International journal of stem cells最新文献

Cardiotoxicity assessment is a crucial step in the drug development process. With growing interest in alternatives to animal testing, preclinical cardiotoxicity evaluation has become increasingly important. Human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) offer a physiologically relevant in vitro model for this purpose. As a result, electrophysiological analysis platforms using iPSC-CMs have gained attention. However, conventional microelectrode array (MEA) chips rely on metal electrodes, which are costly and optically opaque. This lack of transparency limits detailed morphological observation of the cells. In this study, we employed an MEA chip incorporating transparent and conductive indium tin oxide (ITO) electrodes to simultaneously monitor both morphological changes and field potential (FP) of iPSC-CMs. iPSC-CMs cultured on ITO chips exhibited stable electrophysiological signals reflecting coupled depolarization and repolarization, along with self-organization. Short-term exposure to ion channel blockers did not induce noticeable morphological alterations; however, dose-dependent changes in FPs were observed. In contrast, treatment with cardiotoxic drugs resulted in morphological damage and reduced cell viability, accompanied by progressive alterations in key FP parameters over the treatment period. These findings demonstrate the potential of ITO-based MEA as next-generation cardiotoxicity evaluation platforms capable of real-time monitoring of both drug-induced electrophysiological responses and optical cellular changes.

Pyrene (Pyr), a representative subtype of polycyclic aromatic hydrocarbons, is primarily generated during the incomplete combustion of organic matter. As an environmental pollutant, Pyr has been reported to exert adverse effects on various physiological systems. However, data regarding its cardiotoxicity remain limited. In this study, we investigated the acute cardiotoxic effects of Pyr using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). hiPSC-CMs were exposed to various doses of Pyr, and both cell viability and functional parameters were evaluated. Pyr did not affect cell viability under 30-minute and 2-hour exposure conditions regardless of dose. However, significant differences were observed in the dual-cardiotoxicity evaluation based on a microelectrode array, which allows simultaneous assessment of electrophysiological signals and contractility in CMs. Pyr decreased beat period and field potential duration in a dose-dependent manner, resembling the acute cardiotoxicity pattern of I_Kr and I_CaL channel blockers, and progressively reduced spike amplitude over time. Pyr also progressively reduced spike amplitude over time. Although a transient decrease in beat amplitude was observed at high dose, it recovered over time, while the excitation-contraction delay was reduced. Taken together, these findings demonstrate that Pyr can induce functional cardiotoxicity even under acute exposure and highlight the value of the established evaluation method for the development of safer alternative substances.

Extracellular vesicles (EVs) are crucial mediators of intercellular communication, which facilitate the transfer of bioactive molecules such as proteins, lipids, and nucleic acids. Their high biocompatibility and intrinsic targeting abilities make them promising candidates for therapeutics, drug delivery, and disease biomarkers. In liver diseases, EVs are essential in liver regeneration, fibrosis modulation, and ischemia-reperfusion injury repair, and EV-derived biomarkers have shown potential for non-invasive disease monitoring, particularly in hepatitis B virus infection, non-alcoholic fatty liver disease, and hepatocellular carcinoma. This review provides a comprehensive overview of EV biology, cellular sources, isolation techniques, and strategies to enhance their therapeutic potential. Furthermore, we discuss the role of EVs in liver regeneration and their clinical application in biomarker discovery. Despite significant advancements in EV-based therapies, challenges such as scalability, standardization, immunogenicity, and regulatory approval remain key hurdles for clinical translation. Future research should focus on optimizing EV bioengineering, refining isolation methods, and addressing regulatory concerns to facilitate successful application of EVs in liver disease management and precision medicine.

Human chemically derived hepatic progenitors (hCdHs) reprogrammed using three chemicals-HGF, A83-01, and CHIR99021 (collectively denoted as "HAC")-have been suggested as a novel therapeutic for patients with severe liver diseases in our previous study. Despite its high proliferation and re-differentiation ability into functional hepatocytes, the reprogramming mechanism of hCdHs remained unknown. Recently, it has been reported that autophagy, a self-degradation process, is responsible for stem cell metabolism. In this study, we investigated whether autophagy regulates the generation mechanism of CdHs, mainly using hepatocytes from C57BL/6 mice, with additional analysis using human hepatocytes. As a result, we found that autophagy flux is inhibited during the generation of mouse CdHs (mCdHs) by A83-01, which is compensated by CHIR99021. Moreover, the suppression of autophagy by bafilomycin A1 enhanced the proliferation ability of mCdHs during the generation process. hCdHs also showed a similar autophagy inhibition pattern to mCdHs during the generation process. Taken together, our study indicates that autophagy is downregulated during the generation of CdHs, promoting their proliferation. This may contribute to the production of hCdHs with stable productivity, which may serve as a therapeutic for severe liver diseases.

Idiopathic pulmonary fibrosis (IPF) is characterized by maladaptive epithelial-mesenchymal crosstalk and progressive extracellular matrix accumulation, whereas currently available antifibrotic agents merely decelerate functional decline. This study investigated whether exosomes derived from human mesenchymal stem cells derived from embryonic stem cells (ESC-MSCs) restore epithelial stress responses and attenuate fibrotic remodeling. Human IPF lung transcriptomes were integrated with a bleomycin-induced murine model analyzed by RNA sequencing and protein signaling, together with cigarette smoke extract-induced injury in A549 epithelial cells. ESC-MSCs-derived exosomes exhibited typical morphology and size distribution, enrichment of tetraspanins, and absence of endoplasmic reticulum contamination, consistent with high-purity preparations. Across human IPF and bleomycin-injured lungs, transcriptomic profiling revealed prominent enrichment of extracellular matrix and cytoskeletal gene programs, whereas mitogen-activated protein kinase (MAPK) and Smad families displayed only modest alterations at the mRNA level. In vivo administration of exosomes during the fibrotic remodeling phase, via either intravenous or intratracheal delivery, resulted in improved body weight, reduced lung weight-to-body weight ratios, and decreased collagen deposition and Ashcroft scores. These structural and functional improvements were accompanied by suppression of profibrotic and mesenchymal markers and selective attenuation of activator protein-1 (AP-1) activity. In epithelial injury models, ESC-MSCs-derived exosomes enhanced cell viability, restored redox homeostasis, and constrained stress-induced mesenchymal gene expression and MAPK phosphorylation in both co-treatment and post-treatment settings. Collectively, these data support an epithelial- centered mechanism in which ESC-MSCs-derived exosomes re-establish oxidative balance and selectively restrict AP-1-driven stress signaling, thereby secondarily limiting extracellular matrix accumulation and fibrotic remodeling.

Ovarian cancer remains one of the most lethal gynecologic malignancies, with limited responsiveness to standard chemotherapy and poor long-term prognosis. Tumor-associated macrophages, particularly M2-polarized populations, play a crucial role in immune suppression and tumor progression. Human induced pluripotent stem cells (hiPSCs) can differentiate into functional immune cells, providing an unlimited and patient-specific source for cell-based immunotherapy. In this study, we investigated the therapeutic potential of hiPSC-derived macrophages (hiMACs), specifically M1-polarized hiMACs, against ovarian cancer. In a co-culture system, M1-hiMACs significantly reduced the viability of ovarian cancer cells, inducing apoptosis and necrosis, whereas M0 macrophages showed minimal effects. In vivo, intravenous administration of M1-hiMACs into nude mice bearing ovarian cancer cells resulted in a dose-dependent reduction in tumor volume. Furthermore, combination therapy with paclitaxel and M1-hiMACs led to greater tumor regression and enhanced histological necrosis compared to either treatment alone. These findings demonstrate the potent anti-tumor effects of M1-hiMACs and highlight their potential for cellular immunotherapy for ovarian cancer, particularly in combination with chemotherapy.

The brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroprotection, and we have previously demonstrated BDNF-mediated neuroprotective effects in mesenchymal stromal cells (MSCs). The present study aimed to investigate whether BDNF-overexpressing MSCs enhance the therapeutic efficacy of naïve MSCs in a preclinical model of severe neonatal intraventricular hemorrhage (IVH). We exposed primary rat neuronal cells to 40 U of thrombin overnight in vitro. Subsequently, the neuronal cells were co-cultured with either naïve MSCs or BDNF-overexpressing MSCs (1×10⁵ cells in 1 mL media) for 24 hours. Next, 300 μL of maternal blood was injected into bilateral ventricles on postnatal day (P)4 to induce severe IVH in newborn Sprague-Dawley male rats. At P6, either naïve MSCs or BDNF-overexpressing MSCs (1×10⁵ cells in 10 μL saline) were transplanted intraventricularly. Behavioral function tests, including passive avoidance, followed by endpoint analyses of brain tissue and cerebrospinal fluid were performed at P35. BDNF-overexpressing MSCs enhanced the effects of naïve MSCs against cell death, cytotoxicity, and oxidative stress in vitro. Notably, naïve and BDNF-overexpressing MSCs did not attenuate post-hemorrhagic ventricular dilatation, neuronal cell death, or gliosis. However, BDNF-overexpressing MSCs attenuated microglial activation. Furthermore, inflammatory cytokine (interleukin [IL]-1α, IL-1β, IL-6, and tumor necrosis factor-α) levels and memory function assessed using a passive avoidance test significantly improved in the BDNF-overexpressing MSC transplanted group compared with the naïve MSC transplanted group. Our data suggest that BDNF-overexpressing MSCs may offer superior protective effects to naïve MSCs in a neonatal IVH model.

A rare disease is generally defined as a medical condition that affects a small proportion of the population, though specific thresholds vary across countries. Despite regional differences, these definitions consistently reflect the low prevalence of such conditions, the limited availability of effective treatments, and the pressing need for targeted research and regulatory support. As a result of their rarity and low commercial potential, rare diseases have historically represented an area of market failure, where investment and research have been limited and often neglected. However, since the 1990s, each country has guaranteed continuous support to research and development projects to promote the advancements of rare disease treatments, achieving a growth rate greater than that of the entire pharmaceutical industry. In this review, we examine the status of orphan drug development using an advanced therapy medicinal product (ATMP) approach in the growing rare disease market, with a particular focus on cell therapies and gene therapies, which constitute the most actively developed and clinically applied categories within ATMPs. We also explore strategic approaches through which the orphan drug industry can utilize ATMPs, especially these two modalities, to enhance its competitiveness.

Bronchopulmonary dysplasia (BPD), characterized by impaired alveolarization and dysregulated vascularization, is a severe health burden for neonates worldwide. Hyperoxia induced acute lung injury is a major contributor to the progression and deterioration of BPD. An increasing number of animal studies have revealed that human umbilical cord blood derived mononuclear cells (hUCB-MNCs) infusion significantly attenuated the hyperoxia-induced acute lung injury through regeneration capacity. Currently, clinical application requires determination of the optimal dose and adjustment to good manufacturing practices. In this work, we comprehensively investigated the optimal dose of hUCB-MNCs in alleviating hyperoxia-induced lung injury in neonatal C57BL6/J mice. Mice with hyperoxia exposure were implanted with low (3×10⁴ cells/kg, Dl), middle (3×10⁵ cells/kg, Dm) and high (3×10⁶ cells/kg, Dh) dose of hUCB-MNCs at postnatal day 7. Three weeks after graft, characteristics exhibited in lungs including morphology, function and cytokine expression were thoroughly analyzed. Implantation of hUCB-MNCs sharply reverted the impaired lung architecture induced by hyperoxia exposure dose dependently as evidenced by indicated parameters. Attenuated expression of IL-1β concomitant with enhanced expression of IL-10 and IL-2 were shown in Dh inoculated groups, where Dl and Dm failed to restore the level of IL-10, IL-1β and IL-2. Significantly re-escalated marker of angiogenic marker VEGFA, CD31 in lung tissue were uniquely observed in Dh group. Mechanistically, our study revealed the appropriate dose of intravenous infusion of hUCB-MNCs in alleviating hyperoxia-induced lung injury through modulating reactive oxygen species response in neonatal mice. Therefore, a tight control of hUCB-MNCs density or levels of CB-MNC related products is of great significance.

There is mounting epidemiologic and experimental evidence of the harmful effects of exposure to fine particulate matter (PM2.5) on human lung health. However, the current utilization of in vitro two-dimensional (2D) cell culture and in vivo animal models falls short in accurately recapitulating the complexity, functions, and development of the human lung. Recently, technologies for creating 3D biomimetic lung organoids from human tissue and pluripotent stem cells that mimic the structure and function of human organs have been rapidly developed. Human lung organoids are currently being applied in various studies such as disease modeling, drug efficacy testing, and regenerative medicine. In the field of environmental toxicology, human lung organoids offer a promising solution for more accurately assessing the health impacts of exposure to PM2.5 and to the limitations posed by 2D cultures and animal models. In this review, we summarize the effects of PM2.5 exposure on human lung and other organoids, as well as the molecular and genetic impacts of such exposure using human organoids. Furthermore, the development of lung-on-a-chip technology to mimic the microenvironment and its utilization for evaluating the pulmotoxicity of PM2.5 exposure are discussed.