International journal of stem cells最新文献

Critical limb ischemia (CLI) is a severe manifestation of peripheral arterial disease, often resulting in ischemic rest pain, non-healing ulcers, or gangrene. Due to the limited effectiveness of conventional revascularization techniques in 5%∼20% of patients, alternative therapeutic approaches are needed. This Phase 1/2a clinical trial evaluated the safety, tolerability, and efficacy of allogeneic adipose tissue-derived mesenchymal stem cell clusters (ADMSCCs) in patients with CLI who were not eligible for standard revascularization methods. The study was conducted in two phases: Phase 1 used a 3＋3 dose-escalation design to determine tolerability, and Phase 2a assessed efficacy at the maximum tolerated dose. Twenty patients were treated with ADMSCCs, with safety (adverse events and dose-limiting toxicity) and efficacy (pain intensity, walking distance, and ulcer size) as primary endpoints. ADMSCCs were injected intramuscularly, and patients were monitored for 24 weeks. ADMSCCs were well-tolerated, with no serious adverse events or dose-limiting toxicities observed. Significant reductions in ischemic pain and increases in pain-free walking distance were noted at 4, 12, and 24 weeks. Although ankle-brachial index and toe-brachial index showed no significant changes, ulcer healing was observed in one participant. These findings suggest that ADMSCC therapy may be a viable alternative for patients with CLI, with a favorable safety profile and sustained therapeutic effects. Further studies with larger sample sizes and randomized control groups are needed to confirm these results and explore integration with existing treatments.

Cell viability is an indispensable aspect of cells in the field of drug discovery, cell biology, and biomedical research to assess the physiological conditions of cells such as healthiness, functionality, survivability, etc. Recently, there have been several methods for determining the cell viability through either cell staining with trypan blue and acridine orange, propidium iodide, calcein-AM, etc., or colorimetric assays such as cell counting kit-8 assay. However, these methods have some limitations like time-consuming, expensive, unstable, individual variability, etc. Even present artificial intelligence software such as QuPath, ImageJ, etc., can only determine the cell viability after cell staining. Therefore, we attempted to determine whether cells are alive or not depending on the visual characteristics of an individual cell using Teachable Machine, a web-based artificial intelligence tool provided by Google. Labeling work to assign correct answers to learning data consumes a lot of time and human costs because it is usually done manually. To solve this problem, labeling was automated by recognizing and extracting only individual cells from the image using the contour function to increase time efficiency. In addition, many datasets were created to evaluate and compare the performances of models. Based on the results, the model that showed the best performance showed an accuracy of more than 80%. In conclusion, this model could minimize analysis time, expenses, individual variability, etc., enhancing the efficacy and reproducibility of biological experiments in the fields of drug discovery, drug development, and biological research.

Compared with conventional mesenchymal stem cells (MSCs), induced mesenchymal stem cells (iMSCs) from induced pluripotent stem cells are unique cell sources for tissue regeneration. The effect of extracellular vesicles (EVs) secreted from iMSCs on inhibiting acute kidney injury (AKI) to chronic kidney disease (CKD) transition was not reported. In this study, we investigated whether EVs from iMSCs (iMSC-EVs) could inhibit AKI-to-CKD transition. iMSC-EVs exhibited the general characteristics of EVs, such as protein marker expression, morphology, and size. Additionally, iMSC-EVs were detected in renal tissues after intravenous injection. In human renal tubular epithelial cells, the increase in pro-fibrotic gene expression in response to transforming growth factor β1 treatment was decreased by iMSC-EVs. In a mouse model of the AKI-to-CKD transtion induced by folic acid, repeated administration of iMSC-EVs restored renal function at day 14. Specifically, iMSC-EVs reduced interstitial fibrosis, sustained inflammation, various types of cell death, and the number of immune cells infiltrating kidneys. Capillary rarefaction in renal tissue was also reversed by iMSC-EVs. Our results demonstrate that iMSC-EVs reduced interstitial fibrosis, inflammation, and cell death occurring during the CKD transition after AKI. Thus, iMSC-EVs have the potential to block AKI-to-CKD transition.

Stem cells derived from human orbicularis oculi muscle (hOOM) are a valuable resource for cell therapy. However, when stem cells are continuously cultured, their abilities tend to deteriorate over time. One method to address this issue is to use basic fibroblast growth factor (bFGF) to maintain the stem cell functionality. The limitation is that bFGF is unstable under mammalian cell culture conditions with a half-life of only 8 hours, which poses a significant challenge to the production and maintenance of high-quality stem cells. In this study, we used thermostable bFGF (TS-bFGF) and demonstrated that hOOM-derived stem cells cultured with TS-bFGF exhibited superior proliferation, stem cell function, reduced reactive oxygen species, and cellular senescence delay effect compared to cells cultured with wild-type bFGF. Considering the pivotal role of stem cells in broad ranges of applications such as regenerative medicine and cultured meat, we anticipate that TS-bFGF, owing to its thermostability and long-lasting properties, will contribute significantly to the acquisition of high-quality stem cells.

Muscle satellite cells (SCs), also known as muscle stem cells, are crucial for the regeneration, maintenance, and growth of skeletal muscles. SCs possess a distinctive capability to self-renew and differentiate, rendering them highly promising candidates for regenerative therapies and emerging cellular agriculture applications, including cultured meat production. This review explores the mechanisms that govern SC activation, proliferation, and commitment, and emphasizes their functional heterogeneity across anatomical regions. Region-specific gene expression, including that of homeobox (Hox) genes, contributes to the positional identity and myogenic potential. Understanding these regulatory landscapes is essential for optimizing SC expansion and improving their applications in muscle repair, stem cell-based therapies, and cellular manufacturing systems.

Mitigating obesity is a pivotal strategy for addressing metabolic diseases, including cardiovascular diseases, liver diseases, and diabetes. Although pear extract exhibits various pharmacological effects in regenerative diseases, such as skin, nerve, and adipose tissue dysfunction, by eliminating excessive reactive oxygen species, its exact clinical role in obesity has not been well studied. In this study, we investigated the efficacy and safety of pear extract (UPhenon®), a dietary ingredient extracted from unripe pear (Pyrus pyrifolia), in Korean participants with obesity. The participants underwent a 12-week, randomized, double-blind placebo-controlled trial. Body fat mass, body weight, body mass index (BMI), and hematological and blood chemistry parameters were assessed. No adverse effects or significant changes were observed in the supplementation or placebo groups. Additionally, the two groups did not differ significantly in body fat mass, body weight, BMI, hematological parameters, or blood chemistry parameters, except for the liver-specific enzyme, aspartate aminotransferase. Interestingly, compared with the supplementation and placebo groups, after 12 weeks of pear extract administration, a significant decrease in aspartate aminotransferase levels was recorded, indicating that pear extract partially attenuates obesity-induced liver damage. Furthermore, when compared with baseline measurements, a significant reduction in body fat mass (-802.61±1,460.82 g, p<0.0007), body weight (-1.28±1.29 kg, p<0.0001), and BMI (-0.46±0.46 kg/m², p<0.0001) was observed after 12 weeks of pear extract administration. Taken together, our results suggest that pear extract supplementation may effectively reduce obesity without adverse effects and it may be a promising alternative to synthetic anti-obesity drugs.

Induced pluripotent stem cells (iPSCs) are a promising cell source for regenerative medicine. Clinical applications require a large number of functional red blood cells (RBCs), making it essential to ensure the proliferation of actively dividing, nucleated erythroblasts derived from iPSCs. Small molecules can enhance the efficiency and frequency of iPSC-derived cell differentiation. Sirtuin 1, a key enzyme in multiple biological processes, has been implicated in enhancing iPSC-derived cell differentiation. However, the specific effects of Sirtuin 1 on erythroblast proliferation from iPSCs remain unclear. Here, we developed a protocol to examine the effects of Sirtuin 1 on erythroblasts after endothelial-to-hematopoietic transition (EHT). We found that Sirtuin 1 activation increased the frequency of CD71^＋CD235a^＋ erythroblasts at the early stage after EHT, suggesting a role for Sirtuin 1 in the proliferation of these specified erythroblasts. These findings reveal that Sirtuin 1 activation benefits erythroblast proliferation and could be considered for translational application in large-scale RBC culture.

Endometrial stem cells (EnSCs) are mesenchymal stem cells (MSCs) derived from endometrial tissue and serve as a valuable MSC source, as they are naturally replenished during menstruation. Exosomes, vesicles secreted by cells, contain various biomolecules such as proteins and nucleic acids and play crucial roles in intracellular communication, protein and nucleic acid metabolism, immune response regulation, and antigen presentation. This study investigated the protein profiles of EnSC-derived exosomes isolated from the endometrium of menstruating women and compared them with those of adipose-derived stem cell (ASC)-derived exosomes. After isolating EnSCs and ASCs, MSC characteristics were confirmed, and the purified exosomes were analyzed to determine their individual protein compositions. EnSCs, which can be obtained through non-invasive methods, exhibit multipotency similar to other MSCs and demonstrate rapid proliferation in vitro. Proteomic analysis of exosomal proteins revealed that 236 proteins were significantly more abundant in EnSC-derived exosomes than in ASC-derived exosomes, whereas 84 proteins were significantly more abundant in ASC-derived exosomes than in EnSC-derived exosomes. These findings indicate that EnSC-derived exosomes contain unique proteins compared to ASC-derived exosomes, as demonstrated through proteomic profiling. While further clinical studies are required, EnSCs hold promise as a potential therapeutic option in regenerative medicine, similar to current cell therapy products under development.

The increasing ethical concerns and regulatory restrictions surrounding animal testing have accelerated the development of advanced in vitro models that more accurately replicate human physiology. Among these, stem cell-based systems and organoids have emerged as revolutionary tools, providing ethical, scalable, and physiologically relevant alternatives. This review explores the key trends and driving factors behind the adoption of these models, such as technological advancements, the principles of the 3Rs (Replacement, Reduction, and Refinement), and growing regulatory support from agencies like the OECD and FDA. It also delves into the development and application of various model systems, including 3D reconstructed tissues, induced pluripotent stem cell-derived cells, and microphysiological systems, highlighting their potential to replace animal models in toxicity evaluation, disease modeling, and drug development. A critical aspect of implementing these models is ensuring robust quality control protocols to enhance reproducibility and standardization, which is necessary for gaining regulatory acceptance. Additionally, we discuss advanced strategies for assessing toxicity and efficacy, focusing on organ-specific evaluation methods and applications in diverse fields such as pharmaceuticals, cosmetics, and food safety. Despite existing challenges related to scalability, standardization, and regulatory alignment, these innovative models represent a transformative step towards reducing animal use and improving the relevance and reliability of preclinical testing outcomes.

Intrauterine adhesion (IUA) caused by endometrial injury is the most common cause of female uterine infertility. Current treatments offer limited clinical benefits. In this study, we investigated the role of human umbilical cord mesenchymal stem cells (hUCMSCs) loaded collagen scaffold in the regeneration of injured human endometrium in an IUA rat model. Following the construction of the IUA rat model by mechanical injury, collagen scaffold, hUCMSCs, or hUCMSCs-loaded collagen scaffold was transplanted. The implantation of hUCMSCs-loaded collagen scaffold significantly increased the thickness of the endometrium, the number of endometrial glands and the abundance of blood vessels in IUA rats. Moreover, hUCMSCs-loaded collagen scaffold treatment significantly reduced endometrial fibrosis, increased the expression of Vegf, Integrin β3, Lif, and Igf-1, and finally improved endometrial receptivity in IUA rats. Taken together, our observations suggest that hUCMSCs-loaded collagen scaffold could be a practical therapeutic for treating IUA and restoring regeneration.