High-resolution Microscopy Images Research Articles

SARS-CoV-2: enhancement and segmentation of high-resolution microscopy images-Part I.

Possibly, and due to poor eating habits and unhealthy lifestyle, many viruses are transmitted to human people. Such is the case, of the novel coronavirus SARS-Cov-2, which has expanded of exponential way, practically, to whole world population. For this reason, the enhancement of real microscopic images of this coronavirus is of great importance. Of this way, one can highlight the S-spikes and visualizing those areas that show a high density, which are related to active zones of viral germination and major spread of the virus. The SARS-Cov-2 images were captured from nasopharyngeal samples of Cuban symptomatic individuals (RT-PCR positives for SARS-CoV-2) and processed via scanning electron microscopy. However, many times these microscopic images present some blurring problems, and the S-spikes do not look well defined. Therefore, the aim of this work is to propose new computational methods to carry out enhancement and segmentation of SARS-Cov-2 high-resolution microscopic images. The proposed strategy obtained very satisfactory results, and we validated its performance, together with specialist physicians, on a set of 1005 images. Due to the importance of the obtained results, this first work will be addressed to the application of the proposed algorithm. A second paper will deeply analyze the theory related to these algorithms.

FPM app: an open-source MATLAB application for simple and intuitive Fourier ptychographic reconstruction.

Fourier ptychographic microscopy (FPM) is a computational microscopy technique that enables large field of view and high-resolution microscopic imaging of biological samples. However, the FPM does not yet have an adequately capable open-source software. In order to fill this gap we are presenting novel, simple, universal, semi-automatic and highly intuitive graphical user interface (GUI) open-source application called the FPM app enabling wide-scale robust FPM reconstruction. Apart from implementing the FPM in accessible GUI app, we also made several improvements in the FPM image reconstruction process itself, making the FPM more automatic, noise-robust and faster. FPM app was implemented in MATLAB and all MATLAB codes along with standalone executable version of the FPM app and the online documentation are freely accessible at https://github.com/MRogalski96/FPM-app. Our exemplary FPM datasets may be downloaded at https://bit.ly/2MxNpGb. Supplementary data are available at Bioinformatics online.

Carcinoma Type Classification From High-Resolution Breast Microscopy Images Using a Hybrid Ensemble of Deep Convolutional Features and Gradient Boosting Trees Classifiers.

Breast cancer is one of the main causes behind cancer deaths in women worldwide. Yet, owing to the complexity of the histopathological images and the arduousness of manual analysis task, the entire diagnosis process becomes time-consuming and the results are often contingent on the pathologist's subjectivity. Thus developing an automated, precise histopathological image classification system is crucial. This paper presents a novel hybrid ensemble framework consisting of multiple fine-tuned convolutional neural network (CNN) architectures as supervised feature extractors and eXtreme gradient boosting trees (XGBoost) as a top-level classifier, for patch wise classification of high-resolution breast histopathology images. Due to the semantic complexity of the patch images, a single CNN architecture may not always extract high quality features, and the traditional Softmax classifier might not provide ideal results for classifying the CNN extracted features. Thus we aim to improve patch wise classification by proposing a hybrid ensemble model that incorporates different discriminating feature representations of the patches, coupled with XGBoost for robust classification. Experimental results show that our proposed method outperforms state-of-the-art methods to the best of our knowledge.

YeastNet: Deep-Learning-Enabled Accurate Segmentation of Budding Yeast Cells in Bright-Field Microscopy

Accurate and efficient segmentation of live-cell images is critical in maximizing data extraction and knowledge generation from high-throughput biology experiments. Despite recent development of deep-learning tools for biomedical imaging applications, great demand for automated segmentation tools for high-resolution live-cell microscopy images remains in order to accelerate the analysis. YeastNet dramatically improves the performance of the non-trainable classic algorithm, and performs considerably better than the current state-of-the-art yeast-cell segmentation tools. We have designed and trained a U-Net convolutional network (named YeastNet) to conduct semantic segmentation on bright-field microscopy images and generate segmentation masks for cell labeling and tracking. YeastNet enables accurate automatic segmentation and tracking of yeast cells in biomedical applications. YeastNet is freely provided with model weights as a Python package on GitHub.

Label-free histological imaging of tissues using Brillouin light scattering contrast.

Brillouin light scattering offers a unique label-free approach to measure biomechanical properties non-invasively. While this technique is used in biomechanical analysis of cells and tissues, its potential for visualizing structural features of tissues based on the biomechanical contrast has not been much exploited. Here, we present high-resolution Brillouin microscopy images of four basic tissue types: muscular, connective, epithelial, and nervous tissues. The Brillouin contrast distinguishes between muscle fiber cells and endomysium in skeletal muscle and reveals chondrocytes along with spatially varying stiffness of the extracellular matrix in articular cartilage. The hydration-sensitive contrast can visualize the stratum corneum, epidermis, and dermis in the skin epithelium. In brain tissues, the Brillouin images show the mechanical heterogeneity across the cortex and deeper regions. This work demonstrates the versatility of using the Brillouin shift as histological contrast for examining intact tissue substructures via longitudinal modulus without the need for laborious tissue processing steps.

Quantitative Investigation of Mechanosensing in B Cell Activation

B cell activation is triggered by specific binding events between the B cell receptor (BCR) and antigens presented by antigen-presenting cells (APCs). B cell activation is well-characterised biochemically, but the role of physical factors is poorly understood. It has been shown in vitro that for a given antigen density, B cell triggering is enhanced on stiff substrates relative to softer substrates. When the substrate rigidity is kept constant, B cell triggering positively correlates with antigen affinity up to 50 µM−1, above which B cells respond maximally independent of antigen affinity. Additionally, the minimum antigen density required to induce a B cell response inversely correlates with antigen affinity. B cells can sense these myriad physical parameters through information encoded in BCR-antigen bonds, although the mechanisms are unclear. Here, we aim to understand how B cell responses to antigen are influenced by physical factors in the immune synapse. We are using high-resolution fluorescence microscopy and quantitative image analysis to systematically investigate how antigen affinity, antigen density and substrate stiffness influence B cell activation. This work will help build a quantitative understanding of B cell mechanosensing, which is important for the rational design of new vaccines and immunotherapies.

Microfluidic electrical impedance assessment of red blood cell-mediated microvascular occlusion.

Alterations in the deformability of red blood cells (RBCs), occurring in hemolytic blood disorders such as sickle cell disease (SCD), contribute to vaso-occlusion and disease pathophysiology. There are few functional in vitro assays for standardized assessment of RBC-mediated microvascular occlusion. Here, we present the design, fabrication, and clinical testing of the Microfluidic Impedance Red Cell Assay (MIRCA) with embedded capillary network-based micropillar arrays and integrated electrical impedance measurement electrodes to address this need. The micropillar arrays consist of microcapillaries ranging from 12 μm to 3 μm, with each array paired with two sputtered gold electrodes to measure the impedance change of the array before and after sample perfusion through the microfluidic device. We define RBC occlusion index (ROI) and RBC electrical impedance index (REI), which represent the cumulative percentage occlusion and cumulative percentage impedance change, respectively. We demonstrate the promise of MIRCA in two common red cell disorders, SCD and hereditary spherocytosis. We show that the electrical impedance measurement reflects the microvascular occlusion, where REI significantly correlates with ROI that is obtained via high-resolution microscopy imaging of the microcapillary arrays. Further, we show that RBC-mediated microvascular occlusion, represented by ROI and REI, associates with clinical treatment outcomes and correlates with in vivo hemolytic biomarkers, lactate dehydrogenase (LDH) level and absolute reticulocyte count (ARC) in SCD. Impedance measurement obviates the need for high-resolution imaging, enabling future translation of this technology for widespread access, portable and point-of-care use. Our findings suggest that the presented microfluidic design and the integrated electrical impedance measurement provide a reproducible functional test for standardized assessment of RBC-mediated microvascular occlusion. MIRCA and the newly defined REI may serve as an in vitro therapeutic efficacy benchmark for assessing the clinical outcome of emerging RBC-modifying targeted and curative therapies.

Sequential peripheral enrichment of H2A.Zac and H3K9me2 during trophoblast differentiation in human embryonic stem cells.

During the transition from pluripotency to a lineage-committed state, chromatin undergoes large-scale changes in structure, involving covalent modification of histone tails, use of histone variants and gene position changes with respect to the nuclear periphery. Here, using high-resolution microscopy and quantitative image analysis, we surveyed a panel of histone modifications for changes in nuclear peripheral enrichment during differentiation of human embryonic stem cells to a trophoblast-like lineage. We found two dynamic modifications at the nuclear periphery, acetylation of histone H2A.Z (H2A.Zac), and dimethylation of histone H3 at lysine 9 (H3K9me2). We demonstrate successive peripheral enrichment of these markers, with H2A.Zac followed by H3K9me2, over the course of 4 days. We find that H3K9me2 increases concomitantly with, but independently of, expression of lamin A, since deletion of lamin A did not affect H3K9me2 enrichment. We further show that inhibition of histone deacetylases causes persistent and increased H2A.Z acetylation at the periphery, delayed H3K9me2 enrichment and failure to differentiate. Our results show a concerted change in the nature of peripheral chromatin occurs upon differentiation into the trophoblast state.

<p class="Body"><strong><em>Thyreophagus plocepasseri</em></strong><strong> sp. n., a new parthenogenetic species of acarid mites (Acariformes: Acaridae) from Kenya</strong></p>

To date, some species in the genus Thyreophagus, such as Th. entomophagus and Th. cracentiseta, have been shown to be useful factitious prey for mass-rearing of predacious phytoseiid mites, one of the most common groups of mites used for biological control. Here, we describe a new species, Thyreophagus plocepasseri sp. n. from Kenya that can serve as a factitious prey as well. In addition, the new species is asexual, a trait that can be advantageous for its mass-rearing in industrial settings. In the description, we use high-resolution light microscope imaging and extensive comparison with a similar species, Thyreophagus athiasae, for which the type was studied. We review the literature on asexual acarid mites and point to a lack of data on the presence of sex-manipulating bacteria (Wolbachia, Cardinium) in these asexual mite lineages. Based on the literature, these bacteria are known to induce parthenogenesis in several haplodiploid mites, but they have not been linked so far to parthenogenesis inducement in diplodiploid acarid mites.

WITHDRAWN: Wear analysis of woven glass / nanofiller fiber reinforced hybrid composites

This article primarily investigates the tribological behavior of the hybrid nanocomposite subjected to wear analysis. The hybrid nanocomposite laminates were prepared using woven roven glass reinforced in epoxy resin matrix, in which the nano Cerium(IV)-Zirconium(IV)Oxide was used as filling material. The influence of the nano particle content was studied by varying the weight percentage of nanoparticle (0.5, 1, and 1.5 wt%). The mechanical stirring was employed for better dispersion of nanoparticle in the matrix. These laminate was performed with wear analysis by using pin-on-disc arrangement, with specific load, velocity and sliding distance value. It is visible that the wear was minimized on the addition of the nanoparticle. When fibious quantity of nano particle (1 wt%) included, the specific wear rate was minimized upto 65%. The homogenously dispersed nano Cerium(IV)-Zirconium(IV)Oxide reduced the wear abrasives. The high resolution HRSEM and microscopic images were used to examine the morphology of the hybrid nanocomposite.

Assessment of Red Blood Cell-Mediated Microvascular Occlusion in Sickle Cell Disease By a Novel Electrical Impedance-Based Microfluidic Device

Introduction: Sickle cell disease (SCD) is a recessive genetic disorder caused by the mutated sickle hemoglobin (HbS) in red blood cells (RBCs). HbS polymerizes in a hypoxic environment, which leads to increased adhesiveness and decreased deformability of RBCs, and ultimately contributes to microvascular occlusion in SCD. As RBC deformability and the associated microvascular occlusion are predictors of individual microcirculatory health, previous studies have developed microfluidic devices for deformability-based RBC sorting in microscale flow, albeit with relatively low throughput. An easy-to-use, point-of-care assay to rapidly assess RBC-mediated microvascular occlusion can be clinically useful in examining the outcome of novel targeted and curative therapies, such as anti-sickling drugs and gene therapies, for patients with SCD. Here, we present an electrical impedance-based microfluidic device and functional assessment of RBC-mediated microvascular occlusion in SCD. Methods: Venous blood samples were collected in EDTA from subjects with homozygous SCD (HbSS, N=12) and controls (HbAA, N=5) under consent in an IRB-approved protocol. Microfluidic devices were fabricated using standard photolithography and polydimethylsiloxane (PDMS) micro-molding protocols. The microchannel consisted of micropillar arrays forming microcapillaries from 3-12 μm, with each array coupled with a pair of gold electrodes on the channel bottom surface (Figure 1A). Two 40-μm-wide side passageways mimicking the anastomoses in the capillary bed were designed to prevent microchannel upstream clogging (Figure 1A inset). A macroscopic view of the device is shown in Figure 1B. The 12-μm array was designed to filter large-cell aggregates and was excluded from our analysis. An impedance analyzer coupled with a custom printed-circuit board was used to record the electrical impedance at a spot frequency of 10 kHz. Prior to the experiments, the microchannel was blocked and rinsed to prevent non-specific adhesion of blood cells. Thereafter, the initial electrical impedance reading of each array was obtained. RBCs suspended at 20% hematocrit in PBS were then perfused through the microchannel under the same inlet pressure for 20 min. Next, the microchannel was washed and a second electrical impedance reading was obtained. The microchannel was then imaged under an inverted microscope, and occlusions of each array were manually quantified. The electrical impedance and occlusion results are reported as percent changes. Data are reported as mean ± standard deviation (SD). Pearson's correlation coefficient (PCC) was used to derive correlation statistics. Results: We observed increased microcapillary occlusion caused by HbSS- vs. HbAA-containing RBCs (Figure 1C, mean microcapillary occlusion percentage ± SD (%) = 24.33 ± 16.88 vs. 5.01 ± 1.25 for 3-μm array, 6.05 ± 4.09 vs. 2.19 ± 0.59 for 4-μm array, 2.77 ± 2.59 vs. 0.82 ± 0.82 for 6-μm array, 1.08 ± 2.28 vs. 0 ± 0 for 8-μm array, and 0.42 ± 1.14 vs. 0 ± 0 for 10-μm array). Similarly, we observed elevated electrical impedance change induced by HbSS- vs. HbAA-containing RBCs (Figure 1D, mean electrical impedance change ± SD (%) = 12.03 ± 8.97 vs. 2.44 ± 0.84 for 3-μm array, 1.79 ± 1.65 vs. 0.91 ± 0.42 for 4-μm array, 0.88 ± 1.14 vs. 0.58 ± 0.67 for 6-μm array, 0.16 ± 0.31 vs. 0.32 ± 0.37 for 8-μm array, and 0.06 ± 0.16 vs. 0.05 ± 0.17 for 10-μm array). Moreover, we found that the electrical impedance changes of individual arrays exhibited a significant correlation to the occlusion percentage within the corresponding arrays (Figure 1E, PCC = 0.9817, N = 85, p < 0.001). Conclusions: Findings suggest that a novel microfluidic platform integrated with micropillar arrays and electrical impedance readout can be used for standardized in vitro functional assessment of RBC-mediated microvascular occlusion in SCD. Electrical impedance change due to RBC-mediated microcapillary occlusion may serve as a new parameter for monitoring RBC health and function without the need for high-resolution microscopic imaging. RBC mediated microcapillary occlusion may serve as a new parameter to assess the clinical efficacy of treatments that improve RBC deformability and rheology, such as hemoglobin modifying drugs, anti-sickling agents, and therapies with curative intent. Disclosures Maji: Xatek Inc.: Patents & Royalties. An:Hemex Health, Inc.: Patents & Royalties. Ahuja:Genentech: Consultancy, Honoraria; Sanofi Genzyme: Consultancy, Honoraria; XaTek, Inc.: Consultancy, Patents & Royalties, Research Funding. Little:BioChip Labs: Patents & Royalties: SCD Biochip (patent, no royalties); Hemex Health, Inc.: Patents & Royalties: Microfluidic electropheresis (patent, no royalties); Bluebird Bio: Research Funding; GBT: Research Funding; GBT: Membership on an entity's Board of Directors or advisory committees; NHLBI: Research Funding. Mohseni:Xatek Inc.: Consultancy, Patents & Royalties, Research Funding. Suster:Xatek Inc.: Consultancy, Patents & Royalties, Research Funding. Gurkan:BioChip Labs: Patents & Royalties; Xatek Inc.: Patents & Royalties; Dx Now Inc.: Patents & Royalties; Hemex Health, Inc.: Consultancy, Current Employment, Patents & Royalties, Research Funding.

Ex vivo Live Cell Imaging of Nanoparticle-Cell Interactions in the Mouse Lung.

A successful clinical translation of novel nanoparticle-based cancer therapeutics requires a thorough preclinical investigation of their interaction with immune, tumor and endothelial cells as well as components of the tumor-microenvironment. Although high-resolution microscopy images of fixed tumor tissue specimens can provide valuable information in this regard, they are only static snapshots of a momentary event. Here we describe a superior alternative fluorescence microscopy approach to assess the feasibility of investigating nanoparticle-cell interactions in the mouse lung live and over time at nanometer resolution. We applied fluorescent lung tumor cells and Barium-based fluorescently labeled nanoparticles to nude mice or to CD68-EGFP transgenic mice for visualization of the monocyte-macrophage lineage. Shortly before imaging, fluorescently labeled lectin was intravenously injected for staining of the blood vessels. The lung was filled ex vivo with 1% agarose and individual lung lobes were imaged over time using a confocal microscope with Airyscan technology. Time series demonstrate that live cell imaging of lung lobes can be performed for at least 4 h post mortem. Time-lapse movies illustrate the dynamics of the nanoparticles within the pulmonary circulation and their uptake by immune cells. Moreover, the exchange of nanoparticle material between cancer cells was observed over time. Fluorescent monocytes in lungs of CD68-EGFP transgenic mice could be visualized within blood vessels in the process of interaction with tumor cells and nanoparticles. This high resolution ex vivo live cell imaging approach provides an excellent 4D tool to obtain valuable information on the behavior of tumor and immune cells at first encounter with nanoparticles and may contribute to the understanding of how nanoparticles interact with cells supporting the development of therapeutic strategies based on nanoparticulate drug delivery systems.

Multiplex Fourier ptychographic reconstruction with model-based neural network for Internet of Things

Fourier ptychographic microscopy (FPM) is a newly developed technique to capture wide field-of-view (FOV) and high-resolution images that meet the demands of Internet of Things (IoT). FPM enlarges the equivalent numerical aperture of the system and achieves phase imaging by simply employing an angle-varied illumination module. Recently, researches propose to perform the FPM reconstruction with deep learning servers which is costly and requires large datasets. In this paper, we present a new FPM image reconstruction framework termed multi-NNP for Internet of Medical Things (IoMT). Multi-NNP performs multiplex ptychographic reconstruction with a model-based neural network locally rather than on deep learning servers. Our framework simplifies the process and improves the reconstruction performance which promotes the application of wide-field, high-resolution microscopic images in IoMT. Experimental results demonstrate the performance and effectiveness of the proposed framework.

Systematic evaluation of particle loss during handling in the percutaneous transluminal angioplasty for eight different drug-coated balloons

Paclitaxel drug coated balloons (DCBs) should provide optimal drug transfer exclusively to the target tissue. The aim of this study was to evaluate the particle loss by handling during angioplasty. A robotic arm was developed for systematic and reproducible drug abrasion experiments. The contact force on eight different commercially available DCB types was gradually increased, and high-resolution microscopic images of the deflated and inflated balloons were recorded. Three types of DCBs were classified: no abrasion of the drug in both statuses (deflated and inflated), significant abrasion only in the inflated status, and significant abrasion in both statuses. Quantitative measurements via image processing confirmed the qualitative classification and showed changes of the drug area between 2.25 and 45.73% (13.28 ± 14.29%) in the deflated status, and between 1.66 and 40.41% (21.43 ± 16.48%) in the inflated status. The structures and compositions of the DCBs are different, some are significantly more susceptible to drug loss. Particle loss by handling during angioplasty leads to different paclitaxel doses in the target regions for same DCB types. Susceptibility to involuntary drug loss may cause side effects, such as varying effective paclitaxel doses, which may explain variations in studies regarding the therapeutic outcome.

¡Estudiando el Desarrollo Embrionario y Fetal con el Microscopio Virtual! En Tiempos de Covid-19

La Microscopía Virtual es una herramienta tecnológica que permite la visualización de imágenes digitales microscópicas de gran resolución a través de un computador imitando la funcionalidad de un microscopio óptico tradicional. El presente trabajo presenta nuestra experiencia en el uso de esta modalidad de trabajo, útil hoy en día, en medio de la pandemia por Covid-19.

RTIP: A FULLY AUTOMATED ROOT TIP TRACKER FOR MEASURING PLANT GROWTH WITH INTERMITTENT PERTURBATIONS.

RTip is a tool to quantify plant root growth velocity using high resolution microscopy image sequences at sub-pixel accuracy. The fully automated RTip tracker is designed for high-throughput analysis of plant phenotyping experiments with episodic perturbations. RTip is able to auto-skip past these manual intervention perturbation activity, i.e. when the root tip is not under the microscope, image is distorted or blurred. RTip provides the most accurate root growth velocity results with the lowest variance (i.e. localization jitter) compared to six tracking algorithms including the top performing unsupervised Discriminative Correlation Filter Tracker and the Deeper and Wider Siamese Network. RTip is the only tracker that is able to automatically detect and recover from (occlusion-like) varying duration perturbation events.

Consistency and variation of protein subcellular location annotations.

A major challenge for protein databases is reconciling information from diverse sources. This is especially difficult when some information consists of secondary, human-interpreted rather than primary data. For example, the Swiss-Prot database contains curated annotations of subcellular location that are based on predictions from protein sequence, statements in scientific articles, and published experimental evidence. The Human Protein Atlas (HPA) consists of millions of high-resolution microscopic images that show protein spatial distribution on a cellular and subcellular level. These images are manually annotated with protein subcellular locations by trained experts. The image annotations in HPA can capture the variation of subcellular location across different cell lines, tissues, or tissue states. Systematic investigation of the consistency between HPA and Swiss-Prot assignments of subcellular location, which is important for understanding and utilizing protein location data from the two databases, has not been described previously. In this paper, we quantitatively evaluate the consistency of subcellular location annotations between HPA and Swiss-Prot at multiple levels, as well as variation of protein locations across cell lines and tissues. Our results show that annotations of these two databases differ significantly in many cases, leading to proposed procedures for deriving and integrating the protein subcellular location data. We also find that proteins having highly variable locations are more likely to be biomarkers of diseases, providing support for incorporating analysis of subcellular location in protein biomarker identification and screening.

Lissajous scanning structured illumination microscopy.

High-resolution fluorescent microscopic imaging techniques are in high demand to observe detailed structures or dynamic mechanisms of biological samples. Structured illumination microscopy (SIM) has grabbed much attention in super-resolution imaging due to simple configuration, high compatibility with common fluorescent molecules, and fast image acquisition. Here, we report Lissajous scanning SIM (LS-SIM) by using a high fill-factor Lissajous scanning micromirror and laser beam modulation. The LS-SIM was realized by a Lissajous scanned structured illumination module, relay optics, and a conventional fluorescent microscope. The micromirror comprises an inner mirror and an outer frame, which are scanned at pseudo-resonance with electrostatic actuation. The biaxial scanning frequencies are selected by the frequency selection rule for high fill-factor (> 80%) Lissajous scanning. Structured illumination (SI) was then realized by modulating the intensity of a laser beam at the least common multiple (LCM) of the scanning frequencies. A compact Lissajous scanned SI module containing a fiber-optic collimator and Lissajous micromirror has been fully packaged and coupled with relay optics and a fiber-based diode pumped solid state (DPSS) laser including acousto-optic-modulator (AOM). Various structured images were obtained by shifting the phase and orientation of the illumination patterns and finally mounted with a conventional fluorescent microscope. The LS-SIM has experimentally demonstrated high-resolution fluorescent microscopic imaging of reference targets and human lung cancer cell PC-9 cells. The LS-SIM exhibits the observable region in spatial frequency space over 2x, the line-edge sharpness over 1.5x, and the peak-to-valley (P-V) ratio over 2x, compared to widefield fluorescent microscopy. This method can provide a new route for advanced high-resolution fluorescent microscopic imaging.

High-Resolution Vertical Polarization Excited Dark-Field Microscopic Imaging of Anisotropic Gold Nanorods for the Sensitive Detection and Spatial Imaging of Intracellular microRNA-21.

As an important biomarker for early diagnosis of cancers, sensitive detection and high-resolution imaging of microRNA-21 in cancer cells have become important and challengeable. In this work, highly sensitive detection and spatial imaging of intracellular microRNA-21 were realized by the reduced signal background through vertical polarization excitation with a polarizer. The lateral local surface plasmon resonance property of gold nanorods (AuNRs) displayed a pronounced green color with low scattering intensity, which was adjusted to red color with strong scattering intensity when the core-satellite gold nanoparticle (AuNP) assembly was constructed on the side of AuNRs through a catalyzed hairpin assembly (CHA) circuit in the presence of microRNA-21. This unique approach allows for effectively reducing the strong background signal to improve the sensitivity of detection. Additionally, the proposed strategy can not only realize the sensitive detection of microRNA-21 with the limit of detection as low as 2 pM (3σ) but also achieve the high spatial imaging of cancer cells, which provided a specific strategy for the construction and imaging of intracellular imaging probes. It is believed that the simple and sensitive approach on the basis of lateral local surface plasmon resonance property of anisotropic AuNRs with excellent sensitivity combined with high spatial imaging holds promising potentials to visualize intracellular microRNAs with low abundance.

Abstract 4791: Metabolic switch from glycolysis to oxidative phosphorylation (ox-phos) provides survival advantage to anti-androgen-treated prostate cancer cells and make them vulnerable to mitochondrial metabolism inhibitors IACS-010759 and CB-839

Abstract Background: Most cancer cells depend more on glycolysis for their energy need compared with their normal counterparts incubated under identical condition. In addition to glycolysis, tumor cells also engage mitochondrial ox-phos to support growth. Here, we show that PCa cells surviving under anti-androgen enzalutamide (ENZA) treatment switch from glycolysis to ox-phos for their energy need and are more vulnerable to mitochondria-targeted metabolic inhibitors. We have also standardized a high-resolution quantitative fluorescence microscopic method to detect this metabolic switch in patient circulating tumor cells (CTCs). Methods: Seahorse assay has been used to compare mitochondrial metabolism in ENZA treated anti-androgen-sensitive LNCaP and -resistant C4-2 and PCa2b cells. The Seahorse data were supported by mass spectroscopic analysis of corresponding metabolites and metabolic fluxes. An ex vivo fluorescence staining for the CTC mitochondria with high ox-phos followed by high-resolution quantitative microscopic image analysis method has been standardized to follow such changes in cultured cells and patient CTCs. Results: Seahorse, mass spectroscopy and high-resolution microscopy of mitochondrial ox-phos showed that ENZA significantly decreases glycolysis and increases ox-phos in all surviving PCa cells within 24h of treatment. These cells are more vulnerable to treatment with mitochondrial ox-phos inhibitor IACS-010759 and a glutaminase inhibitor CB-839. High-resolution microscopic analysis of CTCs has thus far been performed in 18 patient blood samples. Six out of the 18 patients developed resistance to anti-androgen therapy within 0-6 months of sample collection. CTCs from all six patients showed a relatively higher average fluorescence due to high mitochondrial ox-phos as compared with the rest of the patients. Discussion: The data presented here may lead to informed combination therapy for selected PCa patients developing resistance to anti-androgen therapy for better clinical outcome. Citation Format: Hirak S. Basu, Nathaniel Wilganowski, Samantha Robertson, Sumankalai Ramachandran, Amado Zurita-Saavedra, Mark Titus, Evan Cohen, James Reuben, George Wilding. Metabolic switch from glycolysis to oxidative phosphorylation (ox-phos) provides survival advantage to anti-androgen-treated prostate cancer cells and make them vulnerable to mitochondrial metabolism inhibitors IACS-010759 and CB-839 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4791.