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.

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.

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.

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.

Methanol extract of Codium fragile inhibits tumor necrosis factor-ɑ-induced matrix metalloproteinase-9 and invasiveness of MDA-MB-231 cells by suppressing nuclear factor-κB activation

Objective:To evaluate whether the methanol extract of Codium fragile(MECF) regulates tumor necrosis factor-α(TNF-α)-induced invasion of human breast cancer MDA-MB-231 cells by suppressing matrix metalloproteinase-9(MMP-9).Methods:Reverse transcriptionpolymerase chain reaction(RT-PCR) and western blot analysis were performed to analyze the expression of MMP-9 and nuclear factor-κB(NF-κB) subunits,p65 and p50,and IκB in MDA-MB-231 cells.3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide(MTT) assay was used for cell viability.MMP-9 activity and invasion were measured by gelatin zymography and a matrigel invasion assay,respectively.NF- κB activity was measured by an electrophoretic mobility shift assay and luciferase activity.Results:MECF had no effects on cell viability up to a concentration of 100 μg/mL in human breast cancer MDA-MB-231 cells regardless of the presence of TNF-α.MDA-MB-231 cells that were stimulated with TNF-α showed a marked increase of invasion compared to the untreated control,whereas pretreatment with MECF downregulated the TNF-α-induced invasion of MDA-MB-231 cells.Additionally,zymography,western blot analysis,and reverse transcriptase-polymerase chain reaction(RT-PCR) confirmed that MECF decreased TNF-α-induced MMP-9 expression and activity which is a key regulator for cancer invasion.According to an electrophoretic morbidity shift assay,pretreatment with MECF in MDA-MB-231 cells significantly decreased the TNF-α-induced DNA-binding activity of nuclear factor- κB(NF- κB),which is an important transcription factor for regulating cancer invasion-related genes such as MMP-9.Furthermore,treatment with MECF sustained the expression of p65 and p50 in response to TNF-α in the cytosolic compartment.The luciferase assay demonstrated that MECF attenuated TNF-α-induced NF- κB luciferase activity.Conclusion:MECF exhibited its antiinvasive capability by downregulating TNF-α-induced MMP-9 expression,resulting from the suppression of NF- κB activity in the human breast cancer cell line MDA-MB-231.

Macrophage Inflammatory Protein-lalpha mediates Matrix Metalloproteinase-9 enhancement in human adherent monocytes fed with malarial pigment

Objective:To investigate the role of macrophage inflammatory protein-1alpha(MIP-1 alpha) in the detrimental enhancement of matrix mnetalloproteinase-9(MMP-9) expression,release and activity induced by phagocytosis of malarial pigment(haemozoin,HZ) in human monocytes. Methods:Human adherent monocytes were unfed/fed with native HZ for 2 h.After 24 hours. MIP-1 alpha production was evaluated by ELISA in cell supernatants.Alternatively.HZunfed /fed monocytes were treated in presence/absence of anti-human MIP-1 alpha blocking antibodies or recombinant human MIP-lalpha for 15 h(RNA studies) or 24 h(protein studies): therefore,MMP-9 mRNA expression was evaluated in cell lysatcs by Real Time RT-PCR,whereas proMMP-9 and active MMP-9 protein release were measured in cell supernatants by Western blotting and gelatin zvmography.Results:Phagocytosis of HZ by human monocytes increased production of MIP-1 alpha.mRNA expression of MMP-9 and protein release of proMMP-9 and active MMP-9.All the HZ-enbancing effects on MMP-9 were abrogated by anti-human MIP- 1 alpha blocking antibodies and mimicked by recombinant human MIP-l alpha.Conclusions: The present work suggests a role for MIP-lalpha in the HZ-dependent enhancement of MMP-9 expression,release and activity observed in human monocytes.higbligbtiug new detrimental effects of HZ-triggered proinflammatory response by phagocytic cells in falciparum malaria.

Association of Matrix Metalloproteinase-9 and p53 Gene Polymorphisms with Genetic Susceptibility to No-small-cell Lung Cancer

Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with the risk and progression of many cancers. In this study, we evaluated the association of the R279Q polymorphism of MMP-9 or the A1/A2 polymorphism of p53 gcne with the risk of no-small-cell lung cancer（NSCLC） in Han population of Northeast China. We examined the frequency of SNPs in the two kinds of genes of 50 patients with NSCLC and 50 cancer-free controls frequency-matched by age and sex. Polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） technique was used to determine the genotypes. The results indicate that the 279RR genotype in MMP-9 gene and the A1/A2 genotype in p53 gene show a significantly increased risk of NSCLC. Therefore, the MMP-9 279RR and p53 A1/A2 genotypes may be used as markers for susceptibility to NSCLC in Han population of Northeast China.

Imbalance of matrix metalloproteinase-9 and matrix metalloproteinase tissue inhibitor-1 may contribute to hemorrhage in cerebellar arteriovenous malformations

In this study, we determined the expression levels of matrix metalloproteinase-2 and -9 and matrix metalloproteinase tissue inhibitor-1 and -2 in brain tissues and blood plasma of patients undergoing surgery for cerebellar arteriovenous malformations or primary epilepsy （control group）. Immunohistochemistry and enzyme-linked immunosorbent assay revealed that the expression of matrix metalloproteinase-9 and matrix metalloproteinase tissue inhibitor-1 was significantly higher in patients with cerebellar arteriovenous malformations than in patients with primary epilepsy. The ratio of matrix metalloproteinase-9 to matrix metalloproteinase tissue inhibitor-1 was significantly higher in patients with hemorrhagic cerebellar arteriovenous malformations compared with those with non-hemorrhagic malformations. Matrix metalloproteinase-2 and matrix metalloproteinase tissue inhibitor-2 levels were not significantly changed. These findings indicate that an imbalance of matrix metalloproteinase-9 and matrix metalloproteinase tissue inhibitor-I, resulting in a relative overabundance of matrix metalloproteinase-9, might be the underlying mechanism of hemorrhage of cerebellar arteriovenous malformations.

Changes in serum cellular adhesion molecule and matrix metalloproteinase-9 levels in patients with cerebral infarction following hyperbaric oxygen therapy A case and intergroup control study

BACKGROUND： Animal studies have confirmed that hyperbaric oxygen （HBO） therapy can reduce matrix metalloproteinase activity and blood brain barrier permeability, thereby exhibiting neuroprotective effects. However, at present, consensus does not exist in terms of its clinical efficacy. OBJECTIVE： To validate the significance of changes in serum cellular adhesion molecule and MMP-9 levels in patients with cerebral infarction following HBO therapy. DESIGN, TIME AND SETTING： This randomized, controlled, neurobiochemical study was performed at the Department of Neurology, Affiliated Hospital of Qingdao University Medical College between December 2002 and March 2006. PARTICIPANTS： A total of 112 patients with acute cerebral infarction of internal carotid artery, comprising 64 males and 48 females, averaging （67 ±11） years, were recruited and randomized to a HBO group （n = 50） and a routine treatment group （n = 62）. An additional 30 gender- and age-matched normal subjects, consisting of 17 males and 13 females, averaging （63 ± 9） years, were enrolled as control subjects. METHODS： The routine treatment group received routine drug treatment and rehabilitation exercise. HBO treatment was additionally performed in the HBO group, once a day, for a total of 10 days. MAIN OUTCOME MEASURES： Serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9 were detected by enzyme linked immunosorbent assay. RESULTS： Upon admission, serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9 were significantly increased in patients with cerebral infarction, compared with control subjects （P 〈 0.01）. Following HBO and routine treatments, serum levels of the above-mentioned indices were significantly reduced in the HBO and routine treatment groups （P 〈 0.01）. Moreover, greater efficacy was observed in the HBO group, compared with the routine treatment group （P 〈 0.05 or P 〈 0.01）. CONCLUSION： Intergroup comparison and case-control results indicated that HBO noticeably reduced serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9.

Expressions of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in malignant peripheral nerve sheath tumor

BACKGROUND： Matrix metalloproteinase-9 （MMP-9） can degrade collagen IV （the main structural ingredient of basilar membrane）, and it also plays an important role in tumor vascularization, tumor cell progression, formation of metastatic focus, etc. Tissue inhibitor of metalloproteinase-1 （T1MP-1） can bind with MMP-9 to form 1 ： 1 compound and inhibit its activity, and can negatively regulate the tumor progression and metastasis. OBJECTIVE： To analyze the relationship of MMP-9 and T1MP-1 expressions with the pathological grade, metastasis and prognosis of malignant peripheral nerve sheath tumor （MPNST）. DESIGN： An observational comparative experiment. SETTING： Heze Medical College. PARTICIPANTS： Fifty-eight surgical pathological samples, which were clearly diagnosed to be MPNST, were collected from the pathological laboratory archives in the Department of Pathology, Heze Municipal Hospital from January 1988 to December 2003. The MPNST pathological types were common tumor in 53 cases, malignant triton tumor in 2 cases, epithelial MPNST in 2 cases and MPNST with gland differentiation in 1 case. The pathological grade was grade 1 in 11 cases, grade 2 in 24 cases and grade 3 in 23 cases. Besides, the resected tumor samples of 20 patients with benign peripheral nerve tumor （10 cases of nerve sheath tumor and 10 cases of neurofibromatosis） and the normal peripheral nerves （by-products of some surgeries） of 5 patients were also collected. The samples were used with the approval of the patients. Rat-anti-human MMP-9, TIMP-1 monoclonal antibody and S-P kit were purchased from Fuzhou Maixin Biotechnology, Co.,Ltd. METHODS： The documented paraffin blocks were again prepared to sections of 5 lJ m. The expressions of MMP-9 and TIMP-1 in the samples were detected with mmunohistochemical S-P method. The relationships of the MPNST severity, recurrence, metastasis and survival rate with the expressions of MMP-9 and TIMP-1 were analyzed. MAIN OUTCOME MEASURES： Relationships of MMP-9 and TIMP-1 expressions with the MPNST severity and prognosis. RESULTS： ①Expressions of MMP-9 and TIMP-1 in three tissues： MMP-9 and TIMP-1 stainings were mainly observed in cytoplasm. Among the 58 MPNST patients, the MMP-9 expression was significantly higher than those in normal peripheral nerve and benign tumor （P 〈 0.05）, while the TIMP-1 expression in MPNST was lower than those in normal peripheral nerve and benign tumor （P 〈 0.05）. ②Relationship of MMP-9 and TIMP-1 expressions with the severity and prognosis of MPNST： The expressions of both proteins were observed in the four subtypes. The positive expression of MMP-9 in the MPNST patients of grades 2 - 3 was significantly higher than that in the MPNST patients of grade 1 （P 〈 0.05）, while the expression of MMP-9 was significantly lower than that in the MPNST patients of grade 1 （P 〈 0.05）. The metastatic rate was positively correlated with MMP-9 expression （r =1.696, P 〈 0.05）, but negatively correlated with TIMP-1 expression （r = - 2.125, P 〈 0.05）. CONCLUSION： MMP-9 and TIMP-1 are associated with MPNST pathological grades and metastasis, and can be used as the indicators for judging the severity and orognosis of MPNST.

Combination of neutrophil gelatinase-associated lipocalin and matrix metalloproteinase-9 are biomarkers for the detection of colon tubular adenocarcinoma

BACKGROUND Tubular adenocarcinoma of the colon,which originates from the epithelium of the glands,is a major health concern worldwide.However,it is difficult to detect at an early stage.The lack of biomarkers is a main barrier to the diagnosis and treatment of tubular adenocarcinoma.Neutrophil gelatinase-associated lipocalin(NGAL)is a secreted protein that induces the expression of matrix metalloproteinase-9(MMP-9)and is involved in various tumors.NGAL and MMP-9 have been reported to be associated with tumorigenesis and development.They may have potential as biomarkers for diagnosis of tubular adenocarcinoma of the colon.AIM To determine whether NGAL and MMP-9 can be used as potential biomarkers to indicate the progression of tubular adenocarcinoma of the colon.METHODS Samples were collected from surgically excised tissue from various patients.The content of pro-gastrin-releasing peptide(pro-GRP)in the serum was measured by an electrochemiluminescence immunoassay.The expression patterns of NGAL and MMP-9 and the relationship between NGAL and MMP-9 were examined by quantitative real-time PCR,Western blotting and immunohistochemical analysis.RESULTS In this study,we found that NGAL and MMP-9 can be used as biomarkers for the detection of tubular adenocarcinoma of the colon and that their combination improved diagnostic accuracy.By analyzing the expression of NGAL in tubular adenocarcinoma at different levels,we found that NGAL expression was significantly upregulated in primary tubular adenocarcinoma tissues compared with normal tissues.The upregulation of NGAL expression was strongly correlated with both the degree of differentiation and the disease stage(I–III),indicating that NGAL could serve as a diagnostic biomarker for tubular adenocarcinoma.When using NGAL as a biomarker for diagnosis,the accuracy was similar to that achieved with the widely used biomarker pro-GRP,suggesting that NGAL is reliable.Moreover,the expression of MMP-9 was also strongly correlated with the differentiation stage,demonstrating that MMP-9 could be used as a biomarker to indicate the progression of tubular adenocarcinoma of the colon.More importantly,the combination of NGAL and MMP-9 produced a more accurate diagnosis of tubular adenocarcinoma,and these results were further confirmed by immunohistochemical analysis of tissue sections.CONCLUSION Our study demonstrated that both NGAL and MMP-9 can be used as biomarkers for the diagnosis of colon tubular adenocarcinoma and that the results could be further improved by combining them.

Cooperative binding of calcium ions modulates the tertiary structure and catalytic activity of Matrix-Metalloproteinase-9

To ascertain the molecular basis of Ca2+-mediated activation of matrix metalloproteinase-9 (MMP-9), we determined the accessibility of tryptophan residues to externally added acrylamide as quencher in the absence and presence of the metal ion. The steady-state and time resolved fluorescence data revealed that MMP-9 possesses two classes of tryptophan residues, “exposed” and “buried” which are quenched by the collisional rate constants (kq) of 3.2′ 109M-1.s-1 and 7.5′ 108M-1.s-1, respectively. These values are impaired by approximately two and three-fold, respectively, in the presence of 10 mM Ca2+. The Stern-Volmer constants (Ksv values) predicted from the time resolved fluorescence data (in the absence of Ca2+ ) satisfied the dynamic quenching model of the enzyme’s tryptophan residues. This was not the case in the presence of Ca2+;the steady-state acrylamide quenching data could only be explained by a combination of “dynamic” and “static” quenching models. A cumulative account of these data led to the suggestion that the binding of Ca2+ modulated the tertiary structure of the protein by decreasing the dynamic flexibility of the enzyme, which is manifested in further structuring of the enzyme’s active site pocket toward facilitating catalysis. Arguments are presented that the binding of Ca2+ at distal sites “dynamically” communicates with the active site residues of MMP-9 during catalysis.

Prognostic Value of the Matrix Metalloproteinase-9 and Its Relation to Clinicopathological Features in Women with Invasive Breast Cancer

Background: Invasive breast cancer is the most common type of malignancy in women worldwide. Matrix Metalloproteinase-9 is a member of degrading enzymes required for tumor metastasis. Aim: To assess the prognostic significance of the Matrix Metalloproteinase-9 expression in invasive breast cancer and its association with the clinicopathological features. Patients and Methods: Cross-sectional study was conducted at the Oncology and Nuclear Therapy Unit, Suez Canal University Hospital. The study involved 33 females that were registered between January 1st, 2008 and December, 31st, 2012. The eligible participants had a confirmed non-metastatic invasive ductal carcinoma, underwent surgery that their paraffin blocks containing tumor were available. The participants’ tissue specimens were immune stained for Matrix Metalloproteinase-9 expression level in the hospital pathology lab. Survival analysis and correlation models were conducted to explore the association between Matrix Metalloproteinase-9 expression level with clinicopathological parameters and survival. Results: The mean age of participants was 51.2 ± 9.9 years. The mortality rate was 18.2%. The mean Matrix Metalloproteinase-9 expression was 5.42 (±3.37);57.6% showed high expression level. There was no significant correlation with clinicopathological features. Nottingham Prognostic Index was a significant predictor of mortality. Overall survival and disease-free survival were insignificantly different among cases with low and high MMP-9 expression. Conclusion: Tissue Matrix Metalloproteinase-9 expression level does not play a significant role in disease progression. However, Nottingham Prognosis Index is a significant predictor of mortality among studied breast cancer cases.

Inhibition of matrix metalloproteinase-9 secretion by dimethyl sulfoxide and cyclic adenosine monophosphate in human monocytes

BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic and regulatory pathways that mediate MMP-9 secretion.There is significant evidence for regulation of inflammation by dimethyl sulfoxide(DMSO)and 3',5'-cyclic adenosine monophosphate(cAMP),thus investigation of how these two molecules may regulate both MMP-9 and tumor necrosis factorα(TNFα)secretion by human monocytes was of high interest.The hypothesis tested in this study was that DMSO and cAMP regulate MMP-9 and TNFαsecretion by distinct mechanisms.AIM To investigate the regulation of lipopolysaccharide(LPS)-stimulated MMP-9 and tumor necrosis factorαsecretion in THP-1 human monocytes by dimethyl sulfoxide and cAMP.METHODS The paper describes a basic research study using THP-1 human monocyte cells.All experiments were conducted at the University of Missouri-St.Louis in the Department of Chemistry and Biochemistry.Human monocyte cells were grown,cultured,and prepared for experiments in the University of Missouri-St.Louis Cell Culture Facility as per accepted guidelines.Cells were treated with LPS for selected exposure times and the conditioned medium was collected for analysis of MMP-9 and TNFαproduction.Inhibitors including DMSO,cAMP regulators,and anti-TNFαantibody were added to the cells prior to LPS treatment.MMP-9 secretion was analyzed by gel electrophoresis/western blot and quantitated by ImageJ software.TNFαsecretion was analyzed by enzyme-linked immuno sorbent assay.All data is presented as the average and standard error for at least 3 trials.Statistical analysis was done using a two-tailed paired Student t-test.P values less than 0.05 were considered significant and designated as such in the Figures.LPS and cAMP regulators were from Sigma-Aldrich,MMP-9 standard and antibody and TNFαantibodies were from R&D Systems,and amyloid-βpeptide was from rPeptide.RESULTS In our investigation of MMP-9 secretion from THP-1 human monocytes,we made the following findings.Inclusion of DMSO in the cell treatment inhibited LPSinduced MMP-9,but not TNFα,secretion.Inclusion of DMSO in the cell treatment at different concentrations inhibited LPS-induced MMP-9 secretion in a dosedependent fashion.A cell-permeable cAMP analog,dibutyryl cAMP,inhibited both LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the adenylyl cyclase activator forskolin inhibited LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the general cAMP phosphodiesterase inhibitor IBMX reduced LPS-induced MMP-9 and TNFαin a dose-dependent fashion.Pre-treatment of monocytes with an anti-TNFαantibody blocked LPSinduced MMP-9 and TNFαsecretion.Amyloid-βpeptide induced MMP-9 secretion,which occurred much later than TNFαsecretion.The latter two findings strongly suggested an upstream role for TNFαin mediating LPS-stimulate MMP-9 secretion.CONCLUSION The cumulative data indicated that MMP-9 secretion was a distinct process from TNFαsecretion and occurred downstream.First,DMSO inhibited MMP-9,but not TNFα,suggesting that the MMP-9 secretion process was selectively altered.Second,cAMP inhibited both MMP-9 and TNFαwith a similar potency,but at different monocyte cell exposure time points.The pattern of cAMP inhibition for these two molecules suggested that MMP-9 secretion lies downstream of TNFαand that TNFαmay a key component of the pathway leading to MMP-9 secretion.This temporal relationship fit a model whereby early TNFαsecretion directly led to later MMP-9 secretion.Lastly,antibody-blocking of TNFαdiminished MMP-9 secretion,suggesting a direct link between TNFαsecretion and MMP-9 secretion.

Study on matrix metalloproteinase-2, 9 in peri-implant sulcular fluid

Objective: To study the expression of matrix metalloproteinases-2, 9 (MMP-2, MMP-9) of healthy implant and peri-implant sulcular fluid (PISF) by enzyme-linked immunosorbent assay (ELISA) method, and evaluate the level of MMP-2 and MMP-9 in sulcular fluid as an objective indicator of tissue inflammation around implants. Methods: A total of 40 implants were selected from 30 patients who were treated with dental implants and were divided into two groups: the inflammatory group and the healthy control group with 20 pieces respectively. ELISA double antibody sandwich method was used to detect the levels of MMP-2 and MMP-9 in PISF. Results: The MMP-2 and MMP-9 expressions were significantly different between the healthy implant group and the peri-implant group (p < .05). The concentration of MMP-2, MMP-9, and the amount of sulcular fluid in the inflammatory implant group were positively correlated with the clinical parameters (probing depth [PD], modified sulcus bleeding index [mSBI]). Conclusions: Under physiological conditions, the levels of MMP-2 and MMP-9 were low. When the periodontal tissue was stimulated by inflammation, the expression levels of MMP-2 and MMP-9 were increased, which could reflect the severity of inflammation. The increase levels of MMP-2 and MMP-9 in PISF could better reflect the health status of peri-implant tissues, which could be used as an objective indicator to assist in the diagnosis of peri-implant inflammation.

MicroRNA-223及MMP-9在风湿性心瓣膜病合并心房颤动患者中的表达及临床意义

目的探索miRNA-223与金属基质蛋白酶(matrix metalloproteinases,MMP)在风湿性心瓣膜病(风心病)合并心房颤动(房颤)患者的表达水平及在房颤心肌结构重构的发生机制。方法风心病接受瓣膜置换术患者31例,其中风心病窦性心律组15例,风心病慢性房颤组16例。收集患者右心房心肌组织,实时荧光定量聚合酶链反应检测心房肌组织和血清miRNA-223的相对表达量。酶联免疫吸附试验及免疫组织化学检测血清及心肌组织MMP-9蛋白的表达及分布水平;苏木素-伊红染色及Masson染色观察心肌组织病理结构及胶原纤维含量变化。结果与窦性心律组相比,房颤组心房肌组织miRNA-223表达水平升高,差异有统计学意义(0.0603±0.0228 vs.0.0261±0.0035,P<0.01);房颤组血清MMP-9表达水平高于窦性心律组,差异有统计学意义[(4.2281±0.9165)ng/mL vs.(2.7613±1.2166)ng/mL,P<0.05]。MMP-9蛋白表达水平与胶原容积分数(collagen volume fraction,CVF)呈正相关(r=0.406,P<0.05);MiRNA-223表达水平与MMP-9蛋白表达呈正相关(r=0.901,P<0.05)。结论房颤患者心房组织中miRNA-223及MMP-9蛋白表达水平均升高。

脑泰方提取物干预大鼠脑缺血后MMP-9-mRNA及PA-mRNA表达研究

目的研究大鼠脑缺血后益气活血中药脑泰方提取物(黄芪、川芎、地龙、僵蚕)干预对缺血区脑水肿及MMP-9-mRNA、PA-mRNA表达的影响。方法随机将SD大鼠分为假手术组、模型组、脑泰方提取物(NTE)低、中、高剂量组(3,9,27g/kg)。各组大鼠预处理ig给药连续3d,每日1次,MCAO模型制备术后ig给药1d。术后1d取材检测各组脑组织含水量,RT-PCR检测MMP-9-mRNA及PA-mRNA表达。结果实验表明高、中NTE组与模型组比较,脑含水量均有明显降低(P<0.05)。NTE高剂量组脑缺血区MMP-9-mRNA、PA-mRNA表达明显降低(P<0.05)。结论脑泰方提取物干预可减轻脑水肿的发生,可能是通过降低MMP-9-mRNA及PA-mRNA的表达,减少MMP-9、PA的生成,发挥保护急性脑缺血血脑屏障的作用。