PPARβ与MMP-9参与蛛网膜下腔出血后早期脑损伤的机制研究

发布时间：2018-06-30 05:48

本文选题：PPARβ + NF-κB　；参考：《重庆医科大学》2014年博士论文

【摘要】：目的通过测定大鼠蛛网膜下腔出血（SAH）后早期海马过氧化物酶体增生物激活受体β（PPARβ），核因子-κB（NF-κB），基质金属蛋白酶9（MMP-9）的表达变化，探讨三者在蛛网膜下腔出血后参与早期脑损伤(early brain injury, EBI)的相关分子机制。方法 1.建立大鼠SAH模型：采用视交叉前池注血法构建大鼠SAH模型。 2. PPARβ、NF-κB、MMP-9的表达：选取不同的时间点。 3. Real-time PCR方法检测PPARβ、NF-κB、MMP-9mRNA表达，用Western blotting和免疫组化方法检测PPARβ、NF-κB、MMP-9蛋白表达情况。 4.细胞凋亡的检测：采用原位末端标记法（TUNEL）观察大鼠海马组织内神经元凋亡。 5.组织病理学检测：通过检测大鼠脑内伊文思蓝（Evans blue, EB）含量观察大鼠BBB通透性的改变，并通过检测大鼠脑含水量（brainwater content, BWC）观察大鼠脑水肿。 6.干预治疗的作用：利用PPARβ特异性激动剂GW0742增加PPARβ的表达，观察其与细胞凋亡、BBB通透性及脑水肿的变化关系以及对EBI的保护作用。结果 1. PPARβ、NF-κB、MMP-9的表达：与sham组相比，大鼠SAH后6h海马PPARβ蛋白表达和mRNA含量开始明显减少，以后逐渐降低，72h达最低（P0.05)；与sham组相比，大鼠SAH后6h海马NF-κB蛋白表达和mRNA含量开始明显增加，以后逐渐增高，72h达高峰（P0.05)；与sham组相比，大鼠SAH后6h海马MMP-9蛋白表达和mRNA含量开始明显增加，以后逐渐增高，72h达高峰（P0.05)。 2. TUNEL检测发现：大鼠SAH后6h开始出现TUNEL阳性细胞，随后逐渐增多，72h时最多。SAH后6h，12h，24h，48h，72h大鼠TUNEL阳性细胞数均显著高于sham组（P0.05）。 3.组织病理学检测发现：SAH后12h大鼠脑内EB含量及BWC开始显著升高，以后逐渐升高，72h达最高。与sham组相比，SAH后6h，12h，24h，48h，72h大鼠脑组织EB含量及BWC显著增高（P0.05）。 4.干预治疗显示：SAH后72h，GW0742能够明显增加PPARβ的表达，同时降低NF-κB和MMP-9的表达（P0.05）；GWO742组海马TUNEL阳性神经元数量与SAH组相比明显增加（P0.05），GWO742组大鼠脑内EB含量和BWC与SAH组相比明显降低（P0.05）。结论 1.大鼠SAH后PPARβ可能通过NF-κB从转录水平调节MMP-9的表达，导致海马神经元发生失巢性凋亡，参与早期脑损伤的病理过程。 2. PPARβ特异性激动剂GW0742能增加PPARβ的表达，减少细胞凋亡，减轻BBB通透性的改变，缓解脑水肿，具有潜在的神经保护作用。
[Abstract]:Objective to investigate the expression of peroxisome proliferator-activated receptor 尾 (PPAR 尾), nuclear factor- 魏 B (NF- 魏 B) and matrix metalloproteinase-9 (MMP-9) in rat hippocampus after subarachnoid hemorrhage (SAH). Objective: to explore the molecular mechanisms involved in early brain injury (early brain injury,) after subarachnoid hemorrhage. Method 1. Establishment of rat SAH model: the rat SAH model was established by injecting blood into the anterior cistern of optic chiasma. 2. Expression of PPAR 尾 -NF- 魏 B- MMP-9 at different time points. 3. 3%. Real-time PCR was used to detect the expression of MMP-9 mRNA in PPAR 尾 -NF- 魏 B, and Western blotting and immunohistochemistry were used to detect the expression of MMP-9 protein. 4. Detection of apoptosis: in situ end labeling (Tunel) was used to observe neuronal apoptosis in rat hippocampal tissue. Histopathological examination: the changes of BBB permeability and brain water content (brainwater content, BWC) were observed by detecting the content of Evans blue (EB) in rat brain. The effect of intervention therapy: GW0742, a specific agonist of PPAR 尾, was used to increase the expression of PPAR 尾, and to observe the relationship between the expression of PPAR 尾 and the permeability of apoptosis BBB and brain edema and the protective effect on EBI. Result 1. Compared with sham group, the expression of PPAR 尾 protein and mRNA began to decrease at 6 h after sham, and then decreased to the lowest at 72 h after SAH (P0.05), compared with sham group, NF- 魏 B protein expression and mRNA content in hippocampus began to increase at 6 h after sham. Compared with the sham group, the expression of MMP-9 protein and the content of MMP-9 in hippocampus began to increase significantly at 6 h after sham, and then increased to the peak at 72 h after SAH (P0.05). Tunel detection showed that the number of Tunel positive cells in rats was significantly higher than that in sham group (P0.05). The number of Tunel positive cells began to appear at 6 h after SAH and increased gradually at 72 h. The number of Tunel positive cells in rats was significantly higher than that in sham group at 12 h, 24 h and 48 h after SAH (P0.05). Histopathological examination showed that the content of EB and BWC in brain began to increase significantly at 12 h after WSAH and reached the highest level at 72 h later. Compared with sham group, the content of EB in brain tissue and the content of BWC in brain tissue of rats were significantly higher than those in sham group at 6 h, 12 h, 24 h and 48 h, respectively (P0.05). Intervention therapy showed that GW0742 significantly increased the expression of PPAR 尾 and decreased the expression of NF- 魏 B and MMP-9 (P0.05). The number of Tunel positive neurons in the hippocampus of the GWO 742 group was significantly higher than that in the SAH group (P0.05) and the content of EB and BWC in the brain of the GWO _ 742 group was significantly lower than that in the SAH group (P0.05). Conclusion 1. After SAH, PPAR 尾 may regulate the expression of MMP-9 through NF- 魏 B at the transcriptional level, resulting in apoptosis of hippocampal neurons, which may participate in the pathological process of early brain injury. 2. PPAR 尾 -specific agonist GW0742 can increase the expression of PPAR 尾, reduce apoptosis, alleviate the change of BBB permeability, relieve brain edema, and have potential neuroprotective effect.
【学位授予单位】：重庆医科大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R743.35

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