International journal of stem cells最新文献

Glutathione (GSH), the main cellular antioxidant, dynamically influences tumor growth, metastasis, and resistance to therapy in the tumor microenvironment (TME), which comprises cancer cells, immune cells, stromal cells, and non-cellular components, including the extracellular matrix, metabolites, hypoxia, and acidity. Cancer stem cells (CSCs) and T cells are minor but significant cell subsets of the TME. GSH dynamics influences the fate of CSCs and T cells. Here, we explored GSH dynamics in CSCs and T cells within the TME, as well as therapeutic approaches that could target these dynamics.

Mesenchymal stem cells in the dental tissue indicate a disposition for differentiation into diverse dental lineages and contain enormous potential as the important means for regenerative medicine in dentistry. Among various dental tissues, the dental pulp contains stem cells, progenitor cells and odontoblasts for maintaining dentin homeostasis. The conventional culture of stem cells holds a limit as the living tissue constitutes the three-dimensional (3D) structure. Recent development in the organoid cultures have successfully recapitulated 3D structure and advanced to the assembling of different types. In the current study, the protocol for 3D explant culture of the human dental pulp tissue has been established by adopting the organoid culture. After isolating dental pulp from human tooth, the intact tissue was placed between two layers for Matrigel with addition of the culture medium. The reticular outgrowth of pre-odontoblast layer continued for a month and the random accumulation of dentin was observed near the end. Electron microscopy showed the cellular organization and in situ development of dentin, and immunohistochemistry exhibited the expression of odontoblast and stem cell markers in the outgrowth area. Three-dimensional explant culture of human dental pulp will provide a novel platform for understanding stem cell biology inside the tooth and developing the regenerative medicine.

Sine oculis homeobox 1 (Six1) is an important factor for embryonic development and carcinoma malignancy. However, the localization of Six1 varies due to protein size and cell types in different organs. In this study, we focus on the expression and localization of Six1 in male reproductive organ via bioinformatics analysis and immunofluorescent detection. The potential interacted proteins with Six1 were also predicted by protein-protein interactions (PPIs) and Enrichr analysis. Bioinformatic data from The Cancer Genome Atlas and Genotype-Tissue Expression project databases showed that SIX1 was highly expressed in normal human testis, but low expressed in the testicular germ cell tumor sample. Human Protein Atlas examination verified that SIX1 level was higher in normal than that in cancer samples. The sub-localization of SIX1 in different reproductive tissues varies but specifically in the cytoplasm and membrane in testicular cells. In mouse cells, single cell RNA-sequencing data analysis indicated that Six1 expression level was higher in mouse spermatogonial stem cells (mSSCs) and differentiating spermatogonial than in other somatic cells. Immunofluorescence staining showed the cytoplasmic localization of Six1 in mouse testis and mSSCs. Further PPIs and Enrichr examination showed the potential interaction of Six1 with bone morphogenetic protein 4 (Bmp4) and catenin Beta-1 (CtnnB1) and stem cell signal pathways. Cytoplasmic localization of Six1 in male testis and mSSCs was probably associated with stem cell related proteins Bmp4 and CtnnB1 for stem cell development.

Nucleotide-binding oligomerization domain 1 (NOD1), a cytosolic pattern recognition receptor protein, plays a crucial role in innate immune responses. However, the functional expression of NOD1 in mesenchymal stem cells (MSCs) derived from endometriosis remains unclear. The aim of this study was to explore the functions of NOD1 in ectopic endometrial lesions. Tissues and MSCs were isolated from both normal endometrium and endometriosis. Immunohistochemistry and real time quantitative polymerase chain reaction (RT-qPCR) were used to determine the expression of NOD1 in the tissues/MSCs. Quantification of various cytokines was performed using RT-qPCR and enzyme-linked immunosorbent assay. To confirm the proliferation, invasion/migration, and apoptotic viabilities of the samples, Cell Counting Kit-8, clonogenic formation, transwell assays, and apoptotic experiments were conducted. Higher levels of NOD1 expression were detected in the ectopic-MSCs obtained from endometriosis compared to those from the endometrium. The expression of interleukin-8 was higher in the ectopic-MSCs than in the eutopic-MSCs. Pretreatment with NOD1 agonist significantly enhanced the proliferation and invasion/migration of eutopic-MSCs. Additionally, the NOD1 inhibitor ML-130 significantly reduced the proliferation, clone formation, invasion, and migration abilities of the ectopic-MSCs, having no effect on their apoptosis capacity. Our findings suggest that the expression of NOD1 in ectopic-MSCs may contribute to the progression of ectopic endometrial lesions.

Tissue-specific adult stem cells are pivotal in maintaining tissue homeostasis, especially in the rapidly renewing intestinal epithelium. At the heart of this process are leucine-rich repeat-containing G protein-coupled receptor 5-expressing crypt base columnar cells (CBCs) that differentiate into various intestinal epithelial cells. However, while these CBCs are vital for tissue turnover, they are vulnerable to cytotoxic agents. Recent advances indicate that alternative stem cell sources drive the epithelial regeneration post-injury. Techniques like lineage tracing and single-cell RNA sequencing, combined with in vitro organoid systems, highlight the remarkable cellular adaptability of the intestinal epithelium during repair. These regenerative responses are mediated by the reactivation of conserved stem cells, predominantly quiescent stem cells and revival stem cells. With focus on these cells, this review unpacks underlying mechanisms governing intestinal regeneration and explores their potential clinical applications.

With recent advances in adeno-associated virus (AAV)-based gene therapy, efficacy and toxicity screening have become essential for developing gene therapeutic drugs for retinal diseases. Retinal organoids from human pluripotent stem cells (hPSCs) offer a more accessible and reproducible human test platform for evaluating AAV-based gene therapy. In this study, hPSCs were differentiated into retinal organoids composed of various types of retinal cells. The transduction efficiencies of AAV2 and AAV8, which are widely used in clinical trials of inherited retinal diseases, were analyzed using retinal organoids. These results suggest that retinal organoids derived from hPSCs serve as suitable screening platforms owing to their diverse retinal cell types and similarity to the human retina. In summary, we propose an optimal stepwise protocol that includes the generation of retinal organoids and analysis of AAV transduction efficacy, providing a comprehensive approach for evaluating AAV-based gene therapy for retinal diseases.

An organoid is a self-organized three-dimensional structure derived from stem cells that mimics the structure, cell composition, and functional characteristics of specific organs and tissues and is used for evaluating the safety and effectiveness of drugs and the toxicity of industrial chemicals. Organoid technology is a new methodology that could replace testing on animals testing and accelerate development of precision and regenerative medicine. However, large variations in production can occur between laboratories with low reproducibility of the production process and no internationally agreed standards for quality evaluation factors at endpoints. To overcome these barriers that hinder the regulatory acceptance and commercialization of organoids, Korea established the Organoid Standards Initiative in September 2023 with various stakeholders, including industry, academia, regulatory agencies, and standard development experts, through public and private partnerships. This developed general guidelines for organoid manufacturing and quality evaluation and for quality evaluation guidelines for organoid-specific manufacturing for the liver, intestines, and heart through extensive evidence analysis and consensus among experts. This report is based on the common standard guideline v1.0, which is a general organoid manufacturing and quality evaluation to promote the practical use of organoids. This guideline does not focus on specific organoids or specific contexts of use but provides guidance to organoid makers and users on materials, procedures, and essential quality assessment methods at end points that are essential for organoid production applicable at the current technology level.

Recent advancements in organoid technology have led to a vigorous movement towards utilizing it as a substitute for animal experiments. Organoid technology offers versatile applications, particularly in toxicity testing of pharmaceuticals or chemical substances. However, for the practical use in toxicity testing, minimal guidance is required to ensure reliability and relevance. This paper aims to provide minimal guidelines for practical uses of kidney organoids derived from human pluripotent stem cells as a toxicity evaluation model in vitro.

To address the limitations of animal testing, scientific research is increasingly focused on developing alternative testing methods. These alternative tests utilize cells or tissues derived from animals or humans for in vitro testing, as well as artificial tissues and organoids. In western countries, animal testing for cosmetics has been banned, leading to the adoption of artificial skin for toxicity evaluation, such as skin corrosion and irritation assessments. Standard guidelines for skin organoid technology becomes necessary to ensure consistent data and evaluation in replacing animal testing with in vitro methods. These guidelines encompass aspects such as cell sourcing, culture techniques, quality requirements and assessment, storage and preservation, and organoid-based assays.

The objective of standard guideline for utilization of human lung organoids is to provide the basic guidelines required for the manufacture, culture, and quality control of the lung organoids for use in non-clinical efficacy and inhalation toxicity assessments of the respiratory system. As a first step towards the utilization of human lung organoids, the current guideline provides basic, minimal standards that can promote development of alternative testing methods, and can be referenced not only for research, clinical, or commercial uses, but also by experts and researchers at regulatory institutions when assessing safety and efficacy.