Biology subjects

Rottier, R.

Publications and source records attributed to Rottier, R..

4 recordsLinked to original sources

bioRxiv2026

Vessel Organoids Reveal FOXF1 Variant-Specific Regulation of Mesoderm and Capillary Development

How allelic variants in lineage-regulating transcription factors drive diverging human developmental outcomes remains poorly understood. This is partly due to the lack of human model systems. Here, we used vessel organoids from human induced pluripotent stem cells (hiPSCs) to resolve variant-specific functions of Forkhead Box F1 (FOXF1), a critical regulator of mesoderm and vascular development. Using three patient-derived hiPSC lines harboring unique FOXF1 variants, we show that heterozygous variants cause capillary maldevelopment of varying severity. Single-nucleus multiomic analysis revealed variant-specific mechanisms - a severe variant impairs differentiation of nascent mesoderm to lateral plate mesoderm and disrupts vascular progenitor specification, while moderate variants permit mesoderm differentiation but rewire vascular progenitor states and function. Restoration of wild-type FOXF1 via lipid nanoparticle-mediated mRNA delivery rescued capillary formation in a variant- and developmental-stage-dependent manner. Together, these findings demonstrate that different variants disrupt stage-specific FOXF1 functions in human mesoderm-to-vascular development, underscoring the importance of variant-specific therapeutic strategies. HIGHLIGHTS O_LIHuman vessel organoids reveal variant-specific roles of FOXF1 in mesoderm patterning and capillary development. C_LIO_LISevere FOXF1 variant c.253T>A (p.F85I) impairs nascent mesoderm-to-lateral plate mesoderm differentiation and disrupts vascular progenitor specification. C_LIO_LI Moderate FOXF1 variants differentially rewire endothelial and mural progenitor cell states and function. C_LIO_LILipid nanoparticle-mediated FOXF1 mRNA delivery rescues capillary formation in a variant- and developmental-stage-dependent manner. C_LI

developmental biology↗

bioRxiv2022

CLASP1 is essential for neonatal lung function and survival in mice

The first breath of air at birth marks the beginning of extrauterine life, and breathing problems due to incomplete lung development or acute respiratory distress are common in premature babies and respiratory diseases. However, the underlying molecular mechanisms remain poorly understood. Here we show that the microtubule plus-end-tracking protein CLASP1 is required for neonatal lung function and survival. CLASP1 is expressed in the lungs and associated respiratory structures throughout embryonic development. Clasp1 disruption in mice caused intrauterine growth restriction and neonatal lethality due to acute respiratory failure. Knockout animals showed impaired lung inflation associated with smaller rib cage formation and abnormal diaphragm innervation. Live-cell analysis of microtubule dynamics in cultured hippocampal neurons revealed an increased catastrophe rate, consistent with a role of CLASP1 in neurite outgrowth. Histological and gene expression studies indicated that CLASP1 is required for normal pneumocyte differentiation and fetal lung maturation. Thus, CLASP1-mediated regulation of microtubule dynamics assists multiple systems essential for neonatal lung function and survival.

developmental biology↗

bioRxiv2020

The SARS-CoV-2 multibasic cleavage site facilitates early serine protease-mediated entry into organoid-derived human airway cells

After the SARS-CoV outbreak in 2003, a second zoonotic coronavirus named SARS-CoV-2, emerged late 2019 in China and rapidly caused the COVID-19 pandemic leading to a public health crisis of an unprecedented scale. Despite the fact that SARS-CoV-2 uses the same receptor as SARS-CoV, transmission and pathogenesis of both viruses seem to be quite distinct. A remarkable feature of the SARS-CoV-2 spike is the presence of a multibasic cleavage site, which is absent in the SARS-CoV spike. The viral spike protein not only attaches to the entry receptor, but also mediates fusion after cleavage by host proteases. Here, we report that the SARS-CoV-2 spike multibasic cleavage site increases infectivity on differentiated organoid-derived human airway cells. Compared with SARS-CoV, SARS-CoV-2 entered faster into the lung cell line Calu-3, and more frequently formed syncytial cells in differentiated organoid-derived human airway cells. Moreover, the multibasic cleavage site increased entry speed and plasma membrane serine protease usage relative to endosomal entry using cathepsins. Blocking serine protease activity using the clinically approved drug camostat mesylate effectively inhibited SARS-CoV-2 entry and replication in differentiated organoid-derived human airway cells. Our findings provide novel information on how SARS-CoV-2 enters relevant airway cells and highlight serine proteases as an attractive antiviral target. Significance StatementHighly pathogenic coronaviruses have spilled from animals to humans three times in the past two decades. Late 2019, SARS-CoV-2 emerged in China and was declared a pandemic by March 2020. The other two highly pathogenic coronaviruses, SARS-CoV and MERS-CoV, emerged in 2002 and 2012, respectively, but did not attain sustained human-to-human transmission. Given the high diversity of coronaviruses in animals, urbanization and increased air travel, future coronavirus pandemics are likely to occur intermittently. Identifying which factors determine pandemic potential and pathogenicity are therefore of key importance to global health. Additionally, there is an urgent need to rapidly translate fundamental knowledge to the clinic, a process that is expedited through the use of relevant cell culture systems.

microbiology↗

bioRxiv2020

SOX21 modulates SOX2-initiated differentiation of epithelial cells in the extrapulmonary airways

SOX2 expression levels are crucial for the balance between maintenance and differentiation of airway progenitor cells during development and regeneration. Here, we describe SOX21 patterning of the proximal airway epithelium which coincides with high levels of SOX2. Airway progenitor cells in this SOX2+/SOX21+ zone show differentiation to basal cells, specifying cells for the extrapulmonary airways. We show that loss of SOX21 results in increased differentiation of progenitor cells during murine lung development. SOX21 inhibits SOX2-induced differentiation by antagonizing SOX2 binding on different promotors. SOX21 remains expressed in adult tracheal epithelium and submucosal glands, where SOX21 modulates SOX2-induced differentiation in a similar fashion. Using fetal lung organoids and adult bronchial epithelial cells, we show that SOX2+SOX21+ regionalization is conserved in human. Thus SOX21 modulates SOX2-initiated differentiation in extrapulmonary epithelial cells during development and regeneration after injury.

cell biology↗