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

Objective: To explore the expression of endoplasmic reticulum stress (ERS) associated proteins in livers of severely burned rats and examine its potential significance.

Methods: 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).

Results: 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).

Conclusion: ERS activates and expressions of associated proteins GRP78, CHOP, active caspase-12 and active caspase-3 increase in livers of severely burned rats.