Effect Of Hepatic Stellate Cell Derived IL11 On Hepatocyte Injury In Hepatic Fibrosis

Hepatic fibrosis(HF)is a common pathological result caused by various chronic irritations.It is the performance of liver repair of hepatic fibrosis.HF is not only one of the most important pathological processes in chronic liver disease,but also an important factor in the further deterioration of chronic hepatitis and cirrhosis.The early symptoms of hepatic fibrosis are not clinically obvious.It is found that Hepatic Stellate Cells(HSCs)are very important effector cells in hepatic fibrosis.After being activated,they activate and differentiate into myofibroblast-like cells,resulting in the disorder of liver structure and the formation of hepatic fibrosis.In addition,activated HSCs secrete a large number of cytokines and extracellular matrix(ECM).It has been reported that various cytokines including IL-11 can be secreted during the activation of hepatic stellate cells.Our research group’s previous protein mass spectrometry analysis of LX-2-derived conditioned medium also found high expression of IL-11.interleukin-11(IL-11)is a versatile cytokine that binds to its specific receptor,IL-11 RA,and regulates important cellular processes through a common gp130 receptor.IL-11 plays a wide role in cell activation,proliferation,apoptosis and other physiological processes.Studies have shown that IL-11 can inhibit the apoptosis and necrosis of glandular epithelial cells,inhibit the apoptosis of myocardial cells,and inhibit the apoptosis of neuronal cells in cerebral ischemia.It has also been found that IL-11 promotes hepatocyte apoptosis in drug-induced liver injury models.Promotes hepatocyte death,steatosis,and inflammation in the nonalcoholic NASH model.However,IL-11 inhibits hepatocyte necrosis and apoptosis during hepatic ischemia reperfusion.Hepatocyte apoptosis is one of the main factors of liver injury in hepatic fibrosis.Inhibiting hepatocyte apoptosis can reduce liver inflammation and liver fibrosis levels.Therefore,in the process of liver fibrosis,HSCs activate and prolifze and secrete a large amount of IL-11,and the effect on liver cells remains unclear.Based on the above research background,this study studied the level and role of IL-11 in HF progression through cell and animal experiments,and revealed the mechanism between HF and IL-11.To explore potential clinical indicators and treatment for HF patients.In the early stage,we collected human blood and detected by ELISA that the content of IL-11 increased with the severity of liver injury,and immunohistochemistry of human liver fibrosis tissues was found to be strongly positive for IL-11.We constructed a CCl4(Carbon tetrachloride)induced HF mouse model,and demonstrated the successful establishment of the model through the changes of alanine aminotransferase(ALT),aspartate aminotransferase(AST)and pathological markers such as HE,MASSON,and Sirius scarlet staining.The differential expression of IL-11 was detected by ELISA,IHC,PCR,western blotting,and TUNEL staining,and the apoptosis rate of hepatocytes was increased.After silencing IL-11 with recombinant adeno-associated virus r AAV8,the degree of liver fibrosis and apoptosis of liver cells were significantly reduced in mice.At the same time,we found that alpha-smooth muscle actin(α-SMA)co-localized with IL-11 in liver tissue of HF mice by immunofluorescence double staining,suggesting that IL-11 is likely produced by HSCs in liver fibrosis.In vitro experiments,transforming growth factor TGF-β1 was used to stimulate liver stellate cells LX-2 to simulate the activation process of HSCs in vivo,and elevated IL-11 expression was detected by ELISA,western blotting,IF,and other experiments.In order to further explore the effect of IL-11 on hepatocyte damage in hepatic fibrosis,we first used MTT kit to screen the appropriate concentration of exogenous IL-11,and then used IL-11 to stimulate human normal hepatocyte LO-2.By western blotting,we found that the expressions of two receptors of IL-11,IL-11 RA and gp130,as well as apoptotic indicators,were increased.Then,we incubated liver cells with activated LX-2-derived Condition Medium(CM).Flow cytometry showed that the apoptosis rate of the three groups decreased when IL-11 was knocked down in LX-2-derived conditioned medium by RNA interference technique,IL-11 RA was knocked down in LO-2 cells,and IL-11 neutralizing antibody was added to LX-2-derived conditioned medium.This result was further verified by western blotting experiments.In terms of the mechanism of action,exogenous IL-11 was used to stimulate LO-2 cells.western blotting experiments showed that the expression levels of p-JNK,p-ERK and p-P53 proteins were all up-regulated,which proved that IL-11 could promote the apoptosis of LO-2through JNK and ERK signaling pathways.In conclusion,activated hepatic stellate cells can promote the apoptosis of hepatocytes by secreting IL-11,thus promoting the rapid development of hepatic fibrosis.Therefore,hepatic stellate cell derived IL-11 is a promising new target for fibrosis treatment.