Involvement of growth differentiation factor-15/macrophage inhibitory cytokine-1 (GDF-15/MIC-1) in oxLDL-induced apoptosis of human macrophages in vitro and in arteriosclerotic lesions

Proximal and distant expression of growth differentiation factor 15 (GDF15) correlate with neurological deficit following experimental ischemic stroke

BACKGROUND AND PURPOSE

Growth differentiation factor 15 (GDF15) has emerged as a promising biomarker in cerebro-cardiovascular disease, particularly in acute and chronic inflammatory stress situations. However, understanding the origins, targets and functions of GDF15 in clinical situations, such as ischemic stroke, remains a complex challenge. This study aims to assess the sources of GDF15 production following an experimental ischemic stroke.

METHODS

Adult male Wistar rats underwent cerebral embolization through microspheres injection into the left or right internal carotid artery. Two hours post-surgery, GDF15 expression was analyzed in the brain, blood, lungs, liver and heart using quantitative RT-PCR and Western blotting.

RESULTS

Stroke model induced large cerebral infarcts accompanied by severe neurological deficits. GDF15 gene expression exhibited a substantial increase in the ipsilateral cortex and cerebellum, with a lesser extent in the contralateral cortex. Regarding GDF15 protein expression, proGDF15 levels were elevated in the 3 aforementioned organs mentioned and the heart. However, the mature form of GDF15 was exclusively present and increased in the heart. Finally, the expression of GDF15 expression was correlated with the neurological deficit score.

CONCLUSIONS

Our findings suggest that both the GDF15 gene and pro-protein are expressed in the ischemic brain after a stroke, while only its mature form is expressed remotely in in the heart. The impact of increased GDF15 in the heart following a stroke remains to be established. This is particularly relevant in understanding its relationships with poor neurological outcomes, determining whether it may contribute to stroke-induced cardiac dysfunction.

Correlations between growth differentiation factor 15 (GDF-15) serum levels and gene polymorphism with type 2 diabetes mellitus

Purpose

To date, the relationship between Growth Differentiation Factor 15 (GDF-15) gene polymorphism and the risk of type 2 diabetes mellitus (T2DM) has not been clarified. Our study aims to explore the association between serum GDF-15 levels and related gene polymorphism with the risk of T2DM in a Chinese rural Yao population.

Methods

This was a 1:1 case-control study with 179 T2DM patients and 179 age- and sex-matched control participants. Serum GDF-15 levels were measured by enzyme-linked immunosorbent assay, and polymorphisms (rs1059519, rs1059369, rs1804826 and rs1054564) were genotyped by MassArray mass spectrometry.

Results

Serum GDF-15 (sGDF-15) levels were higher in patients with T2DM and glycosylated hemoglobin (HbA1c) ≥ 6.5 % compared to that in controls (p < 0.001). The area under the curve (AUC) corresponding to sGDF-15 levels was 0.626. Serum GDF-15 was positively correlated with fasting plasma glucose (FPG) (rs = 0.150, p < 0.001) and HbA1c (rs = 0.160, p < 0.001). The frequency of GDF-15 gene rs1054564 GC + CC genotype was significantly associated with increased risk of T2DM compared to GG genotype (OR = 1.724, 95CI: 1.046-2.841, p = 0.033). Frequencies of rs1804826 T allele (β additive = 113.318, p = 0.026) and rs1054564 C allele (β additive = 247.282, p = 0.001, β dominant = 286.109, p = 0.001) was significantly correlated with higher sGDF-15. The rs1059519 C allele was negatively correlated with FPG (β recessive = -0.607, p = 0.047) and HbA1c (β recessive = -0.456, p = 0.020).

Conclusion

Serum GDF-15 levels were positively correlated with FPG and HbA1c. The GDF-15 rs1054564 GC + CC genotype was associated with a significantly higher T2DM risk. The rs1059519 C allele was negatively correlated with FPG and HbA1c.

Identification of a distinct cluster of GDF15high macrophages induced by in vitro differentiation exhibiting anti-inflammatory activities

Introduction

Macrophage-mediated inflammatory response may have crucial roles in the pathogenesis of a variety of human diseases. Growth differentiation factor 15 (GDF15) is a cytokine of the transforming growth factor-β superfamily, with potential anti-inflammatory activities. Previous studies observed in human lungs some macrophages which expressed a high level of GDF15.

Methods

In the present study, we employed multiple techniques, including immunofluorescence, flow cytometry, and single-cell RNA sequencing, in order to further clarify the identity of such GDF15high macrophages.

Results

We demonstrated that macrophages derived from human peripheral blood mononuclear cells and rat bone marrow mononuclear cells by in vitro differentiation with granulocyte-macrophage colony stimulating factor contained a minor population (~1%) of GDF15high cells. GDF15high macrophages did not exhibit a typical M1 or M2 phenotype, but had a unique molecular signature as revealed by single-cell RNA sequencing. Functionally, the in vitro derived GDF15high macrophages were associated with reduced responsiveness to pro-inflammatory activation; furthermore, these GDF15high macrophages could inhibit the pro-inflammatory functions of other macrophages via a paracrine mechanism. We further confirmed that GDF15 per se was a key mediator of the anti-inflammatory effects of GDF15high macrophage. Also, we provided evidence showing that GDF15high macrophages were present in other macrophage-residing human tissues in addition to the lungs. Further scRNA-seq analysis in rat lung macrophages confirmed the presence of a GDF15high sub-population. However, these data indicated that GDF15high macrophages in the body were not a uniform population based on their molecular signatures. More importantly, as compared to the in vitro derived GDF15high macrophage, whether the tissue resident GDF15high counterpart is also associated with anti-inflammatory functions remains to be determined. We cannot exclude the possibility that the in vitro priming/induction protocol used in our study has a determinant role in inducing the anti-inflammatory phenotype in the resulting GDF15high macrophage cells.

Conclusion

In summary, our results suggest that the GDF15high macrophage cells obtained by in vitro induction may represent a distinct cluster with intrinsic anti-inflammatory functions. The (patho)physiological importance of these cells in vivo warrants further investigation.

A machine learning algorithm for peripheral artery disease prognosis using biomarker data

Peripheral artery disease (PAD) biomarkers have been studied in isolation; however, an algorithm that considers a protein panel to inform PAD prognosis may improve predictive accuracy. Biomarker-based prediction models were developed and evaluated using a model development (n = 270) and prospective validation cohort (n = 277). Plasma concentrations of 37 proteins were measured at baseline and the patients were followed for 2 years. The primary outcome was 2-year major adverse limb event (MALE; composite of vascular intervention or major amputation). Of the 37 proteins tested, 6 were differentially expressed in patients with vs. without PAD (ADAMTS13, ICAM-1, ANGPTL3, Alpha 1-microglobulin, GDF15, and endostatin). Using 10-fold cross-validation, we developed a random forest machine learning model that accurately predicts 2-year MALE in a prospective validation cohort of PAD patients using a 6-protein panel (AUROC 0.84). This algorithm can support PAD risk stratification, informing clinical decisions on further vascular evaluation and management.

Evaluation of the relationship between atherosclerosis and Helicobacter pylori infection with measurement of growth differentiation factor 15 and atherosclerosis indicators in adults with no comorbidity

BACKGROUND

The aim of this study was to investigate presence of subclinical atherosclerosis by measuring carotid intima-media thickness (CIMT) in patients with Helicobacter pylori (HP) and to assess effects of HP on atherosclerosis by evaluating markers of atherosclerosis and blood growth differentiation factor (GDF-15) levels.

MATERIALS AND METHODS

This cross-sectional study included 59 patients without comorbid disease who had HP and 30 healthy controls without HP in upper endoscopic biopsy. In order to assess atherosclerosis, the CIMT measurement was performed by sonography. Serum GDF-15 level was measured by ELISA method. In all patients, atherosclerosis markers were recorded. Atherogenic indices were calculated, including Castelli risk index I and II (TG/HDL-c and LDL-c/HDL-c, respectively), plasma atherogenic index (PAI; log TG/HDL-c), non-HDL-c (TH-HDL-c) and atherogenic coefficient (AC; non-HDL-HDL-c).

RESULTS

The GDF-15 level and CIMT were significantly higher in HP-positive group when compared to HP-negative group (p≤0.001). There was a significant correlation between serum GDF-15 level and CIMT (r=0.445; p≤0.001). There was no correlation between other atherosclerosis markers and serum GDF-15 level or CIMT. The bacterial intensity on endoscopic specimen was only correlated with CIMT (p<0.001). Vitamin B12 and D levels were comparable among groups.

CONCLUSION

This study suggested that there was a correlation between GDF-15 level and subclinical atherosclerosis development in patients with HP. However, GDF-15 level, which was found to be elevated while atherogenic indices were normal, can be an earlier marker for subclinical atherosclerosis.

Atrial myopathy

This paper delves into the progressive concept of atrial myopathy, shedding light on its development and its impact on atrial characteristics. It extensively explores the intricate connections between atrial myopathy, atrial fibrillation (AF), and strokes. Researchers have sought additional contributors to AF-related strokes due to the absence of a clear timing correlation between paroxysmal AF episodes and strokes in patients with cardiac implantable electronic devices. Through various animal models and human investigations, a close interrelation among aging, inflammation, oxidative stress, and stretching mechanisms has been identified. These mechanisms contribute to fibrosis, alterations in electrical properties, autonomic remodeling, and a heightened pro-thrombotic state. These interconnected factors establish a detrimental cycle, exacerbating atrial myopathy and elevating the risk of sustained AF and strokes. By emphasizing the significance of atrial myopathy and the risk of strokes that are distinct from AF, the paper also discusses methods for identifying patients with atrial myopathy. Moreover, it proposes an approach to incorporate the concept of atrial myopathy into clinical practice to guide anticoagulation decisions in individuals with AF.

GDF-15 Inhibits ADP-Induced Human Platelet Aggregation through the GFRAL/RET Signaling Complex

Growth differentiation factor-15 (GDF-15) is proposed to be strongly associated with several cardiovascular diseases, such as heart failure and atherosclerosis. Moreover, some recent studies have reported an association between GDF-15 and platelet activation. In this study, we isolated peripheral blood platelets from healthy volunteers and evaluated the effect of GDF-15 on adenosine diphosphate (ADP)-induced platelet activation using the platelet aggregation assay. Subsequently, we detected the expression of GDF-15-related receptors on platelets, including the epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), human epidermal growth factor receptor 3 (HER3), transforming growth factor-beta receptor I (TGF-βRI), transforming growth factor-beta receptor II (TGF-βRII), glial-cell-line-derived neurotrophic factor family receptor α-like (GFRAL), and those rearranged during transfection (RET). Then, we screened for GDF-15 receptors using the GDF-15-related receptor microarray comprising these recombinant proteins. We also performed the immunoprecipitation assay to investigate the interaction between GDF-15 and the receptors on platelets. For the further exploration of signaling pathways, we investigated the effects of GDF-15 on the extracellular signal-regulated kinase (ERK), protein kinase B (AKT), and Janus kinase 2 (JAK2) pathways. We also investigated the effects of GDF-15 on the ERK and AKT pathways and platelet aggregation in the presence or absence of RET agonists or inhibition. Our study revealed that GDF-15 can dose-independently inhibit ADP-induced human platelet aggregation and that the binding partner of GDF-15 on platelets is GFRAL. We also found that GDF-15 inhibits ADP-induced AKT and ERK activation in platelets. Meanwhile, our results revealed that the inhibitory effects of GDF-15 can be mediated by the GFRAL/RET complex. These findings reveal the novel inhibitory mechanism of ADP-induced platelet activation by GDF-15.

A comprehensive multiomics approach reveals that high levels of sphingolipids in cardiac cachexia adipose tissue are associated with inflammatory and fibrotic changes

Cardiac cachexia is a deadly consequence of advanced heart failure that is characterised by the dysregulation of adipose tissue homeostasis. Once cachexia occurs with heart failure, it prevents the normal treatment of heart failure and increases the risk of death. Targeting adipose tissue is an important approach to treating cardiac cachexia, but the pathogenic mechanisms are still unknown, and there are no effective therapies available. Transcriptomics, metabolomics, and lipidomics were used to examine the underlying mechanisms of cardiac cachexia. Transcriptomics investigation of cardiac cachexia adipose tissue revealed that genes involved in fibrosis and monocyte/macrophage migration were increased and strongly interacted. The ECM-receptor interaction pathway was primarily enriched, as shown by KEGG enrichment analysis. In addition, gene set enrichment analysis revealed that monocyte chemotaxis/macrophage migration and fibrosis gene sets were upregulated in cardiac cachexia. Metabolomics enrichment analysis demonstrated that the sphingolipid signalling pathway is important for adipose tissue remodelling in cardiac cachexia. Lipidomics analysis showed that the adipose tissue of rats with cardiac cachexia had higher levels of sphingolipids, including Cer and S1P. Moreover, combined multiomics analysis suggested that the sphingolipid metabolic pathway was associated with inflammatory-fibrotic changes in adipose tissue. Finally, the key indicators were validated by experiments. In conclusion, this study described a mechanism by which the sphingolipid signalling pathway was involved in adipose tissue remodelling by inducing inflammation and fat fibrosis in cardiac cachexia.

GDF-15 at admission predicts cardiovascular death, heart failure, and bleeding outcomes in patients with CAD

AIMS

We aimed to investigate the independent associations between growth differentiation factor 15 (GDF-15) level at admission and cardiovascular (CV) death, thrombotic events, heart failure (HF), and bleeding outcomes in patients with coronary artery disease (CAD).

METHODS AND RESULTS

We measured the plasma concentrations of GDF-15 centrally in patients from the BIomarker-based Prognostic Assessment for patients with Stable angina and acute coronary Syndrome (BIPass) registry, which consecutively enrolled patients with CAD from November 2017 to September 2019 at five tertiary hospitals in China. The outcomes included CV death, thrombotic events [myocardial infarction (MI) and ischaemic stroke], HF events [acute HF during hospitalization and hospitalization for HF post-discharge (A/H HF) and cardiogenic shock], and bleeding outcomes [non-coronary artery bypass grafting-related major bleeding and clinically significant bleeding (CSB)] during the 12 month follow-up period after hospitalization. Among 6322 patients with CAD {65.4% male, median age 63.7 [inter-quartile range (IQR)] 56.0-70.1 years}, the median concentration of plasma GDF-15 at admission was 1091 (IQR 790.5-1635.0) ng/L. Higher concentrations of GDF-15 were associated with an increased risk of CV death [hazard ratio (HR) 1.98, 95% confidence interval (CI) 1.35-2.88, P < 0.001], A/H HF (HR 2.69, 95% CI 1.92-3.77, P < 0.001), cardiogenic shock (HR 1.46, 95% CI 1.04-2.05, P = 0.029), and CSB (HR 1.48, 95% CI 1.22-1.79, P < 0.001), but not for MI or stroke, after adjusting for clinical risk factors and prognostic biomarkers. Adding GDF-15 to the model with risk factors and biomarkers improved the net reclassification for CV death, A/H HF, cardiogenic shock, and CSB.

CONCLUSIONS

In patients with CAD, admission levels of GDF-15 were associated with an increased 1 year risk of CV death, HF, and bleeding outcomes, but not with thrombotic events. GDF-15 may be a prognostic biomarker for CV death, HF, and bleeding outcomes and could be used to refine the risk assessment of these specific clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04044066.

GDF15 affects venous thrombosis by promoting EndMT through smad2/p-smad2 pathway

BACKGROUND

Endothelial-to-mesenchymal transition (EndMT) is a pathophysiological change in the vascular endothelium commonly seen in the cardiovascular system. Elevated serum Growth differiention factor 15 (GDF15) has been reported in VTE patients, but the relationship and mechanism between GDF15, EndMT and VTE are still unclear.

METHODS

We performed a retrospective clinical study, and human serum GDF15 expression levels were detected. The mouse DVT model was established through subtotal ligation of the mouse inferior vena cava, and then we detected intimal changes and thrombi in the stenotic inferior vena cava by haematoxylin-eosin (HE) staining, Masson staining, and Sirius Red staining. The expression levels of GDF15 and SM22 were detected by immunohistochemistry and RT‒qPCR. Serum samples of mice were collected, and the expression level of GDF15 in serum was detected. Human umbilical vein endothelial cells (HUVECs) were stimulated with a cytokine mixture (TGF-β1 + TNF-α + IL-1β). The role and mechanism of GDF15 in EndMT and VTE were detected in HUVECs and in a DVT mice model.

RESULTS

We found that serum GDF15 levels in both VTE patients and mouse DVT models were higher than those in the control group. EndMT was increased in the stenotic vascular tissue of mice. Further experiments showed that GDF15 could promote the EndMT of HUVECs and reduce their anticoagulation and antifibrinolytic ability through the smad2/p-smad2/snail pathway. Inhibition of mature GDF15 release can significantly reduce venous thrombotic fibre deposition in mice.

CONCLUSIONS

GDF15 positively promotes EndMT through activation of the Smad2/psmad2/snail pathway, and inhibition of GDF15 expression can alleviate the EndMT process, further improving the coagulation and fibrinolytic function of endothelial cells and thus reducing the local fibre deposition of venous thrombi.

Growth differentiation factor-15 and prediction of cancer-associated thrombosis and mortality: a prospective cohort study

BACKGROUND

Patients with cancer are at increased risk of venous thromboembolism (VTE) and arterial thromboembolic/thrombotic events (ATEs). Growth differentiation factor-15 (GDF-15) improves cardiovascular risk assessment, but its predictive utility in patients with cancer remains undefined.

OBJECTIVES

To investigate the association of GDF-15 with the risks of VTE, ATE, and mortality in patients with cancer and its predictive utility alongside established models.

METHODS

The Vienna Cancer and Thrombosis Study (CATS)-a prospective, observational cohort study of patients with newly diagnosed or recurrent cancer-which was followed for 2 years, served as the study framework. Serum GDF-15 levels at study inclusion were measured, and any association with VTE, ATE, and death was determined using competing risk (VTE/ATE) or Cox regression (death) modeling. The added value of GDF-15 to established VTE risk prediction models was assessed using the Khorana and Vienna CATScore.

RESULTS

Among 1531 included patients with cancer (median age, 62 years; 53% men), median GDF-15 levels were 1004 ng/L (IQR, 654-1750). Increasing levels of GDF-15 were associated with the increased risks of VTE, ATE, and all-cause death ([subdistribution] hazard ratio per doubling, 1.16 [95% CI, 1.03-1.32], 1.30 [95% CI, 1.11-1.53], and 1.57 [95% CI, 1.46-1.69], respectively). After adjustment for clinically relevant covariates, the association only prevailed for all-cause death (hazard ratio, 1.21; 95% CI, 1.10-1.33) and GDF-15 did not improve the performance of the Khorana or Vienna CATScore.

CONCLUSION

GDF-15 is strongly associated with survival in patients with cancer, independent of the established risk factors. While an association with ATE and VTE was identified in univariable analysis, GDF-15 was not independently associated with these outcomes and failed to improve established VTE prediction models.

Growth differentiation factor 15 predicts cardiovascular events in stable coronary artery disease

BACKGROUND

Growth differentiation factor 15 (GDF-15) has been explored as a potential biomarker for various inflammatory diseases and cardiovascular events. This study aimed to assess the predictive role of GDF-15 levels in cardiovascular events and all-cause mortality, considering traditional risk factors and other biomarkers.

METHODS

A prospective study was conducted and 3699 patients with stable coronary artery disease (CAD) were enrolled into the research. Baseline GDF-15 levels were measured. Median follow-up was 3.1 years during the study. We analyzed clinical variables and several biomarkers. Multivariable Cox regression analysis was performed to evaluate prognostic performance of GDF-15 levels in predicting myocardial infarction (MI), heart failure, stroke, cardiovascular death, and non-cardiovascular death.

RESULTS

Baseline GDF-15 levels for 3699 patients were grouped by quartile (≤ 1153, 1153-1888, 1888-3043, > 3043 ng/L). Higher GDF-15 levels were associated with older age, male gender, history of hypertension, and elevated levels of N-terminal pro B-type natriuretic peptide (NT-pro BNP), soluble suppression of tumorigenesis-2 (sST2), and creatine (each with P < 0.001). Adjusting for established risk factors and biomarkers in Cox proportional hazards models, a 1 standard deviation (SD) increase in GDF-15 was associated with elevated risk of clinical events [hazard ratio (HR) = 2.18, 95% confidence interval (CI): (1.52-3.11)], including: MI [HR = 2.83 95% CI: (1.03-7.74)], heart failure [HR = 2.71 95% CI: (1.18-6.23)], cardiovascular and non-cardiovascular death [HR = 2.48, 95% CI (1.49-4.11)] during the median follow up of 3.1 years.

CONCLUSIONS

Higher levels of GDF-15 consistently provides prognostic information for cardiovascular events and all cause death, independent of clinical risk factors and other biomarkers. GDF-15 could be considered as a valuable addition to future risk prediction model in secondary prevention for predicting clinical events in patient with stable CAD.

Serum Concentration of Growth Differentiation Factor 15 and Atherosclerosis among General Older Japanese Individuals with Normal Weight

Growth differentiation factor 15 (GDF-15), which modulates cellular energy balance, is reported to be positively associated with cardiovascular disease. However, there have been no reports about the association between serum GDF-15 concentration and atherosclerosis as evaluated by carotid intima-media thickness (CIMT) among the general population. A cross-sectional study of 536 Japanese individuals aged 60 to 69 years was conducted. To avoid the influence of abnormal cellular energy balance, this study only included participants who had a normal body mass index (BMI) and normal thyroid hormone (free thyroxine and free triiodothyronine) levels. A significant positive association between serum GDF-15 concentration and atherosclerosis was observed. In the sex- and age-adjusted model (Model 1), the odds ratio (OR) (95% confidence interval (CI)) for the logarithmic value of GDF-15 and atherosclerosis was 2.62 (1.67, 5.87). This association remained after adjusting for thyroid function and renal function (Model 2) and further adjusting for known cardiovascular risk factors (Model 3). The corresponding values were 2.61 (1.15, 5.93) for Model 2 and 2.49 (1.08, 5.71) for Model 3, respectively. Serum GDF-15 concentrations could help us to estimate the risk of atherosclerosis by indicating the status of cellular energy balance, which is related to mitochondrial activity among comparative healthy older individuals.

Relationship Between Plasma Growth Differentiation Factor 15 Levels and Complications of Type 2 Diabetes Mellitus: A Cross-sectional Study

OBJECTIVE

Our aim in this study was to identify the associations between growth differentiation factor 15 (GDF15) and type 2 diabetes mellitus (T2DM) complications in a community-based population in China.

METHODS

Based on a cross-sectional study registered in the National Basic Public Health Service for disease management of Changshu in China, a total of 1,689 T2DM patients were enrolled and tested further for plasma GDF15 levels. Macrovascular (cardiovascular disease and diabetic foot) and microvascular (diabetic kidney disease [DKD], diabetic retinopathy, and neuropathy) complications were evaluated. Logistic regression models were conducted to identify the associations of GDF15 with the risk of diabetes complications, and linear regression models were used to assess relationships between GDF15 and other clinical features.

RESULTS

Overall, 459 of the 1,689 T2DM patients (27.18%) had complications. GDF15 levels were significantly higher in patients with any type of complication compared with their counterparts. With each standard deviation increase of base 10 logarithms of GDF15 (lg-GDF15), the risk of overall complications increased by 1.17-fold (95% confidence interval [CI], 1.03 to 1.32). In contrast to macrovascular complications, associations of GDF15 with microvascular complications appeared to be stronger (adjusted odds ratio [OR], 1.24; 95% CI, 1.08 to 1.43), especially for DKD (adjusted OR, 1.51; 95% CI, 1.19 to 1.93). Subgroup analyses showed that the strength of association between GDF15 and complications varied by distinct age and T2DM duration subgroups. Patients with 2 or more types of complications had higher levels of GDF15 than those with fewer types of complications. Also, linear relationships were identified between GDF15 and several liver and kidney function indices.

CONCLUSION

Higher GDF15 levels were associated with T2DM complications, especially DKD. GDF15 may serve as a biomarker for monitoring the deterioration of T2DM.

Prognostic value of growth differentiation factor-15 in patients with coronary artery disease: A meta-analysis and systematic review

Background and aims

The predictive value of growth differentiation factor-15 (GDF-15) for individual cardiovascular outcomes remained controversial in patients with coronary artery disease (CAD). We aimed to investigate the effects of GDF-15 on all-cause death, cardiovascular death, MI and stroke in CAD patients.

Methods

We searched PubMed, EMBASE, Cochrane library and Web of Science till 30 December, 2020. Hazard ratios (HRs) were combined with fixed or random effect meta-analyses. Subgroup analyses were performed in different disease types. Sensitivity analyses were used to evaluate the stability of the results. Publication bias was tested using funnel plots.

Results

A total of 10 studies with 49,443 patients were included in this meta-analysis. Patients with the highest GDF-15 concentrations had significantly increased risk of all-cause death (HR 2.24; 95% CI: 1.95-2.57), cardiovascular death (HR 2.00; 95% CI: 1.66-2.42), MI (HR 1.42; 95% CI: 1.21-1.66) after adjusting clinical characteristics and prognostic biomarkers (hs-TnT, cystatin C, hs-CRP, and NT-proBNP) but except for stroke (HR 1.43; 95% CI: 1.01-2.03, p = 0.05). For the outcome of all-cause death and cardiovascular death, subgroup analyses revealed consistent results. Sensitivity analyses showed that the results were stable. Funnel plots showed that there was no publication bias.

Conclusion

In CAD patients with elevated GDF-15 levels on admission, there were independently significant risks for all-cause death and cardiovascular death. The highest concentrations of GDF-15 had a lower predictive effect on MI than all-cause death and cardiovascular death. The association of GDF-15 with the outcome of stroke needs to be further studied.

Growth differentiation factor 15 and cardiovascular risk: individual patient meta-analysis

AIMS

Levels of growth differentiation factor 15 (GDF-15), a cytokine secreted in response to cellular stress and inflammation, have been associated with multiple types of cardiovascular (CV) events. However, its comparative prognostic performance across different presentations of atherosclerotic cardiovascular disease (ASCVD) remains unknown.

METHODS AND RESULTS

An individual patient meta-analysis was performed using data pooled from eight trials including 53 486 patients. Baseline GDF-15 concentration was analyzed as a continuous variable and using established cutpoints (<1200 ng/L, 1200-1800 ng/L, > 1800 ng/L) to evaluate its prognostic performance for CV death/hospitalization for heart failure (HHF), major adverse cardiovascular events (MACE), and their components using Cox models adjusted for clinical variables and established CV biomarkers. Analyses were further stratified on ASCVD status: acute coronary syndrome (ACS), stabilized after recent ACS, and stable ASCVD. Overall, higher GDF-15 concentration was significantly and independently associated with an increased rate of CV death/HHF and MACE (P < 0.001 for each). However, while GDF-15 showed a robust and consistent independent association with CV death and HHF across all presentations of ASCVD, its prognostic association with future myocardial infarction (MI) and stroke only remained significant in patients stabilized after recent ACS or with stable ASCVD [hazard ratio (HR): 1.24, 95% confidence interval (CI): 1.17-1.31 and HR: 1.16, 95% CI: 1.05-1.28 for MI and stroke, respectively] and not in ACS (HR: 0.98, 95% CI: 0.90-1.06 and HR: 0.87, 95% CI: 0.39-1.92, respectively).

CONCLUSION

Growth differentiation factor 15 consistently adds prognostic information for CV death and HHF across the spectrum of ASCVD. GDF-15 also adds prognostic information for MI and stroke beyond clinical risk factors and cardiac biomarkers but not in the setting of ACS.

Significant increase of serum extracellular vesicle-packaged growth differentiation factor 15 in type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Growth differentiation factor 15 (GDF15) is a stress-inducible factor involved in the inflammatory progression of many complications, including type 2 diabetes mellitus (T2DM). Growing evidence suggests that molecules in extracellular vesicles (EVs) are associated with diabetes or diabetes-related complications. However, the correlation between serum extracellular vesicle-derived growth differentiation factor15 (EV-GDF15) and T2DM is unknown. The aim of this cross-sectional study is to investigate whether serum EV-GDF15 is associated with T2DM incidence.

METHODS

116 individuals, including 78 T2DM and 38 non-T2DM, were recruited as participants. The concentrations of serum EV-GDF15 and serum GDF15 were determined by Luminex assay. Serum EVs were obtained by ultracentrifugation. Multivariate stepwise regression analysis was used to determine the association between serum GDF15 levels and fasting plasma glucose (FPG) as well as glycated hemoglobin (HbA1c). The association of serum EV-GDF15 levels with T2DM was determined by multivariate logistic regression analysis.

RESULTS

Our data showed that the levels of serum EV-GDF15 and serum GDF15 were significantly increased in T2DM patients compared with non-T2DM subjects (EV-GDF15 levels, 13.68 (6.61-23.44) pg/mL vs. 5.56 (3.44-12.09) pg/mL, P < 0.001; and serum GDF15 levels, 1025.49 (677.87-1626.36) pg/mL vs. 675.46 (469.53-919.98) pg/mL, P < 0.001). There was a linear correlation between EV-GDF15 levels and fasting plasma glucose (FPG) and Hemoglobin A1C (HbA1c) levels (normalized β = 0.357, P < 0.001; normalized β = 0.409, P < 0.001, respectively). Elevated levels of EV-GDF15 were accompanied by an increase in the proportion of patients with T2DM (from 47.5 to 78.9%) and a progressive independent association with the incidence of T2DM (from OR = 3.06, 95% CI 1.02-9.19, P = 0.047 to OR = 3.75, 95% CI 1.14-12.26, P = 0.029). Notably, high levels of serum GDF15 plus high levels of serum EV-GDF15 were significantly associated with T2DM more than either alone.

CONCLUSION

This study elucidated that increased levels of GDF15 in serum EVs were independently associated with T2DM.

Exploring the Link Between the Serum/Blood Levels of Heavy Metals (Pb, As, Cd, and Cu) and 2 Novel Biomarkers of Cardiovascular Stress (Growth Differentiation Factor 15 and Soluble Suppression of Tumorigenicity 2) in Copper Smelter Workers

OBJECTIVE

Studying the association between the occupational exposure to Pb, As, Cd, and Cu with the serum levels of 2 novel biomarkers of cardiovascular stress; growth differentiation factor 15 and soluble suppression of tumorigenicity 2, in some Egyptian Cu smelter workers.

METHODS

Forty-one exposed workers and 41 administrative controls were clinically evaluated. Serum/blood levels of heavy metals and biomarkers were measured for both groups.

RESULTS

The smelter workers showed significantly elevated levels of heavy metals and biomarkers compared with controls. The elevated serum levels of both biomarkers were significantly and positively correlated with each other, the levels of heavy metals, and the duration of employment of the exposed workers.

CONCLUSIONS

There was a significant association between the levels of heavy metals and both biomarkers among the smelter workers. Further prospective studies should be performed.

The Cytokine Growth Differentiation Factor-15 and Skeletal Muscle Health: Portrait of an Emerging Widely Applicable Disease Biomarker

Growth differentiation factor 15 (GDF-15) is a stress-induced transforming growth factor-β superfamily cytokine with versatile functions in human health. Elevated GDF-15 blood levels associate with multiple pathological conditions, and are currently extensively explored for diagnosis, and as a means to monitor disease progression and evaluate therapeutic responses. This review analyzes GDF-15 in human conditions specifically focusing on its association with muscle manifestations of sarcopenia, mitochondrial myopathy, and autoimmune and viral myositis. The use of GDF-15 as a widely applicable health biomarker to monitor muscle disease is discussed, and its potential as a therapeutic target is explored.

Growth differentiation factor-15 as a biomarker of atherosclerotic coronary plaque: Value in people living with and without HIV

Background

Increased rates of cardiovascular diseases (CVD) and larger subclinical high-risk coronary plaques in coronary CT angiography have been observed in people living with HIV (PLWH) treated with antiretroviral therapy (ART) compared to HIV-uninfected people. Growth differentiation factor-15 (GDF-15) is a cytokine emerging as an optimal marker for CVD in the general population.

Methods

We cross-sectionally analyzed plasma of 95 PLWH on ART and 52 controls. We measured GDF-15, fibroblast growth factor-21 (FGF-21), glucagon-like peptide-2 (GLP-2), soluble urokinase plasminogen activator receptor (suPAR), CRP, and anti-CMV and anti-EBV IgG levels. All participants had no clinical CVD and underwent coronary CT angiography with the 3D reconstruction of coronary artery atherosclerotic plaques. Total plaque volume (TPV) and low attenuation plaque volume (LAPV, defined as density &lt;30 Hounsfield Units) were calculated (mm3).

Results

In both PLWH and controls, GDF-15 levels were increased in participants with presence of coronary plaque vs. without (p = 0.04 and p &lt; 0.001, respectively) and correlated with TPV (r = 0.27, p = 0.009 and r = 0.62, p &lt; 0.001, respectively) and LAPV (r = 0.28, p = 0.008, r = 0.60, p &lt; 0.001, respectively). However, in a multivariate model, GDF-15 was independently associated with LAPV in controls only (adjusted OR 35.1, p = 0.04) and not in PLWH, mainly due to confounding by smoking. Other markers were not independently associated with plaque volume, except for anti-EBV IgGs in controls (adjusted OR 3.51, p = 0.02).

Conclusion

In PLWH, GDF-15 and smoking seemed to synergistically contribute to coronary plaque volume. Conversely, increased GDF-15 levels were associated with the presence of coronary artery plaques in people without HIV, independently of CV risk factors.

An Overview of Circulating Pulmonary Arterial Hypertension Biomarkers

Pulmonary arterial hypertension (PAH), also known as Group 1 Pulmonary Hypertension (PH), is a PH subset characterized by pulmonary vascular remodeling and pulmonary arterial obstruction. PAH has an estimated incidence of 15-50 people per million in the United States and Europe, and is associated with high mortality and morbidity, with patients' survival time after diagnosis being only 2.8 years. According to current guidelines, right heart catheterization is the gold standard for diagnostic and prognostic evaluation of PAH patients. However, this technique is highly invasive, so it is not used in routine clinical practice or patient follow-up. Thereby, it is essential to find new non-invasive strategies for evaluating disease progression. Biomarkers can be an effective solution for determining PAH patient prognosis and response to therapy, and aiding in diagnostic efforts, so long as their detection is non-invasive, easy, and objective. This review aims to clarify and describe some of the potential new candidates as circulating biomarkers of PAH.

Identification of Five Hub Genes Based on Single-Cell RNA Sequencing Data and Network Pharmacology in Patients With Acute Myocardial Infarction

Acute myocardial infarction (AMI) has a high mortality. The single-cell RNA sequencing (scRNA-seq) method was used to analyze disease heterogeneity at the single-cell level. From the Gene Expression Omnibus (GEO) database (GSE180678), AMI scRNA-seq were downloaded and preprocessed by the Seurat package. Gene expression data came from GSE182923. Cell cluster analysis was conducted. Cell types were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were performed on hub genes. Drugs were predicted by protein–protein interaction (PPI) and molecular docking. In total, 7 cell clusters were defined based on the scRNA-seq dataset, and the clusters were labeled as 5 cell types by marker genes. Hematopoietic stem cell types as a differential subgroups were higher in AMI than in healthy tissues. From available databases and PPI analysis, 52 common genets were identified. Based on 52 genes, 5 clusters were obtained using the MCODE algorithm, and genes in these 5 clusters involved in immune and inflammatory pathways were determined. Correlation analysis showed that hematopoietic stem cell types were negatively correlated with ATM, CARM1, and CASP8 but positively correlated with CASP3 and PPARG. This was reversed with immune cells. Molecular docking analysis showed that DB05490 had the lowest docking score with PPARG. We identified 5 hub genes (ATM, CARM1, CASP8, CASP3, and PPARG) involved in AMI progression. Compound DB05490 was a potential inhibitor of PPAG.

Association of GDF-15, hs-cTnT and NT-proBNP with coronary artery disease in patients undergoing elective angiography

Aim: This study investigated the association between plasma levels of GDF-15, hs-cTnT and NT-proBNP and the presence of coronary artery disease (CAD) in stable patients referred for elective coronary angiography. Methods: The outcome of CAD was defined as an ordinal variable with 3 levels. The association between each biomarker and the outcome was tested using the Winell and Lindbäck method. Results: In unadjusted analysis of 252 patients, GDF-15 and hs-cTnT were associated with the presence and extent of CAD. In multivariate regression analysis including traditional risk factors, this association was no longer significant. Conclusion: NT-proBNP, GDF-15 and hs-cTnT plasma levels do not seem to improve the predictive ability of traditional risk factors for CAD in stable patients referred for coronary angiography.

Diabetes, GDF-15 and incident heart failure: the atherosclerosis risk in communities study

AIMS/HYPOTHESIS

Elevated circulating growth differentiation factor-15 (GDF-15), a marker of cellular stress, is associated with both heart failure (HF) and diabetes. However, it is unclear to what extent GDF-15 is associated with HF among individuals with and without diabetes.

METHODS

We evaluated 10,570 participants free of HF at Visit 3 (1993-1995) of the Atherosclerosis Risk in Communities study. We used Cox regression to evaluate the joint associations of GDF-15 and diabetes with incident HF. Models were adjusted for traditional cardiovascular risk factors.

RESULTS

Among a total of 10,570 individuals (mean age of 60.0 years, 54% women, 27% black adults), elevated GDF-15 (≥75th percentile) was more common in people with diabetes compared with those without diabetes (32.8% vs 23.6%, p<0.0001). During 23 years of follow-up, there were 2429 incident HF events. GDF-15 (in quartiles) was independently associated with HF among those with and without diabetes, with a stronger association among individuals with diabetes (p-for-diabetes-GDF-15 interaction = 0.034): HR for highest vs lowest GDF-15 quartile (reference): 1.64 (95% CI 1.41, 1.91) among those without diabetes and 1.72 (95% CI 1.32, 2.23) among those with diabetes. Individuals with diabetes and elevated GDF-15 had the highest risk of incident HF (HR 2.46; 95% CI 1.99, 3.03). After accounting for HF risk factors, GDF-15 provided additional prognostic information among participants with diabetes (ΔC statistic for model with vs model without GDF-15: +0.008, p = 0.001) and among those without diabetes (+0.006, p<0.0001).

CONCLUSIONS/INTERPRETATION

In a community-based sample of US adults, GDF-15 provided complementary prognostic information on the HF risk, especially among individuals with diabetes.

Circulating Growth Differentiation Factor 15 Is Associated with Diabetic Neuropathy

Background: Growth differentiation factor (GDF15) is a superfamily of transforming growth factor-beta which has been suggested to be correlated with various pathological conditions. The current study aimed to investigate the predicted role of circulating GDF15 in diabetic metabolism characteristics and diabetic neuropathy. Methods: 241 diabetic patients and 42 non-diabetic subjects were included to participate in the study. The plasma GDF15 levels were measured using ELISA. Chronic kidney disease and albuminuria were defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guideline. The nerve conductive study (NCS) was performed with measurement of distal latency, amplitude, nerve conduction velocity (NCV), H-reflex, and F-wave studies. Results: The diabetic group had a significantly higher prevalence of chronic kidney disease and higher plasma GDF15 level. After adjusting for age and BMI, GDF15 was significantly positively correlated with waist circumference (r = 0.332, p = <0.001), hip circumference (r = 0.339, p < 0.001), HbA1c (r = 0.302, p < 0.001), serum creatine (r = 0.146, p = 0.017), urine albumin/creatinine ratio (r = 0.126, p = 0.040), and HOMA-IR (r = 0.166, p = 0.007). As to NCS, GDF15 was significantly correlated with all latency and amplitude of sensory and motor nerves, as well as F-wave and H-reflex latencies. The area under the curve (AUC) in predicting tibial motor nerve neuropathy (MNCV) in all subjects and in the diabetic group for GDF15 was 0.646 (p = 0.001) and 0.610 (p = 0.012), respectively; for HbA1c was 0.639 (p = 0.001) and 0.604 (p = 0.018), respectively. Predicting ulnar sensory nerve neuropathy for GDF15 was 0.639 (p = 0.001) and 0.658 (p = 0.001), respectively; for HbA1c was 0.545 (p = 0.307) and 0.545 (p = 0.335), respectively. Predicting median sensory nerve neuropathy for GDF15 was 0.633 (p = 0.007) and 0.611 (p = 0.032), respectively; for HbA1c was 0.631 (p = 0.008) and 0.607 (p = 0.038), respectively. Predicting CKD for GDF15 was 0.709 (95% CI, 0.648−0.771), p < 0.001) and 0.676 (95% CI, 0.605−0.746), p < 0.001), respectively; for HbA1c was 0.560 (95% CI, 0.493−0.627); p = 0.080) and 0.515 (95% CI, 0.441−0.588); p = 0.697), respectively. Conclusions: We suggest that there is a significant association between the increased serum GDF-15 level and metabolic parameters and diabetic neuropathy. Plasma GDF15 may be an independent predictor of diabetic neuropathy.

Cadmium exposure and growth differentiation factor-15 (GDF-15) levels in non-smoking older adults

BACKGROUND

Cadmium (Cd) exposure is a risk factor for cardiovascular disease (CVD); however, understanding the effects of Cd at the cellular level remains incomplete. Since growth differentiation factor-15 (GDF-15) is a cytokine produced in many cell types in response to tissue injury and inflammation that may capture several pathways between Cd and CVD, this study examined the relationship between blood Cd levels and serum GDF-15 concentrations in community-dwelling older adults.

METHODS

Cd and GDF-15 were measured in 1942 non-smoking individuals aged 65+ with no previous history of CVD. The association of Cd with GDF-15 was evaluated in linear regression models that adjusted for sociodemographic, lifestyle and biological risk factors, inflammatory biomarkers (IL-6, C-reactive protein and neutrophil to lymphocyte ratio), and markers of vascular damage (NTproBNP and cTnT-hs).

RESULTS

Geometric mean Cd exposure was 0.11 μg/L (0.09 in never- and 0.15 in former-smokers) and geometric mean GDF-15 was 1186.21 pg/mL (1182.67 in never- and 1191.66 in former-smokers). In multivariable analyses, we found a dose-response association between Cd levels and GDF-15: adjusted mean percentage differences in GDF-15 (95% confidence interval) per 2-fold increase in Cd concentrations in the overall non-smoking population and in never smokers were, respectively, 2.54% (1.01, 4.06) and 2.50% (0.47, 4.54). In spline regression, the dose-response relationship was progressive over the range of Cd concentrations with no significant departures from linearity.

CONCLUSIONS

Cd exposure may be related to enhanced GDF-15 expression. Future studies with repeated GDF-15 measurements should confirm the present findings to better understand the biological mechanisms underlying this association.

Biomarkers Associated with Cardiovascular Disease in COVID-19

Coronavirus disease-19 (COVID-19) emerged late December 2019 in the city of Wuhan, China and has since spread rapidly all over the world causing a global pandemic. While the respiratory system is the primary target of disease manifestation, COVID-19 has been shown to also affect several other organs, making it a rather complex, multi-system disease. As such, cardiovascular involvement has been a topic of discussion since the beginning of the COVID-19 pandemic, primarily due to early reports of excessive myocardial injury in these patients. Treating physicians are faced with multiple challenges in the management and early triage of patients with COVID-19, as disease severity is highly variable ranging from an asymptomatic infection to critical cases rapidly deteriorating to intensive care treatment or even fatality. Laboratory biomarkers provide important prognostic information which can guide decision making in the emergency department, especially in patients with atypical presentations. Several cardiac biomarkers, most notably high-sensitive cardiac troponin (hs-cTn) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), have emerged as valuable predictors of prognosis in patients with COVID-19. The purpose of this review was to offer a concise summary on prognostic cardiac biomarkers in COVID-19 and discuss whether routine measurements of these biomarkers are warranted upon hospital admission.

Risk Assessment after ST-Segment Elevation Myocardial Infarction: Can Biomarkers Improve the Performance of Clinical Variables?

Introduction: Myocardial infarction with ST-segment elevation (STEMI) is the coronary artery disease associated with the highest risk of morbimortality; however, this risk is heterogeneous, usually being evaluated by clinical scores. Risk assessment is a key factor in personalized clinical management of patients with this disease. Aim: The aim of this study was to assess whether some new cardiac biomarkers considered alone, combined in a multibiomarker model or in association with clinical variables, improve the short- and long-term risk stratification of STEMI patients. Materials and Methods: This was a retrospective observational study of 253 patients with STEMI. Blood samples were obtained before or during the angiography. The assessed biomarkers were C-terminal fragment of insulin-like growth factor binding protein-4 (CT-IGFBP4), high sensitive cardiac troponin T (hs-cTnT), N-terminal fragment of probrain natriuretic peptide (NT-proBNP), and growth differentiation factor 15 (GDF-15); they reflect different cardiovascular (CV) physiopathological pathways and underlying pathologies. We registered in-hospital and follow-up mortalities and their causes (cardiovascular and all-cause) and major adverse cardiac events (MACE) during a two year follow-up. Discrimination, survival analysis, model calibration, and reclassification of the biomarkers were comprehensively evaluated. Results and Discussion: In total, 55 patients (21.7%) died, 33 in-hospital and 22 during the follow-up, most of them (69.1%) from CV causes; 37 MACE occurred during follow-up. Biomarkers showed good prognostic ability to predict mortality, alone and combined with the multibiomarker model. A predictive clinical model based on age, Killip–Kimball class, estimated glomerular filtration rate (eGFR), and heart rate was derived by multivariate analysis. GDF-15 and NT-proBNP significantly improved risk assessment of the clinical model, as shown by discrimination, calibration, and reclassification of all the end-points except for all-cause mortality. The combination of NT-proBNP and hs-cTnT improved CV mortality prediction. Conclusions: GDF-15 and NT-proBNP added value to the usual risk assessment of STEMI patients.

Association of growth differentiation factor-15 level with adverse outcomes in patients with stable coronary artery disease: A meta-analysis

BACKGROUND AND AIMS

Studies on the association between growth-differentiation factor-15 (GDF-15) level and adverse outcomes have yielded conflicting results in patients with stable coronary artery disease (CAD). This meta-analysis aimed to evaluate the association of baseline GDF-15 level with adverse outcomes in stable CAD patients.

METHODS

Two authors independently searched PubMed and Embase databases from inception to May 31, 2021 for available studies that investigated the association of baseline GDF-15 level with all-cause mortality, cardiovascular mortality, or major adverse cardiovascular events (MACEs) in stable CAD patients. Pooled multivariable adjusted hazard ratio (HR) with 95% confidence interval (CI) was calculated for the highest vs. the lowest GDF-15 level.

RESULTS

Seven studies that involved 28,765 stable CAD patients were identified and analyzed. The meta-analysis showed that the highest GDF-15 level was associated with higher risk of MACEs (HR 1.42; 95% CI 1.29-1.57; p < 0.001), cardiovascular mortality (HR 1.64: 95% CI 1.25-2.14; p < 0.001), and all-cause mortality (HR 2.01; 95% CI 1.67-2.42; p < 0.001) when compared the lowest GDF-15 level. Moreover, the values of GDF-15 level in predicting MACEs were consistently observed in each named subgroup.

CONCLUSIONS

Elevated blood GDF-15 level is an independent predictor of MACEs, cardiovascular mortality, and all-cause mortality in stable CAD patients. The baseline GDF-15 level may play an important role in the risk stratification of stable CAD patients.

Growth Differentiation Factor-15 Predicts Death and Stroke Event in Outpatients With Cardiovascular Risk Factors: The J-HOP Study

Background Growth differentiation factor-15 (GDF-15) has emerged as a novel biomarker to predict all-cause death in community-dwelling individuals and patients with cardiovascular disease. We evaluated the prognostic value of GDF-15 in outpatients with cardiovascular risk factors. Methods and Results GDF-15 levels were measured in 3562 outpatients with cardiovascular risk factors in the J-HOP (Japan Morning Surge-Home Blood Pressure) study, a nationwide prospective study. Participants were stratified according to tertiles of GDF-15 and followed up for all-cause death and cardiovascular disease. During a mean follow-up period of 6.6 years, there were 155 all-cause deaths, 81 stroke events including cerebral infarction and intracranial hemorrhage, and 141 cardiac events including cardiac artery disease and heart failure. Patients with higher GDF-15 levels were associated with risks of all-cause death and stroke events (except for cardiac events) after adjustment for traditional risk factors and other prognostic biomarkers (NT-proBNP [N-terminal pro-B-type natriuretic peptide], high-sensitivity troponin T; all-cause death, hazard ratio, 2.38; 95% CI, 1.26-4.48; P=0.007; stroke events, hazard ratio, 2.93; 95% CI, 1.31-6.56, P=0.009; compared with the lowest tertile). Furthermore, incorporating GDF-15 to the predictive models for all-cause death improved discrimination and reclassification significantly. For stroke events, GDF-15 showed similar diagnostic accuracy to NT-proBNP and high-sensitivity troponin T. Conclusions In Japanese outpatients with cardiovascular risk factors, GDF-15 improves risk stratification for all-cause death when compared with NT-proBNP and high-sensitivity troponin T. GDF-15 was associated with increased risks of stroke events beyond conventional risk factors and other prognostic markers; however, the predictive ability for stroke events was equivalent to NT-proBNP and high-sensitivity troponin T. Registration URL: http://www.umin.ac.jp/ctr.; Unique identifier: UMIN000000894.

Characterization of atherosclerotic plaques in blood vessels with low oxygenated blood and blood pressure (Pulmonary trunk): role of growth differentiation factor-15 (GDF-15)

BACKGROUND

Growth differentiation factor (GDF)-15 is linked to inflammation, cancer, and atherosclerosis. GDF-15 is expressed in most tissues but is extremely induced under pathological conditions. Elevated serum levels are suggested as a risk factor and a marker for cardiovascular diseases. However, the cellular sources and the effects of GDF-15 on the cardiovascular system have not been completely elucidated including progression, and morphology of atherosclerotic plaques. Thus, this work aimed to characterize the influence of GDF-15 deficiency on the morphology of atherosclerotic plaques in blood vessels with low-oxygen blood and low blood pressure as the pulmonary trunk (PT), in hypercholesterolemic ApoE-/- mice.

METHODS

GDF-15-/- ApoE-/- mice were generated by crossbreeding of ApoE-/-- and GDF-15-/- mice. After feeding a cholesterol-enriched diet (CED) for 20 weeks, samples of the brachiocephalic trunk (BT) and PT were dissected and lumen stenosis (LS) was measured. Furthermore, changes in the cellularity of the PT, amounts of apoptosis-, autophagy-, inflammation- and proliferation-relevant proteins were immunohisto-morphometrically analyzed. Additionally, we examined an atherosclerotic plaque in a human post mortem sample of the pulmonary artery.

RESULTS

After CED the body weight of GDF-15-/-ApoE-/- was 22.9% higher than ApoE-/-. Double knockout mice showed also an 35.3% increase of plasma triglyceride levels, whereas plasma cholesterol was similar in both genotypes. LS in the BT and PT of GDF-15-/-ApoE-/- mice was significantly reduced by 19.0% and by 6.7% compared to ApoE-/-. Comparing LS in PT and BT of the same genotype revealed a significant 38.8% (ApoE-/-) or 26.4% (GDF-15-/-ApoE-/-) lower LS in the PT. Immunohistomorphometry of atherosclerotic lesions in PT of GDF-15-/-ApoE-/- revealed significantly increased levels (39.8% and 7.3%) of CD68 + macrophages (MΦ) and α-actin + smooth muscle cells than in ApoE-/-. The density of TUNEL + , apoptotic cells was significantly (32.9%) higher in plaques of PT of GDF-15-/-ApoE-/- than in ApoE-/-. Analysis of atherosclerotic lesion of a human pulmonary artery showed sm-α-actin, CD68+, TUNEL+, Ki67+, and APG5L/ATG+ cells as observed in PT. COX-2+ and IL-6+ immunoreactivities were predominantly located in endothelial cells and subendothelial space. In BT and PT of GDF15-/-ApoE-/- mice the necrotic area was 10% and 6.5% lower than in ApoE-/-. In BT and PT of GDF15-/-ApoE-/- we found 40% and 57% less unstable plaques than ApoE-/- mice.

CONCLUSIONS

Atherosclerotic lesions occur in both, BT and PT, however, the size is smaller in PT, possibly due to the effect of the low-oxygen blood and/or lower blood pressure. GDF-15 is involved in atherosclerotic processes in BT and PT, although different mechanisms (e.g. apoptosis) in these two vessels seem to exist.

Emerging roles of growth differentiation factor-15 in brain disorders (Review)

Brain disorders, such as Alzheimer's and Parkinson's disease and cerebral stroke, are an important contributor to mortality and disability worldwide, where their pathogenesis is currently a topic of intense research. The mechanisms underlying the development of brain disorders are complex and vary widely, including aberrant protein aggregation, ischemic cell necrosis and neuronal dysfunction. Previous studies have found that the expression and function of growth differentiation factor-15 (GDF15) is closely associated with the incidence of brain disorders. GDF15 is a member of the TGFβ superfamily, which is a dimer-structured stress-response protein. The expression of GDF15 is regulated by a number of proteins upstream, including p53, early growth response-1, non-coding RNAs and hormones. In particular, GDF15 has been reported to serve an important role in regulating angiogenesis, apoptosis, lipid metabolism and inflammation. For example, GDF15 can promote angiogenesis by promoting the proliferation of human umbilical vein endothelial cells, apoptosis of prostate cancer cells and fat metabolism in fasted mice, and GDF15 can decrease the inflammatory response of lipopolysaccharide-treated mice. The present article reviews the structure and biosynthesis of GDF15, in addition to the possible roles of GDF15 in Alzheimer's disease, cerebral stroke and Parkinson's disease. The purpose of the present review is to summarize the mechanism underlying the role of GDF15 in various brain disorders, which hopes to provide evidence and guide the prevention and treatment of these debilitating conditions.

GDF-15 Suppresses Atherosclerosis by Inhibiting oxLDL-Induced Lipid Accumulation and Inflammation in Macrophages

The growth differentiation factor-15 (GDF-15) may be involved in atherosclerosis. However, the role of GDF-15 in atherosclerosis remains unclear. The main goal of this study was to verify the role and mechanism of GDF-15 in atherogenesis. We first compared the serum GDF-15 level between patients with coronary atherosclerosis and healthy people. And then one ApoE^-/- mouse model of atherosclerosis was used to explore the effects of GDF-15 on oxidized low-density lipoprotein (oxLDL) accumulation, atherosclerosis-related gene expression, and lipid accumulation-related protein expression in mouse macrophages. As a result, the level of serum GDF-15 in patients with coronary atherosclerosis was significantly higher than that in healthy people. In the mouse model, GDF-15 expression was elevated in the core of plaque, and it was secreted mainly by the macrophages. In addition, GDF-15 decreased oxLDL-induced lipid accumulation and inflammation activation in macrophages. GDF-15 decreased the mRNA expressions of CD36, LOX1, and TLR4 that are associated with lipoprotein accumulation in macrophages. Further study showed that GDF-15 might suppress oxLDL-induced lipoprotein accumulation via inhibiting CD36 and LOX1 and decrease inflammation in macrophages by inhibiting TLR4. Thus, GDF-15 may suppress atherosclerosis and plaque formation by inhibiting lipoprotein accumulation and inflammation activation.

GDF-15 Deficiency Reduces Autophagic Activity in Human Macrophages In Vitro and Decreases p62-Accumulation in Atherosclerotic Lesions in Mice

(1) Background: Growth differentiation factor-15 (GDF-15) is associated with cardiovascular diseases and autophagy in human macrophages (MΦ). Thus, we are interested in investigating autophagic mechanisms with special respect to the role of GDF-15. (2) Methods: Recombinant (r)GDF-15 and siRNA GDF-15 were used to investigate the effects of GDF-15 on autophagic and lysosomal activity, as well as autophagosome formation by transmission electron microscopy (TEM) in MΦ. To ascertain the effects of GDF-15^−/− on the progression of atherosclerotic lesions, we used GDF-15^−/−/ApoE^−/− and ApoE^−/− mice under a cholesterol-enriched diet (CED). Body weight, body mass index (BMI), blood lipid levels and lumen stenosis in the brachiocephalic trunk (BT) were analyzed. Identification of different cell types and localization of autophagy-relevant proteins in atherosclerotic plaques were performed by immunofluorescence. (3) Results: siGDF-15 reduced and, conversely, rGDF-15 increased the autophagic activity in MΦ, whereas lysosomal activity was unaffected. Autophagic degradation after starvation and rGDF-15 treatment was observed by TEM. GDF-15^−/−/ApoE^−/− mice, after CED, showed reduced lumen stenosis in the BT, while body weight, BMI and triglycerides were increased compared with ApoE^−/− mice. GDF-15^−/− decreased p62-accumulation in atherosclerotic lesions, especially in endothelial cells (ECs). (4) Conclusion: GDF-15 seems to be an important factor in the regulation of autophagy, especially in ECs of atherosclerotic lesions, indicating its crucial pathophysiological function during atherosclerosis development.

Plasma levels of growth differentiation factor 15 are associated with future risk of venous thromboembolism

Growth differentiation factor 15 (GDF-15), a marker of inflammation and oxidative stress, has emerged as a biomarker for arterial cardiovascular disease. However, the association between GDF-15 and venous thromboembolism (VTE) remains uncertain. We therefore investigated the association between plasma GDF-15 levels and future risk of incident VTE and explored the potential of a causal association using Mendelian randomization (MR). We conducted a population-based nested case-control study comprising 416 VTE patients and 848 age- and sex-matched controls derived from the Tromsø Study. Logistic regression was used to calculate odds ratios (ORs) for VTE across GDF-15 quartiles. For the MR, we used data from the International Network on Venous Thrombosis (INVENT) consortium to examine whether single nucleotide polymorphisms (SNPs) associated with GDF-15 levels with genome-wide significance were related to VTE. We found that the ORs for VTE increased across GDF-15 quartiles (Ptrend = .002). Participants with GDF-15 values in the highest quartile (≥358 pg/mL) had an OR for VTE of 2.05 (95% confidence interval, 1.37-3.08) compared with those with GDF-15 in the lowest quartile (<200 pg/mL) in the age- and sex-adjusted model. ORs remained essentially the same after further adjustment for body mass index, smoking, hormone therapy, physical activity, and C-reactive protein. Similar results were obtained for provoked/unprovoked events, deep vein thrombosis, and pulmonary embolism. GDF-15 levels, as predicted by the SNPs, were not associated with VTE in MR. Our results indicate that high GDF-15 levels are associated with increased risk of VTE, but MR suggests that this association is not causal.

Evaluation of Growth Differentiation Factor-15 in Patients with or without Coronary Artery Disease

Background:

Growth-differentiation factor-15 (GDF-15) is a distant member of the transforming growth factor-beta cytokine superfamily expressed in human atherosclerotic plaque macrophages. In this study, we sought to compare GDF-15 between patients with coronary artery disease and control group.

Methods:

In this cross-sectional study, 176 subjects were enrolled, consisted of 88 coronary artery disease patients (CAD group) and 88 non-CAD participants (control group. Clinical and demographic data, comprising of family history of CAD, history, and lifestyle factors, hypertension, diabetes, and some blood parameters (e.g. glucose, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)), triglyceride, high-sensitivity C-reactive protein (hs-CRP)).

Results:

Mean age of the patients was 55.5±11.1 years (age range: 28–80 years). Of all the participants, 91 (51.7%) were male and 85 (48.3%) female. Hs-CRP, LDL-C, and GDF-15 levels were significantly higher in the CAD patients (P=0.091, P=0.008, and P<0.001, respectively). Total cholesterol, hematocrit, and hemoglobin were significantly higher in the controls (P=0.002, P=0.011, and P=0.055, respectively). The area under the receiver operating characteristic curve yielded the satisfactory result of 0.9 (95% CI, 0.8-0.9; P<0.001). The optimum cut-off value of GDF-15 was 1233 ng/L with 71% specificity and 71% sensitivity for CAD diagnosis.

Conclusion:

These data suggest that serum GDF-15 might be useful in prediction of CAD. (www.actabiomedica)

Cardiac Biomarkers in hypertensive disorders of pregnancy

In recent years, biomarkers have taken a central place in the assessment of cardiovascular diseases – from prediction to management and prognosis. On the other hand, enough evidence exists to assume that hypertensive disorders of pregnancy share a certain connection with cardiovascular diseases – from common risk factors and underlying mechanisms to the presence of a higher risk for women for the development of a great number of cardiovascular diseases, such as arterial hypertension, coronary atherosclerosis, stroke, peripheral artery disease, venous thromboembolism, and even a higher cardiovascular mortality. The key to a better understanding of the unfavorable cardiovascular profile of women with a hypertensive disorder of pregnancy may lie in their assessment with biomarkers, typically used in the field of cardiology. In this review, we have included studies investigating the use of cardiovascular biomarkers during or after a hypertensive pregnancy, namely, natriuretic peptides, high-sensitivity cardiac troponins, growth/differentiation factor 15 (GDF15), soluble suppression of tumorigenicity-2 (sST2), and galectin-3.

Relationship between plasma growth differentiation factor-15 level and estimated glomerular filtration rate in type 2 diabetes patients with and without albuminuria

AIM

To assess the relationship between growth differentiation factor-15 (GDF-15) levels and estimated glomerular filtration rate (eGFR) in type 2 diabetes mellitus (DM) patients with and without albuminuria.

METHODS

We examined 324 patients with type 2 DM in a cross-sectional study. eGFR was determined using equations from creatinine (eGFR_cr) and the combination of creatinine and cystatin C (eGFR_cr-cys). The patients were classified into two groups based on urinary albumin: creatinine ratio (ACR): the normoalbuminuria group (urinary ACR < 30 mg/g) and the albuminuria group (urinary ACR ≥ 30 mg/g).

RESULTS

In individuals both with and without albuminuria, higher GDF-15 levels were associated with lower eGFR_cr and eGFR_cr-cys. Plasma GDF-15 levels were inversely correlated with eGFR_cr in individuals both with and without albuminuria (γ = -0.624, p < 0.001 and γ = -0.509, p < 0.001, respectively). A multiple regression analysis showed that GDF-15 levels were significantly associated with eGFR_cr after adjusting for age, sex and other confounders, including urinary ACR as a continuous or categorical variable (β = -0.309, p < 0.001 and β = -0.318, p < 0.001, respectively). Similarly, these results were replicated when eGFR_cr-cys was considered instead of eGFR_cr in correlation and regression analyses.

CONCLUSION

GDF-15 levels were inversely associated with eGFR in patients with type 2 DM. This relationship was independent of albuminuria status.

Growth Differentiation Factor (GDF)-15 and Cardiometabolic Outcomes among Older Adults: The Atherosclerosis Risk in Communities Study

INTRODUCTION

Laboratory studies suggest an involvement of growth differentiation factor 15 (GDF-15) in metabolic dysregulation. However, the utility of GDF-15 for assessing risk of cardiometabolic outcomes has not been rigorously examined among older adults.

METHODS

We conducted a cross-sectional analysis of older adults who attended visit 6 (2016-2017) of the Atherosclerosis Risk in Communities (ARIC) Study. We used multivariable logistic regression to quantify cross-sectional associations of GDF-15 (in quartiles) with prevalent diabetes, obesity, atherosclerotic cardiovascular disease (ASCVD), subclinical myocardial stress/injury (assessed by NT-proB-type Natriuretic Peptide [NT-proBNP] and high-sensitivity cardiac troponin T [hs-cTnT]), and heart failure (HF).

RESULTS

Among 3792 ARIC study participants (mean age 80 years, 59% women, 23% Blacks and 77% Whites, mean GDF-15: 2094.9 pg/mL [SD: 1395.6]), higher GDF-15 concentrations (highest vs. lowest quartile) were positively associated with diabetes (adjusted odds ratio [aOR]:] : 2.48, 95% CI : 1.89, 3.26), ASCVD (aOR: 1.57, 95% CI: 1.16, 2.11), increased hscTnT (aOR: 2.27, 95%CI: 1.54, 3.34), increased NT-proBNP (aOR: 1.98, 95%CI: 1.46, 2.70), and HF (aOR: 3.22, 95%CI : 2.13, 4.85), in models adjusted for demographics and traditional cardiovascular risk factors.

CONCLUSIONS

In this sample of older US black and whites, increased GDF-15 was positively associated with diabetes, ASCVD, HF, and markers of subclinical myocardial stress or injury. These results illustrate the diverse aspects of the link between GDF-15 and diseases states, and its potential utility as robust biomarker of adverse cardiometabolic outcomes.

Growth Differentiation Factor 15 (GDF-15) as potential cardiovascular risk biomarker in Antiphospholipid Syndrome

OBJECTIVE

An interplay between thrombo-inflammatory and atherogenic mechanisms is recognized in cardiovascular disease pathogenesis (CVD) in antiphospholipid syndrome (APS). Herein, we examine associations of growth differentiation factor-15 (GDF-15), a pro-inflammatory cytokine identified as potent CVD risk biomarker in the general population, with subclinical atherosclerosis in APS.

METHODS

We measured plasma GDF-15 levels by an electrochemiluminescence immunoassay (cut-off 1200 pg/mL) and examined carotid intima-media thickness (IMT) and the presence of carotid and femoral plaques using vascular ultrasound in 80 patients with APS (44 primary, 36 systemic lupus erythematosus (SLE)/APS) and 40 healthy controls. We calculated the aGAPSSCVD, a revised adjusted Global APS Score (aGAPSS) to predict CVD, including lupus anticoagulant, anticardiolipin and anti-beta2glycoprotein-I antibodies, and hypertension, dyslipidemia, obesity, diabetes and smoking.

RESULTS

GDF-15 levels were higher in APS patients vs. controls adjusting for age and gender (absolute difference: 281 (95% CI: 141-421) pg/mL, p < 0.001). GDF-15 levels ≥1200 pg/mL were associated with higher mean IMT of right and left carotid (beta coefficient 0.068 (95% CI: 0.020, 0.116), p = 0.006) compared with GDF-15 levels <1200 pg/mL. GDF-15 was independently associated with mean IMT adjusting for gender and aGAPSSCVD (beta coefficient 0.059 (95% CI: 0.008-0.110, p = 0.024), and additionally for statin (p = 0.025) and hydroxychloroquine use (p = 0.011). GDF-15 levels ≥1200 pg/mL were associated with 2.4 higher odds for atherosclerotic plaques (OR = 2.438 (95% CI: 0.906, 6.556), p = 0.078), while this effect reduced adding more covariates in the model.

CONCLUSION

GDF-15 is independently associated with subclinical atherosclerosis in APS patients suggesting its potential role in CVD risk stratification in APS.

Relationship between plasma growth differentiation factor-15 levels and diabetic retinopathy in individuals with type 2 diabetes

The purpose of our study was to investigate the relationship between plasma growth differentiation factor-15 (GDF-15) concentrations and diabetic retinopathy in patients with type 2 diabetes mellitus (DM). We evaluated 235 patients with type 2 DM in a cross-sectional study. Significantly increased levels of the plasma GDF-15 were found in individuals with diabetic retinopathy versus those without. According to the degree of diabetic retinopathy, there was a significant difference in the average plasma GDF-15 levels (no diabetic retinopathy, 1114 ng/L; nonproliferative diabetic retinopathy, 1327 ng/L; proliferative diabetic retinopathy, 1445 ng/L; p for trend = 0.035) after adjustments for confounders. Logistic regression analyses indicated that plasma GDF-15 concentrations were significantly associated with diabetic retinopathy (odds ratio per 1 standard deviation increment in the log-transformed value, 1.78; 95% confidence interval, 1.05-3.03, p = 0.032). Our study showed a significant positive relationship between plasma GDF-15 concentrations and diabetic retinopathy in type 2 DM patients.

Biomarkers for Heart Failure Prognosis: Proteins, Genetic Scores and Non-coding RNAs

Heart failure (HF) is a complex disease in which cardiomyocyte injury leads to a cascade of inflammatory and fibrosis pathway activation, thereby causing decrease in cardiac function. As a result, several biomolecules are released which can be identified easily in circulating body fluids. The complex biological processes involved in the development and worsening of HF require an early treatment strategy to stop deterioration of cardiac function. Circulating biomarkers provide not only an ideal platform to detect subclinical changes, their clinical application also offers the opportunity to monitor disease treatment. Many of these biomarkers can be quantified with high sensitivity; allowing their clinical application to be evaluated beyond diagnostic purposes as potential tools for HF prognosis. Though the field of biomarkers is dominated by protein molecules, non-coding RNAs (microRNAs, long non-coding RNAs, and circular RNAs) are novel and promising biomarker candidates that encompass several ideal characteristics required in the biomarker field. The application of genetic biomarkers as genetic risk scores in disease prognosis, albeit in its infancy, holds promise to improve disease risk estimation. Despite the multitude of biomarkers that have been available and identified, the majority of novel biomarker candidates are not cardiac-specific, and instead may simply be a readout of systemic inflammation or other pathological processes. Thus, the true value of novel biomarker candidates in HF prognostication remains unclear. In this article, we discuss the current state of application of protein, genetic as well as non-coding RNA biomarkers in HF risk prognosis.

Association of Exhaled Carbon Monoxide With Ideal Cardiovascular Health, Circulating Biomarkers, and Incidence of Heart Failure in the Framingham Offspring Study

Background Exhaled carbon monoxide (eCO) is directly associated with traditional cardiovascular disease risk factors and incident cardiovascular disease. However, its relation with the cardiovascular health score and incidence of heart failure (HF) has not been investigated. Methods and Results We measured eCO in 3521 Framingham Heart Study Offspring participants attending examination cycle 6 (mean age 59 years, 53% women). We related the cardiovascular health score (composite of blood pressure, fasting plasma glucose, total cholesterol, body mass index, smoking, diet, and physical activity) to eCO adjusting for age, sex, and smoking. Higher cardiovascular health scores were associated with lower eCO (β=-0.02, P<0.0001), even among nonsmokers. Additionally, C-reactive protein, plasminogen activator inhibitor-1, fibrinogen, growth differentiation factor-15, homocysteine, and asymmetrical dimethylarginine were positively associated with eCO (P≤0.003 for all). The age- and sex-adjusted and multivariable-adjusted heritabilities of eCO were 49.5% and 31.4%, respectively. Over a median follow-up of 18 years, 309 participants (45% women) developed HF. After multivariable adjustment, higher eCO was associated with higher risk of HF (hazards ratio per SD increment: 1.39; 95% CI, 1.19-1.62 [P<0.001]) and with higher risk of HF with reduced ejection fraction (N=144 events; hazard ratio per SD increment in eCO: 1.43; 95% CI, 1.15-1.77 [P=0.001]). Conclusions In our community-based sample, higher levels of eCO were associated with lower cardiovascular health scores, an adverse cardiovascular biomarker profile, and a higher risk of HF, specifically HF with reduced ejection fraction. Our findings suggest that carbon monoxide may identify a novel pathway to HF development.

Cardiac Biomarkers and Risk of Mortality in CKD (the CRIC Study)

Introduction

Cardiovascular disease (CVD) is the leading cause of mortality among individuals with chronic kidney disease (CKD). Cardiac biomarkers of myocardial distention, injury, and inflammation may signal unique pathways underlying CVD in CKD. In this analysis, we studied the association of baseline levels and changes in 4 traditional and novel cardiac biomarkers with risk of all-cause, CV, and non-CV mortality in a large cohort of patients with CKD.

Methods

Among 3664 adults with CKD enrolled in the Chronic Renal Insufficiency Cohort Study, we conducted a cohort study to examine the associations of baseline levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac high-sensitivity troponin T (hsTnT), growth differentiation factor−15 (GDF-15), and soluble ST-2 (sST-2) with risks of all-cause and cardiovascular (CV) mortality. Among a subcohort of 842 participants, we further examined the associations between change in biomarker levels over 2 years with risk of all-cause mortality. We used Cox proportional hazards regression models and adjusted for demographics, kidney function measures, cardiovascular risk factors, and medication use.

Results

After adjustment, elevated baseline levels of each cardiac biomarker were associated with increased risk of all-cause mortality: NT-proBNP (hazard ratio [HR] = 1.92, 95% confidence interval [CI] = 1.73−2.12); hsTnT (HR = 1.62, 95% CI = 1.48, 1.78]); GDF-15 (HR = 1.61, 95% CI = 1.46−1.78]); and sST-2 (HR = 1.26, CI = 1.16−1.37). Higher baseline levels of all 4 cardiac biomarkers were also associated with increased risk of CV. Declines in NT-proBNP (adjusted HR = 0.55, 95% CI = 0.36−0.86) and sST2 (HR = 0.55, 95% CI = 0.36−0.86]) over 2 years were associated with lower risk of all-cause mortality.

Conclusion

In a large cohort of CKD participants, elevations of NT-proBNP, hsTnT, GDF-15, and sST-2 were independently associated with greater risks of all-cause and CV mortality.

Growth differentiation factor-15 is associated with cardiovascular outcomes in patients with coronary artery disease

Background

Growth differentiation factor-15 (GDF-15) is a marker of inflammation, oxidative stress and it is associated with adverse prognosis in cardiovascular disease. The aim of the present cohort study is to investigate the prognostic value of GDF-15 in patients with coronary artery disease (CAD) during long-term follow up.

Methods

A total of 3641 consecutive patients with CAD were prospectively enrolled into the study and followed up for major adverse cardiovascular events (MACEs) and all-cause death up to 5.3–7.6 years. Plasma GDF-15 was measured and clinical data and long-term events were registered. The patients were subsequently divided into three groups by the levels of GDF-15 and the prognostic value of GDF-15 level with MACEs and all-cause death was evaluated.

Results

After a median follow-up at 6.4 years later, 775 patients (event rate of 21%) had developed MACEs and 275 patients died (event rate of 7.55%). Kaplan–Meier analysis indicated that the patients with GDF-15 > 1800 ng/L were significantly associated with an increased risk of MACEs and all-cause death. Cox regression analysis indicated that GDF-15 > 1800 ng/L were independently associated with the composite of MACEs (HR 1.74; 95% CI 1.44–2.02; P < 0.001) and all-cause death (HR 2.04; 95% CI 1.57–2.61; P < 0.001). For MACEs, GDF-15 significantly improved the C-statistic (area under the curve, 0.583 [95% CI 0.559–0.606] to 0.628 [0.605–0.651]; P < 0.001), net reclassification index (0.578; P = 0.031), and integrated discrimination index (0.021; P = 0.027). For all-cause death, GDF-15 significantly improved the C-statistic (0.728 [95% CI 0.694–0.761] to 0.817 [0.781–0.846]; P < 0.001), net reclassification index (0.629; P = 0.001), and integrated discrimination index (0.035; P = 0.002).

Conclusions

In the setting of CAD, GDF-15 is associated with long-term MACEs and all-cause death, and provides incremental prognostic value beyond traditional risks factors.

Growth differentiation factor 15 in adverse cardiac remodelling: from biomarker to causal player

Heart failure is a growing health issue as a negative consequence of improved survival upon myocardial infarction, unhealthy lifestyle, and the ageing of our population. The large and complex pathology underlying heart failure makes diagnosis and especially treatment very difficult. There is an urgent demand for discriminative biomarkers to aid disease management of heart failure. Studying cellular pathways and pathophysiological mechanisms contributing to disease initiation and progression is crucial for understanding the disease process and will aid to identification of novel biomarkers and potential therapeutic targets. Growth differentiation factor 15 (GDF15) is a proven valuable biomarker for different pathologies, including cancer, type 2 diabetes, and cardiovascular diseases. Although the prognostic value of GDF15 in heart failure is robust, the biological function of GDF15 in adverse cardiac remodelling is not fully understood. GDF15 is a distant member of the transforming growth factor-β family and involved in various biological processes including inflammation, cell cycle, and apoptosis. However, more research is suggesting a role in fibrosis, hypertrophy, and endothelial dysfunction. As GDF15 is a pleiotropic protein, elucidating the exact role of GDF15 in complex disease processes has proven to be a challenge. In this review, we provide an overview of the role GDF15 plays in various intracellular and extracellular processes underlying heart failure, and we touch upon crucial points that need consideration before GDF15 can be integrated as a biomarker in standard care or when considering GDF15 for therapeutic intervention.

GDF15: A Hormone Conveying Somatic Distress to the Brain

GDF15 has recently gained scientific and translational prominence with the discovery that its receptor is a GFRAL-RET heterodimer of which GFRAL is expressed solely in the hindbrain. Activation of this receptor results in reduced food intake and loss of body weight and is perceived and recalled by animals as aversive. This information encourages a revised interpretation of the large body of previous research on the protein. GDF15 can be secreted by a wide variety of cell types in response to a broad range of stressors. We propose that central sensing of GDF15 via GFRAL-RET activation results in behaviors that facilitate the reduction of exposure to a noxious stimulus. The human trophoblast appears to have hijacked this signal, producing large amounts of GDF15 from early pregnancy. We speculate that this encourages avoidance of potential teratogens in pregnancy. Circulating GDF15 levels are elevated in a range of human disease states, including various forms of cachexia, and GDF15-GFRAL antagonism is emerging as a therapeutic strategy for anorexia/cachexia syndromes. Metformin elevates circulating GDF15 chronically in humans and the weight loss caused by this drug appears to be dependent on the rise in GDF15. This supports the concept that chronic activation of the GDF15-GFRAL axis has efficacy as an antiobesity agent. In this review, we examine the science of GDF15 since its identification in 1997 with our interpretation of this body of work now being assisted by a clear understanding of its highly selective central site of action.

Assessment of Growth Differentiation Factor 15 Levels on Coronary Flow in Patients with STEMI Undergoing Primary PCI

Growth Differentiation Factor-15 (GDF-15) is a strong predictor of decreased myocardial salvage and subsequent higher risk of death in patients with STEMI, but no information has been published regarding the association of GDF-15 levels with coronary blood flow in STEMI. We hypothesized that elevated GDF-15 levels would be associated with impaired flow and perfusion in the setting of STEMI treated with primary PCI. Eighty consecutive patients who were admitted with STEMI within 6 h from symptom onset were enrolled in the study. Patients were divided into two groups based upon the Thrombolysis in Myocardial Infarction (TIMI) flow grade. Group 1 was defined as TIMI Grade 0, 1 and 2 flows. Angiographic success was defined as TIMI 3 flow (group 2). GDF-15 and high sensitive CRP were measured. Major adverse cardiac events (MACE) were defined as stent thrombosis, nonfatal myocardial infarction and in-hospital mortality. There were 35 patients (mean age 64 ± 11.8 and 20% female) in group 1 and 45 patients (mean age 66.8 ± 11.5 and 29% female) in group 2. GDF-15 and hs-CRP levels were significantly higher in group 1 than in group 2 (1670 ± 831pg/mL vs. 733 ± 124 pg/mL, p < 0.001; and 19.8 ± 10.6 vs. 11.3 ± 4.9, p < 0.001). GDF-15 level ≥920 pg/mL measured on admission had a 94% sensitivity and 91% specificity in predicting no-reflow at ROC curve analysis. In-hospital MACE was also significantly higher in group 1 (28.6% vs. 2.2%, p: 0.001). Additionally, there was a significant correlation between hs-CRP and GDF-15 (r: 0.6030.56; p < 0.001). The GDF-15 level on admission is a strong and independent predictor of poor coronary blood flow following primary PCI and in hospital MACE among patients with STEMI. Except for predictive value, GDF-15 levels may be a useful biomarker for the stratification of risk in patients with STEMI, and may carry further therapeutic implications.

Renoprotective and Immunomodulatory Effects of GDF15 following AKI Invoked by Ischemia-Reperfusion Injury

BACKGROUND

Gdf15 encodes a TGF-β superfamily member that is rapidly activated in response to stress in multiple organ systems, including the kidney. However, there has been a lack of information about Gdf15 activity and effects in normal kidney and in AKI.

METHODS

We used genome editing to generate a Gdf15 ^nuGFP-CE mouse line, removing Gdf15 at the targeted allele, and enabling direct visualization and genetic modification of Gdf15-expressing cells. We extensively mapped Gdf15 expression in the normal kidney and following bilateral ischemia-reperfusion injury, and quantified and compared renal responses to ischemia-reperfusion injury in the presence and absence of GDF15. In addition, we analyzed single nucleotide polymorphism association data for GDF15 for associations with patient kidney transplant outcomes.

RESULTS

Gdf15 is normally expressed within aquaporin 1-positive cells of the S3 segment of the proximal tubule, aquaporin 1-negative cells of the thin descending limb of the loop of Henle, and principal cells of the collecting system. Gdf15 is rapidly upregulated within a few hours of bilateral ischemia-reperfusion injury at these sites and new sites of proximal tubule injury. Deficiency of Gdf15 exacerbated acute tubular injury and enhanced inflammatory responses. Analysis of clinical transplantation data linked low circulating levels of GDF15 to an increased incidence of biopsy-proven acute rejection.

CONCLUSIONS

Gdf15 contributes to an early acting, renoprotective injury response, modifying immune cell actions. The data support further investigation in clinical model systems of the potential benefit from GDF15 administration in situations in which some level of tubular injury is inevitable, such as following a kidney transplant.

GDF-15 is associated with thrombus burden in patients with deep venous thrombosis

INTRODUCTION

Growth differentiation factor-15 (GDF-15) has been identified as a predictor in cardiovascular diseases and acute pulmonary embolism. However, the association of GDF-15 and deep venous thrombosis (DVT) remains unclear. This study aimed to investigate levels of GDF-15 in patients with DVT, and determine its association with the thrombus burden.

MATERIALS AND METHODS

72 newly diagnosed DVT patients and 30 healthy volunteers were enrolled, and the levels of plasma GDF-15 were detected. To explore the relationship between GDF-15 and thrombus severity, we analyzed the thrombus burden and the association with pulmonary embolism of DVT patients. In vitro, the effect of GDF-15 on platelet aggregation and thrombin/antithrombin activity were investigated.

RESULTS

We found that the mean levels of plasma GDF-15 in DVT patients were significantly higher than those in healthy controls (1448.78 ± 61.98 pg/ml VS 805.70 ± 112.95 pg/ml, P < 0.001). Furthermore, GDF-15 showed an increase with more venous segments with thrombus (P < 0.001), and the patients with higher levels of GDF-15 and more thrombus segments showed higher scores of Wells-PE and Geneva and increased incidence of pulmonary embolism (P < 0.05). In vitro, we confirmed that GDF-15 significantly reduced platelet aggregation induced by ADP and the effect was concentration-dependent (P < 0.001). However, GDF-15 showed no direct effect on thrombin and anti-thrombin activity.

CONCLUSIONS

Increased GDF-15 level was associated with more thrombus severity of DVT patients and GDF-15 could inhibit platelet aggregation induced by ADP in vitro. These findings suggest that GDF-15 might not only be an indicator for thrombus severity but also be a potential treatment target in DVT.