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1.
Org Biomol Chem ; 21(28): 5725-5731, 2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37381727

RESUMO

The first total synthesis of icosalide A, an antibacterial depsipeptide that is unique in that it contains two lipophilic beta-hydroxy acids, has been achieved by following Fmoc solid-phase peptide synthesis in combination with solution-phase synthesis. The ambiguity in the absolute stereochemistry of icosalide A has been resolved by synthesizing the reported structures and other relevant diastereomers of icosalides and comparing their NMR data. NMR-based structure elucidation of icosalide A revealed a well-folded structure with cross-strand hydrogen bonds similar to the anti-parallel beta-sheet conformation in peptides and displayed a synergistic juxtaposition of the aliphatic sidechains. 12 analogues of icosalide A were synthesized by varying the constituent lipophilic beta-hydroxy acid residues, and their biological activities against Bacillus thuringiensis and Paenibacillus dendritiformis were explored. Most of these icosalide analogues showed an MIC of 12.5 µg mL-1 against both bacteria. Swarming inhibition by icosalides was least in B. thuringiensis (8.3%) compared to that in P. dendritiformis (33%). Furthermore, this is the first report of icosalides showing assured inhibitory action (MIC between 2 and 10 µg mL-1) against the active stage of Mycobacterium tuberculosis and cancer cell lines such as HeLa and ThP1. This study could help optimize icosalides for anti-TB, antibacterial, and anti-cancer activities.


Assuntos
Amidas , Ésteres , Amidas/farmacologia , Ésteres/química , Antibacterianos/farmacologia , Peptídeos , Espectroscopia de Ressonância Magnética
2.
Dermatol Ther ; 35(10): e15745, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36190009

RESUMO

BACKGROUND: Glomus tumors are rare tumors arising from the mesenchymal smooth muscle cells of the glomus body. They are extremely painful tumors but because of their subungual location, remain mostly underdiagnosed. AIM: To characterize the demographic, clinical, onychoscopic, radiological features and management outcome of subungual glomus tumor. Material & methods- 15 patients with a total of 16 subungual glomus tumors were evaluated and their demographic data, history, clinical features, investigations, treatment, and follow-up were analyzed. RESULTS: Glomus tumors had a female preponderance (11/15) with thumb being the commonest site. All patients presented with intractable pain. Nail discoloration was observed in 11/16 (68.8%) lesions and nail plate deformity in 6/16 (37.5%) lesions. Common features on onychosocpy were pink glow and linear vascular structures. Doppler sonography and/or magnetic resonance imaging confirmed the diagnosis of glomus tumor in all the lesions. Surgical excision was done under local anesthesia using a trans-ungual approach and no recurrence was seen. CONCLUSIONS: High index of suspicion, meticulous clinical assessment along with radiological investigations can help in the early diagnosis. Complete surgical excision is the treatment of choice to prevent recurrence.


Assuntos
Tumor Glômico , Doenças da Unha , Neoplasias Cutâneas , Feminino , Tumor Glômico/diagnóstico , Tumor Glômico/epidemiologia , Tumor Glômico/cirurgia , Humanos , Imageamento por Ressonância Magnética , Doenças da Unha/diagnóstico , Doenças da Unha/epidemiologia , Doenças da Unha/cirurgia , Unhas/patologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/cirurgia
3.
J Infect Dis ; 223(11): 1943-1947, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32992328

RESUMO

Circumsporozoite protein (CSP) coats the Plasmodium falciparum sporozoite surface and is a major malaria subunit vaccine target. We measured epitope-specific reactivity to field-derived CSP haplotypes in serum samples from Malian adults and children on a custom peptide microarray. Compared to children, adults showed greater antibody responses and responses to more variants in regions proximal to and within the central repeat region. Children acquired short-lived immunity to an epitope proximal to the central repeat region but not to the central repeat region itself. This approach has the potential to differentiate immunodominant from protective epitope-specific responses when combined with longitudinal infection data.


Assuntos
Anticorpos Antiprotozoários/imunologia , Formação de Anticorpos , Vacinas Antimaláricas , Malária Falciparum , Adulto , Criança , Epitopos , Humanos , Vacinas Antimaláricas/imunologia , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Mali , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Vacinas de Subunidades Antigênicas/imunologia
4.
Malar J ; 18(1): 273, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409360

RESUMO

BACKGROUND: Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1) antigens play a critical role in host immune evasion. Serologic responses to these antigens have been associated with protection from clinical malaria, suggesting that antibodies to PfEMP1 antigens may contribute to natural immunity. The first N-terminal constitutive domain in a PfEMP1 is the Duffy binding-like alpha (DBL-α) domain, which contains a 300 to 400 base pair region unique to each particular protein (the DBL-α "tag"). This DBL-α tag has been used as a marker of PfEMP1 diversity and serologic responses in malaria-exposed populations. In this study, using sera from a malaria-endemic region, responses to DBL-α tags were compared to responses to the corresponding entire DBL-α domain (or "parent" domain) coupled with the succeeding cysteine-rich interdomain region (CIDR). METHODS: A protein microarray populated with DBL-α tags, the parent DBL-CIDR head structures, and downstream PfEMP1 protein fragments was probed with sera from Malian children (aged 1 to 6 years) and adults from the control arms of apical membrane antigen 1 (AMA1) vaccine clinical trials before and during a malaria transmission season. Serological responses to the DBL-α tag and the DBL-CIDR head structure were measured and compared in children and adults, and throughout the season. RESULTS: Malian serologic responses to a PfEMP1's DBL-α tag region did not correlate with seasonal malaria exposure, or with responses to the parent DBL-CIDR head structure in either children or adults. Parent DBL-CIDR head structures were better indicators of malaria exposure. CONCLUSIONS: Larger PfEMP1 domains may be better indicators of malaria exposure than short, variable PfEMP1 fragments such as DBL-α tags. PfEMP1 head structures that include conserved sequences appear particularly well suited for study as serologic predictors of malaria exposure.


Assuntos
Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/fisiologia , Proteínas de Protozoários/imunologia , Adulto , Criança , Pré-Escolar , Sequência Conservada , Humanos , Lactente , Pessoa de Meia-Idade , Estrutura Terciária de Proteína , Adulto Jovem
5.
J Infect Dis ; 216(4): 468-476, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28931241

RESUMO

Background: Amplified copy number in the plasmepsin II/III genes within Plasmodium falciparum has been associated with decreased sensitivity to piperaquine. To examine this association and test whether additional loci might also contribute, we performed a genome-wide association study of ex vivo P. falciparum susceptibility to piperaquine. Methods: Plasmodium falciparum DNA from 183 samples collected primarily from Cambodia was genotyped at 33716 genome-wide single nucleotide polymorphisms (SNPs). Linear mixed models and random forests were used to estimate associations between parasite genotypes and piperaquine susceptibility. Candidate polymorphisms were evaluated for their association with dihydroartemisinin-piperaquine treatment outcomes in an independent dataset. Results: Single nucleotide polymorphisms on multiple chromosomes were associated with piperaquine 90% inhibitory concentrations (IC90) in a genome-wide analysis. Fine-mapping of genomic regions implicated in genome-wide analyses identified multiple SNPs in linkage disequilibrium with each other that were significantly associated with piperaquine IC90, including a novel mutation within the gene encoding the P. falciparum chloroquine resistance transporter, PfCRT. This mutation (F145I) was associated with dihydroartemisinin-piperaquine treatment failure after adjusting for the presence of amplified plasmepsin II/III, which was also associated with decreased piperaquine sensitivity. Conclusions: Our data suggest that, in addition to plasmepsin II/III copy number, other loci, including pfcrt, may also be involved in piperaquine resistance.


Assuntos
Resistência a Medicamentos/genética , Proteínas de Membrana Transportadoras/genética , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Quinolinas/farmacologia , Artemisininas/farmacologia , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Camboja , Variações do Número de Cópias de DNA , DNA de Protozoário/genética , Loci Gênicos , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Concentração Inibidora 50 , Desequilíbrio de Ligação , Proteínas de Membrana Transportadoras/metabolismo , Mutação , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Modelos de Riscos Proporcionais , Proteínas de Protozoários/metabolismo , Sensibilidade e Especificidade , Falha de Tratamento
6.
J Biol Chem ; 291(43): 22386-22403, 2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-27605667

RESUMO

The bacterial transcription elongation factor NusG stimulates the Rho-dependent transcription termination through a direct interaction with Rho. The mechanistic basis of NusG dependence of the Rho function is not known. Here, we describe Rho* mutants I168V, R221C/A, and P235H that do not require NusG for their termination function. These Rho* mutants have acquired new properties, which otherwise would have been imparted by NusG. A detailed analyses revealed that they have more stable interactions at the secondary RNA binding sites of Rho, which reduced the lag in initiating its ATPase as well as the translocase activities. These more stable interactions arose from the significant spatial re-orientations of the P, Q, and R structural loops of the Rho central channel. We propose that NusG imparts similar conformational changes in the central channel of Rho, yielding faster isomerization of the open to the closed hexameric states of the latter during its RNA-loading step. This acceleration stabilizes the Rho-RNA interactions at many terminators having suboptimal rut sites, thus making Rho-NusG interactions so essential in vivo Finally, identification of the NusG binding sites on the Rho hexamer led us to conclude that the former exerts its effect allosterically.


Assuntos
Proteínas de Escherichia coli/metabolismo , Conformação de Ácido Nucleico , Fatores de Alongamento de Peptídeos/metabolismo , RNA Bacteriano/metabolismo , Fator Rho/metabolismo , Fatores de Transcrição/metabolismo , Terminação da Transcrição Genética/fisiologia , Regulação Alostérica/fisiologia , Substituição de Aminoácidos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Mutação de Sentido Incorreto , Fatores de Alongamento de Peptídeos/genética , RNA Bacteriano/genética , Fator Rho/genética , Fatores de Transcrição/genética
7.
BMC Genomics ; 18(1): 332, 2017 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-28449639

RESUMO

BACKGROUND: The benefit of increasing genomic sequence data to the scientific community depends on easy-to-use, scalable bioinformatics support. CloVR-Comparative combines commonly used bioinformatics tools into an intuitive, automated, and cloud-enabled analysis pipeline for comparative microbial genomics. RESULTS: CloVR-Comparative runs on annotated complete or draft genome sequences that are uploaded by the user or selected via a taxonomic tree-based user interface and downloaded from NCBI. CloVR-Comparative runs reference-free multiple whole-genome alignments to determine unique, shared and core coding sequences (CDSs) and single nucleotide polymorphisms (SNPs). Output includes short summary reports and detailed text-based results files, graphical visualizations (phylogenetic trees, circular figures), and a database file linked to the Sybil comparative genome browser. Data up- and download, pipeline configuration and monitoring, and access to Sybil are managed through CloVR-Comparative web interface. CloVR-Comparative and Sybil are distributed as part of the CloVR virtual appliance, which runs on local computers or the Amazon EC2 cloud. Representative datasets (e.g. 40 draft and complete Escherichia coli genomes) are processed in <36 h on a local desktop or at a cost of <$20 on EC2. CONCLUSIONS: CloVR-Comparative allows anybody with Internet access to run comparative genomics projects, while eliminating the need for on-site computational resources and expertise.


Assuntos
Computação em Nuvem , Genômica/métodos , Software , Automação , Genoma Microbiano/genética , Alinhamento de Sequência , Análise de Sequência
8.
Malar J ; 16(1): 343, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28818101

RESUMO

BACKGROUND: VAR2CSA, a member of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family, mediates the binding of P. falciparum-infected erythrocytes to chondroitin sulfate A, a surface-associated molecule expressed in placental cells, and plays a central role in the pathogenesis of placental malaria. VAR2CSA is a target of naturally acquired immunity and, as such, is a leading vaccine candidate against placental malaria. This protein is very polymorphic and technically challenging to sequence. Published var2csa sequences, mostly limited to specific domains, have been generated through the sequencing of cloned PCR amplicons using capillary electrophoresis, a method that is both time consuming and costly, and that performs poorly when applied to clinical samples that are commonly polyclonal. A next-generation sequencing platform, Pacific Biosciences (PacBio), offers an alternative approach to overcome these issues. METHODS: PCR primers were designed that target a 5 kb segment in the 5' end of var2csa and the resulting amplicons were sequenced using PacBio sequencing. The primers were optimized using two laboratory strains and were validated on DNA from 43 clinical samples, extracted from dried blood spots on filter paper or from cryopreserved P. falciparum-infected erythrocytes. Sequence reads were assembled using the SMRT-analysis ConsensusTools module. RESULTS: Here, a PacBio sequencing-based approach for recovering a segment encoding the majority of VAR2CSA's extracellular region is described; this segment includes the totality of the first four domains in the 5' end of var2csa (~5 kb), from clinical malaria samples. The feasibility of the method is demonstrated, showing a high success rate from cryopreserved samples and more limited success from dried blood spots stored at room temperature, and characterized the genetic variation of the var2csa locus. CONCLUSIONS: This method will facilitate a detailed analysis of var2csa genetic variation and can be adapted to sequence other hypervariable P. falciparum genes.


Assuntos
Antígenos de Protozoários/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Plasmodium falciparum/genética , Análise de Sequência de DNA/métodos , Teste em Amostras de Sangue Seco , Eritrócitos/parasitologia , Humanos
9.
Bioinformatics ; 30(21): 3125-7, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25075113

RESUMO

SUMMARY: Circleator is a Perl application that generates circular figures of genome-associated data. It leverages BioPerl to support standard annotation and sequence file formats and produces publication-quality SVG output. It is designed to be both flexible and easy to use. It includes a library of circular track types and predefined configuration files for common use-cases, including. (i) visualizing gene annotation and DNA sequence data from a GenBank flat file, (ii) displaying patterns of gene conservation in related microbial strains, (iii) showing Single Nucleotide Polymorphisms (SNPs) and indels relative to a reference genome and gene set and (iv) viewing RNA-Seq plots. AVAILABILITY AND IMPLEMENTATION: Circleator is freely available under the Artistic License 2.0 from http://jonathancrabtree.github.io/Circleator/ and is integrated with the CloVR cloud-based sequence analysis Virtual Machine (VM), which can be downloaded from http://clovr.org or run on Amazon EC2.


Assuntos
Genômica/métodos , Software , Gráficos por Computador , Gardnerella vaginalis/genética , Anotação de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Análise de Sequência de RNA
11.
Emerg Infect Dis ; 20(3): 364-71, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24565502

RESUMO

Three recently sequenced strains isolated from patients during an outbreak of Mycobacterium abscessus subsp. massiliense infections at a cystic fibrosis center in the United States were compared with 6 strains from an outbreak at a cystic fibrosis center in the United Kingdom and worldwide strains. Strains from the 2 cystic fibrosis outbreaks showed high-level relatedness with each other and major-level relatedness with strains that caused soft tissue infections during an epidemic in Brazil. We identified unique single-nucleotide polymorphisms in cystic fibrosis and soft tissue outbreak strains, separate single-nucleotide polymorphisms only in cystic fibrosis outbreak strains, and unique genomic traits for each subset of isolates. Our findings highlight the necessity of identifying M. abscessus to the subspecies level and screening all cystic fibrosis isolates for relatedness to these outbreak strains. We propose 2 diagnostic strategies that use partial sequencing of rpoB and secA1 genes and a multilocus sequence typing protocol.


Assuntos
Surtos de Doenças , Infecções por Mycobacterium/epidemiologia , Mycobacterium/isolamento & purificação , Brasil , Fibrose Cística/complicações , Genoma Bacteriano , Humanos , Tipagem de Sequências Multilocus , Mycobacterium/classificação , Mycobacterium/genética , Infecções por Mycobacterium/complicações , Infecções por Mycobacterium/diagnóstico , Infecções por Mycobacterium/microbiologia , Filogenia , Polimorfismo de Nucleotídeo Único , Reino Unido , Estados Unidos
12.
Mol Ther Oncol ; 32(1): 200758, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38596304

RESUMO

Oncolytic viruses are engineered to selectively kill tumor cells and have demonstrated promising results in early-phase clinical trials. To further modulate the innate and adaptive immune system, we generated AZD4820, a vaccinia virus engineered to express interleukin-12 (IL-12), a potent cytokine involved in the activation of natural killer (NK) and T cells and the reprogramming of the tumor immune microenvironment. Testing in cultured human tumor cell lines demonstrated broad in vitro oncolytic activity and IL-12 transgene expression. A surrogate virus expressing murine IL-12 demonstrated antitumor activity in both MC38 and CT26 mouse syngeneic tumor models that responded poorly to immune checkpoint inhibition. In both models, AZD4820 significantly upregulated interferon-gamma (IFN-γ) relative to control mice treated with oncolytic vaccinia virus (VACV)-luciferase. In the CT26 study, 6 of 10 mice had a complete response after treatment with AZD4820 murine surrogate, whereas control VACV-luciferase-treated mice had 0 of 10 complete responders. AZD4820 treatment combined with anti-PD-L1 blocking antibody augmented tumor-specific T cell immunity relative to monotherapies. These findings suggest that vaccinia virus delivery of IL-12, combined with immune checkpoint blockade, elicits antitumor immunity in tumors that respond poorly to immune checkpoint inhibitors.

13.
Indian Dermatol Online J ; 14(6): 807-813, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38099045

RESUMO

Background: Onychomycosis (OM) is the most common nail disorder accounting for 40-50% of all onychopathies. Onychomycosis is caused by dermatophytes in majority, mostly Trichophyton (T.) rubrum followed by T. mentragrophytes var. interdigitale. However, there is a variation in the etiological profile with the subset of population, time, and geographical location. In immunocompromised hosts, non-dermatophytic molds (NDMs) and yeasts like Candida albicans and Candida parapsilosis are the main causative agents. Diabetes mellitus (DM) is a well-established risk factor for OM. Aim and Objectives: This study was conducted to determine the clinical and mycological characteristics of OM in diabetic patients and to evaluate the clinico-etiological correlation, if any. Materials and Methods: Three hundred consecutive diabetic patients were screened, of whom 102 (34%) patients were diagnosed with OM based on clinical, mycological, dermoscopic, and histological criteria. Results: Distal lateral subungual onychomycosis was the most common clinical variant seen in 80 (78.43%) patients. Fungal culture was positive in 57 (55.88%) of which NDMs constituted approximately half (47.61%) of the isolates, followed by Candida species (30.15%) and dermatophytes (22.22%). The clinico-mycological correlation was performed to look for the association of various fungi with the clinical type of OM. Distal lateral subungual onychomycosis was majorly caused by NDMs (51.02%), followed by Candida species (28.57%), and dermatophytes (20.40%). Conclusion: Non-dermatophytic molds are increasingly incriminated as the causative organisms for OM in DM and must be considered as potential pathogens in the present scenario, thus necessitating the change in the treatment options accordingly.

14.
Indian J Dermatol Venereol Leprol ; 89(5): 710-717, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37067104

RESUMO

Background Though diabetes mellitus (DM) is a well-recognised risk factor for onychomycosis (OM), the epidemiology of OM in diabetic patients remains largely unexplored, especially from the Indian subcontinent. Aims and objectives To estimate the prevalence of OM in diabetic patients, to identify and analyse risk factors, and correlate the severity of nail changes with glycemic control (HBA1c). Methods This cross-sectional, analytical study involved 300 diabetic patients. Patients with the clinical diagnosis of OM, supplanted by at least two of the four tests (KOH, culture, onychoscopy and nail histopathology) were considered cases of OM. Demographic and haematological profile was analysed using chi-square test/ Fischer's exact test. Logistic regression was applied to assess the independent risk factors. Results The prevalence of OM in DM patients was 34% (102/300) and significant risk factors included; age >60 years, male gender, closed shoes, disease duration >5 years, high BMI (>25) and lack of awareness about nail changes. Distal and lateral subungual OM (78%) was the commonest presentation followed by proximal subungual OM, superficial OM and total dystrophic OM. Correlation between HbA1c and the number of nails involved was found to be significant. Limitation As cases were recruited from a hospital setting, there could be chances of Berksonian bias. Conclusion The prevalence of OM in diabetic patients is high and the severity of nail changes correlates with HbA1C levels. It is important to diagnose OM early in order to treat and prevent complications.


Assuntos
Diabetes Mellitus , Onicomicose , Humanos , Masculino , Pessoa de Meia-Idade , Onicomicose/diagnóstico , Onicomicose/epidemiologia , Onicomicose/tratamento farmacológico , Estudos Transversais , Prevalência , Centros de Atenção Terciária , Hemoglobinas Glicadas , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Índia/epidemiologia
15.
Int J Biol Macromol ; 248: 125847, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37460075

RESUMO

Uncontrolled amyloid aggregation is a frequent cause of neurodegenerative disorders such as prions and Alzheimer's disease (AD). As a result, many drug development approaches focus on evaluating novel molecules that can alter self-recognition pathways. Herein, we designed and synthesized the cyclometallated pyrene (Pd-1 and Pd-3) and anthracene (Pd-2) based palladium complexes ([Pd((L1)Cl] Pd-1, [Pd(L2)Cl](Pd-2), and [Pd(L3)Cl] (Pd-3)). This study explores the effect of these complexes on the aggregation, fibrillation, and amyloid formation of bovine serum albumin (BSA) and Aß1-42 peptide. Several spectroscopic methods were used to characterize all the Pd-complexes, and the molecular structure of Pd-3 was determined by X-ray crystallography. The secondary structures were studied using circular dichroism (CD) and transmission electron microscopy (TEM), while amyloid aggregation and inhibitory activities were investigated using the Thioflavin-T (ThT) fluorescence assay. Molecular docking of the Pd-complex (Pd-3) was done using fibril (PDB: 2BEG) and monomeric (PDB: 1IYT) peptides using Auto-dock Vina. As a result, the hydrogen bonding and hydrophobic interaction between the aromatic rings of the Pd-complexes and the amino acids of amyloid-ß peptides significantly reduced the production of ordered ß-sheets of amyloid fibrils and protein aggregation in the presence of Pd-2 and Pd-3 complexes.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Humanos , Peptídeos beta-Amiloides/metabolismo , Paládio , Fragmentos de Peptídeos/química , Simulação de Acoplamento Molecular , Receptor de Morte Celular Programada 1 , Doença de Alzheimer/metabolismo , Amiloide/química , Dicroísmo Circular
16.
Int J Biol Macromol ; 239: 124197, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36972817

RESUMO

Misfolding and protein aggregation have been linked to numerous human neurodegenerative disorders such as Alzheimer's, prion, and Parkinson's diseases. Ruthenium (Ru) complexes have received considerable attention in studying protein aggregation due to their interesting photophysical and photo properties. In this study, we have synthesized the novel Ru complexes ([Ru(p-cymene)Cl(L-1)][PF6](Ru-1), and [Ru(p-cymene)Cl(L-2)][PF6](Ru-2)) and investigated their inhibitory activity against the bovine serum albumin (BSA) aggregation and the Aß1-42 peptides amyloid formation. Several spectroscopic methods were used to characterize these complexes, and the molecular structure of the complex was determined by X-ray crystallography. Amyloid aggregation and inhibition activities were examined using the Thioflavin-T (ThT) assay, and the secondary structures of the protein were analyzed by circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM). The cell viability assay was carried out on the neuroblastoma cell line, revealing that the complex Ru-2 showed better protective effects against Aß1-42 peptide toxicity on neuro-2a cells than the complex Ru-1. Molecular docking studies elucidate the binding sites and interactions between the Ru-complexes and Aß1-42 peptides. The experimental studies revealed that these complexes significantly inhibited the BSA aggregation and Aß1-42 amyloid fibril formation at 1:3 and 1:1 molar concentrations, respectively. Antioxidant assays demonstrated that these complexes act as antioxidants, protecting from amyloid-induced oxidative stress. Molecular docking studies with the monomeric Aß1-42 (PDB: 1IYT) show hydrophobic interaction, and both complexes bind preferably in the central region of the peptide and coordinate with two binding sites of the peptide. Hence, we suggest that the Ru-based complexes could be applied as a potential agent in metallopharmaceutical research against Alzheimer's disease.


Assuntos
Complexos de Coordenação , Rutênio , Humanos , Peptídeos beta-Amiloides/metabolismo , Agregados Proteicos , Rutênio/farmacologia , Rutênio/química , Simulação de Acoplamento Molecular , Proteínas Amiloidogênicas , Amiloide/metabolismo , Complexos de Coordenação/química
17.
Clin Cancer Res ; 29(3): 560-570, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36455147

RESUMO

PURPOSE: Tumoral programmed cell death ligand-1 (PD-L1) expression is common in human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC). We assessed whether a DNA vaccine targeting HPV-16/18 E6/E7 with IL12 adjuvant (MEDI0457) combined with the PD-L1 inhibitor durvalumab could enhance HPV-specific T-cell response and improve outcomes in recurrent/metastatic HPV-16/18-associated HNSCC. PATIENTS AND METHODS: In this phase Ib/IIa study, immunotherapy-naïve patients with ≥1 previous platinum-containing regimen (neoadjuvant/adjuvant therapy or for recurrent/metastatic disease) received MEDI0457 7 mg intramuscularly with electroporation on weeks 1, 3, 7, and 12, then every 8 weeks, plus durvalumab 1,500 mg intravenously on weeks 4, 8, and 12, then every 4 weeks, until confirmed progression and/or unacceptable toxicity. Coprimary objectives were safety and objective response rate (ORR; H0: ORR ≤ 15%); secondary objectives included 16-week disease control rate (DCR-16), overall survival (OS), and progression-free survival (PFS). RESULTS: Of 35 treated patients, 29 were response evaluable (confirmed HPV-associated disease; received both agents). ORR was 27.6% [95% confidence interval (CI), 12.7-47.2; four complete responses, four partial responses]; responses were independent of PD-L1 tumor-cell expression (≥25% vs. <25%). DCR-16 was 44.8% (95% CI, 26.5-64.3). Median PFS was 3.5 months (95% CI, 1.9-9.0); median OS was 29.2 months (15.2-not calculable). Twenty-eight (80.0%) patients had treatment-related adverse events [grade 3: 5 (14.3%); no grade 4/5], resulting in discontinuation in 2 (5.7%) patients. HPV-16/18-specific T cells increased on treatment; 4 of 8 evaluable patients had a >2-fold increase in tumor-infiltrating CD8+ T cells. CONCLUSIONS: MEDI0457 plus durvalumab was well tolerated. While the primary efficacy endpoint was not reached, clinical benefit was encouraging.


Assuntos
Neoplasias de Cabeça e Pescoço , Infecções por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Papillomavirus Humano , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Infecções por Papillomavirus/complicações , Papillomavirus Humano 16/genética , Antígeno B7-H1/genética , Papillomavirus Humano 18
18.
Virulence ; 14(1): 2215602, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37221835

RESUMO

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/metabolismo
19.
Dalton Trans ; 51(42): 16371-16382, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36250384

RESUMO

The chemotherapeutic potential of ruthenium(II) complexes has recently attracted researchers' interest as antibacterial and anticancer agents. In this study, two novel half-sandwich imine-based Ru complexes ([Ru(p-cymene)Cl(L-1)][PF6] (Ru-1) and [Ru(p-cymene)Cl(L-2)][PF6] (Ru-2)) were reported for their deoxyribonucleic acid (DNA) binding and antitubercular, antibacterial, and anticancer activities. The molecular structure of Ru-2 was obtained by single-crystal X-ray crystallography. DNA interaction studies were conducted by UV-Vis absorbance and fluorescence spectral titration which gave rise to DNA binding constants (Kb) of 1.32 × 106 and 1.82 × 106 for Ru-1 and Ru-2, respectively and the Stern-Volmer binding constant (KSV) values for Ru-1 and Ru-2 were 1.7763 × 104 M-1 and 7.6 × 103 M-1, respectively. The in vitro antitubercular activity was evaluated against Mycobacterium tuberculosis H37Ra. The antibacterial potential of both the Ru-complexes was examined against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. The half-maximal inhibitory concentration (IC50) values for the antitubercular activity of Ru-1 and Ru-2 were 4.87 ± 1.32 µM and 5.78 ± 0.54 µM, respectively. A cytotoxic study of these complexes was performed against the human breast cancer cell line (MCF-7) and the human embryonic kidney cell line (HEK293) (normal cells). The study revealed meaningful activity of the Ru-1 complex against (cancer) MCF-7 cells, while the viability of HEK293 (normal) cells in the presence of Ru-2 was higher as compared to a reference drug 5FU. We suggest that these kinds of Ru-complexes could have potential for application in metallopharmaceuticals.


Assuntos
Antineoplásicos , Complexos de Coordenação , Rutênio , Humanos , Rutênio/farmacologia , Rutênio/química , Complexos de Coordenação/química , Células HEK293 , Antibacterianos/farmacologia , Antibacterianos/química , Antineoplásicos/farmacologia , Antineoplásicos/química , DNA/química , Linhagem Celular Tumoral
20.
Bioinformatics ; 26(15): 1819-26, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20519285

RESUMO

MOTIVATION: New sequencing technologies have accelerated research on prokaryotic genomes and have made genome sequencing operations outside major genome sequencing centers routine. However, no off-the-shelf solution exists for the combined assembly, gene prediction, genome annotation and data presentation necessary to interpret sequencing data. The resulting requirement to invest significant resources into custom informatics support for genome sequencing projects remains a major impediment to the accessibility of high-throughput sequence data. RESULTS: We present a self-contained, automated high-throughput open source genome sequencing and computational genomics pipeline suitable for prokaryotic sequencing projects. The pipeline has been used at the Georgia Institute of Technology and the Centers for Disease Control and Prevention for the analysis of Neisseria meningitidis and Bordetella bronchiseptica genomes. The pipeline is capable of enhanced or manually assisted reference-based assembly using multiple assemblers and modes; gene predictor combining; and functional annotation of genes and gene products. Because every component of the pipeline is executed on a local machine with no need to access resources over the Internet, the pipeline is suitable for projects of a sensitive nature. Annotation of virulence-related features makes the pipeline particularly useful for projects working with pathogenic prokaryotes. AVAILABILITY AND IMPLEMENTATION: The pipeline is licensed under the open-source GNU General Public License and available at the Georgia Tech Neisseria Base (http://nbase.biology.gatech.edu/). The pipeline is implemented with a combination of Perl, Bourne Shell and MySQL and is compatible with Linux and other Unix systems.


Assuntos
Genoma Bacteriano/genética , Genômica/métodos , Células Procarióticas , Bordetella bronchiseptica/genética , Georgia , Neisseria meningitidis/genética , Análise de Sequência de DNA/métodos , Software
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