Modulation Of Matrix Metalloproteinases Activity Research Articles

Plasminogen application improves plastic closure of wound defects in patients with chronic diabetic wounds

Background. Chronic diabetic foot ulcers and wounds are significant complications associated with diabetes, comprising approximately 85% of purulent-necrotic lesions affecting the lower extremities. The development of these wounds is influenced by pathogenetic factors such as hyperglycemia, neuropathy, and existing infections, which contribute to metabolic disturbances, including tissue hypoxia and the activation of proteolytic enzymes known as matrix metalloproteinases (MMPs). Aim. To explore the therapeutic potential of autologous plasminogen in facilitating the healing process of diabetic wounds through the modulation of MMP activity. Materials and Methods. The study enrolled 45 patients diagnosed with chronic diabetic wounds, who were assigned to two distinct groups. The control group (n=25) received conventional treatment approaches, while the intervention group consisted of 20 patients treated with autologous plasminogen applications. Results. After 18 days of treatment, a substantial reduction of 3.5-fold in MMP-2 and MMP-9 activity was observed within the intervention group, accompanied by complete wound closure in 16 patients. Additionally, four patients underwent autodermoplasty, successfully achieving wound defect closure through effective graft integration. In contrast, the control group exhibited consistently elevated MMP activity levels throughout the entire observation period. Conclusions. The activity of matrix metalloproteinases (MMPs) in chronic diabetic wounds reaches dramatic levels, making spontaneous wound healing impossible. The application of autologous Pg allows modulation of this activity and creates favorable conditions for wound healing by reducing excessive MMP activity, improving blood supply, and resolving inflammatory processes. Keywords: chronic wounds, diabetes mellitus, matrix metalloproteinases, plasminogen, autodermoplasty.

The Spinal Extracellular Matrix Modulates a Multi-level Protein Net and Epigenetic Inducers Following Peripheral Nerve Injury

The extracellular matrix (ECM) of the central nervous system (CNS) plays a pivotal role in the pathogenesis of several neurodegenerative and neuroinflammatory disorders. Among the major factors, matrix metalloproteinases (MMPs) are actively involved in ECM remodeling and directly affect neuro-glial interactions. Since disease-related functional alterations mostly rely on the proteome, modulation of MMPs activity may be a strategy to correct mechanisms behind neurological disorders. We here investigated modifications of signaling components related to the central pathways in spinal maladaptive plasticity following spared nerve injury (SNI) of the sciatic nerve, and after treatment with the MMPs inhibitor GM6001 for 3 or 8 days. We found that GM6001 reduced the massive astrocytic and microglial activation indicative of reactive gliosis. Functional activity of GM6001 was paralleled by its significant effect on expression levels of the purinergic P2X4 receptor (P2X4R), the transcription factors NFκB and RPBJ, as well as levels of the nerve growth factor (NGF) receptor TrkA. Moreover, we showed that histone deacetylases 1 and 2 (HDAC1, HDAC2) were differentially modulated after SNI and GM6001 treatments for 3 or 8 days. Our data suggest a multi-level network of interactions across ECM and the neuroglial network involving MMPs, the neurotrophin system, intracellular signaling, and epigenetic modifications.

Modulation of Matrix Metalloproteinases Activity in the Ventral Horn of the Spinal Cord Re-stores Neuroglial Synaptic Homeostasis and Neurotrophic Support following Peripheral Nerve Injury.

Modulation of extracellular matrix (ECM) remodeling after peripheral nerve injury (PNI) could represent a valid therapeutic strategy to prevent maladaptive synaptic plasticity in central nervous system (CNS). Inhibition of matrix metalloproteinases (MMPs) and maintaining a neurotrophic support could represent two approaches to prevent or reduce the maladaptive plastic changes in the ventral horn of spinal cord following PNI. The purpose of our study was to analyze changes in the ventral horn produced by gliopathy determined by the suffering of motor neurons following spared nerve injury (SNI) of the sciatic nerve and how the intrathecal (i.t.) administration of GM6001 (a MMPs inhibitor) or the NGF mimetic peptide BB14 modulate these events. Immunohistochemical analysis of spinal cord sections revealed that motor neuron disease following SNI was associated with increased microglial (Iba1) and astrocytic (GFAP) response in the ventral horn of the spinal cord, indicative of reactive gliosis. These changes were paralleled by decreased glial aminoacid transporters (glutamate GLT1 and glycine GlyT1), increased levels of the neuronal glutamate transporter EAAC1, and a net increase of the Glutamate/GABA ratio, as measured by HPLC analysis. These molecular changes correlated to a significant reduction of mature NGF levels in the ventral horn. Continuous i.t. infusion of both GM6001 and BB14 reduced reactive astrogliosis, recovered the expression of neuronal and glial transporters, lowering the Glutamate/GABA ratio. Inhibition of MMPs by GM6001 significantly increased mature NGF levels, but it was absolutely ineffective in modifying the reactivity of microglia cells. Therefore, MMPs inhibition, although supplies neurotrophic support to ECM components and restores neuro-glial transporters expression, differently modulates astrocytic and microglial response after PNI.

The Role of Collagen Charge Clusters in the Modulation of Matrix Metalloproteinase Activity

Members of the matrix metalloproteinase (MMP) family selectively cleave collagens in vivo. Several substrate structural features that direct MMP collagenolysis have been identified. The present study evaluated the role of charged residue clusters in the regulation of MMP collagenolysis. A series of 10 triple-helical peptide (THP) substrates were constructed in which either Lys-Gly-Asp or Gly-Asp-Lys motifs replaced Gly-Pro-Hyp (where Hyp is 4-hydroxy-L-proline) repeats. The stabilities of THPs containing the two different motifs were analyzed, and kinetic parameters for substrate hydrolysis by six MMPs were determined. A general trend for virtually all enzymes was that, as Gly-Asp-Lys motifs were moved from the extreme N and C termini to the interior next to the cleavage site sequence, kcat/Km values increased. Additionally, all Gly-Asp-Lys THPs were as good or better substrates than the parent THP in which Gly-Asp-Lys was not present. In turn, the Lys-Gly-Asp THPs were also always better substrates than the parent THP, but the magnitude of the difference was considerably less compared with the Gly-Asp-Lys series. Of the MMPs tested, MMP-2 and MMP-9 most greatly favored the presence of charged residues with preference for the Gly-Asp-Lys series. Lys-Gly-(Asp/Glu) motifs are more commonly found near potential MMP cleavage sites than Gly-(Asp/Glu)-Lys motifs. As Lys-Gly-Asp is not as favored by MMPs as Gly-Asp-Lys, the Lys-Gly-Asp motif appears advantageous over the Gly-Asp-Lys motif by preventing unwanted MMP hydrolysis. More specifically, the lack of Gly-Asp-Lys clusters may diminish potential MMP-2 and MMP-9 collagenolytic activity. The present study indicates that MMPs have interactions spanning the P23-P23' subsites of collagenous substrates.

Overexpression of Catalase in Vascular Smooth Muscle Cells Prevents the Formation of Abdominal Aortic Aneurysms

Elevated levels of oxidative stress have been reported in abdominal aortic aneurysms (AAA), but which reactive oxygen species promotes the development of AAA remains unclear. Here, we investigate the effect of hydrogen peroxide (H2O2)-degrading enzyme catalase on the formation of AAA. AAA were induced with the application of calcium chloride (CaCl2) on mouse infrarenal aortas. The administration of PEG-catalase, but not saline, attenuated the loss of tunica media and protected against AAA formation (0.91 ± 0.1 versus 0.76 ± 0.09 mm). Similarly, in a transgenic mouse model, catalase overexpression in the vascular smooth muscle cells preserved the thickness of tunica media and inhibited aortic dilatation by 50% (0.85 ± 0.14 versus 0.57 ± 0.08 mm). Further studies showed that injury with CaCl2 decreased catalase expression and activity in the aortic wall. Pharmacological administration or genetic overexpression of catalase restored catalase activity and subsequently decreased matrix metalloproteinase activity. In addition, a profound reduction in inflammatory markers and vascular smooth muscle cell apoptosis was evident in aortas of catalase-overexpressing mice. Interestingly, as opposed to infusion of PEG-catalase, chronic overexpression of catalase in vascular smooth muscle cells did not alter the total aortic H2O2 levels. The data suggest that a reduction in aortic wall catalase activity can predispose to AAA formation. Restoration of catalase activity in the vascular wall enhances aortic vascular smooth muscle cell survival and prevents AAA formation primarily through modulation of matrix metalloproteinase activity.

Monocyte-derived dendritic cell subpopulations use different types of matrix metalloproteinases inhibited by GM6001

Matrix metalloproteinases (MMPs) are endopeptidases with the potential to cleave extracellular matrix, support tissue renewal and regulate cell migration. Functional activities of MMPs are regulated by tissue inhibitors of MMPs (TIMPs) and disruption of the MMP–TIMP balance has pathological consequences. Here we studied the expression and secretion of MMPs and TIMPs in CD1a− and CD1a+ monocyte-derived dendritic cell (DC) subpopulations. Our results showed that monocytes express TIMPs but lack MMPs, whereas upon differentiation to moDCs and in response to activation signals the expression of MMPs is increased and that of TIMPs is decreased. MMP-9 is expressed dominantly in the CD1a− subpopulation, while MMP-12 is preferentially expressed in CD1a+ cells. Experiments performed with the synthetic MMP inhibitor GM6001 revealed that this drug efficiently inhibits the migration of moDCs through inactivation of MMPs. We conclude that modulation of MMP activity by GM6001 emerges as a novel approach to manipulate DC migration under inflammatory conditions.

Metalloproteinases and Their Associated Genes Contribute to the Functional Integrity and Noise-Induced Damage in the Cochlear Sensory Epithelium

Matrix metalloproteinases (MMPs) and their related gene products regulate essential cellular functions. An imbalance in MMPs has been implicated in various neurological disorders, including traumatic injuries. Here, we report a role for MMPs and their related gene products in the modulation of cochlear responses to acoustic trauma in rats. The normal cochlea was shown to be enriched in MMP enzymatic activity, and this activity was reduced in a time-dependent manner after traumatic noise injury. The analysis of gene expression by RNA sequencing and qRT-PCR revealed the differential expression of MMPs and their related genes between functionally specialized regions of the sensory epithelium. The expression of these genes was dynamically regulated between the acute and chronic phases of noise-induced hearing loss. Moreover, noise-induced expression changes in two endogenous MMP inhibitors, Timp1 and Timp2, in sensory cells were dependent on the stage of nuclear condensation, suggesting a specific role for MMP activity in sensory cell apoptosis. A short-term application of doxycycline, a broad-spectrum inhibitor of MMPs, before noise exposure reduced noise-induced hearing loss and sensory cell death. In contrast, a 7 d treatment compromised hearing sensitivity and potentiated noise-induced hearing loss. This detrimental effect of the long-term inhibition of MMPs on noise-induced hearing loss was further confirmed using targeted Mmp7 knock-out mice. Together, these observations suggest that MMPs and their related genes participate in the regulation of cochlear responses to acoustic overstimulation and that the modulation of MMP activity can serve as a novel therapeutic target for the reduction of noise-induced cochlear damage.

Modulation of matrix metalloproteinase activity in human thyroid cancer cell lines using demethylating agents and histone deacetylase inhibitors

The purpose of this study was to investigate the effects of treating human thyroid cancer cell lines with demethylating agents and histone deacetylase (HDAC) inhibitors to see if they would downregulate expression and activity of the matrix metalloproteinases (MMP)-2 and MMP-9, resulting in inhibition of growth and invasion. A total of 1 papillary cancer cell line (TPC-1) and 3 follicular thyroid cancer cell lines (FTC-133, FTC-236, and FTC-238) were treated with the demethylating agent 5-azacytidine (5-AZC) and the HDAC inhibitors trichostatin A (TSA) and valproic acid (VA). The activity of MMP proteins was determined using gelatin zymography, and commercially available assays were used to quantify growth inhibition and thyroid cancer cell invasion. Treatment with TSA and VA resulted in decreased protein activity of MMP-2 and MMP-9 in all cell lines in a dose-dependent manner after 48 hours of treatment compared with untreated controls. In addition, 5-, TSA, and VA caused inhibition of growth in the range of 25-80% for all cell lines at 24, 48, and 72 hours. VA and TSA significantly decreased cell invasion in the FTC-133 and TPC-1 cell lines. The HDAC inhibitors TSA and VA decreased the protein activity of MMP-2 and MMP-9 and, in combination with the demethylating agent 5-AZC, inhibited cellular growth in human papillary and follicular thyroid cancer cell lines. These results elucidate our understanding of the pathways affected by the demethylating agents and HDAC inhibitors, and provide further evidence that MMPs are a potentially useful target for molecular therapies in patients with aggressive or refractory thyroid cancers.

The effect of matrix metalloproteinase inhibition on tendon-to-bone healing in a rotator cuff repair model

Recent studies have demonstrated a potentially critical role of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the pathophysiology of rotator cuff tears. We hypothesize that local delivery of a MMP inhibitor after surgical repair of the rotator cuff will improve healing at the tendon-to-bone surface interface. Sixty-two male Sprague-Dawley rats underwent acute supraspinatus detachment and repair. In the control group (n=31), the supraspinatus was repaired to its anatomic footprint. In the experimental group (n=31), recombinant alpha-2-macroglobulin (A2M) protein, a universal MMP inhibitor, was applied at the tendon-bone interface with an identical surgical repair. Animals were sacrificed at 2 and 4 weeks for histomorphometry, immunohistochemistry, and biomechanical testing. Statistical comparisons were performed using unpaired t tests. Significance was set at P < .05. Significantly greater fibrocartilage was seen at the healing enthesis in the A2M-treated specimens compared with controls at 2 weeks (P < .05). Significantly greater collagen organization was observed in the A2M-treated animals compared with controls at 4 weeks (P < .01). A significant reduction in collagen degradation was observed at both 2 and 4 weeks in the experimental group (P < .05). Biomechanical testing revealed no significant differences in stiffness or ultimate load-to-failure. Local delivery of an MMP inhibitor is associated with distinct histologic differences at the tendon-to-bone interface after rotator cuff repair. Modulation of MMP activity after rotator cuff repair may offer a novel biologic pathway to augment tendon-to-bone healing after rotator cuff repair.

Modulation of Matrix Metalloproteinase Activity by Tobacco Cigarette Smoke

Tobacco smoking is a highly addictive social behavior and a major cause of morbidity and mortality. It causes or exacerbates a multitude of pathological conditions and in both the adult and the fetus may have various detrimental effects. Tobacco smoke contains more than 4000 chemicals including a huge repertoire of addictive and/or toxic components including nicotine, benzene, cadmium, vinyl chloride, chromium and 2-naphthylamine, all of which are recognized carcinogens (WHO). All of these agents have been implicated in a myriad of pathological conditions. Nevertheless the mechanisms by which tobacco smoke induces these pathological changes is not clear. Several areas of particular relevance relate to smoke-induced connective tissue alterations and of course genetic changes. In the case of the former, smokeinduced skin and oral cavity related alterations in connective tissue have received some attention. In both cases matrix metalloproteinases (MMPs) are implicated in tissue degradation and reduced collagen synthesis. While such changes may not be life threatening, other smoke induced changes in organs such as the lungs or heart carry with them potential for significant increases in mortality or morbidity. The direct exposure endured by the lungs to inhaled smoke, whether as primary smoke from the cigarette or as secondary from the environment, now generally termed passive smoking, may be associated with altered MMP gene expression in lung airway epithelium and be related to development of chronic obstructive pulmonary disease or asthma. The present review will provide background on structure and function of the MMPs and examine the evidence that tobacco smoke alters MMP gene expression and MMP activity and the role these changes may play in connective tissue changes in tissues and cells. We will also discuss ongoing work in our laboratory which is directed to determining smoke-induced alterations in MMP release particularly in lung cells.

Modulation of Matrix Metalloproteinase Activity by Tobacco Cigarette Smoke

Modulation of Matrix Metalloproteinase Activity by Tobacco Cigarette Smoke

Relaxin in Human Pregnancy

Relaxin has beneficial effects upon the endometrium which are responsible for establishment of pregnancy. We have demonstrated that relaxin stimulates endometrial decidualization, the structural and biochemical changes in endometrial parenchymal cells, and the accompanying angiogenesis, modulation of matrix metalloproteinase activity, and increased concentrations in local immune cells which are required for implantation. Our recent data also demonstrate that either too much or too little relaxin can be detrimental. Elevated circulating maternal relaxin concentrations (hyperrelaxinemia) are associated with premature birth. This is likely due to the effects of relaxin at the level of the cervix, via upsetting the balance in the maintenance of cervical connective tissue architecture. In addition, the absence of circulating relaxin during pregnancy in women may have negative consequences upon glucose metabolism.

MMPs in glaucoma

Abstract Purpose: Extracellular matrix turnover is mediated by matrix metalloproteinases (MMPs), a large family of endopeptidases with variable substrate spectra. The activity of these enzymes is regulated in part by specific endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). Dysregulated expression of MMPs and TIMPs has been implicated in many ocular disease processes accompanied by abnormal matrix production including glaucoma. The purpose of this review is to highlight recent insights into the roles of MMPs and TIMPs in the regulation of aqueous humor outflow and retinal ganglion cell death in chronic open‐angle glaucoma. Methods: Basic research and review of the literature. Results: MMPs have been shown to affect matrix remodeling and outflow resistance in the trabecular meshwork, and to influence ganglion cell fate by matrix remodelling and glutamate receptor processing in the retina. Several current glaucoma therapies including topical prostaglandin analogues and laser trabeculoplasty have been shown to induce MMP activation in the outflow pathways. Changes in the expression of MMPs and TIMPs have been also shown to be involved in conjunctival wound healing after glaucoma filtration surgery. Conclusions: Modulation of MMP activity may provide an attractive adjunctive treatment option to improve outflow facility, to attenuate retinal ganglion cell loss, and to reduce conjunctival scarring in glaucoma patients.

Modulation of matrix metalloproteinase activity by silver-containing dressings

Modulation of matrix metalloproteinase activity by silver-containing dressings

Matrix metalloproteinase activity synergizes with α2β1 integrins to enhance collagen remodeling

Cell-matrix interactions transmit a wealth of information about the extracellular environment. In return, a variety of responses from the cell are initiated by changes in the matrix. One such response involves the positive regulation of matrix metalloproteinases (MMPs) by alpha2beta1 integrin attaching to a specific extracellular matrix component, collagen. This study explores the relationship between mechanical and biochemical functions of alpha2beta1 integrins as it pertains to regulating matrix remodeling. To understand this relationship, the individual influences of MMP activity and alpha2beta1 integrin function on collagen gel contraction were studied. We have observed little evidence of mutual participation in matrix remodeling by the alpha2beta1 integrin and MMP activity in cell models where alpha2 is minimally expressed. In cells expressing high levels of alpha2, we see an increase in gel contraction that is enhanced by MMP activity. Measuring tension as it builds within the gel reveals that alpha2beta1 integrin presence correlates with force output but is insensitive to MMP activity. These data strongly suggest that alpha2beta1 regulates collagen gel remodeling through multiple simultaneous mechanisms including force generation and modulation of MMP activity.

Myocardial remodeling after discrete radiofrequency injury: effects of tissue inhibitor of matrix metalloproteinase-1 gene deletion.

Discrete myocardial lesions created through the delivery of radiofrequency (RF) energy can expand; however, the mechanisms have not been established. Matrix metalloproteinases (MMPs) play an important role in myocardial remodeling, and MMP activity can be regulated by the tissue inhibitors of the metalloproteinases (TIMPs). This study examined the role of TIMP-1 in postinjury myocardial remodeling. Lesions were created on the left ventricular (LV) epicardium of wild-type (WT, 8-12 wk, 129SVE) and age-matched TIMP-1 gene-deficient (timp-1(-/-)) mice through the delivery of RF current (80 degrees C, 30 s). Heart mass, LV scar volumes, and collagen content were measured at 1 h and 3, 7, and 28 days postinjury (n = 10 each). Age-matched, nonablated mice were used as reference controls (n = 5). Heart mass indexed to tibial length increased in WT and timp-1(-/-) mice but was greater in the timp-1(-/-) mice by 7 days. Scar volumes increased in a time-dependent manner in both groups but were higher in the timp-1(-/-) mice than the WT mice at 7 days (1.48 +/- 0.09 vs. 1.20 +/- 0.11 mm(3).mg(-1).mm, P < 0.05) and remained higher at 28 days. In the remote myocardium, wall thickness was greater and relative collagen content was lower in the timp-1(-/-) mice at 28 days postinjury. Discrete myocardial RF lesions expand in a time-dependent manner associated with myocyte hypertrophy remote to the scar. Moreover, postinjury myocardial remodeling was more extensive with TIMP-1 gene deletion. Thus TIMP-1 either directly or through modulation of MMP activity may regulate myocardial remodeling following infliction of a discrete injury.

Mice without uPA, tPA, or plasminogen genes are resistant to experimental choroidal neovascularization.

To evaluate the presence and potential involvement of members of the plasminogen/plasminogen activator (Plg/PA) system in the exudative form of age-related macular degeneration (AMD). The expression of PA members mRNA was evaluated in human and experimental choroidal neovascularization (CNV) by RT-PCR. The presence and activity of PA was studied by immunofluorescence and in situ zymography. The influence of endogenous plasminogen (Plg), urokinase (uPA), tissue type plasminogen activator (tPA), and uPA receptor (uPAR) was explored in single-gene-deficient mice in a model of laser-induced CNV. Members of the Plg/PA system were present both in human and murine CNV. The absence of Plg, uPA, or tPA significantly decreased the development of experimental CNV compared with wild-type or uPAR-deficient mice. This effect could be attributable, partly to a modulation of matrix metalloproteinase activity, but also to an accumulation of fibrinogen-fibrin in the laser-induced wounds. Together with previous work done by the authors, this study indicates that choroidal neovascularization is extremely sensitive to the modulation of Plg/PA system activity. This may provide a new strategy for the treatment of exudative AMD.

Matrix metalloproteinases in the progression of heart failure: potential therapeutic implications.

Matrix metalloproteinases (MMPs) are a family of functionally related zinc-containing enzymes that denature and degrade fibrillar collagens and other components of the extracellular matrix. Myocardial extracellular matrix remodelling and fibrosis regulated by MMPs are believed to be important contributors to the progression of heart failure. The role of MMPs in cardiac fibrosis and the progression of heart failure, along with the possibility of halting the progression of heart failure by modulating extracellular matrix remodelling are important issues under intense study. MMPs are increased in the failing hearts of both animal models and patients with heart failure. MMP inhibition may therefore modulate extracellular matrix remodelling and the progression of heart failure. It is a great advantage that various MMP inhibitors have been developed initially for the treatment of cancer, arthritis and other diseases believed to be associated with increased MMP activity. Several preclinical studies have shown that treatment of heart failure in animal models with MMP inhibitors results in less collagen matrix damage, favourable extracellular matrix remodelling, and improved cardiac structure and function. The results suggest that modulation of MMP activity can prevent myocardial dysfunction and the progression of heart failure through alterations in the remodelling process of extracellular matrix and the left ventricle. Although these promising results suggest potential benefits of MMP inhibition for human heart failure, no clinical data evaluating MMP inhibitors in heart failure have been reported. As the preclinical evidence continues to grow and the potential of MMP inhibition for the treatment of heart failure continues to unfold, MMP inhibition may prove to be an effective treatment for heart failure.

Interplay of matrix metalloproteinases, tissue inhibitors of metalloproteinases and their regulators in cardiac matrix remodeling

Myocardial fibrosis due to maladaptive extracellular matrix remodeling contributes to dysfunction of the failing heart. Further elucidation of the mechanism by which myocardial fibrosis and dilatation can be prevented or even reversed remains of great interest as a potential means to limit myocardial remodeling and dysfunction. Matrix metalloproteinases (MMPs) are the driving force behind extracellular matrix degradation during remodeling and are increased in the failing human heart. MMPs are regulated by a variety of growth factors, cytokines, and matrix fragments such as matrikines. In the present report, we discuss the regulation of MMPs, the role of MMPs in the development of cardiac fibrosis, and the modulation of MMP activity using gene transfer and knockout technologies. We also present recent findings from our laboratory on the regulation of the extracellular MMP inducer (EMMPRIN), MMPs, and transforming growth factor-beta(1) in the failing human heart before and after left ventricular assist device support, as well as the possibility of preventing ventricular fibrosis using different anti-MMP strategies. Several studies suggest that such modulation of MMP activity can alter ventricular remodeling, myocardial dysfunction, and the progression of heart failure. It is therefore suggested that the interplay of MMPs and their regulators is important in the development of the heart failure phenotype, and myocardial fibrosis in heart failure may be modified by modulating MMP activity.

Modulation of matrix metalloproteinase activity in human saphenous vein grafts using adenovirus-mediated gene transfer

Background: Neointima formation after human saphenous vein grafting (hSVG) involves several matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). This study assessed the feasibility of modulating MMP activity in hSVGs by adenovirus-mediated gene transfer. Methods: First, 1 × 10 9 plaque-forming units (pfu) of replication-deficient recombinant adenoviruses encoding either β-galactosidase (Ad βgal), MMP-3 (AdMMP-3), or TIMP-1 (AdTIMP-1) were added into the lumen of hSVGs for 1 hour. After incubation at 37° C for 24 hours, specimens were analyzed by immunohistochemistry, in situ zymography, and X-gal staining. Results: By X-gal staining Ad β gal-infected hSVGs stained positively in the intima and occasionally in the media. Immunohistochemistry of AdMMP-3- and AdTIMP-1-infected hSVGs localized these proteins to the intima. In situ zymography showed increased MMP activity in the intima of AdMMP-3-infected hSVGs relative to AdTIMP-1- or Ad β gal-infected vessels. Conclusions: MMP-3 and TIMP activity can be regulated in hSVGs by replication-deficient recombinant adenoviruses. We have previously demonstrated that MMP-3 or TIMP-1 transduction, or both, inhibit SMC migration in an in vitro reconstituted vessel wall. Modulation of MMP activity may thus afford high patency rates in genetically engineered hSVGs. However, adenovirus-mediated gene delivery is limited to the vessel's intima; strategies to infect medial smooth muscle cells need to be developed. (Surgery 1998;124:129-36)