Growth differentiation factor-15, a novel systemic biomarker of oxidative stress, inflammation, and cellular aging: Potential role in cardiovascular diseases

Leveraging DNA methylation to create Epigenetic Biomarker Proxies that inform clinical care: A new framework for Precision Medicine

The lack of accurate, cost-effective, and clinically relevant biomarkers remains a major barrier to incorporating omic data into clinical practice. Previous studies have shown that DNA methylation algorithms have utility as surrogate measures for selected proteins and metabolites. We expand upon this work by creating DNAm surrogates, termed epigenetic biomarker proxies (EBPs), across clinical laboratories, the metabolome, and the proteome. After screening >2,500 biomarkers, we trained and tested 1,694 EBP models and assessed their incident relationship with 12 chronic diseases and mortality, followed up to 15 years. We observe broad clinical relevance: 1) there are 1,292 and 4,863 FDR significant incident and prevalent associations, respectively; 2) most of these associations are replicated when looking at the lab-based counterpart, and > 62% of the shared associations have higher odds and hazard ratios to disease outcomes than their respective observed measurements; 3) EBPs of current clinical biochemistries detect deviations from normal with high sensitivity and specificity. Longitudinal EBPs also demonstrate significant changes corresponding to the changes observed in lab-based counterparts. Using two cohorts and > 30,000 individuals, we found that EBPs validate across healthy and sick populations. While further study is needed, these findings highlight the potential of implementing EBPs in a simple, low-cost, high-yield framework that benefits clinical medicine.

GDF-15 as a proxy for epigenetic aging: associations with biological age markers, and physical function

Growth differentiation factor 15 (GDF-15) has emerged as a significant biomarker of aging, linked to various physiological and pathological processes. This study investigates circulating GDF-15 levels in a cohort of healthy individuals from the Balearic Islands, exploring its associations with biological age markers, including multiple DNA methylation (DNAm) clocks, physical performance, and other age-related biomarkers. Seventy-two participants were assessed for general health, body composition, and physical function, with GDF-15 levels quantified using ELISA. Our results indicate that GDF-15 levels significantly increase with age, particularly in individuals over 60. Strong positive correlations were observed between GDF-15 levels and DNAm GrimAge, DNAm PhenoAge, Hannum, and Zhang clocks, suggesting that GDF-15 could serve as a proxy for epigenetic aging. Additionally, GDF-15 levels were linked to markers of impaired glycemic control, systemic inflammation, and physical decline, including decreased lung function and grip strength, especially in men. These findings highlight the use of GDF-15 as a biomarker for aging and age-related functional decline. Given that GDF-15 is easier to measure than DNA methylation, it has the potential to be more readily implemented in clinical settings for broader health assessment and management.

Older patients affected by COVID-19: investigating the existence of biological phenotypes

INTRODUCTION

COVID-19 provides an opportunity to examine biological phenotypes (observable morphological, functional and biological characteristics) in individuals who experience the same acute condition, potentially revealing differences in response to acute external stressors. The aim our study was to investigate biological phenotypes in older patients hospitalized for COVID-19, exploiting a panel of aging biomarkers.

METHODS

Data were gathered from the FRACOVID Project, an observational multicenter study, aimed to evaluate the impact of frailty on health-related outcomes in patients 60 + with COVID-19 in Northern Italy. A hierarchical cluster analysis was run using log-transformed and scaled values of TNF-a, IL-1 beta, IL-6, PAI-1, GDF-15, NT-proBNP, and Cystatin C evaluated at admission.

RESULTS

Eighty-one participants (mean age 75.3 years; 60.5% male) were evaluated. Frailty was identified in 42% of the sample and 27.2% were unable to ambulate outdoors. The mean hospital stay was 24.7 days, with an in-hospital mortality rate of 18.5%. Three biological phenotypes were found: (1) 'inflammatory', with high inflammatory biomarkers; (2) 'organ dysfunction', characterized by elevated cystatin C and NT-proBNP, and lower inflammatory markers; and (3) 'unspecific', with lower NT-proBNP and GDF-15 levels, and intermediate concentrations of other biomarkers. The 'organ dysfunction' phenotype showed the highest mean age and prevalence of frailty, disability, and chronic diseases. The 'inflammatory' phenotype showed the highest burden of respiratory and systemic signs and symptoms of infection.

CONCLUSION

Biological phenotypes might be used to identify different clinical and functional phenotypes in individuals affected by COVID-19.

A Comprehensive Review of Cardiovascular Disease Management: Cardiac Biomarkers, Imaging Modalities, Pharmacotherapy, Surgical Interventions, and Herbal Remedies

Cardiovascular diseases (CVDs) continue to be a major global health concern, representing a leading cause of morbidity and mortality. This review provides a comprehensive examination of CVDs, encompassing their pathophysiology, diagnostic biomarkers, advanced imaging techniques, pharmacological treatments, surgical interventions, and the emerging role of herbal remedies. The review covers various cardiovascular conditions such as coronary artery disease, atherosclerosis, peripheral artery disease, deep vein thrombosis, pulmonary embolism, cardiomyopathy, rheumatic heart disease, hypertension, ischemic heart disease, heart failure, cerebrovascular diseases, and congenital heart defects. The review presents a wide range of cardiac biomarkers such as troponins, C-reactive protein, CKMB, BNP, NT-proBNP, galectin, adiponectin, IL-6, TNF-α, miRNAs, and oxylipins. Advanced molecular imaging techniques, including chest X-ray, ECG, ultrasound, CT, SPECT, PET, and MRI, have significantly enhanced our ability to visualize myocardial perfusion, plaque characterization, and cardiac function. Various synthetic drugs including statins, ACE inhibitors, ARBs, β-blockers, calcium channel blockers, antihypertensives, anticoagulants, and antiarrhythmics are fundamental in managing CVDs. Nonetheless, their side effects such as hepatic dysfunction, renal impairment, and bleeding risks necessitate careful monitoring and personalized treatment strategies. In addition to conventional therapies, herbal remedies have garnered attention for their potential cardiovascular benefits. Plant extracts and their bioactive compounds, such as flavonoids, phenolic acids, saponins, and alkaloids, offer promising cardioprotective effects and enhanced cardiovascular health. This review underscores the value of combining traditional and modern therapeutic approaches to improve cardiovascular outcomes. This review serves as a vital resource for researchers by integrating a broad spectrum of information on CVDs, diagnostic tools, imaging techniques, pharmacological treatments and their side effects, and the potential of herbal remedies.

Neutralizing antibody against GDF15 for treatment of cancer-associated cachexia

GDF15 (growth differentiation factor 15), also known as macrophage inhibitory cytokine 1 (MIC-1), is a circulating protein involved in the regulation of energy balance and weight control. Elevated levels of GDF15 have been associated with cachexia and reduced survival rates in cancer patients. Through the activation of the GFRAL (GDNF-family receptor α-like)-RET (Rearranged during Transfection) signaling pathway, GDF15 can induce weight loss, making it a potential target for treating cachexia. Currently, there are no approved antibody drugs specifically targeting GDF15 for cancer cachexia treatment. However, efforts have been made to develop antibody-based therapeutics against this emerging target. In this study, we generated a monoclonal antibody KY-NAb-GDF15 against GDF15 that effectively blocks downstream signaling mediated by GFRAL upon stimulation by GDF15. This antibody demonstrates robust neutralizing activity and exhibits high binding specificity. Importantly, our findings indicate that this antibody holds promise in alleviating cancer-induced cachexia and mitigating chemotherapy-induced weight loss, thereby offering significant therapeutic potential for managing cancer cachexia.

Cardiac Biomarkers and Their Role in Identifying Increased Risk of Cardiovascular Complications in COVID-19 Patients

Cardiovascular disease (CVD) is a global health concern, causing significant morbidity and mortality. Both lifestyle and genetics influence the development of CVD. It is often diagnosed late, when the treatment options are limited. Early diagnosis of CVD with help of biomarkers is necessary to prevent adverse outcomes. SARS-CoV-2 infection can cause cardiovascular complications even in patients with no prior history of CVD. This review highlights cardiovascular biomarkers, including novel ones, and their applications as diagnostic and prognostic markers of cardiovascular complications related to SARS-CoV-2 infection. Patients with severe SARS-CoV-2 infection were shown to have elevated levels of cardiac biomarkers, namely N-terminal pro-brain natriuretic peptide (NT-pro-BNP), creatine kinase-myocardial band (CK-MB), and troponins, indicating acute myocardial damage. These biomarkers were also associated with higher mortality rates and therefore should be used throughout COVID-19 patient care to identify high-risk patients promptly to optimize their outcomes. Additionally, microRNAs (miRNAs) are also considered as potential biomarkers and predictors of cardiac and vascular damage in SARS-CoV-2 infection. Identifying molecular pathways contributing to cardiovascular manifestations in COVID-19 is essential for development of early biomarkers, identification of new therapeutic targets, and better prediction and management of cardiovascular outcomes.

Cardiac and noncardiac biomarkers in patients undergoing anthracycline chemotherapy - a prospective analysis

BACKGROUND

Biomarkers represent a potential tool to identify individuals at risk for anthracycline-induced cardiotoxicity (AICT) prior to symptom onset or left ventricular dysfunction.

METHODS

This study examined the levels of cardiac and noncardiac biomarkers before, after the last dose of, and 3-6 months after completion of doxorubicin chemotherapy. Cardiac biomarkers included 5th generation high-sensitivity cardiac troponin T (cTnT), N-terminal pro-brain natriuretic peptide, growth/differentiation factor-15 (GDF-15), and soluble suppression of tumorigenesis-2 (sST2). Noncardiac biomarkers included activated caspase-1 (CASP-1), activated caspase-3, C-reactive protein, tumor necrosis factor-α, myeloperoxidase (MPO), galectin-3, and 8-hydroxy-2'-deoxyguanosine. Echocardiographic data (LVEF and LVGLS) were obtained at pre- and post-chemotherapy. Subanalysis examined interval changes in biomarkers among high (cumulative doxorubicin dose ≥ 250 mg/m2) and low exposure groups.

RESULTS

The cardiac biomarkers cTnT, GDF-15, and sST2 and the noncardiac biomarkers CASP-1 and MPO demonstrated significant changes over time. cTnT and GDF-15 levels increased after anthracycline exposure, while CASP-1 and MPO decreased significantly. Subanalysis by cumulative dose did not demonstrate a larger increase in any biomarker in the high-dose group.

CONCLUSIONS

The results identify biomarkers with significant interval changes in response to anthracycline therapy. Further research is needed to understand the clinical utility of these novel biomarkers.

Impairments of intestinal arginine and NO metabolisms trigger aging-associated intestinal barrier dysfunction and 'inflammaging'

Aging is considered a state of low grade inflammation, occurring in the absence of any overt infection often referred to as 'inflammaging'. Maintaining intestinal homeostasis may be a target to extend a healthier status in older adults. Here, we report that even in healthy older men low grade bacterial endotoxemia is prevalent. In addition, employing multiple mouse models, we also show that while intestinal microbiota composition changes significantly during aging, fecal microbiota transplantation to old mice does not protect against aging-associated intestinal barrier dysfunction in small intestine. Rather, intestinal NO homeostasis and arginine metabolism mediated through arginase and NO synthesis is altered in small intestine of aging mice. Treatment with the arginase inhibitor norNOHA prevented aging-associated intestinal barrier dysfunction, low grade endotoxemia and delayed the onset of senescence in peripheral tissue e.g., liver. Intestinal arginine and NO metabolisms could be a target in the prevention of aging-associated intestinal barrier dysfunction and subsequently decline and 'inflammaging'.

Early Protective Role of Inflammation in Cardiac Remodeling and Heart Failure: Focus on TNFα and Resident Macrophages

Cardiac hypertrophy, initiated by a variety of physiological or pathological stimuli (hemodynamic or hormonal stimulation or infarction), is a critical early adaptive compensatory response of the heart. The structural basis of the progression from compensated hypertrophy to pathological hypertrophy and heart failure is still largely unknown. In most cases, early activation of an inflammatory program reflects a reparative or protective response to other primary injurious processes. Later on, regardless of the underlying etiology, heart failure is always associated with both local and systemic activation of inflammatory signaling cascades. Cardiac macrophages are nodal regulators of inflammation. Resident macrophages mostly attenuate cardiac injury by secreting cytoprotective factors (cytokines, chemokines, and growth factors), scavenging damaged cells or mitochondrial debris, and regulating cardiac conduction, angiogenesis, lymphangiogenesis, and fibrosis. In contrast, excessive recruitment of monocyte-derived inflammatory macrophages largely contributes to the transition to heart failure. The current review examines the ambivalent role of inflammation (mainly TNFα-related) and cardiac macrophages (Mφ) in pathophysiologies from non-infarction origin, focusing on the protective signaling processes. Our objective is to illustrate how harnessing this knowledge could pave the way for innovative therapeutics in patients with heart failure.