Search bioRxiv⌕ Search

Biology subjects

Nagayama, M.

Publications and source records attributed to Nagayama, M..

3 recordsLinked to original sources

Spatial confinement induces reciprocating migration of epidermal keratinocytes and forms triphasic epithelia

Epithelial cells undergo epithelial-mesenchymal transition (EMT) during migration and regain their epithelial phenotype in the post-migration phase (mesenchymal-epithelial transition; MET). We established an experimental system that reproduces a three-compartment epithelial structure comprising the original epithelium, its EMT state, and its MET state. Keratinocytes (KCs), skin epithelial cells, placed on a microporous membrane migrated through 3.0-{micro}m or larger micropores. The 3.0-{micro}m-pored membrane induced an epithelial structure with three distinct states: stratified KCs above the membrane, KCs showing EMT within the micropores, and a new stratified epithelium under the membrane. The membrane with larger micropores failed to maintain the three-compartment epithelial structure. Live imaging revealed that KCs moved in an oscillatory manner, with actin-rich filopodia-like structures extending into and out of the 3.0-{micro}m micropores, while the cells migrated unidirectionally into larger micropores. Piezo1 and keratin 6 were identified as negative modulators of KC entry into and exit from the 3.0-{micro}m micropores. These results demonstrate that non-cancerous epithelial cells migrate through confined spaces in an oscillatory manner, which might contribute to the formation of a three-compartment epithelial structure that recapitulates key aspects of wound healing.

cell biology↗

Cell-cell adhesion drives patterning in stratified epithelia

Epithelia consist of proliferating and differentiating cells that often display patterned arrangements. However, the mechanism regulating these spatial arrangements remains unclear. Here, we show that cell-cell adhesion dictates multicellular patterning in stratified epithelia. When cultured keratinocytes, a type of epithelial cell in the skin, are subjected to starvation, they spontaneously develop a pattern characterized by areas of high and low cell density. Pharmacological and knockout experiments show that adherens junctions are essential for patterning, whereas mathematical modeling indicates that cell-cell adhesion alone is sufficient to form regions with high/low cell density. This phenomenon, called cell-cell adhesion-induced patterning (CAIP), influences cell differentiation and proliferation through Yes-associated protein modulation. Starvation, which induces CAIP, enhances the stratification of the epithelia. These findings highlight the intrinsic self-organizing property of epithelial cells and indicate that CAIP modulation might promote wound healing in clinical settings.

cell biology↗

Subepidermal blisters are healed by wedge-shaped keratinocytes of hair follicle origin

Injury in adult tissue generally reactivates developmental programs to foster regeneration, but it is not known whether this paradigm applies to growing tissue. Here, by employing blisters, we show that epidermal wounds heal at the expense of skin development. The regenerated epidermis suppresses the expression of tissue morphogenesis genes accompanied by delayed hair follicle (HF) growth. Lineage tracing experiments, cell proliferation dynamics, and mathematical modeling reveal that the progeny of HF junctional zone stem cells, which undergo a morphological transformation, repair the blisters while not promoting HF development. In contrast, the contribution of interfollicular stem cell progeny to blister healing is small. These findings demonstrate that tissue development can be sacrificed for the sake of wound regeneration and suggest that tissue repair does not coincide with the reactivation of developmental programs in all regenerative contexts. Our study elucidates the key cellular mechanism of wound healing in skin blistering diseases.

cell biology↗