ABSTRACT
Objective:To explore the mechanism of miR-494 negatively regulating ROCK1 and PTEN in inhibiting apoptosis of pancreatic cells and participating in the occurrence and development of acute pancreatitis.Methods:Pancreatic acinar cells AR42J from rats were treated by caerulein, and then the levels of amylase, tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1) and IL-6 in the supernatant of cell culture were detected by ELISA to verify the cell model of acute pancreatitis. RT-PCR was used to detect the expression of miR-494 in normal AR42J cells (control group) and acute pancreatitis cell model (model group). Flow cytometry was used to detect the apoptosis of the control group, negative control miRNA transfected acute pancreatitis cell model (negative control group) and miR-494 transfected acute pancreatitis cell model (miR-494 transfection group). Western blot was used to detect the expression of ROCK1 and PTEN in the control group, negative control group and miR-494 transfection group.Results:The levels of amylase, TNF-α, IL-1 and IL-6 in the supernatant of AR42J cells treated with caerulein for 8 h and 12 h were significantly higher than those at 0 h and the control group ( P<0.05), indicating that the model was successfully constructed. The expression levels of miR-494 at 8 h, 12 h and 24 h after the establishment of acute pancreatitis cell model were significantly higher than those at 4 h and the control group ( P < 0.05). The apoptosis rate of the model group was significantly higher than that of the control group ( P<0.05), and the apoptosis rate of the miR-494 transfection group was significantly lower than that of the model group ( P<0.05). The expression levels of ROCK1 and PTEN in the miR-494 transfection group were significantly lower than those in the model group and negative control group ( P<0.05). Conclusions:When acute pancreatitis occurs, overexpression of miR-494 can inhibit the expression of pro-apoptotic protein, thus inhibiting the apoptosis of pancreatic acinar cells and promoting the development of acute pancreatitis.
ABSTRACT
Objective:To explore the mechanism of pioglitazone in reducing lung injury induced by acute pancreatitis.Methods:Thirty healthy male SD rats were randomly(random number) divided into the sham operation group, model group and pioglitazone group, with 10 rats in each group. After anesthesia, the rats in the sham operation group were injected with normal saline retrogradely through the pancreaticobiliary duct. In the model group, after anesthesia, the rats were retrogradely injected with sodium taurocholate into the pancreaticobiliary duct to construct the lung injury model of severe acute pancreatitis. In the pioglitazone group, the model was established after intraperitoneal injection of pioglitazone. Six rats in each group were randomly selected and killed 12 h after operation, and then lung tissue and venous blood were collected. The levels of serum amylase and TNF-α and NO in lung tissue homogenate were detected and compared among the three groups; the expression of TLR2 mRNA and TLR4 mRNA in lung tissue was detected by RT-PCR and compared among the three groups; the lung tissue pathological injury score and lung leakage index were calculated and compared among the three groups. The correlation of TLR2 and TLR4’s mRNA expression with lung tissue pathological injury score and lung leakage index was analyzed.Results:The levels of serum amylase and the levels of TNF-α and NO in lung tissue homogenate in the model group were significantly higher than those in the sham operation group, and the above indexes in the pioglitazone group were significantly lower than those in the model group ( P<0.05). The expression levels of TLR2 mRNA and TLR4 mRNA in lung tissue, the lung tissue pathological injury score and lung leakage index in the model group were significantly higher than those in the sham operation group, and the above indexes in the pioglitazone group were significantly lower than those in the model group ( P<0.05). Spearman correlation analysis showed that the expression levels of TLR2 mRNA and TLR4 mRNA in lung tissue were significantly positively correlated with the lung tissue pathological injury score ( rs=0.959, P<0.001; rs=0.924, P<0.001). Pearson correlation analysis showed that the expression levels of TLR2 mRNA and TLR4 mRNA in lung tissue were significantly positively correlated with the lung leakage index ( r=0.957, P<0.001; r=0.958, P<0.001). Conclusions:Pioglitazone may reduce the severity of severe acute pancreatitis induced lung injury by inhibiting the expression of TLR2 mRNA and TLR4 mRNA in lung tissue.
ABSTRACT
Objective@#To explore the role of toll-like receptor 4 (TLR4)/NF-κB signaling pathway in acute necrotizing pancreatitis (ANP)-associated lung injury and the intervention of lipoxin A4 (LXA4) analogue.@*Methods@#Forty-five Sprague-Dawley rats were randomly(random number)divided into the sham operation group, experimental group, and intervention group, each group containing 15 rats. ANP animal models were prepared by injecting sodium taurocholate into biliopancreatic tube in the experimental group. No sodium taurocholate was injected into biliopancreatic duct in the sham operation group. After the preparation of ANP animal models in the intervention group, LXA4 was injected through the tail vein. Rats in each group were randomly divided into 3 subgroups (n=5 each subgroup). The serum amylase, TNF- α, IL-1β, IL-6 and endotoxin levels were detected 6, 12 and 24 h after the operation. The lung injury scores were assessed and the lung wet/dry weight ratio was calculated. The expressions of TLR4 and NF-κB p65 in lung tissues were detected by Western blot.@*Results@#Serum levels of amylase, TNF-α, IL-1β, IL-6 and endotoxin in the experimental and intervention groups were significantly higher than those in the sham operation group, while the levels of the above indicators in the intervention group was significantly lower than those in the experimental group, and the differences were statistically significant (P<0.05). Postoperative lung injury scores and lung wet/dry weight ratio in the experimental group were significantly higher than those in the sham operation group, and the differences were statistically significant (P<0.05). Lung injury scores in the intervention group 6 h after operation had no significant difference compared with those in the sham operation group (P>0.05), while lung wet/dry weight ratio in the intervention group 6 h after operation, and lung injury scores and lung wet/dry weight ratio in the intervention group 12 h or 24 h respectively after operation were significantly higher than those in the sham operation group, with statistically significant differences (P<0.05). Postoperative lung injury scores and lung wet/dry weight ratio in the intervention group were significantly lower than those in the experimental group, and the differences were statistically significant (P<0.05). The expressions of TLR4 and p65 in the lung tissues of the experimental and intervention groups were significantly higher than those of the sham operation group, and the expressions of TLR4 and p65 in the lung tissues of the intervention group were significantly lower than those of the experimental group, with statistically significant differences (P<0.05).@*Conclusions@#LXA4 can reduce the severity of acute necrotizing pancreatitis-associated lung injury, and its mechanism is related to reducing the stimulation of endotoxin, thus inhibiting TLR4 signaling pathway and the activation of p65 to down-regulate the level of pro-inflammatory cytokines.
ABSTRACT
Objective To explore the role of toll-like receptor 4 (TLR4)/NF-κB signaling pathway in acute necrotizing pancreatitis (ANP)-associated lung injury and the intervention of lipoxin A4 (LXA4) analogue.Methods Forty-five Sprague-Dawley rats were randomly(random number)divided into the sham operation group,experimental group,and intervention group,each group containing 15 rats.ANP animal models were prepared by injecting sodium taurocholate into biliopancreatic tube in the experimental group.No sodium taurocholate was injected into biliopancreatic duct in the sham operation group.After the preparation of ANP animal models in the intervention group,LXA4 was injected through the tail vein.Rats in each group were randomly divided into 3 subgroups (n=5 each subgroup).The serum amylase,TNF-α,IL-1β,IL-6 and endotoxin levels were detected 6,12 and 24 h after the operation.The lung injury scores were assessed and the lung wet/dry weight ratio was calculated.The expressions of TLR4 and NF-rκB p65 in lung tissues were detected by Western blot.Results Serum levels of amylase,TNF-α,IL-1β,IL-6 and endotoxin in the experimental and intervention groups were significantly higher than those in the sham operation group,while the levels of the above indicators in the intervention group was significantly lower than those in the experimental group,and the differences were statistically significant (P＜0.05).Postoperative lung injury scores and lung wet/dry weight ratio in the experimental group were significantly higher than those in the sham operation group,and the differences were statistically significant (P＜0.05).Lung injury scores in the intervention group 6 h after operation had no significant difference compared with those in the sham operation group (P ＞ 0.05),while lung wet/dry weight ratio in the intervention group 6 h after operation,and lung injury scores and lung wet/dry weight ratio in the intervention group 12 h or 24 h respectively after operation were significantly higher than those in the sham operation group,with statistically significant differences (P＜0.05).Postoperative lung injury scores and lung wet/dry weight ratio in the intervention group were significantly lower than those in the experimental group,and the differences were statistically significant (P＜0.05).The expressions of TLR4 and p65 in the lung tissues of the experimental and intervention groups were significantly higher than those of the sham operation group,and the expressions of TLR4 and p65 in the lung tissues of the intervention group were significantly lower than those of the experimental group,with statistically significant differences (P＜0.05).Conclusions LXA4 can reduce the severity of acute necrotizing pancreatitis-associated lung injury,and its mechanism is related to reducing the stimulation of endotoxin,thus inhibiting TLR4 signaling pathway and the activation of p65 to down-regulate the level of pro-inflammatory cytokines.