Suchergebnisse

The inheritance of the midbody remnant (MBR) breaks the symmetry of the two daughter cells, with functional consequences for lumen and primary cilium formation by polarized epithelial cells, and also for development and differentiation. However, despite its importance, neither the relationship between the plasma membrane and the inherited MBR nor the mechanism of MBR inheritance is well known. Here, the analysis by correlative light and ultra-high-resolution scanning electron microscopy reveals a membranous stalk that physically connects the MBR to the apical membrane of epithelial cells. The stalk, which derives from the uncleaved side of the midbody, concentrates the ESCRT machinery. The ESCRT CHMP4C subunit enables MBR inheritance, and its depletion dramatically reduces the percentage of ciliated cells. We demonstrate (1) that MBRs are physically connected to the plasma membrane, (2) how CHMP4C helps maintain the integrity of the connection, and (3) the functional importance of the connection. ; Spanish Ministerio de Ciencia e Innovación (MICIN), Agencia Estatal de Investigación, y Fondo Europeo de Desarrollo Regional, European Union (MICIN/AEI/FEDER, UE), and by Wellcome Trust funding (WT102871MA, the Comunidad deMadrid (S2018/NMT-4291 TEC2-SPACE), MICIN (project CSIC13-4E-1794), and EU (FEDER, FSE)

The inheritance of the midbody remnant (MBR) breaks the symmetry of the two daughter cells, with functional consequences for lumen and primary cilium formation by polarized epithelial cells, and also for development and differentiation. However, despite its importance, neither the relationship between the plasma membrane and the inherited MBR nor the mechanism of MBR inheritance is well known. Here, the analysis by correlative light and ultra-high-resolution scanning electron microscopy reveals a membranous stalk that physically connects the MBR to the apical membrane of epithelial cells. The stalk, which derives from the uncleaved side of the midbody, concentrates the ESCRT machinery. The ESCRT CHMP4C subunit enables MBR inheritance, and its depletion dramatically reduces the percentage of ciliated cells. We demonstrate (1) that MBRs are physically connected to the plasma membrane, (2) how CHMP4C helps maintain the integrity of the connection, and (3) the functional importance of the connection. ; This work was supported by a grant ( PGC2018-095643-B-I00 ) to M.A.A. from the Spanish Ministerio de Ciencia e Innovación (MICIN), Agencia Estatal de Investigación , y Fondo Europeo de Desarrollo Regional , European Union ( MICIN /AEI/FEDER, UE), and by Wellcome Trust funding ( WT102871MA ) to J.M.-S. We also acknowledge the Micro and Nanofabrication Laboratory of the Instituto de Micro y Nanotecnología (MiNa), which is funded by the Comunidad de Madrid ( S2018/NMT-4291 TEC2SPACE), MICIN (project CSIC13-4E-1794 ), and EU (FEDER, FSE), for invaluable help on SEM. A contract ( FPU14/00295 ) and a short-term fellowship from EMBO to J.C.-A. are also acknowledged. ; Peer reviewed

Orlova, Bellin, Mummery, and colleagues combined three hiPSC-derived cardiac cell types in 3D microtissues. Cardiomyocytes matured structurally and functionally. Replacing healthy hiPSC-cardiac fibroblasts with patient fibroblasts recapitulated aspects of arrhythmogenic cardiomyopathy. Single-cell transcriptomics, electrophysiology, metabolomics, and ultrastructural analysis revealed roles for CX43 gap junctions and cAMP signaling in the tri-cell-type dialog.Cardiomyocytes (CMs) from human induced pluripotent stem cells (hiPSCs) are functionally immature, but this is improved by incorporation into engineered tissues or forced contraction. Here, we showed that tri-cellular combinations of hiPSC-derived CMs, cardiac fibroblasts (CFs), and cardiac endothelial cells also enhance maturation in easily constructed, scaffold-free, three-dimensional microtissues (MTs). hiPSC-CMs in MTs with CFs showed improved sarcomeric structures with T-tubules, enhanced contractility, and mitochondrial respiration and were electrophysiologically more mature than MTs without CFs. Interactions mediating maturation included coupling between hiPSC-CMs and CFs through connexin 43 (CX43) gap junctions and increased intracellular cyclic AMP (cAMP). Scaled production of thousands of hiPSC-MTs was highly reproducible across lines and differentiated cell batches. MTs containing healthy-control hiPSC-CMs but hiPSC-CFs from patients with arrhythmogenic cardiomyopathy strikingly recapitulated features of the disease. Our MT model is thus a simple and versatile platform for modeling multicellular cardiac diseases that will facilitate industry and academic engagement in high-throughput molecular screening. ; European Research Council (ERCAdG 323182 STEMCARDIOVASC); European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 602423; European Union's Horizon 2020 Research and Innovation Programme under grant agreement no. 668724; Netherlands Organ-on-Chip Initiative, an NWO Gravitation project funded by the Ministry of Education, Culture and Science of the government of the Netherlands; Transnational Research Project on Cardiovascular Diseases (JTC2016_FP-40-021 ACMHF); the Netherlands Organisation for Health Research and Development ZonMW (MKMD project no. 114022504);