Three-dimensional visualization of protein expression in mouse brain structures using imaging mass spectrometry

The structural organization of the brain is important for normal brain function and is critical to understand in order to evaluate changes that occur during disease processes. Three-dimensional (3D) imaging of the mouse brain is necessary to appreciate the spatial context of structures within the brain. In addition, the small scale of many brain structures necessitates resolution at the ∼10 μm scale. 3D optical imaging techniques, such as optical projection tomography (OPT), have the ability to image intact large specimens (1 cm3) with ∼5 μm resolution. In this work we assessed the potential of autofluorescence optical imaging methods, and specifically OPT, for phenotyping the mouse brain. We found that both specimen size and fixation methods affected the quality of the OPT image. Based on these findings we developed a specimen preparation method to improve the images. Using this method we assessed the potential of optical imaging for phenotyping. Phenotypic differences between wild-type male and female mice were quantified using computer-automated methods. We found that optical imaging of the endogenous autofluorescence in the mouse brain allows for 3D characterization of neuroanatomy and detailed analysis of brain phenotypes. This will be a powerful tool for understanding mouse models of disease and development and is a technology that fits easily within the workflow of biology and neuroscience labs.

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Analyzing Liposomal Drug Delivery Systems in Three-Dimensional Cell Culture Models Using MALDI Imaging Mass Spectrometry

Analytical Chemistry ◽

10.1021/acs.analchem.7b02006 ◽

2017 ◽

Vol 89 (16) ◽

pp. 8453-8458 ◽

Cited By ~ 26

Author(s):

Jessica K. Lukowski ◽

Eric M. Weaver ◽

Amanda B. Hummon

Keyword(s):

Mass Spectrometry ◽

Drug Delivery Systems ◽

Imaging Mass Spectrometry ◽

Three Dimensional ◽

Maldi Imaging ◽

Liposomal Drug ◽

Culture Models ◽

Cell Culture Models ◽

Dimensional Cell ◽

Liposomal Drug Delivery

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ET-13 CONTROL OF ACTIVATED MICROGLIA THROUGH P2X4 RECEPTOR IN RADIATION BRAIN NECROSIS

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz039.043 ◽

2019 ◽

Vol 1 (Supplement_2) ◽

pp. ii10-ii10

Author(s):

Kondo Natsuko ◽

Sakurai Yoshinori ◽

Takayuki Kajihara ◽

Takushi Takada ◽

Nobuhiko Takai ◽

...

Keyword(s):

Mass Spectrometry ◽

Mouse Brain ◽

Right Hemisphere ◽

Imaging Mass Spectrometry ◽

Underlying Mechanism ◽

Lipid Mediators ◽

Tumor Patients ◽

P2x4 Receptor ◽

Activated Microglia ◽

Brain Radiation

Abstract INTRODUCTION Brain radiation necrosis (RN) is severe adverse event after radiation therapy for brain tumor patients, especially in case of re-irradiation. Although corticosteroids or vitamin E, etc. are clinically used for RN, the effect is limited and underlying mechanism is to be cleared. Therefore, we established RN mouse model with irradiating right hemisphere of mouse brain using proton beam at dose of 60 Gy [Kondo et al., 2015]. In this study, we investigated change of phospholipids and lipid mediators after irradiation using this RN model in correlation with microglia activation. METHODS After irradiation, change of phospholipids and lipid mediators in mouse brain was investigated using imaging mass spectrometry and LC-MS. Immunohistochemistry on microglia and P2X4 receptor, a receptor for lysophosphatidylcholine (LPC) was performed. RESULTS In imaging mass spectrometry, 1 and 4 months after irradiation, phosphatidylcholine (PC): (16:0/20:4), (18:0/20:4) decreased in irradiated area compared non-irradiated area. On the other hand, LPC: (16:0) increased in irradiated area compared to non-irradiated area after 1 month and 4 months irradiation. PC (16:0/20:4) is a precursor of LPC (16:0) and arachidonic acid (20:4). By LC-MS, LPC was twice higher in irradiated area compared to non-irradiated, 6 months after irradiation. Microglia was highly activated in irradiated area compared to non-irradiated from 3 months after irradiation to 8 months and strongly co-expressed P2X4 receptor was confirmed in irradiated area after 6 months. Preliminary P2X4 receptor agonist administration test prolonged the RN to 12 months after irradiation. CONCLUSION In RN, LPC may continuously activated microglia through P2X4 receptor and cause chronic inflammation after irradiation. P2X4 agonist administration test including action resolution and immunohistochemistry is ongoing.

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