Mesenchymal stem cells: a friend or foe in immune-mediated diseases

Bone marrow mesenchymal stem cells alleviate liver fibrosis after rat liver transplantation through JAK1/STAT5 pathway

OBJECTIVE

The effectiveness of bone marrow mesenchymal stem cells (BMSCs) in post-transplantation liver fibrosis has not been studied. The aim of this study was to investigate the effect of BMSCs on liver fibrosis and their role in the Janus-activated kinase (JAK) 1/ signal transducer and activator of transcription (STAT) 5 pathway after liver transplantation (LT).

METHODS

A rat model of post-LT liver fibrosis induced by cold ischemia injury was successfully established. BMSCs were injected into the rats through the portal vein. Hepatic stellate cell (HSC)-T6 were co-cultured with BMSCs in vitro after hypoxia-reoxygenation. JAK1 inhibitor Abrocitinib and JAK1 agonist RO8191 were used to study the JAK1/STAT5 signaling pathway.

RESULTS

BMSCs significantly alleviated liver fibrosis caused by cold ischemia-reperfusion injury after rat LT in vivo. After BMSCs transplantation, the levels of JAK1 and p-STAT5 in rat liver were significantly reduced. After using Abrocitinib, the stage of liver fibrosis and the levels of collagen type I alpha 1 chain (COL1A1) and actin alpha 2 (ACTA2) decreased. After using RO8191, the stage of liver fibrosis and the levels of COL1A1 and ACTA2 increased. BMSCs significantly reduced the activation of HSC-T6 after hypoxia-reoxygenation in vitro. After co-culturing with BMSCs after HSC-T6 hypoxia-reoxygenation, the levels of JAK1 and p-STAT5 were significantly reduced. After the addition of Abrocitinib, the levels of COL1A1 and ACTA2 decreased in HSC-T6; in contrast, after adding RO8191, the levels of COL1A1 and ACTA2 increased in HSC-T6 after hypoxia-reoxygenation. After using anti-IL7 antibody or anti-IL7Rα in vivo and in vitro, the stage of liver fibrosis and the levels of COL1A1 and ACTA2 decreased as well as the phosphorylation level of STAT5.

CONCLUSIONS

BMSCs alleviate hepatic cell damage, reduce hepatic cell-derived IL7, downregulate IL7R/JAK1/STAT5 in HSCs, thereby reducing HSCs' activation and ultimately alleviating liver fibrosis after liver transplantation.

Harnessing stem cell therapeutics in LPS-induced animal models: mechanisms, efficacies, and future directions

The severity and threat posed by inflammation are well documented, and lipopolysaccharides (LPS), as important inducers of inflammatory responses, are widely recognized for studying host immunity and the resulting tissue and organ damage. The LPS-induced disease model, triggers a remarkable release of inflammatory factors, immune and coagulation dysfunction, and damage to vital organs such as the brain, lungs, heart, liver, and kidneys. Recently, the role of mesenchymal stem cells (MSCs) in various clinical diseases has garnered significant attention due to their immunomodulatory, anti-inflammatory, tissue healing, anti-apoptotic, and antibacterial properties. Despite the common use of LPS models to induce disease models and simulate acute inflammation, the integration of stem cell therapy within these models remains underexplored. This article integrates the LPS induced animal model and reviews the current evidence regarding the therapeutic mechanisms of stem cells in LPS-induced disease models across various human body systems. Furthermore, this review predicts and hypothesizes the feasibility and potential of using stem cells in disease models that have not yet been extensively studied, based on existing animal inflammation models.

An Interplay Between Pericytes, Mesenchymal Stem Cells, and Immune Cells in the Process of Tissue Regeneration

Immediately after injury, damaged cells elicit tissue regeneration, a healing process that enables optimal renewal and regrowth of injured tissues. Results obtained in a large number of experimental studies suggested that the cross talk between pericytes, mesenchymal stem cells (MSC), tissue-resident stem cells, and immune cells has a crucially important role in the regeneration of injured tissues. Pericytes, MSCs, and immune cells secrete bioactive factors that influence each other's behavior and function. Immune cells produce inflammatory cytokines and chemokines that influence pericytes' migration, proliferation, and transition to MSC. MSC releases immunoregulatory factors that induce the generation of immunosuppressive phenotype in inflammatory immune cells, alleviating detrimental immune responses in injured tissues. MSC also produces various growth factors that influence the differentiation of tissue-resident stem cells into specific cell lineages, enabling the successful regeneration of injured tissues. A better understanding of molecular mechanisms that regulate crosstalk between pericytes, MSC, and immune cells in injured tissues would enable the design of new therapeutic approaches in regenerative medicine. Accordingly, in this review paper, we summarized current knowledge related to the signaling pathways that are involved in the pericytes' activation, pericytes-to-MSC transition, differentiation of tissue-resident stem cells, and MSC-dependent modulation of immune cell-driven inflammation, which are crucially responsible for regeneration of injured tissues.

Improving the Wound Healing Process: Pivotal role of Mesenchymal stromal/stem Cells and Immune Cells

Wound healing, a physiological process, involves several different types of cells, from immune cells to non-immune cells, including mesenchymal stromal/stem cells (MSC), and their interactions. Immune cells including macrophages, neutrophils, dendritic cells (DC), innate lymphoid cells (ILC), natural killer (NK) cells, and B and T lymphocytes participate in wound healing by secreting various mediators and interacting with other cells. MSCs, as self-renewing, fast proliferating, and multipotent stromal/stem cells, are found in a wide variety of tissues and critically involved in different phases of wound healing by secreting various molecules that help to improve tissue healing and regeneration. In this review, first, we described the four main phases of wound healing, second, we reviewed the function of MSCs, MSC secretome and immune cells in improving the progress of wound repair (mainly focusing on skin wound healing), third, we explained the immune cells/MSCs interactions in the process of wound healing and regeneration, and finally, we introduce clinical applications of MSCs to improve the process of wound healing.

Healing the cornea: Exploring the therapeutic solutions offered by MSCs and MSC-derived EVs

Affecting a large proportion of the population worldwide, corneal disorders constitute a concerning health hazard associated to compromised eyesight or blindness for most severe cases. In the last decades, mesenchymal stem/stromal cells (MSCs) demonstrated promising abilities in improving symptoms associated to corneal diseases or alleviating these affections, especially through their anti-inflammatory, immunomodulatory and pro-regenerative properties. More recently, MSC therapeutic potential was shown to be mediated by the molecules they release, and particularly by their extracellular vesicles (EVs; MSC-EVs). Consequently, using MSC-EVs emerged as a pioneering strategy to mitigate the risks related to cell therapy while providing MSC therapeutic benefits. Despite the promises given by MSC- and MSC-EV-based approaches, many improvements are considered to optimize the therapeutic significance of these therapies. This review aspires to provide a comprehensive and detailed overview of current knowledge on corneal therapies involving MSCs and MSC-EVs, the strategies currently under evaluation, and the gaps remaining to be addressed for clinical implementation. From encapsulating MSCs or their EVs into biomaterials to enhance the ocular retention time to loading MSC-EVs with therapeutic drugs, a wide range of ground-breaking strategies are currently contemplated to lead to the safest and most effective treatments. Promising research initiatives also include diverse gene therapies and the targeting of specific cell types through the modification of the EV surface, paving the way for future therapeutic innovations. As one of the most important challenges, MSC-EV large-scale production strategies are extensively investigated and offer a wide array of possibilities to meet the needs of clinical applications.

Effects of Hydrogels on Mesenchymal Stem/Stromal Cells Paracrine Activity and Extracellular Vesicles Production

Mesenchymal stem/stromal cells (MSCs) are a valuable source of paracrine factors, as they have a remarkable secretory capacity, and there is a sizeable knowledge base to develop industrial and clinical production protocols. Promising cell-free approaches for tissue regeneration and immunomodulation are driving research towards secretome applications, among which extracellular vesicles (EVs) are steadily gaining attention. However, the manufacturing and application of EVs is limited by insufficient yields, knowledge gaps, and low standardization. Facing these limitations, hydrogels represent a versatile three-dimensional (3D) culture platform that can incorporate extracellular matrix (ECM) components to mimic the natural stem cell environment in vitro; via these niche-mimicking properties, hydrogels can regulate MSCs' morphology, adhesion, proliferation, differentiation and secretion capacities. However, the impact of the hydrogel's architectural, biochemical and biomechanical properties on the production of EVs remains poorly understood, as the field is still in its infancy and the interdependency of culture parameters compromises the comparability of the studies. Therefore, this review summarizes and discusses the reported effects of hydrogel encapsulation and culture on the secretion of MSC-EVs. Considering the effects of cell-material interactions on the overall paracrine activity of MSCs, we identify persistent challenges from low standardization and process control, and outline future paths of research, such as the synergic use of hydrogels and bioreactors to enhance MSC-EV generation.

Mesenchymal Stem-Cell-Derived Exosomes as Novel Drug Carriers in Anti-Cancer Treatment: A Myth or Reality?

Although cancer therapy has significantly advanced in recent decades, patients and healthcare professionals are still quite concerned about adverse effects due to the non-targeted nature of currently used chemotherapeutics. Results obtained in a large number of recently published experimental studies indicated that mesenchymal stem-cell-derived exosomes (MSC-Exos), due to their biocompatibility, ability to cross biological barriers, and inherent targeting capabilities, could be used as a promising drug-delivery system for anti-cancer therapies. Their lipid bilayer protects cargo of anti-cancer drugs, making them excellent candidates for the delivery of therapeutic agents. MSC-Exos could be engineered to express ligands specific for tumor cells and, therefore, could selectively deliver anti-cancer agents directly in malignant cells, minimizing side effects associated with chemotherapeutic-dependent injury of healthy cells. MSC-Exos can carry multiple therapeutic agents, including anti-cancer drugs, micro RNAs, and small bioactive molecules, which can concurrently target multiple signaling pathways, preventing tumor growth and progression and overcoming resistance of tumor cells to many standard chemotherapeutics. Accordingly, in this review article, we summarized current knowledge and future perspectives about the therapeutic potential of MSCs-Exos in anti-cancer treatment, opening new avenues for the targeted therapy of malignant diseases.

NO-mediated DNA damage induced by polystyrene nanoparticles triggers program cell death in mesenchymal stem cells

Daily contact with considerable amounts of polystyrene nanoparticles (PSNPs) may cause harmful effects on the living organisms, through mechanisms that are not fully understood. The study aimed to evaluate the cytotoxic and genotoxic effects of PSNPs (size 200 nm and 40 nm) in mesenchymal stem cells (MSCs). In order to estimate cellular uptake and retention of nanoplastics, PSNP-treated cells have been analyzed by transmission electron microscopy. For assessing morphology and viability of MSCs after PSNP treatment at two environmentally relevant doses (0.47 and 4.7 μl/ml) for 24 hours, HE and Giemsa staining were performed. Annexin V‑FITC/PI assay was used to quantify PSNPs-mediated cell death. Genotoxicity of PSNPs was evaluated by Comet test. The capacity of PSNPs to trigger the production of free radicals in MSCs was also evaluated. TEM confirmed endocytosis of PSNPs. Decreased cell volume, nuclear hyperchromatism, edge aggregation, and formation of densely stained apoptotic bodies, indicated that PSNP-treated MSCs undergo apoptosis. The presented data showed that both concentration of PS particles significantly increased early apoptotic cell death in comparison to untreated cells. Moreover, both doses of PSNPs significantly increased the genetic damage index in MSCs in dose-dependent manner. In conclusion, PSNPs penetrate, accumulate and induce cytotoxic and genotoxic damage in MSCs.

Mesenchymal Stem Cell-Sourced Exosomes as Potentially Novel Remedies for Severe Dry Eye Disease

Severe dry eye disease (DED) is an inflammatory condition characterized by a lack of sufficient moisture or lubrication on the surface of the eye, significantly impacting the quality of life and visual function. Since detrimental immune response is crucially responsible for the development and aggravation of DED, therapeutic agents which modulate phenotype and function of eye-infiltrated inflammatory immune cells could be used for the treatment of severe DED. Due to their potent immunomodulatory properties, mesenchymal stem cells (MSCs) represent potentially new remedies for the treatment of inflammatory eye diseases. The majority of MSC-sourced bioactive factors are contained within MSC-derived exosomes (MSC-Exos), nano-sized extracellular vesicles which, due to their nanosize dimension and lipid envelope, easily by pass all biological barriers in the body and deliver their cargo directly into the target immune cells. MSC-Exos contain a variety of bioactive proteins (growth factors, immunoregulatory molecules, cytokines, and chemokines) lipids, and microRNAs (miRNAs) which affect viability, proliferation, phenotype, and function of eye-infiltrated immune cells. Accordingly, MSC-Exos may modulate the progression of inflammatory eye diseases, including DED. Therefore, in this review article, we summarized the current knowledge regarding molecular and cellular mechanisms which were responsible for trophic, anti-inflammatory, immunoregulatory, and regenerative properties of MSC-Exos in the treatment of severe DED. For this purpose, an extensive literature review was carried out in February 2024 across several databases (Medline, Embase, and Google Scholar), from 2000 to the present. Eligible studies delineated molecular and cellular mechanisms responsible for the MSC-Exos-based modulation of immune cell-driven eye inflammation in DED, and their findings were analyzed in this review. Results obtained in these studies demonstrated beneficial effects of MSC-Exos in the treatment of severe DED, paving the way for their future clinical use in ophthalmology. Trial Registration: ClinicalTrials.gov identifier: NCT04213248, NCT06475027, NCT06543667, NCT05738629.

Efficacy of umbilical cord-derived mesenchymal stem cells and exosomes in conjunction with standard IBD drug on immune responses in an IBD mouse model

BACKGROUND

Inflammatory bowel disease (IBD) is a persistent inflammation of the digestive system, and Mesenchymal Stem Cells (MSCs) and their exosomes have demonstrated potential as treatments for this condition. The objective of this research was to examine the possible effectiveness of intraperitoneal injection of umbilical cord-MSCs (UC-MSCs) and their exosomes through a two-time injection regimen in a mouse model.

METHOD

In this study, an animal model of a specific type of IBD in C57BL/6 mice, induced by dextran sulfate sodium (DSS), was utilized. The mice were treated with MSCs, exosomes, Mesalazine, and a combination of them. Upon sacrificing the mice, colon and spleen tissues were isolated to assess the changes in the mice's weight, colon length, spleen weight, and colitis' pathological symptoms. IL-10 and IL-17 levels were measured, and Treg and Th17 cell percentages were determined as well. Furthermore, colon tissue was stained to investigate histopathological changes.

RESULTS

In the groups that received MSCs, there was a significant reduction in the disease activity index and their combinations with exosomes and Mesalazine compared to the colitis group. Colon length increased in all groups except the exosome group. Histological measures were notably reduced in the MSC groups and their combinations. Significant increases in the IL-10 level of colon tissue and the proportion of Treg present in the spleen were observed in the groups receiving MSC and combination treatment. Furthermore, these groups showed a notable reduction in the percentage of spleen Th17 cells. However, IL17A decreased non-significantly in all groups.

CONCLUSION

The results showed that intraperitoneal injection of UC-MSCs and their combination with exosome and Mesalazine in a murine colitis model improved the disease's symptoms. Therefore, MSCs and their combination with exosomes can be a promising therapeutic approach along with other common drugs for IBD, but exosomes alone could not significantly reduce the symptoms of colitis.

Amniotic fluid-derived stem cells: potential factories of natural and mimetic strategies for congenital malformations

BACKGROUND

Mesenchymal stem cells (MSCs) derived from gestational tissues offer a promising avenue for prenatal intervention in congenital malformations although their application is hampered by concerns related to cellular plasticity and the need for invasive, high-risk surgical procedures. Here, we present naturally occurring exosomes (EXOs) isolated from amniotic fluid-derived MSCs (AF-MSCs) and their mimetic analogs (MIMs) as viable, reproducible, and stable alternatives. These nanovesicles present a minimally invasive therapeutic option, addressing the limitations of MSC-based treatments while retaining therapeutic efficacy.

METHODS

MIMs were generated from AF-MSCs by combining sequential filtration steps through filter membranes with different porosity and size exclusion chromatography columns. A physicochemical, structural, and molecular comparison was conducted with exosomes (EXOs) released from the same batch of cells. Additionally, their distribution patterns in female mice were evaluated following in vivo administration, along with an assessment of their safety profile throughout gestation in a mouse strain predisposed to neural tube defects (NTDs). The possibility to exploit both formulations as mRNA-therapeutics was explored by evaluating cell uptake in two different cell types(fibroblasts, and macrophages) and mRNA functionality overtime in an in vitro experimental setting as well as in an ex vivo, whole embryo culture using pregnant C57BL6 dams.

RESULTS

Molecular and physiochemical characterization showed no differences between EXOs and MIMs, with MIMs determining a threefold greater yield. Biodistribution patterns following intraperitoneal administration were comparable between the two particle types, with the uterus being among targeted organs. No toxic effects were observed in the dams during gestation, nor were there any malformations or significant differences in the number of viable versus dead fetuses detected. MIMs delivered a more intense and prolonged expression of mRNA encoding for green fluorescent protein in macrophages and fibroblasts. An ex-vivo whole embryo culture demonstrated that MIMs mainly accumulate at the level of the yolk sac, while EXOs reach the embryo.

CONCLUSIONS

The present data confirms the potential application of EXOs and MIMs as suitable tools for prevention and treatment of NTDs and proposes MIMs as prospective vehicles to prevent congenital malformations caused by in utero exposure to drugs.

Impact of Tissue Factor Gene Knockout on Coagulation Properties of Umbilical Cord-Derived Multipotent Mesenchymal Stromal/Stem Cells

Multipotent mesenchymal stromal/stem cells (MSCs) refer to a population of stem cells that exhibit distinct progenitor cell characteristics including the potential for differentiation into a wide range of cell types. MSCs have become a promising candidate for cell therapy and tissue regeneration due to their unique properties, such as their ability to differentiate into multiple cell types, their capacity for expansion, self-renewal, and immune-regulatory effects. However, reports have brought attention to thrombosis-related complications associated with MSCs therapy in the last decade. As tissue factor (TF) is a powerful coagulation activator expressed by MSCs that stimulates the extrinsic coagulation pathway, we investigated the thrombotic properties of human umbilical cord MSCs (HUCMSCs) after knocking out the TF gene. MSCs populations that obtained from umbilical cord were cultured and expanded in the appropriate medium cell culture. The identity of the MSCs was verified through flow cytometry, and their ability to differentiate into osteogenic and adipogenic lineages. Two gRNAs for Exons 1 and 2 of the TF gene have been designed and cloned into px458 vector's backbone (pSpCas9 (BB)-2A-GFP). Following transfecting of gRNAs into HUCMSCs and successfully knocking out the TF gene using GAP-PCR, the impact of normal and knockout HUCMSCs on coagulation was assessed through prothrombin time (PT), D-dimer level, clotting time (CT), and turbidity assay. Furthermore, the impact of TF knockout (TFKO) on MMP19 expression was assessed. Our results revealed that the PT was prolonged and D-dimer level was decreased in TFKO group compared to normal HUCMSCs. These findings suggest that TF gene plays a crucial role in regulating coagulation in HUCMSCs. Also, a significant reduction in MMP19 expression was observed within the TFKO group.

Exploring the multiple therapeutic mechanisms and challenges of mesenchymal stem cell-derived exosomes in Alzheimer's disease

Alzheimer's disease (AD) is a severe neurodegenerative disorder, and the current treatment options are limited. Mesenchymal stem cell-derived exosomes (MSC-Exos) have garnered significant attention due to their unique biological properties, showcasing tremendous potential as an acellular alternative therapy for AD. MSC-Exos exhibit excellent biocompatibility and low immunogenicity, enabling them to effectively cross the blood-brain barrier (BBB) and deliver therapeutic molecules directly to target cells. They are highly efficacious in delivering nucleic acid-based drugs. Moreover, the production process of MSC-Exos benefits from a high proliferation capacity and multilineage differentiation potential, allowing for production while maintaining a stable composition. Despite the significant theoretical advantages of MSC-Exos, their clinical use still faces multiple challenges, including cross-contamination during isolation and purification processes, the complexity of their components, and the presence of potential adverse paracrine factors. Future research needs to focus on optimizing separation and purification techniques, enhancing delivery methods to improve therapeutic efficacy, and performing detailed analyses of the components of MSC-Exos. In summary, MSC-Exos hold promise as an effective option for the treatment of AD and other neurodegenerative diseases, driving their clinical research and use in related fields.

Mesenchymal stem cell application in pulmonary disease treatment with emphasis on their interaction with lung-resident immune cells

Due to the vital importance of the lungs, lung-related diseases and their control are very important. Severe inflammatory responses mediated by immune cells were among the leading causes of lung tissue pathology and damage during the COVID-19 pandemic. In addition, uncontrolled immune cell responses can lead to lung tissue damage in other infectious and non-infectious diseases. It is essential to control immune responses in a way that leads to homeostasis. Immunosuppressive drugs only suppress inflammatory responses and do not affect the homeostasis of reactions. The therapeutic application of mesenchymal stem cells (MSCs), in addition to restoring immune homeostasis, can promote the regeneration of lung tissue through the production of growth factors and differentiation into lung-related cells. However, the communication between MSCs and immune cells after treatment of pulmonary diseases is essential, and investigating this can help develop a clinical perspective. Different studies in the clinical phase showed that MSCs can reverse fibrosis, increase regeneration, promote airway remodeling, and reduce damage to lung tissue. The proliferation and differentiation potential of MSCs is one of the mechanisms of their therapeutic effects. Furthermore, they can secrete exosomes that affect the function of lung cells and immune cells and change their function. Another important mechanism is that MSCs reduce harmful inflammatory responses through communication with innate and adaptive immune cells, which leads to a shift of the immune system toward regulatory and hemostatic responses.

The Therapeutic Potential of Exosomes vs. Matrix-Bound Nanovesicles from Human Umbilical Cord Mesenchymal Stromal Cells in Osteoarthritis Treatment

Osteoarthritis (OA) is a degenerative joint disease with limited therapeutic options, where inflammation plays a critical role in disease progression. Extracellular vesicles (EV) derived from mesenchymal stromal cells (MSC) have shown potential as a therapeutic approach for OA by modulating inflammation and alleviating degenerative processes in the joint. This study evaluated the therapeutic effects for the treatment of OA of two types of EV-exosomes and matrix-bound nanovesicles (MBV)-both derived from the human umbilical cord MSC (UC-MSC) via differential ultracentrifugation. Different phenotypes of human monocyte-derived macrophages (MDM) were used to study the anti-inflammatory properties of EV in vitro, and the medial meniscectomy-induced rat model of knee osteoarthritis (MMx) was used in vivo. The study found that both EV reduced pro-inflammatory cytokines IL-6 and TNF-α in MDM. However, exosomes showed superior results, preserving the extracellular matrix (ECM) of hyaline cartilage, and reducing synovitis more effectively than MBVs. Additionally, exosomes downregulated inflammatory markers (TNF-α, iNOS) and increased Arg-1 expression in macrophages and synovial fibroblasts, indicating a stronger anti-inflammatory effect. These results suggest UC-MSC exosomes as a promising therapeutic option for OA, with the potential for modulating inflammation and promoting joint tissue regeneration.

Exosomes in nanomedicine: a promising cell-free therapeutic intervention in burn wounds

Burn injuries are serious injuries that have a big impact on a person's health and can even cause death. Incurring severe burns can incite an immune response and inflammation within the body, alongside metabolic changes. It is of utmost importance to grasp the fact that the effects of the burn injury extend beyond the body, affecting the mind and overall well-being. Burn injuries cause long-lasting changes that need to be taken care of in order to improve their quality of life. The intricate process of skin regeneration at the site of a burn wound involves a complex and dynamic interplay among diverse cells, growth factors, nerves, and blood vessels. Exciting opportunities have arisen in the field of stem cells and regenerative medicine, allowing us to explore the development of cell-free-based alternatives that can aid in the treatment of burn injuries. These cell-free-based therapies have emerged as a promising facet within regenerative medicine. Exosomes, also referred to as naturally occurring nanoparticles, are small endosome-derived vesicles that facilitate the delivery of molecular cargo between the cells, thus allowing intercellular communication. The knowledge gained in this field has continued to support their therapeutic potential, particularly in the domains of wound healing and tissue regeneration. Notably, exosomes derived from mesenchymal stem cells (MSCs) can be safely administered in the system, which is then adeptly uptaken and internalized by fibroblasts/epithelial cells, subsequently accelerating essential processes such as migration, proliferation, and collagen synthesis. Furthermore, exosomes released by immune cells, specifically macrophages, possess the capability to modulate inflammation and effectively diminish it in adjacent cells. Exosomes also act as carriers when integrated with a scaffold, leading to scarless healing of cutaneous wounds. This comprehensive review examines the role of exosomes in burn wound healing and their potential utility in regeneration and repair.

Mechanism of mesenchymal stem cells in liver regeneration: Insights and future directions

Mesenchymal stem cells (MSCs) are a prevalent source for stem cell therapy and play a crucial role in modulating both innate and adaptive immune responses. Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of triglycerides in liver cells and involves immune system activation, leading to histological changes, tissue damage, and clinical symptoms. A recent publication by Jiang et al, highlighted the potential of MSCs to mitigate in NAFLD progression by targeting various molecular pathways, including glycolipid metabolism, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. In this editorial, we comment on their research and discuss the efficacy of MSC therapy in treating NAFLD.

Exogenous MSC based tissue regeneration: a review of immuno-protection strategies from biomaterial scaffolds

Mesenchymal stem cell (MSC)-based tissue engineering holds great potential for regenerative medicine as a means of replacing damaged or lost tissues to restore their structure and function. However, the efficacy of MSC-based regeneration is frequently limited by the low survival rate and limited survival time of transplanted MSCs. Despite the inherent immune privileges of MSCs, such as low expression of major histocompatibility complex antigens, tolerogenic properties, local immunosuppressive microenvironment creation, and induction of immune tolerance, immune rejection remains a major obstacle to their survival and regenerative potential. Evidence suggests that immune protection strategies can enhance MSC therapeutic efficacy by prolonging their survival and maintaining their biological functions. Among various immune protection strategies, biomaterial-based scaffolds or cell encapsulation systems that mediate the interaction between transplanted MSCs and the host immune system or spatially isolate MSCs from the immune system for a specific time period have shown great promise. In this review, we provide a comprehensive overview of these biomaterial-based immune protection strategies employed for exogenous MSCs, highlighting the crucial role of modulating the immune microenvironment. Each strategy is critically examined, discussing its strengths, limitations, and potential applications in MSC-based tissue engineering. By elucidating the mechanisms behind immune rejection and exploring immune protection strategies, we aim to address the challenges faced by MSC-based tissue engineering and pave the way for enhancing the therapeutic outcomes of MSC therapies. The insights gained from this review will contribute to the development of more effective strategies to protect transplanted MSCs from immune rejection and enable their successful application in regenerative medicine.

Analyzing small RNA sequences from canine stem cell-derived extracellular vesicles primed with TNF-α and IFN-γ and exploring their potential in lung repair

Acute lung injury is an acute inflammation disorder that disrupts the lung endothelial and epithelial barriers. In this study, we investigated the extracellular vesicles (EVs) obtained via priming inflammatory cytokines such as tumor necrosis factor (TNF)-α and interferon (IFN)-γ on canine adipose mesenchymal stem cells in improving their anti-inflammatory and/or immunosuppressive potential, and/or their ability to alleviate lipopolysaccharide-induced lung injury in vitro. We also explored the correlation between epithelial-to-mesenchymal transition and the inflammatory repressive effect of primed EVs. Using small RNA-Seq, we confirmed that miR-16 and miR-502 significantly increased in EVs from TNF-α and IFN-γ-primed canine adipose mesenchymal stem cells. The pro and anti-inflammatory cytokines were analyzed in a lipopolysaccharide-induced lung injury model and we found that the EV anti-inflammatory effect improved on priming with inflammatory cytokines. EVs obtained from primed stem cells effectively suppress endothelial-to-mesenchymal transition in a lung injury model. Our results suggest a potential therapeutic approach utilizing EVs obtained from adipose mesenchymal stem cells primed with TNF-α and IFN-γ against lung inflammation and endothelial to mesenchymal transition.

Effect of Priming With Toll-Like Receptor 3 Agonist on Expression of Long Noncoding RNAs in Human Wharton Jelly Mesenchymal Stem Cells

OBJECTIVES

Mesenchymal stem cells are gaining attention in medicine because of their anti-inflammatory and immunosuppressive properties. Inflammatory conditions can modulate immune responses in mesenchymal stem cells.We investigated the expression of long noncoding RNAs (RMRP, MALT1, NKILA,THRIL, and Linc-MAF-4) in humanWharton jelly mesenchymal stem cells primed with polyinosinicpolycytidylic acid.

MATERIALS AND METHODS

Mesenchymal stem cells were isolated from human Wharton jelly by the explant method. To determine the stem nature of the cells, we performed a differentiation test on bone and fat cells. We used flow cytometry analysis to determine surface markers. Umbilical cord mesenchymal stem cells (1 × 105) were cultured in T75 culture flasks in Dulbecco's modified Eagle medium containing 10% fetal bovine serum. After cells reached approximately 80% confluency, cells were exposed to 50 µg/mL of polyinosinic-polycytidylic acid, a Toll-like receptor 3 ligand, for 24, 48, and 72 hours. The control group were cells not exposed to polyinosinic-polycytidylic acid. Real-time polymerase chain reaction evaluated RMRP, MALAT1, NKILA, THRIL, and Linc-MAF-4 long noncoding RNAs.

RESULTS

We observed significantly increased expression of NKILA inWharton jelly mesenchymal stem cells stimulated with polyinosinic-polycytidylic acid at 72 hours compared with expression level in the control group (P < .001).

CONCLUSIONS

Results indicated that a potential mechanism by which the Toll-like receptor 3 ligand improves immunosuppression of mesenchymal stem cells can be attributed to the regulatory role of long noncoding RNAs, possibly through increased expression of anti-inflammatory long noncoding RNAs such as NKILA.

Amniotic fluid-derived stem cells: potential factories of natural and mimetic strategies for congenital malformations

Background

Mesenchymal stem cells (MSCs) from gestational tissues represent promising strategies for in utero treatment of congenital malformations, but plasticity and required high-risk surgical procedures limit their use. Here we propose natural exosomes (EXOs) isolated from amniotic fluid-MSCs (AF-MSCs), and their mimetic counterparts (MIMs), as valid, stable, and minimally invasive therapeutic alternatives.

Methods

MIMs were generated from AF-MSCs by combining sequential filtration steps through filter membranes with different porosity and size exclusion chromatography columns. Physiochemical and molecular characterization was performed to compare them to EXOs released from the same number of cells. The possibility to exploit both formulations as mRNA-therapeutics was explored by evaluating cell uptake (using two different cell types, fibroblasts, and macrophages) and mRNA functionality overtime in an in vitro experimental setting as well as in an ex vivo, whole embryo culture using pregnant C57BL6 dams.

Results

Molecular and physiochemical characterization showed no differences between EXOs and MIMs, with MIMs determining a 3-fold greater yield. MIMs delivered a more intense and prolonged expression of mRNA encoding for green fluorescent protein (GFP) in macrophages and fibroblasts. An ex-vivo whole embryo culture demonstrated that MIMs mainly accumulate at the level of the yolk sac, while EXOs reach the embryo.

Conclusions

The present data confirms the potential application of EXOs for the prenatal repair of neural tube defects and proposes MIMs as prospective vehicles to prevent congenital malformations caused by in utero exposure to drugs.

Mesenchymal Stromal Cells: New Generation Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, which has a high recurrence rate and is incurable due to a lack of effective treatment. Mesenchymal stromal cells (MSCs) are a class of pluripotent stem cells that have recently received a lot of attention due to their strong self-renewal ability and immunomodulatory effects, and a large number of experimental and clinical models have confirmed the positive therapeutic effect of MSCs on IBD. In preclinical studies, MSC treatment for IBD relies on MSCs paracrine effects, cell-to-cell contact, and its mediated mitochondrial transfer for immune regulation. It also plays a therapeutic role in restoring the intestinal mucosal barrier through the homing effect, regulation of the intestinal microbiome, and repair of intestinal epithelial cells. In the latest clinical trials, the safety and efficacy of MSCs in the treatment of IBD have been confirmed by transfusion of autologous or allogeneic bone marrow, umbilical cord, and adipose MSCs, as well as their derived extracellular vesicles. However, regarding the stable and effective clinical use of MSCs, several concerns emerge, including the cell sources, clinical management (dose, route and frequency of administration, and pretreatment of MSCs) and adverse reactions. This article comprehensively summarizes the effects and mechanisms of MSCs in the treatment of IBD and its advantages over conventional drugs, as well as the latest clinical trial progress of MSCs in the treatment of IBD. The current challenges and future directions are also discussed. This review would add knowledge into the understanding of IBD treatment by applying MSCs.

Exosomes encapsulated in hydrogels for effective central nervous system drug delivery

The targeted delivery of pharmacologically active molecules, metabolites, and growth factors to the brain parenchyma has become one of the major challenges following the onset of neurodegeneration and pathological conditions. The therapeutic effect of active biomolecules is significantly impaired after systemic administration in the central nervous system (CNS) because of the blood-brain barrier (BBB). Therefore, the development of novel therapeutic approaches capable of overcoming these limitations is under discussion. Exosomes (Exo) are nano-sized vesicles of endosomal origin that have a high distribution rate in biofluids. Recent advances have introduced Exo as naturally suitable bio-shuttles for the delivery of neurotrophic factors to the brain parenchyma. In recent years, many researchers have attempted to regulate the delivery of Exo to target sites while reducing their removal from circulation. The encapsulation of Exo in natural and synthetic hydrogels offers a valuable strategy to address the limitations of Exo, maintaining their integrity and controlling their release at a desired site. Herein, we highlight the current and novel approaches related to the application of hydrogels for the encapsulation of Exo in the field of CNS tissue engineering.

Smoking and osteoimmunology: Understanding the interplay between bone metabolism and immune homeostasis

Smoking continues to pose a global threat to morbidity and mortality in populations. The detrimental impact of smoking on health and disease includes bone destruction and immune disruption in various diseases. Osteoimmunology, which explores the communication between bone metabolism and immune homeostasis, aims to reveal the interaction between the osteoimmune systems in disease development. Smoking impairs the differentiation of mesenchymal stem cells and osteoblasts in bone formation while promoting osteoclast differentiation in bone resorption. Furthermore, smoking stimulates the Th17 response to increase inflammatory and osteoclastogenic cytokines that promote the receptor activator of NF-κB ligand (RANKL) signaling in osteoclasts, thus exacerbating bone destruction in periodontitis and rheumatoid arthritis. The pro-inflammatory role of smoking is also evident in delayed bone fracture healing and osteoarthritis development. The osteoimmunological therapies are promising in treating periodontitis and rheumatoid arthritis, but further research is still required to block the smoking-induced aggravation in these diseases.

Translational potential

This review summarizes the adverse effect of smoking on mesenchymal stem cells, osteoblasts, and osteoclasts and elucidates the smoking-induced exacerbation of periodontitis, rheumatoid arthritis, bone fracture healing, and osteoarthritis from an osteoimmune perspective. We also propose the therapeutic potential of osteoimmunological therapies for bone destruction aggravated by smoking.

Bone marrow mesenchymal stem cells suppress activated CD4+ T cells proliferation through TGF-beta and IL10 dependent of autophagy in pathological hypoxic microenvironment

BACKGROUND

Bone marrow mesenchymal stem cells (BMSCs) mediated immunomodulation by secreting certain bioactive cytokines has been recognized as a promising approach for disease treatment. However, microenvironmental oxygen tension affect immunomodulatory functions and activate autophagy in BMSCs. The mechanism governing BMSCs immunomodulation in hypoxia hasn't been expounded clearly. The aim of this study is to investigate the function of pathological hypoxia on immunomodulatory properties of bone marrow mesenchymal stem cells and its possible mechanism.

METHODS

BMSCs were cultured in either normoxia (21 % oxygen) or hypoxia (0.1 % oxygen) for 24 h, then electron microscopy (EM) and immunofluorescence staining were used to detect the activation of autophagy. Besides autophagy-related markers were monitored by Western blotting. Atg5 siRNA induced autophagic inhibition. Additional, gene expression levels of Real-time fluorescence quantitative PCR and Western blot were used to detect BMSCs related cytokines. Both the proliferation and apoptosis of CD4+ T cell in co-culture were detected by flow cytometry. Exogenous anti-IL-10 antibody and anti-TGF-β1 antibody were used in co-cultured BMSCs-CM and CD4+ T cells, which enabled us to assess how autophagy affected BMSCs-mediated CD4+ T cell proliferation in low oxygen tension.

RESULT

Compared with normal BMSCs, Hypo-BMSCs enhanced the immunosuppressive effect of BMSCs on CD4+ T cell proliferation, while si-atg5 weakened the inhibition of Hypo-BMSCs. Furthermore, exogenous anti-TGF-β1 antibody and the addition of anti-TGF-β1 antibody reversed the immunosuppressive ability of Hypo-BMSCs.

CONCLUSIONS

Our findings reveal that BMSCs possess significant immunosuppression on CD4+T cell through IL-10 and TGF-β1 dependent of autophagy in hypoxic microenvironment.

Stem Cell-Based Strategies: The Future Direction of Bioartificial Liver Development

Acute liver failure (ALF) results from severe liver damage or end-stage liver disease. It is extremely fatal and causes serious health and economic burdens worldwide. Once ALF occurs, liver transplantation (LT) is the only definitive and recommended treatment; however, LT is limited by the scarcity of liver grafts. Consequently, the clinical use of bioartificial liver (BAL) has been proposed as a treatment strategy for ALF. Human primary hepatocytes are an ideal cell source for these methods. However, their high demand and superior viability prevent their widespread use. Hence, finding alternatives that meet the seed cell quality and quantity requirements is imperative. Stem cells with self-renewing, immunogenic, and differentiative capacities are potential cell sources. MSCs and its secretomes encompass a spectrum of beneficial properties, such as anti-inflammatory, immunomodulatory, anti-ROS (reactive oxygen species), anti-apoptotic, pro-metabolomic, anti-fibrogenesis, and pro-regenerative attributes. This review focused on the recent status and future directions of stem cell-based strategies in BAL for ALF. Additionally, we discussed the opportunities and challenges associated with promoting such strategies for clinical applications.

Comparison between the Regenerative and Therapeutic Impacts of Bone Marrow Mesenchymal Stem Cells and Adipose Mesenchymal Stem Cells Pre-Treated with Melatonin on Liver Fibrosis

BACKGROUND

The distinctive feature of liver fibrosis is the progressive replacement of healthy hepatic cells by the extracellular matrix protein, which is abundant in collagen I and III, with impaired matrix remodeling. The activation of myofibroblastic cells enhances the fibrogenic response of complex interactions of hepatic stellate cells, fibroblasts, and inflammatory cells to produce the excessive deposition of the extracellular protein matrix. This process is activated by multiple fibrogenic mediators and cytokines, such as TNF-α and IL-1β, accompanied with a decrease in the anti-fibrogenic factor NF-κβ. Mesenchymal stem cells (MSCs) represent a promising therapy for liver fibrosis, allowing for a more advanced regenerative influence when cultured with extrinsic or intrinsic proliferative factors, cytokines, antioxidants, growth factors, and hormones such as melatonin (MT). However, previous studies showed conflicting findings concerning the therapeutic effects of adipose (AD) and bone marrow (BM) MSCs; therefore, the present work aimed to conduct a comparative and comprehensive study investigating the impact of MT pre-treatment on the immunomodulatory, anti-inflammatory, and anti-apoptotic effects of AD- and BM-MSCs and to critically analyze whether MT-pre-treated AD-MSCs and BM-MSCs reveal equal or different therapeutic and regenerative potentials in a CCl4-injured liver experimental rat model.

MATERIALS AND METHODS

Six groups of experimental rats were used, with ten rats in each group: group I (control group), group II (CCl4-treated group), group III (CCl4- and BM-MSC-treated group), group IV (CCl4 and MT-pre-treated BM-MSC group), group V (CCl4- and AD-MSC-treated group), and group VI (CCl4 and MT-pre-treated AD-MSC group). Liver function tests and the gene expression of inflammatory, fibrogenic, apoptotic, and proliferative factors were analyzed. Histological and immunohistochemical changes were assessed.

RESULTS

The present study compared the ability of AD- and BM-MSCs, with and without MT pre-treatment, to reduce hepatic fibrosis. Both types of MSCs improved hepatocyte function by reducing the serum levels of ALT, aspartate aminotransferase (AST), alkaline phosphatase (AKP), and total bilirubin (TBIL). In addition, the changes in the hepatocellular architecture, including the hepatocytes, liver sinusoids, central veins, portal veins, biliary ducts, and hepatic arteries, showed a decrease in hepatocyte injury and cholestasis with a reduction in inflammation, apoptosis, and necrosis of the hepatic cells, together with an inhibition of liver tissue fibrosis. These results were augmented by an analysis of the expression of the pro-inflammatory cytokines TNFα and IL-1β, the anti-fibrogenic factor NF-κβ, the apoptotic factor caspase-3, and the proliferative indicators antigen Ki-67 and proliferating cell nuclear antigen (PCNA). These findings were found to be statistically significant, with the restoration of normal parameters in the rats that received AD-MSCs pre-treated with MT, denoting optimal regenerative and therapeutic effects.

CONCLUSIONS

AD-MSCs pre-treated with MT are the preferred choice in improving hepatic fibrosis and promoting the therapeutic and regenerative ability of liver tissue. They represent a very significant tool for future stem cell use in the tissue regeneration strategy for the treatment of liver diseases.

Therapeutic potential of mesenchymal stem cells for cerebral small vessel disease

Cerebral small vessel disease (CSVD), as the most common, chronic and progressive vascular disease on the brain, is a serious neurological disease, whose pathogenesis remains unclear. The disease is a leading cause of stroke and vascular cognitive impairment and dementia, and contributes to about 20% of strokes, including 25% of ischemic strokes and 45% of dementias. Undoubtedly, the high incidence and poor prognosis of CSVD have brought a heavy economic and medical burden to society. The present treatment of CSVD focuses on the management of vascular risk factors. Although vascular risk factors may be important causes or accelerators of CSVD and should always be treated in accordance with best clinical practice, controlling risk factors alone could not curb the progression of CSVD brain injury. Therefore, developing safer and more effective treatment strategies for CSVD is urgently needed. Recently, mesenchymal stem cells (MSCs) therapy has become an emerging therapeutic modality for the treatment of central nervous system disease, given their paracrine properties and immunoregulatory. Herein, we discussed the therapeutic potential of MSCs for CSVD, aiming to enable clinicians and researchers to understand of recent progress and future directions in the field.

The Role of MicroRNAs in Mesenchymal Stem Cell-Based Modulation of Pulmonary Fibrosis

Pulmonary fibrosis is a complex and multifactorial condition that involves a cascade of events, including lung injury, damage of alveolar epithelial cells (AECs), generation of immune cell-driven inflammation, and activation of fibroblasts and their differentiation into myofibroblasts, resulting in the excessive production and deposition of collagen and progressive scarring and fibrosis of the lung tissue. As lung fibrosis advances, the scarring and stiffening of lung tissue can significantly hinder the exchange of oxygen and carbon dioxide, potentially leading to respiratory failure that can be life-threatening. Anti-inflammatory and immunosuppressive drugs are used to slow down the progression of the disease, manage symptoms, and enhance the patient's quality of life. However, prolonged immunosuppression could increase the susceptibility to severe bacterial, viral, or fungal pneumonia in lung-transplant recipients. Therefore, there is an urgent need for new therapeutic agents that can effectively reduce lung inflammation and fibrosis without compromising the protective immune response in patients with severe lung fibrosis. Results obtained in recently published studies demonstrated that mesenchymal stem/stromal cell-derived microRNAs (MSC-miRNAs) could attenuate detrimental immune response in injured lungs and prevent progression of lung fibrosis. Through the post-transcriptional regulation of target mRNA, MSC-miRNAs modulate protein synthesis and affect viability, proliferation, and cytokine production in AECs, fibroblasts, and lung-infiltrated immune cells. In order to delineate molecular mechanisms responsible for beneficial effects of MSC-miRNAs in the treatment of lung fibrosis, in this review article, we summarized current knowledge related to anti-fibrotic and anti-inflammatory pathways elicited in immune cells, AECs, and myofibroblasts by MSC-miRNAs.

Alkali-treated titanium dioxide promotes formation of proteoglycan layer and altered calcification and immunotolerance capacity in bone marrow stem cell

Introduction

In this study, we report that a proteoglycans (PGs)-layer between the bone and titanium dioxide (TiO2) surface after osseointegration improved the calcification capacity and immunotolerance of human bone marrow mesenchymal stem cells (hBMSCs) on TiO2. Alkaline treatment of TiO2 is a method for promoting osteogenesis in hBMSCs. We hypothesized that promotion of osteogenesis due to alkaline treatment was caused by changing PGs-layer on TiO2.

Objective

This study aimed to analyze whether alkaline treatment of TiO2 affects PGs-layer formation and immunotolerance in hBMSCs.

Methods

The topology and wettability of the alkaline-treated titanium (Ti-Al) and unprocessed titanium (Ti-MS) surfaces were characterized. Initial cell attachment, cell proliferation, calcification capacity, alkaline phosphatase activity, PGs-layer formation, PGs function, and the expression of osteogenic and immunotolerance-related genes were analyzed. The conditioned medium (CM) from hBMSCs grown on Ti-Al and Ti-MS was added to macrophages (hMps) and Jurkat cells, and immunotolerance gene expression in these cells was analyzed.

Results

hBMSCs cultured on Ti-Al showed increased initial cell attachment, cell proliferation, PG-layer formation, and osteogenic capacity compared with hBMSCs on Ti-MS. Gene expression of indoleamine 2,3-dioxygenase (IDO) in the hBMSCs cultured on Ti-Al was higher than that in the hBMSCs on Ti-MS. CM from hBMSCs did not affect markers of M1 and M2 macrophages in hMps. CM from hBMSCs cultured on Ti-Al altered the gene expression of Foxp3 in Jurkat cells compared to that of CM from hBMSCs on Ti-MS.

Significance

These results suggest that alkaline treatment of TiO2 altered PGs-layer formation, and changed the osteogenesis and immunotolerance of hBMSCs.

Anti-inflammatory effect of dental pulp stem cells

Dental pulp stem cells (DPSCs) have received a lot of attention as a regenerative medicine tool with strong immunomodulatory capabilities. The excessive inflammatory response involves a variety of immune cells, cytokines, and has a considerable impact on tissue regeneration. The use of DPSCs for controlling inflammation for the purpose of treating inflammation-related diseases and autoimmune disorders such as supraspinal nerve inflammation, inflammation of the pulmonary airways, systemic lupus erythematosus, and diabetes mellitus is likely to be safer and more regenerative than traditional medicines. The mechanism of the anti-inflammatory and immunomodulatory effects of DPSCs is relatively complex, and it may be that they themselves or some of the substances they secrete regulate a variety of immune cells through inflammatory immune-related signaling pathways. Most of the current studies are still at the laboratory cellular level and animal model level, and it is believed that through the efforts of more researchers, DPSCs/SHED are expected to be transformed into excellent drugs for the clinical treatment of related diseases.

Pretreatment of UC-MSCs with IFN-α2 improves treatment of liver fibrosis by recruiting neutrophils

BACKGROUND

The use of umbilical cord mesenchymal stem cells (UC-MSCs) is a burgeoning method for the treatment of liver cirrhosis. However, the secretory phenotype and regulatory ability of UC-MSCs are easily affected by their microenvironment. Ensuring a specific microenvironment to enhance the UC-MSCs phenotype is a potential strategy for improving their therapeutic efficacy. The aim of this study was to explore therapeutic UC-MSCs phenotypes for improving liver fibrosis.

METHODS

RNA-sequencing was used to analyze the response pattern of UC-MSCs after exposure to the serum of cirrhotic patients with HBV. Using immunohistochemistry, quantitative polymerase chain reaction, and immunofluorescence techniques, we evaluated the therapeutic effect of UC-MSCs pretreated with interferon alpha 2 (IFN-α2) (pre-MSCs) in an animal model of cirrhosis. Immunoblotting, ELISA, and other techniques were used to analyze the signaling pathways underlying the IFN-induced changes in UC-MSCs.

RESULTS

UC-MSCs exposed to the serum of patients with hepatitis B-induced cirrhosis showed an enhanced response to type I IFN. The activated type I IFN signal induced the highest secretion of colony-stimulating factor 3 (CSF-3), interleukin (IL)-8, and chemokine (C-C motif) ligand 20 (CCL20) by the UC-MSCs. Pre-MSCs showed a higher therapeutic efficacy than untreated UC-MSCs in an animal model of liver fibrosis. Immunohistochemical analysis revealed that pre-MSCs could recruit neutrophils resulting in an increase in the secretion of matrix metalloprotease 8 that alleviated fibrosis. When neutrophils in animals were depleted, the therapeutic effect of pre-MSCs on fibrosis was inhibited. IFN-α2 altered the secretory phenotype of UC-MSCs by activating phosphorylated signal transducer and activator of transcription 1 and 2 (p-STAT1 and p-STAT2).

CONCLUSIONS

Pre-MSCs exhibited enhanced secretion of CSF-3, IL-8, and CCL20 and recruited neutrophils to alleviate fibrosis. This new strategy can improve cell therapy for liver cirrhosis.

Long-term hypoxic hUCMSCs-derived extracellular vesicles alleviates allergic rhinitis through triggering immunotolerance of their VEGF-mediated inhibition of dendritic cells maturation

BACKGROUND

Extensions of mesenchymal stem cells (MSCs) in vitro may lead to the loss of their biological functions. However, hypoxic culturation has been shown to enhance the proliferation, survival, and immunomodulatory capacity of MSCs.

OBJECTIVE

We aimed to investigate the effects of long-term hypoxic cultivation on the properties of human umbilical cord-derived MSCs (hUCMSCs) and the therapeutic effects of their extracellular vesicles (EVs) in allergic rhinitis (AR).

METHODS

Proliferation, senescence, telomerase activity and multipotent properties of hUCMSCs were analyzed under long-term culturation of hypoxia (1%) or normoxia (21%), and the therapeutic effects of their conditional medium (CM) and EVs were evaluated in OVA-induced AR mice. Effects of hypoxia-EVs (Hy-EVs) or normoxia-EVs (No-EVs) on human monocyte-derived dendritic cells (DCs) were investigated, and the possible mechanisms of Hy-EVs in induction of immunotolerance were further explored.

RESULTS

Long-term hypoxia significantly promoted the proliferation, inhibited cell senescence, maintained the multipotent status of hUCMSCs. Hy-CM and Hy-EVs showed better therapeutic effects in AR mice compared to No-EVs, seen as improvement of AR-related behaviors such as rubbing and sneezing, and attenuation of inflammation in nasal tissues. In addition, Hy-EVs significantly reduced the expressions of HLA-DR, CD80, CD40, and CD83 induced by OVA plus LPS in DCs, inhibiting the maturation of DCs. Furthermore, we observed that VEGF was remarkably enriched in Hy-EVs, but not in No-EVs, and the inhibition of DCs maturation was markedly neutralized by VEGF antibodies, suggesting that VEGF derived from Hy-EVs was responsible for the inhibition of DCs maturation.

CONCLUSION

Our results demonstrated that long-term hypoxia significantly promoted the proliferation, inhibited cell senescence, maintained the multipotent status of hUCMSCs, and hypoxia treated hUCMSCs-derived EVs enhanced their therapeutic effects in AR mice through VEGF-mediated inhibition of DCs maturation.

Augmenting mesenchymal stem cell therapy for osteoarthritis via inflammatory priming: a comparative study on mesenchymal stem cells derived from various perinatal tissue sources

Background: Osteoarthritis (OA), a degenerative disease prevalent among the elderly, poses significant challenges due to its high incidence and disability rates. Regrettably, there exists a lack of effective regenerative therapies for the irreversible degradation of cartilage in OA. Mesenchymal stem cells (MSCs), known for their robust differentiation and immune regulatory capabilities, have emerged as promising candidates for OA treatment. MSCs sourced from perinatal tissues offer the dual advantage of convenience in extraction and ethical non-controversy. However, the heterogeneous nature of MSCs derived from different perinatal tissue sources gives rise to varying therapeutic indications. Moreover, the immune response of MSCs may be modulated under the influence of inflammatory factors. Methods: In this study, we isolated mesenchymal stem cells from distinct parts of human perinatal tissue: umbilical cord-derived MSCs (UC-MSCs), fetal placenta-derived MSCs (FP-MSCs), and umbilical cord placental junction-derived MSCs (CPJ-MSCs). These cells were cultured in vitro and subjected to a 24-hour treatment with the inflammatory mediator Interleukin-1β (IL-1β). Subsequently, the MSCs were evaluated for changes in proliferation, migration, and regulatory capabilities. To assess the comparative anti-injury potential of MSCs from different sources, primary articular chondrocytes (ACs) were exposed to H2O2-induced injury and co-cultured with IL-1β-primed MSCs. Changes in the proliferation, migration, and regulatory abilities of ACs resembling those observed in OA were examined. Results: Following IL-1β treatment, all three types of MSCs displayed decreased rates of proliferation and migration. Notably, their chondrogenic differentiation capacities exhibited an enhancement. Additionally, diverse MSCs exhibited a degree of efficacy in restoring damaged ACs in vitro. Among these, CPJ-MSCs demonstrated superior potential in promoting cartilage cell proliferation, while FP-MSCs displayed notable anti-inflammatory effects. Conclusion: Our findings underscore the substantial capacity of primed FP-MSCs and CPJ-MSCs to alleviate the injury in OA-like ACs. Consequently, this study advocates for the prospective use of preconditioning strategies involving FP-MSCs and CPJ-MSCs in forthcoming OA therapies.

Cigarette smoke attenuates mesenchymal stem cell-based suppression of immune cell-driven acute liver failure

Detrimental effects of smoking on mesenchymal stem cell (MSC)-dependent immunosuppression and hepatoprotection are unknown. Herewith, by using α-galactosylceramide (α-GalCer)-induced liver injury, a well-established murine model of fulminant hepatitis, we examined molecular mechanisms which were responsible for negative effects of cigarette smoke on MSC-dependent immunomodulation. MSC which were grown in cigarette smoke-exposed medium (MSCWS-CM) obtained pro-inflammatory phenotype, were not able to optimally produce hepatoprotective and immunosuppressive cytokines (TGF-β, HGF, IL-10, NO, KYN), and secreted significantly higher amounts of inflammatory cytokines (IFN-γ, TNF-α, IL-17, IL-6) than MSC that were cultured in standard medium never exposed to cigarette smoke (MSCCM). In contrast to MSCCM, which efficiently attenuated α-GalCer-induced hepatitis, MSCWS-CM were not able to prevent hepatocyte injury and liver inflammation. MSCWS-CM had reduced capacity for the suppression of liver-infiltrated inflammatory macrophages, dendritic cells (DCs) and lymphocytes. Although significantly lower number of IL-12-producing macrophages and DCs, TNF-α, IFN-γ or IL-17-producing CD4 + and CD8 +T lymphocytes, NK and NKT cells were noticed in the livers of α-GalCer+MSCCM-treated mice compared to α-GalCer+saline-treated animals, this phenomenon was not observed in α-GalCer-injured mice that received MSCWS-CM. MSCWS-CM could not induce expansion of anti-inflammatory IL-10-producing FoxP3 +CD4 + and CD8 + T regulatory cells and were not able to create immunosuppressive microenvironment in the liver as MSCCM. Similarly as it was observed in mice, MSCWS-CM were not able to optimally inhibit production of inflammatory and hepatototoxic cytokines in activated human Th1/Th17 and NKT1/NKT17 cells, confirming the hypothesis that cigarette smoke significantly attenuates therapeutic potential of MSC in cell-based immunotherapy of inflammatory liver diseases.

Could extracellular vesicles derived from mesenchymal stem cells be a potential therapy for acute pancreatitis-induced cardiac injury?

Acute pancreatitis (AP) often leads to a high incidence of cardiac injury, posing significant challenges in the treatment of severe AP and contributing to increased mortality rates. Mesenchymal stem cells (MSCs) release bioactive molecules that participate in various inflammatory diseases. Similarly, extracellular vesicles (EVs) secreted by MSCs have garnered extensive attention due to their comparable anti-inflammatory effects to MSCs and their potential to avoid risks associated with cell transplantation. Recently, the therapeutic potential of MSCs-EVs in various inflammatory diseases, including sepsis and AP, has gained increasing recognition. Although preclinical research on the utilization of MSCs-EVs in AP-induced cardiac injury is limited, several studies have demonstrated the positive effects of MSCs-EVs in regulating inflammation and immunity in sepsis-induced cardiac injury and cardiovascular diseases. Furthermore, clinical studies have been conducted on the therapeutic application of MSCs-EVs for some other diseases, wherein the contents of these EVs could be deliberately modified through prior modulation of MSCs. Consequently, we hypothesize that MSCs-EVs hold promise as a potential therapy for AP-induced cardiac injury. This paper aims to discuss this topic. However, additional research is essential to comprehensively elucidate the underlying mechanisms of MSCs-EVs in treating AP-induced cardiac injury, as well as to ascertain their safety and efficacy.

Potential functions and therapeutic implications of glioma-resident mesenchymal stem cells

Mesenchymal stem cells (MSCs) are emerging crucial regulators in the tumor microenvironment (TME), which contributes to tumor progression and therapeutic resistance. MSCs are considered to be the stromal components of several tumors, their ultimate contribution to tumorigenesis and their potential to drive tumor stem cells, especially in the unique microenvironment of gliomas. Glioma-resident MSCs (GR-MSCs) are non-tumorigenic stromal cells. The phenotype of GR-MSCs is similar to that of prototype bone marrow-MSCs and GR-MSCs enhance the GSCs tumorigenicity via the IL-6/gp130/STAT3 pathway. The higher percentage of GR-MSCs in TME results in the poor prognosis of glioma patients and illuminate the tumor-promoting roles for GR-MSCs by secreting specific miRNA. Furthermore, the GR-MSC subpopulations associated with CD90 expression determine their different functions in glioma progression and CD90low MSCs generate therapeutic resistance by increasing IL-6-mediated FOXS1 expression. Therefore, it is urgent to develop novel therapeutic strategies targeting GR-MSCs for GBM patients. Despite that several functions of GR-MSCs have been confirmed, their immunologic landscapes and deeper mechanisms associated with the functions are not still expounded. In this review, we summarize the progress and potential function of GR-MSCs, as well as highlight their therapeutic implications based on GR-MSCs in GBM patients.

Mesenchymal stromal cell-derived secretome-based therapy for neurodegenerative diseases: overview of clinical trials

BACKGROUND

Over the past few years, mesenchymal stromal cells (MSCs) have attracted a great deal of scientific attention owing to their promising results in the treatment of incurable diseases. However, there are several concerns about their possible side effects after direct cell transplantation, including host immune response, time-consuming cell culture procedures, and the dependence of cell quality on the donor, which limit the application of MSCs in clinical trials. On the other hand, it is well accepted that the beneficial effects of MSCs are mediated by secretome rather than cell replacement. MSC secretome refers to a variety of bioactive molecules involved in different biological processes, specifically neuro-regeneration.

MAIN BODY

Due to the limited ability of the central nervous system to compensate for neuronal loss and relieve disease progress, mesenchymal stem cell products may be used as a potential cure for central nervous system disorders. In the present study, the therapeutic effects of MSC secretome were reviewed and discussed the possible mechanisms in the three most prevalent central nervous system disorders, namely Alzheimer's disease, multiple sclerosis, and Parkinson's disease. The current work aimed to help discover new medicine for the mentioned complications.

CONCLUSION

The use of MSC-derived secretomes in the treatment of the mentioned diseases has encouraging results, so it can be considered as a treatment option for which no treatment has been introduced so far.

Multipotent Mesenchymal Stem Cell-Based Therapies for Spinal Cord Injury: Current Progress and Future Prospects

Spinal cord injury (SCI) represents a significant medical challenge, often resulting in permanent disability and severely impacting the quality of life for affected individuals. Traditional treatment options remain limited, underscoring the need for novel therapeutic approaches. In recent years, multipotent mesenchymal stem cells (MSCs) have emerged as a promising candidate for SCI treatment due to their multifaceted regenerative capabilities. This comprehensive review synthesizes the current understanding of the molecular mechanisms underlying MSC-mediated tissue repair in SCI. Key mechanisms discussed include neuroprotection through the secretion of growth factors and cytokines, promotion of neuronal regeneration via MSC differentiation into neural cell types, angiogenesis through the release of pro-angiogenic factors, immunomodulation by modulating immune cell activity, axonal regeneration driven by neurotrophic factors, and glial scar reduction via modulation of extracellular matrix components. Additionally, the review examines the various clinical applications of MSCs in SCI treatment, such as direct cell transplantation into the injured spinal cord, tissue engineering using biomaterial scaffolds that support MSC survival and integration, and innovative cell-based therapies like MSC-derived exosomes, which possess regenerative and neuroprotective properties. As the field progresses, it is crucial to address the challenges associated with MSC-based therapies, including determining optimal sources, intervention timing, and delivery methods, as well as developing standardized protocols for MSC isolation, expansion, and characterization. Overcoming these challenges will facilitate the translation of preclinical findings into clinical practice, providing new hope and improved treatment options for individuals living with the devastating consequences of SCI.

Scaling up human mesenchymal stem cell manufacturing using bioreactors for clinical uses

Human mesenchymal stem cells (hMSCs) are multipotent cells and an attractive therapeutic agent in regenerative medicine and intensive clinical research. Despite the great potential, the limitation that needs to be overcome is the necessity of ex vivo expansion because of insufficient number of hMSCs presented within adult organs and the high doses required for a transplantation. As a result, numerous research studies aim to provide novel expansion methods in order to achieve appropriate numbers of cells with preserved therapeutic quality. Bioreactor-based cell expansion provide high-level production of hMSCs in accordance with good manufacturing practice (GMP) and quality standards. This review summarizes current knowledge about the hMSCs manufacturing platforms with a main focus to the application of bioreactors for large-scale production of GMP-grade hMSCs.

Superior protective effects of PGE2 priming mesenchymal stem cells against LPS-induced acute lung injury (ALI) through macrophage immunomodulation

BACKGROUND

Mesenchymal stem cells (MSCs) have demonstrated remarkable therapeutic promise for acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS). MSC secretomes contain various immunoregulatory mediators that modulate both innate and adaptive immune responses. Priming MSCs has been widely considered to boost their therapeutic efficacy for a variety of diseases. Prostaglandin E2 (PGE2) plays a vital role in physiological processes that mediate the regeneration of injured organs.

METHODS

This work utilized PGE2 to prime MSCs and investigated their therapeutic potential in ALI models. MSCs were obtained from human placental tissue. MSCs were transduced with firefly luciferase (Fluc)/eGFP fusion protein for real-time monitoring of MSC migration. Comprehensive genomic analyses explored the therapeutic effects and molecular mechanisms of PGE2-primed MSCs in LPS-induced ALI models.

RESULTS

Our results demonstrated that PGE2-MSCs effectively ameliorated lung injury and decreased total cell numbers, neutrophils, macrophages, and protein levels in bronchoalveolar lavage fluid (BALF). Meanwhile, treating ALI mice with PGE2-MSCs dramatically reduced histopathological changes and proinflammatory cytokines while increasing anti-inflammatory cytokines. Furthermore, our findings supported that PGE2 priming improved the therapeutic efficacy of MSCs through M2 macrophage polarization.

CONCLUSION

PGE2-MSC therapy significantly reduced the severity of LPS-induced ALI in mice by modulating macrophage polarization and cytokine production. This strategy boosts the therapeutic efficacy of MSCs in cell-based ALI therapy.

Empagliflozin-Pretreated Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Attenuated Heart Injury

Objective

Small extracellular vesicles derived from mesenchymal stem cells (MSCs) play important roles in cardiac protection. Studies have shown that the cardiovascular protection of sodium-glucose cotransporter 2 inhibitor (SGLT2i) is independent of its hypoglycemic effect. This study is aimed at investigating whether small extracellular vesicles derived from MSCs pretreated with empagliflozin (EMPA) has a stronger cardioprotective function after myocardial infarction (MI) and to explore the underlying mechanisms.

Methods and Results

We evaluated the effects of EMPA on MSCs and the effects of EMPA-pretreated MSCs-derived small extracellular vesicles (EMPA-sEV) on myocardial apoptosis, angiogenesis, and cardiac function after MI in vitro and in vivo. The small extracellular vesicles of control MSCs (MSC-sEV) and EMPA-pretreated MSCs were extracted, respectively. Small extracellular vesicles were cocultured with apoptotic H9c2 cells induced by H₂O₂ or injected into the infarcted area of the Sprague-Dawley (SD) rat myocardial infarction model. EMPA increased the cell viability, migration ability, and inhibited apoptosis and senescence of MSCs. In vitro, EMPA-sEV inhibited apoptosis of H9c2 cells compared with the control group (MSC-sEV). In the SD rat model of MI, EMPA-sEV inhibited myocardial apoptosis and promoted angiogenesis in the infarct marginal areas compared with the MSC-sEV. Meanwhile, EMPA-sEV reduced infarct size and improved cardiac function. Through small extracellular vesicles (miRNA) sequencing, we found several differentially expressed miRNAs, among which miR-214-3p was significantly elevated in EMPA-sEV. Coculture of miR-214-3p high expression MSC-derived small extracellular vesicles with H9c2 cells produced similar protective effects. In addition, miR-214-3p was found to promote AKT phosphorylation in H9c2 cells.

Conclusions

Our data suggest that EMPA-sEV significantly improve cardiac repair after MI by inhibiting myocardial apoptosis. miR-214-3p at least partially mediated the myocardial protection of EMPA-sEV through the AKT signaling pathway.

Advances in Understanding the Roles of Mesenchymal Stem Cells in Lung Cancer

Lung cancer is the most common and deadliest type of cancer worldwide. Research concerning lung cancer has made considerable progress in recent decades, but lung cancer remains the leading cause of malignancy-related mortality rate. Mesenchymal stem cells (MSCs) mainly exist in fat, umbilical cord blood, bone marrow, bone, and muscle. MSCs are a primary component of the tumor microenvironment (TME). Recent studies have shown that MSCs have roles in lung cancer-related proliferation, invasion, migration, and angiogenesis, but the underlying mechanisms are poorly understood. Because MSCs can migrate to the TME, there is increasing attention toward the use of MSCs in drugs or gene vectors for cancer treatment. This review summarizes the roles and effects of MSCs in lung cancer, while addressing clinical applications of MSCs in lung cancer treatment.

Protective effects of conditioned media of immortalized stem cells from human exfoliated deciduous teeth on pressure ulcer formation

Pressure ulcers (PUs) are increasing with aging worldwide, but there is no effective causal therapy. Although mesenchymal stem cells (MSCs) promote cutaneous wound healing, the effects of the conditioned medium (CM) of MSCs on cutaneous PU formation induced by ischemia-reperfusion injury have been poorly investigated. To address this issue, herein, we first established an immortalized stem cell line from human exfoliated deciduous teeth (SHED). This cell line was revealed to have superior characteristics in that it grows infinitely and vigorously, and stably and consistently secretes a variety of cytokines. Using the CM obtained from the immortalized SHED cell line, we investigated the therapeutic potential on a cutaneous ischemia-reperfusion mouse model for PU formation using two magnetic plates. This is the first study to show that CM from immortalized SHEDs exerts therapeutic effects on PU formation by promoting angiogenesis and oxidative stress resistance through vascular endothelial growth factor and hepatocyte growth factor. Thus, the CM of MSCs has potent therapeutic effects, whereas these therapies have not been implemented in human medicine. To try to meet the regulatory requirements for manufacturing and quality control as much as possible, it is necessary to produce CM that is consistently safe and effective. The immortalization of stem cells could be one of the breakthroughs to meet the regulatory requirements and consequently open up a novel avenue to create a novel type of cell-free regenerative medicine, although further investigation into the quality control is warranted.

Human amniotic mesenchymal stem cells promote endometrium regeneration in a rat model of intrauterine adhesion

Human amniotic transplantation has been proposed to improve the therapeutic efficacy of intrauterine adhesions (IUAs). Human amniotic mesenchymal stem stromal cells (hAMSCs) can differentiate into multiple tissue types. This study aimed to investigate the mechanism by which hAMSCs transplantation promotes endometrial regeneration. The rat models with IUA were established through mechanical and infective methods, and PKH26-labeled hAMSCs were transplanted through the tail vein (combined with/without estrogen). Under three different conditions, hAMSCs differentiated into endometrium-like cells. HE and Mason staining assays, and immunohistochemistry were used to compare the changes in rat models treated with hAMSCs and/or estrogen transplantation. To define the induction of hAMSCs to endometrium-like cells in vitro, an induction medium (cytokines, estrogen) was used to investigate the differentiation of hAMSCs into endometrium-like cells. qRT-polymerase chain reaction (PCR) and western blotting were performed to detect the differentiation of hAMSCs into endometrium-like cells. A greater number of glands, fewer endometrial fibrotic areas, and stronger expression of vascular endothelial growth factor and cytokeratin in the combined group (hAMSCs transplantation combined with estrogen) than in the other treatment groups were observed. hAMSCs could be induced into endometrium-like cells by cytokine treatment (TGF-β1, EGF, and PDGF-BB). Transplantation of hAMSCs is an effective alternative for endometrial regeneration after injury in rats. The differentiation protocol for hAMSCs will be useful for further studies on human endometrial regeneration.

Therapeutic Perspectives for the Clinical Application of Umbilical Cord Hematopoietic and Mesenchymal Stem Cells: Overcoming Complications Arising After Allogeneic Hematopoietic Stem Cell Transplantation

This review focuses on the therapeutic features of umbilical cord blood (UCB) cells as a source for allogeneic hematopoietic stem cell transplantation (aHSCT) in adult and child populations to treat malignant and nonmalignant hematologic diseases, genetic disorders, or pathologies of the immune system, when standard treatment (e.g., chemotherapy) is not effective or clinically contraindicated. In this article, we summarize the immunological properties and the advantages and disadvantages of using UCB stem cells and discuss a variety of treatment outcomes using different sources of stem cells from different donors both in adults and pediatric population. We also highlight the critical properties (total nucleated cell dose depending on HLA compatibility) of UCB cells that reach better survival rates, reveal the advantages of double versus single cord blood unit transplantation, and present recommendations from the most recent studies. Moreover, we summarize the mechanism of action and potential benefit of mesenchymal umbilical cord cells and indicate the most common posttransplantation complications.

Mesenchymal Stem Cells in Radiation-Induced Pulmonary Fibrosis: Future Prospects

Radiation-induced pulmonary fibrosis (RIPF) is a general and fatal side effect of radiotherapy, while the pathogenesis has not been entirely understood yet. By now, there is still no effective clinical intervention available for treatment of RIPF. Recent studies revealed mesenchymal stromal cells (MSCs) as a promising therapy treatment due to their homing and differentiation ability, paracrine effects, immunomodulatory effects, and MSCs-derived exosomes. Nevertheless, problems and challenges in applying MSCs still need to be taken seriously. Herein, we reviewed the mechanisms and challenges in the applications of MSCs in treating RIPF.

Forthcoming complications in recovered COVID-19 patients with COPD and asthma; possible therapeutic opportunities

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been growing swiftly worldwide. Patients with background chronic pulmonary inflammations such as asthma or chronic obstructive pulmonary diseases (COPD) are likely to be infected with this virus. Of note, there is an argument that COVID-19 can remain with serious complications like fibrosis or other pathological changes in the pulmonary tissue of patients with chronic diseases. Along with conventional medications, regenerative medicine, and cell-based therapy could be alternative approaches to compensate for organ loss or restore injured sites using different stem cell types. Owing to unique differentiation capacity and paracrine activity, these cells can accelerate the healing procedure. In this review article, we have tried to scrutinize different reports related to the harmful effects of SARS-CoV-2 on patients with asthma and COPD, as well as the possible therapeutic effects of stem cells in the alleviation of post-COVID-19 complications. Video abstract.

Therapeutic Potential of Mesenchymal Stem Cells in the Treatment of Ocular Graft-Versus-Host Disease

Ocular GVHD (oGVHD), manifested by severe injury of corneal epithelial cells, meibomian and lacrimal glands' dysfunction, is a serious complication of systemic GVHD which develops as a consequence of donor T and natural killer cell-driven inflammation in the eyes of patients who received allogeneic hematopoietic stem cell transplantation. Mesenchymal stem cells (MSC) are, due to their enormous differentiation potential and immunosuppressive characteristics, considered as a potentially new remedy in ophthalmology. MSC differentiate in corneal epithelial cells, suppress eye inflammation, and restore meibomian and lacrimal glands' function in oGVHD patients. MSC-sourced exosomes (MSC-Exos) are extracellular vesicles that contain MSC-derived growth factors and immunoregulatory proteins. Due to the lipid membrane and nano-sized dimension, MSC-Exos easily by-pass all biological barriers in the eyes and deliver their cargo directly in injured corneal epithelial cells and eye-infiltrated leukocytes, modulating their viability and function. As cell-free agents, MSC-Exos address all safety issues related to the transplantation of their parental cells, including the risk of unwanted differentiation and aggravation of intraocular inflammation. In this review article, we summarized current knowledge about molecular mechanisms which are responsible for beneficial effects of MSC and MSC-Exos in the therapy of inflammatory eye diseases, emphasizing their therapeutic potential in the treatment of oGVHD.