Journal of Circulating Biomarkers最新文献

The discovery of urinary extracellular biomarkers has been impeded by the lack of efficient methods for the isolation of extracellular vesicles (EVs: exosomes and microvesicles) and extracellular nucleic acid (RNA and DNA) from urine. Ultracentrifugation (UC), considered the gold standard for vesicle isolation from many biofluids, is efficacious but laborious, and, like most commercially available methods, is unable to isolate enough material from small volumes for protein or RNA-based biomarker discovery. We have developed a novel precipitation method for the isolation of EVs and nucleic acids from urine. The method, which is now commercially available, takes less than 30 min and does not require polyethylene glycol. Transmission electron microscopy and Nanosight particle analysis confirm that the method isolates intact vesicles with a similar size, shape, and number to UC. Immunoblot analysis of preparations made from a variety of urine samples demonstrates that the method isolates multiple vesicle protein markers more efficiently than other commercial kits, especially from more diluted samples. Bioanalyzer, quantitative reverse transcription polymerase chain reaction, and array analysis show that the method is extremely efficient at the isolation of extracellular miRNAs. The Ymir Genomics EV and Extracellular RNA Isolation Kits offer an efficient and rapid alternative to UC and other commercial kits.

The role of pattern of circulating endothelial cell-derived microparticles, platelet-derived microparticles (PMPs), and monocyte-derived microparticles (MMPs) in metabolic syndrome (MetS) patients with chronic heart failure (CHF) is not still understood. The aim of the study was to investigate a pattern of circulating microparticles (MPs) in MetS patients with CHF in relation to neurohumoral and inflammatory activation. The study retrospectively involved 101 patients with MetS and 35 healthy volunteers. Biomarkers were measured at baseline of the study. The results of the study have shown that numerous circulating PMPs- and MMPs in subjects with MetS (with or without CHF) insufficiently distinguished from level obtained in healthy volunteers. We found elevated level of CD31+/annexin V+ MPs in association with lower level of CD62E+ MPs. Therefore, we found that biomarkers of biomechanical stress serum N-terminal brain natriuretic peptide and inflammation (high-sensitive C-reactive protein ,osteoprotegerin) remain statistically significant predictors for decreased CD62E+ to CD31+/annexin V+ ratio in MetS patients with CHF. In conclusion, decreased CD62E+ to CD31+/annexin V+ ratio reflected that impaired immune phenotype of MPs may be discussed as a surrogate marker of CHF development in MetS population.

This study shows that fibroblasts migrating into a collagen matrix release numerous microvesicles into the surrounding medium. By spreading in regions of the matrix far distant from cells of origin, microvesicles carry metalloproteinase 9 (MMP-9) to act upon the collagen fibrils. As a result, the collagen matrix is gradually transformed from a laminar to a fibrillar type of architecture. As shown by western blots and gelatin zymography, MMP-9 is secreted as a 92 kDa precursor and activated upon release of 82 kDa product into the culture medium. Activation is more efficient under three-dimensional than in two-dimensional culturing conditions. While MMP-9 labeling is associated with intraluminal vesicles clustered inside the microvesicles, the microvesicle's integrin β1 marker is bound to the outer membrane. The intraluminal vesicles are recruited from the cortical cytoplasm and eventually released following uploading inside the microvesicle. Here, we propose that fusion of the intraluminal vesicles with the outer microvesicle's membrane could work as a mechanism controlling the extent to which MMP-9 is first activated and then released extracellularly.

We reported that single oncosuppressor-mutated (SOM) cells turn malignant when exposed to cancer patients' sera. We tested the possibility to incorporate this discovery into a biological platform able to detect cancer in healthy individuals and to predict metastases after tumor resection. Blood was drawn prior to tumor resection and within a year after surgery. Blood samples from healthy individuals or metastatic patients were used as negative and positive controls, respectively. Patients at risk for cancer were included in the screening cohort. Once treated, cells were injected into nonobese diabetic/severe combined immunodeficiency mice to monitor tumor growth. All samples of sera coming from metastatic patients transformed SOM cells into malignant cells. Four samples from screened patients transformed SOM cells. Further clinical tests done on these patients showed the presence of early cancerous lesions despite normal tumor markers. Based on the xenotransplants size, we were able to predict metastasis in three patients before diagnostic tests confirmed the presence of the metastatic lesions. These data show that this serum-based platform has potentials to be used for cancer screening and for identification of patients at risks to develop metastases regardless of the Tumor Node Metastasis (TNM) stage or tumor markers level.

Activation of cell death in mammals can be assessed by an increase of an amount of cell-free DNA (cf-DNA) in urine or plasma. We investigated the excretion of cf nuclear DNA (nDNA) and cf mitochondrial DNA (mtDNA) in the urine of rats 3 and 24 months in age after X-irradiation and metformin administration. Analyses showed that prior to treatment, the amount of cf-nDNA was 40% higher and cf-mtDNA was 50% higher in the urine of aged rats compared to that of young animals. At 12 h after irradiation, the content of cf-nDNA and cf-mtDNA in the urine of young rats was increased by 200% and 460%, respectively, relative to the control, whereas in the urine of aged rats, it was 250% and 720% higher. After 6 h following metformin administration, the amount of cf-nDNA and cf-mtDNA in the urine of young rats was elevated by 25% and 55% and by 50% and 160% in the urine of aged rats. Thus, these preliminary data suggest that X-rays and metformin cause a significant increase of cf-DNA in the urine of older rats caused by the active cell death in tissues. These results also suggest that metformin possibly initiates the death of the cells containing structural and functional abnormalities.

Extracellular vesicles (EVs) are widely studied as a system of intercellular communication, as markers of various diseases, as well as a vehicle for delivery of various bioactive molecules to various cells. Investigation of EVs' structure and function requires their isolation and precise quantification. However, in the current literature, there are significant discrepancies in the estimated numbers of EVs in different body fluids. In part, this discrepancy is due to the difference in EVs isolation protocols used by different investigators. A common protocol that includes ExoQuick^™ is often used to isolate EVs from body fluids and culture medium. Here, we show that in the case of isolation of EVs from blood, thrombin should be omitted from the protocol as clots formed due to the thrombin-triggered coagulation may entrap many EVs thus leading to the underestimation of their numbers.

Circulating cell-free DNA (cfDNA) has been described as a prognostic marker for several diseases. Its prognostic value for short-term outcome in stroke patients treated with intravenous thrombolysis remains unexplored. cfDNA was measured on admission in 54 tissue plasminogen activator (tPA)-treated patients and 15 healthy controls using a real-time quantitative polymerase chain reaction assay. Neurological outcome was assessed at 48 h. Predictors of neurological improvement were evaluated by logistic regression analysis, and the additional predictive value of cfDNA over clinical variables was determined by integrated discrimination improvement (IDI). Stroke patients presented higher baseline cfDNA than healthy controls (408.5 (179-700.5) vs. 153.5 (66.9-700.5) kilogenome-equivalents/L, p = 0.123). A trend towards lower cfDNA levels was found in patients who neurologically improved at 48 h (269.5 (143.3-680) vs. 504 (345.9-792.3) kilogenome-equivalents/L, p = 0.130). In logistic regression analysis, recanalization at 1 h and cfDNA < 302.75 kilogenome-equivalents/L was independently associated with neurological improvement after adjustment by age, gender and baseline National Institutes of Health Stroke Scale score. The addition of cfDNA to the clinical predictive model improved its discrimination (IDI = 21.2% (9.2-33.3%), p = 0.009). These data suggest that cfDNA could be a surrogate marker for monitoring tPA efficacy by the prediction of short-term neurological outcome.

Adiponectin secreted from the adipocytes plays pleiotropic, anti-atherosclerotic roles, such as enhancement of insulin secretion and an increase in energy expenditure. The measurement of levels of circulating adiponectin is useful to evaluate the progression of atherosclerosis-related diseases, such as coronary artery disease (CAD), cerebral infarction (CI) and diabetes mellitus (DM). We examined the serum antibody levels against recombinant adiponectin protein via the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) method. The results revealed that the antibody levels were significantly higher in patients with CAD, CI and type 2 DM, than in healthy donors. Receiver operating curve analysis showed that the sensitivity was in a range of 41-48% for CAD, CI and DM. Thus, the serum anti-adiponectin antibody levels could be a common marker for atherosclerosis-related diseases.

Less than 100 nm in size and spherical in form - exosomes - vesicles expelled and taken up by cells, have ignited a new-found fascination. One which is derived from the sheer variety of exosomal content, ranging from microRNAs to transcription factors, capable of affecting a multitude of processes and pathways simultaneously within a target cell. Initially dismissed in 1983 as a waste disposal mechanism, today they form an entire field of research, being documented thus far in invertebrates, mammals, pathogens and potentially some plants. Many studies have suggested these spherical enigmas may possess a function, being implicated in processes ranging from animal behaviour to viral infection. This review will evaluate the evidence for the role of exosomes in physiology and pathophysiology, as well as their potential for application in the diagnosis and treatment of disease.

Heart failure (HF) is multifactorial syndrome with high cardiovascular (CV) morbidity and mortality rates associated with an increasing prevalence worldwide. Measuring plasma levels of circulating biomarkers, i.e., natriuretic peptides, cardiac-specific troponins, metabolomic intermediates, Galectin-3, ST2, cardiotrophin-1, soluble endoglin and growth differentiation factor 15, may assist in the prognostication of HF development. However, the role of biomarker models in the prediction of an early stage of HF with a preserved ejection fraction (HFpEF) and HF with a reduced ejection fraction (HFrEF) is not still understood. This review explores the knowledge regarding the utility of cardiac biomarkers, aiming to reclassify patients with different phenotypes of HF. The review reports that several biomarkers reflected on subsequently alter collagen turnover, cardiac fibrosis and inflammation, which might have diagnostic and predictive value in HFpEF and HFrEF. The best candidates for determining the early stage of HF development were sST2, Galectin-3, CT-1 and GDF-15. However, increased plasma concentrations of these biomarkers were not specific to a distinct disease group of HFpEF and HFrEF. Finally, more investigations are required to determine the role of novel biomarkers in the prediction of HF and the determination of the early stages of HFpEF and HFrEF development.