Molecular subtypes and differentiation programmes of glioma stem cells as determinants of extracellular vesicle profiles and endothelial cell-stimulating activities

We have previously uncovered the impact of oncogenic and differentiation processes on extracellular vesicles (EVs) in cancer. This is of interested in the context of glioma stem cells (GSC) that are responsible for recurrent nature of glioblastoma multiforme (GBM), while retaining the potential to undergo differentiation and self renewal.  GSCs reside in vascular niches where they interact with endothelial cells through a number of mediators including bioactive cargo of EVs. GSCs can be classified as proneural (PN) or mesenchymal (MES) subtypes on the basis of their gene expression profiles and distinct biological characteristics. In the present study we investigated how GSC diversity and differentiation programmes influence their EV-mediated communication potentials. Indeed, molecular subtypes of GBMs and GSCs differ with respect to their expression of EV-related genes (vesiculome) and GSCs with PN or MES phenotypes produce EVs with markedly different characteristics, marker profiles, proteomes and endothelial stimulating activities. For example, while EVs of PN GSC are largely devoid of exosomal markers their counterparts from MES GSCs express ample CD9, CD63 and CD81 tetraspanins. In both GSC subtypes serum-induced differentiation results in profound, but distinct changes of cellular phenotypes including the enhanced EV production, reconfiguration of their proteomes and the related functional pathways. Notably, the EV uptake was a function of both subtype and differentiation state of donor cells. Thus, while, EVs produced by differentiated MES GSCs were internalized less efficiently than those from undifferentiated cells they exhibited an increased stimulatory potential for human brain endothelial cells. Such stimulating activity was also observed for EVs derived from differentiated PN GSCs, despite their even weaker uptake by endothelial cells. These findings suggest that the role of EVs as biological mediators and biomarkers in GBM may depend on the molecular subtype and functional state of donor cancer cells, including cancer stem cells.

Abbreviations: CryoTEM: cryo-transmission electron microscopy; DIFF: differentiated GSCs; EGF: epidermal growth factor; DUC: differential ultracentrifugation; EV: extracellular vesicle; FGF: fibroblast growth factor; GBM: glioblastoma multiforme; GFAP: glial fibrillary acidic protein; GO: gene ontology; GSC: glioma stem cells; HBEC-5i: human brain endothelial cells; MES: mesenchymal cells; MTS - [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; PMT1: proneural-to-mesenchyman transition cell line 1; PN: proneural cells; TEM: transmission electron microscopy; WB: western blotting

Widespread white matter microstructural differences in schizophrenia across 4322 individuals: results from the ENIGMA Schizophrenia DTI Working Group

The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.

Thrombin-reduced miR-27b attenuates platelet angiogenic activities in vitro via enhancing platelet synthesis of anti-angiogenic thrombospondin-1

Essentials It is unclear if platelet micro-RNAs can regulate de novo protein synthesis of platelets. Platelet de novo protein synthesis of thrombospondin-1 (TSP-1) was induced by thrombin. Thrombin stimulation in vitro altered platelet microRNA profiles, including decreased miR-27b. Decreased miR-27b hampers platelet angiogenic activities via enhancing de novo TSP-1 synthesis.

SUMMARY

Background Platelets can synthesize proteins upon activation. Platelets contain a number of microRNAs (miRNA) and a fully functional miRNA effector machinery. It is, however, unclear if platelet miRNAs can regulate protein synthesis of platelets, and whether the regulation may produce a physiological impact. Objectives To investigate if and how platelet miRNAs regulate de novo syntheses of angiogenic regulators and subsequently modulate platelet angiogenic activities. Methods and Results Microarray-based miRNA profiling showed that thrombin stimulation in vitro down- or up-regulated a number of platelet miRNAs, both in the total platelet miRNAs and in Ago2-associated miRNAs. Among those altered miRNAs, miR-27b was down-regulated in both the total and Ago2-immunoprecipitated miRNA profiles of platelets, which was confirmed by reverse transcription-quantitative PCR (RT-qPCR). Using western blotting assays, we showed that thrombin induced platelet de novo synthesis of thrombospondin-1, and that the level of thrombospondin-1 synthesis could reach a level of 3-5-fold higher than that before thrombin stimulation. With either the platelet precursor megakaryocyte cell line MEG-01 cells or mature platelets, we demonstrated that transfection of miR-27b mimic, but not the negative control of miRNA mimic, markedly reduced thrombospondin-1 protein levels. The latter subsequently enhanced platelet-dependent endothelial tube formation on matrigel. Conclusions Thrombin stimulation in vitro reduces platelet miR-27b levels that may markedly enhance thrombin-evoked platelet de novo synthesis of thrombospondin-1. Elevation of platelet miR-27b by transfection inhibits thrombospondin-1 synthesis, and subsequently enhances platelet pro-angiogenic activities. Hence, platelet activation-dependent reduction of miR-27b levels may represent a novel negative regulatory mechanism of platelet angiogenic activities.

Rapid recovery of hypogonadism in male patients with end stage renal disease after renal transplantation

PURPOSE

End stage renal disease (ESRD) in male patients is associated with a high prevalence of hypogonadism. After renal transplantation (RTx) an improvement in gonadal function is often observed. However, the time course of changes in pituitary-gonadal axis after RTx and the influence of renal function, age and anthropometric parameters are not well characterized. We prospectively evaluated pituitary-gonadal axis in male patients with ESRD before and after RTx for up to 1 year.

METHODS

Ninety-seven male patients with ESRD were consecutively investigated on day of surgery and 1, 3, 6, and 12 months after RTx. Time course of changes in sex hormones (total testosterone ((TT)), calculated free testosterone ((cfT)), estradiol (E₂), LH, FSH and prolactin), and interdependence with renal function, age, anthropometric factors, cause of ERDS, time on dialysis, and transplant associated factors were analyzed.

RESULTS

Hypogonadism (TT < 8 nmol/l) was present in 40% of pts prior to RTX and in only 18% at 1 year after RTX. Recovery from hypogonadism was significantly higher in pts < 50 years and occurred within 3 months. RTx resulted in a decrease in E₂/T ratio starting at 1 month and suggesting a shift from estrogen to testosterone production. BMI and waist circumference had the similar impact on T levels after successful RTx compared to patients without renal disease. No specific impact on recovery of hypogonadism was found for time on dialysis prior to RTx and living or cadaver transplantation.

CONCLUSIONS

Successful RTx is associated with a rapid recovery from hypogonadism within 3 months preceeded by improvement in renal function particularly in patients younger than 50 years.

Effect of Intravenous Administration of Cobalt Chloride to Horses on Clinical and Hemodynamic Variables

Background

Cobalt chloride (CoCl₂) is administered to racehorses to enhance performance. The purpose of this study was to evaluate the clinical, cardiovascular, and endocrine effects of parenterally administered CoCl₂.

Objectives

To describe the effects of weekly intravenous doses of CoCl₂ on Standardbred horses.

Animals

Five, healthy Standardbred mares.

Methods

Prospective, randomized, experimental dose‐escalation pilot. Five Standardbred mares were assigned to receive 1 of 5 doses of CoCl₂ (4, 2, 1, 0.5, or 0.25 mg/kg) weekly IV for 5 weeks. Physical examination, blood pressure, cardiac output, and electrocardiography (ECG) were evaluated for 4 hours after administration of the first and fifth doses. Blood and urine samples were collected for evaluation of cobalt concentration, CBC and clinical chemistry, and hormone concentrations.

Results

All mares displayed pawing, nostril flaring, muscle tremors, and straining after CoCl₂ infusion. Mares receiving 4, 2, or 1 mg/kg doses developed tachycardia after dosing (HR 60–126 bpm). Ventricular tachycardia was noted for 10 minutes after administration of the 4 mg/kg dose. Increases in systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) occurred after administration of all doses (4, 2, 1, 0.5, and 0.25 mg/kg). Profound hypertension was observed after the 4 mg/kg dose (SAP/DAP, MAP [mmHg] = 291–300/163–213, 218–279). Hemodynamics normalized by 1–2 hours after administration. ACTH and cortisol concentrations increased within 30 minutes of administration of all CoCl₂ doses, and cardiac troponin I concentration increased after administration of the 4 and 2 mg/kg doses.

Conclusions and Clinical Importance

The degree of hypertension and arrhythmia observed after IV CoCl₂ administration raises animal welfare and human safety concerns.

Life satisfaction and its associated factors among money boys in China

OBJECTIVES

Money Boy (MB) is a unique term used in China referring to a specialized population of men who sell sex to other men. Life satisfaction can influence one's health-related behaviors. The aim of our study was to find out the situation of MBs' life satisfaction and its associated factors.

STUDY DESIGN

A cross-sectional study among MBs was conducted between July and December 2013 in Hunan province, China.

METHODS

Respondent-driven sampling method was used for recruitment, with the initial seven 'seeds' found from a gay dating website, and 234 participants were enrolled into the study. They were asked to complete a questionnaire about their demographic characteristics, work experience as MB, family environment, health-related behaviors, status of self-esteem, self-stigma, and perceived life satisfaction. Descriptive statistics and multiple linear regression analysis were applied.

RESULTS

There were 205 valid questionnaires collected. The results showed that MBs' life satisfaction score was 17.9 ± 6.3. The multiple linear regression model identified five factors correlated with MBs' life satisfaction. Three factors were found to be positively correlated with life satisfaction, consistent condom use with clients (β = 3.093, P = 0.010), interpersonal relationship (β = 1.027, P = 0.017), and self-esteem (β = 0.253, P = 0.005). And two factors were found to be negatively correlated with life satisfaction, seeking for clients through mommy's arrangement (β = -2.091, P = 0.019) and had ever gotten at least one kind of sexually transmitted disease (STDs) (β = -1.971, P = 0.034).

CONCLUSIONS

The present study contributed to a better understanding of MBs' life satisfaction and behavioral and other psychosocial features. It is suggested that comprehensive interventions involving behavioral and psychosocial health promotion approaches are needed for this population. Those programs will be more acceptable among this group and tend to be sustainable.

Aberrant Thalamocortical Connectivity in Juvenile Myoclonic Epilepsy

The purpose of this study was to investigate the functional connectivity (FC) of thalamic subdivisions in patients with juvenile myoclonic epilepsy (JME). Resting state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) data were acquired from 22 JME and 25 healthy controls. We first divided the thalamus into eight subdivisions by performing independent component analysis on tracking fibers and clustering thalamus-related FC maps. We then analyzed abnormal FC in each subdivision in JME compared with healthy controls, and we investigated their associations with clinical features. Eight thalamic sub-regions identified in the current study showed unbalanced thalamic FC in JME: decreased FC with the superior frontal gyrus and enhanced FC with the supplementary motor area in the posterior thalamus increased thalamic FC with the salience network (SN) and reduced FC with the default mode network (DMN). Abnormalities in thalamo-prefrontocortical networks might be related to the propagation of generalized spikes with frontocentral predominance in JME, and the network connectivity differences with the SN and DMN might be implicated in emotional and cognitive defects in JME. JME was also associated with enhanced FC among thalamic sub-regions and with the basal ganglia and cerebellum, suggesting the regulatory role of subcortical nuclei and the cerebellum on the thalamo-cortical circuit. Additionally, increased FC with the pallidum was positive related with the duration of disease. The present study provides emerging evidence of FC to understand that specific thalamic subdivisions contribute to the abnormalities of thalamic-cortical networks in JME. Moreover, the posterior thalamus could play a crucial role in generalized epileptic activity in JME.

Changes in DNA Methylation of Glucocorticoid-Induced Tumor Necrosis Factor Receptor and Its Ligand in Liver Transplantation

Liver transplantation (LT) is the criterion standard of care in patients with end-stage liver disease and those with tumors of hepatic origin in the setting of liver dysfunction. Chronic immune rejection of the liver transplant can lead to bad prognosis for patients. Glucocorticoid-induced tumor necrosis factor receptor (GITR) play a key role in dominant immunologic self-tolerance maintained by CD25+/CD4+ regulatory T cells. Here, we investigated the DNA methylation variations of GITR and GITR ligand (GITRL) using pyrosequencing by analyzing blood DNA samples of patients after LT. Our results showed that the methylation level of certain CpGs, such as CpG_13, in GITRL was significantly reduced after LT. Furthermore, we found that the GITRL methylation statuses of cohorts with no chronic immune rejection were significantly lower compared with cohorts with chronic immune rejection after LT treatment. However, the methylation statuses of GITR were less varied. Using linear regression analysis, we further found that factors such as upper gastrointestinal hemorrhage, splenectomy, and creatinine might affect DNA methylation patterns in chronic immune rejection cohorts. These findings provide novel insights into the pivotal role of GITRL as a potential molecular biomarker for the triage of liver transplantation.