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1.
ACS Appl Bio Mater ; 6(10): 4345-4357, 2023 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-37791902

RESUMEN

The emergence of drug-resistant pathogenic microorganisms has become a public health concern, with demand for strategies to suppress their proliferation in healthcare facilities. The present study investigates the physicochemical and antimicrobial properties of carbon dots (CD-MR) derived from the methyl red azo dye. The morphological and structural analyses reveal that such carbon dots present a significant fraction of graphitic nitrogen in their structures, providing a wide emission range. Based on their low cytotoxicity against mammalian cells and tunable photoluminescence, these carbon dots are applied to bioimaging in vitro living cells. The possibility of using CD-MR to generate reactive oxygen species (ROS) is also analyzed, and a high singlet oxygen quantum efficiency is verified. Moreover, the antimicrobial activity of CD-MR is analyzed against pathogenic microorganisms Staphylococcus aureus, Candida albicans, and Cryptococcus neoformans. Kirby-Bauer susceptibility tests show that carbon dots synthesized from methyl red possess antimicrobial activity upon photoexcitation at 532 nm. The growth inhibition of C. neoformans from CD-MR photosensitization is investigated. Our results show that N-doped carbon dots synthesized from methyl red efficiently generate ROS and possess a strong antimicrobial activity against healthcare-relevant pathogens.


Asunto(s)
Antiinfecciosos , Fotoquimioterapia , Puntos Cuánticos , Animales , Carbono/farmacología , Carbono/química , Especies Reactivas de Oxígeno , Puntos Cuánticos/uso terapéutico , Puntos Cuánticos/química , Fotoquimioterapia/métodos , Antiinfecciosos/farmacología , Antiinfecciosos/uso terapéutico , Compuestos Azo/farmacología , Compuestos Azo/uso terapéutico , Mamíferos
2.
Int J Pharm ; 647: 123508, 2023 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-37832705

RESUMEN

Vulvovaginal candidiasis (VVC) persists as a worrying women's healthcare issue, often relying on suboptimal therapeutics. Novel intravaginal dosage forms focusing on improving patient acceptability and featuring improved biopharmaceutical properties could be interesting alternatives to available antifungal products. Different formulations of sponges based on chitosan (Ch), with or without crosslinking and co-formulated with poly(N-vinylcaprolactam) (PNVCL), were produced for the topical administration of clotrimazole (CTZ) and further tested for physicochemical properties, drug release, cytotoxicity and antifungal activity. Results showed that high amounts of CTZ (roughly 30-50 %) could be incorporated into sponges obtained by using a simple freeze-drying methodology. Cross-linking of Ch with ammonia affected the morphology and mechanical features of sponges and shifted the release profile from sustained (around 20 % and 60 % drug released after 4 h and 24 h, respectively) to fast-releasing (over 90 % at 4 h). The combination of PNVCL with non-crosslinked Ch also allowed tuning drug release, namely by increasing the initial amount of CTZ released in simulated vaginal fluid (roughly 40 % after 4 h), as compared to sponges featuring only non-crosslinked Ch. All formulations displayed low toxicity to cell lines derived from the female genital tract, with viability values kept above 70 % after 24 h incubation with sponge extracts. These also allowed maintaining the rapid onset of the antifungal effects of CTZ at minimum inhibitory concentrations ranging from 0.5 to 16 µg/mL for a panel of six different Candida spp. strains. Overall, proposed sponge formulations appear to be promising alternatives for the safe and effective management of VVC.


Asunto(s)
Candidiasis Vulvovaginal , Quitosano , Femenino , Humanos , Candidiasis Vulvovaginal/tratamiento farmacológico , Clotrimazol , Antifúngicos/química , Quitosano/farmacología , Administración Tópica , Candida albicans
3.
Biochemistry ; 62(17): 2530-2540, 2023 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-37540799

RESUMEN

We investigate the physicochemical effects of pyroglutamination on the QHALTSV-NH2 peptide, a segment of cytosolic helix 8 of the human C-X-C chemokine G-protein-coupled receptor type 4 (CXCR4). This modification, resulting from the spontaneous conversion of glutamine to pyroglutamic acid, has significant impacts on the physicochemical features of peptides. Using a static approach, we compared the transformation in different conditions and experimentally found that the rate of product formation increases with temperature, underscoring the need for caution during laboratory experiments to prevent glutamine cyclization. Circular dichroism experiments revealed that the QHALTSV-NH2 segment plays a minor role in the structuration of H8 CXCR4; however, its pyroglutaminated analogue interacts differently with its chemical environment, showing increased susceptibility to solvent variations compared to the native form. The pyroglutaminated analogue exhibits altered behavior when interacting with lipid models, suggesting a significant impact on its interaction with cell membranes. A unique combination of atomic force microscopy and infrared nanospectroscopy revealed that pyroglutamination affects supramolecular self-assembly, leading to highly packed molecular arrangements and a crystalline structure. Moreover, the presence of pyroglumatic acid has been found to favor the formation of amyloidogenic aggregates. Our findings emphasize the importance of considering pyroglutamination in peptide synthesis and proteomics and its potential significance in amyloidosis.


Asunto(s)
Amiloidosis , Glutamina , Humanos , Péptidos , Quimiocinas/química , Membrana Celular/metabolismo , Dicroismo Circular , Receptores CXCR4/metabolismo
4.
Soft Matter ; 19(26): 4869-4879, 2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37334565

RESUMEN

Bradykinin (BK) is a peptide hormone that plays a crucial role in blood pressure control, regulates inflammation in the human body, and has recently been implicated in the pathophysiology of COVID-19. In this study, we report a strategy for fabricating highly ordered 1D nanostructures of BK using DNA fragments as a template for self-assembly. We have combined synchrotron small-angle X-ray scattering and high-resolution microscopy to provide insights into the nanoscale structure of BK-DNA complexes, unveiling the formation of ordered nanofibrils. Fluorescence assays hint that BK is more efficient at displacing minor-groove binders in comparison with base-intercalant dyes, thus, suggesting that interaction with DNA strands is mediated by electrostatic attraction between cationic groups at BK and the high negative electron density of minor-grooves. Our data also revealed an intriguing finding that BK-DNA complexes can induce a limited uptake of nucleotides by HEK-293t cells, which is a feature that has not been previously reported for BK. Moreover, we observed that the complexes retained the native bioactivity of BK, including the ability to modulate Ca2+ response into endothelial HUVEC cells. Overall, the findings presented here demonstrate a promising strategy for the fabrication of fibrillar structures of BK using DNA as a template, which keep bioactivity features of the native peptide and may have implications in the development of nanotherapeutics for hypertension and related disorders.


Asunto(s)
Bradiquinina , COVID-19 , Humanos , Bradiquinina/química , Bradiquinina/farmacología , Péptidos , Transducción de Señal , Células Endoteliales
5.
Pharmaceutics ; 15(3)2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36986744

RESUMEN

Despite numerous efforts over the last three decades, nucleic acid-based therapeutics still lack delivery platforms in the clinical stage. Cell-penetrating peptides (CPPs) may offer solutions as potential delivery vectors. We have previously shown that designing a "kinked" structure in the peptide backbone resulted in a CPP with efficient in vitro transfection properties. Further optimization of the charge distribution in the C-terminal part of the peptide led to potent in vivo activity with the resultant CPP NickFect55 (NF55). Currently, the impact of the linker amino acid was further investigated in the CPP NF55, with the aim to discover potential transfection reagents for in vivo application. Taking into account the expression of the delivered reporter in the lung tissue of mice, and the cell transfection in the human lung adenocarcinoma cell line, the new peptides NF55-Dap and NF55-Dab* have a high potential for delivering nucleic acid-based therapeutics to treat lung associated diseases, such as adenocarcinoma.

6.
Plants (Basel) ; 12(4)2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36840270

RESUMEN

Several studies have reported stingless Meliponini bees gathering hairs from the labella of Maxillaria spp., including M. ochroleuca, a member of the M. splendens alliance. Such hairs usually contain food materials and are thought to have nutritional value. The papillose labella of representatives of the Maxillaria splendens alliance, however, bear scattered, simple 1-5-celled uniseriate trichomes (hairs) that lack food materials. By contrast, here, as well as polyphenolic compounds, typical labellar papillae usually contain small quantities of starch, protein, and minute droplets of lipid, the last probably involved in the production of fragrance. Towards the labellum apex occur elevated groups of papillae that lack food materials, but contain volatile compounds, probably fragrance precursors. In the past, the terms 'trichomes' or 'hairs' and 'papillae' have been used interchangeably, causing some confusion. Since the trichomes, however, unlike the papillae, are easily detachable and can fragment, it is most likely they, not the papillae, that have previously been observed being collected by bees, but their poor food content indicates that they do not function as food-hairs. Even so, our field observations of M. ochroleuca reveal that stingless bees scrape polyphenol-rich labellar tissue and possibly use this material to produce a resinous, complex, heterogeneous substance commonly referred to as 'bee glue', used for nest construction and repair.

7.
Langmuir ; 39(6): 2380-2388, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36744422

RESUMEN

The systemic delivery of drugs employed by conventional methods has shown to be less effective than a localized delivery system. Many drugs have the effectiveness reduced by fast clearance, increasing the amount required for an efficient treatment. One way to overcome this drawback is through the use of thermoresponsive polymers that undergo a sol-gel transition at physiological temperature, allowing their injection directly in the desired site. In this work, thermosensitive nanocomposites based on poly(N-vinylcaprolactam) and silica particles with 80 and 330 nm were synthesized to be employed as delivery systems for hydrophobic (naringin) and hydrophilic (doxorubicin hydrochloride) drugs. The insertion of SiO2 increased the rheological properties of the nanocomposite at 37 °C, which helps to prevent its diffusion away from the site of injection. The synthesized materials were also able to control the drug release for a period of 7 days under physiological conditions. Due to its higher hydrophobicity and better interaction with the PNVCL matrix, naringin presented a more controlled release. The Korsmeyer-Peppas model indicated different release mechanisms for each drug. At last, a preliminary in vitro study of DOX-loaded nanocomposites cultured with L929 and MB49 cells showed negligible toxic effects on healthy cells and better efficient inhibition of carcinoma cells.


Asunto(s)
Nanocompuestos , Dióxido de Silicio , Portadores de Fármacos/toxicidad , Portadores de Fármacos/química , Doxorrubicina/farmacología , Doxorrubicina/química , Temperatura , Interacciones Hidrofóbicas e Hidrofílicas , Nanocompuestos/toxicidad , Sistemas de Liberación de Medicamentos
8.
Curr Protoc ; 2(12): e610, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36521003

RESUMEN

NeuroPAL (Neuronal Polychromatic Atlas of Landmarks) is a recently developed transgene that labels each of the 118 classes of neurons in C. elegans with various combinations of four fluorescent proteins. This neuron-type-specific labeling helps identify neurons that could otherwise be confused with neighboring neurons. Neuron identification enables researchers to combine new data that they generate on a C. elegans neuron with existing datasets on that same neuron, such as its synaptic connections, neurotransmitters, and transcriptome. An impediment to using NeuroPAL, however, is overcoming the steep learning curve for interpreting three-dimensional (3D) fluorescence images of crowded neural ganglia within which different neurons may be similarly colored, some neurons are only very faintly labeled, and the positions of some neurons are variable. Here, we provide protocols that allow researchers to learn to accurately identify neurons within 3D images of NeuroPAL-labeled animals. We provide 3D reference images that illustrate NeuroPAL labeling of each body region, and additional 3D images as training exercises to learn to accurately carry out C. elegans neuron identifications. We also provide tools to annotate images in 3D, and suggest that such 3D annotated images should be the standard for documenting C. elegans neuron identifications for publication. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Using Imaris software to view and annotate images of NeuroPAL-labeled animals in 3D Alternate Protocol: Using FIJI/ImageJ software to view and annotate images of NeuroPAL-labeled animals in 3D Basic Protocol 2: Identifying tail neurons-an introduction to identifying neurons Basic Protocol 3: Identifying midbody neurons Basic Protocol 4: Identifying anterior head neurons Basic Protocol 5: Identifying posterior head neurons Basic Protocol 6: Identifying ventral head and retrovesicular ganglion neurons.


Asunto(s)
Caenorhabditis elegans , Neuronas , Animales , Caenorhabditis elegans/fisiología , Fluorescencia , Neuronas/fisiología , Imagenología Tridimensional/métodos , Ganglios
10.
Am J Bot ; 109(5): 806-820, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35435242

RESUMEN

PREMISE: Angiosperms distributed over a large geographical area may display considerable phenotypic variation that can be recognized at morphological and micromorphological levels. Here, we investigate the pollination biology and the presence of floral rewards in Brazilian populations of the widely distributed orchid, Brasiliorchis picta. Based on the new data presented here this study investigates the evolution of floral rewards in Maxillariinae, and tests for the occurrence of convergent evolution of food-hairs in this subtribe. METHODS: Micromorphological and histochemical analyses of the labellar tissues were conducted, together with chemical analysis of fragrance and experiments involving the use of chemical baits. The evolution of floral rewards in Maxillariinae were addressed. RESULTS: Microscopy revealed that B. picta offers food-hairs as a reward. Fragrance is produced by abaxially located labellar epidermal papillae. The main compound present in our samples (2-phenylethanol) also occurs in the aggregation pheromone produced by the mandible glands of pollinators, Meliponini bees. Our analyses indicate a high diversity of flower rewards and pollinators displayed by members of Maxillariinae, and support that edible trichomes evolved independently five times in the subtribe. CONCLUSIONS: The high diversity of floral rewards and pollinators displayed by members of Maxillariinae suggests that different pollinator pressures are involved in the evolution of this neotropical subtribe. In addition, the offering of food-hairs, which are generally infrequently encountered in Orchidaceae, arose by convergent evolution in Maxillariinae.


Asunto(s)
Orchidaceae , Animales , Abejas , Flores/anatomía & histología , Cabello , Orchidaceae/anatomía & histología , Polinización , Recompensa
11.
Langmuir ; 38(11): 3434-3445, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35274959

RESUMEN

Peptide-based hydrogels have attracted much attention due to their extraordinary applications in biomedicine and offer an excellent mimic for the 3D microenvironment of the extracellular matrix. These hydrated matrices comprise fibrous networks held together by a delicate balance of intermolecular forces. Here, we investigate the hydrogelation behavior of a designed decapeptide containing a tetraleucine self-assembling backbone and fibronectin-related tripeptides near both ends of the strand. We have observed that this synthetic peptide can produce hydrogel matrices entrapping >99% wt/vol % water. Ultrastructural analyses combining atomic force microscopy, small-angle neutron scattering, and X-ray diffraction revealed that amyloid-like fibrils form cross-linked networks endowed with remarkable thermal stability, the structure of which is not disrupted up to temperatures >80 °C. We also examined the interaction of peptide hydrogels with either NIH3T3 mouse fibroblasts or HeLa cells and discovered that the matrices sustain cell viability and induce morphogenesis into grape-like cell spheroids. The results presented here show that this decapeptide is a remarkable building block to prepare highly stable scaffolds simultaneously endowed with high water retention capacity and the ability to instruct cell growth into tumor-like spheroids even in noncarcinoma lineages.


Asunto(s)
Hidrogeles , Nanoestructuras , Amiloide , Animales , Células HeLa , Humanos , Hidrogeles/química , Ratones , Morfogénesis , Células 3T3 NIH , Nanoestructuras/toxicidad , Péptidos/química , Agua
12.
Langmuir ; 37(24): 7373-7379, 2021 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-34101480

RESUMEN

The insertion of nanoparticles into smart hydrogels can diversify their functionalities by a synergistic combination of the components properties within the hydrogels. While these hybrid systems are attractive to the biomaterials field, careful design and control of their properties are required since the new interactions between the polymer and the nanoparticles can result in changes or the loss of hydrogels stimuli response. In order to understand the physicochemical aspects of the thermoresponsive systems, nanocomposites of poly(N-vinylcaprolactam) (PNVCL) and silica nanoparticles with different sizes and concentrations were synthesized. The UV-vis and DLS techniques showed that the PNVCL has a sharp phase transition at 34 °C, while the nanocomposites have a diffuse transition. The nanocomposites showed an initial coil-globule transition before the phase transition takes place. This was identified by the evolution of the hydrodynamic diameter of the nanocomposite globules before the cloud point temperature (Tcp), which remained constant for PNVCL. This new transition profile can be described by two stages in which microscopic volume transitions occur first, followed by the macroscopic transition that forms the hydrogel. These results show that the proposed nanocomposites can be designed to have tunable stimuli response to smaller temperature variations with the formation of intermediate globule states.


Asunto(s)
Nanocompuestos , Nanosferas , Hidrogeles , Polímeros , Dióxido de Silicio , Temperatura
13.
Phys Chem Chem Phys ; 23(18): 10953-10963, 2021 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-33913458

RESUMEN

Four amphiphilic peptides were synthesized, characterized, and evaluated regarding their efficiency in the catalysis of direct aldol reactions in water. The lipopeptides differ by having a double lipid chain and a guanidinium pyrrole group functionalizing one Lys side chain. All the samples are composed of the amino acids l-proline (P), l-arginine (R), or l-lysine (K) functionalized with the cationic guanidiniocarbonyl pyrrole unit (GCP), l-tryptophan (W), and l-glycine (G), covalently linked to one or two long aliphatic chains, leading to surfactant-like designs with controlled proline protonation state and different stereoselectivity. Critical aggregation concentrations (cac) were higher in the presence of the GCP group, suggesting that self-assembly depends on charge distribution along the peptide backbone. Cryogenic Transmission Electron Microscopy (Cryo-TEM) and Small Angle X-ray Scattering (SAXS) showed a rich polymorphism including spherical, cylindrical, and bilayer structures. Molecular dynamics simulations performed to assess the lipopeptide polymorphs revealed an excellent agreement with core-shell arrangements derived from SAXS data and provided an atomistic view of the changes incurred by modifying head groups and lipid chains. The resulting nanostructures behaved as excellent catalysts for aldol condensation reactions, in which superior conversions (>99%), high diastereoselectivities (ds = 94 : 6), and enantioselectivities (ee = 92%) were obtained. Our findings contribute to elucidate the effect of nanoscale organization of lipopeptide assemblies in the catalysis of aldol reactions in an aqueous environment.


Asunto(s)
Aldehídos/química , Lipopéptidos/química , Microscopía por Crioelectrón , Microscopía Electrónica de Transmisión , Conformación Molecular , Simulación de Dinámica Molecular , Tamaño de la Partícula , Dispersión del Ángulo Pequeño , Agua/química , Difracción de Rayos X
14.
Langmuir ; 37(4): 1531-1541, 2021 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-33481601

RESUMEN

Nanocomposite hydrogels have emerged to exhibit multipurpose properties, boosting especially the biomaterial field. However, the development and characterization of these materials can be a challenge, especially stimuli-sensitive materials with dynamic properties in response to external stimuli. By employing UV-vis spectroscopy and NMR relaxation techniques, we could outline the formation and behavior of thermosensitive nanocomposites obtained by in situ polymerization of poly(N-vinylcaprolactam) (PNVCL) and mesoporous silica nanofibers under temperature stimuli. For instance, inorganic nanoparticles covalently linked to PNVCL changed the pattern of temperature-induced phase transition despite showing similar critical temperatures to neat PNVCL. Thermodynamic parameters indicated the formation of an interconnected system of silica and polymer chains with reduced enthalpic contribution and mobility. The investigation of water molecule and polymer segment motions also revealed that the absorption and release of water happened in a wider temperature range for the nanocomposites, and the polymer segments respond in different ways during the phase transition in the presence of silica. This set of techniques was essential to reveal the polymer motions and structural features in nanocomposite hydrogels under temperature stimuli, demonstrating its potential use as experimental guideline to study multicomponent nanocomposites with diverse functionalities and dynamic properties.

15.
ACS Appl Bio Mater ; 4(8): 6404-6416, 2021 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35006917

RESUMEN

Cell-penetrating peptides (CPPs) are a topical subject potentially exploitable for creating nanotherapeutics for the delivery of bioactive loads. These compounds are often classified into three major categories according to their physicochemical characteristics: cationic, amphiphilic, and hydrophobic. Among them, the group of hydrophobic CPPs has received increasing attention in recent years due to toxicity concerns posed by highly cationic CPPs. The hexapeptide PFVYLI (P, proline; F, phenylalanine; V, valine; Y, tyrosine; L, leucine; and I, isoleucine), a fragment derived from the C-terminal portion of α1-antitrypsin, is a prototypal example of hydrophobic CPP. This sequence shows reduced cytotoxicity and a capacity of nuclear localization, and its small size readily hints at its suitability as a building block to construct nanostructured materials. In this study, we examine the self-assembling properties of PFVYLI and investigate its ability to form noncovalent complexes with nucleic acids. By using a combination of biophysical tools including synchrotron small-angle X-ray scattering and atomic force microscopy-based infrared spectroscopy, we discovered that this CPP self-assembles into discrete nanofibrils with remarkable amyloidogenic features. Over the course of days, these fibrils coalesce into rodlike crystals that easily reach the micrometer range. Despite lacking cationic residues in the composition, PFVYLI forms noncovalent complexes with nucleic acids that retain ß-sheet pairing found in amyloid aggregates. In vitro vectorization experiments performed with double-stranded DNA fragments indicate that complexes promote the internalization of nucleic acids, revealing that tropism toward cell membranes is preserved upon complexation. On the other hand, transfection assays with splice-correction oligonucleotides (SCOs) for luciferase expression show limited bioactivity across a narrow concentration window, suggesting that the propensity to form amyloidogenic aggregates may trigger endosomal entrapment. We anticipate that the findings presented here open perspectives for using this archetypical hydrophobic CPP in the fabrication of nanostructured scaffolds, which potentially integrate properties of amyloids and translocation capabilities of CPPs.


Asunto(s)
Péptidos de Penetración Celular , Ácidos Nucleicos , Proteínas Amiloidogénicas/genética , Péptidos de Penetración Celular/química , Interacciones Hidrofóbicas e Hidrofílicas , Ácidos Nucleicos/metabolismo , Oligonucleótidos/genética , Transfección
16.
Langmuir ; 36(48): 14793-14801, 2020 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-33210929

RESUMEN

The aggregation of two short peptides, [RF] and [RF]4 (where R = arginine and F = phenylalanine), at dipalmitoylphosphatidylcholine (DPPC) model membranes was investigated at the air-water interface using the Langmuir technique and vesicles in aqueous solutions. The molar ratio of the peptide and lipid components was varied to provide insights into the peptide-membrane interactions, which might be related to their cytotoxicity. Both peptides exhibited affinity to the DPPC membrane interface and rapidly adopted ß-sheet-rich structures upon adsorption onto the surface of the zwitterionic membrane. Results from adsorption isotherm and small-angle X-ray scattering experiments showed changes in the structural and thermodynamic parameters of the membrane with increasing peptide concentration. Using atomic force microscopy, we showed the appearance of pores through the bilayer membranes and peptide aggregation at different interfaces, suggesting that the hydrophobic residues might have an effect on both pore size and layer structure, facilitating the membrane disruption and leading to different cytotoxicity effects.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina , Péptidos , Adsorción , Amiloide , Membrana Dobles de Lípidos , Péptidos/toxicidad , Termodinámica
17.
Front Oncol ; 10: 583349, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33163411

RESUMEN

INTRODUCTION: Cord blood transplantation (CBT) recipients are at increased risk of mortality due to delayed immune recovery (IR). Prior studies in CBT patients have shown that recovery of absolute lymphocyte count is predictive of survival after transplant. However, there are no data on the association of T-cell receptor (TCR) and clinical outcomes after CBT. Here we retrospectively performed TCR beta chain sequencing on peripheral blood (PB) samples of 34 CBT patients. METHODS: All patients received a total body irradiation based conditioning regimen and cyclosporine and MMF were used for graft versus host disease (GvHD) prophylaxis. PB was collected pretransplant on days 28, 56, 80, 180, and 1-year posttransplant for retrospective analysis of IR utilizing high-throughput sequencing of TCRß rearrangements from genomic DNA extracted from PB mononuclear cells. To test the association between TCR repertoire diversity and patient outcomes, we conducted a permutation test on median TCR repertoire diversity for patients who died within the first year posttransplant versus those who survived. RESULTS: Median age was 27 (range 1-58 years) and most of the patients (n = 27) had acute leukemias. There were 15 deaths occurring between 34 to 335 days after transplant. Seven deaths were due to relapse. Rapid turnover of T cell clones was observed at each time point, with TCR repertoires stabilizing by 1-year posttransplant. TCR diversity values at day 100 for patients who died between 100 and 365 days posttransplant were significantly lower than those of the surviving patients (p = 0.01). CONCLUSIONS: Using a fast high-throughput TCR sequencing assay we have demonstrated that high TCR diversity is associated with better patient outcomes following CBT. Importantly, this assay is easily performed on posttransplant PB samples, even as early as day 28 posttransplant, making it an excellent candidate for early identification of patients at high risk of death.

18.
Cell Rep ; 32(1): 107858, 2020 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-32640224

RESUMEN

During mammalian meiotic prophase I, programmed DNA double-strand breaks are repaired by non-crossover or crossover events, the latter predominantly occurring via the class I crossover pathway and requiring the cyclin N-terminal domain-containing 1(CNTD1) protein. Using an epitope-tagged Cntd1 allele, we detect a short isoform of CNTD1 in vivo that lacks a predicted N-terminal cyclin domain and does not bind cyclin-dependent kinases. Instead, we find that the short-form CNTD1 variant associates with components of the replication factor C (RFC) machinery to facilitate crossover formation, and with the E2 ubiquitin conjugating enzyme, CDC34, to regulate ubiquitylation and subsequent degradation of the WEE1 kinase, thereby modulating cell-cycle progression. We propose that these interactions facilitate a role for CNTD1 as a stop-go regulator during prophase I, ensuring accurate and complete crossover formation before allowing metaphase progression and the first meiotic division.


Asunto(s)
Intercambio Genético , Ciclinas/metabolismo , Meiosis , Alelos , Animales , Núcleo Celular/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Ciclinas/química , Ciclinas/genética , Mapeo Epitopo , Puntos de Control de la Fase M del Ciclo Celular , Masculino , Profase Meiótica I , Metafase , Ratones Endogámicos C57BL , Mutación/genética , Fase Paquiteno , Antígeno Nuclear de Célula en Proliferación/metabolismo , Proteína de Replicación C/metabolismo , Espermatocitos/metabolismo
19.
Colloids Surf B Biointerfaces ; 193: 111131, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32512370

RESUMEN

In order to make more efficient chitosan-based nanoparticles for transfection in physiological condition, chitosomes composed of chitosan modified with arginine and complexed with DOTAP/DOPE lipids are synthesized (named chitosomes) by reverse phase evaporation technique. Structure analyses of chitosomes with or without plasmid DNA (pDNA) are performed by electrophoresis, zeta potential, dynamic light scattering, small angle X-ray scattering and isothermal titration calorimetry, and transfection efficiency and cytotoxicity are performed in HEK293 T cells. Chitosomes have a positive surface charge (X¯= 52 mV) with an average size of 116 nm, and interaction with pDNA are favored thermodynamically and do not suffer aggregation significantly. In our experimental conditions, the transfection efficiency average reaches 86% ±â€¯3, while the Lipofectamine® reaches 87% ±â€¯5 in vitro. Cytotoxicity of chitosomes are tolerable. Structural analyses show that that chitosomes-pDNA complexes appear to have multilamellar vesicle structures hosting pDNA in-between bilayers which favor interaction with cell membrane and delivery of pDNA. Results show that synthesized chitosomes are promising carriers for gene delivery.


Asunto(s)
Arginina/química , Quitosano/química , ADN/química , Técnicas de Transferencia de Gen , Arginina/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Quitosano/farmacología , ADN/genética , Células HEK293 , Humanos , Liposomas/química , Liposomas/farmacología , Estructura Molecular , Tamaño de la Partícula , Plásmidos , Propiedades de Superficie
20.
Future Microbiol ; 15: 273-285, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32271112

RESUMEN

Aim: To assemble, characterize and assess the antifungal effects of a new fluconazole (FLZ)-carrier nanosystem. Materials & methods: The nanosystem was prepared by loading FLZ on chitosan (CS)-coated iron oxide nanoparticles (IONPs). Antifungal effects were evaluated on planktonic cells (by minimum inhibitory concentration determination) and on biofilms (by quantification of cultivable cells, total biomass, metabolism and extracellular matrix) of Candida albicans and Candida glabrata. Results: Characterization results ratified the formation of a nanosystem (<320 nm) with FLZ successfully embedded. IONPs-CS-FLZ nanosystem reduced minimum inhibitory concentration values and, in general, showed similar antibiofilm effects compared with FLZ alone. Conclusion: IONPs-CS-FLZ nanosystem was more effective than FLZ mainly in inhibiting Candida planktonic cells. This nanocarrier has potential to fight fungal infections.


Asunto(s)
Antifúngicos/química , Antifúngicos/farmacología , Portadores de Fármacos/química , Fluconazol/química , Fluconazol/farmacología , Nanopartículas/química , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Candida albicans/fisiología , Candida glabrata/efectos de los fármacos , Candida glabrata/fisiología , Quitosano/química , Composición de Medicamentos , Pruebas de Sensibilidad Microbiana
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