Stem Cell Research & Therapy最新文献

Background: Huntington's disease (HD) is a genetic neurological disorder predominantly characterised by the progressive loss of GABAergic medium spiny neurons in the striatum resulting in motor dysfunction. One potential strategy for the treatment of HD is the development of cell replacement therapies to restore neuronal circuitry and function by the replacement of lost neurons. We propose the generation of lineage-specific human lateral ganglionic eminence precursors (hiLGEP) using direct reprogramming technology provides a novel and clinically viable cell source for cell replacement therapy for HD.

Methods: hiLGEPs were derived by direct reprogramming of adult human dermal fibroblasts (aHDFs) using chemically modified mRNA (cmRNA) and a defined reprogramming medium. hiLGEPs were differentiated in vitro using an optimised striatal differentiation medium. Acquisition of a striatal precursor and neural cell fate was assessed through gene expression and immunocytochemical analysis of key markers. hiLGEP-derived striatal neuron functionality in vitro was demonstrated by calcium imaging using Cal-520. To investigate the ability for hiLGEP to survive, differentiate and functionally integrate in vivo, we transplanted hiLGEPs into the striatum of quinolinic acid (QA)-lesioned rats and performed behavioural assessment using the cylinder test over the course of 14 weeks. Survival and differentiation of hiLGEPs was assessed at 8 and 14-weeks post-transplant by immunohistochemical analysis.

Results: We demonstrate the capability to generate hiLGEPs from aHDFs using cmRNA encoding the pro-neural genes SOX2 and PAX6, combined with a reprogramming medium containing Gö6983, Y-27,632, N-2 and Activin A. hiLGEPs generated functional DARPP32 + neurons following 14 days of culture in BrainPhys™ media supplemented with dorsomorphin and Activin A. We investigated the ability for hiLGEPs to survive transplantation, differentiate to medium spiny-like striatal neurons and improve motor function in the QA lesion rat model of HD. Fourteen weeks after transplantation, we observed STEM121 + neurons co-expressing MAP2, DARPP32, GAD_65/67, or GABA. Rats transplanted with hiLGEPs also demonstrated reduction in motor function impairment as determined by spontaneous exploratory forelimb use when compared to saline transplanted animals.

Conclusion: This study provides proof-of-concept and demonstrates for the first time that aHDFs can be directly reprogrammed to hiLGEPs which survive transplantation, undergo neuronal differentiation to generate medium spiny-like striatal neurons, and reduce functional impairment in the QA lesion rat model of HD.

Cancer stem cells (CSCs) represent a small yet pivotal subset of tumor cells endowed with self-renewal capabilities. These cells are intricately linked to tumor progression and are central to drug resistance, metastasis, and recurrence. The tumor microenvironment (TME) encompasses the cancer cells and their surrounding milieu, including immune and inflammatory cells, cancer-associated fibroblasts, adjacent stromal tissues, tumor vasculature, and a variety of cytokines and chemokines. Within the TME, cells such as immune and inflammatory cells, endothelial cells, adipocytes, and fibroblasts release growth factors, cytokines, chemokines, and exosomes, which can either sustain or disrupt CSCs, thereby influencing tumor progression. Conversely, CSCs can also secrete cytokines, chemokines, and exosomes, affecting various components of the TME. Exosomes, a subset of extracellular vesicles (EVs), carry a complex cargo of nucleic acids, proteins, and lipids, playing a crucial role in the communication between CSCs and the TME. This review primarily focuses on the impact of exosomes secreted by CSCs (CSC-exo) on tumor progression, including their roles in maintaining stemness, promoting angiogenesis, facilitating metastasis, inducing immune suppression, and contributing to drug resistance. Additionally, we discuss how exosomes secreted by different cells within the TME affect CSCs. Finally, we explore the potential of utilizing exosomes to mitigate the detrimental effects of CSCs or to target and eliminate them. A thorough understanding of the exosome-mediated crosstalk between CSCs and the TME could provide valuable insights for developing targeted therapies against CSCs.

Background: Knee osteoarthritis (OA) is a leading cause of disability, with current treatment options often falling short of providing satisfactory outcomes. Autologous-cultured adipose-derived mesenchymal stem cells (ADMSCs) and stromal vascular fractions (SVFs) have emerged as potential regenerative therapies.

Methods: A comprehensive search was conducted among multiple databases for studies up to June 2023. The risk of bias was assessed in randomized and non-randomized studies, adhering to PRISMA guidelines. The study has been registered with PROSPERO (CRD 42023433160).

Results: Our analysis encompassed 31 studies involving 1,406 patients, of which, 19 studies with 958 patients were included in a meta-analysis, examining both SVF and autologous-cultured ADMSC methods. Significant pain reduction was observed with autologous-cultured ADMSCs starting at 3 months (MD = -2.43, 95% CI, -3.99, -0.86), whereas significant pain mitigation in response to SVF therapy was found to start at 12 months (MD = -2.13, 95% CI, -3.06, -1.21). Both autologous-cultured ADMSCs and SVF provided significant improvement in knee function starting at 12 months (MD = -9.19, 95% CI, -12.48, -5.90 vs. MD = -9.09, 95% CI, -12.67, -5.51, respectively). We found no evidence of severe adverse events linked directly to ADMSC therapy.

Conclusion: Autologous-cultured ADMSCs offer a promising alternative for more rapid pain relief in knee OA, with both ADMSCs and SVF demonstrating substantial long-term benefits in joint function and cartilage regeneration, in the absence of any severe ADMSC-related adverse events.

Stem cell therapies have emerged as a promising approach in regenerative medicine, demonstrating potential in personalized medicine, disease modeling, and drug discovery. Therapies based on induced pluripotent stem cells (iPSCs) particularly stand out for their ability to differentiate into various cell types while avoiding ethical concerns. However, the development and application of these therapies are influenced by varying regulatory frameworks across countries. This study provides a comparative analysis of regulations and research on stem cell therapies in key regions: The European Union (EU), Switzerland, South Korea, Japan, and the United States. First, the study reviews the regulatory frameworks on stem cell therapies. The EU and Switzerland maintain rigorous guidelines that prioritize safety and ethical considerations, which can hinder innovation. In contrast, the United States adopts a more flexible regulatory stance, facilitating the rapid development of stem cell therapies. South Korea and Japan take a balanced approach by incorporating practices from both regimes. These regulatory differences reflect each country's unique priorities and impact the pace and scope of stem cell therapy development. Moreover, the study examines global trends in clinical trials on stem cell treatments based on data obtained from two sources: ClinicalTrials.gov and ICTRP. Findings indicate a significant growth in the number of clinical trials since 2008, particularly in that involving iPSCs. Therapeutic studies involving iPSCs predominantly target conditions affecting the cardiovascular and nervous systems which are considered vital. The results put emphasis on the safety of stem cell treatments. Meanwhile, the number of such trials also varies by country. The United States and Japan, where relatively flexible guidelines on stem cell research are adopted, are in a leading position. However, countries in the EU fall behind with rigorous regulations imposed. This reflects the need for more flexible regulatory guidance for active development of stem cell therapies. The findings underscore the importance of legal frameworks in facilitating innovation while ensuring safety. Regulatory agencies in different countries should collaborate to achieve a balanced global standard to ensure the safe and efficient advancement of stem cell therapies. Global regulatory convergence will promote international collaboration in research and the applicability of new treatments.

Background: This phase II randomized controlled trial tested whether the intracarotid arterial administration (ICAA) of autologous CD34 + cells to patients within 14 ± 7 days after acute ischemic stroke (IS) could be safe and further improve short- and long-term outcomes.

Methods: Between January 2018 and March 2022, 28 consecutive patients were equally randomly allocated to the cell-treated group (CD34 + cells/3.0 × 10⁷/patient) or the control group (receiving optimal medical therapy). CD34 + cells were transfused into the ipsilateral brain infarct zone of cell-treated patients via the ICAA in the catheterization room.

Results: The results demonstrated 100% safety and success rates for the procedure, and no long-term tumorigenesis was observed in cell-treated patients. In cell-treated patients, the angiogenesis capacity of circulating endothelial progenitor cells (EPCs)/Matrigel was significantly greater after treatment than before treatment with granulocyte colony-stimulating factor (all p < 0.001). Blood samples from the right internal jugular vein of the cell-treated patients presented significantly greater levels of the stromal cell-derived factor 1α/EPC at 5, 10 and 30 min compared with 0 min (all p < 0.005). The National Institute of Health Stroke Scale scores were similar upon presentation, but a greater response was observed by Days 30 and 90 in the cell-treated group than in the control group. Tc-99 m brain perfusion was significantly greater at 180 days in the cell-treated group than in the control group (p = 0.046). The combined long-term end points (defined as death/recurrent stroke/or severe disability) were notably lower in the control group compared with the cell-treated group (14.3% vs. 50.0%, p = 0.103).

Conclusion: Intracarotid transfusion of autologous CD34 + cells is safe and might improve long-term outcomes in patients with acute IS. Trial registration ISRCTN, ISRCTN15677760. Registered 23 April 2018- Retrospectively registered, https://doi.org/10.1186/ISRCTN15677760.

Background: The aim of this study was to assess the safety and efficacy of human umbilical cord mesenchymal stromal cells (hUC-MSCs) patch used as an adjuvant therapy in fetal myelomeningocele (MMC) surgery in the ovine model.

Methods: hUC-MSCs were isolated from human umbilical cords (UC) using the explant method, cultured and characterized. hUC-MSCs were then embedded in a fibrin patch. MMC were surgically created at 75 days of gestation and repaired at 89 days of gestation in sheep fetuses. Two groups were compared: the hUC-MSCs group in which MMC was repaired using a cellular patch and the control group, in which MMC was repaired using an acellular patch. Safety was evaluated by clinical ewes' monitoring during gestation, and clinical and histological examinations of lambs after birth. Efficacy was assessed by clinical neurological evaluation at 2 and 24 h of life using the sheep locomotor rating scale and by histological analyses.

Results: Among the 17 operated lambs, nine were born alive: six in the hUC-MSCs group and three in the control group. Overall fetal loss was 47% (8/17) without differences between the two groups. No fever was reported in ewes. No tumors were detected in clinical and histological examinations in the lambs. At 24 h of life, mean Sheep Locomotor Rating score was higher in the hUC-MSCs group than in the control group: 15.0 versus 2.0 (p = 0.07). Histological analyses showed a higher large neurons density in the hUC-MSCs group in comparison with the control group: 9.9 versus 6.3/mm² of gray matter (p = 0.04). Lambs in the hUC-MSCs group had lower fibrosis around the spinal cord and at the level of the MMC scar: 70.9 versus 253.7 μm (p = 0.10) and 691.3 versus 1684.4 μm (p = 0,18), respectively.

Conclusions: Ovine fetal repair of MMC using human UC-MSCs seems to be an effective and safe procedure.

Background: The use of mesenchymal stem cells (MSCs) is recognized as a promising strategy for the treatment of androgenetic alopecia (AGA). However, the underlying mechanism remains to be explored. Here, we evaluated the therapeutic effects and potential mechanisms of the use of human umbilical cord mesenchymal stem cells (hUCMSCs) in dihydrotestosterone (DHT)-induced AGA models in vivo and in vitro.

Methods: Intradermal transplantation of hUCMSCs was performed in AGA model mice and therapeutic effects were evaluated using histological and immunofluorescence staining. Transwell assays were used for co-culture of hUCMSCs and dermal papilla cells (DPCs), and communication was assessed using RT-qPCR, immunofluorescence, and apoptosis analysis. Interactions between DPCs and hair follicle stem cells (HFSCs) were investigated using RT-qPCR, EdU assays, and cell cycle analysis.

Results: Treatment of AGA mice with hUCMSCs promoted hair growth, HFs density, skin thickness, and anagen phase activation, while inhibiting DPCs apoptosis, and promoting HFSCs proliferation. In vitro, hUCMSCs activated Wnt/β-catenin signaling in DPCs via Wntless (Wls), while stimulating growth factor secretion and HFSCs proliferation. Blocking β-catenin degradation with MSAB increased DPCs apoptosis, reduced growth factor secretion, and retarded HFSCs proliferation.

Conclusion: hUCMSCs promoted hair regeneration in AGA model mice. This was found to be dependent on reducing DPCs apoptosis, thereby relieving the inhibitory effects of DPCs on the growth of HFSCs. The activation of the Wnt/β-catenin signaling pathway was shown to play a crucial role in the promotion of hair growth by hUCMSCs in AGA mice.

Background: Neural stem cells (NSCs) are considered to be the most promising cell type for cell replacement therapy in neurodegenerative diseases. However, their low neuronal differentiation ratio impedes their application in such conditions. Elucidating the molecular mechanism of NSC differentiation may provide the necessary experimental basis for expanding their application. Previous studies have indicated that POU3F4 can induce neuronal differentiation of NSCs, this study aims to underly the possible exact mechanism of POU3F4 on the NSC differentiation and development.

Methods: NSCs were isolated and cultured from the hippocampus of neonatal mice. The frozen hippocampal sections were prepared for immunohistochemical staining. Synaptic development was assessed using electron microscopy. High-throughput sequencing was employed to analyze the gene expression profile following the overexpression of Brn4. Gene expression levels were determined through Western blotting and qRT-PCR. Cell cycle and differentiation were evaluated using flow cytometry and immunofluorescent staining.

Results: It was found that POU3F4 promoted the neuronal differentiation of hippocampal NSCs and synapse development, and inhibited NSC proliferation. POU3F4-deficient mice exhibited impairments in learning and memory. RNA sequencing and ChIP assays confirmed that Gli1 was downstream of POU3F4. Loss and gain function experiments indicated that Gli1 mediated POU3F4 promoting neuronal differentiation and synapse development. Forced expression of Gli1 in hippocampus improved learning and memory function of animal models.

Conclusions: The results suggest that POU3F4 and Gli1 promote neuronal differentiation and synaptic development of NSCs, and that Gli1 partially mediates the effects of POU3F4.