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Cell Jun 2024The cleavage of zygotes generates totipotent blastomeres. In human 8-cell blastomeres, zygotic genome activation (ZGA) occurs to initiate the ontogenesis program....
The cleavage of zygotes generates totipotent blastomeres. In human 8-cell blastomeres, zygotic genome activation (ZGA) occurs to initiate the ontogenesis program. However, capturing and maintaining totipotency in human cells pose significant challenges. Here, we realize culturing human totipotent blastomere-like cells (hTBLCs). We find that splicing inhibition can transiently reprogram human pluripotent stem cells into ZGA-like cells (ZLCs), which subsequently transition into stable hTBLCs after long-term passaging. Distinct from reported 8-cell-like cells (8CLCs), both ZLCs and hTBLCs widely silence pluripotent genes. Interestingly, ZLCs activate a particular group of ZGA-specific genes, and hTBLCs are enriched with pre-ZGA-specific genes. During spontaneous differentiation, hTBLCs re-enter the intermediate ZLC stage and further generate epiblast (EPI)-, primitive endoderm (PrE)-, and trophectoderm (TE)-like lineages, effectively recapitulating human pre-implantation development. Possessing both embryonic and extraembryonic developmental potency, hTBLCs can autonomously generate blastocyst-like structures in vitro without external cell signaling. In summary, our study provides key criteria and insights into human cell totipotency.
Topics: Humans; Spliceosomes; Cell Differentiation; Totipotent Stem Cells; Blastomeres; Pluripotent Stem Cells; Zygote; Animals; Cellular Reprogramming; Germ Layers; Mice; Blastocyst; RNA Splicing; Embryonic Development
PubMed: 38843832
DOI: 10.1016/j.cell.2024.05.010 -
Science (New York, N.Y.) Jun 2024Axis formation in fish and amphibians typically begins with a prepattern of maternal gene products. Annual killifish embryogenesis, however, challenges prepatterning...
Axis formation in fish and amphibians typically begins with a prepattern of maternal gene products. Annual killifish embryogenesis, however, challenges prepatterning models as blastomeres disperse and then aggregate to form the germ layers and body axes. We show that , a prepatterning factor thought to break symmetry by stabilizing β-catenin, is truncated and inactive in . Nuclear β-catenin is not selectively stabilized on one side of the blastula but accumulates in cells forming the aggregate. Blocking β-catenin activity or Nodal signaling disrupts aggregate formation and germ layer specification. Nodal signaling coordinates cell migration, establishing an early role for this signaling pathway. These results reveal a surprising departure from established mechanisms of axis formation: Huluwa-mediated prepatterning is dispensable, and β-catenin and Nodal regulate morphogenesis.
Topics: Animals; beta Catenin; Blastula; Body Patterning; Cell Movement; Cell Nucleus; Fundulidae; Germ Layers; Morphogenesis; Nodal Protein; Signal Transduction
PubMed: 38843334
DOI: 10.1126/science.ado7604 -
Journal of Morphology Jun 2024The histological origin of podocysts in scyphozoans has long been undetermined, with uncertainty whether they arise from mesenchymal amoebocytes or stalk and pedal disc...
The histological origin of podocysts in scyphozoans has long been undetermined, with uncertainty whether they arise from mesenchymal amoebocytes or stalk and pedal disc ectoderm in polyps. Histological investigation on the pedal disc was difficult due to the settlement of polyps on hard substrates. In this study, we investigated the histological characteristics of polyps during podocyst production in Asian moon jelly (Aurelia coerulea) with utilizing those attached on thin polystyrene substrates. Fine histological features of the pedal disc became possible after the substrates were decomposed during histological processing. Our findings unequivocally demonstrate that the cell mass of podocysts originates from the ectoderm of the pedal disc and the stalk without the involvement of amoebocytes in the mesoglea. Preceding the podocyst formation, the pedal disc undergoes enlargement facilitated by the elongated stalk ectodermal cells, which attach to a substrate. Subsequently, the pedal disc ectoderm give rise to the primary podocyst cells with accumulating nutrient granules in the cytoplasm and forming the cyst capsule cooperatively with the invaginated pedal disc ectoderm. Direct transformation from the ectodermal cells to podocyst cells suggests that podocyst formation involves tissue dedifferentiation. Throughout the period of podocyst production, the gastrodermis of polyps is physically separated from the ectoderm by the mesoglea and shows no histological changes, and no amoebocytes appear in the mesoglea. These histological properties are totally different from those in other modes of asexual reproduction, which incorporate the endoderm of polyps, suggesting the developmental and evolutionary differences between these asexual reproductions and podocyst production in Scyphozoa.
Topics: Animals; Ectoderm; Scyphozoa; Cell Dedifferentiation
PubMed: 38840450
DOI: 10.1002/jmor.21711 -
Genes & Development Jun 2024The fibroblast growth factor (FGF) pathway is a conserved signaling pathway required for embryonic development. Activated FGF receptor 1 (FGFR1) drives multiple...
The fibroblast growth factor (FGF) pathway is a conserved signaling pathway required for embryonic development. Activated FGF receptor 1 (FGFR1) drives multiple intracellular signaling cascade pathways, including ERK/MAPK and PI3K/AKT, collectively termed canonical signaling. However, unlike -null embryos, embryos containing hypomorphic mutations in lacking the ability to activate canonical downstream signals are still able to develop to birth but exhibit severe defects in all mesodermal-derived tissues. The introduction of an additional signaling mutation further reduces the activity of , leading to earlier lethality, reduced somitogenesis, and more severe changes in transcriptional outputs. Genes involved in migration, ECM interaction, and phosphoinositol signaling were significantly downregulated, proteomic analysis identified changes in interactions with endocytic pathway components, and cells expressing mutant receptors show changes in endocytic trafficking. Together, we identified processes regulating early mesoderm development by mechanisms involving both canonical and noncanonical pathways, including direct interaction with cell adhesion components and endocytic regulation.
Topics: Receptor, Fibroblast Growth Factor, Type 1; Animals; Mesoderm; Signal Transduction; Endocytosis; Gene Expression Regulation, Developmental; Mice; Embryonic Development; Protein Transport; Mutation
PubMed: 38834239
DOI: 10.1101/gad.351593.124 -
Stem Cell Research Aug 2024Truncus arteriosus (TA) is a congenital heart defect where one main blood vessel emerges from the heart, instead of individual aorta and pulmonary artreries. Peripheral...
Truncus arteriosus (TA) is a congenital heart defect where one main blood vessel emerges from the heart, instead of individual aorta and pulmonary artreries. Peripheral mononuclear cells (PBMCs) of a male infant with TA were reporogrammed using Sendai virus. The resultant iPSC line (NCHi015-A) displayed normal colony formation, expressed pluripotency markers, and differentiated into cells from three germ layers. NCHi015-A was matched to the patient's genetic profile, had normal karyotype, retained genetic variants in KMT2D and NOTCH1, and tested negative for reprogramming transgene. This iPSC line can be used for studying congenital heart defects associated with genetic variants in KMT2D and NOTCH1.
Topics: Humans; Induced Pluripotent Stem Cells; Male; Receptor, Notch1; Truncus Arteriosus; DNA-Binding Proteins; Cell Line; Heterozygote; Cell Differentiation; Neoplasm Proteins
PubMed: 38833814
DOI: 10.1016/j.scr.2024.103457 -
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 -
Clinical Medicine Insights. Case Reports 2024Infratemporal fossa (ITF) tumors are rare in children and may present with a variety of symptoms. Teratomas are neoplasms derived from the 3 germ layers and...
Infratemporal fossa (ITF) tumors are rare in children and may present with a variety of symptoms. Teratomas are neoplasms derived from the 3 germ layers and approximately 6% to 10% are within the head and neck. Our study discusses one of the first reported cases of teratoma in the ITF in a pediatric patient. A 3-year-old girl presents with 2 years of recurrent monthly left periorbital swelling accompanied by fevers, skin discoloration, and pain. Prior episodes were treated with antibiotics with incomplete resolution. Imaging revealed a cystic lesion centered in the ITF. She was taken for endoscopic endonasal biopsy of the lesion and had no complications. Pathology revealed a mature teratoma composed primarily of pancreatic tissue. Providers should consider masses such as teratoma in the differential for ITF tumors and periorbital edema unresponsive to typical treatment.
PubMed: 38827640
DOI: 10.1177/11795476241255563 -
Cureus May 2024Teratomas are rare germ cell tumors derived from multiple germinal cell layers. Thyroid teratomas, specifically, are exceptionally uncommon and present unique diagnostic...
Teratomas are rare germ cell tumors derived from multiple germinal cell layers. Thyroid teratomas, specifically, are exceptionally uncommon and present unique diagnostic and therapeutic challenges. Here, we report a case of cervico-mediastinal thyroid teratoma, highlighting diagnostic difficulties and surgical management. A 37-year-old woman presented with right lateral cervical swelling, leading to radiological imaging suggesting a thymic teratoma. However, cytology indicated a colloid cyst. Surgical removal was performed, revealing a mixed-type teratoma originating from the thyroid gland. Thyroid teratomas pose diagnostic and therapeutic challenges due to their rarity and complex nature. Further research is needed to establish standardized guidelines for their management.
PubMed: 38827013
DOI: 10.7759/cureus.59560 -
Developmental Cell May 2024Embryonic stem cells (ESCs) can differentiate into all cell types of the embryonic germ layers. ESCs can also generate totipotent 2C-like cells and trophectodermal...
Embryonic stem cells (ESCs) can differentiate into all cell types of the embryonic germ layers. ESCs can also generate totipotent 2C-like cells and trophectodermal cells. However, these latter transitions occur at low frequency due to epigenetic barriers, the nature of which is not fully understood. Here, we show that treating mouse ESCs with sodium butyrate (NaB) increases the population of 2C-like cells and enables direct reprogramming of ESCs into trophoblast stem cells (TSCs) without a transition through a 2C-like state. Mechanistically, NaB inhibits histone deacetylase activities in the LSD1-HDAC1/2 corepressor complex. This increases acetylation levels in the regulatory regions of both 2C- and TSC-specific genes, promoting their expression. In addition, NaB-treated cells acquire the capacity to generate blastocyst-like structures that can develop beyond the implantation stage in vitro and form deciduae in vivo. These results identify how epigenetics restrict the totipotent and trophectoderm fate in mouse ESCs.
PubMed: 38823394
DOI: 10.1016/j.devcel.2024.05.009 -
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