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.

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

AIM: To investigate the expression of matrix metallopr-oteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10). METHODS: Hepatic fibrosis was induced by CCI4 administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8 rats), CCI4-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type IV collagenase through portal vein catheter and the suspension was centrifuged by 11% Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with β-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h. RESULTS: Compared to group N in the 7th wk, MMP-2 and TIMP-1 mRNA increased in group C (P= 0.001/0.001) and group I (P= 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P= 0.001/0.001). In the 11th wk, MMP-2 mRNA in group I was still lower than that in group C (P = 0.005), but both dropped compared with that in the 7th week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P= 0.001), and increased in group C (P= 0.001) while decreased in group I (P = 0.042) compared with that in the 7th wk. Same results were found by immunocytochemistry. CONCLUSION: Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.

Preparation and in vitro studies of microencapsulated cells releasing human tissue inhibitor of metalloproteinase-2

Objective： To prepare microencapsulated cells releasing human tissue inhibitor ofmetalloproteinase-2 （TIMP-2）, and investigate their biological characteristics in vitro. Methods： Chinese hamster ovary （CHO） cells were stably transfected with a human TIMP-2 expression vector, encapsulated in barium alginate microcapsules and cultured in vitro. Morphological appearance of the microcapsules was observed under a light microscope. Cell viability was assessed using MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay. Enzyme linked immunosorbent assay （ELISA） and reverse zymography were used to confirm the release of biologically active TIMP-2 from the microcapsules. Cryopreservation study of the microencapsulated cells was carried out using dimethyl sulfoxide （DMSO） as preservative agent. Results： The microcapsules appeared like a sphere with diameter of 300-600 ~tm. The surface of the capsule wall was clearly smooth. The microencapsulated cells survived well and kept proliferating over the 6 weeks observed. No significant difference in TIMP-2 secretion was found between encapsulated and unencapsulated cells. Reverse zymography confirmed the bioactivity of MMP （matrix metalloproteinase） inhibition of TIMP-2. The cryopreservation process did not damage the microcapsule morphology nor the viability of the cells inside. Conclusion： Microencapsulated engineered CHO cells survive at least 6 weeks after preparation in vitro, and secrete bioactive TIMP-2 freely from the microcapsules.

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.

Expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in ulcerative colitis

AIM: To examine the expression of metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the colonic mucosa of patients with ulcer- ative colitis (UC). METHODS: Reverse transcription-polymerase chain re- action (RT-PCR) and immunohistochemistry were used to study the expression of MMP-1 and TIMP-1 at both mRNA and protein levels in patients with UC and con- trols. The relationship between MMP-1 mRNA, TIMP-1 mRNA, MMP-1 mRNA/TIMP-1 mRNA ratio and the sever- ity of clinical symptoms of the patients with UC were also analyzed. RESULTS: The expression of MMP-1 mRNA and TIMP-1 mRNA in the ulcerated and inflamed colonic mucosa was signifi cantly higher than that in the non-inflamed colonic mucosa (P < 0.001), but there was no statistically signif i- cant difference in the non-inflamed colonic mucosa of UC patients and normal controls (P > 0.05). The mRNA ex- pression of MMP-1 and TIMP-1 in ulcerated colonic mu- cosa of UC patients was increased by 80-fold and 2.2-fold, respectively when compared with the normal controls. In the inflamed colonic mucosa, the increase was 30-fold and 1.6-fold, respectively. Immunohistochemical analy- sis showed that among the ulcerated, inflamed, and non-inflamed colonic mucosae of UC patients and the normal controls, the positive rate of MMP-1 expression was 87%, 87%, 40% and 35% respectively, and the positive rate of TIMP-1 expression was 89%, 89%, 80% and 75%, respectively. Furthermore, the expression of MMP-1 mRNA, TIMP-1 mRNA and the MMP-1 mRNA/ TIMP-1 mRNA ratio were correlated with the severity of clinical symptoms (P <0.05).CONCLUSION: Excessive expression of MMP-1 in the diseased colonic mucosa causes excessive hydrolysis of the extracellular matrix (ECM) and ulceration in UC pa-tients. MMP-1 mRNA, TIMP-1 mRNA and MMP-1 mRNA/ TIMP-1 mRNA ratio can be used as biomarkers to judge the severity of clinical symptoms in patients with UC. Exogenous TIMP-1 or MMP-1 inhibitor therapy is a novel treatment for patients with UC.

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.

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.

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.

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.

Suppression of matrix metalloproteinase-2 via RNA interference inhibits pancreatic carcinoma cell invasiveness and adhesion

AIM:To investigate the inhibitory effects of RNA interference (RNAi) on expression of matrix metalloproteinase-2 (MMP-2) gene and invasiveness and adhesion of human pancreatic cancer cell line,BxPC-3.METHODS:RNAi was performed using the vector (pGPU6)-based small interference RNA (siRNA) plasmid gene silence system to specifically knock down MMP-2 expression in pancreatic cancer cell line,BxPC-3. Four groups of different specific target sequence in coding region of MMP-2 and one non-specific sequence were chosen to construct four experimental siRNA plasmids of pGPU6-1,pGPU6-2,pGPU6-3 and pGPU6-4,and one negative control siRNA plasmid of pGPU6 (-). MMP-2 expression was measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation and apoptosis were examined by methyl thiazolyl tetrazolium (MTT) and flow cytometry,respectively. The abilities of adhesion and invasion were detected by cell adhesion assay and cell invasion assay using Transwell chambers.RESULTS:The expression of MMP-2 was inhibited and the inhibitory effects of different sequence varied. pGPU6-1 group had the most efficient inhibitory effect,followed by pGPU6-2 and pGPU6-3 groups.Invasiveness and adhesion were more significantly reduced in pGPU6-1,pGPU6-2 and pGPU6-3 groups as compared with pGPU6 (-) and blank control groups. However,no difference concerning cell proliferation and apoptosis was observed after transfection between experiment groups and control groups.CONCLUSION:RNAi against MMP-2 successfully inhibited the mRNA and protein expression of MMP-2 in the pancreatic cancer cell line,BxPC-3,leading to a potent suppression of tumor cell adhesion and invasion without affecting cell proliferation and apoptosis. These findings suggest that the RNAi approach towards MMP-2 may be an effective therapeutic strategy for the clinical management of pancreatic tumor.

Effects of hypoxia,hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 in hepatic stellate cells

AIM: To study the effects of hypoxia, hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 (MMP-2) in hepatic stellate cells (HSC). METHODS: The expressions of MMP-2, tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) and membrane type matrix metalloproteinase-1 (MT1-MMP) in cultured rat HSC were detected by immunocytochemistry (ICC) and in situ hybridization (ISH). The contents of MMP-2 and TIMP-2 in culture supernatant were detected with ELISA and the activity of MMP-2 in supernatant was revealed by zymography. RESULTS: In the situation of hypoxia for 12h, the expression of MMP-2 protein was enhanced (hypoxia group positive indexes: 5.7 +/- 2.0, n=10; control: 3.2 +/- 1.0, n = 7; P【0.05), while TIMP-2 protein was decreased in HSC (hypoxia group positive indexes: 2.5 +/- 0.7, n = 10; control: 3.6 +/- 1.0, n = 7; P 【 0.05), and the activity (total A) of MMP-2 in supernatant declined obviously (hypoxia group: 7.334 +/- 1.922, n = 9; control: 17.277 +/- 7.424, n = 11; P 【 0.01). Compared the varied duration of hypoxia, the changes of expressions including mRNA and protein level as well as activity of MMP-2 were most notable in 6h group. The highest value(A(hypoxia)-A(control)) of the protein and the most intense signal of mRNA were in the period of hypoxia for 6h, along with the lowest activity of MMP-2. In the situation of hyperoxia for 12h, the contents (A(450)) of MMP-2 and TIMP-2 in supernatant were both higher than those in the control, especially the TIMP-2 (hyperoxia group: 0.0499 +/- 0.0144, n = 16; control: 0.0219 +/- 0.0098, n = 14; P 【 0.01), and so was the activity of MMP-2 (hyperoxia group: 5.252 +/- 0.771, n = 14; control: 4.304 +/- 1.083, n = 12; P 【 0.05), and the expression of MT1-MMP was increased. CONCLUSION: HSC is sensitive to the oxygen, hypoxia enhances the expression of MMP-2 and the effect is more marked at the early stage; hyperoxia mainly raises the activity of MMP-2.

Relationship between matrix metalloproteinase-2 mRNA expression and clinicopathological and urokinase-type plasminogen activator system parameters and prognosis in human gastric cancer

AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric cancer. METHODS: Expression of MMP-2 mRNA, uPA, and uPA-R mRNA in tumor tissues and ≥5 cm adjacent normal tissues from 67 cases of gastric cancer was studied using RT-PCR and Northern blot respectively.Survival analyses were done using the Kaplan-Meier method. RESULTS: The expression rates of MMP-2 mRNA,uPA and uPA-R mRNA in tumor tissues (31%,41%,and 51%, respectively) were significantly higher than those in ≥5 cm adjacent tissues (19%, 11%, and 9%; X2=4.59,43.58, and 53.24 respectively, P<0.05,0.0001,and 0.0001, respectively). Expression of MMP-2 mRNA was significantly correlated with lymph node metastasis (metastasis: 61.9%, no metastasis: 39.1%, X2= 7.61, P<0.05),Lauren's classification of diffuse/mixed types:54.2%,intestinal type: 26.3%,X2 = 4.25, P<0.05, expression of uPA and uPA-R mRNA (uPA+: 55.1%, uPA-: 22.2% and uPA-R+: 54.9%, uPA-R-: 18.8%, X2=5.72 and 6.40 respectively, P<0.05).Kaplan-Meier survival analysis of MMP-2 mRNA expression did not show significant difference in all 67 cases, but revealed an association of the expression of MMP-2 mRNA, uPA, and uPA-R mRNA with worse prognosis (P= 0.0083, 0.0160, and 0.0094, respectively). CONCLUSION: MMP-2 may play an important role in the development of invasion and metastasis of gastric cancer.

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.

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.

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

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

Expressions of cyclooxygenase-2 and matrix metalloproteinase-9 in cervical carcinoma and their clinical significance

Objective: To investigate the expressions of cyclooxygenase (COX)-2 and matrix metalloproteinase (MMP)-9 in cervical carcinoma and their clinical significance. Methods: Immunohistochemistry SP method was used to detect the expres- sions of COX-2 and MMP-9 in 72 cases of invasive carcinoma of cervix (ICC) and 16 cases of normal cervical epithelium remote from tumor (NCE). The relationships between the expressions of COX-2, MMP-9 in ICC and some characteristics relating to clinical pathology of cervical carcinoma such as histological grading, lymph node metastasis, stromal invasion and FIGO stage were analyzed statistically. Results: The rates of the positive expressions of COX-2 and MMP-9 in ICC were significantly higher than those in NCE. COX-2: 88.9% (64/72) in group ICC and 12.5% (2/16) in group NCE, P = 0.000; MMP-9: 94.4% (68/72) in group ICC and 43.8% (7/16) in group NCE, P = 0.000. The expression of COX-2 was positively correlated with lymph node metastasis (r = 0.296, P = 0.012) and stromal invasion (r = 0.257, P = 0.029). The expression of MMP-9 was positively correlated with FIGO stage (r = 0.329, P = 0.005) and histological grading (r = 0.351, P = 0.003). The expression of COX-2 was positively correlated with the expression of MMP-9 in ICC (r = 0.297, P = 0.011). Conclusion: The overexpressions of COX-2 and MMP-9 were closely related to the invasion and growth of cervical carcinoma. The tissue with the overexpression of COX-2 had strong invasion ability. COX-2 and MMP-9 had synergistic effect on proliferation, invasion and metastasis of cancer cells. Detecting the coexpression of COX-2 and MMP-9 may be of value in further understanding the biological behavior and predicting the prognosis of cervical carcinoma.

Rosiglitazone uppresses lipopolysaccharide-induced matrix metalloproteinase-2 activity in rat aortic endothelial cells via rasMEK1/2 signaling

ix metalloproteinase(MMPs) plays a key role in the pathogenesis of chronic inflammatory disease,such as atherosclerosis.Among MMPs,MMP-2 is regarded as a major proteinase in atherosclerotic plaque lesions.Peroxisome proliferator activated receptor-gamma(PPARg) ameliorates oxidative stress and the inflammatory response.The aim of the present study was to evaluate the effect of Rosiglitazone on Lipopolysaccharide(LPS)-induced MMP-2 activation as well as its possible mechanism.LPS-induced MMP-2 activity was inhibited by Rosiglitazone(PPARg agonist) in the rat aortic endothelial cells(RAEC).LPS-induced MMP-2 activation was diminished no matter exposure to NF-kB Activation Inhibitor II(JSH-23)or Ras inhibitor,farnesylthiosalicylic acid(FTS). Further study shows that LPS-induced activation of Phospho-Rho A and Phospho-MEKl/2 were significantly inhibited by Rosiglitazone.The activation of NF-kB p65 in the nuclear extract of cells was also significantly suppressed by Rosiglitazone, moreover,the expression of NF-κB p65 was partly activated by GW9662(PPARg antagonist).NF-kB DNA binding activity was also demolished by Rosiglitazone.In summary,our data showed that PPARg agonist,Rosiglitazone suppresses LPS-activated MMP-2 secretion via Ras-MEK1/2 signaling pathways and NF-kB activation.PPARg agonist and Ras-MEK1/2 pathway may be another potential therapeutic target for the disease induced by chronic inflammation.

Cryptotanshinone attenuates isoprenaline-induced cardiac fibrosis in the mouse associated with upregulation and activation of matrix metalloproteinase-2

Objectives The impairment of matrix metallopro- teinase-2(MMP-2)has been associated with the development of cardiac fibrosis.Although the Chinese herb Salvia miltior-rhiza has been widely used in patients with cardiovascular disorders,the mechanisms involved have not been elucidated. The purpose of the present study was to determine whether the administration of cryptotanshinone,an active ingredient of Salvia miltiorrhiza,could prevent the cardiac fibrosis induced by isoprenaline and to investigate the underlying mechanisms. Methods and Results Male C57BL/6 mice were submitted to receive daily injection of 0.9%saline,3 mg/kg isoprenaline, or isoprenaline plus 20 mg/kg cryptotanshinone by gastric gavage for 2 weeks.Herein,we demonstrate that cryptotanshinone can significantly ameliorate the isoprenaline-induced cardiac fibrosis,which was associated with marked up-regulation and activation of MMP-2 in ventricular myocardium. Additionally,we demonstrate that cryptotanshinone can dose-dependently upregulate and activate MMP-2 in cultured cardiac fibroblast.Moreover,incubation with cryptotanshinone also can prevent isoprenaline-induced downregulation and inactivation of MMP-2 in cultured cardiac fibroblast. Conclusions Taken together,our data suggest that cryptotanshinone may become a novel and potent antifibrotic agent. The present findings might further our understanding of the role of MMP-2 in cardiac fibrosis and antifibrotic mechanisms of cryptotanshinone.