Articles by Danielle M. Jorgens in JoVE
Desde Voxels al Conocimiento: Una Guía Práctica para la segmentación del Complejo Microscopía Electrónica 3D-Data Wen-Ting Tsai1, Ahmed Hassan1, Purbasha Sarkar2, Joaquin Correa1,3, Zoltan Metlagel1, Danielle M. Jorgens1, Manfred Auer1,2 1Life Sciences Division, Lawrence Berkeley National Laboratory, 2Joint Bioenergy Institute, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 3National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory El cuello de botella para la microscopía electrónica 3D celular es la extracción de características (segmentación) en mapas muy complejos de densidad 3D. Hemos desarrollado un conjunto de criterios, que proporciona orientación sobre qué enfoque de segmentación (manual, semiautomático o automático) es el más adecuado para los diferentes tipos de datos, proporcionando así un punto de partida para la segmentación efectiva.
Other articles by Danielle M. Jorgens on PubMed
Mammary Collective Cell Migration Involves Transient Loss of Epithelial Features and Individual Cell Migration Within the Epithelium Journal of Cell Science. Jun, 2012 | Pubmed ID: 22344263 Normal mammary morphogenesis involves transitions between simple and multilayered epithelial organizations. We used electron microscopy and molecular markers to determine whether intercellular junctions and apico-basal polarity were maintained in the multilayered epithelium. We found that multilayered elongating ducts had polarized apical and basal tissue surfaces both in three-dimensional culture and in vivo. However, individual cells were only polarized on surfaces in contact with the lumen or extracellular matrix. The basolateral marker scribble and the apical marker atypical protein kinase C zeta localized to all interior cell membranes, whereas PAR3 displayed a cytoplasmic localization, suggesting that the apico-basal polarity was incomplete. Despite membrane localization of E-cadherin and β-catenin, we did not observe a defined zonula adherens connecting interior cells. Instead, interior cells were connected through desmosomes and exhibited complex interdigitating membrane protrusions. Single-cell labeling revealed that individual cells were both protrusive and migratory within the epithelial multilayer. Inhibition of Rho kinase (ROCK) further reduced intercellular adhesion on apical and lateral surfaces but did not disrupt basal tissue organization. Following morphogenesis, segregated membrane domains were re-established and junctional complexes re-formed. We observed similar epithelial organization during mammary morphogenesis in organotypic culture and in vivo. We conclude that mammary epithelial morphogenesis involves a reversible, spatially limited, reduction in polarity and intercellular junctions and active individualistic cell migration. Our data suggest that reductions in polarity and adhesion during breast cancer progression might reflect partial recapitulation of a normal developmental program.
Twist1-induced Dissemination Preserves Epithelial Identity and Requires E-cadherin The Journal of Cell Biology. Mar, 2014 | Pubmed ID: 24590176 Dissemination of epithelial cells is a critical step in metastatic spread. Molecular models of dissemination focus on loss of E-cadherin or repression of cell adhesion through an epithelial to mesenchymal transition (EMT). We sought to define the minimum molecular events necessary to induce dissemination of cells out of primary murine mammary epithelium. Deletion of E-cadherin disrupted epithelial architecture and morphogenesis but only rarely resulted in dissemination. In contrast, expression of the EMT transcription factor Twist1 induced rapid dissemination of cytokeratin-positive epithelial cells. Twist1 induced dramatic transcriptional changes in extracellular compartment and cell-matrix adhesion genes but not in cell-cell adhesion genes. Surprisingly, we observed disseminating cells with membrane-localized E-cadherin and β-catenin, and E-cadherin knockdown strongly inhibited Twist1-induced single cell dissemination. Dissemination can therefore occur with retention of epithelial cell identity. The spread of cancer cells during metastasis could similarly involve activation of an epithelial motility program without requiring a transition from epithelial to mesenchymal character.