Efficacy Of Mesenchymal Stem Cells Research Articles

ThP2.17 - Efficacy of Mesenchymal Stem Cells in the Treatment of Osteonecrosis of Femoral Head

Abstract Introduction Osteonecrosis of the femoral head (ONFH) has substantial morbidity and impacts patient populations worldwide. Mesenchymal stem cells (MSCs) are implicated for their potential in ONFH treatment. The objective of this study is to examine the effectiveness of MSC when compared to existing surgical options in the treatment of ONFH. Method A literature search is conducted through Pubmed, MedlineOvid, and Cochrane. The studies were selected using PRISMA and ROBVIS. Four randomised controlled trials and two preliminary studies with a total of 599 participants were included in the study. Results Progression to advanced stages of ONFH was reduced in bone marrow mesenchymal stem cells (BMMSC) applied in conjunction with core decompression (CD) when compared to CD alone (3.77% vs. 22.7%, p<0.05) and reduced femoral head collapse (28% vs. 72%). Improvement in Hip Harris Score (HHS) when compared to CD alone (31.85 vs. 19.72 control, p = 0.03) was also observed. The joint preservation rate of applying BMMSC in tantalum rod insertion with vascularized iliac grafting in end-stage ONFH patients was greater than that of vascularized iliac grafting alone (83.33% vs. 57% in stage IV patients) and associated with a better outcome (HHS 6.29±6.11 to 77.23±14.75). Improvement in WOMAC, VAS and Lequesne index was also observed when comparing CD with bone grafts and CD, bone grafts and BMMSC. Conclusion The use of MSC applications along with current surgeries has been shown to improve post-operative outcomes and progression to advanced ONFH stages in the treatment of ONFH compared to surgeries done alone.

A drug delivery system of HIF-1α siRNA nanoparticles loaded by mesenchymal stem cells on choroidal neovascularization.

Aim: To assess mesenchymal stem cells (MSCs) as carriers for HIF-1αsiRNA-loaded nanoparticles (NPs) for targeted therapy of experimental choroidal neovascularization (CNV).Materials & methods: A poly (lactic-co-glycolic acid) (PLGA)-core/lipid-shell hybrid NP was designed. The transfection efficacy of MSCs with the hybrid NPs was assessed. Mice were intravenously injected with MSCs after laser photocoagulation and CNV was assessed at 7days post-injection.Results & conclusion: The transfection efficiency of hybrid NPs into MSCs was 72.7%. HIF-1α mRNA expression in 661w cells co-cultured with MSC-hybrid-siRNA NPs was significantly lower. Intravenous delivery of MSC-hybrid-siRNA NPs greatly reduced CNV area and length. Intravenous injection of MSC-hybrid-siRNA NPs achieved therapeutic efficacy in reducing CNV area. The MSC-mediated homing enabled targeted inhibition of ocular angiogenesis.

Mesenchymal stem cell therapy in veterinary ophthalmology: clinical evidence and prospects.

Mesenchymal stem cell (MSC) therapy presents a promising strategy for treating various ocular conditions in veterinary medicine. This review explores the therapeutic potential of MSCs in managing corneal ulcers, immune-mediated keratitis, chronic superficial keratitis, keratoconjunctivitis sicca, retinal degeneration, and ocular burns in feline, equine, and canine patients. Studies have demonstrated the immunomodulatory and regenerative properties of MSCs, highlighting their ability to mitigate inflammation and promote tissue regeneration. Experimental studies have shown the potential of MSC therapy in reducing corneal opacity and vascularization, indicating significant therapeutic advantages. Delivery methods play a crucial role in optimizing the therapeutic efficacy of MSCs in ocular diseases. Various delivery methods, such as intravitreal injection, subconjunctival injection, topical administration, and scaffold-mediated delivery, are being explored to optimize MSC delivery to the target ocular tissues. Clinical trials have shown significant improvements in clinical signs following MSC therapy, underscoring its efficacy in treating ocular diseases. Additionally, tissue engineering approaches incorporating MSCs, growth factors, and scaffolds offer innovative strategies for corneal regeneration and tissue repair. Despite challenges such as standardization of protocols and long-term safety assessment, ongoing research endeavours seek to unlock the full therapeutic potential of MSC therapy in ocular diseases. Future prospects in MSC therapy involve exploring scaffold and hydrogel-based approaches and cell-free therapies leveraging the bioactive molecules released by MSCs. Continued research and development efforts are essential to unlock the full therapeutic potential of MSCs and realize their transformative impact on ocular diseases in veterinary patients.

Mesenchymal stem cell therapy for liver fibrosis need "partner": Results based on a meta-analysis of preclinical studies.

The efficacy of mesenchymal stem cells (MSCs) in treating liver fibrosis has been demonstrated in several clinical studies. However, their low survival and liver implantation rates remain problematic. In recent years, a large number of studies in animal models of liver fibrosis have shown that MSCs combined with drugs can improve the efficacy of MSCs in the treatment of liver fibrosis alone and inhibit its progression to end-stage liver disease. This has inspired new ways of thinking about treating liver fibrosis. To investigate the effectiveness and mechanisms of MSCs combined with drugs in treating liver fibrosis. Data sources included four electronic databases and were constructed until January 2024. The subjects, interventions, comparators, outcomes, and study design principle were used to screen the literature, and the quality of the literature was evaluated to assess the risk of bias. Relevant randomised controlled trials were selected, and the final 13 studies were included in the final study. A total of 13 studies were included after screening. Pooled analysis showed that MSCs combined with drug therapy significantly improved liver function, promoted the repair of damaged liver tissues, reduced the level of liver fibrosis-related indexes, and effectively ameliorated hepatic fibrosis by modulating the hepatic inflammatory microenvironment, promoting the homing of MSCs, and regulating the relevant signaling pathways, and the treatment efficacy was superior to MSCs alone. However, the combined treatment statistics showed no ame-lioration in serum albumin levels (standardized mean difference = 0.77, 95% confidence interval: -0.13 to 1.68, P = 0.09). In conclusion, MSCs combined with drugs for treating liver fibrosis effectively make up for the shortcomings of MSCs in their therapeutic effects. However, due to the different drugs, the treatment mechanism and effect also differ. Therefore, more randomized controlled trials are needed to compare the therapeutic efficacy of different drugs in combination with MSCs, aiming to select the "best companion" of MSCs in treating hepatic fibrosis.

Material-driven immunomodulation and ECM remodeling reverse pulmonary fibrosis by local delivery of stem cell-laden microcapsules

Recent progress in stem cell therapy has demonstrated the therapeutic potential of intravenous stem cell infusions for treating the life-threatening lung disease of pulmonary fibrosis (PF). However, it is confronted with limitations, such as a lack of control over cellular function and rapid clearance by the host after implantation. In this study, we developed an innovative PF therapy through tracheal administration of microfluidic-templated stem cell-laden microcapsules, which effectively reversed the progression of inflammation and fibrotic injury. Our findings highlight that hydrogel microencapsulation can enhance the persistence of donor mesenchymal stem cells (MSCs) in the host while driving MSCs to substantially augment their therapeutic functions, including immunoregulation and matrix metalloproteinase (MMP)-mediated extracellular matrix (ECM) remodeling. We revealed that microencapsulation activates the MAPK signaling pathway in MSCs to increase MMP expression, thereby degrading overexpressed collagen accumulated in fibrotic lungs. Our research demonstrates the potential of hydrogel microcapsules to enhance the therapeutic efficacy of MSCs through cell-material interactions, presenting a promising yet straightforward strategy for designing advanced stem cell therapies for fibrotic diseases.

Activation of Mitochondria in Mesenchymal Stem Cells by Mitochondrial Delivery of Coenzyme Q10.

The efficacy of mesenchymal stem cell (MSC) transplantation has been reported for various diseases. We previously developed a drug delivery system targeting mitochondria (MITO-Porter) by using a microfluidic device to encapsulate Coenzyme Q10 (CoQ10) on a large scale. The current study aimed to confirm if treatment with CoQ10 encapsulated by MITO-Porter enhanced mitochondrial functions in MSCs, with the potential to improve MSC transplantation therapy. We used highly purified human bone marrow-derived MSCs, described as rapidly expanding clones (RECs), and attempted to control and increase the amount of CoQ10 encapsulated in the MITO-Porter using microfluidic device system. We treated these RECs with CoQ10 encapsulated MITO-Porter, and evaluated its cellular uptake, co-localization with mitochondria, changes in mitochondrial respiratory capacity, and cellular toxicity. There was no significant change in mitochondrial respiratory capacity following treatment with the previous CoQ10 encapsulated MITO-Porter; however, mitochondrial respiratory capacity in RECs was significantly increased by treatment with CoQ10-rich MITO-Porter. Utilization of a microfluidic device enabled the amount of CoQ10 encapsulated in MITO-Porter to be controlled, and treatment with CoQ10-rich MITO-Porter successfully activated mitochondrial functions in MSCs. The MITO-Porter system thus provides a promising tool to improve MSC cell transplantation therapy.

Nanozyme-enhanced mitophagy to improve the efficacy of mesenchymal stem cells in myocardial infarction therapy

Mesenchymal stem cell therapy has emerged as a promising approach for the treatment of myocardial infarction. However, the challenge of low cell survival and retention post injection, particularly under the high levels of reactive oxygen species (ROS) and oxidative stress at the infarct site, has hindered their clinical application. Additionally, traditional drug delivery methods, such as intravenous injection, cannot meet the demand for long-term stem cell residence at the infarct site, which is another critical issue that impedes the therapeutic efficacy of stem cells. Herein, we synthesized indocyanine green-enriched Prussian blue nanozyme, called PB@PEI@ICG, which not only possessed remarkable ROS scavenging capability but also exhibited superior fluorescent tracer property. Subsequently, we engineered mesenchymal stem cells (MSCs) with PB@PEI@ICG by co-culture and found that the introduction of the nanozyme significantly enhanced mitophagy by BNIP3 and PINK1 pathways, which in turn promoted ROS scavenging and protected MSCs from cell death induced by the harsh infarct microenvironment. Furthermore, we employed pericardial injection as an alternative delivery method to prolong the residence time of MSCs at the infarct site, enabling real-time tracking via the fluorescence property of the nanozymes. The results demonstrated that PB@PEI@ICG nanozyme could significantly improve the survival and retention of MSCs at the infarct site, thereby enhancing the therapeutic effect for myocardial infarction. In conclusion, this study presents a novel strategy for stem cell therapy in myocardial infarction by using mitophagy-enhancing nanozyme to scavenge ROS for enhancing the therapeutic potential of stem cells.

Effectiveness and mechanisms of mesenchymal stem cell therapy in preclinical animal models of hepatic fibrosis: a systematic review and meta-analysis.

Liver damage due to long-term viral infection, alcohol consumption, autoimmune decline, and other factors could lead to the gradual development of liver fibrosis. Unfortunately, until now, there has been no effective treatment for liver fibrosis. Mesenchymal stem cells, as a promising new therapy for liver fibrosis, can slow the progression of fibrosis by migrating to the site of liver injury and by altering the microenvironment of the fibrotic area. By including all relevant studies to date to comprehensively assess the efficacy of mesenchymal stem cells for the treatment of hepatic fibrosis and to explore considerations for clinical translation and therapeutic mechanisms. Data sources included PubMed, Web of Science, Embase, and Cochrane Library, and were constructed until October 2023. Data for each study outcome indicator were extracted for comprehensive analysis. The overall meta-analysis showed that mesenchymal stem cells significantly improved liver function. Moreover, it inhibited the expression level of transforming growth factor-β [SMD = 4.21, 95% CI (3.02,5.40)], which in turn silenced hepatic stellate cells and significantly reduced the area of liver fibrosis [SMD = 3.61, 95% CI (1.41,5.81)]. Several outcome indicators suggest that mesenchymal stem cells therapy is relatively reliable in the treatment of liver fibrosis. The therapeutic effect is cell dose-dependent over a range of doses, but not more effective at higher doses. Bone-marrow derived mesenchymal stem cells were more effective in treating liver fibrosis than mesenchymal stem cells from other sources. Identifier CRD42022354768.

The autophagy protein RUBCNL/PACER represses RIPK1 kinase-dependent apoptosis and necroptosis

ABSTRACT Mesenchymal stem cells (MSCs) are used in cell therapy; nonetheless, their application is limited by their poor survival after transplantation in a proinflammatory microenvironment. Macroautophagy/autophagy activation in MSCs constitutes a stress adaptation pathway, promoting cellular homeostasis. Our proteomics data indicate that RUBCNL/PACER (RUN and cysteine rich domain containing beclin 1 interacting protein like), a positive regulator of autophagy, is also involved in cell death. Hence, we screened MSC survival upon various cell death stimuli under loss or gain of function of RUBCNL. MSCs were protected from TNF (tumor necrosis factor)-induced regulated cell death when RUBCNL was expressed. TNF promotes inflammation by inducing RIPK1 kinase-dependent apoptosis or necroptosis. We determine that MSCs succumb to RIPK1 kinase-dependent apoptosis upon TNF sensing and necroptosis when caspases are inactivated. We show that RUBCNL is a negative regulator of both RIPK1-dependent apoptosis and necroptosis. Furthermore, RUBCNL mutants that lose the ability to regulate autophagy, retain their function in negatively regulating cell death. We also found that RUBCNL forms a complex with RIPK1, which disassembles in response to TNF. In line with this finding, RUBCNL expression limits assembly of RIPK1-TNFRSF1A/TNFR1 complex I, suggesting that complex formation between RUBCNL and RIPK1 represses TNF signaling. These results provide new insights into the crosstalk between the RIPK1-mediated cell death and autophagy machineries and suggest that RUBCNL, due to its functional duality in autophagy and apoptosis/necroptosis, could be targeted to improve the therapeutic efficacy of MSCs. Abbreviations: BAF: bafilomycin A1; CASP3: caspase 3; Caspases: cysteine-aspartic proteases; cCASP3: cleaved CASP3; CQ: chloroquine; CHX: cycloheximide; cPARP: cleaved poly (ADP-ribose) polymerase; DEPs: differential expressed proteins; ETO: etoposide; MEF: mouse embryonic fibroblast; MLKL: mixed lineage kinase domain-like; MSC: mesenchymal stem cell; MTORC1: mechanistic target of rapamycin kinase complex 1; Nec1s: necrostatin 1s; NFKB/NF-kB: nuclear factor of kappa light polypeptide gene enhancer in B cells; PLA: proximity ligation assay; RCD: regulated cell death; RIPK1: receptor (TNFRSF)-interacting serine-threonine kinase 1; RIPK3: receptor-interacting serine-threonine kinase 3; RUBCNL/PACER: RUN and cysteine rich domain containing beclin 1 interacting protein like; siCtrl: small interfering RNA nonsense; siRNA: small interfering RNA; TdT: terminal deoxynucleotidyl transferase; Tm: tunicamycin; TNF: tumor necrosis factor; TNFRSF1A/TNFR1: tumor necrosis factor receptor superfamily, member 1a

Activation of cellular antioxidative stress and migration activities by purified components from immortalized stem cells from human exfoliated deciduous teeth

Although stem cell-based regenerative medicine has been extensively studied, it remains difficult to reconstruct three dimensional tissues and organs in combination with vascular systems in vitro. One clinically successful therapy is transplantation of mesenchymal stem cells (MSC) into patients with graft versus host disease. However, transplanted cells are immediately damaged and destroyed because of innate immune reactions provoked by thrombogenic inflammation, and patients need to take immunosuppressive drugs for the immunological regulation of allogeneic cells. This reduces the benefits of stem cell transplantation. Therefore, alternative therapies are more realistic options for clinical use. In this study, we aimed to take advantage of the therapeutic efficacy of MSC and use multiple cytokines released from MSC, that is, stem cells from human exfoliated deciduous teeth (SHEDs). Here, we purified components from conditioned media of immortalized SHED (IM-SHED-CM) and evaluated the activities of intracellular dehydrogenase, cell migration, and antioxidative stress by studying the cells. The immortalization of SHED could make the stable supply of CM possible. We found that the fractionated component of 50–100 kD from IM-SHED-CM had higher efficacy than the original IM-SHED-CM in terms of intracellular dehydrogenase and cell migration in which intracellular signal transduction was activated via receptor tyrosine kinases, and the glutathione peroxidase and reductase system was highly active. Although antioxidative stress activities in the fractionated component of 50–100 kD had slightly lower than that of original IM-SHE-CM, the fraction still had the activity. Thus, the use of fractionated components of 50–100 kD from IM-SHED-CM could be an alternative choice for MSC transplantation because the purified components from CM could maintain the effect of cytokines from SHED.

Bibliometric Analysis of MSC-based Therapies for Non-COVID-19 ARDS

Background: Acute respiratory distress syndrome (ARDS) poses a significant challenge as it lacks specific treatments and can occur due to various etiologies. Mesenchymal stem cells (MSCs) have emerged as a promising cell-based therapy for ARDS due to their immunomodulatory, anti-inflammatory, and anti-fibrotic properties. Despite encouraging findings from preclinical studies, clinical evidence supporting the efficacy of MSCs in non-COVID-19 ARDS remains insufficient. Methods: We conducted a systematic search of three major databases (Web of Science Core Collection, Scopus, and PubMed) to identify original articles focusing on MSCs in non-COVID-19 ARDS. Subsequently, we employed the bibliometric package in R Studio to analyze and visualize bibliometric indicators derived from the retrieved articles. Results: Our analysis of 244 original studies revealed a notable trend in research on MSCs and non-COVID-19 ARDS. While the number of publications in this area saw an increase beginning in 2007, it exhibited a decline after 2019, with only 20 articles published in 2022. Notably, a significant proportion (131/244) of these studies originated from Chinese scholars. MSC derivatives emerged as a recent research focus due to their unique advantages as an alternative to MSCs. Specifically, umbilical cord/placental-derived MSCs have gained traction, surpassing the use of bone marrow-derived MSCs by 2022. The route of delivery is still mainly intravenous. Despite the potential advantages of the intratracheal route for lung-related diseases, the intravenous route remains the preferred mode of drug delivery. Conclusion: Research on non-COVID-19 ARDS deserves further attention and investments. Existing studies have primarily focused on MSC derivatives that have shown clinical efficacy. Furthermore, umbilical cord/placental-derived MSCs are expected to replace traditional bone marrow- derived MSCs in research. Intratracheal delivery, which offers advantages for treating pulmonary diseases, still requires extensive experiments to validate.

WTAP/YTHDF1-mediated m6A modification amplifies IFN-γ-induced immunosuppressive properties of human MSCs

IntroductionThe immunosuppressive capacity of mesenchymal stem cells (MSCs) is dependent on the “license” of several pro-inflammatory factors to express immunosuppressive molecular profiles, which determines the therapeutic efficacy of MSCs in immune-mediated inflammatory diseases. Of those, interferon-γ (IFN-γ) is a key inducer for the expression of immunosuppressive molecular profiles; however, the mechanism underlying this effect is unknown. ObjectivesTo elucidate the regulation mechanism and biological functions of N6-methyladenosine (m6A) modification in the immunosuppressive functions by the IFN-γ-licensing MSCs. MethodsEpitranscriptomic microarray analysis and MeRIP-qPCR assay were performed to identify the regulatory effect of WTAP in the IFN-γ-licensing MSCs. RIP-qPCR, western blot, qRT-PCR and RNA stability assays were used to determine the regulation of WTAP/m6A/YTHDF1 signaling axis in the expression of immunosuppressive molecules. Further, functional capacity of T cells was tested using flow cytometry, and both DSS-induced colitis mice and CIA mice were constructed to clarify the effect of WTAP and YTHDF1 in MSC-mediated immunosuppression. ResultsWe identified that IFN-γ increased the m6A methylation levels of immunosuppressive molecules, while WTAP deficiency abolished the IFN-γ-induced promotion of m6A modification. IFN-γ activated ERK signaling, which induced WTAP phosphorylation. Additionally, the stabilization of WTAP post-transcriptionally increased the mRNA expression of immunosuppressive molecules (IDO1, PD-L1, ICAM1, and VCAM1) in an m6A-YTHDF1-dependent manner; this effect further impacted the immunosuppressive capacity of IFN-γ licensing MSCs on activated T cells. Notably, WTAP/YTHDF1 overexpression enhanced the therapeutic efficacy of IFN-γ licensing MSCs and restructures the ecology of inflammation in both colitis and arthritis models. ConclusionOur results showed that m6A modification of IDO1, PD-L1, ICAM1, and VCAM1 mRNA mediated by WTAP-YTHDF1 is involved in the regulation of IFN-γ licensing MSCs immunosuppressive abilities, and shed a light to enhance the clinical therapeutic potential of IFN-γ-licensing MSCs.

Synergistic effect of ex-vivo quality and quantity cultured mononuclear cells and mesenchymal stem cell therapy in ischemic hind limb model mice

IntroductionChronic limb-threatening ischemia (CLTI) is a condition characterized by peripheral arterial disease and tissue damage caused by reduced blood flow. New therapies using various cell types, such as mesenchymal stem cells (MSCs) and mononuclear cells (MNCs), have been developed for the patients unresponsive to conventional therapies. MSCs are promising because of their ability to secrete growth factors essential for vascularization, whereas MNCs contain endothelial progenitor cells that are important for blood vessel formation. However, conventional methods for isolating these cells have limitations, especially in patients with diabetes with dysfunctional cells. To overcome this problem, a culture method called quality and quantity cultured peripheral blood MNCs (MNC-QQ) was developed to efficiently produce high-quality cells from small amounts of peripheral blood. Combining MSCs with MNC-QQs has been hypothesized to enhance therapeutic outcomes. This study aimed to examine the angiogenic efficacy of MSCs with MNC-QQs in models with severe lower limb ischemia. MethodsMNC-QQ was manufactured from the peripheral blood of healthy volunteers, while human bone marrow derived MSCs were purchased. To verify the effects of the MSC and MNC-QQs combination in angiogenesis, we conducted the HUVEC tube formation assay. For in vivo experiments, we created an ischemic limb model using BALB/c nude mice. Saline, MSCs alone, and a combination of MSCs and MNC-QQs were administered intramuscularly into the ischemic limbs. Blood flow was measured over time using laser doppler, and the ischemic limbs were harvested 21 days later for HE staining and immunostaining for histological assessment. ResultsIn-vitro studies demonstrated increased angiogenesis when MSCs were combined with MNC-QQs compared with MSCs alone. In vivo experiments using a mouse model of severe lower limb ischemia showed that combination therapy significantly improved blood flow recovery and limb salvage compared with MSCs alone or saline treatment. Histological analysis revealed enhanced vessel density, arteriogenesis, muscle regeneration, and reduced fibrosis in the MSC+MNC-QQ group compared with those in the saline group. Although the specific interactions between MSCs and MNC-QQs have not been fully elucidated, combined therapy leverages the benefits of both cell types, resulting in improved outcomes for vascular regeneration. ConclusionsThis study highlights the potential of the simultaneous transplantation of MSCs and MNC-QQs as a promising therapeutic approach for CLTI, offering sustained long-term benefits for patients.

Endothelial cell-derived extracellular vesicles modulate the therapeutic efficacy of mesenchymal stem cells through IDH2/TET pathway in ARDS

BackgroundAcute respiratory distress syndrome (ARDS) is a severe and fatal disease. Although mesenchymal stem cell (MSC)-based therapy has shown remarkable efficacy in treating ARDS in animal experiments, clinical outcomes have been unsatisfactory, which may be attributed to the influence of the lung microenvironment during MSC administration. Extracellular vesicles (EVs) derived from endothelial cells (EC-EVs) are important components of the lung microenvironment and play a crucial role in ARDS. However, the effect of EC-EVs on MSC therapy is still unclear. In this study, we established lipopolysaccharide (LPS) - induced acute lung injury model to evaluate the impact of EC-EVs on the reparative effects of bone marrow-derived MSC (BM-MSC) transplantation on lung injury and to unravel the underlying mechanisms.MethodsEVs were isolated from bronchoalveolar lavage fluid of mice with LPS - induced acute lung injury and patients with ARDS using ultracentrifugation. and the changes of EC-EVs were analysed using nanoflow cytometry analysis. In vitro assays were performed to establish the impact of EC-EVs on MSC functions, including cell viability and migration, while in vivo studies were performed to validate the therapeutic effect of EC-EVs on MSCs. RNA-Seq analysis, small interfering RNA (siRNA), and a recombinant lentivirus were used to investigate the underlying mechanisms.ResultsCompared with that in non-ARDS patients, the quantity of EC-EVs in the lung microenvironment was significantly greater in patients with ARDS. EVs derived from lipopolysaccharide-stimulated endothelial cells (LPS-EVs) significantly decreased the viability and migration of BM-MSCs. Furthermore, engrafting BM-MSCs pretreated with LPS-EVs promoted the release of inflammatory cytokines and increased pulmonary microvascular permeability, aggravating lung injury. Mechanistically, LPS-EVs reduced the expression level of isocitrate dehydrogenase 2 (IDH2), which catalyses the formation of α-ketoglutarate (α-KG), an intermediate product of the tricarboxylic acid (TCA) cycle, in BM-MSCs. α-KG is a cofactor for ten-eleven translocation (TET) enzymes, which catalyse DNA hydroxymethylation in BM-MSCs.ConclusionsThis study revealed that EC-EVs in the lung microenvironment during ARDS can affect the therapeutic efficacy of BM-MSCs through the IDH2/TET pathway, providing potential strategies for improving the therapeutic efficacy of MSC-based therapy in the clinic.

All-trans retinoic acid pretreatment of mesenchymal stem cells enhances the therapeutic effect on acute kidney injury.

A promising new therapy option for acute kidney injury (AKI) is mesenchymal stem cells (MSCs). However, there are several limitations to the use of MSCs, such as low rates of survival, limited homing capacity, and unclear differentiation. In search of better therapeutic strategies, we explored all-trans retinoic acid (ATRA) pretreatment of MSCs to observe whether it could improve the therapeutic efficacy of AKI. We established a renal ischemia/reperfusion injury model and treated mice with ATRA-pretreated MSCs via tail vein injection. We found that AKI mice treated with ATRA-MSCs significantly improved renal function compared with DMSO-MSCs treatment. RNA sequencing screened that hyaluronic acid (HA) production from MSCs promoted by ATRA. Further validation by chromatin immunoprecipitation experiments verified that retinoic acid receptor RARα/RXRγ was a potential transcription factor for hyaluronic acid synthase 2. Additionally, an in vitro hypoxia/reoxygenation model was established using human proximal tubular epithelial cells (HK-2). After co-culturing HK-2 cells with ATRA-pretreated MSCs, we observed that HA binds to cluster determinant 44 (CD44) and activates the PI3K/AKT pathway, which enhances the anti-inflammatory, anti-apoptotic, and proliferative repair effects of MSCs in AKI. Inhibition of the HA/CD44 axis effectively reverses the renal repair effect of ATRA-pretreated MSCs. Taken together, our study suggests that ATRA pretreatment promotes HA production by MSCs and activates the PI3K/AKT pathway in renal tubular epithelial cells, thereby enhancing the efficacy of MSCs against AKI.

#2339 All-trans retinoic acid enhances the efficacy of mesenchymal stem cells in acute kidney injury

Abstract Background and Aims Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic strategy for acute kidney injury (AKI), but still suffer from the drawbacks of low survival rate, low homing rate, and uncertain differentiation. In search of better therapeutic strategies, we explored all-trans retinoic acid (ATRA) pretreatment of MSCs to observe whether it could improve the therapeutic efficacy on AKI. Method We established a renal ischemia/reperfusion (I/R) injury model induced by clamping of left renal artery for 30 minutes and contralateral nephrectomy. C57BL/6 mice were randomly divided into 4 groups: sham group, IRI group, MSCs group, and ATRA-MSCs group. MSCs or ATRA-pretreated MSCs were injected via tail vein. GFR was measured by transcutaneous monitoring the clearance of FITC-sinistrin. These mice were sacrificed 3 days after surgery, and the serum creatinine (SCr) and blood urea nitrogen (BUN) levels were measured. The renal pathological changes were examined by Periodic Acid-Schiff staining (PAS). The in vitro hypoxia/reoxygenation (H/R) model was established using human proximal tubular epithelial cells (HK-2 cells). Co-culturing HK-2 cells with MSCs or ATRA-pretreated MSCs. Western blot, quantitative real time-PCR (qRT-PCR), and immunohistochemistry were used to detect mRNA or protein expression. We performed RNA sequencing (RNA-seq) analysis in ATRA-pretreated MSCs. The content of hyaluronic acid (HA) in the supernatant of ATRA-pretreated MSCs culture was detected by ELISA. Hyaluronan synthase mRNA expression level in ATRA-pretreated MSCs assessed by qRT-PCR analysis. The HAS2 promoter-binding transcription factors were forecasted by the JASPAR Transcription Factor Binding Site database. Western blot was used to detect whether P13K/AKT pathway was activated by ATRA-pretreated MSCs. Whether this nephroprotective effect could be reversed were explored by silencing HAS2 or CD44 antibodies. Results The AKI mice showed a significant decrease in GFR and even complete loss of renal function. Administration of MSCs significantly increased GFR, and MSCs pretreated with ATRA further increased GFR. Mice injected with ATRA-pretreated MSCs had significantly lower levels of SCr, BUN and ATN scores compared with untreated MSCs. Western blot, quantitative real-time PCR (qRT-PCR), and immunohistochemistry showed that ATRA pretreated MSCs were more effective in reducing AKI inflammation and apoptosis and promoting proliferative repair than untreated MSCs. GO enrichment analysis demonstrated that the hyaluronan biosynthetic process may be a significantly expressed. HAS2 expression and HA content of MSCS were significantly increased after the addition of ATRA. Analysis for potential transcription factor binding sites revealed that the HAS2 promoter region has multiple potential binding sites for the retinoic acid receptor. Based on the predictions from the JASPAR database, the RXR-RAR heterodimer had the highest prediction score. We then performed ChIP analysis to experimentally verify the binding of RXR-RAR heterodimer transcription factor to HAS2 promoters. We further found that ATRA-pretreated MSCs activated the PI3K/AKT signaling pathway in AKI. As expected, we found that ATRA-pretreated MSCs anti-inflammatory, anti-apoptosis, and pro-proliferation effects were substantially reversed by silencing HAS2 or blocking CD44. Conclusion ATRA promotes HA secretion from MSCs and activates the PI3K/AKT pathway, which in turn enhances the therapeutic efficacy of MSCs on AKI.

The Mechanisms of Mesenchymal Stem Cells in the Treatment of Experimental Autoimmune Encephalomyelitis.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system and is a leading cause of disability in young adults. Most therapeutic strategies are based on immunosuppressant effects. However, none of the drugs showed complete remission and may result in serious adverse events such as infection. Mesenchymal stem cells (MSCs) have gained much attention and are considered a potential therapeutic strategy owing to their immunomodulatory effects and neuroprotective functions. Experimental autoimmune encephalomyelitis (EAE), a classical animal model for MS, is widely used to explore the efficacy and mechanism of MSC transplantation. This review summarises the therapeutic mechanism of MSCs in the treatment of EAE, including the effects on immune cells (T cells, B cells, dendritic cells, natural killer cells) and central nervous system-resident cells (astroglia, microglia, oligodendrocytes, neurons) as well as various strategies to improve the efficacy of MSCs in the treatment of EAE. Additionally, we discuss the clinical application of MSCs for MS patients as well as the challenges and prospects of MSC transplantation.

Wogonin preconditioning of MSCs improved their therapeutic efficiency for colitis through promoting glycolysis.

Inflammatory bowel diseases (IBDs) are prevalent and debilitating diseases with limited clinical treatment strategies. Mesenchymal stem cell (MSCs) are pluripotent stem cells with self-renewal capability and multiple immunomodulatory effects, which make them a promising therapeutic approach for IBDs. Thus, optimization of MSCs regimes is crucial for their further clinical application. Wogonin, a flavonoid-like compound with extensive immunomodulatory and adjuvant effects, has been investigated as a potential pretreatment for MSCs in IBD treatment. In this study, we employed the DSS-induced acute colitis mouse model to compare the therapeutic effectiveness of MSCs in pretreated with or without wogonin and furtherexploretheunderlyingmechanism. Compared to untreated MSCs, MSCwogonin (pretreated with wogonin) showed greater effectiveness in the treatment of colitis. Further experiments revealed that wogonin treatment activated the AKT signaling pathway, resulting in higher cellular glycolysis. Inhibition of AKT phosphorylation by perifosine not only decreased glycolysis but impaired the therapeutic efficiency of MSCwogonin. Consistent with these results, qPCR data indicated that wogonin treatment induced the expression of immunomodulatory molecules IL-10, IDO, and AGR1, which were reduced by perifosine. Together, our data demonstrated that wogonin preconditioning strategy further augmented the therapeutic efficacy of MSCs via promoting glycolysis, which should be a promising strategy for optimizing MSCs therapy in IBDs.

A personalized osteoarthritic joint-on-a-chip as a screening platform for biological treatments

Osteoarthritis (OA) is a highly disabling pathology, characterized by synovial inflammation and cartilage degeneration. Orthobiologics have shown promising results in OA treatment thanks to their ability to influence articular cells and modulate the inflammatory OA environment. Considering their complex mechanism of action, the development of reliable and relevant joint models appears as crucial to select the best orthobiologics for each patient.The aim of this study was to establish a microfluidic OA model to test therapies in a personalized human setting. The joint-on-a-chip model included cartilage and synovial compartments, containing hydrogel-embedded chondrocytes and synovial fibroblasts, separated by a channel for synovial fluid. For the cartilage compartment, a Hyaluronic Acid-based matrix was selected to preserve chondrocyte phenotype. Adding OA synovial fluid induced the production of inflammatory cytokines and degradative enzymes, generating an OA microenvironment. Personalized models were generated using patient-matched cells and synovial fluid to test the efficacy of mesenchymal stem cells on OA signatures. The patient-specific models allowed monitoring changes induced by cell injection, highlighting different individual responses to the treatment. Altogether, these results support the use of this joint-on-a-chip model as a prognostic tool to screen the patient-specific efficacy of orthobiologics.

Heat stress promotes osteogenic and odontogenic differentiation of stem cells from apical papilla via glucose-regulated protein 78-mediated autophagy

Background/purposeHeat stress is essential for improving the efficacy of mesenchymal stem cell (MSC)-based regeneration medicine. However, it is still unclear whether and how heat stress influences the differentiation of stem cells from apical papilla (SCAPs). This research aimed to explore the potential mechanism of glucose-regulated protein 78 (GRP78) in regulating differentiation under heat stress in SCAPs. Materials and methodsThe proliferation ability was assessed using the 5-Ethynyl-2’- deoxyuridine (EdU) assay, cell counting kit assay (CCK-8), and flow cytometry (FCM). The osteogenic and odontogenic differentiation capacities were investigated through Western blot, quantitative reverse transcription polymerase chain reaction (qRT-PCR), alkaline phosphatase (ALP) staining and activity assay, alizarin red S (ARS) staining, as well as immunofluorescence staining. Western blot and transmission electron microscopy (TEM) were used to detect autophagy. ResultsHeat stress enhanced the osteogenic and odontogenic differentiation of SCAPs, but it did not significantly affect proliferation. Besides, GRP78 has been confirmed to modulate the differentiation induced by heat stress. Autophagy triggered by GRP78 enhanced osteogenic and odontogenic differentiation of SCAPs, while the knockdown of GRP78 or the inhibitor of autophagy suppressed the differentiation. ConclusionHeat stress induces osteogenic and odontogenic differentiation of SCAPs through GRP78-mediated autophagy.