Research On MAPK Pathway And Apoptosis Protein In Preeclampasia Patients

Research backgroundPreeclampsia（PE）usually occurs after20weeks of pregnancy, the featuresare hypertension and albuminuria, with organ damage or function failure, PEcan lead to convulsion, coma and even to death. Currently, the cause ofpreeclampsia and pathological mechanism are still important subjects whichbeing widely researched in perinatology. So the change of signal transductionpathway in placenta is one of the critical links in the research of the occurrenceand development of PE.Mitogen-activated protein kinases (MAPK) is one kind of serine/threonineprotein kinase which widely exists in eukaryotic cells, the family consists ofc-Jun-N-terminal kinas（eJNK）、p38kinase and extracellular signal transductionkinase（ERK）etc. MAPK transmits extracellular stimulus signal into cell andthen lead to biological reaction such as proliferation, differentiation, transformand apoptosis etc. ERK mainly mediate cell proliferation, differentiation,transform, whereas JNK and p38have close relations with intracellular and extracellular damage, inflammation, infarct and oxidative stress reaction. Theyare both independent and also react with each other, and participate in thetransduction of various signals in cell.The recasting disorder of trophoblast in spiral arteries in uterus lead tohypoxia, ischemia and perfusion inadequacy of placenta, excessive activation ofplacenta inflammatory factor. Through vitro culturing PE placenta trophocyte, itwas be found that the expression of p-ERK decreases comparing to the normal,but there is no relation between the expression of p-p38and trophocyte.However, animal experiments found that the high expression of p38α is relatedto the defect of placenta, it can increase the apoptosis of trophoblasts andinterstitial cell in placenta, eventually increase the mortality of Fetal rats.Therefore, adjusting tissue and trophoblasts in placenta by MAPK signaltransduction pathway protein in PE is still to be researched.We study the contrast research of serum and placenta tissue ofpreeclampsia and normal women, test the tumor necrosis factors (TNF-α) andIL-6in the PE and the normal, research the expression of MAPK signaltransduction pathway associated protein（p38、JNK、ERK）, proteins concernedwith assapoptosis, MMP-9and TIMP-1in placenta tissue. Research the relationbetween TNF-α and MAPK signal transduction pathway associated protein toprove up the main target protein of PE, so as to supply experimental evidencefor the pathomechanism of PE. The research consists of three sections:Experiment1: Expression of MAPK signal transduction pathwayassociated protein in placenta tissue of preeclampsia patientsObjective: research the relation between tumor necrosis factors TNF-α andMAPK signal transduction pathway associated protein in PE to prove up the main target protein of PE, so as to supply experimental evidence for thepathomechanism of PE.Method: select45PE pregnant women and45normal pregnant womenrespectively in Obstetrics and Gynecology Department of Xijing Hospital,analyse the variation of TNF-α and IL-6in serum by ELISA, detect MAPKsignal transduction pathway associated protein in placenta tissue byimmunohistochemical and western blot, then do relevant analysis.Results:（1）TNF-α and IL-6level in serum of the PE is obviously higher thanthat of the normal pregnant team:1.56±0.3vs0.85±0.1,95.31±1.38vs56.40±1.45pg/ml pg/ml，P<0.01；(2) the expressions of p-p38and p-JNK in placenta tissueof the PE are higher than those of the normal pregnant team (P<0.01）,but theexpression of p-ERK of the PE is lower than that of the normal pregnant team(P<0.01). Meanwhile, the expressions of NF-κBp65、c-fos、c-Jun in placentatissue of the PE are all higher than those of the normal pregnant team (P<0.01）(3) the expressions of TNF-α in serum is positively correlated with theexpressions of p-p38and p-JNK in placenta tissue（r=0.623p＜0.01andr=0.715, p＜0.01），the expressions of TNF-α in serum is negatively correlatedwith the expressions of p-ERK（r=-0.689, p<0.01）.Conclusion: MAPK signal transduction pathway associated protein plays animportant role during the occurrence PE, p-p38、p-JNK participate throughNF-κBp65, c-fos and c-Jun entering nucleolus and showing positive feedback inthe nosogenesis of PE. The variation of TNF-α in serum of patients can reflectthe variation of p-p38and p-JNK in placenta tissue indirectly.Experiment2: Research on apoptosis protein in placenta of preeclampasiapatients Objective: research the expression and clinical significance of Caspase-3.8.9inplacenta of preeclampasia patients. Method: select40cases of pregnant womenin Obstetrics and Gynecology Department of Xijing Hospital, including20casesof preeclampsia and20cases of normal pregnant women as reference group.Examine the expression of Fas/FasL, Caspase-3.8.9and Bcl-2/Bax in placentaof preeclampsia patients and normal pregnant group by immunohistochemicaland western blot. Results: the expression of Fas/FasL and Caspase-3.8.9inplacenta significantly increases while the Bcl-2/Bax is lower in preeclampsiapatients (P<0.01), comparing to that of reference group.Conclusion: In PE group, there are more apoptosis of trophoblasts and theexpressions of caspase-3.8.9and Fas/FasL are higher than those of the normalpregnant team (P<0.01), Bcl-2/Bax is lower than the normal (P<0.01).eventually result in the increase of trophocytes apoptosis. Deduction: highexpression Caspase-3.8.9induces the increase of trophocytes apoptosis ofplacenta in PE, which may be a significant pathologic mechanism for PE.Experiment3: Expression of MMP-9and TIPM-1in placenta ofpreeclampsia patientsObjective: research the expression and clinical significance of MMP-9andTIPM-1in placenta of preeclampsia patients. Method: select40cases ofpregnant women in Xijing Hospital from August2010to February2011,including20cases of preeclampsia and20cases of normal pregnant women asreference group. Examine the expression of MMP-9and TIMP-1in placentatrophoblasts in the two group respectively with immunohistochemical methodand western blot method. Results: the expression of MMP-9in placentatrophocytes decreases significantly (P<0.01) in PE comparing to normal pregnant women, the expression of TIMP-1increases significantly (P<0.01),and ratio of MMP-9/TIMP-1is lower than that of reference group. Conclusion:the unusual expression of MMP-9and TIMP-1in placenta of preeclampsia maybe related to obstacle of trophoblasts entry.