Effects of NLRP3 inflammasome activation on the proliferation, migration and extracellular matrix deposition of pancreatic stellate cells / 中华胰腺病杂志

ABSTRACT

Objective:To investigate the effects of NOD-like receptor protein 3(NLRP3) inflammasome activation on the proliferation, migration and extracellular matrix desposition of activated pancreatic stellate cells(PSCs).Methods:The rat PSCs were isolated, cultured and identified, and were divided into control group or LPS group based on the pretreatment with LPS (10 μg/ml for 24 hours) or without. The expression of NLRP3 inflammasome associated molecules in PSCs culture medium was detected by ELISA. The PSCs with NLRP3 inhibition were constructed by shRNA carrying lentivirus infection and were divided into LPS+ negative control group and LPS+ lentivirus group based on whether the cells were treated with LPS and infected by lentivirus or not. The alteration in cell proliferation and migration were detected by CCK-8 kit and transwell chamber method. The expression of extracellular matrix α-SMA and collagen in PSCs was detected by immunofluorescence staining and the expression of TGF-β mRNA was analyzed by RT-qPCR.Results:The cytoplasm of PSCs which were cultured for 24 hours was rich in bright annular lipid droplets, and the cells expressed desmin. After 7 days of culture, the cell became larger in size, the lipid droplets basically disappeared, and the cells were activated and expressed α-SMA. The expression of caspase-1, IL-1β and IL-18 in the supernatant of PSCs culture medium in LPS group were significantly higher than those in control group (1.55±0.04 vs 0.65±0.03), (2.02±0.04 vs 1.05±0.05) and (1.70±0.05 vs 0.97±0.03), respectively. After inhibiting by lentivirus infection, the expression of NLRP3 in the lentivirus group (0.25±0.04) was significantly lower than that in negative control group (0.68±0.05). In control group, LPS group, LPS+ negative control group and LPS+ lentivirus group, the A490 values was 0.61±0.02, 1.15±0.06, 0.96±0.05, and 0.56±0.01, respectively; the migrating PSCs number was (64.12±4.58), (121.67±8.02), (111.67±4.67) and (69.67±8.08)/HF, respectively; the relative expression of α-SMA was 0.78±0.05, 4.12±0.04, 3.81±0.06 and 0.88±0.05, respectively; the relative expression of collagen was 0.65±0.03, 3.43±0.02, 2.67±0.02 and 0.48±0.03, respectively; and the expression of TGF-β mRNA was 0.22±0.03, 0.89±0.01, 0.86±0.03 and 0.43±0.02, respectively. The A490 value, the migrating cells number, the expression of α-SMA, collagen and the expression of TGF-β mRNA in LPS group and LPS+ negative control group was significantly higher than those in control group and LPS+ lentivirus group, and all the differences were statistically significant (all P value <0.05). Conclusions:NLRP3 inflammasome activation may accelerate the extracellular matrix deposition and pancreatic fibrogenesis by promoting PSCs proliferation and migration ability via regulating the biological functions.