The Effect of Plasminogen Activator Inhibitor-1 on the Activity of HSC and Extracellular Matrix
|Course||Digestion within the science|
|Keywords||hepatic stellate cell plasminogen activator inhibitor-l transforming growth factorβl extracellular matrix hepatic fibrosis|
Objective Liver fibrosis has become the disease hazard severely the health of people,which the activity of hepatic stellate cell(HSC)is the center element and the development of extracellular matrix (ECM)is criticality.As is known, transforming growth factorβ1(TGFβ1) is the strongest cytokine to promote liver fibrosis.It not only can promote HSC’activation and proliferation,but also promote the development of ECM,which result in the development of liver fibrosis.Recently it has been found, HSC express the cytokines of plasminogen activator inhibitor-1(PAI-1)which can anticipate in the development of liver fibrosis,While TGFβ1 could induce the expression of PAI-1.But it has not been known that whether PAI-1 can influence the expression of TGFβ1 and development of ECM.So by means of culturing the HSC in vitro, we investigate the effect of PAI-1 on TGFβ1 and ECM.Methods The proliferation effect of PAI-1 on LX-2 was detected by Methyl thiazolyl tetrazolium(MTT).After incubation with PAI-1 12h,24h,48h,hyaluronic acid(HA), TGFβ1, tissue inhibitor of metalloproteinase -1(TIMP-1) in LX-2 supernatant was observed with ELISA,the protein expression level of smooth muscleɑ-actin(ɑ-SMA),matrix metalloproteinase-2(MMP-2), tissue inhibitor of metalloproteinase -1(TIMP-1), urokinase-type plasminogen activator(uPA)and PAI-1 were detected by immunocytochemistry and the level of PAI-1,TGFβ1 mRNA by reverse transcription polymerase chain reaction (RT-PCR).Results (1)PAI-1 can induce activation and proliferation of LX-2 effectively,and the best concentration is 10ng/ml.(2)The protein expression ofɑ-SMA is in the cytoplasm of LX-2. The expression in the PAI-1 treatment 12h group i(s0.408±0.031),negative control group i(s0.301±0.015). Compared to negative control group, the expression ofɑ-SMA increased significantly(t=5.438, p<0.01).(3) The protein expression of MMP-2、TIMP-1、PAI-1、uPA is in the cytoplasm of LX-2. The expression of MMP-2 in the PAI-1 treatment 12h group is (0.245±0.028), negative control group is (0.233±0.041)Compared to negative control group, the expression of MMP-2 increased slightly(t=0.473, P>0.05); the expression of uPA in 12h group is (0.303±0.052), negative control group is (0.288±0.036).Compared to negative control group, the expression of PLAU increased slightly(t=0.581, P>0.05); the expression of PAI-1 in 12h group is (0.331±0.045), negative control group is (0.205±0.007).Compared to negative control group, the expression of PAI-1 increased significantly(t=4.857,P<0.01); the expression of TIMP-1 in 12h group is (0.412±0.031), negative control group is (0.235±0.011).Compared to negative control group, the expression of TIMP-1 increased significantly(t=9.511,P<0.01).(4)With PAI-1 treated 12h,mRNA expression of TGFβ1 and PAI-1 seperately are (1.839±0.405),(2.325±0.970),compared to negative control groups (1.090±0.123),(0.790±0.156),the difference is significant(t=4.683、4.135,P<0.01). And there is positive relationship between PAI-1 and TGFβ1mRNA(r=0.827,P<0.05).(5)After culured with PAI-1 12h、24h、48h , the expression of TGFβ1 in the cell supernatant seperately are (8.854±3.168)、(44.348±8.415)、(225.819±12.797)pg/ml, compared to negative control groups (0.855±0.744)pg/ml , the difference is significant (F=1566.752,P<0.01); the expression of HA seperately are (2.577±0.801)、(18.177±7.141)、(50.473±4.903)ng/ml, compared to negative control groups(0.450±0.154),the difference is significant(F=235.632,P<0.01); and the TIMP-1 seperately are (2.872±1.396),(20.409±11.821),(96.548±27.154)ng/ml, compared to negative control groups(0.573±0.179)ng/ml, the difference has statistic meaning.(F=67.359,P<0.05).Conclusion This study suggests that PAI-1 can promote HSC activation and ECM development via some cytokines and enzymes, with emphasis on activation of latent TGFβ1 during the progress of liver fibrosis. Inhibiting the upregulation of PAI-1 during liver fibrosis may be an antifibrotic pathway worth exploiting.