Matrix Metalloproteinase Inhibitor Batimastat Research Articles

ENDOTHELIAL BMPR2 LOSS PROMOTES ALTERED IL-15 SIGNALING, CONTRIBUTING TO IMMUNE DYSFUNCTION IN PULMONARY HYPERTENSION

<h3>BACKGROUND</h3> Natural killer (NK) cell impairment is a feature of pulmonary arterial hypertension (PAH) and contributes to disease development in mouse models of NK cell deficiency (Ormiston et al, Circulation, 2012; Ratsep et al, AJP Lung, 2018). PAH is also strongly associated with mutations in BMPR2, the gene encoding the type-II bone morphogenetic protein receptor. Genetic and experimental evidence point to a loss of BMPR2 in the pulmonary endothelium as a critical contributor to disease development. However, the impact of endothelial BMPR2 loss on NK cell impairment in PAH remains unknown. <h3>METHODS AND RESULTS</h3> SiRNA-mediated silencing of BMPR2 in human pulmonary artery endothelial cells (HPAEC) significantly reduced the surface presentation and secretion of the α-type receptor for interleukin-15 (IL-15Rα), a major regulator of NK cell survival, proliferation and activity. Assessment of IL-15Rα transcriptional variants by RNA-Seq and glycosylation by immunoblotting demonstrated that this reduction was not due to changes in receptor transcription or processing. Treatment of HPAECs with the matrix metalloproteinase inhibitor Batimastat also ruled out a role for altered IL-15Rα cleavage with BMPR2 silencing. Instead, confocal microscopy identified impaired trafficking of IL-15Rα through the trans-Golgi-network (TGN) in BMPR2-silenced cells. To evaluate the effects of impaired IL-15 mediated signaling and NK cell loss on PAH development, NK cell-deficient Il15-/- rats and immune-competent Il15+/+ littermates were exposed to either the monocrotaline (MCT) or SUGEN/hypoxia models of experimental pulmonary hypertension. While both male and female Il15-/- rats developed more severe disease than their wildtype counterparts in the SUGEN/Hypoxia model, only male Il15-/- rats demonstrated this enhanced severity in the MCT model, which is the only one of the two models to reproduce the sex-based difference in disease severity that is observed in human PAH patients. Assessment of genes associated with sex hormone signaling and metabolism identified a potential increase in pulmonary Cyp1b1 expression (n=5-7, p=0.08) in male MCT-challenged Il15-/- rats relative to Il15+/+ controls. <h3>CONCLUSION</h3> We have identified the loss of IL-15 signaling as a novel BMPR2-dependent contributor to NK cell impairment and pulmonary arterial hypertension pathogenesis. Ongoing work includes assessing the contribution of sex hormones to immune-mediated disease processes in PAH.

Biophysical model for high-throughput tumor and epithelial cell co-culture in complex biochemical microenvironments

The in vivo tumor microenvironment is a complex niche that includes heterogeneous physical structures, unique biochemical gradients and multiple cell interactions. Its high-fidelity in vitro reconstruction is of fundamental importance to improve current understandings of cell behavior, efficacy predictions and drug safety. In this study, we have developed a high-throughput biochip with hundreds of composite extracellular matrix (ECM) microchambers to co-culture invasive breast cancer cells (MDA-MB-231-RFP) and normal breast epithelial cells (MCF-10A-GFP). The composite ECM is composed of type I collagen and Matrigel which provides a heterogeneous microenvironment that is similar to that of in vivo cell growth. Additionally, the growth factors and drug gradients that involve human epidermal growth factor (EGF), discoidin domain receptor 1 (DDR1) inhibitor 7rh and matrix metalloproteinase inhibitor batimastat allow for the mimicking of the complex in vivo biochemical microenvironment to investigate their effect on the spatial-temporal dynamics of cell growth. Our results demonstrate that the MDA-MB-231-RFP cells and MCF-10A-GFP cells exhibit different spatial proliferation behaviors under the combination of growth factors and drugs. Basing on the experimental data, we have also developed a cellular automata (CA) model that incorporated drug diffusion to describe the experimental phenomenon, as well as employed Shannon entropy (SE) to explore the effect of the drug diffusion coefficient on the spatial-temporal dynamics of cell growth. The results indicate that the uniform cell growth is related to the drug diffusion coefficient, which reveals that the pore size of the ECM plays a key role in the formation of complex biochemical gradients. Therefore, our integrated, biomimetic and high-throughput co-culture platforms, as well as the computational model can be used as an effective tool for investigating cancer pathogenesis and drug development.

ADAM10 and ADAM17 proteases mediate proinflammatory cytokine-induced and constitutive cleavage of endomucin from the endothelial surface

Contact between inflammatory cells and endothelial cells (ECs) is a crucial step in vascular inflammation. Recently, we demonstrated that the cell-surface level of endomucin (EMCN), a heavily O-glycosylated single-transmembrane sialomucin, interferes with the interactions between inflammatory cells and ECs. We have also shown that, in response to an inflammatory stimulus, EMCN is cleared from the cell surface by an unknown mechanism. In this study, using adenovirus-mediated overexpression of a tagged EMCN in human umbilical vein ECs, we found that treatment with tumor necrosis factor α (TNF-α) or the strong oxidant pervanadate leads to loss of cell-surface EMCN and increases the levels of the C-terminal fragment of EMCN 3- to 4-fold. Furthermore, treatment with the broad-spectrum matrix metalloproteinase inhibitor batimastat (BB94) or inhibition of ADAM metallopeptidase domain 10 (ADAM10) and ADAM17 with two small-molecule inhibitors, GW280264X and GI254023X, or with siRNA significantly reduced basal and TNFα-induced cell-surface EMCN cleavage. Release of the C-terminal fragment of EMCN by TNF-α treatment was blocked by chemical inhibition of ADAM10 alone or in combination with ADAM17. These results indicate that cell-surface EMCN undergoes constitutive cleavage and that TNF-α treatment dramatically increases this cleavage, which is mediated predominantly by ADAM10 and ADAM17. As endothelial cell-surface EMCN attenuates leukocyte-EC interactions during inflammation, we propose that EMCN is a potential therapeutic target to manage vascular inflammation.

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Prevention of abdominal aortic aneurysm progression by targeted inhibition of matrix metalloproteinase activity with batimastat-loaded nanoparticles.

Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of development and progression of abdominal aortic aneurysms. Systemic treatments of MMP inhibitors have shown effectiveness in animal models, but it did not translate to clinical success either because of low doses used or systemic side effects of MMP inhibitors. We propose a targeted nanoparticle (NP)-based delivery of MMP inhibitor at low doses to the abdominal aortic aneurysms site. Such therapy will be an attractive option for preventing expansion of aneurysms in patients without systemic side effects. Our previous study showed that poly(d,l-lactide) NPs conjugated with an antielastin antibody could be targeted to the site of an aneurysm in a rat model of abdominal aortic aneurysms. In the study reported here, we tested whether such targeted NPs could deliver the MMP inhibitor batimastat (BB-94) to the site of an aneurysm and prevent aneurysmal growth. Poly(d,l-lactide) NPs were loaded with BB-94 and conjugated with an elastin antibody. Intravenous injections of elastin antibody-conjugated BB-94-loaded NPs targeted the site of aneurysms and delivered BB-94 in a calcium chloride injury-induced abdominal aortic aneurysms in rats. Such targeted delivery inhibited MMP activity, elastin degradation, calcification, and aneurysmal development in the aorta (269% expansion in control versus 40% elastin antibody-conjugated BB-94-loaded NPs) at a low dose of BB-94. The systemic administration of BB-94 alone at the same dose was ineffective in producing MMP inhibition. Targeted delivery of MMP inhibitors using NPs may be an attractive strategy to inhibit aneurysmal progression.

Inhibition of matrix metalloproteinases attenuates brain damage in experimental meningococcal meningitis

BackgroundApproximately 7% of survivors from meningococcal meningitis (MM) suffer from neurological sequelae due to brain damage in the course of meningitis. The present study focuses on the role of matrix metalloproteinases (MMPs) in a novel mouse model of MM-induced brain damage.MethodsThe model is based on intracisternal infection of BALB/c mice with a serogroup C Neisseria meningitidis strain. Mice were infected with meningococci and randomised for treatment with the MMP inhibitor batimastat (BB-94) or vehicle. Animal survival, brain injury and host-response biomarkers were assessed 48 h after meningococcal challenge.ResultsMice that received BB-94 presented significantly diminished MMP-9 levels (p < 0.01), intracerebral bleeding (p < 0.01), and blood-brain barrier (BBB) breakdown (p < 0.05) in comparison with untreated animals. In mice suffering from MM, the amount of MMP-9 measured by zymography significantly correlated with both intracerebral haemorrhage (p < 0.01) and BBB disruption (p < 0.05).ConclusionsMMPs significantly contribute to brain damage associated with experimental MM. Inhibition of MMPs reduces intracranial complications in mice suffering from MM, representing a potential adjuvant strategy in MM post-infection sequelae.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0726-6) contains supplementary material, which is available to authorized users.

Simulated physiological stretch-induced proliferation of human bladder smooth muscle cells is regulated by MMPs

Mechanical stimulation is an essential factor for organisms to develop normally. In bladder development matrix metalloproteinases (MMPs) play an important role through structure remodeling and regulating the cell proliferation. In this study, we investigated the simulated physiological stretch induced proliferation of HBSMCs; MMPs/TIMPs expression in stretch and non-stretch groups. HBSMCs were exposed to cyclic stretch with defined parameters (5%, 10% and 15% elongation). The expression of MMPs and TIMPs in each parameter and non-stretch groups was examined at the transcriptional and translational levels respectively. 5-Ethynyl-2′-deoxyuridine (EdU) assay was used to assess cell proliferation. In the presence of the broad spectrum MMPs inhibitor (Batimastat), cells proliferation, MMPs and tissue inhibitors of metalloproteinases (TIMPs) expression were assessed again. Compared with non-stretch group, HBSMCs in stretch groups showed higher proliferation. The expression of MMP-1, 2, 3, 7 was up-regulated in stretch groups, and it remained at the same high level in 10% and 15% stretch groups. TIMP-1, 2 expression only increased under 15% stretch. Stretch resulted in elevated cell proliferation was abolished by Batimastat. In conclusion, the proliferation of HBSMCs induced by stretch was resulted from the stretch-induced MMPs expression and release.

Inhibition of estrogen-induced pituitary tumor growth and angiogenesis in Fischer 344 rats by the matrix metalloproteinase inhibitor batimastat

The development of estrogen-induced pituitary prolactinoma in Fischer 344 (F344) rats is associated with enhanced neovascularization. Based on the significance of matrix metalloproteinases (MMPs) for tumor growth and angiogenesis, we have studied the effect of batimastat (BB-94), a synthetic MMPs inhibitor (MMPI) on the progression of prolactin-secreting pituitary adenoma in rats. Pituitary tumors were induced in male F344 rats by s.c. implantation of Silastic tubes containing diethylstilbestrol (DES). The effects of chronic treatment with BB-94 (30 mg/kg b.w.) on pituitary weight, cell proliferation, apoptosis and vascular density were evaluated. We have stated that chronic treatment with batimastat caused a significant reduction in the pituitary weight. Batimastat has been found to decrease cell proliferation evaluated by a number of PCNA-positive stained cell nuclei. A marked increase in the apoptotic index within the pituitary was observed in the study group. Moreover, the density of microvessels identified by CD31 was reduced in the group treated with BB-94. The results of our study provide evidence for an inhibitory effect of batimastat, a synthetic MMPI, on the growth and angiogenesis in an experimental model of human prolactinoma. The ability of BB-94 to suppress established pituitary tumor growth suggests a possible application of MMPIs in the treatment of pituitary adenomas.

Influence of the matrix metalloproteinase inhibitor batimastat (BB-94) on periodontal bone destruction in Sprague-Dawley rats.

Matrix metalloproteinases (MMPs) are proteolytic enzymes capable of degrading most macromolecules of the extracellular matrix. It has been assumed that an association exists between MMP activity and periodontal disease progression, but the precise role of MMPs in disease progression is still not fully clarified. Batimastat, or BB-94, is a synthetic broad-spectrum MMP inhibitor not previously examined in periodontal research. If there is an association between MMP activity and periodontal disease progression, then batimastat might be expected to reduce the progression of experimental periodontal disease in rats. The objective of the present study was to determine the effects of batimastat on periodontal status in healthy Sprague-Dawley (SPRD) rats as well as in rats with ligature-induced experimental periodontal disease. Periodontal bone destruction was used as a means of evaluating periodontal destruction by measuring periodontal bone loss on defleshed rat jaws and periodontal bone support on radiographs of the jaws. There was significantly more periodontal bone destruction in the groups treated with batimastat than in the placebo and control groups. This accounted for both ligated and non-ligated groups, irrespective of whether periodontal bone loss (p < 0.05) or periodontal bone support (p < 0.05) were measured. In conclusion, the results of this study did not support the hypothesis that the MMP inhibitor batimastat could reduce the progression of experimental periodontal disease in rats. Instead, significantly increased bone destruction was found in rats treated with batimastat.

Matrix Metalloproteinases 2 and 9 Mediate Epidermal Growth Factor Receptor Transactivation by Gonadotropin-releasing Hormone

Rapid engagement of the extracellular signal-regulated kinase (ERK) cascade via the Gq/11-coupled GnRH receptor (GnRHR) is mediated by transactivation of the epidermal growth factor receptor (EGFR). Here we show that the cross-talk between GnRHR and EGFR in gonadotropic cells is accomplished via gelatinases A and B (matrix metalloproteinases (MMPs) 2 and 9), identifying gelatinases as the first distinct members of the MMP family mediating EGFR transactivation by G protein-coupled receptors. Using a specific MMP2 and MMP9 inhibitor, Ro28-2653, GnRH-dependent EGFR transactivation was abrogated. Proving the specificity of the effect, transient transfection of alphaT3-1 cells with ribozymes directed against MMP2 or MMP9 specifically blocked EGFR tyrosine phosphorylation in response to GnRH stimulation. GnRH challenge of alphaT3-1 cells furthered the release of active MMP2 and MMP9 and increased their gelatinolytic activities within 5 min. Rapid release of activated MMP2 or MMP9 was inhibited by ribozyme-targeted down-regulation of MT1-MMP or MMP2, respectively. We found that GnRH-induced Src, Ras, and ERK activation were also gelatinase-dependent. Thus, gelatinase-induced EGFR transactivation was required to engage the extracellular-signal regulated kinase cascade. Activation of c-Jun N-terminal kinase and p38 MAPK by GnRH was unaffected by EGFR or gelatinase inhibition that, however, suppressed GnRH induction of c-Jun and c-Fos. Our findings suggest a novel role for gelatinases in the endocrine regulation of pituitary gonadotropes.

Metalloproteinase inhibition by batimastat does not reduce neointimal thickening in stented atherosclerotic porcine femoral arteries

Vascular injury results in specific temporal patterns of increased matrix metalloproteinase (MMP) activity. MMPs are known to play a role in remodeling and neointimal (NI) thickening. Although in vitro data on the role of metalloproteinases and their inhibitors on smooth muscle cell migration and proliferation are compelling, evidence for inhibition of NI thickening in vivo is inconsistent and is mostly generated in models of balloon angioplasty instead of the more prevalent stent placement. Data from atherosclerotic models are scarce. The objective of the study was to investigate whether the nonspecific MMP inhibitor batimastat, in concentrations known to influence remodeling, could also inhibit NI thickening following stent placement in an atherosclerotic model. Stents were placed in atherosclerotic femoral arteries in Yucatan micropigs on a high cholesterol diet and followed for 6 weeks. Batimastat or vehicle was administered intraperitoneally. NI thickening was assessed by morphometry. The main finding was that batimastat did not result in a significant decrease in NI thickness. Only following correlation to the amount of preexisting plaque was the difference of 146 μm (19%) statistically significant. Batimastat did not impair wound healing following stenting. Batimastat does not significantly influence the degree of NI thickening at 6 weeks following stenting of atherosclerotic porcine femoral arteries, except when correlated to plaque thickness. Batimastat does not affect vascular wound healing.

Metalloproteinase inhibition by batimastat does not reduce neointimal thickening in stented atherosclerotic porcine femoral arteries

Background Vascular injury results in specific temporal patterns of increased matrix metalloproteinase (MMP) activity. MMPs are known to play a role in remodeling and neointimal (NI) thickening. Although in vitro data on the role of metalloproteinases and their inhibitors on smooth muscle cell migration and proliferation are compelling, evidence for inhibition of NI thickening in vivo is inconsistent and is mostly generated in models of balloon angioplasty instead of the more prevalent stent placement. Data from atherosclerotic models are scarce. The objective of the study was to investigate whether the nonspecific MMP inhibitor batimastat, in concentrations known to influence remodeling, could also inhibit NI thickening following stent placement in an atherosclerotic model. Methods Stents were placed in atherosclerotic femoral arteries in Yucatan micropigs on a high cholesterol diet and followed for 6 weeks. Batimastat or vehicle was administered intraperitoneally. NI thickening was assessed by morphometry. Results The main finding was that batimastat did not result in a significant decrease in NI thickness. Only following correlation to the amount of preexisting plaque was the difference of 146 μm (19%) statistically significant. Batimastat did not impair wound healing following stenting. Conclusion Batimastat does not significantly influence the degree of NI thickening at 6 weeks following stenting of atherosclerotic porcine femoral arteries, except when correlated to plaque thickness. Batimastat does not affect vascular wound healing.

Matrix metalloproteinase abundance in human myocardial fibroblasts: effects of sustained pharmacologic matrix metalloproteinase inhibition

Background – A cause-effect relationship has been established between matrix metalloproteinases (MMPs) and left ventricular (LV) myocardial remodeling through the use of pharmacologic MMP inhibitors. However, the direct effects of MMP inhibition on MMPs and endogenous tissue inhibitors of metalloproteinases (TIMPs) in LV human myocardial fibroblasts (LVHMFs) remain unknown. This study measured MMP-2, MMP-9, MMP-13, MT1-MMP, and TIMP-1 release in LVHMFs. Methods and results – LVHMF cultures were established from six individual patients (passages 2–5) and incubated with and without the broad-spectrum MMP inhibitor PD166793 (100 μM) for 12–36 h. While PD166793 did not influence MMP-2 release, MMP-9 levels based on substrate zymography increased at 36 h by over 30% ( P < 0.05). TIMP-1 levels increased in a time-dependent manner with no effect from PD166793 incubation. However, the MMP-9/TIMP-1 ratio was increased by over 20% from time-matched values following 12–36 h of exposure to PD166793 ( P < 0.05). Similar results obtained after incubation of LVHMF cultures with the broad-spectrum MMP inhibitor Batimastat (BB-94) suggest that these observations are due to a general class effect of broad-spectrum MMP inhibitors. Conclusions – This study is the first to demonstrate that a selective induction and release of an MMP species occurs with sustained exposure to pharmacologic MMP inhibition in LVHMFs. These observations may have particular importance with respect to controlling this proteolytic system in the context of LV myocardial remodeling.

The matrix metalloproteinase inhibitor batimastat inhibits the lung colonisation of orthotopically implanted malignant pancreatic tumor cells in SCID mice.

In this study, we investigated the effect of the matrix metalloproteinase inhibitor batimastat on the lung colonisation of orthotopically implanted malignant pancreatic tumor cells in SCID mice. Following intraperitoneal anaesthesia, 10(6) Panc-TU-1 cells were orthotopically implanted in the head of the pancreas in 20 SCID mice. Seven days later, treatment of 10 of these mice with an intraperitoneal injection of batimastat (30 mg/kg body weight) was begun and continued for 14 days. Of the mice in the untreated control group, 3 were sacrificed and examined after 7 days, a further 3 after 14 days and the remainder together with the group that had been treated after 21 days. Tumor growth was clearly visible between the 14th. and the 21st. postoperative day. The orthotopically implanted tumor cells metastasized between the 2nd. and 3rd. postoperative week in the lung. In the control group, a diffuse metastasis of the lung was observed, but in the group of treated mice no lung metastases were found. In this mouse model, a clear reduction and inhibition of lung metastases from orthotopically implanted pancreatic tumor cells was achieved by treatment with the matrix metalloproteinase inhibitor batimastat.

Validation of an orthotopic model of human lung cancer with regional and systemic metastases

Background. We developed an orthotopic model of human lung cancer that exhibits highly predictable regional and systemic metastases. This study examines the response of the model when treated with conventional and experimental chemotherapy. Methods. NCI-H460 tumor fragments were implanted into the right caudal lung lobe of a nude rat. Treatment commenced 2 weeks later. We assessed response by comparing primary tumor and mediastinal lymph node weights, total body weight, and length of survival with untreated, tumor-bearing control animals. We also calculated the incidence of metastasis to kidney, bone, brain, and contralateral lung in treated versus untreated animals. Results. Mitomycin and cisplatin showed broad activity against primary and metastatic disease. The matrix metalloproteinase inhibitor batimastat, low-dose cisplatin, and mitomycin significantly prolonged survival. High-dose cisplatin caused renal toxicity that shortened survival. Brain metastases did not respond to mitomycin, consistent with its poor blood-brain barrier penetration. Conclusions. Responses were similar to NCI-H460 in vitro data and consistent with clinical experience for these drugs. Drug-related toxicities similar to those seen in clinical practice were detected.

Inhibition of bleomycin-induced pulmonary fibrosis in mice by the matrix metalloproteinase inhibitor batimastat

Bleomycin-induced pulmonary fibrosis is known to be associated with the increased activity of two gelatinases, matrix metalloproteinase (MMP)-2 and MMP-9, in bronchoalveolar lavage (BAL). This study has investigated the effect of a synthetic inhibitor of MMP, batimastat, on the development of pulmonary fibrosis induced by bleomycin administration in mice. Animals were intranasally instilled with saline or bleomycin (0.5 mg in 100 microl per mouse). Batimastat (30 mg/kg) or vehicle alone was administered by intraperitoneal injection 24 h and 1 h before saline or bleomycin instillation, and then daily at the same dosage until the end of the study. Fifteen days after bleomycin administration, BAL was performed and the lung was removed. Treatment of mice with batimastat significantly reduced bleomycin-induced lung fibrosis, as shown in the lung by histopathological examination and by a decrease in hydroxyproline levels. Batimastat also prevented the increase in BAL macrophage and lymphocyte numbers, whereas it did not show any effect on the increased expression of active transforming growth factor-beta (TGF-beta) in BAL. Batimastat treatment was effective in reducing MMP-2 and MMP-9 activity as well as the tissue inhibitor of metalloproteinase-1 (TIMP-1) level in BAL. These results suggest that administration of the MMP inhibitor batimastat is useful in preventing experimental pulmonary fibrosis induced by bleomycin and raises the possibility of a therapeutic approach to human pulmonary fibrotic disease.

Reducing bleeding complications after thrombolytic therapy for stroke: clinical potential of metalloproteinase inhibitors and spin trap agents.

Thrombolysis with alteplase (recombinant tissue plasminogen activator; rtPA) has proven to be beneficial for acute stroke management, despite the narrow window of opportunity for treatment and the increased risk of haemorrhage. Because of the latter, recent studies have attempted to identify compounds that may be given concomitantly with alteplase to reduce the haemorrhage rate Matrix metalloproteinase (MMP) inhibitors have been proposed as potential combination therapy candidates because they prevent MMP-induced production of the cytokine tumour necrosis factor-alpha (TNFalpha), as well as membrane and vessel remodelling following ischaemia. Spin trap agents also have been put forward due to their free radical scavenging capabilities. In the rabbit large clot embolism model, alteplase effectively lysed blood clots, whether or not other drugs were used in combination. However, haemorrhage rate also was increased compared with that in control animals. The alteplase-induced haemorrhage rate was reduced significantly by administration of the MMP inhibitor batimastat (BB-94) or the spin trap agent alpha-phenyl-N-t-butylnitrone (PBN). Other rodent studies have also demonstrated that PBN is effective in decreasing the haemorrhage rate following alteplase administration. Overall, preclinical studies indicate that MMP inhibition or free radical scavenging in combination with alteplase may circumvent the high risk of haemorrhaging with alteplase.

Host metalloproteinases in Lyme arthritis.

To assess the role of matrix metalloproteinases (MMPs) in cartilage and bone erosions in Lyme arthritis We examined synovial fluid from 10 patients with Lyme arthritis for the presence of MMP-2, MMP-3, MMP-9, and "aggrecanase" activity using gelatinolytic zymography and immunoblot analysis. We developed an in vitro model of Lyme arthritis using cartilage explants and observed changes in cartilage degradation in the presence of Borrelia burgdorferi and/or various protease inhibitors. Synovial fluid from patients with Lyme arthritis was found to contain at least 3 MMPs: gelatinase A (MMP-2), stromelysin (MMP-3), and gelatinase B (MMP-9). In addition, there was evidence in 2 patients of "aggrecanase" activity not accounted for by the above enzymes. Infection of cartilage explants with B. burgdorferi resulted in induction of MMP-3, MMP-9, and "aggrecanase" activity. Increased induction of these enzymes by B. burgdorferi alone was not sufficient to cause cartilage destruction in the explants as measured by glycosaminoglycan (GAG) and hydroxyproline release. However, addition of plasminogen, which can act as an MMP activator, to cultures resulted in significant GAG and hydroxyproline release in the presence of B. burgdorferi. The MMP inhibitor batimastat significantly reduced the GAG release and completely inhibited the collagen degradation. MMPs are found in synovial fluids from patients with Lyme arthritis and are induced from cartilage tissue by the presence of B. burgdorferi. Inhibition of MMP activity prevents B. burgdorferi-induced cartilage degradation in vitro.

Beneficial Effects of Batimastat (BB-94), a Matrix Metalloproteinase Inhibitor, in Rat Experimental Colitis

Background and Aims: Matrix metalloproteinases (MMPs) represent a group of enzymes that regulate cell-matrix composition playing a major role in the inflammatory response. In the present study we evaluated the ability of the MMP inhibitor Batimastat (BB-94) to modify the course of experimental colitis induced in the rat by trinitrobenzensulfonic acid (TNB). Methods: Colitis was induced in 40 rats by intracolonic administration of TNB. Animals were divided into four groups of ten rats each: group 1 received only intracolonic TNB, group 2 received TNB+5 mg/kg intraperitoneal BB-94, group 3 TNB+10 mg/kg BB-94 and group 4 TNB+20 mg/kg BB-94. The MMP inhibitor was administered 30 min before induction of colitis and twice daily until death. Ten rats receiving only intracolonic 0.9% saline served as controls. Animals were killed after seven days; segments of colon were removed and used for histological score of inflammation and myeloperoxidase (MPO) activity. Results: Rats receiving only intracolonic 0.9% saline showed no evidence of colitis. The inflammation score was 0.9, MPO activity 0.235 U/mg. Group 1 (TNB-treated rats) exhibited a high inflammation score (12.4) and MPO activity (0.715 U/mg). Conversely, BB-94-treated rats showed, compared to the TNB group, a significantly lower inflammation score and MPO activity in a dose-dependent fashion. Group 2: inflammatory score 10.1, MPO activity 0.474 (p < 0.05 vs. TNB); group 3: inflammatory score 8.3, MPO activity 0.287 (p < 0.01 vs. TNB); group 4: inflammatory score 5.0, MPO activity 0.256 (p < 0.01 vs. TNB). Conclusions: Treatment with BB-94 has dose-dependent beneficial effects on the inflammatory alterations in rat experimental colitis. Thus, the inhibition of MMPs may represent a novel therapeutic approach for treatment of intestinal inflammation.

Responses to anti-angiogenic therapies.

Vascular tumors occur in approximately 10% of infants, and range from small cherry-red lesions to large, life-threatening tumors. Although the majority of these tumors involute after several years, there are few therapeutic options and their use is limited by the risk of side-effects. The recent increase in understanding of angiogenesis has led to investigations of new antiangiogenic treatment options using models of vascular tumors in mice. These studies have demonstrated the success of a variety of antiangiogenic approaches, including systemic administration of the antiangiogenic proteins AGM-1470 and angiostatin or of the matrix metalloproteinase inhibitor batimastat, and gene gun therapy with interleukin-12. Although these trials provide further evidence of the role of angiogenesis in the enlargement of these vascular tumors, their potential utility and safety await future trials in patients.