Stem Cell Reviews and Reports最新文献

Reliable models of the blood-brain barrier (BBB), wherein brain microvascular endothelial cells (BMECs) play a key role in maintenance of barrier function, are essential tools for developing therapeutics and disease modeling. Recent studies explored generating BMEC-like cells from human pluripotent stem cells (hPSCs) by mimicking brain-microenvironment signals or genetic reprogramming. However, due to the lack of comprehensive transcriptional studies, the exact cellular identity of most of these cells remains poorly defined. In this study we aimed to identify the most likely master transcription factors (TFs) for inducing brain endothelial cell (EC) fate and assess the transcriptomic changes following their introduction into immature ECs. Therefore, we first generated PSC-derived immature ECs by transient overexpression of the TF, ETV2. Subsequently, by performing an extensive meta-analysis of transcriptome studies of brain and non-brain ECs, 12 candidate TFs were identified, which might fate immature ECs towards cells with brain EC features. Following combinatorial overexpression of these 12 TFs tagged with unique barcodes, single cell transcriptomics identified a subset of transduced cells that resembled mid-gestational human brain ECs. Assessment of the TF barcodes present in these cells revealed significant enrichment of the TFs ZIC3, TFAP2C, TFAP2A, and DLX2. These TFs might be useful to fate PSC-EC to BMEC-like cells, which could be incorporated in human in vitro BBB models.

Human-induced pluripotent stem cell (hiPSC) technology has been applied in pathogenesis studies, drug screening, tissue engineering, and stem cell therapy, and patient-specific hiPSC-derived cardiomyocytes (hiPSC-CMs) have shown promise in disease modeling, including diabetic cardiomyopathy. High glucose (HG) treatment induces lipotoxicity in hiPSC-CMs, as evidenced by changes in cell size, beating rate, calcium handling, and lipid accumulation. Empagliflozin, an SGLT2 inhibitor, effectively mitigates the hypertrophic changes, abnormal calcium handling, and contractility impairment induced by HG. Glucose concentration influences SGLT2 expression in cardiomyocytes, highlighting its potential role in diabetic cardiomyopathy. These findings support the potential utility of hiPSC-CMs in studying diabetic cardiomyopathy and the efficacy of empagliflozin in ameliorating HG-induced cardiomyocyte dysfunction. Such research may advance developments in precision medicine and therapeutic interventions for patients with diabetic cardiomyopathy.

Over the past decade, research on embryo-derived extracellular vesicles (EVs) has unveiled their critical roles in embryonic development and intercellular communication. EVs secreted by embryos are nanoscale lipid bilayer vesicles that carry bioactive cargo, including proteins, lipids, RNAs, and DNAs, reflecting the physiological state of the source cells. These vesicles facilitate paracrine and autocrine signaling, influencing key processes such as cell differentiation, embryo viability, and endometrial receptivity. Studies reveal that EVs can traverse the zona pellucida, transferring molecular signals that enhance blastocyst formation and support embryo-maternal crosstalk. EVs have emerged as non-invasive biomarkers for embryo quality, with their cargo providing insights into genetic integrity and developmental competence. Advances in isolation and characterization techniques have identified specific microRNA (miRNAs) and transcription factors within EVs, offering potential for use in preimplantation genetic screening (PGS) and sex determination. Moreover, EV-mediated interactions with the maternal environment are critical for successful implantation, as they modulate gene expression and immune responses in endometrial and oviductal cells. Despite these advancements, challenges persist, including the standardization of EV isolation methods and the low yield of EVs DNA from spent culture media. Future research should aim to refine analytical techniques, explore EV-miRNA profiling, and investigate the mechanisms underlying EV-mediated signaling. By addressing these gaps, EVs could revolutionize embryo selection and reproductive technologies, offering new strategies to improve outcomes in assisted reproduction and animal breeding.

The discovery of induced pluripotent stem cells (iPSCs) and protocols for their differentiation into various cell types have revolutionized the field of tissue engineering and regenerative medicine. Developing manufacturing guidelines for safe and GMP-compliant final products has become essential. Allogeneic iPSCs-derived cell therapies are now the preferred manufacturing alternative. This option requires the establishment of clinical-grade master cell banks of iPSCs. This study aimed at reviewing the Quality and Regulatory requirements from the two main authorities in the world-Europe (EMA) and the United States (FDA)-regarding the manufacture of clinical grade master cell banks (iPSCs). The minimum requirements for iPSCs to be used in first-in-human clinical trials were also reviewed, as well as current best practices currently followed by iPSC bank manufacturers for final product characterisation. The methodology used for this work was a review of various sources of information ranging from scientific literature, published guidance documents available on the EMA and FDA websites, GMP and ICH guidelines, and applicable compendial monographs. Manufacturers of iPSCs cell banks looking to qualify them for clinical use are turning to the ICH guidelines and trying to adapt their requirements. Specifically with the impact of the field of iPSC cell banks, the following areas should be subject to guidance and harmonisation: i) expression vectors authorized for iPSC generation; ii) minimum identity testing; iii) minimum purity testing (including adventitious agent testing); and iv) stability testing. Current ICH guidelines for biotechnological/biological products should be extended to cover cell banks used for cell therapies.

Dermatologists have been interested in recent advancements in regenerative therapy. Current research is actively investigating the possibility of placental tissue derivatives to decelerate the skin aging process, enhance skin regeneration, reduce scarring, and prevent hair loss. Amniotic membranes (AM) play a crucial role in regenerative medicine as they serve as a suitable means of transporting stem cells, growth hormones, cytokines, and other essential compounds. Regulating an intricate network of biological processes improves the development and repair of tissues. Studies done by dermatologists indicate that several compounds found in the decidua, umbilical cord, and amniotic membrane have the potential to be used for regeneration. Examples include mesenchymal stem cells, growth factors, and immunomodulatory pharmaceuticals. Due to research and technological developments, scientists may use placental sections to facilitate skin regeneration, minimize scarring, and expedite wound healing. This study examines the current state of dermatological therapy, with a focus on using derivatives obtained from fetal tissue as the basis. The critical areas of study focus on this strategy are the potential benefits, growth opportunities, and recovery rates. Based on a thorough examination of the available literature and clinical data, we want to make definitive conclusions on the possible influence of fetal tissue derivatives in dermatological therapy.

Hematopoietic stem cells are a unique population of tissue-resident multipotent cells with an extensive ability to self-renew and regenerate the entire lineage of differentiated blood cells. Stem cells reside in a highly specialized microenvironment with surrounding supporting cells, forming a complex and dynamic network to preserve and maintain their function. The survival, activation, and quiescence of stem cells are largely influenced by niche-derived signals, with aging niche contributing to a decline in stem cell function. Although the role of niche in regulating hematopoiesis has long been established by transplantation studies, limited methods in observing the process in vivo have eluded a detailed understanding of the various niche components. Danio rerio (zebrafish) has emerged as a solution in the past few decades, enabling discovery of cellular interactions, in addition to chemical and genetic factors regulating HSCs. This review reiterates zebrafish as a suitable model for studies on vertebrate embryonic and adult hematopoiesis, delving into this temporally and spatially dissected multi-step process. The critical role played by epigenetic regulators are discussed, along with contributions of the various physiological processes in sustaining the stem cell population. Stem cell niche transcends mere knowledge acquisition, assuring scope in cell therapy, organoid cultures, aging research, and clinical applications including bone marrow transplantation and cancer. A better understanding of the various niche components could also leverage therapeutic efforts to drive differentiation of HSCs from pluripotent progenitors, sustain stemness in laboratory cultures, and improve stem cell transplantation outcomes.

In the quest to transform vision care, researchers have been investigating novel methods to boost the efficacy of eye drops and enhance the survival of corneal limbal stem cells. Aimed at rejuvenating vision, these innovations seek to tackle a range of ocular conditions and restore sight to those in need. This article examines the most recent advancements in eye drops and corneal limbal stem cells, highlighting their potential to revolutionize ophthalmology. Findings from various studies indicate that the drive to rejuvenate vision has resulted in significant progress within the field of ophthalmology, especially regarding eye drops and corneal limbal stem cells. By improving the effectiveness of eye drops and increasing the survival rates of CLSCs, researchers are creating pathways for more sustainable and effective treatment options. These advancements offer great hope for patients experiencing various ocular issues, suggesting a future where vision restoration is attainable. As research continues to refine these strategies, we can look forward to an era marked by better visual outcomes and an enhanced quality of life for many individuals around the world.

Background: Undifferentiated embryonic cell transcription factor 1 (UTF1) is predominantly expressed in pluripotent stem cells and plays a vital role in embryonic development and pluripotency maintenance. Despite its established importance in murine models, the role of UTF1 on human induced pluripotent stem cells (iPSCs) has not been comprehensively studied.

Methods: This study utilized CRISPR/Cas9 gene editing to create UTF1 knockout in human fibroblasts and iPSCs. We employed episomal vectors for reprogramming UTF1 knockout fibroblasts into iPSCs and analyzed the effects of UTF1 depletion on cellular morphology, pluripotency, and viability through Western blotting, PCR, and flow cytometry. In addition, we integrated an shRNA that downregulated the expression of UTF1 for mechanistic studies to understand the impact of UTF1 depletion in iPSC pluripotency and differentiation.

Results: UTF1 knockout resulted in significantly reduced reprogramming efficiency and increased spontaneous differentiation, indicating its crucial role in maintaining human iPSC identity and stability. In knockdown experiments, gradual loss of UTF1 led to change in cellular morphologies and decreased expression of core pluripotency markers OCT4 and SOX2. Interestingly, unlike complete UTF1 knockout, the gradual downregulation of UTF1 in iPSCs did not result in apoptosis, suggesting that the loss of pluripotency can occur independently of the apoptotic pathways.

Conclusions: UTF1 is essential for maintaining the pluripotency and viability of human iPSCs. Its depletion affects the fundamental properties of stem cells, underscoring the potential challenges in using UTF1-deficient cells for therapeutic applications. Future studies should explore the mechanistic pathways through which UTF1 controls pluripotency and differentiation, which could provide insights into improving iPSC stability for clinical applications.

Pluripotent stem cells have the ability to differentiate into all cells and tissues within the human body, and as a result they are attractive resources for use in basic research, drug discovery and regenerative medicine. In order to successfully achieve this application, starting cell sources ideally require in-depth characterisation to confirm their pluripotent status and their ability to differentiate into tissues representative of the three developmental germ layers. Many different methods to assess potency are employed, each having its own distinct advantages and limitations. Some aspects of this characterisation process are not always well standardised, particularly techniques used to assess pluripotency as a function. In this article, we consider the methods used to establish cellular pluripotency and subsequently analyse characterisation data for over 1590 human pluripotent cell lines from publicly available repositories in the UK and USA. In particular, we focus on the teratoma xenograft assay, its use and protocols, demonstrating the level of variation and the frequency with which it is used. Finally, we reflect on the implications of the findings, and suggest in vitro alternatives using modern innovative technology as a way forward.