Stem Cells Translational Medicine最新文献

Whole-body exposure to ionizing radiation can lead to cellular DNA damage to bone marrow (BM), causing lethal hematopoietic acute radiation syndrome (H-ARS). Extracellular vesicles (EVs) from human BM-derived mesenchymal stromal cells were primed with CRX-527 (CRX), a synthetic TLR4 agonist, characterized and tested as a radiomitigator therapy. Using a xenogeneic H-ARS mouse model, a single in vivo treatment with CRX-EVs administered 4 or 24 hours after lethal irradiation significantly improved weight loss, clinical scores and prolonged survival compared to control treatments. Ex vivo generation of CRX-EV educated monocytes (CRX-EEMos) were also effective in a H-ARS model when administered 24 hours after lethal irradiation. CRX-EVs or CRX-EEMos significantly promoted hematopoiesis in BM and potentially the spleen, leading to restoration of peripheral complete blood counts. CRX-EEMos showed increased gene expression of IL-6 and IL-10: enriched for PD-L1 but low for CD16 in CD14-expressing monocytes. Antisense inhibition of Let-7 microRNAs in CRX-EEMos suppressed IL-10 gene expression and protein secretion, implicating a novel role for Let-7 in radioprotection. CRX-EVs can effectively treat H-ARS by increasing the secretion of anti-inflammatory molecules while stimulating monocytes to promote hematopoiesis in BM. The potential for large-scale production of CRX-EVs as an "off-the-shelf" treatment for H-ARS makes them a potential medical countermeasure for radiological and nuclear threats.

Vascular remodeling, a precursor to atherosclerosis and coronary heart disease, is associated with high morbidity and mortality in individuals with diabetes. The roles of endothelial-mesenchymal transition (EndMT) and human umbilical cord mesenchymal stem cells (hUCMSCs) in this process remain unclear. In this study, we used db/db mice as a diabetic model to investigate the effect of hUCMSCs on metabolic reprogramming and vascular remodeling. We analyzed serum markers, tissue morphology, metabolomics, and endothelial cell-specific proteomics. The results demonstrated that vascular remodeling and EndMT were exacerbated in diabetes and alleviated by hUCMSCs. Metabolomic analysis identified 209 altered metabolites. Most metabolic intermediates were increased, while anti-inflammatory metabolites such as arachidonoyl ethanolamide and sphingosine were decreased in the diabetic state. Treatment with hUCMSCs restored these metabolites to near-normal levels, thereby improving metabolic reprogramming and the vascular microenvironment. Correspondingly, endothelial cell proteomics revealed increased levels of glycolytic enzymes, inflammatory factors, and EndMT markers, including mitogen-activated protein kinase kinase kinase 20 (Map3k20), disintegrin and metalloproteinase domain-containing protein 10 (Adam10), and integrin alpha-8 (Itga8), in diabetes; hUCMSC treatment downregulated these factors. Notably, KEGG and protein-protein interaction analyses indicated that hUCMSCs inhibited the Tgfb1i1/Rock1 axis within the TGF-beta pathway, which drives EndMT. We further verified the expression of these proteins through endothelial immunofluorescent co-staining and confirmed the role of Rock1 in high glucose-induced EndMT in vitro. This study elucidates a potential molecular mechanism and a therapeutic strategy for early atherosclerosis in diabetes and provides a foundation for evaluating endothelial states in vivo.

Cellular reprogramming, a method of "resetting" the epigenetic clock by reversing the differentiation state of cells, has emerged as a promising approach to anti-aging, offering new strategies to slow down the aging process. Researchers convert differentiated cells into a pluripotent stem cell state through transcription factors or chemicals, restoring cellular youthfulness and regenerative capacity. This technology holds potential for tissue repair, lifespan extension, organ function improvement, and treatment of age-related diseases. In addition, cell reprogramming provides a novel pathway for disease modeling and drug screening, potentially accelerating the development and clinical application of anti-aging drugs. However, it faces challenges including safety, efficiency, and ethical considerations. This article focuses on the prospects of small-molecule-induced cell reprogramming for anti-aging, covering its mechanisms, applications, current limitations, and future directions to facilitate clinical translation and breakthroughs in human healthspan extension.

Background: Ulcerative colitis (UC), a chronic inflammatory gastrointestinal disease, is characterized by disrupted intestinal barrier integrity and unresolved endoplasmic reticulum (ER) stress, which drives epithelial apoptosis and disease progression. While mesenchymal stem cells (MSCs), particularly human umbilical cord-derived MSCs (hUC-MSCs), have shown therapeutic potential in UC, their mechanisms in modulating ER stress remain unclear. This study aimed to investigate the role of hUC-MSCs in alleviating ER stress-induced epithelial damage and elucidate the underlying molecular pathways in a murine colitis model and in vitro systems.

Results: Intraperitoneal administration of hUC-MSCs significantly attenuated dextran sulfate sodium (DSS)-induced colitis in mice. Histological analysis revealed restored crypt architecture and reduced epithelial apoptosis. Transcriptomic profiling demonstrated that hUC-MSCs reduced differentially expressed genes in inflammatory bowel disease-related and ER stress response pathways in colon tissues. Mechanistically, hUC-MSCs activated the IRE1/XBP1 axis, increasing Xbp1 splicing and suppressing pro-apoptotic Bcl2l11 expression. In vitro, hUC-MSC-conditioned medium protected colon epithelial cells from TNF-α-induced apoptosis via IRE1/XBP1 activation, an effect abolished by the IRE1 inhibitor 4μ8C.

Conclusions: Our findings demonstrate that hUC-MSCs alleviate UC by mitigating ER stress through IRE1-mediated Xbp1 splicing, thereby reducing epithelial apoptosis and promoting mucosal repair. This study provides a mechanistic foundation for MSC-based therapies targeting ER stress in inflammatory bowel diseases.

Chronic kidney disease (CKD) poses a significant global health burden by reducing quality of life and increasing mortality. Current therapies remain inadequate in halting its progression, necessitating novel treatments to improve outcomes. Adipose-derived stem cells (ADSCs) have emerged as a promising therapeutic option. Phase I/II clinical trials evaluated the efficacy, safety, and tolerability of ELIXCYTE in slowing CKD progression. This multicenter, randomized, open-label study monitored estimated glomerular filtration rate (eGFR) changes over a 48-week period following a single intravenous infusion of ADSCs. Participants were allocated to one of three dosage groups, with primary outcomes assessing eGFR changes and secondary outcomes focusing on safety and tolerability. Results confirmed a favorable safety profile, with no dose-limiting toxicities observed in the low- and moderate-dose groups. Group-based trajectory modeling (GBTM) indicated that, overall, 88.24% of patients exhibited a trend of improvement or stabilization. In the low-dose group, 72.23% of patients demonstrated a stable trend, which was more consistent than in other dosage groups. Furthermore, patients with CKD stage 3B showed a numerically higher proportion of improving trajectories compared to those with stage 4 disease. The low-dose ADSC group exhibited a trend toward more favorable renal function trajectories and fewer adverse events than higher doses, suggesting that lower dosing may provide a balanced profile of safety and potential efficacy. However, despite the preliminary results indicating that ELIXCYTE may effectively slow CKD progression, further large-scale clinical trials are necessary to corroborate these findings and verify the efficacy of ADSC treatment.

Introduction: Mesenchymal stem cell-derived exosomes have garnered considerable attention in regenerative medicine due to their non-immunogenicity, low infusion toxicity, easy accessibility, straightforward preservation, and minimal ethical concerns. While ultracentrifugation is the prevailing method for high-purity exosome isolation, it is limited by low throughput and the need for specialized infrastructure. This study investigates tangential flow filtration (TFF) as a promising alternative for exosome isolation. This technique offers simpler operation, higher yields, and improved recovery rates compared to ultracentrifugation.

Methods: Human umbilical cord mesenchymal stem cells (hUCMSCs) were cultured in a 3D microcarrier-bioreactor system, and exosomes were extracted from the conditioned medium using either ultracentrifugation or an automated and enclosed TFF system. Subsequently, we compared the quantity, quality and therapeutic efficacy of the exosomes isolated via both approaches, evaluating their effects in vitro and in a mouse model of diabetic wound healing.

Results: Our findings demonstrate that the TFF method effectively isolates high-quality exosomes that meet the standards set by the Minimum Information for Studies of Extracellular Vesicles (MISEV) 2023 guidelines, while achieving a significantly higher extraction yield compared to the traditional ultracentrifugation. Furthermore, both TFF and ultracentrifugation-derived exosomes demonstrate comparable biological activity in vitro and similar therapeutic potential for treating diabetic wound healing, potentially through promoting M2 macrophage polarization and angiogenesis.

Conclusion: The results indicate that TFF is a viable method for scalable and efficient exosome production, facilitating advancements in clinical applications for diabetic wound repair.

Background: Acute-on-chronic liver failure (ACLF) is a severe clinical syndrome with a high mortality rate and limited therapeutic options. Macrophage efferocytosis plays an essential role in maintaining tissue homeostasis, and its dysfunction may be associated with the pathogenesis of ACLF. We previously found that mesenchymal stem cell (MSC) treatment in ACLF mice promoted macrophage M2 polarization and elevated the efferocytosis-related protein Mertk, but the underlying mechanisms remained unclear.

Methods: The role of efferocytosis was investigated in liver tissues from ACLF patients and an ACLF mouse model treated with MSC-derived exosomes (MSC-Exos). In vitro experiments utilizing lipopolysaccharide-induced M1 macrophages were conducted to dissect the underlying mechanism, targeting the miRNA let-7a-5p. Engineered exosomes (MSC-Exoslet-7a-5p) were developed via electroporation to validate the therapeutic potential.

Results: Impaired macrophage efferocytosis in liver tissues correlated with poor prognosis in ACLF patients. Treatment with MSC-Exos significantly improved histological morphology, liver function and enhanced efferocytosis in ACLF mice. Mechanistically, MSC-Exos delivered let-7a-5p to M1 macrophages, which downregulated Arid3a and upregulated Mertk expression. Furthermore, engineered MSC-Exoslet-7a-5p promoted efferocytosis more effectively than unmodified exosomes.

Conclusion: MSC-Exos enhance macrophage efferocytosis in ACLF via the let-7a-5p/Arid3a/Mertk axis. Engineered MSC-Exoslet-7a-5p, by boosting this pathway, provide a potential strategy for improving ACLF therapy.

Background: Stroke is a leading cause of death worldwide. Traditional treatments have limitations, stem cell therapy has potential for regeneration after ischemic stroke. This study evaluated the safety and efficacy of allogeneic umbilical cord-derived mesenchymal stem cell (UC-MSC) infusion via the intravenous (IV) and intrathecal (IT) routes for treating neurological sequelae after ischemic stroke.

Methods: This phase II randomized controlled trial involved 32 patients aged 40-75 years with neurological sequelae after ischemic stroke. The patients were randomly assigned into two groups: 16 received two IT UC-MSC infusions plus rehabilitation therapy, and 16 received two IV UC-MSC infusions plus rehabilitation therapy. Additionally, 16 matched controls, paired with the IT group by sex, age (±5 years), and NIHSS, received only rehabilitation. UC-MSCs were administered at 1.5 × 106 cells/kg at baseline and 3 months. Outcomes were assessed at baseline, 3, 6, and 12 months using NIHSS, FIM, MAS, FMS, and SF-36.

Results: No severe adverse events related to UC-MSC therapy were observed. Adverse event rate was lower in the IV group than the IT group. At 6 months, the IV group demonstrated significant improvements in NIHSS (p = 0.046), FIM (p = 0.028), and SF-36 (p < 0.001). At 12 months, both UC-MSC groups showed significant improvements, with greater effects in the IV group (p < 0.001 for SF-36).

Conclusion: Both IV and IT UC-MSC infusions improved neurological recovery and quality of life, with fewer adverse events in the IT group.

Trial registration: NCT05292625.

Induced pluripotent stem cells (iPSCs) are commonly used to model human genetic diseases. Two main strategies are used. The first involves making iPSC lines from individual cases with a disease, and the second involves making disease-relevant gene edits in established iPSC lines. Because generating gene-edited lines is time consuming and expensive, most studies begin with one starting iPSC stock line and evaluate several gene-edited sublines. The current studies focus on gene-editing to model Lesch-Nyhan disease (LND), which is caused by mutations in the HPRT1 gene. The same pathogenic c.508C>T edit was made in four well-established stock lines, and three gene-edited lines were isolated from each. RNA sequencing (RNAseq) was, then, used to evaluate the impact of the gene edit. Gene-edited lines were compared to their corresponding stock lines, as well as to each other. An aggregate analysis of all lines combined was also conducted to determine the most robust findings across all lines. Results from gene editing were further compared with iPSC lines derived from individual cases with LND, to determine how closely findings from gene editing match results obtained with case-derived lines. There were two main findings. First, the same gene edit has a different impact on gene expression when starting with different starting stock lines. Second, the gene editing strategy does not produce the same results as the case-derived strategy. Potential explanations for these differences are addressed, along with the relevance of these two different strategies for disease modeling.

Chronic myeloid leukemia (CML) persists due to leukemic stem cells, notably the CD26+ subset. We investigated correlations between circulating CD26+ leukemic stem cells (LSCs) and BCR::ABL1 transcripts in an extracellular vesicle-enriched secretome (EVES) from plasma samples of 44 CML patients. EVES were characterized and BCR::ABL1 quantified via digital PCR. We observed an inverse correlation between CD26+LSC counts and EVES BCR::ABL1 levels, especially in deep molecular responders (DMR). CD26+LSCs were elevated in patients in treatment-free remission (TFR), while EVES BCR::ABL1 levels were higher in those receiving therapy. These findings suggest distinct dynamics between LSC populations and vesicle-mediated transcript release, with potential implications for CML monitoring and prognosis.