A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury

Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

Long noncoding RNAs HAND2-AS1 ultrasound microbubbles suppress hepatocellular carcinoma progression by regulating the miR-873-5p/tissue inhibitor of matrix metalloproteinase-2 axis

BACKGROUND Increasing data indicated that long noncoding RNAs(lncRNAs)were directly or indirectly involved in the occurrence and development of tumors,including hepatocellular carcinoma(HCC).Recent studies had found that the expression of lncRNA HAND2-AS1 was downregulated in HCC tissues,but its role in HCC progression is unclear.Ultrasound targeted microbubble destruction mediated gene transfection is a new method to overexpress genes.AIM To study the role of ultrasound microbubbles(UTMBs)mediated HAND2-AS1 in the progression of HCC,in order to provide a new reference for the treatment of HCC.METHODS In vitro,we transfected HAND2-AS1 siRNA into HepG2 cells by UTMBs,and detected cell proliferation,apoptosis,invasion and epithelial-mesenchymal transition(EMT)by cell counting kit-8 assay,flow cytometry,Transwell invasion assay and Western blotting,respectively.In addition,we transfected miR-837-5p mimic into UTMBs treated cells and observed the changes of cell behavior.Next,the UTMBs treated HepG2 cells were transfected together with miR-837-5p mimic and tissue inhibitor of matrix metalloproteinase-2(TIMP2)overexpression vector,and we detected cell proliferation,apoptosis,invasion and EMT.In vivo,we established a mouse model of subcutaneous transplantation of HepG2 cells and observed the effect of HAND2-AS1 silencing on tumor formation ability.RESULTS We found that UTMBs carrying HAND2-AS1 restricted cell proliferation,invasion,and EMT,encouraged apoptosis,and HAND2-AS1 silencing eliminated the effect of UTMBs.Additionally,miR-873-5p targets the gene HAND2-AS1,which also targets the 3’UTR of TIMP2.And miR-873-5p mimic counteracted the impact of HAND2-AS1.Further,miR-873-5p mimic solely or in combination with pcDNA-TIMP2 had been transformed into HepG2 cells exposed to UTMBs.We discovered that TIMP2 reversed the effect of miR-873-5p mimic caused by the blocked signalling cascade for matrix metalloproteinase(MMP)2/MMP9.In vivo results showed that HAND2-AS1 silencing significantly inhibited tumor formation in mice.CONCLUSION LncRNA HAND2-AS1 promotes TIMP2 expression by targeting miR-873-5p to inhibit HepG2 cell growth and delay HCC progression.

卵巢癌患者癌组织MMP-10、IL-17A、HMGB1表达与病情严重程度的相关性

目的:探究卵巢癌患者癌组织基质金属蛋白酶10(MMP-10)、白细胞介素17A(IL-17A)、高迁移率族蛋白B1(HMGB1)水平与病情严重程度相关性。方法:将407例卵巢癌患者的临床资料作为观察组,以同期就诊的216例良性卵巢肿瘤患者为对照组。检测并比较两组患者血清MMP-10、IL-17A、HMGB1水平,分析不同参数下卵巢癌患者血清MMP-10、IL-17A、HMGB1水平,利用Spearman分析卵巢癌患者血清MMP-10、IL-17A、HMGB1与FIGO分期、分化程度的相关性。结果:入院时,观察组患者血清MMP-10、IL-17A、HMGB1水平均高于对照组(P<0.05)。不同FIGO分期、分化程度、淋巴结转移卵巢癌患者中血清MMP-10、IL-17A、HMGB1水平有统计学差异(P<0.05)。Spearman分析显示血清MMP-10、IL-17A、HMGB1与FIGO分期、分化程度均呈正相关关系(P<0.05)。结论:血清MMP-10、IL-17A、HMGB1与FIGO分期、分化程度呈正相关,可作为卵巢癌患者病情严重程度的诊断指标。

10-MDP钙盐对小鼠成纤维细胞L929增殖、凋亡及MMPs表达的影响

目的通过10-MDP钙盐对小鼠成纤维细胞L929的研究调查了不同浓度不同结构的10-MDP钙盐对牙周组织的影响。方法通过X射线衍射(X-Ray diffraction,XRD)对合成的三种不同比例10-MDP钙盐进行鉴定。使用CCK-8法检测10-MDP钙盐对小鼠成纤维细胞L929的细胞增殖毒性;流式细胞术检测细胞凋亡;蛋白免疫印迹实验检测细胞基质金属蛋白酶(matrix metalloproteinase,MMP)2、MMP9表达。结果XRD的结果证实三种合成方式均有不同结构10-MDP钙盐的产生;细胞增殖毒性CCK-8实验中仅有1.0 mg/mL MDP-1组在72 h后引起细胞增殖活性降低;各组培养72 h后均不诱导细胞凋亡;0.2 mg/mL和0.1 mg/mL MDP-2、MDP-1组均抑制L929细胞的MMP2和MMP9蛋白分泌。结论10-MDP钙盐可能对牙周组织中成纤维细胞没有细胞毒性作用,并且可以通过抑制MMP2、MMP9蛋白的分泌减少牙周组织破坏。

Expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic stellate cells during rat hepatic fibrosis and its intervention by IL-10

AIM: To investigate the expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10).METHODS: Hepatic fibrosis was induced by CCl4administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8rats), CCl4-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type Ⅳ collagenase through portal vein catheter and the suspension was centrifuged by 11%Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with β-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h.RESULTS: Compared to group N in the 7th wk, MMP-2and TIMP-1 mRNA increased in group C (P= 0.001/0.001)and group I (P = 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P= 0.001/0.001). In the 11th wk, MMP-2 mRNAin group I was still lower than that in group C (P = 0.005),but both dropped compared with that in the 7th week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P= 0.001), and increased in group C (P = 0.001) while decreased in group I (P = 0.042)compared with that in the 7th wk. Same results were found by immunocytochemistry.CONCLUSION: Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.

尿基质金属蛋白酶-10与老年结直肠癌患者根治术后急性肾损伤发生的相关性

目的探讨尿基质金属蛋白酶10(MMP-10)与老年结直肠癌患者根治术后急性肾损伤发生的关系,为临床预防和治疗急性肾损伤发生提供新的参考。方法选取2018年10月—2021年10月在重庆大学附属肿瘤医院接受结直肠癌根治术的老年患者作为研究对象,选取术后发生急性肾损伤者90例为损伤组,术后未发生急性肾损伤者90例为对照组。收集患者围术期一般资料,ELISA法检测患者术后尿MMP-10水平,并进行多因素logistic回归分析。结果损伤组年龄大于对照组,收缩压、总胆固醇、术后并发症总发生率及术后24 h内的尿MMP-10水平均高于对照组,手术时间长于对照组,术中补液量、术中出血量均多于对照组,差异均有统计学意义(P<0.05);将年龄、收缩压、总胆固醇、手术时间、术中补液量、术中出血量、术后并发症发生情况及尿MMP-10水平作为自变量,是否发生急性肾损伤作为因变量进行logistic回归分析,经校正混杂因素后,年龄、术中出血量、术后有并发症及尿MMP-10水平均为老年结直肠癌患者根治术后急性肾损伤发生的独立危险因素(P<0.05)。将尿MMP-10进行三等分后,作为分类变量进一步使用logistic回归分析尿MMP-10水平与老年结直肠癌患者根治术后急性肾损伤发生之间的关系,经多因素校正后,与尿MMP-10低水平组(<1.29μmol/L)患者相比,中水平组(1.29~2.31μmol/L)和高水平组(>2.31μmol/L)的患者术后发生急性肾损伤的风险提高。结论尿MMP-10水平升高与老年结直肠癌患者根治术后急性肾损伤发生密切相关,尿MMP-10是其独立危险因素。

血清ox-LDL、MMP-10对非血管再通治疗ACI患者出血转化风险的预测价值

目的探讨血清氧化型低密度脂蛋白(ox-LDL)、基质金属蛋白酶(MMP)-10对非血管再通治疗急性脑梗死(ACI)患者出血转化风险的预测价值。方法选取2020年6月至2021年3月首发ACI 24 h内入该院且未接受血管再通治疗患者86例为研究对象,根据患者脑梗死后90 d内有无出血转化分为出血转化组28例与非出血转化组58例。收集两组患者临床资料并采用酶联免疫吸附试验法检测血清ox-LDL、MMP-10水平。绘制受试者工作特征(ROC)曲线分析血清ox-LDL、MMP-10水平对非血管再通治疗ACI患者发生出血转化的预测价值,以及Logistics回归分析影响非血管再通治疗ACI患者发生出血转化的危险因素。结果出血转化组入院美国国立卫生研究院卒中量表(NIHSS)评分、大面积梗死占比、LDL-C水平高于非出血转化组,差异有统计学意义(P<0.05)。出血转化组血清ox-LDL、MMP-10水平均高于非出血转化组,差异有统计学意义(P<0.05)。两者联合检测预测非血管再通治疗ACI患者发生出血转化的曲线下面积为0.921,约登指数为0.729,灵敏度为89.3%,特异度为81.7%。Logistics回归分析显示,入院NIHSS评分、大面积梗死、ox-LDL、MMP-10水平为非血管再通治疗ACI患者发生出血转化的危险因素(P<0.05)。结论非血管再通治疗ACI患者ox-LDL、MMP-10水平检测对其发生出血转化具有预测效能。

Picroside Ⅱ down-regulates matrix metalloproteinase-9 expression following cerebral ischemia/reperfusion injury in rats

Studies have shown that Picroside Ⅱ attenuates inflammatory reactions following brain ischemia through the inhibition of the TLR-4-NF-KB signal transduction pathway, and ameliorates cerebral edema through the reduction of aquaporin-4 expression. Matrix metalloproteinase-9 （MMP-9）, located downstream of the TLR-4-NF-KB signal transduction pathway, can degrade the neurovascular matrix, damage the blood-brain barrier to induce cerebral edema, and directly result in neuronal apoptosis and brain injury, Therefore, the present study further observed MMP-9 expression in the brain tissues of rats with cerebral ischemia/reperfusion injury following Picroside Ⅱ treatment. Results demonstrated that Picroside Ⅱ significantly reduced MMP-9 expression in ischemic brain tissues, as well as neuronal apoptosis and brain infarct volume, suggesting Picroside Ⅱ exhibits neuroprotection by down-regulating MMP-9 expression and inhibiting cell apoptosis.

Expression and significance of angiostatin, vascular endothelial growth factor and matrix metalloproteinase-9 in brain tissue of diabetic rats with ischemia reperfusion

Objective: To discuss the expression and significance of angiostatin, vascular endothelial growth factor and matrix metalloproteinase-9 in the brain tissue of diabetic rats with ischemia reperfusion. Methods: A total of 60 male Wistar rats were randomly divided into the normal group, sham group, diabetic cerebral infarction group and single cerebral infarction group according to the random number table, with 15 rats in each group. The high sucrose diet and intraperitoneal injection of streptozotocin were performed for the modeling of diabetic rats, while the thread-occlusion method was employed to build the model of cerebral ischemia reperfusion. The immunohistochemical staining was performed to detect the expression of angiostatin, vascular endothelial growth factor(VEGF) and matrix metalloproteinase-9(MMP-9) in the brain tissue. Results: The expression of angiostatin after the reperfusion in the brain tissue of rats in the single cerebral infarction group and diabetic cerebral infarction group was increased 6 h after the reperfusion, reached to the peak on 1 d and then decreased gradually. The expression of angiostatin in the diabetic cerebral infarction group 6 h, 1 d, 3 d and 7 d after the reperfusion was significantly higher than that in the single cerebral infarction group(P<0.05). VEGF began to be increased 1 h after the reperfusion in the single cerebral infarction group and diabetic cerebral infarction group, reached to the peak at 6 h and then decreased gradually. The expression of VEGF in the diabetic cerebral infarction group at each time point after the reperfusion was significantly lower than that in the single cerebral infarction group(P<0.05). MMP-9 began to be be increased 1 h after the reperfusion in the single cerebral infarction group and diabetic cerebral infarction group, reached to the peak on 1 d and then decreased gradually. The expression of MMP-9 in the diabetic cerebral infarction group at each time point after the reperfusion was significantly higher than that in the single cerebral infarction group(P<0.05). Conclusions: The high glucose environment in which the diabetic cerebral infarction is occurred is to induce the formation of MMP-9 at first and then activate and increase the expression of angiostatin. Afterwards, the expression of VEGF is inhibited, resulting in the poor angiogenesis after cerebral infarction, which thus makes the injury of brain tissue after cerebral infarction even worse than the non-diabetes mellitus.

High matrix metalloproteinase-9 expression induces angiogenesis and basement membrane degradation in stroke-prone spontaneously hypertensive rats after cerebral infarction

Basement membrane degradation and blood-brain barrier damage appear after cerebral infarc- tion, severely impacting neuronal and brain functioning; however, the underlying pathogenetic mechanisms remain poorly understood. In this study, we induced cerebral infarction in stroke- prone spontaneously hypertensive rats by intragastric administration of high-sodium water （1.3% NaC1） for 7 consecutive weeks. Immunohistochemical and immunofluorescence assays demonstrated that, compared with the non-infarcted contralateral hemisphere, stroke-prone spontaneously hypertensive rats on normal sodium intake and Wistar-Kyoto rats, matrix metalloproteinase-9 expression, the number of blood vessels with discontinuous collagen IV expression and microvessel density were significantly higher, and the number of continuous collagen IV-positive blood vessels was lower in the infarct border zones of stroke-prone sponta- neously hypertensive rats given high-sodium water. Linear correlation analysis showed matrix metalloproteinase-9 expression was positively correlated with the number of discontinuously collagen IV-labeled blood vessels and microvessel density in cerebral infarcts of stroke-prone spontaneously hypertensive rats. These results suggest that matrix metalloproteinase-9 upregula- tion is associated with increased regional angiogenesis and degradation of collagen IV, the major component of the basal lamina, in stroke-prone spontaneously hypertensive rats with high-sodi- um water-induced focal cerebral infarction.

Correlation of RECK with Matrix Metalloproteinase-2 in Regulation of Trophoblast Invasion of Early Pregnancy

To study the role of the reversion-inducing-cysteine-rich protein with Kazal motifs （RECK） gene and matrix metalloproteinase-2 （MMP-2） in the regulation of trophoblast invasion of early pregnancy. Immunohistochemistry, Western blot and gelatin zymography were used to detect the RECK protein expression localization, expression level and MMP-2 activation level in the placental tissues harvested from 52 normal pregnant women （27 in the early pregnancy, 25 in the term pregnancy）. Immunohistochemistry showed that RECK expression was found both in villous tissues of early pregnancy group and term pregnancy group and was mainly observed in cell membrane and cytoplasm of cytotrophoblasts and syneytiotrophoblasts. RECK expression increased with gestational time. RECK expression of early pregnancy group was significantly lower than that of term pregnancy group （P〈0.05）. RECK expression was significantly lower in cellular column （CC） with invasion ability. Western blot showed that the RECK protein expression in early pregnancy group was significantly lower than that in term pregnancy （P〈0.05）. The optical density values of RECK protein expression in early pregnancy group and term pregnancy group were 1.35±0.14 and 2.68±0.26, respectively, while MMP-2 activation ratio was contrary to RECK protein expression and decreased with the gestation time （P〈0.01）. The MMP-2 activation ratios of early pregnancy group and term pregnancy group were 0.46±0.05 and 0.10±0.02, respectively. The expression of the tumor inhibitory gene RECK was positively related with the invasion ability of trophoblasts, while the invasion gene MMP-2 was negatively related with the ability. The interaction between RECK and MMP-2 may play an important role in the regulation of the trophoblast invasion in early pregnancy.

Huoxue Rongluo Tablet reduces matrix metalloproteinase-9 expression in infarcted brain tissue

Huoxue Rongluo Tablet was made of tall gastrodis tuber, dahurian angelica root, honeysuckle stem, grassleaf sweetflag rhizome, common flowering quince fruit, figwort root, red peony root and peach seed at a ratio of 3：2：6：2：3：3：3：3. Huoxue Rongluo Tablet is a well-established and common pre- scription for the treatment of cerebral infarction. In this study, a rat model of cerebral ischemia was established and the animals were intragastrically administered Huoxue Rongluo Tablet. This treat- ment reduced infarct volume, decreased matrix metalloproteinase-9 expression, and improved neurological function. Moreover, the effects of Huoxue Rongluo Tablet were better than those of buflomedil pyridoxal phosphate. These results indicate that Huoxue Rongluo Tablet is effective in treating cerebral infarction by regulating matrix metalloproteinase-9 protein expression.

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 expression in early focal cerebral infarction following urokinase thrombolysis in rats

Activity of matrix metalloproteinase-9 increases following cerebral ischemia/reperfusion, and is associated with cerebral microvascular permeability, blood-brain barrier destruction, inflammatory cell infiltration and brain edema. Matrix metalloproteinase-9 also likely participates in thrombolysis. A rat model of middle cerebral artery infarction was established by injecting autologous blood clots into the internal carotid artery. At 3 hours following model induction, urokinase was injected into the caudal vein. Decreased neurological severity score, reduced infarct volume, and increased expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were observed in the cerebral cortex 24 hours after urokinase thrombolysis. These results suggest that urokinase can suppress damage in the acute-early stage of cerebral infarction.

Increased expression of matrix metalloproteinase-9 associated with gastric ulcer recurrence

AIM: To compare matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in gastric ulcer (GU) and chronic superficial gastritis (CSG). METHODS: This study enrolled 63 patients with GU and 25 patients with CSG. During upper gastroduodenal endoscopy, we took samples of gastric mucosa from the antrum and ulcer site from patients with GU, and samples of antral mucosa from patients with CSG. Mucosal biopsy tissues were cultured for 24 h, and the culture supernatant was measured for levels of MMP-9 and TIMP-1. After receiving eradication therapy for Helicobacter pylori (H. pylori ) and 8 wk proton-pump inhibitor therapy for GU, follow-up endoscopy examination was performed after 6 mo and whenever severe symptoms occurred. RESULTS: Levels of MMP-9 and TIMP-1 at the ulcer site or in the antrum were significantly higher in GU than CSG patients. MMP-9 levels at the ulcer site were significantly higher than in the antrum in GU patients, and had a significantly positive correlation with TIMP-1. MMP-9 levels were significantly higher in H. pylori -positive than H. pylori -negative GU and CSG patients. Levels of MMP-9 or TIMP-1 at the ulcer site were associated with the histological severity of activity and inflammation. About 57 GU patients were followed up, and seven had GU recurrence. H. pyloriinfection and MMP-9 levels were risk factors for the recurrence of GU adjusted for age and sex by multiple logistic regression analysis. CONCLUSION: MMP-9 may perform an important function in gastric ulcer formation and recurrence.

EXPRESSION OF MATRIX METALLOPROTEINASE-7 AND FAS LIGAND: THEIR APOPTOSIS-INDUCING EFFECT ON GASTRIC CANCER CELLS

Objective: To investigate the expression of matrix metalloproteinase-7 (MMP-7) and Fas ligand (FasL) in gastric cancer and explore their role in progression of gastric cancer. Methods: Formalin-fixed paraffin and embedded tissues of primary gastric cancer and adjacent non-tumor mucosa from 113 cases were evaluated for MMP-7, FasL and Capase-3 expression by streptavidin-peroxidase (S-P) immunohistochemistry. The expression of the first two proteins in cancer cells of primary foci was compared with clinicopathological parameters of tumors. We also observed the correlation of MMP-7 and FasL expression with Caspase-3 expression in cancer cells of primary foci. Results: MMP-7 positive immunostaining was less frequently detected in adjacent epithelial cells than in cancer cells of primary foci of gastric cancer (P<0.05, 29.2% vs 69.0%), and so was FasL (P<0.05, 34.5% vs 54.0%). MMP-7 expression was associated with tumor size, Borrmann抯 classification, invasive depth, metastasis and TNM staging (P<0.05), but not with growth pattern, Lauren抯 classification, or histological classification (P>0.05). FasL expression was correlated with tumor size, invasive depth, metastasis, Lauren抯 classification, histological classification (P<0.05), while not with Borrmann抯 classification, TNM staging or growth pattern (P>0.05). Cancer cells of primary foci expressed less Caspase-3 than their adjacent epithelial cells (P<0.05, 32.7% vs 50.4%). There was an obvious correlation between FasL, MMP-7 and Caspase-3 expression in cancer cells of primary foci (P<0.05). Co-expression of MMP-7 and FasL paralleled with Caspase-3 expression in cancer cells of primary foci (P<0.05). Conclusion: MMP-7 and FasL expression was up-regulated in gastric carcinogenesis and was principally involved in progression of gastric cancer. FasL expression could reflect the differentiation of gastric cancer cells and underlie the molecular mechanisms of different pathways of gastric tumorigenesis. Co-expression of MMP-7 and FasL could have apoptosis-inducing effect on gastric cancer cells.

终板炎及外周血CXCL10、MMP-1水平与经皮椎间孔镜下髓核摘除术后复发的相关性研究

目的:探究终板炎及外周血CXC趋化因子配体10(CXC chemokine ligand-10,CXCL10)、基质金属蛋白酶1(matrix metalloproteinase-1,MMP-1)水平与经皮椎间孔镜下髓核摘除术后复发的相关性。方法:回顾性分析惠州市中心人民医院2020年1月-2021年6月收治的180例经皮椎间孔镜下髓核摘除术治疗的腰椎间盘突出症患者。两组均行经皮椎间孔镜下髓核摘除术,术后8个月随访,通过核磁共振影像学结果分为未复发组(n=96)与复发组(n=84)。观察两组术前、术后8个月CXCL10、MMP-1、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、CXC趋化因子受体3(CXC-chemokine receptor 3,CXCR3)水平变化及视觉模拟评分法(VAS)、日本骨科协会评估治疗(JOA)评分。分析外周血CXCL10、MMP-1水平及终板炎与经皮椎间孔镜下髓核摘除术后复发的相关性。结果:术前两组CXCL10、MMP-1、TNF-α、CXCR3水平及终板炎发生率比较,差异无统计学意义(P>0.05)。术后8个月,复发组的CXCL10、MMP-1、TNF-α、CXCR3水平及终板炎发生率显著高于未复发组(P<0.05)。术前,两组VAS、JOA评分比较,差异无统计学意义(P>0.05)。术后8个月,未复发组VAS评分显著低于复发组,JOA评分显著高于复发组(P<0.05)。Spearman相关性分析得出终板炎、外周血CXCL10、MMP-1水平与经皮椎间孔镜下髓核摘除术后复发具有良好的正相关性。结论:终板炎、外周血CXCL10和MMP-1水平与经皮椎间孔镜下髓核摘除术后复发呈现正相关性。

Distribution and relative activity of matrix metalloproteinase-2 in human coronal dentin

The presence of matrix metalloproteinase-2 （MMP-2） in dentin has been reported, but its distribution and activity level in mature human coronal dentin are not well understood. The purpose of this study was to determine the MMP-2 distribution and relative activity in demineralized dentin. Crowns of twenty eight human molars were sectioned into inner （ID）, middle （MD）, and outer dentin （OD） regions and demineralized. MMP-2 was extracted with 0.33 mol·L-1 EDTA/2 mol·L-1 guanidine-HCl, pH 7.4, and MMP-2 concentration was estimated with enzyme-linked immunoabsorbant assay （ELISA）. Further characterization was accomplished by Western blotting analysis and gelatin zymography. The mean concentrations of MMP-2 per mg dentin protein in the dentin regions were significantly different （P=0.043）： 0.9 ng （ID）, 0.4 ng （MD）, and 2.2 ng （OD）, respectively. The pattern of MMP-2 concentration was OD〉ID〉MD. Western blotting analysis detected -66 and -72 kDa immunopositive proteins corresponding to pro- and mature MMP-2, respectively, in the ID and MD, and a -66 kDa protein in the OD. Gelatinolytic activity consistent with MMP-2 was detected in all regions. Interestingly, the pattern of levels of Western blot immunodetection and gelatinolytic activity was MD〉ID〉OD. The eoneentration of MMP-2 in human coronal dentin was highest in the region of dentin that contains the dentinoenamel junction and least in the middle region of dentin. However, levels of Western blot immunodetection and gelatinolytic activity did not correlate with the estimated regional concentrations of MMP-2, potentially indicating region specific protein interactions.

Matrix metalloproteinase-9 expression and blood brain barrier permeability in the rat brain after cerebral ischemia/reperfusion injury

BACKGROUND： The integrity of the blood brain barrier （BBB） plays an important role in the patho-physiological process of cerebral ischemia/reperfusion injury. It has been recently observed that metalloproteinase-9 （MMP-9） is closely related to cerebral ischemia/reperfusion injury OBJECTIVE： This study was designed to observe MMP-9 expression in the rat brain after cerebral ischemia/reperfusion injury and to investigate its correlation to BBB permeability. DESIGN, TIME AND SETTING： This study, a randomized controlled animal experiment, was performed at the Institute of Neurobiology, Central South University between September 2005 and March 2006. MATERIALS： Ninety healthy male SD rats, aged 3-4 months, weighing 200-280 g, were used in the present study. Rabbit anti-rat MMP-9 polyclonal antibody （Boster, Wuhan, China） and Evans blue （Sigma, USA） were also used. METHODS： All rats were randomly divided into 9 groups with 10 rats in each group： normal control group, sham-operated group, and ischemia for 2 hours followed by reperfusion for 3, 6, 12 hours, 1, 2, 4 and 7 days groups. In the ischemia/reperfusion groups, rats were subjected to ischemia/reperfusion injury by suture occlusion of the right middle cerebral artery. In the sham-operated group, rats were merely subjected to vessel dissociation. In the normal control group, rats were not modeled. MAIN OUTCOME MEASURES： BBB permeability was assessed by determining the level of effusion of Evans blue. MMP-9 expression was detected by an immunohistochemical method. RESULTS： All 90 rats were included in the final analysis. BBB permeability alteration was closely correlated to ischemia/reperfusion time. BBB permeability began to increase at ischemia/reperfusion for 3 hours, then it gradually reached a peak level at ischemia/reperfusion for 1 day, and thereafter it gradually decreased. MMP-9 expression began to increase at ischemia/reperfusion for 3 hours, then gradually reached its peak level 2 days after perfusion, and thereafter it gradually decreased. CONCLUSION： MMP-9 expression increases in rat brain tissue after focal cerebral ischemia/reperfusion injury, which correlates with increased permeability of the BBB.

Vascular Endothelial Growth Factorl65-regulated Nasopharyngeal Carcinoma Cell Lines Invasion and Migration Involve Expression and Activation of Matrix Metalloproteinase-2

The effect of vascular endothelial growth factor （VEGF） overexpression on matrix metalloproteinase-2 （MMP-2） in nasopharyngeal carcinoma （NPC） cells in vitro and the possible mechanism involved were investigated, and the correlation between the expression of VEGF and MMP-2 in NPC evaluated. The NPC cells were transfected with PAd-trackVEGF165 plasmid. The expression levels of VEGF and MMP-2 mRNA and protein in NPC cells were detected by semi-quantitative RT-PCR and Western blot respectively. It was found that the expression of VEGF and MMP-2 mRNA and protein was significantly increased in NPC cells after transfection of VEGF 165. It was concluded that the expression of VEGF was correlated to the in vitro invasion of NPC cells, and the induction of MMP-2 by VEGF was a key process of NPC cell invasion.