Dual polarity MALDI imaging mass spectrometry on the same pixel points reveals spatial lipid localizations at high-spatial resolutions in rat small intestine

Sensitive laser desorption/ionization obtained via a sublimation-coated 1,5-diaminonaphthalene (1,5-DAN) matrix allowed dual polarity MALDI-IMS analysis on the same pixel points across the jejunal mucosal region in rat small intestine which yielded high-spatial-resolution (10 μm) ion images of several lipid species correlated with the same histological features

Brain region-specific amyloid plaque-associated myelin lipid loss, APOE deposition and disruption of the myelin sheath in familial Alzheimer\u27s disease mice

There is emerging evidence that amyloid beta (A beta) aggregates forming neuritic plaques lead to impairment of the lipid-rich myelin sheath and glia. In this study, we examined focal myelin lipid alterations and the disruption of the myelin sheath associated with amyloid plaques in a widely used familial Alzheimer\u27s disease (AD) mouse model; 5xFAD. This AD mouse model has A beta(42) peptide-rich plaque deposition in the brain parenchyma. Matrix-assisted laser desorption/ionization imaging mass spectrometry of coronal brain tissue sections revealed focal A beta plaque-associated depletion of multiple myelin-associated lipid species including sulfatides, galactosylceramides, and specific plasmalogen phopshatidylethanolamines in the hippocampus, cortex, and on the edges of corpus callosum. Certain phosphatidylcholines abundant in myelin were also depleted in amyloid plaques on the edges of corpus callosum. Further, lysophosphatidylethanolamines and lysophosphatidylcholines, implicated in neuroinflammation, were found to accumulate in amyloid plaques. Double staining of the consecutive sections with fluoromyelin and amyloid-specific antibody revealed amyloid plaque-associated myelin sheath disruption on the edges of the corpus callosum which is specifically correlated with plaque-associated myelin lipid loss only in this region. Further, apolipoprotein E, which is implicated in depletion of sulfatides in AD brain, is deposited in all the A beta plaques which suggest apolipoprotein E might mediate sulfatide depletion as a consequence of an immune response to A beta deposition. This high-spatial resolution matrix-assisted laser desorption/ionization imaging mass spectrometry study in combination with (immuno) fluorescence staining of 5xFAD mouse brain provides new understanding of morphological, molecular and immune signatures of A beta plaque pathology-associated myelin lipid loss and myelin degeneration in a brain region-specific manner

Distinct Cholesterol Localization in Glioblastoma Multiforme Revealed by Mass Spectrometry Imaging

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor in adults and is highly resistant to chemo- and radiotherapies. GBM has been associated with alterations in lipid contents, but lipid metabolism reprogramming in tumor cells is not fully elucidated. One of the key hurdles is to localize the lipid species that are correlated with tumor growth and invasion. A better understanding of the localization of abnormal lipid metabolism and its vulnerabilities may open up to novel therapeutic approaches. Here, we use time-of-flight secondary ion mass spectrometry (ToF-SIMS) to spatially probe the lipid composition in a GBM biopsy from two regions with different histopathologies: one region with most cells of uniform size and shape, the homogeneous part, and the other with cells showing a great variation in size and shape, the heterogeneous part. Our results reveal elevated levels of cholesterol, diacylglycerols, and some phosphatidylethanolamine in the homogeneous part, while the heterogeneous part was dominated by a variety of fatty acids, phosphatidylcholine, and phosphatidylinositol species. We also observed a high expression of cholesterol in the homogeneous tumor region to be associated with large cells but not with macrophages. Our findings suggest that ToF-SIMS can distinguish in lipid distribution between parts within a human GBM tumor, which can be linked to different molecular mechanisms

A randomized controlled trial on the effectiveness of strength training on clinical and muscle cellular outcomes in patients with prostate cancer during androgen deprivation therapy: rationale and design

Background Studies indicate that strength training has beneficial effects on clinical health outcomes in prostate cancer patients during androgen deprivation therapy. However, randomized controlled trials are needed to scientifically determine the effectiveness of strength training on the muscle cell level. Furthermore, close examination of the feasibility of a high-load strength training program is warranted. The Physical Exercise and Prostate Cancer (PEPC) trial is designed to determine the effectiveness of strength training on clinical and muscle cellular outcomes in non-metastatic prostate cancer patients after high-dose radiotherapy and during ongoing androgen deprivation therapy. Methods/design Patients receiving androgen deprivation therapy for 9-36 months combined with external high-dose radiotherapy for locally advanced prostate cancer are randomized to an exercise intervention group that receives a 16 week high-load strength training program or a control group that is encouraged to maintain their habitual activity level. In both arms, androgen deprivation therapy is continued until the end of the intervention period. Clinical outcomes are body composition (lean body mass, bone mineral density and fat mass) measured by Dual-energy X-ray Absorptiometry, serological outcomes, physical functioning (muscle strength and cardio-respiratory fitness) assessed with physical tests and psycho-social functioning (mental health, fatigue and health-related quality of life) assessed by questionnaires. Muscle cellular outcomes are a) muscle fiber size b) regulators of muscle fiber size (number of myonuclei per muscle fiber, number of satellite cells per muscle fiber, number of satellite cells and myonuclei positive for androgen receptors and proteins involved in muscle protein degradation and muscle hypertrophy) and c) regulators of muscle fiber function such as proteins involved in cellular stress and mitochondrial function. Muscle cellular outcomes are measured on muscle cross sections and muscle homogenate from muscle biopsies obtained from muscle vastus lateralis. Discussion The findings from the PEPC trial will provide new knowledge on the effects of high-load strength training on clinical and muscle cellular outcomes in prostate cancer patients during androgen deprivation therapy. Trial registration ClinicalTrials.gov: NCT0065822

Multimodal chemical imaging of a single brain tissue section using ToF-SIMS, MALDI-ToF and immuno/histochemical staining

Cluster ion beam ToF-SIMS and/or MALDI-ToF mass spectrometry imaging (using 1,5-DAN matrix via sublimation) of a single coronal rat brain tissue section followed by classical-or immuno-histochemical staining faclilated a new multimodal chemical imaging workflow allowing complementary correlation of the lipid molecular ion images with the immuno/histological features within cerebellum region of the same brain tisue section

High-resolution, imaging TOF-SIMS: novel applications in medical research

Abstract: The use of high-resolution, imaging TOF-SIMS is described and examples are made to demonstrate the application of the method in medical research. Cytochemistry by TOF-SIMS is shown by localization of diacylglycerol (DG) in cryostat sections of hyaline cartilage and by localization of corticosterone in cryostat sections of the adrenal gland cortex. Quantitative measurements and comparison of groups is shown by comparing the lipid content of adipose tissue from two mouse strains, transgenic mouse expressing the FOXC2 gene and wild-type controls. Finally, biopsies made for histopathological diagnosis of infantile reversible cytochrome c oxidase deficiency myopathy were analyzed in order to define the chemical content of areas showing a pathological structure in the light microscope. The use of high-resolution, imaging TOF-SIMS in medical research allows analysis of intact tissue and probe-free localization of specific target molecules in cells and tissues. The TOF-SIMS analysis is not dependent on penetration of reagents into the sample and also independent of probe reactivity such as cross-reactivity or background staining. The TOF-SIMS method can be made quantitative and allows for analysis of specific target molecules in defined tissue compartments

Cholera Toxin Induces a Transient Depletion of CD8(+) Intraepithelial Lymphocytes in the Rat Small Intestine as Detected by Microarray and Immunohistochemistry

Cholera toxin (CT), besides causing intestinal hypersecretion after intragastric administration or during cholera infection, affects a multitude of regulatory mechanisms within the gut mucosal network, including T cells. By use of microarray screening, real-time PCR, and immunohistochemistry, we demonstrate here a rapid depletion of jejunal CD8(+) intraepithelial lymphocytes (IEL) in rats after intragastric CT challenge. This depletion may depend on CT-induced migration of IEL, since it was associated with a progressive decrease of CD8(+) cells in the epithelium and a contemporary transient increase of such cells, preferentially at the base of the villi, in the lamina propria. A significant decrease in the total number of villous CD8(+) cells at 6 and 18 h after CT challenge was detected; this possibly reflects an efflux from the jejunal mucosa. The kinetics of the CD8(+) IEL demonstrate the return to normal intraepithelial position at original numbers already 72 h after the single CT dose. The induced migration seems to be dependent on the enzymatic A-subunit of CT, since challenge with neither sorbitol nor CT B-subunit did mimic the effects of CT on CD8(+) IEL. Furthermore, a decrease in the level of both RANTES transcript and protein was detected, most likely as a consequence of the CT-induced migration of CD8(+) IEL. These results point to a complex interaction between CT, epithelial cells, and IEL, resulting in a disturbance of the gut homeostasis, which might have relevance for the strong immunomodulatory effects of intragastrically administered CT