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Natural Products and Bioprospecting Nov 2023L-Palmitoylcarnitine (L-PC) is an important endogenous fatty acid metabolite. Its classical biological functions are involved in the regulations of membrane molecular...
L-Palmitoylcarnitine (L-PC) is an important endogenous fatty acid metabolite. Its classical biological functions are involved in the regulations of membrane molecular dynamics and the β-oxidation of fatty acids. Decreased plasma long-chain acylcarnitines showed the association of venous thrombosis, implying anticoagulant activity of the metabolites and inspiring us to investigate if and how L-PC, a long-chain acylcarnitine, takes part in coagulation. Here we show that L-PC exerted anti-coagulant effects by potentiating the enzymatic activities of plasmin and tissue plasminogen activator (tPA). L-PC directly interacts with plasmin and tPA with an equilibrium dissociation constant (KD) of 6.47 × 10 and 4.46 × 10 M, respectively, showing high affinities. In mouse model, L-PC administration significantly inhibited FeCl-induced arterial thrombosis. It also mitigated intracerebral thrombosis and inflammation in a transient middle cerebral artery occlusion (tMCAO) mouse model. L-PC induced little bleeding complications. The results show that L-PC has anti-thrombotic function by potentiating plasmin and tPA.
PubMed: 37938456
DOI: 10.1007/s13659-023-00413-z -
Frontiers in Allergy 2023Amylase trypsin inhibitors (ATIs) play an important role in wheat allergies and potentially in non-coeliac wheat sensitivity. Food processing could be important to... (Review)
Review
Amylase trypsin inhibitors (ATIs) play an important role in wheat allergies and potentially in non-coeliac wheat sensitivity. Food processing could be important to mitigate the pathogenic properties of ATIs, e.g., by denaturation, glycation, enzymatic hydrolysis, cross-linking, and oxidation and reduction. These modifications also impact the solubility and extractability. The complex solubility behaviour of ATI isoforms (water and salt soluble, but also chloroform-methanol soluble, solubility depending on the redox state) becomes even more complex upon processing due to denaturation and (bio)chemical modifications. This significantly hinders the feasibility of quantitative extraction. Moreover, changes in biofunctionality may occur during the process of extraction, and the changes in ATI due to food processing will be more difficult to assess. Heat treatment decreases the extractability of ATIs with water, NaCl, and other buffer extracts, and binding of IgE from wheat-allergic persons to ATIs as observed with Western blotting is decreased or absent. IgE binding is reduced with the total extract in chaotropic and reducing agents. However, it can be increased when the proteins are hydrolyzed by proteases. Fermentation involving certain species of (FLB), followed by baking, decreases the amount of ATIs and IgE binding to ATIs. In yeast-fermented bread, the amount of ATIs decreased in a similar manner, but IgE binding was more prominent, indicating that there was a modification of ATIs that affected the epitope recognition. When isolated ATIs are ingested with high ATI degrading FLB, the immune response in mice is less elevated , when compared with ATI without high ATI degrading FLB. The pathogenic effects on the skin of dogs and one wheat-allergic child are also decreased when soluble proteins or isolated ATIs are reduced with the thioredoxin/thioredoxin reductase NADPH system. Glycation on the other hand has been shown to potentiate the allergenic properties of ATIs as evidenced by the large increase in IgE binding. The impact of food processing on the pathogenic properties of ATIs is hardly studied in humans. There seem to be opportunities to mitigate the pathogenic properties , but potentiation of pathogenic properties is also frequently observed. This requires a deeper understanding on the impact of food processing on the pathogenicity of ATIs.
PubMed: 38075395
DOI: 10.3389/falgy.2023.1228353 -
Journal of Cystic Fibrosis : Official... Mar 2020The treatment of cystic fibrosis (CF) has been transformed by orally-bioavailable small molecule modulators of the cystic fibrosis transmembrane conductance regulator... (Review)
Review
The treatment of cystic fibrosis (CF) has been transformed by orally-bioavailable small molecule modulators of the cystic fibrosis transmembrane conductance regulator (CFTR), which restore function to CF mutants. However, CFTR modulators are not available to all people with CF and better modulators are required to prevent disease progression. Here, we review selectively recent advances in CFTR folding, function and pharmacology. We highlight ensemble and single-molecule studies of CFTR folding, which provide new insight into CFTR assembly, its perturbation by CF mutations and rescue by CFTR modulators. We discuss species-dependent differences in the action of the F508del-CFTR mutation on CFTR expression, stability and function, which might influence pharmacological studies of CFTR modulators in CF animal models. Finally, we illuminate the identification of combinations of two CFTR potentiators (termed co-potentiators), which restore therapeutically-relevant levels of CFTR activity to rare CF mutations. Thus, mechanistic studies of CFTR folding, function and pharmacology inform the development of highly effective CFTR modulators.
Topics: Animals; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Humans; Membrane Transport Modulators; Molecular Medicine; Molecular Targeted Therapy; Mutation; Pharmacogenomic Testing
PubMed: 31902693
DOI: 10.1016/j.jcf.2019.12.009 -
Antibiotics (Basel, Switzerland) Jan 2021Tuberculosis (TB) remains a global health emergency, with an estimated 2 billion people infected across the world, and 1.4 million people dying to this disease every... (Review)
Review
Tuberculosis (TB) remains a global health emergency, with an estimated 2 billion people infected across the world, and 1.4 million people dying to this disease every year. Many aspects of the causative agent, , make this disease difficult for healthcare and laboratory researchers to fight against, such as unique pathophysiology, latent infection and long and complex treatment regimens, thus causing patient non-compliance with the treatment. Development of new drugs is critical for tackling these problems. Repurposing drugs is a promising strategy for generating an effective drug treatment whilst circumventing many of the challenges of conventional drug development. In this regard, the incorporation of immunomodulatory drugs into the standard regimen to potentiate frontline drugs is found to be highly appealing. Drugs of diverse chemical classes and drug categories are increasingly being evidenced to possess antitubercular activity, both in vitro and in vivo. This article explores and discusses the molecular entities that have shown promise in being repurposed for use in anti-TB adjunctive therapy and aims to provide the most up-to-date picture of their progress.
PubMed: 33477812
DOI: 10.3390/antibiotics10010091 -
MSphere Oct 2022Escherichia coli is intrinsically resistant to macrolides due to outer membrane impermeability, but may also acquire macrolide resistance genes by horizontal transfer....
Escherichia coli is intrinsically resistant to macrolides due to outer membrane impermeability, but may also acquire macrolide resistance genes by horizontal transfer. We evaluated the prevalence and types of acquired macrolide resistance determinants in pig clinical E. coli, and we assessed the ability of peptidomimetics to potentiate different macrolide subclasses against strains resistant to neomycin, a first-line antibiotic in the treatment of pig-enteric infections. The erythromycin MIC distribution was determined in 324 pig clinical E. coli isolates, and 62 neomycin-resistant isolates were further characterized by genome sequencing and MIC testing of azithromycin, spiramycin, tilmicosin, and tylosin. The impact on potency achieved by combining these macrolides with three selected peptidomimetic compounds was determined by checkerboard assays in six strains representing different genetic lineages and macrolide resistance gene profiles. Erythromycin MICs ranged from 16 to >1,024 μg/mL. Azithromycin showed the highest potency in wild-type strains (1 to 8 μg/mL), followed by erythromycin (16 to 128 μg/mL), tilmicosin (32 to 256 μg/mL), and spiramycin (128 to 256 μg/mL). Isolates with elevated MIC mainly carried (B), either alone or in combination with other acquired macrolide resistance genes, including (42), (C), (A), (B), and (G). All peptidomimetic-macrolide combinations exhibited synergy (fractional inhibitory concentration index [FICI] < 0.5) with a 4- to 32-fold decrease in the MICs of macrolides. Interestingly, the MICs of tilmicosin in wild-type strains were reduced to concentrations (4 to 16 μg/mL) that can be achieved in the pig intestinal tract after oral administration, indicating that peptidomimetics can potentially be employed for repurposing tilmicosin in the management of E. coli enteritis in pigs. Acquired macrolide resistance is poorly studied in Escherichia coli because of intrinsic resistance and limited antimicrobial activity in Gram-negative bacteria. This study reveals new information on the prevalence and distribution of macrolide resistance determinants in a comprehensive collection of porcine clinical E. coli from Denmark. Our results contribute to understanding the correlation between genotypic and phenotypic macrolide resistance in E. coli. From a clinical standpoint, our study provides an initial proof of concept that peptidomimetics can resensitize E. coli to macrolide concentrations that may be achieved in the pig intestinal tract after oral administration. The latter result has implications for animal health and potential applications in veterinary antimicrobial drug development in view of the high rates of antimicrobial-resistant E. coli isolated from enteric infections in pigs and the lack of viable alternatives for treating these infections.
Topics: Swine; Animals; Escherichia coli; Anti-Bacterial Agents; Azithromycin; Peptidomimetics; Macrolides; Tylosin; Drug Resistance, Bacterial; Spiramycin; Erythromycin; Escherichia coli Infections; Neomycin
PubMed: 36154672
DOI: 10.1128/msphere.00402-22 -
Pharmaceutics Jun 2023Melatonin is a tryptophan derivative synthesized in plants and animals. In humans, melatonin acts on melatonin MT and MT receptors belonging to the G protein-coupled...
Melatonin is a tryptophan derivative synthesized in plants and animals. In humans, melatonin acts on melatonin MT and MT receptors belonging to the G protein-coupled receptor (GPCR) family. Synthetic melatonin receptor agonists are prescribed for insomnia and depressive and circadian-related disorders. Here, we tested 25 commercial plant extracts, reported to have beneficial properties in sleep disorders and anxiety, using cellular assays (2─[I]iodomelatonin binding, cAMP inhibition, ERK1/2 activation and β-arrestin2 recruitment) in mock-transfected and HEK293 cells expressing MT or MT. Various melatonin receptor-dependent and -independent effects were observed. Extract 18 () from dried fruits stood out with very potent effects in melatonin receptor expressing cells. The high content of endogenous melatonin in (5.28 ± 0.46 mg/g extract) is consistent with this observation. contains an additional active principle that potentiates the effect of melatonin on G protein-dependent pathways but not on β-arrestin2 recruitment. Further active principles potentiating exogenous melatonin were detected in several extracts. In conclusion, we identified plant extracts with various effects in GPCR-based binding and signalling assays and identified high melatonin levels and a melatonin-potentiating activity in dried fruit extracts that might be of therapeutic potential.
PubMed: 37514032
DOI: 10.3390/pharmaceutics15071845 -
Frontiers in Molecular Neuroscience 2023The postsynaptic inhibition through GABA receptors (GABAR) relies on two mechanisms, a shunting effect due to an increase in the postsynaptic membrane conductance and,...
The postsynaptic inhibition through GABA receptors (GABAR) relies on two mechanisms, a shunting effect due to an increase in the postsynaptic membrane conductance and, in mature neurons, a hyperpolarization effect due to an entry of chloride into postsynaptic neurons. The second effect requires the action of the K-Cl cotransporter KCC2 which extrudes Cl from the cell and maintains its cytosolic concentration very low. Neuronal chloride equilibrium seems to be dysregulated in several neurological and psychiatric conditions such as epilepsy, anxiety, schizophrenia, Down syndrome, or Alzheimer's disease. In the present study, we used the KCC2 Cre-lox knockdown system to investigate the role of KCC2 in synaptic plasticity and memory formation in adult mice. Tamoxifen-induced conditional deletion of KCC2 in glutamatergic neurons of the forebrain was performed at 3 months of age and resulted in spatial and nonspatial learning impairment. On brain slices, the stimulation of Schaffer collaterals by a theta burst induced long-term potentiation (LTP). The lack of KCC2 did not affect potentiation of field excitatory postsynaptic potentials (fEPSP) measured in the stratum radiatum (dendrites) but increased population spike (PS) amplitudes measured in the CA1 somatic layer, suggesting a reinforcement of the EPSP-PS potentiation, i.e., an increased ability of EPSPs to generate action potentials. At the cellular level, KCC2 deletion induced a positive shift in the reversal potential of GABAR-driven Cl currents (E), suggesting an intracellular accumulation of chloride subsequent to the downregulation of KCC2. After treatment with bumetanide, an antagonist of the Na-K-Cl cotransporter NKCC1, spatial memory impairment, chloride accumulation, and EPSP-PS potentiation were rescued in mice lacking KCC2. The presented results emphasize the importance of chloride equilibrium and GABA-inhibiting ability in synaptic plasticity and memory formation.
PubMed: 37168681
DOI: 10.3389/fnmol.2023.1081657 -
Methods in Molecular Biology (Clifton,... 2020Oncolytic virus therapy is a rapidly expanding branch of cancer immunotherapy and represents a genuine opportunity to improve currently available treatment options....
Oncolytic virus therapy is a rapidly expanding branch of cancer immunotherapy and represents a genuine opportunity to improve currently available treatment options. However, as single agents oncolytic viruses have shown only moderate clinical benefit and many challenges remain before their full potential is realized. Central to this is the efficient delivery of the virus to the tumor site and potentiation of the antitumor immune response. This chapter describes the loading of oncolytic reovirus onto monocytes which act as carriers for delivery of the virus to the tumor site and, as antigen presenting cells, may also thereby potentiate the development of an adaptive antitumor immune response.
Topics: Animals; Antibodies, Viral; Cell- and Tissue-Based Therapy; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Immunity; Immunoconjugates; Immunomodulation; Leukocytes, Mononuclear; Mice; Neoplasms; Oncolytic Virotherapy; Oncolytic Viruses; Reoviridae; Transduction, Genetic
PubMed: 31486041
DOI: 10.1007/978-1-4939-9794-7_14 -
Targets Involved in the Anti-Cancer Activity of Quercetin in Breast, Colorectal and Liver Neoplasms.International Journal of Molecular... Feb 2023Phytochemicals have long been effective partners in the fight against several diseases, including cancer. Among these, flavonoids are valuable allies for both cancer... (Review)
Review
Phytochemicals have long been effective partners in the fight against several diseases, including cancer. Among these, flavonoids are valuable allies for both cancer prevention and therapy since they are known to influence a large panel of tumor-related processes. Particularly, it was revealed that quercetin, one of the most common flavonoids, controls apoptosis and inhibits migration and proliferation, events essential for the development of cancer. In this review, we collected the evidence on the anti-cancer activity of quercetin exploring the network of interactions between this flavonol and the proteins responsible for cancer onset and progression focusing on breast, colorectal and liver cancers, owing to their high worldwide incidence. Moreover, quercetin proved to be also a potentiating agent able to push further the anti-cancer activity of common employed anti-neoplastic agents, thus allowing to lower their dosages and, above all, to sensitize again resistant cancer cells. Finally, novel approaches to delivery systems can enhance quercetin's pharmacokinetics, thus boosting its great potentiality even further. Overall, quercetin has a lot of promise, given its multi-target potentiality; thus, more research is strongly encouraged to properly define its pharmaco-toxicological profile and evaluate its potential for usage in adjuvant and chemoprevention therapy.
Topics: Humans; Quercetin; Neoplasms; Flavonoids; Flavonols; Liver Neoplasms; Colorectal Neoplasms
PubMed: 36769274
DOI: 10.3390/ijms24032952 -
European Journal of Medicinal Chemistry Nov 2023Multidrug-resistant Escherichia coli is a continuously growing worldwide public health problem, in which the well-known AcrAB-TolC tripartite RND efflux pump is a...
Multidrug-resistant Escherichia coli is a continuously growing worldwide public health problem, in which the well-known AcrAB-TolC tripartite RND efflux pump is a critical driver. We have previously described pyridylpiperazines as a novel class of allosteric inhibitors of E. coli AcrB which bind to a unique site in the protein transmembrane domain, allowing for the potentiation of antibiotic activity. Here, we show a rational optimization of pyridylpiperazines by modifying three specific derivatization points of the pyridine core to improve the potency and the pharmacokinetic properties of this chemical series. In particular, this work found that the introduction of a primary amine to the pyridine through ester (29, BDM91270) or oxadiazole (44, BDM91514) based linkers allowed for analogues with improved antibiotic boosting potency through AcrB inhibition. In vitro studies, using genetically engineered mutants, showed that this improvement in potency is mediated through novel interactions with distal acidic residues of the AcrB binding pocket. Of the two leads, compound 44 was found to have favorable physico-chemical properties and suitable plasma and microsomal stability. Together, this work expands the current structure-activity relationship data on pyridylpiperazine efflux pump inhibitors, and provides a promising step towards future in vivo proof of concept of pyridylpiperazines as antibiotic potentiators.
Topics: Escherichia coli; Escherichia coli Proteins; Anti-Bacterial Agents; Pyridines; Multidrug Resistance-Associated Proteins; Carrier Proteins
PubMed: 37459793
DOI: 10.1016/j.ejmech.2023.115630