The Mechanism Of The Autophagy Regulated By IRF9 In Acute Pancreatitis And Its Influence On The Severity Of The Disease

Objective Acute pancreatitis(AP)is a clinically life-threatening acute abdomen,caused by acute inflammation of the pancreas.The disease progression of severe AP is rapid,leading to multiple organ failure,and the prognosis is badly.It has been reported that the mortality rate of severe acute pancreatitis(SAP)is higher than 30%,seriously threating human health and life.However,the current understanding of the pathogenesis of AP is still insufficient,there is no special prevention and treatment for AP in clinic.Therefore,It is particularly important to understand the pathogenesis of AP.Interferon regulatory factor(IRF)plays an important role in transcriptional regulation,cytokine signal transduction,cell differentiation,apoptosis,proliferation regulation and autophagy,and it also participates in the pathogenesis of various diseases.Our purpose is to study the expression of regulatory factor 9(IRF9)and autophagy marker proteins Beclin-1 and LC3 in serum of AP patients with different severity,and whether IRF9 can participate in the development of AP by regulating autophagy.Methods 60 patients,who were diagnosed as AP,were collected in our study in our hospital and 30 healthy subjects were collected as control group from the physical examination center at the same time,The patients included 30 cases of moderate acute pancreatitis(MSAP)and 30 cases of severe acute pancreatitis(SAP).The diagnostic criteria were in accordance with the revised 2012 Atlanta guidelines.Western blot was used to detect the expression of IRF9,Beclin-1 and LC3 in the three groups of blood samples,and the clinical data such as PCT,IL-6,APACHE-II score and SOFA scorewere collected to compare the differences between the groups.We used si-RNA transfection technique to build IRF9 silence AR42 J cell line in vitro experiments.RT-PCR and Western blot were used to identify the degree of the gene silencing,The caerulein was added to construct the cell model of acute pancreatitis.Western blot was also used to detect the expression of autophagy marker proteins LC3 and Beclin-1 in each group and the differences between the groups were compared.ELISA method was used to examine the expressions of inflammation markers including TNF-? and IL-1? in the supernatant of each group and the differences between the groups were compared.Results Western blot was conducted to detect the protein expression of blood samples of AP patients with different severity,and the results showed that the expressions of IRF9,autophagy marker protein LC3 and beclin-1 were the highest in the serum of SAP group,followed by the MSAP group,and the lowest in the healthy group(all P<0.05).The results of correlation analysis indicated that the correlation between IRF9 expression and APACHE? score,PCT,IL-6 was positively correlated,(r value were0.586,0.359,0.533,P < 0.05).There was no significant correlation between IRF9 expression and amylase(r = 0.242,P > 0.242).In vitro experiments,Western blot results showed that the expressions of autophagy marker proteins LC3 and beclin-1were significantly decreased in the IRF9 silenced AP cell model(all P<0.05).ELISA results showed that the expression of inflammatory factors TNF-? and IL-1 ?decreased after IRF9 silencing.Conclusion The autophagy regulated by IRF9 participates in the process of acute pancreatitis and influence on the severity of the disease.