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Nature Communications Dec 2020Snakebite is a medical emergency causing high mortality and morbidity in rural tropical communities that typically experience delayed access to unaffordable...
Snakebite is a medical emergency causing high mortality and morbidity in rural tropical communities that typically experience delayed access to unaffordable therapeutics. Viperid snakes are responsible for the majority of envenomings, but extensive interspecific variation in venom composition dictates that different antivenom treatments are used in different parts of the world, resulting in clinical and financial snakebite management challenges. Here, we show that a number of repurposed Phase 2-approved small molecules are capable of broadly neutralizing distinct viper venom bioactivities in vitro by inhibiting different enzymatic toxin families. Furthermore, using murine in vivo models of envenoming, we demonstrate that a single dose of a rationally-selected dual inhibitor combination consisting of marimastat and varespladib prevents murine lethality caused by venom from the most medically-important vipers of Africa, South Asia and Central America. Our findings support the translation of combinations of repurposed small molecule-based toxin inhibitors as broad-spectrum therapeutics for snakebite.
Topics: Animals; Antivenins; Asia; Benzamidines; Central America; Dimercaprol; Disease Models, Animal; Drug Combinations; Drug Evaluation, Preclinical; Guanidines; Kaplan-Meier Estimate; Male; Mice; Neutralization Tests; Serine Proteases; Snake Bites; Toxins, Biological; Viper Venoms
PubMed: 33323937
DOI: 10.1038/s41467-020-19981-6 -
Scientific Reports Dec 2020An intra-hippocampus injection of kainic acid serves as a model of status epilepticus and the subsequent development of temporal lobe epilepsy. Matrix...
An intra-hippocampus injection of kainic acid serves as a model of status epilepticus and the subsequent development of temporal lobe epilepsy. Matrix metalloproteinase-9 (MMP-9) is an enzyme that controls remodeling of the extracellular milieu under physiological and pathological conditions. In response to brain insult, MMP-9 contributes to pathological synaptic plasticity that may play a role in the progression of an epileptic condition. Marimastat is a metalloproteinase inhibitor that was tested in clinical trials of cancer. The present study assessed whether marimastat can impair the development of epilepsy. The inhibitory efficacy of marimastat was initially tested in neuronal cultures in vitro. As a marker substrate, we used nectin-3. Next, we investigated the blood-brain barrier penetration of marimastat using mass spectrometry and evaluated the therapeutic potential of marimastat against seizure outcomes. We found that marimastat inhibited the cleavage of nectin-3 in hippocampal neuronal cell cultures. Marimastat penetrated the blood-brain barrier and exerted an inhibitory effect on metalloproteinase activity in the brain. Finally, marimastat decreased some seizure parameters, such as seizure score and number, but did not directly affect status epilepticus. The long-term effects of marimastat were evident up to 6 weeks after kainic acid administration, in which marimastat still inhibited seizure duration.
Topics: Animals; Blood-Brain Barrier; Disease Models, Animal; Drug Evaluation, Preclinical; Hydroxamic Acids; Kainic Acid; Male; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Mice, Inbred C57BL; Nectins; Status Epilepticus
PubMed: 33277582
DOI: 10.1038/s41598-020-78341-y -
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 -
International Journal of Molecular... Sep 2020The crucial role of extracellular proteases in cancer progression is well-known, especially in relation to the promotion of cell invasion through extracellular matrix... (Review)
Review
The crucial role of extracellular proteases in cancer progression is well-known, especially in relation to the promotion of cell invasion through extracellular matrix remodeling. This also occurs by the ability of extracellular proteases to induce the shedding of transmembrane proteins at the plasma membrane surface or within extracellular vesicles. This process results in the regulation of key signaling pathways by the modulation of kinases, e.g., the epidermal growth factor receptor (EGFR). Considering their regulatory roles in cancer, therapeutics targeting various extracellular proteases have been discovered. These include the metal-binding agents di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), which increase c-MET degradation by multiple mechanisms. Both the direct and indirect inhibition of protease expression and activity can be achieved through metal ion depletion. Considering direct mechanisms, chelators can bind zinc(II) that plays a catalytic role in enzyme activity. In terms of indirect mechanisms, Dp44mT and DpC potently suppress the expression of the kallikrein-related peptidase-a prostate-specific antigen-in prostate cancer cells. The mechanism of this activity involves promotion of the degradation of the androgen receptor. Additional suppressive mechanisms of Dp44mT and DpC on matrix metalloproteases (MMPs) relate to their ability to up-regulate the metastasis suppressors N-myc downstream regulated gene-1 (NDRG1) and NDRG2, which down-regulate MMPs that are crucial for cancer cell invasion.
Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Transformation, Neoplastic; Chelating Agents; Disease Progression; Drug Design; Drug Screening Assays, Antitumor; Extracellular Fluid; Extracellular Vesicles; Humans; Hydroxamic Acids; Iron; Iron Chelating Agents; Kallikreins; Matrix Metalloproteinases; Molecular Targeted Therapy; Neoplasm Proteins; Oxaprozin; Peptide Hydrolases; Phenylalanine; Protease Inhibitors; Protein Kinases; Pyridines; Thiophenes; Thiosemicarbazones; Zinc
PubMed: 32948029
DOI: 10.3390/ijms21186805 -
Clinical and Experimental Immunology Jan 2021Pseudomonas aeruginosa is the major respiratory pathogen in patients with cystic fibrosis (CF). P. aeruginosa-secreted proteases, in addition to host proteases, degrade...
Pseudomonas aeruginosa is the major respiratory pathogen in patients with cystic fibrosis (CF). P. aeruginosa-secreted proteases, in addition to host proteases, degrade lung tissue and interfere with immune processes. In this study, we aimed at evaluating the possible anti-inflammatory effects of protease inhibitors Marimastat and Ilomastat in the treatment of P. aeruginosa infection. Lung infection with the P. aeruginosa PAO1 strain was established in wild-type and cystic fibrosis transmembrane conductance regulator (CFTR) knock-out C57BL/6 mice expressing a luciferase gene under control of bovine interleukin (IL)-8 promoter. After intratracheal instillation with 150 µM Marimastat and Ilomastat, lung inflammation was monitored by in-vivo bioluminescence imaging and bacterial load in the lungs was assessed. In vitro, the effects of protease inhibitors on PAO1 growth and viability were evaluated. Acute lung infection was established in both wild-type and CFTR knock-out mice. After 24 h, the infection induced IL-8-dependent bioluminescence emission, indicating lung inflammation. In infected mice with ongoing inflammation, intratracheal treatment with 150 µM Marimastat and Ilomastat reduced the bioluminescence signal in comparison to untreated, infected animals. Bacterial load in the lungs was not affected by the treatment, and in vitro the same dose of Marimastat and Ilomastat did not affect PAO1 growth and viability, confirming that these molecules have no additional anti-bacterial activity. Our results show that inhibition of protease activity elicits anti-inflammatory effects in cystic fibrosis (CF) mice with acute P. aeruginosa lung infection. Thus, Marimastat and Ilomastat represent candidate molecules for the treatment of CF patients, encouraging further studies on protease inhibitors and their application in inflammatory diseases.
Topics: Acute Disease; Animals; Cystic Fibrosis; Hydroxamic Acids; Indoles; Mice; Mice, Knockout; Pneumonia, Bacterial; Protease Inhibitors; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 32946591
DOI: 10.1111/cei.13518 -
Biomedicines Aug 2020Animal-derived antivenoms are the only specific therapies currently available for the treatment of snake envenoming, but these products have a number of limitations...
Animal-derived antivenoms are the only specific therapies currently available for the treatment of snake envenoming, but these products have a number of limitations associated with their efficacy, safety and affordability for use in tropical snakebite victims. Small molecule drugs and drug candidates are regarded as promising alternatives for filling the critical therapeutic gap between snake envenoming and effective treatment. In this study, by using an advanced analytical technique that combines chromatography, mass spectrometry and bioassaying, we investigated the effect of several small molecule inhibitors that target phospholipase A (varespladib) and snake venom metalloproteinase (marimastat, dimercaprol and DMPS) toxin families on inhibiting the activities of coagulopathic toxins found in snake venoms. The venoms of , , and , which are known for their potent haemotoxicities, were fractionated in high resolution onto 384-well plates using liquid chromatography followed by coagulopathic bioassaying of the obtained fractions. Bioassay activities were correlated to parallel recorded mass spectrometric and proteomics data to assign the venom toxins responsible for coagulopathic activity and assess which of these toxins could be neutralized by the inhibitors under investigation. Our results showed that the phospholipase A-inhibitor varespladib neutralized the vast majority of anticoagulation activities found across all of the tested snake venoms. Of the snake venom metalloproteinase inhibitors, marimastat demonstrated impressive neutralization of the procoagulation activities detected in all of the tested venoms, whereas dimercaprol and DMPS could only partially neutralize these activities at the doses tested. Our results provide additional support for the concept that combinations of small molecules, particularly the combination of varespladib with marimastat, serve as a drug-repurposing opportunity to develop new broad-spectrum inhibitor-based therapies for snakebite envenoming.
PubMed: 32825484
DOI: 10.3390/biomedicines8090297 -
Toxins May 2020Snakebite envenomation causes over 140,000 deaths every year, predominantly in developing countries. As a result, it is one of the most lethal neglected tropical...
Snakebite envenomation causes over 140,000 deaths every year, predominantly in developing countries. As a result, it is one of the most lethal neglected tropical diseases. It is associated with incredibly complex pathophysiology due to the vast number of unique toxins/proteins present in the venoms of diverse snake species found worldwide. Here, we report the purification and functional characteristics of a Group I (PI) metalloprotease (CAMP-2) from the venom of the western diamondback rattlesnake, . Its sensitivity to matrix metalloprotease inhibitors (batimastat and marimastat) was established using specific in vitro experiments and in silico molecular docking analysis. CAMP-2 shows high sequence homology to atroxase from the venom of and exhibits collagenolytic, fibrinogenolytic and mild haemolytic activities. It exerts a mild inhibitory effect on agonist-induced platelet aggregation in the absence of plasma proteins. Its collagenolytic activity is completely inhibited by batimastat and marimastat. Zinc chloride also inhibits the collagenolytic activity of CAMP-2 by around 75% at 50 μM, while it is partially potentiated by calcium chloride. Molecular docking studies have demonstrated that batimastat and marimastat are able to bind strongly to the active site residues of CAMP-2. This study demonstrates the impact of matrix metalloprotease inhibitors in the modulation of a purified, Group I metalloprotease activities in comparison to the whole venom. By improving our understanding of snake venom metalloproteases and their sensitivity to small molecule inhibitors, we can begin to develop novel and improved treatment strategies for snakebites.
Topics: Animals; Antineoplastic Agents; Antivenins; Binding Sites; Blood Platelets; Catalytic Domain; Collagen; Crotalid Venoms; Crotalus; Drug Repositioning; Erythrocytes; Fibrin; Fibrinolysis; Hemolysis; Humans; Hydroxamic Acids; Matrix Metalloproteinase Inhibitors; Matrix Metalloproteinases; Molecular Docking Simulation; Phenylalanine; Protein Binding; Protein Conformation; Structure-Activity Relationship; Substrate Specificity; Thiophenes
PubMed: 32397419
DOI: 10.3390/toxins12050309 -
Advanced Biosystems Apr 2020Cancer cell motility plays a central role in metastasis and tumor invasion but can be difficult to study accurately in vitro. A simple approach to address this challenge...
Cancer cell motility plays a central role in metastasis and tumor invasion but can be difficult to study accurately in vitro. A simple approach to address this challenge through the production of monolithic, photopatterned 3D tumor constructs in situ in a microfluidic device is described here. Through step-wise fabrication of adjoining hydrogel regions with and without incorporated cells, multidomain structures with defined boundaries are produced. By imaging cells over time, cellular activity with arbitrary control over medium conditions, including drug concentration and flow rate, is studied. First, malignant human colon carcinoma cells (HCT116) are studied for 10 days, comparing invasion dynamics and viability of cells in normal media to those exposed to two independent chemotherapeutic drugs: anti-proliferative 5-fluorouracil and anti-migratory Marimastat. Cytotoxicity is measured and significant differences are observed in cellular dynamics (migrating cell count, distance traveled, and rate) that correlate with the mechanism of each drug. Then, the platform is applied to the selective isolation of infiltrated cells through the photopatterning and subsequent dissolution of cleavable hydrogel domains. As a demonstration, the preferential collection of highly migratory cells (HCT116) over a comparable cell line with low malignancy and migratory potential (Caco-2) is shown.
Topics: Caco-2 Cells; Cell Separation; Colonic Neoplasms; Fluorouracil; HCT116 Cells; Humans; Hydrogels; Hydroxamic Acids; Lab-On-A-Chip Devices; Neoplasm Invasiveness; Neoplasm Metastasis
PubMed: 32293164
DOI: 10.1002/adbi.201900273 -
Integrative Biology : Quantitative... Dec 2019Protrusions are one of the structures that cells use to sense their surrounding environment in a probing and exploratory manner as well as to communicate with other...
Protrusions are one of the structures that cells use to sense their surrounding environment in a probing and exploratory manner as well as to communicate with other cells. In particular, osteoblasts embedded within a 3D matrix tend to originate a large number of protrusions compared to other type of cells. In this work, we study the role that mechanochemical properties of the extracellular matrix (ECM) play on the dynamics of these protrusions, namely, the regulation of the size and number of emanating structures. In addition, we also determine how the dynamics of the protrusions may lead the 3D movement of the osteoblasts. Significant differences were found in protrusion size and cell velocity, when degradation activity due to metalloproteases was blocked by means of an artificial broad-spectrum matrix metalloproteinase inhibitor, whereas stiffening of the matrix by introducing transglutaminase crosslinking, only induced slight changes in both protrusion size and cell velocity, suggesting that the ability of cells to create a path through the matrix is more critical than the matrix mechanical properties themselves. To confirm this, we developed a cell migration computational model in 3D including both the mechanical and chemical properties of the ECM as well as the protrusion mechanics, obtaining good agreement with experimental results.
Topics: Biopolymers; Cell Culture Techniques; Cell Line; Cell Movement; Computer Simulation; Extracellular Matrix; GTP-Binding Proteins; Humans; Hydrogels; Lab-On-A-Chip Devices; Models, Theoretical; Osteoblasts; Protein Glutamine gamma Glutamyltransferase 2; Recombinant Proteins; Transglutaminases; Tubulin
PubMed: 31922533
DOI: 10.1093/intbio/zyz035 -
Signal Transduction and Targeted Therapy 2019Metastasis is a major cause of chemotherapeutic failure and death. Degradation of a specific component of the extracellular matrix (ECM) by matrix metalloproteinases...
Metastasis is a major cause of chemotherapeutic failure and death. Degradation of a specific component of the extracellular matrix (ECM) by matrix metalloproteinases (MMPs) affects the physical barrier of the tumor microenvironment (TME) and induces metastasis. Here, lysolipid-containing thermosensitive liposomes (LTSLs) were prepared to deliver an MMP inhibitor, marimastat (MATT), to the TME to inhibit MMP activity and expression. LTSLs rapidly released their payloads at 42 °C. Compared with the saline control, MATT-LTSLs exhibited enhanced accumulation in the tumor and a 20-fold decrease in tumor growth in 4T1 tumor-bearing mice; moreover, MATT-LTSLs reduced MMP-2 and MMP-9 activity by 50% and 43%, respectively, and downregulated MMP-2 and MMP-9 expression in vivo by 30% and 43%, respectively. Most importantly, MATT-LTSL treatment caused a 7-fold decrease in metastatic lung nodules and a 6-fold reduction in microvessels inside the tumor. We believe this study provides an effective approach for the suppression of metastasis, and the use of a cytotoxic agent in combination with MATT is a potential strategy for metastatic cancer treatment.
PubMed: 31637006
DOI: 10.1038/s41392-019-0054-9