The Role Of Extracellular Matrix, MMPs-2 And TIMP-2 In Severe Preeclampsia Pathogenesis

ObjectiveThrough studying the expression of the collagen typeⅣ, Matrx Metalloproteinases (MMPs)-2 and Tissue Inhibitor of Metalloproteinases (TIMPs)-2 in the placenta of the patients with severe preeclampsia and the women with normal late pregnancy, we sought to explore the relationship of incidence mechanism of severe preeclampsia.MethodsThere were 60 specimens of placenta tissues, half of them were from the patients with severe preeclampsia (study group) and the rest were from the women with nomal late pregnancy (control group). We utilized an immunohistochemical method(s-p method) to detect the positive expression ratio of the collagen typeⅣ, MMPs-2 and TIMP-2 in the placenta tissue of the patients with severe preeclampsia and women with nomal late pregnancy. The experimental data was evaluated by SPSS10.0 statistical software package.Results1. Positive particles of the collagen typeⅣhad certain expreesion in the plasma of mesenchyme cell, trophoblast cell and vascular endothelial cell, mainly by mesenchyme cells. The expreesion was obviously higher in severe preeclampsia than that in nomal late pregnancy.2. There were positive expressions of MMPs-2 and TIMP-2 in the plasma of trophoblast cell, syneytiotrophoblast cell, mesenchyme cell, vascular endothelial cell of the placentas both in nomal late pregnancy group and severe preeclampsia group. The expression of MMPs-2 was weak positive while the expression of TIMP-2 is still positive in the severe preeclampsia group. The positive expression site was mainly in syneytiotrophoblast cell both in the severe preeclampsia group and in the normal late pregnancy group.3. Immunohistochemical scores of the collagen typeⅣin trophoblast cells between two groups: nomal late pregnancy group (5.03±0.36), severe preeclampsia group (1.72±0.43). There were differences between the two groups (T=32.32, P<0.01).4. Immunohistochemical scores of MMPs-2 in trophoblast cells between two groups: nomal late pregnancy group (5.40±0.35), severe preeclampsia group (2.47±0.43). There were differences between the two groups (T=28.26, P<0.01).5. Immunohistochemical scores of TIMP-2 in trophoblast cells between two groups: nomal late pregnancy group (5.14±0.31), severe preeclampsia group (5.25±0.30). There were no differences between the two groups (T=1.406, P>0.05). 6. The average sum of ranks of the ratio of TIMP-2 and MMPs-2 between two groups: The average sum of ranks in the nomal late pregnancy group was 6.32 and the average sum of ranks in the severe preeclampsia group was 9.18. There were differences between the nomal late pregnancy group and the severe preeclampsia group (P<0.01).The positive expression ratio of the ratio of TIMP-2 and MMPs-2 in severe preeclampsia was significantly higher than that in nomal late pregnancy.Conclusion1.The expression of the collagen typeⅣis obviously higher in the severe preeclampsia group than in the nomal late pregnancy group. The expression of MMPs-2 is lower in the severe preeclampsia group than in the nomal late pregnancy group, which may reduce the erosion ability of the trophoblast cells and abate the hydrolysis of the collagen, therefore, the degradation of extracellular matrix is blocked and the collagen typeⅣis accumulated.2. The expression of TIMP-2 is slightly higher in the severe preeclampsia group than in the nomal late pregnancy group. TIMP-2 can specificly inhibit MMPs-2 to be inactive. TIMP-2 may inhibit the degradation of extracellular matrix and affect the nidation of the embyos.3.The heighten and imbalanced proportion of TIMP-2 and MMPs-2 may be one of the reasons which lead to the obstruction of trophoblastic recoinage in severe preeclampsia. TIMP-2 and MMPs-2 make the extracellular matrix of the villus cells increase commonly, which maybe the pathology base of the formation of severe preeclampsia.