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IScience Jun 2024The developing mouse pancreas is surrounded by mesoderm compartments providing signals that induce pancreas formation. Most pancreatic organoid protocols lack this...
The developing mouse pancreas is surrounded by mesoderm compartments providing signals that induce pancreas formation. Most pancreatic organoid protocols lack this mesoderm niche and only partially capture the pancreatic cell repertoire. This work aims to generate pancreatic aggregates by differentiating mouse embryonic stem cells (mESCs) into mesoderm progenitors (MPs) and pancreas progenitors (PPs), without using Matrigel. First, mESCs were differentiated into epiblast stem cells (EpiSCs) to enhance the PP differentiation rate. Next, PPs and MPs aggregated together giving rise to various pancreatic cell types, including endocrine, acinar, and ductal cells, and to endothelial cells. Single-cell RNA sequencing analysis revealed a larger endocrine population within the PP + MP aggregates, as compared to PPs alone or PPs in Matrigel aggregates. The PP + MP aggregate gene expression signatures and its endocrine population percentage closely resembled those of the endocrine population found in the mouse embryonic pancreas, which holds promise for studying pancreas development.
PubMed: 38832019
DOI: 10.1016/j.isci.2024.109959 -
Development (Cambridge, England) Jun 2024During limb bud formation, axis polarities are established as evidenced by the spatially restricted expression of key regulator genes. In particular, the mutually...
TBX3 is essential for establishment of the posterior boundary of anterior genes and upregulation of posterior genes together with HAND2 during the onset of limb bud development.
During limb bud formation, axis polarities are established as evidenced by the spatially restricted expression of key regulator genes. In particular, the mutually antagonistic interaction between the GLI3 repressor and HAND2 results in distinct and non-overlapping anterior-distal Gli3 and posterior Hand2 expression domains. This is a hallmark of the establishment of antero-posterior limb axis polarity, together with spatially restricted expression of homeodomain and other transcriptional regulators. Here, we show that TBX3 is required for establishment of the posterior expression boundary of anterior genes in mouse limb buds. ChIP-seq and differential gene expression analysis of wild-type and mutant limb buds identifies TBX3-specific and shared TBX3-HAND2 target genes. High sensitivity fluorescent whole-mount in situ hybridisation shows that the posterior expression boundaries of anterior genes are positioned by TBX3-mediated repression, which excludes anterior genes such as Gli3, Alx4, Hand1 and Irx3/5 from the posterior limb bud mesenchyme. This exclusion delineates the posterior mesenchymal territory competent to establish the Shh-expressing limb bud organiser. In turn, HAND2 is required for Shh activation and cooperates with TBX3 to upregulate shared posterior identity target genes in early limb buds.
Topics: Animals; T-Box Domain Proteins; Limb Buds; Mice; Gene Expression Regulation, Developmental; Basic Helix-Loop-Helix Transcription Factors; Zinc Finger Protein Gli3; Up-Regulation; Body Patterning; Nerve Tissue Proteins; Homeodomain Proteins; Mesoderm
PubMed: 38828908
DOI: 10.1242/dev.202722 -
BioRxiv : the Preprint Server For... May 2024Malocclusions are common craniofacial malformations which cause quality of life and health problems if left untreated. Unfortunately, the current treatment for severe...
Malocclusions are common craniofacial malformations which cause quality of life and health problems if left untreated. Unfortunately, the current treatment for severe skeletal malocclusion is invasive surgery. Developing improved therapeutic options requires a deeper understanding of the cellular mechanisms responsible for determining jaw bone length. We have recently shown that neural crest mesenchyme (NCM) can alter jaw length by controlling recruitment and function of mesoderm-derived osteoclasts. Transforming growth factor beta (TGF-β) signaling is critical to craniofacial development by directing bone resorption and formation, and heterozygous mutations in TGF-β type I receptor ( are associated with micrognathia in humans. To identify what role TGF-β signaling in NCM plays in controlling osteoclasts during mandibular development, mandibles of mouse embryos deficient in the gene encoding specifically in NCM were analyzed. Our lab and others have demonstrated that mice display significantly shorter mandibles with no condylar, coronoid, or angular processes. We hypothesize that TGF-β signaling in NCM can also direct later bone remodeling and further regulate late embryonic jaw bone length. Interestingly, analysis of mandibular bone through micro-computed tomography and Masson's trichrome revealed no significant difference in bone quality between the mice and controls, as measured by bone perimeter/bone area, trabecular rod-like diameter, number and separation, and gene expression of Collagen type 1 alpha 1 () and Matrix metalloproteinase 13 (). Though there was not a difference in localization of bone resorption within the mandible indicated by TRAP staining, mice had approximately three-fold less osteoclast number and perimeter than controls. Gene expression of receptor activator of nuclear factor kappa-β () and , markers of osteoclasts and their activity, also showed a three-fold decrease in mandibles. Evaluation of osteoblast-to-osteoclast signaling revealed no significant difference between mandibles and controls, leaving the specific mechanism unresolved. Finally, pharmacological inhibition of signaling during the initiation of bone mineralization and resorption significantly shortened jaw length in embryos. We conclude that TGF-β signaling in NCM decreases mesoderm-derived osteoclast number, that TGF-β signaling in NCM impacts jaw length late in development, and that this osteoblast-to-osteoclast communication may be occurring through an undescribed mechanism.
PubMed: 38826301
DOI: 10.1101/2024.05.24.595783 -
Journal of Dental Research Jul 2024A ligature-induced periodontitis model was established in wild-type and CD146; Rosa mice to explore the function of pericytes in alveolar bone formation. We found that...
A ligature-induced periodontitis model was established in wild-type and CD146; Rosa mice to explore the function of pericytes in alveolar bone formation. We found that during periodontitis progression and periodontal wound healing, CD146/NG2 pericytes were enriched in the periodontal tissue areas, which could migrate to the alveolar bone surface and colocalize with ALP/OCN osteoblasts. Chemokine C-X-C motif receptor 4 (CXCR4) inhibition using AMD3100 blocked CD146-Cre pericyte migration and osteogenesis, as well as further exacerbated periodontitis-associated bone loss. Next, primary pericytes were sorted out by magnetic-activated cell sorting and demonstrated that C-X-C motif chemokine ligand 12 (CXCL12) promotes pericyte migration and osteogenesis via CXCL12-CXCR4-Rac1 signaling. Finally, the local administration of an adeno-associated virus for Rac1 overexpression in NG2 pericytes promotes osteoblast differentiation of pericytes and increases alveolar bone volume in periodontitis. Thus, our results provided the evidence that pericytes may migrate and osteogenesis via the CXCL12-CXCR4-Rac1 axis during the pathological process of periodontitis.
Topics: Pericytes; Animals; Osteogenesis; Periodontitis; Cell Movement; Mice; Chemokine CXCL12; Receptors, CXCR4; Alveolar Bone Loss; Signal Transduction; rac1 GTP-Binding Protein; Disease Models, Animal; CD146 Antigen; Osteoblasts; Cell Differentiation; Cyclams; Benzylamines
PubMed: 38822570
DOI: 10.1177/00220345241244687 -
Development (Cambridge, England) Jun 2024Apical expansion of calvarial osteoblast progenitors from the cranial mesenchyme (CM) above the eye is integral to calvarial growth and enclosure of the brain. The...
Apical expansion of calvarial osteoblast progenitors from the cranial mesenchyme (CM) above the eye is integral to calvarial growth and enclosure of the brain. The cellular behaviors and signals underlying the morphogenetic process of calvarial expansion are unknown. Time-lapse light-sheet imaging of mouse embryos revealed calvarial progenitors intercalate in 3D in the CM above the eye, and exhibit protrusive and crawling activity more apically. CM cells express non-canonical Wnt/planar cell polarity (PCP) core components and calvarial osteoblasts are bidirectionally polarized. We found non-canonical ligand Wnt5a-/- mutants have less dynamic cell rearrangements and protrusive activity. Loss of CM-restricted Wntless (CM-Wls), a gene required for secretion of all Wnt ligands, led to diminished apical expansion of Osx+ calvarial osteoblasts in the frontal bone primordia in a non-cell autonomous manner without perturbing proliferation or survival. Calvarial osteoblast polarization, progressive cell elongation and enrichment for actin along the baso-apical axis were dependent on CM-Wnts. Thus, CM-Wnts regulate cellular behaviors during calvarial morphogenesis for efficient apical expansion of calvarial osteoblasts. These findings also offer potential insights into the etiologies of calvarial dysplasias.
Topics: Animals; Osteoblasts; Skull; Mice; Mesoderm; Morphogenesis; Wnt Proteins; Cell Polarity; Wnt-5a Protein; Cell Movement; Cell Proliferation
PubMed: 38814743
DOI: 10.1242/dev.202596 -
Nature Communications May 2024The emergence of new structures can often be linked to the evolution of novel cell types that follows the rewiring of developmental gene regulatory subnetworks....
The emergence of new structures can often be linked to the evolution of novel cell types that follows the rewiring of developmental gene regulatory subnetworks. Vertebrates are characterized by a complex body plan compared to the other chordate clades and the question remains of whether and how the emergence of vertebrate morphological innovations can be related to the appearance of new embryonic cell populations. We previously proposed, by studying mesoderm development in the cephalochordate amphioxus, a scenario for the evolution of the vertebrate head mesoderm. To further test this scenario at the cell population level, we used scRNA-seq to construct a cell atlas of the amphioxus neurula, stage at which the main mesodermal compartments are specified. Our data allowed us to validate the presence of a prechordal-plate like territory in amphioxus. Additionally, the transcriptomic profile of somite cell populations supports the homology between specific territories of amphioxus somites and vertebrate cranial/pharyngeal and lateral plate mesoderm. Finally, our work provides evidence that the appearance of the specific mesodermal structures of the vertebrate head was associated to both segregation of pre-existing cell populations, and co-option of new genes for the control of myogenesis.
Topics: Animals; Mesoderm; Lancelets; Head; Gene Expression Regulation, Developmental; Vertebrates; Somites; Biological Evolution; Transcriptome
PubMed: 38811547
DOI: 10.1038/s41467-024-48774-4 -
Stem Cell Research Aug 2024The SORD neuropathy has been identified as the most common autosomal recessive inherited neuropathy, occurring in thousands of patients worldwide. Fibroblast lines from...
The SORD neuropathy has been identified as the most common autosomal recessive inherited neuropathy, occurring in thousands of patients worldwide. Fibroblast lines from 3 different patients containing the c.753delG; p.Ala253GlnfsTer27 SORD mutations were reprogrammed into induced Pluripotent Stem Cell (iPSC) lines. These iPSC lines demonstrate an apparent normal karyotype and have positive expression of pluripotency markers. These iPSC lines also stain positively for Ectoderm, Endoderm and Mesoderm markers following Embryoid body differentiation. These lines pose to serve as a valuable disease modeling resource for studying the SORD neuropathy, including studying disease phenotype and treatment efficacy.
Topics: Induced Pluripotent Stem Cells; Humans; Mutation; Cell Line; Cell Differentiation; Male; Female
PubMed: 38796985
DOI: 10.1016/j.scr.2024.103449 -
Viruses May 2024SARS-CoV-2 primarily infects the lungs via the ACE2 receptor but also other organs including the kidneys, the gastrointestinal tract, the heart, and the skin. SARS-CoV-2...
SARS-CoV-2 primarily infects the lungs via the ACE2 receptor but also other organs including the kidneys, the gastrointestinal tract, the heart, and the skin. SARS-CoV-2 also infects the brain, but the hematogenous route of viral entry to the brain is still not fully characterized. Understanding how SARS-CoV-2 traverses the blood-brain barrier (BBB) as well as how it affects the molecular functions of the BBB are unclear. In this study, we investigated the roles of the receptors ACE2 and DPP4 in the SARS-CoV-2 infection of the discrete cellular components of a transwell BBB model comprising HUVECs, astrocytes, and pericytes. Our results demonstrate that direct infection on the BBB model does not modulate paracellular permeability. Also, our results show that SARS-CoV-2 utilizes clathrin and caveolin-mediated endocytosis to traverse the BBB, resulting in the direct infection of the brain side of the BBB model with a minimal endothelial infection. In conclusion, the BBB is susceptible to SARS-CoV-2 infection in multiple ways, including the direct infection of endothelium, astrocytes, and pericytes involving ACE2 and/or DPP4 and the blood-to-brain transcytosis, which is an event that does not require the presence of host receptors.
Topics: Blood-Brain Barrier; Humans; SARS-CoV-2; Transcytosis; Angiotensin-Converting Enzyme 2; Pericytes; COVID-19; Virus Internalization; Astrocytes; Dipeptidyl Peptidase 4; Brain; Endocytosis; Human Umbilical Vein Endothelial Cells; Permeability
PubMed: 38793666
DOI: 10.3390/v16050785 -
International Journal of Molecular... May 2024Vascular co-option is a consequence of the direct interaction between perivascular cells, known as pericytes (PCs), and glioblastoma multiforme (GBM) cells (GBMcs). This... (Review)
Review
Vascular co-option is a consequence of the direct interaction between perivascular cells, known as pericytes (PCs), and glioblastoma multiforme (GBM) cells (GBMcs). This process is essential for inducing changes in the pericytes' anti-tumoral and immunoreactive phenotypes. Starting from the initial stages of carcinogenesis in GBM, PCs conditioned by GBMcs undergo proliferation, acquire a pro-tumoral and immunosuppressive phenotype by expressing and secreting immunosuppressive molecules, and significantly hinder the activation of T cells, thereby facilitating tumor growth. Inhibiting the pericyte (PC) conditioning mechanisms in the GBM tumor microenvironment (TME) results in immunological activation and tumor disappearance. This underscores the pivotal role of PCs as a key cell in the TME, responsible for tumor-induced immunosuppression and enabling GBM cells to evade the immune system. Other cells within the TME, such as tumor-associated macrophages (TAMs) and microglia, have also been identified as contributors to this immunomodulation. In this paper, we will review the role of these three cell types in the immunosuppressive properties of the TME. Our conclusion is that the cellular heterogeneity of immunocompetent cells within the TME may lead to the misinterpretation of cellular lineage identification due to different reactive stages and the identification of PCs as TAMs. Consequently, novel therapies could be developed to disrupt GBM-PC interactions and/or PC conditioning through vascular co-option, thereby exposing GBMcs to the immune system.
Topics: Pericytes; Humans; Tumor Microenvironment; Animals; Brain Neoplasms; Glioma; Glioblastoma; Disease Progression; Tumor-Associated Macrophages
PubMed: 38791110
DOI: 10.3390/ijms25105072 -
Cureus Apr 2024Endoscopic third ventriculocysternostomy (ETV) is a minimally invasive neurosurgical technique with good results in the treatment of obstructive hydrocephalus. The...
Endoscopic Ventriculocysternostomy, Magendie Foraminoplasty, and Plexusectomy With Craniovertebral Shunt Placement in a Pediatric Patient With Hydrocephalus and VACTERL Association: A Novel Treatment Option.
Endoscopic third ventriculocysternostomy (ETV) is a minimally invasive neurosurgical technique with good results in the treatment of obstructive hydrocephalus. The VACTERL (vertebrae, anorectal, cardiovascular, tracheal, esophageal, renal, limb defects) association, or VATER syndrome, is defined as congenital malformations, mostly derived from the mesoderm, affecting specific areas. It is diagnosed by the presence of at least three of the seven characteristic malformations that describe it. The association of this pathology and obstructive hydrocephalus in pediatric age is not common, making management and conventional neurosurgical procedures difficult due to the number of underlying pathologies. In this study, we report the management of hydrocephalus and VACTERL association with multiple congenital malformations in a 30-day-old premature neonate (birth at 29 weeks). Operations performed prior to admission to our service included: coloesophagoplasty and placement of esophagostoma in the left anterior cervical region, perineal anorectoplasty, gastrostomy and placement of sigmoidostomy in the left anterior abdominal wall, relaparotomy, gastric suture, sanitation, and abdominal drainage. Upon admission, the patient showed a Grade 3 intraventricular hemorrhage and internal occlusive hydrocephalus due to circulatory blockage of the cerebrospinal fluid (CSF) at the level of the outlet of the fourth ventricle. This was accompanied by intracranial hypertension and refractory cervical syringomyelia. We performed endoscopic ventriculocysternostomy plus plexusectomy plus Magendie foraminoplasty with craniovertebral shunt placement, achieving excellent results after two interventions. This is the first case described in the literature placing a craniovertebral shunt using a lateral-ventricle-to-the-subarachnoid-spinal-space-stenting technique in a patient with VACTERL association, which represents an innovation in the field of minimally invasive pediatric neurosurgery.
PubMed: 38784296
DOI: 10.7759/cureus.58845