ヒト培養滑膜細胞における Matrix Metalloproteinase 産生

Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade various components of the extracellular matrix (ECM). MMPs could also regulate the activity of several non-ECM bioactive substrates and consequently affect different cellular functions. Members of the MMPs family include collagenases, gelatinases, stromelysins, matrilysins, membrane-type MMPs, and others. Pro-MMPs are cleaved into active MMPs, which in turn act on various substrates in the ECM and on the cell surface. MMPs play an important role in the regulation of numerous physiological processes including vascular remodeling and angiogenesis. MMPs may also be involved in vascular diseases such as hypertension, atherosclerosis, aortic aneurysm, and varicose veins. MMPs also play a role in the hemodynamic and vascular changes associated with pregnancy and preeclampsia. The role of MMPs is commonly assessed by measuring their gene expression, protein amount, and proteolytic activity using gel zymography. Because there are no specific activators of MMPs, MMP inhibitors are often used to investigate the role of MMPs in different physiologic processes and in the pathogenesis of specific diseases. MMP inhibitors include endogenous tissue inhibitors (TIMPs) and pharmacological inhibitors such as zinc chelators, doxycycline, and marimastat. MMP inhibitors have been evaluated as diagnostic and therapeutic tools in cancer, autoimmune disease, and cardiovascular disease. Although several MMP inhibitors have been synthesized and tested both experimentally and clinically, only one MMP inhibitor, i.e., doxycycline, is currently approved by the Food and Drug Administration. This is mainly due to the undesirable side effects of MMP inhibitors especially on the musculoskeletal system. While most experimental and clinical trials of MMP inhibitors have not demonstrated significant benefits, some trials still showed promising results. With the advent of new genetic and pharmacological tools, disease-specific MMP inhibitors with fewer undesirable effects are being developed and could be useful in the management of vascular disease.

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Matrix Metalloproteinase Inhibitors as Investigative Tools in the Pathogenesis and Management of Vascular Disease

Angiogenesis, the generation of new capillaries through a process of pre-existing microvessel sprouting, is under stringent control and normally occurs only during embryonic and post-embryonic development, reproductive cycle, and wound repair. However, in many pathological conditions (solid tumor progression, metastasis, diabetic retinopathy, hemangioma, arthritis, psoriasis and atherosclerosis among others), the disease appears to be associated with persistent upregulated angiogenesis. The development of specific anti-angiogenic agents arises as an attractive therapeutic approach for the treatment of cancer and other angiogenesis-dependent diseases. The formation of new blood vessels is a complex multi-step process. Endothelial cells resting in the parent vessels are activated by an angiogenic signal and stimulated to synthesize and release degradative enzymes allowing endothelial cells to migrate, proliferate and finally differentiate to give rise to capillary tubules. Any of these steps may be a potential target for pharmacological intervention. In spite of the disappointing results obtained initially in clinical trials with anti-angiogenic drugs, recent reports with positive results in phases II and III trials encourage expectations in their therapeutic potential. This review discusses the current approaches for the discovery of new compounds that inhibit angiogenesis, with emphasis on the clinical developmental status of anti-angiogenic drugs.

Anti-angiogenic drugs: from bench to clinical trials.

PURPOSE To determine whether postoperative application of a broad-spectrum matrix metalloproteinase (MMP) inhibitor, GM6001 (ilomastat), reduces scarring after glaucoma filtration surgery. METHODS In a randomized, prospective, masked-observer study, 40 New Zealand White rabbits underwent modified glaucoma filtration surgery. The animals were randomly allocated to receive postoperative subconjunctival injections of either phosphate-buffered saline (PBS) or 100 microM ilomastat for 10 days. The animals were killed on days 7, 14, 21, and 30. Clinical characteristics, which included bleb morphology and intraocular pressure, were recorded. Tissue sections were immunohistochemically stained for alpha smooth muscle actin (alphaSMA) and extracellular matrix components in the two groups. RESULTS Surgical outcome was significantly prolonged in the ilomastat-treated group compared with the vehicle-treated group (P < 0.001). At day 30, all the blebs had survived except two in the ilomastat-treated group, whereas no blebs survived to day 30 with vehicle treatment (n = 11). The intraocular pressure remained significantly lower throughout the course of the experiment in the ilomastat group compared with the vehicle group (P < 0.0017). Histologically, less scar tissue was observed at the sclerostomy site with inhibition of MMP, compared with vehicle treatment. CONCLUSIONS The data presented suggest that the healing response after surgery can be modulated by inhibiting the effects of MMPs. Inhibition of MMP significantly improved surgical outcome by reducing the amount of scar tissue produced. By targeting the actions of these proteolytic enzymes, a more controlled and physiological method of modulating scarring may be achieved.

Matrix metalloproteinase inhibition modulates postoperative scarring after experimental glaucoma filtration surgery.

Varicose veins (VVs) are a common venous disease of the lower extremity characterized by incompetent valves, venous reflux, and dilated and tortuous veins. If untreated, VVs could lead to venous thrombosis, thrombophlebitis and chronic venous leg ulcers. Various genetic, hormonal and environmental factors may lead to structural changes in the vein valves and make them incompetent, leading to venous reflux, increased venous pressure and vein wall dilation. Prolonged increases in venous pressure and vein wall tension are thought to increase the expression/activity of matrix metalloproteinases (MMPs). Members of the MMPs family include collagenases, gelatinases, stromelysins, matrilysins, membrane- type MMPs and others. MMPs are known to degrade various components of the extracellular matrix (ECM). MMPs may also affect the endothelium and vascular smooth muscle, causing changes in the vein relaxation and contraction mechanisms. Endothelial cell injury also triggers leukocyte infiltration, activation and inflammation, which lead to further vein wall damage. The vein wall dilation and valve dysfunction, and the MMP activation and superimposed inflammation and fibrosis would lead to progressive venous dilation and VVs formation. Surgical ablation is an effective treatment for VVs, but may be associated with high recurrence rate, and other less invasive approaches that target the cause of the disease are needed. MMP inhibitors including endogenous tissue inhibitors (TIMPs) and pharmacological inhibitors such as zinc chelators, doxycycline, batimastat and marimastat, have been used as diagnostic and therapeutic tools in cancer, autoimmune and cardiovascular disease. However, MMP inhibitors may have side effects especially on the musculoskeletal system. With the advent of new genetic and pharmacological tools, specific MMP inhibitors with fewer undesirable effects could be useful to retard the progression and prevent the recurrence of VVs.

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Matrix metalloproteinases as potential targets in the venous dilation associated with varicose veins.

In a search for a pharmacologic adjuvant in the management of posttraumatic proliferative vitreoretinopathy (PVR), we investigated the effect of intravitreal injection of prinomastat (AG3340) on an experimental model. Posterior penetrating eye trauma was created in one eye each of 24 New Zealand white rabbits. One week after the surgery, all rabbits were randomized (1:1) to receive 0.5 mg prinomastat or the vehicle of the drug intravitreally every week for 6 weeks. The degree of PVR for each hemiretina was scored, and the two scores were summed to obtain a total eye score. The mean total eye score was 3.58 in the treatment group and 5.75 in the control group (p = 0.0307). The numbers of eyes with tractional retinal detachment in the prinomastat-treated (n = 12) and control (n = 12) groups were 3 and 9, respectively (p = 0.0391). These results suggest that intravitreally administered prinomastat has an inhibitory effect on posttraumatic PVR.

The Effect of Prinomastat (AG3340), a Synthetic Inhibitor of Matrix Metalloproteinases, on Posttraumatic Proliferative Vitreoretinopathy

Purpose. We studied the effects of intravitreally administered prinomastat on the take rate and growth of uveal melanoma after xenograft implantation in rabbit uveal melanoma model. Methods. Uveal melanoma xenograft was implanted to suprachoroidal space in each eye of 24 pigmented rabbits which were immunosuppressed with cyclosporine. One week after surgery, the eyes were randomized to receive prinomastat or the vehicle of the prinomastat intravitreally every week for 4 weeks. The take rate of the xenograft, tumor height, apoptosis, and necrosis in the eyes which developed tumors from the treatment and control groups were compared. Results. A tumor mass was identified in 8 of 24 (33%) prinomastat-treated eyes and 20 of 24 (83%) of the vehicle-treated eyes. Echographic mesurements revealed a mean tumor height of 2.2 mm in the prinomastat-treated group and 3.8 mm in the control group in those eyes with take of tumor (p < 0.001). Stereomicroscopic measurements showed a mean tumor height of 1.9 mm in the t...

The effect of prinomastat (AG3340), a synthetic inhibitor of matrix metalloproteinases, on uveal melanoma rabbit model.

Pesticide residues in vegetables (watercress, mustard green, choy sum, daikon, okra, and yam) from Mekong Delta, Vietnam were analysed by liquid chromatography-tandem mass spectroscopy (LC-MS/MS). QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) extraction, matrix-matched calibration, and dynamic multiple reaction monitoring methods were used. The linear range used was 5 - 200 ng/mL, resulting in R2 > 0.99. The recovery was satisfactory with values within 74.47 - 116.93%, and the RSD was < 15% for most compounds. The percentage of samples with residues above the maximum residue levels (MRLs) was 59%. Pesticide residues were detected above their MRLs in samples of watercress (47%), mustard green (80%), choy sum (83%), daikon (87%), and yam (60%). The results indicated the prevalence of pesticide residues in commonly consumed vegetables in Vietnam, and emphasised the urgent need to develop comprehensive intervention measures to reduce the potential health risk to consumers.

Tony Pham

Papers

The Effect of Prinomastat (AG3340), a Synthetic Inhibitor of Matrix Metalloproteinases, on Posttraumatic Proliferative Vitreoretinopathy

The effect of prinomastat (AG3340), a synthetic inhibitor of matrix metalloproteinases, on uveal melanoma rabbit model.

Analysis of popular pesticide residues in Mekong Delta vegetables using a modified QuEChERS method and UPLC-MS/MS