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1.
Mol Cell ; 70(2): 340-357.e8, 2018 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-29628309

RESUMEN

Whereas the actions of enhancers in gene transcriptional regulation are well established, roles of JmjC-domain-containing proteins in mediating enhancer activation remain poorly understood. Here, we report that recruitment of the JmjC-domain-containing protein 6 (JMJD6) to estrogen receptor alpha (ERα)-bound active enhancers is required for RNA polymerase II recruitment and enhancer RNA production on enhancers, resulting in transcriptional pause release of cognate estrogen target genes. JMJD6 is found to interact with MED12 in the mediator complex to regulate its recruitment. Unexpectedly, JMJD6 is necessary for MED12 to interact with CARM1, which methylates MED12 at multiple arginine sites and regulates its chromatin binding. Consistent with its role in transcriptional activation, JMJD6 is required for estrogen/ERα-induced breast cancer cell growth and tumorigenesis. Our data have uncovered a critical regulator of estrogen/ERα-induced enhancer coding gene activation and breast cancer cell potency, providing a potential therapeutic target of ER-positive breast cancers.


Asunto(s)
Neoplasias de la Mama/enzimología , Proliferación Celular , Receptor alfa de Estrógeno/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Complejo Mediador/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Activación Transcripcional , Animales , Sitios de Unión , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Estradiol/farmacología , Receptor alfa de Estrógeno/agonistas , Receptor alfa de Estrógeno/genética , Femenino , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Células MCF-7 , Complejo Mediador/genética , Ratones Endogámicos BALB C , Ratones Desnudos , Unión Proteica , Transporte de Proteínas , Proteína-Arginina N-Metiltransferasas/genética , Transducción de Señal , Activación Transcripcional/efectos de los fármacos
2.
Nano Lett ; 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38855905

RESUMEN

Neurotoxins are known for their extreme lethality. However, due to their enormous diversity, effective and broad-spectrum countermeasures are lacking. This study presents a dual-modal cellular nanoparticle (CNP) formulation engineered for continuous neurotoxin neutralization. The formulation involves encapsulating the metabolic enzyme N-sulfotransferase (SxtN) into metal-organic framework (MOF) nanoparticle cores and coating them with a natural neuronal membrane, termed "Neuron-MOF/SxtN-NPs". The resulting nanoparticles combine membrane-enabled broad-spectrum neurotoxin neutralization with enzyme payload-enabled continuous neurotoxin neutralization. The studies confirm the protection of the enzyme payload by the MOF core and validate the continuous neutralization of saxitoxin (STX). In vivo studies conducted using a mouse model of STX intoxication reveal markedly improved survival rates compared with control groups. Furthermore, acute toxicity assessments show no adverse effects associated with the administration of Neuron-MOF/SxtN-NPs in healthy mice. Overall, Neuron-MOF/SxtN-NPs represent a unique biomimetic nanomedicine platform poised to effectively neutralize neurotoxins, marking an important advancement in the field of countermeasure nanomedicine.

3.
Small ; 20(14): e2309635, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37990378

RESUMEN

Neurotoxins present a substantial threat to human health and security as they disrupt and damage the nervous system. Their potent and structurally diverse nature poses challenges in developing effective countermeasures. In this study, a unique nanoparticle design that combines dual-biomimicry mechanisms to enhance the detoxification efficacy of neurotoxins is introduced. Using saxitoxin (STX), one of the deadliest neurotoxins, and its natural binding protein saxiphilin (Sxph) as a model system, human neuronal membrane-coated and Sxph-loaded metal-organic framework (MOF) nanosponges (denoted "Neuron-MOF/Sxph-NS") are successfully developed. The resulting Neuron-MOF/Sxph-NS exhibit a biomimetic design that not only emulates host neurons for function-based detoxification through the neuronal membrane coating, but also mimics toxin-resistant organisms by encapsulating the Sxph protein within the nanoparticle core. The comprehensive in vitro assays, including cell osmotic swelling, calcium flux, and cytotoxicity assays, demonstrate the improved detoxification efficacy of Neuron-MOF/Sxph-NS. Furthermore, in mouse models of STX intoxication, the application of Neuron-MOF/Sxph-NS shows significant survival benefits in both therapeutic and prophylactic regimens, without any apparent acute toxicity. Overall, the development of Neuron-MOF/Sxph-NS represents an important advancement in neurotoxin detoxification, offering promising potential for treating injuries and diseases caused by neurotoxins and addressing the current limitations in neurotoxin countermeasures.


Asunto(s)
Estructuras Metalorgánicas , Nanopartículas , Animales , Ratones , Humanos , Neurotoxinas , Membrana Celular , Proteínas Portadoras , Nanopartículas/química , Neuronas
4.
Phys Rev Lett ; 132(12): 126402, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38579203

RESUMEN

The GW approximation is widely used for reliable and accurate modeling of single-particle excitations. It also serves as a starting point for many theoretical methods, such as its use in the Bethe-Salpeter equation (BSE) and dynamical mean-field theory. However, full-frequency GW calculations for large systems with hundreds of atoms remain computationally challenging, even after years of efforts to reduce the prefactor and improve scaling. We propose a method that reformulates the correlation part of the GW self-energy as a resolvent of a Hermitian matrix, which can be efficiently and accurately computed using the standard Lanczos method. This method enables full-frequency GW calculations of material systems with a few hundred atoms on a single computing workstation. We further demonstrate the efficiency of the method by calculating the defect-state energies of silicon quantum dots with diameters up to 4 nm and nearly 2,000 silicon atoms using only 20 computational nodes.

5.
BMC Infect Dis ; 24(1): 7, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166793

RESUMEN

BACKGROUND: About 8% of TB cases worldwide are estimated to have rifampicin-susceptible, isoniazid-resistant tuberculosis (Hr-TB), ranging from 5 to 11% regions. However, Hr-TB has not received much attention while comparing to be given high priority to the management of rifampicin-resistant tuberculosis (RR-TB). This study aimed to compare the differences of treatment effects for Hr-TB and RR-TB, so as to intensify the treatment and management of Hr-TB. METHODS: A retrospective study was used to collect bacteriologically positive retreated patients with isoniazid/rifampicin resistant pulmonary tuberculosis, who were conducted at 29 tuberculosis control institutions in China from July 2009 to June 2021. We assessed effectiveness and safety of retreated patients with isoniazid/ rifampicin resistant pulmonary tuberculosis. RESULTS: A total of 147 with either positive smear or cultures were enrolled, and 80 cases were in Hr-TB group and 67 cases were in RR-TB group. There was no significant difference in terms of age, sex, body mass, type of retreatment and comorbid diabetes between the two groups (P > 0.05). The rate of number of lesions involving lung fields ≥ 3 in Hr-TB group 75.9% (60/79) was significantly higher than RR-TB group 56.7% (38/67) (χ2 = 6.077, P = 0.014). There was no statistically significant difference (P = 0.166) with regard to the treatment outcomes of the two groups, the cure rates were 54.7% (41/75) and 53.6% (30/56), respectively, and the failure rate in Hr-TB group 22.7% (17/75) was 10% higher than RR-TB group 10.7% (6/56). The rate of negative sputum smear at the end of the second month (65.7%) in the Hr-TB group was significantly lower than that in the RR-TB group (85.7%) (P = 0.025). There were no significant differences in the incidences of serious adverse reactions and chest X-ray changes between the two groups (P > 0.05). During the 5-year follow-up, recurrence in the Hr-TB group (7 cases, 14.9%) was no significantly lower than that in the RR-TB group (4 cases, 11.8%) (P = 0.754). CONCLUSION: The treatment of retreated Hr-TB patients was difficult and could be statistically similar or considerably worse than RR-TB. It's urgent to conduct further evaluation of the treatment status quo to guide the guideline development and clinical practice of Hr-TB patients.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Tuberculosis Pulmonar , Humanos , Rifampin/uso terapéutico , Isoniazida/uso terapéutico , Antituberculosos/uso terapéutico , Estudios Retrospectivos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Pulmonar/tratamiento farmacológico , Resultado del Tratamiento
6.
Bioorg Chem ; 148: 107451, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38759357

RESUMEN

Aminothiazolyl coumarins as potentially new antimicrobial agents were designed and synthesized in an effort to overcome drug resistance. Biological activity assay revealed that some target compounds exhibited significantly inhibitory efficiencies toward bacteria and fungi including drug-resistant pathogens. Especially, aminothiazolyl 7-propyl coumarin 8b and 4-dichlorobenzyl derivative 11b exhibited bactericidal potential (MBC/MIC = 2) toward clinically drug-resistant Enterococcus faecalis with low cytotoxicity to human lung adenocarcinoma A549 cells, rapidly bactericidal effects and no obvious bacterial resistance development against E. faecalis. The preliminary antibacterial action mechanism studies suggested that compound 11b was able to disturb E. faecalis membrane effectively, and interact with bacterial DNA isolated from resistant E. faecalis through noncovalent bonds to cleave DNA, thus inhibiting the growth of E. faecalis strain. Further molecular modeling indicated that compounds 8b and 11b could bind with SER-1084 and ASP-1083 residues of gyrase-DNA complex through hydrogen bonds and hydrophobic interactions. Moreover, compound 11b showed low hemolysis and in vivo toxicity. These findings of aminothiazolyl coumarins as unique structural scaffolds might hold a large promise for the treatments of drug-resistant bacterial infection.


Asunto(s)
Antibacterianos , Cumarinas , Enterococcus faecalis , Pruebas de Sensibilidad Microbiana , Enterococcus faecalis/efectos de los fármacos , Cumarinas/química , Cumarinas/farmacología , Cumarinas/síntesis química , Humanos , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Relación Estructura-Actividad , Estructura Molecular , Relación Dosis-Respuesta a Droga , Tiazoles/química , Tiazoles/farmacología , Tiazoles/síntesis química , ADN Bacteriano/metabolismo , Células A549 , Hemólisis/efectos de los fármacos
7.
Bioorg Chem ; 144: 107141, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38244381

RESUMEN

In this work, we rationally designed and synthesized two novel triazene-amonafide derivatives 2-(2-(diisopropylamino)ethyl)-5-(3,3-dimethyltriaz-1-en-1-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (D-11) and 5-(3,3-diethyltriaz-1-en-1-yl)-2-(2-(diisopropylamino)ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (D-12) as potential antitumor agents. The DNA damage induced by the intercalation mode of D-11 (D-12) towards DNA was electrochemically detected through the construction of efficient biosensors. The consecutive processes of reversible redox of naphthylimide ring and irreversible oxidation of triazene moiety were elucidated on the surface of glassy carbon electrode (GCE) by CV, SWV, and DPV methods. Electrochemical biosensors were obtained through the immobilization of ctDNA, G-quadruplexes, poly(dG), and poly(dA), respectively, on the clean surface of GCE. After the incubation of biosensors with D-11 or D-12, the peaks of dGuo and dAdo decreased prominently, and the peak of 8-oxoGua appeared at +0.50 V, suggesting that the interaction between D-11 (D-12) and DNA could result in the oxidative damage of guanine. Unexpected, the as-prepared DNA biosensor possessed satisfactory anti-interference property and good practicability in real samples. UV-vis and fluorescence spectra, and gel electrophoresis assays were employed to further confirm the intercalation mode of D-11 (D-12) towards DNA base pairs. Moreover, D-11 was proved to exhibit stronger anti-proliferation activity than mitionafide and amonafide against both A549 and HeLa cell lines.


Asunto(s)
Adenina , Antineoplásicos , ADN , Organofosfonatos , Humanos , Células HeLa , ADN/química , Antineoplásicos/farmacología , Antineoplásicos/química , Carbono/química , Triazenos , Estrés Oxidativo , Isoquinolinas
8.
Artículo en Inglés | MEDLINE | ID: mdl-38639625

RESUMEN

Background: Uremic pruritus is a prevalent clinical symptom in maintenance dialysis patients. Existing evidence establishes a connection between itch transmission and the gastrin-releasing peptide/gastrin-releasing peptide receptor signaling pathway. Objective: To investigate the involvement of the gastrin-releasing peptide/gastrin-releasing peptide receptor in itch sensation signaling within the spinal cord of uremic pruritus. Design: An animal study was conducted. Setting: The research was conducted at the First Hospital of Hebei Medical University. Participants: A total of 50 male C57BL/6J mice (weight: 30-40 g) were acquired from Beijing Weitonglihua Laboratory Animal Center. Interventions: Mice were categorized into five groups: normal, sham, Y, A, and B. The Y group received intrathecal injections of saline (5 ul). The A group received intrathecal injections of gastrin-releasing peptide (0.1 nmol, 5 ul), and the B group received intrathecal injections of the gastrin-releasing peptide receptor antagonist RC-3095 (0.3 mmol, 5 ul). Primary Outcome Measures: (1) Pruritus behavior of mice and (2) expression of gastrin-releasing peptide, gastrin-releasing peptide receptor, and inositol trisphosphate. Results: Scratching times in the Y group significantly surpassed those of normal and sham groups, increasing over time. Gastrin-releasing peptide and receptor expression rose in the uremic pruritus mouse model compared to normal and sham groups (P < .05). Expression of gastrin-releasing peptide and its receptor was significantly elevated in the uremic pruritus mouse model compared to the normal and sham groups (P < .05). Inositol trisphosphate expression in the dorsal spinal horn of Y group mice increased compared to normal and sham groups. Intrathecal gastrin-releasing peptide heightened inositol trisphosphate expression, while the peptide receptor antagonist RC-3095 reduced it. Y group scratching times were higher than normal and sham groups, increasing after intrathecal gastrin-releasing peptide but decreasing after RC-3095 injection. Conclusion: The gastrin-releasing peptide/gastrin-releasing peptide receptor signaling pathway is involved in the development of uremic pruritus.

9.
Nano Lett ; 23(17): 7941-7949, 2023 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-37602707

RESUMEN

Cell membrane-based nanovaccines have demonstrated attractive features due to their inherently multiantigenic nature and ability to be formulated with adjuvants. Here, we report on cellular nanodiscs fabricated from cancer cell membranes and incorporated with a lipid-based adjuvant for antitumor vaccination. The cellular nanodiscs, with their small size and discoidal shape, are readily taken up by antigen-presenting cells and drain efficiently to the lymph nodes. Due to its highly immunostimulatory properties, the nanodisc vaccine effectively stimulates the immune system and promotes tumor-specific immunity. Using a murine colorectal cancer model, strong control of tumor growth is achieved in both prophylactic and therapeutic settings, particularly in combination with checkpoint blockades. Considerable therapeutic efficacy is also observed in treating a weakly immunogenic metastatic melanoma model. This work presents a new paradigm for the design of multiantigenic nanovaccines that can effectively activate antitumor immune responses and may be applicable to a wide range of cancers.


Asunto(s)
Melanoma , Vacunación , Animales , Ratones , Membrana Celular , Membranas , Células Presentadoras de Antígenos , Adyuvantes Inmunológicos/uso terapéutico
10.
J Youth Adolesc ; 53(8): 1820-1831, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38600263

RESUMEN

Although metacognition plays a pivotal role in theoretical accounts of mind wandering, their longitudinal relationships have not yet been investigated during the important developmental period of early adolescence. This study aimed to examine the developmental trajectories of spontaneous and deliberate mind wandering and the dynamic associations between metacognition and two types of mind wandering in early adolescence. A sample of 4302 Chinese students beginning in Grade 4 (47.4% female; initial Mage = 9.84, SDage = 0.47) completed questionnaires on five occasions over 2.5 years. The results showed that deliberate mind wandering, but not spontaneous mind wandering, gradually increased from Grade 4 to Grade 6. Metacognition was negatively related to spontaneous mind wandering but positively related to deliberate mind wandering. These findings provide empirical evidence for theoretical viewpoints from both individual differences and developmental perspectives.


Asunto(s)
Atención , Metacognición , Humanos , Femenino , Masculino , Estudios Longitudinales , Adolescente , Niño , China , Encuestas y Cuestionarios , Desarrollo del Adolescente , Conducta del Adolescente/psicología , Estudiantes/psicología , Pensamiento
11.
Small ; 19(35): e2301144, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37186449

RESUMEN

Because of its light weight and high strength, bamboo is used in many applications around the world. Natural bamboo is built from fiber-reinforced material and exhibits a porous graded architecture that provides its remarkable mechanical performance. This porosity gradient is generated through the unique distribution of densified vascular bundles. Scientists and engineers have been trying to mimic this architecture for a very long time with much of the work focusing on the effect of fiber reinforcement. However, there still lacks quantitative studies on the role of pore gradient design on mechanical properties, in part because the fabrication of bamboo-inspired graded materials is challenging. Here, the steep and continuous porosity gradient through an ingenious cellular design in Moso bamboo is revealed. The effect of gradient design on the mechanical performance is systematically studied by using 3D-printed models. The results show that not only the magnitude of gradient but also its continuity have a significant effect. By introducing a continuous and large gradient, the maximum flexural load and energy absorption capability can be increased by 40% and 110% when comparing to the structure without gradient. These bamboo-inspired cellular architectures can offer efficient solutions for the design of damage tolerant engineering structures.

12.
Small ; 19(52): e2305551, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37635117

RESUMEN

Nanoparticles coated with natural cell membranes have emerged as a promising class of biomimetic nanomedicine with significant clinical potential. Among them, macrophage membrane-coated nanoparticles hold particular appeal due to their versatility in drug delivery and biological neutralization applications. This study employs a genetic engineering approach to enhance their in vivo residence times, aiming to further improve their performance. Specifically, macrophages are engineered to express proline-alanine-serine (PAS) peptide chains, which provide additional protection against opsonization and phagocytosis. The resulting modified nanoparticles demonstrate prolonged residence times when administered intravenously or introduced intratracheally, surpassing those coated with the wild-type membrane. The longer residence times also contribute to enhanced nanoparticle efficacy in inhibiting inflammatory cytokines in mouse models of lipopolysaccharide-induced lung injury and sublethal endotoxemia, respectively. This study underscores the effectiveness of genetic modification in extending the in vivo residence times of macrophage membrane-coated nanoparticles. This approach can be readily extended to modify other cell membrane-coated nanoparticles toward more favorable biomedical applications.


Asunto(s)
Sistemas de Liberación de Medicamentos , Nanopartículas , Ratones , Animales , Sistemas de Liberación de Medicamentos/métodos , Macrófagos/metabolismo , Membrana Celular/metabolismo , Citoplasma
13.
Small ; : e2308327, 2023 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-38044300

RESUMEN

The multifaceted functions of platelets in various physiological processes have long inspired the development of therapeutic nanoparticles that mimic specific platelet features for disease treatment. Here, the development and characterization of platelet membrane-derived nanodiscs (PLT-NDs) as platelet decoys for biological neutralization is reported. In one application, PLT-NDs effectively bind with anti-platelet autoantibodies, thus blocking them from interacting with platelets. In a mouse model of thrombocytopenia, PLT-NDs successfully neutralize pathological anti-platelet antibodies, preventing platelet depletion and maintaining hemostasis. In another application, PLT-NDs effectively neutralize the cytotoxicity of bacterial virulence factors secreted by methicillin-resistant Staphylococcus aureus (MRSA). In a mouse model of MRSA infection, treatment with PLT-NDs leads to significant survival benefits for the infected mice. Additionally, PLT-NDs show good biocompatibility and biosafety, as demonstrated in acute toxicity studies conducted in mice. These findings underscore the potential of PLT-NDs as a promising platelet mimicry for neutralizing various biological agents that target platelets. Overall, this work expands the repertoire of platelet-mimicking nanomedicine by creating a unique disc-like nanostructure made of natural platelet membranes.

14.
Nat Mater ; 21(11): 1324-1332, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36138145

RESUMEN

Bioinspired microrobots capable of actively moving in biological fluids have attracted considerable attention for biomedical applications because of their unique dynamic features that are otherwise difficult to achieve by their static counterparts. Here we use click chemistry to attach antibiotic-loaded neutrophil membrane-coated polymeric nanoparticles to natural microalgae, thus creating hybrid microrobots for the active delivery of antibiotics in the lungs in vivo. The microrobots show fast speed (>110 µm s-1) in simulated lung fluid and uniform distribution into deep lung tissues, low clearance by alveolar macrophages and superb tissue retention time (>2 days) after intratracheal administration to test animals. In a mouse model of acute Pseudomonas aeruginosa pneumonia, the microrobots effectively reduce bacterial burden and substantially lessen animal mortality, with negligible toxicity. Overall, these findings highlight the attractive functions of algae-nanoparticle hybrid microrobots for the active in vivo delivery of therapeutics to the lungs in intensive care unit settings.


Asunto(s)
Nanopartículas , Neumonía Bacteriana , Ratones , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Neumonía Bacteriana/tratamiento farmacológico , Neumonía Bacteriana/microbiología , Pseudomonas aeruginosa , Pulmón
15.
Plant Physiol ; 189(2): 889-905, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35188194

RESUMEN

Mediating induced abscisic acid (ABA) biosynthesis is important for enhancing plant stress tolerance. Here, we found that rice (Oryza sativa L.) osa-miR2105 (miR2105) and the Stress/ABA-activated protein kinase (OsSAPK10) coordinately regulate the rice basic region-leucine zipper transcription factor (bZIP TF; OsbZIP86) at the posttranscriptional and posttranslational levels to control drought-induced ABA biosynthesis via modulation of rice 9-cis-epoxycarotenoid dioxygenase (OsNCED3) expression. OsbZIP86 expression is regulated by miR2105-directed cleavage of the OsbZIP86 mRNA. OsbZIP86 encodes a nuclear TF that binds to the promoter of the ABA biosynthetic gene OsNCED3. OsSAPK10 can phosphorylate and activate OsbZIP86 to enhance the expression of OsNCED3. Under normal growth conditions, altered expression of miR2105 and OsbZIP86 displayed no substantial effect on rice growth. However, under drought conditions, miR2105 knockdown or OsbZIP86 overexpression transgenic rice plants showed higher ABA content, enhanced tolerance to drought, lower rates of water loss, and more stomatal closure of seedlings, compared with wild-type rice Zhonghua 11; in contrast, miR2105 overexpression, OsbZIP86 downregulation, and OsbZIP86 knockout plants displayed opposite phenotypes. Collectively, our results show that the "miR2105-(OsSAPK10)-OsbZIP86-OsNCED3" module regulates the drought-induced ABA biosynthesis without penalty on rice growth under normal conditions, suggesting candidates for improving drought tolerance in rice.


Asunto(s)
Oryza , Ácido Abscísico/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Estrés Fisiológico/genética
16.
Anal Bioanal Chem ; 415(12): 2249-2260, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36920495

RESUMEN

In this work, we design and synthesize 2,2'-(7,9-dimethyl-2,4,6,8-tetraoxo-6,7,8,9-tetrahydropyrimido[5,4-g]pteridine-1,3(2H,4H)-diyl)bis(N,N-bis(2-chloroethyl)acetamide) (PT-MCA) as a novel DNA intercalator and potential antitumor agent. Electrochemical analysis reveals the redox process of PT-MCA on the electrode surface. The bioelectrochemical sensors are obtained by modifying the surface of GCE with calf thymus DNA (ctDNA), poly (dG), poly (dA), and G-quadruplex, respectively. The DNA oxidative damage induced by PT-MCA is investigated by comparing the peak intensity change of dGuo and dAdo and monitoring the peaks of the oxidation products of guanine and/or adenine (8-oxoGua and/or 2,8-oxoAde). UV-vis absorption and fluorescence spectra and gel electrophoresis are further employed to understand the intercalation of PT-MCA into DNA base pairs. Moreover, PT-MCA is proved to exhibit stronger anti-proliferation activity than mitoxantrone against both 4T1 and B16-F10 cancer cells. At last, the oxidative damage of PT-MCA toward ctDNA is not interfered by the coexistence of ions and also can be detected in real serums.


Asunto(s)
Antineoplásicos , Pteridinas , ADN/genética , Antineoplásicos/farmacología , Adenina , Estrés Oxidativo , Daño del ADN
17.
Mol Cell ; 59(6): 931-40, 2015 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-26365380

RESUMEN

Glaucoma, a blinding neurodegenerative disease, whose risk factors include elevated intraocular pressure (IOP), age, and genetics, is characterized by accelerated and progressive retinal ganglion cell (RGC) death. Despite decades of research, the mechanism of RGC death in glaucoma is still unknown. Here, we demonstrate that the genetic effect of the SIX6 risk variant (rs33912345, His141Asn) is enhanced by another major POAG risk gene, p16INK4a (cyclin-dependent kinase inhibitor 2A, isoform INK4a). We further show that the upregulation of homozygous SIX6 risk alleles (CC) leads to an increase in p16INK4a expression, with subsequent cellular senescence, as evidenced in a mouse model of elevated IOP and in human POAG eyes. Our data indicate that SIX6 and/or IOP promotes POAG by directly increasing p16INK4a expression, leading to RGC senescence in adult human retinas. Our study provides important insights linking genetic susceptibility to the underlying mechanism of RGC death and provides a unified theory of glaucoma pathogenesis.


Asunto(s)
Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Glaucoma de Ángulo Abierto/metabolismo , Proteínas de Homeodominio/fisiología , Células Ganglionares de la Retina/fisiología , Transactivadores/fisiología , Secuencia de Aminoácidos , Animales , Estudios de Casos y Controles , Muerte Celular , Línea Celular , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Glaucoma de Ángulo Abierto/genética , Glaucoma de Ángulo Abierto/patología , Humanos , Ratones Endogámicos C57BL , Ratones Noqueados , Datos de Secuencia Molecular , Mutación Missense , Regulación hacia Arriba
18.
Nano Lett ; 22(17): 7057-7065, 2022 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-35998891

RESUMEN

Acinetobacter baumannii is a leading cause of antibiotic-resistant nosocomial infections with high mortality rates, yet there is currently no clinically approved vaccine formulation. During the onset of A. baumannii infection, neutrophils are the primary responders and play a major role in resisting the pathogen. Here, we design a biomimetic nanotoxoid for antivirulence vaccination by using neutrophil membrane-coated nanoparticles to safely capture secreted A. baumannii factors. Vaccination with the nanotoxoid formulation rapidly mobilizes innate immune cells and promotes pathogen-specific adaptive immunity. In murine models of pneumonia, septicemia, and superficial wound infection, immunization with the nanovaccine offers significant protection, improving survival and reducing signs of acute inflammation. Lower bacterial burdens are observed in vaccinated animals regardless of the infection route. Altogether, neutrophil nanotoxoids represent an effective platform for eliciting multivalent immunity to protect against multidrug-resistant A. baumannii in a wide range of disease conditions.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Sepsis , Infecciones por Acinetobacter/tratamiento farmacológico , Infecciones por Acinetobacter/microbiología , Animales , Biomimética , Modelos Animales de Enfermedad , Ratones , Neutrófilos
19.
Nano Lett ; 22(23): 9672-9678, 2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36448694

RESUMEN

Anthrax infections caused by Bacillus anthracis are an ongoing bioterrorism and livestock threat worldwide. Current approaches for management, including extended passive antibody transfusion, antibiotics, and prophylactic vaccination, are often cumbersome and associated with low patient compliance. Here, we report on the development of an adjuvanted nanotoxoid vaccine based on macrophage membrane-coated nanoparticles bound with anthrax toxins. This design leverages the natural binding interaction of protective antigen, a key anthrax toxin, with macrophages. In a murine model, a single low-dose vaccination with the nanotoxoids generates long-lasting immunity that protects against subsequent challenge with anthrax toxins. Overall, this work provides a new approach to address the ongoing threat of anthrax outbreaks and bioterrorism by taking advantage of an emerging biomimetic nanotechnology.


Asunto(s)
Vacunas contra el Carbunco , Carbunco , Toxinas Bacterianas , Animales , Humanos , Ratones , Carbunco/prevención & control , Antígenos Bacterianos , Bacillus anthracis , Nanotecnología
20.
Angew Chem Int Ed Engl ; 62(21): e202301566, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-36853913

RESUMEN

Nanodiscs are a compelling nanomedicine platform due to their ultrasmall size and distinct disc shape. Current nanodisc formulations are made primarily with synthetic lipid bilayers and proteins. Here, we report a cellular nanodisc made with human red blood cell (RBC) membrane (denoted "RBC-ND") and show its effective neutralization against bacterial toxins. In vitro, RBC-ND neutralizes the hemolytic activity and cytotoxicity caused by purified α-toxin or complex whole secreted proteins (wSP) from methicillin-resistant Staphylococcus aureus bacteria. In vivo, RBC-ND confers significant survival benefits for mice intoxicated with α-toxin or wSP in both therapeutic and prevention regimens. Moreover, RBC-ND shows good biocompatibility and biosafety in vivo. Overall, RBC-ND distinguishes itself by inheriting the biological functions of the source cell membrane for bioactivity. The design strategy of RBC-ND can be generalized to other types of cell membranes for broad applications.


Asunto(s)
Toxinas Bacterianas , Staphylococcus aureus Resistente a Meticilina , Humanos , Animales , Ratones , Eritrocitos , Membrana Eritrocítica , Membrana Dobles de Lípidos
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