Human mammary epithelial cells in a mature, stratified epithelial layer flatten and stiffen compared to single and confluent cells.
Biochim Biophys Acta Gen Subj
; 1865(6): 129891, 2021 06.
Article
em En
| MEDLINE
| ID: mdl-33689830
BACKGROUND: The epithelium forms a protective barrier against external biological, chemical and physical insults. So far, AFM-based, micro-mechanical measurements have only been performed on single cells and confluent cells, but not yet on cells in mature layers. METHODS: Using a combination of atomic force, fluorescence and confocal microscopy, we determined the changes in stiffness, morphology and actin distribution of human mammary epithelial cells (HMECs) as they transition from single cells to confluency to a mature layer. RESULTS: Single HMECs have a tall, round (planoconvex) morphology, have actin stress fibers at the base, have diffuse cortical actin, and have a stiffness of 1 kPa. Confluent HMECs start to become flatter, basal actin stress fibers start to disappear, and actin accumulates laterally where cells abut. Overall stiffness is still 1 kPa with two-fold higher stiffness in the abutting regions. As HMECs mature and form multilayered structures, cells on apical surfaces become flatter (apically more level), wider, and seven times stiffer (mean, 7 kPa) than single and confluent cells. The main drivers of these changes are actin filaments, as cells show strong actin accumulation in the regions where cells adjoin, and in the apical regions. CONCLUSIONS: HMECs stiffen, flatten and redistribute actin upon transiting from single cells to mature, confluent layers. GENERAL SIGNIFICANCE: Our findings advance the understanding of breast ductal morphogenesis and mechanical homeostasis.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Citoesqueleto de Actina
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Organogênese
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Glândulas Mamárias Humanas
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Células Epiteliais
Limite:
Female
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Humans
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article