Glutathione dynamics determine the therapeutic efficacy of mesenchymal stem cells for graft-versus-host disease via CREB1-NRF2 pathway

Panoramic lead-immune system interactome reveals diversified mechanisms of immunotoxicity upon chronic lead exposure

Lead exposure is of high prevalence, and over a billion people are chronically exposed to alarming level of lead. Human immune system is highly vulnerable to lead, but the underlying mechanism remains unknown. Using single-cell mass cytometry and mass spectrometry-based proteomics, we performed a panoramic survey of lead targets at both cellular and molecular levels in murine immune system upon chronic lead exposure. We produced a single-cell landscape of lead, thiol metabolism and lead-induced toxicity across all immune cell types. We found that immune cells with extreme thiol metabolism are the most sensitive upon chronic lead exposure. It shows that CD4 + T cells and neutrophils are the most sensitive to lead, which is due respectively to a molecular mechanism rooted in their characteristic thiol metabolic capacity. Meanwhile, we found that lead accumulation by RBC further inflicted secondary toxicity to RBC phagocytes in spleen, e.g. macrophages and neutrophils. Unlike CD4 + T cells, which can be rescued by supplementation with thiol chelator, lead toxicity in these phagocytes cannot be effectively mitigated by thiol chelators. Overall, it forms a multiscale panoramic lead-immune system interactome upon chronic lead exposure, which provides valuable information for proactive prevention, therapy formulation and public health evaluation.

Assessment of the Therapeutic Effectiveness of Glutathione-Enhanced Mesenchymal Stem Cells in Rat Models of Chronic Bladder Ischemia-Induced Overactive Bladder and Detrusor Underactivity

Overactive bladder (OAB) and detrusor underactivity (DUA) are representative voiding dysfunctions with a chronic nature and limited treatment modalities, and are ideal targets for stem cell therapy. In the present study, we investigated the therapeutic efficacy of human mesenchymal stem cells (MSCs) with a high antioxidant capacity generated by the Primed Fresh OCT4 (PFO) procedure in chronic bladder ischemia (CBI)-induced OAB and DUA rat models. Sixteen-week-old male Sprague-Dawley rats were divided into three groups (sham, OAB or DUA, and stem cell groups; n=10, respectively). CBI was induced by bilateral iliac arterial injury (OAB, 10 times; DUA, 30 times) followed by a 1.25% cholesterol diet for 8 weeks. Seven weeks after injury, rats in the stem cell and other groups were injected with 1╳106 PFO-MSCs and phosphate buffer, respectively. One week later, bladder function was analyzed by awake cystometry and bladders were harvested for histological analysis. CBI with a high-fat diet resulted in atrophy of smooth muscle and increased collagen deposits correlating with reduced detrusor contractility in both rat models. Arterial injury 10 and 30 times induced OAB (increased number of non-voiding contractions and shortened micturition interval) and DUA (prolonged micturition interval and increased residual volume), respectively. Injection of PFO-MSCs with the enhanced glutathione dynamics reversed both functional and histological changes; it restored the contractility, micturition interval, residual volume, and muscle layer, with reduced fibrosis. CBI followed by a high-fat diet with varying degrees of arterial injury induced OAB and DUA in rats. In addition, PFO-MSCs alleviated functional and histological changes in both rat models.

Preventive hyperbaric oxygen therapy improves acute graft-versus-host disease by activating the Nrf2/HO-1 pathway

Background

Hyperbaric oxygen therapy (HBOT) has been confirmed as an effective and economical therapeutic modality for treating hemorrhagic cystitis (HC), whether induced by infection or acute graft-versus-host disease (aGVHD), in transplant recipients. However, its potential benefits in treating aGVHD remain largely unknown. This study explored the effects of HBOT on aGVHD and its underlying mechanisms.

Methods

The beneficial effects of HBOT on aGVHD were investigated in a murine model. Manifestations, pathological alterations, reactive oxygen species (ROS) levels in target organs, and survival data of the recipient mice were collected. Nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and its downstream enzyme heme-oxygenase 1 (HO-1) expression in mouse samples were assessed via Western blot and immunohistochemistry analyses. ML385, an Nrf2 inhibitor, was used to validate the protective role of Nrf2 in the beneficial effect of HBOT on aGVHD. Furthermore, we initiated a clinical cohort study and collected data from the patients with definite aGVHD before and after HBOT to validate the preclinical conclusions.

Results

We found that HBOT alleviated aGVHD in mice, which was associated with a significantly prolonged overall survival (OS) and reduced pathological injury, whereas Nrf2 inhibition had the opposite effect. HBOT decreased ROS levels and proinflammatory cytokines, including IL-6 and TNF-α, while upregulated Nrf2 and its downstream antioxidant enzyme HO-1. In the clinical cohort study, the incidence of grades 1-3 aGVHD was significantly lower in the combination arm containing HBOT than in the HBOT-free cohort.

Conclusion

Preventive HBOT can mitigate aGVHD by activating the Nrf2/HO-1 signal transduction pathway, suggesting that HBOT may be a feasible approach for both the prevention and treatment of aGVHD.

Clinical trial registration

ClinicalTrials.gov, identifier NCT04502628.

Insulin-Like Growth Factor 2 Secreted from Mesenchymal Stem Cells with High Glutathione Levels Alleviates Osteoarthritis via Paracrine Rejuvenation of Senescent Chondrocytes

Senescent chondrocytes, which are increased in osteoarthritic (OA) cartilage, promote cartilage defects and the senescent knee microenvironment by inducing senescence to surrounding normal chondrocytes by secreting senescence-associated secretory proteins. Many studies have used mesenchymal stem cells (MSCs) to treat OA, but MSC treatment remains challenging for clinical application owing to MSC quality control, engraftment, and fibrocartilage regeneration. Here, rather than relying on the direct regeneration of MSCs, we present a novel strategy to suppress OA by MSC-mediated senescent chondrocyte targeting via the paracrine activity of MSCs, thereby improving the knee microenvironment. First, to enable quality control of umbilical cord MSCs, priming MSCs by supplementing human platelet lysate (hPL) greatly enhanced MSC functions by increasing cellular glutathione levels throughout serial passaging. Intra-articular injection of primed MSCs successfully suppressed OA progression and senescent chondrocyte accumulation without direct regeneration. Indirect coculture with primed MSCs using transwell ameliorated the senescence phenotypes in OA chondrocytes, suggesting paracrine rejuvenation. Based on secretome analysis, we identified insulin-like growth factor 2 (IGF2) as a key component that induces paracrine rejuvenation by primed MSCs. The rejuvenation effects of IGF2 act through autophagy activation through the up-regulation of autophagy-related gene expression and autophagic flux. To cross-validate the effects of secreted IGF2 in vivo, knockdown of IGF2 in primed MSCs substantially abolished its therapeutic efficacy in a rabbit OA model. Collectively, these findings demonstrate that hPL supplementation enables MSC quality control by increasing MSC glutathione levels. The therapeutic mechanism of primed MSCs was secreted IGF2, which induces paracrine rejuvenation of senescent OA chondrocytes by activating autophagy.

Targeting ferroptosis: opportunities and challenges of mesenchymal stem cell therapy for type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is characterized by progressive β-cell death, leading to β-cell loss and insufficient insulin secretion. Mesenchymal stem cells (MSCs) transplantation is currently one of the most promising methods for β-cell replacement therapy. However, recent studies have shown that ferroptosis is not only one of the key mechanisms of β-cell death, but also one of the reasons for extensive cell death within a short period of time after MSCs transplantation. Ferroptosis is a new type of regulated cell death (RCD) characterized by iron-dependent accumulation of lipid peroxides. Due to the weak antioxidant capacity of β-cells, they are susceptible to cytotoxic stimuli such as oxidative stress (OS), and are therefore susceptible to ferroptosis. Transplanted MSCs are also extremely susceptible to perturbations in their microenvironment, especially OS, which can weaken their antioxidant capacity and induce MSCs death through ferroptosis. In the pathophysiological process of T1DM, a large amount of reactive oxygen species (ROS) are produced, causing OS. Therefore, targeting ferroptosis may be a key way to protect β-cells and improve the therapeutic effect of MSCs transplantation. This review reviews the research related to ferroptosis of β-cells and MSCs, and summarizes the currently developed strategies that help inhibit cell ferroptosis. This study aims to help understand the ferroptosis mechanism of β-cell death and MSCs death after transplantation, emphasize the importance of targeting ferroptosis for protecting β-cells and improving the survival and function of transplanted MSCs, and provide a new research direction for stem cells transplantation therapy of T1DM in the future.

Ex vivo-generated human CD1c+ regulatory B cells by a chemically defined system suppress immune responses and alleviate graft-versus-host disease

IL-10+ regulatory B cells (Bregs) show great promise in treating graft-versus-host disease (GVHD), a life-threatening complication of post-hematopoietic stem cell transplantation. However, obtaining high-quality human IL-10+ Bregs in vitro remains a challenge due to the lack of unique specific markers and the triggering of pro-inflammatory cytokine expression. Here, by uncovering the critical signaling pathways in Breg induction by mesenchymal stromal cells (MSCs), we first established an efficient Breg induction system based on MSCs and GSK-3β blockage (CHIR-99021), which had a robust capacity to induce IL-10+ Bregs while suppressing tumor necrosis factor α (TNF-α) expression. Furthermore, these Breg populations could be identified and enriched by CD1c+. Mechanistically, MSCs induced the expansion of Bregs through the PKA-mediated phosphorylation of cAMP response element-binding protein (CREB). Thus, we developed a chemically defined inducing protocol by PKA-CREB agonist, instead of MSCs, which can also effectively induce CD1c+ Bregs with lower TNF-α expression. Importantly, induced CD1c+ Bregs suppressed the proliferation of peripheral blood mononuclear cells and the inflammatory cytokine secretion of T cells. When adoptively transferred into a humanized mouse model of GVHD, induced CD1c+ Bregs effectively alleviated GVHD. Overall, we established an efficient ex vivo induction system for human Bregs, which has implications for developing novel Bregs-based therapies for GVHD.

Exploration of Key Regulatory Factors in Mesenchymal Stem Cell Continuous Osteogenic Differentiation via Transcriptomic Analysis

BACKGROUND/OBJECTIVES

Mesenchymal stem cells (MSCs) possess the remarkable ability to differentiate into various cell types, including osteoblasts. Understanding the molecular mechanisms governing MSC osteogenic differentiation is crucial for advancing clinical applications and our comprehension of complex disease processes. However, the key biological molecules regulating this process remain incompletely understood.

METHODS

In this study, we conducted systematic re-analyses of published high-throughput transcriptomic datasets to identify and validate key biological molecules that dynamically regulate MSC osteogenic differentiation. Our approach involved a comprehensive analysis of gene expression patterns across human tissues, followed by the rigorous experimental validation of the identified candidates.

RESULTS

Through integrated analytical and experimental approaches, we utilized high-throughput transcriptomics to identify four critical regulators of MSC osteogenic differentiation: PTBP1, H2AFZ, BCL6, and TTPAL (C20ORF121). Among these, PTBP1 and H2AFZ functioned as positive regulators, while BCL6 and TTPAL acted as negative regulators in osteogenesis. The regulatory roles of these genes in osteogenesis were further validated via overexpression experiments.

CONCLUSIONS

Our findings advance our understanding of MSC differentiation fate determination and open new therapeutic possibilities for bone-related disorders. The identification of these regulators provides a foundation for developing targeted interventions in regenerative medicine.

CEACAM1-engineered MSCs have a broad spectrum of immunomodulatory functions and therapeutic potential via cell-to-cell interaction

Mesenchymal stem cells (MSCs) have garnered attention for their regenerative and immunomodulatory capabilities in clinical trials for various diseases. However, the effectiveness of MSC-based therapies, especially for conditions like graft-versus-host disease (GvHD), remains uncertain. The cytokine interferon (IFN)-γ has been known to enhance the immunosuppressive properties of MSCs through cell-to-cell interactions and soluble factors. In this study, we observed that IFN-γ-treated MSCs upregulated the expression of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), associated with immune evasion through the inhibition of natural killer (NK) cell cytotoxicity. To co-opt this immunomodulatory function, we generated MSCs overexpressing CEACAM1 and found that CEACAM1-engineered MSCs significantly reduced NK cell activation and cytotoxicity via cell-to-cell interaction, independent of NKG2D ligand regulation. Furthermore, CEACAM1-engineered MSCs effectively inhibited the proliferation and activation of T cells along with the inflammatory responses of monocytes. In a humanized GvHD mouse model, CEACAM1-MSCs, particularly CEACAM1-4S-MSCs, demonstrated therapeutic potential by improving survival and alleviating symptoms. These findings suggest that CEACAM1 expression on MSCs contributes to MSC-mediated regulation of immune responses and that CEACAM1-engineered MSC could have therapeutic potential in conditions involving immune dysregulation.

Glutathione Dynamics in the Tumor Microenvironment: A Potential Target of Cancer Stem Cells and T Cells

Glutathione (GSH), the main cellular antioxidant, dynamically influences tumor growth, metastasis, and resistance to therapy in the tumor microenvironment (TME), which comprises cancer cells, immune cells, stromal cells, and non-cellular components, including the extracellular matrix, metabolites, hypoxia, and acidity. Cancer stem cells (CSCs) and T cells are minor but significant cell subsets of the TME. GSH dynamics influences the fate of CSCs and T cells. Here, we explored GSH dynamics in CSCs and T cells within the TME, as well as therapeutic approaches that could target these dynamics.

Biomedical application of microalgal-biomaterials hybrid system

Microalgae are a group of microorganisms containing chlorophyll A, which are highly photosynthetic and rich in nutrients. And they can produce multiple bioactive substances (peptides, proteins, polysaccharides, and fatty acids) for biomedical applications. Despite the unique advantages of microalgae-based biotherapy, the insufficient treatment efficiency limits its further application. With the development of nanotechnology, the combination of microalgae and biomaterials can improve therapeutic efficacies, which has attracted increasing attention. In this microalgal-biomaterials hybrid system, biomaterials with excellent optical and magnetic properties play an important role in biological therapy. Microalgae, as a natural vehicle, can increase oxygen content and alleviate hypoxia in diseased areas, further enhancing therapeutic effects. In this review, the synergistic therapeutic effects of microalgal-biomaterials hybrid system in different diseases (cancer, myocardial infarction, ischemia stroke, chronic infection, and intestinal diseases) are comprehensively summarized.

The detection of Gper1 as an important gene promoting jawbone regeneration in the context of estrogen deficiency

Numerous studies have demonstrated that estrogen deficiency inhibit the proliferation and differentiation of pre-osteoblasts in skeleton by affecting osteogenic signaling, lead to decreased bone mass and impaired regeneration. To explore the mechanisms maintaining bone regeneration under estrogen deficiency, we randomly selected 1102 clinical cases, in which female patients aged between 18 and 75 have underwent tooth extraction in Stomatological Hospital of Tongji University, there is little difference in the healing effect of extraction defects, suggesting that to some extent, the regeneration of jawbone is insensitive to the decreased estrogen level. To illuminate the mechanisms promoting jawbone regeneration under estrogen deficiency, a tooth extraction defect model was established in the maxilla of female rats who underwent ovariectomy (OVX) or sham surgery, and jawbone marrow stromal cells (BMSCs) were isolated for single-cell sequencing. Further quantitative PCR, RNA interference, alizarin red staining, immunohistochemistry and western blotting experiments demonstrated that in the context of ovariectomy, maxillary defects promoted G protein-coupled estrogen receptor 1 (Gper1) expression, stimulate downstream cAMP/PKA/pCREB signaling, and facilitate cell proliferation, and thus provided sufficient progenitors for osteogenesis and enhanced the regeneration capacity of the jawbone. Correspondingly, the heterozygous deletion of the Gper1 gene attenuated the phosphorylation of CREB, led to decreased cell proliferation, and impaired the restoration of maxillary defects. This study demonstrates the importance of Gper1 in maintaining jawbone regeneration, especially in the context of estrogen deficiency.

hPMSCs Regulate the Level of TNF-α and IL-10 in Th1 Cells and Improve Hepatic Injury in a GVHD Mouse Model via CD73/ADO/Fyn/Nrf2 Axis

Mesenchymal stem cells (MSCs) ameliorate graft-versus-host disease (GVHD)-induced tissue damage by exerting immunosuppressive effects. However, the related mechanism remains unclear. Here, we explored the therapeutic effect and mechanism of action of human placental-derived MSCs (hPMSCs) on GVHD-induced mouse liver tissue damage, which shows association with inflammatory responses, fibrosis accompanied by hepatocyte tight junction protein loss, the upregulation of Bax, and the downregulation of Bcl-2. It was observed in GVHD mice and Th1 cell differentiation system that hPMSCs treatment increased IL-10 levels and decreased TNF-α levels in the Th1 subsets via CD73. Moreover, hPMSCs treatment reduced tight junction proteins loss and inhibited hepatocyte apoptosis in the livers of GVHD mice via CD73. ADO level analysis in GVHD mice and the Th1 cell differentiation system showed that hPMSCs could also upregulate ADO levels via CD73. Moreover, hPMSCs enhanced Nrf2 expression and diminished Fyn expression via the CD73/ADO pathway in Th1, TNF-α+, and IL-10+ cells. These results indicated that hPMSCs promoted and inhibited the secretion of IL-10 and TNF-α, respectively, during Th1 cell differentiation through the CD73/ADO/Fyn/Nrf2 axis signaling pathway, thereby alleviating liver tissue injury in GVHD mice.

Glutathione dynamics is a potential predictive and therapeutic trait for neoadjuvant chemotherapy response in bladder cancer

Radical cystectomy with preoperative cisplatin-based neoadjuvant chemotherapy (NAC) is the standard care for muscle-invasive bladder cancers (MIBCs). However, the complete response rate to this modality remains relatively low, and current clinicopathologic and molecular classifications are inadequate to predict NAC response in patients with MIBC. Here, we demonstrate that dysregulation of the glutathione (GSH) pathway is fundamental for MIBC NAC resistance. Comprehensive analysis of the multicohort transcriptomes reveals that GSH metabolism and immune-response genes are enriched in NAC-resistant and NAC-sensitive MIBCs, respectively. A machine-learning-based tumor/stroma classifier is applied for high-throughput digitalized immunohistochemistry analysis, finding that GSH dynamics proteins, including glutaminase-1, are associated with NAC resistance. GSH dynamics is activated in cisplatin-resistant MIBC cells, and combination treatment with a GSH dynamics modulator and cisplatin significantly suppresses tumor growth in an orthotopic xenograft animal model. Collectively, these findings demonstrate the predictive and therapeutic values of GSH dynamics in determining the NAC response in MIBCs.

Measuring Glutathione Regeneration Capacity in Stem Cells

Glutathione (GSH) is a chief cellular antioxidant, affecting stem cell functions. The cellular GSH level is dynamically altered by the redox buffering system and transcription factors, including NRF2. Additionally, GSH is differentially regulated in each organelle. We previously reported a protocol for monitoring the real-time GSH levels in live stem cells using the reversible GSH sensor FreSHtracer. However, GSH-based stem cell analysis needs be comprehensive and organelle-specific. Hence, in this study, we demonstrate a detailed protocol to measure the GSH regeneration capacity (GRC) in living stem cells by measuring the intensities of the FreSHtracer and the mitochondrial GSH sensor MitoFreSHtracer using a high-content screening confocal microscope. This protocol typically analyses the GRC in approximately 4 h following the seeding of the cells onto plates. This protocol is simple and quantitative. With some minor modifications, it can be employed flexibly to measure the GRC for the whole-cell area or just the mitochondria in all adherent mammalian stem cells.

Programmed Cell Death in Asthma: Apoptosis, Autophagy, Pyroptosis, Ferroptosis, and Necroptosis

Bronchial asthma is a complex heterogeneous airway disease, which has emerged as a global health issue. A comprehensive understanding of the different molecular mechanisms of bronchial asthma may be an efficient means to improve its clinical efficacy in the future. Increasing research evidence indicates that some types of programmed cell death (PCD), including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis, contributed to asthma pathogenesis, and may become new targets for future asthma treatment. This review briefly discusses the molecular mechanism and signaling pathway of these forms of PCD focuses on summarizing their roles in the pathogenesis and treatment strategies of asthma and offers some efficient means to improve clinical efficacy of therapeutics for asthma in the near future.

Biomimetic scaffold-based stem cell transplantation promotes lung regeneration

Therapeutic options are limited for severe lung injury and disease as the spontaneous regeneration of functional alveolar is terminated owing to the weakness of the inherent stem cells and the dyscrasia of the niche. Umbilical cord mesenchymal-derived stem cells (UC-MSCs) have been applied to clinical trials to promote lung repair through stem cell niche restruction. However, the application of UC-MSCs is hampered by the effectiveness of cell transplantation with few cells homing to the injury sites and poor retention, survival, and proliferation in vivo. In this study, we constructed an artificial three-dimensional (3D) biomimetic scaffold-based MSCs implant to establish a beneficial regeneration niche for endogenous stem cells in situ lung regeneration. The therapeutic potential of 3D biomimetic scaffold-based MSCs implants was evaluated by 3D culture in vitro. And RNA sequencing (RNA-Seq) was mapped to explore the gene expression involved in the niche improvement. Next, a model of partial lung resection was established in rats, and the implants were implanted into the operative region. Effects of the implants on rat resected lung injury repair were detected. The results revealed that UC-MSCs loaded on biomimetic scaffolds exerted strong paracrine effects and some UC-MSCs migrated to the lung from scaffolds and had long-term retention to suppress inflammation and fibrosis in residual lungs and promoted vascular endothelial cells and alveolar type II epithelial cells to enter the scaffolds. Then, under the guidance of the ECM-mimicking structures of scaffolds and the stimulation of the remaining UC-MSCs, vascular and alveolar-like structures were formed in the scaffold region. Moreover, the general morphology of the operative lung was also restored. Taken together, the artificial 3D biomimetic scaffold-based MSCs implants induce in situ lung regeneration and recovery after lung destruction, providing a promising direction for tissue engineering and stem cell strategies in lung regeneration.

High-glutathione mesenchymal stem cells isolated using the FreSHtracer probe enhance cartilage regeneration in a rabbit chondral defect model

BACKGROUND

Mesenchymal stem cells (MSCs) are a promising cell source for cartilage regeneration. However, the function of MSC can vary according to cell culture conditions, donor age, and heterogeneity of the MSC population, resulting in unregulated MSC quality control. To overcome these limitations, we previously developed a fluorescent real-time thiol tracer (FreSHtracer) that monitors cellular levels of glutathione (GSH), which are known to be closely associated with stem cell function. In this study, we investigated whether using FreSHtracer could selectively separate high-functioning MSCs based on GSH levels and evaluated the chondrogenic potential of MSCs with high GSH levels to repair cartilage defects in vivo.

METHODS

Flow cytometry was conducted on FreSHtracer-loaded MSCs to select cells according to their GSH levels. To determine the function of FreSHtracer-isolated MSCs, mRNA expression, migration, and CFU assays were conducted. The MSCs underwent chondrogenic differentiation, followed by analysis of chondrogenic-related gene expression. For in vivo assessment, MSCs with different cellular GSH levels or cell culture densities were injected in a rabbit chondral defect model, followed by histological analysis of cartilage-regenerated defect sites.

RESULTS

FreSHtracer successfully isolated MSCs according to GSH levels. MSCs with high cellular GSH levels showed enhanced MSC function, including stem cell marker mRNA expression, migration, CFU, and oxidant resistance. Regardless of the stem cell tissue source, FreSHtracer selectively isolated MSCs with high GSH levels and high functionality. The in vitro chondrogenic potential was the highest in pellets generated by MSCs with high GSH levels, with increased ECM formation and chondrogenic marker expression. Furthermore, the MSCs' function was dependent on cell culture conditions, with relatively higher cell culture densities resulting in higher GSH levels. In vivo, improved cartilage repair was achieved by articular injection of MSCs with high levels of cellular GSH and MSCs cultured under high-density conditions, as confirmed by Collagen type 2 IHC, Safranin-O staining and O'Driscoll scores showing that more hyaline cartilage was formed on the defects.

CONCLUSION

FreSHtracer selectively isolates highly functional MSCs that have enhanced in vitro chondrogenesis and in vivo hyaline cartilage regeneration, which can ultimately overcome the current limitations of MSC therapy.

Human umbilical cord-derived mesenchymal stem cell transplantation supplemented with curcumin improves the outcomes of ischemic stroke via AKT/GSK-3β/β-TrCP/Nrf2 axis

BACKGROUND

Human umbilical cord-derived mesenchymal stem cell (hUC-MSC) engraftment is a promising therapy for acute ischemic stroke (AIS). However, the harsh ischemic microenvironment limits the therapeutic efficacy of hUC-MSC therapy. Curcumin is an anti-inflammatory agent that could improve inflammatory microenvironment. However, whether it enhances the neuroprotective efficacy of hUC-MSC transplantation is still unknown. In the present study, we investigated the therapeutic efficacy and the possible mechanism of combined curcumin and hUC-MSC treatment in AIS.

METHODS

Middle cerebral artery occlusion (MCAO) mice and oxygen glucose deprivation (OGD) microglia were administrated hUC-MSCs with or without curcumin. Neurological deficits assessment, brain water content and TTC were used to assess the therapeutic effects of combined treatment. To elucidate the mechanism, MCAO mice and OGD microglia were treated with AKT inhibitor MK2206, GSK3β activator sodium nitroprusside (SNP), GSK3β inhibitor TDZD-8 and Nrf2 gene knockout were used. Immunofluorescence, flow cytometric analysis, WB and RT-PCR were used to evaluate the microglia polarization and the expression of typical oxidative mediators, inflammatory cytokines and the AKT/GSK-3β/β-TrCP/Nrf2 pathway protein.

RESULTS

Compared with the solo hUC-MSC-grafted or curcumin groups, combined curcumin-hUC-MSC therapy significantly improved the functional performance outcomes, diminished the infarct volumes and the cerebral edema. The combined treatment promoted anti-inflammatory microglia polarization via Nrf2 pathway and decreased the expression of ROS, oxidative mediators and pro-inflammatory cytokines, while elevating the expression of the anti-inflammatory cytokines. Nrf2 knockout abolished the antioxidant stress and anti-inflammation effects mediated with combined treatment. Moreover, the combined treatment enhanced the phosphorylation of AKT and GSK3β, inhibited the β-TrCP nucleus translocation, accompanied with Nrf2 activation in the nucleus. AKT inhibitor MK2206 activated GSK3β and β-TrCP and suppressed Nrf2 phosphorylation in nucleus, whereas MK2206 with the GSK3β inhibitor TDZD-8 reversed these phenomena. Furthermore, combined treatment followed by GSK3β inhibition with TDZD-8 restricted β-TrCP nucleus accumulation, which facilitated Nrf2 expression.

CONCLUSIONS

We have demonstrated that combined curcumin-hUC-MSC therapy exerts anti-inflammation and antioxidant stress efficacy mediated by anti-inflammatory microglia polarization via AKT/GSK-3β/β-TrCP/Nrf2 axis and an improved neurological function after AIS.

Activating transcription factor-2 supports the antioxidant capacity and ability of human mesenchymal stem cells to prevent asthmatic airway inflammation

Glutathione (GSH), an abundant nonprotein thiol antioxidant, participates in several biological processes and determines the functionality of stem cells. A detailed understanding of the molecular network mediating GSH dynamics is still lacking. Here, we show that activating transcription factor-2 (ATF2), a cAMP-response element binding protein (CREB), plays a crucial role in maintaining the level and activity of GSH in human mesenchymal stem cells (MSCs) by crosstalking with nuclear factor erythroid-2 like-2 (NRF2), a well-known master regulator of cellular redox homeostasis. Priming with ascorbic acid 2-glucoside (AA2G), a stable vitamin C derivative, increased the expression and activity of ATF2 in MSCs derived from human embryonic stem cells and umbilical cord. Subsequently, activated ATF2 crosstalked with the CREB1-NRF2 pathway to preserve the GSH dynamics of MSCs through the induction of genes involved in GSH synthesis (GCLC and GCLM) and redox cycling (GSR and PRDX1). Accordingly, shRNA-mediated silencing of ATF2 significantly impaired the self-renewal, migratory, proangiogenic, and anti-inflammatory capacities of MSCs, and these defects were rescued by supplementation of the cells with GSH. In addition, silencing ATF2 attenuated the ability of MSCs to alleviate airway inflammatory responses in an ovalbumin-induced mouse model of allergic asthma. Consistently, activation of ATF2 by overexpression or the AA2G-based priming procedure enhanced the core functions of MSCs, improving the in vivo therapeutic efficacy of MSCs for treating asthma. Collectively, our findings suggest that ATF2 is a novel modulator of GSH dynamics that determines the core functionality and therapeutic potency of MSCs used to treat allergic asthma.

Safety of Human Embryonic Stem Cell-derived Mesenchymal Stem Cells for Treating Interstitial Cystitis: A Phase I Study

There are still no definite treatment modalities for interstitial cystitis (IC). Meanwhile, stem cell therapy is rising as potential alternative for various chronic diseases. This study aimed to investigate the safety of the clinical-grade mesenchymal stem cells (MSCs) derived from human embryonic stem cells (hESCs), code name MR-MC-01 (SNU42-MMSCs), in IC patients. Three female IC patients with (1) symptom duration >6 months, (2) visual pain analog scale (VAS) ≥4, and (3) one or two Hunner lesions <2 cm in-office cystoscopy within 1 month were included. Under general anesthesia, participants received cystoscopic submucosal injection of SNU42-MMSCs (2.0 × 107/5 mL) at the center or margin of Hunner lesions and other parts of the bladder wall except trigone with each injection volume of 1 mL. Follow-up was 1, 3, 6, 9, and 12 months postoperatively. Patients underwent scheduled follow-ups, and symptoms were evaluated with validated questionnaires at each visit. No SNU42-MMSCs-related adverse events including immune reaction and abnormalities on laboratory tests and image examinations were reported up to 12-month follow-up. VAS pain was temporarily improved in all subjects. No de novo Hunner lesions were observed and one lesion of the first subject was not identifiable on 12-month cystoscopy. This study reports the first clinical application of transurethral hESC-derived MSC injection in three patients with IC. hESC-based therapeutics was safe and proved to have potential therapeutic efficacy in IC patients. Stem cell therapy could be a potential therapeutic option for treating IC.

γ-Glutamylcysteine Exerts Neuroprotection Effects against Cerebral Ischemia/Reperfusion Injury through Inhibiting Lipid Peroxidation and Ferroptosis

Ferroptosis is a non-apoptotic form of cell death driven by iron-dependent lipid peroxidation. Recent evidence indicates that inhibiting ferroptosis could alleviate cerebral ischemia/reperfusion (CIR) injury. γ-glutamylcysteine (γ-GC), an intermediate of glutathione (GSH) synthesis, can upregulate GSH in brains. GSH is the co-factor of glutathione peroxidase 4 (GPX4), which is the negative regulator of ferroptosis. In this study, we explored the effect of γ-GC on CIR-induced neuronal ferroptosis and brain injury. We found that γ-GC significantly reduced the volume of cerebral infarction, decreased the loss of neurons and alleviated neurological dysfunction induced by CIR in rats. Further observation showed that γ-GC inhibited the CIR-caused rupture of the neuronal mitochondrial outer membrane and the disappearance of cristae, and decreased Fe2+ deposition and lipid peroxidation in rat cerebral cortices. Meanwhile, γ-GC altered the expression of some ferroptosis-related proteins in rat brains. Mechanistically, γ-GC increased the expression of GSH synthetase (GSS) for GSH synthesis via protein kinase C (PKC)ε-mediated activation of nuclear factor erythroid 2-related factor (Nrf2). Our findings suggest that γ-GC not only serves as a raw material but also increases the GSS expression for GSH synthesis against CIR-induced lipid peroxidation and ferroptosis. Our study strongly suggests that γ-GC has potential for treating CIR injury.

Microorganism-enabled photosynthetic oxygeneration and ferroptosis induction reshape tumor microenvironment for augmented nanodynamic therapy

Nanodynamic therapy (NDT) based on reactive oxygen species (ROS) generation has been envisioned as a distinct modality for efficient cancer treatment. However, insufficient ROS generation and partial ROS consumption frequently limit the theraputic effect and outcome of NDT owing to the low oxygen (O2) tension and high glutathione (GSH) level in tumor microenvironment (TME). To circumvent these critical issues, we herein proposed and engineered the biodegradable GSH-depletion Mn(III)-riched manganese oxide nanospikes (MnOx NSs) with the photosynthetic bacterial cyanobacteria (Cyan) as a high-efficient and synergistic platform to reshape TME by simultaneously increasing oxygen content and decreasing GSH level. Specifically, under the trigger of acidity, MnOx NSs reacted with photosynthetic oxygen can generate toxic singlet oxygen (1O2). Moreover, MnOx NSs significantly reduced intracellular GSH, resulting in decreased GPX4 activity, which induced tumor cell non-apoptotic ferroptosis. Consequently, this combined strategy based on coadministration with Cyan and MnOx NSs demonstrated the superior antitumor efficacy via amplification of oxidative stress in 4T1 tumor-bearing mice for the synergetic oxygen-augmented nanodynamic/ferroptosis therapy. This work highlights a facile synergistic micro-/nano-system with the specific capability of reshaping TME to augment the sensitivity and therapeutic efficacy of NDT in solid hypoxic tumor therapy.

Methyl 3,4-dihydroxybenzoate inhibits RANKL-induced osteoclastogenesis via Nrf2 signaling in vitro and suppresses LPS-induced osteolysis and ovariectomy-induced osteoporosis in vivo

Osteoporosis deteriorates bone mass and biomechanical strength and is life-threatening to the elderly. In this study, we show that methyl 3,4-dihydroxybenzoate (MDHB), an antioxidant small-molecule compound extracted from natural plants, inhibits receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis in vitro. Furthermore, MDHB attenuates the activation of mitogen-activated protein kinase (MAPK) and NF-κB pathways by reducing the levels of reactive oxygen species (ROS), which leads to downregulated protein expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1). We also confirm that MDHB upregulates the protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), an important transcription factor involved in ROS regulation, by inhibiting the ubiquitination-mediated proteasomal degradation of Nrf2. Next, animal experiments show that MDHB has an effective therapeutic effect on lipopolysaccharide (LPS)- and ovariectomized (OVX)-induced bone loss in mice. Our study demonstrates that MDHB can upregulate Nrf2 and suppress excessive osteoclast activity in mice to treat osteoporosis.

Intratracheal administration of mesenchymal stem cells modulates lung macrophage polarization and exerts anti-asthmatic effects

Mesenchymal stem cells (MSCs) possess immunomodulatory properties that have therapeutic potential for the treatment of inflammatory diseases. This study investigates the effects of direct MSC administration on asthmatic airways. Umbilical cord MSCs (ucMSCs) were intratracheally administered to six-week-old female BALB/c mice sensitized and challenged with ovalbumin; airway hyperresponsiveness (AHR), analyses of airway inflammatory cells, lung histology, flow cytometry, and quantitative real-time PCR were performed. Furthermore, ex vivo and in vitro experiments were performed to assess the effects of ucMSC on M2 activation. Intratracheally administered ucMSCs decreased degree of airway resistance and the number of inflammatory cells such as T helper 2 (Th2) cells, type 2 innate lymphoid cells (ILC2), and macrophages in the murine asthma model. Particularly, MHCII and CD86 expression diminished in dendritic cells and alveolar macrophages (AMs) following ucMSC treatment. SiglecF⁺CD11c⁺CD11b^- AMs show a negative correlation with type II inflammatory cells including Th2 cells, ILC2, and eosinophils in asthmatic mice and were restored following intratracheal ucMSCs treatment. In addition, ucMSCs decreased the macrophage polarization to M2, particularly M2a. The expression levels of markers associated with M2 polarization and Th2 inflammation were also decreased. ucMSC reduced Il-12 and Tnfa expression as well as that of M2 markers such as Cd206 and Retnla ex vivo. Furthermore, the in vitro study using IL-4 treated macrophages confirmed that both direct and indirect MSC treatment significantly reduced the expression of Il-5 and Il-13. In conclusion, ucMSCs appear to suppress type II inflammation by regulating lung macrophages via soluble mediators.

The CDK1/TFCP2L1/ID2 cascade offers a novel combination therapy strategy in a preclinical model of bladder cancer

Aberrant activation of embryogenesis-related molecular programs in urothelial bladder cancer (BC) is associated with stemness features related to oncogenic dedifferentiation and tumor metastasis. Recently, we reported that overexpression of transcription factor CP2-like protein-1 (TFCP2L1) and its phosphorylation at Thr177 by cyclin-dependent kinase-1 (CDK1) play key roles in regulating bladder carcinogenesis. However, the clinical relevance and therapeutic potential of this novel CDK1-TFCP2L1 molecular network remain elusive. Here, we demonstrated that inhibitor of DNA binding-2 (ID2) functions as a crucial mediator by acting as a direct repressive target of TFCP2L1 to modulate the stemness features and survival of BC cells. Low ID2 and high CDK1 expression were significantly associated with unfavorable clinical characteristics. TFCP2L1 downregulated ID2 by directly binding to its promoter region. Consistent with these findings, ectopic expression of ID2 or treatment with apigenin, a chemical activator of ID2, triggered apoptosis and impaired the proliferation, suppressed the stemness features, and reduced the invasive capacity of BC cells. Combination treatment with the specific CDK1 inhibitor RO-3306 and apigenin significantly suppressed tumor growth in an orthotopic BC xenograft animal model. This study demonstrates the biological role and clinical utility of ID2 as a direct target of the CDK1-TFCP2L1 pathway for modulating the stemness features of BC cells.

Combination therapy with apigenin, a powerful antioxidant found in plants such as parsley and camomile, and a drug that inhibits the cell cycle protein CDK1 shows promise for developing therapies for bladder cancer (BC). Switching on genes usually activated in stem cells can cause cancer, including BC. Although CDK1 was known to activate one of these genes in BC cells, no way to suppress the activation had been identified. Jinbeom Heo at University of Ulsan College of Medicine, South Korea, and coworkers investigated CDK1’s role in BC. They found that the transcription factor activated by CDK1 suppressed a protein, ID2, that suppressed stem cell-like characteristics. Simultaneously suppressing CDK1 and boosting ID2 with apigenin strongly repressed tumor growth in a mouse model. These results help point the way to developing new treatment options for BC patients.

Mesenchymal stem cells exert their anti-asthmatic effects through macrophage modulation in a murine chronic asthma model

Despite numerous previous studies, the full action mechanism of the pathogenesis of asthma remains undiscovered, and the need for further investigation is increasing in order to identify more effective target molecules. Recent attempts to develop more efficacious treatments for asthma have incorporated mesenchymal stem cell (MSC)-based cell therapies. This study aimed to evaluate the anti-asthmatic effects of MSCs primed with Liproxstatin-1, a potent ferroptosis inhibitor. In addition, we sought to examine the changes within macrophage populations and their characteristics in asthmatic conditions. Seven-week-old transgenic mice, constitutively overexpressing lung-specific interleukin (IL)-13, were used to simulate chronic asthma. Human umbilical cord-derived MSCs (hUC-MSCs) primed with Liproxstatin-1 were intratracheally administered four days prior to sampling. IL-13 transgenic mice demonstrated phenotypes of chronic asthma, including severe inflammation, goblet cell hyperplasia, and subepithelial fibrosis. Ly6C⁺M2 macrophages, found within the pro-inflammatory CD11c⁺CD11b⁺ macrophages, were upregulated and showed a strong correlation with lung eosinophil counts. Liproxstatin-1-primed hUC-MSCs showed enhanced ability to downregulate the activation of T helper type 2 cells compared to naïve MSCs in vitro and reduced airway inflammation, particularly Ly6C⁺M2 macrophages population, and fibrosis in vivo. In conclusion, intratracheal administration is an effective method of MSC delivery, and macrophages hold great potential as an additional therapeutic target for asthma.

Ultrasensitive Glutathione-Mediated Facile Split-Type Electrochemiluminescence Nanoswitch Sensing Platform

Seeking for an advanced electrochemiluminescence (ECL) platform is still an active and continuous theme in the ECL-sensing realm. This work outlines a femtomolar-level and highly selective glutathione (GSH) and adenosine triphosphate (ATP) ECL assay strategy using a facile split-type gold nanocluster (AuNC) probe-based ECL platform. The system utilizes GSH as an efficient etching agent to turn on the MnO₂/AuNC-based ECL nanoswitch platform. This method successfully achieves an ultrasensitive detection of GSH, which significantly outperformed other sensors. Based on the above excellent results, GSH-related biological assays have been further established by taking ATP as a model. Combined with the high catalytic oxidation ability of DNAzyme, this ECL sensor can realize ATP assay as low as 1.4 fmol without other complicated exonuclease amplification strategies. Thus, we successfully achieved an ultrahigh sensitivity, extremely wide dynamic range, great simplicity, and strong anti-interference detection of ATP. In addition, the actual sample detection for GSH and ATP exhibits satisfactory results. We believe that our proposed high-performance platform will provide more possibilities for the detection of other GSH-related substances and show great prospect in disease diagnosis and biochemical research.

Intravital imaging and single cell transcriptomic analysis for engraftment of mesenchymal stem cells in an animal model of interstitial cystitis/bladder pain syndrome

Mesenchymal stem cell (MSC) therapy is a promising treatment for various intractable disorders including interstitial cystitis/bladder pain syndrome (IC/BPS). However, an analysis of fundamental characteristics driving in vivo behaviors of transplanted cells has not been performed, causing debates about rational use and efficacy of MSC therapy. Here, we implemented two-photon intravital imaging and single cell transcriptome analysis to evaluate the in vivo behaviors of engrafted multipotent MSCs (M-MSCs) derived from human embryonic stem cells (hESCs) in an acute IC/BPS animal model. Two-photon imaging analysis was performed to visualize the dynamic association between engrafted M-MSCs and bladder vasculature within live animals until 28 days after transplantation, demonstrating the progressive integration of transplanted M-MSCs into a perivascular-like structure. Single cell transcriptome analysis was performed in highly purified engrafted cells after a dual MACS-FACS sorting procedure and revealed expression changes in various pathways relating to pericyte cell adhesion and cellular stress. Particularly, FOS and cyclin dependent kinase-1 (CDK1) played a key role in modulating the migration, engraftment, and anti-inflammatory functions of M-MSCs, which determined their in vivo therapeutic potency. Collectively, this approach provides an overview of engrafted M-MSC behavior in vivo, which will advance our understanding of MSC therapeutic applications, efficacy, and safety.

Coprinopsis cinerea uses laccase Lcc9 as a defense strategy to eliminate oxidative stress during fungal-fungal interactions

Frequently, laccases are triggered during fungal cocultivation for overexpression. The function of these activated laccases during coculture has not been clarified. Previously, we reported that Gongronella sp. w5 (w5) (Mucoromycota, Mucoromycetes) specifically triggered the laccase Lcc9 overexpression in Coprinopsis cinerea (Basidiomycota, Agaricomycetes). To systematically analyze the function of the overexpressed laccase during fungal interaction, C. cinerea mycelia before and after the initial Lcc9 overexpression were chosen for transcriptome analysis. Results showed that accompanied by specific utilization of fructose as carbohydrate substrate, oxidative stress derived from antagonistic compounds secreted by w5 appears to be a signal critical for laccase production in C. cinerea. Reactive oxygen species (ROS) decrease in the C. cinerea wild-type strain followed the increase in laccase production and then, lcc9 transcription and laccase activity stopped. By comparison, increased H₂O₂ content and mycelial ROS levels were observed during the entire cocultivation in lcc9 silenced C. cinerea strains. Moreover, lcc9 silencing slowed down the C. cinerea mycelial growth, affected hyphal morphology, and decreased the asexual sporulation in coculture. Our results showed that intracellular ROS acted as signal molecules to stimulate defense responses by C. cinerea with the expression of oxidative stress response regulator Skn7 and various detoxification proteins. Lcc9 takes part as a defense strategy to eliminate oxidative stress during the interspecific interaction with w5. Importance: The overproduction of laccase during interspecific fungal interactions is notoriously known. However, the exact role of the up-regulated laccases remains underexplored. Based on comparative transcriptomic analysis of C. cinerea and gene silencing of laccase Lcc9, here we show that oxidative stress derived from antagonistic compounds secreted by Gongronella sp. w5 was a signal critical for laccase Lcc9 production in Coprinopsis cinerea. Intracellular ROS acted as signal molecules to stimulate defense responses by C. cinerea with the expression of oxidative stress response regulator Skn7 and various detoxification proteins. Ultimately, Lcc9 takes part as a defense strategy to eliminate oxidative stress and help cell growth and development during the interspecific interaction with Gongronella sp. w5. These findings deepened our understanding of fungal interactions in their natural population and communities.

A Preclinical Study of Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells for Treating Detrusor Underactivity by Chronic Bladder Ischemia

Background

The therapeutic effects of human embryonic stem cell-derived multipotent mesenchymal stem cells (M-MSCs) were evaluated for detrusor underactivity (DUA) in a rat model with atherosclerosis-induced chronic bladder ischemia (CBI) and associated mechanisms.

Methods

Sixteen-week-old male Sprague–Dawley rats were divided into five groups (n = 10). The DUA groups underwent 30 bilateral repetitions of endothelial injury to the iliac arteries to induce CBI, while the sham control group underwent a sham operation. All rats used in this study received a 1.25% cholesterol diet for 8 weeks. M-MSCs at a density of 2.5, 5.0, or 10.0 × 10⁵ cells (250 K, 500 K, or 1000 K; K = a thousand) were injected directly into the bladder 7 weeks post-injury, while the sham and DUA group were treated only with vehicle (phosphate buffer solution). One week after M-MSC injection, awake cystometry was performed on the rats. Then, the bladders were harvested, studied in an organ bath, and prepared for histological and gene expression analyses.

Results

CBI by iliac artery injury reproduced voiding defects characteristic of DUA with decreased micturition pressure, increased micturition interval, and a larger residual volume. The pathological DUA properties were improved by M-MSC treatment in a dose-dependent manner, with the 1000 K group producing the best efficacy. Histological analysis revealed that M-MSC therapy reduced CBI-induced injuries including bladder fibrosis, muscular loss, and apoptosis. Transplanted M-MSCs mainly engrafted as vimentin and NG2 positive pericytes rather than myocytes, leading to increased angiogenesis in the CBI bladder. Transcriptomes of the CBI-injured bladders were characterized by the complement system, inflammatory, and ion transport-related pathways, which were restored by M-MSC therapy.

Conclusions

Single injection of M-MSCs directly into the bladder of a CBI-induced DUA rat model improved voiding profiles and repaired the bladder muscle atrophy in a dose-dependent manner.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12015-021-10204-z.

hPMSCs inhibit the expression of PD-1 in CD4+IL-10+ T cells and mitigate liver damage in a GVHD mouse model by regulating the crosstalk between Nrf2 and NF-κB signaling pathway

Background

The activation of T cells and imbalanced redox metabolism enhances the development of graft-versus-host disease (GVHD). Human placenta-derived mesenchymal stromal cells (hPMSCs) can improve GVHD through regulating T cell responses. However, whether hPMSCs balance the redox metabolism of CD4⁺IL-10⁺ T cells and liver tissue and alleviate GVHD remains unclear. This study aimed to investigate the effect of hPMSC-mediated treatment of GVHD associated with CD4⁺IL-10⁺ T cell generation via control of redox metabolism and PD-1 expression and whether the Nrf2 and NF-κB signaling pathways were both involved in the process.

Methods

A GVHD mouse model was induced using 6–8-week-old C57BL/6 and Balb/c mice, which were treated with hPMSCs. In order to observe whether hPMSCs affect the generation of CD4⁺IL-10⁺ T cells via control of redox metabolism and PD-1 expression, a CD4⁺IL-10⁺ T cell culture system was induced using human naive CD4⁺ T cells. The percentage of CD4⁺IL-10⁺ T cells and their PD-1 expression levels were determined in vivo and in vitro using flow cytometry, and Nrf2, HO-1, NQO1, GCLC, GCLM, and NF-κB levels were determined by western blotting, qRT-PCR, and immunofluorescence, respectively. Hematoxylin-eosin, Masson’s trichrome, and periodic acid-Schiff staining methods were employed to analyze the changes in hepatic tissue.

Results

A decreased activity of superoxide dismutase (SOD) and a proportion of CD4⁺IL-10⁺ T cells with increased PD-1 expression were observed in GVHD patients and the mouse model. Treatment with hPMSCs increased SOD activity and GCL and GSH levels in the GVHD mouse model. The percentage of CD4⁺IL-10⁺ T cells with decreased PD-1 expression, as well as Nrf2, HO-1, NQO1, GCLC, and GCLM levels, both in the GVHD mouse model and in the process of CD4⁺IL-10⁺ T cell generation, were also increased, but NF-κB phosphorylation and nuclear translocation were inhibited after treatment with hPMSCs, which was accompanied by improvement of hepatic histopathological changes.

Conclusions

The findings suggested that hPMSC-mediated redox metabolism balance and decreased PD-1 expression in CD4⁺IL-10⁺ T cells were achieved by controlling the crosstalk between Nrf2 and NF-κB, which further provided evidence for the application of hPMSC-mediated treatment of GVHD.

Gastric Cancer Stem Cells: A Glimpse on Metabolic Reprogramming

Gastric cancer (GC) is one of the most widespread causes of cancer-related death worldwide. Recently, emerging implied that gastric cancer stem cells (GCSCs) play an important role in the initiation and progression of GC. This subpopulation comprises cells with several features, such as self-renewal capability, high proliferating rate, and ability to modify their metabolic program, which allow them to resist current anticancer therapies. Metabolic pathway intermediates play a pivotal role in regulating cell differentiation both in tumorigenesis and during normal development. Thus, the dysregulation of both anabolic and catabolic pathways constitutes a significant opportunity to target GCSCs in order to eradicate the tumor progression. In this review, we discuss the current knowledge about metabolic phenotype that supports GCSC proliferation and we overview the compounds that selectively target metabolic intermediates of CSCs that can be used as a strategy in cancer therapy.

An NRF2 Perspective on Stem Cells and Ageing

Redox and metabolic mechanisms lie at the heart of stem cell survival and regenerative activity. NRF2 is a major transcriptional controller of cellular redox and metabolic homeostasis, which has also been implicated in ageing and lifespan regulation. However, NRF2's role in stem cells and their functioning with age is only just emerging. Here, focusing mainly on neural stem cells, which are core to adult brain plasticity and function, we review recent findings that identify NRF2 as a fundamental player in stem cell biology and ageing. We also discuss NRF2-based molecular programs that may govern stem cell state and function with age, and implications of this for age-related pathologies.

Mangiferin Promotes Bregs Level, Activates Nrf2 Antioxidant Signaling, and Inhibits Proinflammatory Cytokine Expression in Murine Splenic Mononuclear Cells In Vitro

Recent studies indicated that regulatory B cells (Bregs) and nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant signaling pathway play important roles in the pathogenesis of chronic graft-versus-host disease (cGVHD). Mangiferin (MA), a polyphenol compound, has been reported to activate Nrf2/antioxidant-responsive element (ARE) signaling pathway. This study was aimed to investigate the effects of MA on Bregs and Nrf2 antioxidant signaling in murine splenic mononuclear cells (MNCs) in vitro. Our results revealed that MA could increase the Bregs level in murine splenic MNCs. Moreover, MA up-regulated the expression of Bregs-associated immunosuppressive factor interleukin-10 (IL-10) by activating the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase (ERK) signaling in murine splenic MNCs. Meanwhile, MA inhibited the proinflammatory cytokines IL-2 and interferon-γ (INF-γ) at both mRNA and protein levels. MA also enhanced the transcription and protein expression of Nrf2 and NADPH quinine oxidoreductase 1 (NQO1), whereas decreased that of Kelch-like ECH-associated protein 1 (Keap1) in murine splenic MNCs. Moreover, MA promoted the proliferation and inhibited the apoptosis of murine splenic MNCs. These results suggested that MA exerts immunosuppressive effects by upregulating the Bregs level, activating the Nrf2 antioxidant pathway, and inhibiting the expression of pro-immunoinflammatory factors. MA, as a natural immunomodulatory and anti-inflammatory agent, may have a potential role in the prophylaxis and treatment of cGVHD.

Role of ex vivo Expanded Mesenchymal Stromal Cells in Determining Hematopoietic Stem Cell Transplantation Outcome

Overall, the human organism requires the production of ∼1 trillion new blood cells per day. Such goal is achieved via hematopoiesis occurring within the bone marrow (BM) under the tight regulation of hematopoietic stem and progenitor cell (HSPC) homeostasis made by the BM microenvironment. The BM niche is defined by the close interactions of HSPCs and non-hematopoietic cells of different origin, which control the maintenance of HSPCs and orchestrate hematopoiesis in response to the body’s requirements. The activity of the BM niche is regulated by specific signaling pathways in physiological conditions and in case of stress, including the one induced by the HSPC transplantation (HSCT) procedures. HSCT is the curative option for several hematological and non-hematological diseases, despite being associated with early and late complications, mainly due to a low level of HSPC engraftment, impaired hematopoietic recovery, immune-mediated graft rejection, and graft-versus-host disease (GvHD) in case of allogenic transplant. Mesenchymal stromal cells (MSCs) are key elements of the BM niche, regulating HSPC homeostasis by direct contact and secreting several paracrine factors. In this review, we will explore the several mechanisms through which MSCs impact on the supportive activity of the BM niche and regulate HSPC homeostasis. We will further discuss how the growing understanding of such mechanisms have impacted, under a clinical point of view, on the transplantation field. In more recent years, these results have instructed the design of clinical trials to ameliorate the outcome of HSCT, especially in the allogenic setting, and when low doses of HSPCs were available for transplantation.

CREB1 protects against the renal injury in a rat model of kidney stone disease and calcium oxalate monohydrate crystals-induced injury in NRK-52E cells

Kidney stone disease (KSD) is a common urinary disease with increasing prevalence worldwide. In this study, we investigated the effect of cyclic AMP responsive element binding protein (CREB) 1 in a KSD model of rat and calcium oxalate monohydrate (COM) crystals-treated NRK-52E cells. Rats were pretreated with lentivirus (LV)-CREB1 vector or LV-control vector and administrated with ethylene glycol + ammonium chloride to induce KSD. It was found that CREB1 was activated in the renal tissue of non-treated KSD rats. Pretreating with LV-CREB1 vector significantly enhanced CREB1 expression in KSD rats. Biochemical analysis for serum and urine showed that upregulation of CREB1 could improve the renal function of KSD rats. Histological analysis confirmed that upregulation of CREB1 alleviated the renal injury in KSD rats. Moreover, the upregulation of CREB1 suppressed the apoptosis in renal tissue of KSD rats through regulating apoptosis-associated proteins. Further study showed that the upregulation of CREB1 could attenuate the oxidative stress in KSD rats as well. More interestingly, the upregulation of CREB1 enhanced the activity of complex I and complex III and the expression of mitochondrial cytochrome c, implicating the effect of CREB1 on improving mitochondrial function in KSD rats. In vitro study confirmed that upregulation of CREB1 inhibited the apoptosis and oxidative stress, while improved the mitochondrial function of NRK-52E cells treated with COM crystals, demonstrating the protective effect of CREB1 on COM crystals-induced renal epithelial cell injury. Therefore, CREB1 might be served as a promising target in the prophylaxis and treatment of KSD.

Therapeutic Efficacy of Human Embryonic Stem Cell-Derived Multipotent Stem/Stromal Cells in Diabetic Detrusor Underactivity: A Preclinical Study

Mesenchymal stem/stromal cell (MSC) therapy is a promising approach for treatment of as yet incurable detrusor underactivity (DUA), which is characterized by decreased detrusor contraction strength and/or duration, leading to prolonged bladder emptying. In the present study, we demonstrated the therapeutic potential of human embryonic stem cell (ESC)-derived multipotent MSCs (M-MSCs) in a diabetic rat model of DUA. Diabetes mellitus (DM) was induced by intraperitoneal injection of streptozotocin (STZ) (50 mg/kg) into 8-week-old female Sprague-Dawley rats. Three weeks later, various doses of M-MSCs (0.25, 0.5, and 1 × 10⁶ cells) or an equivalent volume of PBS were injected into the outer layer of the bladder. Awake cystometry, organ bath, histological, and gene expression analyses were evaluated 1 week (short-term) or 2 and 4 weeks (long-term) after M-MSC transplantation. STZ-induced diabetic rats developed DUA, including phenotypes with significantly longer micturition intervals, increased residual urine amounts and bladder capacity, decreased micturition pressure on awake cystometry, and contractile responses to various stimuli in organ bath studies. Muscle degeneration, mast cell infiltration, fibrosis, and apoptosis were present in the bladders of DM animals. A single local transplantation of M-MSCs ameliorated DUA bladder pathology, including functional changes and histological evaluation, and caused few adverse outcomes. Immunostaining and gene expression analysis revealed that the transplanted M-MSCs supported myogenic restoration primarily by engrafting into bladder tissue via pericytes, and subsequently exerting paracrine effects to prevent apoptotic cell death in bladder tissue. The therapeutic efficacy of M-MSCs was superior to that of human umbilical cord-derived MSCs at the early time point (1 week). However, the difference in efficacy between M-MSCs and human umbilical cord-derived MSCs was statistically insignificant at the later time points (2 and 4 weeks). Collectively, the present study provides the first evidence for improved therapeutic efficacy of a human ESC derivative in a preclinical model of DM-associated DUA.