scholarly journals Pattern regulation in a regenerating jellyfish

Author(s):  
Chiara Sinigaglia ◽  
Sophie Peron ◽  
Jeanne Eichelbrenner ◽  
Sandra Chevalier ◽  
Julia Steger ◽  
...  

AbstractClytia hemisphaerica jellyfish, with their tetraradial symmetry, offer a novel paradigm for addressing patterning mechanisms during regeneration. Here we show that an interplay between mechanical forces, cell migration and proliferation allows jellyfish fragments to regain shape and functionality rapidly, notably by efficient restoration of the central feeding organ (manubrium). Fragmentation first triggers actomyosin-powered remodeling that restores body umbrella shape, causing radial smooth muscle fibers to converge around “hubs” which serve as positional landmarks. Stabilization of these hubs, and associated expression of Wnt6, depends on the configuration of the adjoining muscle fiber “spokes”. Stabilized hubs presage the site of the manubrium blastema, whose growth is Wnt/β-catenin dependent and fueled by both cell proliferation and long-range cell recruitment. Manubrium morphogenesis is modulated by its connections with the gastrovascular canal system. We conclude that body patterning in regenerating jellyfish emerges mainly from local interactions, triggered and directed by the remodeling process.

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Chiara Sinigaglia ◽  
Sophie Peron ◽  
Jeanne Eichelbrenner ◽  
Sandra Chevalier ◽  
Julia Steger ◽  
...  

Jellyfish, with their tetraradial symmetry, offer a novel paradigm for addressing patterning mechanisms during regeneration. Here we show that an interplay between mechanical forces, cell migration and proliferation allows jellyfish fragments to regain shape and functionality rapidly, notably by efficient restoration of the central feeding organ (manubrium). Fragmentation first triggers actomyosin-powered remodeling that restores body umbrella shape, causing radial smooth muscle fibers to converge around ‘hubs’ which serve as positional landmarks. Stabilization of these hubs, and associated expression of Wnt6, depends on the configuration of the adjoining muscle fiber ‘spokes’. Stabilized hubs presage the site of the manubrium blastema, whose growth is Wnt/β-catenin dependent and fueled by both cell proliferation and long-range cell recruitment. Manubrium morphogenesis is modulated by its connections with the gastrovascular canal system. We conclude that body patterning in regenerating jellyfish emerges mainly from local interactions, triggered and directed by the remodeling process.


Author(s):  
Elena Candelotti ◽  
Roberto De Luca ◽  
Roberto Megna ◽  
Mariangela Maiolo ◽  
Paolo De Vito ◽  
...  

Interaction between thyroid hormones and the immune system is reported in the literature. Thyroid hormones, thyroxine, T4, but also T3, act non-genomically through mechanisms that involve a plasma membrane receptor αvβ3 integrin, a co-receptor for insulin-like growth factor-1 (IGF-1). Previous data from our laboratory show a crosstalk between thyroid hormones and IGF-1 because thyroid hormones inhibit the IGF-1-stimulated glucose uptake and cell proliferation in L-6 myoblasts, and the effects are mediated by integrin αvβ3. IGF-1 also behaves as a chemokine, being an important factor for tissue regeneration after damage. In the present study, using THP-1 human leukemic monocytes, expressing αvβ3 integrin in their cell membrane, we focused on the crosstalk between thyroid hormones and either IGF-1 or monocyte chemoattractant protein-1 (MCP-1), studying cell migration and proliferation stimulated by the two chemokines, and the role of αvβ3 integrin, using inhibitors of αvβ3 integrin and downstream pathways. Our results show that IGF-1 is a potent chemoattractant in THP-1 monocytes, stimulating cell migration, and thyroid hormone inhibits the effect through αvβ3 integrin. Thyroid hormone also inhibits IGF-1-stimulated cell proliferation through αvβ3 integrin, an example of a crosstalk between genomic and non-genomic effects. We also studied the effects of thyroid hormone on cell migration and proliferation induced by MCP-1, together with the pathways involved, by a pharmacological approach and docking simulation. Our findings show a different downstream signaling for IGF-1 and MCP-1 in THP-1 monocytes mediated by the plasma membrane receptor of thyroid hormones, integrin αvβ3.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Mingming Yang ◽  
Tomoko Kamishima ◽  
Caroline Dart ◽  
John M Quayle

Introduction: Intimal thickening of blood vessels, a hallmark of several vascular diseases including atherosclerosis and a potential point of therapeutic intervention, is caused by vascular smooth muscle cell proliferation and migration. It has been suggested that oxygen availability in vessels not only regulates behavior of smooth muscle cells but also serves as a trigger that may lead to pathological responses. In this study we determined whether hypoxia elicits proliferative and migratory responses in Human Coronary Artery SMCs (HCASMCs). Methods: Proliferation of HCASMCs was assessed using a 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. SMCs were plated in 96-well plates (n=5), serum starved, and then placed under hypoxic or normoxic conditions for 2, 4 and 6 days (2D/4D/6D) before MTT was added to each well. Absorbance at the wavelength 570 nm was read on an ELISA plate reader, and percent change in cell viability was determined and normalized to control (cell viability under normoxia). Cell migration was characterized by scratch-wound assay. SMCs were seeded in 6 well plates overnight (n=3), then a ‘scratch’ on the cell monolayer was created for each well before putting into different oxygen levels for 4 hours, 12 hours and 24 hours. Images were captured at the beginning and at intervals during cell migration to close the scratch, and the degree of migration was determined by comparing the images. Results: Compared to normoxic condition, cell number changed to 118.1%±1.3% in 5% O 2 (p<0.05) and 98.2%%±1.9% in 1% O 2 after 2D; to 151.9% ±8.5% in 5% O 2 (p<0.001) and 119.4%±5.0% in 1% O 2 (p<0.05) after 4D; and to 163.0%±4.3% in 5% O 2 (p<0.001) and 120.3%±2.2% in 1% O 2 (p<0.05) after 6D. In the cell migration assay, the difference in migration rate between different groups after 4 hours was not obvious, but there was a significant difference after 12 hours (29.3%±1.3% closure in normoxia vs 39.8%±1.9% in 5% O 2 vs 40.9%±3.5% in 1% O 2 , p<0.05) and 24 hours (71.5%±4.4% in normoxia vs 87.2%±2.2% in 5% O 2 vs 87.5%±3.1% in 1% O 2 , p<0.05). Conclusion: Our studies reveal that hypoxia induces both proliferation and migration of HCASMCs.


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