Expressions of matrix metalloproteinases 1 and 3 and their tissue inhibitors in the conjunctival tissue and fibroblasts cultured from conjunctivochalasis

AIM：To investigate the expression of matrix metalloproteinases 1 and 3（MMP-1 and MMP-3） and their tissue inhibitors of metalloproteinases 1 and 3（ TIMP-1 and TIMP-3） in the conjunctiva of eyes with conjunctivochalasis（CCh）.METHODS：The conjunctival tissue was obtained from the CCh patients and controls,the MMPs/TIMPs expression concentration was determined by enzyme-linked immunosorbent assay（ELISA） and immunofluorescence staining.The expression levels of MMPs/TIMPs in the CCh fibroblasts were determined by analyzing its concentration in the cellular supernatant that was abstracted from the in vitro cultured CCh fibroblasts.RESULTS：MMP-1 and MMP-3 levels determined by ELISA were both significantly higher in the CCh group than that in the control group（P= 0.042,0.022,respectively）,so was the levels of TIMP-1（P= 0.010）.No significant difference in the expression of TIMP-3 in conjunctiva was found between the two groups（P= 0.298）.The expression of MMP-1 and MMP-3 were both up-regulated significantly in the CCh group（P= 0.040,0.001,respectively） on immunofluorescence staining.MMP-1 and MMP-3 expression in the fibroblasts were both significantly higher in the CCh group than that in the control group（P= 0.027,0.001,respectively）,while neither the TIMP-1 nor TIMP-3 expression was significantly different between the two groups（P= 0.421,0.237,respectively）.CONCLUSION：The overexpression of MMP-1 and MMP-3 in conjunctival tissue and fibroblasts may play an important role in the pathogenesis and development of CCh.

The Expression of Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases in Idiopathic Interstitisal Pneumonia

Background: Idiopathic interstitial pneumonia is characterized by fibroblast proliferation and extracellular matrix (ECM) accumulation. Matrix metalloproteases (MMPs) and tissue inhibitors of metalloproteases (TIMPs) have been shown to regulate remodeling of the ECM, which indicates that they are important factors in the process of lung fibrosis. Therefore, we evaluated the expression of MMPs and TIMPs in tissues obtained from patients with idiopathic interstitial pneumonia and control tissues. Methods: Thirty-seven patients who were diagnosed with IIP (22: IPF, 13: NSIP, 2: COP) and 5 controls were enrolled in this study. The MMP-2 and -9 activity in lung tissue obtained from these patients was analyzed using gelatin zymography and the levels of TIMP-1 and -2 were measured by western blotting. We also evaluated the expression of MMP-2 and -9, as well as that of TIMP-1 and -2 in lung tissue using immunohistochemistry. Results: The levels of MMP-2 and MMP-9 were significantly increased in patients with IPF compared to those with NSIP and COP. The activities of TIMP-1 and -2 were also higher in patients with IPF than NSIP/COP patients and control subjects. There were no significant differences observed in the activities of MMPs and TIMPs obtained from patients with NSIP/COP and control subjects. The immunohistochemical analysis showed that TIMP-2 and MMP-2 were strongly stained at the fibroblasts of the fibroblastic foci in patients with IPF. Conclusions: These results suggest that over-expression of gelatinases and TIMPs in patients with IPF are important factors in the irreversible fibrosis that is associated with lung parenchyma.

Expressions of matrix metalloproteinases and tissue inhibitor of metalloproteinases after bare and magnetic stent implantation in rabbits

Objective We aimed to investigate whether magnetic stent has preventive effect on in-stent restenosis by observing expressions of matrix metalloproteinase (MMP)2, MMP9, tissue inhibitor of matrix metalloproteinase (TIMP)1 and TIMP2 after balloon angioplasty, bare and magnetic stent implantation in rabbits. Methods Rabbits underwent balloon angioplasty, bare and magnetic stent implantation in the left iliac arteries. The changes of MMPs and TIMPs were examined at various time points in the injured arteries using the methods of zymography, Western blot analysis, reverse transcription-polymerase chain reaction (RT-PCR) and morphometric analysis. Results Balloon angioplasty group (BA) and magnetic stent group (MS) showed lower intrinsic gelatinolytic activity and higher expression of TIMPs with less intimae hyperplasia;Whereas bare stent (BS) group exhibited higher intrinsic gelatinolytic activity and lower expression of TIMPs with significant intimae hyperplasia. Conclusion Magnetic stent probably has preventive effect on in-stent restenosis by changing intrinsic matrix metalloproteinases activity and expression of TIMPs.

Single-nucleotide polymorphisms of matrix metalloproteinases and their inhibitors in gastrointestinal cancer

Matrix metalloproteinases(MMPs) are implicated in cancer development and progression and are associated with prognosis.Single-nucleotide polymorphisms(SNPs) of MMPs,most frequently located in the promoter region of the genes,have been shown to influence cancer susceptibility and/or progression.SNPs of MMP-1,-2,-3,-7,-8,-9,-12,-13 and-21 and of the tissue inhibitor of metalloproteinases(TIMPs) TIMP-1 and TIMP-2 have been studied in digestive tract tumors.The contribution of these polymorphisms to the cancer risk and prognosis of gastrointestinal tumors are reviewed in this paper.

Correlation of matrix metalloproteinase－2, －9, tissue inhibitor－1 of matrix metalloproteinase and CD44 variant 6 in head and neck cancer metastasis

This study aimed to explore the molecular mechanism in tumor invasion and metastasis. The expression of matrix metalloproteinase 2, 9 (MMP 2, MMP 9), tissue inhibitor 1 of matrix metalloproteinase (TIMP 1), cell adhesion molecule 44 variant 6 (CD44v6), HER2/neu and p53 was investigated in 154 patients with head and neck squamous cell carcinoma (SCC) by ABC and ImmunoMax immunohistochemical method. Their clinical relevance and correlation were analysed. The expression of MMP 2, MMP 9, TIMP 1, CD44v6, HER2/neu and p53 was found in cancer cells in 87.01%, 85.71%, 68.18%, 98.05%, 55.19% and 50.65% cases respectively. Linear regression and correlation analysis revealed that there was close positive relationship ( P <0.05) between the expression of MMP 2 and MMP 9, TIMP 1 and CD44v6, HER2/neu and MMP 9, MMP 2 and p53. Up regulation of MMP 2 was accompanied by advanced T stage ( P <0.01) . There was also a trend of MMP 2 expression being related with tumor metastasis. Increased expression of HER2/neu was found in patients with tumor recurrence( P <0.05). The expression of TIMP 1 was higher in laryngeal cancer than that in pharyngeal cancer, and higher in keratinizing and non keratinizing SCC than that in basaloid SCC( P <0.05). These findings suggested that MMP 2 and MMP 9, HER2/neu and MMP 9, MMP 2 and p53 had a coordinate function in aggression of tumor; that MMP 2 had a more important function than MMP 9 in tumor invasion and metastasis; and that HER2/neu might serve as a biomarker for poor prognosis in HNSCC.

Expression of Matrix Metalloproteinase and Its Tissue Inhibitor in Haemangioma

The action mechanism of matrix metalloproteinases-2 （MMP-2） and tissue inhibitor of metalloproteinases-2 （TIMP-2） in the genesis, development and degeneration of haemangioma was investigated by detecting their expression in the tissue of haemangioma in different phases by using the immunohistochemistry. Fifty paraffin-embedded specimens of skin capillary haemangioma were collected, which were documented in the Department of Pathology, Renmin Hospital of Wuhan University from 2000 to 2006. All samples were stained by regular HE method, and proliferative cell nuclear antigen （PCNA） was tested by immunohistochemical S-P method. The samples were classified according to the Mulliken criteria and the expression pattern of PCNA. Immunohistochemical S-P method was ap- plied to detect the expression of MMP-2 and TIMP-2 in proliferative and degenerative phases of cutaneous capillary haemangioma, and in normal skin tissues. In combination with the detection of the expression of factor Ⅷ-related antigen, it was verified that in haemangioma tissues, the cells expressing MMP-2 and TIMP-2 were vascular endothelial cells. The MMP-2 and TIMP-2 expression was quantitatively analyzed by image analysis system （HPIAS-1000）, and one-way ANOVA（107） and SNK（q） test were done to analyze average absorbance （A） and positive area rate of immunohistochemically positive particles by using SPSS11.5. The results showed： （1） Among 50 samples of haemangioma, there were 26 proliferative haemangiomas, and 24 degenerative haemangiomas, respectively; （2） The expression of MMP-2 was weak in normal vascular endothelial cells, cytoplasm of connective tissues and extracellular matrix around blood vessels. The expression of MMP-2 in proliferative group was significantly higher than in degenerative group and control group （normal skin） （P〈0.05）, but there was no statistically significant difference between the latter two groups; （3） TIMP-2 was highly expressed in normal tissues, degenerative vascular endothelial cells, cytoplasm of connective tissues and extracellular matrix around blood vessels. The expression level of TIMP-2 in proliferative phase was significantly lower than in degenerative phase （P〈0.05）, and the expression of TIMP-2 in proliferative phase was significantly different from that in degenerative phase and normal tissues （P〈0.05）. It was concluded that in proliferative phase of haemangioma, MMP-2 may promote over-proliferation of endothelial cells of haemangioma, and in degenerative phase, TIMP-2 can inhibit the proliferation of endothelial cells of haemangioma. The two substances play important roles in the genesis, development and degeneration of haemangiomas.

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.

Serum Matrix Metalloproteinase 3 and Tissue Inhibitor Metalloproteinase 1 in Vascular Dementia: A Comparative Study

Aim: To compare serum level of matrix metalloproteinase 3 (MMP3) and tissue inhibitor metallo-proteinase 1 (TIMP1) in vascular dementia patients and healthy control subjects. Methods: A case control study was carried out in Ain Shams University hospital, Cairo, Egypt. 32 cases with vascular dementia were collected and classified into 2 subgroups;vascular dementia of multiinfarct type (VDMI) 14 patients, and vascular dementia of subcortical type (VDSC) 18 subjects. 23 cases with normal cognitive functions were collected as control group. Cases were subjected to comprehensive geriatric assessment, neurological examination, neuropsychological testing and brain CT scan. Blood sample was collected to analyze serum level of matrix metalloproteinase 3 (MMP3) and tissue inhibitor metalloproteinase 1 (TIMP1). Results: Mean serum level of TIMP1 (20.85 × 103 picogram/ml) was significantly lower than mean serum level of TIMP1 in control group (27.69 × 103 picogram/ml) (p = 0.018). The same finding was also evident when comparing VDMI subgroup mean serum TIMP1 (18.71 × 103 pc/ml) to control group (p = 0.025). There was no significant difference between mean serum MMP3 levels in cases group (mean = 67.39 × 103) as compared to control group (mean = 61.65 × 103 pc/ml) (p = 0.519). Conclusion: Patients with VD particularly VDMI has lower serum level of TIMP1 as compared to control group.

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.

Expression of matrix metalloproteinase-7 and tissue inhibitor of metalloproteinase-2 in human endometrial carcinoma

Objective:To investigate the expression of matrix metalloproteinase-7(MMP-7) and its tissue inhibitor (TIMP-2) in endometrial carcinoma and analyze their significance in endometrial cancer's invasion and metastasis. Methods:Endometrial tissues were collected from 64 patients with endometrial carcinoma,20 patients with endometrial hyperplasia and 20 normal women.The expressions of MMP-7,TIMP-2 in endometrium were measured by immuohistochemistry. Results;Expressions of MMP-7,TIMP-2 in endometrium of patients with endometrial carcinoma were significantly higher than those in normal endometrium(P<0.05).MMP-7 expression increased with surgical-pathological staging,depth of myometrial invasion,histologic grades and lymph node metastasis(P<0.05),while TIMP-2 expression was related to lymph node metastasis(P<0.05).TIMP-2 expression in endometrial cancer was significantly higher than that in hyperplastic endometrium(P<0.05).Expressions of TIMP-2 and MMP-7 in endometrium of patients with endometrial carcinoma were positively correlated(r=0.654,P<0.001). Conclusion:Highly expressed MMP-7 and TIMP-2 in endometrium may be related to development,invasion and metastasis of endometrial cancers.

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.

Complex role of matrix metalloproteinases in angiogenesis

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) play a significant role in regulating angiogenesis, the process of new blood vessel formation. Interstitial collagenase (MMP-1), 72 kDa gelatinase A/type IV collagenase (MMP-2), and 92 kDa gelatinase B/type IV collagenase (MMP-9) dissolve extracellular matrix (ECM) and may initiate and Promote angiogenesis. TIMP-1, TIMP-2, TIMP-3, and possibly,TIMP-4 inhibit neovascularisation. A new paradigm is emerging that matrilysin (MMP-7), MMP-9, and metalloelastase (MMP-12) may block angiogehesis by converting plasndnogen to angiostatin, which is one of the most potent angiogenesis antagonists. MMPs and TIMPs play a complex role in regulating angiogenesis. An understanding of the biochemical and cellular pathways and mechanisms of angiogenesis will provide importal information to allow the control of angiogenesis, e.g. the stimulation of angiogenesis for coronary collateral circulation formation; while the inhibition for treating arthritis and cancer.

Matrix metalloproteinases and gastrointestinal cancers: Impacts of dietary antioxidants

The process of carcinogenesis is tightly regulated by antioxidant enzymes and matrix degrading enzymes, namely, matrix metalloproteinases(MMPs). Degradation of extracellular matrix(ECM) proteins like collagen, proteoglycan, laminin, elastin and fibronectin is considered to be the prerequisite for tumor invasion and metastasis. MMPs can degrade essentially all of the ECM components and, most MMPs also substantially contribute to angiogenesis, differentiation, proliferation and apoptosis. Hence, MMPs are important regulators of tumor growth both at the primary site and in distant metastases; thus the enzymes are considered as important targets for cancer therapy. The implications of MMPs in cancers are no longer mysterious; however, the mechanism of action is yet to be explained. Herein, our major interest is to clarify how MMPs are tied up with gastrointestinal cancers. Gastrointestinal cancer is a variety of cancer types, including the cancers of gastrointestinal tract and organs, i.e., esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The activity of MMPs is regulated by its endogenous inhibitor tissue inhibitor of metallopro-teinase(TIMP) which bind MMPs with a 1:1 stoichiometry. In addition, RECK(reversion including cysteinerich protein with kazal motifs) is a membrane bound glycoprotein that inhibits MMP-2,-9 and-14. Moreover, α2-macroglobulin mediates the uptake of several MMPs thereby inhibit their activity. Cancerous conditions increase intrinsic reactive oxygen species(ROS) through mitochondrial dysfunction leading to altered protease/anti-protease balance. ROS, an index of oxidative stress is also involved in tumorigenesis by activation of different MAP kinase pathways including MMP induction. Oxidative stress is involved in cancer by changing the activity and expression of regulatory proteins especially MMPs. Epidemiological studies have shown that high intake of fruits that rich in antioxidants is associated with a lower cancer incidence. Evidence indicates that some antioxidants inhibit the growth of malignant cells by inducing apoptosis and inhibiting the activity of MMPs. This review is discussed in six subchapters, as follows.

MATRIX METALLOPROTEINASE AND THEIR INHIBITORS: MOLECULAR ASPECTS OF THEIR ROLES IN THE TUMOR METASTASIS

The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes, whose physiological functions include tissue remo-delling and embryogenesis. The importance of this group of proteins in the processes of tumor invasion and metastasis is now widely acknowledged, and has led to the search for MMP inhibitors for use as anticancer treatments in a clinical setting. The review aims to introduce current research relating to MMPs as well as their native and synthetic inhibitor, with particular emphasis on the molecular aspects of their roles in tumor metastasis.

Matrix metalloproteinases in the restorative proctocolectomy pouch of pediatric ulcerative colitis

AIM:To investigate matrix metalloproteinases(MMPs) and their tissue inhibitors(TIMPs) in pouch mucosa of pediatric onset ulcerative colitis(UC).METHODS:In this cross-sectional study,28 patients with pediatric onset UC underwent ileal pouch biopsy 13 years(median) after proctocolectomy.Expression of MMPs-3,-7,-8,-9,-12 and-26 and TIMPs-1,-2 and-3 in samples was examined using immunohistochemichal methods,and another biopsy was used to evaluate the grade of histological inflammation.Two investigators independently graded the immunohistochemical specimens in a semiquantitative fashion,using a scale marking staining intensity as follows:0 = less than 20 positive cells;1 = 20-50 positive cells;2 = 50-200 positive cells;3 = over 20 positive cells.Fecal calprotectin and blood inflammatory markers [serum C-reactive protein(CRP) and erythrocyte sedimentation rate] were determined during a follow-up visit to examine correlations between these markers and the expression of MMPs and TIMPs.RESULTS:Of the 28 patients with pediatric onset UC,nine had not experienced pouchitis,whereas thirteen reported a single episode,and six had recurrent pouchitis(≥ 4 episodes).At the time of the study,six patients required metronidazole.In all of the others,the most recent episode of pouchitis had occurred over one month earlier,and none were on antibiotics.Only four samples depicted no sign of inflammation,and these were all from patients who had not had pouchitis.Two samples were too small to determine the grade of inflammation,but both had suffered pouchitis,the other recurrent.No sample depicted signs of colonic metaplasia.Most pouch samples showed expression of epithelial(e) and stromal(s) MMP-3(e,n = 22;s,n = 20),MMP-7(e,n = 28;s,n = 27),MMP-12(e,n = 20;s,n =24),TIMP-2(e,n = 23;s,n = 23) and MMP-3(e,n = 23;s,n = 28) but MMP-8(e,n = 0;s,n = 1),MMP-9(e,n = 0;s,n = 9) and MMP-26(e,n = 0;s,n = 3) and TIMP-1(n = 0,both) were lacking.In samples with low grade of inflammatory activity,the epithelial MMP-3 and MMP-7 expression was increased(r =-0.614 and r =-0.472,respectively,P < 0.05 in both).MMPs and TIMPs did not correlate with the markers of inflammation,fecal calprotectin,erythrocyte sedimentation rate,or CRP,with the exception of patients with low fecal calprotectin(< 100 μg/g) in whom a higher expression of epithelial MMP-7 was found no differences in MMPor TIMP-profiles were seen in patients with a history of pouchitis compared to ones with no such episodes.Anastomosis with either straight ileoanal anastomosis or ileoanal anastomosis with J-pouch did depict differences in MMP-or TIMP-expression.CONCLUSION:The expression of MMPs pediatric UC pouch in the long-term shares characteristics with inflammatory bowel disease,but inflammation cannot be classified as a reactivation of the disease.

Doxycycline blocks gastric ulcer by regulating matrix metalloproteinase-2 activity and oxidative stress

AIM: To examine the effect of doxycycline on the activity of matrix metalloproteinases (MMPs) and oxidative stress in gastric tissues of rats following gastric injury.METHODS: Gastric ulcers were generated in rats by administration of 70% ethanol,and activity of doxycycline was tested by administration 30 min prior to ethanol.Similarly,the effect of doxycycline was tested in an indomethacin-induced gastric ulcer model.The activities and expression of MMPs were examined by zymography and Western blot analysis.RESULTS: Gastric injury in rats as judged by elevated ulcer indices following exposure to ulcerogen,either indomethacin or ethanol,was reversed significantly by doxycycline.Indomethacin-induced ulcerated gastric tissues exhibited about 12-fold higher proMMP-9 activity and about 5-fold higher proMMP-3 activity as compared to control tissues.Similarly,ethanol induced about 22-fold and about 6-fold higher proMMP-9 and proMMP-3 activities,respectively,in rat gastric tissues.Both proMMP-9 and MMP-3 activities were markedly decreased by doxycycline in ulcerogen treated rat gastric tissues.In contrast,the reduced MMP-2 activity in ulcerated tissues was increased by doxycycline during ulcer prevention.On the other hand,doxycycline inhibited significantly proMMP-9,-2 and -3 activities in vitro.In addition,doxycycline reduced oxidative load in gastric tissues and scavenged H2O2 in vitro.Our results suggest a novel regulatory role of doxycycline on MMP-2 activity in addition to inhibitory action on MMP-9 and MMP-3 during prevention of gastric ulcers.CONCLUSION: This is the first demonstration of dual action of doxycycline,that is,regulation of MMP activity and reduction of oxidative stress in arresting gastric injury.

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.

Modulation of Matrix Metalloproteinase and TIMP-1 Expression by TGF-β_1 in Cultured Human RPE Cells

In order to investigate the effects of TGF-β1 on the expression of MMP-2, -9 and TIMP- 1 in human retinal pigment epithelial （RPE） cells, the third-sixth passage cultured RPE cells were treated with TGF-β1 at different concentrations （0.01, 0. 1, 1.0, 10 ng/mL）, the expression of MMP-2, -9 and TIMP-1 mRNA was detected by semi-qudntitative RT-PCR assays. MMP-2, -9 and TIMP-1 mRNA were expressed in the cultured RPE cells. The values of MMP-2/β-actin in the cells treated with 0.1, 1.0, 10 ng/mL TGF-β1 were 1.04±0.04, 1.07±0.02 and 1.11±0.03, respectively, significantly higher than in the control group （0.96±0.03, P〈0. 05-0.01）. The expression of MMP-2 mRNA could be up-regulated by TGF-β, , in a dose-dependent manner. The expression of MMP-9 mRNA in the cultured RPE cells was slightly up-regulated by various TGF-β1 concentrations treatment. The values of TIMP-1/β-actin in the cells treated with 0.01 and 0.1 ng/ mL TGF-β1 were 0.85 ±0.01 and 0.97 ± 0.02 respectively, significantly lower than in the control group （1.07±0.04, P〈0.01）, indicating that the expression of TIMP-1 mRNA was down-regulated by TGF-β1 at low concentrations. But along with the increase of TGF-β1 concentrations （1.0 and 10 ng/mL）, the expression of TIMP-1 mRNA was slightly up-regulated, not significantly different from that in the control group （P〉0.05）. It was concluded that TGF-β1 might play an important role in the up-regulation of the expression of MMP-2 in RPE cells and result in a directional shift in the balance between MMP and TIMP. This may be facilitated for RPE cells to migrate in the pathogenesis of vitreoretinopathy.

EFFECTS OF GENISTEIN ON INVASION AND MATRIX METALLOPROTEINASE ACTIVITIES OF HT1080 HUMAN FIBROSARCOMA CELLS

Effects of genistein on invasion and matrix metalloproteinase activities were investigated in HT1080 human sarcoma cells.Invasion of HT1080 cells through reconstituted basement membrane was inhibited when the cells were treated with 100 μ mol/L and 200 μ mol/L genistein.At the same concentrations,genistein not only suppressed latent forms of matrix metalloprotinese 2 and 9(MMP 2 and MMP 9) to convert into active forms,but also increase dramatically the tissue inhibitor of metalloproteinase(TIMP 1) mRNA contents and reverse the imbalance of MMPs and TIMPs.However,expressions of MMP 2 and MMP 9 were not significantly affected.Suppression of MMP activation and increase of TIMP 1 expression will decrease matrix degradation by MMPs,and consequently inhibit invasions of the cells.These results emphasized the existence of the imbalance between MMPs and TIMPs in tumor invasion and metastasis formation.The value of genistein as a drug for antiinvasion and anti metastasis chemotherapy was suggested.