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Nature Apr 2024Timothy syndrome (TS) is a severe, multisystem disorder characterized by autism, epilepsy, long-QT syndrome and other neuropsychiatric conditions. TS type 1 (TS1) is...
Timothy syndrome (TS) is a severe, multisystem disorder characterized by autism, epilepsy, long-QT syndrome and other neuropsychiatric conditions. TS type 1 (TS1) is caused by a gain-of-function variant in the alternatively spliced and developmentally enriched CACNA1C exon 8A, as opposed to its counterpart exon 8. We previously uncovered several phenotypes in neurons derived from patients with TS1, including delayed channel inactivation, prolonged depolarization-induced calcium rise, impaired interneuron migration, activity-dependent dendrite retraction and an unanticipated persistent expression of exon 8A. We reasoned that switching CACNA1C exon utilization from 8A to 8 would represent a potential therapeutic strategy. Here we developed antisense oligonucleotides (ASOs) to effectively decrease the inclusion of exon 8A in human cells both in vitro and, following transplantation, in vivo. We discovered that the ASO-mediated switch from exon 8A to 8 robustly rescued defects in patient-derived cortical organoids and migration in forebrain assembloids. Leveraging a transplantation platform previously developed, we found that a single intrathecal ASO administration rescued calcium changes and in vivo dendrite retraction of patient neurons, suggesting that suppression of CACNA1C exon 8A expression is a potential treatment for TS1. Broadly, these experiments illustrate how a multilevel, in vivo and in vitro stem cell model-based approach can identify strategies to reverse disease-relevant neural pathophysiology.
Topics: Animals; Female; Humans; Male; Mice; Alternative Splicing; Autistic Disorder; Calcium; Calcium Channels, L-Type; Cell Movement; Dendrites; Exons; Long QT Syndrome; Neurons; Oligonucleotides, Antisense; Organoids; Prosencephalon; Syndactyly; Interneurons
PubMed: 38658687
DOI: 10.1038/s41586-024-07310-6 -
Italian Journal of Dermatology and... Aug 2023Rubinstein-Taybi Syndrome is a rare congenital multisystem syndrome inherited in an autosomal dominant pattern caused by mutations in CREBBP and EP300 genes in... (Review)
Review
Rubinstein-Taybi Syndrome is a rare congenital multisystem syndrome inherited in an autosomal dominant pattern caused by mutations in CREBBP and EP300 genes in approximately 60% and 10% respectively. These genes encode two highly evolutionarily conserved, ubiquitously expressed, and homologous lysine-acetyltransferases, that are involved in number of basic cellular activities, such as DNA repair, cell proliferation, growth, differentiation, apoptosis of cells, and tumor suppression. It is mainly characterized by global developmental delay, moderate to severe intellectual disability, postnatal retardation, microcephaly, skeletal anomalies including broad/short, angled thumbs and/or large first toes, short stature, and dysmorphic facial features. There is an increased risk to develop tumors mainly meningiomas and pilomatrixomas, without a clear genotype-phenotype correlation. Although not considered as characteristic manifestations, numerous cutaneous anomalies have also been reported in patients with this entity. Both susceptibility to the formation of keloids and pilomatricomas are the most often associated cutaneous features. In this review, we discuss the genetics, diagnosis, and clinical features in Rubinstein-Taybi Syndrome with a review of the major dermatological manifestations.
Topics: Humans; Rubinstein-Taybi Syndrome; Mutation; Intellectual Disability; Genetic Association Studies; Pilomatrixoma; Skin Neoplasms
PubMed: 37282850
DOI: 10.23736/S2784-8671.23.07547-3 -
Nature Sep 2023Craniosynostosis is a group of disorders of premature calvarial suture fusion. The identity of the calvarial stem cells (CSCs) that produce fusion-driving osteoblasts in...
Craniosynostosis is a group of disorders of premature calvarial suture fusion. The identity of the calvarial stem cells (CSCs) that produce fusion-driving osteoblasts in craniosynostosis remains poorly understood. Here we show that both physiologic calvarial mineralization and pathologic calvarial fusion in craniosynostosis reflect the interaction of two separate stem cell lineages; a previously identified cathepsin K (CTSK) lineage CSC (CTSK CSC) and a separate discoidin domain-containing receptor 2 (DDR2) lineage stem cell (DDR2 CSC) that we identified in this study. Deletion of Twist1, a gene associated with craniosynostosis in humans, solely in CTSK CSCs is sufficient to drive craniosynostosis in mice, but the sites that are destined to fuse exhibit an unexpected depletion of CTSK CSCs and a corresponding expansion of DDR2 CSCs, with DDR2 CSC expansion being a direct maladaptive response to CTSK CSC depletion. DDR2 CSCs display full stemness features, and our results establish the presence of two distinct stem cell lineages in the sutures, with both populations contributing to physiologic calvarial mineralization. DDR2 CSCs mediate a distinct form of endochondral ossification without the typical haematopoietic marrow formation. Implantation of DDR2 CSCs into suture sites is sufficient to induce fusion, and this phenotype was prevented by co-transplantation of CTSK CSCs. Finally, the human counterparts of DDR2 CSCs and CTSK CSCs display conserved functional properties in xenograft assays. The interaction between these two stem cell populations provides a new biologic interface for the modulation of calvarial mineralization and suture patency.
Topics: Humans; Mice; Animals; Craniosynostoses; Osteogenesis; Cell Lineage; Phenotype; Stem Cells
PubMed: 37730988
DOI: 10.1038/s41586-023-06526-2 -
The Journal of Clinical Investigation Nov 2023Skull development coincides with the onset of cerebrospinal fluid (CSF) circulation, brain-CSF perfusion, and meningeal lymphangiogenesis, processes essential for brain...
Skull development coincides with the onset of cerebrospinal fluid (CSF) circulation, brain-CSF perfusion, and meningeal lymphangiogenesis, processes essential for brain waste clearance. How these processes are affected by craniofacial disorders such as craniosynostosis are poorly understood. We report that raised intracranial pressure and diminished CSF flow in craniosynostosis mouse models associate with pathological changes to meningeal lymphatic vessels that affect their sprouting, expansion, and long-term maintenance. We also show that craniosynostosis affects CSF circulatory pathways and perfusion into the brain. Further, craniosynostosis exacerbates amyloid pathology and plaque buildup in Twist1+/-:5xFAD transgenic Alzheimer's disease models. Treating craniosynostosis mice with Yoda1, a small molecule agonist for Piezo1, reduces intracranial pressure and improves CSF flow, in addition to restoring meningeal lymphangiogenesis, drainage to the deep cervical lymph nodes, and brain-CSF perfusion. Leveraging these findings, we show that Yoda1 treatments in aged mice with reduced CSF flow and turnover improve lymphatic networks, drainage, and brain-CSF perfusion. Our results suggest that CSF provides mechanical force to facilitate meningeal lymphatic growth and maintenance. Additionally, applying Yoda1 agonist in conditions with raised intracranial pressure and/or diminished CSF flow, as seen in craniosynostosis or with ageing, is a possible therapeutic option to help restore meningeal lymphatic networks and brain-CSF perfusion.
Topics: Mice; Animals; Glymphatic System; Brain; Lymphatic Vessels; Perfusion; Craniosynostoses; Drainage; Ion Channels
PubMed: 37917195
DOI: 10.1172/JCI171468 -
BMJ Case Reports Jun 2024Goldenhar syndrome, also recognised as oculo-auriculo-vertebral spectrum, is a very rare condition distinguished by a diverse array of clinical abnormalities affecting...
Goldenhar syndrome, also recognised as oculo-auriculo-vertebral spectrum, is a very rare condition distinguished by a diverse array of clinical abnormalities affecting the ocular, auditory, vertebral and various organ systems. The pathophysiology of this condition is not fully elucidated due to its inherent genetic variability and rarity. In this report, we present a case of Goldenhar syndrome in a toddler boy, aiming to enhance the existing body of literature on this condition.
Topics: Humans; Goldenhar Syndrome; Male; Child, Preschool
PubMed: 38839403
DOI: 10.1136/bcr-2024-259872 -
Proceedings of the National Academy of... Jul 2023Early placenta development involves cytotrophoblast differentiation into extravillous trophoblast (EVT) and syncytiotrophoblast (STB). Defective trophoblast development...
Early placenta development involves cytotrophoblast differentiation into extravillous trophoblast (EVT) and syncytiotrophoblast (STB). Defective trophoblast development and function may result in severe pregnancy complications, including fetal growth restriction and pre-eclampsia. The incidence of these complications is increased in pregnancies of fetuses affected by Rubinstein-Taybi syndrome, a developmental disorder predominantly caused by heterozygous mutations in CREB-binding protein () or E1A-binding protein p300 (). Although the acetyltransferases CREBBP and EP300 are paralogs with many overlapping functions, the increased incidence of pregnancy complications is specific for mutations. We hypothesized that these complications have their origin in early placentation and that EP300 is involved in that process. Therefore, we investigated the role of EP300 and CREBBP in trophoblast differentiation, using human trophoblast stem cells (TSCs) and trophoblast organoids. We found that pharmacological CREBBP/EP300 inhibition blocks differentiation of TSCs into both EVT and STB lineages, and results in an expansion of TSC-like cells under differentiation-inducing conditions. Specific targeting by RNA interference or CRISPR/Cas9-mediated mutagenesis demonstrated that knockdown of but not inhibits trophoblast differentiation, consistent with the complications seen in Rubinstein-Taybi syndrome pregnancies. By transcriptome sequencing, we identified transforming growth factor alpha (TGFA, encoding TGF-α) as being strongly upregulated upon knockdown. Moreover, supplementing differentiation medium with TGF-α, which is a ligand for the epidermal growth factor receptor (EGFR), likewise affected trophoblast differentiation and resulted in increased TSC-like cell proliferation. These findings suggest that EP300 facilitates trophoblast differentiation by interfering with at least EGFR signaling, pointing towards a crucial role for EP300 in early human placentation.
Topics: Pregnancy; Female; Humans; Trophoblasts; Transforming Growth Factor alpha; Rubinstein-Taybi Syndrome; Cell Differentiation; E1A-Associated p300 Protein; CREB-Binding Protein; Pre-Eclampsia; ErbB Receptors
PubMed: 37406095
DOI: 10.1073/pnas.2217405120 -
Cell Stem Cell Nov 2023The meninges lie in the interface between the skull and brain, harboring lymphatic vasculature and skull progenitor cells (SPCs). How the skull and brain communicate...
The meninges lie in the interface between the skull and brain, harboring lymphatic vasculature and skull progenitor cells (SPCs). How the skull and brain communicate remains largely unknown. We found that impaired meningeal lymphatics and brain perfusion drive neurocognitive defects in Twist1 mice, an animal model of craniosynostosis recapitulating human Saethre-Chotzen syndrome. Loss of SPCs leads to skull deformities and elevated intracranial pressure (ICP), whereas transplanting SPCs back into mutant mice mitigates lymphatic and brain defects through two mechanisms: (1) decreasing elevated ICP by skull correction and (2) promoting the growth and migration of lymphatic endothelial cells (LECs) via SPC-secreted vascular endothelial growth factor-C (VEGF-C). Treating Twist1 mice with VEGF-C promotes meningeal lymphatic growth and rescues defects in ICP, brain perfusion, and neurocognitive functions. Thus, the skull functionally integrates with the brain via meningeal lymphatics, which is impaired in craniosynostosis and can be restored by SPC-driven lymphatic activation via VEGF-C.
Topics: Mice; Humans; Animals; Vascular Endothelial Growth Factor C; Endothelial Cells; Skull; Meninges; Craniosynostoses; Stem Cells
PubMed: 37863055
DOI: 10.1016/j.stem.2023.09.012 -
Techniques in Hand & Upper Extremity... Jun 2024Syndactyly release aims to address skin deficits by resurfacing web spaces and sides of digits to allow independent digital motion while minimizing the risk of web creep...
Syndactyly release aims to address skin deficits by resurfacing web spaces and sides of digits to allow independent digital motion while minimizing the risk of web creep and scar contractures. Conventional methods include the use of a dorsal and interdigitating flaps with full-thickness skin grafts. More recently, there have been several descriptions of "graftless" syndactyly release without skin grafts, thus avoiding a further (usually distant) donor site. However, the indications of when and when not to use these techniques remain unclear. In addition, the inevitable scarring from extra recruitment of local adjacent skin is perhaps underemphasized. In this article, we revisit the trilobed flap technique which serves to balance the amount of skin needed for resurfacing digits while minimizing local donor site scarring. The geometry and nuances of the flap inset are illustrated in detail to guide those embarking on this technique. The trilobed syndactyly release technique is a reproducible, safe, and reliable method for the release of simple syndactyly.
Topics: Humans; Syndactyly; Surgical Flaps; Cicatrix
PubMed: 38764415
DOI: 10.1097/BTH.0000000000000472