[Effects of persistent infections on hepatic fibrosis in mice].

OBJECTIVE

To investigate the effects of persistent infections on hepatic fibrosis in mice, so as to provide insights into the understanding of liver fibrogenesis induced by infections and the treatment of alveolar echinococcosis.

METHODS

Hepatic stellate HSC-T6 and LX-2 cells were exposed to the sera (25, 50 and 100 μL) from infected with , and , germinal layer cells (GCs) and protoscoleces (PSCs) for 48 hours, respectively. The cell proliferation was measured using a CCK-8 assay, and the levels of collagen 1 (Col1) and α-smooth muscle actin (α-SMA) were measured in the culture supernatant of HSC-T6 cells using ELISA. In addition, the serum and liver samples were collected 1, 2, 4, 6, 8 months post-infection with , respectively. The serum Col1 and α-SMA concentrations were measured using enzyme-linked immunosorbent assay (ELISA), and the deposition of collagen fibers was examined in mice livers using Sirius red staining.

RESULTS

The sera of -infected gerbils promoted the proliferation of HSC-T6 and LX-2 cells , and there were significant differences seen in the proliferative rate of HSC-T6 ( = 126.50, < 0.05) and LX-2 cells ( = 201.50, < 0.05) among different serum groups, with the highest proliferative rate of HSC-T6 (573.36% ± 206.34%) and LX-2 cells (940.38% ± 61.65%) found following exposure to 100 μL mouse sera. Exposure to serum from -infected gerbils resulted in an increase in the Col1 and α-SMA levels in the culture supernatant of HSC-T6 cells, with the greatest Col1 (20.99 ng/mL ± 2.01 ng/mL) and α-SMA levels (305.52 pg/mL ± 16.67 pg/mL) measured following exposure to 100 μL sera. The metacestodes (142.65% ± 9.17% and 189.99% ± 7.75%), GCs (118.55% ± 8.96% and 122.54% ± 0.21%) and PSCs of (156.34% ± 17.45% and 160.59% ± 31.41%) all promoted the proliferation of HSC-T6 and LX-2 cells , and there were significant differences in the proliferative rates of HSC-T6 ( = 11.24, < 0.05) and LX-2 cells among groups ( = 47.72, < 0.05). Exposure to resulted in an increase in Col1 and α-SMA levels in the culture supernatant of HSC-T6 cells, and the highest Col1 (4.43 ng/mL ± 2.23 ng/mL) and α-SMA levels (285.20 pg/mL ± 90.67 pg/mL) were detected following treatment with metacestodes. In addition, a persistent increase was seen in the deposition of collagen fibers in mice livers 1 to 8 months post-infection with , with the greatest Col1 level (280.26 ng/mL ± 23.04 ng/mL) seen 6 months post-infection and the highest α-SMA level (33.68 ng/mL ± 4.45 ng/mL) detected 8 months post-infection, respectively.

CONCLUSIONS

Persistent infections promote hepatic stellate cell proliferation, induce an increase in mouse serum Col1 and α-SMA levels, and cause elevated deposition of collagen fibers in mice livers. The infective stage of is a critical period for inducing hepatic fibrosis of alveolar echinococcosis.