RESUMO
Objective:To evaluate the effect of tubastatin A (TubA) on pyroptosis during brain injury after cardiac arrest and resuscitation in swine.Methods:Twenty-two conventional male white swine, weighing 34-39 kg, aged 4-6 months, were divided into 3 groups using a random number table: sham operation group (group S, n=6), cardiac arrest-cardiopulmonary resuscitation (CA-CPR) group ( n=8) and CA-CPR+ TubA group ( n=8). The swine model of CA-CPR was established by 9 min of cardiac arrest and 6 min of cardiopulmonary resuscitation in CA-CPR group and CA-CPR+ TubA group. TubA 4.5 mg/kg (in 50 ml of normal saline) was infused over 1 h via the femoral vein starting from 5 min after resuscitation in CA-CPR+ TubA group. Before developing the model and at 1, 2, 4 and 24 h after resuscitation (T 0-4), blood samples were collected from the femoral vein for determination of the concentrations of neuron specific enolase (NSE) and S100β protein in serum (by enzyme-linked immunosorbent assay). Neurological deficit score (NDS) was evaluated at T 4. The animals were then sacrificed, and their brain cortex tissues were harvested to measure the expression of histone deacetylase 6 (HDAC6), caspase-3, cleaved caspase-3, gasdermin E (GSDME) and GSDME N-terminal (N-GSDME) (by Western blot) and contents of high mobility group box 1 (HMGB1), interleukin-1β (IL-1β) and IL-18 (by enzyme-linked immunosorbent assay). Results:Compared with group S, the serum concentrations of NSE and S100β were significantly increased at T 1-4, NDS was increased at T 4, the expression of HDAC6, caspase-3, cleaved caspase-3, GSDME and N-GSDME in brain cortex was up-regulated, and the contents of HMGB1, IL-1β and IL-18 were increased in CA-CPR and CA-CPR+ TubA groups ( P<0.05). Compared with group CA-CPR, the serum concentrations of NSE and S100β were significantly decreased at T 3, 4, NDS was decreased at T 4, the expression of HDAC6, caspase-3, cleaved caspase-3, GSDME and N-GSDME in brain cortex was down-regulated, and the contents of HMGB1, IL-1β and IL-18 were decreased in group CA-CPR+ TubA ( P<0.05). Conclusions:The mechanism by which TubA alleviates brain injury after cardiac arrest and resuscitation may be related to inhibition of pyroptosis in swine.