Inflammatory glycoproteins in cardiometabolic disorders, autoimmune diseases and cancer

Molecularly imprinted polymer-based SERS sensing of transferrin in human serum

Specific detection of glycoproteins such as transferrin (TRF) related to neurological diseases, hepatoma and other diseases always plays an important role in the field of disease diagnosis. We designed an antibody-free immunoassay sensing method based on molecularly imprinted polymers (MIPs) formed by the polymerization of multiple functional monomers for the sensitive and selective detection of TRF in human serum. In the sandwich surface-enhanced Raman spectroscopy (SERS) sensor, the TRF-oriented magnetic MIP nanoparticles (Fe3O4@SiO2-MIPs) served as capture units to specifically recognize TRF and 4-mercaptophenylboronic acid-functionalized gold nanorods (MPBA-Au NRs) served as SERS probes to label the targets. In order to achieve stronger interaction between the recognition cavities of the prepared MIPs and the different amino acid fragments that make up TRF, Fe3O4@SiO2-MIPs were obtained through polycondensation reactions between more silylating reagents, enhancing the specific recognition of the entire TRF protein and achieving high IF. This sensing method exhibited a good linear response to TRF within the TRF concentration range of 0.01 ng mL-1 to 1 mg mL-1 (R2 = 0.9974), and the LOD was 0.00407 ng mL-1 (S/N = 3). The good stability, reproducibility and specificity of the resulting MIP based SERS sensor were demonstrated. The determination of TRF in human serum confirmed the feasibility of the method in practical applications.

GlycA and CRP Are Genetically Correlated: Insight into the Genetic Architecture of Inflammageing

Inflammageing is a condition of perpetual low-grade inflammation induced by ageing. Inflammageing may be predicted by the C-reactive protein (CRP) or by a recently described biomarker which measures N-glycosylated side chains of the carbohydrate component of several acute-phase proteins known as GlycA. The objective of this study was to examine in depth the genetic relationships between CRP and GlycA as well as between each of them and other selected cytokines, which may shed light on the mechanisms of inflammageing. Using the Olink 96 Inflammation panel, data on inflammatory mediators for 1518 twins from the TwinsUK dataset were acquired. Summary statistics for genome-wide association studies for several cytokines as well as CRP and GlycA were collected from public sources. Extensive genetic correlation analyses, colocalization and genetic enrichment analyses were carried out to detect the shared genetic architecture between GlycA and CRP. Mendelian randomization was carried out to assess potential causal relationships. GlycA predicted examined cytokines with a magnitude twice as great as that of CRP. GlycA and CRP were significantly genetically correlated (Rg = 0.4397 ± 0.0854, p-value = 2.60 × 10-7). No evidence of a causal relationship between GlycA and CRP, or between these two biomarkers and the cytokines assessed was obtained. However, the aforementioned relationships were explained well by horizontal pleiotropy. Five exonic genetic variants annotated to five genes explain the shared genetic architecture observed between GlycA and CRP: IL6R, GCKR, MLXIPL, SERPINA1, and MAP1A. GlycA and CRP possess a shared genetic architecture, but the relationship between them appears to be modest, which may imply the promotion of differing inflammatory pathways. GlycA appears to be a more robust predictor of cytokines compared to CRP.

Establishment of a differential diagnosis method and an online prediction platform for AOSD and sepsis based on gradient boosting decision trees algorithm

OBJECTIVE

The differential diagnosis between adult-onset Still's disease (AOSD) and sepsis has always been a challenge. In this study, a machine learning model for differential diagnosis of AOSD and sepsis was developed and an online platform was developed to facilitate the clinical application of the model.

METHODS

All data were collected from 42 AOSD patients and 50 sepsis patients admitted to Affiliated Hospital of Xuzhou Medical University from December 2018 to December 2021. In addition, 5 AOSD patients and 10 sepsis patients diagnosed in our hospital after March 2022 were collected for external validation. All models were built using the scikit-learn library (version 1.0.2) in Python (version 3.9.7), and feature selection was performed using the SHAP (Shapley Additive exPlanation) package developed in Python.

RESULTS

The results showed that the gradient boosting decision tree(GBDT) optimization model based on arthralgia, ferritin × lymphocyte count, white blood cell count, ferritin × platelet count, and α1-acid glycoprotein/creatine kinase could well identify AOSD and sepsis. The training set interaction test (AUC: 0.9916, ACC: 0.9457, Sens: 0.9556, Spec: 0.9578) and the external validation also achieved satisfactory results (AUC: 0.9800, ACC: 0.9333, Sens: 0.8000, Spec: 1.000). We named this discrimination method AIADSS (AI-assisted discrimination of Still's disease and Sepsis) and created an online service platform for practical operation, the website is http://cppdd.cn/STILL1/ .

CONCLUSION

We created a method for the identification of AOSD and sepsis based on machine learning. This method can provide a reference for clinicians to formulate the next diagnosis and treatment plan.

Functional classification of DDOST variants of uncertain clinical significance in congenital disorders of glycosylation

Congenital disorders of glycosylation (CDG) are rare genetic disorders with a spectrum of clinical manifestations caused by abnormal N-glycosylation of secreted and cell surface proteins. Over 130 genes are implicated and next generation sequencing further identifies potential disease drivers in affected individuals. However, functional testing of these variants is challenging, making it difficult to distinguish pathogenic from non-pathogenic events. Using proximity labelling, we identified OST48 as a protein that transiently interacts with lysyl oxidase (LOX), a secreted enzyme that cross-links the fibrous extracellular matrix. OST48 is a non-catalytic component of the oligosaccharyltransferase (OST) complex, which transfers glycans to substrate proteins. OST48 is encoded by DDOST, and 43 variants of DDOST are described in CDG patients, of which 34 are classified as variants of uncertain clinical significance (VUS). We developed an assay based on LOX N-glycosylation that confirmed two previously characterised DDOST variants as pathogenic. Notably, 39 of the 41 remaining variants did not have impaired activity, but we demonstrated that p.S243F and p.E286del were functionally impaired, consistent with a role in driving CDG in those patients. Thus, we describe a rapid assay for functional testing of clinically relevant CDG variants to complement genome sequencing and support clinical diagnosis of affected individuals.

GlycA as a Novel Biomarker of Systemic Inflammation in Hypothyroidism

Background: GlycA is a novel glycoprotein biomarker of systemic inflammation and cardiovascular risk. Our objective was to assess the levels of GlycA in individuals with hypothyroidism. We also explored whether levothyroxine (LT4)-treated patients had different levels of GlycA, with attention to thyrotropin (TSH) levels. Methods: We performed a cross-sectional analysis, using baseline data from the ELSA-Brasil cohort study. We included only participants with serum TSH and GlycA levels measurements, using magnetic resonance spectroscopy (n = 4745). We excluded individuals with endogenous hyperthyroidism and those using drugs impacting thyroid function. Participants not taking LT4 and whose serum TSH was 0.4-4.0 mIU/L were classified as euthyroid (EU) and those with elevated TSH as undiagnosed hypothyroidism (UH). For those on LT4 (n = 345), adequacy of treatment was defined as TSH within the reference range. Those with TSH <0.4 mIU/L were considered over-treated (OT), and those >4.0 mIU/L, under-treated (UT). Both (UT+OT) were considered inadequately treated (IT). Group comparisons were performed by Kruskal-Wallis, adjusted Chi-square, and the post hoc Dunn test. Additional subgroup analysis were performed in patients with circulating thyroperoxidase antibodies (TPO-Ab+). Respective multivariable analyses were performed to evaluate the relationship between thyroid-related variables and GlycA levels (Generalized Linear Model), as well as an abnormal GlycA (>400 μmol/L; Logistic Binary Regression). Results: The prevalence rate of UH was 9.8% (467/4745) and, among those on LT4, only 61.7% (213/345) were adequately treated (AT). GlycA levels were higher in IT in comparison to EU (429 vs. 410 μmol/L, p < 0.01) but did not differ between UH (413 μmol/L) and euthyroidism. However, the subgroup analysis of those TPO-Ab+ showed that not only those with IT, but also those with UH, had higher levels of GlycA in comparison to euthyroidism (423 and 424 vs. 402 μmol/L, p = 0.04). This association between higher levels of GlycA and IT was maintained even in multivariable analysis (odds ratio 1.53, confidence interval 1.03 to 2.31) Lower levels of GlycA were detected in AT (405 μmol/L,) compared with OT (432 μmol/L, 0.04) and UT (423 μmol/L, p = 0.02). Conclusions: Patients with IT, both OT and UT, had higher GlycA levels, which may be associated with low-grade systemic inflammation and, possibly, increased cardiovascular risk.

Detection of N‑glycoprotein associated with IgA nephropathy in urine as a potential diagnostic biomarker using glycosylated proteomic analysis

The aim of the present study was to elucidate the potential diagnostic value of urinary N-glycoprotein in patients with IgA nephropathy (IgAN) using mass spectrometry (MS). All procedures were performed between June 2021 and June 2023 at Guangan People's Hospital (Guangan, China). Fresh mid-morning fasting midstream urine samples were collected from a total of 30 patients with IgAN and 30 sex- and age-matched healthy volunteers. Data acquired from 6 participants are available through ProteomeXchange with the identifier PXD041151. By comparison between the IgAN group (n=3) and healthy controls (n=3) and selection criteria of P<0.05 and |log fold-change|>2, a total of 11 upregulated and 22 downregulated glycoproteins in patients with IgAN were identified. The results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggested that glycoproteins are involved in various functions, such as the regulation of cell growth, cell adhesion, cellular component organization and protein binding, as well as multiple pathways, including p53, Notch and mTOR signaling pathways. The urine levels of afamin were further measured by ELISA in a validation cohort to assess the diagnostic performance of the single indicator model. In conclusion, MS-based proteomics of urinary glycoproteins may be an alternative option for diagnosing patients with IgAN. Biomarkers of IgAN may include, but are not limited to, CCL25, PD-L1, HLA-DRB1, IL7RD and WDR82. In addition, the levels of urinary AFM indicators are of diagnostic value for IgAN.

Genetic control of N-glycosylation of human blood plasma proteins

Glycosylation is an important protein modification, which influences the physical and chemical properties as well as biological function of these proteins. Large-scale population studies have shown that the levels of various plasma protein N-glycans are associated with many multifactorial human diseases. Observed associations between protein glycosylation levels and human diseases have led to the conclusion that N-glycans can be considered a potential source of biomarkers and therapeutic targets. Although biochemical pathways of glycosylation are well studied, the understanding of the mechanisms underlying general and tissue-specific regulation of these biochemical reactions in vivo is limited. This complicates both the interpretation of the observed associations between protein glycosylation levels and human diseases, and the development of glycan-based biomarkers and therapeutics. By the beginning of the 2010s, high-throughput methods of N-glycome profiling had become available, allowing research into the genetic control of N-glycosylation using quantitative genetics methods, including genome-wide association studies (GWAS). Application of these methods has made it possible to find previously unknown regulators of N-glycosylation and expanded the understanding of the role of N-glycans in the control of multifactorial diseases and human complex traits. The present review considers the current knowledge of the genetic control of variability in the levels of N-glycosylation of plasma proteins in human populations. It briefly describes the most popular physical-chemical methods of N-glycome profiling and the databases that contain genes involved in the biosynthesis of N-glycans. It also reviews the results of studies of environmental and genetic factors contributing to the variability of N-glycans as well as the mapping results of the genomic loci of N-glycans by GWAS. The results of functional in vitro and in silico studies are described. The review summarizes the current progress in human glycogenomics and suggests possible directions for further research.

Plasma levels of GlycA, a pro-inflammatory glycoprotein biomarker, associate with an increased risk of microvascular complications in patients with type 2 diabetes (Zodiac-62)

PURPOSE

GlycA, a pro-inflammatory glycoprotein biomarker, associates with newly developed type 2 diabetes (T2D). We determined the association of plasma GlycA with the development of microvascular complications in patients with established T2D.

METHODS

Plasma GlycA was measured by nuclear magnetic resonance spectrometry in T2D patients without microvascular complications at baseline (n = 145) participating in a longitudinal cohort study of primary care-treated T2D patients (Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) study). Associations of GlycA with incident microvascular complications including nephropathy, retinopathy, and neuropathy, were determined by Cox proportional hazards regression analyses.

RESULTS

After a median follow-up of 3.2 (interquartile range [IQR]: 2.9-3.4) years, 49 patients (33.8%) developed one or more microvascular complications. Median GlycA levels were 453.5 (IQR: 402.0-512.8) μmol/l. GlycA was associated with incident microvascular complications (hazard ratio [HR] per 1-SD increment: 1.28 [95% confidence interval [CI]:1.00-1.63], P = 0.048]), even after adjustment for potential confounders and high-sensitive C-reactive protein (hs-CRP), HR 1.79 [95%CI:1.25-2.57], P = 0.001). In contrast, hs-CRP levels were not significantly associated with the risk of developing microvascular complications (P = 0.792).

CONCLUSION

Higher plasma GlycA is associated with an increased risk of developing microvascular complications in T2D patients. Altered N-glycan branching associated with acute-phase reactive proteins may represent a preferred biomarker of systemic low-grade inflammation in predicting diabetic complications.

Effect of behavioral weight-loss program on biomarkers of cardiometabolic disease risk: Heart Health Study randomized trial

OBJECTIVE

This study aimed to determine whether novel biomarkers of cardiometabolic health improve in response to a 12-month behavioral weight-loss intervention and to compare benefits of diet alone with diet plus physical activity for these biomarkers.

METHODS

Participants (N = 374) were randomized to either diet alone (DIET), diet plus 150 min/wk of prescribed moderate-intensity physical activity (DIET + PA150), or diet plus 250 min/wk of prescribed moderate-intensity physical activity (DIET + PA250). Biomarker concentrations were determined using nuclear magnetic resonance spectroscopy. Mixed models assessed for a time effect, group effect, or group by time interaction.

RESULTS

All groups significantly improved body weight (time: p < 0.0001), Lipoprotein Insulin Resistance Index score (time: p < 0.0001), Diabetes Risk Index score (time: p < 0.0001), branched-chain amino acid concentration (time: p < 0.0001), and GlycA concentration (time: p < 0.0001), with no group effect or group by time interactions.

CONCLUSIONS

All intervention groups prompted a notable beneficial change among biomarkers of insulin resistance and cardiometabolic health. However, the addition of at least moderate-intensity physical activity to a diet-only intervention did not provide any additional benefit. These findings highlight that an average weight loss of approximately 10% profoundly impacts biomarkers of insulin resistance and cardiometabolic disease in adults with overweight or obesity.

Thiol-ene-based microfluidic chips for glycopeptide enrichment and online digestion of inflammation-related proteins osteopontin and immunoglobulin G

Proteins, and more specifically glycoproteins, have been widely used as biomarkers, e.g., to monitor disease states. Bottom-up approaches based on mass spectrometry (MS) are techniques commonly utilized in glycoproteomics, involving protein digestion and glycopeptide enrichment. Here, a dual function polymeric thiol-ene-based microfluidic chip (TE microchip) was applied for the analysis of the proteins osteopontin (OPN) and immunoglobulin G (IgG), which have important roles in autoimmune diseases, in inflammatory diseases, and in coronavirus disease 2019 (COVID-19). TE microchips with larger internal surface features immobilized with trypsin were successfully utilized for OPN digestion, providing rapid and efficient digestion with a residence time of a few seconds. Furthermore, TE microchips surface-modified with ascorbic acid linker (TEA microchip) have been successfully utilized for IgG glycopeptide enrichment. To illustrate the use of the chips for more complex samples, they were applied to enrich IgG glycopeptides from human serum samples with antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The dual functional TE microchips could provide high throughput for online protein digestion and glycopeptide enrichment, showing great promise for future extended applications in proteomics and the study of related diseases.

B4GALT1 as a New Biomarker of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a disease characterized by progressive scarring of the lung that involves the pulmonary interstitium. The disease may rapidly progress, leading to respiratory failure, and the long-term survival is poor. There are no accurate biomarkers available so far. Our aim was to evaluate the expression of the B4GALT1 in patients with IPF. Analysis of B4GALT1 gene expression was performed in silico on two gene sets, retrieved from the Gene Expression Omnibus database. Expression of B4GALT1 was then evaluated, both at the mRNA and protein levels, on lung specimens obtained from lung biopsies of 4 IPF patients, on one IPF-derived human primary cell and on 11 cases of IPF associated with cancer. In silico re-analysis demonstrated that the B4GALT1 gene was overexpressed in patients and human cell cultures with IPF (p = 0.03). Network analysis demonstrated that B4GALT1 upregulation was correlated with genes belonging to the EMT pathway (p = 0.01). The overexpression of B4GALT1 was observed, both at mRNA and protein levels, in lung biopsies of our four IPF patients and in the IPF-derived human primary cell, in other fibrotic non-lung tissues, and in IPF associated with cancer. In conclusion, our results indicate that B4GALT1 is overexpressed in IPF and could represent a novel marker of this disease.

Evidence of a genetically driven metabolomic signature in actively inflamed Crohn's disease

Crohn's disease (CD) is characterised by chronic inflammation. We aimed to identify a relationship between plasma inflammatory metabolomic signature and genomic data in CD using blood plasma metabolic profiles. Proton NMR spectroscopy were achieved for 228 paediatric CD patients. Regression (OPLS) modelling and machine learning (ML) approaches were independently applied to establish the metabolic inflammatory signature, which was correlated against gene-level pathogenicity scores generated for all patients and functional enrichment was analysed. OPLS modelling of metabolomic spectra from unfasted patients revealed distinctive shifts in plasma metabolites corresponding to regions of the spectrum assigned to N-acetyl glycoprotein, glycerol and phenylalanine that were highly correlated (R² = 0.62) with C-reactive protein levels. The same metabolomic signature was independently identified using ML to predict patient inflammation status. Correlation of the individual peaks comprising this metabolomic signature of inflammation with pathogenic burden across 15,854 unselected genes identified significant enrichment for genes functioning within 'intrinsic component of membrane' (p = 0.003) and 'inflammatory bowel disease (IBD)' (p = 0.003). The seven genes contributing IBD enrichment are critical regulators of pro-inflammatory signaling. Overall, a metabolomic signature of inflammation can be detected from blood plasma in CD. This signal is correlated with pathogenic mutation in pro-inflammatory immune response genes.

Risk of Malignancy in Patients with Asthma-COPD Overlap Compared to Patients with COPD without Asthma

Chronic inflammation such as asthma may lead to higher risks of malignancy, which may be inhibited by anti-inflammatory medicine such as inhaled corticosteroids (ICS). The aim of this study was to evaluate if patients with asthma-Chronic Obstructive Pulmonary Disease (COPD) overlap have a higher risk of malignancy than patients with COPD without asthma, and, secondarily, if inhaled corticosteroids modify such a risk in a nationwide multi-center retrospective cohort study of Danish COPD-outpatients with or without asthma. Patients with asthma-COPD overlap were propensity score matched (PSM) 1:2 to patients with COPD without asthma. The endpoint was cancer diagnosis within 2 years. Patients were stratified depending on prior malignancy within 5 years. ICS was explored as a possible risk modifier. We included 50,897 outpatients with COPD; 88% without prior malignancy and 20% with asthma. In the PSM cohorts, 26,003 patients without prior malignancy and 3331 patients with prior malignancy were analyzed. There was no association between asthma-COPD overlap and cancer with hazard ratio (HR) = 0.92, CI = 0.78–1.08, p = 0.31 (no prior malignancy) and HR = 1.04, CI = 0.85–1.26, and p = 0.74 (prior malignancy) as compared to patients with COPD without asthma. ICS did not seem to modify the risk of cancer. In conclusion, in our study, asthma-COPD overlap was not associated with an increased risk of cancer events.

Comparison of self-sampling blood collection for N-glycosylation analysis

Objective

Self-sampling of capillary blood provides easier sample collection, handling, and shipping compared to more invasive blood sampling via venepuncture. Recently, other means of capillary blood collection were introduced to the market, such as Neoteryx sticks and Noviplex cards. We tested the comparability of these two self-sampling methods, alongside dried blood spots (DBS), with plasma acquired from venepunctured blood in N-glycoprofiling of total proteins. We have also tested the intra-day repeatability of the three mentioned self-sampling methods. Capillary blood collection with Neoteryx, Noviplex and DBS was done following the manufacturers’ instructions and N-glycoprofiling of released, fluorescently labelled N-glycans was performed with ultra-performance liquid chromatography.

Results

Comparability with plasma was assessed by calculating the relative deviance, which was 0.674 for DBS, 0.092 for Neoteryx sticks, and 0.069 for Noviplex cards. In repeatability testing, similar results were obtained, with Noviplex cards and Neoteryx sticks performing substantially better than DBS (CVs = 4.831% and 7.098%, compared to 14.305%, respectively). Our preliminary study on the use of Neoteryx and Noviplex self-sampling devices in glycoanalysis demonstrates their satisfactory performance in both the comparability and repeatability testing, however, they should be further tested in larger collaborations and cohorts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05958-9.

Triglyceride-Rich Lipoproteins and Glycoprotein A and B Assessed by 1H-NMR in Metabolic-Associated Fatty Liver Disease

High plasma triglyceride (TG) levels and chronic inflammation are important factors related to metabolic-associated fatty liver disease in patients at cardiovascular risk. Using nuclear magnetic resonance (1H-NMR), we aimed to study the triglyceride-rich lipoprotein (TRL) and acute-phase glycoprotein profiles of a cohort of patients with metabolic disease and their relationship with fatty liver. Plasma samples of 280 patients (type 2 diabetes, 81.1%; obesity, 63.3%; and metabolic syndrome, 91.8%) from the University Hospital Lipid Unit were collected for the measurement of small, medium and large TRL particle numbers and sizes and glycoprotein profiles (Glyc-A and Glyc-B) by 1H-NMR. Liver function parameters, including the fatty liver index (FLI) and fibrosis-4 (FIB-4) score, were assessed. Hepatic echography assessment was performed in 100 patients, and they were followed up for 10 years. TRL particle concentrations showed a strong positive association with Glyc-A and Glyc-B (ρ=0.895 and ρ=0.654, p<0.001, respectively) and with the liver function-related proteins ALT ρ=0.293, p<0.001), AST (ρ=0.318, p<0.001) and GGT (ρ=0.284, p<0.001). Likewise, TRL concentrations showed a positive association with FLI (ρ=0.425, p<0.001) but not with FIB-4. During the follow-up period of 10 years, 18 new cases of steatosis were observed among 64 patients who were disease-free at baseline. Baseline TRL particle numbers and glycoprotein levels were associated with the new development of metabolic-associated fatty liver disease (MAFLD) (AUC=0.692, p=0.018 and AUC=0.669, p=0.037, respectively). Overall, our results indicated that TRL number and acute-phase glycoproteins measured by 1H-NMR could be potential biomarkers of the development of hepatic steatosis in patients at metabolic risk.

Activity of the glycosidases β-galactosidase, α-l-fucosidase, β-N-acetyl-hexosaminidase, and sialidase in uterine tissues from female dogs in diestrus with and without pyometra

This study aimed to compare the activity of selected glycosidases (β-galactosidase, α-l-fucosidase, β-N-acetyl-hexosaminidase, and sialidase) in homogenates of uterine tissues obtained from female dogs with and without pyometra. In addition, it examined the availability of substrates for these glycosidases in the homogenates. The study was carried out on female dogs undergoing ovariohysterectomy for pyometra (n = 10) and clinically healthy dogs (n = 10) undergoing elective spaying. The activity of β-galactosidase, α-l-fucosidase, and β-N-acetyl-hexosaminidase was analyzed using a spectrofluorometer and that of sialidase using a colorimetric method. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis with Alcian Blue (AB) and Periodic Acid-Schiff (PAS) staining was performed to determine the presence of substrates for these glycosidases in the homogenates of uterine tissues. The results revealed that the activity of all the examined glycosidases was significantly higher (P < 0.05) in the uterine tissues isolated from dogs with pyometra in comparison to healthy dogs. The electrophoretic patterns of the selected samples showed several proteins, which contained different sugar moieties stained by AB and PAS and the profiles differed significantly between the pyometra group and the healthy group. Densitometric analysis of AB staining showed patterns between 233 and 148, 86 and 55, and 43 and 20 kDa, which differed markedly in sugar content between the examined groups of animals. Similarly, PAS staining analysis revealed patterns of different molecular weights, between 233 and 117 and between 55 and 32 kDa, which also differed in sugar content. These findings suggest that canine pyometra is accompanied by the increase in the activity of selected glycosidases in the uterus. This could potentially modify the glycan structures of uterine glycoproteins and in result their biological functions. Further studies are needed to elucidate the potential role of the increased activity of glycosidases in the pathogenesis of this disease.

Calorie restriction improves lipid-related emerging cardiometabolic risk factors in healthy adults without obesity: Distinct influences of BMI and sex from CALERIE™ a multicentre, phase 2, randomised controlled trial

BACKGROUND

For many cardiovascular risk factors there is no lower limit to which further reduction will result in decreased disease risk; this includes values within ranges considered normal for healthy adults. This seems to be true for new emerging metabolic risk factors identified by innovative technological advances. Further, there seems to be ever evolving evidence of differential responses to lifestyle interventions by sex and body compositions in the normal range. In this secondary analysis, we had the opportunity to test these principles for newly identified molecular biomarkers of cardiometabolic risk in a young (21-50 years), normal weight healthy population undergoing calorie restriction for two years.

METHODS

The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE™) was a 24-month, multicenter, randomized controlled trial (May 2007-November 2012) in healthy, adults without obesity to evaluate the potential for calorie restriction (CR) to promote anti-aging adaptations, including those associated with disease risk. 218 participants (age 37.9 ± 7.2 years and body mass index (BMI) 25.1 ± 1.7 kg/m², mean±SD) were randomized 2:1 to 24 months of CR (prescribed as 25% reduction from baseline calorie intake) versus ad libitum (AL). Fasting plasma from baseline, 12, and 24 months was used for assessments of lipoproteins, metabolites, and inflammatory markers using nuclear magnetic resonance spectroscopy.

FINDINGS

Averaging 11.9% CR, the CR group had reductions at 12 and 24 months in the cardiovascular disease risk markers, apolipoprotein B and GlycA, and risks for insulin resistance and type 2 diabetes-Lipoprotein Insulin Resistance Index and Diabetes Risk Index (all P_CRvsAL ≤0.0009). Insulin resistance and diabetes risk improvements resulted from CR-induced alterations in lipoproteins, specifically reductions in triglyceride-rich lipoprotein particles and low-density lipoprotein particles, a shift to larger high-density lipoprotein particles (more effective cholesterol transporters), and reductions in branched chain amino acids (BCAAs) (all P_CRvsAL ≤0.004). These CR responses were more pronounced in overweight than normal weight participants and greater in men than women.

INTERPRETATION

In normal to slightly overweight adults without overt risk factors or disease, 12 months of ∼12% CR improved newly identified risk markers for atherosclerotic cardiovascular disease, insulin resistance and type 2 diabetes. These markers suggest that CR improves risks by reducing inflammation and BCAAs and shifting lipoproteins from atherogenic to cholesterol transporting. Additionally, these improvements are greater for men and for those with greater BMIs indicating sex and BMI-influences merit attention in future investigations of lifestyle-mediated improvements in disease risk factors.

FUNDING

The CALERIE™ trial design and implementation were supported by a National Institutes of Health (NIH) U-grant provided to four institutions, the three intervention sites and a coordinating center (U01 AG022132, U01 AG020478, U01 AG020487 U01 AG020480). For this secondary analysis including sample acquisition and processing, data analysis and interpretation, additional funding was provided by the NIH to authors as follows: R01 AG054840 (MO, VBK); R33 AG070455 (KMH, DCP, MB, SBR, CKM, LMR, SKD, CFP, CJR, WEK); P30 DK072476 (CKM, LMR); and U54 GM104940 (CKM, LMR).

Microbiota of Breast Tissue and Its Potential Association with Regional Recurrence of Breast Cancer in Korean Women

Recent studies have reported dysbiosis of the microbiome in breast tissue collected from patients with breast cancer and the association between the microbiota and disease progression. However, the role of the microbiota in breast tissue remains unclear, possibly due to the complexity of breast cancer and various factors, including racial and geographical differences, influencing microbiota in breast tissue. Here, to determine the potential role of microbiota in breast tumor tissue, we analyzed 141 tissue samples based on three different tissue types (tumor, adjacent normal, and lymph node tissues) from the same patients with breast cancer in Korea. The microbiota was not simply distinguishable based on tissue types. However, the microbiota could be divided into two cluster types, even within the same tissue type, and the clinicopathologic factors were differently correlated in the two cluster types. Risk of regional recurrence was also significantly different between the microbiota cluster types (p = 0.014). In predicted function analysis, the pentose and glucuronate interconversions were significantly different between the cluster types (q < 0.001), and Enterococcus was the main genus contributing to these differences (q < 0.01). Results showed that the microbiota of breast tissue could interact with the host and influence the risk of regional recurrence. Although further studies would be recommended to validate our results, this study could expand our understanding on the breast tissue microbiota, and the results might be applied to develop novel prediction methods and treatments for patients with breast cancer.

An Overview of Glycosylation and its Impact on Cardiovascular Health and Disease

The cardiovascular system is a complex and well-organized system in which glycosylation plays a vital role. The heart and vascular wall cells are constituted by an array of specific receptors; most of them are N- glycosylated and mucin-type O-glycosylated. There are also intracellular signaling pathways regulated by different post-translational modifications, including O-GlcNAcylation, which promote adequate responses to extracellular stimuli and signaling transduction. Herein, we provide an overview of N-glycosylation and O-glycosylation, including O-GlcNAcylation, and their role at different levels such as reception of signal, signal transduction, and exogenous molecules or agonists, which stimulate the heart and vascular wall cells with effects in different conditions, like the physiological status, ischemia/reperfusion, exercise, or during low-grade inflammation in diabetes and aging. Furthermore, mutations of glycosyltransferases and receptors are associated with development of cardiovascular diseases. The knowledge on glycosylation and its effects could be considered biochemical markers and might be useful as a therapeutic tool to control cardiovascular diseases.

Glycoprotein Pathways Altered in Frontotemporal Dementia With Autoimmune Disease

Behavioral variant frontotemporal dementia (bvFTD) is a younger onset form of neurodegeneration initiated in the frontal and/or temporal lobes with a slow clinical onset but rapid progression. bvFTD is highly complex biologically with different pathological signatures and genetic variants that can exhibit a spectrum of overlapping clinical manifestations. Although the role of innate immunity has been extensively investigated in bvFTD, the involvement of adaptive immunity in bvFTD pathogenesis is poorly understood. We analyzed blood serum proteomics to identify proteins that are associated with autoimmune disease in bvFTD. Eleven proteins (increased: ATP5B, CALML5, COLEC11, FCGBP, PLEK, PLXND1; decreased: APOB, ATP8B1, FAM20C, LOXL3, TIMD4) were significantly altered in bvFTD with autoimmune disease compared to those without autoimmune disease. The majority of these proteins were enriched for glycoprotein-associated proteins and pathways, suggesting that the glycome is targeted in bvFTD with autoimmune disease.

Pump-Free Microfluidic Device for the Electrochemical Detection of α1-Acid Glycoprotein

α₁-Acid glycoprotein (AGP) is a glycoprotein present in serum, which is associated with the modulation of the immune system in response to stress or injuries, and a biomarker for inflammatory diseases and cancers. Here, we propose a pump-free microfluidic device for the electrochemical determination of AGP. The microfluidic device utilizes capillary-driven flow and a passive mixing system to label the AGP with the Os (VI) complex (an electrochemical tag) inside the main channel, before delivering the products to the electrode surface. Furthermore, thanks to the resulting geometry, all the analytical steps can be carried out inside the device: labeling, washing, and detection by adsorptive transfer stripping square wave voltammetry. The microfluidic device exhibited a linear range from 500 to 2000 mg L^-1 (R² = 0.990) and adequate limit of detection (LOD = 231 mg L^-1). Commercial serum samples were analyzed to demonstrate the success of the method, yielding recoveries around 83%. Due to its simplicity, low sample consumption, low cost, short analysis time, disposability, and portability, the proposed method can serve as a point-of-care/need testing device for AGP.

Sleep and cardiometabolic risk: a cluster analysis of actigraphy-derived sleep profiles in adults and children

STUDY OBJECTIVES

Sleep plays an important role in cardiometabolic health. Although the importance of considering sleep as a multidimensional construct is widely appreciated, studies have largely focused on individual sleep characteristics. The association between actigraphy-derived sleep profiles and cardiometabolic health in healthy adults and children has not been examined.

METHODS

This study used actigraphy-measured sleep data collected between February 2015 and March 2016 in the Child Health CheckPoint study. Participants wore actigraphy monitors (GENEActiv Original, Cambs, UK) on their nondominant wrist for 7 days and sleep characteristics (period, efficiency, timing, and variability) were derived from raw actigraphy data. Actigraphy-derived sleep profiles of 1,043 Australian children aged 11-12 years and 1,337 adults were determined using K-means cluster analysis. The association between cluster membership and biomarkers of cardiometabolic health (blood pressure, body mass index, apolipoproteins, glycoprotein acetyls, composite metabolic syndrome severity score) were assessed using Generalized Estimating Equations, adjusting for geographic clustering, with sex, socioeconomic status, maturity stage (age for adults, pubertal status for children), and season of data collection as covariates.

RESULTS

Four actigraphy-derived sleep profiles were identified in both children and adults: short sleepers, late to bed, long sleepers, and overall good sleepers. The overall good sleeper pattern (characterized by adequate sleep period time, high efficiency, early bedtime, and low day-to-day variability) was associated with better cardiometabolic health in the majority of comparisons (80%).

CONCLUSION

Actigraphy-derived sleep profiles are associated with cardiometabolic health in adults and children. The overall good sleeper pattern is associated with more favorable cardiometabolic health.

Glycoprotein levels and oxidative lung injury in experimental diabetes: effect of oxovanadium(IV) complex based on thiosemicarbazone

Diabetes mellitus (DM) is chronic and metabolic disorder, which is mainly attributed by hyperglycemia. Vanadium salts and their oxo-complexes have been shown to possess insulin-mimetic and anti-diabetic activities in animal models and diabetic patients. The main goal of this study was to investigate the protective effect of oxovanadium(IV) complex based on thiosemicarbazone (VOL) [L: (N(1)-2,4-dihydroxybenzylidene-N-(4)-2-hydroxybenzylidene-S-methyl-isothiosemicarbazidato-oxovanadium(IV)] on glycoprotein components levels and oxidative lung injury of streptozotocin (STZ)-induced diabetic rats. Male Swiss albino rats were separated into four groups. Group I (n = 5): Control (normal) animals, Group II (n = 5): Control animals administered with VOL, Group III (n = 6): STZ-induced diabetic animals, and Group IV (n = 5): STZ-induced diabetic rats treated with VOL. VOL was given to the experimental animals by gavage at a dose of 0.2 mM/kg body weight every day for 12 days. Diabetes was induced by single intraperitoneal injection of STZ (65 mg/kg body weight). On the 12th day, lung tissue samples were taken. Glycoprotein components, advanced oxidation protein products, protein carbonyl, hydroxyproline levels, and prolidase, arginase, xanthine oxidase, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and adenosine deaminase activities significantly increased whereas aryl esterase, paraoxonase-1, carbonic anhydrase, Na⁺/K⁺-ATPase activities remarkably decreased in lung tissue of diabetic rats. Treatment with VOL reversed these effects showing a beneficial effect. The present study shows that VOL has a protective effect against diabetes-induced lung damage as well as on abnormal glycoprotein component levels.

Metabolomics and metabolites in ischemic stroke

Stroke is a major reason for disability and the second highest cause of death in the world. When a patient is admitted to a hospital, it is necessary to identify the type of stroke, and the likelihood for development of a recurrent stroke, vascular dementia, and depression. These factors could be determined using different biomarkers. Metabolomics is a very promising strategy for identification of biomarkers. The advantage of metabolomics, in contrast to other analytical techniques, resides in providing low molecular weight metabolite profiles, rather than individual molecule profiles. Technically, this approach is based on mass spectrometry and nuclear magnetic resonance. Furthermore, variations in metabolite concentrations during brain ischemia could alter the principal neuronal functions. Different markers associated with ischemic stroke in the brain have been identified including those contributing to risk, acute onset, and severity of this pathology. In the brain, experimental studies using the ischemia/reperfusion model (IRI) have shown an impaired energy and amino acid metabolism and confirmed their principal roles. Literature data provide a good basis for identifying markers of ischemic stroke and hemorrhagic stroke and understanding metabolic mechanisms of these diseases. This opens an avenue for the successful use of identified markers along with metabolomics technologies to develop fast and reliable diagnostic tools for ischemic and hemorrhagic stroke.

Association of Circulating Metabolites in Plasma or Serum and Risk of Stroke: Meta-analysis From 7 Prospective Cohorts

OBJECTIVE

To conduct a comprehensive analysis of circulating metabolites and incident stroke in large prospective population-based settings.

METHODS

We investigated the association of metabolites with risk of stroke in 7 prospective cohort studies including 1,791 incident stroke events among 38,797 participants in whom circulating metabolites were measured by nuclear magnetic resonance technology. The relationship between metabolites and stroke was assessed with Cox proportional hazards regression models. The analyses were performed considering all incident stroke events and ischemic and hemorrhagic events separately.

RESULTS

The analyses revealed 10 significant metabolite associations. Amino acid histidine (hazard ratio [HR] per SD 0.90, 95% confidence interval [CI] 0.85, 0.94; p = 4.45 × 10-5), glycolysis-related metabolite pyruvate (HR per SD 1.09, 95% CI 1.04, 1.14; p = 7.45 × 10-4), acute-phase reaction marker glycoprotein acetyls (HR per SD 1.09, 95% CI 1.03, 1.15; p = 1.27 × 10-3), cholesterol in high-density lipoprotein (HDL) 2, and several other lipoprotein particles were associated with risk of stroke. When focused on incident ischemic stroke, a significant association was observed with phenylalanine (HR per SD 1.12, 95% CI 1.05, 1.19; p = 4.13 × 10-4) and total and free cholesterol in large HDL particles.

CONCLUSIONS

We found association of amino acids, glycolysis-related metabolites, acute-phase reaction markers, and several lipoprotein subfractions with the risk of stroke. These findings support the potential of metabolomics to provide new insights into the metabolic changes preceding stroke.

Sleep and cardiometabolic health in children and adults: examining sleep as a component of the 24-h day

STUDY OBJECTIVES

Sleep, physical activity and sedentary time are all known to play a role in cardiometabolic health. Compositional data analysis (CoDA) enables us to examine associations between 24-h use of time and health outcomes.

METHODS

Data were collected in the Child Health CheckPoint study, a one-off national population-cohort study conducted between February 2015 and March 2016. Wrist-worn actigraphy monitors (GENEActiv Original, Cambs, UK) were used to measure activity behaviours (sleep, physical activity and sedentary time) and sleep characteristics (sleep variability, midsleep, efficiency). CoDA was applied to determine the association between 24-h use of time and cardiometabolic risk markers (blood pressure; body mass index; apolipoprotein B/A1; glycoprotein acetyls; and composite metabolic syndrome score). Substitution modelling (one-for-remaining and one-for-one) examined the associations of reallocating sleep time with other activity behaviours.

RESULTS

Data were available for 1073 Australian children aged 11-12 years (50% male) and 1337 adults (13% male). Strong association was found between 24-h use of time and all cardiometabolic health outcomes. Longer sleep was associated with more favourable cardiovascular health. Sleep characteristics other than duration (efficiency, timing, variability) were weakly and inconsistently associated with outcomes. Reallocating time from sleep to moderate-vigorous physical activity (MVPA) had favourable associations with cardiometabolic health, but reallocating from sleep to sedentary time was associated with less favourable cardiometabolic health.

CONCLUSION

The 24-h activity composition is strongly associated with cardiometabolic health in children and adults. Days with more sleep and MVPA are associated with improved cardiometabolic health.

GlycA measured by NMR spectroscopy is associated with disease activity and cardiovascular disease risk in chronic inflammatory diseases

GlycA is a biomarker of systemic inflammation, quantifying both the protein concentrations and glycosylation states of several acute phase proteins. GlycA has been shown to be associated with both subclinical atherosclerosis and with cardiovascular disease (CVD). GlycA levels are higher in acute and chronic inflammation. During ongoing systemic inflammatory processes, GlycA specific acute phase reactants and proteins undergo circulating concentration and glycosylation pattern changes, and these alterations are reflected in the GlycA NMR signal. Additionally, levels associate with ongoing disease severity in individuals with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis thus capturing active inflammation. Furthermore, in these disease states, GlycA is associated with cardiovascular disease (CVD) independent of traditional risk factors including C-reactive protein (CRP). Finally, GlycA levels decrease with exercise, weight loss, and systemic anti-inflammatory agents. Therefore, GlycA appears to be a promising new composite biomarker of active systemic inflammation including assessing CVD risk in patients with inflammatory diseases.

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Patients with chronic inflammatory disorders are at increased risk for cardiovascular diseasenot captured by traditional risk factors.

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GlycA is a biomarker of acute phase reactants by NMR spectroscopy which captures disease activity in human inflammatory diseases.

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GlycA associates with cardiovascular disease and offers a tool to monitor primary disease activity and assess CVD risk in inflammatory diseases.

Dissecting Total Plasma and Protein-Specific Glycosylation Profiles in Congenital Disorders of Glycosylation

Protein N-glycosylation is a multifactorial process involved in many biological processes. A broad range of congenital disorders of glycosylation (CDGs) have been described that feature defects in protein N-glycan biosynthesis. Here, we present insights into the disrupted N-glycosylation of various CDG patients exhibiting defects in the transport of nucleotide sugars, Golgi glycosylation or Golgi trafficking. We studied enzymatically released N-glycans of total plasma proteins and affinity purified immunoglobulin G (IgG) from patients and healthy controls using mass spectrometry (MS). The applied method allowed the differentiation of sialic acid linkage isomers via their derivatization. Furthermore, protein-specific glycan profiles were quantified for transferrin and IgG Fc using electrospray ionization MS of intact proteins and glycopeptides, respectively. Next to the previously described glycomic effects, we report unprecedented sialic linkage-specific effects. Defects in proteins involved in Golgi trafficking (COG5-CDG) and CMP-sialic acid transport (SLC35A1-CDG) resulted in lower levels of sialylated structures on plasma proteins as compared to healthy controls. Findings for these specific CDGs include a more pronounced effect for α2,3-sialylation than for α2,6-sialylation. The diverse abnormalities in glycomic features described in this study reflect the broad range of biological mechanisms that influence protein glycosylation.

Metformin and statin use associate with plasma protein N-glycosylation in people with type 2 diabetes

INTRODUCTION

Recent studies revealed N-glycosylation signatures of type 2 diabetes, inflammation and cardiovascular risk factors. Most people with diabetes use medication to reduce cardiovascular risk. The association of these medications with the plasma N-glycome is largely unknown. We investigated the associations of metformin, statin, ACE inhibitor/angiotensin II receptor blocker (ARB), sulfonylurea (SU) derivatives and insulin use with the total plasma N-glycome in type 2 diabetes.

RESEARCH DESIGN AND METHODS

After enzymatic release from glycoproteins, N-glycans were measured by matrix-assisted laser desorption/ionization mass spectrometry in the DiaGene (n=1815) and Hoorn Diabetes Care System (n=1518) cohorts. Multiple linear regression was used to investigate associations with medication, adjusted for clinical characteristics. Results were meta-analyzed and corrected for multiple comparisons.

RESULTS

Metformin and statins were associated with decreased fucosylation and increased galactosylation and sialylation in glycans unrelated to immunoglobulin G. Bisection was increased within diantennary fucosylated non-sialylated glycans, but decreased within diantennary fucosylated sialylated glycans. Only few glycans were associated with ACE inhibitor/ARBs, while none associated with insulin and SU derivative use.

CONCLUSIONS

We conclude that metformin and statins associate with a total plasma N-glycome signature in type 2 diabetes. Further studies are needed to determine the causality of these relations, and future N-glycomic research should consider medication a potential confounder.

BARICITINIB: NEW PHARMACOTHERAPY OPTIONS FOR RHEUMATOID ARTHRITIS AND OTHER IMMUNE-MEDIATED INFLAMMATORY RHEUMATIC DISEASES

Deciphering the mechanisms of the pathogenesis of immune-mediated inflammatory rheumatic diseases (IMIRDs) in conjunction with designing a wide range of biological agents is one of the major medical advances in the 21st century. A new promising area of pharmacotherapy for IMIRDs is associated with the design of the so-called targeted oral medications that primarily include Janus kinase (JAK) inhibitors. The review presents new data on the efficacy and safety of the new JAK inhibitor baricitinib in treating rheumatoid arthritis and other IMIRDs.

Prospective associations between hsCRP and GlycA inflammatory biomarkers and depression: The Brazilian longitudinal study of adult health (ELSA-Brasil)

BACKGROUND

Although low-grade inflammation is associated with onset and persistence of depression, most biomarkers display modest predictive effects. GlycA (glycoprotein acetylation) is a unique metabolomic composite of pro-inflammatory acute-phase glycoproteins. We hypothesized that GlycA levels would predict depression incidence, remission and persistence, with higher accuracy than high-sensitivity c-reactive protein (hsCRP). We also explored the additive predictive value of GlycA above and beyond hsCRP.

METHODS

Cohort design using the sample of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)'s São Paulo site. Baseline GlycA and hsCRP levels were measured in blood plasma. Depression incidence, remission, and persistence were assessed using the Clinical Interview Scheduled Revised (CIS-R) at two time points separated by a mean of 3.8 years. Multivariable Poisson, logistic and linear regression models were used for prediction. Models were adjusted for sociodemographic and clinical confounders, including age, gender, ethnicity, education, cardiovascular assessments, antidepressant and anti-inflammatory drug use, anxiety disorders, alcohol use, and body mass index.

RESULTS

We included 4,364 participants (53.2% females, mean age 51.4 ± 8.9 years) with no autoimmune disorders. GlycA robustly predicted depression persistence (relative risk of 7.28, 95% confidence interval 1.33-45.57, p = 0.023 in the fully-adjusted model), but not depression onset. Although hsCRP also predicted depression persistence, its effects were fully explained by confounders and by GlycA levels. GlycA also predicted worsening of depressive symptoms in depressed patients and depression persistence vs. remission in fully-adjusted models.

LIMITATIONS

Brief depressive episodes could not be measured by our assessments.

CONCLUSIONS

GlycA might be a new inflammatory prognosis biomarker for depression.

Lipoprotein insulin resistance score and branched-chain amino acids increase after adrenalectomy for unilateral aldosterone-producing adenoma: a preliminary study

BACKGROUND AND AIMS

Primary aldosteronism (PA) due to unilateral aldosterone-producing adenoma (APA) is preferentially treated by unilateral adrenalectomy (ADX), but little is known about the changes in lipid and glucose metabolism that may occur after ADX.

METHODS

We studied 19 non-diabetic patients who did not use lipid-lowering drugs with PA due to APA before and 6 months after unilateral ADX. Fasting plasma lipids, lipoprotein subfractions, branched-chain amino acids (BCAA), and GlycA, a pro-inflammatory glycoprotein biomarker, were measured by nuclear magnetic resonance (NMR) spectroscopy. The Lipoprotein Insulin Resistance (LP-IR) score, which is based on six lipoprotein variables, was calculated.

RESULTS

In all patients, hyperaldosteronism was resolved after ADX. Body mass index and fasting plasma glucose were unchanged, but HbA1c increased (p = 0.002). Plasma triglycerides, large triglyceride-rich lipoprotein (TRL) cholesterol, and large TRL particles were increased (p < 0.01), resulting in an increase in TRL size (p = 0.027). High-density lipoprotein size was decreased (p = 0.015). LP-IR scores (p = 0.001) and total BCAA (p = 0.017) were increased, but GlycA remained unaltered.

CONCLUSIONS

Based on increases in LP-IR scores and BCAA, which each have been shown to predict new onset type 2 diabetes mellitus independent of conventional risk factors in the general population, this preliminary study suggests that diabetes risk is not improved but may even be increased after ADX for APA despite remission of PA.

GlycA: A New Biomarker for Systemic Inflammation and Cardiovascular Disease (CVD) Risk Assessment

The GlycA test is a recently developed proton nuclear magnetic resonance (¹H-NMR) spectroscopy-based assay that has been gaining increased interest as a serum biomarker for systemic inflammation, and consequently, as a potential biomarker for cardiovascular disease (CVD) risk assessment. The test has undergone investigation in several large cohort studies, since its development, to assess its predictive value for incident CVD events, CVD-associated mortality, and all-cause mortality. Despite variation in the generated estimates by these studies, they have all consistently demonstrated moderate-strength positive correlations between baseline GlycA levels, and incident CVD event rates and associated mortality. These correlations withheld testing even after adjusting for several other established CVD risk factors, including notable inflammatory biomarkers such as high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6). Compared with hsCRP, which is a well-known inflammatory biomarker for CVD risk assessment, GlycA has a comparable predictive value for future CVD-related events. However, the indications to pursue GlycA testing, and its clinical utility in patient care management, are yet to be determined. In this review, we define the GlycA test and what it "measures", and provide a brief summary of the findings of studies showing its association with incident CVD rates, and CVD-related mortality, as well as its correlation with other inflammatory biomarkers, namely hsCRP. Finally, we highlight the analytical advantages of the GlycA test, compared with "traditional" inflammatory biomarkers, while also mentioning its current limitations.

Title: Human Serum/Plasma Glycoprotein Analysis by 1H-NMR, an Emerging Method of Inflammatory Assessment

Several studies suggest that variations in the concentration of plasma glycoproteins can influence cellular changes in a large number of diseases. In recent years, proton nuclear magnetic resonance (1H-NMR) has played a major role as an analytical tool for serum and plasma samples. In recent years, there is an increasing interest in the characterization of glycoproteins through 1H-NMR in order to search for reliable and robust biomarkers of disease. The objective of this review was to examine the existing studies in the literature related to the study of glycoproteins from an analytical and clinical point of view. There are currently several techniques to characterize circulating glycoproteins in serum or plasma, but in this review, we focus on 1H-NMR due to its great robustness and recent interest in its translation to the clinical setting. In fact, there is already a marker in H-NMR representing the acetyl groups of the glycoproteins, GlycA, which has been increasingly studied in clinical studies. A broad search of the literature was performed showing a general consensus that GlycA is a robust marker of systemic inflammation. The results also suggested that GlycA better captures systemic inflammation even more than C-reactive protein (CRP), a widely used classical inflammatory marker. The applications reviewed here demonstrated that GlycA was potentially a key biomarker in a wide range of diseases such as cancer, metabolic diseases, cardiovascular risk, and chronic inflammatory diseases among others. The profiling of glycoproteins through 1H-NMR launches an encouraging new paradigm for its future incorporation in clinical diagnosis.

Ketone Bodies Are Mildly Elevated in Subjects with Type 2 Diabetes Mellitus and Are Inversely Associated with Insulin Resistance as Measured by the Lipoprotein Insulin Resistance Index

Background: Quantifying mildly elevated ketone bodies is clinically and pathophysiologically relevant, especially in the context of disease states as well as for monitoring of various diets and exercise regimens. As an alternative assay for measuring ketone bodies in the clinical laboratory, a nuclear magnetic resonance (NMR) spectroscopy-based test was developed for quantification of β-hydroxybutyrate (β-HB), acetoacetate (AcAc) and acetone. Methods: The ketone body assay was evaluated for precision, linearity and stability and method comparisons were performed. In addition, plasma ketone bodies were measured in the Insulin Resistance Atherosclerosis Study (IRAS, n = 1198; 373 type 2 diabetes mellitus (T2DM) subjects). Results: β-HB and AcAc quantified using NMR and mass spectrometry and acetone quantified using NMR and gas chromatography/mass spectrometry were highly correlated (R² = 0.996, 0.994, and 0.994 for β-HB, AcAc, acetone, respectively). Coefficients of variation (%CVs) for intra- and inter-assay precision ranged from 1.3% to 9.3%, 3.1% to 7.7%, and 3.8% to 9.1%, for β-HB, AcAc and acetone, respectively. In the IRAS, ketone bodies were elevated in subjects with T2DM versus non-diabetic individuals (p = 0.011 to ≤0.001). Age- and sex-adjusted multivariable linear regression analysis revealed that total ketone bodies and β-HB were associated directly with free fatty acids (FFAs) and T2DM and inversely with triglycerides and insulin resistance as measured by the Lipoprotein Insulin Resistance Index. Conclusions: Concentrations of the three main ketone bodies can be determined by NMR with good clinical performance, are elevated in T2DM and are inversely associated with triglycerides and insulin resistance.

Relationship between gut microbiota and circulating metabolites in population-based cohorts

Gut microbiota has been implicated in major diseases affecting the human population and has also been linked to triglycerides and high-density lipoprotein levels in the circulation. Recent development in metabolomics allows classifying the lipoprotein particles into more details. Here, we examine the impact of gut microbiota on circulating metabolites measured by Nuclear Magnetic Resonance technology in 2309 individuals from the Rotterdam Study and the LifeLines-DEEP cohort. We assess the relationship between gut microbiota and metabolites by linear regression analysis while adjusting for age, sex, body-mass index, technical covariates, medication use, and multiple testing. We report an association of 32 microbial families and genera with very-low-density and high-density subfractions, serum lipid measures, glycolysis-related metabolites, ketone bodies, amino acids, and acute-phase reaction markers. These observations provide insights into the role of microbiota in host metabolism and support the potential of gut microbiota as a target for therapeutic and preventive interventions.

Overexpression of UDP-Glucose 4-Epimerase Is Associated with Differentiation Grade of Gastric Cancer

The UDP-glucose 4-epimerase (GALE) is a glycosyltransferase, which acts on protein and lipid glycosylation in normal and neoplastic cells. This study is aimed at investigating the differential tissue expression of GALE and its possible association with clinical-pathological parameters and the outcome of gastric adenocarcinoma patients. Seventy-one patients were evaluated in relation to GALE expression by immunohistochemistry. Our results showed that 48 (67.6%) patients were GALE positive and 23 (32.4%) negative. Positive staining was present on well-differentiated and moderate-differentiated histological grade of gastric adenocarcinomas (p < 0.0001). There was no significant association with outcome parameters (p > 0.05). Besides that, our results corroborated with the validation cohort analysis, where the expression of GALE mRNA was also associated with the histological grade (p < 0.001). These results suggest a possible use of this enzyme as a biomarker for well and moderately differentiated tumors.

Impact on cardiometabolic risk of a weight loss intervention with higher protein from lean red meat: Combined results of 2 randomized controlled trials in obese middle-aged and older adults

BACKGROUND

The recognized benefits of a higher protein diet on muscle mass and strength in older adults are tempered by concerns of the potentially negative cardiometabolic impact of dietary sources of animal protein.

OBJECTIVE

The aim of this study was to explore the cardiometabolic impact of 2 weight reduction diets: a higher protein diet, providing balanced portions of lean beef and pork throughout the day, vs. a diet following the Recommended Daily Allowance level of protein in obese middle-aged and older adults.

METHODS

Data from Measuring Eating, Activity and Strength: Understanding the Response-Using Protein and Protein Optimization in Women Enables Results-Using Protein were combined for the present analysis. Subjects were randomly assigned to a 6-month weight loss diet (500 kcal deficit) and prescribed a Recommended Daily Allowance level of protein (0.8 g protein/kg BW), control group, or a higher level of protein (1.2 g protein/kg BW), protein group. For the protein group, lean, high-quality protein was evenly distributed between meals or balanced throughout the day (30 g protein/meal). The following cardiometabolic markers were quantified by nuclear magnetic resonance spectroscopy: lipids, lipoproteins, GlycA, trimethylamine-N-oxide, betaine, branched-chain amino acids, and lipoprotein insulin resistance index scores.

RESULTS

In both groups (control [n = 27] and protein [n = 53]), there were significant (P ≤ .05) changes from baseline in weight loss (-6.2% and -7.2%), distance walked (+53.1 and +75.0 meters), and fasting plasma glucose (-7.5 and -6.2 mg/dL), respectively. At endpoint, protein group had significantly (P ≤ .05) lower triglycerides (-17.3 mg/dL), large very-low-density lipoprotein particle concentration (VLDL-P; -1.2 nmol/L), total low-density lipoprotein particle concentration (LDL-P; -67.8 nmol/L), small LDL-P (-59.4 nmol/L) and lipoprotein insulin resistance index (-5.9), whereas control group had significantly (P ≤ .05) lower GlycA (-13.1 μmol/L), total VLDL-P (-7.9 nmol/L), and small VLDL-P (-7.0 nmol/L). Differences between groups were observed for small VLDL-P (P = .02) and protein intake (P < .0001).

CONCLUSIONS

These findings suggest that a hypocaloric diet with either traditional (0.8 g/kg BW/d) or higher protein (1.2 g/kg BW/d; predominantly from lean red meat) content improves risk markers of cardiovascular disease and type II diabetes in obese middle-aged and older adults. Both diets were also associated with improved physical function, and neither had an adverse impact on cardiometabolic outcomes.

N-glycome signatures in human plasma: associations with physiology and major diseases

N-glycome analysis in total plasma or serum yields information about the levels and glycosylation patterns of major plasma glycoproteins, including immunoglobulins, acute-phase proteins, and apolipoproteins. Until recently, glycomic studies in disease settings largely suffered from small cohort sizes, poor analytical resolution, and poor comparability of results owing to the diversity of analytical techniques. Here, we report on recent advances in high-throughput mass spectrometry glycomics technology that enabled elucidation of N-glycome signatures in the plasma of patients with type 2 diabetes, inflammatory bowel disease, or colorectal cancer. Use of this technology revealed both commonalities and differences among disease fingerprints. Moreover, we summarize findings on glycomic signatures associated with age, sex, and body mass index. High-throughput, high-resolution glycomics technologies, together with robust data analysis workflows, will advance clinical translation.

Primary aldosteronism is associated with decreased low-density and high-density lipoprotein particle concentrations and increased GlycA, a pro-inflammatory glycoprotein biomarker

BACKGROUND

Primary aldosteronism (PA) may confer increased cardiovascular risk beyond effects on systemic blood pressure, but contributing mechanisms remain incompletely understood. We compared plasma (apo)lipoproteins and lipoprotein particle characteristics, GlycA, a pro-inflammatory glycoprotein biomarker of enhanced chronic inflammation, and plasma total branched-chain amino acids (BCAA), measured using nuclear magnetic resonance (NMR) spectroscopy, between patients with PA, control subjects without hypertension, subjects with untreated hypertension and subjects with treated hypertension.

METHODS

Twenty PA patients were individually matched with 2819 control subjects without hypertension, 501 subjects with untreated hypertension and 878 subjects with treated hypertension participating in the PREVEND (Prevention of Renal and Vascular End-Stage Disease) cohort study with respect to age, sex, body mass index, smoking and statin use. The Vantera® Clinical Analyzer was used to determine NMR-based laboratory parameters.

RESULTS

Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) B, apolipoprotein A-I (apoA-I), LDL particle and HDL particle concentrations were all decreased in PA subjects vs control subjects and subjects with untreated hypertension (P < 0.016). Triglycerides (TG) and triglyceride-rich lipoprotein (TRL) concentrations were lower in PA subjects vs subjects with (untreated) hypertension. GlycA was increased in PA vs the three comparator groups (P < 0.016). Total BCAA concentrations were unaltered in PA.

CONCLUSIONS

Primary aldosteronism is associated with lower concentrations of LDL and HDL particles and to some extent also with lower TG and TRL particle concentrations. PA is also characterized by increased GlycA levels, indicating enhanced low-grade chronic inflammation. Low HDL particle concentrations and increased GlycA could contribute to accelerated cardiovascular disease development in PA.

The association between blood copper concentration and biomarkers related to cardiovascular disease risk - analysis of 206 individuals in the Northern Finland Birth Cohort 1966

BACKGROUND

Copper is an abundant trace element in humans where alterations in the circulating concentration could inform on chronic disease aetiology. To date, data are lacking to study how copper may associate with cardiovascular disease (CVD) risk factors in young and healthy population. Molecular evidence suggests an important role of copper in liver metabolism, an essential organ in maintaining cardiovascular health and inflammation, therefore supporting copper as an associated biomarker of the risk.

OBJECTIVE

We performed a cross-sectional analysis to examine the possible associations between blood copper levels and risk factors for CVD and pre-inflammatory process.

DESIGN

The data has been collected from a sub-sample set of the Northern Finland Birth Cohort 1966 (NFBC1966) at 31 years.

PARTICIPANTS

The study included 206 individuals, 116 men and 90 women. To reduce environmental individual variations affecting both copper and the metabolic profile in the study sample, the participants were selected as: i) being born in Finnish Lapland and ii) living in their birth place for the last five years preceding blood sampling.

MAIN OUTCOME MEASURES

Fasting blood copper concentration was measured by inductively coupled plasma mass spectrometer. The CVD risk factors included 6 metabolic clusters (30 cardiovascular and pro-inflammatory factors) assessed by nuclear magnetic resonance. Multivariate linear regression analysis was performed to test the linear association between blood copper and 6 metabolic clusters for CVD risk. Associations were assessed under correction for multiple testing.

RESULTS

Copper (Cu) levels were comparable in men and women, with no difference between sexes (p-value <0.60). In multiple regression models, sex adjusted, copper was associated with 9 metabolites from 4 metabolic clusters. After adjustment with BMI, copper was associated with 4 metabolites from 3 metabolic clusters: glutamine, beta-hydroxybutyrate, alpha-1-acid glycoprotein (AGP) and high-sensitive C-reactive protein (hs-CRP). After correction for multiple testing, Cu was found positively associated with only 2 biomarkers of inflammation including AGP [p = 0.04] and hs-CRP [p = 0.0001].

CONCLUSIONS

Considering the strength and limitation of the study design, the present study does not support evidence for an independent role of copper on biomarkers for CVD risk. Nevertheless, we are reporting a robust association of copper with the inflammatory load that is important to consider in light with the inflammatory component of chronic health. In addition, the association of copper with metabolites may be attributable to BMI or environmental factors associated to it, and warrants further research in large population samples.

Characterization of 1H NMR Plasma Glycoproteins as a New Strategy To Identify Inflammatory Patterns in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease associated with a high index of morbidity and mortality from cardiovascular diseases. We used ¹H NMR to characterize the plasma glycoprotein and lipoprotein profiles of a cohort of patients with RA ( n = 210) versus healthy individuals ( n = 203) to associate them with the RA disease and its severity. Using ¹H NMR, we developed a line-shape method to characterize the two peaks associated with glycoproteins (GlycA and GlycB) and its derived variables: areas of GlycB (Area GlycB) and GlycA (Area GlycA), shape factors of these two peaks (H/W = height/width), and the distance between them (Distance GlycB-GlycA). We also used the advanced lipoprotein test Liposcale (CE) to characterize the lipoprotein subclasses. The standard lipid panel and traditional inflammatory markers such as C-reactive protein, the erythrocyte sedimentation rate, fibrinogen, the rheumatoid factor, anticitrullinated peptide antibodies, and the DAS28 index have also been determined. RA patients presented a significant 10.65% increase in the GlycA associated area compared with the control group ( p = 2.21 × 10^-10). They also presented significantly higher H/W GlycA and GlycB ratios than the control population (H/W GlycB p = 7.88 × 10^-8; H/W GlycA p = 5.61 × 10^-8). The prediction model that uses the traditional inflammatory variables and the ¹H NMR-derived parameters presented an AUC that was almost 10% higher than the model that only uses the traditional inflammatory variables (from 0.7 to 0.79 AUC). We have demonstrated that GlycA and GlycB variables derived from ¹H NMR, along with classic inflammatory parameters, help to improve the classification of individuals with high RA disease activity.

Plasma N-Glycan Signatures Are Associated With Features of Inflammatory Bowel Diseases

BACKGROUND & AIMS

Biomarkers are needed for early detection of Crohn's disease (CD) and ulcerative colitis (UC) or to predict patient outcomes. Glycosylation is a common and complex posttranslational modification of proteins that affects their structure and activity. We compared plasma N-glycosylation profiles between patients with CD or UC and healthy individuals (controls).

METHODS

We analyzed the total plasma N-glycomes of 2635 patients with inflammatory bowel diseases and 996 controls by mass spectrometry with a linkage-specific sialic acid derivatization technique. Plasma samples were acquired from 2 hospitals in Italy (discovery cohort, 1989 patients with inflammatory bowel disease [IBD] and 570 controls) and 1 medical center in the United States (validation cohort, 646 cases of IBD and 426 controls). Sixty-three glycoforms met our criteria for relative quantification and were extracted from the raw data with the software MassyTools. Common features shared by the glycan compositions were combined in 78 derived traits, including the number of antennae of complex-type glycans and levels of fucosylation, bisection, galactosylation, and sialylation. Associations of plasma N-glycomes with age, sex, CD, UC, and IBD-related parameters such as disease location, surgery and medication, level of C-reactive protein, and sedimentation rate were tested by linear and logistic regression.

RESULTS

Plasma samples from patients with IBD had a higher abundance of large-size glycans compared with controls, a decreased relative abundance of hybrid and high-mannose structures, lower fucosylation, lower galactosylation, and higher sialylation (α2,3- and α2,6-linked). We could discriminate plasma from patients with CD from that of patients with UC based on higher bisection, lower galactosylation, and higher sialylation (α2,3-linked). Glycosylation patterns were associated with disease location and progression, the need for a more potent medication, and surgery. These results were replicated in a large independent cohort.

CONCLUSIONS

We performed high-throughput analysis to compare total plasma N-glycomes of individuals with vs without IBD and to identify patterns associated with disease features and the need for treatment. These profiles might be used in diagnosis and for predicting patients' responses to treatment.

GlycA and hsCRP are independent and additive predictors of future cardiovascular events among patients undergoing angiography: The intermountain heart collaborative study

BACKGROUND

GlycA is an inflammatory marker that is raised in patients with cardiometabolic diseases and associated with cardiovascular (CV) events. We sought to determine if GlycA adds independent value to hsCRP for CV risk prediction.

METHODS

Patients in the Intermountain Heart Collaborative Study who underwent coronary angiography and had plasma GlycA and hsCRP levels were studied (n = 2996). Patients were followed for 7.0 ± 2.8 years. GlycA and hsCRP were moderately correlated (r = 0.46, P < .0001). GlycA and hsCRP concentrations were stratified into high and low categories by their median values. Multivariable cox hazard regression was utilized to determine the associations of GlycA quartiles, as well as high and low categories of GlycA and hsCRP, with major adverse cardiovascular events (MACE) defined as the composite of death, myocardial infarction (MI), heart failure (HF) hospitalization, and stroke.

RESULTS

The highest GlycA quartile was associated with future MACE [HR: 1.43; 95% CI: 1.22-1.69; P < .0001]. Patients with high GlycA and high hsCRP had more diabetes, hyperlipidemia, hypertension, HF, renal failure and MI, but not coronary artery disease. High GlycA and hsCRP (H/H) versus low GlycA and hsCRP (L/L) was associated with MACE, death and HF hospitalization, but not MI or stroke. Combined MACE rates were 33.5%, 41.3%, 35.7% and 49.1% for L/L, L/H, H/L and H/H categories of GlycA/hsCRP, respectively (P-trend < .0001). The interaction between GlycA and hsCRP was significant for the outcome of death (P = .03).

CONCLUSION

In this study, levels of GlycA and hsCRP were independent and additive markers of risk for MACE, death and HF hospitalization.

Lipid profile and effect of statin treatment in pooled phase II and phase III baricitinib studies

Objectives

Lipid profiles are altered by active disease in patients with rheumatoid arthritis (RA) and may be further modified by treatment with Janus kinase inhibitors and other disease-modifying antirheumatic drugs.

Methods

Lipid data were analysed from phase II and III studies of 4 mg (n=997) and 2 mg (n=479) oral baricitinib administered once daily in patients with moderate-to-severe active RA. Lipoprotein particle size and number and GlycA were evaluated with nuclear magnetic resonance in one phase III study. The effect of statin therapy on lipid levels was evaluated in patients on statins at baseline and in patients who initiated statins during the study.

Results

Treatment with baricitinib was associated with increased levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides, but no significant change in LDL-C:HDL-C ratio. Lipid levels plateaued after 12 weeks of treatment. Baricitinib treatment increased large LDL and decreased small, dense LDL particle numbers and GlycA. Lipid changes from baseline were not significantly different between baseline statin users and non-users. In patients who initiated statin therapy during the study, LDL-C, triglycerides (baricitinib 4 mg only) and apolipoprotein B decreased to pre-baricitinib levels; HDL-C and apolipoprotein A-I levels remained elevated.

Conclusions

Baricitinib was associated with increased LDL-C, HDL-C and triglyceride levels, but did not alter the LDL-C:HDL-C ratio. Evaluation of cardiovascular event rates during long-term treatment is warranted to further characterise these findings and their possible clinical implications.

Trial registration number

NCT00902486, NCT01469013, NCT01185353, NCT01721044, NCT01721057, NCT01711359, NCT01710358, NCT01885078.

GLA supplementation regulates PHD2 mediated hypoxia and mitochondrial apoptosis in DMBA induced mammary gland carcinoma

The aim of the present study is to evaluate the effect of gamma linolenic acid (GLA) on mitochondrial mediated death apoptosis, hypoxic microenvironment and cholinergic anti-inflammatory pathway against 7, 12-dimethylbenz (a) anthracene (DMBA) induced mammary gland carcinoma. The effects of GLA were evaluated morphologically and biochemically against DMBA induced mammary gland carcinoma. The metabolic study was done for evaluation of biomarkers using ¹H NMR. The present study was also verified through immunoblotting and qRT-PCR studies for the evaluation of various pathways. GLA treatment has a delineate implementation upon morphology of the tissues when evaluated through carmine staining, hematoxyline and eosin staining and scanning electron microscopy. GLA also demarked a commendatory proclamation of the fifteen key serum metabolites analogous with amino acid metabolism and fatty acid metabolism when recognized through¹H NMR studies. The immunoblotting and qRT-PCR studies accomplished that GLA mediated mitochondrial death apoptosis, curtail hypoxic microenvironment along with hindrance of de novo fatty acid synthesis and also mediate the cholinergic anti-inflammatory pathway to proclaim its anticancer effects.