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1.
Angew Chem Int Ed Engl ; 63(18): e202402007, 2024 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-38407551

RESUMEN

Pathological hyperphosphorylation and aggregation of microtubule-associated Tau protein contribute to Alzheimer's Disease (AD) and other related tauopathies. Currently, no cure exists for Alzheimer's Disease. Aptamers offer significant potential as next-generation therapeutics in biotechnology and the treatment of neurological disorders. Traditional aptamer selection methods for Tau protein focus on binding affinity rather than interference with pathological Tau. In this study, we developed a new selection strategy to enrich DNA aptamers that bind to surviving monomeric Tau protein under conditions that would typically promote Tau aggregation. Employing this approach, we identified a set of aptamer candidates. Notably, BW1c demonstrates a high binding affinity (Kd=6.6 nM) to Tau protein and effectively inhibits arachidonic acid (AA)-induced Tau protein oligomerization and aggregation. Additionally, it inhibits GSK3ß-mediated Tau hyperphosphorylation in cell-free systems and okadaic acid-mediated Tau hyperphosphorylation in cellular milieu. Lastly, retro-orbital injection of BW1c tau aptamer shows the ability to cross the blood brain barrier and gain access to neuronal cell body. Through further refinement and development, these Tau aptamers may pave the way for a first-in-class neurotherapeutic to mitigate tauopathy-associated neurodegenerative disorders.


Asunto(s)
Enfermedad de Alzheimer , Tauopatías , Proteínas tau , Humanos , Enfermedad de Alzheimer/metabolismo , Neuronas/metabolismo , Ácido Ocadaico/metabolismo , Ácido Ocadaico/farmacología , Ácido Ocadaico/uso terapéutico , Fosforilación , Proteínas tau/antagonistas & inhibidores , Proteínas tau/metabolismo , Tauopatías/tratamiento farmacológico , Tauopatías/metabolismo , Tauopatías/patología , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/farmacología
2.
Nano Lett ; 22(7): 2826-2834, 2022 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-35344667

RESUMEN

Metal "X" Frameworks (MXFs) constructed from metal ions and biomacromolecules ("X components") via coordination interactions show crystalline structures and diverse functionalities. Here, a series of MXFs composed of various metal ions (e.g., Zn2+, Hf4+, Ca2+) and DNA oligodeoxynucleotides were reported. With MXF consisting of Hf4+ and CpG oligodeoxynucleotides as the example, we show that such Hf-CpG MXF can achieve high-Z elements-enhanced photon radiotherapy and further trigger robust tumor-specific immune responses, thus showing efficient tumor suppression ability. In vivo experiments showed that external beam radiotherapy applied on tumors locally injected with Hf-CpG MXF result in the thorough elimination of primary tumors, complete inhibition of tumor metastasis, and protection against tumor rechallenge by triggering robust antitumor immune responses. Our findings provide a blueprint for fabricating a variety of rationally designed MXFs with desired functions and present the strategy of stimulating whole-body systemic immune responses by only local treatment of radiotherapy.


Asunto(s)
Inmunoterapia , Neoplasias , ADN , Humanos , Inmunidad , Neoplasias/terapia , Oligodesoxirribonucleótidos/farmacología
3.
J Am Chem Soc ; 143(22): 8391-8401, 2021 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-34029474

RESUMEN

Precise and lasting immune checkpoint blockade (ICB) therapy with high objective response rate remains a significant challenge in clinical trials. We thus report the development of an aptamer-based logic computing reaction to covalently conjugate immune checkpoint antagonizing aptamers (e.g., aPDL1 aptamer) on the surface of cancer cells, achieving effective and sustained ICB therapy without the need for antibodies. Specifically, azides were metabolically labeled on the cell-surface glycoproteins as "chemical receptors", enabling cyclooctyne-coupling aPDL1 aptamers to achieve aptamer-based logic computing-mediated azides/cyclooctynes-based bioorthogonal reaction. In stepwise fashion, PDL1 plus azide-bearing glycoproteins are expressed on cells and become multiple inputs in accordance with Boolean logic. Then, if the "AND" conditions of the algorithm are met, cyclooctyne-coupling aptamers are conjugated on the living cell surface, significantly prolonging overall mouse survival by triggering a precise and sustained T cell-mediated antitumor immunotherapy, otherwise not. Our findings indicate that DNA logic computing-mediated cyclooctyne/azide-based bioorthogonal reaction can improve the precision and robustness of ICB therapy, thereby potentially improving the objective response rate.


Asunto(s)
Aptámeros de Nucleótidos/antagonistas & inhibidores , Antígeno B7-H1/antagonistas & inhibidores , Inhibidores de Puntos de Control Inmunológico/farmacología , Algoritmos , Animales , Aptámeros de Nucleótidos/inmunología , Azidas/química , Azidas/farmacología , Antígeno B7-H1/inmunología , Línea Celular Tumoral , Ciclooctanos/química , Ciclooctanos/farmacología , Humanos , Inhibidores de Puntos de Control Inmunológico/química , Inmunoterapia , Ratones
4.
Chembiochem ; 22(4): 754-759, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33051959

RESUMEN

Functional nucleic acids (FNAs) are garnering tremendous interest owing to their high modularity and unique bioactivity. Three-dimensional FNAs have been developed to overcome the issues of nuclease degradation and limited cell uptake. We have developed a new facile approach to the synthesis of multiple three-dimensional FNA nanostructures by harnessing photo-polymerization-induced self-assembly. Sgc8 aptamer and CpG oligonucleotide were modified as macro chain-transfer reagents to mediate in situ polymerization and self-assembly. Diverse structures, including micelles, rods, and short worms, afford these two FNAs afford these two FNAs with higher nuclease resistance in serum serum, greater cellular uptake efficiency, and increased bioactivity.


Asunto(s)
Aptámeros de Nucleótidos/química , Nanoestructuras/química , Ácidos Nucleicos/metabolismo , Oligodesoxirribonucleótidos/química , Polímeros/química , Islas de CpG , Metacrilatos/química , Micelas , Ácidos Nucleicos/química , Polimerizacion
5.
J Am Chem Soc ; 142(8): 3862-3872, 2020 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-31991082

RESUMEN

The lack of blood-brain barrier (BBB) penetrating ability has hindered the delivery of many therapeutic agents for tauopathy treatment. In this study, we report the synthesis of a circular bifunctional aptamer to enhance the in vivo BBB penetration for better tauopathy therapy. The circular aptamer consists of one reported transferrin receptor (TfR) aptamer to facilitate TfR-aptamer recognition-induced transcytosis across BBB endothelial cells, and one Tau protein aptamer that we recently selected to inhibit Tau phosphorylation and other tauopathy-related pathological events in the brain. This novel circular Tau-TfR bifunctional aptamer displays significantly improved plasma stability and brain exposure, as well as the ability to disrupt tauopathy and improve traumatic brain injury (TBI)-induced cognitive/memory deficits in vivo, providing important proof-of-principle evidence that circular Tau-TfR aptamer can be further developed into diagnostic and therapeutic candidates for tauopathies.


Asunto(s)
Aptámeros de Péptidos/metabolismo , Barrera Hematoencefálica , Receptores de Transferrina/metabolismo , Tauopatías/terapia , Transferrina/metabolismo , Proteínas tau/metabolismo , Animales , Humanos , Ratones , Prueba de Estudio Conceptual
6.
J Am Chem Soc ; 141(16): 6458-6461, 2019 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-30942594

RESUMEN

Inspired by this elegant system of cellular adaptivity, we herein report the rational design of a dynamic artificial adaptive system able to sense and respond to environmental stresses in a unique sense-and-respond mode. Utilizing DNA nanotechnology, we constructed an artificial signal feedback network and anchored it to the surface membrane of a model giant membrane vesicle (GMV) protocell. Such a system would need to both senses incoming stimuli and emit a feedback response to eliminate the stimuli. To accomplish this mechanistically, our DNA-based artificial signal system, hereinafter termed DASsys, was equipped with a DNA trigger-induced DNA polymer formation and dissociation machinery. Thus, through a sequential cascade of stimulus-induced DNA strand displacement, DASsys could effectively sense and respond to incoming stimuli. Then, by eliminating the stimulus, the membrane surface would return to its initial state, realizing the formation of a cyclical feedback mechanism. Overall, our strategy opens up a route to the construction of artificial signaling system capable of maintaining homeostasis in the cellular micromilieu, and addresses important emerging challenges in bioinspired engineering.


Asunto(s)
Células Artificiales/química , ADN/química , Células Artificiales/metabolismo , Ingeniería Celular , ADN/metabolismo , Homeostasis , Modelos Moleculares , Nanotecnología
7.
J Am Chem Soc ; 141(43): 17174-17179, 2019 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-31539233

RESUMEN

The DNA strand displacement reaction has had sustained scientific interest in building complicated nucleic acid-based networks. However, extending the fundamental mechanism to more diverse biomolecules in a complex environment remains challenging. Aptamers bind with targeted biomolecules with high affinity and selectivity, thus offering a promising route to link the powers of nucleic acid with diverse cues. Here, we describe three methods that allow facile and efficient displacement reaction of aptamers from the living cell surface using complement DNA (cDNA), toehold-labeled cDNA (tcDNA), and single-stranded binding protein (SSB). The kinetics of the DNA strand displacement reaction is severely affected by complex physicochemical properties of the natural membrane. Toehold-mediated and SSB-mediated aptamer displacement exhibited significantly enhanced kinetics, and they completely removed the aptamer quickly to avoid a false signal caused by aptamer internalization. Because of its simplicity, aptamer displacement enabled detection of membrane protein post-translation and improved selection efficiency of cell-SELEX.


Asunto(s)
Aptámeros de Nucleótidos/química , ADN Complementario/química , Proteínas de la Membrana/análisis , Técnica SELEX de Producción de Aptámeros/métodos , Aptámeros de Nucleótidos/metabolismo , Línea Celular , Membrana Celular/química , Membrana Celular/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Células HeLa , Humanos , Cinética , Proteínas de la Membrana/metabolismo , Biosíntesis de Proteínas , Procesamiento Proteico-Postraduccional , Temperatura
8.
J Am Chem Soc ; 140(22): 6780-6784, 2018 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-29772170

RESUMEN

Circular bivalent aptamers (cb-apt) comprise an emerging class of chemically engineered aptamers with substantially improved stability and molecular recognition ability. Its therapeutic application, however, is challenged by the lack of functional modules to control the interactions of cb-apt with therapeutics. We present the design of a ß-cyclodextrin-modified cb-apt (cb-apt-ßCD) and its supramolecular interaction with molecular therapeutics via host-guest chemistry for targeted intracellular delivery. The supramolecular ensemble exhibits high serum stability and enhanced intracellular delivery efficiency compared to a monomeric aptamer. The cb-apt-ßCD ensemble delivers green fluorescent protein into targeted cells with efficiency as high as 80%, or cytotoxic saporin to efficiently inhibit tumor cell growth. The strategy of conjugating ßCD to cb-apt, and subsequently modulating the supramolecular chemistry of cb-apt-ßCD, provides a general platform to expand and diversify the function of aptamers, enabling new biological and therapeutic applications.


Asunto(s)
Aptámeros de Nucleótidos/química , Sistemas de Liberación de Medicamentos , Proteínas Fluorescentes Verdes/metabolismo , Proteínas Inactivadoras de Ribosomas Tipo 1/metabolismo , beta-Ciclodextrinas/química , Aptámeros de Nucleótidos/farmacología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Proteínas Fluorescentes Verdes/química , Células HeLa , Humanos , Sustancias Macromoleculares/química , Sustancias Macromoleculares/farmacología , Proteínas Inactivadoras de Ribosomas Tipo 1/química , Saporinas , beta-Ciclodextrinas/farmacología
9.
J Am Chem Soc ; 140(41): 13335-13339, 2018 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-30212189

RESUMEN

Aptamers that recognize specific cells in a complex environment have emerged as invaluable molecular tools in bioanalysis and in the development of targeted therapeutics. The selective recognition of aptamers, however, can be compromised by the coexistence of target receptors on both target cells and other cells. To address this problem, we constructed a structure-switchable aptamer (SW-Apt) with reconfigurable binding affinity in accordance with the microenvironment of target cells. The SW-Apt makes use of i-motifs, which are quadruplex structures that form in sequences rich in cytosine. More specifically, we report the design of single-stranded, pH-responsive i-motif-modified aptamers able to bind specifically with target cells by exploiting their pH. Here, the i-motif serves as a structural domain to either facilitate the binding ability of aptamers to target cells or suppress the binding ability of aptamers to nontarget cell based on the pH of the cellular microenvironment. SW-Apt exhibited high binding ability with target cells at acidic pH, while no obvious binding was observed at physiological pH. The i-motif-induced structure-switching was verified with Förster resonance energy transfer and circular dichroism spectroscopy. Notably, SW-Apt exhibits high specificity in serum and excellent stability, likely attributed to the folded quadruplex i-motif structure. This study provides a simple and efficient strategy to chemically modulate aptamer binding ability and thus improve aptamer binding specificity to target cells, irrespective of the coexistence of identical receptors on target and nontarget cells.


Asunto(s)
Aptámeros de Nucleótidos/química , ADN/química , Motivos de Nucleótidos/efectos de los fármacos , Antígenos de Superficie/química , Aptámeros de Nucleótidos/genética , Línea Celular Tumoral , ADN/genética , Ingeniería Genética/métodos , Humanos , Concentración de Iones de Hidrógeno
10.
J Am Chem Soc ; 140(43): 14314-14323, 2018 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-30277395

RESUMEN

Tau proteins are proteins that stabilize microtubules, but their hyperphosphorylation can result in the formation of protein aggregates and, over time, neurodegeneration. This phenomenon, termed tauopathy, is pathologically involved in several neurodegenerative disorders. DNA aptamers are single-stranded oligonucleotides capable of specific binding to target molecules. Using tau epitopes predisposed for phosphorylation, we identified six distinct aptamers that bind to tau at two phosphorylatable epitopes (Thr-231 and Ser-202) and to full-length Tau441 proteins with nanomolar affinity. In addition, several of these aptamers also inhibit tau phosphorylation (IT4, IT5, IT6) and tau oligomerization (IT3, IT4, IT5, IT6). This is the first report to identify tau epitope-specific aptamers. Such tau aptamers can be used to detect tau in biofluids and uncover the mechanism of tauopathy. They can be further developed into novel therapeutic agents in mitigating tauopathy-associated neurodegenerative disorders.


Asunto(s)
Aptámeros de Nucleótidos/farmacología , Epítopos/efectos de los fármacos , Proteínas tau/antagonistas & inhibidores , Animales , Aptámeros de Nucleótidos/química , Epítopos/metabolismo , Humanos , Fosforilación/efectos de los fármacos , Proteínas tau/metabolismo
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