Methodological Developments for Metabolic NMR Spectroscopy from Cultured Cells to Tissue Extracts: Achievements, Progress and Pitfalls

Abstract

This is a broad overview and critical review of a particular group of closely related ex vivo and in vitro metabolic NMR spectroscopic methods. The scope of interest comprises studies of cultured cells and excised tissue, either intact or after physicochemical extraction of metabolites. Our detailed discussion includes pitfalls that have led to erroneous statements in the published literature, some of which may cause serious problems in metabolic and biological interpretation of results. To cover a wide range of work from relevant research areas, we consider not only the most recent achievements in the field, but also techniques that proved to be valid and successful in the past, although they may not have generated a very significant number of papers more recently. Thus, this comparative review also aims at providing background information useful for judiciously choosing between the metabolic ex vivo/in vitro NMR methods presented. Finally, the methods of interest are discussed in the context of, and in relation to, other metabolic analysis protocols such as HR-MAS and cell perfusion NMR, as well as the mass spectrometry approach.

Designing a quality assurance process for quality control of nuclear magnetic resonance metabolomics studies of human blood

“…Further studies may consider that the "spin noise tuning optimum" (SNTO) and sample tube selection have been shown to improve sensitivity and resolution for NMR spectra. 12,13 The present study used traditional 5-mm NMR tubes and did not calibrate the spectra collection instrument to the SNTO. The aim of the present study was to demonstrate the importance of QA/QC procedures and present one basic method for QC that did not include tuning and specificity enhancements.…”

“…The present study of QA/QC, however, may only be considered an example of how to approach this process; more precise QA/QC procedures for a specific potential clinical application will need to be designed and tested individually. Further studies may consider that the “spin noise tuning optimum” (SNTO) and sample tube selection have been shown to improve sensitivity and resolution for NMR spectra 12,13 . The present study used traditional 5‐mm NMR tubes and did not calibrate the spectra collection instrument to the SNTO.…”

Compound-Specific 1D 1H NMR Pulse Sequence Selection for Metabolomics Analyses

“…One-dimensional (1D) 1 H NMR-based metabolomics studies utilize different methods to analyze metabolites in biological samples of plants, animals, humans, and marine organisms. These samples may include serum; plasma; urine; cell extracts; intestinal content; tissue; − plant seeds, flesh, leaves, stems, and roots; − and corals, algae, and jellyfish. − In high-resolution NMR spectroscopy, the focus is on the relational quantification of metabolites and estimation of metabolite concentrations in response to some perturbation. Metabolomics is used to observe relative quantitative changes and find out biomarkers. − Higher-dimensional NMR like pulse sequences of two-dimensional (2D) NMR is also used in metabolomics. − However, compared to a matching 1 H NMR data set, 2D NMR data-processing time is significantly shorter because the signal overlap is not a significant issue and deconvolution is not necessary …”

Therapeutic potential of bone marrow mesenchymal stem cells in cyclophosphamide-induced infertility

“…MSC treatment has been shown to have antioxidant properties in a variety of disease types as MSCs can immediately alleviate oxidative stress-associated damage. Because oxidative stress is linked to cell damage, inflammation, and metabolic dysfunction, it is a crucial pathophysiological process in many disorders ( Emwas et al, 2019 ; Chandra et al, 2021 ; Lutz and Bernard, 2022 ). Oxidative stress, along with redox instability, is caused by chemical elements found in all living cells that perform comparable activities.…”