The Effect Of Iron Accumulation In Liver Kupffer Cells On Acute Liver Damage Induced By Cc14and The Mechanism In Mice

Iron accumulation can cause or worsen liver damage, meanwhile liver damage often accompanies with the existence of iron accumulation phenomenon. Some researches showed that liver Kupffer cell is a key factor between iron accumulation and liver damage. However, the mechanisms are still unknown and need to be further studied.ObjectivesThe chronic model of carbon tetrachloride-induced hepatotoxicity is established in normal mice and mice with iron accumulation in liver Kupffer cells. It is studied whether iron accumulation in liver Kupffer cell could worsen liver damage and its mechanism. It will provide evidence for the detailed mechanism of the effect caused by iron accumulation to liver damage.Materials and methodsThe mice were kept in animal facility. Sixteen male FPN-/-(normal mice) and FPN-/-cre(mice with iron accumulation in liver Kupffer cells) mice were obtained through the genetic type identification. These two genetic types of mice were rand-omly divided into two contol groups and two experimental groups,8mice per group. The mice of two experimental groups were intraperitoneal injected with CCl4, while those of two contol groups were intraperitoneal injected with olive oil. Twenty-four hours after intraperitoneal injection, the levels of serum ALT and AST were detected. Then the mice were condemned to death, the livers were dissectted and weighed to calculate the liver index. Part of the liver tissue was prepared to make the10%liver tissue homogenate for the MDA, SOD and GSH levels detection. Part of the liver tis-sue was fixed with paraffin to do HE and TUNEL staining. The extent of liver dama-ge and the liver cell apoptosis were examined. Part of the liver tissue was prepared for mRNA and protein extraction. The TNF-a, IL-6, TGF-B, Caspase-2and Caspase-8mRNA expression levels were detected by Real-time RT-PCR. The P-P38, P-JNKs, Caspase-2and Caspase-8protein expression levels were detected by Western Blot. The data were calculated x±S The One-Way AN OVA was carried out to analyze the difference among the groups and the S-N-K test was carried out to analyze the difference between each other by use of the SPSS12.0software. The significant level was set at a=0.05.Results1The liver damage indices and liver pathology resultsThe liver index, ALT, AST and MDA levels of the two experimental groups were significantly higher than those of their control groups(.P<0.05), while the SOD and GSH levels were significantly lower than those of their control groups (P<0.05). The differences of liver index, ALT, AST, MDA, SOD and GSH levels between the two control groups were not statistically significant(P>0.05). The liver index, ALT, AST and MDA levels of the FPN-/-cre experimental group were significantly higher than those of the FPN-/-experimental group (P<0.05). The SOD and GSH levels of the FPN-/-cre experimental group were lower than those of the FPN-/-experimental group and the differences were not statistically significant(P>0.05).The liver cell structures of the two control groups were normal, while the liver cell structures of the two experimental groups fractured and disordered. The extent of the liver cell damage was more serious in FPN-/-cre experimental group than that in FPN-/-experimental group.2The mRNA and protein expression levels of related genes and the cell apoptosis resultsThe TNF-a, IL-6, TGF-β, Caspase-2and Caspase-8mRNA levels of the two experimental groups were significantly higher than those of their control groups (P<0.05). The differences of the TNF-a, IL-6, TGF-B, Caspase-2and Caspase-8mRNA levels between the two control groups were not statistically significant (P>0.05). The TNF-a, IL-6and Caspase-2mRNA levels of the FPN-/-cre experi-mental group were significantly higher than those of the FPN-/-experimental group(P><0.05). The TGF-13and Caspase-8mRNA levels of the FPN-/-cre experi-mental group were higher than those of the FPN-/-experimental group and the differences were not statistically significant(P>0.05).The P-JNKs, Caspase-2and Caspase-8protein levels of the two experimental groups were higher than those of their control groups and the differences were not statistically significant(P＞.0.05). The P-P38protein levels of the two experimental groups were significantly lower than those of their control groups(P<0.05). The differences of P-JNKs, P-P38, Caspase-2and Caspase-8protein levels between the two control groups were not significant(P>0.05). The P-JNKs, Caspase-2and Caspase-8protein levels of the FPN-/-cre experimental group were significantly higher than those of the FPN-/-experimental group(P<0.05), while the P-P38protein levels of the FPN-/-cre experimental group were significantly lower than those of the FPN-/-experimental group(P<0.05).The liver cell apoptosis appeared in the two experimental groups while there was no apoptosis in the two control groups. The extent of the liver cell apoptosis was more serious in FPN-/-cre experimental group than that in FPN-/-experimental group.Conclusion1Iron accumulation in liver Kupffer cells can worsen liver damage induced by CCl4.2The effect of iron accumulation in liver Kupffer cells to the liver damage may relate to the increasing of the inflammation factors secretion of the Kupffer cells caused by the iron accumulation, which could promote the cell apoptosis factor secretion through direct stimulation or the change of P38and JNKs pathways, then the liver cell apoptosis is promoted.