Conditioned Medium Obtained from Amnion-Derived Mesenchymal Stem Cell Culture Prevents Activation of Keloid Fibroblasts:

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Skin-derived precursor conditioned medium alleviated photoaging via early activation of TGF-β/Smad signaling pathway by thrombospondin1: In vitro and in vivo studies

Photoaging is one major exogenous factor of skin aging. Efficacy and safety of current anti-photoaging therapies remained to be improved. Our previous studies indicated that skin-derived precursors (SKPs) alleviated photodamage by early activation of TGF-β/Smad signaling pathway via thrombospondin1 (TSP1). However, the research concerning SKP conditioned medium (SKP-CM) has never been reported. In the current study, we aimed to explore the anti-photoaging effects of SKP-CM both in vitro and in vivo, and to elucidate the possible mechanisms. Mouse SKP-CM (mSKP-CM) collection was optimized by a comparative method. The concentration of protein and growth factors in mSKP-CM was detected using BCA protein assay kit and growth factor protein chip. The anti-photoaging effects of mSKP-CM and its regulation of key factors in the TGF-β/Smad signaling pathway were explored using UVA + UVB photoaged mouse fibroblasts (mFBs) and nude mice dorsal skin. The research revealed that mSKP-CM contained significantly higher-concentration of protein and growth factors than mouse mesenchymal stem cell conditioned medium (mDMSC-CM). mSKP-CM alleviated mFBs photoaging by restoring cell viability and relieving senescence and death. ELISA, qRT-PCR, and western blot results implied the potential mechanisms were associated with the early activation of TGF-β/Smad signaling pathway by TSP1. In vivo experiments demonstrated that compared with the topical intradermal mDMSC-CM injection and retinoic acid cream application, the photodamaged mice dorsal skin intradermally injected with mSKP-CM showed significantly better improvement. Consistent with the in vitro results, both western blot and immunohistochemistry results confirmed that protein expression of TSP1, smad2/3, p-smad2/3, TGF-β1, and collagen I increased, and matrix metalloproteinases decreased. In summary, both in vitro and in vivo experiments demonstrated that mSKP-CM alleviated photoaging through an early activation of TGF-β/Smad signaling pathway via TSP1. SKP-CM may serve as a novel and promising cell-free therapeutical approach for anti-photoaging treatment and regenerative medicine.

Clinical evaluation of intralesional umbilical cord-derived mesenchymal stem cells, conditioned medium and triamcinolone acetonide injection for keloid treatment: A pilot study

Topical keloid therapy is performed with triamcinolone acetonide (TA) intralesional injection. However, the recurrence rate is high with various side effects. Mesenchymal stem cells (MSCs) have high proliferative abilities and reduce the activity and proliferation of fibroblast cells in keloids. To overcome the costs and limitations, conditioned medium (CM) is used. This study aims to evaluate feasibility of intralesional injection of umbilical cord MSC (UC-MSC) and conditioned medium (UC-CM) compared to TA for keloid therapy. Twenty-four patients with keloids who met the inclusion criteria were included, randomized into three treatment groups and then got assessed for the sociodemographic data, keloid volume, histopathology (type 1:3 collagen ratio), interleukin-10 (IL-10) levels and Patient and Observer Scar Assessment Scale (POSAS) score during visits. Largest volume regression occurred in the UC-MSC group, followed by UC-CM and then the TA group (UC-MSC: 45.32% ± 2.61%; UC-CM: 43.61% ± 3.67%; TA: 28.34% ± 3.81%; p = 0.003). Similar pattern was also observed in increase in IL-10 levels, the decrease in POSAS scores and the reduction of type 1:3 collagen ratio. Hence, UC-MSC and UC-CM are promisingly more effective than TA for keloid therapy, showcasing their superiority in reducing keloid volume, symptoms and type 1:3 collagen ratio, as well as increasing the levels of IL-10.

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.

Development of a simultaneous and noninvasive measuring method using high-frame rate videography and motion analysis software for the assessment of facial palsy recovery in a rat model

BACKGROUND

For the development of new therapeutic and reconstructive methods for facial nerve palsy, it is critical to validate them in animal models. This study developed a novel evaluation method using a high-speed camera and motion analysis software for rat facial paralysis models. The validity of the new method was verified using normal rats and rats with facial paralysis.

METHODS

The whisker movement was recorded using a high-frame video camera. The video files were processed using motion analysis software, and the angular velocities were measured. The score was calculated as the percentage of movement on the side that had palsy compared with the movement on the normal side. Normal rats were used to examine which of the four indices of angular velocity is appropriate for this evaluation method. Using this method, two types of facial nerve palsy models were compared. Furthermore, the three agents that were predicted to promote axon regeneration from previous studies were evaluated.

RESULTS

The two averages of the protraction and retraction movement velocities of the whiskers were considered as the most appropriate indicators for this new method. Compared with the saline group, all agent groups showed significant differences in the improvement of facial palsy recovery.

CONCLUSIONS

This method is an evaluation method for the effects of therapeutic intervention for facial nerve paralysis in real time without sacrificing animals.

Effect of stem cell conditional medium-loading adhesive hydrogel on TGF-β1-induced endometrial stromal cell fibrosis

Introduction: Uterine adhesion (IUA) is a severe complication that results from uterine operations or uterine infections. Hysteroscopy is considered the gold standard for the diagnosis and treatment of uterine adhesions. Yet, this invasive procedure leads to re-adhesions after hysteroscopic treatment. Hydrogels loading functional additives (e.g., placental mesenchymal stem cells (PC-MSCs)) that can act as physical barriers and promote endometrium regeneration are a good solution. However, traditional hydrogels lack tissue adhesion which makes them unstable under a rapid turnover of the uterus, and PC-MSCs have biosafety risks when used as functional additives. Methods: In this study, we coupled an adhesive hydrogel with a PC-MSCs conditioned medium (CM) to form a hybrid of gel and functional additives (CM/Gel-MA). Results and Discussion: Our experiments show that CM/Gel-MA enhances the activity of endometrial stromal cells (ESCs), promotes cell proliferation, and reduces the expression of α-SMA, collagen I, CTGF, E-cadherin, and IL-6, which helps to reduce the inflammatory response and inhibit fibrosis. We conclude that CM/Gel-MA can more potentially prevent IUA by combining the physical barriers from adhesive hydrogel and functional promotion from CM.

The Secretome of Irradiated Peripheral Mononuclear Cells Attenuates Hypertrophic Skin Scarring

Hypertrophic scars can cause pain, movement restrictions, and reduction in the quality of life. Despite numerous options to treat hypertrophic scarring, efficient therapies are still scarce, and cellular mechanisms are not well understood. Factors secreted by peripheral blood mononuclear cells (PBMCsec) have been previously described for their beneficial effects on tissue regeneration. In this study, we investigated the effects of PBMCsec on skin scarring in mouse models and human scar explant cultures at single-cell resolution (scRNAseq). Mouse wounds and scars, and human mature scars were treated with PBMCsec intradermally and topically. The topical and intradermal application of PBMCsec regulated the expression of various genes involved in pro-fibrotic processes and tissue remodeling. We identified elastin as a common linchpin of anti-fibrotic action in both mouse and human scars. In vitro, we found that PBMCsec prevents TGFβ-mediated myofibroblast differentiation and attenuates abundant elastin expression with non-canonical signaling inhibition. Furthermore, the TGFβ-induced breakdown of elastic fibers was strongly inhibited by the addition of PBMCsec. In conclusion, we conducted an extensive study with multiple experimental approaches and ample scRNAseq data demonstrating the anti-fibrotic effect of PBMCsec on cutaneous scars in mouse and human experimental settings. These findings point at PBMCsec as a novel therapeutic option to treat skin scarring.

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.

Do Mesenchymal Stem Cells Influence Keloid Recurrence?

Introduction

Mesenchymal stem cells (MSCs) have been postulated by a number of authors to be the precursor cells of fibroblasts and myofibroblasts in keloids. They have been seen as a regenerative pool that ensures a steady supply of cells. The objective of our study was to determine MSCs in keloids and normal skin as a determinant of keloid recurrence.

Methods

This was a longitudinal prospective study in which patients with keloid excisions of their specimens analyzed for MSC. A control group of patients matched for age, sex, and body-mass index (BMI) with no history of keloids admitted for elective surgical procedures had their skin samples taken and also analyzed for MSCs. Data collected were analyzed and compared using Student's t, x ², and Fisher's exact t tests.

Results

A total of 61 patients with keloids and a control group of 32 patients were recruited. The male:female ratio was 1:2 and mean age 29.5 and 29.7 years for keloids and controls, respectively. Patients with recurrent keloids had a mean density of 841.4 MSCs/g compared to 578 MSCs/g of tissue for those with no recurrence and 580 MSCs/g for patients with normal skin. Recurrent keloids had a significantly higher percentage of MSCs than those without.

Conclusion

Keloids compared to normal skin had a higher percentage of MSCs, with recurrent keloids demonstrating an even higher count, a possible indicator that MSCs might correlate with severity of keloid disease and recurrence.

An improved explants culture method: Sustainable isolation of keloid fibroblasts with primary characteristics

BACKGROUND

Keloid (KD) is a complex fibroproliferative disease, but the exact mechanisms underlying keloid pathogenesis remain to be elucidated. The primary keloid fibroblasts (KFs) culture in vitro has always been a fundamental measure to study the pathogenesis of keloid. However, the traditional primary culture methods have some limitations, such as a long culture cycle, low specimen utilization rate and so on.

AIMS

Improve the keloid explants culture method sts.

MATERIALS & METHODS

We proposed an improved new "explants multiple culture method"-reusing keloid explants for primary culture and harvesting the primary KFs in specific culture times. Meanwhile, the purity, proliferation, apoptosis, migration, invasion, extracellular matrix synthesis, and some fibrosis and inflammation-related proteins of KFs obtained from the first, fifth, and tenth explants cultures were detected.

RESULTS

The results showed that the culture cycle of this new method (Cell Isolation: 2.67 ± 0.86 days, Explants removal: 8.83 ± 0.79 days, Cell Passage: 15.17 ± 1.39 days) was significantly shorter than that of the traditional method (Cell Isolation: 8.67 ± 1.84 days, Explants removal: 17.67 ± 2.17 days, Cell Passage: 22.67 ± 1.84 days). No significant difference was observed between the phenotypes of the fibroblasts obtained from the first explants culture and cultures less than 10 times (p > 0.05).

DISSCUSSION

Taken together, this study provides an effective method for the primary culture of KFs with a higher specimen utilization rate and shorter culture cycle.

CONCLUSION

This method breaks through the limitation of traditional explants culture requiring a large number of keloid specimens and provides a rich source of KFs for the study of keloid.

Therapeutic Potential of Adipose Stem Cell-Derived Conditioned Medium on Scar Contraction Model

Scars are composed of stiff collagen fibers, which contract strongly owing to the action of myofibroblasts. To explore the substances that modulate scar contracture, the fibroblast-populated collagen lattice (FPCL) model has been used. However, the molecular signature of the patient-derived FPCL model has not been verified. Here, we examined whether the patient-derived keloid FPCL model reflects scar contraction, analyzing detailed gene expression changes using comprehensive RNA sequencing and histological morphology, and revealed that these models are consistent with the changes during human scar contracture. Moreover, we examined whether conditioned media derived from adipose stem cells (ASC-CM) suppress the scar contracture of the collagen disc. Detailed time-series measurements of changes in disc area showed that the addition of ASC-CM significantly inhibited the shrinkage of collagen discs. In addition, a deep sequencing data analysis revealed that ASC-CM suppressed inflammation-related gene expression in the early phase of contraction; in the later phase, this suppression was gradually replaced by extracellular matrix (ECM)-related gene expression. These lines of data suggested the effectiveness of ASC-CM in suppressing scar contractures. Therefore, the molecular analysis of the ASC-CM actions found in this study will contribute to solving medical problems regarding pathological scarring in wound prognosis.

Long-term explant culture: an improved method for consistently harvesting homogeneous populations of keloid fibroblasts

Explant culture is a more suitable method than enzyme digestion for the isolation of keloid fibroblasts (KFs), but it has a longer isolation period. In this study, we propose a long-term explant culture method. Unlike in the conventional explant culture method, we continued culturing explants to isolate KFs rather than discarding them during passage. We demonstrated that keloid explants could be cultured for more than 4 months to continuously yield enriched KFs, and the KFs from the repeatedly cultured explants had shorter isolation times. The biological behavior and fibrotic phenotypic characteristics of the KFs from the explants cultured long term were investigated, and no statistical differences were found compared with the KFs from the original explants. In conclusion, the long-term explant culture method was shown to be efficient for harvesting a large, homogeneous population of KFs. The high efficiency as well as ease of operation and sample saving make this method convenient for researchers working with KFs.

Testis developmental related gene 1 promotes non-small-cell lung cancer through the microRNA-214-5p/Krüppel-like factor 5 axis

Non-small-cell lung cancer (NSCLC) is a frequent malignancy and has a high global incidence. Long noncoding RNAs (lncRNAs) are implicated in carcinogenesis and tumor progression. LncRNA testis developmental related gene 1 (TDRG1) plays a pivotal role in many cancers. This study researched the biological regulatory mechanisms of TDRG1 in NSCLC. Gene expression was assessed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Changes in the NSCLC cell phenotypes were examined using 5-ethynyl-2'-deoxyuridine (EdU), cell counting kit-8 (CCK-8), wound healing, flow cytometry, and Transwell assays. The binding capacity between TDRG1, microRNA-214-5p (miR‑214-5p), and Krüppel-like factor 5 (KLF5) was tested using luciferase reporter and RNA immunoprecipitation (RIP) assays. In this study, we found that TDRG1 was upregulated in NSCLC samples. Functionally, TDRG1 depletion inhibited NSCLC cell growth, migration, and invasion and accelerated apoptosis. In addition, TDRG1 interacted with miR-214-5p, and miR-214-5p directly targeted KLF5. The suppressive effect of TDRG1 knockdown on NSCLC cellular processes was abolished by KLF5 overexpression. Overall, TDRG1 exerts carcinogenic effects in NSCLC by regulating the miR-214-5p/KLF5 axis.

Mesenchymal stem cell conditioned medium attenuates oxidative stress injury in hepatocytes partly by regulating the miR-486-5p/PIM1 axis and the TGF-β/Smad pathway

This study investigated the role of microRNA (miRNA) miR-486-5p in oxidative stress injury in hepatocytes under the treatment of mesenchymal stem cell conditioned medium (MSC-CM). The oxidative stress injury in hepatocytes (L02) was induced by H₂O₂. Human umbilical cord blood MSC-CM (UCB-MSC-CM) was prepared. The effects of UCB-MSC-CM on the proliferation, apoptosis, and inflammatory response in L02 cells were detected by Cell Counting Kit-8 (CCK-8) assay, flow cytometry analysis, and enzyme-linked immunosorbent assay (ELISA). Subsequently, the target of miR-486-5p was predicted using bioinformatics analysis, and the possible signaling pathway addressed by miR-486-5p was explored using western blot. We found that miR-486-5p expression was elevated following oxidative stress injury and was reduced after UCB-MSC-CM treatment. UCB-MSC-CM protected L02 cells against H₂O₂-induced injury by downregulation of miR-486-5p. Proviral integration site for Moloney murine leukemia virus 1 (PIM1) was verified to be targeted by miR-486-5p. UCB-MSC-CM upregulated the expression of PIM1 reduced by H₂O₂ in L02 cells. Additionally, silencing PIM1 attenuated the protective effects of miR-486-5p downregulation against oxidative stress injury. We further demonstrated that UCB-MSC-CM inhibited the TGF-β/Smad signaling in H₂O_2-treated L02 cells by the miR-486-5p/PIM1 axis. Overall, UCB-MSC-CM attenuates oxidative stress injury in hepatocytes by downregulating miR-486-5p and upregulating PIM1, which may be related to the inhibition of TGF-β/Smad pathway.

Long non-coding RNA LINC01207 promotes cell proliferation and migration but suppresses apoptosis and autophagy in oral squamous cell carcinoma by the microRNA-1301-3p/lactate dehydrogenase isoform A axis

Long noncoding RNAs (lncRNAs) have been reported to participate in the progression of various cancers, including oral squamous cell carcinoma (OSCC). This study aims to find out whether lncRNA LINC01207 regulates the progression of OSCC. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to evaluate gene expression in OSCC cells and tissues. Cell viability, proliferation, migration, apoptosis, and autophagy were detected using Cell Counting Kit-8 (CCK-8), colony formation, Transwell assays, flow cytometry, and western blot analysis. Luciferase reporter and RNA immunoprecipitation (RIP) assays were conducted to assess the interactions among genes. We found that LINC01207 was overexpressed in OSCC cells and tissues. LINC01207 silencing inhibited OSCC cell proliferation and migration but promoted apoptosis and autophagy, and LINC01207 overexpression had an opposite result. LINC01207 interacted with microRNA-1301-3p (miR-1301-3p) while lactate dehydrogenase isoform A (LHDA) was targeted by miR1301-3p. Effects caused by LINC01207 downregulation on OSCC cells were reversed by overexpression of LDHA. Overall, LINC01207 promotes OSCC progression via the miR-1301-3p/LDHA axis

Topical Application of Conditioned Medium from Hypoxically Cultured Amnion-Derived Mesenchymal Stem Cells Promotes Wound Healing in Diabetic Mice

BACKGROUND

Mesenchymal stem cells or their conditioned medium improve chronic wound healing, and their effect is enhanced by hypoxia. Diabetic foot ulcers are chronic wounds characterized by abnormal and delayed healing, which frequently require amputation. The authors evaluated the effect of topical application of conditioned medium from hypoxically cultured amnion-derived mesenchymal stem cells on wound healing in diabetic mice.

METHODS

Amnion-derived mesenchymal stem cells were cultured under 21% oxygen to prepare normoxic conditioned medium and under 1% oxygen to prepare hypoxic conditioned medium. Hydrogels containing standard medium, normoxic conditioned medium, or hypoxic conditioned medium were topically applied to excisional wounds of mice with streptozotocin-induced diabetes. Ulcer tissues were harvested on day 9; immunohistochemical and quantitative polymerase chain reaction analyses were performed to analyze angiogenesis, inflammatory cell infiltration, and expression levels of inflammation-related genes.

RESULTS

Hypoxic conditioned medium significantly enhanced wound closure, increased capillary density and epithelization, and reduced macrophage infiltration. It also tended to reduce the infiltration of neutrophils and enhance the infiltration of regulatory T cells; it showed a tendency to downregulate the expression of the inflammation-related genes interleukin-1β, interleukin-6, chemokine ligand 1, and chemokine ligand 2. Normoxic conditioned medium exhibited similar effects, although they were of lesser magnitude than those of hypoxic conditioned medium.

CONCLUSIONS

Hydrogels containing hypoxically cultured, amnion-derived mesenchymal stem cell conditioned medium accelerated wound healing in diabetic mice by enhancing angiogenesis, accelerating epithelization, and suppressing inflammation. Therefore, topical application of amnion mesenchymal stem cell-derived hypoxic conditioned medium could be a novel treatment for diabetic foot ulcers.

Micro- and Nanosized Substances Cause Different Autophagy-Related Responses

With rapid industrialization, humans produce an increasing number of products. The composition of these products is usually decomposed. However, some substances are not easily broken down and gradually become environmental pollutants. In addition, these substances may cause bioaccumulation, since the substances can be fragmented into micro- and nanoparticles. These particles or their interactions with other toxic matter circulate in humans via the food chain or air. Whether these micro- and nanoparticles interfere with extracellular vesicles (EVs) due to their similar sizes is unclear. Micro- and nanoparticles (MSs and NSs) induce several cell responses and are engulfed by cells depending on their size, for example, particulate matter with a diameter ≤2.5 μm (PM2.5). Autophagy is a mechanism by which pathogens are destroyed in cells. Some artificial materials are not easily decomposed in organisms. How do these cells or tissues respond? In addition, autophagy operates through two pathways (increasing cell death or cell survival) in tumorigenesis. Many MSs and NSs have been found that induce autophagy in various cells and tissues. As a result, this review focuses on how these particles interfere with cells and tissues. Here, we review MSs, NSs, and PM2.5, which result in different autophagy-related responses in various tissues or cells.

Characteristics and Therapeutic Potential of Human Amnion-Derived Stem Cells

Stem cells including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult stem cells (ASCs) are able to repair/replace damaged or degenerative tissues and improve functional recovery in experimental model and clinical trials. However, there are still many limitations and unresolved problems regarding stem cell therapy in terms of ethical barriers, immune rejection, tumorigenicity, and cell sources. By reviewing recent literatures and our related works, human amnion-derived stem cells (hADSCs) including human amniotic mesenchymal stem cells (hAMSCs) and human amniotic epithelial stem cells (hAESCs) have shown considerable advantages over other stem cells. In this review, we first described the biological characteristics and advantages of hADSCs, especially for their high pluripotency and immunomodulatory effects. Then, we summarized the therapeutic applications and recent progresses of hADSCs in treating various diseases for preclinical research and clinical trials. In addition, the possible mechanisms and the challenges of hADSCs applications have been also discussed. Finally, we highlighted the properties of hADSCs as a promising source of stem cells for cell therapy and regenerative medicine and pointed out the perspectives for the directions of hADSCs applications clinically.

Human amniotic membrane mesenchymal stem cell-conditioned medium reduces inflammatory factors and fibrosis in ovalbumin-induced asthma in mice

NEW FINDINGS

What is the central question of this study? Is mesenchymal stem cell-conditioned medium capable of improving the pathological alterations of ovalbumin-induced asthma in mice? What is the main finding and its importance? Our study indicated that human amniotic membrane mesenchymal stem cell-conditioned medium is capable of modulating inflammation, fibrosis, oxidative stress and the pathological consequences of ovalbumin-induced allergic asthma in mice.

ABSTRACT

Paracrine factors secreted by mesenchymal stem cells (MSCs) have immunomodulatory, anti-inflammatory and antifibrotic properties, and the conditioned medium (CM) of these cells might have functional capabilities. We examined the effects of human amniotic membrane MSC-CM (hAM-MSC-CM) on ovalbumin (OVA)-induced asthma. Forty male Balb/c mice were randomly divided into the following four groups: control; OVA (sensitized and challenged with OVA); OVA+CM (sensitized and challenged with OVA and treated with hAM-MSC-CM); and OVA+Placebo (sensitized and challenged with OVA and treated with placebo). Forty-eight hours after the last challenge, serum and bronchoalveolar lavage fluid samples were collected and used for evaluation of inflammatory factors and cells, respectively. Lung tissue sections were stained with Haematoxylin and Eosin or Masson's Trichrome to evaluate pathological changes, and oxidative stress was assessed in fresh lung tissues. Treatment with hAM-MSC-CM significantly hindered histopathological changes and fibrosis and reduced the total cell count and the percentage of eosinophils and neutrophils in bronchoalveolar lavage fluid. Furthermore, it reduced serum levels of immunoglobulin E, interleukin-4, transforming growth factor-β and lung malondialdehyde. It also increased serum levels of interferon-γ and interleukin-10, in addition to the enzymatic activity of glutathione peroxidase, catalase and superoxide dismutase in lung tissue in comparison to the OVA and OVA+Placebo groups. This study showed that administration of hAM-MSC-CM can improve pathological conditions, such as inflammation, fibrosis and oxidative stress, in OVA-induced allergic asthma.

An Update on the Potential of Mesenchymal Stem Cell Therapy for Cutaneous Diseases

Mesenchymal stem or stromal cells (MSCs) are nonhematopoietic postnatal stem cells with self-renewal, multipotent differentiation, and potent immunomodulatory and anti-inflammatory capabilities, thus playing an important role in tissue repair and regeneration. Numerous clinical and preclinical studies have demonstrated the potential application of MSCs in the treatment of tissue inflammation and immune diseases, including inflammatory skin diseases. Therefore, understanding the biological and immunological characteristics of MSCs is important to standardize and optimize MSC-based regenerative therapy. In this review, we highlight the mechanisms underlying MSC-mediated immunomodulation and tissue repair/regeneration and present the latest development of MSC-based clinical trials on cutaneous diseases.

Efficacy and safety of umbilical cord mesenchymal stem cells in treatment of cesarean section skin scars: a randomized clinical trial

BACKGROUND

Pathological skin scars, caused by cesarean section, affected younger mothers esthetically and psychosocially and to some extent frustrated obstetricians and dermatologists. Umbilical cord mesenchymal stem cells (UC-MSCs), as a population of multipotent cells, are abundant in human tissues, providing several possibilities for their effects on skin scar tissues. Herein, we performed a randomized, double-blind, placebo-controlled, three-arm clinical trial, aiming to assess the efficacy and safety of UC-MSCs in the treatment of cesarean section skin scars among primiparous singleton pregnant women.

METHODS

Ninety primiparous singleton pregnant women undergoing elective cesarean section were randomly allocated to receive placebo, low-dose (3 × 10⁶ cells), or high-dose (6 × 10⁶ cells) transdermal hydrogel UC-MSCs on the surface of the skin incision. The primary outcome was cesarean section skin scars followed after the sixth month, assessed by the Vancouver Scar Scale (VSS).

RESULTS

All the participants completed their trial of the primary outcome according to the protocol. The mean score of estimated total VSS was 5.52 in all participants at the sixth-month follow-up, with 6.43 in the placebo group, 5.18 in the low-dose group, and 4.71 in the high-dose group, respectively. No significant difference was found between-group in the mean scores for VSS at the sixth month. Additional prespecified secondary outcomes were not found with significant differences among groups either. No obvious side effects or adverse effects were reported in any of the three arms.

CONCLUSION

This randomized clinical trial showed that UC-MSCs did not demonstrate the effects of improvement of cesarean section skin scars.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02772289. Registered on 13 May 2016.

The Effects of the Transforming Growth Factor-β1 (TGF-β1) Signaling Pathway on Cell Proliferation and Cell Migration are Mediated by Ubiquitin Specific Protease 4 (USP4) in Hypertrophic Scar Tissue and Primary Fibroblast Cultures

BACKGROUND Hypertrophic scar results from an abnormal repair response to trauma in the skin and involves fibroblasts proliferation with increased collagen deposition. Transforming growth factor-ß1 (TGF-ß1) and TGF-ß receptor type I (TGF-ßR1) are involved in tissue repair and are increased by ubiquitin-specific protease 4 (USP4). This study aimed to investigate the effects of TGF-ßR1 and USP4 in human tissue samples of hypertrophic scar and on cell proliferation and cell migration in primary fibroblast cultures in vitro. MATERIAL AND METHODS Skin excision tissue samples with adjacent normal skin were obtained from 15 patients with hypertrophic scar, which provided tissue sections and primary fibroblast culture for analysis. Immunohistochemistry detected the expression of USP4 and TGF-ßR1 in tissue sections. MicroRNA (miRNAs) expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was performed to measure protein expression levels. Cultured skin fibroblasts were investigated using immunofluorescence staining. Fibroblast proliferation, apoptosis, and migration were measured with the Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and a wound-healing assay, respectively. RESULTS The expression of USP4 and TGF-ßR1 in hypertrophic scar were increased compared with normal skin. Fibroblasts cultured from hypertrophic scar tissue showed increased expression of of USP4 and TGF-ßR1. Fibroblast transfection with USP4 short-interfering RNA (siRNA) resulted in reduced fibroblast proliferation and migration, and increased apoptosis. Downregulation of USP4 inhibited the expression of TGF-ßR1 protein and increased the expression levels of Smad7 protein. CONCLUSIONS USP4 regulated the proliferation, migration, and apoptosis of hypertrophic scar fibroblasts by regulating the TGF-ß1 signaling pathway.

In Vitro and Ex Vivo Models for Functional Testing of Therapeutic Anti-scarring Drug Targets in Keloids

Significance: Keloids are benign fibro-proliferative raised dermal lesions that spread beyond the original borders of the wound, continue to grow, rarely regress, and are the most common in pigmented individuals after an abnormal wound healing response. The current treatment failure and respective challenges involved highlighting the underlying issue that the etiopathogenesis of keloids is still not well understood. Disease models are required to better understand the disease pathogenesis. It is not possible to establish keloids in animals because of the uniqueness of this disease to human skin. To address this challenge, along these lines, non-animal reproducible models are vital in investigating molecular mechanisms of keloid pathogenesis and therapeutics development. Recent Advances: Various non-animal models have been developed to better understand the molecular mechanisms involved in keloid scarring and aid in identifying and evaluating the therapeutic potential of novel drug candidates. In this scenario, the current review aims at describing in vitro monocultures, co-cultures, organotypic cultures, and ex vivo whole skin keloid tissue organ culture models. Critical Issues and Future Directions: Current treatment options for keloids are far from securing a cure or preventing disease recurrence. Identifying universally accepted effective therapy for keloids has been hampered by the absence of appropriate disease model systems. Animal models do not accurately mimic the disease, thus non-animal model systems are pivotal in keloid research. The use of these models is essential not only for a better understanding of disease biology but also for identifying and evaluating novel drug targets.

Extracellular Vesicles from Amnion-Derived Mesenchymal Stem Cells Ameliorate Hepatic Inflammation and Fibrosis in Rats

Background

There are no approved drug treatments for liver fibrosis and nonalcoholic steatohepatitis (NASH), an advanced stage of fibrosis which has rapidly become a major cause of cirrhosis. Therefore, development of anti-inflammatory and antifibrotic therapies is desired. Mesenchymal stem cell- (MSC-) based therapy, which has been extensively investigated in regenerative medicine for various organs, can reportedly achieve therapeutic effect in NASH via paracrine action. Extracellular vesicles (EVs) encompass a variety of vesicles released by cells that fulfill functions similar to those of MSCs. We herein investigated the therapeutic effects of EVs from amnion-derived MSCs (AMSCs) in rats with NASH and liver fibrosis.

Methods

NASH was induced by a 4-week high-fat diet (HFD), and liver fibrosis was induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl₄) twice a week for six weeks. AMSC-EVs were intravenously injected at weeks 3 and 4 in rats with NASH (15 μg/kg) and at week 3 in rats with liver fibrosis (20 μg/kg). The extent of inflammation and fibrosis was evaluated with quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The effect of AMSC-EVs on inflammatory and fibrogenic response was investigated in vitro.

Results

AMSC-EVs significantly decreased the number of Kupffer cells (KCs) in the liver of rats with NASH and the mRNA expression levels of inflammatory cytokines such as tumor necrosis factor- (Tnf-) α, interleukin- (Il-) 1β and Il-6, and transforming growth factor- (Tgf-) β. Furthermore, AMSC-EVs significantly decreased fiber accumulation, KC number, and hepatic stellate cell (HSC) activation in rats with liver fibrosis. In vitro, AMSC-EVs significantly inhibited KC and HSC activation and suppressed the lipopolysaccharide (LPS)/toll-like receptor 4 (TLR4) signaling pathway.

Conclusions

AMSC-EVs ameliorated inflammation and fibrogenesis in a rat model of NASH and liver fibrosis, potentially by attenuating HSC and KC activation. AMSC-EV administration should be considered as a new therapeutic strategy for chronic liver disease.