Effect Of Hepcidin And LPS On Mouse Iron Status And Iron-related Proteins

Iron is an essential component of numerous proteins and enzymes that are critical for cell respiration, proliferation and signal transduction. Hence, iron deficiency affects the function of multiple tissues. In excess iron is a pro-oxidant and toxic, as labile iron catalyzes the formation of hydroxyl radicals, resulting in the oxidation of surrounding macromolecules. Recently, Hepcidin, a small antimicrobial peptide specifically produced in the liver, has been suggested to be the regulating hormone of iron metabolism.The lack of hepatic Hepcidin expression in upstream stimulation factor 2 (USF2) knockout mice leads to iron overload in liver, pancreas and heart. Conversely, over expression of Hepcidin in transgenic mice causes severe iron deficiency. In order to provide experimental evidence for hepcidin as a regulating hormone of iron metabolism.we studied the iron status and protein involved iron metabolism expression of mice after injection with Hepcidin and LPS.The experiment materials were six months KM mice. Mice were injected with Hepcidin dissolved in normal saline solution by the tail vein, and the Hepcidin dose is 0.1 n g,1ug, 5ug /mouse/day. Mice intravenous injected with normal saline solution were used as control. Mice were killed after five days after injection. In our experiments, RBC HGB HCT MCV of blood, the non-haem iron of Iiver.spleen and kidney ,DMT 1 and FP1 expression in duodenum,liver and spleen had been observed by automated blood analyzer.the method of non-haem iron assay and immunohistochemical method. Furthermore,we also examined the mice liver hepcidin mRNA and TfR2 protein expression after injected with 0.9% normal saline solution or 0.1 mg/kg LPS by the intraperitoneal route. The results of experiments were analyzed with the software of STAT on computer.The research contents and results were as follows:1.Effect of Hepcidin on Iron metabolism(1)Effect of Hepcidin on Hematologic Parameters: Hematologic analysis of blood takenfrom a duplicate series of animals revealed no significant change (P>0.05) inRBCs,HGB,HCT and MCV after the injection of Hepcidin at various dose. (2)Effect of Hepcidin on Tissue Iron Status:The non-haem iron of control mice liver is 284.49 + 39.81,and non-haem iron of liver after the injection of Hepcidin at lug /mouse/day is 369.03 + 36.49. The liver iron levels increased significantly (P<0.01) .Spleen and kidney iron levels had no significant change(P>0.05) after the injection of Hepcidin at lug /mouse/day.The non-haem iron of experimental and control mice spleen are 1028.06+60.80 and 1068.22 +70.84 respectively. The non-haem iron of experimental and control mice kidney are 291.43+30.62 and 325.62+26.48 respectively. (3)î–¬fect of Hepcidin on DMTl and FPl Expression: In duodenum epithelium cell cytoplasm, there were many DMTl and FPl positive cells.In the red pulp macrophages of the spleen, there was distribution of DMTl and FPl staining cells. In the liver, as reported previously, there was apparent DMTl and FPl immunostaining on the surface and cytoplasm of hepatocytes and no staining in nuclear. However, there had no significant change of DMTl and FPl expression in liver, spleen,and duodenum after the injection daily for 5 days of Hepcidin at dose of lug /mouse. 2.1nduction of Hepcidin and TfR2 Expression by LPSThe effect of LPS on Hepcidin mRNA expression in vivo in mouse liver.The LPS at the dose of 0.1mg/kg body weight induced a rapid increase in Hepcidin mRNA. By 1.5 h after LPS, Hepcidin expression increased markedly.The level of mRNA was about 5 .3 times higher (p<0.01) and then the expression subsided . By 18h after LPS, hepatic Hepcidin mRNA expression returned back to the normal level.In the liver, LPS stimulated a increase of TfR2 with peaks of mRNA at 1.5 h (p<0.01), and then the expression subsided .By 3h after LPS, hepatic TfR2 expression returned back to the normal level.Conclusion:1.Effect of Hepcidin on Hematologic Parameters: Hematologic analysis of blood taken from a duplicate series of animals revealed no significant chang...