ADMA, SDMA and L-arginine may be Novel Targets in Pharmacotherapy for Complications due to Cardiopulmonary Bypass

Rapid intestinal and systemic metabolic reprogramming in an immunosuppressed environment

Intrinsic metabolism shapes the immune environment associated with immune suppression and tolerance in settings such as organ transplantation and cancer. However, little is known about the metabolic activities in an immunosuppressive environment. In this study, we employed metagenomic, metabolomic, and immunological approaches to profile the early effects of the immunosuppressant drug tacrolimus, antibiotics, or both in gut lumen and circulation using a murine model. Tacrolimus induced rapid and profound alterations in metabolic activities within two days of treatment, prior to alterations in gut microbiota composition and structure. The metabolic profile and gut microbiome after seven days of treatment was distinct from that after two days of treatment, indicating continuous drug effects on both gut microbial ecosystem and host metabolism. The most affected taxonomic groups are Clostriales and Verrucomicrobiae (i.e., Akkermansia muciniphila), and the most affected metabolic pathways included a group of interconnected amino acids, bile acid conjugation, glucose homeostasis, and energy production. Highly correlated metabolic changes were observed between lumen and serum metabolism, supporting their significant interactions. Despite a small sample size, this study explored the largely uncharacterized microbial and metabolic events in an immunosuppressed environment and demonstrated that early changes in metabolic activities can have significant implications that may serve as antecedent biomarkers of immune activation or quiescence. To understand the intricate relationships among gut microbiome, metabolic activities, and immune cells in an immune suppressed environment is a prerequisite for developing strategies to monitor and optimize alloimmune responses that determine transplant outcomes.

Rapid intestinal and systemic metabolic reprogramming in an immunosuppressed environment

Intrinsic metabolism shapes the immune environment associated with immune suppression and tolerance in settings such as organ transplantation and cancer. However, little is known about the metabolic activities in an immunosuppressive environment. In this study, we employed metagenomic, metabolomic, and immunological approaches to profile the early effects of the immunosuppressant drug tacrolimus, antibiotics, or both in gut lumen and circulation using a murine model. Tacrolimus induced rapid and profound alterations in metabolic activities within two days of treatment, prior to alterations in gut microbiota composition and structure. The metabolic profile and gut microbiome after seven days of treatment was distinct from that after two days of treatment, indicating continuous drug effects on both gut microbial ecosystem and host metabolism. The most affected taxonomic groups are Clostriales and Verrucomicrobiae (i.e., Akkermansia muciniphila), and the most affected metabolic pathways included a group of interconnected amino acids, bile acid conjugation, glucose homeostasis, and energy production. Highly correlated metabolic changes were observed between lumen and serum metabolism, supporting their significant interactions. Despite a small sample size, this study explored the largely uncharacterized microbial and metabolic events in an immunosuppressed environment and demonstrated that early changes in metabolic activities can have significant implications that may serve as antecedent biomarkers of immune activation or quiescence. To understand the intricate relationships among gut microbiome, metabolic activities, and immune cells in an immune suppressed environment is a prerequisite for developing strategies to monitor and optimize alloimmune responses that determine transplant outcomes.

Weighted gene co-expression identification of CDKN1A as a hub inflammation gene following cardiopulmonary bypass in children with congenital heart disease

Background

Congenital heart disease (CHD) is the most common type of birth defect. Most patients with CHD require surgery, and cardiopulmonary bypass (CPB) is the most common surgery performed.

Methods

The present study utilized weighted gene co-expression network analysis (WGCNA) to identify key inflammation genes after CPB for CHD. The GSE132176 dataset was downloaded from the Gene Expression Omnibus(GEO) database for WGCNA to identify the modules closely related to clinical traits. Disease enrichment, functional annotation and pathway enrichment were performed on genes in the module closely related to clinical traits using Enrichr and Metascape. Immune infiltration analysis was also performed on the training dataset using CIBERSORT. Finally, we identified hub genes using high gene significance (GS), high module members (MMs) and Cytoscape, and we verified the hub genes using an independent dataset and Western blot analysis.

Results

WGCNA showed that the brown module with 461 genes had the highest correlation to CHD after CPB. Functional annotation and pathway enrichment analysis were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, which showed that genes in the brown module were enriched in inflammation-related pathways. In the disease enrichment analysis, genes in the brown module were enriched for inflammatory diseases. After the 30 most highly associated brown intramodular genes were screened, a protein-protein interaction network was constructed using the STRING online analysis website. The protein-protein interaction results were then calculated using 12 algorithms in the cytoHubba plugin of Cytoscape software. The final result showed that CDKN1A was the fundamental gene of post-CPB for CHD. Using another independent validation dataset (GSE12486), we confirmed that CDKN1A was significantly differentially expressed between preoperative and postoperative CPB (Wilcoxon, P = 0.0079; T-test, P = 0.006). In addition, CDKN1A expression was elevated in eosinophils, neutrophils, memory CD4 T cells and activated mast cells. Western blot analysis showed that the expression of CDKN1A protein was significantly higher postoperative CPB than preoperative CPB. Moreover, CDKN1A was mainly related to inflammation.

Conclusion

In summary, we found a relationship between CDKN1A and inflammation after CPB for congenital heart disease by WGCNA, experiments and various bioinformatics methods. Thus, CDKN1A maybe serve as a biomarker or therapeutic target for accurate diagnosis and treatment of inflammation after CPB in the future.

A systematic review of the correlation between serum asymmetric dimethylarginine, carotid atherosclerosis and ischaemic stroke

OBJECTIVE

To investigate the correlation between serum asymmetric dimethylarginine (ADMA) and the risk of ischaemic stroke and carotid atherosclerosis in adults.

METHODS

We systematically searched PubMed, EMBASE, Web of Science and other databases for relevant studies on serum ADMA and ischaemic stroke or carotid atherosclerosis, which were published from December 1980 to December 2019. The quality of the included studies was evaluated according to the Cochrane system evaluation standard. The difference in serum ADMA level between ischaemic stroke and control group was selected as the effect size (standardized mean difference, SMD). The pooled analysis was performed using Review Manager (V.5.3).

RESULTS

According to the selection criteria, thirteen studies were included in the meta-analysis after screening. Nine studies compared ADMA levels between the ischaemic stroke group and healthy control group, involving a total of 1315 and 880 subjects in the two groups, respectively. Pooled effect sizes were calculated using the random-effects model due to the high heterogeneity (I²  = 93%, P < .00001). The level of serum ADMA in patients with ischaemic stroke was significantly higher than that in healthy people (SDM = 0.69, 95% CI [0.32, 1.06], P = .0002). Seven of the thirteen articles compared ADMA levels between the carotid arteriosclerosis group and the healthy control group, with 559 and 330 subjects in the two groups, respectively. The random-effects model was applied due to the high heterogeneity (I²  = 91%, P < .00001). The level of serum ADMA in patients with carotid arteriosclerosis was significantly higher than that in healthy people (SDM = 1.03, 95% CI [0.49, 1.57], P = .0002).

CONCLUSION

The serum ADMA may be related to ischaemic stroke, and it is a risk factor for carotid atherosclerosis.

Blood pressure and nitric oxide synthesis capacity in physically active and inactive groups: the SABPA study

Physical activity affects the vasculature through mechanisms related to nitric oxide bioavailability, oxidative stress, and inflammation; with endothelial function at the centre of this triad. In a South African setting, with the prevalence of hypertension and physical inactivity being alarmingly high, we aimed to investigate relationships of vascular function with markers of oxidative stress, inflammation and nitric oxide synthesis capacity in physically active and inactive groups. Based on the 2010 World Health Organisation guidelines, black and white school teachers were divided into physically active (n = 84) and physically inactive (n = 132) groups. Twenty-four-hour blood pressure (24 h BP), total peripheral resistance and Windkessel compliance were measured. Markers of oxidative stress, inflammation and nitric oxide synthesis capacity were analysed. Windkessel compliance (p = 0.041) and homoarginine (p = 0.006) were higher in the physically active group. In the same group, 24 h diastolic BP associated with total glutathione (β = 0.17; p = 0.056), and 24 h BP (systolic blood pressure: β = 0.23, p = 0.006; diastolic blood pressure: β = 0.22, p = 0.019) associated with homoarginine. In the physically inactive group, 24 h BP (systolic blood pressure: β = 0.26, p < 0.001; diastolic blood pressure: β = 0.23, p = 0.007) associated with symmetric dimethylarginine (SDMA). These associations were independent of inflammation. Despite only reaching moderate physical activity levels, vascular function and nitric oxide synthesis capacity were more favourable in the physically active population compared to the physically inactive population. These results may suggest that even moderate physical activity could increase nitric oxide synthesis capacity, which in turn may mitigate the development of cardiovascular disease in this population.

Effects of a herbal formulation, KGC3P, and its individual component, nepetin, on coal fly dust-induced airway inflammation

Coal fly dust (CFD)-induced asthma model is used as an ambient particulate matter model of serious pulmonary damage. We aimed to evaluate the effects of a combination of ginseng and Salvia plebeia R. Br extract (KGC-03-PS; KG3P) and its individual components (hispidulin, nepetin and rosmarinic acid) in a CFD-induced mouse model of airway inflammation (asthma). We also evaluated signal transduction by KG3P and its individual components in the alveolar macrophage cell line, MH-S cells. In vitro, KG3P and its individual components inhibited nitric oxide production and expression of pro-inflammatory mediators and cytokines (iNOS, COX-2, IL-1β, IL-6 and TNF-α) through the NF-κB and MAPK pathways in coal fly ash (CFA)-induced inflammation in MH-S cells. Moreover, in the CFD-induced asthma model in mice, KG3P and its predominant individual component, nepetin, inhibited Asymmetric Dimethyl arginine (ADMA) and Symmetric Dimethyl arginine (SDMA) in serum, and decreased the histopathologic score in the lungs. A significant reduction in the neutrophils and immune cells in BALF and lung tissue was demonstrated, with significant reduction in the expression of the pro-inflammatory cytokines. Finally, IRAK-1 localization was also potently inhibited by KG3P and nepetin. Thus, KG3P extract can be considered as a potent candidate for amelioration of airway inflammation.

Effects of Minimal Extracorporeal Circulation on the Systemic Inflammatory Response and the Need for Transfusion after Coronary Bypass Grafting Surgery

Objectives

The aim of this study is to compare the effects of the minimal extracorporeal circulation (MiECT) on postoperative systemic inflammatory response and the need for transfusion in patients undergoing open heart surgery with cardiopulmonary bypass.

Methods

Patients were divided into two groups; Group M (n=31) included the patients operated via using the MiECT system and Group C (n=27) included the patients operated via using conventional cardiopulmonary bypass (CPB). Perioperative markers of inflammation after cardiopulmonary bypass in both groups were tested by measuring the levels via chemiluminescent immunometric assay. Blood samples were taken consecutively after anesthesia induction, 30^th minute of CPB, on the 6^th, 24^th, and 48^th hours after cardiopulmonary bypass.

Results

The mean amount of priming solution was significantly lower in Group M when compared to Group C (802.60 ± 48.26 and 1603.71 ± 49.85 ml). The mean hematocrit (Hct) value taken immediately after cardiopulmonary bypass was found to be significantly higher in the MiECT patients with respect to the other group (% 32.71 ± 3.98 and % 28.82 ± 4.39). The transfused amounts of erythrocyte suspension and fresh frozen plasma were found to be significantly lower in patients in Group M when compared to those in Group C. Postoperative mediastinal drainage was also significantly lower in patients in Group M with respect to the other group. There was no significant difference between markers of inflammation.

Conclusion

Our results show that MiECT seems to be more advantageous in terms of priming volume, perioperative hematocrit levels, need for blood and blood product transfusion, and mediastinal drainage with respect to the conventional approach after coronary artery bypass grafting.

A Pilot Study to Assess Kidney Functions and Toxic Dimethyl-arginines as Risk Biomarkers in Women with Low Vitamin D Levels

Background

Although vitamin D in not a traditional marker for cardiovascular and renal diseases, several studies have proposed a correlation between vitamin D deficiency and these diseases due to the effect of vitamin D on endothelial function. Asymmetric and symmetric dimethyl arginine (ADMA and SDMA, respectively) are endogenous markers of endothelial dysfunction, and are considered as future markers for the assessment of cardiovascular and renal diseases. The present study investigated the association of kidney function tests (urea and creatinine) and dimethylarginine toxins (ADMA and SDMA) in women with vitamin D insufficiency or deficiency. Indeed, sex hormones (estrogen and testosterone) were analyzed in the participants.

Methods

Women were divided into two groups: premenopausal women (younger than 50 years) and postmenopausal women (older than 50 years). Urea, creatinine, estrogen, testosterone, ADMA, and SDMA levels were analyzed when vitamin D level was deficient or insufficient in the participants.

Results

The premenopausal women group showed no significant correlations between dimethylarginine toxins and renal failure tests or sex hormones. In the elderly (postmenstrual) women group, only SDMA was significantly correlated with urea and creatinine, while both ADMA and SDMA were not correlated with sex hormones.

Conclusions

Although ADMA and SDMA are promising candidates of endothelial dysfunction and are increased in menopause and aging, no direct link between ADMA and further progression of renal failure was observed in women with low vitamin D levels. In contrast, a possible direct correlation between SDMA and renal dysfunction was noticed, but only in an age-dependent manner.

Development of a novel UHPLC-MS/MS-based platform to quantify amines, amino acids and methylarginines for applications in human disease phenotyping

Amine quantification is an important strategy in patient stratification and personalised medicine. This is because amines, including amino acids and methylarginines impact on many homeostatic processes. One important pathway regulated by amine levels is nitric oxide synthase (NOS). NOS is regulated by levels of (i) the substrate, arginine, (ii) amino acids which cycle with arginine and (iii) methylarginine inhibitors of NOS. However, biomarker research in this area is hindered by the lack of a unified analytical platform. Thus, the development of a common metabolomics platform, where a wide range of amino acids and methylarginines can be measured constitutes an important unmet need. Here we report a novel high-throughput ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) platform where ≈40 amine analytes, including arginine and methylarginines can be detected and quantified on a molar basis, in a single sample of human plasma. To validate the platform and to generate biomarkers, human plasma from a well-defined cohort of patients before and after coronary artery bypass surgery, who developed systemic inflammatory response syndrome (SIRS), were analysed. Bypass surgery with SIRS significantly altered 26 amine analytes, including arginine and ADMA. Consequently, pathway analysis revealed significant changes in a range of pathways including those associated with NOS.

Red Blood Cell Distribution Width Improves Reclassification of Patients Admitted to the Emergency Department with Acute Decompensated Heart Failure

BACKGROUND

The usual history of chronic heart failure (HF) is characterized by frequent episodes of acute decompensation (ADHF), needing urgent management in the emergency department (ED). Since the diagnostic accuracy of routine laboratory tests remains quite limited for predicting short-term mortality in ADHF, this retrospective study investigated the potential significance of combining red blood cell distribution width (RDW) with other conventional tests for prognosticating ADHF upon ED admission.

METHODS

We conducted a retrospective study including visits for episodes of ADHF recorded in the ED of the Uni versity Hospital of Verona throughout a 4-year period. Demo - graphic and clinical features were recorded upon patient presentation. All patients were subjected to standard Chest X-ray, electrocardiogram (ECG) and laboratory testing in - cluding creatinine, blood urea nitrogen, B-type natriuretic peptide (BNP), complete blood cell count (CBC), sodium, chloride, potassium and RDW. The 30-day overall mortality after ED presentation was defined as primary endpoint.

RESULTS

The values of sodium, creatinine, BNP and RDW were higher in patients who died than in those who survived, whilst hypochloremia was more frequent in patients who died than in those who survived. The multivariate model, incorporating these parameters, displayed a modest efficiency for predicting 30-day mortality after ED admission (AUC, 0.701; 95% CI, 0.662-0.738; p=0.001). Notably, the inclusion of RDW in the model significantly enhanced prediction efficiency, with an AUC of 0.723 (95% CI, 0.693-0.763; p<0.001). These results were confirmed with net reclassification improvement (NRI) analysis, showing that combination of RDW with conventional laboratory tests resulted in a much better prediction performance (net reclassification index, 0.222; p=0.001).

CONCLUSIONS

The results of our study show that prognostic assessment of ADHF patients in the ED can be significantly improved by combining RDW with other conventional laboratory tests.