Platelet proteome changes in dogs with congestive heart failure

Platelet proteomics: Clinical implications - Decoding the black box!

Platelets are anucleate blood cells traditionally associated with hemostasis but now increasingly recognized for their multifaceted roles in immunity, inflammation, and tissue repair. Advances in platelet proteomics, employing high-throughput techniques such as mass spectrometry, have significantly enhanced our understanding of platelet biology and its clinical implications in transfusion medicine. Platelet proteomics offers a retrospective view of physiological and pathological changes over the platelet's 7-10-day lifespan, making it a unique tool for studying cumulative biological events. Recent applications include the identification of biomarkers for cardiovascular, infectious, autoimmune diseases and cancer. In neurodegeneration and aging, platelets have been explored for their shared molecular pathways with neurons, with findings implicating Tau, amyloid-beta, and alpha-synuclein as potential biomarkers. Proteomics is also emerging as an important factor in the development of evidence-based, tailor-made platelet-derived therapies. While promising, platelet proteomics requires further standardization and computational advances to support transitioning from research to routine clinical practice.

Screening of key genes related to M6A methylation in patients with heart failure

OBJECTIVE

This study aims to identify m6A methylation-related and immune cell-related key genes with diagnostic potential for heart failure (HF) by leveraging various bioinformatics techniques.

METHODS

The GSE116250 and GSE141910 datasets were sourced from the Gene Expression Omnibus (GEO) database. Correlation analysis was conducted between differentially expressed genes (DEGs) in HF and control groups, alongside differential m6A regulatory factors, to identify m6A-related DEGs (m6A-DEGs). Subsequently, candidate genes were narrowed down by intersecting key module genes derived from weighted gene co-expression network analysis (WGCNA) with m6A-DEGs. Key genes were then identified through the Least Absolute Shrinkage and Selection Operator (LASSO) analysis. Correlation analyses between key genes and differentially expressed immune cells were performed, followed by the validation of key gene expression levels in public datasets. To ensure clinical applicability, five pairs of blood samples were collected for quantitative real-time fluorescence PCR (qRT-PCR) validation.

RESULTS

A total of 93 m6A-DEGs were identified (|COR| > 0.6, P < 0.05), and five key genes (LACTB2, NAMPT, SCAMP5, HBA1, and PRKAR2A) were selected for further analysis. Correlation analysis revealed that differential immune cells were negatively associated with the expression of LACTB2, NAMPT, and PRKAR2A (P < 0.05), while positively correlated with SCAMP5 and HBA1 (P < 0.05). Subsequent expression validation confirmed significant differences in key gene expression between the HF and control groups, with consistent expression trends observed across both training and validation sets. The expression trends of LACTB2, PRKAR2A, and HBA1 in blood samples from the qRT-PCR assay aligned with the results derived from public databases.

CONCLUSION

This study successfully identified five m6A methylation-related key genes with diagnostic significance, providing a theoretical foundation for further exploration of m6A methylation's molecular mechanisms in HF.

Impact of heart failure and preoperative platelet count on the postoperative short-term outcome in infective endocarditis patients

BACKGROUND

Heart failure (HF) and platelet count are often considered risk factors for mortality in patients with infective endocarditis (IE); however, their effects on various complications have not been elucidated.

HYPOTHESIS

We speculated that HF and platelet count have significant impact on the short-term outcomes of IE.

METHODS

This single-center retrospective study analyzed data from 320 IE patients who underwent surgery. A multivariate Cox proportional hazards model was used to identify the risk factors for adverse outcomes. The effect of the platelet count on the prognosis of patients with HF was determined by subgroup analysis and Kaplan-Meier analysis.

RESULTS

The study population was divided into the HF group (n = 102) and the non-HF group (n = 218). The median age of the total population was 44.5 years (31-56 years), of which 227 (70.94%) patients were male. The incidence rates of 1-year all-cause mortality, cardiac outcomes, and composite outcomes were respectively almost sixfold, fourfold, and threefold higher in the HF group than in the non-HF group (all p < 0.001). In multivariate Cox regression analysis, HF was an independent risk factor for 1-year all-cause mortality, cardiac outcomes, cerebral outcomes, and composite outcomes. The Kaplan-Meier survival curves revealed that the patients with both HF and thrombocytopenia demonstrated the worst composite outcomes than the patients of the other groups (log-rank p < 0.001). In the HF group, the platelet count was significantly associated with mortality and composite outcomes.

CONCLUSIONS

HF and preoperative platelet count are significantly associated with 1-year all-cause mortality and adverse outcomes postoperatively in IE patients. Patients with HF and thrombocytopenia have the worst short-term prognosis.

Differentially expressed platelet activation-related genes in dogs with stage B2 myxomatous mitral valve disease

BACKGROUND

Peripheral blood carries a reservoir of mRNAs that regulate cardiac structure and function potential. Although it is well recognized that the typical symptoms of Myxomatous Mitral Valve Disease (MMVD) stage B2 are long-standing hemodynamic disorder and cardiac structure remodeling caused by mitral regurgitation, the transcriptomic alterations in blood from such dogs are not understood.

RESULTS

In the present study, comparative high-throughput transcriptomic profiling of blood was performed from normal control (NC) and naturally-occurring MMVD stage B2 (MMVD) dogs. Using Weighted Gene Co-expression Network Analyses (WGCNA), Gene Ontology (GO), and Kyoto Encyclopedia of Gene and Genomes (KEGG), we identified that the turquoise module was the most highly correlated with echocardiographic features and found 64 differentially expressed genes (DEGs) that were significantly enriched in platelet activation related pathways. Therefore, from the turquoise module, we selected five DEGs (MDM2, ROCK1, RIPK1, SNAP23, and ARHGAP35) that, according to real-time qPCR, exhibited significant enrichment in platelet activation related pathways for validation. The results showed that the blood transcriptional abundance of MDM2, ROCK1, RIPK1, and SNAP23 differed significantly (P < 0.01) between NC and MMVD dogs. On the other hand, Correlation Analysis revealed that MDM2, ROCK1, RIPK1, and SNAP23 genes negatively regulated the heart structure parameters, and followed the same trend as observed in WGCNA.

CONCLUSION

We screened four platelet activation related genes, MDM2, ROCK1, RIPK1, and SNAP23, which may be considered as the candidate biomarkers for the diagnosis of MMVD stage B2. These findings provided new insights into MMVD pathogenesis.

Serum Proteomic Profiles Reflect the Stages of Myxomatous Mitral Valve Disease in Dogs

Canine myxomatous mitral valve disease (MMVD) is similar to Barlow's form of MMVD in humans. These valvulopathies are complex, with varying speeds of progression. We hypothesized that the relative abundances of serum proteins would help identify the consecutive MMVD stages and discover new disease pathways on a systemic level. To identify distinction-contributing protein panels for disease onset and progression, we compared the proteomic profiles of serum from healthy dogs and dogs with different stages of naturally occurring MMVD. Dogs were divided into experimental groups on the basis of the left-atrium-to-aorta ratio and normalized left ventricular internal dimension in diastole values. Serum was collected from healthy (N = 12) dogs, dogs diagnosed with MMVD in stages B1 (N = 13) and B2 (N = 12) (asymptomatic), and dogs diagnosed with MMVD in chronic stage C (N = 13) (symptomatic). Serum biochemistry and selected ELISAs (galectin-3, suppression of tumorigenicity, and asymmetric dimethylarginine) were performed. Liquid chromatography-mass spectrometry (LC-MS), tandem mass tag (TMT) quantitative proteomics, and statistical and bioinformatics analysis were employed. Most of the 21 serum proteins with significantly different abundances between experimental groups (p < 0.05, FDR ˂ 0.05) were classified as matrix metalloproteinases, protease inhibitors, scaffold/adaptor proteins, complement components, anticoagulants, cytokine, and chaperone. LC-MS TMT proteomics results obtained for haptoglobin, clusterin, and peptidase D were further validated analytically. Canine MMVD stages, including, for the first time, asymptomatic B1 and B2 stages, were successfully distinguished in dogs with the disease and healthy dogs on the basis of the relative abundances of a panel of specific serum proteins. Most proteins with significantly different abundances were involved in immune and inflammatory pathways. Their role in structural remodeling and progression of canine MMVD must be further investigated. Further research is needed to confirm the resemblance/difference with human MMVD. Proteomics data are available via ProteomeXchange with the unique dataset identifier PXD038475.

Blood Coagulation Disorders in Heart Failure: From Basic Science to Clinical Perspectives

Heart failure (HF) is a clinical syndrome that is divided into 3 subtypes based on the left ventricular ejection fraction. Every subtype has specific clinical characteristics and concomitant diseases, substantially increasing risk of thromboembolic complications, such as stroke, peripheral embolism and pulmonary embolism. Despite the annual prevalence of 1% and devastating clinical consequences, thromboembolic complications are not typically recognized as the leading problem in patients with HF, representing an underappreciated clinical challenge. Although the currently available data do not support routine anticoagulation in patients with HF and sinus rhythm, initial reports suggest that such strategy might be beneficial in a subset of patients at especially high thromboembolic risk. Considering the existing evidence gap, we aimed to review the currently available data regarding coagulation disorders in acute and chronic HF based on the insight from preclinical and clinical studies, to summarize the evidence regarding anticoagulation in HF in special-case scenarios and to outline future research directions so as to establish the optimal patient-tailored strategies for antiplatelet and anticoagulant therapy in HF. In summary, we highlight the top 10 pearls in the management of patients with HF and no other specific indications for oral anticoagulation therapy. Further studies are urgently needed to shed light on the pathophysiological role of platelet activation in HF and to evaluate whether antiplatelet or antithrombotic therapy could be beneficial in patients with HF. LAY SUMMARY: Heart failure (HF) is a clinical syndrome divided into 3 subtypes on the basis of the left ventricular systolic function. Every subtype has specific clinical characteristics and concomitant diseases, substantially increasing the risk of thromboembolic complications, such as stroke, peripheral embolism and pulmonary embolism. Despite the annual prevalence of 1% and devastating clinical consequences, thromboembolic complications are not typically recognized as the leading problem in patients with HF, representing an underappreciated clinical challenge. Although the currently available data do not support routine anticoagulation in patients with HF and no atrial arrhythmia, initial reports suggest that such a strategy might be beneficial in a subset of patients at especially high risk of thrombotic complications. Considering the existing evidence gap, we aimed to review the currently available data regarding coagulation problems in stable and unstable patients with HF based on the insight from preclinical and clinical studies, to summarize the evidence regarding anticoagulation in HF in specific patient groups and to outline future research directions to establish the optimal strategies for antiplatelet and anticoagulant therapy in HF, tailored to the needs of an individual patient. In summary, we highlight the top 10 pearls in the management of patients with HF and no other specific indications for oral anticoagulation therapy.

Urinary Proteomic Signature in Acute Decompensated Heart Failure: Advances into Molecular Pathophysiology

Acute decompensated heart failure (ADHF) is a life-threatening clinical syndrome involving multi-organ function deterioration. ADHF results from multifaceted, dysregulated pathways that remain poorly understood. Better characterization of proteins associated with heart failure decompensation is needed to gain understanding of the disease pathophysiology and support a more accurate disease phenotyping. In this study, we used an untargeted mass spectrometry (MS) proteomic approach to identify the differential urine protein signature in ADHF patients and examine its pathophysiological link to disease evolution. Urine samples were collected at hospital admission and compared with a group of healthy subjects by two-dimensional electrophoresis coupled to MALDI-TOF/TOF mass spectrometry. A differential pattern of 26 proteins (>1.5-fold change, p < 0.005), mostly of hepatic origin, was identified. The top four biological pathways (p < 0.0001; in silico analysis) were associated to the differential ADHF proteome including retinol metabolism and transport, immune response/inflammation, extracellular matrix organization, and platelet degranulation. Transthyretin (TTR) was the protein most widely represented among them. Quantitative analysis by ELISA of TTR and its binding protein, retinol-binding protein 4 (RBP4), validated the proteomic results. ROC analysis evidenced that combining RBP4 and TTR urine levels highly discriminated ADHF patients with renal dysfunction (AUC: 0.826, p < 0.001) and significantly predicted poor disease evolution over 18-month follow-up. In conclusion, the MS proteomic approach enabled identification of a specific urine protein signature in ADHF at hospitalization, highlighting changes in hepatic proteins such as TTR and RBP4.

Serum Proteomic Changes in Dogs with Different Stages of Chronic Heart Failure

Simple Summary

Canine MMVD is a progressive chronic disease with variable clinical signs, with some patients remaining completely asymptomatic while others develop CHF. Here, the aims of the pilot study were to evaluate serum proteins by proteomic analysis in dogs at different stages of chronic heart failure (CHF) due to degenerative mitral valve disease (MMVD), and how these proteins can change after a conventional treatment. Study revealed 157 different proteins; 11 were up- and 21 down-regulated at a statistically significant level in dogs with CHF compared to controls. Based on the bioinformatic analysis, protein–protein interactions between complement proteins, fibrinogen subtypes and others (albumin precursor, serpins, inter-alpha-trypsin inhibitor heavy chain, fetuin, clusterin, apolipoproteins, and alpha-glycoproteins) showed that pathophysiology of CHF seems to be more sophisticated than we had thought. These proteins are associated with several cellular, biologic, and metabolic processes such as immune-inflammatory responses, hemostasis, oxidative stress, and energy metabolism, which might be detrimental in the progression of canine CHF. Their molecular and biological functions as well as roles in the signaling pathways, such as inflammation, cadherin signaling, nicotinic acetylcholine receptor signaling and Wnt signaling make them possible biomarkers and therapeutic targets for the diagnosis and treatments in dogs with different stages of CHF.

Abstract

MMVD, the most common cause of CHF in dogs, is a chronic disease with variable clinical signs, with some patients remaining asymptomatic while others develop CHF. Here, we aimed to evaluate serum proteins by proteomic analysis in dogs at different stages of CHF due to MMVD, and proteome behaviors after conventional treatment. A total of 32 dogs were divided equally into four groups—stage A (healthy/controls), stage B2 (asymptomatic), stage C and stage D (symptomatic)—according to the ACVIM consensus. Serum proteomes were evaluated using LC/MS-based label-free differential proteome analysis. The study revealed 157 different proteins; 11 were up- and 21 down-regulated in dogs with CHF compared to controls. In stage B2 dogs, angiotensinogen (AGT) was up-regulated, but immunoglobulin iota chain-like, lipopolysaccharide-binding protein, and carboxypeptidase (CPN) were down-regulated. In stage C dogs, complement C3 (C3) and inter-alpha-trypsin inhibitor heavy chain were up-regulated, but hemopexin, and actin-cytoplasmic-1 (ACT-1) were down-regulated. In stage D dogs, AGT was up-regulated, whereas tetranectin, paraoxonase-1, adiponectin and ACT-1 were down-regulated. A decrease in CPN, C3 and AGT and an increase in ACT-1 were observed after treatment of dogs in stage C. This pilot study identified that dogs at different stages of CHF show different serum protein composition which has potential to be biomarker for diagnose and treatment monitorization.

Proteomics in dogs: a systematic review

Proteomic analysis is having a rapid development as a method for the detection of biomarkers of diseases in dogs. Dogs in addition to their importance as companion animals, serve as important animal models for research. This study aims to systematically review evidence regarding the studies performed in proteomics in dogs, and specifically those made in serum, saliva, urine and/or plasma. Information searched in October 2020, January 2021 and August 2021, for English language publications of the last decade (2010-2020) were obtained from electronic databases. Screening, data extraction and risk of bias assessment were undertaken by two investigators. The risk of bias was evaluated using the Review Manager (RevMan 5) tool. Meta-analysis and case report studies were not included in this review. Through the screening process a total of 557 publications were identified after the removal of duplicates. Out of these, 65 were fully evaluated and 44 of these were included in the review. Most studies evaluated the proteome of disease and compared it with a healthy population, and most of the articles included were made on serum, followed by saliva. The overall risk of bias for all studies was high, due to an absence in the generation of random sequence. Overall proteomic analysis has allowed the discovery of new physiopathological pathways of diseases and potential biomarkers in the dog, which are addressed in this review.