Search

Background: Long-term morbidity and mortality outcomes of the arterial switch operation (ASO) in patients with transposition of the great arteries and Taussig-Bing anomaly are excellent. With an increasing number of patients reaching adolescence and adulthood, more attention is directed toward quality of life. Our study aimed to determine the health-related quality of life (hrQoL) outcomes in patients after the ASO and identify factors influencing their hrQoL. Methods: In this cross-sectional study, hrQoL of patients after ASO was assessed with the German version of the Short Form-36 (SF-36) and the potential association of specified clinical factors was analyzed. Patients of at least 14 years of age who underwent ASO in our institution from 1983 were considered eligible. Results: Of the 355 questionnaires sent to eligible patients, 261 (73%) were available for analysis. Compared to the reference population, patients who had undergone ASO had a significantly higher score in all subscales of the SF-36 except for vitality ( P < .01). Patients with an implanted pacemaker ( P = .002), patients who required at least one reoperation ( P < .001), and patients currently taking cardiac medication ( P < .004) or oral anticoagulation ( P = .036) had lower physical component scores compared to patients without these factors. Conclusions: Patients’ self-assessed and self-reported hrQoL after ASO (using German version of the Short Form 36) is very good. In this population, hrQoL is influenced by reoperation, the need for a pacemaker, and current cardiac medication or anticoagulant use. The development of strategies designed to mitigate or minimize the requirements for, and/or impact of these factors may lead to better hrQoL in this patient population.

Cyclin-dependent kinase 4 (CDK4) canonical role is to control cell cycle progression from G1 to S phases. However, recent studies reported that CDK4 regulates energy metabolism in non-proliferating cells such as hepatocytes or adipocytes. The objective of our work is to study CDK4 function in skeletal muscle using a model of mice lacking CDK4 (cdk4-/-). By coupling treadmill running to indirect calorimetry, we show that cdk4-/- mice display improved endurance and higher capacity to use fat as fuel during exercise. Isolated muscles lacking CDK4 are more resistant to fatigue in response to repeated contractions and have increased oxidative capacity and mitochondrial content compared to cdk4+/+ muscles. Transcriptomic analysis reveals upregulation of genes controlled by the nuclear receptors estrogen-related receptors (ERRs) in cdk4-/- skeletal muscle, associated with elevated levels of the ERR co-activator PGC1a. Supporting in vivo results, C2C12 myotubes treated with a CDK4 inhibitor have increased mitochondrial oxygen consumption, PGC1α expression and ERR transcriptional activity measured by a luciferase reporter. In normal housing conditions, cdk4-/- mice show an increased basal metabolic rate and are resistant to weight gain and fat accumulation. In conclusion, our study uncovers a role for CDK4 in the control of skeletal muscle metabolism. Moreover, CDK4 inhibition may be an alternative strategy against obesity-associated metabolic disorders.

Light sheet fluorescence microscopy (LSFM) of optically cleared biological samples represents a powerful tool to analyze the 3-dimensional morphology of tissues and organs. Multimodal combinations of LSFM with additional analyses of the identical sample help to limit the consumption of restricted specimen and reduce inter-sample variation. Here, we demonstrate the proof-of-concept that LSFM of cleared brain tissue samples can be combined with Matrix Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging (MALDI-MSI) for detection and quantification of proteins. Samples of freshly dissected murine brain and of archived formalin-fixed paraffin-embedded (FFPE) human brain tissue were cleared (3DISCO). Tissue regions of interest were defined by LSFM and excised, (re)-embedded in paraffin, and sectioned. Mouse sections were coated with sinapinic acid matrix. Human brain sections were pre-digested with trypsin and coated with α-cyano-4-hydroxycinnamic acid matrix. Subsequently, sections were subjected to MALDI-time-of-flight (TOF)-MSI in mass ranges between 0.8 to 4 kDa (human tissue sections), or 2.5–25 kDa (mouse tissue sections) with a lateral resolution of 50 µm. Protein- and peptide-identities corresponding to acquired MALDI-MSI spectra were confirmed by parallel liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. The spatial abundance- and intensity-patterns of established marker proteins detected by MALDI-MSI were also confirmed by immunohistochemistry.

Simple Summary Autophagy is an intracellular catabolic program regulated by multiple external and internal cues. A large amount of evidence unraveled that cell-cycle regulators are crucial in its control. This review highlights the interplay between cell-cycle regulators, including cyclin-dependent kinase inhibitors, cyclin-dependent kinases, and E2F factors, in the control of autophagy all along the cell cycle. Beyond the intimate link between cell cycle and autophagy, this review opens therapeutic perspectives in modulating together these two aspects to block cancer progression. Abstract In the past decade, cell cycle regulators have extended their canonical role in cell cycle progression to the regulation of various cellular processes, including cellular metabolism. The regulation of metabolism is intimately connected with the function of autophagy, a catabolic process that promotes the efficient recycling of endogenous components from both extrinsic stress, e.g., nutrient deprivation, and intrinsic sub-lethal damage. Mediating cellular homeostasis and cytoprotection, autophagy is found to be dysregulated in numerous pathophysiological contexts, such as cancer. As an adaptative advantage, the upregulation of autophagy allows tumor cells to integrate stress signals, escaping multiple cell death mechanisms. Nevertheless, the precise role of autophagy during tumor development and progression remains highly context-dependent. Recently, multiple articles has suggested the importance of various cell cycle regulators in the modulation of autophagic processes. Here, we review the current clues indicating that cell-cycle regulators, including cyclin-dependent kinase inhibitors (CKIs), cyclin-dependent kinases (CDKs), and E2F transcription factors, are intrinsically linked to the regulation of autophagy. As an increasing number of studies highlight the importance of autophagy in cancer progression, we finally evoke new perspectives in therapeutic avenues that may include both cell cycle inhibitors and autophagy modulators to synergize antitumor efficacy.

N-acetylaspartate (NAA) is synthesized by aspartate N-acetyltransferase (gene: Nat8l) from acetyl–coenzyme A and aspartate. In the brain, NAA is considered an important energy metabolite for lipid synthesis. However, the role of NAA in peripheral tissues remained elusive. Therefore, we characterized the metabolic phenotype of knockout (ko) and adipose tissue–specific (ako) Nat8l-ko mice as well as NAA-supplemented mice on various diets. We identified an important role of NAA availability in the brain during adolescence, as 75% of Nat8l-ko mice died on fat-free diet (FFD) after weaning but could be rescued by NAA supplementation. In adult life, NAA deficiency promotes a beneficial metabolic phenotype, as Nat8l-ko and Nat8l-ako mice showed reduced body weight, increased energy expenditure, and improved glucose tolerance on chow, high-fat, and FFDs. Furthermore, Nat8l-deficient adipocytes exhibited increased mitochondrial respiration, ATP synthesis, and an induction of browning. Conversely, NAA-treated wild-type mice showed reduced adipocyte respiration and lipolysis and increased de novo lipogenesis, culminating in reduced energy expenditure, glucose tolerance, and insulin sensitivity. Mechanistically, our data point to a possible role of NAA as modulator of pancreatic insulin secretion and suggest NAA as a critical energy metabolite for adipocyte and whole-body energy homeostasis.—Hofer, D. C., Zirkovits, G., Pelzmann, H. J., Huber, K., Pessentheiner, A. R., Xia, W., Uno, K., Miyazaki, T., Kon, K., Tsuneki, H., Pendl, T., Al Zoughbi, W., Madreiter-Sokolowski, C. T., Trausinger, G., Abdellatif, M., Schoiswohl, G., Schreiber, R., Eisenberg, T., Magnes, C., Sedej, S., Eckhardt, M., Sasahara, M., Sasaoka, T., Nitta, A., Hoefler, G., Graier, W. F., Kratky, D., Auwerx, J., Bogner-Strauss, J. G. N-acetylaspartate availability is essential for juvenile survival on fat-free diet and determines metabolic health.

Quantitative sub-cellular metabolomic measurements can yield crucial insights into the roles of metabolites in cellular processes, but are subject to multiple confounding factors. We developed Stable Isotope Labeling of Essential nutrients in cell Culture - Sub-cellular Fractionation (SILEC-SF), which uses isotope labeled internal standard controls that are present throughout fractionation and processing to quantify acyl-Coenzyme A thioesters in sub-cellular compartments by liquid chromatography-mass spectrometry. We tested SILEC-SF in a range of sample types and examined the compartmentalized responses to oxygen tension, cellular differentiation, and nutrient availability. Application of SILEC-SF to the challenging analysis of the nuclear compartment revealed a nuclear acyl-CoA profile distinct from that of the cytosol, with notable nuclear enrichment of propionyl-CoA. Using isotope tracing we identified the branched chain amino acid (BCAA) isoleucine as a major metabolic source of nuclear propionyl-CoA and histone propionylation, thus revealing a new mechanism of crosstalk between metabolism and the epigenome.

Supplemental Material, sj-docx-1-pch-10.1177_2150135121990651 for Factors Affecting Health-Related Quality of Life After the Arterial Switch Operation by Julie Cleuziou, Anna-Katharina Huber, Martina Strbad, Masamichi Ono, Alfred Hager, Jürgen Hörer and Rüdiger Lange in World Journal for Pediatric and Congenital Heart Surgery

Background: The swift spread of SARS-CoV-2 provides a challenge worldwide. As a consequence of restrictive public health measures like isolation, quarantine, and community containment, the provision of mental health services is a major challenge. Evidence from past virus epidemics and the current SARS-CoV-2 outbreak indicate high prevalence rates of mental health problems (MHP) as short- and long-term consequences. However, a broader picture of MHP among different populations is still lacking. Methods: We conducted a rapid review on MHP prevalence rates published since 2000, during and after epidemics, including the general public, health care workers, and survivors. Any quantitative articles reporting on MHP rates were included. Out of 2855 articles screened, a total of 74 were included in this review. Results: Most original studies on MHP were conducted in China in the context of SARS-CoV-1, and reported on anxiety, depression, post-traumatic stress symptoms/disorder, general psychiatric morbidity, and psychological symptoms. The MHP rates across studies, populations, and epidemics vary substantially. While some studies show high and persistent rates of MHP in populations directly affected by isolation, quarantine, threat of infection, infection, or life-threatening symptoms (e.g. health care workers), other studies report minor effects. Furthermore, even less affected populations (e.g. distant to epidemic epicenter, no contact history with suspected or confirmed cases) can show high rates of MHP. Discussion: MHP vary largely across countries and risk-groups in reviewed studies. The results call attention to potentially high MHP during epidemics. Individuals affected directly by an epidemic might be at a higher risk of short or even long-term mental health impairments. This study delivers insights stemming from a wide range of psychiatric instruments and questionnaires. The results call for the use of validated and standardized instruments, reference norms, and pre-post measurements to better understand the magnitude of the MHP during and after the epidemics. Nevertheless, emerging MHP should be considered during epidemics including the provision of access to mental health care to mitigate potential mental impairments.

This review discusses how the control of proliferation and cell division by cell cycle regulators is also involved in the metabolic adaptive responses when cells need to produce energy. We describe how cell cycle regulators are involved in the control of metabolic pathways, in cell growth and the functionality of organelles including endolysosomes and mitochondria., Adapting to changes in nutrient availability and environmental conditions is a fundamental property of cells. This adaptation requires a multi‐directional coordination between metabolism, growth, and the cell cycle regulators (consisting of the family of cyclin‐dependent kinases (CDKs), their regulatory subunits known as cyclins, CDK inhibitors, the retinoblastoma family members, and the E2F transcription factors). Deciphering the mechanisms accountable for this coordination is crucial for understanding various patho‐physiological processes. While it is well established that metabolism and growth affect cell division, this review will focus on recent observations that demonstrate how cell cycle regulators coordinate metabolism, cell cycle progression, and growth. We will discuss how the cell cycle regulators directly regulate metabolic enzymes and pathways and summarize their involvement in the endolysosomal pathway and in the functions and dynamics of mitochondria.

Summary Metabolism is highly compartmentalized within cells, and the sub-cellular distribution of metabolites determines their use. Quantitative sub-cellular metabolomic measurements can yield crucial insights into the roles of metabolites in cellular processes. Yet, these analyses are subject to multiple confounding factors in sample preparation. We developed Stable Isotope Labeling of Essential nutrients in cell Culture - Sub-cellular Fractionation (SILEC-SF), which uses rigorous internal standard controls that are present throughout fractionation and processing to quantify metabolites in sub-cellular compartments by liquid chromatography-mass spectrometry (LC-MS). Focusing on the analysis of acyl-Coenzyme A thioester metabolites (acyl-CoAs), SILEC-SF was tested in a range of sample types from cell lines to mouse and human tissues. Its utility was further validated by analysis of mitochondrial versus cytosolic acyl-CoAs in the well-defined compartmentalized metabolic response to hypoxia. We then applied the method to investigate metabolic responses in the cytosol and nucleus. Within the cytosol, we found that the mevalonate pathway intermediate 3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) is exquisitely sensitive to acetyl-CoA supply. The nucleus has been an exceptionally challenging compartment in which to quantify metabolites, due in part to its permeability. We applied the SILEC-SF method to nuclei, identifying that the nuclear acyl-CoA profile is distinct from the cytosolic compartment, with notable nuclear enrichment of propionyl-CoA. Altogether, we present the SILEC-SF method as a flexible approach for quantitative sub-cellular metabolic analyses.

This study investigated the role of CDK4 in the oxidative metabolism of brown adipose tissue (BAT). BAT from Cdk4 −/− mice exhibited fewer lipids and increased mitochondrial volume and expression of canonical thermogenic genes, rendering these mice more resistant to cold exposure. Interestingly, these effects were not BAT cell‐autonomous but rather driven by increased sympathetic innervation. In particular, the ventromedial hypothalamus (VMH) is known to modulate BAT activation via the sympathetic nervous system. We thus examined the effects of VMH neuron‐specific Cdk4 deletion. These mice display increased sympathetic innervation and enhanced cold tolerance, similar to Cdk4 −/− mice, in addition to browning of scWAT. Overall, we provide evidence showing that CDK4 modulates thermogenesis by regulating sympathetic innervation of adipose tissue depots through hypothalamic nuclei, including the VMH. This demonstrates that CDK4 not only negatively regulates oxidative pathways, but also modulates the central regulation of metabolism through its action in the brain., CDK4 negatively regulates thermogenesis by suppressing oxidative pathways. This study reveals that CDK4 also modulates the systemic regulation of metabolism through its action in the hypothalamus.

Summary Quantitative subcellular metabolomic measurements can explain the roles of metabolites in cellular processes but are subject to multiple confounding factors. We developed stable isotope labeling of essential nutrients in cell culture-subcellular fractionation (SILEC-SF), which uses isotope-labeled internal standard controls that are present throughout fractionation and processing to quantify acyl-coenzyme A (acyl-CoA) thioesters in subcellular compartments by liquid chromatography-mass spectrometry. We tested SILEC-SF in a range of sample types and examined the compartmentalized responses to oxygen tension, cellular differentiation, and nutrient availability. Application of SILEC-SF to the challenging analysis of the nuclear compartment revealed a nuclear acyl-CoA profile distinct from that of the cytosol, with notable nuclear enrichment of propionyl-CoA. Using isotope tracing, we identified the branched chain amino acid isoleucine as a major metabolic source of nuclear propionyl-CoA and histone propionylation, thus revealing a new mechanism of crosstalk between metabolism and the epigenome.

On-tissue digestion has become the preferred method to identify proteins in mass spectrometry (MS) imaging. In this study, we report advances in data acquisition and protein identification for MS imaging after on-tissue digestion. Tryptic peptides in a coronal mouse brain section were measured at 50 μm pixel size and revealed detailed histological structures, e.g., the ependyma (consisting of one to two cell layers), which was confirmed by H&E staining. This demonstrates that MS imaging of tryptic peptides at or close to cellular resolution is within reach. We also describe a detailed identification workflow which resulted in the identification of 99 proteins (with 435 corresponding peptides), based on comparison with LC-MS/MS data and in silico digest. These results were obtained with stringent parameters, including high mass accuracy in imaging mode (RSME

OBJECTIVEThe dynamic regulation of metabolic pathways can be monitored by stable isotope tracing. Yet, many metabolites are part of distinct processes within different subcellular compartments. Standard isotope tracing experiments relying on analyses in whole cells may not accurately reflect compartmentalized metabolic processes. Analysis of compartmentalized metabolism and the dynamic interplay between compartments can potentially be achieved by stable isotope tracing followed by subcellular fractionation. Although it is recognized that metabolism can take place during biochemical fractionation of cells, a clear understanding of how such post-harvest metabolism impacts the interpretation of subcellular isotope tracing data and methods to correct for this are lacking. We set out to directly assess artifactual metabolism, enabling us to develop and test strategies to correct for it. We apply these techniques to examine the compartment-specific metabolic kinetics of 13C-labeled substrates targeting central metabolic pathways.METHODSWe designed a stable isotope tracing strategy to interrogate post-harvest metabolic activity during subcellular fractionation using liquid chromatography-mass spectrometry (LC-MS).RESULTSWe show that post-harvest metabolic activity occurs rapidly (within seconds) upon cell harvest. With further characterization we reveal that this post-harvest metabolism is enzymatic, and reflects the metabolic capacity of the sub-cellular compartment analyzed; but is limited in the extent of its propagation into downstream metabolites in metabolic pathways. We also propose and test a post-labeling strategy to assess the amount of post-harvest metabolism occurring in an experiment and then to adjust data to account for this. We validate this approach for both mitochondrial and cytosolic metabolic analyses.CONCLUSIONSOur data indicate that isotope tracing coupled with sub-cellular fractionation can reveal distinct and dynamic metabolic features of cellular compartments, and that confidence in such data can be improved by applying a post-labeling correction strategy. We examine compartmentalized metabolism of acetate and glutamine and show that acetyl-CoA is turned over rapidly in the cytosol and acts as a pacemaker of anabolic metabolism in this compartment.

Multimodal tissue analyses that combine two or more detection technologies provide synergistic value compared to single methods and are employed increasingly in the field of tissue-based diagnostics and research. Here, we report a technical pipeline that describes a combined approach of HER2/CEP17 fluorescence in situ hybridization (FISH) analysis with MALDI imaging on the very same section of formalin-fixed and paraffin-embedded (FFPE) tissue. FFPE biopsies and a tissue microarray of human gastroesophageal adenocarcinoma were analyzed by MALDI imaging. Subsequently, the very same section was hybridized by HER2/CEP17 FISH. We found that tissue morphology of both, the biopsies and the tissue microarray, was unaffected by MALDI imaging and the HER2 and CEP17 FISH signals were analyzable. In comparison with FISH analysis of samples without MALDI imaging, we observed no difference in terms of fluorescence signal intensity and gene copy number. Our combined approach revealed adenosine monophosphate, measured by MALDI imaging, as a prognostic marker. HER2 amplification, which was detected by FISH, is a stratifier between good and poor patient prognosis. By integrating both stratification parameters on the basis of our combined approach, we were able to strikingly improve the prognostic effect. Combining molecules detected by MALDI imaging with the gene copy number detected by HER2/CEP17 FISH, we found a synergistic effect, which enhances patient prognosis. This study shows that our combined approach allows the detection of genetic and metabolic properties from one very same FFPE tissue section, which are specific for HER2 and hence suitable for prognosis. Furthermore, this synergism might be useful for response prediction in tumors.

The discovery of significant amounts of metabolically active brown adipose tissue (BAT) in adult humans renders it a promising target for anti-obesity therapies by inducing weight loss through increased energy expenditure. The components of the N-acetylaspartate (NAA) pathway are highly abundant in BAT. Aspartate N-acetyltransferase (Asp-NAT, encoded by Nat8l) synthesizes NAA from acetyl-CoA and aspartate and increases energy expenditure in brown adipocytes. However, the exact mechanism how the NAA pathway contributes to accelerated mobilization and oxidation of lipids and the physiological regulation of the NAA pathway remained elusive. Here, we demonstrate that the expression of NAA pathway genes corresponds to nutrient availability and specifically responds to changes in exogenous glucose. NAA is preferentially produced from glucose-derived acetyl-CoA and aspartate and its concentration increases during adipogenesis. Overexpression of Nat8l drains glucose-derived acetyl-CoA into the NAA pool at the expense of cellular lipids and certain amino acids. Mechanistically, we elucidated that a combined activation of neutral and lysosomal (acid) lipolysis is responsible for the increased lipid degradation. Specifically, translocation of the transcription factor EB to the nucleus activates the biosynthesis of autophagosomes and lysosomes. Lipid degradation within lysosomes accompanied by adipose triglyceride lipase-mediated lipolysis delivers fatty acids for the support of elevated mitochondrial respiration. Together, our data suggest a crucial role of the NAA pathway in energy metabolism and metabolic adaptation in BAT.

// Laura Jacobs 1, * , Stefan Habringer 2, 6, * , Jolanta Slawska 2 , Katharina Huber 3 , Elke Hauf 2 , Zhoulei Li 1 , Yosef Refaeli 4 , Markus Schwaiger 1, 6 , Martina Rudelius 5 , Axel Walch 3 and Ulrich Keller 2, 6 1 Nuclear Medicine Department, Technische Universitat Munchen, Munich, Germany 2 Internal Medicine III, Technische Universitat Munchen, Munich, Germany 3 Analytical Pathology, Helmholtz Zentrum Munchen, Neuherberg, Germany 4 Department of Dermatology, University of Colorado, Denver, CO, USA 5 Department of Pathology, Universitatsklinikum Dusseldorf, Dusseldorf, Germany 6 German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany * Authors contributed equally to this work Correspondence to: Ulrich Keller, email: ulrich.keller@tum.de Keywords: lymphoma, B-cell receptor signaling, positron emission tomography, MALDI imaging mass spectrometry, functional imaging Received: April 28, 2017 Accepted: July 31, 2017 Published: August 24, 2017 ABSTRACT Aberrant B-cell receptor (BCR) signaling is known to contribute to malignant transformation. Two small molecule inhibitors targeting BCR pathway signaling include ibrutinib, a Bruton’s tyrosine kinase (BTK) inhibitor, and idelalisib, a specific Phosphatidylinositol-4,5-bisphosphate 3-kinase delta (PI3Kδ) inhibitor, both of which have been approved for use in haematological malignancies. Despite the identification of various diffuse large B-cell lymphoma (DLBCL) subtypes, mutation status alone is not sufficient to predict patient response and therapeutic resistance can arise. Herein we apply early molecular imaging across alternative activated B-cell (ABC) and germinal center B-cell (GCB) DLBCL subtypes to investigate the effects of BCR pathway inhibition. Treatment with both inhibitors adversely affected cell growth and viability. These effects were partially predictable based upon mutation status. Accordingly, very early 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ( 18 F-FDG-PET) and 3’-deoxy-3’[18F]-fluorothymidine positron emission tomography ( 18 F-FLT-PET) reported tumour regression and reductions in tumour metabolism and proliferation upon treatment. Furthermore, matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI IMS) identified alterations in the proteome of a model of ABC DLBCL upon treatment with ibrutinib or idelalisib. In conclusion we demonstrate that very early molecular imaging adds predictive value in addition to mutational status of DLBCL that may be useful in directing patient therapy.

Drug efficacy strongly depends on the presence of the drug substance at the target site. As vascularization is an important factor for the distribution of drugs in tissues, we analyzed drug distribution as a function of blood vessel localization in tumor tissue. In order to explore distribution of the anti-cancer drugs afatinib, erlotinib, and sorafenib, a combined approach of matrix-assisted laser desorption/ionization (MALDI) drug imaging and immunohistochemical vessel staining was applied and examined by digital image analysis. Two xenograft models were investigated: (1) mice carrying squamous cell carcinoma (FaDu) xenografts (ntumor=13) were treated with afatinib or erlotinib, and (2) sarcoma (A673) xenograft bearing mice (ntumor=8) received sorafenib treatment. MALDI drug imaging revealed a heterogeneous distribution of all anti-cancer drugs. The tumor regions containing high drug levels were associated with a higher degree of vascularization than the regions without drug signals (p

Tryptic peptides of a feline large granular lymphoma cell line were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Seventeen proteins of the T cell receptor signaling pathway could be identified by this approach. So far the existence of these proteins has only been postulated in the protein databases while experimental proof of their expression is predominantly pending. This article suggests where these proteins are located within the T cell receptor signaling pathway, thereby giving a short overview of the structure and function of this cascade.

The aim of this study was to establish an ex vivo model for a faster optimisation of sample preparation procedures, for example matrix choice, in matrix-assisted laser desorption/ionisation (MALDI) drug imaging studies. The ionisation properties of four drugs, afatinib, erlotinib, irinotecan and pirfenidone, were determined in an ex vivo tissue experiment by spotting decreasing dilution series onto liver sections. Hereby, the drug signals were distinctly detectable using different matrix compounds, which allowed the selection of the optimal matrix for each drug. The analysis of afatinib and erlotinib yielded high drug signals with α-cyano-4-hydroxycinnamic acid matrix, whereas 2,3-dihydroxybenzoic acid was identified as optimal matrix for irinotecan and pirfenidone detection. Our method was validated by a MALDI drug imaging approach of in vivo treated mouse tissue resulting in corresponding findings, indicating the spotting method as an appropriate approach to determine the matrix of choice. The present study shows the accordance between the detection of ex vivo spotted drugs and in vivo administered drugs by MALDI-TOF and MALDI-FT-ICR imaging, which has not been demonstrated so far. Our data suggest the ex vivo tissue spotting method as an easy and reliable model to optimise MALDI imaging measurements and to predict drug detection in tissue sections derived from treated mice prior to the recruitment of laboratory animals, which helps to save animals, time and costs.

Adipocyte plasma membrane–associated protein (APMAP) has been described as an adipogenic factor in 3T3-L1 cells with unknown biochemical function; we therefore aimed to investigate the physiologic function of APMAP in vivo. We generated Apmap-knockout mice and challenged them with an obesogenic diet to investigate their metabolic phenotype. We identified a novel truncated adipocyte-specific isoform of APMAP in mice that is produced by alternative transcription. Mice lacking the full-length APMAP protein, the only isoform that is expressed in humans, have an improved metabolic phenotype upon diet-induced obesity, indicated by enhanced insulin sensitivity, preserved glucose tolerance, increased respiratory exchange ratio, decreased inflammatory marker gene expression, and reduced adipocyte size. At the molecular level, APMAP interacts with the extracellular collagen cross-linking matrix proteins lysyl oxidase–like 1 and 3. On a high-fat diet, the expression of lysyl oxidase–like 1 and 3 is strongly decreased in Apmap-knockout mice, paralleled by reduced expression of profibrotic collagens and total collagen content in epididymal white adipose tissue, indicating decreased fibrotic potential. Together, our data suggest that APMAP is a novel regulator of extracellular matrix components, and establish that APMAP is a potential target to mitigate obesity-associated insulin resistance.—Pessentheiner, A. R., Huber, K., Pelzmann, H. J., Prokesch, A., Radner, F. P. W., Wolinski, H., Lindroos-Christensen, J., Hoefler, G., Rülicke, T., Birner-Gruenberger, R., Bilban, M., Bogner-Strauss, J. G. APMAP interacts with lysyl oxidase–like proteins, and disruption of Apmap leads to beneficial visceral adipose tissue expansion.

Background Molecular MRI is becoming increasingly important for preclinical research. Validation of targeted gadolinium probes in tissue however has been cumbersome up to now. Novel methodology to assess gadolinium distribution in tissue after in vivo application is therefore needed. Purpose To establish combined Magnetic Resonance Imaging (MRI) and Mass Spectrometry Imaging (MSI) for improved detection and quantification of Gadofluorine P deposition in scar formation and myocardial remodeling. Materials and methods Animal studies were performed according to institutionally approved protocols. Myocardial infarction was induced by permanent ligation of the left ascending artery (LAD) in C57BL/6J mice. MRI was performed at 7T at 1 week and 6 weeks after myocardial infarction. Gadofluorine P was used for dynamic T1 mapping of extracellular matrix synthesis during myocardial healing and compared to Gd-DTPA. After in vivo imaging contrast agent concentration as well as distribution in tissue were validated and quantified by spatially resolved Matrix-Assisted Laser Desorption Ionization (MALDI) MSI and Laser Ablation – Inductively Coupled Plasma – Mass Spectrometry (LA-ICP-MS) imaging. Results Both Gadofluorine P enhancement as well as local tissue content in the myocardial scar were highest at 15 minutes post injection. R1 values increased from 1 to 6 weeks after MI (1.62 s−1 vs 2.68 s−1, p = 0.059) paralleled by an increase in Gadofluorine P concentration in the infarct from 0.019 mM at 1 week to 0.028 mM at 6 weeks (p = 0.048), whereas Gd-DTPA enhancement showed no differences (3.95 s−1 vs 3.47 s−1, p = 0.701). MALDI-MSI results were corroborated by elemental LA-ICP-MS of Gadolinium in healthy and infarcted myocardium. Histology confirmed increased extracellular matrix synthesis at 6 weeks compared to 1 week. Conclusion Adding quantitative MSI to MR imaging enables a quantitative validation of Gadofluorine P distribution in the heart after MI for molecular imaging.

Summary: The new Austrian Waste Management Act 2002 reforms the definition of waste; the law governing professional waste collection and treatment agencies; and the law governing waste treatment installations; and establishes legislation that is consistent with Community law. This new legislation aims to restrict room within which the Austrian federal provinces may regulate waste management by adopting nine different state acts. This article outlines the major innovations of the Waste Management Act 2002 and compares the Act with previous laws.

Gadolinium(III)-based contrast agents improve the sensitivity and specificity of magnetic resonance imaging (MRI), especially when targeted contrast agents are applied. Because of nonlinear correlation between the contrast agent concentration in tissue and the MRI signal obtained in vivo, quantification of certain biological or pathophysiological processes by MRI remains a challenge. Up to now, no technology has been able to provide a spatially resolved quantification of MRI agents directly within the tissue, which would allow a more precise verification of in vivo imaging results. MALDI imaging mass spectrometry for spatially resolved in situ quantification of gadolinium(III) agents, in correlation to in vivo MRI, were evaluated. Enhanced kinetics of Gadofluorine M were determined dynamically over time in a mouse model of myocardial infarction. MALDI imaging was able to corroborate the in vivo imaging MRI signals and enabled in situ quantification of the gadolinium probe with high spatial resolution.

Most methods currently available for the analysis of chromatin in vivo rely on a priori knowledge of putative chromatin components or their posttranslational modification state. The isolation of defined native chromosomal regions provides an attractive alternative to obtain a largely unbiased molecular description of chromatin. Here, we describe a strategy combining site-specific recombination at the chromosome with an efficient tandem affinity purification protocol to isolate a single-copy gene locus from the yeast Saccharomyces cerevisiae. The method allows robust enrichment of a targeted chromatin domain, making it amenable to compositional, structural, and biochemical analyses. This technique appears to be suitable to obtain a detailed description of chromatin composition and specific posttranslational histone modification state at virtually any genomic locus in yeast.

Most methods currently available for the analysis of chromatin in vivo rely on a priori knowledge of putative chromatin components or their posttranslational modification state. The isolation of defined native chromosomal regions provides an attractive alternative to obtain a largely unbiased molecular description of chromatin. Here, we describe a strategy combining site-specific recombination at the chromosome with an efficient tandem affinity purification protocol to isolate a single-copy gene locus from the yeast Saccharomyces cerevisiae. The method allows robust enrichment of a targeted chromatin domain, making it amenable to compositional, structural, and biochemical analyses. This technique appears to be suitable to obtain a detailed description of chromatin composition and specific posttranslational histone modification state at virtually any genomic locus in yeast.

During severe or chronic hepatic injury, biliary epithelial cells (BECs) undergo rapid activation into proliferating progenitors, a crucial step required to establish a regenerative process known as ductular reaction (DR). While DR is a hallmark of chronic liver diseases, including advanced stages of non-alcoholic fatty liver disease (NAFLD), the early events underlying BEC activation are largely unknown. Here, we demonstrate that BECs readily accumulate lipids during high-fat diet feeding in mice and upon fatty acid treatment in BEC-derived organoids. Lipid overload induces metabolic rewiring to support the conversion of adult cholangiocytes into reactive BECs. Mechanistically, we found that lipid overload activates the E2F transcription factors in BECs, which drive cell cycle progression while promoting glycolytic metabolism. These findings demonstrate that fat overload is sufficient to reprogram BECs into progenitor cells in the early stages of NAFLD and provide new insights into the mechanistic basis of this process, revealing unexpected connections between lipid metabolism, stemness, and regeneration.