Expressions of endoplasmic reticulum stress associated proteins in livers of severely burned rats

Abstract

To explore the expression of endoplasmic reticulum stress (ERS) associated proteins in livers of severely burned rats and examine its potential significance. Sixty-four Wistar rats were randomly divided into the control and burn groups (30% total body surface area full-thickness thermal injury) (n = 32 each). Livers were harvested at Day 1, 4, 7, 14 post-burn. Western blot was used to detect the expressions of endoplasmic reticulum stress associated proteins glucose regulated protein 78 (GRP78), C/EBP-homologous protein (CHOP), active caspase-12 and active caspase-3. Hepatic apoptosis was assessed by the assay of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). Compared with the control group, the expression of GRP78 became elevated at Day 1, 4, 7, 14 post-burn (1.29 ± 0.11 vs 1.00 ± 0.00, 1.28 ± 0.12 vs 0.95 ± 0.16, 1.29 ± 0.14 vs 0.93 ± 0.06, 1.41 ± 0.17 vs 1.02 ± 0.13 respectively); the expression of CHOP was higher at Day 1, 4 (1.72 ± 0.07 vs 1.00 ± 0.00, 1.82 ± 0.18 vs 1.46 ± 0.08 respectively) while active caspase-12 and active caspase-3 increased at Day 1, 4, 7 post-burn (2.05 ± 0.65 vs 1.00 ± 0.00, 2.16 ± 0.69 vs 0.95 ± 0.21, 1.98 ± 0.56 vs 0.90 ± 0.22; 1.96 ± 0.15 vs 1.00 ± 0.00, 1.40 ± 0.14 vs 1.07 ± 0.12, 1.77 ± 0.17 vs 1.15 ± 0.21 respectively); the apoptotic index(%) of hepatocytes was higher at Day 1, 4, 7, 14 post-burn (27.20 ± 3.63 vs 5.00 ± 0.71, 16.40 ± 1.52 vs 5.40 ± 1.14, 27.60 ± 1.82 vs 7.40 ± 1.14, 10.20 ± 1.92 vs 5.20 ± 1.64 respectively). All results were statistically significant (all P < 0.05). ERS activates and expressions of associated proteins GRP78, CHOP, active caspase-12 and active caspase-3 increase in livers of severely burned rats.