Calcium oxalate (CaOx) is the predominant form of kidney stones, associated with significant morbidity and recurrence rates. Mesenchymal stem cells (MSCs) have shown promise in treating renal injury, but their impact on CaOx stone formation remains unclear.

We established a hyperoxaluria-induced AKI model in mice through intraperitoneal injection of glyoxylate. Two types of MSCs, bone marrow-derived MSCs (BMSCs) and umbilical cord-derived mesenchymal stem cells (UMSCs), were injected through tail vein injection. Histological evaluations and blood biochemical tests were performed to assess crystal deposition and kidney function. The inflammatory response and NLRP3 inflammasome activation were assessed using immunofluorescence, immunohistochemistry, TUNEL staining, and qPCR. In vitro, macrophages were cocultured in the presence of MSCs. ELISA was used to measure IL-1β and IL-18 release. MTS assays assessed renal epithelial cell protection. Western blotting evaluated NLRP3 inflammasome activation in macrophages.

Both BMSCs and UMSCs significantly inhibited CaOx crystal deposition and kidney injury by inhibiting NLRP3 inflammasome activation. In vitro, both MSC types suppressed NLRP3 inflammasome activation in macrophages through the NF-κB signaling pathway, leading to decreased release of IL-1β and IL-18 and enhanced protection of renal epithelial cells. This attenuation of renal tubular cell injury is a critical factor in preventing CaOx stone formation.

Our findings reveal that Both BMSCs and UMSCs effectively attenuate hyperoxaluria-induced kidney injury and crystal deposition by inhibiting NLRP3 inflammasome activation. This discovery is helpful for developing new effective therapeutic means for nephrolithiasis.

Spinal cord injury (SCI) leads to acute tissue damage that disrupts the microenvironmental homeostasis of the spinal cord, inhibiting cell survival and function, and thereby undermining treatment efficacy. Traditional stem cell therapies have limited success in SCI, due to the difficulties in maintaining cell survival and inducing sustained differentiation into neural lineages. A new solution may arise from controlling the fate of stem cells by creating an appropriate mechanical microenvironment. In this study, mechanical response stem cell complex (MRSCC) is created as an innovative therapeutic strategy for SCI, utilizing 3D bioprinting technology and gelatin microcarriers (GM) loaded with mesenchymal stem cells (MSCs). GM creates an optimal microenvironment for MSCs growth and paracrine activity. Meanwhile, 3D bioprinting allows accurate control of spatial pore architecture and mechanical characteristics of the cell construct to encourage neuroregeneration. The mechanical microenvironment created by MRSCC is found to activate the Piezo1 channel and prevent excessive nuclear translocation of YAP, thereby increasing neural-related gene expression in MSCs. Transplanting MRSCC in rats with spinal cord injuries boosts sensory and motor recovery, reduces inflammation, and stimulates the regeneration of neurons and glial cells. The MRSCC offers a new tissue engineering solution that can promote spinal cord repair.

Adipose-derived regenerative cells (ADRCs) are one of the most promising cell sources that possess significant therapeutic effects. They have now become a main source of cell therapy for the treatment of ischemic diseases due to their easy accessibility, expansion, and differentiation. Additionally, ADRCs can release multiple paracrine factors and extracellular vesicles that contribute to tissue regeneration by promoting angiogenesis, regulating inflammation, alleviating apoptosis, and inhibiting fibrosis. However, ADRCs still have some limitations to realize their full therapeutic potential. To address these issues, protective mechanistic studies and bioengineering studies have been carried out. This review focused on the recently studied mechanisms, such as paracrine factors, cell fusion, and mitochondrial transfer, involving the therapeutic potential of ADRCs in ischemic diseases and discussed some modification techniques of ADRCs.

Despite many years of investigation into mesenchymal stem cells (MSCs) and their potential for treating inflammatory conditions such as COVID-19, clinical outcomes remain variable due to factors like donor variability, different tissue sources, and diversity within MSC populations. Variations in MSCs' secretory and proliferation profiles, and their proteomic and transcriptional characteristics significantly influence their therapeutic potency, highlighting the need for enhanced characterization methods to better predict their efficacy. This study aimed to evaluate the biological characteristics of MSCs from different tissue origins, selecting the most promising line for further validation in a K18-hACE2 mouse model of SARS-CoV-2 infection.

We studied nine MSC lines sourced from either bone marrow (hBMMSC), dental pulp (hDPMSC), or umbilical cord tissue (hUCMSC). The cells were assessed for their proliferative capacity, immunophenotype, trilineage differentiation, proteomic profile, and in vitro immunomodulatory potential by co-culture with activated lymphocytes. The most promising MSC line was selected for further experimental validation using the K18-hACE2 mouse model of SARS-CoV-2 infection.

The analyzed cells met the minimum criteria for defining MSCs, including the expression of surface molecules and differentiation capacity, showing genetic stability and proliferative potential. Proteomic analysis revealed distinct protein profiles that correlate with the tissue origin of MSCs. The immunomodulatory response exhibited variability, lacking a discernible pattern associated with their origin. In co-culture assays with lymphocytes activated with anti-CD3/CD28 beads, all MSC lines demonstrated the ability to inhibit TNF-α, to induce TGF-β and Indoleamine 2,3-dioxygenase (IDO), with varying degrees of inhibition observed for IFN-γ and IL-6, or induction of IL-10 expression. A module of proteins was found to statistically correlate with the potency of IL-6 modulation, leading to the selection of one of the hUCMSCs as the most promising line. Administration of hUCMSC to SARS-CoV-2-infected K18 mice expressing hACE2 was effective in improving lung histology and modulating of a panel of cytokines.

Our study assessed MSCs derived from various tissues, uncovering significant variability in their characteristics and immunomodulatory capacities. Particularly, hUCMSCs demonstrated potential in mitigating lung pathology in a SARS-CoV-2 infection model, suggesting their promising therapeutic efficacy.

Lung diseases are associated with high morbidity and mortality rates, thereby jeopardizing human health and imposing a great burden on society. Currently, lung diseases are mainly treated with medications, oxygen therapy and mechanical ventilation, but these approaches are unable to effectively reduce the mortality rate. Therefore, lung transplantation remains the ultimate treatment for various chronic lung diseases, but this treatment is also hindered by the limited availability of lung sources, immature technology and a low survival rate after transplantation. With constant changes in the environment, pathogens, type and amount of harmful substances and the prevalence of respiratory diseases, there is an urgent need to identify alternative treatment methods. Research on stem cell therapy has been very successful in recent years, and mesenchymal stem cells (MSCs), together with their secretory bodies, play a significant therapeutic role. Extracellular vesicles of MSCs (MSC-EVs) are also major components of the paracrine secretion of MSCs, including exosomes, microvesicles, and apoptotic bodies, among which exosomes are the most typical. MSC-EVs are believed to be present in various tissues of the human body where they can carry proteins, DNA, RNA and biologically active factors, just to name a few. They can also transmit various biological signals to participate in different biological activities, including the maintenance of homeostasis within the tissue. Several studies have further demonstrated that MSCs and their generated extracellular vesicles play an important role in the treatment of diseases. In this paper, the origin, properties and roles of MSCs and MSC-EVs are reviewed, the mechanisms of different lung diseases, the limitations of current therapeutic options and the roles of MSC-EVs in Chronic Obstructive Pulmonary Disease, asthma, infectious lung disease, lung cancer, pulmonary fibrosis, pulmonary arterial hypertension, and acute lung injury/ acute respiratory distress syndrome are also discussed (Figure 1). In addition, the current limitations and possible future research directions are also discussed in view of providing new ideas for the role of MSC-EVs in the treatment of lung diseases.

The biological properties of human mesenchymal stromal cells (hMSCs) have been explored in over a thousand clinical trials in the last decade. Although hMSCs can be isolated from multiple sources, the degree of biological similarity between cell populations from these sources remains to be determined. A comparative study was performed investigating the growth kinetics and functionality of hMSCs isolated from adipose tissue (AT), bone marrow (BM) and umbilical cord tissue (UCT) expanded in monolayer over five passages. Adult hMSCs (AT, BM) had a slower proliferation ability than the UCT-hMSCs, with no apparent differences in their glucose consumption profile. BM-hMSCs produced higher concentrations of endogenous vascular endothelial growth factor (VEGF) compared to AT- and UCT-hMSCs. This study also revealed that UCT-hMSCs were more efficiently transduced by a lentiviral vector carrying a VEGF gene than their adult counterparts. Following cellular immunophenotypic characterization, no differences across the sources were found in the expression levels of the typical markers used to identify hMSCs. This work established a systematic approach for cell source selection depending on the hMSC's intended clinical application.

UVB radiation induces oxidative stress, DNA damage, and inflammation, leading to skin wrinkling, compromised barrier function, and an increased risk of carcinogenesis. Addressing or preventing photoaging may offer a promising therapeutic avenue for these conditions. Recent research indicated that mesenchymal stem cells (MSCs) exhibit significant therapeutic potential for various skin diseases. Given that extracellular vesicles (EV) can deliver diverse cargo to recipient cells and elicit similar therapeutic effects, we investigated the roles and underlying mechanisms of both adipose-derived MSC-derived EV (AMSC-EV) and umbilical cord-derived MSC-derived EV (HUMSC-EV) in photoaging. Our findings indicated that in vivo, treatment with AMSC-EV and HUMSC-EV resulted in improvements in wrinkles and skin hydration while also mitigating skin inflammation and thickness alterations in both the epidermis and dermis. Additionally, in vitro studies using human keratinocytes (HaCaTs), human dermal fibroblast cells (HDFs), and T-Skin models revealed that AMSC-EV and HUMSC-EV attenuated senescence, reduced levels of reactive oxygen species (ROS) and DNA damage, and alleviated inflammation induced by UVB. Furthermore, EV treatment enhanced cell viability and migration capacity in the epidermis and promoted extracellular matrix (ECM) remodeling in the dermis in photoaged cell models. Mechanistically, proteomics results showed that TIMP1 was highly expressed in both AMSC-EV and HUMSC-EV and could exert similar effects as MSC-EV. In addition, we found that EV and TIMP1 could inhibit Notch1 and downstream targets Hes1, P16, P21, and P53. Collectively, our data suggests that both AMSC-EV and HUMSC-EV attenuate skin photoaging through TIMP1/Notch1.

Mesenchymal stem/stromal cells (MSCs)-based products have unique characteristics compared to other drugs because of their inherently variable effects depending on culture conditions and microenvironment. In some cases, cells can be produced individually, one batch at a time, for personalized therapy. Therefore, it is very important to optimize both culture conditions and medium composition under Good Manufacturing Practice (GMP) standards. MSCs properties have been exploited as potential cell therapies in regenerative medicine. The main mechanism of their protective and regenerative effect is based on their secretory activity. Simultaneously, their secretome is highly variable and sensitive to any change in environmental conditions. Depending on the type of damage and the target application, it is desirable to enhance the secretion of therapeutic factors. Changes in the modulation of environmental conditions can affect survival, migration ability, and both proliferative and clonogenic potentials.

This study cultured Wharton's jelly-derived MSCs (WJ-MSCs) in media with varying concentrations of human platelet lysate (hPL). Two groups were created: one with low hPL concentration and another with a high hPL concentration. The effects of these different hPL concentrations were analyzed by assessing mesenchymal phenotype retention, secretory activity, clonogenic potential, proliferation, and migration capabilities. Additionally, the secretion levels of key therapeutic factors, such as Hepatocyte Growth Factor (HGF), Brain-Derived Neurotrophic Factor (BDNF), and Chemokine Ligand 2 (CCL-2), were measured.

WJ-MSCs maintained their mesenchymal phenotype regardless of hPL concentration. However, a higher concentration of hPL promoted cell clonogenic potential, proliferation, migration, and increased secretion of therapeutic factors.

Adjusting the hPL concentration in the culture medium modulates the response of WJ MSCs and enhances their therapeutic potential. Higher hPL concentration promotes increased secretory activity and improves the regenerative capacity of WJ-MSCs, suggesting a promising strategy to optimize MSC-based therapies.

Human plasma is a natural biomaterial that due to their protein composition is widely used for the development of clinical products, especially in the field of dermatology. In this context, this biomaterial has been used as a scaffold alone or combined with others for the development of cellular human plasma-based skin substitutes (HPSSs). Herein, the biological properties (cell viability, cell metabolic activity, protein secretion profile and histology) of several variations of a clinical HPSS model, regarding the biomaterial composition (alone or combined with six secondary biomaterials - serine, fibronectin, collagen, two types of laminins and hyaluronic acid), the cellular structure (trilayer, bilayer, monolayer and control without cells) and their skin tissue of origin (abdominal or foreskin cells) and the manufacturing process [effect of partial dehydration process in cell viability and comparison between submerged (SUB) and air/liquid interface (ALI) methodologies] have been evaluated and compared. Results reveal that the use of human plasma as a main biomaterial determines the in vitro properties, rather than the secondary biomaterials added. Moreover, the characteristics are similar regardless of the skin cells used (from abdomen or foreskin). However, the manufacture of more complex cellular substitutes (trilayer and bilayer) has been demonstrated to be better in terms of cell viability, metabolic activity and wound healing protein secretion (bFGF, EGF, VEGF-A, CCL5) than monolayer HPSSs, especially when ALI culture methodology is applied. Moreover, the application of the dehydration, although required to achieve an appropriate clinical structure, reduce cell viability in all cases. These data indicate that this HPSS model is robust and reliable and that the several subtypes here analysed could be promising clinical approaches depending on the target dermatological disease.

Ischemic stroke (IS) is a leading cause of death and disability worldwide. Tissue plasminogen activator (tPA) administration and mechanical thrombectomy are the main treatments but have a narrow time window. Mesenchymal stem cells (MSCs), which are easily scalable in vitro and lack ethical concerns, possess the potential to differentiate into various types of cells and secrete a great number of growth factors for neuroprotection and regeneration. Moreover, MSCs have low immunogenicity and tumorigenic properties, showing safety and preliminary efficacy both in preclinical studies and clinical trials of IS. However, it is unlikely that MSC treatment alone will be sufficient to maximize recovery due to the low survival rate of transplanted cells and various mechanisms of ischemic brain damage in the different stages of IS. Preconditioning was used to facilitate the homing, survival, and secretion ability of the grafted MSCs in the ischemic region, while combination therapies are alternatives that can maximize the treatment effects, focusing on multiple therapeutic targets to promote stroke recovery. In this case, the combination therapy can yield a synergistic effect. In this review, we summarize the type of MSCs, preconditioning methods, and combined strategies as well as their therapeutic mechanism in the treatment of IS to accelerate the transformation from basic research to clinical application.

Hypoxic ischemic encephalopathy (HIE) remains a leading cause of neonatal mortality and lifelong disability across the world. While therapeutic hypothermia (HT) is beneficial, it is only partially protective and adjuvant treatments that further improve outcomes are urgently needed. In high-income countries where HT is standard care, novel treatments are tested in conjunction with HT. Mesenchymal stromal cells (MSC) represent a paradigm shift in brain protection, uniquely adapting to the host cellular microenvironment. MSC have low immunogenicity and potent paracrine effects stimulating the host tissue repair and regeneration and reducing inflammation and apoptosis. Preclinical studies in perinatal brain injury suggest that MSC are beneficial after hypoxia-ischemia (HI) and most preclinical studies of MSC with HT show protection. Preclinical and early phase clinical trials have shown that allogenic administration of MSC to neonates with perinatal stroke and HIE is safe and feasible but further safety and efficacy studies of HT with MSC in these populations are needed. Combination therapies that target all stages of the evolution of injury after HI (eg HT, melatonin and MSC) show promise for improving outcomes in HIE.

Wharton's jelly mesenchymal stem cells (WJ-MSCs) are gaining significant attention in regenerative medicine for their potential to treat degenerative diseases and mitigate radiation injuries. WJ-MSCs are more naïve and have a better safety profile, making them suitable for both autologous and allogeneic transplantations. This review highlights the regenerative potential of WJ-MSCs and their clinical applications in mitigating various types of radiation injuries. In this review, we will also describe why WJ-MSCs will become one of the most probable stem cells for future regenerative medicine along with a balanced view on their strengths and weaknesses. Finally, the most updated literature related to both preclinical and clinical usage of WJ-MSCs for their potential application in the regeneration of tissues and organs will also be compiled.

Autism spectrum disorder (ASD) is a neurodevelopmental illness characterized by impaired social interaction and restricted repetitive behaviors or interests. The rising prevalence of ASD diagnosis has triggered a surge in research into investigating the underlying neuropathological processes and finding new therapeutic approaches. ASD is characterized by neuroinflammation and dysregulation of neuro-immune cross-talk, which suggests that stem cell treatment might be a potential therapeutic approach. The beneficial and restorative effects of stem cells are mainly due to their paracrine activity, in which stem cells generate and release extracellular vesicles such as exosomes and distinct secreted non-vesicle soluble proteins, including, growth factors, chemokines, cytokines, and immunomodulatory molecules referred to as the Secretome. In this paper, we reviewed the existing research exploring the therapeutic potential of stem cell secretome focusing on their role in addressing ASD pathology. Furthermore, we proposed a comprehensive mechanism of action for stem cell secretions, encompassing the broader secretome as well as the specific contribution of exosomes, in alleviating ASD neuropathology. Across the reviewed studies, exosomes and secreted soluble factors of the transplanted stem cell demonstrate a potential efficacy in ameliorating autistic-like behaviors. The proposed mechanism of action involves the modulation of signaling pathways implicated in neuroinflammation, angiogenesis, cellular apoptosis, and immunomodulation.

A rising population faces challenges with healing-impaired cutaneous wounds, often leading to physical disabilities. Adipose-derived stem cells (ASCs), specifically in the cell sheet format, have emerged as a promising remedy for impaired wound healing. Human platelet lysate (HPL) provides an attractive alternative to fetal bovine serum (FBS) for culturing clinical-grade ASCs. However, the potential of HPL sheets in promoting wound healing has not been fully investigated. This study aimed to explore the anti-fibrotic and pro-angiogenic capabilities of HPL-cultured ASC sheets and delve into the molecular mechanism.

A rat burn model was utilized to evaluate the efficacy of HPL-cultured ASC sheets in promoting wound healing. ASC sheets were fabricated with HPL, and those with FBS were included for comparison. Various analyses were conducted to assess the impact of HPL sheets on wound healing. Histological examination of wound tissues provided insights into aspects such as wound closure, collagen deposition, and overall tissue regeneration. Immunofluorescence was employed to assess the presence and distribution of transplanted ASCs after treatment. Further in vitro studies were conducted to decipher the specific factors in HPL sheets contributing to angiogenesis.

HPL-cultured ASC sheets significantly accelerated wound closure, fostering ample and organized collagen deposition in the neo-dermis. Significantly more retained ASCs were observed in wound tissues treated with HPL sheets compared to the FBS counterparts. Moreover, HPL sheets mitigated macrophage recruitment and decreased subsequent wound tissue fibrosis in vivo. Immunohistochemistry also indicated enhanced angiogenesis in the HPL sheet group. The in vitro analyses showed upregulation of C-C motif chemokine ligand 5 (CCL5) and angiogenin in HPL sheets, including both gene expression and protein secretion. Culturing endothelial cells in the conditioned media compared to media supplemented with CCL5 or angiogenin suggested a correlation between CCL5 and the pro-angiogenic effect of HPL sheets. Additionally, through neutralizing antibody experiments, we further validated the crucial role of CCL5 in HPL sheet-mediated angiogenesis in vitro.

The present study underscores CCL5 as an essential factor in the pro-angiogenic effect of HPL-cultured ASC sheets during the wound healing process. These findings highlight the potential of HPL-cultured ASC sheets as a promising therapeutic option for healing-impaired cutaneous wounds in clinical settings. Furthermore, the mechanism exploration yields valuable information for optimizing regenerative strategies with ASC products.

This research was supported by the National Science and Technology Council, Taiwan (NSTC112-2321-B-002-018), National Taiwan University Hospital (111C-007), and E-Da Hospital-National Taiwan University Hospital Joint Research Program (111-EDN0001, 112-EDN0002).

Inflammatory bowel disease (IBD) poses a significant challenge in modern medicine, with conventional treatments limited by efficacy and associated side effects, necessitating innovative therapeutic approaches. Mesenchymal stem cells (MSC) have emerged as promising candidates for IBD treatment due to their immunomodulatory properties and regenerative potential. This thesis aims to explore and compare various sources of MSC and evaluate their efficacy in treating IBD. This study comprehensively analyses MSC derived from multiple sources, including bone marrow, adipose tissue, umbilical cord, and other potential reservoirs. Core elements of this investigation include assessing differences in cell acquisition, immunomodulatory effects, and differentiation capabilities among these MSC sources, as well as comparing their clinical trial outcomes in IBD patients to their therapeutic efficacy in animal models. Through meticulous evaluation and comparative analysis, this thesis aims to elucidate disparities in the efficacy of different MSC sources for IBD treatment, thereby identifying the most promising therapeutic applications. The findings of this study are intended to advance our understanding of MSC biology and offer valuable insights for selecting the most effective MSC sources for personalized IBD therapy. Ultimately, this research endeavor will optimise therapeutic strategies for managing inflammatory bowel disease through the utilization of MSC.

Stem cells are recognized as an important target and tool in regenerative engineering. In this study, we explored the feasibility of engineering amniotic fluid-derived mesenchymal stem cell-secreted molecules (afMSC-SMs) as a versatile bioactive material for skin regenerative medicine applications in a time- and cost-efficient and straightforward manner. afMSC-SMs, obtained in powder form through ethanol precipitation, effectively contributed to preserving the self-renewal capacity and differentiation potential of primary human keratinocytes (pKCs) in a xeno-free environment, offering a potential alternative to traditional culture methods for their long-term in vitro expansion, and allowed them to reconstitute a fully stratified epithelium sheet on human dermal fibroblasts. Furthermore, we demonstrated the flexibility of afMSC-SMs in wound healing and hair regrowth through injectable hydrogel and nanogel-mediated transdermal delivery systems, respectively, expanding the pool of regenerative applications. This cell-free approach may offer several potential advantages, including streamlined manufacturing processes, scalability, controlled formulation, longer shelf lives, and mitigation of risks associated with living cell transplantation. Accordingly, afMSC-SMs could serve as a promising therapeutic toolbox for advancing cell-free regenerative medicine, simplifying their broad applicability in various clinical settings.

Mesenchymal stem cells (MSCs) isolated from Wharton's jelly (WJ-MSCs) and adipose tissue (AD-MSCs) are alternative sources for bone marrow-derived MSCs. Owing to their multiple functions in angiogenesis, immune modulation, proliferation, migration, and nerve regeneration, MSC-derived exosomes can be applied in "cell-free cell therapy". Here, we investigated the functional protein components between the exosomes from WJ-MSCs and AD-MSCs to explain their distinct functions. Proteins of WJ-MSC and AD-MSC exosomes were collected and compared based on iTRAQ gel-free proteomics data. Results: In total, 1695 proteins were detected in exosomes. Of these, 315 were more abundant (>1.25-fold) in AD-MSC exosomes and 362 kept higher levels in WJ-MSC exosomes, including fibrinogen proteins. Pathway enrichment analysis suggested that WJ-MSC exosomes had higher potential for wound healing than AD-MSC exosomes. Therefore, we treated keratinocyte cells with exosomes and the recombinant protein of fibrinogen beta chain (FGB). It turned out that WJ-MSC exosomes better promoted keratinocyte growth and migration than AD-MSC exosomes. In addition, FGB treatment had similar results to WJ-MSC exosomes. The fact that WJ-MSC exosomes promoted keratinocyte growth and migration better than AD-MSC exosomes can be explained by their higher FGB abundance. Exploring the various components of AD-MSC and WJ-MSC exosomes can aid in their different clinical applications.

Mesenchymal stem/stromal cells (MSCs) are a promising therapeutic tool in cell therapy and tissue engineering because of their multi-lineage differentiation capacity, immunomodulatory effects, and tissue protective potential. To achieve optimal results as a therapeutic tool, factors affecting MSC potency, including but not limited to cell source, donor age, and cell batch, have been investigated. Although the sex of the donor has been attributed as a potential factor that can influence MSC potency and efficacy, the impact of donor sex on MSC characteristics has not been carefully investigated. In this review, we summarize published studies demonstrating donor-sex-related MSC heterogeneity and emphasize the importance of disclosing donor sex as a key factor affecting MSC potency in cell therapy.

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.

Horses are high-performance athletes prone to sportive injuries such as tendonitis and desmitis. The formation of fibrous tissue in tendon repair remains a challenge to overcome. This impels regenerative medicine to develop innovative therapies that enhance regeneration, retrieving original tissue properties. Multipotent Mesenchymal Stem/Stromal Cells (MSCs) have been successfully used to develop therapeutic products, as they secrete a variety of bioactive molecules that play a pivotal role in tissue regeneration. These factors are released in culture media for producing a conditioned medium (CM). The aforementioned assumptions led to the formulation of equine synovial membrane MSCs (eSM-MSCs)-the cellular pool that naturally regenerates joint tissue-combined with a medium enriched in immunomodulatory factors (among other bioactive factors) produced by umbilical cord stroma-derived MSCs (eUC-MSCs) that naturally contribute to suppressing the immune rejection in the maternal-fetal barrier. A description of an equine sport horse diagnosed with acute tarsocrural desmitis and treated with this formulation is presented. Ultrasonographic ligament recovery occurred in a reduced time frame, reducing stoppage time and allowing for the horse's return to unrestricted competition after the completion of a physical rehabilitation program. This study focused on the description of the therapeutic formulation and potential in an equine desmitis treatment using the cells themselves and their secretomes.

Pulmonary fibrosis (PF) is a progressive fibrosing interstitial pneumonia that leads to respiratory failure and other complications, which is ultimately fatal. Mesenchymal stem cells (MSCs) transplant is a promising strategy to solve this problem, while the procurement of MSCs from the patient for autotransplant remains a challenge.

Here, we presented olfactory mucosa mesenchymal stem cells (OM-MSCs) from mouse turbinate and determined the preventing efficacy of allotransplant for PF. We demonstrated the antiinflammation and immunomodulatory effects of OM-MSCs. Flow cytometric analysis was used to verify the effect of OM-MSCs on monocyte-derived macrophage populations in the lung.

Administration of OM-MSCs reduces inflammation, attenuates the matrix metallopeptidase 13 (MMP13) expression level and restores the bleomycin (BLM)-induced pulmonary fibrosis by assessing the architecture of lung, collagen type I; (COL1A1), actin alpha 2, smooth muscle, aorta (ACTA2/α-SMA) and hydroxyproline. This therapeutic effect of OM-MSCs was related to the increase in the ratio of nonclassical monocytes to proinflammatory monocytes in the lung.

This study suggests that transplant of OM-MSCs represents an effective and safe treatment for PF.

Although Mesenchymal Stem Cells (MSCs)-based therapy has been proposed as a promising strategy for the treatment of chronic lower-extremity ulcers, their optimal sources, amounts, and delivery methods are urgently needed to be determined. In this study, we compared the heterogeneity of the human MSCs derived from bone marrow (BMSCs), umbilical cord (UCMSCs), and adipose tissue (ADSCs) in accelerating wound healing and promoting angiogenesis and explored the underlying mechanism. Briefly, a diabetic rat model with a full-thickness cutaneous wound on the dorsal foot was developed. The wound was topically administered with three types of MSCs. Additionally, we carried out in vitro and in vivo analysis of the angiogenic properties of the MSCs. Moreover, the molecular mechanism of the heterogeneity of the MSCs derived from the three tissues was explored by transcriptome sequencing. When compared with the BMSCs- and UCMSCs-treated groups, the ADSCs-treated group exhibited markedly accelerated healing efficiency, characterized by increased wound closure rates, enhanced angiogenesis, and collagen deposition at the wound site. The three types of MSCs formed three-dimensional capillary-like structures and promoted angiogenesis in vitro and in vivo, with ADSCs exhibiting the highest capacity for tube formation and pro-angiogenesis. Furthermore, transcriptome sequencing revealed that ADSCs had higher expression levels of angiogenesis-associated genes. Our findings indicate that MSCs-based therapy accelerates the healing of ischemia- and diabetes-induced lower-extremity ulcers and that adipose tissue-derived MSCs might be ideal for therapeutic angiogenesis and treatment of chronic ischemic wounds.

Due to their characteristics, mesenchymal stem cells (MSCs) are considered a potential therapy for brain tissue injury or degeneration. Nevertheless, despite the promising results observed, there has been a growing interest in the use of cell-free therapies in regenerative medicine, such as the use of stem cell secretome. This review provides an in-depth compilation of data regarding the secretome composition, protocols used for its preparation, as well as existing information on the impact of secretome administration on various brain conditions, pointing out gaps and highlighting relevant findings. Moreover, due to the ability of MSCs to respond differently depending on their microenvironment, preconditioning of MSCs has been used to modulate their composition and, consequently, their therapeutic potential. The different strategies used to modulate the MSC secretome were also reviewed. Although secretome administration was effective in improving functional impairments, regeneration, neuroprotection, and reducing inflammation in brain tissue, a high variability in secretome preparation and administration was identified, compromising the transposition of preclinical data to clinical studies. Indeed, there are no reports of the use of secretome in clinical trials. Despite the existing limitations and lack of clinical data, secretome administration is a potential tool for the treatment of various diseases that impact the CNS.

Immunity-and-matrix-regulatory cells (IMRCs) derived from human embryonic stem cells have unique abilities in modulating immunity and regulating the extracellular matrix, which could be mass-produced with stable biological properties. Despite resemblance to mesenchymal stem cells (MSCs) in terms of self-renew and tri-lineage differentiation, the ability of IMRCs to repair the meniscus and the underlying mechanism remains undetermined. Here, we showed that IMRCs demonstrated stronger immunomodulatory and pro-regenerative potential than umbilical cord MSCs when stimulated by synovial fluid from patients with meniscus injury. Following injection into the knees of rabbits with meniscal injury, IMRCs enhanced endogenous fibrocartilage regeneration. In the dose-escalating phase I clinical trial (NCT03839238) with eighteen patients recruited, we found that intra-articular IMRCs injection in patients was safe over 12 months post-grafting. Furthermore, the effective results of magnetic resonance imaging (MRI) of meniscus repair and knee functional scores suggested that 5 × 107 cells are optimal for meniscus injury treatment. In summary, we present the first report of a phase I clinical trial using IMRCs to treat meniscus injury. Our results demonstrated that intra-articular injection of IMRCs is a safe and effective therapy by providing a permissive niche for cartilage regeneration.

Following an ischemic injury to the brain, the induction of angiogenesis is critical to neurological recovery. The angiogenic benefits of mesenchymal stem cells (MSCs) have been attributed at least in part to the actions of extracellular vesicles (EVs) that they secrete. EVs are membrane-bound vesicles that contain various angiogenic biomolecules capable of eliciting therapeutic responses and are of relevance in cerebral applications due to their ability to cross the blood-brain barrier (BBB). Though MSCs are commonly cultured under oxygen levels present in injected air, when MSCs are cultured under physiologically relevant oxygen conditions (2-9% O2), they have been found to secrete higher amounts of survival and angiogenic factors. There is a need to determine the effects of MSC-EVs in models of cerebral angiogenesis and whether those from MSCs cultured under physiological oxygen provide greater functional effects.

Human adipose-derived MSCs were grown in clinically relevant serum-free medium and exposed to either headspace oxygen concentrations of 18.4% O2 (normoxic) or 3% O2 (physioxic). EVs were isolated from MSC cultures by differential ultracentrifugation and characterized by their size, concentration of EV specific markers, and their angiogenic protein content. Their functional angiogenic effects were evaluated in vitro by their induction of cerebral microvascular endothelial cell (CMEC) proliferation, tube formation, and angiogenic and tight junction gene expressions.

Compared to normoxic conditions, culturing MSCs under physioxic conditions increased their expression of angiogenic genes SDF1 and VEGF, and subsequently elevated VEGF-A content in the EV fraction. MSC-EVs demonstrated an ability to induce CMEC angiogenesis by promoting tube formation, with the EV fraction from physioxic cultures having the greatest effect. The physioxic EV fraction further upregulated the expression of CMEC angiogenic genes FGF2, HIF1, VEGF and TGFB1, as well as genes (OCLN and TJP1) involved in BBB maintenance.

EVs from physioxic MSC cultures hold promise in the generation of a cell-free therapy to induce angiogenesis. Their positive angiogenic effect on cerebral microvascular endothelial cells demonstrates that they may have utility in treating ischemic cerebral conditions, where the induction of angiogenesis is critical to improving recovery and neurological function.

Mesenchymal stromal cells nowadays emerge as a major player in the field of regenerative medicine and translational research. They constitute, with their derived products, the most frequently used cell type in different therapies. However, their heterogeneity, including different subpopulations, the anatomic source of isolation, and high donor-to-donor variability, constitutes a major controversial issue that affects their use in clinical applications. Furthermore, the intrinsic and extrinsic molecular mechanisms underlying their self-renewal and fate specification are still not completely elucidated. This review dissects the different heterogeneity aspects of the tissue source associated with a distinct developmental origin that need to be considered when generating homogenous products before their usage for clinical applications.

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) exhibit multilineage differentiation potential, adhere to plastic, and express a specific set of surface markers-CD105, CD73, CD90. Although there are relatively well-established differentiation protocols for WJ-MSCs, the exact molecular mechanisms involved in their in vitro long-term culture and differentiation remain to be elucidated. In this study, the cells were isolated from Wharton's jelly of umbilical cords obtained from healthy full-term deliveries, cultivated in vitro, and differentiated towards osteogenic, chondrogenic, adipogenic and neurogenic lineages. RNA samples were isolated after the differentiation regimen and analyzed using an RNA sequencing (RNAseq) assay, which led to the identification of differentially expressed genes belonging to apoptosis-related ontological groups. ZBTB16 and FOXO1 were upregulated in all differentiated groups as compared to controls, while TGFA was downregulated in all groups. In addition, several possible novel marker genes associated with the differentiation of WJ-MSCs were identified (e.g., SEPTIN4, ITPR1, CNR1, BEX2, CD14, EDNRB). The results of this study provide an insight into the molecular mechanisms involved in the long-term culture in vitro and four-lineage differentiation of WJ-MSCs, which is crucial to utilize WJ-MSCs in regenerative medicine.

Mesenchymal stem/stromal cell-derived extracellular vesicles (MSC-EVs) have been considered promising therapeutics for disease treatments. However, MSC-EVs harvested from different tissues present unique biological features reflective of their origins. The heterogeneity of MSC-EVs constitutes an important barrier to their precise application in clinical translation that may probably lead to uncertain therapeutic effects. To give hints for future clinical translation, five MSCs are employed, whose derived EVs are most intensively utilized, namely bone marrow mesenchymal stem/stromal cells (BMMSCs), umbilical cord stem/stromal cells (UCSCs), adipose-derived stem/stromal cells (ASCs), dermal stem/stromal cells (DSCs) and dental pulp stem/stromal cells (DPSCs) and the heterogeneity landscape of the corresponding MSC-EVs are documented. Overall, the basic parameters, stability, and biosafety of different MSC-EVs are indiscriminate. Strikingly, UCSC-EVs exhibit distinguishing productivity. UCSC-EVs as well as DPSC-EVs present better drug loading/delivery capacity. In addition, the heterogeneity of different MSC-EVs in cargo diversity, cellular affinity, organ biodistribution, and therapeutic effects may cue the rational selection in different disease treatments. Through a combined assessment, a rational strategy is combined for selecting MSC-EVs in future clinics. Offering a panoramic view of MSC-EVs harvested from different tissues, the current study may provide guidelines for the precise selection of MSC-EVs in next-generation therapeutics.

Preterm birth and intrapartum related complications account for a substantial amount of mortality and morbidity in the neonatal period despite significant advancements in neonatal-perinatal care. Currently, there is a noticeable lack of curative or preventative therapies available for any of the most common complications of prematurity including bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage, periventricular leukomalacia and retinopathy of prematurity or hypoxic-ischemic encephalopathy, the main cause of perinatal brain injury in term infants. Mesenchymal stem/stromal cell-derived therapy has been an active area of investigation for the past decade and has demonstrated encouraging results in multiple experimental models of neonatal disease. It is now widely acknowledged that mesenchymal stem/stromal cells exert their therapeutic effects via their secretome, with the principal vector identified as extracellular vesicles. This review will focus on summarizing the current literature and investigations on mesenchymal stem/stromal cell-derived extracellular vesicles as a treatment for neonatal diseases and examine the considerations to their application in the clinical setting.

Ischaemic heart disease (IHD) remains the leading cause of mortality worldwide. Current pharmaceutical treatments focus on delaying, rather than preventing disease progression. The only curative treatment available is orthotopic heart transplantation, which is greatly limited by a lack of available donors and the possibility for immune rejection. As a result, novel therapies are consistently being sought to improve the quality and duration of life of those suffering from IHD. Stem cell therapies have garnered attention globally owing to their potential to replace lost cardiac cells, regenerate the ischaemic myocardium and to release protective paracrine factors. Despite recent advances in regenerative cardiology, one of the biggest challenges in the clinical translation of cell-based therapies is determining the most efficacious cell type for repair. Multiple cell types have been investigated in clinical trials; with inconsistent methodologies and isolation protocols making it difficult to draw strong conclusions. This review provides an overview of IHD focusing on pathogenesis and complications, followed by a summary of different stem cells which have been trialled for use in the treatment of IHD, and ends by exploring the known mechanisms by which stem cells mediate their beneficial effects on ischaemic myocardium.

This study aimed to describe the secretome of mesenchymal stem cells derived from feline adipose tissue (AD-MSCs) and compare the effects of different culture conditions on AD-MSC proteomics using a shotgun approach. Adipose tissue was collected from 5 female cats and prepared to culture. Conditioned media was collected at third passage, in which the cells were cultured under 4 conditions, normoxia with fetal bovine serum (N + FBS), hypoxia with FBS (H + FBS), normoxia without FBS (N - FBS), and hypoxia without FBS (H - FBS). Then, the secretome was concentrated and prepared for proteomic approaches. Secretomes cultured with FBS-free medium had more than twice identified proteins in comparison with the secretomes cultured with FBS. In contrast, hypoxic conditions did not increase protein amount and affected only a small proteome fraction. Relevant proteins were related to the extracellular matrix promoting environmental modulation, influencing cell signaling pathways, and providing a suitable environment for cell proliferation and maintenance. Moreover, other proteins were also related to cell adhesion, migration and morphogenesis. Culture conditions can influence protein abundance in AD-MSC secretome, and can give also more specificity to cell and cell-free treatments for different diseases.

Neonatal brain injury resulting from various intractable disorders including intraventricular hemorrhage and hypoxic ischemic encephalopathy still remains a major cause of mortality and morbidities with few effective treatments. Recent preclinical research results showing the pleiotropic neuroprotective effects of stem cell therapy, specifically mesenchymal stem cells (MSCs), suggest that MSCs transplantation might be a promising new therapeutic modality for neuroprotection against the currently intractable and devastating neonatal brain injury with complex multifactorial etiology. This review summarizes recent advances in preclinical stem cell research for treating neonatal brain injury with a focus on the important issues including the mechanism of neuroprotection, and determining the ideal cell source, route, timing and dose of MSCs transplantation.

MSCs have been demonstrated to have a great benefit for type 1 diabetes mellitus (T1DM) due to their strong immunosuppressive and regenerative capacity. However, the comprehensive mechanism is still unclear. Our previous study indicated that transforming growth factor beta induced (TGFBI) is highly expressed in human umbilical cord-derived mesenchymal stem or stromal cells (hUC-MSCs), which are also implicated in T1DM. In this study, we found that infusion of TGFBI knockdown hUC-MSCs displayed impaired therapeutic effects in T1DM mice and decreased immunosuppressive capability. TGFBI knockdown hUC-MSCs could increase the proportion of T-cell infiltration while increasing the expression of IFN-gamma and interleukin-17A in the spleen. In addition, we also revealed that hUC-MSC-derived TGFBI could repress activated T-cell proliferation by interfering with G1/S checkpoint CyclinD2 expression. Our results demonstrate that TGFBI plays a critical role in MSC immunologic regulation. TGFBI could be a new immunoregulatory molecule controlling MSC function for new treatments of T1DM. Schematic Representation of the Immunosuppression capacity of hUC-MSC by TGFBI.

The approaches currently used in osteoarthritis (OA) are mainly short-term solutions with unsatisfactory outcomes. Cell-based therapies are still controversial (in terms of the sources of cells and the results) and require strict culture protocol, quality control, and may have side-effects. A distinct population of stromal cells has an interesting secretome composition that is underrated and commonly ends up as biological waste. Their unique properties could be used to improve the existing techniques due to protective and anti-ageing properties.

In this review, we seek to outline the advantages of the use of conditioned media (CM) and exosomes, which render them superior to other cell-based methods, and to summarise current information on the composition of CM and their effect on chondrocytes.

CM are obtainable from a variety of mesenchymal stromal cell (MSC) sources, such as adipose tissue, bone marrow and umbilical cord, which is significant to their composition. The components present in CMs include proteins, cytokines, growth factors, chemokines, lipids and ncRNA with a variety of functions. In most in vitro and in vivo studies CM from MSCs had a beneficial effect in enhance processes associated with chondrocyte OA pathomechanism.

This review summarises the information available in the literature on the function of components most commonly detected in MSC-conditioned media, as well as the effect of CM on OA chondrocytes in in vitro culture. It also highlights the need to standardise protocols for obtaining CM, and to conduct clinical trials to transfer the effects obtained in vitro to human subjects.

Clinical translation of mesenchymal stem/stromal cell (MSC) therapy has been impeded by the heterogenous nature and limited replicative potential of adult-derived MSCs. Human embryonic stem cell-derived MSCs (hESC-MSCs) that differentiate from immortal cell lines are phenotypically uniform and have shown promise in-vitro and in many disease models. Similarly, adipose tissue-derived MSCs (MSC(AT)) possess potent reparative properties. How these two cell types compare in efficacy, however, remains unknown. We randomly assigned mice to six groups (n = 7-8 each) that underwent unilateral RAS or a sham procedure (3 groups each). Two weeks post-operation, each mouse was administered either vehicle, MSC(AT)s, or hESC-MSCs (5 × 105 cells) into the aorta. Mice were scanned with micro-MRI to determine renal hemodynamics two weeks later and kidneys then harvested. hESC-MSCs and MSC(AT)s were similarly effective at lowering systolic blood pressure. However, MSC(AT)s more robustly increased renal perfusion, oxygenation, and glomerular filtration rate in the post-stenotic kidney, and more effectively mitigated tubular injury, fibrosis, and vascular remodeling. These observations suggest that MSC(AT) are more effective than hESC-MSC in ameliorating kidney dysfunction and tissue injury distal to RAS. Our findings highlight the importance of tissue source in selection of MSCs for therapeutic purposes and underscore the utility of cell-based therapy for kidney disease.

According to strong evidence, diabetes mellitus increases the risk of cognitive impairment. Mesenchymal stem cells have been shown to be potential therapeutic agents for neurological disorders. In the current study, we aimed to examine the effects of Wharton's jelly-derived mesenchymal stem cell-conditioned medium (WJMSC-CM) on learning and memory, oxidative stress, apoptosis, and histological changes in the hippocampus of diabetic rats. Randomly, 35 male Sprague Dawley rats weighing 260-300 g were allocated into five groups: control, diabetes, and three diabetic groups treated with insulin, WJMSC-CM, and DMEM. The injections of insulin (3 U/day, S.C.) and WJMSC-CM (10 mg/week, I.P.) were done for 60 days. The Morris water maze and open field were used to measure cognition and anxiety-like behaviors. Colorimetric assays were used to determine hippocampus glutathione (GSH), malondialdehyde (MDA) levels, and antioxidant enzyme activity. The histopathological evaluation of the hippocampus was performed by Nissl staining. The expression levels of Bax, Bcl-2, BDNF, and TNF-α were detected by real-time polymerase chain reaction (RT-PCR). According to our findings, WJMSC-CM significantly reduced and increased blood glucose and insulin levels, respectively. Enhanced cognition and improved anxiety-like behavior were also found in WJMSC-CM-treated diabetic rats. In addition, WJMSC-CM treatment reduced oxidative stress by lowering MDA and elevating GSH and antioxidant enzyme activity. Reduced TNF-α and enhanced Bcl-2 gene expression levels and elevated neuronal and nonneuronal (astrocytes and oligodendrocytes) cells were detected in the hippocampus of WJMSC-CM-treated diabetic rats. In conclusion, WJMSC-CM alleviated diabetes-related cognitive impairment by reducing oxidative stress, neuroinflammation, and apoptosis in diabetic rats.

The ATP-binding cassette superfamily member ABCB5 identifies a subset of skin-resident mesenchymal stem cells (MSCs) that exhibit potent immunomodulatory and wound healing-promoting capacities along with superior homing ability. The ABCB5+ MSCs can be easily accessed from discarded skin samples, expanded, and delivered as a highly homogenous medicinal product with standardized potency. A range of preclinical studies has suggested therapeutic efficacy of ABCB5+ MSCs in a variety of currently uncurable skin and non-skin inflammatory diseases, which has been substantiated thus far by distinct clinical trials in chronic skin wounds or recessive dystrophic epidermolysis bullosa. Therefore, skin-derived ABCB5+ MSCs have the potential to provide a breakthrough at the forefront of MSC-based therapies striving to fulfill current unmet medical needs. The most recent milestones in this regard are the approval of a phase III pivotal trial of ABCB5+ MSCs for treatment of recessive dystrophic and junctional epidermolysis bullosa by the US Food and Drug Administration, and national market access of ABCB5+ MSCs (AMESANAR®) for therapy-refractory chronic venous ulcers under the national hospital exemption pathway in Germany.