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.

慢性肾脏病患者血清CHI3L1、MMP-13表达水平及其病情评估、预后价值

目的探讨慢性肾脏病患者血清几丁质酶3样蛋白1(CHI3L1)、基质金属蛋白酶-13(MMP-13)表达水平及病情评估、预后价值。方法选取2020年3月至2022年8月在江油市人民医院就诊的208例慢性肾脏病患者作为病例组,按照病情严重程度将208例慢性肾脏病患者分为Ⅰ期组21例、Ⅱ期组42例、Ⅲ期组86例、Ⅳ期组38例、Ⅴ期组21例。另选取同期152例体检健康者作为对照组。根据患者预后情况将208例患者分为预后良好组(n=92)及预后不良组(n=116)。收集受试人员一般资料,采用酶联免疫吸附试验检测血清CHI3L1、MMP-13表达水平,Pearson法分析慢性肾脏病患者血清CHI3L1、MMP-13表达水平的相关性,以及二者与肾小球滤过率(GFR)的相关性,采用Cox回归分析影响慢性肾脏病患者预后的因素。结果对照组、病例组年龄、性别等一般资料比较,差异无统计学意义(P>0.05);病例组患者血清中CHI3L1表达水平较对照组显著增加,但MMP-13表达水平显著降低,差异有统计学意义(P<0.05);随着病情分期增加,患者血清CHI3L1表达水平随之增加,MMP-13表达水平随之降低(P<0.05);预后不良组患者血清CHI3L1表达水平较预后良好组显著增加,MMP-13表达水平显著降低(P<0.05);Pearson法分析显示,慢性肾脏病患者血清CHI3L1、MMP-13表达水平呈负相关,CHI3L1表达水平与GFR呈负相关,MMP-13表达水平与GFR呈正相关(P<0.05)。Cox回归分析显示,血清CHI3L1、MMP-13、GFR为慢性肾脏病患者预后不良的独立影响因素(P<0.05)。结论慢性肾脏病患者血清CHI3L1表达水平升高,MMP-13表达水平降低,二者均可用于病情及预后评估。

Madecassoside impedes invasion of rheumatoid fibroblast-like synoviocyte from adjuvant arthritis rats via inhibition of NF-κB-mediated matrix metalloproteinase-13 expression

Fibroblast-like synoviocytes(FLS) play a pivotal role in Rheumatoid arthritis(RA) pathogenesis through aggressive migration and invasion. Madecassoside(Madec), a triterpenoid saponin present in Centella asiatica herbs, has a potent anti-inflammatory effect. In the present study, Madec exerted an obvious therapeutic effect in reversing the histological lesions in adjuvant-induced arthritis(AIA) rats. To recognize the anti-rheumatoid potentials of Madec, we further investigated whether Madec interfered with FLS invasion and metalloproteinase(MMP) expression. In cultures of primary FLS isolated from the AIA rats, Madec(10 and 30 μmol·L–1) was proven to considerably inhibit migration and invasion of FLS induced by interleukin 1β(IL-1β), but exhibiting no obvious effect on cell proliferation. Madec repressed IL-1β-triggered FLS invasion by prohibiting the expression of MMP-13. Additionally, Madec suppressed MMP-13 transcription via inhibiting the MMP-13 promoter-binding activity of NF-κB. Our results further showed that Madec down-regulated the translocation and phosphorylation of NF-κB as demonstrated by Western blotting and immunofluorescence assays. In conclusion, our results suggest that Madec exerts anti-RA activity via inhibiting the NF-κB/MMP-13 pathway.

Salvia miltiorrhiza-asarum ointment combined with Chinese medical massage alleviates symptoms of osteoarthritis in a rat model through the Notch1/matrix metalloproteinase-13 signaling pathway

OBJECTIVE:This study investigated the effect of salvia miltiorrhiza-asarum ointment(SMAO)plus Chinese medical massage on knee osteoarthritis in a rat model.METHODS:Hulth's method was used to establish a Sprague-Dawley rat model of knee osteoarthritis(OA).The levels of matrix metalloproteinase-13(MMP-13),collagen-Ⅱ,aggrecan,interleukin(IL)-1β,tumor necrosis factor-α(TNF-α),and IL-6 were measured by enzyme-linked immunosorbent assays.The joint space was assessed by a Perlove X-ray system.Histopathology was examined by hematoxylin-eosin and Safranin O staining.The mRNA and protein expression levels of Notch1,MMP-13,collagen-Ⅱ,and aggrecan were measured by quantitative reverse transcription-polymerase chain reaction and Western blotting,respectively.RESULTS:SMAO plus Chinese medical massage significantly decreased the levels of MMP-13,IL-1β,TNF-α,and IL-6,and increased serum collagen-Ⅱ and aggrecan levels.Pathological injury of the knee joint was improved by SMAO treatment.mRNA and protein expression of Notch1 and MMP-13 was remarkably downregulated,but collagen-Ⅱ and aggrecan levels were significantly upregulated in cartilage tissues.CONCLUSION:SMAO combined with Chinese medical massage effectively relieves OA symptoms,which may involve inhibiting inflammation through the Notch1/MMP-13 signaling pathway.

创面渗出液VEGF、MMP-13、TIMP-1水平对负压封闭引流术联合人工真皮修复难愈性创面效果的预测价值

目的观察难愈性创面患者创面渗出液血管内皮生长因子(vascular endothelial growth factor,VEGF)、基质金属蛋白酶13(matrix metalloproteinase-13,MMP-13)、金属蛋白酶抑制剂1(tissue inhibitor of matrix metalloproteinases-1,TIMP-1)水平,并分析其对负压封闭引流术(vacuum sealing drainage,VSD)联合人工真皮修复治疗难愈性创面临床效果的预测价值。方法选取难愈性创面患者60例纳入难愈组,普通创面患者60例为对照组。所有入选者均检测创面渗出液VEGF、MMP-13、TIMP-1水平,并计算MMP-13/TIMP-1值。采用VSD联合人工真皮修复治疗难愈性创面患者,观察临床效果,并依据临床效果将其分为有效组与无效组,比较有效组与无效组创面渗出液VEGF、MMP-13、TIMP-1水平与MMP-13/TIMP-1值,采用Logistic回归分析上述指标对VSD联合人工真皮修复治疗难愈性创面患者效果的影响,并绘制受试者工作特征曲线(receiver operating characteristic curve,ROC),分析上述指标对VSD联合人工真皮修复治疗难愈性创面患者效果的预测价值。结果难愈组MMP-13水平及MMP-13/TIMP-1值高于对照组,VEGF、TIMP-1水平低于对照组(P<0.05)。60例难愈性创面患者经VSD联合人工真皮修复治疗有效49例(81.67%),无效11例(18.33%)。无效组MMP-13、MMP-13/TIMP-1值高于有效组,VEGF、TIMP-1水平低于有效组(P<0.05)。Logistic回归分析结果显示,MMP-13(95%CI:1.037~1.165)及MMP-13/TIMP-1值(95%CI:1.410~3.458)是难愈性创面患者治疗效果的危险因素,VEGF(95%CI:0.972~0.995)、TIMP-1(95%CI:0.264~0.756)是保护因素(P<0.05)。点二列相关性分析结果显示,VEGF、TIMP-1水平与难愈性创面患者VSD联合人工真皮修复治疗效果呈正相关(r=0.410、0.448,P<0.05),MMP-13水平、MMP-13/TIMP-1值与其治疗效果呈负相关(r=-0.477、0.570,P<0.05)。绘制ROC曲线,结果显示,VEGF(95%CI:0.643~0.908)、MMP-13(95%CI:0.706~0.986)、TIMP-1(95%CI:0.712~0.943)水平及MMP-13/TIMP-1值(95%CI:0.829~0.981)对难愈性创面患者治疗效果具有一定预测价值(AUC=0.776、0.846、0.827、0.905)。结论创面渗出液VEGF、MMP-13、TIMP-1、MMP-13/TIMP-1值能够对VSD联合人工真皮修复治疗难愈性创面效果产生重要影响,临床可通过测定VEGF、MMP-13、TIMP-1、MMP-13/TIMP-1值早期预测治疗效果。

基质金属蛋白酶13在靶向治疗骨关节炎的研究进展

骨关节炎(osteoarthritis,OA)是一类常见的慢性退行性疾病,可导致关节软骨、滑膜、软骨下骨等多组织损伤。目前,该疾病的发病机制尚未完全阐明。研究发现基质金属蛋白酶(matrix metalloproteinase,MMPs)与该疾病的发病过程相关,特别是MMP13,其在机体内的表达水平与OA关系密切。近年来,针对MMP13在该疾病发生发展中的作用,靶向MMP13治疗OA具有诸多进展,选择性MMP13抑制剂较广谱MMPs抑制剂具有选择性强、毒副作用低、效能高等优点,但需要频繁给药以维持药物在体内的有效浓度;将与MMP13 mRNA具有选择性互补的小干扰RNA注射入关节腔可有效降低体内MMP13蛋白产生并抑制多种炎症因子表达,且单次注射可较长时间维持药物效果;利用CRISPR⁃Cas9基因编辑技术靶向消融MMP13基因以减弱软骨细胞外基质蛋白的降解从而治疗OA的方式在动物体内外模型中均具有较好效果,但该技术在人体内长期应用的安全性也引发人们的思考。靶向MMP13治疗OA是医学界及科研领域的重要研究方向,未来结合更前沿的生物医学技术将为探索治疗OA提供新的策略。

补肾痹通方联合骨髓间充质干细胞对损伤软骨细胞的保护机制及SOX9、MMP-13表达的影响

目的:探讨补肾痹通方(BSBT)联合骨髓间充质干细胞(BMSCs)对白介素(IL)-1β诱导的损伤软骨细胞的保护机制及性别决定区Y框蛋白9(SOX9)、基质金属蛋白酶13(MMP-13)表达的影响。方法:使用10 ng/ml的IL-1β建立损伤软骨细胞模型,实验分为对照组、模型组(IL-1β)、中药组(IL-1β+BSBT)、干细胞组(IL-1β+BMSCs)和联合组(IL-1β+BSBT+BMSCs);CCK-8法检测各组软骨细胞增殖情况;RT-qPCR法和Western blot法分别检测软骨细胞内SOX9、MMP-13、Ⅱ型胶原α1重组蛋白(COL2A1)、IL-10的基因和蛋白表达;ELISA检测各组细胞培养上清中肿瘤坏死因子-α(TNF-α)、IL-6、胰岛素样生长因子1(IGF-1)、碱性成纤维细胞生长因子(bFGF)的水平。结果:与模型组比较,各组软骨细胞活性显著增强(P<0.01),软骨细胞中的SOX9、COL2A1、IL-10的基因和蛋白水平显著升高(P<0.01),MMP-13的基因和蛋白水平明显降低(P<0.01),软骨细胞培养上清中TNF-α、IL-6的含量显著降低(P<0.01),IGF-1、bFGF的水平升高(P<0.01),其中联合组变化最明显(P<0.05)。结论:BSBT联合BMSCs可有效保护损伤软骨细胞,其机制可能是通过上调SOX9,下调MMP-13,抑制炎症,改善软骨细胞微环境,促进关节软骨的修复与再生。

Inhibiting MMP13 Attenuates Deep Vein Thrombosis in a Mouse Model by Reducing the Expression of Pdpn

Objective:Matrix metalloproteinase 13(MMP13)is an extracellular matrix protease that affects the progression of atherosclerotic plaques and arterial thrombi by degrading collagens,modifying protein structures and regulating inflammatory responses,but its role in deep vein thrombosis(DVT)has not been determined.The purpose of this study was to investigate the potential effects of MMP13 and MMP13-related genes on the formation of DVT.Methods:We altered the expression level of MMP13 in vivo and conducted a transcriptome study to examine the expression and relationship between MMP13 and MMP13-related genes in a mouse model of DVT.After screening genes possibly related to MMP13 in DVT mice,the expression levels of candidate genes in human umbilical vein endothelial cells(HUVECs)and the venous wall were evaluated.The effect of MMP13 on platelet aggregation in HUVECs was investigated in vitro.Results:Among the differentially expressed genes,interleukin 1 beta,podoplanin(Pdpn),and factor VIII von Willebrand factor(F8VWF)were selected for analysis in mice.When MMP13 was inhibited,the expression level of PDPN decreased significantly in vitro.In HUVECs,overexpression of MMP13 led to an increase in the expression level of PDPN and induced platelet aggregation,while transfection of PDPN-siRNA weakened the ability of MMP13 to increase platelet aggregation.Conclusions:Inhibiting the expression of MMP13 could reduce the burden of DVT in mice.The mechanism involves downregulating the expression of Pdpn through MMP13,which could provide a novel gene target for DVT diagnosis and treatment.

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 pattern of matrix metalloproteinases-13 in a rat model of alcoholic liver fibrosis

BACKGROUND: Interstitial collagenase has been considered as an essential enzyme for collagenolysis in liver fi-brosis, because type Ⅰ and Ⅲ collagens increase predominantly in liver fibrosis. The present study aimed to demonstrate the gene expression of matrix metalloproteinases-13 (MMP-13) in the progressive phases of ethanol induced experimental liver fibrosis in rats. METHODS: Thirty-four Sprague-Dawley rats were randomly divided into two groups. The experimental group (24 rats) was given ethanol (44% , 7 g/kg) every day and the control group (10) was given normal saline. Liver samples were harvested from experimental rats at 4, 12 and 24 weeks respectively. The kinetics of MMP-13 mRNA expression was assayed by semi-quantity reverse transcriptase-poly-merase chain reaction (RT-PCR). RESULTS: In normal rat liver, a faint band for MMP-13 mRNA was observed by RT-PCR (0.24±0.41). The gene expression of MMP-13 was increased in the liver of the rats treated with ethanol for 4 weeks (0. 62 ±0. 54), but it was not considered statistically significant (P >0.05). And the livers from 12-week-treated rats showed a marked mRNA expression(1.65 ±0.47, P <0. 01). Once fibrosis became prominent (24 weeks), a faint band of MMP-13 mRNA was observed (0.39±0.25). CONCLUSION: MMP-13 participates in the degradation of newly-formed matrix in the early phase of rat liver fibrosis induced by ethanol, and it was induced in a distinct time frame.

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.

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.