Impacts On Hepcidin Expression From Oryzias Melastigma Under Different Environment Stresses:Hypoxia,Environmental Estrogen And Acidification

Marine organisms are affected by hypoxia, acidification and environment pollutants in the complicated ocean ecosystem, especially in the coastal area. Some researches demonstrate that hypoxia, acidification and environmental estrogen EE2can affect the growth, development, reproduction and gene expression of marine organisms. Hepcidin is a class of cysteine-rich antimicrobial peptides similar to defensins, which is involved in the iron metabolism in addition to antimicrobial function, anemia, hypoxia, proinflammatory and cytokines can regulate the expression of hepcidin. Two hepcidin (OM-hep1, OM-hep2) subunits are identified in Oryzias melastigma and hepcidin2of Acanthopagrus schlegelii (AS-hep2) is discovered in our previous study. This paper studies the impact on hepcidin2and related genes of Acanthopagrus schlegelii by hypoxia, and explores the effect of hypoxia, acidification and the combined effect of hypoxia and EE2on hepcidin and related regulation genes of Oryzias melastigma. The main results are followed:1. The results studied by Real-time PCR showed that OM-hep1and OM-hep2are differently regulated by hypoxia challenge, indicating they may regulate different biological functions. The genes of OM-HIF-la, OM-VEGF (vascular endothelial growth factor) and OM-EPO (Erythropoietin) are involved in the HIF (Hypoxia inducible factor) pathway, hypoxia doesn’t effect the expression of OM-HIF-la and OM-VEGF, but OM-EPO was induced significantly by hypoxia, the relationship was negative (declining O2up expression OM-EPO). EPO can be one of the biomarker of hypoxia. The impact on the expression of OM-IL-6and OM-STAT3are temporary, the impact may be the stress response to hypoxia. OM-p65is one of the NF-κB genes, it’s expression pattern is similar to OM-hep2, unrelated to OM-hep1, indicate that NF-κB is involved in the regulate of hepcidin.2. Hypoxia uneffects the expression of AS-HIF-la but upregulate AS-hep2, even significantly induce the expression of AS-hep2after hypoxia stimulate96hours. This result predicts that AS-hep2plays a role of immune factor under hypoxia. 3. The coaction of hypoxia and EE2uneffect the expression of OM-hepl and OM-hep2in the liver of Oryzias melastigma. OM-HIF-la and OM-VEGF are induced by coaction of hypoxia and EE2after96hours stimulate, and OM-EPO is more sensitive to the combined effect of hypoxia and EE2, which is is significantly upregulated in all time points. The function of coaction is more effective than single stimulate of hypoxia or EE2.4. The expression of OM-hep1and OM-hep2are upregulated along with the embryogenesis, and downregulated to a low stage on20days after hatching, this result shows that hepcidin plays immune function during embryogenesis and larval development. The expression of OM-hepl and OM-hep2uneffected by the stimulation of acidification, the development of various organs contribute to the acid-base balance of Oryzias melastigma. The expression of OM-CYP1A is very low throughout embryogenesis and increased during juvenile development. Acidification uneffects the expression of OM-CYP1A except30and75days after hatched. In summary, Oryzias melastigma can adapted to the acidification environment seted in this study.