講演情報
[II-TKIS-OR-5]Morphological analysis of the pulmonary vein-left atrium connection in mice
○Sou Miyanishi1, Rie Saba1, Kana Kitazaki1, Naoki Takeshita1,2, Yoshiro Nakajima1, Kenta Yashiro1 (1.Anatomy & Developmental Biology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan, 2.Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan)
キーワード：
Total anomalous pulmonary venous return、Pulmonary vein、3D analysis
Total anomalous pulmonary venous return (TAPVR) is a complex congenital heart disease in which pulmonary veins (PVs) drain into the systemic circulation or right atrium rather than the left atrium (LA), resulting in severe neonatal cyanosis that often requires emergent surgical intervention.
Pitx2c, a splice isoform of Pitx2, regulates left-right asymmetry during mouse organogenesis and is specifically expressed in the developing LA. Our unpublished data show that Pitx2c-null mutant ( Pitx2δASE/δASE) mice consistently develop TAPVR accompanied by left atrial right isomerism. These findings suggest that detailed analysis of this mutant may provide important insights into the molecular mechanisms underlying PV-LA connection and TAPVR pathogenesis. However normal PV morphogenesis remains poorly understood. Thus, we conducted a comprehensive analysis of the establishment of PV-LA connection in mouse embryos.
We utilized mouse embryos harboring Tg Tek-Cre and Rosa26CAG-loxP-STOP-loxP-tdTomato alleles to visualize vascular endothelium and performed immunohistochemistry on developing heart and lung. The specimens were cleared with the CUBIC method analyzed by light-sheet fluorescence microscopy, followed by three-dimensional reconstruction. This high-resolution 3D approach allows us to identify subtle morphological features often overlooked by traditional 2D histology. At E11.0, we identified the common PV extending from the pulmonary venous plexus of the lung bud to the LA. Comparative 3D analysis using Pitx2δASE/δASE mutants are currently underway.
Pitx2c, a splice isoform of Pitx2, regulates left-right asymmetry during mouse organogenesis and is specifically expressed in the developing LA. Our unpublished data show that Pitx2c-null mutant ( Pitx2δASE/δASE) mice consistently develop TAPVR accompanied by left atrial right isomerism. These findings suggest that detailed analysis of this mutant may provide important insights into the molecular mechanisms underlying PV-LA connection and TAPVR pathogenesis. However normal PV morphogenesis remains poorly understood. Thus, we conducted a comprehensive analysis of the establishment of PV-LA connection in mouse embryos.
We utilized mouse embryos harboring Tg Tek-Cre and Rosa26CAG-loxP-STOP-loxP-tdTomato alleles to visualize vascular endothelium and performed immunohistochemistry on developing heart and lung. The specimens were cleared with the CUBIC method analyzed by light-sheet fluorescence microscopy, followed by three-dimensional reconstruction. This high-resolution 3D approach allows us to identify subtle morphological features often overlooked by traditional 2D histology. At E11.0, we identified the common PV extending from the pulmonary venous plexus of the lung bud to the LA. Comparative 3D analysis using Pitx2δASE/δASE mutants are currently underway.