Efficacy Of Mesenchymal Stromal Cells Research Articles

Unlocking the full potential of mesenchymal stromal cell therapy for osteoarthritis through machine learning-based in silico trials

Despite the potential of mesenchymal stromal cells (MSCs) in osteoarthritis (OA) treatment, the challenge lies in addressing their therapeutic inconsistency. Clinical trials revealed significantly varied therapeutic outcomes among patients receiving the same allogenic MSCs but different treatment regimens. Therefore, optimizing personalized treatment strategies is crucial to fully unlock MSCs’ potential and enhance therapeutic consistency. We employed the XGBoost algorithm to train a self-collected database comprising 37 published clinical reports to create a model capable of predicting the probability of effective pain relief and Western Ontario and McMaster Universities (WOMAC) index improvement in OA patients undergoing MSC therapy. Leveraging this model, extensive in silico simulations were conducted to identify optimal personalized treatment strategies and ideal patient profiles. Our in silico trials predicted that the individually optimized MSC treatment strategies would substantially increase patients’ chances of recovery compared to the strategies used in reported clinical trials, thereby potentially benefiting 78.1%, 47.8%, 94.4% and 36.4% of the patients with ineffective short-term pain relief, short-term WOMAC index improvement, long-term pain relief and long-term WOMAC index improvement, respectively. We further recommended guidelines on MSC number, concentration, and the patients’ appropriate physical (body mass index, age, etc.) and disease states (Kellgren-Lawrence grade, etc.) for OA treatment. Additionally, we revealed the superior efficacy of MSC in providing short-term pain relief compared to platelet-rich plasma therapy for most OA patients. This study represents the pioneering effort to enhance the efficacy and consistency of MSC therapy through machine learning applied to clinical data. The in silico trial approach holds immense potential for diverse clinical applications.

The Effect of Cell Culture Passage on the Efficacy of Mesenchymal Stromal Cells as a Cell Therapy Treatment.

Background/Objective: Mesenchymal Stromal Cells (MSCs) have been considered a promising treatment for several diseases, such as cardiac injuries. Many studies have analyzed their functional properties; however, few studies have characterized MSCs through successive culture passages. The main objective of this work was to analyze the phenotype and functionality of MSCs isolated from two different sources in five culture passages to determine if the culture passage might influence the efficacy of MSCs as a cell therapy treatment. Methods: Bone Marrow (BM)-MSCs were harvested from the femur of Wistar rats (n = 17) and Adipose Tissue(AT)-MSCs were isolated from inguinal fat (n = 17). MSCs were cultured for five culture passages, and the immunophenotype was analyzed by flow cytometry, the functionality was characterized by adipogenic, osteogenic, and chondrogenic differentiation assays, and cytokine secretion capacity was determined through the quantification of the Vascular Endothelial Growth-Factor, Fibroblast Growth-Factor2, and Transforming Growth-Factorβ1 in the cell supernatant. The ultrastructure of MSCs was analyzed by transmission electron microscopy. Results: BM-MSCs exhibited typical phenotypes in culture passages two, four, and five, and their differentiation capacity showed an irregular profile throughout the five culture passages analyzed. AT-MSCs showed a normal phenotype and differentiation capacity in all the culture passages. BM- and AT-MSCs did not modify their secretion ability or ultrastructural morphology. Conclusions: Throughout the culture passages, BM-MSCs, but not AT-MSCs, exhibited changes in their functional and phenotypic characteristic that might affect their efficacy as a cell therapy treatment. Therefore, the culture passage selected should be considered for the application of MSCs as a cell therapy treatment.

Mesenchymal stromal cells suppress microglial activation and tumor necrosis factor production

Background aimsWhite matter diseases are commonly associated with microglial activation and neuroinflammation. Mesenchymal stromal cells (MSCs) have immunomodulatory properties and thus have the potential to be developed as cell therapy for white matter disease. MSCs interact with resident macrophages to alter the trajectory of inflammation; however, the impact MSCs have on central nervous system macrophages and the effect this has on the progression of white matter disease are unclear. MethodsIn this study, we utilized numerous assays of varying complexity to model different aspects of white matter disease. These assays ranged from an in vivo spinal cord acute demyelination model to a simple microglial cell line activation assay. Our goal was to investigate the influence of human umbilical cord tissue MSCs on the activation of microglia. ResultsMSCs reduced the production of tumor necrosis factor (TNF) by microglia and decreased demyelinated lesions in the spinal cord after acute focal injury. To determine if MSCs could directly suppress the activation of microglia and to develop an efficient potency assay, we utilized isolated primary microglia from mouse brains and the Immortalized MicroGlial Cell Line (IMG). MSCs suppressed the activation of microglia and the release of TNF after stimulation with lipopolysaccharide, a toll-like receptor agonist. ConclusionsIn this study, we demonstrated that MSCs altered the immune response after acute injury in the spinal cord. In numerous assays, MSCs suppressed activation of microglia and release of the pro-inflammatory cytokine TNF. Of these assays, IMG could be standardized and used as an effective potency assay to determine the efficacy of MSCs for treating white matter disease or other neuroinflammatory conditions associated with microglial activation.

Sequential Umbilical Cord Derived Mesenchymal Stromal Cells (MSCs) for the Third-Line Salvage Treatment of Steroid-Refractory Acute GvHD: A Multicenter, Open Label, Phase 1b/2 Trial

Background and Aim: Acute graft-versus-host disease (aGVHD) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT), particularly if treatment is refractory. Human mesenchymal stromal cells (MSCs) have demonstrated safety and efficacy in steroid refractory acute graft versus host disease, due to their well-described immunosuppressive properties, however, clinical trials have resulted in variable success and an optimal source of MSC has yet to be defined. Based on the importance of maternal-fetal interface immune tolerance, the umbilical cord may provide a superior tissue source of MSC to mediate immunomodulation in aGVHD (SR-aGVHD). This study aimed to investigate the safety and efficacy of MSCs delivered as third-line salvage therapy for SR-aGVHD who had received at least two-lines of steroid-containing immunosuppressive therapy. Method: This phase1b/2, multicenter, open-label clinical trial of a third-party, off-the-shelf preparation of human umbilical cord derived mesenchymal stromal cells (hUC-MSCs) (ChiCTR2200061603) enrolled grades II to IV steroid-refractory aGVHD patients who had been treated with at least two-lines of steroid-containing immunosuppressive therapy. This trial consist of 2 parts：a phase Ib dose escalation part using a standard 3+3 design, which planed biweekly i.v. infusions of hUC-MSCs, at 0.5× 10 6 per kg, 1.0× 10 6per kg and 2.0× 10 6 per kg for 3 weeks, to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Phase II of this work is an expansion cohort study of hUC-MSCs at RP2D 1.0×10 6 per kg with 15 patients. The primary endpoint of the study was safety and RP2D. The key secondary endpoints were efficacy of the overall response rate (ORR) at Day 28 and Day 56 defined per the 2014 NIH consensus criteria. Results: From June 23, 2022, through June 12, 2023, a total of 25 patients were enrolled with the median follow up period of 106 (10,210) days. Of the included 25 cases 11 patients (44.0%) were grade III/IV and 14 patients (56.0%) were grade II aGVHD at enrollment. Median patient age was 37.0 (range:24.5-47.0) years, 44.0% male. hUC-MSCs was well tolerated without dose-limiting toxicities in aforementioned three dosages. The reported adverse events (AEs) potentially associated with hUC-MSCs were hypofibrinogenemia (12.0%), upper respiratory tract infection (4.0%), leukopenia (4.0%) and anemia (8.0%) within the median follow-up period of 106 (10, 210) days. Grade 3 or higher AEs were reported in 6 patients (6/25, 24%) with 11 events, all of them were supposed uncorrelated with hUC-MSC. Three patients unfinished the administration:1 was due to withdrawn ICF; 1 was SAE and 1 was due to participate another trial. Up to date of June 12, 2023, twenty of the initial included 25 patients were still in group. And the RP2D of this trial was identified as 1.0× 10 6 per kg. At Day 28, 20 patients (80.0%, 95% CI:59.3%-93.2%) had an overall response, including 10 (40.0%) with complete responses. And at day 56, only one patient loss response, while another non-response patient at day 28 in the dose of 1.0× 10 6 per kg achieved late responses at day 56 ( Table 1). Responses were observed across skin (19/19, 100%), gastrointestinal tract (7/11,72.7%), and liver (2/2, 100.0%) at day 28. Durable overall response at day 56 was 76% (19/25), Figure 1. The median follow-up time after the initiation of hUC-MSC treatment was 106 (10,210) days with the cutoff date of 180 days after recruitment. The probability of 180-day overall survival (OS) and non-relapse mortality was 88.0% (95% CI, 68.8-97.5%) and 8.0% (95% CI, 1.0-26.0%), respectively. The 180-day cumulative incidence of relapse of primary hematologic disease was 8.0% (95%CI,1.0-26.0%). The percentage of total T lymphocyte, neutrophil, cytokine IL-10, IP-10 were statistically decreased in CR group, while CD8+central memory T cell was significantly increased compared to non-CR groups 24h or 96h after hUC-MSC administration (P<0.05）. Conclusion: Collectively, our results support hUC-MSCs as an effective salvage treatment for SR-aGVHD with safe profile. Key words: Acute graft-versus-host disease; allogeneic hematopoietic stem cell transplantation; mesenchymal stromal cells

Adiponectin restores the obesity-induced impaired immunomodulatory function of mesenchymal stromal cells via glycolytic reprogramming

Obesity has been known to negatively modulate the life-span and immunosuppressive potential of mesenchymal stromal cells (MSC). However, it remains unclear what drives the compromised potency of obese MSC. In this study, we examined the involvement of adiponectin, an adipose tissue-derived hormone, in obesity-induced impaired therapeutic function of MSC. Diet-induced obesity leads to a decrease in serum adiponectin, accompanied by impairment of survival and immunomodulatory effects of adipose-derived MSC (ADSC). Interestingly, priming with globular adiponectin (gAcrp) improved the immunomodulatory potential of obese ADSC. Similar effects were also observed in lean ADSC. In addition, gAcrp potentiated the therapeutic effectiveness of ADSC in a mouse model of DSS-induced colitis. Mechanistically, while obesity inhibited the glycolytic capacity of MSC, gAcrp treatment induced a metabolic shift toward glycolysis through activation of adiponectin receptor type 1/p38 MAPK/hypoxia inducible factor-1α axis. These findings suggest that activation of adiponectin signaling is a promising strategy for enhancing the therapeutic efficacy of MSC against immune-mediated disorders.

Ways to increase the regenerative potential of mesenchymal stromal cells

The ability of mesenchymal stromal cells (MSCs) to migrate into tissue defects and stimulate regeneration makes them a valuable resource for cell therapy. However, in many cases, in vitro cultivation and the influence of the pathological microenvironment in the patient’s body reduce the viability and therapeutic efficacy of MSCs, so their regenerative potential needs to be strengthened. Preconditioning with hormones, cytokines, various chemical or physical factors, cultivation in a three-dimensional environment or at a reduced oxygen content improves the ability of MSCs to colonize damaged tissue, survive in it, and produce regulatory molecules for regeneration. The same goals can be achieved by genetic modification of MSCs. In addition, with the help of transfected MSCs, it is possible to deliver genes necessary for the treatment of hereditary or oncological diseases into the tissue. Finally, an alternative to avoid a decrease in the therapeutic potential of subsequently transplanted MSCs during cultivation can be stimulation of the migration of endogenous patient cells from tissue niches through the systemic circulation to the area of damage. The development of these approaches opens the way to increasing the efficiency of using MSCs in regenerative medicine.

Human macrophage migration inhibitory factor potentiates mesenchymal stromal cell efficacy in a clinically relevant model of allergic asthma

Current asthma therapies focus on reducing symptoms but fail to restore existing structural damage. Mesenchymal stromal cell (MSC) administration can ameliorate airway inflammation and reverse airway remodeling. However, differences in patient disease microenvironments seem to influence MSC therapeutic effects. A polymorphic CATT tetranucleotide repeat at position 794 of the human macrophage migration inhibitory factor (hMIF) gene has been associated with increased susceptibility to and severity of asthma. We investigated the efficacy of human MSCs in high- vs. low-hMIF environments and the impact of MIF pre-licensing of MSCs using humanized MIF mice in a clinically relevant house dust mite (HDM) model of allergic asthma. MSCs significantly attenuated airway inflammation and airway remodeling in high-MIF-expressing CATT7 mice but not in CATT5 or wild-type littermates. Differences in efficacy were correlated with increased MSC retention in the lungs of CATT7 mice. MIF licensing potentiated MSC anti-inflammatory effects at a previously ineffective dose. Mechanistically, MIF binding to CD74 expressed on MSCs leads to upregulation of cyclooxygenase 2 (COX-2) expression. Blockade of CD74 or COX-2 function in MSCs prior to administration attenuated the efficacy of MIF-licensed MSCs invivo. These findings suggest that MSC administration may be more efficacious in severe asthma patients with high MIF genotypes (CATT6/7/8).

Abstract 7 2023 Update: Development of COVID-19 Therapies from Birthing Tissues and Cord Blood

Abstract Introduction The Coronavirus pandemic presents a fleeting opportunity to evaluate the safety and efficacy of advanced cell therapy products, such as Mesenchymal Stromal Cells (MSCs), against a virus that attacks multiple organs and causes respiratory distress. With the pandemic winding down, there is a limited amount of clinical data to analyze. Objectives We ask whether perinatal sources of cells have played a significant role in clinical applications of cell therapy for COVID-19? Methods We are the only research group that is performing worldwide tracking of both clinical trials of advanced cell therapy for COVID-19 as well as the reported outcomes of those trials. Our methods were published in Couto et al. 2023 DOI:10.3389/fimmu.2023.1200180/ Results We identified 207 advanced cell therapy trials for COVID-19 through the end of 2022, where 41% employed perinatal cells (sometimes multiple types). We also identified publications from those trials through April 2023, finding 43, where 25 employ perinatal MSCs, 10 employ MSCs from other sources, and 8 are cellular immunotherapy (3 of them from perinatal sources). Thus far, 65% of the published trial outcomes rely on cells of perinatal origin. There are also 8 publications reporting on cell therapy of two or more COVID-19 patients treated under compassionate use programs, where 5 employ perinatal MSCs, 2 employ MSCs from other sources, and 1 employed MSCs of unknown origin. Figure 1 displays a timeline of trials and publications by month. Thus far, numbers of trials surged once and peaked in April 2020, whereas published reports have been appearing at a steady average rate of 1.3 publications per month. Discussion Couto et al. 2023 was the most complete meta-analysis to date of the efficacy of intravenous MSC as a therapy for COVID-19. Combining 24 studies, they found a relative risk reduction for all-cause COVID-19 mortality of RR=0.63 [95% C.I. 0.46; 0.85]. They also found that for the 18 studies employing perinatal MSCs, RR=0.75 [95% C.I. 0.54; 1.02]. Figure 1 represents the first step towards a sequel study where we will repeat the meta-analysis of MSC benefit for COVID-19 mortality with a bigger data set. This figure displays a monthly timeline of advanced cell therapy for COVID-19 in three categories: clinical trials registered worldwide, published outcomes of those clinical trials, and published reports from compassionate use programs that covered two or more patients. The trials data runs over the 36 months Jan. 2020 – Dec. 2022, whereas the publications data runs over the 40 months Jan. 2020 – April 2023.

Abstract 29 Umbilical Cord-derived Mesenchymal Stromal Cells Suppress Microglia Activation Induced by Demyelination

Abstract Introduction White matter diseases are often accompanied by microglial activation and neuroinflammation. Mesenchymal stromal cells (MSCs) manufactured from umbilical cord tissue possess immunomodulatory properties, making them promising candidates for cell therapy in white matter disease. MSCs can interact with resident macrophages and modify the course of inflammation. However, the influence MSCs have on microglia, the resident macrophages of the central nervous system (CNS), and its implications for white matter disease remain uncertain. Objectives From the blood, MSCs traffic to lung and interact with resident macrophages to alter the trajectory of inflammation. We hypothesized that MSCs injected into the cerebrospinal fluid (CSF) would similarly suppress the activation of microglia. Our goals in this study were to test the efficacy MSCs have on microglia activation and develop a relevant potency assay. Methods In this study, we employed a range of assays, including an in vivo acute spinal cord demyelination model, organotypic brain slice cultures, and microglia activation assays with primary microglia and an immortalized cell line. Using these assays, we assessed the impact cord tissue derived MSCs have on microglial activation. Results In spinal cords and brain slices, lysophosphatidylcholine produced robust demyelination and microglia activation that was suppressed by MSCs. To determine if MSCs could directly impact microglia, we isolated primary microglia and activated them in culture with lipopolysachride (LPS), a toll-like receptor agonist. We screen 6 cytokines induced by LPS and determined that MSCs suppress the release of tumor necrosis factor (TNF) from LPS-activated microglia. We confirmed these results in vivo as MSCs blocked TNF production by spinal cord microglia after acute demyelination in the spinal cord. Additionally, we confirmed the ability of MSCs to suppress TNF in a simple assay with a microglia cell line (IMG). Discussion In this study, we demonstrated that cord tissue MSCs altered the immune response, suppressed microglia activation, and the release of TNF, a cytokine known to contribute to white matter damage. Among these assays, IMG could be standardized as an effective potency assay to determine the efficacy of MSC for the use in treatment of white matter disease.

Effect of Expansion Media on Functional Characteristics of Bone Marrow-Derived Mesenchymal Stromal Cells.

The therapeutic efficacy of mesenchymal stromal cells (MSCs) has been shown to rely on their immunomodulatory and regenerative properties. In order to obtain sufficient numbers of cells for clinical applications, MSCs have to be expanded ex vivo. Expansion media with xenogeneic-free (XF) growth-promoting supplements like human platelet lysate (PL) or serum- and xenogeneic-free (SF/XF) formulations have been established as safe and efficient, and both groups provide different beneficial qualities. In this study, MSCs were expanded in XF or SF/XF media as well as in mixtures thereof. MSCs cultured in these media were analyzed for phenotypic and functional properties. MSC expansion was optimal with SF/XF conditions when PL was present. Metabolic patterns, consumption of growth factors, and secretome of MSCs differed depending on the type and concentration of supplement. The lactate per glucose yield increased along with a higher proportion of PL. Many factors in the supernatant of cultured MSCs showed distinct patterns depending on the supplement (e.g., FGF-2, TGFβ, and insulin only in PL-expanded MSC, and leptin, sCD40L PDGF-AA only in SF/XF-expanded MSC). This also resulted in changes in cell characteristics like migratory potential. These findings support current approaches where growth media may be utilized for priming MSCs for specific therapeutic applications.

Challenges in Mesenchymal Stromal Cell-based Therapies.

Over 50 years have passed since discovering mesenchymal stromal cells (MSCs). Initially, despite gaps in the knowledge of the identity of these cells, their therapeutic aspects were recognized. Consequently, MSCs became candidates for treating a wide range of diseases. However, the therapeutic effects of MSCs are not stable in the long term, and there are inconsistent data on their clinical efficacy. Even though more than 1000 MSC-based clinical trials have been registered, and the safety of MSCbased cell therapies has been proven, data on the clinical efficacy of MSCs have not been enough to warrant FDA approval for clinical treatment and marketing purposes. The available information on MSCs still contains some controversies, perhaps owing to little progress in understanding their in vivo identity. MSCs have been used for therapeutic purposes despite poor knowledge of their in vivo origin or functions. Hence, perhaps we need to go back to the basics of MSCs and spend more time understanding the biology of these cells. An improved understanding of MSCs' location and function within tissues may improve their therapeutic efficacy and, consequently, their establishment as a cell therapy product.

Enhancing the Efficacy of Mesenchymal Stromal Cells in COVID-19-related Acute Respiratory Distress Syndrome.

"Enhancing the Efficacy of Mesenchymal Stromal Cells in COVID-19-related Acute Respiratory Distress Syndrome." American Journal of Respiratory and Critical Care Medicine, 0(ja), pp.

Strategy insight: Mechanical properties of biomaterials' influence on hydrogel-mesenchymal stromal cell combination for osteoarthritis therapy.

Osteoarthritis (OA) is a kind of degenerative joint disease usually found in older adults and those who have received meniscal surgery, bringing great suffering to a number of patients worldwide. One of the major pathological features of OA is retrograde changes in the articular cartilage. Mesenchymal stromal cells (MSCs) can differentiate into chondrocytes and promote cartilage regeneration, thus having great potential for the treatment of osteoarthritis. However, improving the therapeutic effect of MSCs in the joint cavity is still an open problem. Hydrogel made of different biomaterials has been recognized as an ideal carrier for MSCs in recent years. This review focuses on the influence of the mechanical properties of hydrogels on the efficacy of MSCs in OA treatment and compares artificial materials with articular cartilage, hoping to provide a reference for further development of modified hydrogels to improve the therapeutic effect of MSCs.

Pooled Analysis of Mesenchymal Stromal Cell-Derived Extracellular Vesicle Therapy for Liver Disease in Preclinical Models.

Although increasing preclinical studies have emphasized the benefits of exosome-related therapies, the efficacy of mesenchymal stromal cell (MSC)-derived extracellular vesicles (EV) for liver injury is unclear. In this work, a pooled analysis was conducted to explore the overall effect of MSC-EV in animal models. A systematic search of the PubMed, EMBASE, Web of Science, and Cochrane Library databases was performed, from initiation to February 2022, for preclinical studies with liver disease models. The treatment outcomes were evaluated based on liver function, histological analysis, and inflammatory cytokines. After screening, 39 studies were included. Pooled analyses demonstrated that MSC-EV therapy significantly improved liver functions (ALB, ALT, AST, ALP, and γ-GT), promoted the repair of injured liver tissue (damaged area, Ishak's score), reduced inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), and increased an anti-inflammatory cytokine (IL-10) compared to the placebo control group. Subgroup analyses indicated that MSC-EV had therapeutic effects on liver fibrosis (n = 16), acute liver injury (n = 11), non-alcoholic fatty liver disease (n = 3), autoimmune hepatitis (n = 4), and hepatic ischemia-reperfusion injury (n = 6). Additionally, the therapeutic effect of EV was comparable to that of MSCs. MSC-EV have therapeutic potential for acute and chronic liver diseases.

TGFβ1 priming enhances CXCR3-mediated mesenchymal stromal cell engraftment to the liver and enhances anti-inflammatory efficacy.

The immunomodulatory characteristics of mesenchymal stromal cells (MSC) confers them with potential therapeutic value in the treatment of inflammatory/immune-mediated conditions. Previous studies have reported only modest beneficial effects in murine models of liver injury. In our study we explored the role of MSC priming to enhance their effectiveness. Herein we demonstrate that stimulation of human MSC with cytokine TGβ1 enhances their homing and engraftment to human and murine hepatic sinusoidal endothelium in vivo and in vitro, which was mediated by increased expression of CXCR3. Alongside improved hepatic homing there was also greater reduction in liver inflammation and necrosis, with no adverse effects, in the CCL4 murine model of liver injury treated with primed MSC. Priming of MSCs with TGFβ1 is a novel strategy to improve the anti-inflammatory efficacy of MSCs.

ABCB5+ mesenchymal stromal cells therapy protects from hypoxia by restoring Ca2+ homeostasis in vitro and in vivo

BackgroundHypoxia in ischemic disease impairs Ca2+ homeostasis and may promote angiogenesis. The therapeutic efficacy of mesenchymal stromal cells (MSCs) in peripheral arterial occlusive disease is well established, yet its influence on cellular Ca2+ homeostasis remains to be elucidated. We addressed the influence of ATP-binding cassette subfamily B member 5 positive mesenchymal stromal cells (ABCB5+ MSCs) on Ca2+ homeostasis in hypoxic human umbilical vein endothelial cells (HUVECs) in vitro and in vivo.MethodsHypoxia was induced in HUVECs by Cobalt (II) chloride (CoCl2) or Deferoxamine (DFO). Dynamic changes in the cytosolic- and endoplasmic reticulum (ER) Ca2+ and changes in reactive oxygen species were assessed by appropriate fluorescence-based sensors. Metabolic activity, cell migration, and tube formation were assessed by standard assays. Acute-on-chronic ischemia in Apolipoprotein E knock-out (ApoE−/−) mice was performed by double ligation of the right femoral artery (DFLA). ABCB5+ MSC cells were injected into the ischemic limb. Functional recovery after DFLA and histology of gastrocnemius and aorta were assessed.ResultsHypoxia-induced impairment of cytosolic and ER Ca2+ were restored by ABCB5+ MSCs or their conditioned medium. Similar was found for changes in intracellular ROS production, metabolic activity, migratory ability and tube formation. The restoration was paralleled by an increased expression of the Ca2+ transporter Sarco-/endoplasmic reticulum ATPase 2a (SERCA2a) and the phosphorylation of Phospholamban (PLN). In acute-on-chronic ischemia, ABCB5+ MSCs treated mice showed a higher microvascular density, increased SERCA2a expression and PLN phosphorylation relative to untreated controls.ConclusionsABCB5+ MSCs therapy can restore cellular Ca2+ homeostasis, which may beneficially affect the angiogenic function of endothelial cells under hypoxia in vitro and in vivo.

Improved efficacy of mesenchymal stromal cells stably expressing CXCR4 and IL-10 in a xenogeneic graft versus host disease mouse model.

Previous clinical trials have shown that mesenchymal stromal cells (MSCs) can modulate graft versus host disease (GvHD) after allogeneic hematopoietic transplantation, although with variable efficacy. To improve the anti-GvHD effect of these cells, adipose tissue derived-human MSCs (Ad-MSCs) were transduced with a lentiviral vector conferring stable expression of CXCR4, a molecule involved in cell migration to inflamed sites, and IL-10, a cytokine with potent anti-inflammatory properties. In vitro experiments showed that the expression of these molecules in Ad-MSCs (named CXCR4-IL10-MSCs) efficiently enhanced their migration towards SDF-1α and also improved their immunomodulatory properties compared to unmodified Ad-MSCs (WT-MSCs). Moreover, using a humanized GvHD mouse model, CXCR4-IL10-MSCs showed improved therapeutic effects, which were confirmed by histopathologic analysis in the target organs. Additionally, compared to WT-MSCs, CXCR4-IL10-MSCs induced a more marked reduction in the number of pro-inflammatory Th1 and Th17 cells, a higher polarization towards an anti-inflammatory T cell profile (CD3+-IL10+ cells), and increased the number of regulatory T and B cells. Our in vitro and in vivo studies strongly suggest that CXCR4-IL10-MSCs should constitute an important new generation of MSCs for the treatment of GvHD in patients transplanted with allogeneic hematopoietic grafts.

The safety and efficacy of mesenchymal stromal cells in ARDS: a meta-analysis of randomized controlled trials

Mesenchymal stromal cells (MSC) have shown potential efficacy in both animal and human trials of acute respiratory distress syndrome (ARDS). Especially during the COVID-19 pandemic, MSC was intensely studied for treating COVID-19-induced ARDS. The purpose of this study is to evaluate the safety and efficacy of MSC in ARDS via a meta-analysis of randomized controlled trials (RCTs). Therefore, a meta-analysis of RCTs of MSC as a therapy for ARDS was conducted. The protocol of this review was registered on Open Science Framework. With no language restriction and according to the “PICOs” principle, searches were conducted on Pubmed and Embase to retrieve any clinical literature on MSC for ARDS. Any RCT, which compared MSC to controls for ARDS, where MSC and controls were intravenously infused, of any dosage, was eligible for inclusion. A total of 13 RCTs, which evaluated MSC versus control for treating ARDS, enrolling a total of 655 cases, met the inclusion criteria and appeared in this meta-analysis. A heterogeneity assessment was carried out using the χ2 test, where a P value less than 0.05 was considered significant. The choice of a fixed-effect or a random-effect model was decided by the I2 value in each of the analyses. This meta-analysis indicated that there was no significant difference in terms of adverse events between MSC and control for ARDS (OR = 0.64, 95% CI [0.34, 1.20], P = 0.17, and I2 = 0%). In comparison with control, MSC could reduce the mortality of ARDS (OR = 0.66, 95% CI [0.46, 0.96], P = 0.03, and I2 = 10%). Based on the results of our meta-analysis, the safety of MSC was demonstrated to be non-inferior to that of standard treatment, and MSC may reduce the mortality rate of ARDS. Though the heterogeneity in the main results was low (I2 < 25%), more high-quality and large-scale clinical trials are needed to further confirm our findings.

Mesenchymal stromal cells and alpha-1 antitrypsin have a strong synergy in modulating inflammation and its resolution.

Rationale: Trauma, surgery, and infection can cause severe inflammation. Both dysregulated inflammation intensity and duration can lead to significant tissue injuries, organ dysfunction, mortality, and morbidity. Anti-inflammatory drugs such as steroids and immunosuppressants can dampen inflammation intensity, but they derail inflammation resolution, compromise normal immunity, and have significant adverse effects. The natural inflammation regulator mesenchymal stromal cells (MSCs) have high therapeutic potential because of their unique capabilities to mitigate inflammation intensity, enhance normal immunity, and accelerate inflammation resolution and tissue healing. Furthermore, clinical studies have shown that MSCs are safe and effective. However, they are not potent enough, alone, to completely resolve severe inflammation and injuries. One approach to boost the potency of MSCs is to combine them with synergistic agents. We hypothesized that alpha-1 antitrypsin (A1AT), a plasma protein used clinically and has an excellent safety profile, was a promising candidate for synergism. Methods: This investigation examined the efficacy and synergy of MSCs and A1AT to mitigate inflammation and promote resolution, using in vitro inflammatory assay and in vivo mouse acute lung injury model. The in vitro assay measured cytokine releases, inflammatory pathways, reactive oxygen species (ROS), and neutrophil extracellular traps (NETs) production by neutrophils and phagocytosis in different immune cell lines. The in vivo model monitored inflammation resolution, tissue healing, and animal survival. Results: We found that the combination of MSCs and A1AT was much more effective than each component alone in i) modulating cytokine releases and inflammatory pathways, ii) inhibiting ROS and NETs production by neutrophils, iii) enhancing phagocytosis and, iv) promoting inflammation resolution, tissue healing, and animal survival. Conclusion: These results support the combined use of MSCs, and A1AT is a promising approach for managing severe, acute inflammation.

Long-term passages of human clonal mesenchymal stromal cells can alleviate the disease in the rat model of collagen-induced arthritis resembling early passages of different heterogeneous cells.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease of unknown cause. The interaction of immune system cells and the secretion of inflammatory cytokines with synovial cells leads to severe inflammation in the affected joints. Currently, medications, including non-steroidal anti-inflammatory drugs, glucocorticoids, and more recently, disease-modifying anti-rheumatic drugs, are used to reduce inflammation. However, long-term use of these drugs causes adverse effects or resistance in a considerable number of RA patients. Recent findings revealed the safety and efficacy of mesenchymal stromal cells (MSCs)-based therapies both in RA animal models and clinical trials. Here, the beneficial effects of bone marrow-derived heterogeneous MSCs (BM-hMSCs) and Wharton jelly-derived MSCs (WJ-MSCs) at early passages were compared to BM-derived clonal MSCs (BM-cMSCs) at high passage number on a rat model of collagen-induced arthritis. Results showed that systemic delivery of MSCs significantly reversed adverse changes in body weight, paw swelling, and arthritis score in all MSC-treated groups. Radiological images and histological evaluation demonstrated the therapeutic effects of MSCs. There was a decrease in serum level of anti-collagen type II immunoglobulin G and the inflammatory cytokines interleukin (IL)-1β, IL-6, IL-17, and tumor necrosis factor-α in all MSC-treated groups. In contrast, an increase in inhibitory cytokines transforming growth factor-β and IL-10 was seen. Notably, the long-term passages of BM-cMSCs could alleviate RA symptoms similar to the early passages of WJ-MSCs and BM-hMSCs. The importance of BM-cMSCs is the potential to establish cell banks with billions of cells derived from a single donor that could be a competitive cell-based therapy to treat RA.