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1.
Biochemistry ; 63(9): 1131-1146, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38598681

RESUMO

Despite the importance of proline conformational equilibria (trans versus cis amide and exo versus endo ring pucker) on protein structure and function, there is a lack of convenient ways to probe proline conformation. 4,4-Difluoroproline (Dfp) was identified to be a sensitive 19F NMR-based probe of proline conformational biases and cis-trans isomerism. Within model compounds and disordered peptides, the diastereotopic fluorines of Dfp exhibit similar chemical shifts (ΔδFF = 0-3 ppm) when a trans X-Dfp amide bond is present. In contrast, the diastereotopic fluorines exhibit a large (ΔδFF = 5-12 ppm) difference in chemical shift in a cis X-Dfp prolyl amide bond. DFT calculations, X-ray crystallography, and solid-state NMR spectroscopy indicated that ΔδFF directly reports on the relative preference of one proline ring pucker over the other: a fluorine which is pseudo-axial (i.e., the pro-4R-F in an exo ring pucker, or the pro-4S-F in an endo ring pucker) is downfield, while a fluorine which is pseudo-equatorial (i.e., pro-4S-F when exo, or pro-4R-F when endo) is upfield. Thus, when a proline is disordered (a mixture of exo and endo ring puckers, as at trans-Pro in peptides in water), it exhibits a small Δδ. In contrast, when the Pro is ordered (i.e., when one ring pucker is strongly preferred, as in cis-Pro amide bonds, where the endo ring pucker is strongly favored), a large Δδ is observed. Dfp can be used to identify inherent induced order in peptides and to quantify proline cis-trans isomerism. Using Dfp, we discovered that the stable polyproline II helix (PPII) formed in the denatured state (8 M urea) exhibits essentially equal populations of the exo and endo proline ring puckers. In addition, the data with Dfp suggested the specific stabilization of PPII by water over other polar solvents. These data strongly support the importance of carbonyl solvation and n → π* interactions for the stabilization of PPII. Dfp was also employed to quantify proline cis-trans isomerism as a function of phosphorylation and the R406W mutation in peptides derived from the intrinsically disordered protein tau. Dfp is minimally sterically disruptive and can be incorporated in expressed proteins, suggesting its broad application in understanding proline cis-trans isomerization, protein folding, and local order in intrinsically disordered proteins.


Assuntos
Flúor , Prolina , Prolina/química , Prolina/análogos & derivados , Flúor/química , Cristalografia por Raios X/métodos , Conformação Proteica , Espectroscopia de Ressonância Magnética/métodos , Peptídeos/química , Ressonância Magnética Nuclear Biomolecular/métodos , Conformação Molecular
2.
ACS Chem Biol ; 19(2): 536-550, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38324914

RESUMO

Native chemical ligation (NCL) at proline has been limited by cost and synthetic access. In addition, prior examples of NCL using mercaptoproline have exhibited stalling of the reaction after thioester exchange, due to inefficient S → N acyl transfer. Herein, we develop methods, using inexpensive Boc-4R-hydroxyproline, for the solid-phase synthesis of peptides containing N-terminal 4R-mercaptoproline and 4R-selenoproline. The synthesis proceeds via proline editing on the N-terminus of fully synthesized peptides on the solid phase, converting an N-terminal Boc-4R-hydroxyproline to the 4S-bromoproline, followed by an SN2 reaction with potassium thioacetate or selenobenzoic acid. After cleavage from the resin and deprotection, peptides with functionalized N-terminal proline amino acids were obtained. NCL reactions with mercaptoproline proceeded slowly under standard NCL conditions, with the S-acyl transthioesterification intermediate observed as a major species. Computational investigations indicated that the bicyclic intermediates and transition states for S → N acyl transfer are sufficiently low in energy (10-15 kcal mol-1 above starting material) that ring strain cannot explain the slow S → N acyl transfer. Instead, the bicyclic zwitterionic tetrahedral intermediate has a low barrier for reversion to the S-acyl intermediate, causing reversion to the thioester (reverse reaction) to occur preferentially over elimination to generate the amide (forward reaction). We hypothesized that a buffer capable of general acid and/or general base catalysis could promote S → N acyl transfer and thus achieve greater efficiency in proline NCL. In the presence of 2 M imidazole at pH 6.8, NCL with mercaptoproline proceeded efficiently to generate the peptide with a native amide bond. NCL with selenoproline also proceeded efficiently to generate the desired products when a thiophenol thioester was employed as a ligation partner. After desulfurization or deselenization, the products obtained were identical to those synthesized directly, confirming that the solid-phase proline editing reactions proceeded stereospecifically and without epimerization.


Assuntos
Peptídeos , Prolina , Hidroxiprolina , Peptídeos/química , Amidas , Compostos de Enxofre
3.
J Nat Prod ; 86(10): 2283-2293, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37843072

RESUMO

The DNAJB1-PRKACA oncogenic gene fusion results in an active kinase enzyme, J-PKAcα, that has been identified as an attractive antitumor target for fibrolamellar hepatocellular carcinoma (FLHCC). A high-throughput assay was used to identify inhibitors of J-PKAcα catalytic activity by screening the NCI Program for Natural Product Discovery (NPNPD) prefractionated natural product library. Purification of the active agent from a single fraction of an Aplidium sp. marine tunicate led to the discovery of two unprecedented alkaloids, aplithianines A (1) and B (2). Aplithianine A (1) showed potent inhibition against J-PKAcα with an IC50 of ∼1 µM in the primary screening assay. In kinome screening, 1 inhibited wild-type PKA with an IC50 of 84 nM. Further mechanistic studies including cocrystallization and X-ray diffraction experiments revealed that 1 inhibited PKAcα catalytic activity by competitively binding to the ATP pocket. Human kinome profiling of 1 against a panel of 370 kinases revealed potent inhibition of select serine/threonine kinases in the CLK and PKG families with IC50 values in the range ∼11-90 nM. An efficient, four-step total synthesis of 1 has been accomplished, enabling further evaluation of aplithianines as biologically relevant kinase inhibitors.


Assuntos
Produtos Biológicos , Carcinoma Hepatocelular , Humanos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases , Carcinoma Hepatocelular/patologia , Serina , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/metabolismo
4.
J Nat Prod ; 86(7): 1855-1861, 2023 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-37368408

RESUMO

Two new caulamidines C (2) and D (4) and three isocaulamidines B, C, and D (1, 3, and 5) along with the known compound caulamidine B (6) were isolated from the marine ascidian Polyandrocarpa sp. Their structures were elucidated by analysis of nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD) data. Isocaulamidines have an altered pattern of N-methyl substitution (N-15 vs N-13 in the caulamidines) with a concomitant double-bond rearrangement to provide a new C-14/N-13 imine functionality. Caulamidine C (2) and isocaulamidine C (3) are the first members of this alkaloid family with two chlorine substituents in the core 6H-2,6-naphthyridine ring system.


Assuntos
Alcaloides , Antineoplásicos , Urocordados , Animais , Urocordados/química , Alcaloides/farmacologia , Alcaloides/química , Espectroscopia de Ressonância Magnética , Imageamento por Ressonância Magnética , Estrutura Molecular
5.
Foot Ankle Orthop ; 8(1): 24730114231164146, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37009419

RESUMO

Background: The peroneus longus (PL) and peroneus brevis (PB) tendons comprise the lateral compartment of the leg and stabilize the foot during weightbearing. Peroneal tendinopathy can precipitate lateral ankle pain and induce functional disability. The progression of peroneal pathology to lateral ankle dysfunction is thought to stem from asymptomatic, subclinical peroneal tendinopathy. There may be clinical benefit to identifying asymptomatic patients with this condition before progression to disability. Various ultrasonographic characteristics have been observed in peroneal tendinopathy. The purpose of this study is to identify the frequency of subclinical tendinopathic characteristics in asymptomatic peroneal tendons. Methods: One hundred seventy participants underwent bilateral foot and ankle ultrasonographic examination. Images were assessed for abnormalities of the PL and PB tendons by a group of physicians who recorded frequencies of abnormalities. This team consisted of an orthopaedic surgeon specializing in foot and ankle surgery, a fifth-year orthopaedic surgery resident, and a family medicine physician with musculoskeletal sonographer certification. Results: A total of 340 PL and 340 PB tendons were assessed. Sixty-eight (20%) PL and 41 (12.1%) PB tendons had abnormal traits. Twenty-four PLs and 22 PBs had circumferential fluid, 16 PLs and 9 PBs had noncircumferential fluid, 27 PLs and 6 PBs had thickening, 36 PLs and 12 PBs had heterogenicity, 10 PLs and 2 PBs had hyperemia, and 1 PL had calcification. In Caucasian participants, male gender was associated with increased frequency of abnormal findings, but there were no other significant differences based on age, body mass index, or ethnicity. Conclusion: In our studied population of 170 patients who had no complaints of associated symptoms, we found that 20% of PLs and 12% of PBs displayed ultrasonographic abnormalities. When we included all unusual findings within and around the tendons, prevalence rates of ultrasonographic abnormalities were 34% for PLs and 22% for PBs. Level of Evidence: Level II, prospective cohort study.

6.
ACS Pharmacol Transl Sci ; 6(4): 633-650, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37082750

RESUMO

The recent demonstration that adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) plays an oncogenic role in a number of important cancers has led to a renaissance in drug development interest targeting this kinase. We therefore have established a suite of biochemical, cell-based, and structural biology assays for identifying and evaluating new pharmacophores for PKA inhibition. This discovery process started with a 384-well high-throughput screen of more than 200,000 substances, including fractionated natural product extracts. Identified active compounds were further prioritized in biochemical, biophysical, and cell-based assays. Priority lead compounds were assessed in detail to fully characterize several previously unrecognized PKA pharmacophores including the generation of new X-ray crystallography structures demonstrating unique interactions between PKA and bound inhibitor molecules.

7.
Biodegradation ; 34(4): 357-369, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36840890

RESUMO

Co-contamination of hydrocarbons with heavy metals in soils often complicates and hinders bioremediation. A comprehensive characterization of site-specific degraders at contaminated sites can help determine if in situ bioremediation processes are sufficient. This study aimed to identify differences in benzene and toluene degradation rates and the microbial communities enriched under aerobic conditions when different concentrations of Cd and Pb are introduced. Microcosms were used to study the degradation of 0.23 mM benzene or 0.19 mM toluene under various concentrations of Pb (up to 240 µM) and Cd (up to 440 µM). Soil collected from a stormwater retention basin receiving runoff from a large parking lot was utilized to seed the microcosms. The hydrocarbon degradation time and rates were measured. After further rounds of amendment and degradation of benzene and toluene, 16S rRNA gene amplicon sequencing and quantitative PCR were used to ascertain the microbial communities enriched under the various concentrations of the heavy metals. The initial degradation time for toluene and benzene was 7 to 9 days and 10 to 13 days, respectively. Degradation rates were similar for each hydrocarbon despite the concentration and presence of metal co-contaminant, however, the enriched microbial communities under each condition differed. Microcosms without metal co-contaminant contained a diversity of putative benzene and toluene degrading bacteria. Cd strongly reduced the richness of the microbial communities. With higher levels of heavy metals, genera such as Ralstonia, Cupriavidus, Azoarcus, and Rhodococcus became more dominant under various conditions. The study finds that highly efficient benzene- and toluene-degrading consortia can develop under variations of heavy metal co-contamination, but the consortia are dependent on the heavy metal type and concentrations.


Assuntos
Metais Pesados , Poluentes do Solo , Benzeno/metabolismo , Tolueno/metabolismo , Cádmio/metabolismo , RNA Ribossômico 16S/genética , Chumbo/metabolismo , Hidrocarbonetos/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Poluentes do Solo/metabolismo
8.
Front Plant Sci ; 12: 652319, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968108

RESUMO

Pennycress (Thlaspi arvense L.) is being domesticated as an oilseed cash cover crop to be grown in the off-season throughout temperate regions of the world. With its diploid genome and ease of directed mutagenesis using molecular approaches, pennycress seed oil composition can be rapidly tailored for a plethora of food, feed, oleochemical and fuel uses. Here, we utilized Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 technology to produce knockout mutations in the FATTY ACID DESATURASE2 (FAD2) and REDUCED OLEATE DESATURATION1 (ROD1) genes to increase oleic acid content. High oleic acid (18:1) oil is valued for its oxidative stability that is superior to the polyunsaturated fatty acids (PUFAs) linoleic (18:2) and linolenic (18:3), and better cold flow properties than the very long chain fatty acid (VLCFA) erucic (22:1). When combined with a FATTY ACID ELONGATION1 (fae1) knockout mutation, fad2 fae1 and rod1 fae1 double mutants produced ∼90% and ∼60% oleic acid in seed oil, respectively, with PUFAs in fad2 fae1 as well as fad2 single mutants reduced to less than 5%. MALDI-MS spatial imaging analyses of phosphatidylcholine (PC) and triacylglycerol (TAG) molecular species in wild-type pennycress embryo sections from mature seeds revealed that erucic acid is highly enriched in cotyledons which serve as storage organs, suggestive of a role in providing energy for the germinating seedling. In contrast, PUFA-containing TAGs are enriched in the embryonic axis, which may be utilized for cellular membrane expansion during seed germination and seedling emergence. Under standard growth chamber conditions, rod1 fae1 plants grew like wild type whereas fad2 single and fad2 fae1 double mutant plants exhibited delayed growth and overall reduced heights and seed yields, suggesting that reducing PUFAs below a threshold in pennycress had negative physiological effects. Taken together, our results suggest that combinatorial knockout of ROD1 and FAE1 may be a viable route to commercially increase oleic acid content in pennycress seed oil whereas mutations in FAD2 will likely require at least partial function to avoid fitness trade-offs.

9.
J Nat Prod ; 84(6): 1831-1837, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34038132

RESUMO

An extract of a Sinularia sp. soft coral showed inhibitory activity against the E3-ubiquitin ligase casitas B-lineage lymphoma proto-oncogene B (Cbl-b). Subsequent bioassay-guided separation of the extract provided a series of terpenoid-derived spermidine and spermine amides that were named sinularamides A-G (1-7). Compounds 1-7 represent new natural products; however, sinularamide A (1) was previously reported as a synthetic end product. The structures of sinularamides A-G (1-7) were elucidated by analysis of spectroscopic and spectrometric data from NMR, IR, and HRESIMS experiments and by comparison with literature data. All of the isolated compounds showed Cbl-b inhibitory activities with IC50 values that ranged from approximately 6.5 to 33 µM.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Antozoários/química , Proteínas Proto-Oncogênicas c-cbl/antagonistas & inibidores , Espermidina/farmacologia , Espermina/farmacologia , Terpenos/farmacologia , Animais , Estrutura Molecular , Palau , Espermidina/isolamento & purificação , Espermina/isolamento & purificação , Terpenos/isolamento & purificação
10.
SLAS Discov ; 26(7): 870-884, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33882749

RESUMO

The transfer of the small protein ubiquitin to a target protein is an intricately orchestrated process called ubiquitination that results in modulation of protein function or stability. Proper regulation of ubiquitination is essential, and dysregulation of this process is implicated in several human diseases. An example of a ubiquitination cascade that is a central signaling node in important disease-associated pathways is that of CBLB [a human homolog of a viral oncogene Casitas B-lineage lymphoma (CBL) from the Cas NS-1 murine retrovirus], a RING finger ubiquitin ligase (E3) whose substrates include a number of important cell-signaling kinases. These include kinases important in immune function that act in the T cell receptor and costimulatory pathways, the Tyro/Axl/MerTK (TAM) receptor family in natural killer (NK) cells, as well as growth factor receptor kinases like epidermal growth factor receptor (EGFR). Loss of CBLB has been shown to increase innate and adaptive antitumor immunity. This suggests that small-molecule modulation of CBLB E3 activity could enhance antitumor immunity in patients. To explore the hypothesis that enzymatic inhibition of E3s may result in modulation of disease-related signaling pathways, we established a high-throughput screen of >70,000 chemical entities for inhibition of CBLB activity. Although CBLB was chosen as a proof-of-principle target for inhibitor discovery, we demonstrate that our assay is generalizable to monitoring the activity of other ubiquitin ligases. We further extended our observed in vitro inhibition with additional cell-based models of CBLB activity. From these studies, we demonstrate that a class of natural product-based alkaloids, known as methyl ellipticiniums (MEs), is capable of inhibiting ubiquitin ligases intracellularly.


Assuntos
Descoberta de Drogas/métodos , Inibidores Enzimáticos/química , Técnicas In Vitro , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/química , Animais , Inibidores Enzimáticos/farmacologia , Ensaios de Triagem em Larga Escala , Humanos , Metilação , Camundongos , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas , Ubiquitinação/efeitos dos fármacos
11.
Global Spine J ; 11(1): 71-75, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32875842

RESUMO

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Gender appears to play in important role in surgical outcomes following acute cervical spine trauma, with current literature suggesting males have a significantly higher mortality following spine surgery. However, no well-adjusted population-based studies of gender disparities in incidence and outcomes of spine surgery following acute traumatic axis injuries exist to our knowledge. We hypothesized that females would receive surgery less often than males, but males would have a higher 1-year mortality following isolated traumatic axis fractures. METHODS: We performed a retrospective cohort study using Medicare claims data that identified US citizens aged 65 and older with ICD-9 (International Classification of Diseases, Ninth Revision) code diagnosis corresponding to isolated acute traumatic axis fracture between 2007 and 2014. Our primary outcome was defined as cumulative incidence of surgical treatment, and our secondary outcome was 1-year mortality. Propensity weighted analysis was performed to balance covariates between genders. Our institutional review board approved the study (IRB #16-0533). RESULTS: There was no difference in incidence of surgery between males and females following acute isolated traumatic axis fractures (7.4 and 7.5 per 100 fractures, respectively). Males had significantly higher 1-year weighted mortality overall (41.7 and 28.9 per 100 fractures, respectively, P < .001). CONCLUSION: Our well-adjusted data suggest there was no significant gender disparity in incidence of surgical treatment over the study period. The data also support previous observations that males have worse outcomes in comparison to females in the setting of axis fractures and spinal trauma regardless of surgical intervention.

12.
J Am Chem Soc ; 142(50): 21178-21188, 2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33263997

RESUMO

Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a molecular target for the sensitization of cancer cells to the FDA-approved topoisomerase inhibitors topotecan and irinotecan. High-throughput screening of natural product extract and fraction libraries for inhibitors of TDP1 activity resulted in the discovery of a new class of knotted cyclic peptides from the marine sponge Axinella sp. Bioassay-guided fractionation of the source extract resulted in the isolation of the active component which was determined to be an unprecedented 42-residue cysteine-rich peptide named recifin A. The native NMR structure revealed a novel fold comprising a four strand antiparallel ß-sheet and two helical turns stabilized by a complex disulfide bond network that creates an embedded ring around one of the strands. The resulting structure, which we have termed the Tyr-lock peptide family, is stabilized by a tyrosine residue locked into three-dimensional space. Recifin A inhibited the cleavage of phosphodiester bonds by TDP1 in a FRET assay with an IC50 of 190 nM. Enzyme kinetics studies revealed that recifin A can specifically modulate the enzymatic activity of full-length TDP1 while not affecting the activity of a truncated catalytic domain of TDP1 lacking the N-terminal regulatory domain (Δ1-147), suggesting an allosteric binding site for recifin A on the regulatory domain of TDP1. Recifin A represents both the first of a unique structural class of knotted disulfide-rich peptides and defines a previously unseen mechanism of TDP1 inhibition that could be productively exploited for potential anticancer applications.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Tirosina , Regulação Alostérica/efeitos dos fármacos , Sequência de Aminoácidos , Domínio Catalítico , Dissulfetos/química , Ensaios de Triagem em Larga Escala , Diester Fosfórico Hidrolases/química
13.
Mar Drugs ; 18(11)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33126420

RESUMO

Three new aryl alkaloids named suberitamides A-C (1-3), were isolated from an extract of the marine sponge Pseudosuberites sp. collected along the coast of North Carolina. Their planar structures were established by extensive nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis. To assign the challenging relative configuration of the saturated five-membered ring in suberitamide A (1), a simple and efficient NMR protocol was applied that is based on the analysis of 2- and 3-bond 1H-13C spin-spin coupling constants using a PIP (pure in-phase) HSQMBC (heteronuclear single quantum multiple bond correlation) IPAP (in-phase and anti-phase) experiment. Suberitamides A (1) and B (2) inhibited Cbl-b, an E3 ubiquitin ligase that is an important modulator of immune cell function, with IC50 values of approximately 11 µM.


Assuntos
Alcaloides/farmacologia , Inibidores Enzimáticos/farmacologia , Poríferos/metabolismo , Proteínas Proto-Oncogênicas c-cbl/antagonistas & inibidores , Alcaloides/isolamento & purificação , Animais , Inibidores Enzimáticos/isolamento & purificação , Estrutura Molecular , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Relação Estrutura-Atividade
14.
Biomed Res Int ; 2020: 3807234, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32953880

RESUMO

MATERIALS AND METHODS: Various aqueous extracts were prepared from this plant and preadministered per os to albino mice 3 h before APAP administration, once daily for one week. Animals from the normal group were given only distilled water while those from negative control received only APAP 250 mg/kg. After treatment, mice were sacrificed, the liver was collected for histopathology analysis, and different biochemical markers (alanine aminotransferase (ALT), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNFα)) were measured. The content of the active extract was analyzed by HPLC/UV. Molecular docking was conducted using iGEMDOCK software, and the drug-likeness and pharmacokinetic profiles were evaluated using Swiss ADME. RESULTS: APAP administration significantly increased (p < 0.001) ALT in liver homogenates when compared to normal controls whereas the stem decoction at 250 mg/kg significantly (p < 0.001) reduced this activity to a normal value comparable to silymarin 50 mg/kg which is better than leaf and root extracts. Moreover, the stem decoction also significantly reduced the MDA levels (p < 0.05) and increased those of GSH, SOD, and CAT (p < 0.001) at doses of 250 and 500 mg/kg compared to the negative control. A significant (p < 0.001) decrease of TNFα levels and leukocyte infiltration was observed following treatment with this extract. The HPLC/UV analysis of the decoction revealed the presence of dihydroxycoumarin, quinine, and scopoletin with the following retention times: 2.6, 5.1, and 7.01 min, respectively. In silico studies showed that quinine and dihydroxycoumarin had great potentials to be orally administered drugs and possessed strong binding affinities with TNFα, TNF receptor, cyclooxygenase-2, iNOS, cytochrome P450 2E1, and GSH reductase. CONCLUSION: Based on these results, L. hastata could be considered a source of promising hepatoprotective compounds with antioxidant and anti-inflammatory properties.


Assuntos
Acetaminofen/efeitos adversos , Apocynaceae/química , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Fígado/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Alanina Transaminase/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/metabolismo , Aspartato Aminotransferases/metabolismo , Catalase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Feminino , Glutationa/metabolismo , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Óxido Nítrico Sintase Tipo II , Folhas de Planta/química , Silimarina/metabolismo , Superóxido Dismutase
15.
Nat Prod Rep ; 37(7): 893-918, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32186299

RESUMO

Covering: up to 2020The National Cancer Institute of the United States (NCI) has initiated a Cancer Moonshot program entitled the NCI Program for Natural Product Discovery. As part of this effort, the NCI is producing a library of 1 000 000 partially purified natural product fractions which are being plated into 384-well plates and provided to the research community free of charge. As the first 326 000 of these fractions have now been made available, this review seeks to describe the general methods used to collect organisms, extract those organisms, and create a prefractionated library. Importantly, this review also details both cell-based and cell-free bioassay methods and the adaptations necessary to those methods to productively screen natural product libraries. Finally, this review briefly describes post-screen dereplication and compound purification and scale up procedures which can efficiently identify active compounds and produce sufficient quantities of natural products for further pre-clinical development.


Assuntos
Produtos Biológicos/química , Bibliotecas de Moléculas Pequenas/química , Bioensaio/métodos , Produtos Biológicos/farmacologia , Descoberta de Drogas/métodos , Ensaios de Triagem em Larga Escala/métodos , Humanos
16.
Phytochemistry ; 173: 112278, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32078832

RESUMO

Following the discovery of a new class of compounds that inhibit the mucosa-associated lymphoid tissue lymphoma translocation 1 (MALT1) protease in a prior study, further chemical investigation of the Dictyosporium digitatum fungus resulted in the identification of 16 additional metabolites, including 12 undescribed compounds (1-12). The constitution and relative configuration of these new molecules were established by comprehensive NMR and HRMS analyses. Their absolute configurations were determined by employing Mosher's ester analysis and TDDFT ECD calculations. Two sesquiterpenes, dictyosporins A (1) and B (2), possess an undescribed eudesmen-type of structural scaffold. The ability of the isolated compounds to inhibit MALT1 proteolytic activity was evaluated, but none of them exhibited significant inhibition.


Assuntos
Ascomicetos , Sesquiterpenos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Solo
17.
Eur Urol Oncol ; 3(2): 224-230, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31948886

RESUMO

BACKGROUND: Rare germline mutations in several genes, primarily DNA repair genes, have been proposed to predict worse prognosis of prostate cancer (PCa). OBJECTIVE: To compare the frequency of germline pathogenic mutations in commonly assayed PCa genes between high- and low-grade PCa in patients initially presenting with clinically localized disease. DESIGN, SETTING, AND PARTICIPANTS: A retrospective case-case study of 1694 PCa patients who underwent radical prostatectomy at Johns Hopkins Hospital, including 706 patients with high-grade (grade group [GG] 4 and GG5) and 988 patients with low-grade (GG1) disease. Germline DNA was sequenced for 13 candidate PCa genes using a targeted next-generation sequencing assay by Ambry Genetics. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Carrier rates of pathogenic mutations were compared between high- and low-grade PCa patients using the Fisher's exact test. RESULTS AND LIMITATIONS: Overall, the carrier rate of germline pathogenic mutations in the 13 genes was significantly higher in high-grade patients (8.64%) than in low-grade patients (3.54%, p = 9.98 × 10-6). Individually, significantly higher carrier rates for patients with high- versus low-grade PCa were found for three genes: ATM (2.12% and 0.20%, respectively, p = 9.35 × 10-5), BRCA2 (2.55% and 0.20%, respectively, p = 8.99 × 10-6), and MSH2 (0.57% and 0%, respectively, p = 0.03). The mutation carrier rate was significantly higher in patients with GG5 than in patients with GG1 disease for the 13 genes overall (13.07% and 3.54%, respectively, p = 1.27 × 10-9); for the three genes ATM, BRCA2, and MSH2 (7.73% and 0.40%, respectively, p = 3.20 × 10-13); and for the remaining nine DNA repair genes (5.07% and 2.43%, respectively, p = 0.02). CONCLUSIONS: In men undergoing treatment for clinically localized disease, pathogenic mutations in 13 commonly assayed genes, especially ATM, BRCA2, and MSH2, are most strongly associated with GG5 PCa. These findings emphasize the importance of genetic testing in men with high-grade PCa, particularly GG5 disease, to inform both treatment decisions and familial risk assessment. PATIENT SUMMARY: Prostate cancer in men with inherited mutations in 13 commonly assayed susceptibility genes is more likely to be high-grade, high-risk disease.


Assuntos
Reparo do DNA/genética , Mutação em Linhagem Germinativa/genética , Estudos de Casos e Controles , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Neoplasias da Próstata , Estudos Retrospectivos
18.
Neurosurg Focus ; 47(4): E15, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31574469

RESUMO

OBJECTIVE: Prenatal myelomeningocele (MMC) closure has been performed in the United States for 2 decades. While prior work has focused on clinical outcomes of prenatal MMC closure, the cost of this procedure in comparison with that of postnatal MMC closure is unclear. The authors' aim was to compare the cost of prenatal versus postnatal MMC closure for both the child and mother at 1 year. METHODS: A prospective database of patients undergoing prenatal and postnatal MMC closure between 2011 and 2018 with 1-year follow-up was retrospectively reviewed. Charge data for relevant admissions were converted to a cost estimate using the authors' institution's Medicare hospital-specific cost-to-charge ratio. Children, mothers, and mother/child pairs were considered separately. The primary outcome was cost. Secondary outcomes included the need for hydrocephalus treatment, length of stay (LOS), and readmissions. Other covariates included gestational age at birth, MMC lesion level, and obstetric complications. RESULTS: The median cost of care for children in the prenatal group was greater, although not significantly so, at $58,406.71 (IQR $16,900.24-$88,951.01) compared with $49,889.95 (IQR $38,425.18-$115,163.86) for children in the postnatal group (p = 0.204). The median cost for mothers in the prenatal group was significantly greater at $24,548.29 (IQR $20,231.55-$36,862.31) compared with $5087.30 (IQR $4430.72-$5362.56) (p < 0.001). The median cost for mother/child pairs in the prenatal group was $102,377.75 (IQR $37,384.30-$118,527.74) compared with $55,667.82 (IQR $42,840.78-$120,058.06) (p = 0.45). Children in the prenatal group had a lower gestational age at birth (235.81 days vs 265.77 days, p < 0.001) and fewer readmissions (33.3% vs 72.7%, p < 0.001), and hydrocephalus treatment was less common (33.3% vs 90.9%, p < 0.001). Index LOS did not differ between children in the prenatal and postnatal groups (26.8 days vs 23.5 days, p = 0.63). Mothers in the prenatal group had longer LOS (15.92 days vs 4.68 days, p < 0.001) and more readmissions (18.5% vs 0.0%, p = 0.06). CONCLUSIONS: The median cost of prenatal versus postnatal MMC closure did not significantly differ from a hospital perspective at 1 year, although variability in cost was high for both groups. When considering the mother alone, prenatal MMC closure was costlier. Future work is needed to assess cost from a patient and societal perspective both at 1 year and beyond.


Assuntos
Hidrocefalia/cirurgia , Medicare/economia , Meningomielocele/cirurgia , Ventriculostomia/economia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Mães , Neuroendoscopia/métodos , Gravidez , Estudos Retrospectivos , Estados Unidos , Ventriculostomia/métodos
19.
J Nat Prod ; 82(1): 154-162, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30600998

RESUMO

Bioassay-guided separation of an extract from a Dictyosporium sp. isolate led to the identification of six new compounds, 1-6, together with five known compounds, 7-11. The structures of the new compounds were primarily established by extensive 1D and 2D NMR experiments. The absolute configurations of compounds 3-6 were determined by comparison of their experimental electronic circular dichroism (ECD) spectra with DFT quantum mechanical calculated ECD spectra. Compounds 3-5 possess novel structural scaffolds, and biochemical studies revealed that oxepinochromenones 1 and 7 inhibited the activity of MALT1 protease.


Assuntos
Inibidores Enzimáticos/isolamento & purificação , Fungos/metabolismo , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia
20.
Eur J Neurol ; 24(2): 427-e6, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28102045

RESUMO

BACKGROUND AND PURPOSE: The presentation of Parkinson's disease patients with mutations in the LRRK2 gene (PDLRRK2 ) is highly variable, suggesting a strong influence of modifying factors. In this context, inflammation is a potential candidate inducing clinical subtypes. METHODS: An extensive battery of peripheral inflammatory markers was measured in human serum in a multicentre cohort of 142 PDLRRK2 patients from the MJFF LRRK2 Consortium, stratified by three different subtypes as recently proposed for idiopathic Parkinson's disease: diffuse/malignant, intermediate and mainly pure motor. RESULTS: Patients classified as diffuse/malignant presented with the highest levels of the pro-inflammatory proteins interleukin 8 (IL-8), monocyte chemotactic protein 1 (MCP-1) and macrophage inflammatory protein 1-ß (MIP-1-ß) paralleled by high levels of the neurotrophic protein brain-derived neurotrophic factor (BDNF). It was also possible to distinguish the clinical subtypes based on their inflammatory profile by using discriminant and area under the receiver operating characteristic curve analysis. CONCLUSIONS: Inflammation seems to be associated with the presence of a specific clinical subtype in PDLRRK2 that is characterized by a broad and more severely affected spectrum of motor and non-motor symptoms. The pro-inflammatory metabolites IL-8, MCP-1 and MIP-1-ß as well as BDNF are interesting candidates to be included in biomarker panels that aim to differentiate subtypes in PDLRRK2 and predict progression.


Assuntos
Inflamação/etiologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Doença de Parkinson/genética , Doença de Parkinson/patologia , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Fator Neurotrófico Derivado do Encéfalo/sangue , Quimiocina CCL2/sangue , Quimiocina CCL4/sangue , Estudos de Coortes , Citocinas/sangue , Progressão da Doença , Feminino , Humanos , Inflamação/genética , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Mutação
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