感染、缺血等损伤对腰椎终板及腰椎间盘退变的影响及机制的研究
发布时间：2018-08-22 14:22
【摘要】：背景作为人体中轴骨的主要承重结构,腰椎在脊柱的各项活动中常需处于压缩、拉伸、侧弯或扭曲等多种复杂的运动状态中,其损伤及退变是人群常见的疾病之一,约60%成人及30%青少年有下腰痛(LBP)病史。既往研究显示下腰痛与椎间盘退行性疾病密切相关,而近年来的研究则提出腰椎终板Modic改变是LBP的危险因素。Modic改变根据MRI信号变化将退变终板分为3种亚型:Ⅰ型Modic改变表现为终板在T1像上信号降低,T2像信号增高,提示急性炎症,骨组织轻微损伤及微骨折;Ⅱ型Modic改变表现为T1及T2像信号均增高,提示终板损伤、炎性改变及组织脂肪变;Ⅲ型Modic改变则表现为终板区域信号在T1及T2像均减低,提示区域骨化。Modic改变的人群整体发病率约为5.8%,其发生率及影响面积随年龄增大而升高,以单纯Ⅱ型Modic改变最为多见(64.2%),其次为Ⅰ/Ⅱ型混合(18.1%)及单纯Ⅰ型(16%)。绝大部分Modic改变均发生于下腰椎位置(L4/L5及L5/S1,83%),其在椎间盘的上/下终板之间分布并无显著差异,且77.9%的Modic改变在同一椎间盘的上/下方成对出现。有关Modic改变的成因现存有多种理论,其中最为经典的是力学损伤机制。椎体终板是腰椎解剖结构的薄弱部位,因此传统理论认为椎间盘内应力可集中于终板,致使终板发生退变。终板的部分区域应力集中的发生可引发终板裂隙,终板下部分区域骨质逐渐钙化,而Modic改变则反映了相应的急性出血水肿(Ⅰ型)-慢性炎症修复(Ⅱ型)-区域骨化(Ⅲ型)的进程。Modic改变的另一种病变机制可能涉及营养方面因素,研究显示维生素D摄入量与Modic改变发生率之间存在正相关,其可能与维生素D对钙离子代谢的影响相关。而吸烟及高血脂引起的血管功能障碍亦被认为与Modic改变发生率呈正相关。此外,近年来痤疮丙酸杆菌(P.acnes)感染与Modic改变引起了广泛的争议及研究。P.acnes的出现与Modic改变的发生高度相关,而双盲病例对照研究显示抗生素治疗对伴有Ⅰ型Modic改变的腰背痛患者具有较好的治疗效果。本研究的兴趣在于进一步研究Modic改变的发生机制,在细胞培养,动物模型两个层面分别观察低毒性细菌感染及组织缺血对腰椎间盘及其相邻终板结构的影响,通过影像学,分子生物学及病理学手段进行评估。目的通过体外细胞培养及动物模型研究,了解骨性终板区感染、缺血等损伤对腰椎间盘及终板的影响,探究其损伤机制,进而探索相应病因下治疗或预防椎间盘疾病的新策略。方法1.获取大鼠椎间盘髓核细胞及终板细胞进行体外培养,给予不同的刺激(P.acnes细菌上清液,缺氧生长环境或血管生长抑制剂)观察细胞生长情况,并收集细胞进行基因表达和细胞活性检测。2.构建经肌间隙开放手术入路的兔腰椎间盘髓核穿刺通道,并以此通道注射痤疮丙酸杆菌建立相应动物模型。收集标本进行影像学检查,基因表达,分子生物学测试,病理学检测等。3.构建兔腰椎间盘终板下穿刺通道,并以此通道注射痤疮丙酸杆菌或博来霉素(血管抑制剂)建立相应动物模型。收集标本进行影像学检查,基因表达,分子生物学测试,病理学检测等评估模型。结果1.低毒性细菌感染或缺氧对椎间盘细胞的刺激作用1.1低毒性细菌感染抑制髓核及终板细胞的生长细胞培养结果显示,当共培养的细菌上清液浓度大于4*106CFU/mL时,髓核细胞发生大量死亡;当浓度小于2.5*105CFU/mL时,髓核细胞生长受到明显抑制。当共培养的细菌上清液浓度大于2*106CFU/mL时,终板软骨细胞发生大量死亡;当浓度小于5*105 CFU/mL时,终板软骨细胞生长受到明显抑制。1.2低毒性细菌感染刺激髓核及终板细胞炎症反应基因的表达基因表达结果显示一定浓度的P.acnes上清液刺激可显著提高髓核及终板细胞的细胞外基质降解相关基因如MMP-9、ADAMTSs等的表达,同时下调细胞外基质,如蛋白聚糖、胶原蛋白等的表达水平。1.3血管生长抑制剂博来霉素对健康终板细胞无显著损伤作用使用62.5μg/ml血管生长抑制剂博来霉素培养正常终板细胞48小时后,终板细胞存活率及活性与对照组相比没有统计学差异;细胞产物表达(Ⅰ型胶原、Ⅱ型胶原、蛋白聚糖等)与对照组相比差异无统计学意义。1.4缺氧环境对髓核及终板细胞的刺激作用细胞培养结果显示,终板细胞在缺氧(5%二氧化碳,3%氧分压)环境下增殖速度减慢约40%,细胞代谢水平降低,无氧代谢产物增加,细胞活性下降;胶原及蛋白聚糖等细胞外加基质合成减少,同时降解基质的MMPs及ADAMTSs表达增加。髓核细胞在缺氧环境中活性未见明显变化,仅有HIF-1α及ADAMTS-5表达上调。2.腰椎间盘内低毒性细菌感染对在体腰椎终板及髓核的影响2.1腰椎间盘内低毒性细菌感染引发显著的的终板区域及椎间盘MRI退变表现通过开放手术经侧方肌间隙入路暴露椎间盘并进行穿刺,椎间盘内注射P.acnes后,可发现在术后2周时即有椎间盘信号降低表现。至术后9月时,几乎所有实验椎间盘均发生不同程度退变。术后3月有部分节段终板区域发生Ⅰ型Modic改变,并在术后6月开始部分转变为Ⅱ型Modic改变。2.2腰椎间盘内低毒性细菌感染引发的椎间盘基质降解及终板区域炎症反应P.acnes椎间盘内感染可显著增加椎间盘组织中细胞外基质(如蛋白聚糖等)的分解,同时引发的炎症反应破坏了终板软骨结构,进一步促进了椎间盘的退变。qPCR显示髓核内前炎症因子如IL-1β、TNF-α、IFN-γ及基质降解酶MMP-9、ADAMTS-5表达显著上调,同时终板区域IL-1β、TNF-α及ADAMTS-5表达量显著升高。提示P.acnes感染引起了较为剧烈的椎间盘及终板区域炎性反应。2.3腰椎间盘内低毒性细菌感染与终板下骨质的吸收与重构P.acnes感染椎间盘内后9月,终板骨结构发生明显骨吸收样改变,骨小梁较为稀疏,骨密度显著降低,骨相对体积显著降低而BS/BV显著升高,骨小梁厚度明显降低。病理切片亦显示在部分区域可见终板区域异位骨化增生情况。3.腰椎终板区低毒性细菌感染及血管抑制对在体腰椎终板及髓核的损伤作用3.1腰椎终板区低毒性细菌感染引发的终板区域及髓核MRI影像学变化通过X线透视下经皮穿刺椎间盘终板下骨,并经该通道注射P.acnes后,可发现在术后6月均无显著椎间盘退变表现。在术后6月时,约1/3椎体邻近终板区域发生T1及T2像MRI信号升高表现,提示发生Ⅱ型Modic改变。3.2腰椎终板区低毒性细菌感染诱发炎症损伤P.acnes终板下感染时,终板下骨内前炎症因子如IL-1β、TNF-α、IFN-γ等表达显著升高,提示P.acnes感染引起的温和而慢性的终板区域炎症样反应。同一时间内,椎间盘内部并无显著炎症因子上升或炎性反应表现。3.3腰椎终板区低毒性细菌感染作用下的骨结构改变病理切片及Micro-CT检查结果显示,相比直接感染椎间盘内而言,终板下骨区域P.acnes感染并无明显终板骨性结构重塑反应,终板下骨仅可见轻度骨吸收反应。同时,病理检查显示部分样本(3例)可见终板裂隙。3.4抑制血管生成在终板区域引发的终板区域MRI影像学变化通过X线透视下经皮穿刺椎间盘终板下骨,并经该通道注射博来霉素抑制血管生成后,可发现在术后6月均无显著椎间盘退变表现。在术后2月、3月及6月时,约1/3椎体邻近终板区域发生T1及T2像MRI信号降低表现,提示发生Ⅲ型Modic改变,即终板区域骨化表现。3.5抑制血管生成在终板区域诱发的骨结构改变对实验动物终板下骨Micro-CT扫描结果显示骨小梁结构稀疏,但厚度增加,BMD升高,骨相对体积增加,提示终板下骨区域发生区域部分吸收,同时在大范围内发生骨化反应。终板下骨内炎症因子如IL-1β、TNF-α表达升高。结论1.低毒性细菌上清液在髓核及软骨终板细胞体外培养时可显著抑制细胞生长,下调细胞外基质蛋白表达水平,同时上调基质降解酶,如MMPs、ADAMTSs的表达。同时,髓核细胞在缺氧环境下增殖速度减缓,代谢水平降低,细胞外基质合成减少而降解增加。血管抑制剂博来霉素在体外培养时并没有显著细胞毒性,不会损害髓核细胞及终板细胞的活性及代谢水平。2.低毒性细菌直接感染腰椎间盘可在术后3-9月引发时间依赖性的终板Modic改变及椎间盘退变,激活髓核及终板内IL-1β、TNF-α、IFN-y等多条炎症通路,并促使终板下骨结构发生骨吸收及骨重构改变。3.低毒性细菌直接感染终板下骨可引发相应区域轻度慢性炎症反应,并在6月后表现为Modic Ⅱ型改变及偶发终板裂隙,但椎间盘本身并无显著退变表现。抑制终板区域血管生成可引发终板区域骨化表现及Ⅲ型Modic改变,并伴有炎性反应。
[Abstract]:BACKGROUND As the main load-bearing structure of the axial bone in the human body, the lumbar spine often needs to be compressed, stretched, curled or twisted in various complex motion states. Its injury and degeneration is one of the common diseases in the population. About 60% of adults and 30% of adolescents have a history of low back pain (LBP). Modic changes in the lumbar endplate were classified into three subtypes according to the changes in MRI signals. Type I Modic changes were characterized by decreased signal intensity on T1 images and increased signal intensity on T2 images, suggesting acute inflammation, slight injury to bone tissue and minimal fracture. The change of DIC showed that the signal of T1 and T2 increased, suggesting endplate injury, inflammation and fatty degeneration; the change of type III Modic showed that the signal of endplate area decreased on T1 and T2 images, suggesting regional ossification. The overall incidence of Modic change was about 5.8%, and its incidence and affected area increased with age, while the change of type II Modic was simple. Most of the Modic changes occurred in the lower lumbar spine (L4/L5 and L5/S1, 83%). There was no significant difference in the distribution of Modic between the upper and lower endplates, and 77.9% of Modic changes occurred in pairs above and below the same intervertebral disc. There are many theories about the cause of formation, among which the most classic one is the mechanism of mechanical damage. The vertebral endplate is the weak part of the lumbar vertebral anatomy, so the traditional theory holds that the stress in the intervertebral disc can be concentrated in the endplate, resulting in the degeneration of the endplate. Another mechanism of Modic changes may involve nutritional factors. Studies have shown that there is a positive correlation between vitamin D intake and the incidence of Modic changes, which may be related to vitamin D pairs. In addition, the prevalence of Modic changes has been widely debated and studied in recent years. The presence of P. acnes is highly correlated with the occurrence of Modic changes, while the double-blind case-control study shows that the presence of P. acnes is highly correlated with the occurrence of Modic changes. Antibiotics have been shown to be effective in the treatment of low back pain with type I Modic alterations. The interest of this study is to further investigate the mechanism of Modic alterations. The effects of low toxic bacterial infection and tissue ischemia on the structure of lumbar intervertebral disc and its adjacent endplates were observed at cell culture and animal model levels, respectively. Objective To investigate the effects of bone endplate infection and ischemia on the lumbar intervertebral disc and endplate, explore the mechanism of injury, and then explore new strategies for the treatment or prevention of intervertebral disc diseases under the corresponding etiology. Methods 1. Rat intervertebral disc nucleus pulposus cells and endplate cells were cultured in vitro. Different stimuli (P. acnes bacterial supernatant, hypoxic growth environment or angiogenesis inhibitors) were given to observe the growth of cells, and the cells were collected for gene expression and cell activity detection. 2. The rabbit lumbar intervertebral disc nucleus pulposus pulposus pulposus perforation was constructed by open muscle space operation. Samples were collected for imaging examination, gene expression, molecular biology test, pathological examination and so on. 3. The rabbit lumbar intervertebral disc endplate puncture passage was constructed, and the corresponding animal model was established by injecting propionibacter acnes or bleomycin (vascular inhibitor) into the passage. Results 1. Stimulation of intervertebral disc cells by hypotoxic bacterial infection or hypoxia 1. Low toxic bacterial infection inhibited the growth of nucleus pulposus and endplate cells. The results showed that the concentration of co-cultured bacterial supernatant was high. At 4*106 CFU/mL, a large number of nucleus pulposus cells died; when the concentration was less than 2.5*105 CFU/mL, the growth of nucleus pulposus cells was significantly inhibited. When the concentration of co-cultured bacterial supernatant was more than 2*106 CFU/mL, a large number of endplate chondrocytes died; when the concentration was less than 5*105 CFU/mL, the growth of endplate chondrocytes was significantly inhibited.1.2 with low toxicity. The expression of inflammatory response genes in nucleus pulposus and endplate cells was stimulated by bacterial infection. The results showed that the expression of extracellular matrix degradation related genes such as MMP-9 and ADAMTSs was significantly increased and the expression of extracellular matrix, such as proteoglycan and collagen, was down-regulated by stimulation with certain concentration of P.acnes supernatant. Ping.1.3 Bleomycin, an angiogenesis inhibitor, did not cause significant damage to healthy endplate cells. After culturing normal endplate cells with Bleomycin, a 62.5 ug/ml angiogenesis inhibitor, for 48 hours, there was no significant difference in the survival rate and activity of endplate cells compared with the control group; the expression of cell products (type I collagen, type II collagen, proteoglycan, etc.) Compared with the control group, there was no significant difference. 1.4 The stimulation effect of hypoxia on nucleus pulposus and endplate cells showed that under hypoxia (5% carbon dioxide, 3% oxygen partial pressure), the proliferation rate of endplate cells slowed down by about 40%, the level of cell metabolism decreased, anaerobic metabolites increased, and cell activity decreased. The activity of nucleus pulposus cells did not change significantly in hypoxic environment, but the expression of HIF-1a and ADAMTS-5 was up-regulated. 2. The effect of low toxic bacterial infection in lumbar intervertebral disc on lumbar endplate and nucleus pulposus in vivo 2.1 Low toxic bacterial infection in lumbar intervertebral disc caused significant changes. The degeneration of endplate area and intervertebral disc on MRI was found at 2 weeks after injection of P. acnes. By 9 months after operation, almost all experimental discs had degenerated to varying degrees. Type I Modic changes occurred in the region of the endplate and partially converted to type II Modic changes at 6 months postoperatively. 2.2 Decomposition of the intervertebral disc matrix caused by low toxic bacterial infections in the lumbar intervertebral disc and inflammatory reaction in the endplate region P. acnes intradiscal infection significantly increased the decomposition of extracellular matrix (such as proteoglycan) in the intervertebral disc tissue, as well. QPCR showed that the expression of pro-inflammatory factors such as IL-1 beta, TNF-a, IFN-gamma, matrix degrading enzymes MMP-9 and ADAMTS-5 in nucleus pulposus was significantly up-regulated, while the expression of IL-1 beta, TNF-a and ADAMTS-5 in the endplate region was significantly increased. Intense inflammatory reaction in the intervertebral disc and endplate. 2.3 Low toxic bacterial infection in the lumbar intervertebral disc and absorption and remodeling of bone under the endplate in the intervertebral disc after P. acnes infection in September, the bone structure of the endplate showed obvious bone resorption-like changes, trabeculae were sparse, bone mineral density was significantly reduced, relative bone volume was significantly reduced, BS/BV was significantly increased, and bone trabeculae were significantly increased. Pathological sections also showed heterotopic ossification and hyperplasia of the endplate region in some areas. 3. Damage of low toxic bacterial infection and vascular inhibition in the lumbar endplate and nucleus pulposus in vivo. 3. MRI imaging changes of the endplate region and nucleus pulposus caused by low toxic bacterial infection in the lumbar endplate region were examined by X-ray fluoroscopy. No significant disc degeneration was found at 6 months after the operation. At 6 months after the operation, T1 and T2 MRI signals were elevated in about 1/3 of the adjacent endplate areas, suggesting the occurrence of type II Modic changes. 3.2 low toxic bacterial infection in the lumbar endplate area induced inflammatory injury P. The expression of proinflammatory factors such as IL-1 beta, TNF-a and IFN-gamma increased significantly in sublaminar infection of acnes, suggesting mild and chronic inflammation-like reactions in the endplate region caused by P. acnes infection. There was no significant increase in inflammatory factors or inflammatory reaction in the intervertebral disc at the same time. 3.3 Low toxic bacterial infection in the lumbar endplate region was present. Pathological sections and micro-CT examination showed that there was no significant end-plate remodeling in P.acnes infection, and only slight bone resorption was observed in the subendplate bone. In addition, some samples (3 cases) showed end-plate fissures.3.4 inhibited blood vessels. No significant disc degeneration was observed at 6 months after surgery. T1 and T2 images were detected in about 1/3 of the adjacent endplate regions at 2 months, 3 months and 6 months after surgery. MRI signal reduction indicated type III Modic changes, i.e. ossification of the endplate area. 3.5 Inhibition of angiogenesis in the endplate area induced bone structural changes in experimental animals under the endplate bone micro-CT scan showed that the trabecular bone structure was sparse, but the thickness increased, BMD increased, relative bone volume increased, suggesting that the area of bone occurring under the endplate region. The expression of inflammatory cytokines such as IL-1beta and TNF-alpha was increased under the endplate. Conclusion 1. Low toxicity bacterial supernatant could inhibit the growth of nucleus pulposus and cartilage endplate cells, down-regulate the expression of extracellular matrix protein and up-regulate the expression of matrix degrading enzymes such as MMPs and ADAMTSs in vitro. At the same time, the proliferation rate of nucleus pulposus cells in hypoxic environment slowed down, the metabolic level decreased, the synthesis of extracellular matrix decreased and the degradation increased. Bleomycin, an inhibitor of blood vessel, had no significant cytotoxicity in vitro, and did not damage the activity and metabolic level of nucleus pulposus cells and endplate cells. 2. Low toxic bacteria directly infected the waist. The intervertebral disc can induce time-dependent changes of Modic and intervertebral disc degeneration from 3 to 9 months after operation, activate multiple inflammatory pathways such as IL-1 beta, TNF-a, IFN-y in the nucleus pulposus and endplate, and promote bone resorption and remodeling in the subendplate bone structure. 3. Low toxic bacteria directly infect the subendplate bone can cause mild chronic inflammatory reaction in the corresponding region. Inhibition of angiogenesis in the endplate region can induce ossification of the endplate region and change of Modic type III with inflammatory reaction.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R681.53
本文编号：2197358
[Abstract]:BACKGROUND As the main load-bearing structure of the axial bone in the human body, the lumbar spine often needs to be compressed, stretched, curled or twisted in various complex motion states. Its injury and degeneration is one of the common diseases in the population. About 60% of adults and 30% of adolescents have a history of low back pain (LBP). Modic changes in the lumbar endplate were classified into three subtypes according to the changes in MRI signals. Type I Modic changes were characterized by decreased signal intensity on T1 images and increased signal intensity on T2 images, suggesting acute inflammation, slight injury to bone tissue and minimal fracture. The change of DIC showed that the signal of T1 and T2 increased, suggesting endplate injury, inflammation and fatty degeneration; the change of type III Modic showed that the signal of endplate area decreased on T1 and T2 images, suggesting regional ossification. The overall incidence of Modic change was about 5.8%, and its incidence and affected area increased with age, while the change of type II Modic was simple. Most of the Modic changes occurred in the lower lumbar spine (L4/L5 and L5/S1, 83%). There was no significant difference in the distribution of Modic between the upper and lower endplates, and 77.9% of Modic changes occurred in pairs above and below the same intervertebral disc. There are many theories about the cause of formation, among which the most classic one is the mechanism of mechanical damage. The vertebral endplate is the weak part of the lumbar vertebral anatomy, so the traditional theory holds that the stress in the intervertebral disc can be concentrated in the endplate, resulting in the degeneration of the endplate. Another mechanism of Modic changes may involve nutritional factors. Studies have shown that there is a positive correlation between vitamin D intake and the incidence of Modic changes, which may be related to vitamin D pairs. In addition, the prevalence of Modic changes has been widely debated and studied in recent years. The presence of P. acnes is highly correlated with the occurrence of Modic changes, while the double-blind case-control study shows that the presence of P. acnes is highly correlated with the occurrence of Modic changes. Antibiotics have been shown to be effective in the treatment of low back pain with type I Modic alterations. The interest of this study is to further investigate the mechanism of Modic alterations. The effects of low toxic bacterial infection and tissue ischemia on the structure of lumbar intervertebral disc and its adjacent endplates were observed at cell culture and animal model levels, respectively. Objective To investigate the effects of bone endplate infection and ischemia on the lumbar intervertebral disc and endplate, explore the mechanism of injury, and then explore new strategies for the treatment or prevention of intervertebral disc diseases under the corresponding etiology. Methods 1. Rat intervertebral disc nucleus pulposus cells and endplate cells were cultured in vitro. Different stimuli (P. acnes bacterial supernatant, hypoxic growth environment or angiogenesis inhibitors) were given to observe the growth of cells, and the cells were collected for gene expression and cell activity detection. 2. The rabbit lumbar intervertebral disc nucleus pulposus pulposus pulposus perforation was constructed by open muscle space operation. Samples were collected for imaging examination, gene expression, molecular biology test, pathological examination and so on. 3. The rabbit lumbar intervertebral disc endplate puncture passage was constructed, and the corresponding animal model was established by injecting propionibacter acnes or bleomycin (vascular inhibitor) into the passage. Results 1. Stimulation of intervertebral disc cells by hypotoxic bacterial infection or hypoxia 1. Low toxic bacterial infection inhibited the growth of nucleus pulposus and endplate cells. The results showed that the concentration of co-cultured bacterial supernatant was high. At 4*106 CFU/mL, a large number of nucleus pulposus cells died; when the concentration was less than 2.5*105 CFU/mL, the growth of nucleus pulposus cells was significantly inhibited. When the concentration of co-cultured bacterial supernatant was more than 2*106 CFU/mL, a large number of endplate chondrocytes died; when the concentration was less than 5*105 CFU/mL, the growth of endplate chondrocytes was significantly inhibited.1.2 with low toxicity. The expression of inflammatory response genes in nucleus pulposus and endplate cells was stimulated by bacterial infection. The results showed that the expression of extracellular matrix degradation related genes such as MMP-9 and ADAMTSs was significantly increased and the expression of extracellular matrix, such as proteoglycan and collagen, was down-regulated by stimulation with certain concentration of P.acnes supernatant. Ping.1.3 Bleomycin, an angiogenesis inhibitor, did not cause significant damage to healthy endplate cells. After culturing normal endplate cells with Bleomycin, a 62.5 ug/ml angiogenesis inhibitor, for 48 hours, there was no significant difference in the survival rate and activity of endplate cells compared with the control group; the expression of cell products (type I collagen, type II collagen, proteoglycan, etc.) Compared with the control group, there was no significant difference. 1.4 The stimulation effect of hypoxia on nucleus pulposus and endplate cells showed that under hypoxia (5% carbon dioxide, 3% oxygen partial pressure), the proliferation rate of endplate cells slowed down by about 40%, the level of cell metabolism decreased, anaerobic metabolites increased, and cell activity decreased. The activity of nucleus pulposus cells did not change significantly in hypoxic environment, but the expression of HIF-1a and ADAMTS-5 was up-regulated. 2. The effect of low toxic bacterial infection in lumbar intervertebral disc on lumbar endplate and nucleus pulposus in vivo 2.1 Low toxic bacterial infection in lumbar intervertebral disc caused significant changes. The degeneration of endplate area and intervertebral disc on MRI was found at 2 weeks after injection of P. acnes. By 9 months after operation, almost all experimental discs had degenerated to varying degrees. Type I Modic changes occurred in the region of the endplate and partially converted to type II Modic changes at 6 months postoperatively. 2.2 Decomposition of the intervertebral disc matrix caused by low toxic bacterial infections in the lumbar intervertebral disc and inflammatory reaction in the endplate region P. acnes intradiscal infection significantly increased the decomposition of extracellular matrix (such as proteoglycan) in the intervertebral disc tissue, as well. QPCR showed that the expression of pro-inflammatory factors such as IL-1 beta, TNF-a, IFN-gamma, matrix degrading enzymes MMP-9 and ADAMTS-5 in nucleus pulposus was significantly up-regulated, while the expression of IL-1 beta, TNF-a and ADAMTS-5 in the endplate region was significantly increased. Intense inflammatory reaction in the intervertebral disc and endplate. 2.3 Low toxic bacterial infection in the lumbar intervertebral disc and absorption and remodeling of bone under the endplate in the intervertebral disc after P. acnes infection in September, the bone structure of the endplate showed obvious bone resorption-like changes, trabeculae were sparse, bone mineral density was significantly reduced, relative bone volume was significantly reduced, BS/BV was significantly increased, and bone trabeculae were significantly increased. Pathological sections also showed heterotopic ossification and hyperplasia of the endplate region in some areas. 3. Damage of low toxic bacterial infection and vascular inhibition in the lumbar endplate and nucleus pulposus in vivo. 3. MRI imaging changes of the endplate region and nucleus pulposus caused by low toxic bacterial infection in the lumbar endplate region were examined by X-ray fluoroscopy. No significant disc degeneration was found at 6 months after the operation. At 6 months after the operation, T1 and T2 MRI signals were elevated in about 1/3 of the adjacent endplate areas, suggesting the occurrence of type II Modic changes. 3.2 low toxic bacterial infection in the lumbar endplate area induced inflammatory injury P. The expression of proinflammatory factors such as IL-1 beta, TNF-a and IFN-gamma increased significantly in sublaminar infection of acnes, suggesting mild and chronic inflammation-like reactions in the endplate region caused by P. acnes infection. There was no significant increase in inflammatory factors or inflammatory reaction in the intervertebral disc at the same time. 3.3 Low toxic bacterial infection in the lumbar endplate region was present. Pathological sections and micro-CT examination showed that there was no significant end-plate remodeling in P.acnes infection, and only slight bone resorption was observed in the subendplate bone. In addition, some samples (3 cases) showed end-plate fissures.3.4 inhibited blood vessels. No significant disc degeneration was observed at 6 months after surgery. T1 and T2 images were detected in about 1/3 of the adjacent endplate regions at 2 months, 3 months and 6 months after surgery. MRI signal reduction indicated type III Modic changes, i.e. ossification of the endplate area. 3.5 Inhibition of angiogenesis in the endplate area induced bone structural changes in experimental animals under the endplate bone micro-CT scan showed that the trabecular bone structure was sparse, but the thickness increased, BMD increased, relative bone volume increased, suggesting that the area of bone occurring under the endplate region. The expression of inflammatory cytokines such as IL-1beta and TNF-alpha was increased under the endplate. Conclusion 1. Low toxicity bacterial supernatant could inhibit the growth of nucleus pulposus and cartilage endplate cells, down-regulate the expression of extracellular matrix protein and up-regulate the expression of matrix degrading enzymes such as MMPs and ADAMTSs in vitro. At the same time, the proliferation rate of nucleus pulposus cells in hypoxic environment slowed down, the metabolic level decreased, the synthesis of extracellular matrix decreased and the degradation increased. Bleomycin, an inhibitor of blood vessel, had no significant cytotoxicity in vitro, and did not damage the activity and metabolic level of nucleus pulposus cells and endplate cells. 2. Low toxic bacteria directly infected the waist. The intervertebral disc can induce time-dependent changes of Modic and intervertebral disc degeneration from 3 to 9 months after operation, activate multiple inflammatory pathways such as IL-1 beta, TNF-a, IFN-y in the nucleus pulposus and endplate, and promote bone resorption and remodeling in the subendplate bone structure. 3. Low toxic bacteria directly infect the subendplate bone can cause mild chronic inflammatory reaction in the corresponding region. Inhibition of angiogenesis in the endplate region can induce ossification of the endplate region and change of Modic type III with inflammatory reaction.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R681.53
【参考文献】
相关期刊论文 前3条
1 韩超;马信龙;王涛;马剑雄;田鹏;臧加成;;Modic改变动物模型的建立及其评估[J];中华骨科杂志;2014年04期
2 蒋欣;Yuichiro Morishita;Hymanson Henry;Jeffrey C.Wang;;腰痛患者MRI上各节段腰椎间盘退变形式与年龄的相关性分析[J];中国脊柱脊髓杂志;2009年11期
3 何镜清;腰痛病人相关因素分析及对策[J];热带医学杂志;2003年01期
，本文编号：2197358
本文链接：https://www.wllwen.com/shoufeilunwen/yxlbs/2197358.html
教材专著
