In vitro comparative study of human mesenchymal stromal cells from dermis and adipose tissue for application in skin wound healing

Mesenchymal stem cells in autoimmune disease: A systematic review and meta-analysis of pre-clinical studies

Mesenchymal Stem Cells (MSCs) are of interest in the clinic because of their immunomodulation capabilities, capacity to act upstream of inflammation, and ability to sense metabolic environments. In standard physiologic conditions, they play a role in maintaining the homeostasis of tissues and organs; however, there is evidence that they can contribute to some autoimmune diseases. Gaining a deeper understanding of the factors that transition MSCs from their physiological function to a pathological role in their native environment, and elucidating mechanisms that reduce their therapeutic relevance in regenerative medicine, is essential. We conducted a Systematic Review and Meta-Analysis of human MSCs in preclinical studies of autoimmune disease, evaluating 60 studies that included 845 patient samples and 571 control samples. MSCs from any tissue source were included, and the study was limited to four autoimmune diseases: multiple sclerosis, rheumatoid arthritis, systemic sclerosis, and lupus. We developed a novel Risk of Bias tool to determine study quality for in vitro studies. Using the International Society for Cell & Gene Therapy's criteria to define an MSC, most studies reported no difference in morphology, adhesion, cell surface markers, or differentiation into bone, fat, or cartilage when comparing control and autoimmune MSCs. However, there were reported differences in proliferation. Additionally, 308 biomolecules were differentially expressed, and the abilities to migrate, invade, and form capillaries were decreased. The findings from this study could help to explain the pathogenic mechanisms of autoimmune disease and potentially lead to improved MSC-based therapeutic applications.

Evaluation of secretomes derived from human dermal and adipose tissue mesenchymal stem/stromal cells for skin wound healing: not as effective as cells

BACKGROUND

Although the paracrine effects of mesenchymal stem/stromal cells (MSCs) have been recognized as crucial mediators of their regenerative effects on tissue repair, the potential of MSC secretomes as effective substitutes for cellular therapies remains underexplored.

METHODS

In this study, we compared MSCs from the human dermis (DSCs) and adipose tissue (ASCs) with their secretomes regarding their efficacy for skin wound healing using a translationally relevant murine model.

RESULTS

Proteomic analysis revealed that while there was a substantial overlap in protein composition between DSC and ASC secretomes, specific proteins associated with wound healing and angiogenesis were differentially expressed. Despite a similar angiogenic potential in vivo, DSC and ASC secretomes were found to be less effective than cells in accelerating wound closure and promoting tissue remodeling.

CONCLUSIONS

Overall, secretome-treated groups showed intermediary results between cells- and control-treated (empty scaffold) groups. These findings highlight that although secretomes possess therapeutic potential, their efficacy might be limited compared to cellular therapies. This study contributes to the growing understanding of MSC secretomes, emphasizes the need for further protocol optimization, and offers insights into their potential applications in regenerative medicine.

Progenitor Cell Sources for 3D Bioprinting of Lymphatic Vessels and Potential Clinical Application

The lymphatic system maintains tissue fluid homeostasis and it is involved in the transport of nutrients and immunosurveillance. It also plays a pivotal role in both pathological and regenerative processes. Lymphatic development in the embryo occurs by polarization and proliferation of lymphatic endothelial cells from the lymph sacs, that is, lymphangiogenesis. Alternatively, lymphvasculogenesis further contributes to the formation of lymphatic vessels. In adult tissues, lymphatic formation rarely occurs under physiological conditions, being restricted to pathological processes. In lymphvasculogenesis, progenitor cells seem to be a source of lymphatic vessels. Indeed, mesenchymal stem cells, adipose stem cells, endothelial progenitor cells, and colony-forming endothelial cells are able to promote lymphatic regeneration by different mechanisms, such as direct differentiation and paracrine effects. In this review, we summarize what is known on the diverse stem/progenitor cell niches available for the lymphatic system, emphasizing the potential that these cells hold for lymphatic tissue engineering through 3D bioprinting and their translation to clinical application.

Advances in mesenchymal stem/stromal cell-based therapy and their extracellular vesicles for skin wound healing

Wound healing is a dynamic and complicated process containing overlapping phases. Presently, definitive therapy is not available, and the investigation into optimal wound care is influenced by the efficacy and cost-effectiveness of developing therapies. Accumulating evidence demonstrated the potential role of mesenchymal stem/stromal cell (MSC) therapy in several tissue injuries and diseases due to their high proliferation and differentiation abilities along with an easy collection procedure, low tumorigenesis, and immuno-privileged status. MSCs have also accelerated wound repair in all phases through their advantageous properties, such as accelerating wound closure, improving re-epithelialization, elevating angiogenesis, suppressing inflammation, and modulating extracellular matrix (ECM) remodeling. In addition, the beneficial therapeutic impacts of MSCs are largely associated with their paracrine functions, including extracellular vesicles (EVs). Exosomes and microvesicles are the two main subgroups of EVs. These vesicles are heterogeneous bilayer membrane structures that contain several proteins, lipids, and nucleic acids. EVs have emerged as a promising alternative to stem cell-based therapies because of their lower immunogenicity, tumorigenicity, and ease of management. MSCs from various sources have been widely investigated in skin wound healing and regeneration. Considering these features, in this review, we highlighted recent studies that the investigated therapeutic potential of various MSCs and MSC-EVs in skin damages and wounds.

Single-stage transplantation combined with epidermal stem cells promotes the survival of tissue-engineered skin by inducing early angiogenesis

BACKGROUND

The composite transplantation of a split-thickness skin graft (STSG) combined with an acellular dermal matrix (ADM) is a promising repair method for full-thickness skin defects. Due to delayed vascularization of the ADM, no currently available engineered skin tissue is able to permanently cover full-thickness skin defects via a single-stage procedure. Epidermal stem cells (EpSCs) have been found to promote angiogenesis in the wound bed. Whether EpSCs can induce early angiogenesis of dermal substitutes and promote the survival of single-stage tissue-engineered skin transplantation needs to be further studied.

METHODS

In vitro, rat vascular endothelial cells (RVECs) were treated with the supernatant of EpSCs cultured in ADM and stimulated for 48 h. RVECs were analysed by RNA sequencing and tube formation assays. For the in vivo experiment, 75 rats were randomly divided into five groups: ADM, ADM + EpSCs (AE), STSG, ADM + STSG (AS), and ADM + STSG + EpSCs (ASE) groups. The quality of wound healing was estimated by general observation and H&E and Masson staining. The blood perfusion volume was evaluated using the LDPI system, and the expression of vascular markers was determined by immunohistochemistry (IHC).

RESULTS

The active substances secreted by EpSCs cultured in ADM promoted angiogenesis, as shown by tube formation experiments and RNA-seq. EpSCs promoted epithelialization of the ADM and vascularization of the ADM implant. The ASE group showed significantly increased skin graft survival, reduced skin contraction, and an improved cosmetic appearance compared with the AS group and the STSG control group.

CONCLUSIONS

In summary, our findings suggest that EpSCs promote the formation of new blood vessels in dermal substitutes and support one-step transplantation of tissue-engineered skin, and thereby provide new ideas for clinical application.

LPS-pretreatment adipose-derived mesenchymal stromal cells promote wound healing in diabetic rats by improving angiogenesis

Mesenchymal stem cells (MSCs) play a key role in wound healing, and the advantages of pretreated MSCs in wound healing have previously been reported. In the present study, we investigated the impact of LPS pretreated human adipose-derived MSCs on skin wound healing in diabetic rats. We found that some improvements occurred through improving angiogenesis. Then, we scrutinized the impact of lipopolysaccharide (LPS) treatment on human adipose-derived MSCs in a high-glucose (HG) medium, as an in vitro diabetic model. In vivo findings revealed significant improvements in epithelialization and angiogenesis of diabetic wounds which received LPS pre-MSCs. Particularly, LPS pre-MSCs-treated diabetic wounds reached considerably higher percentages of wound closure. Also, the granulation tissue of these wounds had higher pronounced epithelialization and more vascularization compared with PBS-treated and MSCs-treated diabetic ones by CD31, VEGF, CD90, collagen 1, and collagen 3 immunostaining. Western-blots analyses indicated that LPS pre-MSCs led to the upregulation of vascular endothelial growth factor (VEGF) and DNMT1. In addition, significantly higher cell viability (proliferation/colonie), and elevated VEGF and DNMT1 protein expression were observed when MSCs were treated with LPS (10 ng/ml, 6 h) in HG culture media. Based on these findings, it is suggested that LPS pre-MSCs could promote wound repair and skin regeneration, in some major processes, via the improvement of cellular behaviors of MSCs in the diabetic microenvironment. The beneficial advantages of LPS treated with mesenchymal stem cells on wound healing may lead to establishing a novel approach as an alternative therapeutic procedure to cure chronic wounds in diabetic conditions.

In vitro study of the mesenchymal stem cells-conditional media role in skin wound healing process: A systematic review

Mesenchymal stromal cell (MSC)-conditioned medium (CM) offers a potential opportunity in the skin wound healing treatment. In this systematic review, an overview of the knowledge on this topic has been provided. A multistep search of the PubMed, Scopus and Science Direct database has been performed to identify papers on MSCs-conditional media used in skin wound healing. Eligibility checks were performed based upon predefined selection criteria. Of the 485 articles initially identified, consequently, only 96 articles apparently related to MSC-conditional media were initially assessed for eligibility. Finally, the 32 articles, strictly regarding the in vitro use of MSCs-conditional media in skin wounds, were analysed. The information analysed highlights the efficacy of MSCs-conditional media on skin wound healing in vitro models. The outcome of this review may be used to guide pre-clinical and clinical studies on the role of MSCs-conditional media in skin wound healing.

Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells and Their Contribution to Angiogenic Processes in Tissue Regeneration

Mesenchymal stem/stromal cells (MSCs) are widely described in the context of their regenerative and immunomodulatory activity. MSCs are isolated from various tissues and organs. The most frequently described sources are bone marrow and adipose tissue. As stem cells, MSCs are able to differentiate into other cell lineages, but they are usually reported with respect to their paracrine potential. In this review, we focus on MSCs derived from adipose tissue (AT-MSCs) and their secretome in regeneration processes. Special attention is given to the contribution of AT-MSCs and their derivatives to angiogenic processes described mainly in the context of angiogenic dysfunction. Finally, we present clinical trials registered to date that concern the application of AT-MSCs and their secretome in various medical conditions.

Culture and characterization of various porcine integumentary-connective tissue-derived mesenchymal stromal cells to facilitate tissue adhesion to percutaneous metal implants

Background

Transdermal osseointegrated prosthesis have relatively high infection rates leading to implant revision or failure. A principle cause for this complication is the absence of a durable impervious biomechanical seal at the interface of the hard structure (implant) and adjacent soft tissues. This study explores the possibility of recapitulating an analogous cellular musculoskeletal-connective tissue interface, which is present at naturally occurring integumentary tissues where a hard structure exits the skin, such as the nail bed, hoof, and tooth.

Methods

Porcine mesenchymal stromal cells (pMSCs) were derived from nine different porcine integumentary and connective tissues: hoof-associated superficial flexor tendon, molar-associated periodontal ligament, Achilles tendon, adipose tissue and skin dermis from the hind limb and abdominal regions, bone marrow and muscle. For all nine pMSCs, the phenotype, multi-lineage differentiation potential and their adhesiveness to clinical grade titanium was characterized. Transcriptomic analysis of 11 common genes encoding cytoskeletal proteins VIM (Vimentin), cell–cell and cell–matrix adhesion genes (Vinculin, Integrin β1, Integrin β2, CD9, CD151), and for ECM genes (Collagen-1a1, Collagen-4a1, Fibronectin, Laminin-α5, Contactin-3) in early passaged cells was performed using qRT-PCR.

Results

All tissue-derived pMSCs were characterized as mesenchymal origin by adherence to plastic, expression of cell surface markers including CD29, CD44, CD90, and CD105, and lack of hematopoietic (CD11b) and endothelial (CD31) markers. All pMSCs differentiated into osteoblasts, adipocytes and chondrocytes, albeit at varying degrees, under specific culture conditions. Among the eleven adhesion genes evaluated, the cytoskeletal intermediate filament vimentin was found highly expressed in pMSC isolated from all tissues, followed by genes for the extracellular matrix proteins Fibronectin and Collagen-1a1. Expression of Vimentin was the highest in Achilles tendon, while Fibronectin and Col1agen-1a1 were highest in molar and hoof-associated superficial flexor tendon bone marrow, respectively. Achilles tendon ranked the highest in both multilineage differentiation and adhesion assessments to titanium metal.

Conclusions

These findings support further preclinical research of these tissue specific-derived MSCs in vivo in a transdermal osseointegration implant model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02666-2.

Evaluation of canine adipose-derived multipotent stromal cell differentiation to ligamentoblasts on tensioned collagen type I templates in a custom bioreactor culture system

OBJECTIVE

To evaluate differentiation of canine adipose-derived multipotent stromal cells (ASCs) into ligamentoblasts on tensioned collagen type I (Col1) templates in a perfusion culture system.

SAMPLES

Infrapatellar fat pad ASCs from healthy stifle joints of 6 female mixed-breed dogs.

PROCEDURES

Third-passage ASCs (6 × 10⁶ cells/template) were loaded onto suture-augmented Col1 templates under 15% static strain in perfusion bioreactors. Forty-eight ASC-Col1 constructs were incubated with ligamentogenic (ligamentogenic constructs; n = 24) or stromal medium (stromal constructs; 24) for up to 21 days. Specimens were collected from each construct after 2 hours (day 0) and 7, 14, and 21 days of culture. Cell number, viability, distribution, and morphology; construct collagen content; culture medium procollagen-I-N-terminal peptide concentration; and gene expression were compared between ligamentogenic and stromal constructs.

RESULTS

ASCs adhered to collagen fibers. Cell numbers increased from days 0 to 7 and days 14 to 21 for both construct types. Relative to stromal constructs, cell morphology and extracellular matrix were more mature and collagen content on day 21 and procollagen-I-N-terminal peptide concentration on days 7 and 21 were greater for ligamentogenic constructs. Ligamentogenic constructs had increased expression of the genes biglycan on day 7, decorin throughout the culture period, and Col1, tenomodulin, fibronectin, and tenascin-c on day 21; expression of Col1, tenomodulin, and tenascin-c increased between days 7 and 21.

CONCLUSIONS AND CLINICAL RELEVANCE

Ligamentogenic medium was superior to stromal medium for differentiation of ASCs to ligamentoblasts on suture-augmented Col1 scaffolds. Customized ligament neotissue may augment treatment options for dogs with cranial cruciate ligament rupture.

Adipose-Derived Stem Cell Conditioned Medium and Wound Healing: A Systematic Review

Adipose-derived stem cells (ASCs) have been growing in popularity for their potential in wound healing and tissue engineering. Stem cell therapies are limited in application, with the need to maintain cell viability and function as well as safety concerns. It has been increasingly reported that the effects of ASCs are predominantly attributable to the paracrine effects of the secreted factors, which can be collected in conditioned medium (CM). The goal of this systematic review is to investigate the effects on wound healing of CM collected from ASC culture. Original articles relevant to ASC-CM and wound healing (in vitro: dermal fibroblast, epidermal keratinocytes and their equivalent cell lines; in vivo: full-thickness wound models) were included. The agreement level of selections between two investigators were calculated by the kappa scores. And the information concerning to the publications, CM preparation and its application and effects were extracted and reported in a systematic way and summarized in tables. In total, 121 publications were initially identified through a search of the PubMed/MEDLINE database with a specific search algorithm, and 36 articles were ultimately included after two screenings. Nineteen were in vitro studies that met the search criteria and 17 were in vivo studies with or without in vitro data. In summary, based on the included articles, treatment with ASC conditioned medium (ASC-CM), to a large extent, resulted in positive effects on wound healing in vitro and in vivo. Modulation of the culture conditions of ASCs producing the CM, including hypoxic conditions, alternative substrates, medium supplementation, as well as genetic modification of cells, favorably promoted the effects of ASC-CM. Finally, a discussion of the future perspectives and therapeutic potential of ASC-CM, which also addresses the limitations of the field, is presented. A limitation of the evidence is the inconsistency in CM preparation methods among included articles. In conclusion, ASC-CM is a promising novel cell-free therapy for wound healing in regenerative medicine and warrants further exploration.

Human adipose-derived mesenchymal stromal cells from face and abdomen undergo replicative senescence and loss of genetic integrity after long-term culture

Body fat depots are heterogeneous concerning their embryonic origin, structure, exposure to environmental stressors, and availability. Thus, investigating adipose-derived mesenchymal stromal cells (ASCs) from different sources is essential to standardization for future therapies. In vitro amplification is also critical because it may predispose cell senescence and mutations, reducing regenerative properties and safety. Here, we evaluated long-term culture of human facial ASCs (fASCs) and abdominal ASCs (aASCs) and showed that both met the criteria for MSCs characterization but presented differences in their immunophenotypic profile, and differentiation and clonogenic potentials. The abdominal tissue yielded more ASCs, and these had higher proliferative potential, but facial cells displayed fewer mitotic errors at higher passages. However, both cell types reduced clonal efficiency over time and entered replicative senescence around P12, as evaluated by progressive morphological alterations, reduced proliferative capacity, and SA-β-galactosidase expression. Loss of genetic integrity was detected by a higher proportion of cells showing nuclear alterations and γ-H2AX expression. Our findings indicate that the source of ASCs can substantially influence their phenotype and therefore should be carefully considered in future cell therapies, avoiding, however, long-term culture to ensure genetic stability.

Therapeutic candidates for keloid scars identified by qualitative review of scratch assay research for wound healing

The scratch assay is an in vitro technique used to analyze cell migration, proliferation, and cell-to-cell interaction. In the assay, cells are grown to confluence and then ‘scratched’ with a sterile instrument. For the cells in the leading edge, the resulting polarity induces migration and proliferation in attempt to ‘heal’ the modeled wound. Keloid scars are known to have an accelerated wound closure phenotype in the scratch assay, representing an overactivation of wound healing. We performed a qualitative review of the recent literature searching for inhibitors of scratch assay activity that were already available in topical formulations under the hypothesis that such compounds may offer therapeutic potential in keloid treatment. Although several shortcomings in the scratch assay literature were identified, caffeine and allicin successfully inhibited the scratch assay closure and inflammatory abnormalities in the commercially available keloid fibroblast cell line. Caffeine and allicin also impacted ATP production in keloid cells, most notably with inhibition of non-mitochondrial oxygen consumption. The traditional Chinese medicine, shikonin, was also successful in inhibiting scratch closure but displayed less dramatic impacts on metabolism. Together, our results partially summarize the strengths and limitations of current scratch assay literature and suggest clinical assessment of the therapeutic potential for these identified compounds against keloid scars may be warranted.

Human foreskin-derived dermal stem/progenitor cell-conditioned medium combined with hyaluronic acid promotes extracellular matrix regeneration in diabetic wounds

BACKGROUND

Diabetic wounds remain a challenging clinical problem, which requires further treatment development. Published data showed that dermis-derived stem/progenitor cells (DSPCs) display superior wound healing in vitro. The beneficial effects of DSPCs are mediated through paracrine secretion, which can be obtained from conditioned medium (CM). Hyaluronic acid (HA) is especially suitable for skin regeneration and delivering bioactive molecules in CM. This study investigated the effect of human foreskin-derived dermal stem/progenitor cell (hFDSPC)-CM combined with HA on a diabetic mouse model and relevant mechanism in vitro.

METHODS

hFDSPCs and human adipose-derived stem cells (hADSCs) were identified, and the respective CM was prepared. PBS, HA, hFDSPC-CM combined with HA, or hADSC-CM combined with HA was topically applied to mice. HE, CD31, CD68, CD86, and CD206 staining was performed to evaluate gross wound condition, angiogenesis, and inflammation, respectively. Masson and Picrosirius red staining was performed to evaluate collagen deposition and maturation. The effects of hFDSPC-CM and hADSC-CM on human keratinocyte cells (HaCaT) and fibroblasts were evaluated in vitro using CCK-8 and EdU assays to determine cell viability and proliferation, respectively. The scratch assay was performed to evaluate cell migration. Tube formation assay was performed on human umbilical vein endothelial cells (HUVECs) to confirm angiogenesis. Extracellular matrix (ECM) metabolic balance-related genes and proteins, such as collagen I (COL 1), collagen III (COL 3), fibronectin (FN), α-SMA, matrix metalloproteinases 1 (MMP-1), matrix metalloproteinases 3 (MMP-3), and transforming growth factor-beta 1 (TGF-β1), were analysed.

RESULTS

hFDSPC-CM combined with HA showed superior wound closure rate over hADSC-CM. Histologically, the hFDSPC-CM combined with HA group showed significantly improved re-epithelialisation, angiogenesis, anti-inflammation, collagen regeneration, and maturation compared to hADSC-CM combined with HA group. In vitro assays revealed that hFDSPC-CM displayed significant advantages on cell proliferation, migration, and ECM regeneration through a TGF-β/Smad signalling pathway compared with hADSC-CM.

CONCLUSIONS

hFDSPC-CM combined with HA was superior for treating diabetic wounds. The underlying mechanism may promote proliferation and migration of epidermal cells with fibroblasts, thus leading to ECM deposition and remodelling. Reduced inflammation may be due to the above-mentioned mechanism.

Preconditioning mesenchymal stromal cells with flagellin enhances the anti‑inflammatory ability of their secretome against lipopolysaccharide‑induced acute lung injury

Acute lung injury (ALI) is a complex condition frequently encountered in the clinical setting. The aim of the present study was to investigate the effect of conditioned media (CM) from human adipose‑derived mesenchymal stromal cells (MSCs) activated by flagellin (F‑CM), a Toll‑like receptor 5 ligand, on inflammation‑induced lung injury. In the in vitro study, RAW264.7 macrophages treated with F‑CM had a higher proportion of cells with the M2 phenotype, lower expression of pro‑inflammatory factors and stronger expression of anti‑inflammatory genes compared with the CM from normal adipose‑derived MSCs. Furthermore, in vivo experiments were performed in mice with ALI induced by intraperitoneal injection of lipopolysaccharide. F‑CM significantly alleviated the lung exudation, inhibited inflammatory cell recruitment in lung tissues and decreased the concentration of inflammatory factors in the bronchoalveolar lavage fluid. These findings indicated that F‑CM has superior anti‑inflammation ability compared with CM, and that it may represent a promising therapeutic approach to the treatment of inflammation‑induced ALI.

Adipose-derived stem cells in wound healing of full-thickness skin defects: a review of the literature. J Plast Surg Hand Surg 2020;54:263-279. [PMID: 32427016 DOI: 10.1080/2000656x.2020.1767116]

The complex process of wound healing can be delayed in circumstances when the natural niche is extremely altered. Adipose-derived stem cells (ADSC) seem to be a promising therapy for these type of wounds. We aim to describe the studies that used ADSC for wound healing after a full-thickness skin defect, the ADSC mechanisms of action, and the outcomes of the different ADSC therapies applied to date. We performed a review by querying PubMed database for studies that evaluated the use of ADSC for wound healing. The Mesh terms, adipose stem cells AND (skin injury OR wound healing) and synonyms were used for the search. Our search recorded 312 articles. A total of 30 articles met the inclusion criteria. All were experimental in nature. ADSC was applied directly (5 [16.7%]), in sheets (2 [6.7%]), scaffolds (14 [46.7%]), skin grafts (3 [10%]), skin flaps (1 [3.3%]), as microvesicles or exosomes (4 [13.3%]), with adhesives for wound closure (1 [3.3%]), and in a concentrated conditioned hypoxia-preconditioned medium (1 [3.3%]). Most of the studies reported a benefit of ADSC and improvement of wound healing with all types of ADSC therapy. ADSC applied along with extracellular matrix, stromal cell-derived factor (SDF-1) or keratinocytes, or ADSC seeded in scaffolds showed better outcomes in wound healing than ADSC alone. ADSC have shown to promote angiogenesis, fibroblast migration, and up-regulation of macrophages chemotaxis to enhance the wound healing process. Further studies should be conducted to assure the efficacy and safety of the different ADSC therapies.

The Potential of a Hair Follicle Mesenchymal Stem Cell-Conditioned Medium for Wound Healing and Hair Follicle Regeneration

The study elucidated the wound healing and hair regeneration properties of a conditioned medium prepared from the culture of human hair follicle mesenchymal stem cells (HFMSCs). The wound-healing effects of mesenchymal stem cell-conditioned medium (MSC-CM) were tested in vitro using scratch assays co-cultured with HaCaT keratinocyte and monitored through optical microscopy. The cell proliferation of HFMSCs and the HaCaT keratinocyte were observed in the presence of different kinds of drugs including UK5099, sodium L-lactate, lactate dehydrogenase-A, MSC-CM, caffeine, and caffeic acid. The hair regeneration properties were investigated in vivo by administrating the MSC-CM solutions to adult B6 mouse models. For quantification, hematoxylin and eosin staining were performed following euthanasia. In vitro results revealed that MSC-CM promotes dermal cell migrations and enhances proliferation of HFMSCs and HaCaT keratinocytes, demonstrating wound-healing properties. Moreover, when the MSC-CM solutions were applied to the shaved mouse skin, a dark area that expanded overtime was seen. Although no hair growth was found, histological analysis proved that a fat layer thickness increment was found under the mouse’s skin, ultimately projecting the formation of new hair growth. MSC-CM promotes the migration and proliferation of dermal keratinocytes that are beneficial for wound healing and hair growth. It is believed that MSC-CM can potentially serve as the basis of alternative therapeutic applications for wound closure and skin regeneration as well as hair growth stimulation and hair loss prevention in alopecia.

Mesenchymal stromal cells from dermal and adipose tissues induce macrophage polarization to a pro-repair phenotype and improve skin wound healing

The process of wound healing restores skin homeostasis but not full functionality; thus, novel therapeutic strategies are needed to accelerate wound closure and improve the quality of healing. In this context, tissue engineering and cellular therapies are promising approaches. Although sharing essential characteristics, mesenchymal stromal cells (MSCs) isolated from different tissues might have distinct properties. Therefore, the aim of this study was to comparatively investigate, by a mouse model in vivo assay, the potential use of dermal-derived MSCs (DSCs) and adipose tissue-derived MSCs (ASCs) in improving skin wound healing. Human DSCs and ASCs were delivered to full-thickness mouse wounds by a collagen-based scaffold (Integra Matrix). We found that the association of both DSCs and ASCs with the Integra accelerated wound closure in mice compared with the biomaterial only (control). Both types of MSCs stimulated angiogenesis and extracellular matrix remodeling, leading to better quality scars. However, the DSCs showed smaller scar size,superior extracellular matrix deposition, and greater number of cutaneous appendages. Besides, DSCs and ASCs reduced inflammation by induction of macrophage polarization from a pro-inflammatory (M1) to a pro-repair (M2) phenotype. In conclusion, both DSCs and ASCs were able to accelerate the healing of mice skin wounds and promote repair with scars of better quality and more similar to healthy skin than the empty scaffold. DSCs associated with Integra induced superior overall results than the Integra alone, whereas scaffolds with ASCs showed an intermediate effect, often not significantly better than the empty biomaterial.

c-Jun Overexpression Accelerates Wound Healing in Diabetic Rats by Human Umbilical Cord-Derived Mesenchymal Stem Cells

Objective

Mesenchymal stem cells (MSCs) are considered a promising therapy for wound healing. Here, we explored the role of c-Jun in diabetic wound healing using human umbilical cord-derived MSCs (hUC-MSCs).

Methods

Freshly isolated hUC-MSCs were subjected to extensive in vitro subcultivation. The cell proliferative and migratory capacities were assessed by the Cell Counting Kit-8 and scratch assays, respectively. c-Jun expression was evaluated by RT-PCR and western blot analysis. The function of c-Jun was investigated with lentivirus transduction-based gene silencing and overexpression. Diabetes mellitus was induced in SD rats on a high-glucose/fat diet by streptozocin administration. Wounds were created on the dorsal skin. The effects of c-Jun silencing and overexpression on wound closure by hUC-MSCs were examined. Reepithelialization and angiogenesis were assessed by histological and immunohistochemical analysis, respectively. Platelet-derived growth factor A (PDGFA), hepatocyte growth factor (HGF), and vascular endothelial growth factor (VEGF) levels were determined by western blot analysis.

Results

hUC-MSCs showed gradually decreased cell proliferation, migration, and c-Jun expression during subcultivation. c-Jun silencing inhibited cell proliferation and migration, while c-Jun overexpression enhanced proliferation but not migration. Compared with untransduced hUC-MSCs, local subcutaneous injection of c-Jun-overexpressing hUC-MSCs accelerated wound closure, enhanced angiogenesis and reepithelialization at the wound bed, and increased PDGFA and HGF levels in wound tissues.

Conclusion

c-Jun overexpression promoted hUC-MSC proliferation and migration in vitro and accelerated diabetic wound closure, reepithelization, and angiogenesis by hUC-MSCs in vivo. These beneficial effects of c-Jun overexpression in diabetic wound healing by hUC-MSCs were at least partially mediated by increased PDGFA and HGF levels in wound tissues.

Regenerative Capacity of Adipose Derived Stem Cells (ADSCs), Comparison with Mesenchymal Stem Cells (MSCs)

Adipose tissue is now on the top one of stem cell sources regarding its accessibility, abundance, and less painful collection procedure when compared to other sources. The adipose derived stem cells (ADSCs) that it contains can be maintained and expanded in culture for long periods of time without losing their differentiation capacity, leading to large cell quantities being increasingly used in cell therapy purposes. Many reports showed that ADSCs-based cell therapy products demonstrated optimal efficacy and efficiency in some clinical indications for both autologous and allogeneic purposes, hence becoming considered as potential tools for replacing, repairing, and regenerating dead or damaged cells. In this review, we analyzed the therapeutic advancement of ADSCs in comparison to bone marrow (BM) and umbilical cord (UC)-mesenchymal stem cells (MSCs) and designed the specific requirements to their best clinical practices and safety. Our analysis was focused on the ADSCs, rather than the whole stromal vascular fraction (SVF) cell populations, to facilitate characterization that is related to their source of origins. Clinical outcomes improvement suggested that these cells hold great promise in stem cell-based therapies in neurodegenerative, cardiovascular, and auto-immunes diseases.

Regenerative Capacity of Adipose Derived Stem Cells (ADSCs), Comparison with Mesenchymal Stem Cells (MSCs)

Adipose tissue is now on the top one of stem cell sources regarding its accessibility, abundance, and less painful collection procedure when compared to other sources. The adipose derived stem cells (ADSCs) that it contains can be maintained and expanded in culture for long periods of time without losing their differentiation capacity, leading to large cell quantities being increasingly used in cell therapy purposes. Many reports showed that ADSCs-based cell therapy products demonstrated optimal efficacy and efficiency in some clinical indications for both autologous and allogeneic purposes, hence becoming considered as potential tools for replacing, repairing, and regenerating dead or damaged cells. In this review, we analyzed the therapeutic advancement of ADSCs in comparison to bone marrow (BM) and umbilical cord (UC)-mesenchymal stem cells (MSCs) and designed the specific requirements to their best clinical practices and safety. Our analysis was focused on the ADSCs, rather than the whole stromal vascular fraction (SVF) cell populations, to facilitate characterization that is related to their source of origins. Clinical outcomes improvement suggested that these cells hold great promise in stem cell-based therapies in neurodegenerative, cardiovascular, and auto-immunes diseases.