Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Saudi Pharm J ; 32(3): 101985, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38380162

RESUMO

This study was designed to assess both the quality and cost aspects of various branded and generic formulations of angiotensin receptor blockers, specifically Irbesartan, Losartan Potassium, Olmesartan Medoxomil, Telmisartan, and Valsartan. The collected samples underwent distinct quality evaluations using the methods outlined in different global Pharmacopoeias (British Pharmacopoeia/European Pharmacopoeia, Indian Pharmacopoeia and United States Pharmacopoeia). These drugs were characterized using Fourier-Transform Infrared Spectroscopy and Nuclear Magnetic Resonance techniques, while their quality and concentration were analysed using High Performance Liquid Chromatography. The release profile of the drugs was examined through dissolution testing. Additionally, a cost comparison analysis was carried out by determining the prevailing market prices of the drugs. The evaluated branded and generic angiotensin receptor blockers were found to meet the established standards for impurities, active drug content, and dissolution as set by these Pharmacopoeias, indicating their optimal quality. Notably, the generic drugs exhibited significantly lower costs compared to their branded counterparts. This study confirms that the quality of generic angiotensin receptor blockers is equivalent to that of their branded counterparts. Consequently, these findings support the practicality of utilizing generic drugs as a more economically sustainable and cost-effective approach to managing diseases, especially those of chronic nature.

2.
J Am Chem Soc ; 145(2): 1460-1469, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36603103

RESUMO

Activity-based sensing (ABS) probes equipped with a NIR bioluminescence readout are promising chemical tools to study cancer biomarkers owing to their high sensitivity and deep tissue compatibility. Despite the demand, there is a dearth of such probes because NIR substrates (e.g., BL660 (a NIR luciferin analog)) are not equipped with an appropriate attachment site for ABS trigger installation. For instance, our attempts to mask the carboxylic acid moiety with standard self-immolative benzyl linkers resulted in significant background signals owing to undesirable ester hydrolysis. In this study, we overcame this longstanding challenge by rationally designing a new hydrolysis-resistant ester-based linker featuring an isopropyl shielding arm. Compared to the parent, the new design is 140.5-fold and 67.8-fold more resistant toward spontaneous and esterase-mediated hydrolysis, respectively. Likewise, we observed minimal cleavage of the ester moiety when incubated with a panel of enzymes possessing ester-hydrolyzing activity. These impressive in vitro results were corroborated through a series of key experiments in live cells. Further, we showcased the utility of this technology by developing the first NIR bioluminescent probe for nitroreductase (NTR) activity and applied it to visualize elevated NTR expression in oxygen deficient lung cancer cells and in a murine model of non-small cell lung cancer. The ability to monitor the activity of this key biomarker in a deep tissue context is critical because it is associated with tumor hypoxia, which in turn is linked to drug resistance and aggressive cancer phenotypes.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Camundongos , Animais , Hidrólise , Ésteres , Corantes Fluorescentes
3.
J Am Chem Soc ; 144(39): 18101-18108, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36153991

RESUMO

The favorable properties of cyanines (e.g., near-infrared (NIR) absorbance and emission) have made this class of dyes popular for a wide variety of biomedical applications. However, many cyanines are prone to rapid photobleaching when irradiated with light. In this study, we have exploited this undesirable trait to develop NIR-nanogels for NIR light-mediated cargo delivery. NIR-nanogels feature a photolabile cyanine cross-linker (Cy780-Acryl) that can cleave via dioxetane chemistry when irradiated. This photochemical process results in the formation of two carbonyl fragments and concomitant NIR-nanogel degradation to facilitate cargo release. In contrast to studies where cyanines are utilized as photocages, our approach does not require direct chemical attachment to the cargo, thus expanding our ability to deliver molecules that cannot be covalently modified. We showcase this feature by encapsulating a palette of small-molecule chemotherapeutics that feature a structurally diverse chemical architecture. To demonstrate site-selective release in vivo, we generated a murine model of breast cancer. Relative to nonlight irradiated and drug-free controls, treatment with NIR-nanogels loaded with paclitaxel (a potent cytotoxic agent) and NIR light resulted in significant attenuation of tumor growth. Moreover, we show via histological staining of the vital organs that minimal off-target effects are observed.


Assuntos
Reposicionamento de Medicamentos , Paclitaxel , Animais , Corantes , Citotoxinas , Camundongos , Nanogéis , Paclitaxel/farmacologia
4.
Int Braz J Urol ; 48(3): 406-455, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34003609

RESUMO

INTRODUCTION: There is an ongoing need to identify various pathological factors that can predict various survival parameters in patients with upper tract urothelial carcinoma (UTUC). With this review, we aim to scrutinize the impact of several pathological factors on recurrence free survival (RFS), cancer-specific survival (CSS) and overall survival (OS) in patients with UTUC. MATERIALS AND METHODS: Systematic electronic literature search of various databases was conducted for this review. Studies providing multivariate hazard ratios (HR) for various pathological factors such as tumor margin, necrosis, stage, grade, location, architecture, lymph node status, lymphovascular invasion (LVI), carcinoma in situ (CIS), multifocality and variant histology as predictor of survival parameters were included and pooled analysis of HR was performed. RESULTS: In this review, 63 studies with 35.714 patients were included. For RFS, all except tumor location (HR 0.94, p=0.60) and necrosis (HR 1.00, p=0.98) were associated with worst survival. All the pathological variables except tumor location (HR 0.95, p=0.66) were associated with worst CSS. For OS, only presence of CIS (HR 1.03, p=0.73) and tumor location (HR 1.05, p=0.74) were not predictor of survival. CONCLUSIONS: We noted tumor grade, stage, presence of LVI, lymph node metastasis, hydronephrosis, variant histology, sessile architecture, margin positivity and multifocality were associated with poor RFS, CSS and OS. Presence of CIS was associated with poor RFS and CSS but not OS. Tumor necrosis was associated with worst CSS and OS but not RFS. Tumor location was not a predictor of any of the survival parameters.


Assuntos
Carcinoma de Células de Transição , Neoplasias Ureterais , Neoplasias da Bexiga Urinária , Neoplasias Urológicas , Carcinoma de Células de Transição/patologia , Humanos , Prognóstico , Estudos Retrospectivos , Neoplasias Urológicas/patologia
5.
Angew Chem Int Ed Engl ; 61(44): e202211774, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-36083191

RESUMO

Obesity is a chronic health condition characterized by the accumulation of excessive body fat which can lead to and exacerbate cardiovascular disease, type-II diabetes, high blood pressure, and cancer through systemic inflammation. Unfortunately, visualizing key mediators of the inflammatory response, such as monoacylglycerol lipase (MGL) and fatty acid amide hydrolase (FAAH), in a selective manner is a profound challenge owing to an overlapping substrate scope that involves arachidonic acid (AA). Specifically, these enzymes work in concert to generate AA, which in the context of obesity, has been implicated to control appetite and energy metabolism. In this study, we developed the first selective activity-based sensing probes to detect MGL (PA-HD-MGL) and FAAH (PA-HD-FAAH) activity via photoacoustic imaging. Activation of PA-HD-MGL and PA-HD-FAAH by their target enzymes resulted in 1.74-fold and 1.59-fold signal enhancements, respectively. Due to their exceptional selectivity profiles and deep-tissue photoacoustic imaging capabilities, these probes were employed to measure MGL and FAAH activity in a murine model of obesity. Contrary to conflicting reports suggesting levels of MGL can be attenuated or elevated, our results support the latter. Indeed, we discovered a marked increase of both targets in the gastrointestinal tract. These key findings set the stage to uncover the role of the endocannabinoid pathway in obesity-mediated inflammation.


Assuntos
Endocanabinoides , Monoacilglicerol Lipases , Animais , Camundongos , Humanos , Monoacilglicerol Lipases/química , Monoacilglicerol Lipases/metabolismo , Ácido Araquidônico , Modelos Animais de Doenças , Amidoidrolases/metabolismo , Obesidade/diagnóstico por imagem , Inflamação
6.
Angew Chem Int Ed Engl ; 60(34): 18860-18866, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34089556

RESUMO

Most photoacoustic (PA) imaging agents are based on the repurposing of existing fluorescent dye platforms that exhibit non-optimal properties for PA applications. Herein, we introduce PA-HD, a new dye scaffold optimized for PA probe development that features a 4.8-fold increase in sensitivity and a red-shift of the λabs from 690 nm to 745 nm to enable ratiometric imaging. Computational modeling was used to elucidate the origin of these enhanced properties. To demonstrate the generalizability of our remodeling efforts, we developed three probes for ß-galactosidase activity (PA-HD-Gal), nitroreductase activity (PA-HD-NTR), and H2 O2 (PA-HD-H2 O2 ). We generated two cancer models to evaluate PA-HD-Gal and PA-HD-NTR. We employed a murine model of Alzheimer's disease to test PA-HD-H2 O2 . There, we observed a PA signal increase at 735 nm of 1.79±0.20-fold relative to background, indicating the presence of oxidative stress. These results were confirmed via ratiometric calibration, which was not possible using the parent HD platform.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Carbocianinas/química , Corantes Fluorescentes/química , Imagem Óptica , Técnicas Fotoacústicas , Doença de Alzheimer/metabolismo , Animais , Encéfalo/diagnóstico por imagem , Modelos Animais de Doenças , Peróxido de Hidrogênio/química , Camundongos , Estrutura Molecular , Estresse Oxidativo
7.
Angew Chem Int Ed Engl ; 59(8): 3307-3314, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31854058

RESUMO

Cyclooxygenase-2 (COX-2) overexpression is prominent in inflammatory diseases, neurodegenerative disorders, and cancer. Directly monitoring COX-2 activity within its native environment poses an exciting approach to account for and illuminate the effect of the local environments on protein activity. Herein, we report the development of CoxFluor, the first activity-based sensing approach for monitoring COX-2 within live cells with confocal microscopy and flow cytometry. CoxFluor strategically links a natural substrate with a dye precursor to engage both the cyclooxygenase and peroxidase activities of COX-2. This catalyzes the release of resorufin and the natural product, as supported by molecular dynamics and ensemble docking. CoxFluor enabled the detection of oxygen-dependent changes in COX-2 activity that are independent of protein expression within live macrophage cells.


Assuntos
Técnicas Biossensoriais/métodos , Ciclo-Oxigenase 2/química , Humanos , Simulação de Dinâmica Molecular
8.
Indian J Urol ; 36(2): 140-141, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32549669

RESUMO

Pancake kidney is a rare form of renal fusion anomaly. Renal cell carcinoma in such an entity is even rarer and poses a challenge in management due to anomalous vessels. We describe one such patient with an emphasis on successful performance of partial nephrectomy by meticulous planning, with good oncological and functional outcomes.

9.
J Am Chem Soc ; 139(31): 10625-10628, 2017 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-28723089

RESUMO

The design of covalent inhibitors in glycoscience research is important for the development of chemical biology probes. Here we report the synthesis of a new carbocyclic mechanism-based covalent inhibitor of an α-glucosidase. The enzyme efficiently catalyzes its alkylation via either an allylic cation or a cationic transition state. We show this allylic covalent inhibitor has different catalytic proficiencies for pseudoglycosylation and deglycosylation. Such inhibitors have the potential to be useful chemical biology tools.


Assuntos
Inibidores de Glicosídeo Hidrolases/síntese química , Glicosídeo Hidrolases/antagonistas & inibidores , Ativação Enzimática/efeitos dos fármacos , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Glicosilação , Modelos Moleculares , Conformação Molecular
12.
J Am Chem Soc ; 137(3): 1181-9, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25562638

RESUMO

Deficiency of the lysosomal glycoside hydrolase glucocerebrosidase (GCase) leads to abnormal accumulation of glucosyl ceramide in lysosomes and the development of the lysosomal storage disease known as Gaucher's disease. More recently, mutations in the GBA1 gene that encodes GCase have been uncovered as a major genetic risk factor for Parkinson's disease (PD). Current therapeutic strategies to increase GCase activity in lysosomes involve enzyme replacement therapy (ERT) and molecular chaperone therapy. One challenge associated with developing and optimizing these therapies is the difficulty in determining levels of GCase activity present within the lysosomes of live cells. Indeed, visualizing the activity of endogenous levels of any glycoside hydrolases, including GCase, has proven problematic within live mammalian cells. Here we describe the successful modular design and synthesis of fluorescence-quenched substrates for GCase. The selection of a suitable fluorophore and quencher pair permits the generation of substrates that allow convenient time-dependent monitoring of endogenous GCase activity within cells as well as localization of activity within lysosomes. These efficiently quenched (∼99.9%) fluorescent substrates also permit assessment of GCase inhibition in live cells by either confocal microscopy or high content imaging. Such substrates should enable improved understanding of GCase in situ as well the optimization of small-molecule chaperones for this enzyme. These findings also suggest routes to generate fluorescence-quenched substrates for other mammalian glycoside hydrolases for use in live cell imaging.


Assuntos
Fibroblastos/enzimologia , Corantes Fluorescentes/química , Glucosilceramidase/metabolismo , Células Cultivadas , Ativação Enzimática , Corantes Fluorescentes/síntese química , Humanos , Lisossomos/metabolismo , Microscopia Confocal , Microscopia de Fluorescência , Estrutura Molecular
13.
ACS Appl Mater Interfaces ; 16(8): 9680-9689, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38364813

RESUMO

Nitric oxide (NO) generated within the tumor microenvironment is an established driver of cancer progression and metastasis. Recent efforts have focused on leveraging this feature to target cancer through the development of diagnostic imaging agents and activatable chemotherapeutics. In this context, porphyrins represent an extraordinarily promising class of molecules, owing to their demonstrated use within both modalities. However, the remodeling of a standard porphyrin to afford a responsive chemical that can distinguish elevated NO from physiological levels has remained a significant research challenge. In this study, we employed a photoinduced electron transfer strategy to develop a panel of NO-activatable porphyrin photosensitizers (NOxPorfins) augmented with real-time fluorescence monitoring capabilities. The lead compound, NOxPorfin-1, features an o-phenylenediamine trigger that can effectively capture NO (via N2O3) to yield a triazole product that exhibits a 7.5-fold enhancement and a 70-fold turn-on response in the singlet oxygen quantum yield and fluorescence signal, respectively. Beyond demonstrating excellent in vitro responsiveness and selectivity toward NO, we showcase the potent photodynamic therapy (PDT) effect of NOxPorfin-1 in murine breast cancer and human non-small cellular lung cancer cells. Further, to highlight the in vivo efficacy, two key studies were executed. First, we utilized NOxPorfin-1 to ablate murine breast tumors in a site-selective manner without causing substantial collateral damage to healthy tissue. Second, we established a nascent human lung cancer model to demonstrate the unprecedented ability of NOxPorfin-1 to halt tumor growth and progression completely. The results of the latter study have tremendous implications for applying PDT to target metastatic lesions.


Assuntos
Neoplasias Pulmonares , Fotoquimioterapia , Porfirinas , Humanos , Animais , Camundongos , Óxido Nítrico , Porfirinas/farmacologia , Porfirinas/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/química , Neoplasias Pulmonares/tratamento farmacológico , Linhagem Celular Tumoral , Microambiente Tumoral
14.
J Biol Chem ; 287(17): 13985-95, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22393053

RESUMO

Agars are abundant polysaccharides from marine red algae, and their chemical structure consists of alternating D-galactose and 3,6-anhydro-L-galactose residues, the latter of which are presumed to make the polymer recalcitrant to degradation by most terrestrial bacteria. Here we study a family 117 glycoside hydrolase (BpGH117) encoded within a recently discovered locus from the human gut bacterium Bacteroides plebeius. Consistent with this locus being involved in agarocolloid degradation, we show that BpGH117 is an exo-acting 3,6-anhydro-α-(1,3)-L-galactosidase that removes the 3,6-anhydrogalactose from the non-reducing end of neoagaro-oligosaccharides. A Michaelis complex of BpGH117 with neoagarobiose reveals the distortion of the constrained 3,6-anhydro-L-galactose into a conformation that favors catalysis. Furthermore, this complex, supported by analysis of site-directed mutants, provides evidence for an organization of the active site and positioning of the catalytic residues that are consistent with an inverting mechanism of catalysis and suggests that a histidine residue acts as the general acid. This latter feature differs from the vast majority of glycoside hydrolases, which use a carboxylic acid, highlighting the alternative strategies that enzymes may utilize in catalyzing the cleavage of glycosidic bonds.


Assuntos
Ágar/química , Glicosídeo Hidrolases/química , Alga Marinha/química , Sítios de Ligação , Catálise , Domínio Catalítico , Cromatografia em Camada Fina/métodos , Clonagem Molecular , Cristalografia por Raios X/métodos , Hidrólise , Modelos Moleculares , Oligonucleotídeos/química , Polissacarídeos/química , Conformação Proteica , Dobramento de Proteína , Especificidade por Substrato
15.
Prog Mol Biol Transl Sci ; 200: 61-89, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37739560

RESUMO

Synthetic phage analysis has been implemented in progressive various areas of biology, such as genetics, molecular biology, and synthetic biology. Many phage-derived technologies have been altered for developing gene circuits to program biological systems. Due to their extremely potent potency, phages also provide greater medical availability against bacterial agents and bacterial diagnostic agents. Its host specificity and our growing ability to manipulate, them further expand its possibility. New Phages also genetically redesign programmable biomaterials with highly tunable properties. Moreover, new phages are central to powerful directed evolution platforms. It is used to enhance existing biological, functions to create new phages. In other sites, the mining of antibiotics, and the emergence and dissemination of more than one type of drug-resistant microbe, a human health concerns. The major point in controlling and treating microbial infections. At present, genetic modifications and biochemical treatments are used to modify phages. Among these, genetic engineering involves the identification of defective proteins, modification of host bodies, recognized receptors, and disruption of bacterial phage resistance signaling gateways.


Assuntos
Bacteriófagos , Terapia por Fagos , Humanos , Antibacterianos , Edição de Genes , Engenharia Genética
16.
Curr Opin Chem Biol ; 74: 102310, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37119771

RESUMO

Bioluminescence imaging is a highly sensitive technique commonly used for various in vivo applications. Recent efforts to expand the utility of this modality have led to the development of a suite of activity-based sensing (ABS) probes for bioluminescence imaging by 'caging' of luciferin and its structural analogs. The ability to selectively detect a given biomarker has presented researchers with many exciting opportunities to study both health and disease states in animal models. Here, we highlight recent (2021-2023) bioluminescence-based ABS probes with an emphasis on probe design and in vivo validation experiments.


Assuntos
Diagnóstico por Imagem , Medições Luminescentes , Animais , Medições Luminescentes/métodos , Luciferinas , Modelos Animais
17.
Urology ; 178: 138-142, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37028522

RESUMO

Exstrophy variants are uncommon developmental anomalies of the bladder; the variants involving only the bladder neck are extremely rare. There are only three case reports of inferior vesical fissure (IVF) to date, and usually it's uncommonly associated with other malformations. A combination of inferior vesical fistula (IVF) as an exstrophy variant with urethral atresia and anorectal malformation has not been described previously. We report a case of IVF in a 4-year-old male previously operated for anorectal malformation who was managed with fistula closure with bladder neck reconstruction of lay open of stenosed urethra. Recognition of the exstrophy variant is important because the treatment and prognosis are very different.


Assuntos
Malformações Anorretais , Extrofia Vesical , Anormalidades do Sistema Digestório , Fístula da Bexiga Urinária , Masculino , Humanos , Pré-Escolar , Bexiga Urinária/cirurgia , Bexiga Urinária/anormalidades , Extrofia Vesical/cirurgia , Extrofia Vesical/complicações , Malformações Anorretais/complicações , Fístula da Bexiga Urinária/cirurgia , Uretra/cirurgia
18.
Clin Case Rep ; 11(10)2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37799566

RESUMO

This case report documents the unusual co-occurrence of immune thrombocytopena (ITP) and chickenpox in a 15-year-old girl. Initial symptoms included shortness of breath, chest pain, and heavy menstrual bleeding. Laboratory results revealed significant anemia and thrombocytopenia. Treatment involved blood transfusions, prednisolone, and iron supplementation. The patient's vesicular skin rash emerged 8 weeks later, prompting the combined diagnosis of ITP and chickenpox. Antiviral treatments, blood transfusions, and supportive care were used in the course of treatment, leading to full recovery. This case emphasizes the importance of prompt diagnosis, appropriate management, and regular follow-up for patients with both chickenpox and ITP. The coexistence of chickenpox and ITP poses a clinical challenge due to the complex interaction between the viral infection and the immune system. The exact mechanism linking these two conditions remains unclear, making it a baffling case that warrants investigation and further understanding. As low is the occurrence of hemorrhagic chickenpox, the presentation of simultaneous chicken pox with or following ITP was found to be rarer, and thus is this enigmatic case presented. Healthcare providers should remain vigilant about such co-occurrences to prevent complications. In order to improve treatment for instances with comparable clinical presentations and advance our collective knowledge, further study is required to better understand the mechanisms relating viral infections and ITP.

19.
J Biol Chem ; 286(14): 12283-91, 2011 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-21288904

RESUMO

Anhydro-N-acetylmuramic acid kinase (AnmK) catalyzes the ATP-dependent conversion of the Gram-negative peptidoglycan (PG) recycling intermediate 1,6-anhydro-N-acetylmuramic acid (anhMurNAc) to N-acetylmuramic acid-6-phosphate (MurNAc-6-P). Here we present crystal structures of Pseudomonas aeruginosa AnmK in complex with its natural substrate, anhMurNAc, and a product of the reaction, ADP. AnmK is homodimeric, with each subunit comprised of two subdomains that are separated by a deep active site cleft, which bears similarity to the ATPase core of proteins belonging to the hexokinase-hsp70-actin superfamily of proteins. The conversion of anhMurNAc to MurNAc-6-P involves both cleavage of the 1,6-anhydro ring of anhMurNAc along with addition of a phosphoryl group to O6 of the sugar, and thus represents an unusual enzymatic mechanism involving the formal addition of H3PO4 to anhMurNAc. The structural complexes and NMR analysis of the reaction suggest that a water molecule, activated by Asp-182, attacks the anomeric carbon of anhMurNAc, aiding cleavage of the 1,6-anhydro bond and facilitating the capture of the γ phosphate of ATP by O6 via an in-line phosphoryl transfer. AnmK is active only against anhMurNAc and not the metabolically related 1,6-anhydro-N-acetylmuramyl peptides, suggesting that the cytosolic N-acetyl-anhydromuramyl-l-alanine amidase AmpD must first remove the stem peptide from these PG muropeptide catabolites before anhMurNAc can be acted upon by AnmK. Our studies provide the foundation for a mechanistic model for the dual activities of AnmK as a hydrolase and a kinase of an unusual heterocyclic monosaccharide.


Assuntos
Proteínas de Bactérias/metabolismo , Ácidos Murâmicos/metabolismo , Fosfotransferases/metabolismo , Pseudomonas aeruginosa/enzimologia , Trifosfato de Adenosina , Proteínas de Bactérias/genética , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Mutagênese Sítio-Dirigida , Fosfotransferases/genética , Estrutura Secundária de Proteína , Pseudomonas aeruginosa/genética
20.
ACS Cent Sci ; 8(4): 461-472, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35505872

RESUMO

Nitric oxide (NO) plays a critical role in acute and chronic inflammation. NO's contributions to cancer are of particular interest due to its context-dependent bioactivities. For example, immune cells initially produce cytotoxic quantities of NO in response to the nascent tumor. However, it is believed that this fades over time and reaches a concentration that supports the tumor microenvironment (TME). These complex dynamics are further complicated by other factors, such as diet and oxygenation, making it challenging to establish a complete picture of NO's impact on tumor progression. Although many activity-based sensing (ABS) probes for NO have been developed, only a small fraction have been employed in vivo, and fewer yet are practical in cancer models where the NO concentration is <200 nM. To overcome this outstanding challenge, we have developed BL660-NO, the first ABS probe for NIR bioluminescence imaging of NO in cancer. Owing to the low intrinsic background, high sensitivity, and deep tissue imaging capabilities of our design, BL660-NO was successfully employed to visualize endogenous NO in cellular systems, a human liver metastasis model, and a murine breast cancer model. Importantly, its exceptional performance facilitated two dietary studies which examine the impact of fat intake on NO and the TME. BL660-NO provides the first direct molecular evidence that intratumoral NO becomes elevated in mice fed a high-fat diet, which became obese with larger tumors, compared to control animals on a low-fat diet. These results indicate that an inflammatory diet can increase NO production via recruitment of macrophages and overexpression of inducible nitric oxide synthase which in turn can drive tumor progression.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA