scholarly journals DAAM mediates the assembly of long-lived, treadmilling stress fibers in collectively migrating epithelial cells in Drosophila

2021 ◽  
Author(s):  
Kristin Sherrard ◽  
Maureen Cetera ◽  
Sally Horne-Badovinac
Keyword(s):  
Epithelial Cells ◽  
Cell Movement ◽  
Stress Fibers ◽  
Linear Trajectory ◽  
Epithelial Migration ◽  
Cells In Culture ◽  
Multiple Cell ◽  
Developmental Switch ◽  
Over Time

Stress fibers (SFs) are actomyosin bundles commonly found in individually migrating cells in culture. However, whether and how cells use SFs to migrate in vivo or collectively is largely unknown. Studying the collective migration of the follicular epithelial cells in Drosophila, we found that the SFs in these cells show a novel treadmilling behavior that allows them to persist as the cells migrate over multiple cell lengths. Treadmilling SFs grow at their fronts by adding new integrin-based adhesions and actomyosin segments over time. This causes the SFs to have many internal adhesions along their lengths, instead of adhesions only at the ends. The front-forming adhesions remain stationary relative to the substrate and typically disassemble as the cell rear approaches. By contrast, a different type of adhesion forms at the terminus of the SF that slides with the trailing edge of the cell as the actomyosin ahead of it shortens. We further show that SF treadmilling depends on cell movement and identify a developmental switch in the formins that mediate SF assembly, with DAAM acting during migratory stages and Diaphanous acting during post-migratory stages. We propose that treadmilling SFs keep each cell on a linear trajectory, thereby promoting the collective motility required for epithelial migration.

scholarly journals DAAM mediates the assembly of long-lived, treadmilling stress fibers in collectively migrating epithelial cells in Drosophila

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kristin M Sherrard ◽  
Maureen Cetera ◽  
Sally Horne-Badovinac
Keyword(s):  
Epithelial Cells ◽  
Cell Movement ◽  
Stress Fibers ◽  
Linear Trajectory ◽  
Epithelial Migration ◽  
Cells In Culture ◽  
Multiple Cell ◽  
Developmental Switch ◽  
Over Time

Stress fibers (SFs) are actomyosin bundles commonly found in individually migrating cells in culture. However, whether and how cells use SFs to migrate in vivo or collectively is largely unknown. Studying the collective migration of the follicular epithelial cells in Drosophila, we found that the SFs in these cells show a novel treadmilling behavior that allows them to persist as the cells migrate over multiple cell lengths. Treadmilling SFs grow at their fronts by adding new integrin-based adhesions and actomyosin segments over time. This causes the SFs to have many internal adhesions along their lengths, instead of adhesions only at the ends. The front-forming adhesions remain stationary relative to the substrate and typically disassemble as the cell rear approaches. By contrast, a different type of adhesion forms at the SF’s terminus that slides with the cell’s trailing edge as the actomyosin ahead of it shortens. We further show that SF treadmilling depends on cell movement and identify a developmental switch in the formins that mediate SF assembly, with Dishevelled-associated activator of morphogenesis acting during migratory stages and Diaphanous acting during postmigratory stages. We propose that treadmilling SFs keep each cell on a linear trajectory, thereby promoting the collective motility required for epithelial migration.

scholarly journals Cross-talk between LAM cells and fibroblasts may influence alveolar epithelial cell behavior in Lymphangioleiomyomatosis

2021 ◽  
Author(s):  
Debbie Clements ◽  
Suzanne Miller ◽  
Roya Babaei-Jadidi ◽  
Mike Adam ◽  
S. Steven Potter ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cross Talk ◽  
Ex Vivo ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Dependent Manner ◽  
Epithelial Migration ◽  
Alveolar Epithelial

Lymphangioleiomyomatosis (LAM) is a female specific cystic lung disease in which TSC2 deficient LAM cells, LAM-Associated Fibroblasts (LAFs) and other cell types infiltrate the lungs. LAM lesions can be associated with type II alveolar epithelial cells (AT2 cells). We hypothesised that the behaviour of AT2 cells in LAM is influenced locally by LAFs. We tested this hypothesis in patient samples and in vitro. In human LAM lung, nodular AT2 cells show enhanced proliferation when compared to parenchymal AT2 cells, demonstrated by increased Ki67 expression. Further, nodular AT2 cells express proteins associated with epithelial activation in other disease states including Matrix Metalloproteinase 7, and Fibroblast Growth Factor 7 (FGF7). In vitro, LAF conditioned medium is mitogenic and positively chemotactic for epithelial cells, increases the rate of epithelial repair and protects against apoptosis. In vitro, LAM patient-derived TSC2 null cells cocultured with LAFs upregulate LAF expression of the epithelial chemokine and mitogen FGF7, which is a potential mediator of fibroblast-epithelial crosstalk, in an mTOR dependent manner. In a novel in vitro model of LAM, ex vivo cultured LAM lung-derived microtissues promote both epithelial migration and adhesion. Our findings suggest that AT2 cells in LAM display a proliferative, activated phenotype and that fibroblast accumulation following LAM cell infiltration into the parenchyma contributes to this change in AT2 cell behaviour. Fibroblast-derived FGF7 may contribute to the cross-talk between LAFs and hyperplastic epithelium in vivo, but does not appear to be the main driver of the effects of LAFs on epithelial cells in vitro.

scholarly journals Reporters to mark and eliminate basal or luminal epithelial cells in culture and in vivo

PLoS Biology ◽  
2018 ◽  
Vol 16 (6) ◽  
pp. e2004049 ◽  
Author(s):  
Olmo Sonzogni ◽  
Jennifer Haynes ◽  
Laurie A. Seifried ◽  
Yahia M. Kamel ◽  
Kai Huang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cells In Culture ◽  
Luminal Epithelial Cells

scholarly journals Differential Effects of Gamma Interferon on Chlamydia trachomatis Growth in Polarized and Nonpolarized Human Epithelial Cells in Culture

1998 ◽  
Vol 66 (5) ◽  
pp. 2349-2351 ◽  
Author(s):  
Colleen D. Kane ◽  
Gerald I. Byrne
Keyword(s):  
Chlamydia Trachomatis ◽  
Epithelial Cells ◽  
Gamma Interferon ◽  
Growth Modulation ◽  
Differential Effects ◽  
Cells In Culture ◽  
Human Epithelial Cells ◽  
Polarized Cells ◽  
Ifn Γ

ABSTRACT The effects of gamma interferon (IFN-γ) on Chlamydia trachomatis growth in polarized epithelial cells were examined. The range of IFN-γ concentrations causing aberrant chlamydial growth was wider in polarized than in nonpolarized cultures. Results indicate that chlamydial growth modulation in polarized cells readily leads to persistence and better reflects in vivo conditions.

scholarly journals Regulation of Myosin II Dynamics by Phosphorylation and Dephosphorylation of Its Light Chain in Epithelial Cells

2007 ◽  
Vol 18 (2) ◽  
pp. 605-616 ◽  
Author(s):  
Toshiyuki Watanabe ◽  
Hiroshi Hosoya ◽  
Shigenobu Yonemura
Keyword(s):  
Epithelial Cells ◽  
Light Chain ◽  
Fluorescent Protein ◽  
Myosin Ii ◽  
Time Lapse ◽  
Stress Fibers ◽  
Interacting Protein ◽  
Cytoskeleton Organization

Nonmuscle myosin II, an actin-based motor protein, plays an essential role in actin cytoskeleton organization and cellular motility. Although phosphorylation of its regulatory light chain (MRLC) is known to be involved in myosin II filament assembly and motor activity in vitro, it remains unclear exactly how MRLC phosphorylation regulates myosin II dynamics in vivo. We established clones of Madin Darby canine kidney II epithelial cells expressing MRLC-enhanced green fluorescent protein or its mutants. Time-lapse imaging revealed that both phosphorylation and dephosphorylation are required for proper dynamics of myosin II. Inhibitors affecting myosin phosphorylation and MRLC mutants indicated that monophosphorylation of MRLC is required and sufficient for maintenance of stress fibers. Diphosphorylated MRLC stabilized myosin II filaments and was distributed locally in regions of stress fibers where contraction occurs, suggesting that diphosphorylation is involved in the spatial regulation of myosin II assembly and contraction. We further found that myosin phosphatase or Zipper-interacting protein kinase localizes to stress fibers depending on the activity of myosin II ATPase.

scholarly journals Ex vivo gut culture for studying differentiation and migration of small intestinal epithelial cells

Open Biology ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 170256 ◽  
Author(s):  
Xiaofei Sun ◽  
Xing Fu ◽  
Min Du ◽  
Mei-Jun Zhu
Keyword(s):  
Epithelial Cells ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Cell Types ◽  
Regulatory Function ◽  
Gut Health ◽  
Gut Development ◽  
Epithelial Migration ◽  
Organoid Culture

Epithelial cultures are commonly used for studying gut health. However, due to the absence of mesenchymal cells and gut structure, epithelial culture systems including recently developed three-dimensional organoid culture cannot accurately represent in vivo gut development, which requires intense cross-regulation of the epithelial layer with the underlying mesenchymal tissue. In addition, organoid culture is costly. To overcome this, a new culture system was developed using mouse embryonic small intestine. Cultured intestine showed spontaneous peristalsis, indicating the maintenance of the normal gut physiological structure. During 10 days of ex vivo culture, epithelial cells moved along the gut surface and differentiated into different epithelial cell types, including enterocytes, Paneth cells, goblet cells and enteroendocrine cells. We further used the established ex vivo system to examine the role of AMP-activated protein kinase (AMPK) on gut epithelial health. Tamoxifen-induced AMPK α 1 knockout vastly impaired epithelial migration and differentiation of the developing ex vivo gut, showing the crucial regulatory function of AMPK α 1 in intestinal health.

The Development of Homologous (Canine/Anti-Canine) Antibodies in Dogs with Haemophilia A (Factor VIII Deficiency): A Ten-Year Longitudinal Study

1993 ◽  
Vol 69 (01) ◽  
pp. 021-024 ◽  
Author(s):  
Shawn Tinlin ◽  
Sandra Webster ◽  
Alan R Giles
Keyword(s):  
Factor Viii ◽  
Canine Model ◽  
Significant Inhibition ◽  
Human Condition ◽  
Haemophilia A ◽  
Variable Expression ◽  
The Family ◽  
Over Time

SummaryThe development of inhibitors to factor VIII in patients with haemophilia A remains as a serious complication of replacement therapy. An apparently analogous condition has been described in a canine model of haemophilia A (Giles et al., Blood 1984; 63:451). These animals and their relatives have now been followed for 10 years. The observation that the propensity for inhibitor development was not related to the ancestral factor VIII gene has been confirmed by the demonstration of vertical transmission through three generations of the segment of the family related to a normal (non-carrier) female that was introduced for breeding purposes. Haemophilic animals unrelated to this animal have not developed functionally significant factor VIII inhibitors despite intensive factor VIII replacement. Two animals have shown occasional laboratory evidence of factor VIII inhibition but this has not been translated into clinical significant inhibition in vivo as assessed by clinical response and F.VIII recovery and survival characteristics. Substantial heterogeneity of inhibitor expression both in vitro and in vivo has been observed between animals and in individual animals over time. Spontaneous loss of inhibitors has been observed without any therapies designed to induce tolerance, etc., being instituted. There is also phenotypic evidence of polyclonality of the immune response with variable expression over time in a given animal. These observations may have relevance to the human condition both in determining the pathogenetic factors involved in this condition and in highlighting the heterogeneity of its expression which suggests the need for caution in the interpretation of the outcome of interventions designed to modulate inhibitor activity.

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