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- Hernroth, Bodil, 1951-, et al.
(författare)
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Immune suppression of the echinoderm Asterias rubens (L.) following long-term ocean acidification
- 2011
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Ingår i: Aquatic Toxicology. - 0166-445X .- 1879-1514. ; 103:3-4, s. 222-224
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Tidskriftsartikel (refereegranskat)abstract
- We compared effects of exposure to predict near-future (2100) ocean acidification (OA; pH 7.7) and normal seawater (Control; pH 8.1) on immune and stress responses in the adult sea star Asterias rubens. Analyses were made after one week and after six months of continuous exposure. Following one week exposure to acidified water, the pH of coelomic fluid was significantly reduced. Levels of the chaperon Hsp70 were elevated while key cellular players in immunity, coelomocytes. were reduced by approximately 50%. Following long-term exposure (six months) levels of Hsp70 returned to control values, whereas immunity was further impaired, evidenced by the reduced phagocytic capacity of coelomocytes and inhibited activation of p38 MAP-kinase. Such impacts of reduced seawater pH may have serious consequences for resistance to pathogens in a future acidified ocean.
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| 3. |
- Hernroth, Bodil, 1951, et al.
(författare)
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Possibility of Mixed Progenitor Cells in Sea Star Arm Regeneration
- 2010
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Ingår i: Journal of Experimental Zoology Part B-Molecular and Developmental Evolution. - : Wiley. - 1552-5007 .- 1552-5015. ; 314B:6, s. 457-468
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Tidskriftsartikel (refereegranskat)abstract
- In contrast to most vertebrates, invertebrate deuterostome echinoderms, such as the sea star Asterias rubens, undergo regeneration of lost body parts. The current hypothesis suggests that differentiated cells are the main source for regenerating arm in sea stars, but there is little information regarding the origin and identity of these cells. Here, we show that several organs distant to the regenerating arm responded by proliferation, most significantly in the coelomic epithelium and larger cells of the pyloric caeca. Analyzing markers for proliferating cells and parameters indicating cell ageing, such as levels of DNA damage, pigment, and lipofuscin contents as well as telomere length and telomerase activity, we suggest that cells contributing to the new arm likely originate from progenitors rather than differentiated cells. This is the first study showing that cells of mixed origin may be recruited from more distant sources of stem/progenitor cells in a sea star, and the first described indication of a role for pyloric caeca in arm regeneration. Data on growth rate during arm regeneration further indicate that regeneration is at the expense of whole animal growth. We propose a new working hypothesis for arm regeneration in sea stars involving four phases: wound healing by coelomocytes, migration of distant progenitor cells of mixed origin including from pyloric caeca, proliferation in these organs to compensate for cell loss, and finally, local proliferation in the regenerating arm J. Exp. Zool. (Mol. Dev. Evol.) 3148:457-468, 2010. (C) 2010 Wiley-Liss, Inc.
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| 4. |
- Ramachandra, Rashmi, et al.
(författare)
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Brittlestars contain highly sulfated chondroitin sulfates/dermatan sulfates that promote fibroblast growth factor 2-induced cell signaling
- 2014
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 24:2, s. 195-207
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Tidskriftsartikel (refereegranskat)abstract
- Glycosaminoglycans (GAGs) isolated from brittlestars, Echinodermata class Ophiuroidea, were characterized, as part of attempts to understand the evolutionary development of these polysaccharides. A population of chondroitin sulfate/dermatan sulfate (CS/DS) chains with a high overall degree of sulfation and hexuronate epimerization was the major GAG found, whereas heparan sulfate (HS) was below detection level. Enzymatic digestion with different chondroitin lyases revealed exceptionally high proportions of di- and trisulfated CS/DS disaccharides. The latter unit appears much more abundant in one of four individual species of brittlestars, Amphiura filiformis, than reported earlier in other marine invertebrates. The brittlestar CS/DS was further shown to bind to growth factors such as fibroblast growth factor 2 and to promote FGF-stimulated cell signaling in GAG-deficient cell lines in a manner similar to that of heparin. These findings point to a potential biological role for the highly sulfated invertebrate GAGs, similar to those ascribed to HS in vertebrates.
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