Regulation Of MMP-2 Activity Research Articles

Role of MMP-2 and CD147 in kidney fibrosis.

Matrix metalloproteinase-2 (MMP-2) and cluster of differentiation 147 (CD147) both play important roles in the development of kidney fibrosis, and CD147 can induce the production and activation of MMP-2. In the early stage of kidney fibrosis, MMP-2 promotes extracellular matrix (ECM) production and accelerates the development of kidney fibrosis, while in the advanced stage, MMP-2 activity decreases, leading to reduced ECM degradation and making it difficult to alleviate kidney fibrosis. The reason for the decrease in MMP-2 activity in the advanced stage is still unclear. On the one hand, it may be related to hypoxia and endocytosis, which lead to changes in the expression of MMP-2-related active regulatory molecules; on the other hand, it may be related to insufficient CD147 function. At present, the specific process by which CD147 is involved in the regulation of MMP-2 activity is not completely clear, and further in-depth studies are needed to clarify the roles of both factors in the pathophysiology of kidney fibrosis.

Salivary Active MMP-2 of Breast Cancer Patients Is Inhibited by Guava Leaves PBS Extract

Matrixmetalloproteinase-2 (MMP-2), also called gelatinase-A, is a 72 Kd protein present in chromosome 16 in human. It is a zinc binding protein, responsible for the degradation of Extra Cellular Matrix (ECM) in normal physiological as well as disease processes like arthritis and cancer. It has a specific role in the cancer development and angiogenesis. MMP-2 contributes to cell migration. MMPs are the key to normal development as well as in the pathology of cancer and other inflammatory diseases. The inhibitors of MMP-2 activity are very important in maintaining the normal activity of MMP-2 and have an important role in the management of cancer. Regulation of MMP-2 activity is done by inhibitors like, TIMPs. In this report, we are discussing about a possible inhibitor(s) present in the PBS extract of guava leaves, inhibiting the active MMP-2 present in the saliva of breast cancer patients.

Cellular uptake of proMMP-2:TIMP-2 complexes by the endocytic receptor megalin/LRP-2

Matrix metalloproteinases (MMPs) are regulated at multiple transcriptional and post-transcriptional levels, among which receptor-mediated endocytic clearance. We previously showed that low-density lipoprotein receptor-related protein-1 (LRP-1) mediates the clearance of a complex between the zymogen form of MMP-2 (proMMP-2) and tissue inhibitor of metalloproteinases, TIMP-2, in HT1080 human fibrosarcoma cells. Here we show that, in BN16 rat yolk sac cells, proMMP-2:TIMP-2 complex is endocytosed through a distinct LRP member, megalin/LRP-2. Addition of receptor-associated protein (RAP), a natural LRP antagonist, caused accumulation of endogenous proMMP-2 and TIMP-2 in conditioned media. Incubation with RAP also inhibited membrane binding and cellular uptake of exogenous iodinated proMMP-2:TIMP-2. Moreover, antibodies against megalin/LRP-2, but not against LRP-1, inhibited binding of proMMP-2:TIMP-2 to BN16 cell surface. BIAcore analysis confirmed direct interaction between the complex and megalin/LRP-2. Conditional renal invalidation of megalin/LRP-2 in mice resulted in accumulation of proMMP-2 and TIMP-2 in their urine, highlighting the physiological relevance of the binding. We conclude that megalin/LRP-2 can efficiently mediate cell-surface binding and endocytosis of proMMP-2:TIMP-2 complex. Therefore megalin/LRP-2 can be considered as a new actor in regulation of MMP-2 activity, an enzyme crucially involved in many pathological processes.

Focal adhesion kinase induces matrix metalloproteinase-2 by involving α5β1-mediated signaling in breast cancer cell, MCF-7

Introduction: Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays a pivotal role in cell invasion. Matrix metalloproteinases (MMPs) are implicated as the key players in cancer cell invasion. Hence, the role of FAK in MMP regulation is very important in understanding tumor progression. Materials and Methods: Here, we studied the role of FAK, its association with other signaling kinases and involvement in the α5β1 integrin receptor-mediated regulation of MMP-2 activity and expression in human breast cancer cell line MCF-7. Results: Immuno blot analysis revealed that FN treatment causes phosphorylation of FAK and FAK gets localized at the cell attachment focal point of MCF-7 cells. FN treatment did not change the mRNA status of FAK but enhanced mRNA level of MMP-2 and MT1-MMP, also caused downregulation of TIMP-2. Co-imunoprecipitation and inhibitor studies revealed the association of FAK with α5β1, Paxillin, PI3K and ERK. siRNA studies revealed that FAK is critical in regulation of activity and expression of MMP-2 and downstream signaling kinases. Conclusion: The interaction of α5β1 integrin with FN initiates a signaling cascade with FAK as its central player. FAK gets phosphorylated and in turn associates with tyrosine kinases like PI3K and ERK. FAK also activates PI3K and ERK that serve as very crucial mediators of the signaling pathway leading to induction of MMP-2 activity and resulting invasion of breast cancer cell, MCF-7.

RETRACTED ARTICLE:Type IV collagen α1-chain noncollagenous domain blocks MMP-2 activation both in-vitro and in-vivo

α1(IV)NC1 inhibits angiogenesis by regulating MAPK activation, this biological function was partly attributed α1(IV)NC1 binding to α1β1-integrin. However, its potent antiangiogenic activity and the molecular targets of α1(IV)NC1 has not been investigated. In the present study, the regulation of MMP-2 activation by α1(IV)NC1 was evaluated. α1β1-integrin which is required for inhibition of angiogenesis is not playing a role in cellular invasion and inhibition of MMP-2 activation by α1(IV)NC1. We found that α1(IV)NC1 binds the CBD of MMP-2 and forming a stable complex that prevents activation of MMP-2. The antiangiogenic activity of α1(IV)NC1 is mediated, in part, by this binding activity. In addition, up-regulation of TIMP-2 by α1(IV)NC1 led to saturation of MT1-MMP binding sites, which in turn led to inhibition of MMP-2 activation. In-vivo studies using α1-integrin null-mice treated with higher doses of α1(IV)NC1 showed integrin independent inhibition of tumor growth and active-MMP-2, without affecting MMP-9, MMP-7 and angiostatin.

Selenium restores defective beta-adrenergic receptor response of thoracic aorta in diabetic rats

Increased oxidative stress is one of the basic contributors to the development of the cardiovascular complications in diabetes. Both endothelial and vascular smooth muscle cell dysfunctions are the main sign involved in the pathogenesis of diabetic cardiovascular dysfunction. Matrix metalloproteinases (MMPs) are expressed in the vasculature, and participate in tissue remodeling under pathological conditions such as increased oxidative stress, whereas little is known about effect of hyperglycemia on regulation of MMPs in vascular system. Therefore, we aimed to evaluate the effect of an antioxidant, sodium selenate treatment (0.3 mg/kg for 4 weeks) on function of streptozotocin-diabetic rat aorta. Sodium selenate treatment improved significantly impaired isoproterenol-induced relaxation responses and contraction responses of the aortic strips, and exhibited marked protection against diabetes-induced degenerative changes in the smooth muscle cell morphology. Biochemical data showed that sodium selenate treatment induced a significant regulation of MMP-2 activity and protein loss as well as normalization of increased levels of tissue nitrite and protein thiol oxidation. In addition, this treatment restored diabetes-induced increased levels of endothelin-1, PKC, and cAMP production in the aortic tissue. Taken together, our data demonstrate that these beneficial effects of sodium selenate treatment in diabetics are related to be not only inhibition of increased oxidative stress but also prevention of both receptor- and smooth muscle-mediated dysfunction of vasculature, in part, via regulation of MMP-2. Such an observation provides evidence for potential therapeutic usage of selenium compounds for the amelioration of vascular disorders in diabetes.

Rapid expression and activation of MMP-2 and MMP-9 upon exposure of human breast cancer cells (MCF-7) to fibronectin in serum free medium

Interactions between tumour cells and the extracellular matrix (ECM) strongly influence tumour development, affecting cell survival, proliferation and migration. Many of these interactions are mediated through a family of cell surface receptors named integrins. Fibronectin and its integrin receptors play important roles in tumour development. The α5β1 integrin interacts with the central cell adhesive region of fibronectin and requires both the RGD and synergy sites for maximal binding. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases. They are capable of digesting the different components of the ECM and basement membrane. The ECM gives structural support to cells and plays a central role in cell adhesion, differentiation, proliferation and migration. Binding of ECM to integrins modulates expression and activity of the different MMPs. Our experimental findings demonstrate that cultivation of human breast cancer cells, MCF-7, in serum free medium in the presence of fibronectin upregulates the activity of MMP-2 and MMP-9. Blocking of α5β1 integrin with anti-α5 monoclonal antibody inhibits the fibronectin-induced MMP activation response appreciably. This strongly indicates α5β1 mediated signalling events in activation of MMP-2 and MMP-9. Phosphorylation of FAK and PI-3 kinase and the nuclear translocation of ERK and NF-κB upon fibronectin binding demonstrate possible participation of the FAK/PI-3K/ERK signalling pathways in the regulation of MMP-2 activity.

Connective tissue growth factor increases matrix metalloproteinase‐2 and suppresses tissue inhibitor of matrix metalloproteinase‐2 production by cultured renal interstitial fibroblasts

The involvement of gelatinase (matrix metalloproteinase-2 [MMP-2] and MMP-9) in the matrix remodeling and development of tubulointerstitial fibrosis has been studied recently, but relatively little is known about the regulators and the mechanisms controlling the activation and expression of gelatinase in renal fibroblasts. In these studies, the production and underlying signaling pathway for gelatinase by exogenous connective tissue growth factor (CTGF) treatment were investigated. Here, we show that CTGF acts as a potent promoter of the activation and expression of MMP-2, but not MMP-9 in normal rat kidney fibroblasts cell line (NRK-49F). We found that CTGF significantly increased the activity of MMP-2, as well as MMP-2 protein in conditioned medium and MMP-2 mRNA levels in cells. In studies to address the mechanisms involved in the regulation of MMP-2 activity, we found that the tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), the inhibitor of MMP-2, decreased significantly when cells were treated with CTGF. Further studies showed that extracellular signal-regulated kinase (ERK) signaling is responsible for most of the CTGF-induced MMP-2 expression and TIMP-2 suppression. When NRK-49F fibroblasts were incubated with CTGF, activation of ERK1/2 signaling was observed. Suppression of ERK1/2 activation with nontoxic concentrations of PD98059, a specific inhibitor of ERK activation, was associated with a reduction of CTGF-stimulated MMP-2 activity and protein expression. In addition, the CTGF-mediated reduction of TIMP-2 activity and protein expression was prevented when ERK1/2 activation was inhibited by PD98059. These results provide evidence that CTGF augments activation of MMP-2 through an effect on MMP-2 protein expression and TIMP-2 suppression, and that these effects are dependent on the activation of the ERK1/2 pathway.

Group IB Secretory Phospholipase A2 Promotes Matrix Metalloproteinase-2-mediated Cell Migration via the Phosphatidylinositol 3-Kinase and Akt Pathway

Secretory phospholipase A(2) (sPLA(2)), abundantly expressed in various cells including fibroblasts, is able to promote proliferation and migration. Degradation of collagenous extracellular matrix by matrix metalloproteinase (MMP) plays a role in the pathogenesis of various destructive disorders, such as rheumatoid arthritis, tumor invasion, and metastasis. Here we show that group IB PLA(2) increased pro-MMP-2 activation in NIH3T3 fibroblasts. MMP-2 activity was stimulated by group IB PLA(2) in a dose- and time-dependent manner. Consistent with MMP-2 activation, sPLA(2) decreased expression of type IV collagen. These effects are due to the reduction of tissue inhibitor of metalloproteinase-2 (TIMP-2) and the activation of the membrane type1-MMP (MT1-MMP). The decrease of TIMP-2 levels in conditioned media and the increase of MT1-MMP levels in plasma membrane were observed. In addition, treatment of cells with decanoyl Arg-Val-Lys-Arg-chloromethyl ketone, an inhibitor of pro-MT1-MMP, suppressed sPLA(2)-mediated MMP-2 activation, whereas treatment with bafilomycin A1, an inhibitor of H(+)-ATPase, sustained MMP-2 activation by sPLA(2). The involvement of phosphatidylinositol 3-kinase (PI3K) and Akt in the regulation of MMP-2 activity was further suggested by the findings that PI3K and Akt were phosphorylated by sPLA(2). Expression of p85alpha and Akt mutants, or pretreatment of cells with LY294002, a PI3K inhibitor, attenuated sPLA(2)-induced MMP-2 activation and migration. Taken together, these results suggest that sPLA(2) increases the pro-MMP-2 activation and migration of fibroblasts via the PI3K and Akt-dependent pathway. Because MMP-2 is an important factor directly involved in the control of cell migration and the turnover of extracellular matrix, our study may provide a mechanism for sPLA(2)-promoted fibroblasts migration.

The Effect of Interferon-γ on Bleomycin Induced Pulmonary Fibrosis in the Rat

Objectives : The matrix metalloproteinases (MMPs) that participate in the extracellular matrix metabolism play a important role in the progression of pulmonary fibrosis. The effects of the MMPs are regulated by several factors including Th-1 cytokines, (). Up to now, is known to inhibit pulmonary fibrosis, but little is known regarding the exact effect of on the regulation of the MMPs. This study investigated the effects of on the pulmonary fibrosis and the expression of the lung MMP-2,-9, TIMP-1,-2, and Th-2 cytokines in aa rat model of bleomycin induced pulmonary fibrosis. Materials and methods : Male, specific pathogen-free Sprague-Dawley rats were subjected to an intratracheal bleomycin instillation. The rats were randomized to a saline control, a bleomycin treated, and a bleomycin+ treated group. The bleomycin+ treated group was subjected to an intramuscular injection of for 14 days. At 3, 7, 14, and 28 days after the bleomycin instillation, the rats were sacrificed and the lungs were harvested. In order to evaluate the effects of the on lung fibrosis and inflammation, the lung hydroxyproline content, inflammation and fibrosis score were measured. Western blotting, zymography and reverse zymography were performed at 3, 7, 14, 28 days after bleomycin instillation in order to evaluate the MMP-2,-9, and TIMP-1,-2 expression level. ELISA was performed to determine the IL-4 and IL-13 level in a lung homogenate. Results : 1. 7 days after bleomycin instillation, inflammatory changes were more severe in the bleomycin+ group than the bleomycin group (bleomycin group : bleomycin+ group=, P treatment (bleomycin group : bleomycin+ group=, P treatment (bleomycin group : bleomycin+ group=, P treatment 3 days after the bleomycin instillation, bleomycin+ group (bleomycin group : bleomycin+ group=, P treatment (bleomycin group : bleomycin+ group=, P groups but this was not significant, and the IL-13 levels showed no difference between the experiment groups. Conclusion : The author found that lung inflammation was increased in the early period but the pulmonary fibrosis was inhibited in the late stage as a result of . The inhibition of pulmonary fibrosis by appeared to be associated with the inhibition of MMP-2 activation by . Further studies on the mechanism of the regulation of MMP-2 activation and the effects of MMP-2 activation on pulmonary fibrosis is warranted in the future.

Spectrum of matrix metalloproteinase expression in primary and metastatic colon cancer: relationship to the tissue inhibitors of metalloproteinases and membrane type-1-matrix metalloproteinase.

The matrix metalloproteinases, MMP-2 and MMP-9, are capable of degrading components of the basement membrane, a vital barrier breached during the progression of colorectal cancer. The regulation of MMP-2 activation and subsequent targets is vital to understanding the metastatic process. MMP-2 was not expressed by colorectal cancer cells (C170 and C170HM 2) in vitro but by stromal fibroblasts (46BR.1GI). There was induction of this MMP upon transwell co-cultivation of the colon cancer cells with the fibroblasts but in vivo growth did not lead to a similar increase in the metastatic tumour cells (C170HM 2), MMP-2 again being attributed to the stromal cells. MMP-2 mRNA was overexpressed in human colorectal tumours compared to normal colorectal tissue, which correlated with Dukes' stage and immunolocalized to the stromal compartment of the tumour tissue. The active form of the MMP-2 enzyme was also present in the colorectal tumour tissue (7/8) but essentially absent in all normal colon samples examined (1/8). MMP-2 activation was not related to an increase in MT-1-MMP mRNA or a decrease in the specific inhibitor TIMP-2 in human tissue. There was however an increase in MMP-2/TIMP-2 ratio in tumour compared to normal. MMP-9, a target of active MMP-2, was present in the metastatic cell line but expression was down-regulated in the tumour cells in vivo, gelatin analysis revealed that MMP-9 was almost entirely attributable to the murine host, confirmed by PCR. There was no increase in mRNA for MMP-9 or its specific inhibitor TIMP-1 in colorectal tumour tissue compared to normal, MMP-9 protein localized to the inflammatory infiltrate. Fibroblast cells may provide malignant epithelial cells with a ready source of enzyme which is crucial to the metastatic process. © 2001 Cancer Research Campaign http://www.bjcancer.com