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Cells Jun 2024Bone/fracture healing is a complex process with different steps and four basic tissue layers being affected: cortical bone, periosteum, fascial tissue surrounding the... (Review)
Review
Bone/fracture healing is a complex process with different steps and four basic tissue layers being affected: cortical bone, periosteum, fascial tissue surrounding the fracture, and bone marrow. Stem cells and their derivatives, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, hematopoietic stem cells, skeletal stem cells, and multipotent stem cells, can function to artificially introduce highly regenerative cells into decrepit biological tissues and augment the healing process at the tissue level. Stem cells are molecularly and functionally indistinguishable from standard human tissues. The widespread appeal of stem cell therapy lies in its potential benefits as a therapeutic technology that, if harnessed, can be applied in clinical settings. This review aims to establish the molecular pathophysiology of bone healing and the current stem cell interventions that disrupt or augment the bone healing process and, finally, considers the future direction/therapeutic options related to stem cells and bone healing.
Topics: Humans; Fracture Healing; Bone Regeneration; Animals; Stem Cells; Stem Cell Transplantation
PubMed: 38920674
DOI: 10.3390/cells13121045 -
Cells Jun 2024Dopaminergic neurons are the predominant brain cells affected in Parkinson's disease. With the limited availability of live human brain dopaminergic neurons to study... (Comparative Study)
Comparative Study
Dopaminergic neurons are the predominant brain cells affected in Parkinson's disease. With the limited availability of live human brain dopaminergic neurons to study pathological mechanisms of Parkinson's disease, dopaminergic neurons have been generated from human-skin-cell-derived induced pluripotent stem cells. Originally, induced pluripotent stem-cell-derived dopaminergic neurons were generated using small molecules. These neurons took more than two months to mature. However, the transcription-factor-mediated differentiation of induced pluripotent stem cells has revealed quicker and cheaper methods to generate dopaminergic neurons. In this study, we compared and contrasted three protocols to generate induced pluripotent stem-cell-derived dopaminergic neurons using transcription-factor-mediated directed differentiation. We deviated from the established protocols using lentivirus transduction to stably integrate different transcription factors into the AAVS1 safe harbour locus of induced pluripotent stem cells. We used different media compositions to generate more than 90% of neurons in the culture, out of which more than 85% of the neurons were dopaminergic neurons within three weeks. Therefore, from our comparative study, we reveal that a combination of transcription factors along with small molecule treatment may be required to generate a pure population of human dopaminergic neurons.
Topics: Humans; Dopaminergic Neurons; Induced Pluripotent Stem Cells; Cell Differentiation; Transcription Factors; Lentivirus
PubMed: 38920646
DOI: 10.3390/cells13121016 -
Cells Jun 2024The advent of induced pluripotent stem cell (iPSC) technology has brought about transformative advancements in regenerative medicine, offering novel avenues for disease...
Efficient Generation of Pancreatic Progenitor Cells from Induced Pluripotent Stem Cells Derived from a Non-Invasive and Accessible Tissue Source-The Plucked Hair Follicle.
The advent of induced pluripotent stem cell (iPSC) technology has brought about transformative advancements in regenerative medicine, offering novel avenues for disease modeling, drug testing, and cell-based therapies. Patient-specific iPSC-based treatments hold the promise of mitigating immune rejection risks. However, the intricacies and costs of producing autologous therapies present commercial challenges. The hair follicle is a multi-germ layered versatile cell source that can be harvested at any age. It is a rich source of keratinocytes, fibroblasts, multipotent stromal cells, and the newly defined Hair Follicle-Associated Pluripotent Stem Cells (HAP). It can also be obtained non-invasively and transported via regular mail channels, making it the ideal starting material for an autologous biobank. In this study, cryopreserved hair follicle-derived iPSC lines (HF-iPS) were established through integration-free vectors, encompassing a diverse cohort. These genetically stable lines exhibited robust expression of pluripotency markers, and showcased tri-lineage differentiation potential. The HF-iPSCs effectively differentiated into double-positive cKIT/CXCR4 definitive endoderm cells and NKX6.1/PDX1 pancreatic progenitor cells, affirming their pluripotent attributes. We anticipate that the use of plucked hair follicles as an accessible, non-invasive cell source to obtain patient cells, in conjunction with the use of episomal vectors for reprogramming, will improve the future generation of clinically applicable pancreatic progenitor cells for the treatment of Type I Diabetes.
Topics: Induced Pluripotent Stem Cells; Humans; Hair Follicle; Cell Differentiation; Pancreas; Female
PubMed: 38920642
DOI: 10.3390/cells13121010 -
Cells Jun 2024The polarised expression of specific transporters in proximal tubular epithelial cells is important for the renal clearance of many endogenous and exogenous compounds....
The polarised expression of specific transporters in proximal tubular epithelial cells is important for the renal clearance of many endogenous and exogenous compounds. Thus, ideally, the in vitro tools utilised for predictions would have a similar expression of apical and basolateral xenobiotic transporters as in vivo. Here, we assessed the functionality of organic cation and anion transporters in proximal tubular-like cells (PTL) differentiated from human induced pluripotent stem cells (iPSC), primary human proximal tubular epithelial cells (PTEC), and telomerase-immortalised human renal proximal tubular epithelial cells (RPTEC/TERT1). Organic cation and anion transport were studied using the fluorescent substrates 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP) and 6-carboxyfluorescein (6-CF), respectively. The level and rate of intracellular ASP accumulation in PTL following basolateral application were slightly lower but within a 3-fold range compared to primary PTEC and RPTEC/TERT1 cells. The basolateral uptake of ASP and its subsequent apical efflux could be inhibited by basolateral exposure to quinidine in all models. Of the three models, only PTL showed a modest preferential basolateral-to-apical 6-CF transfer. These results show that organic cation transport could be demonstrated in all three models, but more research is needed to improve and optimise organic anion transporter expression and functionality.
Topics: Humans; Kidney Tubules, Proximal; Epithelial Cells; Models, Biological; Pyridinium Compounds; Anions; Induced Pluripotent Stem Cells; Biological Transport; Organic Anion Transporters; Cell Line; Cations; Fluoresceins; Organic Cation Transport Proteins
PubMed: 38920639
DOI: 10.3390/cells13121008 -
Nature Cardiovascular Research Oct 2023Missense variants throughout , encoding smooth muscle α-actin (αSMA), predispose to adult-onset thoracic aortic disease, but variants disrupting arginine 179 (R179)...
Missense variants throughout , encoding smooth muscle α-actin (αSMA), predispose to adult-onset thoracic aortic disease, but variants disrupting arginine 179 (R179) lead to Smooth Muscle Dysfunction Syndrome (SMDS) characterized by diverse childhood-onset vascular diseases. Here we show that αSMA localizes to the nucleus in wildtype (WT) smooth muscle cells (SMCs), enriches in the nucleus with SMC differentiation, and associates with chromatin remodeling complexes and SMC contractile gene promotors. The p.R179 αSMA variant shows decreased nuclear localization. Primary SMCs from mice are less differentiated than WT SMCs and and have global changes in chromatin accessibility. Induced pluripotent stem cells from patients with p.R179 variants fail to fully differentiate from neuroectodermal progenitor cells to SMCs, and single-cell transcriptomic analyses of an p.R179H patient's aortic tissue show increased SMC plasticity. Thus, nuclear αSMA participates in SMC differentiation, and loss of this nuclear activity occurs with p.R179 pathogenic variants.
PubMed: 38919852
DOI: 10.1038/s44161-023-00337-4 -
BMB Reports Jun 2024Brain organoid is a three-dimensional (3D) tissue derived from stem cells such as induced pluripotent stem cells (iPSCs) embryonic stem cells (ESCs) that reflect real...
Brain organoid is a three-dimensional (3D) tissue derived from stem cells such as induced pluripotent stem cells (iPSCs) embryonic stem cells (ESCs) that reflect real human brain structure. It replicates the complexity and development of the human brain, enabling studies of the human brain in vitro. With emerging technologies, its application is various, including disease modeling and drug screening. A variety of experimental methods have been used to study structural and molecular characteristics of brain organoids. However, electrophysiological analysis is necessary to understand their functional characteristics and complexity. Although electrophysiological approaches have rapidly advanced for monolayered cells, there are some limitations in studying electrophysiological and neural network characteristics due to the lack of 3D characteristics. Herein, electrophysiological measurement and analytical methods related to neural complexity and 3D characteristics of brain organoids are reviewed. Overall, electrophysiological understanding of brain organoids allows us to overcome limitations of monolayer in vitro cell culture models, providing deep insights into the neural network complex of the real human brain and new ways of disease modeling.
PubMed: 38919012
DOI: No ID Found -
Nature Communications Jun 2024Although our understanding of the involvement of heterochromatin architectural factors in shaping nuclear organization is improving, there is still ongoing debate...
Although our understanding of the involvement of heterochromatin architectural factors in shaping nuclear organization is improving, there is still ongoing debate regarding the role of active genes in this process. In this study, we utilize publicly-available Micro-C data from mouse embryonic stem cells to investigate the relationship between gene transcription and 3D gene folding. Our analysis uncovers a nonmonotonic - globally positive - correlation between intragenic contact density and Pol II occupancy, independent of cohesin-based loop extrusion. Through the development of a biophysical model integrating the role of transcription dynamics within a polymer model of chromosome organization, we demonstrate that Pol II-mediated attractive interactions with limited valency between transcribed regions yield quantitative predictions consistent with chromosome-conformation-capture and live-imaging experiments. Our work provides compelling evidence that transcriptional activity shapes the 4D genome through Pol II-mediated micro-compartmentalization.
Topics: Animals; Mice; Mouse Embryonic Stem Cells; Transcription, Genetic; RNA Polymerase II; Chromosomal Proteins, Non-Histone; Cohesins; Heterochromatin; Chromosomes; Chromatin; Cell Cycle Proteins; Gene Expression Regulation
PubMed: 38918438
DOI: 10.1038/s41467-024-49727-7 -
Nature Communications Jun 2024The development of haematopoiesis involves the coordinated action of numerous genes, some of which are implicated in haematological malignancies. However, the biological...
The development of haematopoiesis involves the coordinated action of numerous genes, some of which are implicated in haematological malignancies. However, the biological function of many genes remains elusive and unknown functional genes are likely to remain to be uncovered. Here, we report a previously uncharacterised gene in haematopoiesis, identified by screening mutant embryonic stem cells. The gene, 'attenuated haematopoietic development (Ahed)', encodes a nuclear protein. Conditional knockout (cKO) of Ahed results in anaemia from embryonic day 14.5 onward, leading to prenatal demise. Transplantation experiments demonstrate the incapacity of Ahed-deficient haematopoietic cells to reconstitute haematopoiesis in vivo. Employing a tamoxifen-inducible cKO model, we further reveal that Ahed deletion impairs the intrinsic capacity of haematopoietic cells in adult mice. Ahed deletion affects various pathways, and published databases present cancer patients with somatic mutations in Ahed. Collectively, our findings underscore the fundamental roles of Ahed in lifelong haematopoiesis, implicating its association with malignancies.
Topics: Animals; Hematopoiesis; Mice; Mice, Knockout; Humans; Female; Hematopoietic Stem Cells; Mice, Inbred C57BL; Mutation; Anemia; Male; Embryonic Stem Cells
PubMed: 38918373
DOI: 10.1038/s41467-024-49252-7 -
Acta Neuropathologica Jun 2024Alzheimer's disease (AD) is the most common cause of dementia, and disease mechanisms are still not fully understood. Here, we explored pathological changes in human...
Xenografted human iPSC-derived neurons with the familial Alzheimer's disease APP mutation reveal dysregulated transcriptome signatures linked to synaptic function and implicate LINGO2 as a disease signaling mediator.
Alzheimer's disease (AD) is the most common cause of dementia, and disease mechanisms are still not fully understood. Here, we explored pathological changes in human induced pluripotent stem cell (iPSC)-derived neurons carrying the familial AD APP mutation after cell injection into the mouse forebrain. APP mutant iPSCs and isogenic controls were differentiated into neurons revealing enhanced Aβ production, elevated phospho-tau, and impaired neurite outgrowth in APP neurons. Two months after transplantation, APP and control neural cells showed robust engraftment but at 12 months post-injection, APP grafts were smaller and demonstrated impaired neurite outgrowth compared to controls, while plaque and tangle pathology were not seen. Single-nucleus RNA-sequencing of micro-dissected grafts, performed 2 months after cell injection, identified significantly altered transcriptome signatures in APP iPSC-derived neurons pointing towards dysregulated synaptic function and axon guidance. Interestingly, APP neurons showed an increased expression of genes, many of which are also upregulated in postmortem neurons of AD patients including the transmembrane protein LINGO2. Downregulation of LINGO2 in cultured APP neurons rescued neurite outgrowth deficits and reversed key AD-associated transcriptional changes related but not limited to synaptic function, apoptosis and cellular senescence. These results provide important insights into transcriptional dysregulation in xenografted APP neurons linked to synaptic function, and they indicate that LINGO2 may represent a potential therapeutic target in AD.
Topics: Humans; Induced Pluripotent Stem Cells; Alzheimer Disease; Neurons; Transcriptome; Animals; Amyloid beta-Protein Precursor; Mice; Nerve Tissue Proteins; Mutation; Membrane Proteins; Synapses; Amyloid beta-Peptides; Signal Transduction
PubMed: 38918213
DOI: 10.1007/s00401-024-02755-5 -
Cell Stem Cell Jun 2024Aging is the biggest risk factor for the development of Alzheimer's disease (AD). Here, we performed a whole-genome CRISPR screen to identify regulators of neuronal age...
Aging is the biggest risk factor for the development of Alzheimer's disease (AD). Here, we performed a whole-genome CRISPR screen to identify regulators of neuronal age and show that the neddylation pathway regulates both cellular age and AD neurodegeneration in a human stem cell model. Specifically, we demonstrate that blocking neddylation increased cellular hallmarks of aging and led to an increase in Tau aggregation and phosphorylation in neurons carrying the APP mutation. Aged APP but not isogenic control neurons also showed a progressive decrease in viability. Selective neuronal loss upon neddylation inhibition was similarly observed in other isogenic AD and in Parkinson's disease (PD) models, including PSEN cortical and LRRK2 midbrain dopamine neurons, respectively. This study indicates that cellular aging can reveal late-onset disease phenotypes, identifies new potential targets to modulate AD progression, and describes a strategy to program age-associated phenotypes into stem cell models of disease.
PubMed: 38917806
DOI: 10.1016/j.stem.2024.06.001