Resistance Training Diminishes the Expression of Exosome CD63 Protein without Modification of Plasma miR-146a-5p and cfDNA in the Elderly

Aging-associated inflammation is characterized by senescent cell-mediated secretion of high levels of inflammatory mediators, such as microRNA (miR)-146a. Moreover, a rise of circulating cell-free DNA (cfDNA) is also related to systemic inflammation and frailty in the elderly. Exosome-mediated cell-to-cell communication is fundamental in cellular senescence and aging. The plasma changes in exercise-promoted miR-146a-5p, cfDNA, and exosome release could be the key to facilitate intercellular communication and systemic adaptations to exercise in aging. Thirty-eight elderly subjects (28 trained and 10 controls) volunteered in an 8-week resistance training protocol. The levels of plasma miR-146a-5p, cfDNA, and exosome markers (CD9, CD14, CD63, CD81, Flotillin [Flot]-1, and VDAC1) were measured prior to and following training. Results showed no changes in plasma miR-146a-5p and cfDNA levels with training. The levels of exosome markers (Flot-1, CD9, and CD81) as well as exosome-carried proteins (CD14 and VDAC1) remained unchanged, whereas an attenuated CD63 response was found in the trained group compared to the controls. These findings might partially support the anti-inflammatory effect of resistance training in the elderly as evidenced by the diminishment of exosome CD63 protein expression, without modification of plasma miR-146a-5p and cfDNA.

High serum extracellular vesicle miR-10b expression predicts poor prognosis in patients with acute myeloid leukemia

BACKGROUND

Increasing evidence have demonstrated that serum extracellular vesicle microRNAs (EV-miRNAs) are promising noninvasive biomarkers for various cancer types.

OBJECTIVE

In this study, we aimed to investigate and evaluate the potential clinical significance of serum EV-miR-10b for acute myeloid leukemia (AML).

METHODS

Blood samples were collected from a cohort of 95 de novo AML patients and 80 healthy individuals. Of all AML patients, 51 patients were considered as cytogenetic normal AML (CN-AML). Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to measure the expression levels of serum EV-miR-10b.

RESULTS

The extracellular vesicles we extracted from the serum samples were positive for EV/exosome markers including TSG101, CD63, Flotillin-1 and CD9. The expression levels of serum EV-miR-10b were significantly higher in AML/CN-AML patients than healthy controls. In addition, serum EV-miR-10b expression was strongly correlated with aggressive clinical characteristics. Moreover, receiver operating characteristic analysis showed serum EV-miR-10b yielded an area under the curve of 0.875, with 77.89% specificity and 82.50% sensitivity in identifying AML patients from normal controls. Furthermore, AML patients with higher serum EV-miR-10b expression had significantly shorter survival and serum EV-miR-10b was demonstrated to be an independent prognostic marker for overall survival in AML.

CONCLUSIONS

Taken together, serum EV-miR-10b might serve as a promising biomarker for predicting the prognosis of AML.

The Aging Process Alters IL-1β and CD63 Levels Differently in Extracellular Vesicles Obtained from the Plasma and Cerebrospinal Fluid

OBJECTIVE(S)

The aim of this study was to investigate exosomal markers and inflammatory cargo of extracellular vesicles (EVs) obtained from cerebrospinal fluid (CSF) and plasma in the aging process. We also studied the inflammatory cargo by quantifying IL-1β levels.

METHODS

Male Wistar rats, aged 3 and 21 months, were used (n = 12 in each group). The CSF and plasma of animals were collected, and isolation of EVs was performed using a commercial kit. Total protein concentration, acetylcholinesterase (AChE) activity, and CD63 and IL-1β levels were evaluated.

RESULTS

AChE activity in EVs increased in both samples, specifically in the circulating EVs and those in the CSF of the older group. An age-related increase was observed in CD63 levels in EVs from the CSF but a decrease was observed in plasma EVs of the older group. Student's t test showed that the young adult rats had significantly higher circulating IL-1β levels in the EVs compared to the aged ones, without any effect on central content.

CONCLUSION

Our data suggest that the normal aging process causes different changes in the profiles of central and circulating EVs. Altered IL-1β levels in circulating EVs can be linked, at least partly, to age-related inflammatory conditions, and a disruption of the CFS exosomes in aged rats, evaluated by CD63 levels, can be related to susceptibility to neurodegenerative disorders.

Telomeric repeat-containing RNA (TERRA) constitutes a nucleoprotein component of extracellular inflammatory exosomes

Telomeric repeat-containing RNA (TERRA) has been identified as a telomere-associated regulator of chromosome end protection. Here, we report that TERRA can also be found in extracellular fractions that stimulate innate immune signaling. We identified extracellular forms of TERRA in mouse tumor and embryonic brain tissue, as well as in human tissue culture cell lines using RNA in situ hybridization. RNA-seq analyses revealed TERRA to be among the most highly represented transcripts in extracellular fractions derived from both normal and cancer patient blood plasma. Cell-free TERRA (cfTERRA) could be isolated from the exosome fractions derived from human lymphoblastoid cell line (LCL) culture media. cfTERRA is a shorter form (∼200 nt) of cellular TERRA and copurifies with CD63- and CD83-positive exosome vesicles that could be visualized by cyro-electron microscopy. These fractions were also enriched for histone proteins that physically associate with TERRA in extracellular ChIP assays. Incubation of cfTERRA-containing exosomes with peripheral blood mononuclear cells stimulated transcription of several inflammatory cytokine genes, including TNFα, IL6, and C-X-C chemokine 10 (CXCL10) Exosomes engineered with elevated TERRA or liposomes with synthetic TERRA further stimulated inflammatory cytokines, suggesting that exosome-associated TERRA augments innate immune signaling. These findings imply a previously unidentified extrinsic function for TERRA and a mechanism of communication between telomeres and innate immune signals in tissue and tumor microenvironments.

A Potential Mechanism of High-Dose Ticagrelor in Modulating Platelet Activity and Atherosclerosis Mediated by Thymic Stromal Lymphopoietin Receptor

Abnormal expression of thymic stromal lymphopoietin (TSLP) and its receptor (TSLPR) was found in patients with acute coronary syndrome. Ticagrelor, an oral platelet ADP P2Y12 receptor antagonist, is widely used in these patients. The aim of this study was to verify whether different doses of ticagrelor regulated plaque progression and platelet activity by modulating TSLP/TSLPR. Seventy-five ApoE-/- mice were randomly divided into five groups: (1) high-cholesterol diet (HCD, n = 15); (2) HCD plus ticagrelor 25 mg/kg/d (T1, n = 15); (3) HCD plus ticagrelor 50 mg/kg/d (T2, n = 15); (4) HCD plus ticagrelor 100 mg/kg/d (T3, n = 15); and (5) a normal diet group (ND, n = 15). At day 0 and at week 16, blood lipids and serum TSLP levels, expression of TSLPR, CD62, and CD63, platelet aggregation, platelet ATP release, PI3K/Akt signaling pathway, and plaque morphology were assessed. HCD increased TSLPR expression and atherosclerosis progression but high-dose ticagrelor (100 mg/kg) moderated this trend. TSLPR was positively correlated with Akt1, platelet aggregation, corrected plaque area, and vulnerability index in the T3 group (P<0.01). In conclusion, low-dose ticagrelor only inhibited platelet activity. Besides this inhibition, high-dose ticagrelor modulated platelet activity and atherosclerosis mediated by TSLPR, potentially through the PI3K/Akt signal pathway.

Impact of the serum- and glucocorticoid-inducible kinase 1 on platelet dense granule biogenesis and secretion

BACKGROUND

Platelet secretion is critical to development of acute thrombotic occlusion. Platelet dense granules contain a variety of important hemostatically active substances. Nevertheless, biogenesis of platelet granules is poorly understood.

OBJECTIVES

Serum- and glucocorticoid-inducible kinase 1 (SGK1) has been shown to be highly expressed in platelets and megakaryocytes, but its role in the regulation of platelet granule biogenesis and its impact on thrombosis has not been investigated so far.

METHODS AND RESULTS

Electron microscopy analysis of the platelet ultrastructure revealed a significant reduction in the number and packing of dense granules in platelets lacking SGK1 (sgk1(-/-) ). In sgk1(-/-) platelets serotonin content was significantly reduced and activation-dependent secretion of ATP, serotonin and CD63 significantly impaired. In vivo adhesion after carotis ligation was significantly decreased in platelets lacking SGK1 and occlusive thrombus formation after FeCl3 -induced vascular injury was significantly diminished in sgk1(-/-) mice. Transcript levels and protein abundance of dense granule biogenesis regulating GTPase Rab27b were significantly reduced in sgk1(-/-) platelets without affecting Rab27b mRNA stability. In MEG-01 cells transfection with constitutively active (S422) (D) SGK1 but not with inactive (K127) (N) SGK1 significantly enhanced Rab27b mRNA levels. Sgk1(-/-) megakaryocytes show significantly reduced expression of Rab27b and serotonin/CD63 levels compared with sgk1(+/+) megakaryocytes. Proteome analysis identified nine further vesicular transport proteins regulated by SGK1, which may have an impact on impaired platelet granule biogenesis in sgk1(-/-) platelets independent of Rab27b.

CONCLUSIONS

The present observations identify SGK1 as a novel powerful regulator of platelet dense granule biogenesis, platelet secretion and thrombus formation. SGK1 is at least partially effective because it regulates transcription of Rab27b in megakaryocytes.

[Basophil activation test--a practical approach to diagnosis of common respiratory allergy]

BACKGROUND

The diagnosis of immediate allergy is based on clinical data, skin prick tests (SPT), and measurements of allergen-specific IgE (sIgE). Basophil activation test (BAT) can supplement these methods and obviate their disadvantages, and possibly replace allergen challenge tests, such as a nasal provocative test (NPT). In this study, we assessed the influence of different storage times on BAT results. Futhermore, we compared the results of SPT, sIgE and NPT against BAT for common aeroallergens.

METHODS

BAT was performed in twelve patients with allergic rhinitis sensitized to birch pollen or mites 1, 4 and 24 hours after blood sampling. CD63 was used as an activation marker. Three serial 10-fold dilutions (1:1, 1:10, 100) of allergen extract were employed. The further 10 individuals allergic to mites undergone complete diagnostic evaluation including SPT, sIgE measurements, NPT and BAT. Receiver operating characteristic (ROC) curves were used to compare the diagnostic techniques and tests conditions.

RESULTS

Basophil activation expressed as stimulation index did not decline significantly up to 24h. Exposure to causal allergens resulted in a dose-dependent increase in expression of CD63 on peripheral blood basophils in tested individuals. We did not observed substantial differences in results of the investigated diagnostic methods determined by a ROC analysis.

CONCLUSIONS

Flow-assisted diagnosis of common respiratory allergy relies upon allergen-induced activation of blood basophils can be a useful approach to determine the clinically relevant allergen in sensitized individuals. BAT with inhaled allergens can be performed within 24 hours after blood collecting into a tube with EDTA. Allergen suitable for NPT in appropriate dilutions is a good reagent for use in BAT.

Evaluation of a whole blood remote platelet function test for the diagnosis of mild bleeding disorders

BACKGROUND

Mild platelet function disorders (PFDs) are complex and difficult to diagnose. The current gold standard test, light transmission aggregometry (LTA), including lumi-aggregometry, is time and labour intensive and blood samples must be processed within a limited time after venepuncture. Furthermore, many subjects with suspected PFDs do not show a platelet abnormality on LTA.

OBJECTIVE

To assess the diagnostic potential of an easy-to-use remote platelet function test (RPFT) as a diagnostic pre-test for suspected PFDs.

METHODS

A remote platelet function test was compared with lumi-aggregometry in participants recruited to the Genotyping and Phenotyping of Platelets Study (GAPP, ISRCTN 77951167). For the RPFT, whole blood was stimulated with platelet agonists, stabilized with PAMFix and returned to the central laboratory for analysis of P-selectin and CD63 by flow cytometry.

RESULTS

For the 61 study participants (42 index cases and 19 relatives) there was a good agreement between lumi-aggregometry and the RPFT, with diagnosis being concordant in 84% of cases (κ = 0.668, P < 0.0001). According to both tests, 29 participants were identified to have a deficiency in platelet function and 22 participants appeared normal. There were four participants where lumi-aggregometry revealed a defect but the RPFT did not, and six participants where the RPFT detected an abnormal platelet response that was not identified by lumi-aggregometry.

CONCLUSION

This study suggests that the RPFT could be an easy-to-use pre-test to select which participants with bleeding disorders would benefit from extensive platelet phenotyping. Further development and evaluation of the test are warranted in a wider population of patients with excessive bleeding and could provide informative screening tests for PFDs.

Increased platelet activation in early symptomatic vs. asymptomatic carotid stenosis and relationship with microembolic status: results from the Platelets and Carotid Stenosis Study

BACKGROUND

Cerebral microembolic signals (MES) may predict increased stroke risk in carotid stenosis. However, the relationship between platelet counts or platelet activation status and MES in symptomatic vs. asymptomatic carotid stenosis has not been comprehensively assessed.

SETTING

University teaching hospitals.

METHODS

This prospective, pilot observational study assessed platelet counts and platelet activation status, and the relationship between platelet activation and MES in asymptomatic vs. early (≤ 4 weeks after TIA/stroke) and late phase (≥ 3 months) symptomatic moderate or severe (≥ 50%) carotid stenosis patients. Full blood count measurements were performed, and whole blood flow cytometry was used to quantify platelet surface activation marker expression (CD62P and CD63) and circulating leucocyte-platelet complexes. Bilateral simultaneous transcranial Doppler ultrasound monitoring of the middle cerebral arteries was performed for 1 h to classify patients as MES positive or MES negative.

RESULTS

Data from 31 asymptomatic patients were compared with 46 symptomatic patients in the early phase, and 35 of these patients were followed up to the late phase after symptom onset. The median platelet count (211 vs. 200 × 10(9)  L(-1) ; P = 0.03) and the median percentage of lymphocyte-platelet complexes was higher in early symptomatic than asymptomatic patients (2.8 vs. 2.4%; P = 0.001). The percentage of lymphocyte-platelet complexes was higher in early symptomatic than in asymptomatic patients with ≥ 70% carotid stenosis (P = 0.0005) and symptomatic patients recruited within 7 days of symptom onset (P = 0.028). Complete TCD data were available in 25 asymptomatic, 31 early phase symptomatic and 27 late phase symptomatic patients. Twelve per cent of asymptomatic vs. 32% of early phase symptomatic (P = 0.02) and 19% of late phase symptomatic patients (P = 0.2) were MES positive. Early symptomatic MES-negative patients had a higher percentage of lymphocyte-platelet complexes than asymptomatic MES-negative patients (2.8 vs. 2.3%; P = 0.0085).

DISCUSSION

Recently, symptomatic carotid stenosis patients have had higher platelet counts (potentially reflecting increased platelet production, mobilization or reduced clearance) and platelet activation status than asymptomatic patients. MES were more frequently detected in early symptomatic than asymptomatic patients, but the differences between late symptomatic and asymptomatic groups were not significant. Increased lymphocyte-platelet complex formation in recently symptomatic vs. asymptomatic MES-negative patients indicates enhanced platelet activation in this early symptomatic subgroup. Platelet biomarkers, in combination with TCD, have the potential to aid risk-stratification in asymptomatic and symptomatic carotid stenosis patients.

Detection of exosomal biomarker by electric field-induced release and measurement (EFIRM)

Exosomes biomarkers mediating important biological process, especially in the systemic disease diagnostics and therapeutics, yet the protective exosomal vesicle structure hinders rapid, simple detection of the harbored molecules. We have established a new method, the electric field-induced release and measurement (EFIRM), which can simultaneously disrupt exosomes to release the contents and on-site monitoring the harbored exosomal RNA/proteins biomarkers. When exposed to a non-uniform electrical field, exosomal RNA and proteins are rapidly released. Bio-recognition of these biomolecules is carried out concurrently. We tested the hypothesis that the lung cancer cell line, H460 stably transfected with hCD63-GFP, would shed hCD63-GFP expressing exosomes that could be detected in serum and saliva. We confirmed in vivo that H460-CD63-GFP shed exosomes were transported to blood and saliva. This result demonstrates for the first time tumor-shed exosomes were detected in saliva, in addition to blood, presenting a new translational utility of exosome-based biomarker detection in saliva.

Platelets express and release osteocalcin and co-localize in human calcified atherosclerotic plaques

BACKGROUND

Although vascular-calcification mechanisms are only partially understood, the role of circulating calcifying cells and non-collagenous bone matrix proteins in the bone-vascular axis is emerging. In spite of the fact that platelets represent a cellular interface between hemostasis, inflammation and atherosclerosis, and have a myeloid precursor, a possible involvement in the modulation of vascular calcification has rarely been investigated. We investigated if osteocalcin (OC) is released by platelets and described OC expression in patients with carotid artery occlusive disease.

METHODS

Expression and release of OC were determined by Western blot, immunofluorescence, fluorescence-activated cell sorting (FACS) and ELISA in human resting and activated platelets and megakaryocytes. Co-localization of platelet aggregates, macrophages, OC and calcifications was studied in carotid endarterectomy specimens and normal tissues.

RESULTS

Human platelets expressed OC and co-localized with CD63 in δ-granules. Upon activation with an endogenous mechanism, platelets released OC in the extracellular medium. Expression of OC in megakaryocytes suggested lineage specificity. The OC count in circulating platelets and the released amount were significantly higher in patients with carotid artery occlusive disease than in healthy controls (P < 0.0001) in spite of similar serum levels. In atherosclerotic plaques, OC strongly overlapped with CD41+ platelets in the early stage of calcification, but this was not seen in normal tissues. CD68+OC+ cells were present at the periphery of the calcified zone.

CONCLUSIONS

Given the active role played by platelets in the atherosclerotic process, the involvement of OC release from platelets in atherosclerotic lesions and the impact of genetic and cardiovascular risk factors in mediating bone-marrow preconditioning should be investigated further.

[Basophil CD63 expression in the blood of the anaphylactic shock rat]

OBJECTIVE

To explore the value of flow cytometry in anaphylactic shock diagnosis by CD63 expression being detected using flow cytometry to conform the activation of basophils.

METHODS

Sixteen rats were randomly divided into two groups: control group and anaphylactic shock group. The model of anaphylactic shock rat with ovalbumin injection was established. CD63, CD45 and CD203c antibody combination, flow cytometry was employed to detected blood basophil CD63 expression. Immunofluorescence method was employed to observe the CD63 immunofluorescence staining in the rat lung tissue.

RESULTS

(1) Pure basophils were obtained by CD45 and CD203c gating. (2) The percentages of basophils CD63 were (17.34 +/- 2.04)% and (1.52 +/- 0.35)% in the experimental and control group, respectively. The differences between two groups were statistically significant (P < 0.01). (3) Compared with the control group, the expression of CD63 in basophils increased in anaphylactic shock lung tissue.

CONCLUSION

The detection of CD63 by flow cytometry could be the supplement of vivo allergic reactions and have good clinical value.

Circulating microparticles in patients with benign and malignant ovarian tumors

BACKGROUND

Microparticles are known to be increased in various malignancies. In this prospective study, microparticle levels were evaluated in patients with benign and malignant ovarian lesions.

PATIENTS AND METHODS

Microparticles from platelets/megakaryocytes, activated platelets and endothelial cells, tissue factor exposing microparticles and D-dimer values were examined in patients with newly diagnosed ovarian lesions before surgery, and were correlated with tumor histology.

RESULTS

Higher counts of CD63-positive microparticles were detected in patients with ovarian cancer [mean=276×10(6) (range: 64-948)/l; n=12] as compared to patients with benign ovarian tumors [146×10(6) (45-390)/l; n=21; p=0.014]. D-dimer values were also increased in patients with cancer [860 (180-4500) ng/l versus 280 (170-2720) ng/l; p=0.001].

CONCLUSION

Elevated levels of CD63-positive microparticles and D-dimer reflect the procoagulant phenotype of these patients. However, for the discrimination between benign and malignant ovarian tumors, measuring preoperative levels of microparticles does not seem to be helpful.