Fiber-Optic Time-Resolved Fluorescence Sensor for in Vitro Serotonin Determination

At pH 7 and with the excitation at wavelengths above 315 nm, previously unreported fluorescence of 5-HT (5-hydroxytryptamine) is observed. Two fluorescence bands were observed for 5-HT; the first emits at around 390 nm with an associated lifetime near 1 ns, and the other (well known) emits at 340 nm with an associated lifetime of 2.7 ns. With both static and time-resolved fluorescences, the spectral and temporal effects of the excitation wavelength were studied between 285 and 340 nm. With these basic spectroscopic properties as a starting point, a fiber-optic chemical sensor (FOCS) was developed in order to measure 5-HT with a single-fiber configuration, nitrogen laser excitation, and fast digitizing techniques. Temporal effects including fluorescence of the optical fiber were studied and compared with measurements both directly in cuvette and through the fiber-optic sensor. Less than thirty seconds are required for each measurement. A detection limit of 5-HT is reached in the range of 5 μM. Our system, with an improved sensitivity, could therefore be a possible and convenient “tool” for in vivo determination of 5-HT.

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Influence of Oxidative Stress on Time-Resolved Oxygen Detection by [Ru(Phen)3]2+ In Vivo and In Vitro

Molecules ◽

10.3390/molecules26020485 ◽

2021 ◽

Vol 26 (2) ◽

pp. 485

Author(s):

Veronika Huntosova ◽

Denis Horvath ◽

Robert Seliga ◽

Georges Wagnieres

Keyword(s):

Oxidative Stress ◽

Tissue Oxygenation ◽

Intact Cell ◽

Molecular Probes ◽

Stress Factors ◽

Time Resolved ◽

Invasive Approach ◽

Oxygen Detection

Detection of tissue and cell oxygenation is of high importance in fundamental biological and in many medical applications, particularly for monitoring dysfunction in the early stages of cancer. Measurements of the luminescence lifetimes of molecular probes offer a very promising and non-invasive approach to estimate tissue and cell oxygenation in vivo and in vitro. We optimized the evaluation of oxygen detection in vivo by [Ru(Phen)3]2+ in the chicken embryo chorioallantoic membrane model. Its luminescence lifetimes measured in the CAM were analyzed through hierarchical clustering. The detection of the tissue oxygenation at the oxidative stress conditions is still challenging. We applied simultaneous time-resolved recording of the mitochondrial probe MitoTrackerTM OrangeCMTMRos fluorescence and [Ru(Phen)3]2+ phosphorescence imaging in the intact cell without affecting the sensitivities of these molecular probes. [Ru(Phen)3]2+ was demonstrated to be suitable for in vitro detection of oxygen under various stress factors that mimic oxidative stress: other molecular sensors, H2O2, and curcumin-mediated photodynamic therapy in glioma cancer cells. Low phototoxicities of the molecular probes were finally observed. Our study offers a high potential for the application and generalization of tissue oxygenation as an innovative approach based on the similarities between interdependent biological influences. It is particularly suitable for therapeutic approaches targeting metabolic alterations as well as oxygen, glucose, or lipid deprivation.

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BanLec-eGFP Chimera as a Tool for Evaluation of Lectin Binding to High-Mannose Glycans on Microorganisms

Biomolecules ◽

10.3390/biom11020180 ◽

2021 ◽

Vol 11 (2) ◽

pp. 180

Author(s):

Zorana Lopandić ◽

Luka Dragačević ◽

Dragan Popović ◽

Uros Andjelković ◽

Rajna Minić ◽

...

Keyword(s):

Fluorescent Protein ◽

Lectin Binding ◽

Three Dimensional ◽

Data Bank ◽

Salmonella Typhi ◽

Excitation Wavelength ◽

Protein Data Bank Entry ◽

High Mannose

Fluorescently labeled lectins are useful tools for in vivo and in vitro studies of the structure and function of tissues and various pathogens such as viruses, bacteria, and fungi. For the evaluation of high-mannose glycans present on various glycoproteins, a three-dimensional (3D) model of the chimera was designed from the crystal structures of recombinant banana lectin (BanLec, Protein Data Bank entry (PDB): 5EXG) and an enhanced green fluorescent protein (eGFP, PDB 4EUL) by applying molecular modeling and molecular mechanics and expressed in Escherichia coli. BanLec-eGFP, produced as a soluble cytosolic protein of about 42 kDa, revealed β-sheets (41%) as the predominant secondary structures, with the emission peak maximum detected at 509 nm (excitation wavelength 488 nm). More than 65% of the primary structure was confirmed by mass spectrometry. Competitive BanLec-eGFP binding to high mannose glycans of the influenza vaccine (Vaxigrip®) was shown in a fluorescence-linked lectin sorbent assay (FLLSA) with monosaccharides (mannose and glucose) and wild type BanLec and H84T BanLec mutant. BanLec-eGFP exhibited binding to mannose residues on different strains of Salmonella in flow cytometry, with especially pronounced binding to a Salmonella Typhi clinical isolate. BanLec-eGFP can be a useful tool for screening high-mannose glycosylation sites on different microorganisms.

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EJE Prize 2013: Regulation of aldosterone secretion: from physiology to disease

Acta Endocrinologica ◽

10.1530/eje-13-0263 ◽

2013 ◽

Vol 168 (6) ◽

pp. R85-R93 ◽

Cited By ~ 30

Author(s):

Felix Beuschlein

Keyword(s):

High Throughput Sequencing ◽

Secondary Hypertension ◽

Small Sample ◽

Cellular Systems ◽

Common Disease ◽

Aldosterone Secretion ◽

Technical Developments ◽

Starting Point

Arterial hypertension is a major cardiovascular risk factor that affects between 10 and 40% of the population in industrialized countries. Primary aldosteronism (PA) is the most common form of secondary hypertension with an estimated prevalence of around 10% in referral centers and 4% in a primary care setting. Despite its high prevalence until recently, the underlying genetic and molecular basis of this common disease had remained largely obscure. Over the past decade, a number of insights have been achieved that have relied onin vitrocellular systems, wild-type and genetically modifiedin vivomodels, as well as clinical studies in well-characterized patient populations. This progress has been made possible by a number of independent technical developments including that of specific hormone assays that allow measurement in small sample volumes as well as genetic techniques that enable high-throughput sequencing of a large number of samples. Furthermore, animal models have provided important insights into the physiology of aldosterone regulation that have served as a starting point for investigation of mechanisms involved in autonomous aldosterone secretion. Finally, national and international networks that have built up registries and biobanks have been instrumental in fostering translational research endeavors in PA. Therefore, it is to be expected that in the near future, further pathophysiological mechanisms that result in autonomous aldosterone secretion will be unraveled.

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ISFET and Fiber Optic Sensor Technologies: In Vivo Experience for Critical Care Monitoring

Chemical Reviews ◽

10.1021/cr068120y ◽

2008 ◽

Vol 108 (2) ◽

pp. 826-844 ◽

Cited By ~ 24

Author(s):

Bruce A. McKinley

Keyword(s):

Critical Care ◽

Fiber Optic ◽

Fiber Optic Sensor ◽

Optic Sensor

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Extending the excitation wavelength from UV to visible light for a europium complex-based mitochondria targetable luminescent probe for singlet oxygen

Dalton Transactions ◽

10.1039/c8dt02829j ◽

2018 ◽

Vol 47 (37) ◽

pp. 12852-12857 ◽

Cited By ~ 10

Author(s):

Hua Ma ◽

Xin Wang ◽

Bo Song ◽

Liu Wang ◽

Zhixin Tang ◽

...

Keyword(s):

Visible Light ◽

Singlet Oxygen ◽

Europium Complex ◽

Excitation Wavelength ◽

Luminescent Probe ◽

Luminescence Detection

A visible-light-excitable Eu3+ complex-based luminescent probe for the time-gated luminescence detection of singlet oxygen in vitro and in vivo.

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Continuous in-vivo monitoring of metronidazole in cerebrospinal fluid by a on-line flow-cell fiber-optic chemical sensor system

Analytica Chimica Acta ◽

10.1016/0003-2670(96)00178-x ◽

1996 ◽

Vol 331 (1-2) ◽

pp. 103-109 ◽

Cited By ~ 5

Author(s):

Wei Li ◽

Jian Chen

Keyword(s):

Cerebrospinal Fluid ◽

Chemical Sensor ◽

Fiber Optic ◽

Flow Cell ◽

Sensor System ◽

In Vivo Monitoring ◽

Line Flow ◽

On Line

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SARS-CoV-2 Spike triggers barrier dysfunction and vascular leak via integrins and TGF-β signaling

10.1101/2021.12.10.472112 ◽

2021 ◽

Author(s):

Scott B Biering ◽

Francielle Tramontini Gomes de Sousa ◽

Laurentia V. Tjang ◽

Felix Pahmeier ◽

Richard Ruan ◽

...

Keyword(s):

Transcriptional Response ◽

Barrier Dysfunction ◽

Vascular Leak ◽

Endothelial Barrier Dysfunction ◽

Mechanistic Insight ◽

Starting Point ◽

Signaling Axis ◽

Insight Into

Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of this pathology are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) glycoprotein of SARS-CoV-2 and epithelial/endothelial cells are sufficient to trigger barrier dysfunction in vitro and vascular leak in vivo, independently of viral replication and the ACE2 receptor. We identify an S-triggered transcriptional response associated with extracellular matrix reorganization and TGF-β signaling. Using genetic knockouts and specific inhibitors, we demonstrate that glycosaminoglycans, integrins, and the TGF-β signaling axis are required for S-mediated barrier dysfunction. Our findings suggest that S interactions with barrier cells are a contributing factor to COVID-19 disease severity and offer mechanistic insight into SARS-CoV-2 triggered vascular leak, providing a starting point for development of therapies targeting COVID-19 pathogenesis.

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