammatory skin diseases can be supplied transiently using miRNA mimics and agomir. miRNA-based therapies that can target multiple genes in a given pathway are potential candidates for the treatment of skin inflammation. This review article offers an overview of the function of miRNA in skin inflammation regulation, with a focus on psoriasis, AD, and cutaneous wounds. Some bioactive molecules can target and modulate miRNAs to achieve the objective of inflammation suppression. This review also reports the anti-inflammatory efficacy of these molecules through modulating miRNA expression. The main limitations of miRNA-based therapies are rapid biodegradation and poor skin and cell penetration. Consideration was given to improving these drawbacks using the approaches of cell-penetrating peptides (CPPs), nanocarriers, exosomes, and low-frequency ultrasound. A formulation design for successful miRNA delivery into skin and target cells is also described in this review. The possible use of miRNAs as biomarkers and therapeutic modalities could open a novel opportunity for the diagnosis and treatment of inflammation-associated skin diseases.

The Role of microRNA in the Inflammatory Response of Wound Healing

Wound healing, a highly complex pathophysiological response to injury, includes four overlapping phases of hemostasis, inflammation, proliferation, and remodeling. Initiation and resolution of the inflammatory response are the primary requirements for wound healing, and are also key events that determines wound quality and healing time. Currently, the number of patients with persistent chronic wounds has generally increased, which imposes health and economic burden on patients and society. Recent studies have found that microRNA(miRNA) plays an essential role in the inflammation involved in wound healing and may provide a new therapeutic direction for wound treatment. Therefore, this review focused on the role and significance of miRNA in the inflammation phase of wound healing.

Beyond the Code: Noncoding RNAs in Skin Wound Healing

An increasing number of noncoding RNAs (ncRNAs) have been found to regulate gene expression and protein functions, playing important roles in diverse biological processes and diseases. Their crucial functions have been reported in almost every cell type and all stages of skin wound healing. Evidence of their pathogenetic roles in common wound complications, such as chronic nonhealing wounds and excessive scarring, is also accumulating. Given their unique expression and functional properties, ncRNAs are promising therapeutic and diagnostic entities. In this review, we discuss current knowledge about the functional roles of noncoding elements, such as microRNAs, long ncRNAs, and circular RNAs, in skin wound healing, focusing on in vivo evidence from studies of human wound samples and animal wound models. Finally, we provide a perspective on the outlook of ncRNA-based therapeutics in wound care.

microRNA-106b derived from endothelial cell-secreted extracellular vesicles prevents skin wound healing by inhibiting JMJD3 and RIPK3

Intriguingly, microRNAs (miRs) transferred as cargo in extracellular vesicles (EVs) can modulate wound healing through their regulation of fibroblast functions. In this study, we investigated the effects of miR‐106b transfer via EVs derived from human umbilical vein endothelial cells (HUVECs) on skin wound healing. Dual‐luciferase reporter gene assay identified that miR‐106b could target and inhibit JMJD3. RT‐qPCR analysis showed EVs isolated from HUVECs had enriched expression of miR‐106b. LL29 fibroblast cells and HaCaT keratinocytes were co‐cultured with HUVEC‐derived EVs, in which miR‐106b had been up‐regulated or down‐regulated by its mimic or inhibitor. The co‐culture with HUVEC‐derived EVs increased miR‐106b expression, and reduced the viability and adhesion of LL29 and HaCaT cells, whereas the inhibition of miR‐106b in HUVEC‐derived EVs enhanced the viability and adhesion of LL29 and HaCaT cells through up‐regulation of JMJD3. Next, we showed that JMJD3 overexpression enhanced LL29 and HaCaT cell viability and adhesion through elevating RIPK3, which induced the phosphorylation of AKT during the wound‐healing process. We next developed a mouse skin wound model to investigate the actions of miR‐106b in vivo after 14 days. The delivery of miR‐106b via HUVEC‐derived EVs delayed wound healing through suppression of collagen I content and angiogenesis, but had no effects on pro‐inflammatory cytokines. In conclusion, miR‐106b from HUVEC‐derived EVs inhibits JMJD3 and RIPK3, leading to the inhibition of skin wound healing, thus constituting a new therapeutic target.

The role of miRNAs in the inflammatory phase of skin wound healing

<abstract> <p>Wound healing (WH) is a fundamental physiological process to keep the integrity of the skin, therefore impaired and chronic WH is a common and severe medical problem and represent one of the biggest challenges of public health. The resolution of the WH inflammatory phase is characterized by a complex series of events that involves many cellular types, especially neutrophils, macrophages and inflammatory mediators, which are crucial for a correct wound closure. MicroRNAs (miRNAs) play essential roles in wound repair. In fact, miR-142 is linked to inflammation modulating neutrophils' chemotaxis and polarization, while the polarization of M1 toward the M2 phenotype is driven by miR-223 and miR-132 is linked to chemokines and cytokines that activate endothelial cells and attract leukocytes and peripheral cells to the damage site. Thus, understanding the dysregulation of miRNAs in WH will be decisive for the development of new and more effective therapies for the management of chronic wounds.</p> </abstract>

The Immune Functions of Keratinocytes in Skin Wound Healing

As the most dominant cell type in the skin, keratinocytes play critical roles in wound repair not only as structural cells but also exerting important immune functions. This review focuses on the communications between keratinocytes and immune cells in wound healing, which are mediated by various cytokines, chemokines, and extracellular vesicles. Keratinocytes can also directly interact with T cells via antigen presentation. Moreover, keratinocytes produce antimicrobial peptides that can directly kill the invading pathogens and contribute to wound repair in many aspects. We also reviewed the epigenetic mechanisms known to regulate keratinocyte immune functions, including histone modifications, non-protein-coding RNAs (e.g., microRNAs, and long noncoding RNAs), and chromatin dynamics. Lastly, we summarized the current evidence on the dysregulated immune functions of keratinocytes in chronic nonhealing wounds. Based on their crucial immune functions in skin wound healing, we propose that keratinocytes significantly contribute to the pathogenesis of chronic wound inflammation. We hope this review will trigger an interest in investigating the immune roles of keratinocytes in chronic wound pathology, which may open up new avenues for developing innovative wound treatments.

Extracellular vesicle-carried microRNA-27b derived from mesenchymal stem cells accelerates cutaneous wound healing via E3 ubiquitin ligase ITCH

Mesenchymal stem cells (MSCs) have been highlighted as promising candidate cells in relation to cutaneous wound healing. The current study aimed to investigate whether MSC-derived extracellular vesicles (EVs) could transfer microRNA-27b (miR-27b) to influence cutaneous wound healing. The miR-27b expression was examined in the established cutaneous wound mouse model, and its correlation with the wound healing rate was evaluated by Pearson's correlation analysis. The identified human umbilical cord MSC-derived EVs were co-cultured with human immortal keratinocyte line HaCaT and human skin fibroblasts (HSFs). The mice with cutaneous wound received injections of MSC-derived EVs. The effects of EVs or miR-27b loaded on wound healing and cellular functions were analysed via gain- and loss-of-function approaches in the co-culture system. Dual-luciferase reporter gene assay was employed to verify the relationship between miR-27b and Itchy E3 ubiquitin protein ligase (ITCH). Rescue experiments were conducted to investigate the underlying mechanisms associated with the ITCH/JUNB/inositol-requiring enzyme 1α (IRE1α) axis. miR-27b was down-regulated in the mouse model, with its expression found to be positively correlated with the wound healing rate. Abundant miR-27b was detected in the MSC-derived EVs, while EV-transferred miR-27b improved cutaneous wound healing in mice and improved proliferation and migration of HaCaT cells and HSFs in vitro. As a target of miR-27b, ITCH was found to repress cell proliferation and migration. ITCH enhanced the JUNB ubiquitination and degradation, ultimately inhibiting JUNB and IRE1α expressions and restraining wound healing. Collectively, MSC-derived EVs transferring miR-27b can promote cutaneous wound healing via ITCH/JUNB/IRE1α signalling, providing insight with clinical implications.

MicroRNA Expression in Cutaneous Lupus: A New Window to Understand Its Pathogenesis

Background

The role of miRNAs in the pathogenesis of cutaneous lupus has not been studied.

Objective

It was to assess the levels of a selected panel of circulating miRNAs that could be involved in the regulation of the immune response, inflammation, and fibrosis in cutaneous lupus.

Methods

It was a cross-sectional study. We included 22 patients with subacute (SCLE) and 20 with discoid (DLE) lesions, and 19 healthy donors (HD). qRT-PCR for miRNA analysis, flow cytometry in peripheral blood, and skin immunohistochemistry were performed to determine the distribution of CD4 T cells and regulatory cells and their correlation with circulating miRNAs.

Results

miR-150, miR-1246, miR-21, miR-23b, and miR-146 levels were downregulated in SCLE vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE γ⁺ with miR-1246 in SCLE, whereas CD123⁺/CD196⁺/IDO⁺ cells were positively associated with miR-150 in DLE. In the tissue, CD4⁺/IL-4⁺ and CD20⁺/IL-10⁺ cells were positively associated with miR-21 and CD4⁺/IFN-γ⁺ with miR-1246 in SCLE, whereas CD123⁺/CD196⁺/IDO⁺ cells were positively associated with miR-150 in DLE. In the tissue, CD4⁺/IL-4⁺ and CD20⁺/IL-10⁺ cells were positively associated with miR-21 and CD4⁺/IFN-β, thyroid hormone, and cancer signaling pathways were shared between miR-21, miR-31, miR-23b, miR-146a, miR-1246, and miR-150.

Conclusions

A downregulation of miR-150, miR-1246, and miR-21 in both CLE varieties vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE

miR-23b Negatively Regulates Sepsis-Induced Inflammatory Responses by Targeting ADAM10 in Human THP-1 Monocytes

Background

Previous studies have demonstrated pivotal roles of disintegrin and metalloproteinase 10 (ADAM10) in the pathogenesis of sepsis. MicroRNA- (miR-) 23b has emerged as an anti-inflammatory factor that prevents multiple autoimmune diseases. However, the underlying mechanisms of miR-23b in the regulation of ADAM10 and sepsis remain uncharacterized.

Methods

The expression levels of ADAM10 and miR-23b were detected by quantitative RT-PCR and western blot analysis. Cytokine production and THP-1 cell apoptosis were measured by enzyme-linked immunosorbent and annexin V apoptosis assays. Bioinformatics analyses and qRT-PCR, western blot, and luciferase reporter assays were performed to identify ADAM10 as the target gene of miR-23b.

Results

miR-23b expression was downregulated in the peripheral blood mononuclear cells of sepsis patients and LPS-induced THP-1 cells and was negatively correlated with the expression of ADAM10 and inflammatory cytokines. miR-23b regulated ADAM10 expression by directly binding to the 3′-UTR of ADAM10 mRNA. The overexpression of miR-23b alleviated the LPS-stimulated production of inflammatory cytokines (TNF-α, IL-1β, and IL-6) and apoptosis by targeting ADAM10 in THP-1 cells. The inhibitor or knockdown of ADAM10 elicited effects similar to those of miR-23b on THP-1 cells upon LPS stimulation.

Conclusions

The present study demonstrated that miR-23b negatively regulated LPS-induced inflammatory responses by targeting ADAM10. The molecular regulatory mechanism of miR-23b in ADAM10 expression and sepsis-induced inflammatory consequences may provide potential therapeutic targets for sepsis.