Potential Biomarkers For Cardiovascular Disease Research Articles

Metalloproteinases in the pathogenesis and progression of metabolic syndrome: potential targets for improved outcomes

Matrix metalloproteinases (MMPs) constitute a family of more than 25 calcium- dependent, zinc-containing endopeptidases, synthesized by multiple cell types. These enzymes play an important role during physiological tissue development and remodeling and angiogenesis, as well as in pathophysiological conditions such as obesity and atherosclerotic process. Moreover, circulating levels of MMPs have emerged as potential biomarkers of cardiovascular disease. MMPs are regulated by different factors such as insulin resistance and obesity. Different components of the metabolic syndrome have been identified as possible stimulus for the synthesis and activity of MMPs. On the other hand, pro-inflammatory and anti-inflammatory cytokines, such as leptin and adiponectin, respectively, are associated with the regulation of MMPs. Leptin induces expression of MMP-2 activators as well as expression of MMP-2, MMP-9, and tis- sue inhibitor of metalloproteinase (TIMP)-1 in different human cells. Adiponectin may play a protective role in plaque rupture through selectively increasing TIMP expression. The hepatic manifestation of metabolic syndrome is nonalcoholic fatty liver disease (NAFLD). MMPs may remodel the liver parenchyma during the process of liver fibrosis. MMP-2 and MT1-MMP have been considered to be fibrogenic enzymes.There are few studies analyzing the role of MMPs in NAFLD, and most of them include study on mRNA expression, but even the results on their expression pattern remains controversial. MMPs could be considered as possible therapeutic targets. Different studies demonstrated that metformin, thiazolidinediones, and antibiotics could have inhibitory effects on the expression of MMPs; however, a rational study of lifestyle modifications as well as further studies of pharmacological therapies that influence MMPs are necessary to generate the information that physicians will probably need to improve the treatment of patients. The aim of this revision is to update the data about MMPs in the pathogenesis and progression of metabolic syndrome and the possible effect of different drugs on the behavior of these enzymes.

Osteoprotegerin in Cardiometabolic Disorders.

Osteoprotegerin (OPG), a glycoprotein traditionally implicated in bone remodelling, has been recently related to cardiovascular disease (CVD). Human studies show a positive relationship between circulating OPG, vascular damage, and CVD, and as such OPG has emerged as a potential biomarker for CVD. This review focuses on the relationship between circulating OPG and different endocrine cardiometabolic alterations such as type 1 and 2 diabetes. The association of OPG with diabetic complications (neuropathy, nephropathy, or retinopathy) as well as with atherosclerosis, coronary artery calcification, morbidity, and mortality is pointed out. Moreover, OPG modulation by different treatments is also established. Besides, other associated diseases such as obesity, hypertension, and metabolic syndrome, which are known cardiovascular risk factors, are also considered.

Plasma levels of microRNA-499 provide an early indication of perioperative myocardial infarction in coronary artery bypass graft patients.

BackgroundRecent studies indicated that microRNAs (miRNAs, miRs) were important for many biological and pathological processes, and they might be potential biomarkers for cardiovascular diseases. The present study aims to determine the release patterns of miRNAs in cardiac surgery and to analyze the ability of miRs to provide early prediction of perioperative myocardial infarction (PMI) in patients undergoing coronary artery bypass graft (CABG) surgery.Methodology/Principal FindingsThirty on-pump CABG patients were recruited in this study; and miR-499, miR-133a and miR-133b, cardiac troponin I (cTnI) were selected for measurement. Serial plasma samples were collected at seven perioperative time points (preoperatively, and 1, 3, 6, 12, 24, and 48 hours after declamping) and were tested for cTnI and miRs levels. Importantly, miR levels peaked as early as 1–3 hours, whereas cTnI levels peaked at 6 hours after declamping. Peak plasma concentrations of miRs correlated significantly with cTnI (miR-499, r = 0.583, P = 0.001; miR-133a, r = 0.514, P = 0.006; miR-133b, r = 0.437, P = 0.05), indicating the degree of myocardial damage. In addition, 30 off-pump CABG patients were recruited; miR-499 and miR-133a levels were tested, which were significantly lower in off-pump group than in on-pump group. A prospective cohort of CABG patients (n = 120) was recruited to study the predictive power of miRs for PMI. The diagnosis of PMI strictly adhered to the principles of universal definition of myocardial infarction. The data analysis revealed that miR-499 had higher sensitivity and specificity than cTnI, and indicated that miR-499 could be an independent risk factor for PMI.ConclusionOur results demonstrate that circulating miR-499 is a novel, early biomarker for identifying perioperative myocardial infarction in cardiac surgery.

Influence of pre-analytical and analytical factors on osteoprotegerin measurements

IntroductionOsteoprotegerin (OPG), an osteoclastogenesis inhibitor implicated in bone remodelling, has emerged as a potential biomarker for cardiovascular disease. In order to implement OPG determination in the clinical laboratory, it is crucial to identify the most appropriate specimen type, preparation and measurement conditions. The present study focuses on identifying the pre-analytical variables that may influence OPG measurements. MethodsSerum and plasma (in EDTA, heparin and citrate) were collected from 45 healthy volunteers (men (n=21, 46.7%), women (n=24, 53.3%)). OPG was analysed by ELISA. The influence of the centrifugation speed, the number of freeze–thaw cycles, delay in sample processing, thermo-stability and endogenous interfering agents (haemolysis, triglycerides, bilirubin, cholesterol and RANKL) were studied. ResultsOPG concentrations were significantly lower (p<0.0001) in serum (1015±357pg/mL) than in all plasma samples (1314±448pg/mL in EDTA, 1209±417pg/mL in heparin and 1260±498pg/mL in citrate).Increasing centrifugation speed (200g to 3000g) did not change serum OPG concentration (p=0.88). However, OPG concentration significantly increased when centrifuged serum samples were stored at 48h at room temperature (p<0.0001). Repeated freeze–thaw cycles did not modify OPG levels until 4cycles (p<0.0001). Increasing time before processing the samples (2h and 6h) raised OPG concentrations both at room temperature (p<0.0001) or 4°C (p<0.001).Positive concentration-dependent interference of triglycerides was found in the analysed pooled samples; however, OPG concentrations were falsely diminished with haemoglobin interference. Bilirubin, cholesterol and RANKL did not interfere with OPG measurements.

Circulating and adipose tissue matrix metalloproteinases in cardiometabolic risk environments: pathophysiological aspects.

Matrix metalloproteinases (MMPs) play an important role during physiological tissue remodeling in embryonic development and angiogenesis, as well as in pathophysiological conditions such as obesity and development and vulnerability of atherosclerotic plaque. Moreover, MMP circulating levels have emerged as potential biomarkers of cardiovascular disease. MMP expression and activity are regulated by different factors such as insulin resistance and obesity. Expanded fat tissue has been demonstrated to be an active organ, where MMPs also exert a role in adipogenesis, angiogenesis, and proliferation of extracellular matrix (ECM). However, the lack of association between adipose tissue and plasma levels of some MMPs, specifically MMP-2 and MMP-9, suggests that this tissue is not a major contributor to circulating gelatinases. MMPs are also co-expressed or co-repressed in response to inflammatory adipocytokines, like adiponectin and leptin. Adiponectin may also play a protective role in plaque rupture through selectively increasing the tissue inhibitor of metalloproteinase (TIMP) expression. Leptin induces the expression of MMP-2 activators as well as the expression of MMP-2, MMP-9, and TIMP-1 in different human cells. Furthermore, sex hormones also participate in MMP regulation. In postmenopausal women, hormone replacement therapy produces an increase in MMP activity, leading to a breakdown in ECM homeostasis and accelerated progression of vascular pathologies. Besides, in men, an inverse relationship between testosterone levels and MMP-2 activity has been described. It is still necessary to go forward in the study of MMPs in different metabolic situations to corroborate their role as vulnerable plaque biomarkers.

Microparticles as potential biomarkers of cardiovascular disease.

Primary prevention of cardiovascular disease is a choice of great relevance because of its impact on health. Some biomarkers, such as microparticles derived from different cell populations, have been considered useful in the assessment of cardiovascular disease. Microparticles are released by the membrane structures of different cell types upon activation or apoptosis, and are present in the plasma of healthy individuals (in levels considered physiological) and in patients with different pathologies. Many studies have suggested an association between microparticles and different pathological conditions, mainly the relationship with the development of cardiovascular diseases. Moreover, the effects of different lipid-lowering therapies have been described in regard to measurement of microparticles. The studies are still controversial regarding the levels of microparticles that can be considered pathological. In addition, the methodologies used still vary, suggesting the need for standardization of the different protocols applied, aiming at using microparticles as biomarkers in clinical practice.

GW24-e2411 Circulating miR-499 associated with perioperative myocardial injury after coronary artery bypass graft surgery

ObjectivesMicroRNAs (miRNAs) play key roles in diverse biological and pathological processes, including the regulation of proliferation, apoptosis and cellular differentiation. Recently, circulating miRNAs have been proposed as potential biomarkers for...

GW24-e2497 Circulating MicroRNAs as Potential Biomarkers of Coagulation Dysfunction in Patients with Vulnerable Coronary Artery Disease

ObjectivesThe activation of coagulation and fibrinolysis plays a critical role in the incidence of coronary events. MicroRNAs (miRNAs) are small non-coding ribonucleic acids (RNAs) that negatively regulate gene expression on...

A liquid chromatography and tandem mass spectrometry method for the determination of potential biomarkers of cardiovascular disease

A simple, accurate and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantitation of α-ketoglutaric acid (α-KG), L-carnitine (L-CAR) and acetyl-L-carnitine (acetyl-L-CAR) in human urine as potential biomarkers of cardiovascular disease. The separation was performed using an isocratic elution of 0.1% formic acid in water and acetonitrile (97:3, v/v) on an Acclaim 120 C8 column (150 mm × 4.6 mm, 3.0 μm). The flow rate of the mobile phase was 1.2 mL/min and the total assay run time was 3 min. Detection was performed on a triple-quadrupole mass spectrometer in selected reaction monitoring (SRM) mode via an electrospray ionization (ESI) source in positive and negative ion modes. This method covered a linearity range of 0.1-500 ng/mL for L-CAR and acetyl-L-CAR and 1-1000 ng/mL for α-KG with lower limits of quantification (LLOQ) of 0.08 ng/mL for L-CAR, 0.04 ng/mL for acetyl-L-CAR and 0.8 ng/mL for α-KG. The intra-day and inter-day precision and accuracy of the quality control samples exhibited relative standard deviations of less than 5.54% and relative error values from -5.95% to 3.11%. Analyte stability was evaluated under various sample preparation, analysis and storage conditions and varied from -9.89% to -0.47%. A two-step solid-phase extraction (SPE) procedure using silica gel and quaternary amine cartridges was used for urine sample cleanup. The average recoveries for all analyzed compounds were better than 86.64% at three concentrations. The method was successfully applied for the quantitation of α-KG, L-CAR and acetyl-L-CAR in human urine samples.

Cardiovascular disease in end-stage renal disease

The number of end-stage renal disease (ESRD) patients is progressively growing with more than 60,000 ESRD patients on renal replacement therapy in Korea. The mortality risk in ESRD patients is approximately 10 to 20-fold higher compared to the general population, which is mainly attributed to prevalent cardiovascular disease in these patients. However, the risk factors for cardiovascular disease in ESRD patients are different from the general population, and useful biomarkers for predicting cardiovascular mortality are not completely defined. The nationwide multicenter Clinical Research Center (CRC) for ESRD program was initiated in Korea not only to elucidate the incidence and prevalence of cardiovascular disease in ESRD patients but also to identify potential risk factors including various biomarkers for cardiovascular disease. A prospective cohort of 864 incident hemodialysis patients, from 34 dialysis centers of the CRC for ESRD in Korea, was followed up for 36 months, and the clinical outcome of these patients was reviewed. This article presents the recent data from the CRC for ESRD program, and, in addition, brief reviews on key risk factors and potential biomarkers for cardiovascular disease in ESRD patients.

Abstract 3713: Possible Role Of Circulating Cellular Microparticles In Progressive Hypertension And Middle Cerebral Artery Remodeling

Circulating cellular microparticles (MPs) are potential biomarkers for cardiovascular diseases and are also suggested to be involved in the pathogenesis of hypertension and stroke. We assessed the hypothesis that circulating MPs could have implications in influencing mean arterial pressure (MAP) and middle cerebral artery (MCA) remodeling via changes in their levels and contents. Male C57BL/6 mice were fed with normal diet (control) or induced to progressive hypertension by infusion with angiotensin II (ANG II, 42µg/kg/h, osmotic minipump) and fed with high-salt diet (HSD, 8% NaCl) plus L-NAME (120 mg/kg/day, in drinking water) for 2 (for MPs donor) and 4 weeks (for MP infusion study). Circulating MPs isolated from control (cMPs) or hypertensive (hMPs) mice were isolated as we previously described (Chen, et al, AJP, 2011). The levels of circulating endothelial MPs (EMPs) and endothelial progenitor cells-MPs (EPC-MPs) were analyzed using flow cytometry by staining with CD144 (EMPs), CD34 and VEGFR2 (EPC-MPs), respectively. The mRNA levels of CXCR4, endothelial nitric oxide synthase (eNOS), NOX2 and tumor necrosis factor-alpha (TNF-a) in circulating MPs were determined by quantitative real-time RT-PCR. In separate experiment, control or hypertensive mice were treated with infusion of cMPs or hMPs (1x10 5 /100µl) via tail vein once per week for two continuous weeks, and sacrificed at the end of experiment (week four). MAP was measured using radiotelemetric probe. The lumen/wall in the MCA was determined by Hematoxylin and Eosin staining. Results showed ( table ): 1) Mice infused with ANG II and fed with HSD and L-NAME showed progressive hypertension and MCA remodeling. 2) The levels of EMP and EPC-MPs were significantly increased in hypertensive mice. 3) hMPs carried less CXCR4 and eNOS, and higher NOX2 and TNF-a mRNAs when compared with cMPs. 4) Infusion of hMPs increased MAP and MCA remodeling in hypertensive mice, but only induced MCA remodeling in control mice. 5) cMPs decreased MAP and MCA in hypertensive mice, but had no effect on MCA remodeling and MAP in control mice. In conclusion, circulating MPs could be served as biomarkers and used for developing therapeutic avenues for progressive hypertensive and MCA remodeling.

Reconstruction and analysis of human heart-specific metabolic network based on transcriptome and proteome data

The availability and utility of genome-scale metabolic networks have exploded with modern genome-sequencing capabilities. However, these generic models overlooked actual physiological states of the tissues and included all the reactions implied by the genome annotations. To address this problem, we reconstructed a human heart-specific metabolic network based on transcriptome and proteome data. The resulting model consists of 2803 reactions and 1880 metabolites, which correspond to 1721 active enzymes in human heart. Using the model, we detected 24 epistatic interactions in human heart, which are useful in understanding both the structure and function of cardiovascular systems. In addition, a set of 776 potential biomarkers for cardiovascular disease (CVD) has been successfully explored, whose concentration is predicted to be either elevated or reduced because of 278 possible dysfunctional cardiovascular-associated genes. The model could also be applied in predicting selective drug targets for eight subtypes of CVD. The human heart-specific model provides valuable information for the studies of cardiac activity and development of CVD.

Proteomic detection of nitroproteins as potential biomarkers for cardiovascular disease

Increased levels of reactive oxygen and nitrogen species are linked to many human diseases and can be formed as an indirect result of the disease process. The accumulation of specific nitroproteins which correlate with pathological processes suggests that nitration of protein tyrosine represents a dynamic and selective process, rather than a random event. Indeed, in numerous clinical disorders associated with an upregulation in oxidative stress, tyrosine nitration has been limited to certain cell types and to selective sites of injury. Additionally, proteomic studies show that only certain proteins are nitrated in selective tissue extracts. A growing list of nitrated proteins link the negative effects of protein nitration with their accumulation in a wide variety of diseases related to oxidation. Nitration of tyrosine has been demonstrated in diverse proteins such as cytochrome c, actin, histone, superoxide dismutase, α-synuclein, albumin, and angiotensin II. In vitro and in vivo aspects of redox-proteomics of specific nitroproteins that could be relevant to biomarker analysis and understanding of cardiovascular disease mechanism will be discussed within this review.

Abstract 5081: Circulating Microparticles as Potential Biomarkers for Primary Intracerebral Hemorrhage Stroke

Introduction: Primary intracerebral hemorrhage (ICH) stroke is a serious complication of uncontrolled hypertension. Recent clinical studies have shown that circulating microparticles (MPs) from endothelia (EMPs), platelets (PMPs) and endothelial progenitor cells (EPC-MPs) are potential biomarkers for cardiovascular diseases. However, the role of circulating MPs in ICH stroke is unknown. Methods and Results: The human renin and angiotensinogen transgenic (R+A+) and the control (R−A−) mice (male, 8 –10 weeks) were fed with normal diet or high salt diet (8% NaCl, HSD) plus nitric oxide synthase inhibitor L-NAME (120 mg/kg/day) in drinking water for two weeks. Mean arterial pressure (MAP) was measured using telemetric probes. Circulating MPs were identified by membrane markers, CD62E (for EMPs), CD62P (for PMPs), and CD34 and VEGFR2 (for EPC-MPs) using flow cytometry. The severity of ICH was determined by histological analysis of total bleeding area. The lumen/wall in the middle cerebral artery (MCA) was histologically measured. Results (Table and Figure ) showed: The R+A+ mice were hypertensive and had higher basal level of circulating PMPs and EMPs with no difference in EPC-MPs; After fed with HSD and L-NAME, R+A+ mice had severe hypertension and 50% of them developed ISH stroke within two weeks; There was a further increase of EMPs and a decrease of EPC-MPs in R+A+ mice with ICH stroke; There were strong correlations of EMPs (r=0.44~0.61) and EPC-MPs (r=−0.52~0.78) with MAP, MCA lumen/wall and total area of bleeding sites. Conclusion: Circulating EPC-MPs and EMPs could serve as useful biomarkers for uncontrolled hypertension, MCA remodeling and ICH stroke. Table. Blood pressure, circulating MPs and MCA lumen/wall in R+A+ and R−A− mice fed with normal diet or HSD and L-NAME for two weeks Fig. Hemorrhages in the brain (A, D: brainstem: B, E: cerebellum; C,F: basal ganglia) and MCA remodeling, A–C; R+A+ mice fed with HSD+L-NAME; D–F: R−A− mice fed with HSD+L-NAME; G: R−A− mice fed with normal diet, H: R−A− mice fed with HSD+L-NAME; I: R+A+ mice fed with HSD+L-NAME