Effect of Organic Selenium during HS in Broiler Chicken: The Interplay of HSP-70 and PGC-1α

Abstract

Background: ROS ( Reactive Oxygen Species) accumulated during heat stress induced oxidative stress is involved in triggering the activation of transcription factor, heat shock factor-1 (HSF-1) which further results in the up regulation of HSP. A cooperation between PGC1α and HSF1 in the induction of HSPs in response to thermal stress was reported in mice. Thus, the present study was conducted to investigate the effect of HS (Heat Stress) on HSP-70 and PGC-1α expression in broilers. Method: The study was conducted in two phases, one during autumn and the other during summer with a total of 300 birds. During the first phase, 60 chicks were divided into six replicates with 10 birds in each and during the second phase, 240 chicks were divided into four groups with six replicates containing 10 birds in each. The experimental rations given to different groups were as control (Basal ration), HS I (Basal ration), HS II (Basal ration+0.3 ppm Se, HS III (Basal ration+0.6 ppm Se) and HS IV (Basal ration+0.9 ppm Se). Hepatic tissues were collected for analysis at 21 d and 42 d. Result: The MDA levels and expression of HSP-70 protein in hepatic tissues were increased due to HS both at 21 and 42 d, while the expression of PGC-1α protein increased at 42 d. Se supplementation at 0.3 ppm was effective in decreasing the concentration of MDA and HSP-70 protein at 21d, whereas 0.6 ppm and 0.9 ppm were effective at 42d. Se supplementation decreased the expression of PGC-1α protein at 42 d during HS.