PALP: An imaging method for detecting and quantifying polyunsaturated phospholipids via peroxidation

ABSTRACTPolyunsaturated phospholipids are essential for multiple cellular functions; however, their uncontrolled peroxidation leads to ferroptosis. Here we describe photochemical activation of membrane lipid peroxidation (PALP), which uses localized laser pulses to induce lipid peroxidation photochemically. While PALP bypasses enzymatic requirements for lipid peroxidation, the resulting BODIPY-C11-based signal is largely correlated with local polyunsaturated phospholipid concentration on membranes. This technique enables non-invasive reporting of lipid unsaturation levels and sensitivity to ferroptosis in live cells.

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POS1388 ULTRASOUND FOR PANNICULITIS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.663 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 977.1-977

Author(s):

A. Potapova ◽

O. Egorova ◽

O. Alekseeva ◽

A. Volkov ◽

S. Radenska-Lopovok

Keyword(s):

Dynamic Range ◽

Subcutaneous Fat ◽

Diagnostic Value ◽

High Energy ◽

Contralateral Side ◽

Imaging Method ◽

Non Invasive ◽

M 12

Background:Ultrasound (US) is a non-invasive and safe imaging method that allows in vivo differentiation of the morphological structures of subcutaneous fat (SCF) tissue in in normal and pathology.Objectives:Reveal features of ultrasound changes in SCF in panniculitis (Pn).Methods:57 patients (f – 45, m - 12) aged 18 - 67 years with an initial diagnosis of erythema nodosum and a disease duration of 3.6 ± 1.4 years were examined. In addition to the general clinical examination, a computed tomography of the chest organs and a pathomorphological examination of a skin biopsy from the site of the node were performed. Ultrasound was performed on a MyLabTwice apparatus (ESAOTE, Italy) using a multi-frequency linear transducer (10-18 MHz) with the PD technique, the parameters of which were adapted for recording low-speed flows (PRF 300-600 Hz, low filter, dynamic range - 20-40 dB), the presence of vascularization was assessed not only in the affected area, but also on the contralateral side using high-energy Doppler.Results:33 patients were diagnosed with septal Pn (SPn), 24 - lobular Pn (LPn). In all cases, the diagnosis was verified by histological examination. Ultrasound made it possible to assess the thickness, echoicity and vascularization of the SCF. In 35 patients, significant thickening of the SCF was revealed (as compared to the contralateral side), of which in 14 cases with SPn, in 21 - with LPn. Significant diffuse thickening of the SCF with the contralateral side was observed in 18 patients, incl. in 12 (66%) patients with LPn. Limited thickening was more typical for SPn (73%). A significant increase in the echoicity of the SCF was noted in all forms of Pn. A “lobular” echo pattern with an anechogenic environment was observed in 25 patients, of which 18 (72%) had LPn. An increase in vascularization compared to the contralateral side was recorded in 30 cases (SPn-17, LPn-13).Conclusion:The obtained preliminary results indicate the important role of ultrasound in assessing the depth and prevalence of the inflammatory process at Pn. To clarify the diagnostic value of this method, further studies are needed on a larger sample of patients.Disclosure of Interests:None declared

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Fluorescent Probes for Live Cell Thiol Detection

Molecules ◽

10.3390/molecules26123575 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3575

Author(s):

Shenggang Wang ◽

Yue Huang ◽

Xiangming Guan

Keyword(s):

Fluorescent Probes ◽

Biological System ◽

High Sensitivity ◽

Intracellular Distribution ◽

Live Cell ◽

Live Cells ◽

High Demand ◽

Non Invasive

Thiols play vital and irreplaceable roles in the biological system. Abnormality of thiol levels has been linked with various diseases and biological disorders. Thiols are known to distribute unevenly and change dynamically in the biological system. Methods that can determine thiols’ concentration and distribution in live cells are in high demand. In the last two decades, fluorescent probes have emerged as a powerful tool for achieving that goal for the simplicity, high sensitivity, and capability of visualizing the analytes in live cells in a non-invasive way. They also enable the determination of intracellular distribution and dynamitic movement of thiols in the intact native environments. This review focuses on some of the major strategies/mechanisms being used for detecting GSH, Cys/Hcy, and other thiols in live cells via fluorescent probes, and how they are applied at the cellular and subcellular levels. The sensing mechanisms (for GSH and Cys/Hcy) and bio-applications of the probes are illustrated followed by a summary of probes for selectively detecting cellular and subcellular thiols.

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Low extracellular magnesium ions induce lipid peroxidation and activation of nuclear factor-kappa B in canine cerebral vascular smooth muscle: possible relation to traumatic brain injury and strokes

Neuroscience Letters ◽

10.1016/s0304-3940(03)00134-4 ◽

2003 ◽

Vol 341 (3) ◽

pp. 189-192 ◽

Cited By ~ 23

Author(s):

Burton M Altura ◽

Asefa Gebrewold ◽

Aimin Zhang ◽

Bella T Altura

Keyword(s):

Traumatic Brain Injury ◽

Lipid Peroxidation ◽

Smooth Muscle ◽

Brain Injury ◽

Vascular Smooth Muscle ◽

Nuclear Factor Kappa B ◽

Nuclear Factor ◽

Magnesium Ions ◽

Nuclear Factor Kappa ◽

Induce Lipid Peroxidation

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Quantification of Volatile Aldehydes Deriving from In Vitro Lipid Peroxidation in the Breath of Ventilated Patients

Molecules ◽

10.3390/molecules26113089 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3089

Author(s):

Lukas M. Müller-Wirtz ◽

Daniel Kiefer ◽

Sven Ruffing ◽

Timo Brausch ◽

Tobias Hüppe ◽

...

Keyword(s):

Lipid Peroxidation ◽

Fatty Acids ◽

Polyunsaturated Fatty Acids ◽

Breathing Circuit ◽

Aliphatic Aldehydes ◽

Mechanically Ventilated ◽

Non Invasive ◽

Plastic Parts ◽

Ventilated Patients

Exhaled aliphatic aldehydes were proposed as non-invasive biomarkers to detect increased lipid peroxidation in various diseases. As a prelude to clinical application of the multicapillary column–ion mobility spectrometry for the evaluation of aldehyde exhalation, we, therefore: (1) identified the most abundant volatile aliphatic aldehydes originating from in vitro oxidation of various polyunsaturated fatty acids; (2) evaluated emittance of aldehydes from plastic parts of the breathing circuit; (3) conducted a pilot study for in vivo quantification of exhaled aldehydes in mechanically ventilated patients. Pentanal, hexanal, heptanal, and nonanal were quantifiable in the headspace of oxidizing polyunsaturated fatty acids, with pentanal and hexanal predominating. Plastic parts of the breathing circuit emitted hexanal, octanal, nonanal, and decanal, whereby nonanal and decanal were ubiquitous and pentanal or heptanal not being detected. Only pentanal was quantifiable in breath of mechanically ventilated surgical patients with a mean exhaled concentration of 13 ± 5 ppb. An explorative analysis suggested that pentanal exhalation is associated with mechanical power—a measure for the invasiveness of mechanical ventilation. In conclusion, exhaled pentanal is a promising non-invasive biomarker for lipid peroxidation inducing pathologies, and should be evaluated in future clinical studies, particularly for detection of lung injury.

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Increased isoprostane biosynthesis in alzheimer's disease: Correlation of a specific non invasive index of lipid peroxidation with disease severity

Neurobiology of Aging ◽

10.1016/s0197-4580(00)83319-9 ◽

2000 ◽

Vol 21 ◽

pp. 220 ◽

Cited By ~ 3

Author(s):

Domenico Pratico ◽

Christopher C. Clark ◽

Virginia M-Y. Lee ◽

John Q. Trojanowski ◽

Garret A. FitzGerald

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Lipid Peroxidation ◽

Disease Severity ◽

Non Invasive

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Full characterization of GPCR monomer–dimer dynamic equilibrium by single molecule imaging

The Journal of Cell Biology ◽

10.1083/jcb.201009128 ◽

2011 ◽

Vol 192 (3) ◽

pp. 463-480 ◽

Cited By ~ 241

Author(s):

Rinshi S. Kasai ◽

Kenichi G. N. Suzuki ◽

Eric R. Prossnitz ◽

Ikuko Koyama-Honda ◽

Chieko Nakada ◽

...

Keyword(s):

Equilibrium Constant ◽

Single Molecule ◽

Dynamic Equilibrium ◽

Dissociation Rate ◽

Formyl Peptide Receptor ◽

Live Cells ◽

Imaging Method ◽

Full Characterization ◽

Before And After ◽

Dissociation Rate Constants

Receptor dimerization is important for many signaling pathways. However, the monomer–dimer equilibrium has never been fully characterized for any receptor with a 2D equilibrium constant as well as association/dissociation rate constants (termed super-quantification). Here, we determined the dynamic equilibrium for the N-formyl peptide receptor (FPR), a chemoattractant G protein–coupled receptor (GPCR), in live cells at 37°C by developing a single fluorescent-molecule imaging method. Both before and after liganding, the dimer–monomer 2D equilibrium is unchanged, giving an equilibrium constant of 3.6 copies/µm2, with a dissociation and 2D association rate constant of 11.0 s−1 and 3.1 copies/µm2s−1, respectively. At physiological expression levels of ∼2.1 receptor copies/µm2 (∼6,000 copies/cell), monomers continually convert into dimers every 150 ms, dimers dissociate into monomers in 91 ms, and at any moment, 2,500 and 3,500 receptor molecules participate in transient dimers and monomers, respectively. Not only do FPR dimers fall apart rapidly, but FPR monomers also convert into dimers very quickly.

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CRISPR-mediated Multiplexed Live Cell Imaging of Nonrepetitive Genomic Loci

10.1101/2020.03.03.974923 ◽

2020 ◽

Author(s):

Patricia A. Clow ◽

Nathaniel Jillette ◽

Jacqueline J. Zhu ◽

Albert W. Cheng

Keyword(s):

Live Cell Imaging ◽

Cell Imaging ◽

Repetitive Sequences ◽

Binary Sequence ◽

Three Dimensional ◽

Live Cell ◽

Live Cells ◽

Imaging Method ◽

Genomic Locus ◽

Time Dynamics

AbstractThree-dimensional (3D) structures of the genome are dynamic, heterogeneous and functionally important. Live cell imaging has become the leading method for chromatin dynamics tracking. However, existing CRISPR- and TALE-based genomic labeling techniques have been hampered by laborious protocols and low signal-to-noise ratios (SNRs), and are thus mostly applicable to repetitive sequences. Here, we report a versatile CRISPR/Casilio-based imaging method, with an enhanced SNR, that allows for one nonrepetitive genomic locus to be labeled using a single sgRNA. We constructed Casilio dual-color probes to visualize the dynamic interactions of cohesin-bound elements in single live cells. By forming a binary sequence of multiple Casilio probes (PISCES) across a continuous stretch of DNA, we track the dynamic 3D folding of a 74kb genomic region over time. This method offers unprecedented resolution and scalability for delineating the dynamic 4D nucleome.One Sentence SummaryCasilio enables multiplexed live cell imaging of nonrepetitive DNA loci for illuminating the real-time dynamics of genome structures.

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