The role of endoplasmic reticulum stress-mediated apoptosis of splenic lymphocytes in the postresuscitation immunosuppression in a porcine model

Wang Yanyang; Gu Wei

doi:10.3969/j.issn.1002-1949.2024.11.007

Abstract：Objective To explore whether endoplasmic reticulum stress-mediated apoptosis of splenic T lymphocytes is involved in postresuscitation immunosuppression in a porcine model.Methods A porcine model of cardiac arrest(CA)with ventricular fibrillation for 8 min was established.26 pigs were randomly divided into sham surgery(Sham)group(n=6),return of spontaneous circulation(ROSC)12 h group(n=10)and ROSC 24 h group(n=10).After ROSC,the number and proportion of T lymphocyte subsets in peripheral blood was detected by flow cytometry;Western blot and real-time reverse transcription-polymerase chain reaction(RT-PCR)methods were used to detect the protein quantification and messenger RNA(mRNA)levels of glucose-regulated protein 78(GRP78)and C/EBP homologous protein(CHOP)in splenic T lymphocytes,respectively.Terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL)method was used to observe the apoptosis of splenic T lymphocytes.Results A total of 8 of 20 animals were successfully defibrillated with the first shock.The number of shocks,total defibrillation energy and ROSC time were(2.9±1.6),(472.9±169.1)J and(6.3±2.4)min,respectively.In ROSC 12 h group and ROSC 24 h group,the CD4+T lymphocytes in the peripheral blood of piglets were significantly lower than those in the Sham group[(28.4±2.3)％and(24.1±1.6)％vs.(48.4±2.9)％,P＜0.05].Splenic T lymphocytes showed significant apoptosis,the apoptosis index in ROSC 12 h group and ROSC 24 h group was significantly higher than that in the Sham group[(0.102±0.031)％and(0.125±0.058)％vs.(0.035±0.014)％,P＜0.01].The protein quantification of GRP78(0.167±0.049 and 0.263±0.049 vs.0.091±0.025)and CHOP(0.146±0.027 and 0.150±0.048 vs.0.075±0.015),and mRNA levels of GRP78(4.767±1.890 and 7.706±2.919 vs.1)and CHOP(3.110±0.767 and 3.923±0.915 vs.1)in splenic T lymphocytes showed significant increases in ROSC 12 h group and ROSC 24 h group compared with the Sham group,respectively(P＜0.01).Conclusions The endoplasmic reticulum stress-mediated apoptotic pathway is involved in the apoptosis of splenic T lymphocytes after resuscitation,which may be one of the main mechanisms leading to postresuscitation immunosuppression.