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Wint, H.

Publications and source records attributed to Wint, H..

3 recordsLinked to original sources

Piezo1 couples fluid shear stress to adaptive genome dynamics by integrating cytoplasmic-nuclear mechanotransduction

Fluid shear stress (FSS) regulates endothelial morphology and function through flow-responsive gene expression programs. Yet, how mechanical forces are transmitted across cytoplasmic and nuclear compartments to regulate genome adaptive response remains unclear. Here, we show that FSS induces rapid nuclear remodeling characterized by nuclear compaction and apical nuclear indentations. These changes are driven by reorganization of perinuclear actin and microtubule cytoskeleton into apical linear cytoskeletal cables that constrain the nuclear surface. Concurrently, the mechanosensitive ion channel Piezo1 redistributes from the plasma membrane to these perinuclear deformations. Quantitative molecular imaging under flow reveals a transient adaptive cell state characterized by chromatin reorganization and epigenetic remodeling, accompanied by altered mobility of the flow-responsive transcription factor KLF2. Pharmacological inhibition of Piezo1 abolishes FSS-induced nuclear deformation and uncouples chromatin reorganization from KLF2 dynamic changes. Together, these findings reveal that endothelial mechanotransduction exploits physical principles of nuclear organization to regulate transcription factor behavior and adaptive genome responses across biological scales.

Cell Biology↗

Combined forces of hydrostatic pressure and actin polymerization drive endothelial tip cell migration and sprouting angiogenesis

Cell migration is a key process in the shaping and formation of tissues. During sprouting angiogenesis, endothelial tip cells invade avascular tissues by generating actomyosin-dependent forces that drive cell migration and vascular expansion. Surprisingly, ECs can still invade if actin polymerization is inhibited. In this study, we show that endothelial tip cells employ an alternative mechanism of cell migration that is dependent on Aquaporin (Aqp)-mediated water inflow and increase in hydrostatic pressure. In the zebrafish, ECs express aqp1a.1 and aqp8a.1 in newly formed vascular sprouts in a VEGFR2-dependent manner. Aqp1a.1 and Aqp8a.1 loss-of-function studies show an impairment in intersegmental vessels formation because of a decreased capacity of tip cells to increase their cytoplasmic volume and generate membrane protrusions, leading to delayed tip cell emergence from the dorsal aorta and slower migration. Further inhibition of actin polymerization resulted in a greater decrease in sprouting angiogenesis, indicating that ECs employ two mechanisms for robust cell migration in vivo. Our study thus highlights an important role of hydrostatic pressure in tissue morphogenesis.

developmental biology↗

Pacsin 2-dependent N-cadherin internalization regulates the migration behaviour of malignant cancer cells

Cell migration is essential for both physiological and pathological processes such as embryonic morphogenesis, wound repair and metastasis of cancer cells. Collective cell migration is the coordinated movement of multiple cells connected with cadherin-based adherence junctions. Cadherins undergo dynamic intracellular trafficking and their surface level is determined by a balance between endocytosis, recycling and degradation. However, regulatory mechanisms of cadherin turnover in the collective cell migration remain to be elucidated. In this study, we show that a BAR domain protein pacsin 2 plays an essential role in collective cell migration by regulating the internalization of N-cadherin in human bladder cancer cells T24. Pacsin 2 and its associating GTPase dynamin 2 colocalized with N-cadherin at the cell periphery in T24 cells. Depletion of either pacsin 2 or dynamin 2 induced interdigitating cell-cell contacts enriched with N-cadherin. Imaging analyses of the wound healing assay showed that pacsin 2-depleted T24 cells migrated in a collective and directed manner in contrast with randomly migrating control cells. Furthermore, cell-surface biotinylation assay showed that internalization of N-cadherin is attenuated in pacsin 2-depleted cells. Interestingly, the GST-pulldown assay demonstrated that the SH3 domain of pacsin 2 binds to the cytoplasmic domain of N-cadherin, suggesting that surface levels of N-cadherin are regulated by pacsin 2-mediated endocytosis. These data support new insights into a novel endocytic route of N-cadherin in collective cell migration providing pacsin 2 as a possible therapeutic target for cancer metastasis.

cell biology↗