| bjective: This topic research the influence of the Wnt signaling pathways to leptomeninges fibrosis after intraventricular hemorrhage(IVH) in rats. The experiment is to explore the role of Wnt signaling pathways in leptomeningeal fibrosis in rats after IVH, by detecting the expression change of PICP, which is the fibrosis marker in CSF after IVH, the activation of Wnt signaling pathways(β-catenin, Wnt3a) in the brain tissue. This maybe can provide the new mentality and the method to the clinical treatment of leptomeningeal fibrosis after IVH. Methods: 1. Use brain stereotaxic instrument to injection the autologous blood of tail vein into lateral ventricle of rats to establish the animal model of IVH. 2. 75 male SD rats of clean grade, weight 180g~200g, were randomly divided into three groups, Intraventricular hemorrhage group(IVH)(n=25), Control group(n=25), Normal control group(n=25). Each group divided into 3d, 6d, 10 d, 14 d, 21 d, a total of five subgroups by beheading time. IVH group using secondary injections slowly pushed on 20μL anticoagulation autologous venous blood into the lateral ventricle of rats; Control group only puncture to the lateral ventricle, not injection of autologous blood; Normal control group without treatment, the normal feeding. 3. In 21 d, use MASSON staining to determine the extent of leptomeningeal fibrosis. At different time points, ria method is used to detect PICP content in rat cerebrospinal fluid, using immunohistochemical method to detect the activation of Wnt signaling pathways(β-catenin, Wnt3a) in the brain tissue. Specimen collection and statistical analysis of data. Results: 1. MASSON staining showed IVH group rats leptomeninges grey value were significantly lower than Control group and Normal control group(P<0.01), thickness were significantly higher than Control group and Normal control group(P<0.01), the leptomeninges collagen fiber content were significantly higher than Control group and Normal control group(P<0.01); The indexes between Control group and Normal control group there was no significant difference(P>0.05). 2. The change of PICP concentration: The PICP concentration in CSF in Control group and Normal control group have no obvious change at various time points(P>0.05); PICP concentration in CSF in Control group and Normal control group there was no significant difference between groups(P>0.05); PICP concentration levels in CSF in IVH group were significantly higher than Control group and Normal control group(P<0.01). 3. The expression of Wnt3 a protein: In Normal control group and Control group, Wnt3 a protein in brain tissue has no obvious change at various time points(P>0.05); Wnt3 a protein in brain tissue in Control group and Normal control group there was no significant difference between groups(P>0.05); Expression level of Wnt3 a protein in brain tissue in IVH group were significantly higher than Control group and Normal control group(P<0.01). 4. The expression of β-catenin protein:In Normal control group and Control group, β-catenin protein in brain tissue has no obvious change at various time points(P>0.05); β-catenin protein in brain tissue in Control group and Normal control group there was no significant difference between groups(P>0.05); Expression level of β-catenin protein in brain tissue in IVH group were significantly higher than Control group and Normal control group(P<0.01). 5. In IVH group, PICP concentration in CSF and Wnt3 a protein in brain tissue were positively correlated(R2=0.942, P<0.01). PICP concentration in CSF and β-catenin protein in brain tissue were positively correlated(R2=0.958, P<0.01). Wnt3 a protein and β-catenin protein in brain tissue were positively correlated(R2=0.905, P<0.01). Conclusion: 1. The application of brain stereotaxic instrument, adopting the method of secondary injection of blood, make IVH model of rat, the method is simple, high maneuverability, and the pathophysiology in this model is nearly as same as human, is the ideal animal model of IVH. 2. 21 d after IVH, leptomeninges apparent collagen hyperplasia, fibrosis formation. MASSON staining of the leptomeninges can be used as a testing index of the leptomeninges fibrosis. 3. After IVH, PICP concentration significantly increased in rat CSF. The continuous occurrence and accumulation of leptomeninges fibrosis may accelerate chronic hydrocephalus after the formation of IVH. The concentration of PICP sustained high expression associated with the severity of fibrosis. 4. After IVH, Wnt3 a protein and β-catenin protein in brain tissue were increased. There was a positive correlation between the Increase of Wnt3 a protein, β-catenin protein and PICP in IVH group, which prompt that the activation of Wnt signaling pathways(β-catenin, Wnt3a) might play an important role in the development of leptomeningeal fibrosis after IVH. |
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