基质金属蛋白酶_
基质金属蛋白酶
生命科学研究LIFE SCIENCE RESEARCH1999年 第3卷 第3期 Vol.3 No.3 1999基质金属蛋白酶吴二喜 王凤飞 Norman McKIE摘 要：基质金属蛋白酶是一类分解细胞外基质组分的锌蛋白酶。
它们在有机体生长发育中的细胞外基质逆转与重塑以及疾病中的病理损害起着极为重要的作用。
基质金属蛋白酶的表达和活性在不同细胞水平受到严密调控，如细胞因子、生长因子以及激素的调节。
基质金属蛋白酶以酶原形式分泌，随后被其它蛋白酶如胞浆素或非蛋白酶类化学物质如有机汞所激活。
所有基质金属蛋白酶都受到天然抑制剂金属蛋白酶组织抑制剂所抑制。
两者的不平衡导致许多疾病的发生，如肿瘤侵入及转移。
合成基质金属蛋白酶组织抑制剂所抑制，如Marimastat能控制肿瘤转移的发生及进一步扩散。
本文将对基质金属蛋白酶的特征、分子区域结构、底物特性、激活机制、调控方式等方面进行最新概述。
关键词：基质金属蛋白酶；金属蛋白酶组织抑制剂；胶原酶；明胶酶；基质酶；膜型基质金属蛋白酶中图分类号：Q51；Q55 文献标识码：AMatrix MetalloproteinasesWU Er-xi1*，WANG Feng-fei1*，Norman McKIE2（1．Department of Human Metabolism and Clinical Biochemistry，University of Sheffield Medical School，Beech Hill Road，Sheffield S10 2RX，UK； 2．Department of Rheumatology，University of Newcastle-upon-Tyne Medical School Framlington Place，Newcastle-upon-Tyne NE2 4HH，UK）Abstract：Matrix metalloproteinases (MMPs) are zinc proteinases that degrade compounds of the extracellular matrix (ECM). These enzymes play a pivotal role in turnover and remodelling of the ECM during organism growth and development and the pathological destruction of tissues in diseases. The activities of metalloproteinases are tightly controlled at several different cellular levels such as modulation by cytokines, growth factors and hormones. MMPs are secreted as zymogens which can be activated by other proteinases such as plasmin or non-proteolytic agents such as organomercurials. All MMPs are inhibited by their natural inhibitors,tissue inhibitors of matrix metalloproteinases(TIMPs). Imbalance between MMPs and TIMPs has been implicated in many diseases such as tumour invasion and metastasis. The synthetic MMP inhibitors such as Marimastat can prevent the growthand further spread of established metastases.Key words：MMPs；TIMPs；collagenases；gelatinases；stromelysins；membrane type MMPsT0 Introduction Matrix metalloproteinases (MMPs) are also called matrixins. Since the first MMP was discovered by Gross and Lapiere in 1962, numerous other MMPs have been described and characterized. To date at least 14 MMPs have been found (Table 1). According to their structural properties and substrate specificities, MMPs can be divided into sub-Table 1 The matrix metalloproteinase family*Enzymes MMP No．**EC No．Mr（kDa）latent/activeExtracellular matrixsubstratesCollagenases Interstitial collagenase MMP1EC 3．4．24．757/48Collagen Ⅰ，Ⅱ，Ⅲ，Ⅶ，Ⅹ；gelatin，entactin，tenascin，aggrecan，progelatinaseA，progelatinase BNeutrophil collagenase MMP8EC3．4．24．3485/65Collagen Ⅰ，Ⅱ，Ⅲ；aggrecanCollagenase 3MMP13 60/48Collagen Ⅰ，ⅡGelatinases Gelatinase A MMP2EC 3．4．24．2472/66Collagen Ⅰ，Ⅳ，Ⅴ，Ⅶ，Ⅹ；gelatin，fibronectin，laminin，aggrecan elastin，progelatinase BGelatinase B MMP9EC 3．4．24．3592/84Collagen Ⅳ，Ⅴ；gelatin，elastin，entactin，aggrecan，vitronectinStromelysins Stromelysin 1MMP3EC 3．4．24．1760/50Collagen Ⅱ，Ⅳ，Ⅸ，Ⅹ，Ⅺ；gelatin，laminin，fibronectin，elastin，tenascin，aggrecan，procollagenase，progelatinase B，neutrophil procollagenaseStromelysin 2MMP10EC 3．4．24．2253/47Collagen Ⅳ，laminin，fibronectin，elastin，aggrecan，procollagenaseStromelysin 3MMP11 65/45Serpins，α1-PI，α2-antiplasmin，insulin-like growth factor-bindingprotein-1Others Matrilysin MMP7EC 3．4．24．2328/21Collagen Ⅳ，gelatins，laminin，fibronectin，entactin，elastin，aggrecan，progelatinaseA，progelatinase B，procollagenaseMetalloelastase MMP12EC．3．4．24．6552/43ElastinMembrane type MMPs MT1-MMP MMP14 63/54Progelatinase A，procollagenase 3，collagen，proteoglycan，fibronectin，tenascinMT2-MMP MMP15 72/61Progelatinase A，procollagenase 3，collagen，proteoglycan，fibronectin，tenascinMT3-MMP MMP16 64/55Progelatinase A MT4-MMP MMP17 70/54Unknown*Compiled from sources including Sang and Douglas[2]；Shingleton et al．[3]；Nagase [4]；Pei et al．[19]；Mari et al．[44]；Murphy et al．[96]；Takino et al．[28，46]andCockett et al．[116]**Some MMPs have been omitted．MMP5 and MMP2 are the same enzyme[5]，MMP4 and MMP6 have been described in only one laboratory and there are no sequence data to date [5]．There are some novel MMPs which have been found recently，see text for details．groups: collagenases, gelatinases, stromelysins, membrane type MMPs (MT-MMP) andothers[1～4]. This review summarises the characteristics, domain structure, substratespecificity, activation mechanisms, regulation, functions of the MMPs.1 Main characteristics of the MMPs All MMPs have a number of common characteristics which are also helpful to identify new members. These properties[2, 5～7]are: 1）they share a common domain structure comprising signal, propeptide, catalytic, and C- terminal hemopexin-like domains (except MMP7) (Fig．1).Fig．1 The domain structure of the matrix metalloproteinases2）They are secreted as zymogens. 3）Their activation can be achieved by other proteinases or organomercurials. 4）Their proteinase activity is blocked by 1,10-phenanthroline and chelating agents. 5）Activation is accompanied by a loss of molecular weight. 6）The active site contains metal ion zinc. 7）Their activity is inhibited by tissue inhibitor of metalloproteinases (TIMPs). 8）The active enzymes cleave one or more components of the extracellular matrix. 9）The enzymes act in neutral pH and need calcium ions for stability.2 Domain structure of MMPs After comparing the primary amino acid sequences of the MMP members, it can be seen that these proteins are divided into several distinct domains that are conserved among family members[1]. The largest MMP member (MMP9) has 7 domains in order from N-terminal: signal, propeptide, catalytic, fibronectin-like,α2V collagen-like, hinge, and C-terminal hemopexin-like. The simplest member MMP7 has only signal, propeptide and catalytic domains. The newly discovered MT-MMPs have a transmembrane domain[8]. All MMPs produce a signal as a leader sequence which cells cleave prior to secretion. The propeptide is lost on activation. For example, the human fibroblast collagenase is synthesized as a preproenzyme of Mr 54 kDa (57 kDa in Table 1) with the signal peptide of19 amino acids[9]. The primary secretion products of human fibroblast collagenase consist ofa minor glycosylated form of Mr 57 kDa and a major unglycosylated polypeptide of Mr 52 kDa[9]. 81 amino acids are removed after proteolytic activation of human fibroblast collagenase[9]. The catalytic domain contains a conserved zinc binding site comprising the sequence HEXGHXXGXXH[2]. The zinc acts as an active site and is ligated by the three-histidine residues of the zinc binding consensus sequence. The glutamic acid residue in the conserved zinc binding site acts as the catalytic base and proton shuttle during proteolysis and is involved in the fixation of a zinc-bound water molecule[10]. The structural integrity of the zinc-binding active site is maintained by a conserved methionine that is called “Met-turn”[10]. The catalytic domain also contains a calcium-binding region where the calcium ion is believed to stabilize the enzyme[11]. With the exception of matrilysin (MMP7), the MMPs contain an additional feature, that is their hemopexin-like or vitronectin-like C-terminal domain[1]. This domain is thought to help determine substrate specificity[1,5]. Thiscould be true, since recently Gohlke et al.[12]have found that the topology and the side chain arrangements of gelatinase A (MMP2) and fibroblast collagenases are very similar, but there are significant differences in surface charge and contouring. They thought these differences may be a factor in allowing the MMP2 C-terminal domain to bind to TIMP2. Very recently, Brooks et al.[13,14]have found that MMP2 can bind αvβ3 through its hemopexin-like domain. Besides the prototype domain structure, the gelatinases contain three tandem domains with sequences similar to the collagen-binding domain of fibronectin. The fibronectin-like domain is thought to be involved in the binding of two gelatinases to their substrate[5]. The MT-MMPs contain a transmembrane domain and a furin recognition site which is also found in stromelysin 3[8,15](Fig．1).3 Substrate specificity of MMPs The collagenases mainly cleave interstitial collagens (type I, II and III), unlike other MMPs, their substrate specificity is well defined. Collagenase action on the α2-macroglobulin results in the cleavage of Gly-Leu Peptide bond[5]．They cleave the Gly-Ile peptide bond of α1(I) chain of collagen and Gly-Leu peptide bond of α2(I) chain of collagen[5]. The substrate cleavage pattern for collagenases is that P1 "residue is invariably hydrophobic (Leu, Ile, Val) and that P1 is usually Gly or a hydrophobic residue[5,16]. The gelatinases cleave denatured collagens and type IV collagen. As shown in table 1, while gelatinase A (MMP2) can also cleave the fibronectin and laminin, major components of the basement membrane, gelatinase B (MMP9) can only cleave the basement membrane component entactin[2]. Stromelysin 1 and 2 have a broad pH optimum and more general activity and are able to degrade many ECM proteins including proteoglycans, gelatins, fibronectin, laminin, elastin, type IV collagen and type IX collagen[17]． Niedzwiecki et al.[18]tested the substrate specificity of the human stromelysin 1 and found the preferences at P3, P2, P1, P1 ", and P2 "are for the hydrophobic amino acids Pro, Leu, Ala, Nva, and Trp, respectively. The mature stromelysin 3 does not degrade any major ECM components. Up to now, the only known substrates for stromelysin 3 are α1-proteinase inhibitor, serine proteinase inhibitors, α2-antiplasmin, and insulin-like growth factor-binding protein-1 [19,20]. However, the substrate specificity overlaps among the MMP members. The gelatinase A (MMP2) can also cleave triple helical type I collagen generating the 3/4 and 1/4 length collagen fragments characteristic of interstitial collagenases[21]. The cleavage site is the same Gly-Ile/Leu bond as the interstitial collagenases[21]. In fact all of the MMPs cleave gelatin and fibronectin at some rate[1]. Almost every MMP degrades an octapeptide containing collagen sequence GPQGIAGQ[5].4 Activation mechanisms of MMPs The MMPs are secreted in a latent form that is subsequently converted into the mature enzymes. The inactive zymogen can be processed into active forms by numerous reagentsincluding proteinases such as trypsin and plasmin; conformational perturbants such as sodium dodecyl sulfate (SDS); heavy metals such as Au (I) compounds and organomercurials; oxidants such as NaSCN; disulfide reagents such as oxidized glutathione; and sulfhydryl alkylating agents such as N-ethylmaleimide[22]. The latent proform of MMPs contains the highly conserved PRCGVNPD sequence with an unpaired cysteine residue. The cysteine residue links to the active site zinc, which blocks the active site. A ‘cysteine switch’ activation mechanism has been proposed[22,23](Fig． 2). In other words, in the latent form of MMPs, the cysteine residue with the thiol group coordinates the catalytically essential zinc ion in the active site of enzyme. Some reagents such as SDS can dissociate the cysteine residue from the zinc ion[22]. From this hypothesis, each MMP should have an unpaired cysteine residue and a zinc-binding site. In fact, all MMPs contain the PRCGVNPD sequence with an unpaired cysteine residue in the propeptide domain and the HEXXHXXGXXH sequence in the catalytic domain. Very recently, it has been shown that he structure of human pro-MMP2 supports this hypothesis[24]. The loops within the propeptide domain act as bait for activating proteinases. The prodomain structure breaks down and its shielding of the catalytic cleft is withdrawn upon cleavage, which allow water to enter and hydrolyze the coordination of the cysteine residue to the zinc ion[24]. All MT-MMPs found to date and stromelysin 3 contain a consensus sequence RXR/KR, which has already been found to be essential in the activation of stromelysin 3 and MT1-MMP by furin [15,25,26]. MMPs also have the ability to activate one another[27]. MT1-MMP[8]and MT3-MMP[28]have been shown to activate MMP2. MMP7 can activate MMP1, MMP2, MMP3 and MMP9[29]. MMP3 activates MMP1[30], MMP8[31], MMP9[32]and MMP13[33]. MMP2 and MT1-MMP activate MMP13[34], while MMP10 activates MMP8[35]. It has also been well documented that MMPs and serine proteinases can act on the proforms of one another [36,37]. Plasmin can cleave the prodomains of MMPs such as collagenase and stromelysin and activate these enzymes[36,37]. MMP7 can catalyze the formation of low molecular weight pro-urokinase and urokinase[38].Fig．2 Cysteine switch mechanism for activation of MMPsProteinases such as trypsin and plasmin cleave the propeptide，ahead of the cysteine to generate intermediate forms．Alternatively，nonproteolytic agents such as aminiphenyl-mercuric acetate （APMA） and sodium dodecy1 sulfate （SDS） will modify the cysteine．In a second step，these intermediate forms can be autoproteolytically cleaved to remove the propeptide and confer permanent activity．5 Regulation of MMPs The activities of metalloproteinases are tightly controlled at several different cellular levels. There are five points: (i) modulation of gene expression by cytokines, growth factors and hormones; (ii) synthesis and secretion of proMMPs; (iii) selective expression of MMP genes in specific tissue/cell types; (iv) activation of proenzymes; and (v) inhibition of the active enzymes[7,36,39,40]. It is known that the MMPs are not constitutively expressed in most tissue types but their mRNAs can be induced by treatment with many kinds of agents such as cytokines, growth factors, hormones, tumour promoter and oncogene products. In some cases the induction of more than one MMP is coordinately regulated, for example, MMP1 and MMP3 are often coordinately expressed[40]. The synthesis of MMP1 and MMP3 can be upregulated by 12-O-tetradecanoyl-phorbol-13-acetate (TPA), interleukin 1 (IL1), tumor necrosis factor α(TNFα), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and platelet derived growth factor (PDGF) and be downregulated by transforming growth factor β (TGF-β), interferon γ (IFN-γ) retinoic acid and dexamethasone[40], and MMP1 is down regulated by IL4[41]. The selective expression of MMP genes in specific tissue/cell types is one method of regulation of MMPs. Interstitial collagenase (MMP1) arises from connective tissue fibroblasts and macrophages. Neutrophil collagenase (MMP8) is only produced by cells of the neutrophil lineage. Stromelysin 1 (MMP3) is not widely expressed normally, but can be readily induced by growth factors, cytokines, tumour promoters and oncogene products in cultured mesenchymal cells such as chondrocytes and connective tissue fibroblasts. Stromelysin 2 (MMP10) is usually expressed in macrophages, keratinocytes and tumour cells[40,42]. Stromelysin 3 (MMP11) is often expressed in tumour stromal cells[37,40,43,44]. Gelatinase A (MMP2) is the most widespead of all MMPs and is frequently elevated in malignancies as well as occurring in connective tissue cells[36,40]. Gelatinase B (MMP9) is expressed in transformed and tumour-derived cells, neutrophil, corneal epithelial cells, cytotrophoblasts and keratinocytes[36]. Matrilysin is expressed in immature monocytes[36]. Metalloelastase (MMP12) is found in macrophages. MT1-MMP is expressed in tumour stroma cells[45]. MT2-MMP is produced by a human oral malignant melanoma and a human placenta[46]. MT3-MMP is expressed in normal tissues such as lung and kidney and cultured cells such as the squamous cell carcinoma cell line OSC-19 and human embryonal lung fibroblasts[28]. MT4-MMP is expressed in primary breast carcinomas and breast cancer cell lines examined[47]. All MMPs are inhibited by natural inhibitors called tissue inhibitors of metalloproteinases (TIMPs) of which four have been described (Table 2). TIMPs 1, 2 and 4 are secreted extracellularly in soluble form whereas TIMP3 binds to the ECM. All TIMPs share 35%～40% sequence identity and considerable higher structural similarity. The TIMPs bind with high affinity and 1∶1 molar ratio to active MMPs resulting in the loss of proteinase activity. All TIMPs contain 12 cysteine residues that have been shown to form disulfide bonds generating 6 loops. The mechanism of inhibition of MMPs by TIMPs is widely felt to be unclear. Murphy[39]. pointed out that the TIMP C-terminal domain has several different MMP binding sites that act to increase the rate of inhibition. Further studies such as site-directed mutagenesis and the crystal structure research of the complex of MMP and TIMP will facilitate understanding of the mechanism. TIMPs play a pivotal role in the regulation of ECM degradation/remodelling. Disruption of the balance between MMPs and TIMPs has been implicated in many diseases such as tumour invasion and metastasis. Besides their inhibitory activities, the TIMPs play a role in growth-promotion[48]. Some effective synthetic MMP inhibitors also can inhibit MMPs[49,50]. For example, the hydroxamate-based inhibitors such as BB94 (batimastat) and BB2516 (marimastat) can inhibit metastatic spread of tumoursand block the process of tumour neovasculariation[51～54]. The hydroxamate group in thesemolecules can combine with the zinc atom in the active site of MMPs[49,50].Table 2 Comparison of TIMP family members* TIMP1TIMP2TIMP3TIMP4 Molecular mass28kDa21kDa24kDa22kDa Glycosylation yes no no/yes no Binding properties proMMP9proMMP2ECM proMMP2Transcripts0.9kb 1.1 and 3.5kb 4.5,2.8,2.4and 1.2kb1.4，4.1，2.1，1.2，and 0.97kbModulation of gene expression by TGF-β1updown or noobvious effectup not determinedMajor sites ofexpressionOvary，bone Placenta Kidney，brain Heart Chromosome locationof human genexq1117q2522q12.1～13.22p25 *Compiled from sources including Stetler-Stevenson[117]；Greene et al．[118]；Wick et al．[119]；Chamber and Matrisian[120]and Olson et al．[121]6 MMPs in physiological processes and pathological destruction Normal expression of MMPs is associated with turnover and remodelling of the ECM during growth and development. Cawston[7]summarised the involvement of MMPs in the normal turnover of connective tissue matrix. The MMPs are involved in the normal physiological processes such as ovulation and embryo implantation, embryological development, angiogenesis, bone turnover, uterine resorption and cervical ripening[7]. The MMPs are associated with the pathological destruction of tissues in diseases[1,7]. They are implicated in the processes such as wound healing, corneal ulceration, tumour growth and metastasis, periodontal disease, rheumatoid arthritis, arteriosclerosis and aortic aneurism[1,7]. Considerable research has been directed toward understanding both the steps involved in tumour cell invasion and metastasis and the molecular mechanism of the process. MMPs are thought to be one of the main contributors to tumour invasion and metastasis since they can degrade all of the components of basement membranes which the tumour cellsmust traverse[55～58]. Now the gene-targeting experiments have facilitated the examinationsof the effects that their absence, mutation or overexpression, in various physiological and pathological processes[59]. In the following sections more detailed information is presented on several MMP family members.7 Collagenases I, II and III (MMP1, MMP8 and MMP13) The group of enzymes termed collagenases includes 3 members: MMP1 (interstitialcollagenase or fibroblast collagenase), MMP8 (neutrophil collagenase) and MMP13 (collagenase 3). Their sequences share around 50%[33]. They cleave all three α chains of native types I, II, III collagens at a single site resulting in fragments corresponding to three-quarters and one-quarter of their initial length by hydrolyzing the peptide bond Gly-[Ile orLeu][60～62]. They do not degrade collagen IV and V, which are cleaved by otherproteinases[63～66]. The collagenases can also cleave type X collagen[67]. The threecollagenases have their own preference in cleaving the collagens. The preferred substrate of collagenase 3 (MMP13) is collagen type II[33], fibroblast collagenase (MMP1) preferentially cleaves collagen type III[68]and neutrophil collagenase (MMP8) prefers to cleave type I collagen[69]. Also collagenase 3 has a much stronger gelatinolytic activity than its homologous counterparts MMP1 and MMP8[33]. To date MMP1 expression has not been found in rats or mice[33]. All collagenases are located in the human chromosome 11q22.3 cluster[70,71]and share a highly conserved gene structure[72,73]. The expression of MMP13 in cartilage and its preference to degrade type II collagen suggests that it plays a critical role in the arthritides[74]. X ray crystallographic analyses of MMP1 and MMP8 are available now. The structures show that their catalytic domains harbour two zinc ions and one or twocalcium ions[75～77]. The structure consists of a five-stranded β sheet and three α helices[75].8 Gelatinases A and B (MMP2 and MMP9) Gelatinases, also called type IV collagenases, contain two members: MMP2 and MMP9. They degrade denatured collagens, type IV, V, VII, X, and XII collagens,vitronectin, aggrecan, elastin, galectin 3 and laminin[78～83]. Recently, it has beendemonstrated that MMP2 degrades native interstitial collagens[21]. MMP2 is the most widely distributed MMP[1]. Overexpression of gelatinases has been demonstrated in many tumorsystems and has been linked to tumour invasion[84～87]. While the proMMP2 is often foundcomplexed with the TIMP2 and is activated by MT1-MMP[88,89], the proMMP9 is associated with the TIMP1[78,90]. The regulation of MMP2 and MMP9 gene expression is different[91]. The promoter of MMP9 gene has a TATA-like sequence and a TPA response element, while MMP2 gene has no TATA motif-like sequence in the vicinity of the start site for transcription and TPA response element in its promoter[91]. There is a structural difference between MMP2 and MMP9 that comprises an extended 54 amino acid hinge region sequence which shares some homology with the α2 chain of type V collagen[78]. Brooks et al.[13,14]have found that MMP2 can directly bind integrin αvβ3. They further demonstrated that MMP2 binds αvβ3 through its hemopexin-like domain. It is likely to be distinct from other αvβ3-directed ligands as MMP2 has no RGD sequence[13,14]. Brooks et al.[14]have also found that PEX, a fragment of MMP2, which contains the C-terminal hemopexin-like domain, prevents MMP2 binding to αvβ3 and blocks cells surfacecollagenolytic activity. PEX is likely to be a natural breakdown product of MMP2 since the active form (62 kDa) of MMP2 can be further processed to a smaller species (43 kDa) resulting from autocatalytic removal of the 29 kDa hemopexin-like domain without the presence of TIMP2[14,92]. Both MMP2 and MMP9 are located on human chromosome 16[93].9 Stromelysins 1, 2 and 3 (MMP3, MMP10 and MMP11) MMP3 (stromelysin 1), MMP10 (stromelysin 2) and MMP11 (stromelysin 3) belong to this group. Stromelysins have wide substrate specificity. Stromelysin 1 degrades aggrecan, fibronectin， gelatin， laminin， type II， IV， IX， X， XI collagens and elastin[2,94]. It also participates in activation of other proMMPs such as proMMP1, proMMP8 and proMMP9[31,32,80]. MMP3 is not readily expressed in tissue but can be induced by cytokines such as IL1 and TNFα, growth factors and tumour promoters such as PMA[1,5,95]. Stromelysin 2 cleaves aggrecan, laminin, fibronectin, elastin and type IV[2]. It is transcriptionally active in normal human cells such as keratinocytes and it encodes the secreted Stromelysin 2[42]. Stromelysin 3 is a newly characterized MMP. It can degrade serpin, α1-proteinase inhibitor (α1-PI), α2-antiplasmin, and insulin-like growth factor-binding protein-1[19,20]; the truncated stromelysin 3 can also degrade fibronectin, laminin, aggrecan and type IV[96]. Stromelysin 3 is often found expressed in stromal cells surrounding primary and metastatic carcinomas[43]and may be involved in promoting local tumor development. Recently it has been suggested that the tumor-specific processing of stromelysin 3 to the 35 kDa protein is likely to be an important regulatory mechanism, since the generation of 35 kDa stromelysin in tumour/stroma coculture requires basic fibroblast growth factor (bFGF) and an MMP-like enzyme[44]. Unlike other MMPs, prodomain of stromelysin 3 contains a furin cleavage site, and therefore stromelysin 3 can be processed directly to its 45 kDa active form by furin within the constitutive secretory pathway[15]. MMP3 and MMP10 are located in the human chromosome cluster 11q22.3[70,72], while MMP11 is mapped to the Q11.2 region of chromosome 22[97]．10 Membrane type-matrix metalloproteinases (MMP15, MMP16, MMP17 and MMP18) Membrane type matrix metalloproteinases (MT-MMPs), comprising MT1-MMP, MT2-MMP2, MT3-MMP and MT4-MMP (MMP14, MMP15, MMP16 and MMP17, respectively) are a novel subgroup of MMPs which contain a transmembrane domain and a short cytoplasmic domain in addition to the signal, pro-, catalytic, hemopexin-like and C-terminal domains which are common to other MMPs. To date, four MT-MMPs have been described [8,28,47,98]. From the alignment of amino acid sequences for MT-MMPs[47], it can be seen that they have at least 30% sequence homology to each other. Like other MMPs, they contain cysteine switch sequence, zinc binding site and Met-turn. However, they have an insertion between the propeptide and the catalytic domain in addition to the above mentionedmembrane-binding domain and short cytoplasmic domain. This insertion as in stromelysin 3 contains a potential cleavage site of furin or furin like convertase[8,15]. It has already been demonstrated that furin can cleave this sequence in pro-stromelysin 3 and proMT1-MMP [15,25,26]. However, the proMT1-MMP is proteolytically activated by human plasmin[99]. Okumura et al.[99]proposed that this is an extracellular proteinase activator of proMT1-MMP whereas the intracellular mechanism of activation is mediated by furin or a furin-like enzyme. The second insertion is found in proteinase domain; the function of these 8 amino acids is not known. The third insertion which contains the hydrophobic transmembrane domain is located in the C-terminal. The transmembrane domain of MT-MMPs plays an essential role in the progelatinase A (proMMP2) activation function of MT-MMPs, although some portions of the truncated form remain on the cell surface after the removal of this domain[100]. In MT1-MMP, the activation complex is a trimer comprising MT1-MMP, progelatinase A and TIMP2[88,89]. A recent study has suggested that MT1-MMP is a TIMP2 receptor[101]. This is further confirmed by another recent study[73]that TIMP2 and MT1-MMP form a complex for activation of progelatinase A. TIMP2 and TIMP3 can efficiently inhibit MT1-MMP whereas TIMP1 is a poor inhibitor for MT1-MMP[102]. Will et al.[102] also demonstrated that TIMP2 and TIMP3 can bind more rapidly to the catalytic domain of MT1-MMP than to the catalytic domain of MMP2. At the same time, two groups showed that MMP14, MMP15 and MMP16 locate in chromosomes 14, 16 and 8, respectively [103,104]. The MT-MMP gene loci are dispersed whereas most MMPs are clustered on chromosome 11q22.3[70,71], suggesting that the MT-MMPs may be a genetically distinct subgroup of MMPs. It has been suggested that the MT-MMPs play a critical role in tumor cell invasion and in ECM degradation[8,57,102]. MT-MMPs also can degrade ECM components[25,105,106].11 Others This group includes MMPs such as matrilysin (MMP7) and metalloelastase (MMP12). Matrilysin, also called putative metalloproteinase 1 (pump 1), is the smallest member of the MMP family. Unlike other MMPs, it lacks a C-terminal hemopexin-like domain. MMP7 can degrade various ECM components. It also can activate other proMMPs such as proMMP1, 3, 2 and 9[29]. Metalloelastase (MMP12) is also called macrophage elastase (ME). The expression of human macrophage elastase (HME) is mainly restricted to tissue macrophages [107]. Besides the substrate elastin listed in Table 1, the purified recombinant HME can degrade fibronectin, laminin, entactin, type IV collagen, chondroinan sulfate, and heparan sulfate[108]. Chandler et al.[109]also demonstrated that HME can degrade myelin basic protein and processes a TNF α fusion protein. Therefore Gronski et al.[108]suggested that HME may be essential for macrophages to penetrate basement membranes and remodel injured tissue during inflammation. MMP7 and MMP12 are allocated in the human chromosome cluster 11q22.3[70,72,107].。
基质金属蛋白酶,分类
基质金属蛋白酶,分类基质金属蛋白酶，听起来就像是科学界里的一群超级英雄，专门对付那些让人头疼的细胞外基质。
想象一下，咱们的身体里面，就像是一个错综复杂的城市，血管、神经、细胞，啥都有，它们得靠一种叫做“细胞外基质”的东西来保持秩序，就像是城市里的道路、桥梁和建筑。
而基质金属蛋白酶呢，就是那些能够“拆迁”和“改造”这些基础设施的特种部队。
这些家伙可不是吃素的，它们有着强大的分解能力，能把那些老旧的、不再需要的细胞外基质给拆掉，让新的、更有活力的结构能够长出来。
就像是城市里的拆迁队，虽然看起来是在搞破坏，但实际上是在为城市的发展腾出空间，让新的建筑能够拔地而起。
基质金属蛋白酶这个大家族里，成员可不少，每个成员都有自己的特长和喜好。
有的擅长对付胶原蛋白，那可是构成皮肤、骨骼和血管的重要成分；有的则喜欢分解弹性蛋白，让咱们的皮肤能够保持弹性，不容易长皱纹；还有的专门对付那些让细胞黏在一起的物质，就像是城市里的“胶水”，让细胞们能够紧紧地团结在一起。
这些基质金属蛋白酶，平时都乖乖地待在自己的岗位上，不会随便乱动。
但是，一旦身体里面出现了什么异常，比如炎症、癌症啥的，它们就会像是被激活了一样，开始疯狂地工作起来。
就像是城市里的消防员，平时默默无闻，但一旦有火情发生，就会立刻冲上前去，扑灭大火。
不过，话说回来，这些基质金属蛋白酶要是太过头了，也会带来麻烦。
就像是拆迁队拆得太猛了，把好好的房子也给拆了，那可就不妙了。
如果它们过度活跃，就会破坏掉那些原本应该保留的细胞外基质，导致身体出现问题。
比如，皮肤上的伤口久久不能愈合，骨骼变得脆弱容易骨折，甚至还会出现肿瘤。
所以，咱们的身体里，还得有一套机制来管理这些基质金属蛋白酶，让它们既能够发挥自己的作用，又不会过度破坏。
就像是城市里的规划局，得时刻关注着拆迁队的动向，确保他们的工作既合法又合规。
科学家们对基质金属蛋白酶的研究，也是越来越深入了。
他们就像是侦探一样，不断地寻找着这些特种部队的踪迹，了解它们的习性，以便更好地利用它们，为人类的健康服务。
基质金属蛋白酶12
基质金属蛋白酶12
基质金属蛋白酶12（MMP12）是一种酶类，可在许多生理和病理过程中发挥重要作用。
它主要存在于肺组织中，可促进肺气肿、支气管扩张和哮喘等疾病的发生和发展。
此外，MMP12还参与肿瘤转移、动脉粥样硬化和关节炎等多种疾病的发生和发展。
因此，MMP12成为了许多疾病的治疗和预防的重要靶点。
目前，一些MMP12的抑制剂已经在研发中，并显示出了潜在的治疗效果。
未来，MMP12的研究将有助于更好地了解其在生理和病理过程中的作用，以及开发更有效的治疗策略。
- 1 -。
酶谱法检测血清基质金属蛋白酶MMP生物化学与分子生物学
酶谱法检测血清基质金属蛋白酶MMP生物化学与分子生物学引言酶谱法是一种常用的方法，用于测定血清基质金属蛋白酶（Matrix Metalloproteinase，简称MMP）的活性。
MMP是一类重要的蛋白酶，参与多种生理和病理过程，包括组织再生、肿瘤转移等。
本文将介绍血清基质金属蛋白酶MMP的生物化学特性以及酶谱法的原理和操作步骤。
血清基质金属蛋白酶MMP的生物化学特性血清基质金属蛋白酶（MMP）是一类富含锌离子的蛋白酶，在生物体内起到调节基质降解的重要作用。
MMP主要由细胞外基质成分和细胞表面的蛋白酶组成，包括胶原酶、明胶酶等。
这些酶在正常生理过程中，如组织再生和修复中，起到调节细胞迁移、基质降解的作用。
然而，在许多疾病的进展中，MMP的活性过高或过低都可能导致病理性结果，如肿瘤的转移和心肌梗塞。
MMP的活性可以通过多种方法进行检测，其中酶谱法是一种常用且灵敏的方法之一。
酶谱法检测血清基质金属蛋白酶MMP的原理酶谱法是一种使用荧光信号来测定酶活性的方法。
在血清基质金属蛋白酶MMP的检测中，常使用一种荧光基质作为底物，这种底物在未被酶降解时会发出弱的荧光信号，但在被酶降解时会发出明显的荧光信号。
利用这种差别，可以通过测量荧光信号的强度来反映MMP的活性。
酶谱法的操作步骤包括以下几个方面：1.实验前准备：清洗试管和工具，准备所需试剂和样品。
2.底物制备：制备稀释的荧光底物，使其浓度适用于实验。
3.样品处理：将待测的血清样品加入试管中，同时添加荧光底物。
4.反应混合：轻轻摇动试管，使样品和底物充分混合，然后放置在恒温器中反应一段时间。
5.测量荧光信号：使用荧光检测仪器来测量样品中荧光信号的强度。
6.数据分析：根据荧光信号的变化来计算MMP的活性，并进行数据统计和分析。
酶谱法是一种常用的方法，用于检测血清基质金属蛋白酶MMP的活性。
通过测量荧光信号的强度，可以间接反映MMP的活性水平。
酶谱法具有操作简单、结果可靠、灵敏度高等优点，在生物化学和分子生物学研究中得到了广泛应用。
基质金属蛋白酶的生理功能
基质金属蛋白酶的生理功能基质金属蛋白酶，也称为MMPs，是一类能够分解细胞外基质蛋白的酶，其生理功能与许多不同的信号通路以及多种疾病的发展有关。
这些酶在人体内广泛分布，参与各种生理和病理过程，包括生长发育、血管生成、免疫反应、组织修复、肿瘤侵袭、骨骼破坏等等。
基质金属蛋白酶家族的共同特征是结构相似，具有类似的活性位点以及酶底物特异性。
这类酶主要包括两类：胶原酶和凝血酶样酶。
胶原酶主要分解胶原及其它基质蛋白，而凝血酶样酶主要分解凝血因子以及其它蛋白质。
这些酶的活性普遍受到细胞外基质环境中多种信号通路的影响，包括细胞因子、生长因子、胞外基质成分以及微环境温度、pH等等。
在生长发育过程中，基质金属蛋白酶起着非常重要的作用。
它们参与了胚胎植入、器官形成以及组织分化等过程。
例如，MMPs 通过分解细胞外基质促进组织分化，促进胎儿生长发育。
同时，它们也参与了一些疾病的发展，例如先天性心脏病、关节炎等。
基质金属蛋白酶也对免疫反应具有重要作用。
在细胞外的免疫反应中，它们参与了白细胞的趋化和浸润，以及细胞外基质重构和增殖。
在某些自身免疫性疾病中，它们的过度活化可能导致免疫系统的炎症反应，如类风湿性关节炎。
在组织修复过程中，基质金属蛋白酶也具有很重要的作用。
它们可以分解放置在创伤或炎症部位的受损细胞外基质，并在组织修复过程中促进血管生成和细胞移植。
例如，在心肌梗死后，MMPs可以促进心肌细胞增殖和重塑，从而参与了心脏组织的修复。
基质金属蛋白酶也被广泛应用于肿瘤和血管发生研究中。
肿瘤细胞通过调节MMPs的活性来促进侵袭和转移。
MMPs可以侵蚀血管基质，降低血管壁的稳定性，而血管壁的破裂有利于肿瘤细胞进一步侵袭。
因此，MMPs已经成为肿瘤治疗和预后评估的目标。
此外，基质金属蛋白酶对骨骼疾病的发展也有着重要作用。
它们在骨重塑及骨吸收过程中都有贡献。
在骨折愈合过程中，MMPs 也能够参与骨组织的修复和重塑。
总之，基质金属蛋白酶在人体内的生理功能非常广泛。
基质金属蛋白酶测量意义
基质金属蛋白酶测量意义【摘要】基质金属蛋白酶是一类重要的酶，在生物体内发挥着关键作用。
测量基质金属蛋白酶的意义在疾病诊断、药物研发、癌症研究、心血管疾病研究、以及炎症和免疫相关疾病中均具有重要的价值。
该测量技术的不断发展也为相关领域的研究提供了有力支撑。
未来，基质金属蛋白酶测量在临床应用中的前景仍然广阔，同时也将继续为科学研究和医学进步作出贡献。
基质金属蛋白酶测量的重要性不可忽视，其在疾病诊断和治疗上的应用前景广阔，为促进健康领域的发展做出了重要贡献。
【关键词】基质金属蛋白酶、测量意义、疾病诊断、药物研发、癌症、心血管疾病、炎症、免疫、临床应用、未来发展、重要性。
1. 引言1.1 基质金属蛋白酶测量意义的重要性基质金属蛋白酶测量意义的重要性体现在其在生物体内的关键作用和在疾病诊断、药物研发、癌症研究、心血管疾病研究以及炎症和免疫相关疾病中的广泛应用。
基质金属蛋白酶是一类重要的蛋白酶，在细胞生物学和生物化学中扮演着关键的角色。
它们参与细胞外基质的降解和重塑，调控细胞内信号通路，影响细胞迁移、增殖和凋亡等生命活动。
测量基质金属蛋白酶的活性和表达水平可以帮助我们更好地了解疾病的发生和发展机制，为药物研发和治疗提供重要依据。
基质金属蛋白酶测量意义的重要性不仅体现在科学研究领域，也在临床诊断和治疗中具有重要意义。
深入研究和开发基质金属蛋白酶测量技术，探索其在各种疾病中的应用潜力，将对未来医学领域的发展产生重要的影响。
1.2 基质金属蛋白酶在生物体内的作用基质金属蛋白酶在生物体内的作用是非常重要的。
这类酶在细胞内起着关键的调控作用，参与了许多生物学过程。
基质金属蛋白酶可以降解细胞外基质，促进细胞迁移和侵袭。
这对于细胞的生长、分化和转移都至关重要。
基质金属蛋白酶还能调控细胞外信号通路，影响细胞的生存、增殖和凋亡。
它们还参与了血管生成、免疫应答和炎症反应等生理过程。
基质金属蛋白酶在维持生物体内环境稳定性和功能平衡方面扮演着重要角色。
基质金属蛋白酶-2,9在白血病中的研究现状
・
６ ２・ ６
国际内科学杂志 ２０ ０ ８年 １ 月第 ３ １ ５卷第 １ 勇 １
基 质金 属蛋 白酶． ， 在 白血病中 的研 究现状 ２９
胡 婷 综述 ； 刘加 军 审校
摘 要 ：基质 金 属 蛋 白酶 （ ＭＰ 是一 类 能 降 解 细 胞 外 基 质 成 分 的蛋 白 水 解 酶 ， 表 达 与 多 种 肿 瘤 的 生 Ｍ ） 其
关键词 ：基质金属蛋白酶 ； 基质金属蛋 白酶抑制剂 ； 白血病
中 图分 类号 ：Ｒ ３． 文 献 标 识码 ：Ａ 文 章 编 号 ：０ ４２ ６ （０ ８ １－６ ２ ４ ７３７ １０ —３９ ２０ ）１ ６ － ０ ０
Ｄｅ ｅ ｏ ｖ ｌ ｐｍ ｅ ｅ ｅ ｒ ｈ ｏ ｍ ａｔｉ ｅ ａ ｌｐｒ ｔ ｉ ｓ ｓ２ ｎｔｏｆ ｒ ｓ ａ ｃ ｎ ｒ ｘ ｍ ｔ ｌｏ ｏ ｅｎａ ｅ － ａｎｄ ｍ ｅａｌｏ ｏ ｅｎａ ｅ － ｉ ｌｕｋ ｍ ｉ ＨＵ ｔ ｌ ｐｒ ｔｉ ｓ ｓ９ ｎ ｅ ｅ ａ
ｐ ｏ ｎ ｓｓｉ ｅ ｅ ｉ ｒ ｉｃ ｓｅ ． ｒ ｇ ｏ ｉ ｎ ｌｕｋ ｍ ａ ｗｅ ｅ ｄ ｓ ｕ ｓ ｄ Ｋｅ ｒ ｙ ｗｏ ｄｓ：Ｍ ａｒｘ ｍｅａ ｌｐ ｏｅｎａ ｅ；Ｍ ａｒｘ ｍ ｅａｌｐ ｏｅ ｎ ｓ ｎｈｂｉ ｒ Ｌ ｕｋ ｍｉ ｔｉ ｔｌｏ ｒ ｔｉ ｓ ｔｉ ｔｌｏ ｒ ｔｉ ａ ｅ ｉ ｉ ｔ ； ｅ ｅ ａ ｏ
基质金属蛋白酶3说明书
基质金属蛋白酶3说明书
基质金属蛋白酶3（Matrix Metalloproteinase 3）是一种酶类蛋白质，属于基质金属蛋白酶家族。
它也被称为stromelysin-1或者proteoglycanase，是一种能够降解基质组分的酶。
基质金属蛋白酶3是由酶原前体产生的，经过外源酶的切割后活性化。
基质金属蛋白酶3在细胞外基质的重塑中起着重要的作用。
它能够降解胶原、纤维连接蛋白、弹力纤维和其他基质组分。
基质金属蛋白酶3在生理和病理过程中起着重要的调节作用。
它参与了胚胎发育、组织修复、纤维化和肿瘤的发展。
它的活性和表达水平受到多种因素的调节，包括生长因子、细胞因子和细胞外基质中的其他蛋白质。
基质金属蛋白酶3在许多疾病中具有重要的作用。
例如，在关节炎患者中，基质金属蛋白酶3的活性显著增加，导致关节结构的破坏。
此外，它还参与了心脏病、神经系统疾病和某些癌症的发展过程。
基质金属蛋白酶3可以通过多种技术进行检测和测量，包括酶活性测定、免疫组化和基因表达分析。
在使用基质金属蛋白酶3的相关试剂和产品时，必须严格按照产品说明书进行操作。
同时，需要遵循实验室安全规范和操作指南，以确保实验的准确性和安全性。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
基质金属蛋白酶_基质金属蛋白酶细胞外基质和基底膜重塑是癌细胞侵袭转移过程中的关键环节，需借助于蛋白降解酶的表达和激活。
基质蛋白酶主要有以下数种：丝氨酸蛋白酶类，包括血浆酶原激活剂；半胱氨酸蛋白酶类，包括组织蛋白酶0在内的溶酶体酶；金属蛋白酶类0^1&110^^0^611^565) [1]。
金属蛋白酶类在肿瘤侵袭过程中的作用近年来倍受关注，大量证据表明基质金属蛋白酶，特别是基质金属蛋白酶- 2 (matrix metalloproteinase-2, MMP-2)在肿瘤细胞介导的细胞外基质降解中起关键作用，临床研究表明，順?_2活性和表达的增加与人类多种恶性肿瘤侵袭转移潜能及预后密切相关[2〜4]。
一.嫩识-2基因及其表达和激活的调节MMP-2基因位于人类染色体16q21,由13个外显子和12个内含子所组成，结构基因总长度为27此，与其他金属蛋白酶不同，_-2基因5'旁侧序列促进子区域含有2个60盒而不是1414盒[5]。
_-2以前酶原的形式由多种细胞分泌，如成纤维细胞、巨噬细胞、内皮细胞和恶性肿瘤细胞等。
与其他金属蛋白酶相似，嫩1?-2分子含有氨基末端片段、金属结合片段及竣基末端片段，其中带有高度保守序列PRCGV/NPD的氨基末端具有一个不配对的半胱氨酸残基，该残基与激活位点的锌原子相互作用介导着—_2的前体状态；金属结合片段是公认的锌结合部位，其含旁侧有2个组氨酸的保守序列册4出羧基末端具有类似凝血酶的片段，该片段的具体功能尚未明确。
此外，_-2还具有一个 58个氨基酸残基组成的明胶结合片段，此片段与纤维连接素的明胶结合11型基元相似[6]。
目前认为，_-2表达和功能的调节发生于转录、分泌、前酶原的激活、细胞表面的结合以及与来源于肿瘤或宿主细胞的MMP抑制剂的相互作用等多个不同的水平。
MMP-2的转录调节与其他金属蛋白酶相比具有一定的独特性，如佛波醇酯(phorbol 6316：^通过仙-1位点的介导增加腿?-9和间质胶原酶的表达，而題?-2基因促进子区域未能测得4?-1位点[5]；转化生长因子-p l(TGF-p 1)通过其抑制元素11£抑制间质胶原酶的表达[7],而10?-0 1却能诱导人类细胞株转录出高水平的丽?_2信使核糖核酸(—4) [8]。
此外，整合素受体和丁則161^5(：化)亦能诱导MMP-2的转录表达。
MMP_2在细胞外以前酶原的状态存在，体外实验表明有机汞化合物和蛋白酶等均可通过干扰氨基末端不配对半胱氨酸残基与激活位点的锌原子间的相互作用，导致前酶原氨基末端80个氨基酸片段的自身催化降解转化成酶原，获得胶原溶解的活性，激活的酶原进行自身蛋白降解，最终产生具有稳定活性62^)酶，这种激活过程被称为“半胱氨酸开^¾(cysteine switch)，，假说[9]。
由于膜型MMP即MTl-MMP的成功克隆和排序，MMP_2在体内激活的受体机制已被基本阐明。
将町1-剛？质粒转染入0^-1细胞株内后，.^!!'^*!{^即表达于该细胞株的胞膜，并导致__2酶原的特异性激活[10]。
研究发现，MMP_2 酶原的激活依赖丁‘由11邮-2(1^85收inhibitor of ^6七&110口1^^61服56-2)与MTl-MMP结合始动的一个三元复合体的形式，虽然高浓度的TIMP-2抑制MMP_2 的活性[11]。
MMPS活性调节的关键是TIMPS对其酶活性的抑制作用。
研究表明MMP_2及其前体均可与11肥-2结合，但结合位点并不相同。
_-2前体-11即-2复合体在不裂解的情况卜仍可被继续激活产生MMP_2活性，该活性能被额外的TIMP-2完全抑制[12]。
所以丽?-2与1^«5-2的相对浓度最终决定麗?-2胶原降解的能力。
關?-2的主要底物为吖型胶原，其次还有乂、VD、K、乂型胶原及纤维连接素和弹性蛋白等。
二.嫩11)-2与恶性肿瘤的侵袭转移体外实验结果显示，ras基因诱导的恶性肿瘤细胞株的MMP-2表达增加，激活MMP-2的单克隆抗体能促进A2058细胞株的侵袭能力，而抑制MMP_2的单抗则使42058细胞株穿透重组基底膜的能力明显减弱[13]。
打服-2对肿瘤侵袭转移的抑制是NMP_2与肿瘤侵袭转移相关性的又一佐证。
TIMP-2过度表达，能抑制转移性ras转化小鼠胚胎成纤维细胞裸鼠静脉注射后肺转移灶的形成，以及体内肿瘤的生长速度和癌细胞的浸润特性[14]。
VaisaneneUS [15] 嫌^-2表达是皮肤黑色素瘤的独立预后因素；Levy [16]采用此11±61^印迹分析技术发现72%的直、结肠腺癌—_2 _八水平异常增高；P0ulsom等 [17]采用原位杂交技术，结果显示结肠肿瘤组织间质细胞能合成嫌^』，且与肿瘤细胞一起参与浸润癌特异性的组织重塑和基底膜降解过程。
Davies [18]研究表明膀胱癌组织中丽?-2 —々主要位于间质细胞而不是肿瘤上皮细胞，MMP-2 表达水平与肿瘤分化程度及浸润深度密切相关。
免疫组化染色显示腿?-2蛋白主要表达于肿瘤细胞膜和胞浆内，而原位杂交技术则发现MMP_2 mRNA主要存在于肿瘤细胞周围的间质细胞如成纤维细胞和内皮细胞。
两种方法结果不一致的原因可能是(1)肿瘤细胞摄取来源于成纤维细胞的MMP-2蛋白；（2)肿瘤细胞与间质细胞MMP-2 mRNA翻译率及细胞内蛋白贮存能力的不同；以及(3)原位杂交技术和免疫组化检测阈值的不同等[19]。
多数学者认为肿瘤细胞和间质细胞均能合成MMP-2，且肿瘤细胞可通过多种机制诱导间质细胞丽?_2的合成和分泌。
如肿瘤细胞表达的一种与免疫球蛋白超家族同源的细胞表而受体，胶原酶刺激因子0^3«又称细胞外題？诱导因子，能刺激成纤维细胞的_-2表达[11]。
MMP-2与胃癌关系的研究是近年来开展的新课题。
1994年Schwart等[20]研究胃癌细胞株SK-GT的MMP-2 mRNA表达，结果发现浸润型细胞株SK-GT1、 SK-GT5及SK-GT6表达MMP_2,而非浸润型细胞株SK_GT2和SK_GT4不表达MMP-2；此外，丨響^表达阳性细胞株来源病人的预后明显差于阴性者。
D' £^化等[21]报道正常胃黏膜上皮退《3-2呈阴性表达，胃癌细胞_-2主要表达于细胞膜，分化差的胃癌细胞_-2表达阳性率显著高于分化较好者，进展期胃癌的MMP_2阳性率高于早期胃癌。
提示MMP-2表达的检测有助于胃癌病期进展的评估。
51^等[22]研究表明胃癌组织的丨偏?-2表达显著高于邻近非癌黏膜组织，（；03(多因素回归分析显示_-2高表达胃癌患者预后较差。
后继研究检测胃癌组织MMP_2及其非活性前体的表达情况，发现进展期胃癌和早期胃癌MMP_2前体的阳性率分别为67%和46%，MMP-2则仅限于进展期胃癌，血管侵犯阳性的胃癌腿?-2前体阳性率显著高于阴性者[23]。
1996年Nomura[24]通过采用免疫组化、三明治酶免疫分析及明胶酶谱学等多种测检手段，研究发现腿?-2主要表达于进展期胃癌，并与肿瘤的血管侵犯密切相关，认为 _-2前体的激活是胃癌细胞扩散的关键环节。
Mori [25]通过分析阶1-_和MMP-2在胃癌组织中的表达情况，认为MTl-MMP通过胃癌的胃壁浸润和淋巴结转移影响患者的预后，奶识^激活与胃癌进展密切相关。
Caenazzo [26]研究胃癌组织MTl-NMP与MMP-I mRNA的比率，发现检测MTl_MMP与NMP mRNA的比率可作为胃癌术前新的分子生物学预后指标。
然而，有研究表明肌识-2表达仅与胃癌患者生存率有单因素相关的趋势，而不是预后的独立指标，高…八受体表达的胃癌患者组则存在MMP_2与预后的相关性，提示仅在MMP_2的激活酶过度表达的情况下，謝?-2可作为胃癌的预后因素[27]。
TIMP-2与MMP-2在胃癌侵袭转移中的重要性亦颇受关注。
一项前瞻性研究表明，胃黏膜内癌11肥-2表达阳性率为63%，顯?-2阳性率为19%，进展期胃癌TIMP-2表达阳性率下降而MMP_2阳性率升高，预后分析结果显示胃癌原发灶 TIMP-2高表达而MMP_2低表达者生存时间显著延长。
所以TIMP-2和MMP_2在胃癌的负相关作用作为整体调节胃癌细胞的浸润转移，并可能具有重要的预后意义[28] o四.小结MMP-2的表达、有效激活及蛋白降解功能的发挥受诸多因素如膜激活剂、整合素受体的表达及基质成分和11斯-2的调控。
大多数研究表明，—-2表达与胃癌侵袭转移及预后密切相关。
然而，对_-2及其与胃癌关系的研究尚处于初始阶段，对与MMP_2密切相关的基质蛋白降解关键调节机制的深入剖析，将有助于对胃癌侵袭转移机制的进一步认识，从而为将来的抗胃癌转移治疗方案提供方向性的目标。
参考文献1 Jonbs JL, Walker RA. Control of matrix raetalloproteinaseactivity in cancer. J Pathol 1997;183 : 377-379.2 Liotta LA, Tryggvason K, Garbisa S，et al. Metastatic potential correlates with enzymatic degradation of basement membrane collagen.Naturel980;284 I 67-68.3 Davies B, Miles DW， Happerfield LC, et al. Activity of type IV collagenases in benign and malignant breast disease. Br JCancerl993;67 ： 1126-1131.4 Davies B, Waxman J, Wasan H, et al. Levels of matrixmetalloproteinase in bladder cancer correlate with tumor grade andinvasion. Cancer Resl993;53 : 5365-5369.5 Huhtala P, Chow LT, Tryggvason K. Structure of the human typeIV collagenase gene. J Biol Chem 1990;265 : 1107-1108.6 Fridman R, Fuerst TR, Bird RE, et al. Domain structure ofhuman 72-KDa, gelatinase/type IV collagenase. J Biol Chera1992;267 ： 15398-15405.7 Kerr LD, Miller DB, Matrisian LM. TGF-P 1 inhibition oftransin/stromelysin gene expression is mediated through a fos binding sequence, cell 1990;61 : 267-278.8 Stetler-Stevenson WG. Type IV coll agenases in tumor invasionand metastasis. Cancer Metastasis Rev 1990;9 : 289-303.9 Van wart HE, Birkedal-Hansen H. The cysteine switch:principleof regulation of metalloproteinase activity with potentialapplicability to the entire matrix metalloproteinase gene family.Proc Natl Acad Sci USA1990;87 ： 5578-5582.10 Sato H, Takino T, Okada Y， et aL A matrix metalloproteinaseexpressed on the surface of invasive tumor cells. Nature 1994；370 ： 61-65.11 Strongin AY, Collier I， Bannikov G, et al. Mechanism of cellsurface activation membrane metalloproteinase. J Biol Chem1995;270 ： 5331-5338.12 Goldberg GI, Marmer BL, Grant GA， et al. Human 72-KDa type IV collagenase forms a complex with a tissue inhibitor ofmetalloproteinase inhibitor. Proc Natl Acad Sci USA 1989;86 : 8207- 8211.13 Hoghta M, Hujanen E, Jurpeenniemi-Hujanen T3 et al.Modulation of type-IV collagenase activity and invasive behavior of metastatic human melanoma(A2058) cells in vitro by monoclonalantibodies to type-IV collagenase. Int J cancer 1990;46 : 282-286.14 Declerck YA, Perez N, Shimada H， et al. Inhibition ofinvasion and metastasis in cells tansfected with a inhibitor ofmetalloproteinases. Cancer res 1992;52 ； 701-708.15 Vaisanen A, Kallioinen M, Jaskinen PJ,et al. Prognostic value of MMP-2 immunoreactive protein 72KD type IV collagenase in primary skin melanoma. J pathol 1998;186 I 51-58.16 Levy AT, Cioce V， Sobel ME, et al. Increased expression ofthe Mr 72, 000 type collagenase in human colonic adenocarcinoma.Cancer Res 1991;51 ： 439-444.17 Poulsom R, Pignatelli M， Stetler-Stevenson WG， et al. Stromal expression of 72Kda type IV collagenase (MMP-2) and TIMP-2 mRNAS in colorectal neoplasia, am J Pathol 1992;141 : 389-396.18 Davies B， Waxman J, Wasan H, et al. Levels of matrixmetalloproteinases in bidder cancer correlate with tumor grade andinvasion. Cancer Resl993;53 : 5365-5369.19 Nomura H, Fujimoto N， Seiki M, et al. Enhanced production ofmatrix metalloproteinases and activation of matrix metalloproteinase- 2 (Gelatinase A) in human gastric carcinomas. Int J Cancer1996;69 ： 9-16.20 Schwart GK, Wang H, Lampen N， et al. Defining the invasivephenotype of proximal gastric cancer cells. Cancer 1994;73 : 22-27.21 D' Errico A, Garbisa S, Liotta LA， et al. Augmentation oftype IV collagenase, lamin receptor, Ki 67 proliferation antigenassociated with human colon, gastric and breast carcinoma progression. Mod Pathol 1991;4 ： 239-246.22 Sier CF, Kabben FJ, Ganesh S，et al. Tissue levels of matrix metalloproteinases MMP-2 and MMP-9 are related to the overall survival of patients with gastric carcinoma. Br J Cancer1996;74 ： 413-417.23 Nomura H, Sato H, Seiki M, et al. Expression of membrane type raatrrx metalloproteinase in human gastric carcinomas. Cancer Res1995;55 ： 3263-3266.24 Nomura H, Fujimoto N， Seiki M, et al. Enhanced production ofmatrix metalloproteinases and activation of matrix metalloproteinase 2 (gelatinase A) in human gastric carcinomas. Int J Cancer 1996;69 : 9- 16.25 Mori M，Mimori K，Shiraishi J, et al. Analysis of MTl-MMP and MMP-2 expression in human gastric cancers. Int J Cancer 1997;74 ； 316- 321.26 Caena C, Onisto M, Sartor L，et al. Augmented membrane type 1 matrix metalloproteinase (MTl-MMP): MMP-2 messenger RNA ratio ingastric carcinomas with poor prognosis. Clin Cancer Res 1998;4 ； 2 179-2186.27 Allgayer H, Heiss MM, Sohildberg FW. Prognostic factors ingastric cancer. Br J Surgery 1997;84 : 1651-1664.28 Grigioni WF, D' Errico A, Fortunato C, et al. Prognosis of gastric carcinoma revealed interactions between tumor cells and basement membrane. Mod pathol 1994;7 : 220-225.。