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1.
Chem Rev ; 123(7): 3976-4050, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36990451

RESUMO

DNA nanotechnology is a unique field, where physics, chemistry, biology, mathematics, engineering, and materials science can elegantly converge. Since the original proposal of Nadrian Seeman, significant advances have been achieved in the past four decades. During this glory time, the DNA origami technique developed by Paul Rothemund further pushed the field forward with a vigorous momentum, fostering a plethora of concepts, models, methodologies, and applications that were not thought of before. This review focuses on the recent progress in DNA origami-engineered nanomaterials in the past five years, outlining the exciting achievements as well as the unexplored research avenues. We believe that the spirit and assets that Seeman left for scientists will continue to bring interdisciplinary innovations and useful applications to this field in the next decade.


Assuntos
Nanoestruturas , DNA , Nanotecnologia/métodos
2.
Nano Lett ; 23(14): 6330-6336, 2023 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-37440701

RESUMO

Membrane morphology and its dynamic adaptation regulate many cellular functions, which are often mediated by membrane proteins. Advances in DNA nanotechnology have enabled the realization of various protein-inspired structures and functions with precise control at the nanometer level, suggesting a viable tool to artificially engineer membrane morphology. In this work, we demonstrate a DNA origami cross (DOC) structure that can be anchored onto giant unilamellar vesicles (GUVs) and subsequently polymerized into micrometer-scale reconfigurable one-dimensional (1D) chains or two-dimensional (2D) lattices. Such DNA origami-based networks can be switched between left-handed (LH) and right-handed (RH) conformations by DNA fuels and exhibit potent efficacy in remodeling the membrane curvatures of GUVs. This work sheds light on designing hierarchically assembled dynamic DNA systems for the programmable modulation of synthetic cells for useful applications.


Assuntos
Nanoestruturas , Nanoestruturas/química , Conformação de Ácido Nucleico , Nanotecnologia/métodos , DNA/química , Lipossomas Unilamelares , Lipídeos
3.
Angew Chem Int Ed Engl ; 62(9): e202213992, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36423337

RESUMO

Control over multiple optical elements that can be dynamically rearranged to yield substantial three-dimensional structural transformations is of great importance to realize reconfigurable plasmonic nanoarchitectures with sensitive and distinct optical feedback. In this work, we demonstrate a transformable plasmonic helix system, in which multiple gold nanoparticles (AuNPs) can be directly transported by DNA swingarms to target positions without undergoing consecutive stepwise movements. The swingarms allow for programmable AuNP translocations in large leaps within plasmonic nanoarchitectures, giving rise to tailored circular dichroism spectra. Our work provides an instructive bottom-up solution to building complex dynamic plasmonic systems, which can exhibit prominent optical responses through cooperative rearrangements of the constituent optical elements with high fidelity and programmability.

4.
Cell Commun Signal ; 20(1): 155, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36229856

RESUMO

Age-related macular degeneration (AMD), a progressive chronic disease of the central retina, is a leading cause of blindness worldwide. Activated macrophages recruited to the injured eyes greatly contribute to the pathogenesis of choroidal neovascularization (CNV) in exudative AMD (wet AMD). This study describes the effects of cyclooxygenase-2 (COX2)/prostaglandin E2 (PGE2) signalling on the macrophage activation and CNV formation of wet AMD. In a mouse model of laser-induced wet AMD, the mice received an intravitreal injection of celecoxib (a selective COX2 inhibitor). Optical coherence tomography (OCT), fundus fluorescein angiography (FFA), choroidal histology of the CNV lesions, and biochemical markers were assessed. The level of PGE2 expression was high in the laser-induced CNV lesions. Macrophage recruitment and CNV development were significantly less after celecoxib treatment. E-prostanoid1 receptor (EP1R)/protein kinase C (PKC) signalling was involved in M2 macrophage activation and interleukin-10 (IL-10) production of bone marrow-derived macrophages (BMDMs) in vitro. In addition, IL-10 was found to induce the proliferation and migration of human choroidal microvascular endothelial cells (HCECs). Thus, the PGE2/EP1R signalling network serves as a potential therapeutic target for CNV of the wet-type AMD. Video abstract.


Assuntos
Neovascularização de Coroide , Interleucina-10 , Animais , Celecoxib/farmacologia , Neovascularização de Coroide/etiologia , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Dinoprostona/metabolismo , Células Endoteliais/metabolismo , Humanos , Interleucina-10/metabolismo , Macrófagos/metabolismo , Camundongos , Proteína Quinase C/metabolismo
5.
Chem Biodivers ; 19(6): e202100753, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35560720

RESUMO

Aiming at the excellent killing effect of N-phenylmaleimide (N-PMI) on microorganisms, this article used structural simulation analysis, fluorescence analysis, confocal laser scanning microscope and SEM to find that the double bond in N-PMI could interact with the sulfur groups in the membrane protein, changing its conformation, rupturing the plasma membrane of the cell, leaking the contents, and ultimately causing the death of the microorganisms. Therefore, once the double bond participated in the polymerization, N-PMI lost its antimicrobial function. N-PMI could achieve azeotropic copolymerization with MMA through reactive extrusion polymerization. N-PMI with a content of 5 % can be evenly inserted into the PMMA chain segment during the copolymerization reaction, thereby increasing the Tg of pure PMMA by up to 15 °C, which provided the PMMA-co-PMI copolymer with resistance to boiling water sterilization advantageous conditions. In addition, N-PMI with a content of 5 % has little effect on the transparency of PMMA after participating in the copolymerization. Moreover, the trace amount of residual N-PMI made the material have excellent antimicrobial function, and the bacteriostatic zone is extremely small, which provided an excellent guarantee for the safety and durability of the material. As a medical biological material, the PMMA-co-PMI copolymer has a good industrialization application prospects.


Assuntos
Anti-Infecciosos , Polimetil Metacrilato , Antibacterianos/farmacologia , Maleimidas , Polímeros/química , Polímeros/farmacologia , Polimetil Metacrilato/química , Polimetil Metacrilato/farmacologia
6.
Exp Eye Res ; 207: 108568, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33839112

RESUMO

Hydrocinnamoyl-L-valylpyrrolidine (AS-1), a synthetic low-molecule mimetic of myeloid differentiation primary response gene 88 (MyD88), inhibits inflammation by disrupting the interaction between the interleukin-1 receptor (IL-1R) and MyD88. Here, we describe the effects of AS-1 on injury-induced increases in inflammation and neovascularization in mouse corneas. Mice were administered a subconjunctival injection of 8 µL AS-1 diluent before or after corneal alkali burn, followed by evaluation of corneal resurfacing and corneal neovascularization (CNV) by slit-lamp biomicroscopy and clinical assessment. Corneal inflammation was assessed by whole-mount CD45+ immunofluorescence staining, and corneal hemangiogenesis and lymphangiogenesis following injury were evaluated by immunostaining for the vascular markers isolectin B4 (IB4) and the lymphatic vascularized marker lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1), respectively. Additionally, corneal tissues were collected to determine the expression of 35 cytokines, and we detected activation of IL-1RI, MyD88, and mitogen-activated protein kinase (MAPK). The results showed that alkali conditions increased the number of CD45+ cells and expression of vascular endothelial growth factor (VEGF)-A, VEGF-C, and LYVE1 in corneas, with these levels decreased in the AS-1-treated group. Moreover, AS-1 effectively prevented alkali-induced cytokine production, blocked interactions between IL-1RI and MyD88, and inhibited MAPK activation post-alkali burn. These results indicated that AS-1 prevented alkali-induced corneal hemangiogenesis and lymphangiogenesis by blocking IL-1RI-MyD88 interaction, as well as extracellular signal-regulated kinase phosphorylation, and could be efficacious for the prevention and treatment of corneal alkali burn.


Assuntos
Queimaduras Químicas/prevenção & controle , Neovascularização da Córnea/prevenção & controle , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Queimaduras Oculares/induzido quimicamente , Pirrolidinas/uso terapêutico , Valina/análogos & derivados , Inibidores da Angiogênese , Animais , Biomarcadores/metabolismo , Western Blotting , Queimaduras Químicas/enzimologia , Queimaduras Químicas/patologia , Neovascularização da Córnea/enzimologia , Neovascularização da Córnea/patologia , Epitélio Corneano/efeitos dos fármacos , Epitélio Corneano/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Queimaduras Oculares/enzimologia , Queimaduras Oculares/patologia , Proteínas do Olho/metabolismo , Humanos , Imunoprecipitação , Linfangiogênese/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Reação em Cadeia da Polimerase em Tempo Real , Hidróxido de Sódio , Valina/uso terapêutico
7.
Small ; 16(6): e1905987, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31917513

RESUMO

Mechanically interlocked molecules have marked a breakthrough in the field of topological chemistry and boosted the vigorous development of molecular machinery. As an archetypal example of the interlocked molecules, catenanes comprise macrocycles that are threaded through one another like links in a chain. Inspired by the transition metal-templated approach of catenanes synthesis, the hierarchical assembly of DNA origami catenanes templated by gold nanoparticles is demonstrated in this work. DNA origami catenanes, which contain two, three or four interlocked rings are successfully created. In particular, the origami rings within the individual catenanes can be set free with respect to one another by releasing the interconnecting gold nanoparticles. This work will set the basis for rich progress toward DNA-based molecular architectures with unique structural programmability and well-defined topology.


Assuntos
Catenanos , DNA Catenado , Ouro , Nanopartículas Metálicas , Catenanos/química , DNA/química , DNA Catenado/química , Ouro/química , Nanopartículas Metálicas/química
8.
Nano Lett ; 19(9): 6385-6390, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31438681

RESUMO

DNA nanotechnology allows for the realization of complex nanoarchitectures in which the spatial arrangements of different constituents and most functions can be enabled by DNA. When optically active components are integrated in such systems, the resulting nanoarchitectures not only provide great insights into the self-assembly of nanoscale elements in a systematic way but also impart tailored optical functionality to DNA origami. In this Letter, we demonstrate DNA-assembled multilayer nanosystems, which can carry out coordinated and reversible sliding motion powered by DNA fuels. Gold nanoparticles cross-link DNA origami filaments to define the configurations of the multilayer nanoarchitectures as well as to mediate relative sliding between the neighboring origami filaments. Meanwhile, the gold nanoparticles serve as optical probes to dynamically interact with the fluorophores tethered on the filaments, rendering in situ detection of the stepwise sliding processes possible. This work seeds the basis to implement DNA-assembled complex optical nanoarchitectures with programmability and addressability, advancing the field with new momentum.


Assuntos
DNA/química , Ouro/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura
9.
Diabetologia ; 62(2): 335-348, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30411254

RESUMO

AIMS/HYPOTHESIS: Diabetic retinopathy is a common microvascular complication of diabetes mellitus and is initiated by inflammation and apoptosis-associated retinal endothelial cell damage. Prostaglandin E2 (PGE2) has emerged as a critical regulator of these biological processes. We hypothesised that modulating PGE2 and its E-prostanoid receptor (EP2R) would prevent diabetes mellitus-induced inflammation and microvascular dysfunction. METHODS: In a streptozotocin (STZ)-induced rat model of diabetes, rats received intravitreal injection of PGE2, butaprost (a PGE2/EP2R agonist) or AH6809 (an EP2R antagonist). Retinal histology, optical coherence tomography, ultrastructure of the retinal vascular and biochemical markers were assessed. RESULTS: Intravitreal injection of PGE2 and butaprost significantly accelerated retinal vascular leakage, leucostasis and endothelial cell apoptosis in STZ-induced diabetic rats. This response was ameliorated in diabetic rats pre-treated with AH6809. In addition, pre-treatment of human retinal microvascular endothelial cells with AH6809 attenuated PGE2- and butaprost-induced activation of caspase 1, activation of the complex containing nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like protein containing a C-terminal caspase-activation and recruitment domain (ASC), and activation of the EP2R-coupled cAMP/protein kinase A/cAMP response element-binding protein signalling pathway. CONCLUSIONS/INTERPRETATION: The PGE2/EP2R signalling pathway is involved in STZ-induced diabetic retinopathy and could be considered as a potential target for diabetic retinopathy prevention and treatment.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Retinopatia Diabética/metabolismo , Dinoprostona/metabolismo , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Transdução de Sinais/fisiologia , Alprostadil/análogos & derivados , Alprostadil/farmacologia , Animais , Dinoprostona/farmacologia , Humanos , Inflamassomos/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Corpo Vítreo/metabolismo , Xantonas/farmacologia
10.
Nano Lett ; 17(11): 7125-7130, 2017 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-28990389

RESUMO

In response to environmental variations, living cells need to arrange the conformational changes of macromolecules to achieve the specific biofunctions. Inspired by natural molecular machines, artificial macromolecular assemblies with controllable nanostructures and environmentally responsive functions can be designed. By assembling macromolecular nanostructures with noble metal nanoparticles, environmental information could be significantly amplified and modulated. However, manufacturing dynamic plasmonic nanostructures that are efficiently responsive to different stimuli is still a challenging task. Here we demonstrate a stimulus-responsive plasmonic nanosystem based on DNA origami-organized gold nanorods (GNRs). L-shaped GNR dimers were assembled on rhombus-shaped DNA origami templates. The geometry and chiral signals of the GNR nanoarchitectures respond to multiple stimuli, including glutathione reduction, restriction enzyme action, pH change, or photoirradiation. While the glutathione reduction or restriction enzyme caused irreversible changes in the plasmonic circular dichroism (CD) signals, both pH and light irradiation triggered reversible changes in the plasmonic CD. Our system transduces external stimuli into conformational changes and circular dichroism responses in near-infrared (NIR) wavelengths. By this approach, programmable optical reporters for essential biological signals can be fabricated.


Assuntos
DNA/química , Ouro/química , Nanoestruturas/química , Nanotubos/química , Dicroísmo Circular , Dimerização , Concentração de Íons de Hidrogênio , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Nanotubos/ultraestrutura , Oxirredução , Processos Fotoquímicos
11.
Angew Chem Int Ed Engl ; 57(11): 2846-2850, 2018 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-29377456

RESUMO

Metallic bowtie nanoarchitectures can produce dramatic electric field enhancement, which is advantageous in single-molecule analysis and optical information processing. Plasmonic bowtie nanostructures were successfully constructed using a DNA origami-based bottom-up assembly strategy, which enables precise control over the geometrical configuration of the bowtie with an approximate 5 nm gap. A single Raman probe was accurately positioned at the gap of the bowtie. Single-molecule surface-enhanced Raman scattering (SM-SERS) of individual nanostructures, including ones containing an alkyne group, was observed. The design achieved repeatable local field enhancement of several orders of magnitude. This method opens the door on a novel strategy for the fabrication of metal bowtie structures and SM-SERS, which can be utilized in the design of highly-sensitive photonic devices.

12.
Artigo em Inglês | MEDLINE | ID: mdl-28634987

RESUMO

Silkworm (Bombyx mori) is an economically beneficial insect. Its growth and development are regulated by endogenous hormones. In the present study, we found that feeding titanium dioxide nanoparticles (TiO2 NP) caused a significant increase of body size. TiO2 NP stimulated the transcription of several genes, including the insulin-related hormone bombyxin, PI3K/Akt/TOR (where PI3K is phosphatidylinositol 3-kinase and TOR is target of rapamycin), and the adenosine 5'-monophosphateactivated protein kinase (AMPK)/target of rapamycin (TOR) pathways. Differentially expressed gene (DEG) analysis documented 26 developmental hormone signaling related genes that were differentially expressed following dietary TiO2 NP treatment. qPCR analysis confirmed the upregulation of insulin/ecdysteroid signaling genes, such as bombyxin B-1, bombyxin B-4, bombyxin B-7, MAPK, P70S6K, PI3k, eIF4E, E75, ecdysteroid receptor (EcR), and insulin-related peptide binding protein precursor 2 (IBP2). We infer from the upregulated expression of bombyxins and the signaling network that they act in bombyxin-stimulated ecdysteroidogenesis.


Assuntos
Bombyx/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Titânio/farmacologia , Animais , Bombyx/efeitos dos fármacos , Bombyx/genética , Perfilação da Expressão Gênica , Genes de Insetos , Hormônios de Inseto/metabolismo , Nanopartículas
13.
Small ; 11(38): 5134-41, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26248642

RESUMO

A self-assembled DNA origami (DO)-gold nanorod (GNR) complex, which is a dual-functional nanotheranostics constructed by decorating GNRs onto the surface of DNA origami, is demonstrated. After 24 h incubation of two structured DO-GNR complexes with human MCF7 breast cancer cells, significant enhancement of cell uptake is achieved compared to bare GNRs by two-photon luminescence imaging. Particularly, the triangle shaped DO-GNR complex exhibits optimal cellular accumulation. Compared to GNRs, improved photothermolysis against tumor cells is accomplished for the triangle DO-GNR complex by two-photon laser or NIR laser irradiation. Moreover, the DO-GNR complex exhibits enhanced antitumor efficacy compared with bare GNRs in nude mice bearing breast tumor xenografts. The results demonstrate that the DO-GNR complex can achieve optimal two-photon cell imaging and photothermal effect, suggesting a promising candidate for cancer diagnosis and therapy both in vitro and in vivo.


Assuntos
DNA/química , Ouro/química , Nanotubos/química , Neoplasias/terapia , Conformação de Ácido Nucleico , Nanomedicina Teranóstica , Animais , Humanos , Hipertermia Induzida , Células MCF-7 , Camundongos , Nanotubos/ultraestrutura , Fototerapia , Espectrofotometria Ultravioleta
14.
Small ; 10(2): 399-406, 2014 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-24039035

RESUMO

Noble metal nanoparticles have attracted much interest in the heterogeneous catalysis. Particularly, efficient manipulation of the responsive catalytic properties of the metal nanoparticles is an interesting topic. In this work, a simple and efficient strategy is developed to regulate the pH-responsive catalytic activities of glucose oxidase (GOx)-mimicking gold nanoparticles (AuNPs). Four DNA strands (regulating strands) that differ slightly in sequences are used to interact non-covalently with citrate-capped AuNPs, resulting in markedly distinct pH-dependent catalytic behavior of AuNPs. This is ascribed to the characteristic pH-induced conformational change of the DNA strands that leads to the different adsorption capability to the NPs surface, as demonstrated by pH-CD profiles of the respective DNA molecules. The pH-dependent catalysis of AuNPs is also encoded with structural information of the double-stranded DNA (including regulating strands and their complementary strands) that has conformation resistant or responsive to pH change. As a result, the catalysis can be programmed into an AND gate, a XNOR gate or a NOT gate, using pH and complementary strand as the inputs, the nanoparticle activity as the output and the regulating strands as the programs. This work can be expanded by engineering the catalytic behavior of noble metal nanoparticles to respond smartly to a variety of environmental stimuli, such as metal ions or light wavelengths. These results may provide insight into understanding ligand-regulated nanometallic catalysis.


Assuntos
DNA/química , Ouro/química , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/química , Catálise , Dicroísmo Circular
15.
Ying Yong Sheng Tai Xue Bao ; 35(6): 1705-1715, 2024 Jun.
Artigo em Zh | MEDLINE | ID: mdl-39235030

RESUMO

Understanding the composition and spatial distribution patterns of microbial communities in plateau peatland soils is crucial for preserving the structural and functional stability of highland wetlands. We collected 50 soil samples from the core conservation area of Zoige peatland along horizontal and vertical distributions to analyze the soil bacterial and fungal diversity by using high-throughput sequencing technology, combined with Mantel tests and multiple regression on matrices (MRM) statistical methods, as well as the spatial distribution characteristics of community structure similarity at a local scale. The results showed that the dominant soil bacterial and fungal groups were Chloroflexi (accounting for 33.2% and 25.1% of the total bacterial community in horizontal and vertical directions, respectively) and Ascomycota (54.7% and 76.4%). The similarity of microbial community structure in both horizontal and vertical directions decreased with increasing spatial distance of the sampling points. The turnover rates of bacterial and fungal communities in the vertical direction were 8.8 and 8.6 times as those in the horizontal direction, respectively. Based on the relative abundance of the communities, we classified microbes into six groups. As the number of rare species in the community increased, the slope of community distance decay decreased. The conditionally rare or abundant taxa (CRAT) category group showed the most similar spatial distribution characteristics to the total microbial community. Mantel analysis indicated that soil organic carbon, total nitrogen, and available phosphorus were key factors driving the distribution of bacterial and fungal communities in the horizontal direction, while soil organic carbon, available carbon, pH, and soil bulk density were the main factors determining the vertical distribution. MRM analysis further showed that both soil physicochemical indicators and spatial distance significantly affected the assembly of microbial communities, where soil factors explained more about the vertical distribution of microbial communities than the horizontal distribution. The impact of soil factors on microbial community distribution was much greater than that of spatial factors through diffusion limitation. In summary, the microbial communities in the plateau peatland soils exhibited more pronounced vertical distribution differences and environmental response characteristics.


Assuntos
Bactérias , Fungos , Microbiologia do Solo , China , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/crescimento & desenvolvimento , Bactérias/genética , Fungos/classificação , Fungos/isolamento & purificação , Fungos/crescimento & desenvolvimento , Áreas Alagadas , Análise Espacial , Biodiversidade , Altitude , Solo/química , Microbiota , Chloroflexi/classificação , Chloroflexi/crescimento & desenvolvimento , Chloroflexi/isolamento & purificação , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/isolamento & purificação
16.
Sci Adv ; 10(33): eadn8903, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39151012

RESUMO

Proteins self-assemble to function in living cells. They may execute essential tasks in the form of monomers, complexes, or supramolecular cages via oligomerization, achieving a sophisticated balance between structural topology and functional dynamics. The modularity and programmability make DNA origami unique in mimicking these key features. Here, we demonstrate three-dimensional reconfigurable DNA origami pincers (DOPs) that multitask on giant unilamellar vesicles (GUVs). By programmably adjusting their pinching angle, the DOPs can dynamically control the degree of GUV remodeling. When oligomerized on the GUV to form origami cages, the DOP units interact with one another and undergo reorganization, resulting in the capture, compartmentalization, and detachment of lipid fragments. This oligomerization process is accompanied with membrane disruptions, enabling the passage of cargo across the membrane. We envisage that interfacing synthetic cells with engineered, multifunctional DNA nanostructures may help to confer customized cellular properties, unleashing the potential of both fields.


Assuntos
DNA , Nanoestruturas , Lipossomas Unilamelares , Lipossomas Unilamelares/química , Lipossomas Unilamelares/metabolismo , DNA/química , Nanoestruturas/química , Conformação de Ácido Nucleico
17.
Small Methods ; : e2401041, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39233553

RESUMO

DNA nanostructures have shown great potential in biomedical fields. However, the immune responses, especially the activation of the cGAS-STING signaling (A-cGSs), induced by DNA nanostructures, remain incompletely understood. Here, the ability of various DNA nanostructures from double-stranded DNA (dsDNA), single-stranded tiles (SSTs) to DNA origami is investigated on A-cGSs. Unlike natural dsDNA which triggers potent A-cGSs, the structural interconnectivity of various DNA configurations can substantially reduce the occurrence of A-cGSs, irrespective of their form, dimensions, and conformation. However, wireframe DNA nanostructures can activate the cGAS-STING signaling, suggesting that decreasing A-cGSs is dsDNA compactness-dependent. Based on this, a reconfigurable DNA Origami Domino Array (DODA) is used to systematically interrogate how dsDNA influences the A-cGSs and demonstrates that the length, number, and space of dsDNA array coordinately influence the activation level of cGAS-STING signaling, realizing a regulation of innate immune response. The above data and findings enhance the understanding of how DNA nanostructures affect cellular innate immune responses and new insights into the modulation of innate immune responses by DNA nanomedicine.

18.
Sci Total Environ ; 912: 169002, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38040347

RESUMO

Lake ice, as a crucial component of the cryosphere, serves as a sensitive indicator of climate change. Fine-scale monitoring of spatiotemporal patterns in lake ice phenology holds significant importance in scientific research and environmental management. However, the rapid and dynamic nature of the freeze-thaw process of lake ice poses challenges to existing methods, resulting in their limited application in small lakes. In this study, we propose a novel approach of investigating ice phenology of lakes in various sizes. We conducted a case study in Hoh Xil, known for its vulnerability to climate change and a wide distribution of small lakes, to analyze the ice phenology of 372 lakes (>1 km2) during 2017-2021. Firstly, ensemble machine-learning model was developed for lake ice identification from Landsat-8/9 and Sentinel-2 A/B imagery. The accuracy evaluation reveals the overall good performance for ice extraction results based on Landsat-8/9 (97.03 %) and Sentinel-2 A/B (96.89 %). Next, the XGBoost models were employed to reconstruct ice coverages on unobserved dates for the freezeup and breakup periods, respectively. Totally, 744 XGBoost models were constructed for the study lakes, and the majority of them perform well. Based on the reconstructed daily ice coverage, phenology parameters could be extracted for examining the spatiotemporal characteristics of ice cover and possible relationships with lake sizes and terrains. From early-October to early-November, the Hoh Xil lakes freeze from the northwest to the southeast, while the breakup period starts in late-March and lasts until late-June. Moreover, the results indicate relatively small variability in freezeup-end dates among lakes, but significant differences in breakup dates, showing a greater sensitivity to temperature variations. Furthermore, ice phenology in small lakes exhibit stronger consistency with subtle climatic fluctuations. The results highlight the significant role of ice phenology in small lakes, as they dominate the overall tendency of ice phenology in Hoh Xil.

19.
Ying Yong Sheng Tai Xue Bao ; 34(11): 2958-2968, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37997406

RESUMO

Wetlands serve as atmospheric carbon dioxide (CO2) sinks, as well as atmospheric methane (CH4) source due to the anaerobic soil environment. Although some studies report that the CH4 emission from wetlands partially offset their net CO2 uptake, there is no global data analysis on the offset of net ecosystem exchange of CO2 (NEE) by CH4 emission in wetland ecosystems. In this study, we collected the data sets of NEE and CH4 flux which were simultaneously measured in the inland wetlands (peatland and non-peatland wetland) and coastal wetlands (seagrass beds, salt marshes and mangroves) around the world. The results showed that all types of wetlands were atmospheric CO2 sink, with the NEE values ranking as follows: mangrove (-2011.0 g CO2·m-2·a-1) < salt marsh (-1636.6 g CO2·m-2·a-1) < non-peatland wetland (-870.8 g CO2·m-2·a-1) < peatland (-510.7 g CO2·m-2·a-1) < seagrass bed (-61.6 g CO2·m-2·a-1). When CH4 flux being converted into CO2-equivalent flux (CO2-eq flux) based on the 100-year scale global warming potentials, we found that the CH4 emissions partially offset 19.4%, 14.0%, 36.1%, 64.9% and 60.1% of the net CO2 uptake in seagrass beds, salt marshes, mangroves, non-peatland wetland and peatland, respectively. Over the 20-year scale, CH4 emissions partially offset 57.3%, 41.4%, 107.0%, 192.0% and 177.3% of the net CO2 uptake, respectively. Some mangroves, peatlands, and non-peatland wetlands acted as net CO2 equivalent source. Over the 100-year scale, the net greenhouse gas balance of each wetland ecosystem was negative value, which indicated that even accounting CH4 emission, wetland ecosystem was still an atmospheric carbon sink. Our results indicated that clarifying the main regulation mechanism of CH4 emission from wetland ecosystems and proposing reasonable CH4 reduction measures are crucial to maintain the carbon sink function in wetland ecosystems, and to mitigate the trend of climate warming.


Assuntos
Ecossistema , Áreas Alagadas , Sequestro de Carbono , Dióxido de Carbono , Metano
20.
Environ Pollut ; 336: 122470, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37657723

RESUMO

Dinotefuran, a third-generation neonicotinoid insecticide, is widely utilized in agriculture for pest control; however, its environmental consequences and risks to non-target organisms remain largely unknown. Bombyx mori is an economically important insect and a good toxic detector for environmental assessments. In this study, ultrastructure analysis showed that dinotefuran exposure caused an increase in autophagic vesicles in the silk gland. Dinotefuran exposure triggered elevated levels of oxidative stress in silk glands. Reactive oxygen species, oxidized glutathione disulfide, glutathione peroxidase, the activities of UDP glucuronosyl-transferase and carboxylesterase were induced in the middle silk gland, while malondialdehyde, reactive oxygen species, superoxide dismutase , oxidized glutathione disulfide were increased in the posterior silk gland. Global transcription patterns revealed the physiological responses were induced by dinotefuran. Dinotefuran exposure substantially induced the expression levels of many genes involved in the mTOR and PI3K - Akt signaling pathways in the middle silk gland, whereas many differentially expressed genes involved in fatty acid and pyrimidine metabolism were found in the posterior silk gland. Additionally, functional, ultrastructural, and transcriptomic analysis indicate that dinotefuran exposure induced an increase of autophagy in the silk gland. This study illuminates the toxicity effects of dinotefuran exposure on silkworms and provides new insights into the underlying molecular toxicity mechanisms of dinotefuran to nontarget organisms.

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