New methodology to obtain High Resolution aliased HSQC

Simultaneous acquisition of two 2D HSQC spectra with different 13C spectral widths . Pau Nolis, Kumar Motiram-Corral, Míriam Pérez-Trujillo and TeodorParella.

https://doi.org/10.1016/j.jmr.2019.01.004A

ABSTRACT:

A time-efficient NMR strategy that involves the interleaved acquisition of two 2D HSQC spectra having different spectral widths in the indirect 13C dimension is presented. We show how the two equivalent coherence transfer pathways involved in sensitivity-enhanced HSQC experiments are managed selectively and detected separately in different FID periods within the same scan. The feasibility of this new SADA-HSQC (Spectral Aliasing in Dually Acquired HSQC) technique is demonstrated by recording simultaneously two complementary datasets, conventional and highly-resolved spectral-aliased 2D HSQC spectra, in a single NMR experiment. Combining the information from both datasets, accurate chemical shift determination and excellent signal dispersion is achieved in a unique measurement using only few t1 increments.

Prenatal cerebral and cardiac metabolic changes in a rabbit model of fetal growth restriction

Simões, Rui V., Miquel E. Cabañas, Carla Loreiro, Miriam Illa, Fatima Crispi & Eduard Gratacós. 2018. Assessment of prenatal cerebral and cardiac metabolic changes in a rabbit model of fetal growth restriction based on 13C-labelled substrate infusions and ex vivo multinuclear HRMAS. PLOS ONE 13(12). e0208784. DOI: 10.1371/journal.pone.0208784

Background: We have used a previously reported rabbit model of fetal growth restriction (FGR), reproducing perinatal neurodevelopmental and cardiovascular impairments, to investigate the main relative changes in cerebral and cardiac metabolism of term FGR fetuses during nutrient infusion.

Methods: FGR was induced in 9 pregnant New Zealand rabbits at 25 days of gestation: one horn used as FGR, by partial ligation of uteroplacental vessels, and the contralateral as control (appropriate for gestation age, AGA). At 30 days of gestation, fasted mothers under anesthesia were infused i.v. with 1-13C-glucose (4 mothers), 2-13C-acetate (3 mothers), or not infused (2 mothers). Fetal brain and heart samples were quickly harvested and frozen down. Brain cortex and heart apex regions from 30 fetuses were studied ex vivo by HRMAS at 4°C, acquiring multinuclear 1D and 2D spectra. The data were processed, quantified by peak deconvolution or integration, and normalized to sample weight.

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Job offer for the INSPiRE-MED project

We are recruiting an Early Stage Researcher to work on the implementation of high-resolution MRSI methods in a pre-clinical scanner as part of the INSPiRE-MED European project.

We seek a highly motivated and qualified individual as Early Stage Researcher for a three-year applied research project. The successful candidate will contribute to the development of advanced biomedical research tools in the field of Magnetic Resonance Spectroscopy and Imaging, and its application to the clinical day-to-day practice.

Project description: This position is one of the 15 ESR positions of the INSPiRE-MED European Training Network, which focuses on the development of Magnetic Resonance Spectroscopy (MRS) and MR Spectroscopic Imaging (MRSI) combined with Positron Emission Tomography (PET), enhanced by machine learning techniques.

The main aim of the PhD project (ESR4) will be the implementation of innovative high spatial resolution MRSI methods in a pre-clinical scanner. The ultimate goal will be the validation of optimal methods for improving imaging biomarker development of brain tumour in longitudinal studies of therapy response in mouse glioblastoma models. The project will involve evaluation of the methodology performance limits, repeatability and reproducibility compared to stock Bruker Biospec MRSI sequences and the assessment of speed-up MRSI methods in a 7-Tesla pre-clinical scanner.

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INSPiRE-MED project awarded to GABRMN & SeRMN

Integrating Magnetic Resonance Spectroscopy and Multimodal Imaging for Research and Education in MEDicine (INSPiRE-MED) is an European research project awarded in the call H2020-MSCA-ITN-2018, of the MSCA-ITN-ETN – European Training Networks, to a consortium of partners including the GABRMN and SeRMN at UAB. The project is coordinated by Prof. Dominique Sappey-Marinier, of the Université Lyon-1 Claude-Bernard, Lyon, France. The scientist-in-charge at UAB will be Prof. Carles Arús (GABRMN), and Silvia Lope-Piedrafita (SeRMN) and Miquel Cabañas (SeRMN) will participate as senior scientists in the project.

Starting 1st of January 2019, the INSPiRE-MED Initial Training Network will investigate the theoretical and practical aspects of in vivo Magnetic Resonance Spectroscopy (MRS) and Spectroscopic Imaging (MRSI) with applications in oncology and neurology.

The network will host 15 Early Stage Researchers in the field of biomedical imaging, particularly in the field of Magnetic Resonance Spectroscopy (MRS) and MR Spectroscopic Imaging (MRSI) combined with Positron Emission Tomography (PET) and enhanced by machine learning techniques. The research training is supervised by a consortium of 12 academic partners with an established collaborative track record in R&D and 9 industrial partners from the broad and competitive preclinical and clinical imaging sector.

The main research topic to be carried at UAB —in close collaboration with other project members— will be the implementation of innovative high spatial resolution MRSI methods in a pre-clinical scanner. The ultimate goal will be the validation of optimal methods for improving imaging biomarker development of brain tumour in longitudinal studies of therapy response in mouse glioblastoma models.

Continue reading INSPiRE-MED project awarded to GABRMN & SeRMN

Beneficial effects of Uric Acid Treatment After Stroke in Hypertensive Rats

Jiménez-Xarrié, Elena, Belén Pérez, Ana Paula Dantas, Lídia Puertas-Umbert, Joan Martí-Fabregas, Ángel Chamorro, Anna Maria Planas, Elisabet Vila, Francesc Jiménez-Altayó. 2018. Uric Acid Treatment After Stroke Prevents Long-Term Middle Cerebral Artery Remodelling and Attenuates Brain Damage in Spontaneously Hypertensive Rats. Translational Stroke Research. DOI: 10.1007/s12975-018-0661-8

Hypertension is the most important modifiable risk factor for stroke and is associated with poorer post-stroke outcomes. The antioxidant uric acid is protective in experimental normotensive ischaemic stroke. However, it is unknown whether this treatment exerts long-term protection in hypertension. The authors aimed to evaluate the impact of transient intraluminal middle cerebral artery (MCA) occlusion (90min)/reperfusion (1–15 days) on brain and vascular damage progression in adult and spontaneously hypertensive rats (SHR) treated with uric acid. Ischaemic brain damage was assessed longitudinally with magnetic resonance imaging at the Nuclear Magnetic Resonance Service of the Universitat Autònoma de Barcelona.

In SHR rats, more severe brain damage and poorer neurofunctional outcomes were coupled to higher cortical cerebral blood flow at the onset of reperfusion, a transient increase in oxidative stress and long-lasting stroke-induced MCA hypertrophic remodelling. Thus, stroke promotes larger brain and vascular damage in hypertensive rats that persists for long-time. Uric acid administered during early reperfusion attenuated short- and long-term brain injuries in both normotensive and hypertensive rats, an effect that was associated with abolishment of the acute oxidative stress response and prevention of stroke-induced long lasting MCA remodelling in hypertension. These results suggest that uric acid might be an effective strategy to improve stroke outcomes in hypertensive subjects.

New time-efficient approach in TOCSY and HSQC experiments

Nolis, P., Motiram-Corral, K., Pérez-Trujillo, M., & Parella, T. (2018). Interleaved Dual NMR Acquisition of Equivalent Transfer Pathways in TOCSY and HSQC experiments. ChemPhysChem. DOI: 10.1002/cphc.20180103

A dual NMR data acquisition strategy to handle and detect two active equivalent transfer pathways is presented and discussed. We illustrate the power of this time-efficient approach by collecting two different 2D spectra simultaneously in a single experiment: (i) TOCSY or HSQC-TOCSY spectra with different mixing times, (ii) F2-13C-coupled and decoupled HSQC spectra, (iii) conventional and pureshift HSQC spectra, and (iv) complementary HSQC and HSQC-TOCSY spectra.

Saving time using different NMR concepts

Nolis, P., Motiram-Corral, K., Pérez-Trujillo, M., & Parella, T. (2018). Broadband homodecoupled Time-Shared 1H-13C and 1H-15N HSQC experiments. Journal Magnetic Resonance. DOI: 10.1016/j.jmr.2018.11.005

The concepts of pure-shift NMR and time-shared NMR are merged in a single NMR experiment. A 13C/15N time-shared version of the real-time BIRD-based broadband homodecoupled HSQC experiment is described. This time-efficient approach affords simultaneously 1H-13C and 1H-15N pure-shift HSQC spectra in a single acquisition, while achieving substantial gains in both sensitivity and spectral resolution. We also present a related 13C/15N-F2-coupled homodecoupled version of the CLIP-HSQC experiment for the simultaneous measurement of 1JCH and 1JNH from the simplified doublets observed along the direct dimension. Finally, a novel J-resolved HSQC experiment has been designed for the simple and automated determination of both 1JCH/1JNH from a 2D J-resolved spectrum.

4 experiments in 1 shot

Motiram-Corral, K., Pérez-Trujillo, M., Nolis, P., & Parella, T. (2018). Implementing one-shot multiple-FID acquisition into homonuclear and heteronuclear NMR experiments. Chemical Communications. DOI: 10.1039/C8CC08065H

Multiple-FID acquisition (MFA) within the same scan is applied to acquire simultaneously multiple 2D spectra from a single NMR experiment. A discussion on the incorporation of the MFA strategy in several homonuclear and heteronuclear 2D pulse sequences is presented. As a proof of concept, a set of novel COSY, TOCSY and HMBC experiments are reported as a time-efficient solution in small-molecule NMR spectroscopy.

Pulse programs & Datasets

MRI/MRS in treated Alzheimer mice

Differential effects of apoE and apoJ mimetic peptides on the action of an anti-Aβ scFv in 3xTg-AD mice” by L. Montoliu-Gaya, J. Güell-Bosch, G. Esquerda-Canals, A.R. Roda, G. Serra-Mir, S. Lope-Piedrafita, J.L. Sánchez-Quesada, S. Villegas. Biochem Pharmacol. 2018, 155:380-392. DOI: 10.1016/j.bcp.2018.07.012.

Anti-Aβ immunotherapy has emerged as a promising approach to treat Alzheimer’s disease (AD). The single-chain variable fragment scFv-h3D6 is an anti-Aβ antibody fragment that lacks the Fc region, which is associated with the induction of microglial reactivity by the full-length monoclonal antibody bapineuzumab. ScFv-h3D6 was previously shown to restore the levels of apolipoprotein E (apoE) and apolipoprotein J (apoJ) in a tripletransgenic- AD (3xTg-AD) mouse model. Since apoE and apoJ play an important role in the development of AD, we aimed to study the in vivo effect of the combined therapy of scFv-h3D6 with apoE and apoJ mimetic peptides (MPs).

Magnetic Resonance Imaging showed a general tendency of the different treatments to protect against the reduction in brain volume. This protection was further suggested by MRS, since all the treatments tended to recover the levels of Ala, which is involved in the alanine-glucose cycle, and NAA, which is a marker for cell viability. All the treatments in the present work recovered the IL-33 levels, and apoE-MP showed a potent anti-inflammatory effect in terms of glial activation that was decreased in the presence of scFv-h3D6, whereas the combination of apoJ-MP and scFvh3D6 was not detrimental. Moreover, the endogenous apoE and apoJ levels were decreased by scFvh3D6, but the MPs induced a simultaneous increase in both apolipoproteins, which reflects a coordinated expression between them.

Exopolysaccharides from olive brines could reduce the adhesion of ETEC K88 to intestinal epithelial cells

“Exopolysaccharides from olive brines could reduce the adhesion of ETEC K88 to intestinal epithelial cells”  by Y. Zhu, G. Gonzalez-Ortiz, R. Jiménez-Díaz, M. Pérez-Trujillo, T. Parella, P. Lopez-Colom, SM Martín-Orúe. Food & function, 2018, 9, 3884-3894. DOI: https://doi.org/10.1039/c8fo00690c

This study aims to explore the biological functions of the isolated exopolysaccharides (EPSs) produced during the industrial fermentation of olives against enterotoxigenic E. coli (ETEC) K88. Exopolysaccharides were isolated from five industrial fermenters. Analysis of their monosaccharide composition by GLC revealed that the main components were glucose (27%–50%) and galactose (23%–33%) followed by rhamnose (4–23%) and arabinose (6–17%). The 1H NMR spectrum showed a very similar profile between samples, and a more in-depth analysis revealed the presence of an α-pyranose in the form of α-D-Glcp-(1→) and two different α-furanoses, with chemicals shift values, suggesting the presence of α-D-Glcf and α-D-Galf. Miniaturized in vitro tests demonstrated the ability of EPS samples to attach specifically to ETEC K88 (P < 0.05) with variable intensities. The competition test did not show the ability to block the ETEC K88 adhesion to IPEC-J2 cells; however, in the displacement test, all EPS samples were shown to effectively remove the pathogens attached to the cells (P < 0.01). These results suggest that the EPSs produced during the fermentation of table green olives could interfere with the attachment of opportunistic pathogens onto the intestinal epithelial cells. This would open the possibility of novel functional properties for this traditional Mediterranean fermented food and for the isolated EPSs as candidates for nutraceutics to be used in human and/or animal diets in the prevention and treatment of ETEC diarrhoea.