scholarly journals Differences in metabolomic profiles of male db/db and s/s, leptin receptor mutant mice

2012 ◽  
Vol 44 (6) ◽  
pp. 374-381 ◽  
Author(s):  
Nadia Saadat ◽  
Heidi B. IglayReger ◽  
Martin G. Myers ◽  
Peter Bodary ◽  
Smiti V. Gupta
Keyword(s):  
Mouse Models ◽  
Intracellular Signaling ◽  
Leptin Receptor ◽  
Deuterium Oxide ◽  
Active Form ◽  
Mutant Mice ◽  
Metabolic Effects ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Signaling Domain

Leptin, a protein hormone secreted by adipose tissue, plays an important role in regulating energy metabolism and the immune response. Despite similar extremes of adiposity, mutant mouse models, db/db, carrying spontaneous deletion of the active form of the leptin receptor (LEPR-B) intracellular signaling domain, and the s/s, carrying a specific point mutation leading to a dysfunctional LEPR-B-STAT3 signaling pathway, have been shown to have robust differences in glucose homeostasis. This suggests specific effects of leptin, mediated by non-STAT3 LEPR-B pathways. Differences in the LEPR-B signaling pathways in these two LEPR-B mutant mice models are expected to lead to differences in metabolism. In the current study, the hypothesized differences in metabolism were investigated using the metabolomics approach. Proton nuclear magnetic resonance spectroscopy (1HNMR) was conducted on 24 h urine samples in deuterium oxide using a 500 MHz instrument at 25°C. Principle Component Analysis showed clear separation of urine NMR spectra between the groups ( P < 0.05). The CHENOMX metabolite database was used to identify several metabolites that differed between the two mouse models. Significant differences ( P < 0.05) in metabolites associated with the glycine, serine, and homocysteine metabolism were observed. The results demonstrate that the metabolomic profile of db/db and s/s mice are fundamentally different and provide insight into the unique metabolic effects of leptin exerted through non-STAT3 LEPR-B pathways.

scholarly journals Inactivation of Signal Transducer and Activator of Transcription 3 in Proopiomelanocortin (Pomc) Neurons Causes Decreased Pomc Expression, Mild Obesity, and Defects in Compensatory Refeeding

Endocrinology ◽  
2007 ◽  
Vol 148 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Allison W. Xu ◽  
Linda Ste-Marie ◽  
Christopher B. Kaelin ◽  
Gregory S. Barsh
Keyword(s):  
Intracellular Signaling ◽  
Leptin Receptor ◽  
Neuronal Response ◽  
Fold Increase ◽  
Total Body Weight ◽  
Mutant Mice ◽  
Signal Transducer ◽  
Energy Status ◽  
Total Body ◽  
Transcription 3

Leptin is an adipocyte-derived hormone that signals body energy status to the brain by acting on multiple neuronal subgroups in the hypothalamus, including those that express proopiomelanocortin (Pomc) and agouti-related protein (Agrp). Signal transducer and activator of transcription 3 (Stat3) is an important intracellular signaling molecule activated by leptin, and previous studies have shown that mice carrying a mutated leptin receptor that abolished Stat3 binding are grossly obese. To determine the extent to which Stat3 signaling in Pomc neurons was responsible for these effects, we constructed Pomc-specific Stat3 mutants using a Cre recombinase transgene driven by the Pomc promoter. We find that Pomc expression is diminished in the mutant mice, suggesting that Stat3 is required for Pomc transcription. Pomc-specific Stat3 female mutant mice exhibit a 2-fold increase in fat pad mass but only a slight increase in total body weight. Mutant mice remain responsive to leptin-induced hypophagia and are not hypersensitive to a high-fat diet; however, mutant mice fail to mount a normal compensatory refeeding response. These results demonstrate a requirement for Stat3 in transcriptional regulation of Pomc but indicate that this circuit is only one of several components that underlie the neuronal response to leptin and the role of Stat3 in that response.

scholarly journals Differences in molecular phenotype in mouse and human hypertrophic cardiomyopathy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Styliani Vakrou ◽  
Yamin Liu ◽  
Li Zhu ◽  
Gabriela V. Greenland ◽  
Bahadir Simsek ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hypertrophic Cardiomyopathy ◽  
Mouse Models ◽  
Pathway Analysis ◽  
Intracellular Signaling ◽  
Mutant Mice ◽  
Disease Stage ◽  
Specific Gene ◽  
Cardiac Phenotype ◽  
Established Disease

AbstractHypertrophic cardiomyopathy (HCM) is characterized by phenotypic heterogeneity. We investigated the molecular basis of the cardiac phenotype in two mouse models at established disease stage (mouse-HCM), and human myectomy tissue (human-HCM). We analyzed the transcriptome in 2 mouse models with non-obstructive HCM (R403Q-MyHC, R92W-TnT)/littermate-control hearts at 24 weeks of age, and in myectomy tissue of patients with obstructive HCM/control hearts (GSE36961, GSE36946). Additionally, we examined myocyte redox, cardiac mitochondrial DNA copy number (mtDNA-CN), mt-respiration, mt-ROS generation/scavenging and mt-Ca2+ handling in mice. We identified distinct allele-specific gene expression in mouse-HCM, and marked differences between mouse-HCM and human-HCM. Only two genes (CASQ1, GPT1) were similarly dysregulated in both mutant mice and human-HCM. No signaling pathway or transcription factor was predicted to be similarly dysregulated (by Ingenuity Pathway Analysis) in both mutant mice and human-HCM. Losartan was a predicted therapy only in TnT-mutant mice. KEGG pathway analysis revealed enrichment for several metabolic pathways, but only pyruvate metabolism was enriched in both mutant mice and human-HCM. Both mutant mouse myocytes demonstrated evidence of an oxidized redox environment. Mitochondrial complex I RCR was lower in both mutant mice compared to controls. MyHC-mutant mice had similar mtDNA-CN and mt-Ca2+ handling, but TnT-mutant mice exhibited lower mtDNA-CN and impaired mt-Ca2+ handling, compared to littermate-controls. Molecular profiling reveals differences in gene expression, transcriptional regulation, intracellular signaling and mt-number/function in 2 mouse models at established disease stage. Further studies are needed to confirm differences in gene expression between mouse and human-HCM, and to examine whether cardiac phenotype, genotype and/or species differences underlie the divergence in molecular profiles.

Dynamics of Cryoprotectant Permeation in Porcine Heart Valve Leaflets

2003 ◽  
Vol 12 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Jonathan R. T. Lakey ◽  
Lisa M. H. Helms ◽  
Gabrielle Moser ◽  
Bruce Lix ◽  
Carolyn M. Slupsky ◽  
...  
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Isolated Heart ◽  
Deuterium Oxide ◽  
Tissue Bank ◽  
Quantitative Measure ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Temperature Dependent ◽  
Improved Methods

Valve replacement is a common cardiovascular procedure for the treatment of a variety of congenital and acquired defects. Many surgical programs rely on cryopreserved heart valves from regional tissue bank programs to meet clinical demands. Current cryopreservation strategies for heart valves are empirically derived. The aim of this study was to use proton nuclear magnetic resonance spectroscopy (NMR) to monitor changes in cryoprotectant concentration in isolated heart valve leaflets. Porcine aortic valves were locally obtained, freshly isolated, and allowed to equilibrate at various experimental temperatures (22°C, 10°C, 4°C) for 1 h prior to immersion in 1 M Me2SO solution. At defined intervals (0, 0.25, 0.5, 1, 2, 6, and 24 h) the valves were removed from the Me2SO and the leaflets were rapidly dissected and equilibrated in deuterium oxide (D2O). Using previously described techniques the Me2SO concentration in the heart valve leaflets was determined by NMR and the diffusion coefficient was calculated as a function of time and temperature. Heart valve leaflets were fully equilibrated with Me2SO after approximately 2 h of exposure at 22°C while equilibrium was not reached >6 h or more at 10°C and 4°C. These results indicate that that permeation of Me2SO in heart valves is strongly temperature dependent. Furthermore, this study provides a quantitative measure of Me2SO permeation and cryoprotectant at equilibration in heart valve leaflets. The clinical applications of these findings may help to optimize the balance between the protective and toxic effects of cryoprotectants and lead to improved methods of preservation of heart valves.

scholarly journals A Serum Metabolomics Classifier Derived from Elderly Patients with Metastatic Colorectal Cancer Predicts Relapse in the Adjuvant Setting

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2762
Author(s):  
Samantha Di Donato ◽  
Alessia Vignoli ◽  
Chiara Biagioni ◽  
Luca Malorni ◽  
Elena Mori ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Risk Stratification ◽  
Elderly Patients ◽  
Metastatic Colorectal Cancer ◽  
Early Stage ◽  
Prospective Trial ◽  
Proton Nuclear Magnetic Resonance ◽  
P Value ◽  
Resonance Spectroscopy ◽  
Metabolomic Fingerprinting

Adjuvant treatment for patients with early stage colorectal cancer (eCRC) is currently based on suboptimal risk stratification, especially for elderly patients. Metabolomics may improve the identification of patients with residual micrometastases after surgery. In this retrospective study, we hypothesized that metabolomic fingerprinting could improve risk stratification in patients with eCRC. Serum samples obtained after surgery from 94 elderly patients with eCRC (65 relapse free and 29 relapsed, after 5-years median follow up), and from 75 elderly patients with metastatic colorectal cancer (mCRC) obtained before a new line of chemotherapy, were retrospectively analyzed via proton nuclear magnetic resonance spectroscopy. The prognostic role of metabolomics in patients with eCRC was assessed using Kaplan–Meier curves. PCA-CA-kNN could discriminate the metabolomic fingerprint of patients with relapse-free eCRC and mCRC (70.0% accuracy using NOESY spectra). This model was used to classify the samples of patients with relapsed eCRC: 69% of eCRC patients with relapse were predicted as metastatic. The metabolomic classification was strongly associated with prognosis (p-value 0.0005, HR 3.64), independently of tumor stage. In conclusion, metabolomics could be an innovative tool to refine risk stratification in elderly patients with eCRC. Based on these results, a prospective trial aimed at improving risk stratification by metabolomic fingerprinting (LIBIMET) is ongoing.

scholarly journals Occurrence of Cis-11,12-Methylene-Hexadecanoic Acid in the Red Alga Solieria pacifica (Yamada) Yoshida

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2286
Author(s):  
Gwang-Woo Kim ◽  
Jae-Man Sim ◽  
Yutaka Itabashi ◽  
Min-Jeong Jung ◽  
Joon-Young Jun
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Red Alga ◽  
Proton Nuclear Magnetic Resonance ◽  
Animal Origin ◽  
Monoenoic Acid ◽  
Resonance Spectroscopy ◽  
Hexadecenoic Acid ◽  
Cyclopropane Fatty Acid ◽  
Hexadecanoic Acid

Fatty acids in marine algae have attracted the attention of natural chemists because of their biological activity. The fatty acid compositions of the Solieriaceae families (Rhodophyceae, Gaigartinales) provide interesting information that unusual cyclic fatty acids have been occasionally found. A survey was conducted to profile the characteristic fatty acid composition of the red alga Solieria pacifica (Yamada) Yoshida using gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy (IR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). In S. pacifica, two cyclopentyl fatty acids, 11-cyclopentylundecanoic acid (7.0%), and 13-cyclopentyltridecanoic acid (4.9%), and a cyclopropane fatty acid, cis-11,12-methylene-hexadecanoic acid (7.9%) contributed significantly to the overall fatty acid profile. In particular, this cyclopropane fatty acid has been primarily found in bacteria, rumen microorganisms or foods of animal origin, and has not previously been found in any other algae. In addition, this alga contains a significant amount of the monoenoic acid cis-11-hexadecenoic acid (9.0%). Therefore, cis-11,12-methylene-hexadecanoic acid in S. pacifica was likely produced by methylene addition to cis-11-hexadecenoic acid.

scholarly journals Neuroendocrine Neoplasms: Identification of Novel Metabolic Circuits of Potential Diagnostic Utility

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 374
Author(s):  
Beatriz Jiménez ◽  
Mei Ran Abellona U ◽  
Panagiotis Drymousis ◽  
Michael Kyriakides ◽  
Ashley K. Clift ◽  
...  
Keyword(s):  
1H Nmr ◽  
Cancer Metabolism ◽  
Proton Nuclear Magnetic Resonance ◽  
Neuroendocrine Neoplasms ◽  
Resonance Spectroscopy ◽  
Diagnostic Utility ◽  
Signalling Molecules ◽  
Prognostic Accuracy ◽  
Diagnostic Potential ◽  
Healthy Control

The incidence of neuroendocrine neoplasms (NEN) is increasing, but established biomarkers have poor diagnostic and prognostic accuracy. Here, we aim to define the systemic metabolic consequences of NEN and to establish the diagnostic utility of proton nuclear magnetic resonance spectroscopy (1H-NMR) for NEN in a prospective cohort of patients through a single-centre, prospective controlled observational study. Urine samples of 34 treatment-naïve NEN patients (median age: 59.3 years, range: 36–85): 18 had pancreatic (Pan) NEN, of which seven were functioning; 16 had small bowel (SB) NEN; 20 age- and sex-matched healthy control individuals were analysed using a 600 MHz Bruker 1H-NMR spectrometer. Orthogonal partial-least-squares-discriminant analysis models were able to discriminate both PanNEN and SBNEN patients from healthy control (Healthy vs. PanNEN: AUC = 0.90, Healthy vs. SBNEN: AUC = 0.90). Secondary metabolites of tryptophan, such as trigonelline and a niacin-related metabolite were also identified to be universally decreased in NEN patients, while upstream metabolites, such as kynurenine, were elevated in SBNEN. Hippurate, a gut-derived metabolite, was reduced in all patients, whereas other gut microbial co-metabolites, trimethylamine-N-oxide, 4-hydroxyphenylacetate and phenylacetylglutamine, were elevated in those with SBNEN. These findings suggest the existence of a new systems-based neuroendocrine circuit, regulated in part by cancer metabolism, neuroendocrine signalling molecules and gut microbial co-metabolism. Metabonomic profiling of NEN has diagnostic potential and could be used for discovering biomarkers for these tumours. These preliminary data require confirmation in a larger cohort.

Effects of ethanol on gastric epithelial cell phospholipid dynamics and cellular function

1987 ◽  
Vol 252 (2) ◽  
pp. G237-G243
Author(s):  
R. E. Bailey ◽  
R. A. Levine ◽  
J. Nandi ◽  
E. H. Schwartzel ◽  
D. H. Beach ◽  
...  
Keyword(s):  
Membrane Structure ◽  
Lipid Membrane ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Dependent Manner ◽  
Chloride Uptake ◽  
Peak Intensity ◽  
Low Concentrations ◽  
Resonance Band ◽  
Dose Dependent

The lipid profile of isolated gastric superficial epithelial cells (SEC) was evaluated by proton nuclear magnetic resonance spectroscopy (1H-NMR). The most conspicuous resonance band in SEC spectra was due to the protons of +N(CH3)3 groups of phosphatidylcholine and, to a lesser degree, other phospholipid derivatives, on the basis of their chemical shift and addition of purified phospholipids. NMR of cell lysates and phospholipid extracts of SEC in deutero-chloroform provided further spectral resolution of these components. Phospholipase or ethanol treatments of SEC produced membrane disorganization reflected as increased peak intensity of the phospholipid signals. In addition, ethanol, in a dose-dependent manner, attenuated paranitrophenyl phosphatase activity, which correlated with inhibition of total and ouabain-sensitive 86Rubidium chloride uptake by SEC. This study suggests that NMR used in conjunction with other biochemical techniques can monitor SEC membrane structure-function relationships. NMR is a potentially powerful noninvasive probe to show changes in lipid membrane organization induced by low concentrations of ethanol (1%) and may indicate an early sign of "cytotoxicity" in intact SEC.

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