Inhibition of growth of Asian keloid cells with human umbilical cord Wharton's jelly stem cell-conditioned medium

Identification of potential therapeutic target SPP1 and related RNA regulatory pathway in keloid based on bioinformatics analysis

OBJECTIVE

To explore the complex mechanisms of keloid, new approaches have been developed by different strategies. However, conventional treatment did not significantly reduce the recurrence rate. This study aimed to identify new biomarkers and mechanisms for keloid progression through bioinformatics analyses.

METHODS

In our study, microarray datasets for keloid were downloaded from the GEO database. Differentially expressed genes (DEGs) were identified by R software. Multiple bioinformatics tools were used to identify hub genes, and reverse predict upstream miRNAs and lncRNA molecules of target hub genes. Finally, the total RNA-sequencing technique and miRNA microarray were combined to validate the identified genes.

RESULTS

Thirty-one DEGs were screened out and the upregulated hub gene SPP1 was finally identified, which was consistent with our RNA-sequencing analysis results and validation dataset. In addition, a ceRNA network of mRNA (SPP1)-miRNA (miR-181a-5p)-lncRNA (NEAT1, MALAT1, LINC00667, NORAD, XIST and MIR4458HG) was identified by the bioinformatics databases. The results of our miRNA microarray showed that miR-181a-5p was upregulated in keloid, also we found that the lncRNA NEAT1 could affect keloid progression by retrieving the relevant literature.

CONCLUSIONS

We speculate that SPP1 is a potential candidate biomarker and therapeutic target for patients with keloid, and NEAT1/miR-181a-5p/SPP1 might be the RNA regulatory pathway that regulates keloid formation.

Subcellular Fractionation and Metaproteogenomic Identification and Validation of Key Differentially Expressed Molecular Targets for Keloid Disease

Keloid disease (KD) is a common connective tissue disorder of unknown aetiopathogenesis with ill-defined treatment. Keloid scars present as exophytic fibroproliferative reticular lesions postcutaneous injury, and even though KD remains neoplastically benign, keloid lesions behave locally aggressive, invasive and expansive. To date, there is limited understanding and validation of biomarkers identified through combined proteomic and genomic evaluation of KD. Therefore, the aim in this study was to identify putative causative candidates in KD by performing a comprehensive proteomics analysis of subcellular fractions as well as the whole cell, coupled with transcriptomics data analysis of normal compared with KD fibroblasts. We then applied novel integrative bioinformatics analysis to demonstrate that NF-kB-p65 (RELA) from the cytosolic fraction and CAPN2 from the whole-cell lysate were statistically significantly upregulated in KD and associated with alterations in relevant key signaling pathways, including apoptosis. Our findings were further confirmed by showing upregulation of both RELA and CAPN2 in KD using flow cytometry and immunohistochemistry. Moreover, functional evaluation using real-time cell analysis and flow cytometry demonstrated that both omeprazole and dexamethasone inhibited the growth of KD fibroblasts by enhancing the rate of apoptosis. In conclusion, subcellular fractionation and metaproteogenomic analyses have identified, to our knowledge, 2 previously unreported biomarkers of significant relevance to keloid diagnostics and therapeutics.

Umbilical cord-derived mesenchymal stem cell secretome promotes skin regeneration and rejuvenation: From mechanism to therapeutics

How to effectively repair cutaneous wounds and promote skin rejuvenation has always been a challenging issue for clinical medicine and medical aesthetics. Current conventional medicines exhibit several drawbacks, including limited therapeutic effects, prolonged treatment periods, and high costs. As a novel cell-free therapy, the umbilical cord-derived mesenchymal stem cell (UCMSC) secretome may offer a promising approach for skin regeneration and rejuvenation. The UCMSC secretome is a collection of all proteins secreted by mesenchymal stem cells, including conditioned media, exosomes, and other substances. The UCMSC secretome has numerous abilities to accelerate acute wound healing, including high fibroblast and keratinocyte proliferative activity, pro-angiogenesis, anti-inflammation, anti-fibrosis, and anti-oxidative stress. Its impact on the four stages of wound healing is manifested by inducing the haemostasis phase, inhibiting the inflammation phase, promoting the proliferation phase, and regulating the remodelling phase. Furthermore, it is highly effective in the treatment of chronic wounds, alopecia, aging, and skin homeostasis disturbance. This review focuses on the clinical therapies and application prospects of the UCMSC secretome, encompassing its source, culture, separation, identification, storage, and pretreatment. Additionally, a discussion on the dosage, administration route, efficacy, and biosafety in the clinical situation is presented. This review aims to provide scientific support for the mechanistic investigation and clinical utilisation of the UCMSC secretome in wound healing and skin rejuvenation.

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.

IGFBP-7 secreted by adipose-derived stem cells inhibits keloid formation via the BRAF/MEK/ERK signaling pathway

BACKGROUND

Adipose tissue-derived stem cells (ASCs) have important clinical significance as regulators of skin scar tissue regeneration. ASCs inhibit keloid formation and increase insulin-like growth factor-binding protein-7 (IGFBP-7) expression. However, whether ASCs inhibit keloid formation through IGFBP-7 remains unclear.

OBJECTIVE

We aimed to assess the roles of IGFBP-7 in keloid formation.

METHODS

We analyzed the proliferation, migration, and apoptosis of keloid fibroblasts (KFs) treated with recombinant IGFBP-7 (rIGFBP-7) or by co-culture with ASCs using CCK8 assays, transwell assays, and flow cytometry, respectively. In addition, immunohistochemical staining, quantitative polymerase chain reaction, human umbilical vein endothelial cell tube formation, and western blotting experiments were used to assess keloid formation.

RESULTS

IGFBP-7 expression was significantly lower in keloid tissues than that in normal skin tissues. Stimulation of KFs with rIGFBP-7 at different concentrations or by co-culture with ASCs resulted in decreased KF proliferation. Additionally, KF stimulation with rIGFBP-7 resulted in increased apoptosis of KFs. IGFBP-7 also reduced angiogenesis in a concentration-dependent manner, and stimulation with different rIGFBP-7 concentrations or co-culture of KFs with ASCs inhibited the expression of transforming growth factor-β1, vascular endothelial growth factor, collagen I, interleukin (IL)-6, IL-8, B-raf proto-oncogene (BRAF), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK) in KFs.

CONCLUSION

Collectively, our findings suggested that ASC-derived IGFBP-7 prevented keloid formation by inhibiting the BRAF/MEK/ERK signaling pathway.

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.

Relationship between asporin and extracellular matrix behavior: A literature review

Asporin (ASPN), as a member of the small leucine-rich repeat proteoglycan family, is a type of protein that is found in the extracellular matrix. Collagen deposition or transformation is involved in a variety of pathological processes. ASPN is identified in cancerous tissue, pathological cardiac tissue, articular cartilage, keloid, and fibrotic lung tissue, and it has a role in the development of cancer, cardiovascular, bone and joint, keloid, and pulmonary fibrosis by interfering with collagen metabolism. This review article summarizes the data on ASPN expressions in mouse and human and highlights that overexpress of ASPN might play a role in a variety of diseases. Although our knowledge of ASPN is currently limited, these instances may help us better understand how it interacts with diseases.

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.

Identification and characterization of four immune-related signatures in keloid

A keloid is a fibroproliferative disorder of unknown etiopathogenesis that requires ill-defined treatment. Existing evidence indicates that the immune system plays an important role in the occurrence and development of keloid. However, there is still a lack of research on the immune-related signatures of keloid. Here we identified immune-related signatures in keloid and explored their pathological mechanisms. Transcriptomic datasets (GSE7890, GSE92566, and GSE44270) of keloid and normal skin tissues were obtained from the Gene Expression Omnibus database. The overlap of differentially expressed genes and immune-related genes was considered as differentially expressed immune-related genes (DEIGs). Functional analysis, expression, and distribution were applied to explore the function and characteristics of DEIGs, and the expression of these DEIGs in keloid and normal skin tissues was verified by immunohistochemistry. Finally, we conducted interactive network analysis and immune infiltration analysis to determine the therapeutic potential and immune correlation. We identified four DEIGs (LGR5, PTN, JAG1, and DKK1). In these datasets, only GSE7890 met the screening criteria. In the GSE7890 dataset, DKK1 and PTN were downregulated in keloid, whereas JAG1 and LGR5 were upregulated in keloid. In addition, we obtained the same conclusion through immunohistochemistry. Functional analysis indicated that these four DEIGs were mainly involved in stem cell, cell cycle, UV response, and therapy resistance. Through interactive network analysis, we found that these DEIGs were associated with drugs currently used to treat keloid, such as hydrocortisone, androstanolone, irinotecan, oxaliplatin, BHQ-880, and lecoleucovorin. Finally, many immune cells, including CD8⁺ T cells, resting memory CD4⁺ T cells, and M1 macrophages, were obtained by immune infiltration analysis. In conclusion, we identified four immune signaling molecules associated with keloid (LGR5, PTN, JAG1, and DKK1). These immune-related signaling molecules may be important modules in the pathogenesis of keloid. Additionally, we developed novel therapeutic targets for the treatment of this challenging disease.

Mesenchymal Stromal Cell-Conditioned Medium for Skin Diseases: A Systematic Review

The skin is the largest organ of the human body, and its dysfunction is related to many diseases. There is a need to find new potential effective therapies for some skin conditions such as inflammatory diseases, wound healing, or hair restoration. Mesenchymal stromal cell (MSC)-conditioned medium (CM) provides a potential opportunity in the treatment of skin disease. Thus, the objective of this review is to evaluate the uses of MSC-CM for treating skin diseases in both animal and human models. A systematic review was conducted regarding the use of MSC-CM for treating skin conditions. One hundred one studies were analyzed. MSC-CM was evaluated in wound healing (55), hypertrophic scars (9), flap reperfusion (4), hair restoration (15), skin rejuvenation (15), and inflammatory skin diseases (3). MSC-CM was obtained from different MSC sources, mainly adipose tissue, bone marrow, and umbilical cord blood. MSC-CM was tested intravenously, intraperitoneally, subcutaneously, intradermally or intralesionally injected or topically applied. MSC-CM was used in both animals and humans. MSC-CM improved wound healing, hair restoration, skin rejuvenation, atopic dermatitis, and psoriasis in both animals and humans. MSC-CM also decreased hypertrophic scars and flap ischemia in animal models. In conclusion, MSC-CM is a promising therapy for skin conditions. Further studies are needed to corroborate safety and effectiveness and to standardize CM manufacturing.

Asporin inhibits collagen matrix-mediated intercellular mechanocommunications between fibroblasts during keloid progression

Keloids are fibrotic lesions that grow unceasingly and invasively and are driven by local mechanical stimuli. Unlike other fibrotic diseases and normal wound healing, keloids exhibit little transformation of dermal fibroblasts into α-SMA⁺ myofibroblasts. This study showed that asporin is the most strongly expressed gene in keloids and its gene-ontology terms relate strongly to ECM metabolism/organization. Experiments with human dermal cells (HDFs) showed that asporin overexpression/treatment abrogated the HDF ability to adopt a perpendicular orientation when subjected to stretching tension. It also induced calcification of the surrounding 3D collagen matrix. Asporin overexpression/treatment also prevented the HDFs from remodeling the surrounding 3D collagen matrix, leading to a disorganized network of thick, wavy collagen fibers that resembled keloid collagen architecture. This in turn impaired the ability of the HDFs to contract the collagen matrix. Asporin treatment also made the fibroblasts impervious to the fibrous collagen contraction of α-SMA⁺ myofibroblasts, which normally activates fibroblasts. Thus, by calcifying collagen, asporin prevents fibroblasts from linearly rearranging the surrounding collagen; this reduces both their mechanosensitivity and mechanosignaling to each other through the collagen network. This blocks fibroblast activation and differentiation into the mature myofibroblasts that efficiently remodel the extracellular matrix. Consequently, the fibroblasts remain immature, highly proliferative, and continue laying down abundant extracellular matrix, causing keloid growth and invasion. Notably, dermal injection of asporin-overexpressing HDFs into murine wounds recapitulated keloid collagen histopathological characteristics. Thus, disrupted interfibroblast mechanocommunication may promote keloid progression. Asporin may be a new diagnostic biomarker and therapeutic target for keloids.

Circular RNA CircCOL5A1 Sponges the MiR-7-5p/Epac1 Axis to Promote the Progression of Keloids Through Regulating PI3K/Akt Signaling Pathway

Keloids, as a result of abnormal wound healing in susceptible individuals, are characterized by the hyper-proliferation of fibroblasts and exaggerated deposition of extracellular matrix. Current surgical and therapeutic modalities provide limited satisfactory results. Growing evidence has highlighted the roles of circRNAs in acting as miRNA sponges. However, up to date, the regulatory mechanism of circRNAs in the pathological process of keloids has rarely been reported. In this study, cell proliferation, cell migration, flow cytometry, western blotting, fluorescence in situ hybridization, dual-luciferase activity, and immunohistochemistry assays were applied to explore the roles and mechanisms of the circCOL5A1/miR-7-5p/Epac1 axis in the keloid. The therapeutic potential of circCOL5A1 was investigated by establishing keloid implantation models. The RT-qPCR result revealed that circCOL5A1 expression was obviously higher in keloid tissues and keloid fibroblasts. Subsequent cellular experiments demonstrated that circCOL5A1 knockdown repressed the proliferation, migration, extracellular matrix (ECM) deposition, whereas promoted cell apoptosis, through the PI3K/Akt signaling pathway. Furthermore, RNA-fluorescence in situ hybridization (RNA-FISH) illustrated that both circCOL5A1 and miR-7-5p were located in the cytoplasm. The luciferase reporter gene assay confirmed that exact binding sites were present between circCOL5A1 and miR-7-5p, as well as between miR-7-5p and Epac1. Collectively, the present study revealed that circCOL5A1 functioned as competing endogenous RNA (ceRNA) by adsorbing miR-7-5p to release Epac1, which contributed to pathological hyperplasia of keloids through activating the PI3K/Akt signaling pathway. Our data indicated that circCOL5A1 might serve as a novel promising therapeutic target and represent a new avenue to understand underlying pathogenesis for keloids.

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.