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1.
Biomacromolecules ; 23(5): 2170-2183, 2022 05 09.
Article in English | MEDLINE | ID: mdl-35465654

ABSTRACT

The emergence of "superbugs" is not only problematic and potentially lethal for infected subjects but also poses serious challenges for the healthcare system. Although existing antibacterial agents have been effective in some cases, the side effects and biocompatibility generally present difficulties. The development of new antibacterial agents is therefore urgently required. In this work, we have adapted a strategy for the improvement of poly(hexamethylene guanidine) hydrochloride (PHMG), a common antibacterial agent. This involves copolymerization of separate monomer units in varying ratios to find the optimum ratio of the hydrocarbon to guanidine units for antibacterial activity. A series of these copolymers, designated as PGB, was synthesized. By varying the guanidine/hydrophobic ratio and the copolymer molecular weight, a structure-optimized PGB was identified that showed broad-spectrum antibacterial activity and excellent biocompatibility in solution. In an antibacterial assay, the copolymer with the optimum composition (hydrophobic unit content 25%) inhibited >99% Staphylococcus aureus and was compatible with mammalian cells. A polyurethane emulsion containing this PGB component formed transparent, flexible films (PGB-PU films) on a wide range of substrate surfaces, including soft polymers and metals. The PGB-PU films showed excellent bacteriostatic efficiency against nosocomial drug-resistant bacteria, such as Pseudomonas aeruginosa and methicillin-resistant S. aureus (MRSA). It is concluded that our PGB polymers can be used as bacteriostatic agents generally and in particular for the design of antibacterial surfaces in medical devices.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Alkanes , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Guanidine/chemistry , Guanidine/pharmacology , Guanidines/pharmacology , Humans , Mammals , Microbial Sensitivity Tests , Polymers/chemistry , Polymers/pharmacology , Prostaglandins B
2.
Microbiol Spectr ; 10(2): e0074821, 2022 Apr 27.
Article in English | MEDLINE | ID: mdl-35319278

ABSTRACT

PRS17, a variant of human immunodeficiency virus type I protease (HIV-1 PR), has 17 mutated residues showing high levels of multidrug resistance. To describe the effects of these mutated residues on the dynamic properties and the binding mechanism of PR with substrate and inhibitor, focused on six systems (two complexes of WT PR and PRS17 with inhibitor Darunavir (DRV), two complexes of WT PR and PRS17 with substrate analogue CA-p2, two unligand WT PR and PRS17), we performed multiple molecular dynamics (MD) simulations combined with MM-PBSA and solvated interaction energy (SIE) methods. For both the unligand PRs and ligand-PR complexes, the results from simulations revealed 17 mutated residues alter the flap-flap distance, the distance from flap regions to catalytic sites, and the curling degree of the flap tips. These mutated residues changed the flexibility of the flap region in PR, and thus affected its binding energy with DRV and CA-p2, resulting in differences in sensitivity. Hydrophobic cavity makes an important contribution to the binding of PR and ligands. And most noticeable of all, the binding of the guanidine group in CA-p2 and Arg8' of PRS17 is useful for increasing their binding ability. These results have important guidance for the further design of drugs against multidrug resistant PR. IMPORTANCE Developing effective anti-HIV inhibitors is the current requirement to cope with the emergence of the resistance of mutants. Compared with the experiments, MD simulations along with energy calculations help reduce the time and cost of designing new inhibitors. Based on our simulation results, we propose two factors that may help design effective inhibitors against HIV-1 PR: (i) importance of hydrophobic cavity, and (ii) introduction of polar groups similar to the guanidine group.


Subject(s)
HIV Protease Inhibitors , HIV-1 , Binding Sites , Darunavir/pharmacology , Guanidines/pharmacology , HIV Protease , HIV Protease Inhibitors/chemistry , HIV Protease Inhibitors/metabolism , HIV Protease Inhibitors/pharmacology , HIV-1/chemistry , HIV-1/genetics , Humans , Ligands , Molecular Dynamics Simulation , Mutation
3.
Food Funct ; 13(6): 3572-3589, 2022 Mar 21.
Article in English | MEDLINE | ID: mdl-35262159

ABSTRACT

Flavonoid compounds such as luteolin exhibit hypolipidemic effects, and there are few reports on the hypoglycemic activity of luteolin derivatives. In this research, 6,8-(1,3-diaminoguanidine) luteolin (DAGL) and its Cr complex (DAGL·Cr) were obtained as a result of structural modifications to luteolin, and the hypoglycemic activities and the composition of intestinal microbiota in T2DM mice were investigated. This study found that DAGL and DAGL·Cr could significantly restore body weight, FBG, OGTT, AUC, and GSP in T2DM mice. Moreover, the pancreatic islet function index and the biochemical indicators of serum and the liver were also significantly improved. The histopathological results also showed that DAGL and DAGL·Cr had a stronger repair ability in the liver and the pancreas. It was also revealed that the potential hypoglycemic mechanism of DAGL and DAGL·Cr was involved in the simultaneous regulation of PI3K/AKT-1/GSK-3ß/GLUT-4 and PI3K/AKT-1/mTOR/S6K1/IRS-1. Furthermore, DAGL and DAGL·Cr could also regulate the structure of the intestinal microbiota and increase the content of SCFA to relieve the symptoms of hyperglycemia in T2DM mice. This included a significant reduction in the ratio of Firmicutes and Bacteroidetes (F/B), and at the genus level, an increase in the relative abundance of Alistipe and Ruminiclostridium, and improvement in the content of SCFA in the feces of T2DM mice. In conclusion, in this study, DAGL and DAGL·Cr were found to improve hyperglycemia in T2DM mice by improving the pancreatic islet function index, regulating the biochemical indicators of serum and the liver, repairing damaged tissues, and regulating the PI3K/AKT-1 signaling pathway as well as reducing F/B, increasing the relative abundance of intestinal beneficial microbiota, and the content of SCFA in the feces. The hypoglycemic effect of DAGL·Cr on the body weight, serum IL-10, serum IL-6, and pancreatic islet function index was significantly better than that of DAGL.


Subject(s)
Diabetes Mellitus, Type 2 , Gastrointestinal Microbiome , Luteolin , Animals , Chromium/pharmacology , Diabetes Mellitus, Type 2/metabolism , Glycogen Synthase Kinase 3 beta , Guanidines/analysis , Guanidines/pharmacology , Hypoglycemic Agents/pharmacology , Luteolin/analysis , Luteolin/pharmacology , Mice , Organometallic Compounds/pharmacology , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism
4.
Proc Natl Acad Sci U S A ; 119(10): e2122287119, 2022 03 08.
Article in English | MEDLINE | ID: mdl-35238637

ABSTRACT

SignificanceMetformin is the most commonly prescribed drug for the treatment of type 2 diabetes mellitus, yet the mechanism by which it lowers plasma glucose concentrations has remained elusive. Most studies to date have attributed metformin's glucose-lowering effects to inhibition of complex I activity. Contrary to this hypothesis, we show that inhibition of complex I activity in vitro and in vivo does not reduce plasma glucose concentrations or inhibit hepatic gluconeogenesis. We go on to show that metformin, and the related guanides/biguanides, phenformin and galegine, inhibit complex IV activity at clinically relevant concentrations, which, in turn, results in inhibition of glycerol-3-phosphate dehydrogenase activity, increased cytosolic redox, and selective inhibition of glycerol-derived hepatic gluconeogenesis both in vitro and in vivo.


Subject(s)
Electron Transport Complex IV/antagonists & inhibitors , Gluconeogenesis , Guanidines/pharmacology , Hypoglycemic Agents/pharmacology , Metformin/pharmacology , Phenformin/pharmacology , Animals , Glucose/metabolism , Glycerol/metabolism , Glycerolphosphate Dehydrogenase/antagonists & inhibitors , Liver/drug effects , Liver/metabolism , Oxidation-Reduction , Pyridines/pharmacology
5.
Nature ; 603(7899): 25-27, 2022 03.
Article in English | MEDLINE | ID: mdl-35233098

Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Clinical Trials as Topic , Drug Repositioning , Host-Pathogen Interactions/drug effects , SARS-CoV-2/drug effects , Adenosine Monophosphate/administration & dosage , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/therapeutic use , Administration, Oral , Alanine/administration & dosage , Alanine/analogs & derivatives , Alanine/therapeutic use , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/therapeutic use , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/administration & dosage , Antibodies, Neutralizing/economics , Antibodies, Neutralizing/therapeutic use , Antiviral Agents/administration & dosage , Antiviral Agents/pharmacology , COVID-19/economics , COVID-19/immunology , COVID-19/mortality , COVID-19/virology , COVID-19 Vaccines , Cytidine/analogs & derivatives , Cytidine/therapeutic use , Depsipeptides/pharmacology , Depsipeptides/therapeutic use , Dexamethasone/administration & dosage , Dexamethasone/therapeutic use , Drug Combinations , Drug Synergism , Esters/pharmacology , Esters/therapeutic use , Guanidines/pharmacology , Guanidines/therapeutic use , Hospitalization , Humans , Hydroxylamines/therapeutic use , Internationality , Lactams/therapeutic use , Leucine/therapeutic use , Mice , National Institutes of Health (U.S.)/organization & administration , Nitriles/therapeutic use , Peptide Elongation Factor 1/antagonists & inhibitors , Peptides, Cyclic/pharmacology , Peptides, Cyclic/therapeutic use , Proline/therapeutic use , Protease Inhibitors/pharmacology , Protease Inhibitors/therapeutic use , RNA-Dependent RNA Polymerase/antagonists & inhibitors
6.
Viruses ; 14(2)2022 02 14.
Article in English | MEDLINE | ID: mdl-35215982

ABSTRACT

Inhibition of transmembrane serine protease 2 (TMPRSS2) is expected to block the spike protein-mediated fusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nafamostat, a potent TMPRSS2 inhibitor as well as a candidate for anti-SARS-CoV-2 drug, possesses the same acyl substructure as camostat, but is known to have a greater antiviral effect. A unique aspect of the molecular binding of nafamostat has been recently reported to be the formation of a covalent bond between its acyl substructure and Ser441 in TMPRSS2. In this study, we investigated crucial elements that cause the difference in anti-SARS-CoV-2 activity of nafamostat and camostat. In silico analysis showed that Asp435 significantly contributes to the binding of nafamostat and camostat to TMPRSS2, while Glu299 interacts strongly only with nafamostat. The estimated binding affinity for each compound with TMPRSS2 was actually consistent with the higher activity of nafamostat; however, the evaluation of the newly synthesized nafamostat derivatives revealed that the predicted binding affinity did not correlate with their anti-SARS-CoV-2 activity measured by the cytopathic effect (CPE) inhibition assay. It was further shown that the substitution of the ester bond with amide bond in nafamostat resulted in significantly weakened anti-SARS-CoV-2 activity. These results strongly indicate that the ease of covalent bond formation with Ser441 in TMPRSS2 possibly plays a major role in the anti-SARS-CoV-2 effect of nafamostat and its derivatives.


Subject(s)
Antiviral Agents/pharmacology , Benzamidines/pharmacology , Computer Simulation , Guanidines/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/drug effects , Benzamidines/chemistry , COVID-19/drug therapy , Cell Line , Guanidines/chemistry , Humans , Molecular Dynamics Simulation , Protease Inhibitors/chemistry , Serine Endopeptidases/metabolism , Virus Internalization/drug effects
7.
Mar Drugs ; 20(2)2022 Jan 29.
Article in English | MEDLINE | ID: mdl-35200638

ABSTRACT

Liver cancers, such as hepatocellular carcinoma (HCC), are a highly prevalent cause of cancer-related deaths. Current treatments to combat liver cancer are limited. (-)-Agelasidine A, a compound isolated from the methanol extract of Agelasnakamurai, a sesquiterpene guanidine derived from sea sponge, has antibacterial activity. We demonstrated its anticancer capabilities by researching the associated mechanism of (-)-agelasidine A in human liver cancer cells. We found that (-)-agelasidine A significantly reduced viability in Hep3B and HepG2 cells, and we determined that apoptosis was involved in the (-)-agelasidine A-induced Hep3B cell deaths. (-)-Agelasidine A activated caspases 9, 8, and 3, as well as PARP. This effect was reversed by caspase inhibitors, suggesting caspase-mediated apoptosis in the (-)-agelasidine A-treated Hep3B cells. Moreover, the reduced mitochondrial membrane potential (MMP) and the release of cytochrome c indicated that the (-)-agelasidine A-mediated mitochondrial apoptosis was mechanistic. (-)-Agelasidine A also increased apoptosis-associated proteins (DR4, DR5, FAS), which are related to extrinsic pathways. These events were accompanied by an increase in Bim and Bax, proteins that promote apoptosis, and a decrease in the antiapoptotic protein, Bcl-2. Furthermore, our results presented that (-)-agelasidine A treatment bridged the intrinsic and extrinsic apoptotic pathways. Western blot analysis of Hep3B cells treated with (-)-agelasidine A showed that endoplasmic reticulum (ER) stress-related proteins (GRP78, phosphorylated PERK, phosphorylated eIF2α, ATF4, truncated ATF6, and CHOP) were upregulated. Moreover, 4-PBA, an ER stress inhibitor, could also abrogate (-)-agelasidine A-induced cell viability reduction, annexin V+ apoptosis, death receptor (DR4, DR5, FAS) expression, mitochondrial dysfunction, and cytochrome c release. In conclusion, by activating ER stress, (-)-agelasidine A induced the extrinsic and intrinsic apoptotic pathways of human HCC.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/drug therapy , Guanidines/pharmacology , Liver Neoplasms/drug therapy , Sulfones/pharmacology , Animals , Antineoplastic Agents/isolation & purification , Apoptosis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Cytochromes c/metabolism , Endoplasmic Reticulum Stress/drug effects , Guanidines/isolation & purification , Hep G2 Cells , Humans , Membrane Potential, Mitochondrial/drug effects , Porifera/chemistry , Sulfones/isolation & purification
8.
Eur J Med Chem ; 232: 114189, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-35196598

ABSTRACT

Influenza is a century-old disease that continues to baffle humans by its frequently changing nature, seasonal epidemics, and occasional pandemics. Approximately 9% of the world's population is infected by the influenza virus annually. The emergence of novel strains because of rapid mutations as well as interspecies disease contamination, limits the efficiency of strain-specific vaccines. Anti-influenza drugs such as neuraminidase inhibitors, M2 ion channel inhibitors, etc. have become the first line of defense in prophylaxis and early containment of the disease. But the growing drug resistance due to drug-induced selective pressure has also limited the efficacy of those drugs. Because we can't predict the next strain types, their virulence, or the severity of the next epidemic/pandemic caused by influenza virus, we ought to gear up for the development of novel anti-influenza drugs with a broad spectrum of reactivity against all strains and subtypes, better bioavailability, easier administrative pathways, and lesser adverse effects. Various new compounds with each having significantly different target molecules and pharmacologic activity have shown potential against influenza virus strains in laboratory situations as well as clinical trials. We should also consider combination therapy to boost the efficacy of existing drugs. This review is aiming to succinctly document the recent signs of progress regarding anti-influenza drugs both in the market and under investigation.


Subject(s)
Influenza, Human , Orthomyxoviridae , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Enzyme Inhibitors/pharmacology , Guanidines/pharmacology , Humans , Influenza, Human/drug therapy , Neuraminidase
9.
Sci Rep ; 12(1): 2825, 2022 02 18.
Article in English | MEDLINE | ID: mdl-35181714

ABSTRACT

The high quality, yield and purity total RNA samples are essential for molecular experiments. However, harvesting high quality RNA in Lilium davidii var. unicolor is a great challenge due to its polysaccharides, polyphenols and other secondary metabolites. In this study, different RNA extraction methods, namely TRIzol method, the modified TRIzol method, Kit method and cetyltrimethylammonium bromide (CTAB) method were employed to obtain total RNA from different tissues in L. davidii var. unicolor. A Nano drop spectrophotometer and 1% agarose gel electrophoresis were used to detect the RNA quality and integrity. Compared with TRIzol, Kit and CTAB methods, the modified TRIzol method obtained higher RNA concentrations from different tissues and the A260/A280 ratios of RNA samples were ranged from 1.97 to 2.27. Thus, the modified TRIzol method was shown to be the most effective RNA extraction protocol in acquiring RNA with high concentrations. Furthermore, the RNA samples isolated by the modified TRIzol and Kit methods were intact, whereas different degrees of degradation happened within RNA samples isolated by the TRIzol and CTAB methods. In addition, the modified TRIzol method could also isolate high-quality RNA from other edible lily bulbs. Taken together, the modified TRIzol method is an efficient method for total RNA isolation from L. davidii var. unicolor.


Subject(s)
Lilium/chemistry , RNA, Plant/isolation & purification , Cetrimonium/pharmacology , Guanidines/pharmacology , Phenols/pharmacology , Plant Roots/drug effects , Plant Roots/genetics , Polyphenols/pharmacology , RNA, Plant/chemistry
10.
Int J Mol Sci ; 23(3)2022 Jan 28.
Article in English | MEDLINE | ID: mdl-35163454

ABSTRACT

Aging of the retina is accompanied by a sharp increase in the content of lipofuscin granules and bisretinoid A2E in the cells of the retinal pigment epithelium (RPE) of the human eye. It is known that A2E can have a toxic effect on RPE cells. However, the specific mechanisms of the toxic effect of A2E are poorly understood. We investigated the effect of the products of photooxidative destruction of A2E on the modification of bovine serum albumin (BSA) and hemoglobin from bovine erythrocytes. A2E was irradiated with a blue light-emitting diode (LED) source (450 nm) or full visible light (400-700 nm) of a halogen lamp, and the resulting water-soluble products of photooxidative destruction were investigated for the content of carbonyl compounds by mass spectrometry and reaction with thiobarbituric acid. It has been shown that water-soluble products formed during A2E photooxidation and containing carbonyl compounds cause modification of serum albumin and hemoglobin, measured by an increase in fluorescence intensity at 440-455 nm. The antiglycation agent aminoguanidine inhibited the process of modification of proteins. It is assumed that water-soluble carbonyl products formed as a result of A2E photodestruction led to the formation of modified proteins, activation of the inflammation process, and, as a consequence, to the progression of various senile eye pathologies.


Subject(s)
Hemoglobins/chemistry , Retinoids/chemistry , Retinoids/pharmacology , Serum Albumin, Bovine/chemistry , Animals , Cattle , Guanidines/pharmacology , Hemoglobins/drug effects , Light , Mass Spectrometry , Retinoids/radiation effects , Serum Albumin, Bovine/drug effects , Thiobarbiturates/chemistry , Water/chemistry
11.
PLoS One ; 17(2): e0263840, 2022.
Article in English | MEDLINE | ID: mdl-35148353

ABSTRACT

Emergence and spread of malaria vectors resistant to the available insecticides required a new and efficacious insecticide. Residual efficacy of Fludora® Fusion was evaluated against insecticide susceptible Anopheles arabiensis in ten circular huts similar to the residential huts. Fludora® Fusion WP-SB 56.25, FICAM WP80 and Clothianidin WG70 were sprayed, by experienced technician, on interior wall surfaces: paint, dung, smooth mud, and rough mud. WHO cone bioassays were carried out a month after spraying and thereafter on monthly intervals for 12 months. Knockdown was recorded at 60 minutes and mortality at 24 hours, 48 hours and 72 hours holding time post-exposure. Fludora Fusion induced 100% An. arabiensis mortality during the first four months post-treated on all surface types at 24 hours holding time post-exposure. Its activity remained over 80% from the fifth to the twelfth month post-treated on the surfaces with the exception of two assessment points, at seventh month and eleventh month, on paint and smooth mud surfaces. FICAM induced 100% mortality rate during the first 4 months and 92% mortality during the fifth month post-treatment on painted surfaces. Its activity was over 96% mortality 1-month post-treatment on smooth mud and rough mud surfaces and 92% mortality 2-month post-treatment on dung surfaces. Clothianidin caused 89% and 86% mortality 1-month post-treatment on smooth mud and rough mud surfaces. Fludora Fusion can be used as alternative indoor residual insecticide spraying against An. arabiensis in Ethiopia.


Subject(s)
Anopheles/drug effects , Guanidines/pharmacology , Neonicotinoids/pharmacology , Nitriles/pharmacology , Phenylcarbamates/pharmacology , Pyrethrins/pharmacology , Thiazoles/pharmacology , Animals , Anopheles/growth & development , Drug Combinations , Ethiopia , Female , Housing , Mosquito Control , Surface Properties , Time Factors
12.
Eur J Pharmacol ; 919: 174795, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-35122868

ABSTRACT

N-methyl-D-aspartate (NMDA) receptors are affected by many pharmaceuticals. In this work, we studied the action of the serine protease inhibitors nafamostat, gabexate and camostat, and an antiprotozoal compound, furamidine, on native NMDA receptors in rat hippocampal pyramidal neurons. Nafamostat, furamidine and gabexate inhibited these receptors with IC50 values of 0.20 ± 0.04, 0.64 ± 0.13 and 16 ± 3 µM, respectively, whereas camostat was ineffective. Nafamostat and furamidine showed voltage-dependent inhibition, while gabexate showed practically voltage-independent inhibition. Nafamostat and furamidine demonstrated tail currents, implying a 'foot-in-the-door' mechanism of action; gabexate did not demonstrate any signs of 'foot-in-the-door' or trapping channel block. Gabexate action was also not competitive, suggesting allosteric inhibition of NMDA receptors. Furamidine and nafamostat are structurally similar to the previously studied diminazene and all three demonstrated a 'foot-in-the-door' mechanism. They have a rather rigid, elongated structures and cannot fold into more compact forms. By contrast, the gabexate molecule can fold, but its folded structure differs drastically from that of typical NMDA receptor blockers, in agreement with its voltage-independent inhibition. These findings provide a better understanding of the structural determinants of NMDA receptor antagonism, while also supporting the potential clinical repurposing of these drugs as neuroprotectors for glaucoma and other neurodegenerative diseases.


Subject(s)
Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Serine Proteinase Inhibitors/pharmacology , Animals , Benzamidines/pharmacology , Benzamidines/therapeutic use , Drug Repositioning , Esters/pharmacology , Esters/therapeutic use , Gabexate/pharmacology , Gabexate/therapeutic use , Guanidines/pharmacology , Guanidines/therapeutic use , Hippocampus/drug effects , Inhibitory Concentration 50 , Male , Models, Animal , Neurodegenerative Diseases/drug therapy , Pyramidal Cells/drug effects , Rats , Rats, Wistar , Serine Proteinase Inhibitors/therapeutic use
13.
Life Sci Alliance ; 5(4)2022 04.
Article in English | MEDLINE | ID: mdl-35110354

ABSTRACT

BACKGROUND: There are limited effective prophylactic/early treatments for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Viral entry requires spike protein binding to the angiotensin-converting enzyme-2 receptor and cleavage by transmembrane serine protease 2 (TMPRSS2), a cell surface serine protease. Targeting of TMPRSS2 by either androgen blockade or direct inhibition is in clinical trials in early SARS-CoV-2 infection. METHODS: We used differentiated primary human airway epithelial cells at the air-liquid interface to test the impact of targeting TMPRSS2 on the prevention of SARS-CoV-2 infection. RESULTS: We first modelled the systemic delivery of compounds. Enzalutamide, an oral androgen receptor antagonist, had no impact on SARS-CoV-2 infection. By contrast, camostat mesylate, an orally available serine protease inhibitor, blocked SARS-CoV-2 entry. However, oral camostat is rapidly metabolised in the circulation, with poor airway bioavailability. We therefore modelled local airway administration by applying camostat to the apical surface of differentiated airway cultures. We demonstrated that a brief exposure to topical camostat effectively restricts SARS-CoV-2 infection. CONCLUSION: These experiments demonstrate a potential therapeutic role for topical camostat for pre- or post-exposure prophylaxis of SARS-CoV-2, which can now be evaluated in a clinical trial.


Subject(s)
Respiratory Mucosa/drug effects , Respiratory Mucosa/metabolism , Respiratory Mucosa/virology , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/administration & dosage , Administration, Topical , Androgens/metabolism , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/pharmacology , COVID-19/prevention & control , COVID-19/virology , Cells, Cultured , Epithelial Cells , Esters/pharmacology , Gene Expression , Goblet Cells/immunology , Goblet Cells/metabolism , Guanidines/pharmacology , Host-Pathogen Interactions/drug effects , Humans , Serine Endopeptidases/genetics , Signal Transduction , Virus Internalization/drug effects , Virus Replication/drug effects
14.
Stem Cell Reports ; 17(2): 307-320, 2022 02 08.
Article in English | MEDLINE | ID: mdl-35063125

ABSTRACT

Neurological complications are common in COVID-19. Although SARS-CoV-2 has been detected in patients' brain tissues, its entry routes and resulting consequences are not well understood. Here, we show a pronounced upregulation of interferon signaling pathways of the neurovascular unit in fatal COVID-19. By investigating the susceptibility of human induced pluripotent stem cell (hiPSC)-derived brain capillary endothelial-like cells (BCECs) to SARS-CoV-2 infection, we found that BCECs were infected and recapitulated transcriptional changes detected in vivo. While BCECs were not compromised in their paracellular tightness, we found SARS-CoV-2 in the basolateral compartment in transwell assays after apical infection, suggesting active replication and transcellular transport of virus across the blood-brain barrier (BBB) in vitro. Moreover, entry of SARS-CoV-2 into BCECs could be reduced by anti-spike-, anti-angiotensin-converting enzyme 2 (ACE2)-, and anti-neuropilin-1 (NRP1)-specific antibodies or the transmembrane protease serine subtype 2 (TMPRSS2) inhibitor nafamostat. Together, our data provide strong support for SARS-CoV-2 brain entry across the BBB resulting in increased interferon signaling.


Subject(s)
Blood-Brain Barrier/virology , Central Nervous System/virology , SARS-CoV-2/physiology , Virus Internalization , Antibodies/pharmacology , Benzamidines/pharmacology , COVID-19/pathology , COVID-19/virology , Endothelial Cells/cytology , Endothelial Cells/metabolism , Endothelial Cells/virology , Guanidines/pharmacology , Humans , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/metabolism , Models, Biological , RNA, Viral/metabolism , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Virus Internalization/drug effects
15.
Int J Mol Sci ; 23(2)2022 Jan 10.
Article in English | MEDLINE | ID: mdl-35054915

ABSTRACT

The choice of effective biocides used for routine hospital practice should consider the role of disinfectants in the maintenance and development of local resistome and how they might affect antibiotic resistance gene transfer within the hospital microbial population. Currently, there is little understanding of how different biocides contribute to eDNA release that may contribute to gene transfer and subsequent environmental retention. Here, we investigated how different biocides affect the release of eDNA from mature biofilms of two opportunistic model strains Pseudomonas aeruginosa ATCC 27853 (PA) and Staphylococcus aureus ATCC 25923 (SA) and contribute to the hospital resistome in the form of surface and water contaminants and dust particles. The effect of four groups of biocides, alcohols, hydrogen peroxide, quaternary ammonium compounds, and the polymeric biocide polyhexamethylene guanidine hydrochloride (PHMG-Cl), was evaluated using PA and SA biofilms. Most biocides, except for PHMG-Cl and 70% ethanol, caused substantial eDNA release, and PHMG-Cl was found to block biofilm development when used at concentrations of 0.5% and 0.1%. This might be associated with the formation of DNA-PHMG-Cl complexes as PHMG-Cl is predicted to bind to AT base pairs by molecular docking assays. PHMG-Cl was found to bind high-molecular DNA and plasmid DNA and continued to inactivate DNA on surfaces even after 4 weeks. PHMG-Cl also effectively inactivated biofilm-associated antibiotic resistance gene eDNA released by a pan-drug-resistant Klebsiella strain, which demonstrates the potential of a polymeric biocide as a new surface-active agent to combat the spread of antibiotic resistance in hospital settings.


Subject(s)
Anti-Infective Agents/pharmacology , Biofilms/drug effects , DNA, Bacterial/drug effects , Disinfectants/pharmacology , Guanidines/pharmacology , Anti-Infective Agents/chemical synthesis , Anti-Infective Agents/chemistry , DNA, Bacterial/chemistry , Disinfectants/chemistry , Guanidines/chemical synthesis , Guanidines/chemistry , Nucleic Acid Conformation/drug effects , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Structure-Activity Relationship
16.
Biomed Res Int ; 2022: 1558860, 2022.
Article in English | MEDLINE | ID: mdl-35039793

ABSTRACT

Increasing outbreaks of new pathogenic viruses have promoted the exploration of novel alternatives to time-consuming vaccines. Thus, it is necessary to develop a universal approach to halt the spread of new and unknown viruses as they are discovered. One such promising approach is to target lipid membranes, which are common to all viruses and bacteria. The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has reaffirmed the importance of interactions between the virus envelope and the host cell plasma membrane as a critical mechanism of infection. Metadichol®, a nanolipid emulsion of long-chain alcohols, has been demonstrated as a strong candidate that inhibits the proliferation of SARS-CoV-2. Naturally derived substances, such as long-chain saturated lipid alcohols, reduce viral infectivity, including that of coronaviruses (such as SARS-CoV-2) by modifying their lipid-dependent attachment mechanism to human host cells. The receptor ACE2 mediates the entry of SARS-CoV-2 into the host cells, whereas the serine protease TMPRSS2 primes the viral S protein. In this study, Metadichol® was found to be 270 times more potent an inhibitor of TMPRSS2 (EC50 = 96 ng/mL) than camostat mesylate (EC50 = 26000 ng/mL). Additionally, it inhibits ACE with an EC50 of 71 ng/mL, but it is a very weak inhibitor of ACE2 at an EC50 of 31 µg/mL. Furthermore, the live viral assay performed in Caco-2 cells revealed that Metadichol® inhibits SARS-CoV-2 replication at an EC90 of 0.16 µg/mL. Moreover, Metadichol® had an EC90 of 0.00037 µM, making it 2081 and 3371 times more potent than remdesivir (EC50 = 0.77 µM) and chloroquine (EC50 = 1.14 µM), respectively.


Subject(s)
Fatty Alcohols/pharmacology , SARS-CoV-2/drug effects , Viruses/drug effects , Animals , Antiviral Agents/pharmacology , COVID-19/drug therapy , Cell Line , Chlorocebus aethiops , Esters/pharmacology , Guanidines/pharmacology , Humans , Lipid Metabolism/physiology , Lipids/chemistry , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Serine Endopeptidases/drug effects , Serine Endopeptidases/metabolism , Serine Proteases/metabolism , Serine Proteinase Inhibitors/pharmacology , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Virus Attachment/drug effects , Virus Internalization/drug effects
17.
Chem Biodivers ; 19(3): e202100839, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35037382

ABSTRACT

To discover novel pesticide candidates, a series of sulfoximine derivatives were designed and synthesized via the oxidation coupling reaction of sulfides and N-alkyl nitroguanidines. The compounds were evaluated for their antifungal activity against six phytopathogenic fungi. Most of them exhibited a broad spectrum of fungicidal activity in vitro. Compound 8IV-b displayed good fungicidal activity against Sclerotinia sclerotiorum, Rhizoctonia solani, Botrytis cinerea, Fusarium graminearum, and Phytophthora capsici, with EC50 value of 12.82, 12.50, 17.25, 31.08, and 30.11 mg/L, respectively. In addition, compounds 8III-c and 8IV-e had EC50 values of 22.23 and 20.67 mg/L against P. capsic, which were significantly better than that of the commercial procymidone (118.15 mg/L). Strikingly, 8IV-d exhibited satisfactory fungicidal activity against B. cinerea, which was comparable to control procymidone in terms of their EC50 values (7.42 versus 10.83 mg/L), and the bioassays in vivo further confirmed that 8IV-d possessed potent protective effect against B. cinerea at 200 mg/L (72.2 %). These present findings will facilitate the design and development of novel potent fungicides.


Subject(s)
Antifungal Agents , Fungicides, Industrial , Antifungal Agents/pharmacology , Botrytis , Fungicides, Industrial/pharmacology , Guanidines/pharmacology , Structure-Activity Relationship
18.
J Neuroinflammation ; 19(1): 8, 2022 Jan 06.
Article in English | MEDLINE | ID: mdl-34991643

ABSTRACT

BACKGROUND: The serine protease inhibitor nafamostat has been proposed as a treatment for COVID-19, by inhibiting TMPRSS2-mediated viral cell entry. Nafamostat has been shown to have other, immunomodulatory effects, which may be beneficial for treatment, however animal models of ssRNA virus infection are lacking. In this study, we examined the potential of the dual TLR7/8 agonist R848 to mimic the host response to an ssRNA virus infection and the associated behavioural response. In addition, we evaluated the anti-inflammatory effects of nafamostat in this model. METHODS: CD-1 mice received an intraperitoneal injection of R848 (200 µg, prepared in DMSO, diluted 1:10 in saline) or diluted DMSO alone, and an intravenous injection of either nafamostat (100 µL, 3 mg/kg in 5% dextrose) or 5% dextrose alone. Sickness behaviour was determined by temperature, food intake, sucrose preference test, open field and forced swim test. Blood and fresh liver, lung and brain were collected 6 h post-challenge to measure markers of peripheral and central inflammation by blood analysis, immunohistochemistry and qPCR. RESULTS: R848 induced a robust inflammatory response, as evidenced by increased expression of TNF, IFN-γ, CXCL1 and CXCL10 in the liver, lung and brain, as well as a sickness behaviour phenotype. Exogenous administration of nafamostat suppressed the hepatic inflammatory response, significantly reducing TNF and IFN-γ expression, but had no effect on lung or brain cytokine production. R848 administration depleted circulating leukocytes, which was restored by nafamostat treatment. CONCLUSIONS: Our data indicate that R848 administration provides a useful model of ssRNA virus infection, which induces inflammation in the periphery and CNS, and virus infection-like illness. In turn, we show that nafamostat has a systemic anti-inflammatory effect in the presence of the TLR7/8 agonist. Therefore, the results indicate that nafamostat has anti-inflammatory actions, beyond its ability to inhibit TMPRSS2, that might potentiate its anti-viral actions in pathologies such as COVID-19.


Subject(s)
Benzamidines , Guanidines , Inflammation/drug therapy , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors , Toll-Like Receptor 7/immunology , Virus Diseases/drug therapy , Animals , Benzamidines/pharmacology , Benzamidines/therapeutic use , COVID-19/complications , COVID-19/drug therapy , Guanidines/pharmacology , Guanidines/therapeutic use , Illness Behavior/drug effects , Imidazoles/administration & dosage , Imidazoles/immunology , Inflammation/metabolism , Inflammation/virology , Male , Mice , Serine Proteinase Inhibitors/pharmacology , Serine Proteinase Inhibitors/therapeutic use , Toll-Like Receptor 7/agonists , Virus Diseases/metabolism , Virus Diseases/virology
19.
PLoS One ; 17(1): e0262233, 2022.
Article in English | MEDLINE | ID: mdl-34986201

ABSTRACT

The micro- and macro-complications in diabetes mellitus (DM) mainly arise from the damage induced by Amadori and advanced glycation end products, as well as the released free radicals. The primary goal of DM treatment is to reduce the risk of micro- and macro-complications. In this study, we looked at the efficacy of aminoguanidine (AG) to prevent the production of early glycation products in alloxan-diabetic rabbits. Type1 DM was induced in rabbits by a single intravenous injection of alloxan (90 mg/kg body weight). Another group of rabbits was pre-treated with AG (100 mg/kg body weight) prior to alloxan injection; this was followed by weekly treatment with 100 mg/kg of AG for eight weeks. Glucose, insulin, and early glycation products (HbA1C and fructosamine) were measured in control, diabetic and AG treated diabetic rabbits. The effects of hyperglycemia on superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx), reduced glutathione (rGSH), nitric oxide, lipid peroxides, and protein carbonyl were investigated. Alloxan-diabetic rabbits had lower levels of SOD, CAT, Gpx, and rGSH than control rabbits. Nitric oxide levels were considerably greater. AG administration restored the activities of SOD, CAT, Gpx enzymes up to 70-80% and ameliorated the nitric oxide production. HbA1c and fructosamine levels were considerably lower in AG-treated diabetic rabbits. The observed control of hyperglycemia and amadori adducts in alloxan-diabetic rabbits by AG may be attributed to decrease of stress and restoration of antioxidant defenses.


Subject(s)
Antioxidants/administration & dosage , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 1/drug therapy , Guanidines/administration & dosage , Hyperglycemia/drug therapy , Alloxan , Animals , Antioxidants/pharmacology , Case-Control Studies , Catalase/metabolism , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 1/chemically induced , Diabetes Mellitus, Type 1/metabolism , Drug Administration Schedule , Gene Expression Regulation/drug effects , Glutathione/metabolism , Glutathione Peroxidase/metabolism , Guanidines/pharmacology , Hyperglycemia/chemically induced , Hyperglycemia/metabolism , Lipid Peroxidation/drug effects , Nitric Oxide/metabolism , Oxidative Stress/drug effects , Rabbits , Superoxide Dismutase/metabolism
20.
Emerg Microbes Infect ; 11(1): 277-283, 2022 Dec.
Article in English | MEDLINE | ID: mdl-34951565

ABSTRACT

The novel SARS-CoV-2 Omicron variant (B.1.1.529), first found in early November 2021, has sparked considerable global concern and it has >50 mutations, many of which are known to affect transmissibility or cause immune escape. In this study, we sought to investigate the virological characteristics of the Omicron variant and compared it with the Delta variant which has dominated the world since mid-2021. Omicron variant replicated more slowly than the Delta variant in transmembrane serine protease 2 (TMPRSS2)-overexpressing VeroE6 (VeroE6/TMPRSS2) cells. Notably, the Delta variant replicated well in Calu3 cell line which has robust TMPRSS2 expression, while the Omicron variant replicated poorly in this cell line. Competition assay showed that Delta variant outcompeted Omicron variant in VeroE6/TMPRSS2 and Calu3 cells. To confirm the difference in entry pathway between the Omicron and Delta variants, we assessed the antiviral effect of bafilomycin A1, chloroquine (inhibiting endocytic pathway), and camostat (inhibiting TMPRSS2 pathway). Camostat potently inhibited the Delta variant but not the Omicron variant, while bafilomycin A1 and chloroquine could inhibit both Omicron and Delta variants. Moreover, the Omicron variant also showed weaker cell-cell fusion activity when compared with Delta variant in VeroE6/TMPRSS2 cells. Collectively, our results suggest that Omicron variant infection is not enhanced by TMPRSS2 but is largely mediated via the endocytic pathway. The difference in entry pathway between Omicron and Delta variants may have an implication on the clinical manifestations or disease severity.


Subject(s)
COVID-19/virology , SARS-CoV-2/physiology , Serine Endopeptidases/metabolism , Virus Internalization , Virus Replication , Animals , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Chlorocebus aethiops , Chloroquine/pharmacology , Endocytosis/drug effects , Esters/pharmacology , Guanidines/pharmacology , Humans , Immune Evasion , Lung Neoplasms/pathology , Macrolides/pharmacology , Recombinant Proteins/metabolism , SARS-CoV-2/genetics , Vero Cells , Virus Cultivation , Virus Internalization/drug effects , Whole Genome Sequencing
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