Fluorescence Microscopy Research Articles

Unconventional localization of PAI-1 in PML bodies: A possible link with cellular growth of endothelial cells

Plasminogen activator inhibitor-1 (PAI-1/Serpin E1) is classically known for its antifibrinolytic activity via inhibiting uPA and tPA of the fibrinolytic pathway. PAI-1 has a paradoxical role in tumor progression, and its molecular functions are poorly understood. PAI-1 is a widely accepted secretory protease inhibitor, however, a study suggested the localization of PAI-1 in the cytoplasm and the nucleus. Besides the plethora of its biological functions as a secretory protein, intracellular localization, and functions of PAI-1 remain unexplored at the molecular level. In this study, using various in silico approaches, we showed that PAI-1 possesses a nuclear export signal. Using the CRM1-specific inhibitor leptomycin B, we demonstrated that PAI-1 has a functional CRM1-dependent NES, indicating the possibility of its nuclear localization. Further, we confirm that PAI-1 is localized in the nucleus of endothelial cells using fluorescence microscopy and immunoprecipitation. Notably, we identified an unconventional distribution of PAI-1 in the PML bodies of the nucleus of normal endothelial cells, while the protein was restricted in the cytoplasm of slow-growing cells. The data showed that the localization of PAI-1 in PML bodies is highly correlated with the growth potential of endothelial cells. This conditional nucleocytoplasmic shuttling of PAI-1 during the aging of cells could impart a strong link to its age-related functions and tumor progression. Together, this study identifies the novel behavior of PAI-1 that might be linked with cell aging and may be able to unveil the elusive role of PAI-1 in tumor progression.

Ants avoid food contaminated with micro- and nanoplastics

Micro- and nanoplastics (MNP) have recently received particular attention in freshwater and marine ecosystems, but less is known about their impact on terrestrial species. Ants can be used as biological indicators for many types of pollutants and are therefore a good candidate to explore the effects of MNP pollution. In the present study, we investigated the ability of workers from seven colonies of the acrobat ant Crematogaster scutellaris to detect MNP in their food. After two days of starvation, groups of ten ants were tested for their preference toward control and polyethylene-treated solutions. Every 5 min over a total 20 min period, the number of workers feeding on either solution was counted. The results showed that C. scutellaris workers could detect and avoid contaminated food, feeding more often on the uncontaminated solution in the first 10 min. However, after 10 min the food preference was no longer significant between the groups, likely owing to feeding satiation. We then assessed whether this feeding behaviour is sufficient to cause the accumulation of MNP in the ant. We thereby provided a solution containing fluorescent MNP (fMNP) at the same concentration as in the previous experiments. Observation of the ants' mouthparts using fluorescent light microscopy showed that after 10 min dense aggregations of fMNP were visible. Further investigations are needed to understand the mechanisms of detection of MNP by ants, and the accumulation dynamics in ants’ bodies. Moreover, the effects of MNP on the integrity and fitness of ant colonies, as well as the potential transfer across terrestrial trophic chains should be explored.

Organic extracts from sustainable hybrid poplar hairy root cultures as potential natural antimicrobial and antibiofilm agents.

In order to meet growing consumer demands in terms of naturalness, the pharmaceutical, food, and cosmetic industries are looking for active molecules of plant origin. In this context, hairy roots are considered a promising biotechnological system for the sustainable production of compounds of interest. Poplars (genus Populus, family Salicaceae) are trees of ecological interest in temperate alluvial forests and are also cultivated for their industrial timber. Poplar trees also produce specialized metabolites with a wide range of bioactive properties. The present study aimed to assess the hybrid poplar hairy root extracts for antimicrobial and antibiofilm activities against four main life-threatening strains of Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. Ethyl acetate extracts from two hairy root lines (HP15-3 and HP A4-12) showed significant antibacterial properties as confirmed by disc diffusion assay. Antibiofilm activities were found to be dose dependent with significant biofilm inhibition (75-95%) recorded at 1000µg.mL-1 in all the bacterial strains tested. Dose-dependent enhancement in the release of exopolysaccharides was observed in response to treatment with extracts, possibly because of stress and bacterial cell death. Fluorescence microscopy confirmed loss of cell viability of treated bacterial cells concomitant with increased production of reactive oxygen species compared to the untreated control. Overall, this study demonstrates for the first time a high potential of poplar hairy root extracts as a natural and safe platform to produce antimicrobial agents in pharmaceutical, food, industrial water management, or cosmetic industries.

Raman microscopy allows to follow internalization, subcellular accumulation and fate of iron oxide nanoparticles in cells

An important issue in the context of both potenial toxicity of iron oxide nanoparticles (IONP) and their medical applications is tracking of the internalization process of these nanomaterials into living cells, as well as their localization and fate within them. The typical methods used for this purpose are transmission electron microscopy, confocal fluorescence microscopy as well as light-scattering techniques including dark-field microscopy and flow cytometry. All the techniques mentioned have their advantages and disadvantages. Among the problems it is necessary to mention complicated sample preparation, difficult interpretation of experimental data requiring qualified and experienced personnel, different behavior of fluorescently labeled IONP comparing to those label-free or finally the lack of possibility of chemical composition characteristics of nanomaterials.The purpose of the present investigation was the assessment of the usefulness of Raman microscopy for the tracking of the internalization of IONP into cells, as well as the optimization of this process. Moreover, the study focused on identification of the potential differences in the cellular fate of superparamagnetic nanoparticles having magnetite and maghemite core.The Raman spectra of U87MG cells which internalized IONP presented additional bands which position depended on the used laser wavelength. They occurred at the wavenumber range 1700–2400 cm−1 for laser 488 nm and below the wavenumber of 800 cm−1 in case of laser 532 nm. The intensity of the mentioned Raman bands was higher for the green laser (532 nm) and their position, was independent and not characteristic on the primary core material of IONP (magnetite, maghemite).The obtained results showed that Raman microscopy is an excellent, non-destructive and objective technique that allows monitoring the process of internalization of IONP into cells and visualizing such nanoparticles and/or their metabolism products within them at low exposure levels. What is more, the process of tracking IONP using the technique may be further improved by using appropriate wavelength and power of the laser source.

Wheat lesion mimic homology gene TaCAT2 enhances plant resistance to biotic and abiotic stresses

Lesion mimic mutants (LMMs) refer to the spontaneous formation of disease-like spots on leaves without any obvious pathogen infection. The LMM genes can regulate plant immunity, thus promoting the defense of crops against pathogens. However, there is a lack of systematic understanding of the regulatory mechanism of LMMs in wheat. This study identified a wheat LMM TaCAT2, a homolog of the Arabidopsis CAT2. The prediction of the cis-regulatory element revealed that TaCAT2 was involved in the response of plants to various hormones and stresses. RT-qPCR analysis indicated that TaCAT2 was significantly up-regulated by NaCl, drought, and Fusarium graminearum infection. Fluorescence microscopy showed that the TaCAT2 was localized to the peroxisome. Overexpression of TaCAT2 enhanced plant resistance to Phytophthora infestation and F. graminearum by constitutionally activating SA and JA pathways. VIGS of TaCAT2 enhanced the sensitivity of wheat to F. graminearum. Further, TaCAT2 enhanced stress resistance by scavenging the excessive ROS and increasing the activities of antioxidative enzymes. This study lays the basis for the functional identification of TaCAT2 and its applicability in the disease resistance of wheat.

Dosing interval of coagulant and flocculant influences settling behavior of coal slime

ABSTRACT Using the high-speed motion acquisition system, we studied the settling process of the coal flocs under different addition interval time. The gray value and zeta potential of supernatant generally increased as the interval time increased, proving the effect of interval time on coal slime sedimentation. Furthermore, the interval time 25 s presented the smallest floc amount. The floc size and zeta potential were measured via the inverted fluorescence microscope and the micro electrophoresis, respectively. The interval time 25 s presented the fastest settling velocity. The floc amount in supernatant roughly decreased as the zeta potential increased. The settling velocity decreased with the settling time. The results can provide valuable insight into the development of technology for coal slime sedimentation.

Light sheet microscope scanning of biointegrated microlasers for localized refractive index sensing

Whispering gallery mode (WGM) microlasers are highly sensitive to localized refractive index changes allowing to link their emission spectrum to various chemical, mechanical, or physical stimuli. Microlasers recently found applications in biological studies within single cells, in three-dimensional samples such as multicellular spheroids, or in vivo. However, detailed studies of biological samples also need to account for the structural heterogeneity of tissues and live animals, therefore requiring a combination of high-resolution microscopy and laser spectroscopy. Here, we design and construct a light sheet fluorescence microscope with a coupled spectrometer for use in microlaser studies for combined high-resolution, high-speed imaging and WGM spectral analysis. The light sheet illumination profile and the decoupled geometry of excitation and emission hereby directly affect the lasing and sensing properties, mainly through geometric constraints and by light coupling effects. We demonstrate the basic working principle of microlaser spectroscopy under light sheet excitation and measure the absolute refractive index within agarose and in zebrafish tail muscle tissue. We further analyze the light coupling conditions that lead to the occurrence of two separate oscillation planes. These so-called cross modes can be scanned around the entire microlaser surface, which allows to estimate a surface-averaged refractive index profile of the microlaser environment.

Advancing cellular insights: Super-resolution STORM imaging of cytoskeletal structures in human stem and cancer cells

Fluorescence microscopy is an important tool for cell biology and cancer research. Present-day approach of implementing advanced optical microscopy methods combined with immunofluorescence labelling of specific proteins in cells is now able to deliver optical super-resolution up to ∼25 nm. Here we perform super-resolved imaging using standard immunostaining protocol combined with easy stochastic optical reconstruction microscopy (easySTORM) to observe structural differences of two cytoskeleton elements, actin and tubulin in three different cell types namely human bone marrow-derived mesenchymal stem cells (MSCs), human glioblastoma (U87MG) and breast cancer (MDAMB-231) cells. The average width of the actin bundle obtained from STORM images of stem cells is observed to be larger than the same for U87MG and MDAMB-231 cells. No significant difference is however noticed in the width of the tubulin within the same cells. We also study the functional effect on the 2D migration potential of MDAMB-231 cells silenced for NICD1 and β-catenin. Although similar migration speed is observed for cells with the above two conditions compared to their control cells, easySTORM images show that widths of the actin in MDAMB-231 cells in β-catenin silenced is significantly lower than the same in control cells. Such minute differences however are not observable in widefield images. The outcome of our easySTORM investigation should benefit the researchers carrying out detailed investigations of the cellular structure and potential therapeutic applications.

Ultrasonic Cigarettes: Chemicals and Cytotoxicity are Similar to Heated-Coil Pod-Style Electronic Cigarettes.

Our purpose was to test the hypothesis that ultrasonic cigarettes (u-cigarettes), which operate at relatively low temperatures, produce aerosols that are less harmful than heated-coil pod-style electronic cigarettes (e-cigarettes). The major chemicals in SURGE u-cigarette fluids and aerosols were quantified, their cytotoxicity and cellular effects were assessed, and a Margin of Exposure risk assessment was performed on chemicals in SURGE fluids. Four SURGE u-cigarette flavor variants ("Blueberry Ice," "Watermelon Ice," "Green Mint," and "Polar Mint") were evaluated. Flavor chemicals were quantified in fluids and aerosols using gas chromatography/mass spectrometry. Cytotoxicity and cell dynamics were assessed using the MTT assay, live-cell imaging, and fluorescence microscopy. WS-23 (a coolant) and total flavor chemical concentrations in SURGE were similar to e-cigarettes, while SURGE nicotine concentrations (13-19 mg/mL) were lower than many fourth generation e-cigarettes. Transfer efficiencies of dominant chemicals to aerosols in SURGE ranged from 44-100%. SURGE fluids and aerosols had four dominant flavor chemicals (>1 mg/mL). Toxic aldehydes were usually higher in SURGE aerosols than in SURGE fluids. SURGE fluids and aerosols had aldehyde concentrations significantly higher than pod-style e-cigarettes. Chemical constituents, solvent ratios, and aldehydes varied among SURGE flavor variants. SURGE fluids and aerosols inhibited cell growth and mitochondrial reductases, produced attenuated and round cells, and depolymerized actin filaments, effects that depended on pod flavor, chemical constituents, and concentration. The MOEs for nicotine, WS-23, and propylene glycol were <100 based on consumption of 1-2 SURGE u-cigarettes/day. Replacing the heating coil with a sonicator did not eliminate chemicals, including aldehydes, in aerosols or diminish toxicity in comparisons between SURGE and other e-cigarette pod products. The high concentrations of nicotine, WS-23, flavor chemicals, and aldehydes and the cytotoxicity of SURGE aerosols do not support the hypothesis that aerosols from u-cigarettes are less harmful than those from e-cigarettes.

Platelet Angiopoietin-1 Protects Against Murine Models of Tumor Metastasis.

In addition to their fundamental roles in preserving vascular integrity, platelets also contribute to tumor angiogenesis and metastasis. However, despite being a reservoir for angiogenic and metastatic cytokines, platelets also harbor negative regulators of tumor progression. Angpt1 (angiopoietin-1) is a cytokine essential for developmental angiogenesis that also protects against tumor cell metastasis through an undefined mechanism. Although activated platelets release Angpt1 from α-granules into circulation, the contributions of platelet Angpt1 to tumor growth, angiogenesis, and metastasis have not been investigated. Using cytokine arrays and ELISAs, we first compared platelet Angpt1 levels in breast and melanoma mouse tumor models to tumor-free controls. We then assessed tumor growth and metastasis in mice lacking megakaryocyte and platelet Angpt1 (Angpt1Plt KO). The spontaneous metastasis of mammary-injected tumor cells to the lungs was quantified using RT-PCR. The lung colonization of intravenously injected tumor cells and tumor cell extravasation were determined using fluorescent microscopy and flow cytometry. Platelet Angpt1 is selectively upregulated in the PyMT (polyoma middle tumor antigen) breast cancer mouse model, and platelets are the principal source of Angpt1 in blood circulation. While primary tumor growth and angiogenesis were unaffected, Angpt1Plt KO mice had both increased spontaneous lung metastasis and tumor cell lung colonization following mammary or intravenous injection, respectively. Although platelet Angpt1 did not affect initial tumor cell entrapment in the lungs, Angpt1Plt KO mice had increased tumor cell retention and extravasation. Serum from Angpt1Plt KO mice increased endothelial permeability and reduced VE-cadherin expression at endothelial junctions compared with serum from control mice (Angpt1WT). Platelets provide an intravascular source of Angpt1 that restrains tumor metastasis by preserving the lung microvasculature to limit tumor cell extravasation.

The translesion polymerase Pol Y1 is a constitutive component of the B. subtilis replication machinery.

Unrepaired DNA damage encountered by the cellular replication machinery can stall DNA replication, ultimately leading to cell death. In the DNA damage tolerance pathway translesion synthesis (TLS), replication stalling is alleviated by the recruitment of specialized polymerases to synthesize short stretches of DNA near a lesion. Although TLS promotes cell survival, most TLS polymerases are low-fidelity and must be tightly regulated to avoid harmful mutagenesis. The gram-negative bacterium Escherichia coli has served as the model organism for studies of the molecular mechanisms of bacterial TLS. However, it is poorly understood whether these same mechanisms apply to other bacteria. Here, we use in vivo single-molecule fluorescence microscopy to investigate the TLS polymerase Pol Y1 in the model gram-positive bacterium Bacillus subtilis. We find significant differences in the localization and dynamics of Pol Y1 in comparison to its E. coli homolog, Pol IV. Notably, Pol Y1 is constitutively enriched at or near sites of replication in the absence of DNA damage through interactions with the DnaN clamp; in contrast, Pol IV has been shown to be selectively enriched only upon replication stalling. These results suggest key differences in the roles and mechanisms of regulation of TLS polymerases across different bacterial species.

Frequency-multiplexed aberration measurement for confocal microscopy

In single-photon confocal fluorescence microscopy, optical aberration affects both excitation and detection light paths, thus can severely degrade image quality. We incorporated an adaptive optics (AO) module into a confocal microscope and used a frequency-multiplexed aberration measurement method to measure and correct sample-induced aberration. We demonstrated that this method can measure aberration using signals from features of different sizes and recover diffraction-limited imaging performance. Applying our AO confocal microscope to imaging through and within living zebrafish larvae, as well as in the mouse brain in vivo, we showed that aberration correction can substantially improve confocal image brightness, resolution, and contrast.

Establishment of a stable THP-1 cell line expressing PSMB9-eGFP-His protein and detection of immunoproteasome activity

The ubiquitin/proteasome system (UPS) plays a crucial role in maintaining cellular protein homeostasis. The catalytic activity of proteasome in the UPS is regulated by β1 (PSMB6), β2 (PSMB7), and β5 (PSMB5) subunits. Interferon (IFN)-γ, tumor necrosis factor (TNF)-α, inflammation, and oxidative stress can induce the replacement of β1, β2, and β5 with their respective immuno-subunits β1i (PSMB9), β2i (PSMB10), and β5i (PSMB8), which can be assembled into the immunoproteasome. Compared with the standard proteasome, the immunoproteasome exerts enhanced regulatory effects on immune responses, such as processing and presenting MHC class Ⅰ antigens, production of pro-inflammatory cytokines, and T cell differentiation and proliferation. Abnormal aggregation of immunoproteasomes can cause neurodegenerative diseases like Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. To explore the function of PSMB9 after bacterial infection, we constructed a lentivirus plasmid overexpressing PSMB9-eGFP-His and transfected the plasmid into HEK293T cells for packaging by using a triple-plasmid system in this study. After screening with puromycin, we obtained a stable human leukemia monocytic THP-1 cell line expressing the fusion protein of PSMB9. Western blotting (WB) and fluorescence microscopy verified the expression of the fusion protein in the stable THP-1 cells. Quantitative PCR (qPCR) was employed to measure the copies of PSMB9-eGFP in THP-1 cells. Immunofluorescence results found that eGFP-His did not affect the subcellular localization of PSMB9. The purification with nickel affinity chromatography confirmed that the fusion protein could be assembled into the 20S immunoproteasome and exhibited cleaving activity for fluorescent peptide substrates. These results indicated that the PSMB9-eGFP fusion gene was integrated into the chromosome, and could be stably expressed in the constructed THP-1 cell line. This cell line can be utilized for the research on subcellular localization, dynamic expression, and activity of PSMB9 in live cells at different infection conditions and disease stages. It also provides a model for the stable cell lines construction of other immunoproteasome subunits PSMB8 and PSMB10.

Eccentric contraction increases hydrogen peroxide levels and alters gene expression through Nox2 in skeletal muscle of male mice.

Hydrogen peroxide (H2O2) is one of the key signaling factors regulating skeletal muscle adaptation to muscle contractions. Eccentric (ECC) and concentric (CONC) contractions drive different muscle adaptations with ECC resulting in greater changes. The present investigation tested the hypothesis that ECC produces higher cytosolic and mitochondrial H2O2 concentrations [H2O2] and alters gene expression more than CONC. Cytosolic and mitochondrial H2O2-sensitive fluorescent proteins, HyPer7 and MLS-HyPer7, were expressed in the anterior tibialis muscle of C57BL6J male mice. Before and for 60 min after either CONC or ECC (100 Hz, 50 contractions), [H2O2]cyto and [H2O2]mito were measured by in vivo fluorescence microscopy. RNA sequencing was performed in control (non-contracted), CONC and ECC muscles to identify genes impacted by the contractions. [H2O2]cyto immediately after ECC was greater than after CONC (CONC: + 6%, ECC: + 11% vs rest, p < 0.05) and remained higher for at least 60 min into recovery. In contrast, the elevation of [H2O2]mito was independent of the contraction modes (Time; p < 0.0042, contraction mode; p = 0.4965). The impact of ECC on [H2O2]cyto were abolished by NADPH oxidase 2 (Nox2) inhibition (GSK2795039). Differentially expressed genes were not present after CONC or ECC+GSK but were found after ECC and were enriched for vascular development and apoptosis-related genes, among others. In conclusion, in mouse anterior tibialis ECC, but not CONC, evoke a pronounced cytosolic H2O2 response, caused by Nox2, that is mechanistically linked to gene expression modifications.

Investigating the applicability of storage stability test for waste plastic modified bitumen: Morphological analyses

Plastics have proven as effective modifiers for asphalt binders; however, significant knowledge gaps exist around appropriateness of standard method of storage stability test and phase separation mechanism. These gaps are even more critical when using waste plastics containing polymeric cross-contamination. This study addresses these gaps through the application of asphalt tests, fluorescence microscopy (FM) and image processing techniques. The FM and image processing results showed that there is a relationship between elevated plastic swelling rates and plastic dispersion in bitumen matrix. Quantitative analysis of the images indicated that LDPE and LLDPE modified binders exhibited the lowest level of phase separation (5 %), followed by HDPE modified binder (13 %), and PP modified binder showed the highest level (20 %). Furthermore, cross-contamination of LDPE, LLDPE, and HDPE with PP notably worsened the storage stability of the resulting modified binders by approximately 10 %. The findings from FM and image processing indicated that the softening point test conducted through the storage stability tube test is insufficient for assessing the storage stability of plastic modified binders. To further validate this point, asphalt performance was examined for asphalt mixtures made with the binders before and after storage stability test. The findings demonstrated a substantial influence of phase separation of binder on key properties of the resulting asphalt mixture.

Novel hypermorphic variants in IRF2BP2 identified in patients with common variable immunodeficiency and autoimmunity

The interferon regulatory factor 2 binding protein 2 (IRF2BP2) is a transcriptional regulator, functioning a transcriptional corepressor by interacting with the interferon regulatory factor-2. The ubiquitous expression of IRF2BP2 by diverse cell types and tissues suggests its potential involvement in different cell signalling pathways. Variants inIRF2BP2have been recently identified to cause familial common variable immunodeficiency (CVID) characterized by immune dysregulation.This study investigated three rare novel variants inIRF2BP2, identified in patients with primary antibody deficiency and autoimmunity by whole exome-sequencing (WES). Following transient overexpression of EGFP-fused mutants in HEK293 cells and transfection in Jurkat cell lines, we used fluorescence microscopy, real-time PCR and Western blotting to analyze their effects on IRF2BP2 expression, subcellular localization, nuclear translocation of IRF2, and the transcriptional activation of NFκB1(p50).We found altered IRF2BP2 mRNA and protein expression levels in the mutants compared to the wild type after IRF2BP2 overexpression. In confocal fluorescence microscopy, variants in the C-terminal RING finger domain showed an irregular aggregate formation and distribution instead of the expected nuclear localization compared to the variants in the N-terminal zinc finger domain and their wildtype counterpart. Immunoblotting revealed an impaired IRF2 and NFκB1 (p50) nuclear localization in the mutants compared to the IRF2BP2 wildtype counterpart. LPS stimulation reduced IRF2BP2 mRNA expression in the variants compared to the wild type.Our findings significantly contribute to understanding the clinical significance of IRF2BP2 mutations in the pathogenesis of immunodeficiency and immune dysregulation. We observed impairment of the nuclear translocation of IRF2 and NFκB1 (p50) due to the upregulation of IRF2BP2, potentially affecting specific gene expressions involved in immune regulation.

High Throughput Imaging and Analysis of Intracellular Dynamics with Correlative Label-Free and Fluorescence Microscopy

High Throughput Imaging and Analysis of Intracellular Dynamics with Correlative Label-Free and Fluorescence Microscopy

Structural and Mechanical Characterization of DNA-Tethered Membranes on Graphene.

Lipid membranes that are separated from the surface of graphene by DNA tethers were prepared by surface functionalization with pyrene coupled to single-stranded DNA (ssDNA), followed by self-assembly of the mixture of ssDNA-functionalized phospholipid and the matrix phospholipids. The formation of uniform membranes was confirmed by fluorescence microscopy, and the structures of the systems before and after hybridization in the direction perpendicular to the global plane of the membranes were investigated using high-energy X-ray reflectivity. The thickness values of the DNA spacers (15 and 37 bp) calculated from the best-fit results were less than the expected thicknesses of the double-stranded DNA (dsDNA) chains taking the upright conformation, indicating that the DNA spacers are tilted with respect to the direction normal to the surface. The Young's moduli of the DNA-tethered membranes obtained by AFM nanoindentation showed higher values than the membranes with no DNA tethers, which suggests that the DNA layer resists against the compression, lifting up the membrane. Intriguingly, the presence of DNA tethers caused no increase in the yield depth. The smaller thickness values as well as the unchanged yield depth suggest that the dsDNA chains can tilt and rotate, which can be attributed to the flexible pyrene-DNA junction.

Cellular Characterization of Kernels of Zea mays L. by Confocal, SEM and Hyperspectral Fluorescence Microscopy

Cellular Characterization of Kernels of <i>Zea mays</i> L. by Confocal, SEM and Hyperspectral Fluorescence Microscopy

Evaluation of Fluorescence Contrast for the Differentiation of Ex Vivo Tissue Slides from Collagen-Related Degenerative Skin Diseases

Histopathological analysis is one of the primary pillars in clinical diagnostics. The efforts to implement optical techniques aim at alleviating the burden of delivering timely and accurate diagnoses. We have explored the potential application of unstained tissue slides’ autofluorescence to differentiate collagen-related skin degenerative diseases, such as psoriasis, lupus erythematosus, scleroderma, and Syndrome of Raynaud. This exploration involved two techniques: fluorescence microscopy combined with colorimetric analysis and synchronous fluorescence spectroscopy. We addressed the main characteristic peculiarities of the examined samples and discussed the evaluation of potential classification parameters along with their diagnostic values.