Spatial metabolomics using mass-spectrometry imaging to decipher the impact of high red meat diet on the colon metabolome in rat.

Colorectal cancer (CRC) is the third most common cancer in the world with a higher prevalence in the developed countries, mainly caused by environmental and lifestyle factors such as diet, particularly red meat consumption. The metabolic impact of high red meat consumption on the epithelial part of the colon was investigated using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MSI), to specifically analyze the epithelial substructure. Ten colons from rats fed for 100 days high red or white meat diet were subjected to untargeted MSI analyses using two spatial resolutions (100 μm and 10 μm) to evaluate metabolite changes in the epithelial part and to visualize the distribution of metabolites of interest within the epithelium crypts.

Insights into posttranslational regulation of skeletal muscle contractile function by the acetyltransferases, p300 and CBP.

Mice with skeletal muscle-specific and inducible double knockout of the lysine acetyltransferases, p300 (E1A binding protein p300) and CBP (cAMP-response element-binding protein binding protein), referred to as i-mPCKO, demonstrate a dramatic loss of contractile function in skeletal muscle and ultimately die within 7 days. Given that many proteins involved in ATP generation and cross-bridge cycling are acetylated, we investigated whether these processes are dysregulated in skeletal muscle from i-mPCKO mice and, thus, whether they could underlie the rapid loss of muscle contractile function. Just 4-5 days after inducing knockout of p300 and CBP in skeletal muscle from adult i-mPCKO mice, there was ∼90% reduction in ex vivo contractile function in the extensor digitorum longus (EDL) and a ∼65% reduction in in vivo ankle dorsiflexion torque, as compared with wild type (WT; i.

Excess Intramyocellular Lipid Does Not Affect Muscle Fiber Biophysical Properties in Mice or People With Metabolically Abnormal Obesity.

Observational studies have shown correlations between intramyocellular lipid (IMCL) content and muscle strength and contractile function in people with metabolically abnormal obesity. However, a clear physiologic mechanism for this association is lacking, and causation is debated. We combined immunofluorescent confocal imaging with force measurements on permeabilized muscle fibers from metabolically normal and metabolically abnormal mice and people with metabolically normal (defined as normal fasting plasma glucose and glucose tolerance) and metabolically abnormal (defined as prediabetes and type 2 diabetes) overweight/obesity to evaluate relationships among myocellular lipid droplet characteristics (droplet size and density) and biophysical (active contractile and passive viscoelastic) properties.

Insights into post-translational regulation of skeletal muscle contractile function by the acetyltransferases, p300 and CBP.

Unlabelled: Mice with skeletal muscle-specific inducible double knockout of the lysine acetyltransferases, p300 (E1A binding protein p300) and CBP (cAMP-response element-binding protein binding protein), referred to as i-mPCKO, demonstrate a dramatic loss of contractile function in skeletal muscle and ultimately die within 7 days. Given that many proteins involved in ATP generation and cross-bridge cycling are acetylated, we investigated whether these processes are dysregulated in skeletal muscle from i-mPCKO mice and thus could underlie the rapid loss of muscle contractile function. Just 4-5 days after inducing knockout of p300 and CBP in skeletal muscle from adult i-mPCKO mice, there was ∼90% reduction in contractile function in the extensor digitorum longus (EDL) and a ∼65% reduction in ankle dorsiflexion torque, as compared to wildtype (WT; i.

Evaluation of dried-blood spots and a hematocrit-independent procedure in lysosomal diseases screening using multiplexed tandem mass spectrometry assays.

Background: Dried blood spots (DBS) are widely used as a non-invasive sampling method, especially in newborn screening (NBS). Despite its numerous advantages, conventional DBS might be limited by the hematocrit effect when analyzing a punch, depending on its position in the blood spot. This effect could be avoided using hematocrit-independent sampling devices such as the hemaPEN®.

Large-Scale Interlaboratory DI-FT-ICR MS Comparability Study Employing Various Systems.

Ultrahigh resolution mass spectrometry (UHR-MS) coupled with direct infusion (DI) electrospray ionization offers a fast solution for accurate untargeted profiling. Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers have been shown to produce a wealth of insights into complex chemical systems because they enable unambiguous molecular formula assignment even if the vast majority of signals is of unknown identity. Interlaboratory comparisons are required to apply this type of instrumentation in quality control (for food industry or pharmaceuticals), large-scale environmental studies, or clinical diagnostics.

Imaging Matrix-Assisted Laser Desorption/Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of oxaliplatin derivatives in human tissue sections.

Mass Spectrometry Imaging is an effective technology that allows to determine the in-situ distribution of endogen and/or exogen small molecules. It is a rapidly emerging approach for visualizing drugs and their metabolites within biological tissues. Matrix-Assisted Laser Desorption Ionization (MALDI) Mass Spectrometry Imaging (MSI) coupled to high resolving power analyzer (e.

Integrative Metabolomics Reveals Deep Tissue and Systemic Metabolic Remodeling in Glioblastoma.

(1) Background: Glioblastoma is the most common malignant brain tumor in adults. Its etiology remains unknown in most cases. Glioblastoma pathogenesis consists of a progressive infiltration of the white matter by tumoral cells leading to progressive neurological deficit, epilepsy, and/or intracranial hypertension.

Muscle metabolic remodelling patterns in Duchenne muscular dystrophy revealed by ultra-high-resolution mass spectrometry imaging.

Duchenne muscular dystrophy (DMD) is a common and severe X-linked myopathy, characterized by muscle degeneration due to altered or absent dystrophin. DMD has no effective cure, and the underlying molecular mechanisms remain incompletely understood. The aim of this study is to investigate the metabolic changes in DMD using mass spectrometry-based imaging.

National Survey of US HIV Clinicians: Knowledge and Attitudes About the Affordable Care Act and Opinions of its Impact on Quality of Care and Barriers to Care.

Background: The Affordable Care Act's (ACA's) major reforms started in 2014. In addition to assessing HIV clinicians' ACA knowledge and attitudes, this study aims to evaluate HIV clinicians' perspectives on whether the ACA has impacted the quality of HIV care and whether it addresses the main barriers to HIV care.

Methods: HIV clinicians were emailed a survey weblink in 2018.

Lactotrehalose, an Analog of Trehalose, Increases Energy Metabolism Without Promoting Clostridioides difficile Infection in Mice.

Background & Aims: Trehalose is a disaccharide that might be used in the treatment of cardiometabolic diseases. However, trehalose consumption promotes the expansion of Clostridioides difficile ribotypes that metabolize trehalose via trehalose-6-phosphate hydrolase. Furthermore, brush border and renal trehalases can reduce the efficacy of trehalose by cleaving it into monosaccharides.

Optimization of ion trajectories in a dynamically harmonized Fourier-transform ion cyclotron resonance cell using a design of experiments strategy.

Rationale: With the recent introduction of the dynamically harmonized Fourier-transform ion cyclotron resonance (FT-ICR) cell, the complexity of tuning has expanded drastically, and fine-tuning of the direct current voltages is required to optimize the ion cloud movement. As this adjustment must typically be performed manually, more reliable computational methods would be useful.

Methods: Here we propose a computational method based on a design of experiments (DoE) strategy to overcome the limits of classical manual tuning.

Monitoring of phosphorylation using immobilized kinases by on-line enzyme bioreactors hyphenated with High-Resolution Mass Spectrometry.

Nucleosides analogues are the cornerstone of the treatment of several human diseases. They are especially at the forefront of antiviral therapy. Their therapeutic efficiency depends on their capacity to be converted to the active nucleoside triphosphate form through successive phosphorylation steps catalyzed by nucleoside/nucleotide kinases.

A new optimization strategy for MALDI FTICR MS tissue analysis for untargeted metabolomics using experimental design and data modeling.

Ultra-high-resolution imaging mass spectrometry using matrix-assisted laser desorption ionization (MALDI) MS coupled to a Fourier transform ion cyclotron resonance (FTICR) mass analyzer is a powerful technique for the visualization of small molecule distribution within biological tissues. The FTICR MS provides ultra-high resolving power and mass accuracy that allows large molecular coverage and molecular formula assignments, both essential for untargeted metabolomics analysis. These performances require fine optimizations of the MALDI FTICR parameters.

Preexisting Commensal Dysbiosis Is a Host-Intrinsic Regulator of Tissue Inflammation and Tumor Cell Dissemination in Hormone Receptor-Positive Breast Cancer.

It is unknown why some patients with hormone receptor-positive (HR) breast cancer present with more aggressive and invasive disease. Metastatic dissemination occurs early in disease and is facilitated by cross-talk between the tumor and tissue environment, suggesting that undefined host-intrinsic factors enhance early dissemination and the probability of developing metastatic disease. Here, we have identified commensal dysbiosis as a host-intrinsic factor associated with metastatic dissemination.

A maternal high-fat, high-sucrose diet induces transgenerational cardiac mitochondrial dysfunction independently of maternal mitochondrial inheritance.

Maternal obesity is correlated with cardiovascular disease in offspring, with a 1.3-fold increase in events observed in offspring of obese women. We have observed that obesity-exposed oocytes demonstrate impaired mitophagy and transmit damaged mitochondria to the offspring.

Transgenerational impact of maternal obesogenic diet on offspring bile acid homeostasis and nonalcoholic fatty liver disease.

Studies show maternal obesity is a risk factor for metabolic syndrome and nonalcoholic fatty liver disease (NAFLD) in offspring. Here we evaluated potential mechanisms underlying these phenotypes. Female C57Bl6 mice were fed chow or an obesogenic high-fat/high-sucrose (HF/HS) diet with subsequent mating of F and F female offspring to lean males to develop F and F generations, respectively.

Monitoring of successive phosphorylations of thymidine using free and immobilized human nucleoside/nucleotide kinases by Flow Injection Analysis with High-Resolution Mass Spectrometry.

Nucleosides and their analogues play a crucial role in the treatment of several diseases including cancers and viral infections. Their therapeutic efficiency depends on their capacity to be converted to the active nucleoside triphosphates form through successive phosphorylation steps catalyzed by nucleoside/nucleotide kinases. It is thus mandatory to develop an easy, rapid, reliable and sensitive enzyme activity tests.

TLC-UV hyphenated with MALDI-TOFMS for the screening of invertase substrates in plant extracts.

In this study, thin-layer chromatography (TLC) hyphenated with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was developed for the screening of invertase substrates in complex matrices. BfrA, a specific β-D-fructofuranosidase from Leishmania major, was chosen as a model enzyme to screen biological activity in plant extracts due to its capacity to hydrolyze specific carbohydrates. TLC was considered to be a reliable technique for screening substrates (bioactive molecules) in plant extracts due to its quantitative capabilities whereas MALDI-TOFMS was particularly useful for rapid identification.

Validation of a thin-layer chromatography/densitometry method for the characterization of invertase activity.

This paper presents a kinetic study of invertase, a specific fructofuranosidase cloned from the Leishmania major genome. The kinetic parameters of the β-d-fructofuranosidase from Leishmania major (BfrA) were determined using Thin-Layer Chromatography (TLC) and UV-densitometry (TLC@UV) specifically developed for the separation and detection of three carbohydrates namely sucrose, glucose and fructose. Separation was performed on TLC silica gel 60 F254 plates impregnated with sodium bisulphate and citrate and heated prior to development.

Constitutive activation of CaMKKα signaling is sufficient but not necessary for mTORC1 activation and growth in mouse skeletal muscle.

Skeletal muscle loading/overload stimulates the Ca²⁺-activated, serine/threonine kinase Ca²⁺/calmodulin-dependent protein kinase kinase-α (CaMKKα); yet to date, no studies have examined whether CaMKKα regulates muscle growth. The purpose of this study was to determine if constitutive activation of CaMKKα signaling could stimulate muscle growth and if so whether CaMKKα is essential for this process. CaMKKα signaling was selectively activated in mouse muscle via expression of a constitutively active form of CaMKKα using in vivo electroporation.

Constitutively active CaMKKα stimulates skeletal muscle glucose uptake in insulin-resistant mice in vivo.

In insulin-sensitive skeletal muscle, the expression of constitutively active Ca(2+)/calmodulin-dependent protein kinase kinase α (caCaMKKα) stimulates glucose uptake independent of insulin signaling (i.e., Akt and Akt-dependent TBC1D1/TBC1D4 phosphorylation).

Detection of respiratory syncytial virus, parainfluenzavirus 3, adenovirus and rhinovirus sequences in respiratory tract of infants by polymerase chain reaction and hybridization.

Background: Immunofluorescence assay (IFA) of viral antigens in nasal aspirates is largely used for the diagnosis of respiratory syncytial virus (RSV), parainfluenzavirus (PIV) type 3 and adenovirus (AdV) infections, whilst rhinovirus (RV) are detected by virus isolation technique (VIT) only. Using the two techniques, IFA and VIT, a significant number of specimens remain negative in spite of clinical and epidemiological presumptions of viral infection.

Objectives And Study Design: The polymerase chain reaction (PCR) should improve the sensitivity of viral detection in clinical specimens.