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.

Stromal vascular fraction (SVF), a heterogeneous cell population primarily derived from adipose tissue, is widely utilized in regenerative therapies for its wound-healing properties and accessibility. While its immediate availability is advantageous, repeated harvesting can be burdensome, especially for elderly patients, and the regenerative capacity of SVF declines with donor age. Long-term cryopreservation offers a potential solution by allowing the banking of SVF from younger donors for future use; however, the impact of this process on SVF functionality remains elusive. This study investigates the stemness and wound-healing potential of SVF following prolonged cryopreservation.

SVF cells were isolated from adipose tissue harvested from twelve patients and cryopreserved for either two months (short-term cryopreserved SVF, S-SVF) or 12-13 years (long-term cryopreserved SVF, L-SVF), with six patients in each group. In vitro assays assessed cell viability and stemness, while in vivo assays evaluated wound-healing ability by administering thawed SVF cells from each group to dorsal wounds in immunodeficient mice, compared with a control group. Non-parametric statistical tests analyzed the differences between groups.

L-SVF exhibited significantly lower stemness compared to S-SVF. Importantly, the L-SVF group showed significantly improved wound healing compared with the control group, although the wound-healing effect of L-SVF was inferior to that of the S-SVF.

This study demonstrated that, despite reduced stemness, L-SVF retains partial wound-healing potential after 12-13 years of cryopreservation. These findings highlight the need for optimized cryopreservation protocols to enhance SVF viability and regenerative capacity for clinical applications.

Stem cell-based therapies have emerged as a promising frontier in the treatment of gastrointestinal disorders, offering potential solutions for challenges posed by conventional treatments. This review comprehensively examines recent advancements in cell-based therapeutic strategies, particularly focusing on stem cell applications, immunotherapy, and cellular therapies for digestive diseases. It highlights the successful differentiation of enteric neural progenitors from pluripotent stem cells and their application in animal models, such as Hirschsprung disease. Furthermore, the review evaluates clinical trials and experimental studies demonstrating the potential of stem cells in regenerating damaged tissues, modulating immune responses, and promoting healing in conditions like Crohn's disease and liver failure. By addressing challenges, such as scalability, immunogenicity, and ethical considerations, the review underscores the translational opportunities and obstacles in realizing the clinical potential of these therapies. Concluding with an emphasis on future directions, the study provides insights into optimizing therapeutic efficacy and fostering innovations in personalized medicine for digestive disorders.

Acute graft-versus-host disease (aGVHD) is a major complication of allogeneic hematopoietic cell transplantation (allo-HCT) that is caused by donor immune cells attacking and damaging host tissues. Immune suppressive small molecule and protein-based therapeutics targeting donor anti-host immune cells are currently used for GVHD prophylaxis and treatment. Even with these therapies, aGVHD progresses to life-threatening steroid-refractory aGVHD (SR-aGVHD) in up to 50% of cases and is a risk factor for the subsequent development of debilitating chronic GVHD. To improve aGVHD-related outcomes, donor graft engineering techniques and adoptive transfer of immune modulatory cells have been explored. Highly rigorous donor graft T-cell depletion approaches have revealed that mitigation of aGVHD can be accompanied by slow immune recovery post-allo-HCT and reduction in anti-microbial and anti-leukemia responses resulting in increased relapse and infection rates, respectively. Recent T-cell separation techniques allowing for precision graft engineering by selectively eliminating aGVHD-causing T-cells (eg, naïve T-cells) without loss of T-cells with beneficial functions and retaining and/or enriching immune regulatory populations (eg, regulatory T-cells (Tregs) or myeloid-derived suppressor cells) have been tested and will continue to improve. Clinical cell-based regulatory therapies have been employed for targeting SR-aGVHD, particularly mesenchymal stem cells (MSCs) and more recently, Tregs. In this review, we summarize aGVHD pathophysiology, highlight newly discovered aGVHD mechanisms, and discuss current and emerging cellular and graft manipulation approaches for aGVHD prevention and treatment.

Steroid-refractory acute Graft-versus-Host Disease (SR-aGVHD) is a potentially fatal complication occurring in approximately 60-70% of severe grade III-IV GVHD cases, with a higher incidence in patients with gastrointestinal (GI) involvement. GI aGVHD is associated with poor prognosis, with a 2-year overall survival (OS) rate of only 25% in patients with stage 3-4 GI involvement. Mesenchymal stromal cells (MSC) have emerged as a promising therapeutic option due to their favorable efficacy and safety profile. However, data on bone marrow (BM)-derived MSC use in biopsy-proven grade III-IV SR-aGVHD with GI involvement, particularly in stage 3-4 cases, remain limited.

This prospective, observational, single-arm, single-center study assessed the efficacy and safety of BM-derived MSC for treating adult patients with biopsy-proven grade III-IV SR-aGVHD with predominant GI involvement. Early (1st-2nd) passage BM-derived MSC were administered weekly at a target dose of 1x106 MSC/kg in two regimens: up to three (MSC3) and six doses (MSC6).

Fifty-seven adult patients with biopsy-proven III-IV grade SR-aGVHD (93% with GI involvement) received MSC treatment. The overall response rate (ORR) was 39% and 42% on Days 14 and 28, respectively, with no significant differences between the two MSC groups (Day 28 ORR 38% for MSC3 and 44% for MSC6). In patients with stage 3-4 GI involvement, the ORR was 26% and 36% at the corresponding time points with comparable efficacy between the two MSC groups (Day 28 ORR 31% for MSC3 and 38% for MSC6). Day 14 and Day 28 responders had significantly higher OS compared to non-responders (52% vs. 7%, p=0.000; 54% vs. 5%, p=0.000), with a comparable OS benefit observed in patients with stage 3-4 GI involvement (45% vs. 8%, p=0.005; 42% vs. 6%, p=0.005), respectively. MSC treatment had a favorable safety profile. The one, 5 and 10-year OS rates were 27%, 24%, and 24%, respectively.

The grade III-IV SR-aGVHD patients, including cases with biopsy-proven severe GI involvement, had significantly better clinical outcomes if responses to MSC treatment were observed on Days 14 and 28. Intensified MSC administration schedule has failed to improve the clinical outcomes. MSC studies focusing on aGVHD prevention and (or) first-line treatment in combination with other agents should be considered.

Acute graft-versus-host disease (aGvHD) remains a significant complication of allogeneic hematopoietic cell transplantation, with 40% of patients failing to respond to high-dose steroids. Ruxolitinib has become the standard treatment for steroid-refractory aGvHD (SR-GvHD), but its failure in approximately one-third of cases highlights the need for alternative therapies. Mesenchymal stromal cells (MSCs), known for their immunomodulatory properties, are suggested as a treatment option, but their role in SR-GvHD remains unclear. To better understand MSC therapy outcomes, the EBMT Cellular Therapy & Immunobiology Working Party conducted a survey of centers treating >20 SR-GvHD patients with MSCs between 2007 and 2020. Data from 313 patients were analyzed, revealing a 44.5% overall response rate at day 28. Responders at day 7 had a higher likelihood of maintaining responses by day 28. Using a landmark analysis, the overall survival at 12 months, conditional on being alive at day 28, was 39.2%. Survival at 12 months was 48.6% for responders, compared to 24.4% for non-responders. Despite manufacturing variabilities, MSCs produced by academic pharma appear effective in SR-GvHD, offering a viable treatment alternative for heavily pretreated patients. These findings support further investigation of MSCs to establish standardized protocols and validate their efficacy as third-line therapy for SR-GvHD.

The clinical efficacy of mesenchymal stem cell (MSC) therapy for inflammatory bowel disease (IBD) is inconsistent and often fails to match promising preclinical findings. To improve outcome, we compared MSCs isolated from human uterine myometrium (Ut), a readily-available tissue source from a unique immune niche, to bone marrow (BM) MSCs, the most common source, in a murine IBD model with mechanisms underlying differential effects. In this study, human BMMSCs and UtMSCs were intravenously administered to mice with dextran sulfate sodium-induced colitis and evaluated for disease activity, microbiome composition, and cellular immunity. Bioinformatics analyses including patient data were performed to further specify involved mechanisms with subsequent functional validation performed. We found that UtMSC but not BMMSC treatment significantly reversed disease parameters by improving microbiome and reducing mesenteric lymph node IFN-γ and IL-17A-secreting T cells. Transcriptomic analysis revealed UtMSCs had reduced MHC II pathway activation compared to BMMSCs. Functional validation confirmed UtMSCs compared to BMMSCs expressed lower IFN-γ receptors, prevent MHC II-mediated human unstimulated T cell activation, and modulated stimulated T helper (Th) cells away from effector phenotypes while increasing regulatory T cells (Tregs) and IL-10 levels. Bioinformatics from IBD patients resistant to non-T cell-specific therapies implicated persistent MHC II-mediated Th1/Th17 activation as key drivers of disease. Overall, UtMSCs outperformed BMMSCs in improving microbiota, avoiding IFN-γ responses, and modulating overall Th responses, suggesting this MSC source may offer more significant effectiveness for IBD and Th1/Th17-mediated conditions. Our findings also highlight that understanding MSC source-specific therapeutic mechanisms is crucial for optimizing clinical therapies.

Type 1 diabetes (T1D) is an autoimmune disorder characterized by the destruction of insulin-producing β-cells in the pancreas. Despite advances in insulin therapy and β-cell replacement, a definitive cure addressing the underlying cause of the disease, that is the loss of immune tolerance to β-cells remains elusive. Emerging strategies to reshape the immune response to pancreatic autoantigens include the adoptive transfer of ex vivo cultured regulatory cells, either mesenchymal stem cells (MSCs), regulatory T cells (Tregs), or dendritic cells (DCs), collectively known as regulatory cell therapy. This review aims to provide an overview of the regulatory cell-based approaches for T1D currently under development. Although several clinical trials have demonstrated the safety of in vivo administration of regulatory cells to T1D patients, only mild signs of efficacy have been reported. The most promising results were observed in patients with shorter disease duration and higher residual β-cell mass, suggesting that early interventions may result in clinical benefit. Significant challenges remain, including the long-term efficacy and stability of the infused products. In the future, approaches combining regulatory cell-based therapies with immunomodulatory agents or strategies to restore the damaged insulin-producing cells may hold the key to achieving a functional cure for T1D.

Rheumatic diseases are chronic immune-mediated disorders affecting multiple organ systems and significantly impairing patients' quality of life. Current treatments primarily provide symptomatic relief without offering a cure. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic option due to their ability to differentiate into various cell types and their immunomodulatory, anti-inflammatory, and regenerative properties. This review aims to summarize the clinical progress of MSC therapy in rheumatic diseases, highlight key findings from preclinical and clinical studies, and discuss challenges and future directions.

A comprehensive review of preclinical and clinical studies on MSC therapy in rheumatic diseases, including systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, osteoarthritis, osteoporosis, Sjögren's syndrome, Crohn's disease, fibromyalgia, systemic sclerosis, dermatomyositis, and polymyositis, was conducted. Emerging strategies to enhance MSC efficacy and overcome current limitations were also analyzed.

Evidence from preclinical and clinical studies suggests that MSC therapy can reduce inflammation, modulate immune responses, and promote tissue repair in various rheumatic diseases. Clinical trials have demonstrated potential benefits, including symptom relief and disease progression delay. However, challenges such as variability in treatment response, optimal cell source and dosing, long-term safety concerns, and regulatory hurdles remain significant barriers to clinical translation. Standardized protocols and further research are required to optimize MSC application.

MSC therapy holds promise for managing rheumatic diseases, offering potential disease-modifying effects beyond conventional treatments. However, large-scale, well-controlled clinical trials are essential to establish efficacy, safety, and long-term therapeutic potential. Addressing current limitations through optimized treatment protocols and regulatory frameworks will be key to its successful integration into clinical practice.

Inflammatory bowel disease (IBD) can present as either Crohn's disease or ulcerative colitis. Both phenotypes are inflammatory conditions of the gastrointestinal tract. Despite scientific advances, the overall incidence and morbidity of IBD continues to increase worldwide. Fortunately, we continue to develop novel therapies, in hopes of providing safer, more effective treatment options. Such therapies include cell therapy, exosome therapy, hyperbaric oxygen therapy, and central nerve stimulation. The aim of this review is to briefly highlight each of these novel therapeutic interventions as they relate to the treatment of IBD.

The December 2024 US Food and Drug Administration (FDA) approval of Mesoblast's Ryoncil (remestemcel-L-rknd)-allogeneic bone marrow mesenchymal stromal cell (MSC(M)) therapy-in pediatric acute steroid-refractory graft-versus-host-disease finally ended a long-lasting drought on approved MSC clinical products in the United States. While other jurisdictions-including Europe, Japan, India, and South Korea-have marketed autologous or allogeneic MSC products, the United States has lagged in its approval. The sponsor's significant efforts and investments, working closely with the FDA addressing concerns regarding clinical efficacy and consistent MSC potency through an iterative process that spanned several years, was rewarded with this landmark approval. This approval will revive investment and enthusiasm in MSC products, further approvals in major markets, and will continue to foreshadow the long-predicted success of MSCs as a pharmaceutical.

Osteoarthritis (OA) is a chronic joint disease that has long been considered a simple wear-and-tear condition. Over the past decade, research has revealed that various inflammatory features of OA, such as low-grade peripheral inflammation and synovitis, contribute substantially to the pathophysiology of the disease. Technological advances in the past 5 years have revealed a large diversity of innate and adaptive immune cells in the joints, particularly in the synovium and infrapatellar fat pad. Notably, the presence of synovial lymphoid structures, circulating autoantibodies and alterations in memory T cell and B cell populations have been documented in OA. These data indicate a potential contribution of self-reactivity to the disease pathogenesis, blurring the often narrow and inaccurate line between chronic inflammatory and autoimmune diseases. The diverse immune changes associated with OA pathogenesis can vary across disease phenotypes, and a better characterization of their underlying molecular endotypes will be key to stratifying patients, designing novel therapeutic approaches and ultimately ameliorating treatment allocation. Furthermore, examining both articular and systemic alterations, including changes in the gut-joint axis and microbial dysbiosis, could open up novel avenues for OA management.

Our previous study revealed that mesenchymal stem cells (MSCs) can secrete large amounts of the chemokine CCL2 under inflammatory conditions and alleviate idiopathic pneumonia syndrome (IPS) by promoting regulatory CCR2 + CD4 + T-cell formation through the CCL2‒CCR2 axis. Given the abundance of macrophages in lung tissue, how these macrophages are regulated by MSC-based prophylaxis via IPS and their interactions with T cells in lung tissue during allo-HSCT are still not fully understood.

An IPS mouse model was established, and MSC-based prophylaxis was administered. In vitro coculture systems and an IPS model were used to study the interactions among MSCs, macrophages and T cells.

Prophylactic administration of MSCs induced M2 polarization and alleviated acute graft-versus-host disease (aGVHD) and lung injury in an IPS mouse model. In vitro coculture studies revealed that M2 polarization was induced by MSC-released CCL2 and that these M2 macrophages promoted the formation of regulatory CCR2 + CD4 + T cells. Blocking the CCL2-CCR2 interaction in vitro reversed MSC-induced M2 polarization and abolished the induction of CCR2 + CD4 + T-cell formation. Additionally, in vivo administration of a CCL2 or CCR2 antagonist in the IPS mouse model exacerbated aGVHD and lung injury, accompanied by a reduction in M2 macrophages and reduced formation of regulatory CCR2 + CD4 + T cells in lung tissue.

MSCs alleviate IPS by facilitating M2 polarization via the CCL2‒CCR2 axis and further inducing the formation of regulatory CCR2 + CD4 + T cells.

Perianal fistulizing Crohn's disease is one of the most disabling phenotypes of Crohn's disease, due to the severe impairment in quality of life including social and personal wellbeing. A multimodal approach with patient-tailored care is the key to optimal management of this condition. Medical therapy is needed to optimize the luminal disease, and surgical intervention is required to control any associated perianal sepsis and attempt palliative or definitive fistula repair. While several medical and surgical options are available, the majority of patients continue to have symptomatic disease. Fortunately, this continues to drive novel innovations which are revolutionizing the treatment and outcomes of perianal fistulizing Crohn's disease. However, there continues to be a need for randomized trials and consistent metrics utilized for classification and treatment outcomes in order to accurately describe optimal treatment outcomes.

Mesenchymal stem/stromal cells (MSCs) have been exploited as an experimental cell therapy in a broad array of clinical applications but have underperformed based on results from pre-clinical studies due to gaps in translating pre-clinical findings to human patients. Herein, we isolated mouse MSCs from pelvic bone marrow (BMP), a preferred source for human MSCs, and compared their growth, differentiation, and immuno-modulatory activity to those derived from long bone marrow (BML), the traditional source of mouse MSCs. We report that BMP-MSCs exhibit significantly enhanced growth kinetics in 5% and 21% oxygen saturation and superior bi-lineage differentiation and hematopoiesis-supporting activity as compared to BML-MSCs. Additionally, we show that TNF upregulates inducible nitric oxide synthase (NOS2) in BML- and BMP- MSCs and augments their immune suppressive activity in cell-based assays, while interferon-gamma (INFG) upregulates indoleamine, 2-3, dioxygenase (IDO1) and enhances the immune suppressive activity of only BMP-MSCs. These results indicate that mouse MSCs sourced from different bone compartments exhibit measurable differences in critical quality attributes, and these differences are comparable to those observed across species. Based on these differences, BMP- MSCs represent a useful resource to model the behavior of human BM-derived MSCs.

Diabetes mellitus (DM) is a fatal metabolic disease characterized by persistent hyperglycemia. In recent studies, mesenchymal stem cell (MSC)-derived exosomes, which are being investigated clinically as a cell-free therapy for various diseases, have gained attention due to their biomimetic properties that closely resemble natural cellular communication systems. These MSC-derived exosomes inherit the regenerative and protective effects from MSCs, inducing pancreatic β-cell proliferation and inhibiting apoptosis, as well as ameliorating insulin resistance by suppressing the release of various inflammatory cytokines. Consequently, MSC-derived exosomes have attracted attention as a novel treatment for DM as an alternative to stem cell therapy. In this review, we will introduce the potential of MSC-derived exosomes for the treatment of DM by discussing the studies that have used MSC-derived exosomes to treat DM, which have shown therapeutic effects in both type 1 and type 2 DM.

Mesenchymal stem cells (MSCs) have been widely used in the treatment of various inflammatory diseases. The inadequate understanding of MSCs and their heterogeneity can impact the immune environment, which may be the cause of the good outcomes of MSCs-based therapy that cannot always be achieved. Recently, stem cells from human exfoliated deciduous teeth (SHED) showed great potential in inflammatory and autoimmune diseases due to their immature properties compared with MSCs. In our study, single-cell RNA sequencing (scRNA-seq) revealed that SHED in a low differentiation state (S7) exhibited the powerful ability to recruit multiple immune cells. In contrast, SHED in a relatively high differentiation state (S1) may hold a solid ability to secret many factors with paracrine signaling capacity. The analysis result shows that SHED has more robust immunomodulatory properties than human bone marrow-derived mesenchymal stem cells (hBMSCs) or human umbilical cord-derived mesenchymal stem cells (hUCMSCs). When co-cultured with PBMCs, SHED can enhance the proliferation of Treg and down-regulate TNF-α in vitro. SHED may have some advantages in the treatment of inflammatory and autoimmune diseases.

Mesenchymal stromal cells (MSC) have immunomodulatory and hematopoiesis-supporting properties that could potentially benefit hematopoietic stem cell (HSC) engraftment and decrease the incidence and/or severity of graft-versus-host disease (GVHD).

Based on our previous pilot study, we established a multicenter, prospective, randomized, double-blind trial evaluating the efficacy of co-infusing third-party MSC (1.5-3 × 106/kg) versus placebo on the day of HSC transplantation (HCT) to prevent GVHD in recipients of HLA-mismatched unrelated donors after reduced-intensity conditioning.

The study planned to include 120 patients to improve 1-year overall survival (OS) from 55 to 77% but was stopped after 9 years for low recruitment (n = 38). One-year OS was 74% in the MSC group and 80% in the placebo group. In multivariate analysis, the incidence of grade II-IV acute GVHD was significantly lower in patients receiving MSC (HR 0.332, 95% CI 0.124-0.890, p = 0.0284). No difference was observed in the incidences of chronic GVHD, infection or relapse, overall or progression-free survival at 1 year or long-term, or hematopoietic and immune reconstitution.

Despite premature study closure, the suggested beneficial effect of MSC co-transplantation for the prevention of acute GVHD in HLA-mismatched HCT warrants further investigation.

Umbilical cord blood (UCB) is an alternative source of stem cells for patients lacking a 9/10 or 10/10 HLA identical donor. However, after UCB transplantation, time to engraftment and immune recovery are prolonged, increasing the risk of fatal complications. Mesenchymal stromal cells (MSC) can support hematopoietic engraftment and have immunosuppressive effects. The primary objective of this phase I/II multicenter study was to determine the feasibility and safety of UCB transplantation with co-infusion of third party MSC, as assessed by treatment related mortality (TRM) at day 100. Secondary objectives were engraftment, immune recovery, occurrence of graft versus host disease (GVHD), infections, disease free survival, relapse incidence and overall survival. Eleven patients were grafted according to this protocol. Allogeneic transplantation after co-infusion appears feasible with 18 % TRM at day 100. Engraftment data show a median time of 16 days to neutrophil and 27 days to platelet recovery, which is shorter than what is usually reported after UCB transplantation. Only 1 episode of acute GVHD was reported. In conclusion, MSC and UCB co-transplantation is feasible and might help overcome some of the drawbacks of UCB transplantation.

The intrinsic healing ability of articular cartilage is poor after injury or illness, and untreated injury could lead to cartilage degeneration and ultimately osteoarthritis. iMSCs are derived from embryonic induced pluripotent stem cells and have strong therapeutic capabilities in the repair of cartilage defects, while the mechanism of action is unclear. The aim of this study is to clarify the repair mode of iMSCs on cartilage defects in rat knee joints, elucidate the chemotactic effect of iMSCs on autologous BMSCs in rats, and provide a basis for the treatment of cartilage defects and endogenous regeneration with iMSCs.

Based on the establishment of the rat cartilage defect model, the reparative effect of iMSCs on the rat cartilage defect was evaluated. The cartilage repair was evaluated by quantitative score, H&E staining, Masson staining and Safranin-O staining, and the metabolic changes of iMSCs in the joint cavity were detected in vivo. The expression of SOX9, CD29, CD90, ColⅠ, ColⅡ, PCNA, SDF-1, and CXCR4 was detected by immunohistochemistry (IHC), IF, flow cytometry, respectively. After co-culturing iMSCs with BMSCs in vitro, the expression of CXCR4/SDF-1 on the cell membrane surface of BMSCs was detected by western blotting.; The level of p-Akt and p-Erk1/2 in total protein of BMSCs were detected by western blotting.

Our research results provide experimental evidence for the treatment of cartilage defects and endogenous regeneration with iMSCs; This also provides new ideas for the clinical treatment of cartilage defects using iMSCs.

An essential aspect of ensuring availability and stability of mesenchymal stem/stromal cells (MSCs) products for clinical use is that these cells are cryopreserved before individual infusion into patients. Currently, cryopreservation of MSCs involves use of a cryoprotectant solution containing dimethyl sulfoxide (DMSO). However, it is recognized that DMSO may be toxic for both the patient and the MSC product. In this Production Assistance for Cellular Therapies (PACT) and Biomedical Excellence for Safer Transfusion (BEST) Collaborative study, we compared a novel DMSO-free solution with DMSO containing cryoprotectant solutions for freezing MSCs.

A DMSO-free cryoprotectant solution containing sucrose, glycerol, and isoleucine (SGI) in a base of Plasmalyte A was prepared at the University of Minnesota. Cryoprotectant solutions containing 5-10% DMSO (in-house) were prepared at seven participating centers (five from USA, one each from Australia and Germany). The MSCs were isolated from bone marrow or adipose tissue and cultured ex vivo per local protocols at each center. The cells in suspension were frozen by aliquoting into vials/bags. For six out of the seven centers, the vials/bags were placed in a controlled rate freezer (one center placed them at -80°C freezer overnight) before transferring to liquid nitrogen. The cells were kept frozen for at least one week before thawing and testing. Pre- and post-thaw assessment included cell viability and recovery, immunophenotype as well as transcriptional and gene expression profiles. Linear regression, mixed effects models and two-sided t-tests were applied for statistical analysis.

MSCs had an average viability of 94.3% (95% CI: 87.2-100%) before cryopreservation, decreasing by 4.5% (95% CI: 0.03-9.0%; P: 0.049) and 11.4% (95% CI: 6.9-15.8%; P< 0.001), for MSCs cryopreserved in the in-house and SGI solutions, respectively. The average recovery of viable MSCs cryopreserved in the SGI was 92.9% (95% CI: 85.7-100.0%), and it was lower by 5.6% (95% CI: 1.3-9.8%, P < 0.013) for the in-house solution. Additionally, MSCs cryopreserved in the two solutions had expected level of expressions for CD45, CD73, CD90, and CD105 with no significant difference in global gene expression profiles.

MSCs cryopreserved in a DMSO-free solution containing sucrose, glycerol, and isoleucine in a base of Plasmalyte A had slightly lower cell viability, better recovery, and comparable immunophenotype and global gene expression profiles compared to MSCs cryopreserved in DMSO containing solutions. The average viability of MSCs in the novel solution was above 80% and, thus, likely clinically acceptable. Future studies are suggested to test the post-thaw functions of MSCs cryopreserved in the novel DMSO-free solution.

Bone marrow-mesenchymal stromal cells (BM-MSCs) are key components of the BM niche, where they regulate hematopoietic stem progenitor cell (HSPC) homeostasis by direct contact and secreting soluble factors. BM-MSCs also protect the BM niche from excessive inflammation by releasing anti-inflammatory factors and modulating immune cell activity. Thanks to these properties, BM-MSCs were successfully employed in pre-clinical HSPC transplantation models, increasing the rate of HSPC engraftment, accelerating the hematological reconstitution, and reducing the risk of graft failure. However, their clinical use requires extensive in vitro expansion, potentially altering their biological and functional properties. In this work, we analyzed the transcriptomic profile of human BM-MSCs sorted as CD45-, CD105+, CD73+, and CD90+ cells from the BM aspirates of heathy-donors and corresponding ex-vivo expanded BM-MSCs. We found the expression of immune and inflammatory genes downregulated upon cell culture and selected the transcription factor EGR1 to restore the MSC properties. We overexpressed EGR1 in BM-MSCs and performed in vitro tests to study the functional properties of EGR1-overexpressing BM-MSCs. We concluded that EGR1 increased the MSC response to inflammatory stimuli and immune cell control and potentiated the MSC hematopoietic supportive activity in co-culture assay, suggesting that the EGR1-based reprogramming may improve the BM-MSC clinical use.

Mesenchymal stromal cell (MSC) apoptosis is required for in vivo immunosuppression. However, the induction of apoptosis is heavily dependent on the recipient's immune system. In graft-versus-host disease (GvHD), patients who fail to respond to MSCs are in fact those whose immune cells are unable to induce MSC apoptosis ex vivo. The information is critical to explain why responses in clinical trials vary even though the same sources of MSC products are infused. More importantly, it highlights the need for an alternative MSC treatment for the nonresponders. By using a mouse model of ovalbumin (OVA)-induced allergic inflammation, we demonstrated that we could generate apoptotic MSCs (ApoMSCs) in vitro and use them to successfully reduce allergic airway inflammation. In order to address the logistics of their potential future clinical application, we have shown that ApoMSCs could be cryopreserved without impairing efficacy compared to freshly generated ApoMSCs. We have also highlighted that MSCs need to undergo complete apoptosis before cryopreservation to retain their immunosuppressive activity. The cryopreserved ApoMSCs could serve as a potential future off-the-shelf cellular product, in particular for patients who suffer from inflammatory conditions yet do not harbor the immune capacity to induce MSC apoptosis in vivo. Our data provide proof-of-concept that under laboratory conditions, ApoMSCs can be successfully frozen and thawed without affecting their anti-inflammatory activity, as tested in a murine model of allergic inflammation.

Mesenchymal stromal cells (MSCs) have been used in multiple clinical trials for steroid-refractory moderate-severe (grade II-IV) acute graft-versus-host disease (aGVHD) across the world over the last two decades. Despite very promising results in a variety of trials, it failed to get widespread approval by regulatory agencies such as the U.S. Food and Drug Administration and the European Medicines Agency. What lessons can we learn from this for future studies on MSCs and other cell therapy products? Broad heterogeneity among published trials using MSCs in aGVHD was likely the core problem. We propose a standardized approach in regards to donor-related factors, MSCs-related characteristics, as well as clinical trial design, to limit heterogeneity in trials for aGVHD and to fulfill the requirements of regulatory agencies. This approach may be expanded beyond MSCs to other Cell and Gene therapy products and trials in other diseases.

This study explores the application of adipose-derived mesenchymal stromal cells (adMSCs) as a therapy for ocular inflammatory diseases utilizing a chronic GVHD model.

Human adMSCs were administered via subconjunctival injection into mice with chronic ocular GVHD. Clinical scores and changes in T cell populations were analyzed.

The study showed significant improvement in corneal integrity, including epithelial damage, opacity, thickness, and structure, after subconjunctival adMSC transplantation. Additionally, adMSC transplantation increased CD45+ and Foxp3+ Tregs while decreasing CD4+ T cells, 1IL17A+ Th17 cells, and IFNγ+ Th1 cells in local cervical lymph nodes. Moreover, adMSC-conditioned media enhanced wound closure and cell migration toward the wound bed in vitro. The cells disappeared within a week suggesting that trophic factors were involved.

The dual benefit of adMSCs in immune-related ocular disorders underscores their potential for clinical application. This study focuses on subconjunctival delivery, effects of adMSCs and migration post-injection, with implications for optimizing cellular therapy application. The observed dual action, combining immunomodulation and tissue repair enhancement, underscores holistic approach of adMSC therapy in regenerative medicine, making it a potent treatment for diseases involving inflammation and tissue damage in the ocular surface.

Emphysema in patients with chronic obstructive pulmonary disease (COPD) is characterized by progressive inflammation. Preclinical studies suggest that lung volume reduction surgery (LVRS) and mesenchymal stromal cell (MSC) treatment dampen inflammation. We investigated the effects of bone marrow-derived MSC (BM-MSC) and LVRS on circulating and pulmonary immune cell profiles in emphysema patients using mass cytometry. Blood and resected lung tissue were collected at the first LVRS (L1). Following 6-10 weeks of recovery, patients received a placebo or intravenous administration of 2 × 106 cells/kg bodyweight BM-MSC (n = 5 and n = 9, resp.) in week 3 and 4 before the second LVRS (L2), where blood and lung tissue were collected. Irrespective of BM-MSC or placebo treatment, proportions of circulating lymphocytes including central memory CD4 regulatory, effector memory CD8 and γδ T cells were higher, whereas myeloid cell percentages were lower in L2 compared to L1. In resected lung tissue, proportions of Treg (p = 0.0067) and anti-inflammatory CD163- macrophages (p = 0.0001) were increased in L2 compared to L1, while proportions of pro-inflammatory CD163+ macrophages were decreased (p = 0.0004). There were no effects of BM-MSC treatment on immune profiles in emphysema patients. However, we observed alterations in the circulating and pulmonary immune cells upon LVRS, suggesting the induction of anti-inflammatory responses potentially needed for repair processes.

This detailed review describes innovative strategies and current products for gene and cell therapy at different stages of research and development to treat recessive dystrophic epidermolysis bullosa (RDEB) which is associated with the functional deficiency of collagen type VII alpha 1 (C7) caused by defects in the COL7A1 gene. The use of allogenic mesenchymal stem/stromal cells, which can be injected intradermally and intravenously, appears to be the most promising approach in the field of RDEB cell therapy. Injections of genetically modified autologous dermal fibroblasts are also worth mentioning under this framework. The most common methods of RDEB gene therapy are gene replacement using viral vectors and gene editing using programmable nucleases. Ex vivo epidermal transplants (ETs) based on autologous keratinocytes (Ks) have been developed using gene therapy methods; one such ET successively passed phase III clinical trials. Products based on the use of two-layer transplants have also been developed with both types of skin cells producing C7. Gene products have also been developed for local use. To date, significant progress has been achieved in the development of efficient biomedical products to treat RDEB, one of the most severe hereditary diseases.

Alveolar capillary endothelial cell (EC) injury has a pivotal role in driving acute respiratory distress syndrome (ARDS) progression and maintaining endothelial homeostasis. A previous ex vivo study revealed that overexpression of homeobox B4 (HOXB4) in bone marrow mesenchymal stem cells (BMSCs) enhanced protection against lipopolysaccharide (LPS)-induced EC injury by activating the Wnt/β-catenin pathway. This in vivo study was performed to verify whether BMSCs overexpressing HOXB4 exert similar protective effects on LPS-induced acute lung injury (ALI) in an animal model.

The ALI rat model was established by intraperitoneal injection of LPS. Wildtype BMSCs or BMSCs overexpressing HOXB4 were then injected via the tail vein. The lung characteristics of rats were visualized by computed tomography. Lung histopathological characteristics and collagen deposition were assessed by hematoxylin-eosin and Masson's staining, respectively, which were combined with the lung wet/dry ratio and proinflammatory factor levels in bronchoalveolar lavage fluid to further evaluate therapeutic effects. Expression of β-catenin and VE-cadherin was assessed by western blotting and immunofluorescence.

Compared with wildtype BMSCs, overexpression of HOXB4 optimized the therapeutic effects of BMSCs, which manifested as improvements in lung exudation and histopathological features, reduced lung collagen deposition, amelioration of lung permeability, attenuation of lung inflammation, and enhanced expression of β-catenin and VE-cadherin proteins.

HOXB4-overexpressing BMSCs optimized the protective effect against LPS-induced ALI by partially activating Wnt/β-catenin signaling.

The use of dental pulp stem cells (DPSCs) in clinical applications instead of bone marrow stem cells is a very promising method capable of significantly changing the future of medical treatment. If further studies prove that DPSCs and the cells differentiated from them do not stimulate the immune system, these cells can be used more reliably in treatment of autoimmune diseases.

In this research, we examined the isolated DPSCs and differentiated osteoblasts from them in medium without inflammatory stimulants in terms of TLR3 and TLR4 gene expression and inflammatory cytokines, including TNF-α and IL-8 using qRT-PCR, and measured the concentration of inflammatory cytokines IL-8 and TNF-α produced by these two types of cells through ELISA.

The obtained results showed that the expression level of inflammatory cytokines IL-8 and TNF-α in differentiated osteoblasts is significantly different as compared with DPSCs. However, no significant difference was observed in TLR-4 expression between two groups. An increase in TNF-α expression level was found to directly correlate with an increase in the expression of IL-8. The concentration of cytokine TNF-α in osteoblasts was significantly higher than that of IL-8 in DPSCs.

In comparison to DPSCs, osteoblast cells first lead to inflammatory responses. These responses reduce overtime. However, DPSCs retain their immunomodulatory properties and do not show inflammatory responses.

Mesenchymal stromal cells (MSCs) have been extensively studied as a potential treatment for steroid refractory acute graft-versus-host disease (aGVHD). However, the majority of clinical trials have focused on bone marrow-derived MSCs.

In this study, we report the outcomes of 86 patients with grade III-IV (82.6% grade IV) steroid refractory aGVHD who were treated with human umbilical cord-derived mesenchymal stromal cells (UC-MSCs). The patient cohort included 17 children and 69 adults. All patients received intravenous infusions of UC-MSCs at a dose of 1 × 106 cells per kg body weight, with a median of 4 infusions (ranging from 1 to 16).

The median time between the onset of aGVHD and the first infusion of UC-MSCs was 7 days (ranging from 3 to 88 days). At day 28, the overall response (OR) rate was 52.3%. Specifically, 24 patients (27.9%) achieved complete remission, while 21 (24.4%) exhibited partial remission. The estimated survival probability at 100 days was 43.7%. Following a median follow-up of 108 months (ranging from 61 to 159 months), the survival rate was approximately 11.6% (10/86). Patients who developed acute lower GI tract and liver GVHD exhibited poorer OR rates at day 28 compared to those with only acute lower GI tract GVHD (22.2% vs. 58.8%; p= 0.049). No patient experienced serious adverse events.

These finding suggest that UC-MSCs are safe and effective in both children and adults with steroid refractory aGVHD. UC-MSCs could be considered as a feasible treatment option for this challenging conditon. (NCT01754454).

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

To evaluate the co-transplantation efficacy of umbilical cord mesenchymal stem cells (UC-MSCs) and peripheral blood stem cells (PBSCs) as a novel approach for refractory or relapsed severe aplastic anemia (R/R SAA) in children and adolescents, thirty-two children and adolescents diagnosed with R/R SAA underwent a retrospective chart review. The patients were categorized into two groups based on the source of PBSCs: the matched sibling donor (MSD) group and the unrelated donor (UD) group. No adverse events related to UC-MSC infusion occurred in any of the patients. The median time for neutrophil engraftment was 13 days (range: 10-23 days), and for platelets, it was 15 days (range: 11-28 days). Acute GVHD of Grade I-II and moderate chronic GVHD were observed in 21.8 and 12.5% of cases, respectively. No statistically significant differences were found between the MSD and UD groups in terms of engraftment, GVHD, and complications, including infection and hemorrhagic cystitis. The median follow-up time was 38.6 months (range: 1.4-140.8 months). As of October 31, 2021, five patients had succumbed, while 27 (84.4%) survived. The 5-year OS rate showed no statistically significant difference between the MSD and UD groups (84.8 ± 10.0 vs. 82.4 ± 9.2%, p = 0.674). In conclusion, the application of UC-MSCs in the treatment of R/R SAA in PBSC transplantation is reliable and safe, they had no graft rejection, low incidence of severe GVHD which may have been contributed by the co-infusion of MSC.

Mesenchymal stromal stem cells (MSCs) possess a remarkable potential for numerous clinical applications due to their unique properties including self-renewal, immunomodulation, paracrine actions and multilineage differentiation. However, the translation of MSC-based Advanced Therapy Medicinal Products (ATMPs) into the clinic has frequently met with inconsistent outcomes. One of the suspected reasons for this issue is the inherent and extensive variability that exists among such ATMPs, which makes the interpretation of their clinical efficacy difficult to assess, as well as to compare the results of various studies. This variability stems from numerous reasons including differences in tissue sources, donor attributes, variances in manufacturing protocols, as well as modes of administration. MSCs can be isolated from various tissues including bone marrow, umbilical cord, adipose tissue and others, each with its unique phenotypic and functional characteristics. While MSCs from different sources do share common features, they also exhibit distinct gene expression profiles and functional properites. Donor-specific factors such as age, sex, body mass index, and underlying health conditions can influence MSC phenotype, morphology, differentiation potential and function. Moreover, variations in preparation of MSC products introduces additional heterogeneity as a result of cell culture media composition, presence or absence of added growth factors, use of different serum supplements and culturing techniques. Once MSC products are formulated, storage protocols play a pivotal role in its efficacy. Factors that affect cell viability include cell concentration, delivery solution and importantly, post-thawing protocols where applicable. Ensuing, differences in administration protocols can critically affect the distribution and functionallity of administered cells. As MSC-based therapies continue to advance through numerous clinical trials, implication of strategies to reduce product heterogeneity is imperative. Central to addressing these challenges is the need for precise prediction of clinical responses, which require well-defined MSC populations and harmonized assessment of their specific functions. By addressing these issues by meaningful approaches, such as, e.g., MSC pooling, the field can overcome barriers to advance towards more consistent and effective MSC-based therapies.

Inflammatory bowel disease remains a difficult disease to effectively treat, especially fistulizing Crohn's disease. Perianal fistulas in the setting of Crohn's disease remain an area of unmet need with significant morbidity in this patient population. Up to one third of Crohn's patients will have perianal fistulizing disease and current medical and surgical interventions are of limited efficacy. Thus, most patients experience significant morbidity, narcotic use, and loss of employment and end up with multiple surgical interventions. Mesenchymal stem cells (MSCs) have shown efficacy in phase 3 clinical trials, but considerable infrastructure challenges make MSCs limited with regard to scalability in clinical practice. Extracellular vesicles, being derived from MSCs and capturing the secretome functionality of MSCs, offer similar physiological utility regarding mechanism, while also providing an off the shelf regenerative medicine product that could be widely used in daily clinical practice.

Despite the continuous improvement in the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT), acute graft-versus-host disease (GVHD) remains a major complication and cause of death. In recent years, with the emergence of new drugs for the prevention and treatment of acute GVHD and the update of a series of clinical studies, there have been varying degrees of changes in the routine prevention and treatment regimens for acute GVHD. Based on the main research achievements and the accumulation of clinical experience in this field in recent years, this consensus further updates the "The Consensus on Allogeneic Hematopoietic Stem Cell Transplantation for Hematological Diseases in China-Acute Graft-Versus-Host Disease (2020) .

Mesenchymal stromal cells (MSC) from adult bone marrow are the most commonly used cells in clinical trials. MSCs from single donors are the preferred starting material but suffer from a major setback of being heterogeneous that results in unpredictable and inconsistent clinical outcomes. To overcome this, we developed a method of pooling MSCs from different donors and created cell banks to cater clinical needs. Initially, the master cell banks (MCBs) were created at passage 1 (P1) from the bone marrow MSCs isolated from of nine different donors. At this stage, MCBs from three different donors were mixed in equal proportion and expanded till P3 to create working cell banks. Further, the pooled cells and individual donor MSCs were expanded till P5 and cryopreserved and extensively characterised. There was a large heterogeneity among the individual donor MSCs in terms of growth kinetics (90% Coefficient of variation (CV) for cell yield and 44% CV for population doubling time at P5), immunosuppressive ability (30% CV at 1:1 and 300% CV at 1:10 ratio), and the angiogenic factor secretion potential (20% CV for VEGF and71% CV for SDF-1). Comparatively, the pooled cells have more stable profiles (60% CV for cell yield and 7% CV for population doubling time at P5) and exhibit better immunosuppressive ability (15% CV at 1:1 and 32% CV at 1:10 ratio ) and consistent secretion of angiogenic factors (16% CV for VEGF and 51% CV for SDF-1). Further pooling does not compromise the trilineage differentiation capacity or phenotypic marker expression of the MSCs. The senescence and in vitro tumourigenicity characteristics of the pooled cells are also similar to those of individual donor MSCs. We conclude that pooling of MSCs from three different donors reduces heterogeneity among individual donors and produces MSCs with a consistent secretion and higher immunosuppressive profile.