Effects Of Macrophage Migration Inhibitory Factor(MIF) With Inflammatory Diseases Of Fish

The culture scale of L.crocea and E.awoara are enlarging,a variety of infectious diseases have become increasingly frequent,such as V.alginolyticus disease,V.parahaemolyticus disease and cryptocaryonosis,causing serious economic losses.As a main proinflammatory media,macrophage migration inhibitory factor(MIF)plays an important role in inflammatory diseases of fishes.Tissues distribution of MIF in pathologically identified and healthy L.crocea and E.awoara were detected.The results are as follow:First,tissues distribution of MIF in V.alginolyticus disease and cryptocaryonosis of L.crocea were detected by immunohistochemistry.All negative controls showed no reactivity,MIF staining was intense in disease of L.crocea tissues.The spleen,intense and head kidney specimens showed high reactivity in an upward trend.The MIF staining rate of the spleen,intense and head kidney were 56 %,64 % and 92 % in V.alginolyticus disease of L.crocea tissues.The MIF staining rate of the liver,spleen,intense and head kidney were 25 %,54 %,86 % and90 % in cryptocaryonosis of L.crocea tissues.MIF expression rate difference was statistically significant(P<0.05).It showed that MIF plays an important role in the pathogenesis of L.crocea.Second,MIF and TNF-a,IL-1 expression correlation were detected by ELISA in V.alginolyticus disease,cryptocaryonosis and V.parahaemolyticus disease of L.crocea and E.awoara tissues.The results showed that,compared with the healthy control group,the concentrations of MIF,TNF-α,IL-1 of diseased fish tissues were increased to varying degrees.The difference was statistically significant(P<0.05).Third,MIF expression was detected by realtime PCR in V.alginolyticus and V.parahaemolyticus disease of E.awoara tissues.The results showed that the MIF expression in disease of L.crocea tissues was significantly higher than the healthy control group.Expression in the head kidney,liver,spleen,brain expression levels was significantly higher than in other tissues.Through multiple sequence alignment sequence analysis of cDNA of MIF in E.awoara,the consistency of the protein of MIF was up more than 92 % with O.fasciatus,T.albacares,D.labrax,S.ocellatus and E.coioides.Experiments showed the functional conservatism of MIF.