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Toxins Jul 2022Within Neotropical pit-vipers, the Mexican/Central-American clade consisting of , , , and is a wide-ranging, morphologically and ecologically diverse group of snakes....
Within Neotropical pit-vipers, the Mexican/Central-American clade consisting of , , , and is a wide-ranging, morphologically and ecologically diverse group of snakes. Despite their prevalence, little is known of the functional aspects of their venoms. This study aimed to fill the knowledge gap regarding coagulotoxic effects and to examine the potential of different therapeutic approaches. As a general trait, the venoms were shown to be anticoagulant but were underpinned by diverse biochemical actions. Pseudo-procoagulant activity (i.e., thrombin-like), characterized by the direct cleavage of fibrinogen to form weak fibrin clots, was evident for , , and In contrast, other venoms cleaved fibrinogen in a destructive (non-clotting) manner, with and being the most potent. In addition to actions on fibrinogen, clotting enzymes were also inhibited. FXa was only weakly inhibited by most species, but and were extremely strong in their inhibitory action. Other clotting enzymes were more widely inhibited by diverse species spanning the full taxonomical range, but in each case, there were species that had these traits notably amplified relatively to the others. and were the most potent amongst those that inhibited the formation of the prothrombinase complex and were also amongst the most potent inhibitors of Factor XIa. While most species displayed only low levels of thrombin inhibition, potently inhibited this clotting factor. The regional polyvalent antivenom produced by Instituto Picado Clodomiro was tested and was shown to be effective against the diverse anticoagulant pathophysiological effects. In contrast to the anticoagulant activities of the other species, was uniquely procoagulant through the activation of Factor VII and Factor XII. This viperid species is the first snake outside of the elapid snake clade to be shown to activate FVII and the first snake venom of any kind to activate FXII. Interestingly, while small-molecule metalloprotease inhibitors prinomastat and marimastat demonstrated the ability to prevent the procoagulant toxicity of , neither ICP antivenom nor inhibitor DMPS showed this effect. The extreme variation among the snakes here studied underscores how venom is a dynamic trait and how this can shape clinical outcomes and influence evolving treatment strategies.
Topics: Animals; Anticoagulants; Antivenins; Crotalid Venoms; Crotalinae; Elapid Venoms; Elapidae; Fibrinogen; Snake Venoms; Thrombin; Viperidae
PubMed: 35893753
DOI: 10.3390/toxins14080511 -
Arthritis and Rheumatism Jun 2003To characterize the clinical and histopathologic changes in a rat model of broad-spectrum matrix metalloproteinase (MMP)-induced musculoskeletal syndrome (MSS), and to...
OBJECTIVE
To characterize the clinical and histopathologic changes in a rat model of broad-spectrum matrix metalloproteinase (MMP)-induced musculoskeletal syndrome (MSS), and to facilitate research into the causes and treatments of MSS in humans.
METHODS
Male Lewis rats weighing 150-180 gm were administered 10-30 mg of the broad-spectrum MMP inhibitor marimastat over a 2-week period via surgically implanted subcutaneous osmotic pumps. The animals were monitored and scored for the onset and severity of MSS, using clinical and histologic parameters.
RESULTS
Marimastat-treated rats exhibited various clinical signs, including compromised ability to rest on their hind feet, high-stepping gait, reluctance or inability to move, and hind paw swelling. Histologically, marimastat-treated rat joints were characterized by soft tissue and bone changes, such as increased epiphyseal growth plate, synovial hyperplasia, and increased cellularity in the joint capsule and extracapsular ligaments. The severity of MSS, as judged by clinical criteria (2 blinded observers using 3 clinical parameters), paw volume, and histologic score, was nearly identical. The observed changes were indistinguishable from those reported for primate models and mimic MSS in humans.
CONCLUSION
This simple and sensitive model of MSS is an attractive alternative for studying the pathology of MSS.
Topics: Animals; Cartilage, Articular; Dose-Response Relationship, Drug; Enzyme Inhibitors; Foot; Gait; Growth Plate; Hindlimb; Hydroxamic Acids; Infusion Pumps, Implantable; Joints; Male; Matrix Metalloproteinase Inhibitors; Musculoskeletal Diseases; Rats; Rats, Inbred Lew; Single-Blind Method; Synovial Membrane
PubMed: 12794843
DOI: 10.1002/art.11030 -
Bioengineering & Translational Medicine May 2019The treatment of metastatic cancer is a great challenging issue throughout the world. Conventional chemotherapy can kill the cancer cells and, whereas, would exacerbate...
The treatment of metastatic cancer is a great challenging issue throughout the world. Conventional chemotherapy can kill the cancer cells and, whereas, would exacerbate the metastasis and induce drug resistance. Here, a new combinatorial treatment strategy of metastatic cancer was probed via subsequentially dosing dual nanomedicines, marimastat-loaded thermosensitive liposomes (MATT-LTSLs) and paclitaxel nanocrystals (PTX-Ns), via intravenous and intratumoral injection. First, the metastasis was blocked and cancer cells were locked in the tumor microenvironment (TME) by delivering the matrix metalloproteinase (MMP) inhibitor, MATT, to the tumor with LTSLs, downregulating the MMPs by threefold and reducing the degradation of the extracellular matrix. And then, the "locked" cancer cells were efficiently killed via intratumoral injection of the other cytotoxic nanomedicine, PTX-Ns, along with no metastasis and 100% inhibition of tumor growth. This work highlights the importance of the TME's integrity in the chemotherapy duration. We believe this is a generalized strategy for cancer treatment and has potential guidance for the clinical administration.
PubMed: 31249880
DOI: 10.1002/btm2.10130 -
EBioMedicine Mar 2021We developed a preclinical protocol for the screening of candidate drugs able to control myopia and prevent its progression. The protocol uses zebrafish, C57BL/6 mice,...
BACKGROUND
We developed a preclinical protocol for the screening of candidate drugs able to control myopia and prevent its progression. The protocol uses zebrafish, C57BL/6 mice, and golden Syrian hamster models of myopia.
METHODS
A morpholino (MO) targeting the zebrafish lumican gene (zlum) was injected into single-cell zebrafish embryos, causing excessive expansion of the sclera. A library of 640 compounds with 2 matrix metalloproteinase (MMP) inhibitors (marimastat and batimastat), which have the potential to modulate scleral remodelling, was screened to identify candidates for mitigating scleral diameter expansion in zlum-MO-injected embryos. The myopia-prevention ability of compounds discovered to have superior potency to inhibit scleral expansion was validated over 4 weeks in 4-week-old C57BL/6 mice and 3-week-old golden Syrian hamsters with form-deprivation myopia (FDM). Changes in the refractive error and axial length were investigated. Scleral thickness, morphology of collagen fibrils in the posterior sclera, messenger RNA (mRNA) expressions, and protein levels of transforming growth factor-β2 (TGF-β2), tissue inhibitor of metalloproteinase-2 (TIMP-2), MMP-2, MMP-7, MMP-9, and collagen, type I, alpha 1 (collagen Iα1) were investigated in C57BL/6 mice, and MMP-2, MMP-9, and MMP activity assays were conducted in these mice.
FINDINGS
In the zebrafish experiment, atropine, marimastat, batimastat, doxycycline, and minocycline were the drugs that most effectively reduced expansion of scleral equatorial diameter. After 28-day treatment in diffuser-wearing mice and 21-day treatment in lid-sutured hamsters, myopic shift and axial elongation were significantly mitigated by eye drops containing 1% atropine, 50 µM marimastat, 5 µM batimastat, or 200 µM doxycycline. MMP-2 mRNA expression in mouse sclera was lower after treatment with atropine, marimastat, batimastat, or doxycycline. The protein levels and activity of MMP-2 and MMP-7 were significantly reduced after treatment with atropine, marimastat, batimastat, doxycycline, and minocycline. Furthermore, scleral thickness and collagen fibril diameter were not lower after treatment with atropine, marimastat, batimastat, or doxycycline than those of occluded eyes.
INTERPRETATION
Stepwise drug screening in a range of models from zlum-MO-injected zebrafish to rodent FDM models identified effective compounds for preclinical myopia control or prevention. On the basis of the 640 compounds that were screened, MMP inhibitors may offer alternatives for clinical trials.
FUNDING
This research was supported by grants from Taiwan's Ministry of Science and Technology and Ministry of Health and Welfare.
Topics: Animals; Atropine; Cricetinae; Disease Models, Animal; Drug Evaluation, Preclinical; Embryo, Nonmammalian; Hydroxamic Acids; Lumican; Matrix Metalloproteinase 2; Matrix Metalloproteinase Inhibitors; Mice; Mice, Inbred C57BL; Morpholinos; Myopia; Phenylalanine; Sclera; Thiophenes; Tissue Inhibitor of Metalloproteinase-2; Zebrafish; Zebrafish Proteins
PubMed: 33691248
DOI: 10.1016/j.ebiom.2021.103263 -
Acta Pharmaceutica Sinica. B Oct 2020Repurposing small molecule drugs and drug candidates is considered as a promising approach to revolutionise the treatment of snakebite envenoming. In this study, we...
Repurposing small molecule drugs and drug candidates is considered as a promising approach to revolutionise the treatment of snakebite envenoming. In this study, we investigated the inhibiting effects of the small molecules varespladib (nonspecific phospholipase A inhibitor), marimastat (broad spectrum matrix metalloprotease inhibitor) and dimercaprol (metal ion chelator) against coagulopathic toxins found in Crotalinae (pit vipers) snake venoms. Venoms from , , and were separated by liquid chromatography, followed by nanofractionation and mass spectrometry identification undertaken in parallel. Nanofractions of the venom toxins were then subjected to a high-throughput coagulation assay in the presence of different concentrations of the small molecules under study. Anticoagulant venom toxins were mostly identified as phospholipases A, while procoagulant venom activities were mainly associated with snake venom metalloproteinases and snake venom serine proteases. Varespladib was found to effectively inhibit most anticoagulant venom effects, and also showed some inhibition against procoagulant toxins. Contrastingly, marimastat and dimercaprol were both effective inhibitors of procoagulant venom activities but showed little inhibitory capability against anticoagulant toxins. The information obtained from this study aids our understanding of the mechanisms of action of toxin inhibitor drug candidates, and highlights their potential as future snakebite treatments.
PubMed: 33163338
DOI: 10.1016/j.apsb.2020.09.005 -
Nature Communications Dec 2023Morbidity from snakebite envenoming affects approximately 400,000 people annually. Tissue damage at the bite-site often leaves victims with catastrophic life-long...
Morbidity from snakebite envenoming affects approximately 400,000 people annually. Tissue damage at the bite-site often leaves victims with catastrophic life-long injuries and is largely untreatable by current antivenoms. Repurposed small molecule drugs that inhibit specific snake venom toxins show considerable promise for tackling this neglected tropical disease. Using human skin cell assays as an initial model for snakebite-induced dermonecrosis, we show that the drugs 2,3-dimercapto-1-propanesulfonic acid (DMPS), marimastat, and varespladib, alone or in combination, inhibit the cytotoxicity of a broad range of medically important snake venoms. Thereafter, using preclinical mouse models of dermonecrosis, we demonstrate that the dual therapeutic combinations of DMPS or marimastat with varespladib significantly inhibit the dermonecrotic activity of geographically distinct and medically important snake venoms, even when the drug combinations are delivered one hour after envenoming. These findings strongly support the future translation of repurposed drug combinations as broad-spectrum therapeutics for preventing morbidity caused by snakebite.
Topics: Mice; Humans; Animals; Snake Bites; Snake Venoms; Drug Combinations
PubMed: 38097534
DOI: 10.1038/s41467-023-43510-w -
Biomolecules Apr 2023Ectopic calcification and dysregulated extracellular matrix remodeling are prominent hallmarks of the complex heterogenous pathobiochemistry of pseudoxanthoma elasticum...
Ectopic calcification and dysregulated extracellular matrix remodeling are prominent hallmarks of the complex heterogenous pathobiochemistry of pseudoxanthoma elasticum (PXE). The disease arises from mutations in , an ATP-binding cassette transporter expressed predominantly in the liver. Neither its substrate nor the mechanisms by which it contributes to PXE are completely understood. The fibroblasts isolated from PXE patients and mice were subjected to RNA sequencing. A group of matrix metalloproteinases (MMPs) clustering on human chromosome 11q21-23, respectively, murine chromosome 9, was found to be overexpressed. A real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and immunofluorescent staining confirmed these findings. The induction of calcification by CaCl resulted in the elevated expression of selected MMPs. On this basis, the influence of the MMP inhibitor Marimastat (BB-2516) on calcification was assessed. PXE fibroblasts (PXEFs) exhibited a pro-calcification phenotype basally. PXEF and normal human dermal fibroblasts responded with calcium deposit accumulation and the induced expression of osteopontin to the addition of Marimastat to the calcifying medium. The raised MMP expression in PXEFs and during cultivation with calcium indicates a correlation of ECM remodeling and ectopic calcification in PXE pathobiochemistry. We assume that MMPs make elastic fibers accessible to controlled, potentially osteopontin-dependent calcium deposition under calcifying conditions.
Topics: Humans; Mice; Animals; Pseudoxanthoma Elasticum; Osteopontin; Calcium; Calcinosis; Phenotype; Matrix Metalloproteinases; Multidrug Resistance-Associated Proteins
PubMed: 37189419
DOI: 10.3390/biom13040672 -
Gut Oct 2014Polycystic liver diseases (PCLDs) are genetic disorders characterised by progressive bile duct dilatation and/or cyst development. Their pathogenesis is a consequence of...
OBJECTIVE
Polycystic liver diseases (PCLDs) are genetic disorders characterised by progressive bile duct dilatation and/or cyst development. Their pathogenesis is a consequence of hyperproliferation, hypersecretion and microRNA alterations in cholangiocytes. Here we evaluate the role of matrix metalloproteases (MMPs) in the hepatic cystogenesis of PCLDs.
DESIGN
Metalloprotease activity was measured by microfluorimetric assays in normal and polycystic cholangiocyte cultures from humans and rats, and gene expression by real time quantitative PCR. The role of cytokines, oestrogens and growth factors present in the cystic fluid of PCLD patients was evaluated for MMP activity. The MMP inhibitor marimastat was examined for cystic expansion in vitro and in polycystic kidney (PCK) rats.
RESULTS
Polycystic human and rat cholangiocytes displayed increased MMP activity, which was associated with increased mRNA levels of different MMPs. Interleukin (IL)-6 and IL-8, and 17β-oestradiol, all stimulated MMP activity in human cholangiocytes. The presence of antibodies against IL-6 and/or IL-8 receptor/s inhibited baseline MMP hyperactivity of polycystic human cholangiocytes but had no effect on normal human cholangiocytes. MMP-3 was overexpressed in cystic cholangiocytes from PCLD human and PCK rat livers by immunohistochemistry. Marimastat reduced MMP hyperactivity of polycystic human and rat cholangiocytes and blocked the cystic expansion of PCK cholangiocytes cultured in three-dimensions. Chronic treatment of 8-week-old PCK rats with marimastat inhibited hepatic cystogenesis and fibrosis.
CONCLUSIONS
PCLDs are associated with cholangiocyte MMP hyperactivity resulting from autocrine/paracrine stimulation by IL-6 and IL-8. Inhibition of this MMP hyperactivity with marimastat decreased hepatic cystogenesis in vitro and in an animal model of PCLD, offering a potential therapeutic tool.
Topics: Animals; Bile Ducts; Blotting, Western; Cell Culture Techniques; Cysts; Cytokines; Cytophotometry; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Humans; Hydroxamic Acids; Immunohistochemistry; Liver; Liver Diseases; Male; Metalloendopeptidases; Rats; Real-Time Polymerase Chain Reaction
PubMed: 24436140
DOI: 10.1136/gutjnl-2013-305281 -
The Journal of Parasitology Aug 2018In the course of a structure based drug discovery program the known anticancer candidate marimastat was uncovered as a potent inhibitor of an enzyme in nematode cuticle...
In the course of a structure based drug discovery program the known anticancer candidate marimastat was uncovered as a potent inhibitor of an enzyme in nematode cuticle biogenesis. It was shown to kill Caenorhabditis elegans, and the sheep parasites Haemonchus contortus and Teladorsagia circumcinta via an entirely novel nematode-specific pathway, specifically by inhibiting cuticle-remodelling enzymes that the parasites require for the developmentally essential moulting process. This discovery prompted an investigation of the compound's effect on Heligmosomoides polygyrus parasites in a mouse model of helminth infection. Mice were administered the drug via oral gavage daily from day of infection for a period of 2 wk. A second group received the drug via intra-peritoneal implantation of an osmotic minipump for 4 wk. Control groups were administered identical volumes of water by oral gavage in both cases. Counts of H. polygyrus faecal egg and larval load showed that marimastat effected a consistent and significant reduction in egg laying, and a consistent but minor reduction in adult worm load when administered every day, starting on the first day of infection. However, the drug failed to have any significant effect on egg counts or worm burdens when administered to mice with established infections. Therefore, marimastat does not appear to show promise as an anthelmintic in gastrointestinal nematode infections, although other metalloproteases such as batimastat may prove more effective.
PubMed: 30085900
DOI: 10.1645/18-33 -
British Journal of Clinical Pharmacology Jan 1998To assess the tolerability and pharmacokinetic profile of single and repeat doses of the oral matrix metalloproteinase inhibitor marimastat in healthy male volunteers. (Clinical Trial)
Clinical Trial Randomized Controlled Trial
AIMS
To assess the tolerability and pharmacokinetic profile of single and repeat doses of the oral matrix metalloproteinase inhibitor marimastat in healthy male volunteers.
METHODS
A total of 31 subjects participated in two placebo-controlled, rising-dose studies. The first study assessed the pharmacokinetics and tolerability of single doses of marimastat of 25, 50, 100, 200, 400 and 800 mg. In the second study, continuous dosing over 6.5 days with three incremental dose levels of 50, 100 and 200 mg twice daily was assessed. Full pharmacokinetic profiles were obtained on days 0 and 6, and trough concentrations were measured on all days. For each pharmacokinetic profile in the studies, summary measures including Cmax, tmax, elimination half-life and AUC were calculated. Urinary drug weights were also measured. All adverse events were documented, and haematological and biochemical variables, vital signs and ECGs were monitored throughout the study.
RESULTS
Peak plasma concentrations were observed at 1.5-3 h for all subjects at all doses. Peak levels were approximately proportional to dose, as was drug exposure as calculated by AUC. Data from both studies indicate that the terminal elimination half-life is of the order of 8-10 h, and that there is no unexpected drug accumulation. Marimastat was well-tolerated, with adverse effects being mild and occurring with similar frequency to placebo. Small but reversible elevations in liver transaminases were noted with repeat dosing of marimastat, the most significant of these occurring at a dose of 200 mg twice daily.
CONCLUSION
Single and repeat oral doses of marimastat in healthy male subjects appear to be well-tolerated. The drug is rapidly absorbed with high peak levels achieved. It has a terminal elimination half-life of 8-10 h which would support twice daily dosing in further clinical trials.
Topics: Administration, Oral; Adolescent; Adult; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Enzyme Inhibitors; Humans; Hydroxamic Acids; Male; Metalloendopeptidases; Middle Aged; Placebos
PubMed: 9489589
DOI: 10.1046/j.1365-2125.1998.00639.x