The Research Of Synergistic Effect Between Hsp70and PARP-1in Rat Hepatic Ischemia-reperfusion Injury

Objective:We plan to build the high expression model of Hsp70by heat stress to research thecytoprotection of high level Hsp70in hepatic ischemia-reperfusion injury of rat and therelationship between Hsp70and PARP-1which belongs to a kind of DNA protectionproteins.Methods:35healthy SD rats were randomly divided into5groups which includeH+/P-,H+/P+,H-/P+, PC and NC. The rats of group H-/P+and H+/P-are gived thestimulate of heat stress and the intervention of drugs which will restrain the expressionof Hsp70and PARP-1respectively. The group of PC only accept the operation ofhepatic ischemia reperfusion and the NC group is a sham-operation group. We built theHIRI model with the method of Pringle’. Collect the specimen of blood to detect ALTto estimate the degree of liver function damage. We take liver specimens for HEstaining to observe the liver tissue morphology change. The expression of Hsp70andPARP-1is determined by immunohistochemistry. Moreover we also detect theexpression of Hsp70by Western blot. The detection of hepatocyte apoptosis isdetermined by TUNEL technique. We analysis the results of immunohistochemistryand WB with professional image analysis software, then count and analyze measureddata with SPSS16.0software.Results:1. HE staining：in the PC group, hepatocyte swelling is obvious in the lightmicroscope, the boundary of hepatic cords and hepatic sinus is not clear, hepatic sinusbecome stenosed, lobular central vein and hepatic sinus congested, portal area is visibleinfiltrated by neutrophil. Liver tissue morphology change of H+/P+group is not so obvious. The NC group does not have this damage.2. Serum ALT test: comparing PC with the other groups, the result is that PCgroup is higher than the other groups(P<0.01).H+/P+is lower thanPC,H-/P+,H+/P-(P <0.01).Comparing H-/P+with H+/P-,there is also an significantdifference (P <0.01).3. Immunohistochemistry of Hsp70display that staining signal is mainly locatedin cytoplasm and some appear in the cell nucleal. Tan is the labeling of positive cell thatis mainly distributed around lobular central vein. Comparing H+/P+with H+/P–group,the expression of Hsp70have no significant difference (P=0.05), and H-/P+is lowerthan the former two groups (P <0.01), meaning that the model is success;4. PARP-1immunohistochemistry study showed that tan particles mainly locatedin the nucleu and the positive cells were around lobular central vein. Statistical analysisshowed that comparing between the groups of H+/P-,H+/P+,H-/P+, H+/P-group’expression of PARP-1was lower than the other groups(P<0.01) and the other groupshad no significant difference (P≥0.05);5. WB confirmed immunohistochemical test results about Hsp70expression.Statistical analysis display that H+/P-and H+/P+group have no significant difference;H-/P+and PC group also have no significant difference, both P>0.05. H+/P-andH+/P+, respectively, compared with other groups, there are significant difference,higher than other groups（P<0.01）. Compared with the other four groups, NCobviously lower than the other four groups（P<0.01）.So heat stress promote the highexpression of Hsp70and quercetin inhibit it’ expression;6. TUNEL display that the nucleu of apoptotic cell is density dyed to deep tan.The number of apoptotic cell in H+/P-group is less than H-/P+group（P<0.05）andH+/P+is also less than H-/P+，H+/P-and PC(P<0.01). Compared with other groups,the group of PC have significant difference(P<0.01). So Hsp70play a protect role inHIRI. From our findings, Hsp70is better to protect liver cell from damage thanPARP-1. Conclusion:1. The results show that Hsp70reduces apoptosis of liver cell and relieve thedamage of liver function in HIRI;2. In HIRI, PARP-1reduces liver cells apoptosis and play a role of protectingliver cells;3. Hsp70will be better to protect liver cell damage from HIRI when PARP-1express in hepatocyte. Hsp70and PARP-1have a synergistic effect in hepatocyteduring HIRI.