Effects of manganese and hypoxia on coelomocyte renewal in the echinoderm, Asterias rubens (L.)

Crustacean hematopoiesis

“…The expression of PlRunt mRNA was also rapidly induced in HPT cells in response to the injection of microbial polysaccharides prior to the release of new hemocytes into circulation, and therefore might be a marker for differentiation within the HPT (Söderhäll et al, 2003a). Similarly, a RUNX factor was demonstrated as important in coelomocyte synthesis in Asterias rubens (Oweson et al, 2010).…”

Immunological function in marine invertebrates: Responses to environmental perturbation

“…Manganese contamination had previously been shown to reduce the number of circulating haemocytes in the Norway lobster Nephrops norvegicus [70,71] and the blue mussel M. edulis [72], yet increase coelomocyte numbers in A. rubens [73]. Whilst Oweson et al [69] also showed manganese to increase number of coelomocytes, proliferation of haematopoietic cells and the number of dividing cells in the coelomic epithelium, believed to be the main tissue for renewal of coelomocytes in sea stars [74], this study failed to show any effect of hypoxia on coelomocyte numbers or cell proliferation. This reflects results from previous studies on A. rubens that found the numbers of circulating coelomocytes to be unchanged by other physical stressors including temperature and salinity [75].…”

“…To further elucidate the way in which environmental stressors affect haemocytes, Oweson et al [69] investigated the effect of manganese and hypoxia on the proliferation of haematopoietic cells and the number of circulating immune cells (coelomocytes in echinoderms) in the common starfish Asterias rubens, together with measuring the composition of coelomocyte sub-populations. Manganese contamination had previously been shown to reduce the number of circulating haemocytes in the Norway lobster Nephrops norvegicus [70,71] and the blue mussel M. edulis [72], yet increase coelomocyte numbers in A. rubens [73].…”

Manganese: A New Emerging Contaminant in the Environment

“…In summary, the authors concluded that the exposure of Asterias rubens to manganese impaired their immune response, but induced renewal of coelomocytes, assuring survival. Co-occurrence of manganese with hypoxic conditions does not inhibit the elevated production of coelomocytes, but probably affects the composition of the subpopulations of these immune cells since hypoxia, but not manganese, increased the mRNA expression of Runt, a transcription factor, assumed necessary for cell differentiation (Oweson et al, 2010).…”