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.

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.

Time-dependent matrix metalloproteinases and tissue inhibitor of metalloproteinases expression change in fusarium solani keratitis

AIM： To investigate matrix metalloproteinases（MMPs）and tissue inhibitor of metalloproteinases（TIMPs）expression during the progress of fusarium solani（F.solani） keratitis in a rat model.· METHODS： A rat model of F.solani keratitis was produced using corneal scarification and a hand-made contact lens. MMPs and TIMPs expressiond were explored in this rat model of F.solani keratitis using real-time polymerase chain reaction（PCR） and DIF.GM6001（400 μmol/m L） was used to treat infected corneas. The keratitis duration, amount and area of corneal neovascularization（CNV） were evaluated.·RESULTS： MMP-3 expression was 66.3 times higher in infected corneas compared to normal corneas. MMP-8,-9,and-13 expressions were significantly upregulated in the mid-period of the infection, with infected- to-normal ratios of 4.03, 39.86, and 5.94, respectively. MMP-2 and-7expressions increased in the late period, with the infected-to-normal ratios of 5.94 and 16.22, respectively.TIMP-1 expression was upregulated in the early period,and it was 43.17 times higher in infected compared to normal corneas, but TIMP-2,-3, and-4 expressions were mildly downregulated or unchanged. The results of DIF were consistent with the result of real-time PCR.GM6001, a MMPs inhibitor, decreased the duration of F.solani infection and the amount and area of CNV.·CONCLUSION： MMPs and TIMPs contributed into the progress of F.solani keratitis.

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.

Expression of tissue inhibitor of metalloproteinase-1 in progression muscular dystrophy

Objective Tissue inhibitor of metalloproteinase-1 （TIMP-1） is a muhifunctional protein that has thc capacity to modify cellular activities and to modulate matrix turnover. This paper revealed the contributive role of TIMP-1 in progressive muscular dystrophy （PMD）. Methods We examined the expression and cellular localization of TIMP-1 protein using biopsied frozen muscle from patients with Duchenne muscular dystrophy （DMD）, Becker muscular dystrophy （BMD） , congenital muscular dystrophy （CMD） by immunohistochemistry, double immunofluorescence and Western blot analysis. Results The results of immunohistochemistry and double immunofluorescence showed that TIMP-1 was positive only in vascular endothelial cells of normal muscles. Immunohistochemistry and Western blot analysis showed that the staining intensity was distinctly increased in some dystrophic muscles of PMD for TIMP-1. Double immunofluorescence revealed that TIMP-1 strongly expressed in the regenerating muscle fibers, macrophages and macrophage infiltrating necrotic fibers. Some activated fibroblasts in endomysium and perimysium of DMD and CMD muscles were also positive for TIMP- 1. Conclusion The functional consequence of overexpression of TIMP-1 in the dystrophic muscles is unknown, but the elevated local expression of TIMP-1 in diseased muscles of PMD and their distinct distribution pattern provide evidence that TIMP-1 may participate in the pathogenesis of PMD.

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.

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.

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.

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.

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.

Electroacupuncture ameliorates blood-brain barrier disruption after ischemic stroke through histone acetylation regulation at the matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 2 genes

OBJECTIVE:To explore whether the regulation of matrix metalloproteinase 9(MMP-9)/tissue inhibitors of MMPs(TIMPs)gene expression through histone acetylation is a possible mechanism by which electroacupuncture(EA)protects blood-brain barrier(BBB)integrity in a middle cerebral artery occlusion(MCAO)rat model.METHODS:Male Sprague-Dawley rats were divided into four groups:the sham group,the MCAO group,the MCAO+EA(MEA)group,and the MCAO+EA+HAT inhibitor(HATi)group.The MCAO model was generated by blocking the middle cerebral artery.EA was applied to Baihui(GV20).Samples were collected 1 or 3 d after reperfusion.Neurological function scores and Evans blue extravasation were employed to evaluate the poststroke injury.The effect of EA on MMP-9/TIMPs gene expression was assessed by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)and chromatin immunoprecipitation(ChIP).RESULTS:Our results showed that EA treatment prominently improved neurological function and ameliorated BBB disruption.The RT-qPCR assay showed that EA reduced the expression of MMP-9 and promoted TIMP-2 mRNA expression,but HATi reversed these effects of EA.In addition,ChIP results revealed that EA decreased the enrichment of H3K9ace/H3K27ace at MMP-9 promoters and notably stimulated the recruitment of H3K9ace/H3K27ace at TIMP-2 promoter.CONCLUSION:EA treatment at Baihui(GV20)regulates the transcription of MMP-9 and TIMP-2 through histone acetylation modification in the acute stage of stroke,which preserves the structural integrity of the BBB in MCAO rats.These findings suggested that the histone acetylation-mediated transcriptional activity of target genes may be a crucial mechanism of EA treatment in stroke.

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.

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.

Tissue Inhibitor of Metalloprotease-1(TIMP-1)Regulates Adipogenesis of Adipose-derived Stem Cells(ASCs)via the Wnt Signaling Pathway in an MMP-independent Manner

Tissue inhibitor of m etalloprotease-1(TIM P-1)is a tissue inhibitor o f matrix metalloproteinases(MMPs).It however exerts multiple effects on biological processes,such as cell growth,proliferation,differentiation and apoptosis,in an MMP-independent manner.This study aimed to examine the role of TIMP-1 in adipogenesis of adipose-derived stem cells(ASCs)and the underlying mechanism.We knocked down the TIMP-1 gene in ASCs through lentiviral vectors encoding TIMP-1 small interfering RNA(siRNA),and then found that the knockdown of TIMP-1 in ASCs promoted the adipogenic differentiation of stem cells and inhibited the Wnt/β-catenin signaling pathway in ASCs.We also noted that mutant TIMP-1 without the inhibitory activity on MMPs promoted the activation of Wnt/β-catenin pathway as well as the recombinant wild type TIMP-1 did,which indicated that the effect of TIMP-1 on Wnt/β-catenin pathway was MMPindependent.Our study suggested that TIMP-1 negatively regulated the adipogenesis of ASCs via the Wnt/β-catenin signaling pathway in an MMP-independent manner.

Occurrence of Two Distinct types of Tissue Inhibitors of Metallo-proteinases-2 in Fugu rubripes

In this study, genes of two distinct tissue inhibitors of metalloproteinases-2 (TIMP-2) from Japanese puffer fishFugu rubripes, Fugu TIMP-2a and TIMP-2b, were cloned. The open reading frames of Fugu TIMP-2a and TIMP-2b cDNAsare composed of 660 and 657 nucleotides and 220 and 219 amino acids, respectively. Both Fugu TIMP-2s contain 12 cysteineresidues, which might form six disulfide bonds as in other animals’ TIMP-2s. Reverse-transcribed polymerase chain reactionanalysis showed the mRNAs of Fugu TIMP-2a and TIMP-2b to be expressed in some tissues examined with different expres-sion patterns. These findings suggest that the two distinct Fugu TIMP-2s might perform different functions in Fugu tissues.

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.