Exosomes from miR-29a-modified adipose-derived mesenchymal stem cells reduce excessive scar formation by inhibiting TGF-β2/Smad3 signaling

Adipose stem cell-derived exosomes in the treatment of wound healing in preclinical animal models: a meta-analysis

Background

Wound healing has always been a serious issue for doctors and primary health care systems. In addition, adipose stem cell-derived exosomes have been proven to play a positive and effective role in tissue repair and regeneration. A systematic review of these preclinical studies was performed to assess the efficacy of adipose stem cell-derived exosomes (ADSC-Exos) in treating wounds. This article aimed to study the effectiveness of ADSC-Exos for the treatment of animal skin wounds and includes a meta-analysis of exosomes from general wounds and diabetic ulcer wounds in in vitro models of animals to provide a theoretical basis for clinical translation.

Methods

A total of 19 studies with 356 animals were identified by searching the PubMed, Cochrane, MEDLINE Complete, Web of Science, CNKI and Wanfang databases from inception to 15 November 2022. No language or time restrictions were applied. Stata17 was used for all the data analyses.

Results

The meta-analysis showed that ADSC-Exo therapy significantly improved the wound healing rate in the control group, except in the diabetes group on day 7. Day 7 of general wounds [standard mean difference (SMD) 2.87, 95% confidence interval (CI) 1.91-3.83)] and day 14 (SMD 2.89, 95%CI 1.47-4.30). Day 14 (SMD 3.43, 95%CI 1.28-5.58) of diabetic wounds. Other outcomes, such as blood vessel density, collagen deposition and wound re-epithelization, improved with the administration of ADSC-Exos.

Conclusions

A meta-analysis showed that ADSC-Exo therapy applied to general and diabetic wounds can promote neovascularization, improve epithelization and collagen fiber deposition, promote healing, and reduce scar formation. ADSC-Exos have broad potential in preclinical research and clinical fields.

Bioengineered mesenchymal stem cell-derived exosomes: emerging strategies for diabetic wound healing

Diabetic wounds are among the most common complications of diabetes mellitus and their healing process can be delayed due to persistent inflammatory reactions, bacterial infections, damaged vascularization and impaired cell proliferation, which casts a blight on patients'health and quality of life. Therefore, new strategies to accelerate diabetic wound healing are being positively explored. Exosomes derived from mesenchymal stem cells (MSC-Exos) can inherit the therapeutic and reparative abilities of stem cells and play a crucial role in diabetic wound healing. However, poor targeting, low concentrations of therapeutic molecules, easy removal from wounds and limited yield of MSC-Exos are challenging for clinical applications. Bioengineering techniques have recently gained attention for their ability to enhance the efficacy and yield of MSC-Exos. In this review, we summarise the role of MSC-Exos in diabetic wound healing and focus on three bioengineering strategies, namely, parental MSC-Exos engineering, direct MSC-Exos engineering and MSC-Exos combined with biomaterials. Furthermore, the application of bioengineered MSC-Exos in diabetic wound healing is reviewed. Finally, we discuss the future prospects of bioengineered MSC-Exos, providing new insights into the exploration of therapeutic strategies.

Extracellular vesicles derived from "serum and glucose" deprived HUCMSCs promoted skin wound healing through enhanced angiogenesis

Extracellular vesicles (EVs) produced from MSCs were currently considered as a novel therapeutic agent for skin tissue regeneration and repair. Preconditioning stem cells may activate more molecular pathways and release more bioactive agents. In this study, we obtained EVs from normal (N-EVs) and serum- and glucose-deprived (SGD-EVs) human umbilical cord mesenchymal stem cells (HUCMSCs), and showed that SGD-EVs promoted the migration, proliferation, and tube formation of HUVECs in vitro. In vivo experiments utilizing a rat model show that both N-EVs and SGD-EVs boosted angiogenesis of skin defects and accelerated skin wound healing, while treating wounds with SGD-EVs led to faster skin healing and enhanced angiogenesis. miRNA sequencing showed that miR-29a-3p was abundant in SGD-EVs, and overexpressing miR-29a-3p enhanced the angiogenic ability of HUVECs, while inhibiting miR-29a-3p presented the opposite effect. Further studies demonstrated that miR-29a-3p directly targeted CTNNBIP1, which mediated angiogenesis of HUCMSCs-derived EVs through inhibiting CTNNBIP1 to activate Wnt/β-catenin signaling pathway. Taken together, these findings suggested that SGD-EVs promote angiogenesis via transferring miR-29a-3p, and activation of Wnt/β-catenin signaling pathway played a crucial role in SGD-EVs-induced VEGFA production during wound angiogenesis. Our results offered a new avenue for modifying EVs to enhance tissue angiogenesis and augment its role in skin repair.

Microglial uptake of hADSCs-Exo mitigates neuroinflammation in ICH

Intracerebral hemorrhage (ICH) is associated with secondary neuroinflammation, leading to severe central nervous system damage. Exosomes derived from human adipose-derived mesenchymal stem cells (hADSCs-Exo) have shown potential therapeutic effects in regulating inflammatory responses in ICH. This study aims to investigate the role of hADSCs-Exo in ICH and its underlying mechanism involving miRNA-mediated regulation of formyl peptide receptor 1 (FPR1). Flow cytometry was used to identify hADSCs and extract exosomes. Transmission electron microscopy and Western blot were performed to confirm the characteristics of the exosomes. In vitro experiments were conducted to explore the uptake of hADSCs-Exo by microglia cells and their impact on inflammatory responses. In vivo, an ICH mouse model was established, and the therapeutic effects of hADSCs-Exo were evaluated through neurological function scoring, histological staining, and immunofluorescence. Bioinformatics tools and experimental validation were employed to identify miRNAs targeting FPR1. hADSCs-Exo were efficiently taken up by microglia cells and exhibited anti-inflammatory effects by suppressing the release of inflammatory factors and promoting M1 to M2 transition. In the ICH mouse model, hADSCs-Exo significantly improved neurological function, reduced hemorrhage volume, decreased neuronal apoptosis, and regulated microglia polarization. miR-342-3p was identified as a potential regulator of FPR1 involved in the neuroprotective effects of hADSCs-Exo in ICH. hADSCs-Exo alleviate neuroinflammation in ICH through miR-342-3p-dependent targeting of FPR1, providing a new therapeutic strategy for ICH.

Insights into the role of mesenchymal stem cells in cutaneous medical aesthetics: from basics to clinics

With the development of the economy and the increasing prevalence of skin problems, cutaneous medical aesthetics are gaining more and more attention. Skin disorders like poor wound healing, aging, and pigmentation have an impact not only on appearance but also on patients with physical and psychological issues, and even impose a significant financial burden on families and society. However, due to the complexities of its occurrence, present treatment options cannot produce optimal outcomes, indicating a dire need for new and effective treatments. Mesenchymal stem cells (MSCs) and their secretomics treatment is a new regenerative medicine therapy that promotes and regulates endogenous stem cell populations and/or replenishes cell pools to achieve tissue homeostasis and regeneration. It has demonstrated remarkable advantages in several skin-related in vivo and in vitro investigations, aiding in the improvement of skin conditions and the promotion of skin aesthetics. As a result, this review gives a complete description of recent scientific breakthroughs in MSCs for skin aesthetics and the limitations of their clinical applications, aiming to provide new ideas for future research and clinical transformation.

Mechanisms and therapeutic research progress in intestinal fibrosis

Intestinal fibrosis is a common complication of chronic intestinal diseases with the characteristics of fibroblast proliferation and extracellular matrix deposition after chronic inflammation, leading to lumen narrowing, structural and functional damage to the intestines, and life inconvenience for the patients. However, anti-inflammatory drugs are currently generally not effective in overcoming intestinal fibrosis making surgery the main treatment method. The development of intestinal fibrosis is a slow process and its onset may be the result of the combined action of inflammatory cells, local cytokines, and intestinal stromal cells. The aim of this study is to elucidate the pathogenesis [e.g., extracellular matrix (ECM), cytokines and chemokines, epithelial-mesenchymal transition (EMT), differentiation of fibroblast to myofibroblast and intestinal microbiota] underlying the development of intestinal fibrosis and to explore therapeutic advances (such as regulating ECM, cytokines, chemokines, EMT, differentiation of fibroblast to myofibroblast and targeting TGF-β) based on the pathogenesis in order to gain new insights into the prevention and treatment of intestinal fibrosis.

Optimizing mesenchymal stem cell extracellular vesicles for chronic wound healing: Bioengineering, standardization, and safety

Chronic wounds represent a significant global burden, afflicting millions with debilitating complications. Despite standard care, impaired healing persists due to factors like persistent inflammation and impaired tissue regeneration. Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) offer an innovative regenerative medicine approach, delivering stem cell-derived therapeutic cargo in engineered nanoscale delivery systems. This review examines pioneering bioengineering strategies to engineer MSC-EVs into precision nanotherapeutics for chronic wounds. Emerging technologies like CRISPR gene editing, microfluidic manufacturing, and biomimetic delivery systems are highlighted for their potential to enhance MSC-EV targeting, optimize therapeutic cargo enrichment, and ensure consistent clinical-grade production. However, key hurdles remain, including batch variability, rigorous safety assessment for potential tumorigenicity, immunogenicity, and biodistribution profiling. Crucially, collaborative frameworks harmonizing regulatory science with bioengineering and patient advocacy hold the key to expediting global clinical translation. By overcoming these challenges, engineered MSC-EVs could catalyze a new era of off-the-shelf regenerative therapies, restoring hope and healing for millions afflicted by non-healing wounds.

Insights into the role of adipose-derived stem cells and secretome: potential biology and clinical applications in hypertrophic scarring

Scar tissue is the inevitable result of repairing human skin after it has been subjected to external destructive stimuli. It leads to localized damage to the appearance of the skin, accompanied by symptoms such as itching and pain, which reduces the quality of life of the patient and causes serious medical burdens. With the continuous development of economy and society, there is an increasing demand for beauty. People are looking forward to a safer and more effective method to eliminate pathological scarring. In recent years, adipose-derived stem cells (ADSCs) have received increasing attention from researchers. It can effectively improve pathological scarring by mediating inflammation, regulating fibroblast proliferation and activation, and vascular reconstruction. This review focuses on the pathophysiological mechanisms of hypertrophic scarring, summarizing the therapeutic effects of in vitro, in vivo, and clinical studies on the therapeutic effects of ADSCs in the field of hypertrophic scarring prevention and treatment, the latest application techniques, such as cell-free therapies utilizing ADSCs, and discussing the advantages and limitations of ADSCs. Through this review, we hope to further understand the characterization of ADSC and clarify the effectiveness of its application in hypertrophic scarring treatment, so as to provide clinical guidance.

MEG3 shuttled by exosomes released from human bone marrow mesenchymal stem cells promotes TP53 stability to regulate MCM5 transcription in keloid fibroblasts

BACKGROUND

Despite the interest in mesenchymal stem cells (MSC), their potential to treat abnormal scarring, especially keloids, is yet to be described. The present study aimed to investigate the therapeutic potential of exosomes derived from human bone marrow MSCs (hBMSC-Exos) in alleviating keloid formation.

METHODS

Exosomes were isolated from hBMSC, and keloid fibroblasts (KFs) were treated with hBMSC-Exos. Cell counting kit-8, wound healing, transwell invasion, immunofluorescence, and western blot assays were conducted to study the malignant phenotype of KFs. Mice were induced with keloids and treated with hBMSC-Exos. The effect of hBMSC-Exos on keloid formation in vivo was evaluated by hematoxylin and eosin staining, Masson staining, immunohistochemistry, and western blotting. The GSE182192 dataset was screened for differentially expressed long non-coding RNA during keloid formation. Next, maternally expressed gene 3 (MEG3) was knocked down in hBMSC to obtain hBMSC-Exossh-MEG3. The molecular mechanism of MEG3 was investigated by bioinformatic screening, and the relationship between MEG3 and TP53 or MCM5 was verified.

RESULTS

hBMSC-Exos inhibited the malignant proliferation, migration, and invasion of KFs at same time as promoting their apoptosis, Moreover, hBMSC-Exos reduced the expression of fibrosis- and collagen-related proteins in the cells and the formation of keloids caused by KFs. The reduction in MEG3 enrichment in hBMSC-Exos weakened the inhibitory effect of hBMSC-Exos on KF activity. hBMSC-Exos delivered MEG3 to promote MCM5 transcription by TP53 in KFs. Overexpression of MCM5 in KFs reversed the effects of hBMSC-Exossh-MEG3, leading to reduced KF activity.

CONCLUSIONS

hBMSC-Exos delivered MEG3 to promote the protein stability of TP53, thereby activating MCM5 and promoting KF activity.

Applications of Exosomal miRNAs from Mesenchymal Stem Cells as Skin Boosters

The skin is the outer layer of the human body, and it is crucial in defending against injuries and damage. The regenerative capacity of aging and damaged skin caused by exposure to external stimuli is significantly impaired. Currently, the rise in average life expectancy and the modern population's aesthetic standards have sparked a desire for stem-cell-based therapies that can address skin health conditions. In recent years, mesenchymal stem cells (MSCs) as therapeutic agents have provided a promising and effective alternative for managing skin regeneration and rejuvenation, attributing to their healing capacities that can be applied to damaged and aged skin. However, it has been established that the therapeutic effects of MSC may be primarily mediated by paracrine mechanisms, particularly the release of exosomes (Exos). Exosomes are nanoscale extracellular vesicles (EVs) that have lipid bilayer and membrane structures and can be naturally released by different types of cells. They influence the physiological and pathological processes of recipient cells by transferring a variety of bioactive molecules, including lipids, proteins, and nucleic acids such as messenger RNAs (mRNAs) and microRNAs (miRNAs) between cells, thus playing an important role in intercellular communication and activating signaling pathways in target cells. Among them, miRNAs, a type of endogenous regulatory non-coding RNA, are often incorporated into exosomes as important signaling molecules regulating protein biosynthesis. Emerging evidence suggests that exosomal miRNAs from MSC play a key role in skin regeneration and rejuvenation by targeting multiple genes and regulating various biological processes, such as participating in inflammatory responses, cell migration, proliferation, and apoptosis. In this review, we summarize the recent studies and observations on how MSC-derived exosomal miRNAs contribute to the regeneration and rejuvenation of skin tissue, with particular attention to the applications of bioengineering methods for manipulating the miRNA content of exosome cargo to improve their therapeutic potential. This review can provide new clues for the diagnosis and treatment of skin damage and aging, as well as assist investigators in exploring innovative therapeutic strategies for treating a multitude of skin problems with the aim of delaying skin aging, promoting skin regeneration, and maintaining healthy skin.

The Role and Prospects of Mesenchymal Stem Cells in Skin Repair and Regeneration

Mesenchymal stem cells (MSCs) have been recognized as a cell therapy with the potential to promote skin healing. MSCs, with their multipotent differentiation ability, can generate various cells related to wound healing, such as dermal fibroblasts (DFs), endothelial cells, and keratinocytes. In addition, MSCs promote neovascularization, cellular regeneration, and tissue healing through mechanisms including paracrine and autocrine signaling. Due to these characteristics, MSCs have been extensively studied in the context of burn healing and chronic wound repair. Furthermore, during the investigation of MSCs, their unique roles in skin aging and scarless healing have also been discovered. In this review, we summarize the mechanisms by which MSCs promote wound healing and discuss the recent findings from preclinical and clinical studies. We also explore strategies to enhance the therapeutic effects of MSCs. Moreover, we discuss the emerging trend of combining MSCs with tissue engineering techniques, leveraging the advantages of MSCs and tissue engineering materials, such as biodegradable scaffolds and hydrogels, to enhance the skin repair capacity of MSCs. Additionally, we highlight the potential of using paracrine and autocrine characteristics of MSCs to explore cell-free therapies as a future direction in stem cell-based treatments, further demonstrating the clinical and regenerative aesthetic applications of MSCs in skin repair and regeneration.

Exosomal microRNA-Based therapies for skin diseases

Based on engineered cell/exosome technology and various skin-related animal models, exosomal microRNA (miRNA)-based therapies derived from natural exosomes have shown good therapeutic effects on nine skin diseases, including full-thickness skin defects, diabetic ulcers, skin burns, hypertrophic scars, psoriasis, systemic sclerosis, atopic dermatitis, skin aging, and hair loss. Comparative experimental research showed that the therapeutic effect of miRNA-overexpressing exosomes was better than that of their natural exosomes. Using a dual-luciferase reporter assay, the targets of all therapeutic miRNAs in skin cells have been screened and confirmed. For these nine types of skin diseases, a total of 11 animal models and 21 exosomal miRNA-based therapies have been developed. This review provides a detailed description of the animal models, miRNA therapies, disease evaluation indicators, and treatment results of exosomal miRNA therapies, with the aim of providing a reference and guidance for future clinical trials. There is currently no literature on the merits or drawbacks of miRNA therapies compared with standard treatments.

Kinetics of Inflammatory Mediators in the Immune Response to Burn Injury: Systematic Review and Meta-Analysis of Animal Studies

Burns are often accompanied by a dysfunctional immune response, which can lead to systemic inflammation, shock, and excessive scarring. The objective of this study was to provide insight into inflammatory pathways associated with burn-related complications. Because detailed information on the various inflammatory mediators is scattered over individual studies, we systematically reviewed animal experimental data for all reported inflammatory mediators. Meta-analyses of 352 studies revealed a strong increase in cytokines, chemokines, and growth factors, particularly 19 mediators in blood and 12 in burn tissue. Temporal kinetics showed long-lasting surges of proinflammatory cytokines in blood and burn tissue. Significant time-dependent effects were seen for IL-1β, IL-6, TGF-β1, and CCL2. The response of anti-inflammatory mediators was limited. Burn technique had a profound impact on systemic response levels. Large burn size and scalds further increased systemic, but not local inflammation. Animal characteristics greatly affected inflammation, for example, IL-1β, IL-6, and TNF-α levels were highest in young, male rats. Time-dependent effects and dissimilarities in response demonstrate the importance of appropriate study design. Collectively, this review presents a general overview of the burn-induced immune response exposing inflammatory pathways that could be targeted through immunotherapy for burn patients and provides guidance for experimental set-ups to advance burn research.

Non-coding RNAs in hypertrophic scars and keloids: Current research and clinical relevance: A review

Hypertrophic scars (HS) and keloids (KD) are lesions that develop as a result of excessive fibroblast proliferation and collagen deposition in response to dermal injury, leading to dysregulation of the inflammatory, proliferative, and remodeling phases during wound healing. HS and KD affect up to 90 % of the population and are associated with lower quality of life, physical health, and mental status in patients. Efficient targeted treatment represents a significant challenge, primarily due to our limited understanding of their underlying pathogenesis. Non-coding RNAs (ncRNAs), which constitute a significant portion of the human transcriptome with minimal or no protein-coding capacity, have been implicated in various cellular physiologies and pathologies and may serve as diagnostic indicators or therapeutic targets. NcRNAs have been found to be aberrantly expressed and regulated in HS and KD. This review provides a summary of the expression profiles and molecular mechanisms of three common ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in HS and KD. It also discusses their potential as biomarkers for the diagnosis and treatment of these diseases and provides novel insights into epigenetic-based diagnosis and treatment strategies for HS and KD.

Targeting Signalling Pathways in Chronic Wound Healing

Chronic wounds fail to achieve complete closure and are an economic burden to healthcare systems due to the limited treatment options and constant medical attention. Chronic wounds are characterised by dysregulated signalling pathways. Research has focused on naturally derived compounds, stem-cell-based therapy, small molecule drugs, oligonucleotide delivery nanoparticles, exosomes and peptide-based platforms. The phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT), Wingless-related integration (Wnt)/β-catenin, transforming growth factor-β (TGF-β), nuclear factor erythroid 2-related factor 2 (Nrf2), Notch and hypoxia-inducible factor 1 (HIF-1) signalling pathways have critical roles in wound healing by modulating the inflammatory, proliferative and remodelling phases. Moreover, several regulators of the signalling pathways were demonstrated to be potential treatment targets. In this review, the current research on targeting signalling pathways under chronic wound conditions will be discussed together with implications for future studies.

Therapeutic role of exosomes and conditioned medium in keloid and hypertrophic scar and possible mechanisms

Exosomes, ranging from 40 to 160 nm in diameter, are extracellular lipid bilayer microvesicles that regulate the body's physiological and pathological processes and are secreted by cells that contain proteins, nucleic acids, amino acids and other metabolites. Previous studies suggested that mesenchymal stem cell (MSC)-derived exosomes could either suppress or support keloid and hypertrophic scar progression. Although previous research has identified the potential value of MSC-exosomes in keloid and hypertrophic scar, a comprehensive analysis of different sources of MSC-exosome in keloid and hypertrophic scar is still lacking. This review mainly discusses different insights regarding the roles of MSC-exosomes in keloid and hypertrophic scar treatment and summarizes possible underlying mechanisms.

The functions and clinical application potential of exosomes derived from mesenchymal stem cells on wound repair: a review of recent research advances

Wound repair is a complex problem for both clinical practitioners and scientific investigators. Conventional approaches to wound repair have been associated with several limitations, including prolonged treatment duration, high treatment expenses, and significant economic and psychological strain on patients. Consequently, there is a pressing demand for more efficacious and secure treatment modalities to enhance the existing treatment landscapes. In the field of wound repair, cell-free therapy, particularly the use of mesenchymal stem cell-derived exosomes (MSC-Exos), has made notable advancements in recent years. Exosomes, which are small lipid bilayer vesicles discharged by MSCs, harbor bioactive constituents such as proteins, lipids, microRNA (miRNA), and messenger RNA (mRNA). These constituents facilitate material transfer and information exchange between the cells, thereby regulating their biological functions. This article presents a comprehensive survey of the function and mechanisms of MSC-Exos in the context of wound healing, emphasizing their beneficial impact on each phase of the process, including the regulation of the immune response, inhibition of inflammation, promotion of angiogenesis, advancement of cell proliferation and migration, and reduction of scar formation.

Adipose-derived mesenchymal stem cells-sourced exosomal microRNA-7846-3p suppresses proliferation and pro-angiogenic role of keloid fibroblasts by suppressing neuropilin 2

BACKGROUND

Exosomes (Exos) and their contained microRNAs (miRNAs) have been emergingly recognized as key regulators in spanning biological processes, including proliferation and angiogenesis.

AIM OF THE STUDY

This work investigates the function of Exos derived from adipose-derived mesenchymal stem cells (adMSCs) in viability of keloid fibroblasts (KFs).

METHODS

Abnormally expressed miRNAs in keloid tissues were screened using the GEO dataset GSE113620. Meanwhile, miRNAs enriched in adMSC-Exos were predicted by bioinformatics system. Exos were extracted from acquired adMSCs and identified, which were co-incubated with KFs. Uptake of Exos by KFs was examined by fluorescence staining. Viability, proliferation, and apoptosis of KFs were analyzed by CCK-8, EdU labeling, and TUNEL assays. Conditioned medium of KFs was collected to stimulate angiogenesis of human umbilical vein endothelial cells (HUVECs). Binding between miR-7846-3p and neuropilin 2 (NRP2) was validated by luciferase assay. Protein levels of NRP2 and the Hedgehog pathway molecules were analyzed by western blot analysis.

RESULTS

miR-7846-3p was predicted as an exosomal miRNA aberrantly expressed in keloids. AdMSC-Exos reduced viability, proliferation, and apoptosis resistance of KFs, and they blocked the angiogenesis of HUVECs. miR-7846-3p targeted NRP2 mRNA. miR-7846-3p upregulation in KFs suppressed NRP2 expression and reduced the expression of Hedgehog pathway molecules SHH, SMO, and GLI1. Either miR-7846-3p inhibition in Exos or NRP2 overexpression in KFs blocked the effects of Exos and restored the viability, proliferation, and pro-angiogenic role of KFs.

CONCLUSION

This work unravels that adMSC-Exos-derived miR-7846-3p suppresses NRP2 and inactivates the Hedgehog signaling to reduce proliferation and pro-angiogenic role of KFs.

Exosomal microRNAs from Mesenchymal Stem Cells: Novel Therapeutic Effect in Wound Healing

BACKGROUND

Wound healing is a complicated biological process that leads to the regeneration of damaged skin tissue. Determining the methods to promote wound healing has become a hot topic in medical cosmetology and tissue repair research. Mesenchymal stem cells (MSCs) are a group of stem cells with the potential of self-renewal and multi-differentiation. MSCs transplantation has a broad application prospect in wound healing therapy. Many studies have demonstrated that the therapeutic capacity of MSCs is mainly mediated by paracrine actions. Exosomes (EXOs), which are nanosized vesicles carrying a variety of nucleic acids, proteins and lipids, are an important component of paracrine secretion. It has been demonstrated that exosomal microRNAs (EXO-miRNAs) play a key role in the function of exosomes.

METHODS

In this review, we focus on current research on miRNAs from MSC-derived exosomes (MSC-EXO miRNAs) in terms of sorting, releasing and function and their effects on inflammation regulation, epidermal cell function, fibroblast function, and extracellular matrix formation. At last, we discuss the current attempts to improve the treatment of MSC-EXO-miRNAs.

RESULTS

Many studies have demonstrated that MSC-EXO miRNAs play a key role in promoting wound healing. They have been shown to regulate inflammation response, enhance epidermal cell proliferation and migration, stimulate fibroblast proliferation and collagen synthesis, and regulate extracellular matrix formation. Besides, there have been a number of strategies developed to promote MSC-EXO and MSC-EXO miRNAs for wound healing treatment.

CONCLUSION

Utilizing the association of exosomes from MSCs with miRNAs may be a promising strategy to promote trauma healing. MSC-EXO miRNAs may provide a new approach to promote wound healing and improve the quality of life for patients with skin injuries.

Mechanisms and applications of adipose-derived stem cell-extracellular vesicles in the inflammation of wound healing

Wound healing is a sophisticated process consisting of serial phases with overlaps, including hemostasis, inflammation, proliferation, and remodeling. The inflammation response is an early response that plays a crucial role in eliminating microbes and clearing damaged cell debris. However, in some pathological circumstances, such as diabetes mellitus, ischemia, trauma, deep burn, etc., abnormal inflammation can cause impaired wound healing. Adipose-derived stem cells (ADSCs) belong to the mesenchymal stem cell (MSC) family and exhibit prospective applications in tissue regeneration and dermatological repairs. ADSC-secreted extracellular vesicles (ADSC-EVs) mimic the functions of ADSCs without the concerns of cell survival, immune response, or ethical issues. Studies have revealed that ADSC-EVs can inhibit abnormal inflammation responses and accelerate wound healing through various mechanisms. Moreover, some studies explored modifications in the cargo components of ADSC-EVs to enhance their therapeutic efficacy. Given the increasing studies focusing on the potential of ADSC-EVs in wound healing, how they interfere with different phases of this process has been investigated in pieces. In this review, we summarized all up-to-date evidence to map a clearer picture of the underlying mechanisms of ADSC-EVs in inflammation response. The applications of ADSC-EVs aiming at inflammation in the healing process were also reviewed to provide therapeutic strategies for future investigators.

The Potential Role of Exosomes in Aesthetic Plastic Surgery: A Review of Current Literature

Despite an increasing surge of exosome use throughout the aesthetic arena, a paucity of published exosome-based literature exists. Exosomes are membrane-bound extracellular vesicles derived from various cell types, exerting effects via intercellular communication and regulation of several signaling pathways. The purpose of this review was to summarize published articles elucidating mechanisms and potential applications, report available products and clinical techniques, and prompt further investigation of this emerging treatment within the plastic surgery community.

Methods

A literature review was performed using PubMed with keywords exosomes, secretomes, extracellular vesicles, plastic surgery, skin rejuvenation, scar revision, hair growth, body contouring, and breast augmentation. Publications from 2010 to 2021 were analyzed for relevance and level of evidence. A Google search identified exosome distributors, where manufacturing/procurement details, price, efficacy, and clinical indications for use were obtained by direct contact and summarized in table format.

Results

Exosomes are currently derived from bone marrow, placental, adipose, and umbilical cord tissue. Laboratory-based exosome studies demonstrate enhanced outcomes in skin rejuvenation, scar revision, hair restoration, and fat graft survival on the macro and micro levels. Clinical studies are limited to anecdotal results. Prices vary considerably from $60 to nearly $5000 based on company, source tissue, and exosome concentration. No exosome-based products are currently Food and Drug Administration-approved.

Conclusions

Administered alone or as an adjunct, current reports show promise in several areas of aesthetic plastic surgery. However, ongoing investigation is warranted to further delineate concentration, application, safety profile, and overall outcome efficacy.

Advancements in adipose-derived stem cell therapy for skin fibrosis

Pathological scarring and scleroderma, which are the most common conditions of skin fibrosis, pathologically manifest as fibroblast proliferation and extracellular matrix (ECM) hyperplasia. Fibroblast proliferation and ECM hyperplasia lead to fibrotic tissue remodeling, causing an exaggerated and prolonged wound-healing response. The pathogenesis of these diseases has not been fully clarified and is unfortunately accompanied by exceptionally high medical needs and poor treatment effects. Currently, a promising and relatively low-cost treatment has emerged-adipose-derived stem cell (ASC) therapy as a branch of stem cell therapy, including ASCs and their derivatives-purified ASC, stromal vascular fraction, ASC-conditioned medium, ASC exosomes, etc., which are rich in sources and easy to obtain. ASCs have been widely used in therapeutic settings for patients, primarily for the defection of soft tissues, such as breast enhancement and facial contouring. In the field of skin regeneration, ASC therapy has become a hot research topic because it is beneficial for reversing skin fibrosis. The ability of ASCs to control profibrotic factors as well as anti-inflammatory and immunomodulatory actions will be discussed in this review, as well as their new applications in the treatment of skin fibrosis. Although the long-term effect of ASC therapy is still unclear, ASCs have emerged as one of the most promising systemic antifibrotic therapies under development.

MicroRNA-29a Mitigates Laminectomy-Induced Spinal Epidural Fibrosis and Gait Dysregulation by Repressing TGF-β1 and IL-6

Spinal epidural fibrosis is one of the typical features attributable to failed back surgery syndrome, with excessive scar development in the dura and nerve roots. The microRNA-29 family (miR-29s) has been found to act as a fibrogenesis-inhibitory factor that reduces fibrotic matrix overproduction in various tissues. However, the mechanistic basis of miRNA-29a underlying the overabundant fibrotic matrix synthesis in spinal epidural scars post-laminectomy remained elusive. This study revealed that miR-29a attenuated lumbar laminectomy-induced fibrogenic activity, and epidural fibrotic matrix formation was significantly lessened in the transgenic mice (miR-29aTg) as compared with wild-type mice (WT). Moreover, miR-29aTg limits laminectomy-induced damage and has also been demonstrated to detect walking patterns, footprint distribution, and moving activity. Immunohistochemistry staining of epidural tissue showed that miR-29aTg was a remarkably weak signal of IL-6, TGF-β1, and DNA methyltransferase marker, Dnmt3b, compared to the wild-type mice. Taken together, these results have further strengthened the evidence that miR-29a epigenetic regulation reduces fibrotic matrix formation and spinal epidural fibrotic activity in surgery scars to preserve the integrity of the spinal cord core. This study elucidates and highlights the molecular mechanisms that reduce the incidence of spinal epidural fibrosis, eliminating the risk of gait abnormalities and pain associated with laminectomy.

Simulated microgravity altered the proliferation, apoptosis, and extracellular matrix formation of L929 fibroblasts and the transforming growth factor-β1/Smad3 signaling pathway

Exposure to microgravity can adversely affect the fitness of astronauts. The integrity of the skin plays a crucial role in protecting against mechanical forces and infections, fluid imbalance, and thermal dysregulation. In brief, the skin wound may cause unknown challenges to the implementation of space missions. Wound healing is a physiological process that relies on the synergistic action of inflammatory cells, extracellular matrix (ECM), and various growth factors to maintain the integrity of skin after trauma. Fibroblasts are present almost throughout the entire process of wound repair, especially in the scar formation at the endpoint of wound healing. However, there is limited knowledge about the extent to which fibroblasts are affected by the lack of gravity during wound healing. In this study, we utilized the rotary cell culture system, a ground-based facility that mimics the weightless condition, to study the alterations of L929 fibroblast cells under simulated microgravity (SMG). Our results demonstrated that the SM condition exerted negative influences on the proliferation and ECM formation of the L929 fibroblast. Whereas, the apoptosis of fibroblast was significantly upregulated upon exposure to SMG conditions. Moreover, the transforming growth factor-β1/Smad3 (TGF-β1/smad3) signaling pathway of L929 fibroblast related to wound repair was also altered significantly under a weightless environment. Overall, our study provided evidence that fibroblasts are strongly sensitive to SMG and elucidated the potential value of the TGF-β1/Smad3 signaling pathway modulating wound healing in the future practice of space medicine.

Mesenchymal Stem Cell Derived Extracellular Vesicles: Promising Nanomedicine for Cutaneous Wound Treatment

A skin wound represents a rupture caused by external damage or the existence of underlying pathological conditions. Sometimes, skin wound healing processes may place a heavy burden on patients, families, and society. Wound healing processes mainly consist of several continuous, dynamic, but overlapping stages, namely, the coagulation stage, inflammation stage, proliferation stage, and remodeling stage. Bacterial infection, excessive inflammation, impaired angiogenesis, and scar formation constitute the four significant factors impeding the recovery efficacy of skin wounds. This encourages scientists to develop multifunctional nanomedicines to meet challenging needs. As we know, mesenchymal stem cells (MSCs) have been widely explored for wound repair owing to their unique capability for self-renewal and multipotency. However, problems including immune concerns and legal restrictions should be properly resolved before MSC-based therapeutics are safely and widely used in clinics. Besides, maintaining the high viability/proliferation capability of MSCs during administration processes and therapy procedures is also one of the biggest technical bottlenecks. Extracellular vesicles (EVs) are cell-derived nanovesicles, that not only possess the basic characteristics and functions of their corresponding maternal cells but also contain several outstanding advantages including abundant sources, excellent biocompatibility, and convenient administration routes. Furthermore, the membrane surface and cavity are easy to flexibly modify to meet versatile application needs. Recently, MSC-derived EVs have emerged as promising therapeutics for skin wound repair. However, current reviews are too broad and rarely focused on the specific roles of EVs in the different stages of wound recovery. Therefore, it is quite necessary to demonstrate the significance of stem cell-derived EVs in promoting wound healing from several specific aspects. Here, this review primarily tries to provide critical comments on current advances in EVs derived from MSCs for wound repair, particularly elaborating on their impressive roles in effectively eliminating infections, inhibiting inflammation, promoting angiogenesis, and reducing scar formation. Last but not least, current limitations and future prospects of EVs derived from MSCs in the areas of wound repair are also objectively analyzed.

Noncoding RNAs: Master Regulator of Fibroblast to Myofibroblast Transition in Fibrosis

Myofibroblasts escape apoptosis and proliferate abnormally under pathological conditions, especially fibrosis; they synthesize and secrete a large amount of extracellular matrix (ECM), such as α-SMA and collagen, which leads to the distortion of organ parenchyma structure, an imbalance in collagen deposition and degradation, and the replacement of parenchymal cells by fibrous connective tissues. Fibroblast to myofibroblast transition (FMT) is considered to be the main source of myofibroblasts. Therefore, it is crucial to explore the influencing factors regulating the process of FMT for the prevention, treatment, and diagnosis of FMT-related diseases. In recent years, non-coding RNAs, including microRNA, long non-coding RNAs, and circular RNAs, have attracted extensive attention from scientists due to their powerful regulatory functions, and they have been found to play a vital role in regulating FMT. In this review, we summarized ncRNAs which regulate FMT during fibrosis and found that they mainly regulated signaling pathways, including TGF-β/Smad, MAPK/P38/ERK/JNK, PI3K/AKT, and WNT/β-catenin. Furthermore, the expression of downstream transcription factors can be promoted or inhibited, indicating that ncRNAs have the potential to be a new therapeutic target for FMT-related diseases.

Bioengineered MSC-derived exosomes in skin wound repair and regeneration

Refractory skin defects such as pressure ulcers, diabetic ulcers, and vascular ulcers represent a challenge for clinicians and researchers in many aspects. The treatment strategies for wound healing have high cost and limited efficacy. To ease the financial and psychological burden on patients, a more effective therapeutic approach is needed to address the chronic wound. MSC-derived exosomes (MSC-exosomes), the main bioactive extracellular vesicles of the paracrine effect of MSCs, have been proposed as a new potential cell-free approach for wound healing and skin regeneration. The benefits of MSC-exosomes include their ability to promote angiogenesis and cell proliferation, increase collagen production, regulate inflammation, and finally improve tissue regenerative capacity. However, poor targeting and easy removability of MSC-exosomes from the wound are major obstacles to their use in clinical therapy. Thus, the concept of bioengineering technology has been introduced to modify exosomes, enabling higher concentrations and construction of particles of greater stability with specific therapeutic capability. The use of biomaterials to load MSC-exosomes may be a promising strategy to concentrate dose, create the desired therapeutic efficacy, and maintain a sustained release effect. The beneficial role of MSC-exosomes in wound healing is been widely accepted; however, the potential of bioengineering-modified MSC-exosomes remains unclear. In this review, we attempt to summarize the therapeutic applications of modified MSC-exosomes in wound healing and skin regeneration. The challenges and prospects of bioengineered MSC-exosomes are also discussed.

An updated review of the immunological mechanisms of keloid scars

Keloid is a type of disfiguring pathological scarring unique to human skin. The disorder is characterized by excessive collagen deposition. Immune cell infiltration is a hallmark of both normal and pathological tissue repair. However, the immunopathological mechanisms of keloid remain unclear. Recent studies have uncovered the pivotal role of both innate and adaptive immunity in modulating the aberrant behavior of keloid fibroblasts. Several novel therapeutics attempting to restore regulation of the immune microenvironment have shown variable efficacy. We review the current understanding of keloid immunopathogenesis and highlight the potential roles of immune pathway-specific therapeutics.

Exosomes based advancements for application in medical aesthetics

Beauty is an eternal pursuit of all people. Wound repair, anti-aging, inhibiting hyperpigmentation and hair loss are the main demands for medical aesthetics. At present, the repair and remodeling of human body shape and function in medical aesthetics are often achieved by injection of antioxidants, hyaluronic acid and botulinum toxin, stem cell therapy. However, there are some challenges, such as difficulty controlling the injection dose, abnormal local contour, increased foreign body sensation, and the risk of tumor occurrence and deformity induced by stem cell therapy. Exosomes are tiny vesicles secreted by cells, which are rich in proteins, nucleic acids and other bioactive molecules. They have the characteristics of low immunogenicity and strong tissue penetration, making them ideal for applications in medical aesthetics. However, their low yield, strong heterogeneity, and long-term preservation still hinder their application in medical aesthetics. In this review, we summarize the mechanism of action, administration methods, engineered production and preservation technologies for exosomes in medical aesthetics in recent years to further promote their research and industrialization in the field of medical aesthetics.

Keloid Patient Plasma-Derived Exosomal hsa_circ_0020792 Promotes Normal Skin Fibroblasts Proliferation, Migration, and Fibrogenesis via Modulating miR-193a-5p and Activating TGF-β1/Smad2/3 Signaling

Background

Keloids are fibroproliferative disorders, which seriously affect the quality of life of patients with keloids. Additionally, circRNAs are enriched within exosomes derived from human blood samples, whereas their relationship with keloids remains largely unknown. It has been reported that hsa_circ_0020792 was abnormally upregulated in keloid tissues. However, the role of keloid patient plasma-derived exosomal hsa_circ_0020792 in the formation and development of keloids is not well understood.

Methods

Exosomes were isolated from the peripheral blood plasma of the patients with keloids (keloid patient-Exo) and healthy controls (Healthy control-Exo). The hsa_circ_0020792 and miR-193a-5p levels in keloid patient-Exo and healthy control-Exo, as well as in keloid fibroblasts and normal skin fibroblasts (NFs) were evaluated by RT-qPCR.

Results

The level of hsa_circ_0020792 was remarkably increased in keloid patient-Exo and keloid fibroblasts compared with that in Healthy control-Exo and NFs, respectively. In addition, keloid patient-Exo obviously enhanced the viability, migration, and extracellular matrix (ECM) synthesis, but reduced the apoptosis of NFs. Moreover, keloid patient-Exo notably promoted the fibrogenesis of NFs, as characterized by enhanced TGF-β signaling, increased expressions of phosphorylated Smad2/3. However, downregulation of hsa_circ_0020792 markedly reversed the promoting effects of keloid patient-Exo on cell growth, migration, and myofibroblast activation and fibrogenesis. Furthermore, downregulation of hsa_circ_0020792 significantly reduced the viability, migration, and fibrogenesis in NFs, whereas these phenomena were reversed by miR-193a-5p inhibitor.

Conclusion

Collectively, keloid patient plasma-derived exosomal hsa_circ_0020792 could promote the proliferation, migration, and fibrogenesis of NFs via modulating miR-193a-5p and activating TGF-β1/Smad2/3 signaling.

Advances in microRNA from adipose-derived mesenchymal stem cell-derived exosome: focusing on wound healing

Skin wounds are a common condition causing economic burden and they represent an urgent clinical need, especially chronic wounds. Numerous studies have been conducted on the applications of stem cell therapy in wound healing, with adipose-derived mesenchymal stem cells (ADMSCs) playing a major role since they can be isolated easily, yielding a high number of cells, the less invasive harvesting required, the longer life span and no ethical issues. However, the lack of standardized doses and protocols, the heterogeneity of clinical trials, as well as the incompatibility of the immune system limit its application. Recent studies have demonstrated that specific stem cell functions depend on paracrine factors, including extracellular vesicles, in which microRNAs in exosomes (Exo-miRNAs) are essential in controlling their functions. This paper describes the application and mechanism whereby ADMSC-Exo-miRNA regulates wound healing. ADMSC-Exo-miRNA is involved in various stages in wounds, including modulating the immune response and inflammation, accelerating skin cell proliferation and epithelialization, promoting vascular repair, and regulating collagen remodeling thereby reducing scar formation. In summary, this acellular therapy based on ADMSC-Exo-miRNA has considerable clinical potential, and provides reference values for developing new treatment strategies for wound healing.

Engineered stem cell exosomes for oral and maxillofacial wound healing

Wound healing of the oral and maxillofacial area affects the quality of life and mental health of the patient; therefore, effective therapies are required to promote wound healing. However, traditional treatment methods have limited efficacy. Exosomes secreted by stem cells used for oral and maxillofacial wound healing have shown outstanding results. Stem cell-derived exosomes possess the regenerative and repair ability of stem cells. Moreover, they are nontumorigenic and have good biosafety. However, the application of natural stem cell exosomes is limited owing to their low yield, impurity, lack of targeting, and low drug delivery rate. Many modification methods have been developed to engineered stem cell exosomes with beneficial properties, such as modifying parent cells and directly processing stem cell exosomes. These methods include coincubation, genetic engineering, electroporation, ultrasound, and artificial synthesis of engineered stem cell exosomes. These engineered stem cell exosomes can cargo nucleic acids, proteins, and small molecules. This gives them anti-inflammatory and cell proliferation regulatory abilities and enables the targeted promotion of efficient soft tissue repair after trauma. Engineered stem cell exosomes can decrease inflammation, promote fibroblast proliferation, and angiogenesis, and decrease scar formation to promote oral and maxillofacial wound healing, including diabetic and burn wounds. Thus, engineered stem cell exosomes are an effective treatment that has the potential for oral and maxillofacial wound healing.

Exosome Derived from Mesenchymal Stem Cells Alleviates Pathological Scars by Inhibiting the Proliferation, Migration and Protein Expression of Fibroblasts via Delivering miR-138-5p to Target SIRT1

Introduction

The therapies of using exosomes derived from mesenchymal stem cells (MSC-Exo) for wound healing and scar attenuation and micro RNAs (miRNAs) for regulation of genes by translational inhibition and mRNA destabilization obtained great achievements. Silent information regulator 1 (SIRT1) is the silent information, which has an intricate role in many biological processes. However, the effects of SIRT1 and miR-138-5p loaded in MSC-Exo on pathological scars remain unclear.

Methods

MSC-Exo was isolated and identified by ultracentrifugation, transmission electron microscopy, nanoparticle size measuring instrument and Western blot assays. The relationship between SIRT1 and miR-138-5p was verified by a double-luciferase reporter assay. Cell Counting Kit-8, Τranswell, scratch, and Western blot assays were used to evaluate the proliferation and migration of human skin fibroblasts (HSFs), and the protein expression of SIRT1, NF-κB, α-SMA and TGF-β1 in HSFs, respectively. Flow cytometry was used to assess the apoptosis and cell cycle of HSFs affected by SIRT1.

Results

Our study demonstrated that miR-138-5p loaded in MSC-Exo could attenuate proliferation, migration and protein expression of HSFs-derived NF-κB, α-SMA, and TGF-β1 by targeting to SIRT1 gene, which confirmed the potential effects of MSC-Exo in alleviating pathological scars by performing as a miRNA’s delivery vehicle.

Conclusion

Exosomes derived from MSCs acting as a delivery vehicle to deliver miR-138-5p can downregulate SIRT1 to inhibit the growth and protein expression of HSFs and attenuate pathological scars.

Stem cell-derived exosomal transcriptomes for wound healing

Wound healing is a complex and integrated process of the interaction of various components within the injured tissue. Accumulating evidence suggested that stem cell-derived exosomal transcriptomes could serve as key regulatory molecules in wound healing in stem cell therapy. Stem cell-derived exosomal transcriptomes mainly consist of long noncoding RNAs (lncRNAs), microRNAs (miRNAs), circular RNAs (circRNAs) and messenger RNAs (mRNAs). In this article we presented a brief introduction on the wound repair process and exosomal transcriptomes. Meanwhile, we summarized our current knowledge of the involvement of exosomal transcriptomes in physiological and pathological wound repair process including inflammation, angiogenesis, and scar formation.

Identifying miRNAs Associated with the Progression of Keloid through mRNA-miRNA Network Analysis and Validating the Targets of miR-29a-3p in Keloid Fibroblasts

Background. Keloid has brought great trouble to people and currently has no uniformly successful treatment. It is urgent to find new targets to effectively prevent the progress of keloid. The current research mainly identifies the differentially expressed genes (DEGs) in keloid through high-throughput sequencing technology and bioinformatics analysis technology, to screen new therapeutic targets and potential biomarkers. However, due to the different samples, different control groups, and small sample sizes, the sequencing results obtained from different studies are quite different and lack reliability. It is necessary to analyze the existing datasets in a reasonable way. Methods. Datasets about keloid were filtered in Gene Expression Omnibus (GEO) and ArrayExpress databases according to the inclusion and exclusion criteria. The discovery datasets were used for summarizing significant DEGs, and the validation datasets were to validate the mRNA and miRNA expression levels. The Encyclopedia of RNA Interactomes (ENCORI) online platform was used to predict the interactions between miRNAs and their target mRNAs. Protein-protein interaction network (PPI network) analysis and functional enrichment analysis were conducted. miRNA-mRNA network was established by Cytoscape software and verified in keloid tissue ( $n=8$ ) by RT-qPCR. miR-29a-3p mimic and inhibitor were transfected into keloid fibroblasts (KFs) to preliminary verify its targets, the prognostic value of which was estimated by the receiver operating characteristic (ROC) curve. Results. A total of 6 datasets involving 20 patients were included. 15 miRNAs and 12 target mRNAs were identified as potential biomarkers for keloid patients. The RT-qPCR results showed that miR-29a-3p, miR-92a-3p, and miR-143-3p were downregulated, and all their target mRNAs were upregulated in keloid tissue ( $P<0.05$ ). The expression of COL1A1, COL1A2, COL3A1, COL5A1, and COL5A2 decreased when miR-29a-3p was overexpressed but increased when miR-29a-3p was knocked down ( $P<0.05$ ). And these genes had a good performance in the diagnosis of keloid, especially when using keloid nonlesional skin or normal scar tissues as controls. Conclusion. The miRNA-mRNA network, especially miR-29a-3p and its targets, may provide insights into the underlying pathogenesis of keloid and serve as potential biomarkers for keloid treatment.

Adipose stem cells-released extracellular vesicles as a next-generation cargo delivery vehicles: a survey of minimal information implementation, mass production and functional modification

OBJECTIVES

To investigate current situation of minimal information implementation highlighted by minimal information for studies of extracellular vesicles 2018 (MISEV2018) guidelines, and explore technological advances towards mass production and functional modification in aesthetic, plastic and reconstructive surgery.

METHODS

Original articles on extracellular vesicles (EVs) of adipose stem cells (ASCs) were identified. Statistics upon minimal information for EVs research, such as species, cell types, culture conditions, conditioned media harvesting parameters, EVs isolation/storage/identification/quantification, functional uptake and working concentration, were analyzed.

RESULTS

The items of cell culture conditions such as passage number, seeding density, conditioned media harvesting time, functional uptake and working concentration were poorly documented, with a reporting percentage of 47.13%, 54.02%, 29.89%, 62.07% and 36.21%, respectively. However, there were some studies not reporting information of ASCs origin, culture medium, serum, EVs isolation methods, quantification and identification of EVs, accounting for 3.45%, 10.34%, 6.90%, 3.45%, 18.39% and 4.02%, respectively. Serum deprivation and trophic factors stimuli were attempted for EVs mass production. Several technological advances towards functional modification included hypoxia pre-condition, engineering EVs and controlled release. Presently, ASCs EVs have been applied in multiple fields, including diabetic/non-diabetic wound healing, angiogenesis, inflammation modulation, fat grafting, hair regeneration, antiaging, and healing and regeneration of cartilage/bone/peripheral nerve/tendon.

CONCLUSION

Our results highlight normative reporting of ASCs EVs in functional studies to increase reliability and reproducibility of scientific publications. The advances towards mass production and functional modification of ASCs EVs are also recommended to enhance therapeutic effects.

miR-96-5p Induces Orbital Fibroblasts Differentiation by Targeting Smad7 and Promotes the Development of Thyroid-Associated Ophthalmopathy

Background

Recent evidence shows that adipogenic differentiation of orbital fibroblasts (OFs) promotes the development of thyroid-associated ophthalmopathy (TAO), an organ-specific immune disease. Furthermore, miR-96-5p has been linked to adipogenic differentiation of C2C12 myoblasts and is significantly correlated with the severity of TAO. The purpose of this study is to look into the role of miR-96-5p in the adipogenesis of OFs with TAO.

Methods

The orbital tissues from TAO patients and non-TAO participants were collected, and primary OFs were isolated and cultured for further analysis. miR-96-5p expression was examined using qRT-PCR. The adipogenic differentiation of OFs was then studied.

Results

Orbital fibroblasts isolated from adipose tissues of TAO patients (t-OFs) demonstrated greater adipogenic differentiation ability than OFs isolated from adipose tissues of non-TAO participants. miR-96-5p was found to be overexpressed in the orbital tissues of TAO patients and t-OFs. Further research revealed that miR-96-5p, by targeting Smad7, could exacerbate PPAR-γ/C/EBPα signaling-induced adipogenic differentiation of t-OFs. However, inhibiting miR-96-5p could block t-OFs adipogenic differentiation-mediated adipogenesis via Smad7/PPAR-γ/C/EBPα.

Conclusions

miR-96-5p plays a critical regulatory role in the development of TAO by targeting Smad7 and promoting adipogenic differentiation of OFs.

Research update of adipose tissue-based therapies in regenerative dermatology

Mesenchymal stromal/stem cells (MSCs) have a spontaneous propensity to support tissue homeostasis and regeneration. Among the several sources of MSCs, adipose-derived tissue stem cells (ADSCs) have received major interest due to the higher mesenchymal stem cells concentration, ease, and safety of access. However, since a significant part of the natural capacity of ADSCs to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines, lipids, and extracellular matrix components, several studies focused on cell-free strategies. Furthermore, adipose cell-free derivatives are becoming more attractive especially for non-volumizing purposes, such as most dermatological conditions. However, when keratinocytes, fibroblasts, melanocytes, adipocytes, and hair follicle cells might not be locally sourced, graft of materials containing concentrated ADSCs is preferred. The usage of extracellular elements of adipose tissue aims to promote a self-autonomous regenerative microenvironment in the receiving area restoring physiological homeostasis. Hence, ADSCs or their paracrine activity are currently being studied in several dermatological settings including wound healing, skin fibrosis, burn, and aging.The present work analyzing both preclinical and clinical experiences gives an overview of the efficacy of adipose tissue-derivatives like autologous fat, the stromal vascular fraction (SVF), purified ADSCs, secretome and extracellular matrix graft in the field of regenerative medicine for the skin.