Small Heat Shock Proteins and Eicosanoid Pathways Modulate Caspase-1 Activity in the Fat Bodies of Antheraea pernyi

Abstract

After heat shock injury, a group of proteins that regulate protein-folding processes are synthesised to prevent damage. Caspase is an enzyme responsible for the execution ostress-induced apoptosis. Heat shock proteins (Hsp) are capable of modulating caspase activity. In addition to changes in protein synthesis, heat shock causes the release of arachidonic acid (AA) from plasma membranes and the subsequent synthesis of eicosanoids, i.e., activation of the AA pathways. The development of cytoprotective strategies might depend on whether caspase-1 activity is affected by heat shock preconditioning and the associated pharmacological modulations after heat shock injury. Therefore, we studied the effects of heat shock preconditioning and modulations of the eicosanoid pathways on Ap-sHSP20.8 and on the final apoptotic effector enzyme caspase-1 to clarify whether these effects were modulated in the fat bodies of Antheraea pernyi injured by heat shock. We concluded that eicosanoid biosynthesis inhibitors might be utilised to simultaneously decrease Hsp 20.8 synthesis and to increase caspase-1 activity. Modifications of the eicosanoid pathways might also be used to mediate caspase-1 activity under hyperthermic conditions, suggesting a novel mechanism for regulation of caspase-1 in the fat bodies of A. pernyi