Growth differentiation factor-15 as a biomarker of coronary microvascular dysfunction in ST-segment elevation myocardial infarction

Background

The predictive value of growth differentiation factor-15 (GDF-15) in coronary microvascular dysfunction (CMD) following primary percutaneous coronary intervention (PPCI) in ST-segment elevation myocardial infarction (STEMI) patients is unclear.

Methods

This study continuously recruited STEMI patients treated with PPCI at the Chest Pain Center of Qilu Hospital of Shandong University from April 2023 to December 2023. Blood samples were taken before PPCI and the level of circulating GDF-15 was measured by enzyme-linked immunosorbent assay (ELISA), and the patients were divided into CMD and Control group according to angiographic microvascular resistance (AMR) (cut-off value 2.50 mmHg*s/cm). The differences in GDF-15 expression levels between the two groups were compared, and the predictive value of GDF-15 for CMD was systematically evaluated.

Results

A total of 134 patients, with an average age of 59.78 ± 12.69 years and 75.37 % being male, were included in this study. Multivariable logistic regression revealed a significant association between GDF-15 and CMD (adjusted OR = 2.505, 95 % CI: 1.661-3.779, P < 0.001). The area under the curve (AUC) of GDF-15 for CMD was 0.782 (95 % CI: 0.704-0.861), with a sensitivity of 0.795 and specificity of 0.643 in predicting CMD in PPCI. The AUC of the GDF-15 model (Model With GDF-15) was 0.867 (95 % CI: 0.806-0.928), significantly outperforming the clinical baseline model (Model Without GDF-15) (Δ AUC = 0.079, 95 % CI: 0.020-0.138, P = 0.009). Furthermore, the net reclassification improvement (NRI) was 0.854 (95 % CI: 0.543-1.166, P < 0.001), and the integrated discrimination improvement (IDI) was 0.151 (95 % CI: 0.089-0.213, P < 0.001).

Conclusions

GDF-15 can serve as a biomarker for predicting the development of CMD in STEMI patients undergoing PPCI.

Senescence of endothelial cells promotes phenotypic changes in adventitial fibroblasts: possible implications for vascular aging

Aging is the most important risk factor for the development of cardiovascular diseases. Senescent cells release plethora of factors commonly known as the senescence-associated secretory phenotype, which can modulate the normal function of the vascular wall. It is currently not well understood if and how endothelial cell senescence can affect adventitial niche. The aim of this study was to characterize oxidative stress-induced endothelial cells senescence and identify their paracrine effects on the primary cell type of the adventitia, the fibroblasts. Human aortic endothelial cells (HAEC) were treated with hydrogen peroxide to induce premature senescence. Mass spectrometry analysis identified several proteomic changes in senescent HAEC with top upregulated secretory protein growth differentiation factor 15 (GDF-15). Treatment of the human adventitial fibroblast cell line (hAdv cells) with conditioned medium (CM) from senescent HAEC resulted in alterations in the proteome of hAdv cells identified in mass spectrometry analysis. Majority of differentially expressed proteins in hAdv cells treated with CM from senescent HAEC were involved in the uptake and metabolism of lipoproteins, mitophagy and ferroptosis. We next analyzed if some of these changes and pathways might be regulated by GDF-15. We found that recombinant GDF-15 affected some ferroptosis-related factors (e.g. ferritin) and decreased oxidative stress in the analyzed adventitial fibroblast cell line, but it had no effect on erastin-induced cell death. Contrary, silencing of GDF-15 in hAdv cells was protective against this ferroptotic stimuli. Our findings can be of importance for potential therapeutic strategies targeting cell senescence or ferroptosis to alleviate vascular diseases.

Unsupervised clustering to differentiate rheumatoid arthritis patients based on proteomic signatures

OBJECTIVE

Patients with rheumatoid arthritis (RA) have different presentations and prognoses. Cluster analysis based on proteomic signatures creates independent phenogroups of patients with different pathophysiological backgrounds. We aimed to identify distinct pathophysiological clusters of RA patients based on circulating proteomic biomarkers.

METHOD

This was a cohort study including 399 RA patients. Clustering was performed on 94 circulating proteins (92 CVDII Olink®, high-sensitivity troponin T, and C-reactive protein). Unsupervised clustering was performed using a partitioning cluster algorithm.

RESULTS

The clustering algorithm identified two distinct clusters: cluster 1 (n = 223) and cluster 2 (n = 176). Compared with cluster 1, cluster 2 included older patients with a higher burden of comorbidities (cardiovascular and RA related), more erosive and longer RA duration, more dyspnoea and fatigue, walking a shorter distance in the Six-Minute Walk Test, with more severe diastolic dysfunction, and a 4.5-fold higher risk of death or hospitalization for cardiovascular reasons. Tumour necrosis factor (TNF) receptor superfamily-related pathways were mainly responsible for the model's discriminative ability.

CONCLUSION

Using unsupervised cluster analysis based on proteomic phenotypes, we identified two clusters of RA patients with distinct biomarkers profiles, clinical characteristics, and different outcomes that could reflect different pathophysiological backgrounds. TNF receptor superfamily-related proteins may be used to distinguish subgroups.

TRAIL and its receptors in cardiac diseases

Cardiovascular disease is a leading cause of death worldwide. Loss of cardiomyocytes that occurs during many types of damage to the heart such as ischemic injury and stress caused by pressure overload, diminishes cardiac function due to their limited regenerative capacity and promotes remodeling, which further damages the heart. Cardiomyocyte death occurs through two primary mechanisms, necrosis and apoptosis. Apoptosis is a highly regulated form of cell death that can occur through intrinsic (mitochondrial) or extrinsic (receptor mediated) pathways. Extrinsic apoptosis occurs through a subset of Tumor Necrosis Receptor (TNF) family receptors termed "Death Receptors." While some ligands for death receptors have been extensively studied in the heart, such as TNF-α, others have been virtually unstudied. One poorly characterized cardiac TNF related ligand is TNF-Related Apoptosis Inducing Ligand (TRAIL). TRAIL binds to two apoptosis-inducing receptors, Death Receptor (DR) 4 and DR5. There are also three decoy TRAIL receptors, Decoy Receptor (DcR) 1, DcR2 and osteoprotegerin (OPG). While TRAIL has been extensively studied in the cancer field due to its ability to selectively induce apoptosis in transformed cell types, emerging clinical evidence points towards a role for TRAIL and its receptors in cardiac pathology. This article will highlight our current understanding of TRAIL and its receptors in normal and pathological conditions in the heart.

Baseline fibroblast growth factor 23 is associated with long-term mortality in ST-elevation myocardial infarction-results from the augsburg myocardial infarction registry

Background

The aim of this study was to investigate the association between inflammatory plasma protein concentrations and long-term mortality in patients with ST-elevation myocardial infarction (STEMI).

Methods

For 343 STEMI patients recorded between 2009 and 2013 by the population-based Myocardial Infarction Registry Augsburg, 92 inflammatory plasma proteins were measured at the index event using the OLINK inflammation panel. In multivariable-adjusted Cox regression models, the association between each plasma protein and all-cause long-term mortality was investigated. Median follow-up time was 7.6 (IQR: 2.4) years. For plasma protein that showed a strong association with long-term mortality, a 5-year survival ROC analysis was performed.

Results

One plasma protein, namely Fibroblast Growth Factor 23 (FGF-23), was particularly well associated with long-term mortality in the multivariable-adjusted Cox model with an FDR-adjusted p-value of <0.001 and a Hazard Ratio (HR) of 1.57 [95% CI: 1.29-1.91]. In the 5-years ROC analysis, an AUC of 0.6903 [95% CI: 0.594-0.781] was estimated for FGF-23. All other plasma protein didńt show strong associations, each marker with FDR-adjusted p-values >0.05 in the multivariable-adjusted Cox models.

Conclusions

FGF-23 is independently associated with long-term mortality after STEMI and might play an important role in the response to myocardial injury. The results suggest FGF-23 to be a useful marker in the long-term treatment of STEMI patients and a potential target for drug development.

TRAIL or TRAIL-R2 as a Predictive Biomarker for Mortality or Cardiovascular Events: A Systematic Review and Meta-analysis

ABSTRACT

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and TRAIL-receptor-2 (TRAIL-R2) are associated with atherosclerosis. This meta-analysis aimed to investigate the potential association between TRAIL/TRAIL-R2 with mortality or cardiovascular (CV) events. PubMed, Embase, and Cochrane Library were searched for reports published up to May 2021. Reports were included when the association between TRAIL or TRAIL-R2 and mortality or CV events was reported. Considering the heterogeneity between studies, we used the random-effects model for all analyses. Ultimately, the meta-analysis included 18 studies (16,295 patients). The average follow-up ranged from 0.25 to 10 years. Decreased TRAIL levels were negatively associated with all-cause mortality [rank variable, hazard ratio (HR), 95% CI, 2.93, 1.94-4.42; I2 = 0.0%, Pheterogeneity = 0.835]. Increased TRAIL-R2 levels were positively associated with all-cause mortality (continuous variable, HR, 95% CI, 1.43, 1.23-1.65; I2 = 0.0%, Pheterogeneity = 0.548; rank variable, HR, 95% CI, 7.08, 2.70-18.56; I2 = 46.5%, Pheterogeneity = 0.154), CV mortality (continuous variable, HR, 95% CI, 1.33, 1.14-1.57; I2 = 0.0%, Pheterogeneity = 0.435), myocardial infarction (continuous variable, HR, 95% CI, 1.23, 1.02-1.49; rank variable, HR, 95% CI, 1.49, 1.26-1.76; I2 = 0.7%, Pheterogeneity = 0.402), and new-onset heart failure (rank variable, HR, 95% CI, 3.23, 1.32-7.87; I2 = 83.0%, Pheterogeneity = 0.003). In conclusion, decreased TRAIL was negatively associated with all-cause mortality, and increased TRAIL-R2 was positively associated with all-cause mortality, CV mortality, myocardial infarction, and heart failure.

The Prognostic, Diagnostic, and Therapeutic Potential of TRAIL Signalling in Cardiovascular Diseases

TNF-related apoptosis-inducing ligand (TRAIL) was originally discovered, almost 20 years ago, for its ability to kill cancer cells. More recent evidence has described pleiotropic functions, particularly in the cardiovascular system. There is potential for TRAIL concentrations in the circulation to act as prognostic and/or diagnostic factors for cardiovascular diseases (CVD). Pre-clinical studies also describe the therapeutic capacity for TRAIL signals, particularly in the context of atherosclerotic disease and diseases of the myocardium. Because diabetes mellitus significantly contributes to the progression and pathogenesis of CVDs, in this review we highlight recent evidence for the prognostic, diagnostic, and therapeutic potential of TRAIL signals in CVDs, and where relevant, the impact of diabetes mellitus. A greater understanding of how TRAIL signals regulate cardiovascular protection and pathology may offer new diagnostic and therapeutic avenues for patients suffering from CVDs.

Are the results from a multiplex proteomic assay and a conventional immunoassay for NT-proBNP and GDF-15 comparable?

BACKGROUND

We aimed to compare absolute plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) obtained by a conventional immunoassay with the corresponding relative concentrations from a proximity extension assay (PEA) and compare the prognostic impact of the protein levels obtained from these assays.

METHODS

We evaluated 437 patients with peripheral arterial disease (PAD) and a population-based cohort of 643 individuals without PAD. Correlations were calculated using Spearman's rank correlation coefficients (rho). The discriminatory accuracy of the protein levels to predict future cardiovascular events was analyzed with Cox regression and presented as time-dependent areas under the receiver-operator-characteristic curves (tdAUCs).

RESULTS

For NT-proBNP, the two assays correlated with rho 0.93 and 0.93 in the respective cohort. The PEA values leveled off at higher values in both cohorts. The corresponding correlations for GDF-15 were 0.91 and 0.89. At 5 years follow-up, the tdAUCs in the patient cohort were similar for NT-proBNP and GDF-15 regardless of assay used (0.65-0.66). The corresponding tdAUCs in the population-based cohort were between 0.72 and 0.77.

CONCLUSION

Except for the highest levels of NT-proBNP, we suggest that PEA data for NT-proBNP and GDF-15 reliably reflects absolute plasma levels and contains similar prognostic information.

Inflammatory plasma proteins predict short-term mortality in patients with an acute myocardial infarction

BACKGROUND

The aim of this study was to investigate the association between inflammatory markers and 28-day mortality in patients with ST-elevation myocardial infarction (STEMI).

METHODS

In 398 STEMI patients recorded between 2009 and 2013 by the population-based Myocardial Infarction Registry Augsburg, 92 protein biomarkers were measured in admission arterial blood samples using the OLINK inflammatory panel. In multivariable-adjusted logistic regression models, the association between each marker and 28-day mortality was investigated. The values of the biomarkers most significantly associated with mortality were standardized and summarized to obtain a prediction score for 28-day mortality. The predictive ability of this biomarker score was compared to the established GRACE score using ROC analysis. Finally, a combined total score was generated by adding the standardized biomarker score to the standardized GRACE score.

RESULTS

The markers IL-6, IL-8, IL-10, FGF-21, FGF-23, ST1A1, MCP-1, 4E-BP1, and CST5 were most significantly associated with 28-day mortality, each with FDR-adjusted (false discovery rate adjusted) p-values of < 0.01 in the multivariable logistic regression model. In a ROC analysis, the biomarker score and the GRACE score showed comparable predictive ability for 28-day mortality (biomarker score AUC: 0.7859 [CI: 0.6735-0.89], GRACE score AUC: 0.7961 [CI: 0.6965-0.8802]). By combining the biomarker score and the Grace score, the predictive ability improved with an AUC of 0.8305 [CI: 0.7269-0.9187]. A continuous Net Reclassification Improvement (cNRI) of 0.566 (CI: 0.192-0.94, p-value: 0.003) and an Integrated Discrimination Improvement (IDI) of 0.083 ((CI: 0.016-0.149, p-value: 0.015) confirmed the superiority of the combined score over the GARCE score.

CONCLUSIONS

Inflammatory biomarkers may play a significant role in the pathophysiology of acute myocardial infarction (AMI) and AMI-related mortality and might be a promising starting point for personalized medicine, which aims to provide each patient with tailored therapy.

Using multimarker screening to identify biomarkers associated with cardiovascular death in patients with atrial fibrillation

AIMS

Atrial fibrillation (AF) is associated with higher mortality. Biomarkers may improve the understanding of key pathophysiologic processes in AF that lead to death. Using a new multiplex analytic technique, we explored the association between 268 biomarkers and cardiovascular (CV) death in anticoagulated patients with AF.

METHODS AND RESULTS

A case-cohort design with 1.8- to 1.9-year follow-up. The identification cohort included 517 cases and 4057 randomly selected patients from ARISTOTLE. The validation cohort included 277 cases and 1042 randomly selected controls from RE-LY. Plasma collected at randomization was analysed with conventional immunoassays and the OLINK proximity extension assay panels: CVDII, CVDIII, and Inflammation. Association between biomarkers and CV death was evaluated using Random Survival Forest, Boruta, and adjusted Cox-regression analyses. The biomarkers most strongly and consistently associated with CV death were as follows (hazard ratio for inter-quartile comparison [95% CI]): N-terminal pro-B-type natriuretic peptide [NT-proBNP; 1.63 (1.37-1.93)], cardiac troponin T [cTnT-hs; 1.60 (1.35-1.88)], interleukin-6 [IL-6; 1.29 (1.13-1.47)], growth differentiation factor-15 [GDF-15; 1.30 (1.10-1.53)], fibroblast growth factor 23 [FGF-23; 1.21 (1.10-1.33)], urokinase receptor [uPAR; 1.38 (1.16-1.64)], trefoil factor 3 [TFF3; 1.27 (1.10-1.46)], tumour necrosis factor receptor 1 [TNFR1; 1.21 (1.01-1.45)], TNF-related apoptosis-inducing ligand receptor 2 [TRAILR2; 1.18 (1.04-1.34)], and cathepsin L1 [CTSL1; 1.22 (1.07-1.39)].

CONCLUSION

In this comprehensive screening of 268 biomarkers in anticoagulated patients with AF, the underlying mechanisms most strongly associated with CV death were cardiorenal dysfunction (NT-proBNP, cTnT-hs, CTSL1, TFF3), oxidative stress (GDF-15), inflammation (IL-6, GDF-15), calcium balance, vascular and renal dysfunction (FGF-23), fibrinolysis (suPAR), and apoptosis (TNFR1, TRAILR2). These findings provide novel insights into pathophysiologic aspects associated with CV death in AF.

CLINICALTRIALS.GOV IDENTIFIER

NCT00412984 and NCT00262600.

Circulating growth differentiation factor 15 levels and apolipoprotein B to apolipoprotein A1 ratio in coronary artery disease patients with type 2 diabetes mellitus

BACKGROUND

Clinical investigations have found that there was a close association between T2DM and adverse cardiovascular events, with possible mechanisms included inflammation, apoptosis, and lipid metabolism disorders. High serum GDF-15 concentration and the apolipoprotein B/apolipoprotein A1 ratio (ApoB/ApoA1) are involved in the above-mentioned mechanisms and are thought to be related to the occurrence of adverse cardiovascular events. However, it remains unclear whether circulating GDF-15 levels and the ApoB/ApoA1 ratio are related to T2DM patients with CAD.

METHODS

T2DM patients with or without CAD were eligible for this study. According to the inclusion and exclusion criteria, 502 T2DM patients were enrolled between January 2021 and December 2021 and were then divided into T2DM group (n = 249) and CAD group (n = 253). The ApoB, ApoA1 and GDF-15 concentrations were measured at hospital admission and the ApoB/ApoA1 ratio was then calculated.

RESULTS

Compared with T2DM group, serum GDF-15 levels and ApoB/ApoA1 ratio increased in CAD group. Furthermore, a positive relationship between the occurrence of CAD in diabetic population and circulating GDF-15 concentrations and ApoB/ApoA1 ratio was observed in logistic regression analysis (p < 0.01). Restrictive cubic spline analysis after adjusted for multiple risky variables showed that serum GDF-15 or ApoB/ApoA1 ratio correlated positively with CAD.

CONCLUSIONS

Circulating GDF-15 levels and serum ApoB/ApoA1 ratio vary in CAD group and T2DM group. ApoB/ApoA1 and GDF-15 may be helpful for predicting the occurrence of CAD in patients with T2DM.

Bidirectional Relationship Between Cancer and Heart Failure: Insights on Circulating Biomarkers

Cancer and heart failure are the two leading causes of death in developed countries. These two apparently distinct clinical entities share similar risk factors, symptoms, and pathophysiological mechanisms (inflammation, metabolic disturbances, neuro-hormonal and immune system activation, and endothelial dysfunction). Beyond the well-known cardiotoxic effects of oncological therapies, cancer and heart failure are thought to be tied by a bidirectional relationship, where one disease favors the other and vice versa. In this context, biomarkers represent a simple, reproducible, sensitive and cost-effective method to explore such relationship. In this review, we recapitulate the evidence on cardiovascular and oncological biomarkers in the field of cardioncology, focusing on their role in treatment-naïve cancer patients. Cardioncological biomarkers are useful tools in risk stratification, early detection of cardiotoxicity, follow-up, and prognostic assessment. Intriguingly, these biomarkers might contribute to better understand the common pathophysiology of cancer and heart failure, thus allowing the implementation of preventive and treatment strategies in cardioncological patients

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) in Patients after Acute Stroke: Relation to Stroke Severity, Myocardial Injury, and Impact on Prognosis

Background: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is known to be associated with poor prognosis after cardiovascular events. We aimed to assess the dynamic changes in TRAIL levels and the relation of TRAIL level to stroke severity, its impact on the short-term outcomes, and its association with markers of cardiac injury in patients after acute stroke. Methods: Between August 2020 and August 2021, 120 consecutive patients, 104 after acute ischemic stroke (AIS), 76 receiving reperfusion therapy, and 16 patients after intracerebral hemorrhage (ICH) were enrolled in our study. Blood samples were obtained from patients at the time of admission, 24 h later, and 48 h later to determine the plasma level of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and high-sensitive Troponin I (hs-TnI). Twelve-lead ECGs were obtained at the time of admission, 24 h later, 48 h later, and at the release of the patients. Evaluations were performed using the National Institutes of Health Stroke Scale (NIHSS) at the time of admission and using the modified Rankin Scale (mRS) 90 days following the patient’s discharge from the hospital. Results: We observed a connection between lower TRAIL levels and stroke severity evaluated using the NIHSS (p = 0.044) on the first day. Lower TRAIL showed an association with severe disability and death as evaluated using the mRS at 90 days, both after 24 (p = 0.0022) and 48 h (p = 0.044) of hospitalization. Moreover, we observed an association between lower TRAIL and NT-proBNP elevation at the time of admission (p = 0.039), after 24 (p = 0.043), and after 48 h (p = 0.023) of hospitalization. In the ECG analysis, lower TRAIL levels were associated with the occurrence of premature ventricular extrasystoles (p = 0.043), and there was an association with prolonged QTc interval (p = 0.052). Conclusions: The results show that lower TRAIL is associated with stroke severity, unfavorable functional outcome, and short-term mortality in patients after acute ischemic stroke. Moreover, we described the association with markers of cardiac injury and ECG changes.

Prognostic role of inflammatory cytokines and novel adipokines in acute myocardial infarction: An updated and comprehensive review

Acute myocardial infarction (AMI) is one of the major causes of morbidity and mortality worldwide. The inflammation response during and after AMI is common and seems to play a key role in the peri-AMI period, related with ischaemia-reperfusion injury, adverse cardiac remodelling, infarct size and poor prognosis. In this article, we provide an updated and comprehensive overview of the most important cytokines and adipokines involved in the complex pathophysiology mechanisms in AMI, summarizing their prognostic role post-AMI. Data so far support that elevated levels of the major proinflammatory cytokines TNFα, IL-6 and IL-1 and the adipokines adiponectin, visfatin and resistin, are linked to high mortality and morbidity. In contrary, there is evidence that anti-inflammatory cytokines and adipokines as IL-10, omentin-1 and ghrelin can suppress the AMI-induced inflammatory response and are correlated with better prognosis. Mixed data make unclear the role of the novel adipokines leptin and apelin. After all, imbalance of pro-inflammatory and anti-inflammatory cytokines may result in worst AMI prognosis. The incorporation of these inflammation biomarkers in established prognostic models could further improve their prognostic power improving overall the management of AMI patients.

IL-6, IL-1RA and Resistin as Predictors of Left Ventricular Remodelling and Major Adverse Cardiac Events in Patients with Acute ST Elevation Myocardial Infarction

Despite continuous advances in diagnostic and therapeutic methods, acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. Considering the role of inflammation in AMI etiopathogenesis, we aimed to explore the role of a group of three inflammatory cytokines (IL-1RA, IL-6 and resistin) as an independent prognostic factor for LVR assessed by 3D echocardiography and MACE in patients with STEMI. We enrolled 41 patients with STEMI who underwent primary PCI. We assessed the occurrence of LVR (defined as an increase of over 20% in end-diastolic left ventricular volume at 6 months compared with baseline values) and MACE. Using the enzyme-linked immunosorbent assays (ELISA) method, we measured plasmatic levels of IL-6, IL-1RA and resistin (within 48 h after AMI and at 6 months). Out of 41 STEMI patients, 20.5% presented signs of LVR at follow up, and in 24.4%, MACE occurred. In univariate logistic regression analysis, baseline levels of IL-6 (OR = 1.042, p = 0.004), IL-1RA (OR = 1.004, p = 0.05) and resistin (OR = 1.7, p = 0.007) were all significantly associated with LVR. ROC analysis showed that the three cytokines as a group (AUC 0.946, p = 0.000) have a better predictive value for LVR than any individual cytokine. The group of cytokines also proved to have a better predictive value for MACE together than separately (AUC = 0.875, p = 0.000 for ROC regression model). IL-6, IL-1RA and resistin plasma levels at baseline have a good predictive value both as independent variables and also as a group for the development of adverse LVR and MACE at 6 months follow up after STEMI.

Pathophysiological pathways related to high plasma GDF-15 concentrations in patients with heart failure

AIMS

Elevated concentrations of Growth Differentiation factor 15 (GDF-15) in patients with heart failure (HF) have been consistently associated with worse clinical outcomes, but what disease mechanisms high GDF-15 concentrations represent remains unclear. Here, we aim to identify activated pathophysiological pathways related to elevated GDF-15 expression in patients with HF.

METHODS AND RESULTS

In 2279 patients with HF, we measured circulating levels of 363 biomarkers. Then, we performed a pathway over-representation analysis to identify key biological pathways between patients in the highest and lowest GDF-15 concentration quartiles. Data were validated in an independent cohort of 1705 patients with HF. In both cohorts, the strongest up-regulated biomarkers in those with high GDF-15 were fibroblast growth factor 23 (FGF-23), death receptor 5 (TRAIL-R2), WNT1-inducible-signaling pathway protein 1 (WISP-1), TNF Receptor Superfamily Member 11a (TNFRSF11A), leukocyte immunoglobulin-like receptor subfamily B member 4 (LILRB4), and Trefoil Factor 3 (TFF3). Pathway over-representation analysis revealed that high GDF-15 patients had increased activity of pathways related to inflammatory processes, notably positive regulation of chemokine production; response to interleukin 6 (IL-6); tumour necrosis factor (TNF) and death receptor activity; and positive regulation of T cell differentiation and inflammatory response. Furthermore, we found pathways involved in regulation of insulin-like growth factor (IGF) receptor signalling and regulatory pathways of tissue, bones, and branching structures. GDF-15 quartiles significantly predicted all-cause mortality and HF hospitalization.

CONCLUSION

Patients with HF and high plasma concentrations of GDF-15 are characterized by increased activation of inflammatory pathways and pathways related to IGF-1 regulation and bone/tissue remodelling.

A Dual Role for Death Receptor 5 in Regulating Cardiac Fibroblast Function

The fibrotic response is involved in nearly all forms of heart failure and dysregulated responses can lead to enhanced cardiac dysfunction. TNF-related apoptosis-inducing ligand (TRAIL) and its receptor, death receptor (DR) 5, are associated with multiple forms of heart failure, but their role in the heart is poorly defined. Our previous study identified DR5 expression on cardiac fibroblasts however, the impact of DR5 on fibroblast function remains unexplored. To investigate the role of DR5 in cardiac fibroblasts, a variety of fibroblast functions were examined following treatment with the endogenous ligand, TRAIL, or small molecule agonist, bioymifi. DR5 activation did not induce apoptosis in naïve fibroblasts but activated ERK1/2 signaling to increase proliferation. However, upon activation and differentiation to myofibroblasts, DR5 expression was elevated, and DR5 agonists induced caspase 3 activation resulting in myofibroblast apoptosis. To investigate the impact of DR5 regulation of fibroblasts in vivo, a chronic isoproterenol administration model of heart failure was used. Wild-type (WT) mice receiving isoproterenol had increased hypertrophy, cardiomyocyte death, and fibrosis and decreased contractility compared to vehicle treated animals. DR5 knockout (KO) mice had no overt baseline phenotype however, following isoproterenol infusion, increased cardiomyocyte death and hypertrophy in comparison to isoproterenol treated WT animals was observed. DR5KO mice had an augmented fibrotic response with isoproterenol treatment compared with WT, which corresponded with additional decreases in contractility. These findings identify a dual role for DR5 in cardiac fibroblast function through enhanced naïve fibroblast proliferation, which switches to a pro-apoptotic function upon differentiation to myofibroblasts. This is important in heart failure where DR5 activation suppresses maladaptive remodeling and may represent a novel therapeutic target for the treatment of heart failure.

White blood cell subtypes as predictors of adverse cardiac events

BACKGROUND

White blood cell (WBC) subtypes have been associated with major adverse cardiovascular events (MACEs) in acute myocardial infarction (AMI). More recently, combining neutrophil and lymphocyte counts or lymphocyte and monocyte counts into a ratio has found to be promising for predicting MACE. This study aimed to confirm the association between MACE and the following WBC subtypes: neutrophils, lymphocytes, monocytes, neutrophil-lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR).

METHODS

In a cohort of 860 AMI patients, we collected levels of WBC subtypes from the earliest blood tests recorded prior to angiography. Data on baseline demographics and one-year outcomes were also collected.

RESULTS

At one year, 130 patients (15.1%) developed MACE. NLR and LMR were significantly associated with MACE on univariate analysis (P = 0.006 and 0.005, respectively). However, when combined into a multivariate model with age, hypertension, prior myocardial infarction and Type 2 diabetes, neither NLR nor LMR had significant associations (odds ratio = 1.058 and 0.966, P = 0.069 and 0.612, respectively).

CONCLUSION

As NLR and LMR were correlated with MACE only on univariate analysis, we do not believe that they are predictive enough to be used alone in a clinical setting. Further studies are required to assess the prognostic ability of these ratios in combination with other inflammatory markers.

Screening of biomarkers for prediction of multisite artery disease in patients with recent myocardial infarction

A few studies have examined biomarkers in patients with myocardial infarction (MI) and peripheral artery disease (PAD), i.e. multisite artery disease (MSAD). The aim of the study was firstly, to associate biomarkers with the occurrence of PAD/MSAD and secondly, if those can, in addition to clinical characteristics, identify MI patients with MSAD.In two prospectively observational studies including unselected patients with recent MI, PAD was defined as an abnormal ankle-brachial index (ABI) score (<0.9 or >1.4). The proximity extension assay (PEA) technique was used, simultaneously analyzing 92 biomarkers with association to cardiovascular disease. Biomarkers were tested for univariate associations with PAD. Random forest was used to identify biomarkers with a higher association to PAD. The additional discriminatory accuracy of adding biomarkers to clinical characteristics was analyzed by the c-statistics. Nine biomarkers were identified as significantly associated with MSAD/PAD in the primary patient cohort, analyzed early after the MI. In the prediction analysis, six biomarkers were identified associated with PAD. Three of these; Tumor necrosis factor receptor (TNFR-1), Tumor necrosis factor receptor 2 (TNFR-2) and Growth Differentiation Factor 15 (GDF-15) improved c-statistics when added to clinical characteristics from 0.683 (95% CI 0.610-0.756) to 0.715 (95% CI 0.645-0.784) in the primary patient cohort with a similar result, 0.729 (95% CI 0.687-0.770) to 0.752 (95% CI 0.771-0.792) in the secondary patient cohort. Biomarkers associated with inflammatory pathways are associated with MSAD in MI patients. Three biomarkers of 92; TNFR-1, TNFR-2 and GDF-15, in this exploratory added information in the prediction of MSAD and emphasis the importance of further studies.

Osteoprotegerin and RANKL-RANK-OPG-TRAIL signalling axis in heart failure and other cardiovascular diseases

Osteoprotegerin (OPG) is a glycoprotein involved in the regulation of bone remodelling. OPG regulates osteoclast activity by blocking the interaction between the receptor activator of nuclear factor kappa B (RANK) and its ligand (RANKL). More and more studies confirm the relationship between OPG and cardiovascular diseases. Numerous studies have confirmed that a high plasma concentration of OPG and a low concentration of tumour necrosis factor–related apoptosis inducing ligand (TRAIL) together with a high OPG/TRAIL ratio are predictors of poor prognosis in patients with myocardial infarction. A high plasma OPG concentration and a high ratio of OPG/TRAIL in the acute myocardial infarction are a prognostic indicator of adverse left ventricular remodelling and of the development of heart failure. Ever more data indicates the participation of OPG in the regulation of the function of vascular endothelial cells and the initiation of the atherosclerotic process in the arteries. Additionally, it has been shown that TRAIL has a protective effect on blood vessels and exerts an anti-atherosclerotic effect. The mechanisms of action of both OPG and TRAIL within the cells of the vascular wall are complex and remain largely unclear. However, these mechanisms of action as well as their interaction in the local vascular environment are of great interest to researchers. This article presents the current state of knowledge on the mechanisms of action of OPG and TRAIL in the circulatory system and their role in cardiovascular diseases. Understanding these mechanisms may allow their use as a therapeutic target in cardiovascular diseases in the future.

Red cell distribution width in patients with diabetes and myocardial infarction: An analysis from the EXAMINE trial

AIM

To determine the clinical correlates of increased red blood cell distribution width (RDW), its potential mechanistic association with multiple circulating biomarkers, and its prognostic value in patients with type 2 diabetes (T2D) who had a recent acute coronary syndrome.

METHODS

We used time-updated Cox models applied to patients enrolled in the Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care (EXAMINE) trial.

RESULTS

A total of 5380 patients were included, the median age was 61 years and 32% were women. Patients with higher RDW were older, more frequently women, with a longer diabetes duration and increased co-morbidities. An RDW of more than 16.1% (both baseline and time-updated) was independently associated with the study primary composite outcome of non-fatal myocardial infarction, non-fatal stroke or cardiovascular death (time-updated adjusted HR = 1.36, 95% CI = 1.16-1.61, p < .001), all-cause death (time-updated adjusted HR = 2.01, 95% CI = 1.60-2.53, p < .001), as well as mortality from non-cardiovascular causes (time-updated adjusted HR = 2.67, 95% CI = 1.72-4.15, p < .001). RDW had a weak-to-moderate correlation with haemoglobin and circulating markers that reflected inflammation, apoptosis, fibrosis and congestion. Alogliptin did not alter RDW values.

CONCLUSIONS

RDW is a marker of disease severity associated with a multitude of poor outcomes, including both cardiovascular and non-cardiovascular death. RDW correlated modestly with inflammatory, pro-apoptotic, pro-fibrotic and congestion markers, and its levels were not affected by alogliptin during the course of the trial.

Blocking the death checkpoint protein TRAIL improves cardiac function after myocardial infarction in monkeys, pigs, and rats

Myocardial infarction (MI) is a leading cause of death worldwide for which there is no cure. Although cardiac cell death is a well-recognized pathological mechanism of MI, therapeutic blockade of cell death to treat MI is not straightforward. Death receptor 5 (DR5) and its ligand TRAIL [tumor necrosis factor (TNF)-related apoptosis-inducing ligand] are up-regulated in MI, but their roles in pathological remodeling are unknown. Here, we report that blocking TRAIL with a soluble DR5 immunoglobulin fusion protein diminished MI by preventing cardiac cell death and inflammation in rats, pigs, and monkeys. Mechanistically, TRAIL induced the death of cardiomyocytes and recruited and activated leukocytes, directly and indirectly causing cardiac injury. Transcriptome profiling revealed increased expression of inflammatory cytokines in infarcted heart tissue, which was markedly reduced by TRAIL blockade. Together, our findings indicate that TRAIL mediates MI directly by targeting cardiomyocytes and indirectly by affecting myeloid cells, supporting TRAIL blockade as a potential therapeutic strategy for treating MI.

Predicting outcome in acute myocardial infarction: an analysis investigating 175 circulating biomarkers

AIMS 

There is a paucity of studies comprehensively comparing the prognostic value of larger arrays of biomarkers indicative of different pathobiological axes in acute myocardial infarction (MI).

METHODS AND RESULTS 

In this explorative investigation, we simultaneously analysed 175 circulating biomarkers reflecting different inflammatory traits, coagulation activity, endothelial dysfunction, atherogenesis, myocardial dysfunction and damage, apoptosis, kidney function, glucose-, and lipid metabolism. Measurements were performed in samples from 1099 MI patients (SWEDEHEART registry) applying two newer multimarker panels [Proximity Extension Assay (Olink Bioscience), Multiple Reaction Monitoring mass spectrometry]. The prognostic value of biomarkers regarding all-cause mortality, recurrent MI, and heart failure hospitalizations (median follow-up ≤6.6 years) was studied using Lasso analysis, a penalized logistic regression model that considers all biomarkers simultaneously while minimizing the risk for spurious findings. Tumour necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2), ovarian cancer-related tumour marker CA 125 (CA-125), and fibroblast growth factor 23 (FGF-23) consistently predicted all-cause mortality in crude and age/sex-adjusted analyses. Growth-differentiation factor 15 (GDF-15) was strongly predictive in the crude model. TRAIL-R2 and B-type natriuretic peptide (BNP) consistently predicted heart failure hospitalizations. No biomarker predicted recurrent MI. The prognostic value of all biomarkers was abrogated following additional adjustment for clinical variables owing to our rigorous statistical approach.

CONCLUSION 

Apart from biomarkers with established prognostic value (i.e. BNP and to some extent GDF-15), several 'novel' biomarkers (i.e. TRAIL-R2, CA-125, FGF-23) emerged as risk predictors in patients with MI. Our data warrant further investigation regarding the utility of these biomarkers for clinical decision-making in acute MI.

Osteoprotegerin predicts cardiovascular events in patients treated with hemodialysis

BACKGROUND

Disturbances in bone mineral metabolism are associated with increased mortality and cardiovascular events (CVEs). However, the association between bone-associated protein biomarkers, mortality, and CVEs independent of cytokine activation remains unknown. This study aimed to investigate bone-associated protein biomarkers, and the association with inflammatory cytokines, and cardiovascular outcomes.

METHODS

This prospective study enrolled hemodialysis (HD) patients in Denmark between December 2010 and March 2011. Using a proximity extension proteomics assay, nine bone-associated proteins were examined: cathepsin D (CTSD), cathepsin L1 (CTSL1), dickkopf-related protein 1 (Dkk-1), fibroblast growth factor 23 (FGF-23), leptin, osteoprotegerin (OPG), receptor activator of nuclear factor kappa-Β ligand (RANKL), TNF-related apoptosis-inducing ligand (TRAIL), and TNF-related apoptosis-inducing ligand receptor 2 (TRAIL-R2). The importance of the bone-associated protein markers was evaluated by a random forest algorithm (RF). The association between bone-associated proteins with all-cause death, cardiovascular death, and CVEs was analyzed in multivariable Cox models adjusted for age, gender, comorbidities, laboratory data, and dialysis duration.

RESULTS

We enrolled 331 patients (63.7% men; mean [SD] age, 65 [14.6] years) in a prospective cohort study with five years follow-up. When adjusting for confounders, CTSL1 remained associated with all-cause death, and four biomarkers were associated with CVE. However, the association between bone markers and the outcomes was attenuated after adjusting for inflammatory proteins, and just OPG remained associated with CVE in the adjusted model. Evaluating the importance of bone markers by RF, OPG was the most important marker related to CVEs. OPG also improved the prediction of CVE when added clinical information alone in integrated discrimination improvement and net reclassification improvement analyses.

DISCUSSION

OPG, a well-known bone biomarker, was associated with CVEs independent of cytokine activity. In contrast, the association between CVEs and the remaining three bone-associated proteins (TRAIL-R2, CTSD, and CTSL1) was affected by cytokine inflammation activity.

let-7 microRNAs: Their Role in Cerebral and Cardiovascular Diseases, Inflammation, Cancer, and Their Regulation

The let-7 family is among the first microRNAs found. Recent investigations have indicated that it is highly expressed in many systems, including cerebral and cardiovascular systems. Numerous studies have implicated the aberrant expression of let-7 members in cardiovascular diseases, such as stroke, myocardial infarction (MI), cardiac fibrosis, and atherosclerosis as well as in the inflammation related to these diseases. Furthermore, the let-7 microRNAs are involved in development and differentiation of embryonic stem cells in the cardiovascular system. Numerous genes have been identified as target genes of let-7, as well as a number of the let-7’ regulators. Further studies are necessary to identify the gene targets and signaling pathways of let-7 in cardiovascular diseases and inflammatory processes. The bulk of the let-7’ regulatory proteins are well studied in development, proliferation, differentiation, and cancer, but their roles in inflammation, cardiovascular diseases, and/or stroke are not well understood. Further knowledge on the regulation of let-7 is crucial for therapeutic advances. This review focuses on research progress regarding the roles of let-7 and their regulation in cerebral and cardiovascular diseases and associated inflammation.

TRAIL and Cardiovascular Disease-A Risk Factor or Risk Marker: A Systematic Review

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a pro-apoptotic protein showing broad biological functions. Data from animal studies indicate that TRAIL may possibly contribute to the pathophysiology of cardiomyopathy, atherosclerosis, ischemic stroke and abdominal aortic aneurysm. It has been also suggested that TRAIL might be useful in cardiovascular risk stratification. This systematic review aimed to evaluate whether TRAIL is a risk factor or risk marker in cardiovascular diseases (CVDs) focusing on major adverse cardiovascular events. Two databases (PubMed and Cochrane Library) were searched until December 2020 without a year limit in accordance to the PRISMA guidelines. A total of 63 eligible original studies were identified and included in our systematic review. Studies suggest an important role of TRAIL in disorders such as heart failure, myocardial infarction, atrial fibrillation, ischemic stroke, peripheral artery disease, and pulmonary and gestational hypertension. Most evidence associates reduced TRAIL levels and increased TRAIL-R2 concentration with all-cause mortality in patients with CVDs. It is, however, unclear whether low TRAIL levels should be considered as a risk factor rather than a risk marker of CVDs. Further studies are needed to better define the association of TRAIL with cardiovascular diseases.

GDF-15 as a Biomarker in Cardiovascular Disease

In the last years, several diagnostic and prognostic biomarkers have been studied in cardiovascular disease. Growth differentiation factor-15 (GDF-15), a cytokine belonging to the transforming growth factor- (TGF-) family, is highly up-regulated in stress and inflammatory conditions and has been correlated to myocardial injury and pressure cardiac overload in animal models. This new biomarker has been positively correlated with increased risk of cardiovascular events in population studies and shown an independent predictor of mortality in patients with coronary artery disease and heart failure. This review aimed to summarize the current evidence on the diagnostic and prognostic value of GDF-15 in different settings in cardiology.

Plasma proteins associated with cardiovascular death in patients with chronic coronary heart disease: A retrospective study

BACKGROUND

Circulating biomarkers are associated with the development of coronary heart disease (CHD) and its complications by reflecting pathophysiological pathways and/or organ dysfunction. We explored the associations between 157 cardiovascular (CV) and inflammatory biomarkers and CV death using proximity extension assays (PEA) in patients with chronic CHD.

METHODS AND FINDINGS

The derivation cohort consisted of 605 cases with CV death and 2,788 randomly selected non-cases during 3-5 years follow-up included in the STabilization of Atherosclerotic plaque By Initiation of darapLadIb TherapY (STABILITY) trial between 2008 and 2010. The replication cohort consisted of 245 cases and 1,042 non-cases during 12 years follow-up included in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study between 1997 and 2000. Biomarker levels were measured with conventional immunoassays and/or with the OLINK PEA panels CVD I and Inflammation. Associations with CV death were evaluated by Random Survival Forest (RF) and Cox regression analyses. Both cohorts had the same median age (65 years) and 20% smokers, while there were slight differences in male sex (82% and 76%), hypertension (70% and 78%), and diabetes (39% and 30%) in the respective STABILITY and LURIC cohorts. The analyses identified 18 biomarkers with confirmed independent association with CV death by Boruta analyses and statistical significance (all p < 0.0001) by Cox regression when adjusted for clinical characteristics in both cohorts. Most prognostic information was carried by N-terminal prohormone of brain natriuretic peptide (NTproBNP), hazard ratio (HR for 1 standard deviation [SD] increase of the log scale of the distribution of the biomarker in the replication cohort) 2.079 (95% confidence interval [CI] 1.799-2.402), and high-sensitivity troponin T (cTnT-hs) HR 1.715 (95% CI 1.491-1.973). The other proteins with independent associations were growth differentiation factor 15 (GDF-15) HR 1.728 (95% CI 1.527-1.955), transmembrane immunoglobulin and mucin domain protein (TIM-1) HR 1.555 (95% CI 1.362-1.775), renin HR 1.501 (95% CI 1.305-1.727), osteoprotegerin (OPG) HR 1.488 (95% CI 1.297-1.708), soluble suppression of tumorigenesis 2 protein (sST2) HR 1.478 (95% CI 1.307-1.672), cystatin-C (Cys-C) HR 1.370 (95% CI 1.243-1.510), tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) HR 1.205 (95% CI 1.131-1.285), carbohydrate antigen 125 (CA-125) HR 1.347 (95% CI 1.226-1.479), brain natriuretic peptide (BNP) HR 1.399 (95% CI 1.255-1.561), interleukin 6 (IL-6) HR 1.478 (95% CI 1.316-1.659), hepatocyte growth factor (HGF) HR 1.259 (95% CI 1.134-1.396), spondin-1 HR 1.295 (95% CI 1.156-1.450), fibroblast growth factor 23 (FGF-23) HR 1.349 (95% CI 1.237-1.472), chitinase-3 like protein 1 (CHI3L1) HR 1.284 (95% CI 1.129-1.461), tumor necrosis factor receptor 1 (TNF-R1) HR 1.486 (95% CI 1.307-1.689), and adrenomedullin (AM) HR 1.750 (95% CI 1.490-2.056). The study is limited by the differences in design, size, and length of follow-up of the 2 studies and the lack of results from coronary angiograms and follow-up of nonfatal events.

CONCLUSIONS

Profiles of levels of multiple plasma proteins might be useful for the identification of different pathophysiological pathways associated with an increased risk of CV death in patients with chronic CHD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00799903.

An IL-6-IL-8 score derived from principal component analysis is predictive of adverse outcome in acute myocardial infarction

INTRODUCTION

Many studies have shown that elevated biomarkers of inflammation following acute myocardial infarction (AMI) are associated with major adverse cardiovascular events (MACE). However, the optimal way of measuring the complex inflammatory response following AMI has not been determined. In this study we explore the use of principal component analysis (PCA) utilising multiple inflammatory cytokines to generate a combined cytokine score that may be predictive of MACE post-AMI.

METHODS

Thirteen inflammatory cytokines were measured in plasma of 317 AMI patients, drawn 48-72 h following symptom onset. Patients were followed-up for one year to determine the incidence of MACE. PCA was used to generate a combined score using six cytokines that were detectable in the majority of patients (IL-1β, -6, -8, and -10; MCP-1; and RANTES), and using a subset of cytokines that were associated with MACE on univariate analysis. Multivariate models using baseline characteristics, elevated individual cytokines and PCA-derived scores determined independent predictors of MACE.

RESULTS

IL-6 and IL-8 were significantly associated with MACE on univariate analysis and were combined using PCA into an IL-6-IL-8 score. The combined cytokine score and IL-6-IL-8 PCA-derived score were both significantly associated with MACE on univariate analysis. In multivariate models IL-6-IL-8 scores (OR = 2.77, p = 0.007) and IL-6 levels (OR = 2.18, p = 0.035) were found to be independent predictors of MACE.

CONCLUSION

An IL-6-IL-8 score derived from PCA was found to independently predict MACE at one year and was a stronger predictor than any individual cytokine, which suggests this may be an appropriate strategy to quantify inflammation post-AMI. Further investigation is required to determine the optimal set of cytokines to measure in this context.

Use of proteomics to identify biomarkers associated with chronic kidney disease and long-term outcomes in patients with myocardial infarction

BACKGROUND

Patients with chronic kidney disease (CKD) have poor outcomes following myocardial infarction (MI). We performed an untargeted examination of 175 biomarkers to identify those with the strongest association with CKD and to examine the association of those biomarkers with long-term outcomes.

METHODS

A total of 175 different biomarkers from MI patients enrolled in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry were analysed either by a multiple reaction monitoring mass spectrometry assay or by a multiplex assay (proximity extension assay). Random forests statistical models were used to assess the predictor importance of biomarkers, CKD and outcomes.

RESULTS

A total of 1098 MI patients with a median estimated glomerular filtration rate of 85 mL min^-1 /1.73 m² were followed for a median of 3.2 years. The random forests analyses, without and with adjustment for differences in demography, comorbidities and severity of disease, identified six biomarkers (adrenomedullin, TNF receptor-1, adipocyte fatty acid-binding protein-4, TNF-related apoptosis-inducing ligand receptor 2, growth differentiation factor-15 and TNF receptor-2) to be strongly associated with CKD. All six biomarkers were also amongst the 15 strongest predictors for death, and four of them were amongst the strongest predictors of subsequent MI and heart failure hospitalization.

CONCLUSION

In patients with MI, a proteomic approach could identify six biomarkers that best predicted CKD. These biomarkers were also amongst the most important predictors of long-term outcomes. Thus, these biomarkers indicate underlying mechanisms that may contribute to the poor prognosis seen in patients with MI and CKD.

Insight into the divergent role of TRAIL in non-neoplastic neurological diseases

Tumour necrosis factor–related apoptosis‐inducing ligand (TRAIL) is a member of the tumour necrosis factor (TNF) superfamily which mainly induces apoptosis of tumour cells and transformed cell lines with no systemic toxicity, whereas they share high sequence homology with TNF and CD95L. These unique effects of TRAIL have made it an important molecule in oncology research. However, the research on TRAIL‐related antineoplastic agents has lagged behind and has been limited by the extensive drug resistance in cancer cells. Given the several findings showing that TRAIL is involved in immune regulation and other pleiotropic biological effects in non‐malignant cells, TRAIL and its receptors have attracted widespread attention from researchers. In the central nervous system (CNS), TRAIL is highly correlated with malignant tumours such as glioma and other non‐neoplastic disorders such as acute brain injury, CNS infection and neurodegenerative disease. Many clinical and animal studies have revealed the dual roles of TRAIL in which it causes damage by inducing cell apoptosis, and confers protection by enhancing both pro‐ and non‐apoptosis effects in different neurological disorders and at different sites or stages. Its pro‐apoptotic effect produces a pro‐survival effect that cannot be underestimated. This review extensively covers in vitro and in vivo experiments and clinical studies investigating TRAIL. It also provides a summary of the current knowledge on the TRAIL signalling pathway and its involvement in pathogenesis, diagnosis and therapeutics of CNS disorders as a basis for future research.

Melatonin regulates oxidative stress and apoptosis in fetal hearts of pinealectomised RUPP rats

OBJECTIVE

This study aimed to investigate the effects of melatonin on cardiac oxidative stress and apoptosis in the fetal heart in RUPP rats.

METHODS

The fetal heart samples were obtained from melatonin administrated RUPP rats.

RESULTS

Our results indicate that preeclampsia exacerbated by melatonin deficiency triggers hypoxic conditions, both mis/un-folded protein response, oxidative stress-induced DNA damage and apoptosis. Melatonin treatment provided significant therapeutic effects on fetal hearts via regulating all these stress response at cellular and molecular levels.

CONCLUSION

Melatonin may be considered as a potential molecule for development of preventive strategies to reduce the PE induced risk of cardiovascular diseases in offspring.

Targeted multiplex proteomics for prediction of all-cause mortality during long-term follow-up in outpatients with peripheral arterial disease

BACKGROUND AND AIMS

Patients with peripheral arterial disease (PAD) are at high risk for fatal events. We aimed to investigate the ability among several serum proteins to predict all-cause mortality in outpatients with PAD.

METHODS

Consecutive outpatients with carotid and/or lower extremity PAD were included in the discovery cohort (n = 436), and subjects with PAD from a population-based sample in the validation cohort (n = 129). Blood samples were analyzed for 81 proteins by a proximity extension assay. The proteins best predicting incident all-cause mortality were identified using L₁-regularized Cox regression. The added value of the identified proteins to clinical risk markers was evaluated by Cox regression models and presented by the area under the receiver operator characteristics curves (AUC).

RESULTS

In the discovery cohort (mean age 70 years; 59% men), 195 died (4.8 events per 100 person-years) during a 10.3 years median follow-up. The clinical risk markers generated an AUC of 0.70 (95% confidence interval [95%CI] 0.65-0.76). The two serum protein biomarkers with best prediction of all-cause mortality were growth differentiation factor 15 and tumor necrosis factor-related apoptosis-inducing ligand receptor 2. Adding these proteins to the clinical risk markers significantly improved prediction (p < 0.001) and yielded an AUC of 0.76 (95%CI 0.71-0.80). A higher discriminatory performance was observed in the validation cohort (AUC 0.84; 95% CI 0.76-0.92).

CONCLUSIONS

In a large-sample targeted proteomics assay, we identified two proteins that improved risk prediction beyond the COPART risk score. The use of high-throughput proteomics assays may identify potential biomarkers for improved risk prediction in patients with PAD.

Characterization of lamprey (Lampetra japonica) tnfr10-like gene: A potential granulocyte marker molecule and its immune functions

Tumor necrosis factor receptor superfamily (TNFRSF) is an ancient protein superfamily. By binding to tumor necrosis factor (TNF), it can participate in inflammatory response, apoptosis, lymphocyte homeostasis and tissue development. Seven TNFR members have previously been identified in lampreys but detailed functions of TNFR members are not yet to be resolved. Here, we demonstrate some of the distinguishing features of TNFR10-like member which belongs to TNFRSF. The immunohistochemical results indicate that the TNFR10-like protein is abundant in vascular epithelial cells of the lamprey typhlosole and gills. The expression of tnfr10-like gene has a significantly increased at transcription level after Vibrio anguillarum, Staphylococcus aureus and Poly (I:C) stimulation. Notably, TNFR10-like is specifically expressed in the granulocytes of lamprey peripheral blood and supraneural body. Besides, overexpression tnfr10-like gene in HEK-293 T cells cause a decrease in cell activity and able to activate nuclear transcription factor-κB (NF-κB). Together, these results imply that L-TNFR10-like may play a vital role as a potential marker in lamprey granulocytes and may also be involved in regulation of immune response mediated by itself.

GDF-15 is associated with sudden cardiac death due to incident myocardial infarction

AIMS

Preventing sudden cardiac death (SCD) due to acute myocardial infarction (MI) in previously healthy patients is challenging. Proteomic analysis may lead to an understanding of biological mechanisms and provide predictive biomarkers.

METHODS

In this prospective, nested case-control study from northern Sweden, 87 candidate cardiovascular protein biomarkers were studied in 244 individuals who later died within 24 h from an incident MI and 244 referents without MI and individually matched for age, sex and date of health examination and alive at the date of event in the index person. Association analysis was conducted using conditional logistic regression. Bonferroni correction was applied to avoid false positive findings.

RESULTS

Ten proteins were associated with future SCD due to acute MI in the non-adjusted analysis. The strongest association were found for growth differentiation factor 15 (GDF-15) with an odds ratio (OR) of 1.79 (95% confidence interval [CI] 1.41, 2.25) per standard deviation increase in protein, and urokinase-type plasminogen activator receptor with an OR of 1.66 (95% CI 1.34, 2.06). In models adjusted for lipid levels, body mass index, education, smoking, hypertension and C-reactive protein, only association with GDF-15 remained (OR 1.47 (95% 1.11, 1.95)).

CONCLUSION

Elevated levels of GDF-15 are associated with increased risk of SCD within 24 h of incident MI. Further research may enable the use of GDF-15 together with other clinical and biological markers to guide primary preventive interventions for individuals at high risk for SCD.

Association between inflammatory cytokines and long-term adverse outcomes in acute coronary syndromes: A systematic review

BACKGROUND

Inflammatory cytokines are involved in the pathophysiology of acute coronary syndromes (ACS) and have been associated with major adverse cardiovascular events (MACE). We systematically reviewed studies investigating the ability of multiple cytokines to predict MACE in ACS patients with follow-up of at least one year.

METHODS

A Medical Subject Heading search criteria was applied on Ovid Medline(R), EMBASE, EMBASE Classic and Cochrane Library to systematically identify relevant studies published between 1945 and 2017 that had an observational study design or were randomised controlled trials. Studies were excluded if only one cytokine was analysed, follow-up period was less than one year, subjects were non-human, or blood samples were taken more than 10 days from symptom onset.

RESULTS

Ten observational studies met the inclusion criteria. Six had acceptable internal validity when evaluated for quality. The studies were varied in terms of study methods (time of blood collection, study population, cytokines assessed, MACE definition, follow-up length) and result reporting, so a meta-analysis could not be conducted. Six of the studies found significant associations between individual cytokines and MACE. Four studies measured the combined effects of multiple cytokines to predict MACE, and all had statistically significant results.

CONCLUSION

A combination of multiple cytokines had a better association with MACE than individual cytokines. It appears promising for future studies to determine the optimal multi-marker methodology and confirm its predictive value.

The association between serum growth differentiation factor 15 levels and lower extremity atherosclerotic disease is independent of body mass index in type 2 diabetes

BACKGROUND

Clinical and basic investigations have indicated a significant association between circulating growth differentiation factor 15 (GDF15) and cardiovascular disease; however, the relationship between GDF15 and lower extremity atherosclerotic disease (LEAD) has been less studied. The present study aimed to explore the association between GDF15 and LEAD in Chinese patients with type 2 diabetes mellitus (T2DM). Considering that obesity is an important factor associated with circulating GDF15 levels, whether the relationship between serum GDF15 levels and LEAD is affected by body mass index (BMI) was also analysed.

METHODS

A total of 376 hospitalized T2DM patients were enrolled (161 with LEAD and 215 without LEAD). A sandwich enzyme-linked immunosorbent assay was used to detect the serum GDF15 levels. The femoral intima-media thickness (F-IMT) and LEAD were assessed by ultrasonography.

RESULTS

Patients with LEAD had significantly higher serum GDF15 levels than those without LEAD, regardless of whether their BMI was < 25 kg/m² or ≥ 25 kg/m² (both P < 0.05). Serum GDF15 levels were independently positively related to the F-IMT (standardized β = 0.162, P = 0.002). After adjusting for confounding factors, per 1-standard deviation (SD) increase in the serum GDF15 levels was significantly related to an approximately 1.4-fold increased risk of LEAD in the total population (P < 0.05). Regardless of whether the BMI was < 25 kg/m² or ≥ 25 kg/m², this association remained significant, with approximately 1.6- and 1.4-fold increased risks of LEAD, respectively (both P < 0.05).

CONCLUSIONS

High serum GDF15 levels were significantly correlated with an increased risk of LEAD in T2DM patients, and this relationship was independent of BMI.

GDF-15 in Pulmonary and Critical Care Medicine

GDF-15 (growth differentiation factor 15) acts both as a stress-induced cytokine with diverse actions at different body sites and as a cell-autonomous regulator linked to cellular senescence and apoptosis. For multiple reasons, this divergent transforming growth factor-β molecular superfamily member should be better known to pulmonary researchers and clinicians. In ambulatory individuals, GDF-15 concentrations in peripheral blood are an established predictive biomarker of all-cause mortality and of adverse cardiovascular events. Concentrations upon admission of critically ill patients (without or with sepsis) correlate with organ dysfunction and independently predict short- and long-term mortality risk. GDF-15 is a major downstream mediator of p53 activation, but it can also be induced independently of p53, notably by nonsteroidal antiinflammatory agents. GDF-15 blood concentrations are markedly elevated in adults and children with pulmonary hypertension. Concentrations are also increased in chronic obstructive pulmonary disease, in which they contribute to mucus hypersecretion, airway epithelial cell senescence, and impaired antiviral defenses, which together with murine data support a role for GDF-15 in chronic obstructive pulmonary disease pathogenesis and progression. This review summarizes biological and clinical data on GDF-15 relevant to pulmonary and critical care medicine. We highlight the recent discovery of a central nervous system receptor for GDF-15, GFRAL (glial cell line-derived neurotrophic factor family receptor-α-like), an important advance with potential for novel treatments for obesity and cachexia. We also describe limitations and controversies in the existing literature, and we delineate research questions that must be addressed to determine whether GDF-15 can be therapeutically manipulated in other clinical settings.

The clinical impact of growth differentiation factor-15 in heart disease: A 2019 update

Growth differentiation factor-15 (GDF-15), also known as macrophage inhibitory cytokine-1 (MIC-1) or non-steroidal anti-inflammatory drug-activated gene (NAG-1) has been identified as a biomarker of response to treatment and prognosis in cardiovascular diseases. GDF-15 is a member of the transforming growth factor-β superfamily and is involved in several pathological conditions such as inflammation, cancer, cardiovascular, pulmonary and renal diseases. Cardiac myocytes produce and secrete GDF-15 in response to oxidative stress, stimulation with angiotensin II or proinflammatory cytokines, ischemia, and mechanical stretch. Other cellular sources of GDF-15 production are macrophages, vascular smooth muscle cells, endothelial cells, and adipocytes, which secrete GDF-15 in response to oxidative or metabolic stress or stimulation of proinflammatory cytokines. GDF-15 is induced in hypertrophic and dilated cardiomyopathy after volume overload, ischemia, and heart failure. GDF-15 can be used as a marker of prognosis in patients with cardiovascular disorders, in combination with conventional prognostic factors, such as N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hs-TnT).

Death receptor 5 contributes to cardiomyocyte hypertrophy through epidermal growth factor receptor transactivation

Cardiomyocyte survival and death contributes to many cardiac diseases. A common mechanism of cardiomyocyte death is through apoptosis however, numerous death receptors (DR) have been virtually unstudied in the context of cardiovascular disease. Previous studies have identified TNF-related apoptosis inducing ligand (TRAIL) and its receptor, DR5, as being altered in a chronic catecholamine administration model of heart failure, and suggest a role of non-canonical signaling in cardiomyocytes. Furthermore, multiple clinical studies have identified TRAIL or DR5 as biomarkers in the prediction of severity and mortality following myocardial infarction and in heart failure development risk suggesting a role of DR5 signaling in the heart. While TRAIL/DR5 have been extensively studied as a potential cancer therapeutic due to their ability to selectively activate apoptosis in cancer cells, TRAIL and DR5 are highly expressed in the heart where their function is uncharacterized. However, many non-transformed cell types are resistant to TRAIL-induced apoptosis suggesting non-canonical functions in non-cancerous cell types. Our goal was to determine the role of DR5 in the heart with the hypothesis that DR5 does not induce cardiomyocyte apoptosis but initiates non-canonical signaling to promote cardiomyocyte growth and survival. Histological analysis of hearts from mice treated with a DR5 agonists showed increased hypertrophy with no differences in cardiomyocyte death, fibrosis or function. Mechanistic studies in the heart and isolated cardiomyocytes identified ERK1/2 activation with DR5 agonist treatment which contributed to hypertrophy. Furthermore, epidermal growth factor receptor (EGFR) was activated following DR5 agonist treatment through activation of MMP and HB-EGFR cleavage and specific inhibitors of MMP and EGFR prevented DR5-mediated ERK1/2 signaling and hypertrophy. Taken together, these studies identify a previously unidentified role for DR5 in the heart, which does not promote apoptosis but acts through non-canonical MMP-EGFR-ERK1/2 signaling mechanisms to contribute to cardiomyocyte hypertrophy.

Education and Lifestyle Factors Are Associated with DNA Methylation Clocks in Older African Americans

DNA methylation (DNAm) clocks are important biomarkers of cellular aging and are associated with a variety of age-related chronic diseases and all-cause mortality. Examining the relationship between education and lifestyle risk factors for age-related diseases and multiple DNAm clocks can increase the understanding of how risk factors contribute to aging at the cellular level. This study explored the association between education or lifestyle risk factors for age-related diseases and the acceleration of four DNAm clocks, including intrinsic (IEAA) and extrinsic epigenetic age acceleration (EEAA), PhenoAge acceleration (PhenoAA), and GrimAge acceleration (GrimAA) in the African American participants of the Genetic Epidemiology Network of Arteriopathy. We performed both cross-sectional and longitudinal analyses. In cross-sectional analyses, gender, education, BMI, smoking, and alcohol consumption were all independently associated with GrimAA, whereas only some of them were associated with other clocks. The effect of smoking and education on GrimAA varied by gender. Longitudinal analyses suggest that age and BMI continued to increase GrimAA, and that age and current smoking continued to increase PhenoAA after controlling DNAm clocks at baseline. In conclusion, education and common lifestyle risk factors were associated with multiple DNAm clocks. However, the association with each risk factor varied by clock, which suggests that different clocks may capture adverse effects from different environmental stimuli.

Cathepsin D improves the prediction of undetected diabetes in patients with myocardial infarction

Background: Newer therapeutic agents for type 2 diabetes mellitus can improve cardiovascular outcomes, but diabetes remains underdiagnosed in patients with myocardial infarction (MI). We sought to identify proteomic markers of undetected dysglycaemia (impaired fasting glucose, impaired glucose tolerance, or diabetes mellitus) to improve the identification of patients at highest risk for diabetes. Materials and methods: In this prospective cohort, 626 patients without known diabetes underwent oral glucose tolerance testing (OGTT) during admission for MI. Proximity extension assay was used to measure 81 biomarkers. Multivariable logistic regression, adjusting for risk factors, was used to evaluate the association of biomarkers with dysglycaemia. Subsequently, lasso regression was performed in a 2/3 training set to identify proteomic biomarkers with prognostic value for dysglycaemia, when added to risk factors, fasting plasma glucose, and glycated haemoglobin A1c. Determination of discriminatory ability was performed in a 1/3 test set. Results: In total, 401/626 patients (64.1%) met the criteria for dysglycaemia. Using multivariable logistic regression, cathepsin D had the strongest association with dysglycaemia. Lasso regression selected seven markers, including cathepsin D, that improved prediction of dysglycaemia (area under the receiver operator curve [AUC] 0.848 increased to 0.863). In patients with normal fasting plasma glucose, only cathepsin D was selected (AUC 0.699 increased to 0.704). Conclusions: Newly detected dysglycaemia, including manifest diabetes, is common in patients with acute MI. Cathepsin D improved the prediction of dysglycaemia, which may be helpful in the a priori risk determination of diabetes as a motivation for confirmatory OGTT.

Long-term prognostic value of growth differentiation factor-15 in acute coronary syndromes

BACKGROUND

Growth Differentiation Factor-15 (GDF-15) predicts death and cardiovascular events in acute coronary syndromes (ACS). We aimed to assess the long-term prognostic value of GDF-15 in ACS.

METHODS

We included 358 patients with ACS who underwent coronary angiography. Plasma GDF-15 was measured and clinical data and long-term events were registered. Incremental value of GDF-15 for prognosing all-cause death above a clinical model including GRACE score, left ventricular ejection fraction <40%, prior myocardial infarction and age was assessed.

RESULTS

GDF-15 concentrations >1800 ng/L were associated with an increased prevalence of cardiovascular risk factors. During 6.5 years of follow-up 56 patients died, 7 had values of GDF-15 < 1200 ng/L, 7 between 1200 and 1800 ng/L and 42 > 1800 ng/L. After adjustment for potential confounders, GDF-15 > 1800 ng/L were independently associated with all-cause death (HR 4.09; 95% CI 1.57-10.71; p = .004) and the composite of major adverse cardiovascular events (MACE) (HR 2.48; 95% CI 1.41-4.34; p = .001). For long-term all-cause death a significant increase of ROC curve was seen after addition of GDF-15 to a clinical model 0.876 (95% CI 0.823-0.928; p = .014). Same improvements were found for net reclassification improvement (0.776; 95% CI 0.494-1.037; p < .001) and integrated discrimination improvement (0.112; 95% CI 0.055-0.169; p < .001). Multivariate competing risk model showed a significant association between GDF-15 > 1800 ng/L and the incidence of heart failure but not of myocardial infarction.

CONCLUSIONS

In the setting of ACS, GDF-15 is associated with long-term all-cause death, MACE and heart failure and provides incremental prognostic value beyond traditional risks factor.