Small heat shock proteins (sHSPs) can regulate protein folding and protect cells from stress. To investigate the role of sHSPs in the silk-producing insect Antheraea pernyi response to microorganisms, a sHsp gene termed as Ap-sHSP21.4, was identified. This gene encoded a 21.4 kDa protein which shares the conserved structure of insect sHsps and belongs to sHSP21.4 family. Ap-sHSP21.4 was highly expressed in fat body and up-regulated in midgut and fat body of A. pernyi challenged with Escherichia coli, Beauveria bassiana and nuclear polyhedrosis virus (NPV), which was determined by quantitative real-time PCR. Meanwhile, knock down of Ap-sHSP21.4 with dsRNA result in the decrease at the expression levels of several immune response-related genes (defensin, Dopa decarboxylase, Toll1, lysozyme and Kazal-type serine protease inhibitor). Additionally, the impact of eicosanoid biosynthesis on the expression of Ap-sHSP21.4 response to NPV was determined using qPCR, inhibitors of eicosanoid biosynthesis significantly suppress Ap-HSP21.4 expression upon NPV challenge. All together, Ap-sHSP21.4 was involved in the immunity of A. pernyi against microorganism and possibly mediated by eicosanoids pathway. These results will shed light in the understanding of the pathogen-host interaction in A. pernyi.
Activation of mast cells by different stimuli triggers the release of a huge range of mediators, including de-novo synthesized eicosanoids, which are highly biologically active lipid mediators.
Eicosanoid Biosynthesis - YouTube
AB - Intense lipid mobilization during the transition period in dairy cows is associated with increased disease susceptibility. The potential impact of altered plasma nonesterified fatty acids (NEFA) concentrations and composition on host inflammatory responses that may contribute to disease incidence and severity are not known. The objective of this study was to evaluate if increased NEFA concentrations could modify vascular inflammatory responses in vitro by changing the expression of important inflammatory mediators that are important in the pathogenesis of infectious diseases of transition cows such as mastitis and metritis. Bovine aortic endothelial cells (BAEC) were cultured with different concentrations of a NEFA mixture that reflected the plasma NEFA composition during different stages of lactation. The expression of cytokines, adhesion molecules, and eicosanoids were measured to assess changes in BAEC inflammatory phenotype. Addition of NEFA mixtures altered the fatty acid profile of BAEC by increasing the concentration of stearic acid (C18:0) and decreasing the content of arachidonic acid (C20:4n6c) and other long-chain polyunsaturated fatty acids in the phospholipid fraction. A significant increase also occurred in mRNA expression of cytokine and adhesion molecules that are associated with increased inflammatory responses during the transition period. Expression of cyclooxygenase 2, an important enzyme associated with eicosanoid biosynthesis, was increased in a NEFA concentration-dependent manner. The production of linoleic acid-derived eicosanoids 9- and 13-hydroxyoctadecadienoic acids also was increased significantly after treatment with NEFA mixtures. This research described for the first time specific changes in vascular inflammatory response during in vitro exposure to NEFA mixtures that mimic the composition and concentration found in cows during the transition period. These findings could explain, in part, alterations in inflammatory responses observed during intense lipid mobilization stages such as in the transition period of dairy cows. Future studies should analyze specific mechanisms by which high NEFA concentrations induce a vascular proinflammatory phenotype including the effect of 9 and 13-hydroxyoctadecadienoic acids and other lipid mediators.