scholarly journals Correlative optical photothermal infrared and X-ray fluorescence for chemical imaging of trace elements and relevant molecular structures directly in neurons

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Nadja Gustavsson ◽  
Agnes Paulus ◽  
Isak Martinsson ◽  
Anders Engdahl ◽  
Kadda Medjoubi ◽  
...  
Keyword(s):  
Trace Elements ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Chemical Imaging ◽  
Molecular Structures ◽  
Chemical Information ◽  
Electromagnetic Spectrum ◽  
Elemental Distribution ◽  
Amyloid Β Protein ◽  
X Ray

AbstractAlzheimer’s disease (AD) is the most common cause of dementia, costing about 1% of the global economy. Failures of clinical trials targeting amyloid-β protein (Aβ), a key trigger of AD, have been explained by drug inefficiency regardless of the mechanisms of amyloid neurotoxicity, which are very difficult to address by available technologies. Here, we combine two imaging modalities that stand at opposite ends of the electromagnetic spectrum, and therefore, can be used as complementary tools to assess structural and chemical information directly in a single neuron. Combining label-free super-resolution microspectroscopy for sub-cellular imaging based on novel optical photothermal infrared (O-PTIR) and synchrotron-based X-ray fluorescence (S-XRF) nano-imaging techniques, we capture elemental distribution and fibrillary forms of amyloid-β proteins in the same neurons at an unprecedented resolution. Our results reveal that in primary AD-like neurons, iron clusters co-localize with elevated amyloid β-sheet structures and oxidized lipids. Overall, our O-PTIR/S-XRF results motivate using high-resolution multimodal microspectroscopic approaches to understand the role of molecular structures and trace elements within a single neuronal cell.

scholarly journals Effects of S-2474, a novel nonsteroidal anti-inflammatory drug, on amyloid β protein-induced neuronal cell death

2001 ◽  
Vol 134 (3) ◽  
pp. 673-681 ◽  
Author(s):  
Tatsurou Yagami ◽  
Keiichi Ueda ◽  
Kenji Asakura ◽  
Toshiyuki Sakaeda ◽  
Takayuki Kuroda ◽  
...  
Keyword(s):  
Cell Death ◽  
Neuronal Cell Death ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Amyloid Β Protein ◽  
Inflammatory Drug ◽  
Β Protein ◽  
Anti Inflammatory

Thiosemicarbazonate complexes with affinity for amyloid-β fibers: synthesis, characterization and biological studies

2019 ◽  
Vol 11 (19) ◽  
pp. 2527-2546 ◽  
Author(s):  
Arantxa Pino-Cuevas ◽  
Paula D Raposinho ◽  
Célia Fernandes ◽  
António Paulo ◽  
Ulrich Abram ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Blood Brain Barrier ◽  
Free Ligand ◽  
Amyloid Β ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Biological Studies ◽  
Similar Affinity

Aim: Obtain radioimages of amyloid-β fibers using 99mTc-complexes. Methodology: Tridentate thiosemicarbazone and thiocarbonohydrazone ligands containing fragments (stilbene, azobenzene, benzothiazole or benzoxazole) with affinity for amyloid-ß fibers and its Re(I) complexes have been prepared. The molecular structures of several ligands and complexes were determined by x-ray diffraction. Binding affinity studies toward Aß1-42 fibers were performed for the ligands and Re(I) complexes. The ability of formation of some 99mTc(I) complexes, their biodistribution and in vivo stability have been established. Results & conclusion: Complexes of stilbene and benzothiazole thiosemicarbazonates show similar affinity for amyloid-β fibers to the free ligand. These 99mTc complexes present a reasonable in vivo stability and a low capability to cross the blood–brain barrier although not sufficient to brain amyloid imaging.

scholarly journals Propofol and Thiopental Suppress Amyloid Fibril Formation and GM1 Ganglioside Expression through the γ-Aminobutyric Acid A Receptor

2013 ◽  
Vol 118 (6) ◽  
pp. 1408-1416 ◽  
Author(s):  
Naoki Yamamoto ◽  
Hajime Arima ◽  
Takeshi Sugiura ◽  
Hiroyuki Hirate ◽  
Hideo Taniura ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Cell Surface ◽  
Specific Binding ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Fibril Formation ◽  
Aminobutyric Acid ◽  
Amyloid Β Protein ◽  
Gm1 Ganglioside ◽  
Free System

Abstract Background: The incidence of Alzheimer disease may increase after surgical interventions. Amyloid β-protein (Aβ) fibrillogenesis, which is closely related to Alzheimer disease, is reportedly accelerated by exposure to anesthetics. However, the effects of GM1 ganglioside (GM1) on Αβ fibrillogenesis have not yet been reported. The current study was designed to examine whether the anesthetics propofol and thiopental are associated with Αβ assembly and GM1 expression on the neuronal cell surface. Methods: PC12N cells and cultured neuronal cells were treated with propofol or thiopental, and GM1 expression in treated and untreated cells was determined by the specific binding of horseradish peroxidase-conjugated cholera toxin subunit B (n = 5). The effects of an inhibitor of the γ-aminobutyric acid A receptor was also examined (n= 5). In addition, the effects of the anesthetics on GM1 liposome-induced Αβ assembly were investigated (n = 5). Finally, the neurotoxicity of the assembled Αβ fibrils was studied by the lactate dehydrogenase release assay (n = 6). Results: Propofol (31.2±4.7%) and thiopental (34.6±10.5%) decreased GM1 expression on the cell surface through the γ-aminobutyric acid A receptor. The anesthetics inhibited Αβ fibril formation from soluble Αβ in cultured neurons. Moreover, propofol and thiopental suppressed GM1-induced fibril formation in a cell-free system (propofol, 75.8±1.9%; thiopental, 83.6±1.9%) and reduced the neurotoxicity of a mixture containing Aβ and GM1 liposomes (propofol, 35.3±16.4%; thiopental, 21.3±11.6%). Conclusions: Propofol and thiopental have direct and indirect inhibitory effects on Αβ fibrillogenesis.

Effects of endothelin B receptor agonists on amyloid β protein (25–35)-induced neuronal cell death

2002 ◽  
Vol 948 (1-2) ◽  
pp. 72-81 ◽  
Author(s):  
Tatsurou Yagami ◽  
Keiichi Ueda ◽  
Kenji Asakura ◽  
Takayuki Kuroda ◽  
Satoshi Hata ◽  
...  
Keyword(s):  
Cell Death ◽  
Neuronal Cell Death ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Amyloid Β Protein ◽  
Endothelin B Receptor ◽  
Receptor Agonists ◽  
Β Protein ◽  
Endothelin B

scholarly journals Leptin inhibits amyloid β-protein fibrillogenesis by decreasing GM1 gangliosides on the neuronal cell surface through PI3K/Akt/mTOR pathway

2014 ◽  
Vol 131 (3) ◽  
pp. 323-332 ◽  
Author(s):  
Naoki Yamamoto ◽  
Mamoru Tanida ◽  
Rika Kasahara ◽  
Kazuya Sobue ◽  
Kenji Suzuki
Keyword(s):  
Cell Surface ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Mtor Pathway ◽  
Amyloid Β Protein ◽  
Β Protein

X-Ray Fluorescence Microtomography on a SiC Nuclear Fuel Shell

1998 ◽  
Vol 524 ◽  
Author(s):  
M. Naghedolfeizi; ◽  
J.-S. Chung ◽  
G. E. Ice ◽  
W. B. Yun ◽  
Z. Cai ◽  
...  
Keyword(s):  
Trace Elements ◽  
Nuclear Fuel ◽  
Element Distribution ◽  
Trace Element Distribution ◽  
Fuel Particle ◽  
Elemental Distribution ◽  
X Ray ◽  
Triso Fuel ◽  
Fuel Particles ◽  
Kapton Tape

ABSTRACTTRISO fuel particles contain a small kernel of nuclear fuel encapsulated by alternating layers of C and a barrier layer of SiC. The TRISO fuel particle is used in an advanced nuclear fuel where the SiC shell provides the primary barrier for radioactive elements in the kernel. The performance of this barrier is key to containment. We have used x-ray fluorescence microtomography to measure the trace element distribution in a SiC shell. Prior to our measurements the nuclear fuel and C layers were leached from the particle. The shell was then encapsulated by kapton tape to simplify handling. The shell was mounted on a glass fiber and measurements were made with an ∼1 x3 ωm2 x-ray probe on beamline 2-ID at the APS. The distribution of trace elements in the SIC shell was reconstructed after correcting the data for artifacts arising from absorption and scattering off the kapton tape. The observed trace elements are distributed in small <1ωm regions through the SiC shell. The trace elements can be attributed to radiation enhanced diffusion of elements in the kernel or to trace elements introduced during fabrication. X-ray fluorescence microtomography is an ideal tool for this work because it is a penetrating nondestructive probe sensitive to trace elements in a low Z matrix and because it provides a picture of the elemental distribution in the shell.

Elemental distribution within polymorphic inconnu (Stenodus leucichthys) otoliths is affected by crystal structure

1999 ◽  
Vol 56 (10) ◽  
pp. 1898-1903 ◽  
Author(s):  
Randy Brown ◽  
Kenneth P Severin
Keyword(s):  
Crystal Structure ◽  
Trace Elements ◽  
Ionic Composition ◽  
Elemental Abundance ◽  
Elemental Distribution ◽  
Otolith Chemistry ◽  
X Ray Diffraction ◽  
Otolith Growth ◽  
X Ray ◽  
Scanning Electron

The chemistry and crystal structure of sagittal otoliths from inconnu (Stenodus leucichthys) were examined optically, with an electron microprobe, a scanning electron microscope, and with X-ray diffraction techniques. The distributions of strontium (Sr), sodium (Na), potassium (K), and calcium (Ca) were determined with line scans and area maps of thin, transverse otolith sections. Regions depleted in Sr, Na, and K were found to be discordant with optical annuli and were optically distinct from other regions of the otoliths. These patterns of trace element depletion cannot be explained by models of otolith growth that are based on ionic composition of endolymph fluids as the sole control of otolith composition. Electron micrographs showed the depleted regions of the otoliths to be of a different crystal structure than other regions of the otoliths. X-ray diffraction analyses revealed the presence of vaterite in otoliths with depleted regions, while otoliths without depleted regions showed no evidence of vaterite. The depleted areas may be composed of vaterite, and the crystal structure of vaterite may prevent certain trace elements from incorporating in the otolith. Scientists using fish otolith chemistry to infer environmental conditions or life history should be aware that elemental abundance within otoliths may be affected by other processes as well.

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