[Effect of high fat on fibrosis in rat hepatic stellate cells].
OBJECTIVE
To investigate the effect of high fat on the expression of high-mobility group box 1 (HMGB1),α-smooth muscle actin (α-SMA), and matrix metalloproteinase-2 (MMP-2) in rat hepatic stellate cells (HSC-T6 cells).


METHODS
HSC-T6 cells were cultured in vitro and treated with palmitic acid (PA) at a concentration of 300μmol/L for 24 hours, and the HSC-T6 cells in the control group were treated with bovine serum albumin (BSA) of the same volume for 24 hours; Western blot was used to measure the expression ofα-SMA and MMP-2. The HSC-T6 cells in the dose-effect group were treated with PA at concentrations of 0, 100, 200, 300, 500, and 1000μmol/L for 24 hours; the HSC-T6 cells in the time-effect group were treated with PA for 0, 4, 8, 12, 24, and 48 hours; in the control group, PA was replaced by BSA of the same volume; Western blot was used to measure the expression of HMGB1,α-SMA, and MMP-2. The HSC-T6 cells were treated with recombinant HMGB1 (rHMGB1) at concentrations of 0, 50, 100, 200, and 500 ng/ml for 48 hours, and in the control group, PA was replaced by phosphate buffer of the same volume. Western blot was used to measure the expression ofα-SMA and MMP-2. The HSC-T6 cells in the PA group were treated with PA at a concentration of 300μmol/L for 24 hours; the HSC-T6 cells in the PA+HMGB1-siRNA group were treated with PA at a concentration of 300μmol/L for 24 hours after HMGB1 in HSC-T6 cells was down-regulated; in the blank control group, PA was replaced by BSA of the same volume. Western blot was used to measure the expression of HMGB1,α-SMA, and MMP-2. One-way analysis of variance was applied for continuous data, and the t-test was applied for comparison between two groups.


RESULTS
(1) The expression ofα-SMA and MMP-2 increased significantly after HSC-T6 cells were treated with PA at a concentration of 300μmol/L for 24 hours (P< 0.05). (2) Compared with the HSC-T6 cells in the untreated group (0μmol/L), the HSC-T6 cells treated with different concentrations of PA showed significant increases in the expression of HMGB1 and MMP-2 (P< 0.01), as well as a significant increase in the expression ofα-SMA at concentrations of 200, 300, 500, and 1000μmol/L (P< 0.01); the HSC-T6 cells treated with PA at a concentration of 300μmol/L for different periods of time showed varying degrees of increase in the expression of HMGB1,α-SMA, and MMP-2, with significant increases at 16, 24, and 48 hours (P< 0.01). (3) Compared with the HSC-T6 cells in the untreated group (0 ng/ml), the HSC-T6 cells treated with rHMGB1 at concentrations of 100, 200, and 500 ng/ml for 48 hours showed significant increases in the expression ofα-SMA and MMP-2 (P< 0.05). (4) Compared with the HSC-T6 cells in the PA group, the HSC-T6 cells treated with PA+HMGB1-siRNA for 24 hours showed significant reductions in the expression of HMGB1,α-SMA, and MMP-2 (P< 0.05).


CONCLUSIONS
High fat can increase the expression ofα-SMA and MMP-2 through up-regulating the expression of HMGB1 in HSC-T6, and thus lead to the development of liver fibrosis.
Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
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Yuan
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Li
D000199:Actins / Q000378:metabolism*; D000818:Animals; D005355:Fibrosis; D024243:HMGB1 Protein / Q000235:genetics / Q000378:metabolism*; D055166:Hepatic Stellate Cells / Q000502:physiology*; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000473:pathology; D020778:Matrix Metalloproteinase 2; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D051381:Rats
C541116:ACTA2 protein, human; D000199:Actins; D024243:HMGB1 Protein; D034741:RNA, Small Interfering; D020778:Matrix Metalloproteinase 2