RESUMO
Adipose tissue is an important source of adipokines involved in anti- and pro-inflammatory effects. Their involvement in certain cancers such as breast and colon cancer is known but in gliomas it remains unexplored till date. The aim of this study was to assess the status of adipokines as prognostic markers of gliomas (low grade gliomas [LGG] and glioblastoma mutiforme [GBM]). Expression status (messenger RNA [mRNA]), overall survival (OS) and disease-free survival (DFS) was identified using gene expression profiling interactive analysis server. Clinicopathological analysis and correlation between different adipokines was performed using Xena server. Protein expression status was analyzed using tissue sections from the Human Protein Atlas. Out of 11 adipokines studied visfatin (NAMPT), apelin (APLN), granulin (GRN), serpin peptidase inhibitor/plasminogen activator inhibitor type 1 (PAI-1) member 1 (SERPINE1), and chemokine (C-C motif) ligand 2 (CCL2) mRNA levels were significantly upregulated in both LGG and GBM. Interleukin 6 (IL6) mRNA was found be significantly upregulated only in GBM. NAMPT, GRN, SERPINE1, and IL6 showed reduced OS as well as worst DFS for patients having higher mRNA expression in LGG. Increased expression of CCL2 showed worst OS in LGG patients while resistin (RETN) and GRN showed the worst OS in GBM patients. Higher expression of RETN, GRN, IL6, SERPINE1, and CCL2 were found to be positively correlated with shorter DFS in GBM. In the clinicopathological analysis, NAMPT, GRN, IL6, SERPINE1, and CCL2 expressions were significantly associated between the neoplasm histological G2 and G3 grades. Furthermore, expression of NAMPT, GRN, tumor necrosis factor, IL6, SERPINE1, and CCL2 were significantly associated with histological type in LGG patients. NAMPT, GRN, SERPINE1, CCL2, and RETN expression were found to be correlated with each other in gliomas. Finally, NAMPT, GRN, and SERPINE1 were also found to be upregulated using immunohistochemistry in a lower grade and high grade gliomas as compared to normal cells. In conclusion, we have identified key adipokines, namely NAMPT, GRN, and SERPINE1 as potential diagnostic and prognostic markers that might be instrumental in the development and progression of gliomas.
Assuntos
Neoplasias Encefálicas/metabolismo , Citocinas/metabolismo , Glioblastoma/metabolismo , Glioma/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Progranulinas/metabolismo , Adipocinas/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/mortalidade , Sobrevivência Celular , Progressão da Doença , Intervalo Livre de Doença , Feminino , Perfilação da Expressão Gênica , Glioblastoma/diagnóstico , Glioblastoma/mortalidade , Glioma/diagnóstico , Glioma/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/genética , Prognóstico , RNA Mensageiro/metabolismo , Resultado do Tratamento , Adulto JovemRESUMO
Diphenyl ether derivatives inhibit mycobacterial cell wall synthesis by inhibiting an enzyme, enoyl-acyl carrier protein reductase (InhA), which catalyses the last step in the fatty acid synthesis cycle of genus Mycobacterium. To select and validate a protein crystal structure of enoyl-acyl carrier protein reductase of Mycobacterium tuberculosis for designing inhibitors using molecular modelling, a cross-docking and correlation study was performed. A series of novel 1-(3-(3-hydroxy-4-phenoxyphenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl) ethan-1-ones were synthesized from this model and screened for their antitubercular activity against M. tuberculosis H37Rv. Compound PYN-8 showed good antitubercular activity on M. tuberculosis H37Rv (MIC = 4-7 µM) and Mycobacterium bovis (% inhibition at 10 µM = 95.91%). Cytotoxicity of all the synthesized derivatives was assessed using various cell lines, and they were found to be safe. Structure of PYN-8 was also confirmed by single-crystal X-ray diffraction. The molecular modelling studies also corroborated the biological activity of the compounds. Further, in silico findings revealed that all these tested compounds exhibited good ADME properties and drug likeness and thus may be considered as potential candidates for further drug development.
Assuntos
Antituberculosos/síntese química , Antituberculosos/farmacologia , Éteres Fenílicos/síntese química , Éteres Fenílicos/farmacologia , Tuberculose/tratamento farmacológico , Proteínas de Bactérias/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Simulação por Computador , Cristalografia por Raios X , Desenho de Fármacos , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Testes de Sensibilidade Microbiana/métodos , Simulação de Acoplamento Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Células PC-3 , Relação Estrutura-Atividade , Tuberculose/metabolismoRESUMO
A new series of novel triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether) analogues were designed, synthesized, and screened for their in vitro antimycobacterial and antibacterial activities. Most of the compounds showed significant activity against Mycobacterium tuberculosis H37Rv strain with minimum inhibitory concentration (MIC) values in 20-40 µM range in GAST/Fe medium when compared with triclosan (43 µM) in the first week of assay, and after additional incubation, seven compounds, that is, 2a, 2c, 2g, 2h, 2i, 2j, and 2m, exhibited MIC values at the concentration of 20-40 µM. The compounds also showed more significant activity against Bacillus subtilis and Staphylococcus aureus. The synthesized compounds showed druggable properties, and the predicted ADME (absorption, distribution, metabolism, and excretion) properties were within the acceptable limits. The in silico studies predicted better interactions of compounds with target protein residues and a higher dock score in comparison with triclosan. Molecular dynamics simulation study of the most active compound 2i was performed in order to further explore the stability of the protein-ligand complex and the protein-ligand interaction in detail.
Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Triclosan/farmacologia , Aminas/síntese química , Aminas/química , Aminas/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antituberculosos/síntese química , Antituberculosos/química , Bacillus subtilis/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Triclosan/análogos & derivados , Triclosan/químicaRESUMO
C4-phenylthio ß-lactams are a new family of antibacterial agents that have activity against two phylogenetically distant bacteria - Mycobacterium tuberculosis (Mtb) and Moraxella catarrhalis (M. cat). These compounds are effective against ß-lactamase producing Mtb and M. cat unlike the clinically relevant ß-lactam antibiotics. The structure-activity relationship for the C4 phenylthio ß-lactams has not yet been completely defined. Earlier efforts in our laboratories established that the C4-phenylthio substituent is essential for antimicrobial activity, while the N1 carbamyl substituent plays a more subtle role. In this present study, we investigated the role that the stereochemistry at C4 plays in these compounds' antibacterial activity. This was achieved by synthesizing and testing the antimicrobial activity of diastereomers with a chiral carbamyl group at N1. Our findings indicate that a strict stereochemistry for the C4-phenylthio ß-lactams is not required to obtain optimal anti-Mtb and anti-M. cat activity. Furthermore, the structure-bioactivity profiles more closely relate to the electronic requirement of the phenylthiogroup. In addition, the MICs of Mtb are sensitive to growth medium composition. Select compounds showed activity against non-replicating and multi-drug resistant Mtb.
Assuntos
Antibacterianos/farmacologia , Moraxella catarrhalis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Compostos de Sulfidrila/farmacologia , beta-Lactamas/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Moraxella catarrhalis/crescimento & desenvolvimento , Mycobacterium tuberculosis/crescimento & desenvolvimento , Relação Estrutura-Atividade , Compostos de Sulfidrila/síntese química , Compostos de Sulfidrila/química , beta-Lactamas/síntese química , beta-Lactamas/químicaRESUMO
We deleted subunits I (cydA) and II (cydB) of the Mycobacterium tuberculosis cytochrome bd menaquinol oxidase. The resulting ΔcydA and ΔcydAB mutants were hypersusceptible to compounds targeting the mycobacterial bc1 menaquinol-cytochrome c oxidoreductase and exhibited bioenergetic profiles indistinguishable from strains deficient in the ABC-type transporter, CydDC, predicted to be essential for cytochrome bd assembly. These results confirm CydAB and CydDC as potential targets for drugs aimed at inhibiting a terminal respiratory oxidase implicated in pathogenesis.
Assuntos
Citocromos c/efeitos dos fármacos , Complexo IV da Cadeia de Transporte de Elétrons/efeitos dos fármacos , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Antituberculosos/farmacologia , Descoberta de Drogas , Genoma Bacteriano/genética , Testes de Sensibilidade Microbiana , Fosforilação Oxidativa/efeitos dos fármacos , Oxigênio/metabolismo , Consumo de Oxigênio/genética , Deleção de Sequência/genéticaRESUMO
Several derivatives of aminobenzoboroxole have been prepared starting from 2-boronobenzaldehyde. All of these derivatives have been evaluated for their anti-mycobacterial activity on Mycobacterium smegmatis and cytotoxicity on breast cancer cell line MCF7. Based on these studies, all the tested molecules have been found to be generally non-toxic and benzoboroxoles with unsubstituted (primary) amines have been found to exhibit good anti-mycobacterial activity. Some of the key compounds have been evaluated for their anti-tubercular activity on Mycobacterium tuberculosis H37Rv using 7H9 and GAST media. 7-Bromo-6-aminobenzoboroxole 4 has been identified as the lead candidate compound for further development.
RESUMO
The prevalence of drug resistance in both clinical and community settings as a consequence of alterations of biosynthetic pathways, enzymes or cell wall architecture is a persistent threat to human health. We have designed, synthesized, and tested a novel class of non-transpeptidase, ß-lactamase resistant monocyclic ß-lactams that carry an arylthio group at C4. These thioethers exhibit inhibitory and cidal activity against serine ß-lactamase producing Mycobacterium tuberculosis wild type strain (Mtb) and multiple (n=8) ß-lactamase producing Moraxella catarrhalis clinical isolates.
Assuntos
Antibacterianos/farmacologia , Moraxella catarrhalis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , beta-Lactamas/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/enzimologia , Mycobacterium tuberculosis/enzimologia , beta-Lactamas/química , beta-Lactamas/metabolismoRESUMO
We report here a series of five chemically diverse scaffolds that have in vitro activities on replicating and hypoxic nonreplicating bacilli by targeting the respiratory bc1 complex in Mycobacterium tuberculosis in a strain-dependent manner. Deletion of the cytochrome bd oxidase generated a hypersusceptible mutant in which resistance was acquired by a mutation in qcrB. These results highlight the promiscuity of the bc1 complex and the risk of targeting energy metabolism with new drugs.
Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Complexo IV da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Sítios de Ligação , Transporte de Elétrons/efeitos dos fármacos , Complexo IV da Cadeia de Transporte de Elétrons/genética , Metabolismo Energético/efeitos dos fármacos , Técnicas de Inativação de Genes , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/genética , Oxazinas/química , Estrutura Terciária de Proteína , Piridinas/farmacologia , Xantenos/químicaRESUMO
Linezolid is a drug with proven human antitubercular activity whose use is limited to highly drug-resistant patients because of its toxicity. This toxicity is related to its mechanism of actionâlinezolid inhibits protein synthesis in both bacteria and eukaryotic mitochondria. A highly selective and potent series of oxazolidinones, bearing a 5-aminomethyl moiety (in place of the typical 5-acetamidomethyl moiety of linezolid), was identified. Linezolid-resistant mutants were cross-resistant to these molecules but not vice versa. Resistance to the 5-aminomethyl molecules mapped to an N-acetyl transferase (Rv0133) and these mutants remained fully linezolid susceptible. Purified Rv0133 was shown to catalyze the transformation of the 5-aminomethyl oxazolidinones to their corresponding N-acetylated metabolites, and this transformation was also observed in live cells of Mycobacterium tuberculosis. Mammalian mitochondria, which lack an appropriate N-acetyltransferase to activate these prodrugs, were not susceptible to inhibition with the 5-aminomethyl analogues. Several compounds that were more potent than linezolid were taken into C3HeB/FeJ mice and were shown to be highly efficacious, and one of these (9) was additionally taken into marmosets and found to be highly active. Penetration of these 5-aminomethyl oxazolidinone prodrugs into caseum was excellent. Unfortunately, these compounds were rapidly converted into the corresponding 5-alcohols by mammalian metabolism which retained antimycobacterial activity but resulted in substantial mitotoxicity.
Assuntos
Antituberculosos , Mycobacterium tuberculosis , Oxazolidinonas , Pró-Fármacos , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Antituberculosos/farmacologia , Antituberculosos/química , Mycobacterium tuberculosis/efeitos dos fármacos , Oxazolidinonas/farmacologia , Oxazolidinonas/química , Animais , Testes de Sensibilidade Microbiana , Camundongos , Humanos , Linezolida/farmacologia , Linezolida/química , Farmacorresistência Bacteriana , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismoRESUMO
Carbapenems such as meropenem are being investigated for their potential therapeutic utility against highly drug-resistant tuberculosis. These ß-lactams target the transpeptidases that introduce interpeptide cross-links into bacterial peptidoglycan thereby controlling rigidity of the bacterial envelope. Treatment of Mycobacterium tuberculosis (Mtb) with the ß-lactamase inhibitor clavulanate together with meropenem resulted in rapid, polar, cell lysis releasing cytoplasmic contents. In Mtb it has been previously demonstrated that 3-3 cross-linkages [involving two diaminopimelate (DAP) molecules] predominate over 4-3 cross-linkages (involving one DAP and one D-alanine) in stationary-phase cells. We purified and analysed peptidoglycan from Mtb and found that 3-3 cross-linkages predominate throughout all growth phases and the ratio of 4-3/3-3 linkages does not vary significantly under any growth condition. Meropenem treatment was accompanied by a dramatic accumulation of unlinked pentapeptide stems with no change in the tetrapeptide pools, suggesting that meropenem inhibits both a D,D-carboxypeptidase and an L,D-transpeptidase. We purified a candidate D,D-carboxypeptidase DacB2 and showed that meropenem indeed directly inhibits this enzyme by forming a stable adduct at the enzyme active site. These results suggest that the rapid lysis of meropenem-treated cells is the result of synergistically inhibiting the transpeptidases that introduce 3,3-cross-links while simultaneously limiting the pool of available substrates available for cross-linking.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Regulação para Baixo/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , D-Ala-D-Ala Carboxipeptidase Tipo Serina/metabolismo , Tienamicinas/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/genética , Humanos , Meropeném , Mycobacterium tuberculosis/genética , D-Ala-D-Ala Carboxipeptidase Tipo Serina/antagonistas & inibidores , D-Ala-D-Ala Carboxipeptidase Tipo Serina/genéticaRESUMO
BACKGROUND: Granulibacter bethesdensis is a recently described member of the Acetobacteraceae family that has been isolated from patients with chronic granulomatous disease (CGD). Its pathogenesis, environmental reservoir(s), and incidence of infection among CGD patients and the general population are unknown. METHODS: Detected antigens were identified by mass spectroscopy after 2-dimensional electrophoresis and immunoaffinity chromatography. The prevalence of Granulibacter immunoreactivity was assessed through immunoblotting and enzyme-linked immunosorbent assay (ELISA). RESULTS: Methanol dehydrogenase (MDH) and formaldehyde-activating enzyme were recognized during analysis of sera from infected patients. Unique patterns of immunoreactive bands were identified in Granulibacter extracts, compared with extracts of other Acetobacteraceae species. By use of criteria based on these specific bands, specimens from 79 of 175 CGD patients (45.1%) and 23 of 93 healthy donors (24.7%) reacted to all 11 bands. An ELISA that used native MDH to capture and detect immunoglobulin G was developed and revealed high-titer MDH seroreactivity in culture-confirmed cases and 5 additional CGD patients. Testing of samples collected prior to culture-confirmed infection demonstrated instances of recent seroconversion, as well as sustained seropositivity. Infection of CGD mice with G. bethesdensis confirmed acquisition of high-titer antibody-recognizing MDH. CONCLUSIONS: These serologic tests suggest that Granulibacter immunoreactivity is more common among CGD patients and, perhaps, among healthy donors than was previously suspected. This finding raises the possibility that clinical presentations of Granulibacter infection may be underappreciated.
Assuntos
Acetobacteraceae/imunologia , Doenças Transmissíveis Emergentes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Acetobacteraceae/enzimologia , Adolescente , Adulto , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/imunologia , Oxirredutases do Álcool/metabolismo , Animais , Anticorpos Antibacterianos/sangue , Doenças Transmissíveis Emergentes/imunologia , Regulação Bacteriana da Expressão Gênica/fisiologia , Infecções por Bactérias Gram-Negativas/imunologia , Doença Granulomatosa Crônica/imunologia , Doença Granulomatosa Crônica/microbiologia , Humanos , Imunoglobulina G/sangue , Camundongos , Estudos Soroepidemiológicos , Testes Sorológicos , Adulto JovemRESUMO
BACKGROUND: Mycobacterium abscessus subspecies massiliense (M. massiliense) is increasingly recognized as an emerging bacterial pathogen, particularly in cystic fibrosis (CF) patients and CF centres' respiratory outbreaks. We characterized genomic and phenotypic changes in 15 serial isolates from two CF patients (1S and 2B) with chronic pulmonary M. massiliense infection leading to death, as well as four isolates from a CF centre outbreak in which patient 2B was the index case. RESULTS: Comparative genomic analysis revealed the mutations affecting growth rate, metabolism, transport, lipids (loss of glycopeptidolipids), antibiotic susceptibility (macrolides and aminoglycosides resistance), and virulence factors. Mutations in 23S rRNA, mmpL4, porin locus and tetR genes occurred in isolates from both CF patients. Interestingly, we identified two different spontaneous mutation events at the mycobacterial porin locus: a fusion of two tandem porin paralogs in patient 1S and a partial deletion of the first porin paralog in patient 2B. These genomic changes correlated with reduced porin protein expression, diminished 14C-glucose uptake, slower bacterial growth rates, and enhanced TNF-α induction in mycobacteria-infected THP-1 human cells. Porin gene complementation of porin mutants partly restored 14C-glucose uptake, growth rate and TNF-α levels to those of intact porin strains. CONCLUSIONS: We hypothesize that specific mutations accumulated and maintained over time in M. massiliense, including mutations shared among transmissible strains, collectively lead to more virulent, host adapted lineages in CF patients and other susceptible hosts.
Assuntos
Fibrose Cística , Mycobacterium abscessus , Mycobacterium , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Fibrose Cística/microbiologia , Genômica , Glucose , Pulmão , Mutação , Mycobacterium/genética , Mycobacterium abscessus/genética , Fator de Necrose Tumoral alfa/genética , Porinas/genética , Porinas/metabolismoRESUMO
The carbapenems imipenem and meropenem in combination with clavulanic acid reduced the bacterial burden in Mycobacterium tuberculosis-infected macrophages by 2 logs over 6 days. Despite poor stability in solution and a short half-life in rodents, treatment of chronically infected mice revealed significant reductions of bacterial burden in the lungs and spleens. Our results show that meropenem has activity in two in vivo systems, but stability and pharmacokinetics of long-term administration will offer significant challenges to clinical evaluation.
Assuntos
Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ácido Clavulânico/farmacologia , Ácido Clavulânico/uso terapêutico , Mycobacterium tuberculosis/efeitos dos fármacos , Tienamicinas/farmacologia , Tienamicinas/uso terapêutico , Animais , Antibacterianos/farmacocinética , Linhagem Celular , Ácido Clavulânico/farmacocinética , Quimioterapia Combinada , Macrófagos/microbiologia , Meropeném , Camundongos , Tienamicinas/farmacocinéticaRESUMO
SQ109, a 1,2-diamine related to ethambutol, is currently in clinical trials for the treatment of tuberculosis, but its mode of action remains unclear. Here, we demonstrate that SQ109 disrupts cell wall assembly, as evidenced by macromolecular incorporation assays and ultrastructural analyses. SQ109 interferes with the assembly of mycolic acids into the cell wall core of Mycobacterium tuberculosis, as bacilli exposed to SQ109 show immediate inhibition of trehalose dimycolate (TDM) production and fail to attach mycolates to the cell wall arabinogalactan. These effects were not due to inhibition of mycolate synthesis, since total mycolate levels were unaffected, but instead resulted in the accumulation of trehalose monomycolate (TMM), the precursor of TDM and cell wall mycolates. In vitro assays using purified enzymes showed that this was not due to inhibition of the secreted Ag85 mycolyltransferases. We were unable to achieve spontaneous generation of SQ109-resistant mutants; however, analogs of this compound that resulted in similar shutdown of TDM synthesis with concomitant TMM accumulation were used to spontaneously generate resistant mutants that were also cross-resistant to SQ109. Whole-genome sequencing of these mutants showed that these all had mutations in the essential mmpL3 gene, which encodes a transmembrane transporter. Our results suggest that MmpL3 is the target of SQ109 and that MmpL3 is a transporter of mycobacterial TMM.
Assuntos
Adamantano/análogos & derivados , Antituberculosos/farmacologia , Proteínas de Bactérias/efeitos dos fármacos , Parede Celular/metabolismo , Fatores Corda/metabolismo , Etilenodiaminas/farmacologia , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Mycobacterium tuberculosis/metabolismo , Ácidos Micólicos/metabolismo , Aciltransferases/metabolismo , Adamantano/farmacologia , Aerobiose , Antígenos de Bactérias/metabolismo , Parede Celular/efeitos dos fármacos , Cromatografia em Camada Fina , Farmacorresistência Bacteriana/genética , Metabolismo dos Lipídeos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica , Mutação/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/ultraestruturaRESUMO
Rising antimicrobial resistance challenges our ability to combat bacterial infections. The problem is acute for tuberculosis (TB), the leading cause of death from infection before COVID-19. Here, we developed a framework for multiple pharmaceutical companies to share proprietary information and compounds with multiple laboratories in the academic and government sectors for a broad examination of the ability of ß-lactams to kill Mycobacterium tuberculosis (Mtb). In the TB Drug Accelerator (TBDA), a consortium organized by the Bill & Melinda Gates Foundation, individual pharmaceutical companies collaborate with academic screening laboratories. We developed a higher order consortium within the TBDA in which four pharmaceutical companies (GlaxoSmithKline, Sanofi, MSD, and Lilly) collectively collaborated with screeners at Weill Cornell Medicine, the Infectious Disease Research Institute (IDRI), and the National Institute of Allergy and Infectious Diseases (NIAID), pharmacologists at Rutgers University, and medicinal chemists at the University of North Carolina to screen â¼8900 ß-lactams, predominantly cephalosporins, and characterize active compounds. In a striking contrast to historical expectation, 18% of ß-lactams screened were active against Mtb, many without a ß-lactamase inhibitor. One potent cephaloporin was active in Mtb-infected mice. The steps outlined here can serve as a blueprint for multiparty, intra- and intersector collaboration in the development of anti-infective agents.
Assuntos
COVID-19 , Mycobacterium tuberculosis , Animais , Indústria Farmacêutica , Camundongos , SARS-CoV-2 , Universidades , beta-Lactamas/farmacologiaRESUMO
Tuberculosis (TB) is one of the primary causes of deaths due to infectious diseases. The current TB regimen is long and complex, failing of which leads to relapse and/or the emergence of drug resistance. There is a critical need to understand the mechanisms of resistance development. With increasing drug pressure, Mycobacterium tuberculosis (Mtb) activates various pathways to counter drug-related toxicity. Signaling modules steer the evolution of Mtb to a variant that can survive, persist, adapt, and emerge as a form that is resistant to one or more drugs. Recent studies reveal that about 1/3rd of the annotated Mtb proteome is modified post-translationally, with a large number of these proteins being essential for mycobacterial survival. Post-translational modifications (PTMs) such as phosphorylation, acetylation, and pupylation play a salient role in mycobacterial virulence, pathogenesis, and metabolism. The role of many other PTMs is still emerging. Understanding the signaling pathways and PTMs may assist clinical strategies and drug development for Mtb. In this review, we explore the contribution of PTMs to mycobacterial physiology, describe the related cellular processes, and discuss how these processes are linked to drug resistance. A significant number of drug targets, InhA, RpoB, EmbR, and KatG, are modified at multiple residues via PTMs. A better understanding of drug-resistance regulons and associated PTMs will aid in developing effective drugs against TB.
Assuntos
Resistência a Medicamentos/genética , Mycobacterium tuberculosis/genética , Processamento de Proteína Pós-Traducional/genética , Tuberculose/tratamento farmacológico , Antituberculosos/uso terapêutico , Proteínas de Bactérias/genética , Humanos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/patogenicidade , Proteômica , Tuberculose/genética , Tuberculose/microbiologiaRESUMO
A major constraint in reducing tuberculosis epidemic is the emergence of strains resistant to one or more of clinically approved antibiotics, which emphasizes the need of novel drugs with novel targets. Genetic knockout strains of Mycobacterium tuberculosis (Mtb) have established that tryptophan (Trp) biosynthesis is essential for the bacterium to survive in vivo and cause disease in animal models. An anthranilate-like compound, 6-FABA, was previously shown to synergize with the host immune response to Mtb infection in vivo. Herein, we present a class of anthranilate-like compounds endowed with good antimycobacterial activity and low cytotoxicity. We show how replacing the carboxylic moiety with a hydrazide led to a significant improvement in both activity and cytotoxicity relative to the parent compound 6-FABA. Several new benzohydrazides (compounds 20-31, 33, 34, 36, 38 and 39) showed good activities against Mtb (0.625 ≤ MIC≤6.25 µM) and demonstrated no detectable cytotoxicity against Vero cell assay (CC50 ≥ 1360 µM). The target preliminary studies confirmed the hypothesis that this new class of compounds inhibits Trp biosynthesis. Taken together, these findings indicate that fluorophenylbenzohydrazides represent good candidates to be assessed for drug discovery.
Assuntos
Antituberculosos/farmacologia , Hidrazinas/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Triptofano/antagonistas & inibidores , Animais , Antituberculosos/síntese química , Antituberculosos/química , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Hidrazinas/síntese química , Hidrazinas/química , Estrutura Molecular , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/metabolismo , Relação Estrutura-Atividade , Triptofano/biossíntese , Células VeroRESUMO
BACKGROUND: Direct bronchial spread of tuberculosis was extensively described in pre-antibiotic human pathology literature but this description has been overlooked in the post-antibiotic era, in which most pathology data come from animal models that emphasise the granuloma. Modern techniques, such as [18F]2-fluoro-2-deoxy-D-glucose (FDG) PET-CT scans, might provide further insight. Our aim was to understand normal early tuberculosis resolution patterns on pulmonary PET-CT scans in treated patients with tuberculosis who were subsequently cured. METHODS: In this observational analysis, we analysed data from PredictTB, an ongoing, prospective, randomised clinical trial that examined sequential baseline and week 4 FDG-PET-CT scans from participants successfully treated (sputum culture negative 18 months after enrolment) for drug-susceptible pulmonary tuberculosis in South Africa and China. Participants who were aged 18-75 years, GeneXpert MTB/RIF positive for tuberculosis and negative for rifampicin resistance, had not yet started tuberculosis treatment, had not been treated for active tuberculosis within the previous 3 years, and met basic safety laboratory criteria were included and participants with diabetes, HIV infection, or with extrapulmonary tuberculosis including pleural tuberculosis were excluded. Scans were assessed by two readers for the location of tuberculosis lesions (eg, cavities and consolidations), bronchial thickening patterns, and changes from baseline to week 4 of treatment. FINDINGS: Among the first 124 participants (enrolled from June 22, 2017, to Sept 27, 2018) who were successfully treated, 161 primarily apical cavitary lesions were identified at baseline. Bronchial thickening and inflammation linking non-cavitary consolidative lesions to cavities were observed in 121 (98%) of 124 participants' baseline PET-CT scans. After 4 weeks of treatment, 21 (17%) of 124 participants had new or expanding lesions linked to cavities via bronchial inflammation that were not present at baseline, particularly participants with two or more cavities at baseline and participants from South Africa. INTERPRETATION: In participants with pulmonary tuberculosis who were subsequently cured, the location of cavitary and non-cavitary lesions at baseline and new lesions at week 4 of treatment suggest a cavitary origin of disease and bronchial spread through the lungs. Bronchial spread from cavities might play a larger role in the spread of pulmonary tuberculosis than has been appreciated. Elucidating cavity lesion dynamics and Mycobacterium tuberculosis viability within cavities might better explain treatment outcomes and why some patients are cured and others relapse. FUNDING: Bill & Melinda Gates Foundation, European and Developing Countries Clinical Trials Partnership, China Ministry of Science and Technology, National Natural Science Foundation of China, and National Institutes of Health. TRANSLATIONS: For the Chinese, Afrikaans and Xhosa translations of the abstract see Supplementary Materials section.