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PLoS Biology Apr 2024As tissues grow and change shape during animal development, they physically pull and push on each other, and these mechanical interactions can be important for...
As tissues grow and change shape during animal development, they physically pull and push on each other, and these mechanical interactions can be important for morphogenesis. During Drosophila gastrulation, mesoderm invagination temporally overlaps with the convergence and extension of the ectodermal germband; the latter is caused primarily by Myosin II-driven polarised cell intercalation. Here, we investigate the impact of mesoderm invagination on ectoderm extension, examining possible mechanical and mechanotransductive effects on Myosin II recruitment and polarised cell intercalation. We find that the germband ectoderm is deformed by the mesoderm pulling in the orthogonal direction to germband extension (GBE), showing mechanical coupling between these tissues. However, we do not find a significant change in Myosin II planar polarisation in response to mesoderm invagination, nor in the rate of junction shrinkage leading to neighbour exchange events. We conclude that the main cellular mechanism of axis extension, polarised cell intercalation, is robust to the mesoderm invagination pull. We find, however, that mesoderm invagination slows down the rate of anterior-posterior cell elongation that contributes to axis extension, counteracting the tension from the endoderm invagination, which pulls along the direction of GBE.
Topics: Animals; Mesoderm; Gastrulation; Ectoderm; Myosin Type II; Drosophila melanogaster; Cell Polarity; Drosophila Proteins; Embryo, Nonmammalian; Morphogenesis; Body Patterning; Drosophila
PubMed: 38683880
DOI: 10.1371/journal.pbio.3002611 -
PLoS Biology Apr 2024Brain pericytes are one of the critical cell types that regulate endothelial barrier function and activity, thus ensuring adequate blood flow to the brain. The genetic...
Brain pericytes are one of the critical cell types that regulate endothelial barrier function and activity, thus ensuring adequate blood flow to the brain. The genetic pathways guiding undifferentiated cells into mature pericytes are not well understood. We show here that pericyte precursor populations from both neural crest and head mesoderm of zebrafish express the transcription factor nkx3.1 develop into brain pericytes. We identify the gene signature of these precursors and show that an nkx3.1-, foxf2a-, and cxcl12b-expressing pericyte precursor population is present around the basilar artery prior to artery formation and pericyte recruitment. The precursors later spread throughout the brain and differentiate to express canonical pericyte markers. Cxcl12b-Cxcr4 signaling is required for pericyte attachment and differentiation. Further, both nkx3.1 and cxcl12b are necessary and sufficient in regulating pericyte number as loss inhibits and gain increases pericyte number. Through genetic experiments, we have defined a precursor population for brain pericytes and identified genes critical for their differentiation.
Topics: Animals; Brain; Cell Differentiation; Chemokine CXCL12; Gene Expression Regulation, Developmental; Homeodomain Proteins; Mesoderm; Neural Crest; Pericytes; Receptors, CXCR4; Signal Transduction; Transcription Factors; Zebrafish; Zebrafish Proteins
PubMed: 38683849
DOI: 10.1371/journal.pbio.3002590 -
Frontiers in Bioscience (Landmark... Apr 2024Pericytes, a specific type of mesenchymal cell that surround the basement membrane of pulmonary venules and capillaries. They are crucial pathological features observed... (Review)
Review
Pericytes, a specific type of mesenchymal cell that surround the basement membrane of pulmonary venules and capillaries. They are crucial pathological features observed in individuals with the severe lung disease of pulmonary fibrosis (PF). The presence of pericytes leads to inflammation and fibrosis in the lung interstitium and alveolar space due to the release of various cytokines and chemokines. Pericytes also stimulate the proliferation and activation of fibroblasts, thereby promoting the progression of PF. Previous studies examining the mechanism of action of pericytes have primarily focused on cell signal transduction pathways, cell growth and death processes, and the synthesis and breakdown of extracellular matrix (ECM). Notably, the transforming growth factor-β (TGF-β) and Wnt signaling pathways have been associated with the action of pericytes in driving the progression of PF. It is therefore clear that pericytes play an essential role in the development of PF, while also offering possible avenues for targeted therapeutic intervention against this condition. The current article provides a comprehensive review on how pericytes contribute to inflammatory responses, as well as their importance for understanding the mechanism of PF. In addition, this review discusses the potential use of pericyte-targeted approaches for the treatment of patients affected by this debilitating lung disease.
Topics: Pericytes; Humans; Pulmonary Fibrosis; Animals; Transforming Growth Factor beta; Signal Transduction; Extracellular Matrix; Wnt Signaling Pathway
PubMed: 38682199
DOI: 10.31083/j.fbl2904141 -
Frontiers in Bioscience (Landmark... Apr 2024Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder characterized by aberrant amyloid precursor protein (APP) cleavage, pathological... (Review)
Review
Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder characterized by aberrant amyloid precursor protein (APP) cleavage, pathological aggregations of beta-amyloid (Aβ) that make up Aβ plaques and hyperphosphorylation of Tau that makes up neurofibrillary tangles (NFTs). Although progress has been made in research on AD, the fundamental causes of this disease have not been fully elucidated. Recent studies have shown that vascular dysfunction especially the loss of pericytes plays a significant role in the onset of AD. Pericytes play a variety of important roles in the nervous system including the regulation of the cerebral blood flow (CBF), the formation and maintenance of the blood-brain barrier (BBB), angiogenesis, and the clearance of toxic substances from the brain. Pericytes participate in the transport of Aβ through various receptors, and Aβ acts on pericytes to cause them to constrict, detach, and die. The loss of pericytes elevates the levels of Aβ1-40 and Aβ1-42 by disrupting the integrity of the BBB and reducing the clearance of soluble Aβ from the brain interstitial fluid. The aggravated deposition of Aβ further exacerbates pericyte dysfunction, forming a vicious cycle. The combined influence of these factors eventually results in the loss of neurons and cognitive decline. Further exploration of the interactions between pericytes and Aβ is beneficial for understanding AD and could lead to the identification of new therapeutic targets for the prevention and treatment of AD. In this review, we explore the characterization of pericytes, interactions between pericytes and other cells in the neurovascular unit (NVU), and the physiological functions of pericytes and dysfunctions in AD. This review discusses the interactions between pericytes and Aβ, as well as current and further strategies for preventing or treating AD targeting pericytes.
Topics: Pericytes; Alzheimer Disease; Humans; Amyloid beta-Peptides; Blood-Brain Barrier; Animals; Brain
PubMed: 38682184
DOI: 10.31083/j.fbl2904136 -
Medical Review (2021) Apr 2024Pluripotent stem cells (PSCs), characterized by self-renewal and capacity of differentiating into three germ layers, are the programmable building blocks of life.... (Review)
Review
Pluripotent stem cells (PSCs), characterized by self-renewal and capacity of differentiating into three germ layers, are the programmable building blocks of life. PSC-derived cells and multicellular systems, particularly organoids, exhibit great potential for regenerative medicine. However, this field is still in its infancy, partly due to limited strategies to robustly and precisely control stem cell behaviors, which are tightly regulated by inner gene regulatory networks in response to stimuli from the extracellular environment. Synthetic receptors and genetic circuits are powerful tools to customize the cellular sense-and-response process, suggesting their underlying roles in precise control of cell fate decision and function reconstruction. Herein, we review the progress and challenges needed to be overcome in the fields of PSC-based cell therapy and multicellular system generation, respectively. Furthermore, we summarize several well-established synthetic biology tools and their applications in PSC engineering. Finally, we highlight the challenges and perspectives of harnessing synthetic biology to PSC engineering for regenerative medicine.
PubMed: 38680679
DOI: 10.1515/mr-2023-0050 -
Stem Cell Research Jun 2024GATA6 is expressed during early embryogenesis and localizes to endoderm- and mesoderm-derived tissues during later embryogenesis. Here, we established a human induced...
GATA6 is expressed during early embryogenesis and localizes to endoderm- and mesoderm-derived tissues during later embryogenesis. Here, we established a human induced pluripotent stem cell (hiPSC) line expressing EGFP under GATA6 gene. EGFP coding sequence was introduced into the C-terminus of GATA6 in KSCBi017-A hiPSCs through homologous recombination using CRISPR/Cas9 system. The successfully edited line, KSCBi017-A-1, was selected and confirmed by sequencing. The line had a normal karyotype and exhibited potential to differentiate into three germ layers while it expressed EGFP upon endoderm induction. KSCBi017-A-1 cells can be used to monitor the expression of GATA6 during differentiation. This cell line is available from Korea National Stem Cell Bank.
Topics: Induced Pluripotent Stem Cells; Humans; CRISPR-Cas Systems; GATA6 Transcription Factor; Green Fluorescent Proteins; Cell Line; Cell Differentiation
PubMed: 38678980
DOI: 10.1016/j.scr.2024.103426 -
International Journal of Molecular... Apr 2024Human-induced pluripotent stem cells (hiPSCs) offer a promising source for generating dental epithelial (DE) cells. Whereas the existing differentiation protocols were...
Human-induced pluripotent stem cells (hiPSCs) offer a promising source for generating dental epithelial (DE) cells. Whereas the existing differentiation protocols were time-consuming and relied heavily on growth factors, herein, we developed a three-step protocol to convert hiPSCs into DE cells in 8 days. In the first phase, hiPSCs were differentiated into non-neural ectoderm using SU5402 (an FGF signaling inhibitor). The second phase involved differentiating non-neural ectoderm into pan-placodal ectoderm and simultaneously inducing the formation of oral ectoderm (OE) using LDN193189 (a BMP signaling inhibitor) and purmorphamine (a SHH signaling activator). In the final phase, OE cells were differentiated into DE through the application of Purmorphamine, XAV939 (a WNT signaling inhibitor), and BMP4. qRT-PCR and immunostaining were performed to examine the expression of lineage-specific markers. ARS staining was performed to evaluate the formation of the mineralization nodule. The expression of PITX2, SP6, and AMBN, the emergence of mineralization nodules, and the enhanced expression of AMBN and AMELX in spheroid culture implied the generation of DE cells. This study delineates the developmental signaling pathways and uses small molecules to streamline the induction of hiPSCs into DE cells. Our findings present a simplified and quicker method for generating DE cells, contributing valuable insights for dental regeneration and dental disease research.
Topics: Humans; Induced Pluripotent Stem Cells; Cell Differentiation; Epithelial Cells; Tooth; Ectoderm; Cells, Cultured; Bone Morphogenetic Protein 4; Pyrazoles; Signal Transduction; Small Molecule Libraries; Morpholines; Purines; Pyrimidines
PubMed: 38673725
DOI: 10.3390/ijms25084138 -
PAX1 represses canonical Wnt signaling pathway and plays dual roles during endoderm differentiation.Cell Communication and Signaling : CCS Apr 2024Paired box 1 (PAX1) is a transcription factor and essential for the development of pharyngeal pouches-derived tissues, including thymus. PAX1 mutations are identified...
BACKGROUND
Paired box 1 (PAX1) is a transcription factor and essential for the development of pharyngeal pouches-derived tissues, including thymus. PAX1 mutations are identified in Severe Combined Immunodeficiency (SCID) patients with Otofaciocervical Syndrome Type 2 (OTFCS2). However, despite the critical roles of PAX1 in embryonic development and diseases, detailed insights into its molecular mode of action are critically missing.
METHODS
The repressing roles of PAX1 and SCID associated mutants on Wnt signaling pathway were investigated by luciferase reporter assays, qRT-PCR and in situ hybridization in HEK293FT, HCT116 cells and zebrafish embryos, respectively. Co-immunoprecipitation (co-IP) and western blotting assays were carried out to identify the molecular mechanisms underlying PAX1's role on Wnt signaling pathway. hESC based endoderm differentiation, flow cytometry, high-throughput sequencing data analysis, and qRT-PCR assays were utilized to determine the roles of PAX1 during endoderm differentiation.
RESULTS
Here, we show that PAX1 represses canonical Wnt signaling pathway in vertebrate cells. Mechanically, PAX1 competes with SUMO E3 ligase PIASy to bind to TCF7L2, thus perturbing TCF7L2 SUMOylation level, further reducing its transcriptional activity and protein stability. Moreover, we reveal that PAX1 plays dual roles in hESC-derived definitive and foregut/pharyngeal endoderm cells, which give rise to the thymus epithelium, by inhibiting Wnt signaling. Importantly, our data show PAX1 mutations found in SCID patients significantly compromise the suppressing ability of PAX1 on Wnt signaling.
CONCLUSIONS
Our study presents a novel molecular mode of action of PAX1 in regulation of canonical Wnt signaling and endoderm differentiation, thus providing insights for the molecular basis of PAX1 associated SCID, offering better understanding of the behavior of PAX1 in embryogenesis.
Topics: Humans; Wnt Signaling Pathway; Cell Differentiation; Endoderm; Animals; Zebrafish; HEK293 Cells; Transcription Factor 7-Like 2 Protein; HCT116 Cells; Paired Box Transcription Factors
PubMed: 38664733
DOI: 10.1186/s12964-024-01629-3 -
NanoImpact Apr 2024The objective of this investigation was to evaluate the influence of micro- and nanoplastic particles composed of polyethylene terephthalate (PET), a significant...
The objective of this investigation was to evaluate the influence of micro- and nanoplastic particles composed of polyethylene terephthalate (PET), a significant contributor to plastic pollution, on human brain vascular pericytes. Specifically, we delved into their impact on mitochondrial functionality, oxidative stress, and the expression of genes associated with oxidative stress, ferroptosis and mitochondrial functions. Our findings demonstrate that the exposure of a monoculture of human brain vascular pericytes to PET particles in vitro at a concentration of 50 μg/ml for a duration of 3, 6 and 10 days did not elicit oxidative stress. Notably, we observed a reduction in various aspects of mitochondrial respiration, including maximal respiration, spare respiratory capacity, and ATP production in pericytes subjected to PET particles for 3 days, with a mitochondrial function recovery at 6 and 10 days. Furthermore, there were no statistically significant alterations in mitochondrial DNA copy number, or in the expression of genes linked to oxidative stress and ferroptosis, but an increase of the expression of the gene mitochondrial transcription factor A (TFAM) was noted at 3 days exposure. These outcomes suggest that, at a concentration of 50 μg/ml, PET particles do not induce oxidative stress in human brain vascular pericytes. Instead, at 3 days exposure, PET exposure impairs mitochondrial functions, but this is recovered at 6-day exposure. This seems to indicate a potential mitochondrial hormesis response (mitohormesis) is incited, involving the gene TFAM. Further investigations are warranted to explore the stages of mitohormesis and the potential consequences of plastics on the integrity of the blood-brain barrier and intercellular interactions. This research contributes to our comprehension of the potential repercussions of nanoplastic pollution on human health and underscores the imperative need for ongoing examinations into the exposure to plastic particles.
Topics: Humans; Oxidative Stress; Polyethylene Terephthalates; Mitochondria; Pericytes; Brain; Nanoparticles; Microplastics; Cells, Cultured
PubMed: 38663501
DOI: 10.1016/j.impact.2024.100508 -
International Journal of Oral Science Apr 2024Precise orchestration of cell fate determination underlies the success of scaffold-based skeletal regeneration. Despite extensive studies on mineralized parenchymal...
Precise orchestration of cell fate determination underlies the success of scaffold-based skeletal regeneration. Despite extensive studies on mineralized parenchymal tissue rebuilding, regenerating and maintaining undifferentiated mesenchyme within calvarial bone remain very challenging with limited advances yet. Current knowledge has evidenced the indispensability of rebuilding suture mesenchymal stem cell niches to avoid severe brain or even systematic damage. But to date, the absence of promising therapeutic biomaterials/scaffolds remains. The reason lies in the shortage of fundamental knowledge and methodological evidence to understand the cellular fate regulations of scaffolds. To address these issues, in this study, we systematically investigated the cellular fate determinations and transcriptomic mechanisms by distinct types of commonly used calvarial scaffolds. Our data elucidated the natural processes without scaffold transplantation and demonstrated how different scaffolds altered in vivo cellular responses. A feasible scaffold, polylactic acid electrospinning membrane (PLA), was next identified to precisely control mesenchymal ingrowth and self-renewal to rebuild non-osteogenic suture-like tissue at the defect center, meanwhile supporting proper osteointegration with defect bony edges. Especially, transcriptome analysis and cellular mechanisms underlying the well-orchestrated cell fate determination of PLA were deciphered. This study for the first time cellularly decoded the fate regulations of scaffolds in suture-bony composite defect healing, offering clinicians potential choices for regenerating such complicated injuries.
Topics: Tissue Scaffolds; Animals; Transcriptome; Bone Regeneration; Polyesters; Skull; Mesenchymal Stem Cells; Mesoderm; Cell Differentiation; Tissue Engineering; Cranial Sutures; Biocompatible Materials
PubMed: 38654018
DOI: 10.1038/s41368-024-00295-y