Aims: The embryonic epicardium is a source of smooth muscle cells and fibroblasts of the coronary vasculature and of the myocardium, but the molecular circuits that direct the temporal and spatial generation of these cell types from epicardium-derived cells are only partly known. We aimed to elucidate the functional significance of the conserved epicardial expression of the T-box transcription factor gene Tbx18 using transgenic technology in the mouse.
Methods And Results: We show by cellular and molecular analyses that in Tbx18-deficient mice the epicardium is formed normally and that epicardial cells undergo an epithelial-mesenchymal transition, differentiate into smooth muscle cells and fibroblasts, and form a normal coronary vasculature and fibrous skeleton. Prolonged expression of Tbx18 in epicardium-derived cells by a transgenic approach in vivo does not affect the differentiation and migratory behaviour of these cells. In contrast, epicardial misexpression of a transcriptional activator version of Tbx18, Tbx18VP16, results in premature smooth muscle differentiation of epicardial cells. Inhibition of Notch and transforming growth factor beta receptor signalling in Tbx18VP16 expressing epicardial cells in explant cultures reverts this phenotype.
Conclusion: Tbx18 is dispensable for epicardial development, yet a repressive T-box function may be required to prevent premature smooth muscle cell differentiation by repressing transforming growth factor beta receptor and Notch signalling in the embryonic epicardium.
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http://dx.doi.org/10.1093/cvr/cvs277 | DOI Listing |
Exp Physiol
January 2025
Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.
The mechanisms linking maternal asthma (MA) exposure in utero and subsequent risk of asthma in childhood are not fully understood. Pathological airway remodelling, including reticular basement membrane thickening, has been reported in infants and children who go on to develop asthma later in childhood. This suggests altered airway development before birth as a mechanism underlying increased risk of asthma in children exposed in utero to MA.
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January 2025
Departments of Pathology.
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View Article and Find Full Text PDFAnal Chem
January 2025
Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Microelectrodes offer exceptional sensitivity, rapid response, and versatility, making them ideal for real-time detection and monitoring applications. Photoelectrochemical (PEC) sensors have shown great value in many fields due to their high sensitivity, fast response, and ease of operation. Nevertheless, conventional PEC sensing relies on cumbersome external light sources and bulky electrodes, hindering its miniaturization and implantation, thereby limiting its application in real-time disease monitoring.
View Article and Find Full Text PDFRationale: Airflow obstruction refractory to β2 adrenergic receptor (β2AR) agonists is an important clinical feature of infant respiratory syncytial virus (RSV) bronchiolitis, with limited treatment options. This resistance is often linked to poor drug delivery and potential viral infection of airway smooth muscle cells (ASMCs). Whether RSV inflammation causes β2AR desensitization in infant ASMCs is unknown.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Respiratory Department II, National Clinical Research Center for Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
Multisystemic smooth muscle dysfunction syndrome (MSMDS) is an autosomal dominant disorder caused by mutations in the gene, resulting in variable clinical manifestation and multi-organ dysfunction. Interstitial lung disease (ILD) is a rare phenotype of this condition. We describe a rare infant case of an 8-month-old boy who presented with progressively worsening dyspnea, along with intermittent episodes of respiratory distress and cyanosis since birth.
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