RESUMO
The gene regulatory networks that govern seed development are complex, yet very little is known about the genes and processes that are controlled by DNA methylation. Here, we performed single-base resolution DNA methylome analysis and found that CHH methylation increased significantly throughout seed development in litchi. Based on the association analysis of differentially methylated regions and weighted gene co-expression network analysis (WGCNA), 46 genes were identified as essential DNA methylation-regulated candidate genes involved in litchi seed development, including LcSR45, a homolog of the serine/arginine-rich (SR) splicing regulator SR45. LcSR45 is predominately expressed in the funicle, embryo, and seed integument, and displayed increased CHH methylation in the promoter during seed development. Notably, silencing of LcSR45 in a seed-aborted litchi cultivar significantly improved normal seed development, whereas the ectopic expression of LcSR45 in Arabidopsis caused seed abortion. Furthermore, LcSR45-dependent alternative splicing events were found to regulate genes involved in seed development. Together, our findings demonstrate that LcSR45 is hypermethylated, and plays a detrimental role in litchi seed development, indicating a global increase in DNA methylation at this stage.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Litchi , Litchi/genética , Litchi/metabolismo , Metilação de DNA , Splicing de RNA , Sementes , Frutas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Arabidopsis/metabolismoRESUMO
Litchi chinensis Sonn. is an important evergreen fruit crop cultivated in the tropical and subtropical regions. The edible portion of litchi fruit is the aril, which contains a high concentration of sucrose, glucose, and fructose. In this study, we review various aspects of sugar transport, metabolism, and signaling during fruit development in litchi. We begin by detailing the sugar transport and accumulation during aril development, and the biosynthesis of quebrachitol as a transportable photosynthate is discussed. We then document sugar metabolism in litchi fruit. We focus on the links between sugar signaling and seed development as well as fruit abscission. Finally, we outline future directions for research on sugar metabolism and signaling to improve fruit yield and quality.
Assuntos
Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Litchi/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Sacarose/metabolismo , Transporte Biológico , Frutas/metabolismo , Litchi/metabolismo , Proteínas de Plantas/genética , Transdução de SinaisRESUMO
As new 2D layered nanomaterials, Bi2 O2 Se nanoplates have unique semiconducting properties that can benefit biomedical applications. Herein, a facile top-down approach for the synthesis of Bi2 O2 Se quantum dots (QDs) in a solution is described. The Bi2 O2 Se QDs with a size of 3.8 nm and thickness of 1.9 nm exhibit a high photothermal conversion coefficient of 35.7% and good photothermal stability. In vitro and in vivo assessments demonstrate that the Bi2 O2 Se QDs possess excellent photoacoustic (PA) performance and photothermal therapy (PTT) efficiency. After systemic administration, the Bi2 O2 Se QDs accumulate passively in tumors enabling efficient PA imaging of the entire tumors to facilitate imaging-guided PTT without obvious toxicity. Furthermore, the Bi2 O2 Se QDs which exhibit degradability in aqueous media not only have sufficient stability during in vivo circulation to perform the designed therapeutic functions, but also can be discharged harmlessly from the body afterward. The results reveal the great potential of Bi2 O2 Se QDs as a biodegradable multifunctional agent in medical applications.
Assuntos
Bismuto/uso terapêutico , Neoplasias/terapia , Compostos Organosselênicos/uso terapêutico , Técnicas Fotoacústicas/métodos , Fototerapia/métodos , Pontos Quânticos , Bismuto/química , Linhagem Celular Tumoral , Humanos , Compostos Organosselênicos/química , Difração de Pó , Compostos de Selênio , Espectrofotometria Ultravioleta , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
BACKGROUND: SWEETs (Sugar Will Eventually be Exported transporters) function as sugar efflux transporters that perform diverse physiological functions, including phloem loading, nectar secretion, seed filling, and pathogen nutrition. The SWEET gene family has been identified and characterized in a number of plant species, but little is known about in Litchi chinensis, which is an important evergreen fruit crop. RESULTS: In this study, 16 LcSWEET genes were identified and nominated according to its homologous genes in Arabidopsis and grapevine. Multiple sequence alignment showed that the 7 alpha-helical transmembrane domains (7-TMs) were basically conserved in LcSWEETs. The LcSWEETs were divided into four clades (Clade I to Clade IV) by phylogenetic tree analysis. A total of 8 predicted motifs were detected in the litchi LcSWEET genes. The 16 LcSWEET genes were unevenly distributed in 9 chromosomes and there was one pairs of segmental duplicated events by synteny analysis. The expression patterns of the 16 LcSWEET genes showed higher expression levels in reproductive organs. The temporal and spatial expression patterns of LcSWEET2a and LcSWEET3b indicated they play central roles during early seed development. CONCLUSIONS: The litchi genome contained 16 SWEET genes, and most of the genes were expressed in different tissues. Gene expression suggested that LcSWEETs played important roles in the growth and development of litchi fruits. Genes that regulate early seed development were preliminarily identified. This work provides a comprehensive understanding of the SWEET gene family in litchi, laying a strong foundation for further functional studies of LcSWEET genes and improvement of litchi fruits.
Assuntos
Litchi/genética , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Plantas/genética , Sementes/crescimento & desenvolvimento , Cromossomos de Plantas , Sequência Conservada , DNA de Plantas , Perfilação da Expressão Gênica , Genes de Plantas , Filogenia , Sementes/genética , Alinhamento de Sequência , SinteniaRESUMO
This paper describes the tri-phase all-optical switching and broadband nonlinear optical response in Bi2Se3 nanosheets. Using Bi2Se3 nanosheets dispersion solution as the sample, the spatial phase of controlled light can be modulated as three phases (unchanging, focusing, diffraction) by changing the incident intensity of controlling light. The mechanism is conjectured that the controlling light changes the phase distribution of overlapping region and then modulates the phase distribution of the controlled light. Based on Gerchberg-Saxton algorithm, the phase distribution of the controlling light and controlled light is retrieved from the transmitted patterns. In dynamic spatial self-phase modulation (SSPM) experiment, the three processes including self-focusing, self-diffraction ring formation, and self-diffraction ring deformation can also be observed. In addition, the SSPM of controlling light is measured at the typical wavelengths from 350 nm to 1160 nm, which demonstrates that this all-optical switching is available in broadband. These results provide the great potential of Bi2Se3 as an all-optical switching for various optoelectronic applications.
RESUMO
Poly(vinylpyrrolidone)-encapsulated Bi2 Se3 nanosheets with a thickness of 1.7 nm and diameter of 31.4 nm are prepared by a solution method. Possessing an extinction coefficient of 11.5 L g(-1) cm(-1) at 808 nm, the ultrathin Bi2 Se3 nanosheets boast a high photothermal conversion efficiency of 34.6% and excellent photoacoustic performance. After systemic administration, the Bi2 Se3 nanosheets with the proper size and surface properties accumulate passively in tumors enabling efficient photoacoustic imaging of the entire tumors to facilitate photothermal cancer therapy. In vivo biodistribution studies reveal that they are expelled from the body efficiently after 30 d. The ultrathin Bi2 Se3 nanosheets have large clinical potential as metabolizable near-infrared-triggered theranostic agents.
Assuntos
Nanopartículas/química , Fototerapia/métodos , Animais , Humanos , Hipertermia Induzida , Nanoestruturas/química , Nanomedicina Teranóstica/métodosRESUMO
A titanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP, the BP after surface coordination exhibits excellent stability during dispersion in water and exposure to air for a long period of time, thereby significantly extending the lifetime and spurring broader application of BP.
RESUMO
Black phosphorus quantum dots (BPQDs) were synthesized using a liquid exfoliation method that combined probe sonication and bath sonication. With a lateral size of approximately 2.6â nm and a thickness of about 1.5â nm, the ultrasmall BPQDs exhibited an excellent NIR photothermal performance with a large extinction coefficient of 14.8 L g(-1)â cm(-1) at 808â nm, a photothermal conversion efficiency of 28.4%, as well as good photostability. After PEG conjugation, the BPQDs showed enhanced stability in physiological medium, and there was no observable toxicity to different types of cells. NIR photoexcitation of the BPQDs in the presence of C6 and MCF7 cancer cells led to significant cell death, suggesting that the nanoparticles have large potential as photothermal agents.
Assuntos
Fósforo/química , Pontos Quânticos , Linhagem Celular Tumoral , Humanos , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
Common methods to prepare SERS (surface-enhanced Raman scattering) probes rely on random conjugation of Raman dyes onto metal nanostructures, but most of the Raman dyes are not located at Raman-intense electromagnetic hotspots thus not contributing to SERS enhancement substantially. Herein, a competitive reaction between transverse gold overgrowth and dye conjugation is described to achieve site selective conjugation of Raman dyes to the hotspots (ends) on gold nanorods (GNRs). The preferential overgrowth on the nanorod side surface creates a barrier to prevent the Raman dyes from binding to the side surface except the ends of the GNRs, where the highest SERS enhancement factors are expected. The SERS enhancement observed from this special structure is dozens of times larger than that from conjugates synthesized by conventional methods. This simple and powerful strategy to prepare SERS probes can be extended to different anisotropic metal nanostructures with electromagnetic hotspots and has immense potential in in-depth SERS-based biological imaging and single-molecule detection.
Assuntos
Nanotecnologia , Nanotubos/química , Análise Espectral Raman , Anisotropia , Corantes/química , Meios de Contraste/química , Radiação Eletromagnética , Ouro/química , Nanopartículas Metálicas/química , Metais/química , Microscopia Eletrônica de Transmissão , Nanoestruturas/química , Espalhamento de Radiação , Ressonância de Plasmônio de Superfície , Propriedades de SuperfícieRESUMO
Manganese phosphosulphide (MnPS3 ), a newly emerged and promising member of the 2D metal phosphorus trichalcogenides (MPX3 ) family, has aroused abundant interest due to its unique physicochemical properties and applications in energy storage and conversion. However, its potential in the field of biomedicine, particularly as a nanotherapeutic platform for cancer therapy, has remained largely unexplored. Herein, a 2D "all-in-one" theranostic nanoplatform based on MnPS3 is designed and applied for imaging-guided synergistic photothermal-chemodynamic therapy. (Iron) Fe (II) ions are immobilized on the surface of MnPS3 nanosheets to facilitate effective chemodynamic therapy (CDT). Upon surface modification with polydopamine (PDA) and polyethylene glycol (PEG), the obtained Fe-MnPS3 /PDA-PEG nanosheets exhibit exceptional photothermal conversion efficiency (η = 40.7%) and proficient pH/NIR-responsive Fenton catalytic activity, enabling efficient photothermal therapy (PTT) and CDT. Importantly, such nanoplatform can also serve as an efficient theranostic agent for multimodal imaging, facilitating real-time monitoring and guidance of the therapeutic process. After fulfilling the therapeutic functions, the Fe-MnPS3 /PDA-PEG nanosheets can be efficiently excreted from the body, alleviating the concerns of long-term retention and potential toxicity. This work presents an effective, precise, and safe 2D "all-in-one" theranostic nanoplatform based on MnPS3 for high-efficiency tumor-specific theranostics.
Assuntos
Indóis , Neoplasias , Fototerapia , Polímeros , Ferro , Terapia Fototérmica , Linhagem Celular Tumoral , Polietilenoglicóis/química , Imagem Multimodal/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/terapiaRESUMO
Lignin is dietary fiber from plant cell walls with multiple biological antioxidant and anti-inflammatory activities. However, whether lignin protects from ulcerative colitis (UC) and underlying mechanisms is unclear. Herein, UC mouse modeling was established with dextran sulfate sodium (DSS) and treatment with lignin for 1 week. Results showed that lignin inhibited the disease activity index (DAI), histological damage, and cell death in UC mice. We also found that lignin reversed the alterations of ferroptotic features in DSS-induced mice and ferroptotic cells, as evidenced by increased expression of GPX4 and 4-HNE and decreased transferrin expression, ameliorating the phenomenon of iron overload, GSH depletion, and ROS and MDA production. Furthermore, the increased expression of NRF2 was observed in IECs under lignin treatment. Also, the upstream regulatory molecule ERK of NRF2 was activated. Further research revealed that lignin can bind GPR37. Meanwhile, lignin was able to alleviate colitis by improving the composition of the intestinal flora in DSS mice and its effect was similar to that of 5-ASA. Taken together, these findings suggest that lignin protects against ferroptosis in UC by combining GPR37 and activating the ERK-NRF2-GPX4 signaling axis, which provides new ideas for clinical intervention in the treatment of UC.
RESUMO
Cellobionic acid (CBA), a kind of aldobionic acid, offers potential applications in the fields of pharmaceutical, cosmetic, food, and chemical industry. To tackle the high cost of the substrate cellobiose in CBA production using quinoprotein glucose dehydrogenase, this study developed a coenzyme-free and phosphate-balanced in vitro synthetic enzymatic biosystem (ivSEBS) to enable the sustainable CBA synthesis from cost-effective starch in one-pot via the CBA-synthesis module and gluconic acid-supply module. The metabolic fluxes of this artificial biosystem were strengthened using design-build-test-analysis strategy, which involved exquisite pathway design, meticulous enzyme selection, module validation and integration, and optimization of the key enzyme dosage. Under the optimized conditions, a remarkable concentration of 6.2 g/L CBA was achieved from initial 10 g/L maltodextrin with a starch-to-CBA molar conversion rate of 60 %. Taking into account that the biosystem simultaneously accumulated 3.6 g/L of gluconic acid, the maltodextrin utilization rate was calculated to be 93.3 %. Furthermore, a straightforward scaling-up process was performed to evaluate the industrial potential of this enzymatic biosystem, resulting in a yield of 21.2 g/L CBA from 50 g/L maltodextrin. This study presents an artificial ivSEBS for sustainable production of CBA from inexpensive starch, demonstrating an alternative paradigm for biomanufacturing of other aldobionic acids.
Assuntos
Gluconatos , Amido , Dissacarídeos/metabolismoRESUMO
Although there is increasing evidence suggesting that DNA methylation regulates seed development, the underlying mechanisms remain poorly understood. Therefore, we aimed to shed light on this by conducting whole-genome bisulfite sequencing using seeds from the large-seeded cultivar 'HZ' and the abortive-seeded cultivar 'NMC'. Our analysis revealed that the 'HZ' seeds exhibited a hypermethylation level compared to the 'NMC' seeds. Furthermore, we found that the genes associated with differentially methylated regions (DMRs) and differentially expressed genes (DEGs) were mainly enriched in the reactive oxygen species (ROS) metabolic pathway. To investigate this further, we conducted nitroblue tetrazolium (NBT) and 2,7-Dichlorodihydrofluorescein (DCF) staining, which demonstrated a significantly higher amount of ROS in the 'NMC' seeds compared to the 'HZ' seeds. Moreover, we identified that the gene LcGPX6, involved in ROS scavenging, exhibited hypermethylation levels and parallelly lower expression levels in 'NMC' seeds compared to 'HZ' seeds. Interestingly, the ectopic expression of LcGPX6 in Arabidopsis enhanced ROS scavenging and resulted in lower seed production. Together, we suggest that DNA methylation-mediated ROS production plays a significant role in seed development in litchi, during which hypermethylation levels of LcGPX6 might repress its expression, resulting in the accumulation of excessive ROS and ultimately leading to seed abortion.
RESUMO
BACKGROUND: Extraintestinal metastasis is the main therapeutic challenge for colorectal cancer, the third most common cancer worldwide. Various components of the tumor microenvironment, especially cancer-associated fibroblasts (CAFs), play important roles in tumor metastasis. NAMPT is often overexpressed in tumor tissues and is associated with poorer prognosis. However, the specific roles of NAMPT as well as NAD+ in tumor metastasis are relatively unknown. Therefore, we investigated the role of NAMPT and related NAD+ metabolism in cancer-associated fibroblasts mediated colorectal cancer metastasis. OBJECTIVE: This study sought to explore the molecular mechanism of FK866 in CAFs cell and colorectal cancer proliferation and metastasis. METHODS: The expression of NAMPT in clinical tissues were detected by immunohistochemically analysis. To investigate the role of NAMPT and NAD+ in the interactions between cancer cells and cancer-associated fibroblasts in tumor microenvironment, we isolated CAFs from normal and cancer tissues of clinical colorectal cancer patients. CAFs were treated with different concentrations of FK866, inhibitor of NAMPT, then the NAD+ content was detected using kits, the expression of CAFs activity and stemness indexes was assessed by Western blot and immunofluorescence. The secreted factors of these cells were analyzed by cellular inflammatory factor microarrays. The migration of SW480 after co-cultured with FK866-treated CAFs was detected by Transwell. Finally, high-throughput sequencing was performed to identify the proteins that are associated with the effect of altered NAD+ in CAFs on the migration of cancer cells. RESULTS: NAMPT expression is significantly higher in colorectal cancer tissues, especially in metastatic cancer patients, than that in normal tissues. Inhibition of NAMPT by FK866 in CAFs decreases the expression of activity indicators (α-SMA, PDGFRß), stemness indicators (BMI-1, OCT4), inflammatory factors and chemokines. Meanwhile, FK866 treatment inhibits the migration ability of SW480 cells co-cultured with CAFs. Finally, high-throughput sequencing reveals that PITX3 are down-regulated after NAD+ reduction in CAFs, which could be reversed by adding NAM, a raw material for NAD+ synthesis. CONCLUSION: Inhibition of the NAMPT-mediated NAD+ synthesis by FK866 may decrease the activation and stemness of CAFs, reduce the secretion of inflammatory and chemokines by suppressing the expression of PITX3, resulting in the suppression of colorectal cancer metastasis.
Assuntos
Fibroblastos Associados a Câncer , Neoplasias Colorretais , Humanos , NAD/metabolismo , NAD/farmacologia , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Acrilamidas/farmacologia , Piperidinas/farmacologia , Neoplasias Colorretais/metabolismo , Microambiente TumoralRESUMO
Colorectal cancer (CRC) is a cancer with a high morbidity and mortality worldwide. Hence, developing new therapeutic drugs for CRC is very important. Moxidectin (MOX) has shown good anti-glioblastoma effect both in vitro and in vivo. This study aimed to elucidate the anti-CRC effect of MOX and its potential mechanism by investigating the influence of MOX on the viability, apoptosis, necrosis and autophagy of colorectal cancer cells (HCT15 and SW620) and its underlying mechanisms. It was found that MOX can induce autophagy arrest, promote autophagy initiation, inhibit autophagic flux and cell proliferation, simultaneously PI3K-Akt-mTOR signaling pathway and microtubule acetylation. Furthermore, MOX suppressed the growth of xenograft tumors, which was consistent with the in vitro results.
Assuntos
Neoplasias Colorretais , Fosfatidilinositol 3-Quinases , Autofagia , Neoplasias Colorretais/tratamento farmacológico , Humanos , Macrolídeos , Proteínas Proto-Oncogênicas c-akt , Serina-Treonina Quinases TORRESUMO
As a prominent class of 2D transition metal dichalcogenides (TMDCs), niobium diselenide nanosheets (NbSe2 NSs) have garnered tremendous interest on account of promising applications pertaining to optoelectronics and energy storage. Although NbSe2 NSs have many unique advantages such as inherent biocompatibility and broad absorption in the NIR region, their biomedical applications have rarely been reported, especially as therapeutic agents for the second near-infrared (NIR-II) range. Herein, a biodegradable nanotherapeutic platform consisting of NbSe2 NSs is designed and demonstrated for NIR-II light-triggered photothermal therapy. NbSe2 NSs synthesized by grinding and liquid exfoliation exhibit superior photothermal conversion efficiency (48.3%) and remarkable photothermal stability in the NIR-II region. In vitro assessment demonstrates that NbSe2 NSs have favorable photothermal cell ablation efficiency and biocompatibility. After intravenous injection in vivo, the NbSe2 NSs accumulate passively in tumor sites to facilitate fluorescence imaging and tumor ablation by NIR-II illumination. Furthermore, as a result of gradual degradation in the physiological environment, NbSe2 NSs can be excreted from the body to avoid potential toxicity caused by long-term retention in vivo. The results reveal a promising NIR-II light-triggered PTT strategy with the aid of NbSe2 NSs and the platform is expected to have large potential in cancer theranostics.
Assuntos
Neoplasias , Nióbio , Humanos , Nióbio/farmacologia , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológicoRESUMO
The photochemical activity of black phosphorus (BP) in near-infrared (NIR) light controlled in situ biomineralization is investigated. Owing to the excellent NIR absorption, irradiation with NIR light not only promotes degradation of BP into PO4 3-, but also enhances the chemical activity to accelerate the reaction between PO4 3- and Ca2+ and promote in situ biomineralization. Mineralization of hydrogels is demonstrated by the preparation of BP incorporated hydrogel (BP@Hydrogel) which delivers greatly improved biomineralization performance under NIR illumination. The biomineralization process which can be controlled by modulating the light irradiation time and location has a high potential in controlling the mechanical properties and osteoinductive ability in tissue engineering. This study also provides insights into the degradation, photochemical activity, and new biological/biomedical applications of BP.
RESUMO
A reliable surface-enhanced Raman scattering (SERS) substrate composed of two-dimensional (2D) MXene (Ti3C2Tx) nanosheets and gold nanorods (AuNRs) is designed and fabricated for sensitive detection of organic pollutants. The AuNRs are uniformly distributed on the surface of the 2D MXene nanosheets because of the strong electrostatic interactions, forming abundant SERS hot spots. The MXene/AuNR SERS substrate exhibits high sensitivity and excellent reproducibility in the determination of common organic dyes such as rhodamine 6G, crystal violet, and malachite green. The detection limits are 1 × 10-12, 1 × 10-12, and 1 × 10-10 M, and relative standard deviations determined from 13 areas on each sample are 18.1, 10.1, and 15.6%, respectively. In the determination of more complex organic pesticides and pollutants, the substrate also shows excellent sensitivity and quantitative detection, and the detection limits for thiram and diquat of 1 × 10-10 and 1 × 10-8 M, respectively, are much lower than the contaminant levels stipulated by the US Environmental Protection Agency. The MXene/AuNR composite constitutes an efficient SERS platform for reliable and high-sensitivity environmental analysis and food safety monitoring.
Assuntos
Poluentes Ambientais/análise , Ouro/química , Nanotubos/química , Compostos Orgânicos/análise , Análise Espectral Raman/métodos , Eletricidade Estática , Titânio/química , Corantes/análise , Limite de Detecção , Modelos Moleculares , Conformação MolecularRESUMO
We report a novel metal-corrosion route beyond traditional top-down or bottom-up strategies for the mass production of 2D TMOs with a self-supported structure. The self-supported 2D Co3O4, a typical TMO, exhibits excellent electrocatalytic activity and stability in the oxygen evolution reaction surpassing those of commercial precious metal RuO2 catalysts at high currents.