RESUMO
The microtubule-associated protein tau oligomerizes, but the actions of oligomeric tau (oTau) are unknown. We have used Cry2-based optogenetics to induce tau oligomers (oTau-c). Optical induction of oTau-c elicits tau phosphorylation, aggregation, and a translational stress response that includes stress granules and reduced protein synthesis. Proteomic analysis identifies HNRNPA2B1 as a principle target of oTau-c. The association of HNRNPA2B1 with endogenous oTau was verified in neurons, animal models, and human Alzheimer brain tissues. Mechanistic studies demonstrate that HNRNPA2B1 functions as a linker, connecting oTau with N6-methyladenosine (m6A) modified RNA transcripts. Knockdown of HNRNPA2B1 prevents oTau or oTau-c from associating with m6A or from reducing protein synthesis and reduces oTau-induced neurodegeneration. Levels of m6A and the m6A-oTau-HNRNPA2B1 complex are increased up to 5-fold in the brains of Alzheimer subjects and P301S tau mice. These results reveal a complex containing oTau, HNRNPA2B1, and m6A that contributes to the integrated stress response of oTau.
Assuntos
Adenosina/análogos & derivados , Doença de Alzheimer/metabolismo , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/metabolismo , Processamento Pós-Transcricional do RNA , RNA/metabolismo , Proteínas tau/metabolismo , Adenosina/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Estudos de Casos e Controles , Modelos Animais de Doenças , Progressão da Doença , Feminino , Células HEK293 , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/genética , Humanos , Masculino , Metilação , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Agregados Proteicos , Agregação Patológica de Proteínas , RNA/genética , Índice de Gravidade de Doença , Proteínas tau/genéticaRESUMO
Human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causative pathogen of the COVID-19 pandemic, exerts a massive health and socioeconomic crisis. The virus infects alveolar epithelial type 2 cells (AT2s), leading to lung injury and impaired gas exchange, but the mechanisms driving infection and pathology are unclear. We performed a quantitative phosphoproteomic survey of induced pluripotent stem cell-derived AT2s (iAT2s) infected with SARS-CoV-2 at air-liquid interface (ALI). Time course analysis revealed rapid remodeling of diverse host systems, including signaling, RNA processing, translation, metabolism, nuclear integrity, protein trafficking, and cytoskeletal-microtubule organization, leading to cell cycle arrest, genotoxic stress, and innate immunity. Comparison to analogous data from transformed cell lines revealed respiratory-specific processes hijacked by SARS-CoV-2, highlighting potential novel therapeutic avenues that were validated by a high hit rate in a targeted small molecule screen in our iAT2 ALI system.
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Células Epiteliais Alveolares/metabolismo , COVID-19/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , SARS-CoV-2/metabolismo , Células Epiteliais Alveolares/patologia , Células Epiteliais Alveolares/virologia , Animais , Antivirais , COVID-19/genética , COVID-19/patologia , Chlorocebus aethiops , Efeito Citopatogênico Viral , Citoesqueleto , Avaliação Pré-Clínica de Medicamentos , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Células-Tronco Pluripotentes Induzidas/virologia , Fosfoproteínas/genética , Transporte Proteico , Proteoma/genética , SARS-CoV-2/genética , Transdução de Sinais , Células Vero , Tratamento Farmacológico da COVID-19RESUMO
Simultaneous spatial mapping of the activity of multiple enzymes in a living system can elucidate their functions in health and disease. However, methods based on monitoring fluorescent substrates are limited. Here, we report the development of nitrile (C≡N)-tagged enzyme activity reporters, named nitrile chameleons, for the peak shift between substrate and product. To image these reporters in real time, we developed a laser-scanning mid-infrared photothermal imaging system capable of imaging the enzymatic substrates and products at a resolution of 300 nm. We show that when combined, these tools can map the activity distribution of different enzymes and measure their relative catalytic efficiency in living systems such as cancer cells, Caenorhabditis elegans, and brain tissues, and can be used to directly visualize caspase-phosphatase interactions during apoptosis. Our method is generally applicable to a broad category of enzymes and will enable new analyses of enzymes in their native context.
Assuntos
Diagnóstico por Imagem , Nitrilas , CorantesRESUMO
High-precision neuromodulation plays a pivotal role in elucidating fundamental principles of neuroscience and treating specific neurological disorders. Optical neuromodulation, enabled by spatial resolution defined by the diffraction limit at the submicrometer scale, is a general strategy to achieve such precision. Optogenetics offers single-neuron spatial resolution with cellular specificity, whereas the requirement of genetic transfection hinders its clinical application. Direct photothermal modulation, an alternative nongenetic optical approach, often associates a large temperature increase with the risk of thermal damage to surrounding tissues.Photoacoustic (also called optoacoustic) neural stimulation is an emerging technology for neural stimulation with the following key features demonstrated. First, the photoacoustic approach demonstrated high efficacy without the need for genetic modification. The generated pulsed ultrasound upon ns laser pulses with energy ranging from a few µJ to tens of µJ is sufficient to activate wild-type neurons. Second, the photoacoustic approach provides sub-100-µm spatial precision. It overcomes the fundamental wave diffraction limit of ultrasound by harnessing the localized ultrasound field generated through light absorption. A spatial precision of 400 µm has been achieved in rodent brains using a fiber-based photoacoustic emitter. Single-cell stimulation in neuronal cultures in vitro and in brain slices ex vivo is achieved using tapered fiber-based photoacoustic emitters. This precision is 10 to 100 times better than that for piezo-based low-frequency ultrasound and is essential to pinpoint a specific region or cell population in a living brain. Third, compared to direct photothermal stimulation via temperature increase, photoacoustic stimulation requires 40 times less laser energy dose to evoke neuron activities and is associated with a minimal temperature increase of less than 1 °C, preventing potential thermal damage to neurons. Fourth, photoacoustics is a versatile approach and can be designed in various platforms aiming at specific applications. Our team has shown the design of fiber-based photoacoustic emitters, photoacoustic nanotransducers, soft biocompatible photoacoustic films, and soft photoacoustic lenses. Since they interact with neurons through ultrasound without the need for direct contact, photoacoustic enables noninvasive transcranial and dura-penetrating brain stimulation without compromising high precision.In this Account, we will first review the basic principles of photoacoustic and discuss the key design elements of PA transducers for neural modulation guided by the principle. We will also highlight how these design goals were achieved from a materials chemistry perspective. The design of different PA interfaces, their unique capability, and their applications in neural systems will be reviewed. In the end, we will discuss the remaining challenges and future perspectives for this technology.
Assuntos
Neurônios , Técnicas Fotoacústicas , Técnicas Fotoacústicas/métodos , Animais , Humanos , Optogenética/métodos , Encéfalo/diagnóstico por imagemRESUMO
One of the biggest challenges in microbiome research in environmental and medical samples is to better understand functional properties of microbial community members at a single-cell level. Single-cell isotope probing has become a key tool for this purpose, but the current detection methods for determination of isotope incorporation into single cells do not allow high-throughput analyses. Here, we report on the development of an imaging-based approach termed stimulated Raman scattering-two-photon fluorescence in situ hybridization (SRS-FISH) for high-throughput metabolism and identity analyses of microbial communities with single-cell resolution. SRS-FISH offers an imaging speed of 10 to 100 ms per cell, which is two to three orders of magnitude faster than achievable by state-of-the-art methods. Using this technique, we delineated metabolic responses of 30,000 individual cells to various mucosal sugars in the human gut microbiome via incorporation of deuterium from heavy water as an activity marker. Application of SRS-FISH to investigate the utilization of host-derived nutrients by two major human gut microbiome taxa revealed that response to mucosal sugars tends to be dominated by Bacteroidales, with an unexpected finding that Clostridia can outperform Bacteroidales at foraging fucose. With high sensitivity and speed, SRS-FISH will enable researchers to probe the fine-scale temporal, spatial, and individual activity patterns of microbial cells in complex communities with unprecedented detail.
Assuntos
Bacteroidetes , Firmicutes , Microbioma Gastrointestinal , Hibridização in Situ Fluorescente , Análise Espectral Raman , Bacteroidetes/metabolismo , Firmicutes/metabolismo , Humanos , Hibridização in Situ Fluorescente/métodos , Isótopos , Análise de Célula Única , Análise Espectral Raman/métodos , Açúcares/metabolismoRESUMO
Fatty acids are an important source of energy and a key component of phospholipids in membranes and organelles. Saturated fatty acids (SFAs) are converted into unsaturated fatty acids (UFAs) by stearoyl Co-A desaturase (SCD), an enzyme active in cancer. Here, we studied how the dynamics between SFAs and UFAs regulated by SCD impacts ovarian cancer cell survival and tumor progression. SCD depletion or inhibition caused lower levels of UFAs vs. SFAs and altered fatty acyl chain plasticity, as demonstrated by lipidomics and stimulated Raman scattering (SRS) microscopy. Further, increased levels of SFAs resulting from SCD knockdown triggered endoplasmic reticulum (ER) stress response with brisk activation of IRE1α/XBP1 and PERK/eIF2α/ATF4 axes. Disorganized ER membrane was visualized by electron microscopy and SRS imaging in ovarian cancer cells in which SCD was knocked down. The induction of long-term mild ER stress or short-time severe ER stress by the increased levels of SFAs and loss of UFAs led to cell death. However, ER stress and apoptosis could be readily rescued by supplementation with UFAs and reequilibration of SFA/UFA levels. The effects of SCD knockdown or inhibition observed in vitro translated into suppression of intraperitoneal tumor growth in ovarian cancer xenograft models. Furthermore, a combined intervention using an SCD inhibitor and an SFA-enriched diet initiated ER stress in tumors growing in vivo and potently blocked their dissemination. In all, our data support SCD as a key regulator of the cancer cell fate under metabolic stress and point to treatment strategies targeting the lipid balance.
Assuntos
Sobrevivência Celular , Endorribonucleases , Ácidos Graxos Insaturados , Neoplasias Ovarianas , Progressão da Doença , Ácidos Graxos Dessaturases , Ácidos Graxos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Feminino , Humanos , Fosfolipídeos , Proteínas Serina-Treonina Quinases , Estearoil-CoA Dessaturase/metabolismoRESUMO
INTRODUCTION: This study explored the association between psoriasis and the weight-adjusted waist index (WWI), a newly developed measure of adiposity. The research was conducted among adults in the United States. METHODS: Utilizing survey data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2009 to 2014, the present study aimed to investigate the potential correlation between psoriasis and WWI within a sample of 15,920 adult participants. Employing multivariable logistic regression and nonlinear curve fitting techniques, we analyzed this plausible association. Additionally, a subgroup analysis was conducted to ascertain the consistency across diverse populations. RESULTS: A significant positive association was discovered between psoriasis and WWI in the investigated sample of 15,920 adults. After conducting a comprehensive adjustment of the model, it was observed that each incremental unit of WWI was significantly associated with an 14% elevated likelihood of developing psoriasis (OR = 1.16, 95% CI 1.01-1.36). Moreover, individuals belonging to the highest quartile of WWI exhibited a 47% higher risk of psoriasis compared to those in the lowest quartile (OR = 1.44, 95% CI 1.01-2.06). This positive correlation remained consistent across various subgroups. The study also compared WWI with BMI and waist circumference, finding that WWI is a more stable metric of obesity. CONCLUSIONS: Our study suggested that in US adults, there is a positive association between WWI and psoriasis. It also indicated that WWI showed potential as a valuable index of psoriasis among the general population.
Assuntos
Índice de Massa Corporal , Inquéritos Nutricionais , Psoríase , Circunferência da Cintura , Humanos , Psoríase/epidemiologia , Masculino , Feminino , Estudos Transversais , Estados Unidos/epidemiologia , Pessoa de Meia-Idade , Adulto , Obesidade/epidemiologia , Fatores de Risco , Peso Corporal , AdiposidadeRESUMO
OBJECTIVES: Computed tomographic perfusion (CTP) can play an auxiliary role in the selection of patients with acute ischemic stroke for endovascular treatment. However, data on CTP in non-stroke patients with intracranial arterial stenosis are scarce. We aimed to investigate images in patients with asymptomatic intracranial arterial stenosis to determine the detection accuracy and interpretation time of large/medium-artery stenosis or occlusion when combining computed tomographic angiography (CTA) and CTP images. METHODS: We retrospectively reviewed 39 patients with asymptomatic intracranial arterial stenosis from our hospital database from January 2021 to August 2023 who underwent head CTP, head CTA, and digital subtraction angiography (DSA). Head CTA images were generated from the CTP data, and the diagnostic performance for each artery was assessed. Two readers independently interpreted the CTA images before and after CTP, and the results were analyzed. RESULTS: After adding CTP maps, the accuracy (area under the curve) of diagnosing internal carotid artery (R1: 0.847 vs. 0.907, R2: 0.776 vs. 0.887), middle cerebral artery (R1: 0.934 vs. 0.933, R2: 0.927 vs. 0.981), anterior cerebral artery (R1: 0.625 vs. 0.750, R2: 0.609 vs. 0.750), vertebral artery (R1: 0.743 vs. 0.764, R2: 0.748 vs. 0.846), and posterior cerebral artery (R1: 0.390 vs. 0.575, R2: 0.390 vs. 0.585) occlusions increased for both readers (p < 0.05). Mean interpretation time (R1: 72.4 ± 6.1 s vs. 67.7 ± 6.4 s, R2: 77.7 ± 3.8 s vs. 72.6 ± 4.7 s) decreased when using a combination of both images both readers (p < 0.001). CONCLUSIONS: The addition of CTP images improved the accuracy of interpreting CTA images and reduced the interpretation time in asymptomatic intracranial arterial stenosis. These findings support the use of CTP imaging in patients with asymptomatic intracranial arterial stenosis.
Assuntos
AVC Isquêmico , Humanos , Estudos Retrospectivos , Constrição Patológica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Angiografia por Tomografia Computadorizada/métodos , Perfusão , Angiografia Cerebral/métodosRESUMO
Impairments in spatial navigation in humans can be preclinical signs of Alzheimer's disease. Therefore, cognitive tests that monitor deficits in spatial memory play a crucial role in evaluating animal models with early stage Alzheimer's disease. While Chinese tree shrews (Tupaia belangeri) possess many features suitable for Alzheimer's disease modeling, behavioral tests for assessing spatial cognition in this species are lacking. Here, we established reward-based paradigms using the radial-arm maze and cheeseboard maze for tree shrews, and tested spatial memory in a group of 12 adult males in both tasks, along with a control water maze test, before and after bilateral lesions to the hippocampus, the brain region essential for spatial navigation. Tree shrews memorized target positions during training, and task performance improved gradually until reaching a plateau in all 3 mazes. However, spatial learning was compromised post-lesion in the 2 newly developed tasks, whereas memory retrieval was impaired in the water maze task. These results indicate that the cheeseboard task effectively detects impairments in spatial memory and holds potential for monitoring progressive cognitive decline in aged or genetically modified tree shrews that develop Alzheimer's disease-like symptoms. This study may facilitate the utilization of tree shrew models in Alzheimer's disease research.
Assuntos
Doença de Alzheimer , Tupaia , Humanos , Masculino , Animais , Adulto , Idoso , Tupaiidae , Memória Espacial , Musaranhos , Aprendizagem em Labirinto , Modelos Animais de DoençasRESUMO
While protein aggregation is a hallmark of many neurodegenerative diseases, acquiring structural information on protein aggregates inside live cells remains challenging. Traditional microscopy does not provide structural information on protein systems. Routinely used fluorescent protein tags, such as Green Fluorescent Protein (GFP), might perturb native structures. Here, we report a counter-propagating mid-infrared photothermal imaging approach enabling mapping of secondary structure of protein aggregates in live cells modeling Huntington's disease. By comparing mid-infrared photothermal spectra of label-free and GFP-tagged huntingtin inclusions, we demonstrate that GFP fusions indeed perturb the secondary structure of aggregates. By implementing spectra with small spatial step for dissecting spectral features within sub-micrometer distances, we reveal that huntingtin inclusions partition into a ß-sheet-rich core and a É-helix-rich shell. We further demonstrate that this structural partition exists only in cells with the [RNQ+] prion state, while [rnq-] cells only carry smaller ß-rich non-toxic aggregates. Collectively, our methodology has the potential to unveil detailed structural information on protein assemblies in live cells, enabling high-throughput structural screenings of macromolecular assemblies.
Assuntos
Proteína Huntingtina , Doença de Huntington , Agregados Proteicos , Doença de Huntington/patologia , Doença de Huntington/metabolismo , Humanos , Proteína Huntingtina/química , Proteína Huntingtina/metabolismo , Proteína Huntingtina/genética , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/metabolismoRESUMO
Potential associations between the risk of neurodegenerative diseases and circulating levels of amino acids have been implied in both experimental research and observational studies. However, because of the confounding and reverse causality, the findings could be biased. We aimed to determine whether circulating amino acid levels have potential effects on the risk of neurodegenerative diseases through a more robust analysis. So, we performed a total of two MR analyses, a discovery two-sample MR analysis, and a replication test, using summary-level genome-wide association study (GWAS) data, both with circulating levels of amino acids as exposure and risk of neurodegenerative diseases as an outcome. The potential causalities between nine amino acids (Glutamine [Glu], Leucine [Leu], Isoleucine [Ile], Phenylalanine [Phe], Valine [Val], Alanine [Ala], Tyrosine [Tyr], Histidine [His], and Glycine [Gly]) and six neurodegenerative disorders (Alzheimer's disease [AD], Parkinson's disease [PD], Multiple sclerosis [MS], Frontotemporal dementia [FTD], Lewy body dementia [DLB], Amyotrophic lateral sclerosis [ALS]) were explored in this study. According to the discovery MR analysis, 1 SD. increase in circulating levels of Gln was genetically determined to result in a 13% lower risk of AD (IVW ORSD [95% CI] = 0.872 [0.822, 0.926]; FDR = 7.46 × 10-5 ) while PD risk was decreased to 63% per SD. increase of circulating Leu levels (IVW ORSD [95% CI] = 0.628 [0.467, 0.843]; FDR = 0.021). Results from the replication test provide further evidence of the potential association between circulating Gln levels and AD risk (IVW ORSD [95% CI] = 0.094 [0.028, 0.311]; FDR = 9.98 × 10-4 ). Meanwhile, sensitivity analysis demonstrated that the significant relationships revealed by our two-sample MR outcomes were reliable. Our analyses provided robust evidence of causal associations between circulating levels of Gln and AD risk as well as circulating Leu levels and risk of PD. However, the underlying mechanisms remain to be further investigated.
Assuntos
Doença de Alzheimer , Doença por Corpos de Lewy , Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Aminoácidos/genética , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Doenças Neurodegenerativas/genética , Glutamina , CausalidadeRESUMO
Schisandra chinensis is a monoecious plant with unisex flowers. The fruit of S. chinensis is of high medical with economic value. The yield of S. chinensis fruit is related to the ratio of its female and male flowers. However, there is little research on its floral development and sex differentiation. To elucidate the possible mechanism for the sex differentiation of S. chinensis, we collected 18 samples of female and male flowers from three developmental stages and performed a comparative RNA-seq analysis aimed at identifying differentially expressed genes (DEGs) that may be related to sex differentiation. The results showed 936, 7179, and 6890 differentially expressed genes between female and male flowers at three developmental stages, respectively, and 466 candidate genes may play roles in sex differentiation. KEGG analysis showed genes involved in the flavonoid biosynthesis pathway and DNA replication pathway were essential for the development of female flowers. 51 MADS-box genes and 10 YABBY genes were identified in S. chinensis. The DEGs analysis indicated that MADS-box and YABBY genes were strongly related to the sex determination of S. chinensis. RT-qPCR confirmed the RNA-seq results of 20 differentially expressed genes, including three male-biased genes and 17 female-biased genes. A possible regulatory model of sex differentiation in S. chinensis was proposed according to our results. This study helps reveal the sex-differentiation mechanism of S. chinensis and lays the foundation for regulating the male-female ratio of S. chinensis in the future.
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Schisandra , Schisandra/genética , Diferenciação Sexual , Perfilação da Expressão Gênica , Transcriptoma , Flores , Regulação da Expressão Gênica de PlantasRESUMO
Simultaneous identification and metabolic analysis of microbes with single-cell resolution and high throughput are necessary to answer the question of "who eats what, when, and where" in complex microbial communities. Here, we present a mid-infrared photothermal-fluorescence in situ hybridization (MIP-FISH) platform that enables direct bridging of genotype and phenotype. Through multiple improvements of MIP imaging, the sensitive detection of isotopically labeled compounds incorporated into proteins of individual bacterial cells became possible, while simultaneous detection of FISH labeling with rRNA-targeted probes enabled the identification of the analyzed cells. In proof-of-concept experiments, we showed that the clear spectral red shift in the protein amide I region due to incorporation of 13C atoms originating from 13C-labeled glucose can be exploited by MIP-FISH to discriminate and identify 13C-labeled bacterial cells within a complex human gut microbiome sample. The presented methods open new opportunities for single-cell structure-function analyses for microbiology.
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Bactérias , RNA Ribossômico , Humanos , Hibridização in Situ Fluorescente/métodos , RNA Ribossômico/análise , Bactérias/genética , Sondas de Oligonucleotídeos/genética , AmidasRESUMO
Antimicrobial resistance poses great threats to global health and economics. Current gold-standard antimicrobial susceptibility testing (AST) requires extensive culture time (36-72 h) to determine susceptibility. There is an urgent need for rapid AST methods to slow down antimicrobial resistance. Here, we present a rapid AST method based on wide-field mid-infrared photothermal imaging of protein synthesis from 13C-glucose in Escherichia coli. Our wide-field approach achieved metabolic imaging for hundreds of bacteria at the single-cell resolution within seconds. The perturbed microbial protein synthesis can be probed within 1 h after antibiotic treatment in E. coli cells. The susceptibility of antibiotics with various mechanisms of action has been probed through monitoring protein synthesis, which promises great potential of the proposed platform toward clinical translation.
Assuntos
Antibacterianos , Escherichia coli , Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Bactérias , Diagnóstico por ImagemRESUMO
Candida albicans (C. albicans), a major fungal pathogen, causes life-threatening infections in immunocompromised individuals. Fluconazole (FLC) is recommended as first-line therapy for treatment of invasive fungal infections. However, the widespread use of FLC has resulted in increased antifungal resistance among different strains of Candida, especially C. albicans, which is a leading source of hospital-acquired infections. Here, by hyperspectral stimulated Raman scattering imaging of single fungal cells in the fingerprint window and pixel-wise spectral unmixing, we report aberrant ergosteryl ester accumulation in azole-resistant C. albicans compared to azole-susceptible species. This accumulation was a consequence of de novo lipogenesis. Lipid profiling by mass spectroscopy identified ergosterol oleate to be the major species stored in azole-resistant C. albicans. Blocking ergosterol esterification by oleate and suppressing sterol synthesis by FLC synergistically suppressed the viability of C. albicans in vitro and limited the growth of biofilm on mouse skin in vivo. Our findings highlight a metabolic marker and a new therapeutic strategy for targeting azole-resistant C. albicans by interrupting the esterified ergosterol biosynthetic pathway.
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Antifúngicos , Candida albicans , Animais , Camundongos , Antifúngicos/química , Azóis/farmacologia , Azóis/metabolismo , Análise Espectral Raman , Ésteres/metabolismo , Ácido Oleico/metabolismo , Testes de Sensibilidade Microbiana , Fluconazol/metabolismo , Ergosterol/farmacologia , Ergosterol/metabolismoRESUMO
Optical coherence tomography (OCT) is a label-free, non-invasive 3D imaging tool widely used in both biological research and clinical diagnosis. Conventional OCT modalities can only visualize specimen tomography without chemical information. Here, we report a bond-selective full-field OCT (BS-FF-OCT), in which a pulsed mid-infrared laser is used to modulate the OCT signal through the photothermal effect, achieving label-free bond-selective 3D sectioned imaging of highly scattering samples. We first demonstrate BS-FF-OCT imaging of 1â µm PMMA beads embedded in agarose gel. Next, we show 3D hyperspectral imaging of up to 75â µm of polypropylene fiber mattress from a standard surgical mask. We then demonstrate BS-FF-OCT imaging on biological samples, including cancer cell spheroids and C. elegans. Using an alternative pulse timing configuration, we finally demonstrate the capability of BS-FF-OCT on imaging a highly scattering myelinated axons region in a mouse brain tissue slice.
Assuntos
Caenorhabditis elegans , Tomografia de Coerência Óptica , Animais , Camundongos , Tomografia de Coerência Óptica/métodos , Imageamento TridimensionalRESUMO
Vibrational microscopy based on coherent Raman scattering is a powerful tool for high-speed chemical imaging, but its lateral resolution is bound to the optical diffraction limit. On the other hand, atomic force microscopy (AFM) provides nano-scale spatial resolution, yet with lower chemical specificity. In this study, we leverage a computational approach called pan-sharpening to merge AFM topography images and coherent anti-Stokes Raman scattering (CARS) images. The hybrid system combines the advantages of both modalities, providing informative chemical mapping with â¼20 nm spatial resolution. CARS and AFM images were sequentially acquired on a single multimodal platform, which facilitates image co-localization. Our image fusion approach allowed for discerning merged neighboring features previously invisible due to the diffraction limit and identifying subtle unobservable structures with the input from AFM images. Compared to tip-enhanced CARS measurement, sequential acquisition of CARS and AFM images enables higher laser power to be used and avoids any tip damage caused by the incident laser beams, resulting in a significantly improved CARS image quality. Together, our work suggests a new direction for achieving super-resolution coherent Raman scattering imaging of materials through a computational approach.
RESUMO
BACKGROUND: Aspirin resistance (AR) results in major adverse cardiovascular events, and DNA methylation might participate in the regulation of this pathological process. METHODS: In present study, a sum of 35 patients with AR and 35 non-AR (NAR) controls were enrolled. Samples from 5 AR and 5 NAR were evaluated in an 850 BeadChip DNA methylation assay, and another 30 AR versus 30 NAR were evaluated to validate the differentially methylated CpG loci (DML). Then, qRT-PCR was used to investigate the target mRNA expression of genes at CpG loci. Finally, Gene Ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to reveal the enriched pathways. RESULTS: The AR and NAR groups displayed significant differences in DNA methylation at 7707 positions, with 270 hypermethylated sites (e.g., cg09555818 located in APOC2) and 7437 sites hypomethylated sites (e.g., cg26828689 located in SLC12A5). Six DML were validated by pyrosequencing, and it was confirmed that DNA methylation (cg16391727, cg21008208, cg21293749, and cg13945576) was related to the increasing risk of AR. The relative mRNA expression of the ROR1 gene was also associated with AR (p = 0.007), suggesting that the change of cg21293749 in DNA methylation might lead to differential ROR1 mRNA expression, ultimately resulting in AR. Furthermore, the identified differentially methylated sites were associated with the molecular pathways such as circadian rhythms and insulin secretion. CONCLUSION: Hence, the distinct DNA methylation might play a vital role in the biological regulation of AR through the pathways such as circadian rhythms.
Assuntos
Síndrome Coronariana Aguda , Metilação de DNA , Humanos , Metilação de DNA/genética , Síndrome Coronariana Aguda/tratamento farmacológico , Síndrome Coronariana Aguda/genética , Aspirina/farmacologia , RNA Mensageiro/genética , Ilhas de CpG/genéticaRESUMO
OBJECTIVES: This study aims to reveal immunophenotypes associated with immunotherapy response in bladder cancer, identify the signature genes of immune subtypes, and provide new molecular targets for improving immunotherapy response. METHODS: Bladder cancer immunophenotypes were characterized in the bulk RNA sequencing dataset GSE32894 and Imvigor210, and gene expression signatures were established to identify the immunophenotypes. Expression of gene signatures were validated in single-cell RNA sequencing dataset GSE145140 and human proteins expression data source. Investigation of Immunotherapy Response was performed in IMvigor210 dataset. Prognosis of tumor immunophenotypes was further analyzed. RESULTS: Inflamed and immune-excluded immunophenotypes were characterized based on the tumor immune cell scores. Risk score models that were established rely on RNA sequencing profiles and overall survival of bladder cancer cohorts. The inflamed tumors had lower risk scores, and the low-risk tumors were more likely to respond to atezolizumab, receiving complete response/partial response (CR/PR). Patients who responded to atezolizumab had higher SRRM4 and lower NPHS1 and TMEM72 expression than the non-responders. SRRM4 expression was a protective factor for bladder cancer prognosis, while the NPHS1 and TMEM72 showed the opposite pattern. CONCLUSION: This study provided a novel classification method for tumor immunophenotypes. Bladder cancer immunophenotypes can predict the response to immune checkpoint blockade. The immunophenotypes can be identified by the expression of signature genes.