Stratification of hypertension and SARS-CoV-2 infection by quantitative NMR spectroscopy of human blood serum

Quantitative Blood Serum IVDr NMR Spectroscopy in Clinical Metabolomics of Cancer, Neurodegeneration, and Internal Medicine

Despite more than two decades of metabolomics having joined the "omics" scenery, to date only a few novel blood metabolite biomarkers have found their way into the clinic. This is changing now by massive large-scale population metabolic phenotyping for both healthy and disease cohorts. Here, nuclear magnetic resonance (NMR) spectroscopy is a method of choice, as typical blood serum markers can be easily quantified and by knowledge of precise reference concentrations, more and more NMR-amenable biomarkers are established, moving NMR from research to clinical application. Besides customized approaches, to date two major commercial platforms have evolved based on either 600 MHz (14.1 Tesla) or 500 MHz (11.7 Tesla) high-field NMR systems. This chapter provides an introduction into the field of quantitative in vitro diagnostics research (IVDr) NMR at 600 MHz and its application within clinical research of cancer, neurodegeneration, and internal medicine.

Postprandial Effects of Four Test Meals Containing Wholegrain Rye or Refined Wheat Foods on Circulating Incretins, Ghrelin, Glucose, and Inflammatory Markers

BACKGROUND

High intake of whole grains has consistently been associated with reduced risk of obesity, coronary artery disease, and type 2 diabetes. Dietary interventions have shown beneficial metabolic effects of whole grains, but the metabolic response varies with different types of cereals.

OBJECTIVES

We evaluate the metabolic effects of substituting refined wheat with wholegrain rye foods within a complex diet, examining the day-long postprandial response of glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), ghrelin, glucose, and inflammatory biomarkers in individuals with overweight and obesity.

METHODS

Twenty-nine healthy adults with body mass index of 32 ± 9 kg/m2 were randomly assigned to 3 intervention days, separated by 1-wk washout. Participants adhered to a hypocaloric diet rich in wholegrain rye for 1 intervention and refined wheat for the second intervention and were randomly assigned to either diet for the third intervention with continuous blood sampling.

RESULTS

No differences in GIP, GLP-1, or ghrelin levels were found between the diets when measured throughout the whole intervention day. GIP total area under the curve after the rye-based lunch was 31% (P < 0.05) lower compared with the wheat-based lunch, and ghrelin concentrations were 29% (P < 0.05) lower after the rye-based dinner. Baseline Homeostatic Model Assessment for Insulin Resistance-adjusted model showed 61% (P = 0.015) lower whole-day GLP-1 and 40% (P = 0.03) lower GIP after the rye-based diet. Day-long glucose incremental area under the curve was 30% (P < 0.001) lower after the rye-based diet, and glycemic variability was measured as SD reduced (-0.13 mmol/L, P = 0.04). The rye-based diet compared with refined wheat induced higher glycoprotein N-acetylation A, as measured by z-scores (0.36, P = 0.014).

CONCLUSIONS

Overall, no day-long differences in gut hormone levels were observed, but the wholegrain rye-based compared with refined wheat-based dinner showed lower postprandial ghrelin concentrations. The rye-based diet improved day-long glycemic control in individuals with overweight and obesity. Observations of diet-induced inflammation after whole-grain rye intake warrant further investigation.

TRIAL REGISTRATION NUMBER

This study was registered at Clinical Trials Registry of clinicaltrials.gov (NCT05004584): https://clinicaltrials.gov/study/NCT05004584?locStr=Gothenburg,%20Sweden&country=Sweden&state=V%C3%A4stra%20G%C3%B6taland%20County&city=Gothenburg&distance=50&term=appetite&aggFilters=status:com&rank=1.

Cholesterol and Cholesterol-Lowering Medications in COVID-19-An Unresolved Matter

Infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause coronavirus disease 2019 (COVID-19), a disease with very heterogeneous symptoms. Dyslipidaemia is prevalent in at least 20% of Europeans, and dyslipidaemia before SARS-CoV-2 infection increases the risk for severe COVID-19 and mortality by 139%. Many reports described reduced serum cholesterol levels in virus-infected patients, in particular in those with severe disease. The liver is the major organ for lipid homeostasis and hepatic dysfunction appears to occur in one in five patients infected with SARS-CoV-2. Thus, SARS-CoV-2 infection, COVID-19 disease severity and liver injury may be related to impaired cholesterol homeostasis. These observations prompted efforts to assess the therapeutic opportunities of cholesterol-lowering medications to reduce COVID-19 severity. The majority of studies implicate statins to have beneficial effects on disease severity and outcome in COVID-19. Proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies have also shown potential to protect against COVID-19. This review describes the relationship between systemic cholesterol levels, liver injury and COVID-19 disease severity. The potential effects of statins and PCSK9 in COVID-19 are summarised. Finally, the relationship between cholesterol and lung function, the first organ to be affected by SARS-CoV-2, is described.

Rapid and Self-Administrable Capillary Blood Microsampling Demonstrates Statistical Equivalence with Standard Venous Collections in NMR-Based Lipoprotein Analysis

We investigated plasma and serum blood derivatives from capillary blood microsamples (500 μL, MiniCollect tubes) and corresponding venous blood (10 mL vacutainers). Samples from 20 healthy participants were analyzed by 1H NMR, and 112 lipoprotein subfraction parameters; 3 supramolecular phospholipid composite (SPC) parameters from SPC1, SPC2, and SPC3 subfractions; 2 N-acetyl signals from α-1-acid glycoprotein (Glyc), GlycA, and GlycB; and 3 calculated parameters, SPC (total), SPC3/SPC2, and Glyc (total) were assessed. Using linear regression between capillary and venous collection sites, we explained that agreement (Adj. R2 ≥ 0.8, p < 0.001) was witnessed for 86% of plasma parameters (103/120) and 88% of serum parameters (106/120), indicating that capillary lipoprotein, SPC, and Glyc concentrations follow changes in venous concentrations. These results indicate that capillary blood microsamples are suitable for sampling in remote areas and for high-frequency longitudinal sampling of the majority of lipoproteins, SPCs, and Glycs.

The Accumulation of Phenyllactic Acid Impairs Host Glutamine Metabolism and Inhibits African Swine Fever Virus Replication: A Novel Target for the Development of Anti-ASFV Drugs

African swine fever (ASF) is a highly contagious and hemorrhagic disease caused by infection with the African swine fever virus (ASFV), resulting in a mortality rate of up to 100%. Currently, there are no effective treatments and commercially available vaccines for ASF. Therefore, it is crucial to identify biochemicals derived from host cells that can impede ASFV replication, with the aim of preventing and controlling ASF. The ASFV is an acellular organism that promotes self-replication by hijacking the metabolic machinery and biochemical resources of host cells. ASFV specifically alters the utilization of glucose and glutamine, which are the primary metabolic sources in mammalian cells. This study aimed to investigate the impact of glucose and glutamine metabolic dynamics on the rate of ASFV replication. Our findings demonstrate that ASFV infection favors using glutamine as a metabolic fuel to facilitate self-replication. ASFV replication can be substantially inhibited by blocking glutamine metabolism. The metabolomics analysis of the host cell after late-stage ASFV infection revealed a significant disruption of normal glutamine metabolic pathways due to the abundant expression of PLA (phenyllactic acid). Pretreatment with PLA also inhibited ASFV proliferation and glutamine consumption following infection. The metabolomic analysis also showed that PLA pretreatment greatly slowed down the metabolism of amino acids and nucleotides that depend on glutamine. The depletion of these building blocks directly hindered the replication of ASFV by decreasing the biosynthetic precursors produced during the replication of ASFV's progeny virus. These findings provide valuable insight into the possibility of pursuing the development of antiviral drugs against ASFV that selectively target metabolic pathways.

Longitudinal NMR-Based Metabolomics Study Reveals How Hospitalized COVID-19 Patients Recover: Evidence of Dyslipidemia and Energy Metabolism Dysregulation

Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), can manifest as long-term symptoms in multiple organ systems, including respiratory, cardiovascular, neurological, and metabolic systems. In patients with severe COVID-19, immune dysregulation is significant, and the relationship between metabolic regulation and immune response is of great interest in determining the pathophysiological mechanisms. We aimed to characterize the metabolomic footprint of recovering severe COVID-19 patients at three consecutive timepoints and compare metabolite levels to controls. Our findings add proof of dysregulated amino acid metabolism in the acute phase and dyslipidemia, glycoprotein level alterations, and energy metabolism disturbances in severe COVID-19 patients 3-4 months post-hospitalization.