Stem Cell Reviews and Reports最新文献

Polycomb Repressive Complex 1 (PRC1) is a group of epigenetic regulatory complexes critical for mammalian development. Elucidating PRC1 composition and function across cell types and developmental stages is key to understanding the epigenetic regulation of cell fate determination. In this study, we discovered POGZ, a prominent autism spectrum disorder (ASD) risk factor, as a novel component of PRC1.6, forming the PRC1.6-POGZ complex. Functional assays revealed that POGZ elicits transcriptional repression that is dependent on RING1B expression. Analysis of publicly available data showed that POGZ highly colocalizes with RING1B and HP1g, two PRC1.6 components, at genes involved in multiple aspects of transcriptional regulation in embryonic mouse cortical cells. Although Pogz knockout (KO) does not compromise stem cell pluripotency, Pogz ablation in neuronal progenitor cells (NPCs) led to widespread transcriptomic dysregulation with failed activation of key neuronal genes. Finally, we demonstrated that PRC1.6-POGZ regulates neuronal differentiation by repressing bone morphogenetic protein (BMP) signaling. These findings reveal a mechanism by which PRC1 and POGZ coordinate transcription during neuronal differentiation and demonstrate that disrupting this complex impairs BMP signaling, potentially contributing to neurodevelopmental disorders such as ASD.

Metastasis and therapy resistance are main clinical challenges of pancreatic ductal adenocarcinoma (PDAC) still limiting patient`s prognosis. Both are dependent on tumor cell plasticity, which allows rapid adaptation of tumor cells to changing microenvironmental conditions. Epithelial-Mesenchymal-Transition (EMT), a process by which carcinoma cells acquire invasive abilities, is associated with a gain of cancer stem cell (CSC) properties. Different CSC phenotypes were described in PDAC, whereby high levels of the CSC marker Nestin was identified in CSC clones of mesenchymal Panc1 cells, while CSC clones of epithelial Panc89 cells were characterized by a high SOX2 expression. To investigate the functional impact of these CSC markers in PDAC cells with different EMT phenotypes, expression of either CSC marker was silenced in heterogenous (parental) and CSC PDAC populations to analyze their impact on essential malignancy associated properties.SiRNA-mediated knockdown (KD) of NES and/or SOX2 in Panc1 and Panc89 cell variants (parental and CSC population), respectively, was successfully achieved. Decreased NES expression in Panc1 cell variants and decreased SOX2 expression in Panc89 cell variants significantly inhibited self-renewing properties, however, only marginally impacted cell growth, EMT marker expression, migration and invasion properties as well as response to chemotherapy. Overall, our data indicate that Nestin and SOX2 are crucial mediators of self-renewal capabilities of mesenchymal and epithelial PDAC cell variants, respectively, but that further factors are required for the maintenance of other malignancy associated properties.

The persistence and drug resistance of leukemic stem cells (LSCs) are major challenges in the treatment of acute myeloid leukemia (AML). Ferroptosis, a novel form of programmed cell death, has emerged as a promising strategy for eradicating LSCs. This review provides a systematic analysis of LSC ferroptosis resistance and explores the interplay between iron metabolism, lipid peroxidation, and antioxidant defense mechanisms. We propose a novel predictive model based on single-cell multiomics data that integrates iron homeostasis regulators (TfR1, GPX4, and FTH1) to assess the susceptibility of LSCs to ferroptosis. A key innovation of this study was the in-depth exploration of LSC ferroptotic heterogeneity and its interaction with the tumor microenvironment, shedding light on new approaches for precision AML therapy. Based on these findings, we introduced an innovative treatment paradigm combining ferroptosis inducers (e.g., erastin, RSL3) with immunotherapies (such as PD-L1 inhibitors and CAR-T cell therapy) to enhance LSC clearance and minimize measurable residual disease (MRD). This review fills a critical knowledge gap in the study of ferroptosis in LSCs, providing a theoretical foundation and translational insights for future AML treatment strategies.

Background: Glucagon-like peptide-1 receptor agonists, originally developed for managing type 2 diabetes, have gained attention for their weight-reducing and broader biological effects. Among these, their influence on human mesenchymal stem cells remains underexplored, despite the critical role of mesenchymal stem cells in tissue regeneration and secretion of bioactive factors.

Methods: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify and evaluate in vitro studies investigating the effects of glucagon-like peptide-1 receptor agonists and their analogues on human mesenchymal stem cell functions, including proliferation, differentiation, signaling, apoptosis, and tissue-specific applications. Risk of bias was assessed using an adapted Quality Assessment Tool for In Vitro Studies (QUIN) tool.

Results: Thirty-eight eligible studies were identified. Glucagon-like-peptide-1 receptor agonist, like native glucagon-like peptide-1, Exendin-4, and Liraglutide, exert context-, dose-, and timing-dependent effects on human mesenchymal stem cells. They modulate proliferation and overall promote osteogenesis while inhibiting adipogenesis. Key pathways, including Wnt/β-catenin, bone morphogenetic protein 2/Smad, phosphoinositide 3-kinase/Akt and protein kinase A, play a role in this. Furthermore, these agents modulate inflammation, reduce apoptosis, and improve stem cell functions even under diabetic or inflammatory conditions. Exendin-4 facilitated tenogenic and insulin-producing cell differentiation, particularly in engineered scaffolds or genetically engineered human mesenchymal stem cells.

Conclusion: Glucagon-like peptide-1 receptor agonists modulate key pathways in human mesenchymal stem cells to influence survival, differentiation, and metabolic function, suggesting promising therapeutic potential beyond glycemic control. However, heterogeneous experimental designs and limited translational data necessitate further standardized and in vivo research to define clinical applications.

Background & aims: Human induced pluripotent stem cell (hiPSC)-derived hepatic endoderm (HE) is a potential treatment for liver diseases, but its heterogeneity poses challenges. Hepatic specification, the conversion of hiPSC-derived endoderm (DE) into HE, is critical for HE induction. Caudal homeobox transcription factor 2 (CDX2) regulates multiple signalling pathways during embryonic development and directs organogenesis. While CDX2 is a key regulator of organ development, its role during hepatic specification remains unclear.

Methods: HE markers were detected using western blotting (WB) and immunofluorescence (IF). The CDX2 regulatory axis was identified using mRNA-seq and bioinformatics analysis. During hepatic specification, the relative pathways PI3K-AKT, WNT, epithelial‒mesenchymal transition (EMT) and extracellular matrix (ECM) were confirmed using WB. Hepatocyte-like functions were evaluated based on glycogen content, indocyanine green (ICG) uptake and albumin levels. The therapeutic efficacy of HE cells was evaluated in a mouse liver injury model.

Results: Overexpression of CDX2 resulted in enhanced expression and function of HE markers during hepatic specification. mRNA-seq and bioinformatics analysis revealed differentially expressed genes following CDX2 overexpression that target the PI3K-AKT and WNT pathways, which was confirmed by WB. Furthermore, the results showed that EMT and the ECM degradation were suppressed by CDX2 overexpression (p < 0.05). In addition, SB-3CT, an matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) inhibitor, effectively promoted the formation of HE cells derived from hiPSC-DEs. Functionally, hepatocyte-like cells derived from HE cells through CDX2 overexpression presented increased glycogen levels, ICG uptake and albumin production. On the other hand, liver functions and acute injuries were significantly ameliorated when CDX2-modulated HE cells were transplanted into a mouse model.

Conclusions: CDX2 promotes HE formation through inhibition of the PI3K-Akt and Wnt/β-catenin pathways, as well as suppression of EMT and ECM degradation. Moreover, transplantation of CDX2-modulated HE cells represents an effective therapeutic approach for liver injury treatment.

The liver is a highly versatile and resilient organ that is crucial for metabolism, detoxification, digestion, and immune regulation. Its remarkable regenerative capacity is driven primarily by two key cellular processes: hepatocyte polyploidy and cellular senescence. This review explores the complex roles of polyploidy, in which hepatocytes possess multiple chromosome sets, and senescence, characterized by irreversible cell cycle arrest, in maintaining liver homeostasis and facilitating regeneration. Polyploid hepatocytes increase genetic and metabolic diversity, enabling the liver to withstand stress and recover from injury through mechanisms such as compensatory regeneration, depolyploidization, and the fusion of extrinsic stem cells. Concurrently, cellular senescence acts as a protective barrier against uncontrolled cell proliferation and genomic instability while also promoting tissue repair via the senescence-associated secretory phenotype (SASP). The interplay between polyploidy and senescence is regulated by critical molecular pathways, including the Hippo, PI3K/Akt, and p53 signaling pathways, which balance cell proliferation, differentiation, and apoptosis. Additionally, this review discusses the therapeutic potential of targeting these processes to increase liver regeneration, prevent fibrosis, and reduce the risk of hepatocellular carcinoma (HCC). Emerging strategies such as senolytic drugs, stem cell therapies, and cytokine modulation offer promising avenues for treating chronic liver diseases. However, challenges remain in fully understanding the functional distinctions between diploid and polyploid hepatocytes and managing the dual roles of senescence. Future research should focus on molecular insights and targeted interventions to optimize liver health and regenerative outcomes.

RAB27A plays an essential role in the regulation of exocytosis and intracellular vesicle trafficking. Loss-of-function mutations in the RAB27A gene cause dysfunctional immune cells and Griscelli Syndrome Type 2 (GS-2), whereas upregulation of RAB27A in cancer cells is associated with a worse prognosis and increased metastasis. Here, we wanted to assess the potential side effects of overexpression of RAB27A in different types of healthy stem cells as preparation for the development of gene therapy for GS-2. Bone marrow mesenchymal stem cells (BM-MSCs) were obtained from GS-2 patients and healthy donors. Healthy murine bone marrow-derived and human cord blood-derived hematopoietic stem/progenitor cells (HSPCs) were transduced with different lentiviral vectors carrying a codon-optimized RAB27A (RAB27Aco) transgene. Cells were used for in vitro functional assays and assessed using flow cytometry, Western Blot and RT-PCR. In vivo transplantation assays in mice were used to assess the effect of RAB27A on stem cell function. Engraftment was assessed using flow cytometry, sections of BM-MSC injection sites were analyzed using histological staining. Overexpression of RAB27A resulted in phenotypic changes in BM-MSCs and decreased colony-forming capacity of HSPCs. Transplantation of RAB27A + stem cells was not associated with any tumorigenesis. Despite high expression of RAB27A in HSPCs before transplantation, RAB27A levels in peripheral blood, bone marrow, and spleen cells remained low, indicating overexpression of RAB27A may have affected the long-term reconstitution potential. Development of gene therapy for GS-2 may require fine-tuning of RAB27A expression but is not likely to be complicated by RAB27A-induced tumorigenesis.

Background: Mesenchymal stem cell (MSC)-based tissue engineering is largely mediated by extracellular vesicles (EVs), particularly exosomes (Exos). The biological activity of Exos is strongly influenced by the isolation method, yet no standardized approach exists.

Methods: Dental pulp stem cell (DPSC)-derived Exos were isolated using ultracentrifugation (UC) or size exclusion chromatography (SEC). UC-Exos and SEC-Exos were characterized for morphology, size, yield, protein content, and proteomic profiles. Their effects on periodontal ligament stem cells (PDLSCs) were assessed, including proliferation, migration, and osteogenic differentiation. In vivo bone regeneration was evaluated in rat calvarial defects using Exos combined with bone-grafting material.

Results: SEC-Exos yielded exosomes with higher purity, greater particle counts, and lower protein contamination than UC-Exos. Proteomic profiling showed enrichment of osteogenic factors, including ENPP2 and afamin, in SEC-Exos. Functionally, UC-Exos promoted PDLSC proliferation and migration, while SEC-Exos more effectively enhanced osteogenic differentiation. Both Exos improved PDLSC functions dose-dependently and, when combined with bone grafts, consistently promoted calvarial bone regeneration. Notably, osteocalcin expression was higher in SEC-Exos-treated defects.

Conclusions: The isolation method critically determines the biological performance of DPSC-derived Exos. UC-Exos may be preferable for stimulating proliferation and migration, whereas SEC-Exos show advantages in osteogenic differentiation. Both approaches facilitated bone regeneration in vivo, suggesting that exosome isolation strategies should be tailored to experimental requirements and therapeutic objectives to optimize translational outcomes.

Significance statement: The isolation method critically determines the biological performance of DPSC-derived exosomes. SEC-Exos, enriched in osteogenic factors such as ENPP2 and afamin, preferentially enhanced osteogenic differentiation, whereas UC-Exos promoted proliferation and migration. Both approaches supported consistent bone regeneration in vivo, underscoring that the optimal isolation strategy should be tailored to specific experimental and therapeutic objectives to advance translational applications.