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Cell Reports Methods May 2024Organoids, self-organizing three-dimensional (3D) structures derived from stem cells, offer unique advantages for studying organ development, modeling diseases, and... (Review)
Review
Organoids, self-organizing three-dimensional (3D) structures derived from stem cells, offer unique advantages for studying organ development, modeling diseases, and screening potential therapeutics. However, their translational potential and ability to mimic complex in vivo functions are often hindered by the lack of an integrated vascular network. To address this critical limitation, bioengineering strategies are rapidly advancing to enable efficient vascularization of organoids. These methods encompass co-culturing organoids with various vascular cell types, co-culturing lineage-specific organoids with vascular organoids, co-differentiating stem cells into organ-specific and vascular lineages, using organoid-on-a-chip technology to integrate perfusable vasculature within organoids, and using 3D bioprinting to also create perfusable organoids. This review explores the field of organoid vascularization, examining the biological principles that inform bioengineering approaches. Additionally, this review envisions how the converging disciplines of stem cell biology, biomaterials, and advanced fabrication technologies will propel the creation of increasingly sophisticated organoid models, ultimately accelerating biomedical discoveries and innovations.
PubMed: 38759654
DOI: 10.1016/j.crmeth.2024.100779 -
Stem Cell Reports May 2024The differentiation of human pluripotent stem cells into ventral mesencephalic dopaminergic (DA) fate is relevant for the treatment of Parkinson's disease. Shortcuts to...
The differentiation of human pluripotent stem cells into ventral mesencephalic dopaminergic (DA) fate is relevant for the treatment of Parkinson's disease. Shortcuts to obtaining DA cells through direct reprogramming often include forced expression of the transcription factor LMX1A. Although reprogramming with LMX1A can generate tyrosine hydroxylase (TH)-positive cells, their regional identity remains elusive. Using an in vitro model of early human neural tube patterning, we report that forced LMX1A expression induced a ventral-to-dorsal fate shift along the entire neuroaxis with the emergence of roof plate fates despite the presence of ventralizing molecules. The LMX1A-expressing progenitors gave rise to grafts containing roof plate-derived choroid plexus cysts as well as ectopically induced TH-positive neurons of a forebrain identity. Early activation of LMX1A prior to floor plate specification was necessary for the dorsalizing effect. Our work suggests using caution in employing LMX1A for the induction of DA fate, as this factor may generate roof plate rather than midbrain fates.
PubMed: 38759646
DOI: 10.1016/j.stemcr.2024.04.010 -
Stem Cell Reports May 2024Lung alveolar structure and function are maintained by subsets of alveolar type II stem cells (AT2s), but there is a need for characterization of these subsets and their...
Lung alveolar structure and function are maintained by subsets of alveolar type II stem cells (AT2s), but there is a need for characterization of these subsets and their associated niches. Here, we report a CD44 subpopulation of AT2s characterized by increased expression of genes that regulate immune signaling even during steady-state homeostasis. Disruption of one of these immune regulatory transcription factor STAT1 impaired the stem cell function of AT2s. CD44 cells were preferentially located near macro- blood vessels and a supportive niche constituted by LYVE1 endothelial cells, adventitial fibroblasts, and accumulated hyaluronan. In this microenvironment, CD44 AT2 cells were more responsive to transformation by KRAS than general AT2 cells. Moreover, after bacterial lung injury, there was a significant increase of CD44 AT2s and niche components distributed throughout the lung parenchyma. Taken together, CD44 AT2 cells and their perivascular niche regulate tissue homeostasis and tumor formation.
PubMed: 38759645
DOI: 10.1016/j.stemcr.2024.04.009 -
Medicine May 2024Cancer stem cells (CSCs) are a subset of cells with self-renewal ability and tumor generating potential. Accumulated evidence has revealed that CSCs were shown to...
Cancer stem cells (CSCs) are a subset of cells with self-renewal ability and tumor generating potential. Accumulated evidence has revealed that CSCs were shown to contribute to tumorigenesis, metastasis, recurrence and resistance to chemoradiotherapy. Therefore, CSCs were regarded as promising therapeutic targets in cancer. This study is the first to reveal the development process, research hotspots, and trends of entire CSCs research field through bibliometric methods. All relevant publications on CSCs with more than 100 citations (notable papers) and the 100 most cited papers (top papers) during 1997 to 2023 were extracted and analyzed. Cancer research published the largest number of papers (184 papers). The USA accounted for the most publications (1326 papers). Rich, JN was the author with the most publications (56 papers) and the highest M-index (3.111). The most contributive institution was the University of Texas System (164 papers). Before 2007, research mainly focused on the definition and recognition of CSCs. Between 2007 and 2016, with the emergence of the terms such as "sonic hedgehog," "metabolism," "oxidative phosphorylation," and "epithelial mesenchymal transition," research began to shift toward exploring the mechanisms of CSCs. In 2016, the focus transitioned to the tumor microenvironment and the ecological niches. The analysis of papers published in major journals since 2021 showed that "transcription," "inhibition," and "chemoresistance" emerged as new focused issues. In general, the research focus has gradually shifted from basic biology to clinical transformation. "Tumor microenvironment" and "chemo-resistance" should be given more attention in the future.
Topics: Neoplastic Stem Cells; Bibliometrics; Humans; Biomedical Research; Neoplasms; Tumor Microenvironment
PubMed: 38758889
DOI: 10.1097/MD.0000000000038125 -
Medicine May 2024Studies have suggested that Vitamin D deficiency is associated with the occurrence of both type 1 and type 2 diabetes, and that vitamin D-binding proteins (VDBP) are...
Studies have suggested that Vitamin D deficiency is associated with the occurrence of both type 1 and type 2 diabetes, and that vitamin D-binding proteins (VDBP) are necessary for metabolic stress in pancreatic α-cells. However, the causal relationship between serum 25-hydroxyvitamin D [25(OH)D] levels, VDBP, and the risk of diabetes mellitus (DM) remains unclear. Mendelian randomization (MR) was used to investigate the causal relationship between 25(OH)D, VDBP, and DM. Relevant recent data were downloaded from the NHGRI-EBI Catalog of published genome-wide association studies (GWAS) and filtered for single nucleotide polymorphisms (SNPs). We used multiple MR methods, including inverse variance weighting (IVW), and performed sensitivity analyses to detect whether pleiotropy or heterogeneity biased the results. There was a causal relationship between genetically predicted VDBP levels and serum 25(OH)D levels, and serum 25(OH)D levels increased with increasing VDBP levels (IVW: β = 0.111, OR = 1.117, 95% CI:1.076-1.162, P = 1.41 × 10-8). There was no causal relationship between the genetically predicted VDBP levels, serum 25(OH)D levels, and DM (VDBP: IVW β:0.001, OR:1.001, 95% CI:0.998-1.003, P > .05; 25(OH)D: IVW β: -0.009, OR:0.991, 95% CI:0.982-1.001, P = .068). Sensitivity analysis indicated that horizontal pleiotropy was unlikely to bias causality in this study. MR analysis results demonstrated a positive causal relationship between VDBP levels and serum 25(OH)D levels in the European population. The 25(OH)D and VDBP levels were not causally related to an increased risk of diabetes.
Topics: Humans; Mendelian Randomization Analysis; Vitamin D-Binding Protein; Vitamin D; Polymorphism, Single Nucleotide; Genome-Wide Association Study; Diabetes Mellitus, Type 2; Vitamin D Deficiency
PubMed: 38758851
DOI: 10.1097/MD.0000000000038219 -
Science Advances May 2024Trauma rapidly mobilizes the immune response of surrounding tissues and activates regeneration program. Manipulating immune response to promote tissue regeneration shows...
Trauma rapidly mobilizes the immune response of surrounding tissues and activates regeneration program. Manipulating immune response to promote tissue regeneration shows a broad application prospect. However, the understanding of bone healing dynamics at cellular level remains limited. Here, we characterize the landscape of immune cells after alveolar bone injury and reveal a pivotal role of infiltrating natural killer T (NKT) cells. We observe a rapid increase in NKT cells after injury, which inhibit osteogenic differentiation of mesenchymal stem cells (MSCs) and impair alveolar bone healing. is up-regulated in NKT cells after injury. Systemic administration of CXCL2-neutralizing antibody or genetic deletion of improves the bone healing process. In addition, we fabricate a gelatin-based porous hydrogel to deliver NK1.1 depletion antibody, which successfully promotes alveolar bone healing. In summary, our study highlights the importance of NKT cells in the early stage of bone healing and provides a potential therapeutic strategy for accelerating bone regeneration.
Topics: Bone Regeneration; Animals; Natural Killer T-Cells; Mice; Osteogenesis; Chemokine CXCL2; Mesenchymal Stem Cells; Cell Differentiation; Mice, Inbred C57BL
PubMed: 38758783
DOI: 10.1126/sciadv.adl6343 -
Protein & Cell May 2024Tissue formation and organ homeostasis is achieved by precise coordination of proliferation and differentiation of stem cells and progenitors. While deregulation of...
Tissue formation and organ homeostasis is achieved by precise coordination of proliferation and differentiation of stem cells and progenitors. While deregulation of these processes can result in degenerative disease or cancer, their molecular interplays remain unclear. Here we show that the switch of human pluripotent stem cell (hPSC) self-renewal to differentiation is associated with the induction of distinct cyclin dependent kinase inhibitors (CDKIs). In hPSCs, Activin/Nodal/TGFβ signalling maintains CDKIs in a poised state via SMAD2/3-NANOG-OCT4-EZH2-SNON transcriptional complex. Upon gradual differentiation, CDKIs are induced by successive transcriptional complexes between SMAD2/3-SMYD2 and developmental regulators such as EOMES, thereby lengthening the G1 phase. This, in turn, induces SMAD2/3 transcriptional activity by blocking its linker phosphorylation. Such SMAD2/3-CDKI positive feedback loops drive the exit from pluripotency and stepwise cell fate specification that could be harnessed for producing cells for therapeutic applications. Our study uncovers fundamental mechanisms how cell fate specification is interconnected to cell cycle dynamics and provides insight to autonomous circuitries governing tissue self-formation.
PubMed: 38758030
DOI: 10.1093/procel/pwae031 -
ELife May 2024Erythropoiesis and megakaryopoiesis are stringently regulated by signaling pathways. However, the precise molecular mechanisms through which signaling pathways regulate...
Erythropoiesis and megakaryopoiesis are stringently regulated by signaling pathways. However, the precise molecular mechanisms through which signaling pathways regulate key transcription factors controlling erythropoiesis and megakaryopoiesis remain partially understood. Herein, we identified heat shock cognate B (HSCB), which is well known for its iron-sulfur cluster delivery function, as an indispensable protein for friend of GATA 1 (FOG1) nuclear translocation during erythropoiesis of K562 human erythroleukemia cells and cord-blood-derived human CD34+CD90+hematopoietic stem cells (HSCs), as well as during megakaryopoiesis of the CD34+CD90+HSCs. Mechanistically, HSCB could be phosphorylated by phosphoinositol-3-kinase (PI3K) to bind with and mediate the proteasomal degradation of transforming acidic coiled-coil containing protein 3 (TACC3), which otherwise detained FOG1 in the cytoplasm, thereby facilitating FOG1 nuclear translocation. Given that PI3K is activated during both erythropoiesis and megakaryopoiesis, and that FOG1 is a key transcription factor for these processes, our findings elucidate an important, previously unrecognized iron-sulfur cluster delivery independent function of HSCB in erythropoiesis and megakaryopoiesis.
Topics: Erythropoiesis; Humans; Transcription Factors; Phosphatidylinositol 3-Kinases; K562 Cells; Thrombopoiesis; Signal Transduction; Nuclear Proteins; Cell Nucleus; Protein Transport; Hematopoietic Stem Cells; HSC70 Heat-Shock Proteins; Active Transport, Cell Nucleus
PubMed: 38757931
DOI: 10.7554/eLife.95815 -
ELife May 2024The fragile X syndrome (FXS) represents the most prevalent form of inherited intellectual disability and is the first monogenic cause of autism spectrum disorder. FXS...
The fragile X syndrome (FXS) represents the most prevalent form of inherited intellectual disability and is the first monogenic cause of autism spectrum disorder. FXS results from the absence of the RNA-binding protein FMRP (fragile X messenger ribonucleoprotein). Neuronal migration is an essential step of brain development allowing displacement of neurons from their germinal niches to their final integration site. The precise role of FMRP in neuronal migration remains largely unexplored. Using live imaging of postnatal rostral migratory stream (RMS) neurons in -null mice, we observed that the absence of FMRP leads to delayed neuronal migration and altered trajectory, associated with defects of centrosomal movement. RNA-interference-induced knockdown of shows that these migratory defects are cell-autonomous. Notably, the primary mRNA target implicated in these migratory defects is microtubule-associated protein 1B (MAP1B). Knocking down MAP1B expression effectively rescued most of the observed migratory defects. Finally, we elucidate the molecular mechanisms at play by demonstrating that the absence of FMRP induces defects in the cage of microtubules surrounding the nucleus of migrating neurons, which is rescued by MAP1B knockdown. Our findings reveal a novel neurodevelopmental role for FMRP in collaboration with MAP1B, jointly orchestrating neuronal migration by influencing the microtubular cytoskeleton.
Topics: Fragile X Mental Retardation Protein; Animals; Neurons; Microtubule-Associated Proteins; Cell Movement; Mice; Mice, Knockout; Fragile X Syndrome; Gene Knockdown Techniques
PubMed: 38757694
DOI: 10.7554/eLife.88782 -
Aging Cell May 2024Impaired mitochondrial function is a hallmark of aging and a major contributor to neurodegenerative diseases. We have shown that disrupted mitochondrial dynamics...
Impaired mitochondrial function is a hallmark of aging and a major contributor to neurodegenerative diseases. We have shown that disrupted mitochondrial dynamics typically found in aging alters the fate of neural stem cells (NSCs) leading to impairments in learning and memory. At present, little is known regarding the mechanisms by which neural stem and progenitor cells survive and adapt to mitochondrial dysfunction. Using Opa1-inducible knockout as a model of aging and neurodegeneration, we identify a decline in neurogenesis due to impaired stem cell activation and progenitor proliferation, which can be rescued by the mitigation of oxidative stress through hypoxia. Through sc-RNA-seq, we identify the ATF4 pathway as a critical mechanism underlying cellular adaptation to metabolic stress. ATF4 knockdown in Opa1-deficient NSCs accelerates cell death, while the increased expression of ATF4 enhances proliferation and survival. Using a Slc7a11 mutant, an ATF4 target, we show that ATF4-mediated glutathione production plays a critical role in maintaining NSC survival and function under stress conditions. Together, we show that the activation of the integrated stress response (ISR) pathway enables NSCs to adapt to metabolic stress due to mitochondrial dysfunction and metabolic stress and may serve as a therapeutic target to enhance NSC survival and function in aging and neurodegeneration.
PubMed: 38757355
DOI: 10.1111/acel.14165