[Impact of unfractionated heparin on serum and liver tissue expression of heparanase in the liver injury of mice with sepsis].

OBJECTIVE: To investigate the effect of unfractionated heparin on the expression of serum and liver tissue heparanase (HPA) in mice with liver injury induced by sepsis.

METHODS: Forty-eight healthy male C57BL/6 mice aged 6-8 weeks were divided into groups according to random number table method. Twenty-four septic mice models (CLP group) were established by cecal ligation and puncture (CLP); the other 24 mice underwent sham operation (sham group), only laparotomy and abdominal closure were performed without ligation. Twelve mice in sham group and CLP group received heparin pretreatment (sham+UFH group, CLP+UFH group), and 8 U heparin unfractionated heparin (diluted to 200 μL) was injected into the tail vein of the mice at 30 minutes and 12 hours after operation respectively. The other 12 mice were injected with the same amount of normal saline. The serum and liver tissues of mice were collected at 4 and 24 hours after CLP. The levels of serum HPA, interleukin (IL-6, IL-1β), tumor necrosis factor-α (TNF-α), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured by enzyme linked immunosorbent assay (ELISA). The pathological changes of liver tissue were observed with hematoxylin eosin (HE) staining. The expression of HPA in liver tissue was detected by immunohistochemistry.

RESULTS: Compared with the sham group, the levels of serum HPA, IL-6, IL-1β, TNF-α, ALT and AST in the CLP group were increased significantly, and increased further over time. The histopathology examination was performed, and abnormal structure, inflammatory cell infiltration, liver cell necrosis could be found in the tissue. The expression level of HPA in liver tissue was detected by immunohistochemistry, which was increased after CLP. This indicated that the animal model of sepsis was successfully prepared. Compared with CLP group, serum HPA, inflammatory factors and transaminase levels were significantly decreased at 4 hours after operation in group CLP+UFH [HPA (ng/L): 76.72±2.75 vs. 101.55±7.54, IL-6 (ng/L): 51.16±5.68 vs. 63.89±3.26, IL-1β (ng/L): 31.53±2.90 vs. 40.87±2.88,TNF-α (ng/L): 171.76±5.60 vs. 194.62±14.13, ALT (μg/L): 0.26±0.09 vs. 0.62±0.17, AST (μg/L): 1.03±0.22 vs. 1.45±0.08, all P < 0.05]. At 24 hours, it was significantly higher than that of 4 hours, but they were significantly lower than those in CLP group [HPA (ng/L): 125.30±7.80 vs. 302.50±17.81, IL-6 (ng/L): 81.16±4.54 vs. 176.56±5.45, IL-1β (ng/L): 61.13±2.80 vs. 113.73±3.96, TNF-α (ng/L): 328.47±10.79 vs. 599.62±10.20, ALT (μg/L): 0.38±0.17 vs. 0.91±0.26, AST (μg/L): 1.16±0.15 vs. 1.88±0.08, all P < 0.05]. It was shown by HE staining that the edema of liver tissue decreased and inflammatory cell infiltration decreased. It was shown by immunohistochemistry that the expression level of HPA in liver tissue was significantly decreased [A value (×10-3 ): 2.49±0.93 vs. 6.05±1.22 at 4 hours, 1.86±0.77 vs. 7.55±0.35 at 24 hours, both P < 0.05]. There was no significant difference in indexes between the sham+UFH group and the sham group.

CONCLUSIONS: The expression of HPA was significantly increased during sepsis in mice. Unfractionated heparin may mitigate liver injury by inhibiting HPA.