Glioblastoma stem cell-derived exosomes induce M2 macrophages and PD-L1 expression on human monocytes.

Exosomes can mediate a dynamic method of communication between malignancies, including those sequestered in the central nervous system and the immune system. We sought to determine whether exosomes from glioblastoma (GBM)-derived stem cells (GSCs) can induce immunosuppression. We report that GSC-derived exosomes (GDEs) have a predilection for monocytes, the precursor to macrophages.

A cerebrospinal fluid microRNA signature as biomarker for glioblastoma.

Purpose: To develop a cerebrospinal fluid (CSF) miRNA diagnostic biomarker for glioblastoma.

Experimental Design: Glioblastoma tissue and matched CSF from the same patient (obtained prior to tumor manipulation) were profiled by TaqMan OpenArray Human MicroRNA Panel. CSF miRNA profiles from glioblastoma patients and controls were created from three discovery cohorts and confirmed in two validation cohorts.

Analysis of extracellular RNA in cerebrospinal fluid.

We examined the extracellular vesicle (EV) and RNA composition of pooled normal cerebrospinal fluid (CSF) samples and CSF from five major neurological disorders: Alzheimer's disease (AD), Parkinson's disease (PD), low-grade glioma (LGG), glioblastoma multiforme (GBM), and subarachnoid haemorrhage (SAH), representing neurodegenerative disease, cancer, and severe acute brain injury. We evaluated: (I) size and quantity of EVs by nanoparticle tracking analysis (NTA) and vesicle flow cytometry (VFC), (II) RNA yield and purity using four RNA isolation kits, (III) replication of RNA yields within and between laboratories, and (IV) composition of total and EV RNAs by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and RNA sequencing (RNASeq). The CSF contained ~106 EVs/μL by NTA and VFC.

Novel human neuronal tau model exhibiting neurofibrillary tangles and transcellular propagation.

Tauopathies are a class of neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementia and progressive supranuclear palsy, which are associated with the pathological aggregation of tau protein into neurofibrillary tangles (NFT). Studies have characterized tau as a "prion-like" protein given its ability to form distinct, stable amyloid conformations capable of transcellular and multigenerational propagation in clonal fashion. It has been proposed that progression of tauopathy could be due to the prion-like propagation of tau, suggesting the possibility that end-stage pathologies, like NFT formation, may require an instigating event such as tau seeding.

Prediction of conversion from mild cognitive impairment to dementia with neuronally derived blood exosome protein profile.

Introduction: Levels of Alzheimer's disease (AD)-related proteins in plasma neuronal derived exosomes (NDEs) were quantified to identify biomarkers for prediction and staging of mild cognitive impairment (MCI) and AD.

Methods: Plasma exosomes were extracted, precipitated, and enriched for neuronal source by anti-L1CAM antibody absorption. NDEs were characterized by size (Nanosight) and shape (TEM) and extracted NDE protein biomarkers were quantified by ELISAs.

Optimizing preservation of extracellular vesicular miRNAs derived from clinical cerebrospinal fluid.

Background: Tumor specific genetic material can be detected in extracellular vesicles (EVs) isolated from blood, cerebrospinal fluid (CSF), and other biofluids of glioblastoma patients. As such, EVs have emerged as a promising platform for biomarker discovery. However, the optimal procedure to transport clinical EV samples remains poorly characterized.

Comparative Analysis of Technologies for Quantifying Extracellular Vesicles (EVs) in Clinical Cerebrospinal Fluids (CSF).

Extracellular vesicles (EVs) have emerged as a promising biomarker platform for glioblastoma patients. However, the optimal method for quantitative assessment of EVs in clinical bio-fluid remains a point of contention. Multiple high-resolution platforms for quantitative EV analysis have emerged, including methods grounded in diffraction measurement of Brownian motion (NTA), tunable resistive pulse sensing (TRPS), vesicle flow cytometry (VFC), and transmission electron microscopy (TEM).

miRNA contents of cerebrospinal fluid extracellular vesicles in glioblastoma patients.

Analysis of extracellular vesicles (EVs) derived from plasma or cerebrospinal fluid (CSF) has emerged as a promising biomarker platform for therapeutic monitoring in glioblastoma patients. However, the contents of the various subpopulations of EVs in these clinical specimens remain poorly defined. Here we characterize the relative abundance of miRNA species in EVs derived from the serum and cerebrospinal fluid of glioblastoma patients.

A genome-wide miRNA screen revealed miR-603 as a MGMT-regulating miRNA in glioblastomas.

MGMT expression is a critical determinant for therapeutic resistance to DNA alkylating agents. We previously demonstrated that MGMT expression is post-transcriptionally regulated by miR-181d and other miRNAs. Here, we performed a genome-wide screen to identify MGMT regulating miRNAs.

Genome-wide shRNA screen revealed integrated mitogenic signaling between dopamine receptor D2 (DRD2) and epidermal growth factor receptor (EGFR) in glioblastoma.

Glioblastoma remains one of the deadliest of human cancers, with most patients succumbing to the disease within two years of diagnosis. The available data suggest that simultaneous inactivation of critical nodes within the glioblastoma molecular circuitry will be required for meaningful clinical efficacy. We conducted parallel genome-wide shRNA screens to identify such nodes and uncovered a number of G-Protein Coupled Receptor (GPCR) neurotransmitter pathways, including the Dopamine Receptor D2 (DRD2) signaling pathway.

Synthesis and delivery of short, noncoding RNA by B lymphocytes.

Evolutionarily conserved short (20-30 nucleotides) noncoding RNAs (microRNAs) are powerful regulators of gene expression in a variety of physiological and pathological processes. As such, means to efficiently modulate microRNA function constitute an important therapeutic opportunity. Here we demonstrate that primary B lymphocytes can be genetically programmed with nonviral plasmid DNA for the biogenesis and delivery of antisense sequences (anti-microRNA) against microRNA-150 (miR-150).

MiR-21 in the extracellular vesicles (EVs) of cerebrospinal fluid (CSF): a platform for glioblastoma biomarker development.

Glioblastoma cells secrete extra-cellular vesicles (EVs) containing microRNAs (miRNAs). Analysis of these EV miRNAs in the bio-fluids of afflicted patients represents a potential platform for biomarker development. However, the analytic algorithm for quantitative assessment of EV miRNA remains under-developed.

Differential expression of miR-145 in children with Kawasaki disease.

Background: Kawasaki disease is an acute, self-limited vasculitis of childhood that can result in structural damage to the coronary arteries. Previous studies have implicated the TGF-β pathway in disease pathogenesis and generation of myofibroblasts in the arterial wall. microRNAs are small non-coding RNAs that modulate gene expression at the post-transcriptional level and can be transported between cells in extracellular vesicles.

Biogenesis of extracellular vesicles (EV): exosomes, microvesicles, retrovirus-like vesicles, and apoptotic bodies.

Recent studies suggest both normal and cancerous cells secrete vesicles into the extracellular space. These extracellular vesicles (EVs) contain materials that mirror the genetic and proteomic content of the secreting cell. The identification of cancer-specific material in EVs isolated from the biofluids (e.

Neuro-oncologic applications of exosomes, microvesicles, and other nano-sized extracellular particles.

The discovery that tumor-derived proteins and nucleic acids can be detected in nano-sized vesicles in the plasma and cerebrospinal fluid of patients afflicted with brain tumors has expanded opportunities for biomarker and therapeutic discovery. Through delivery of their contents to surrounding cells, exosomes, microvesicles, and other nano-sized extracellular vesicles secreted by tumors modulate their environment to promote tumor growth and survival. In this review, we discuss the biological processes mediated by these extracellular vesicles and their applications in terms of brain tumor diagnosis, monitoring, and therapy.

Identification and functional analysis of CT069 as a novel transcriptional regulator in Chlamydia.

Only a small number of transcription factors have been predicted in Chlamydia spp., which are obligate intracellular bacteria that include a number of important human pathogens. We used a bioinformatics strategy to identify novel transcriptional regulators from the Chlamydia trachomatis genome by predicting proteins with the general structure and characteristic functional domains of a bacterial transcription factor.

CT406 encodes a chlamydial ortholog of NrdR, a repressor of ribonucleotide reductase.

Chlamydia trachomatis is an obligate intracellular bacterium that is dependent on its host cell for nucleotides. Chlamydia imports ribonucleotide triphosphates (NTPs) but not deoxyribonucleotide triphosphates (dNTPs) and instead uses ribonucleotide reductase to convert imported ribonucleotides into deoxyribonucleotides for DNA synthesis. The genes encoding ribonucleotide reductase have been recently shown to be negatively controlled by a conserved regulator called NrdR.

The cell-penetrating peptide, Pep-1, has activity against intracellular chlamydial growth but not extracellular forms of Chlamydia trachomatis.

Objectives: In the course of studies to identify novel treatment strategies against the pathogenic bacterium, Chlamydia, we tested the carrier peptide, Pep-1, for activity against an intracellular infection.

Methods: Using a cell culture model of Chlamydia trachomatis infection, the effect of Pep-1 was measured by incubating the peptide with extracellular chlamydiae prior to infection, or by adding Pep-1 to the medium at varying times after infection, and assaying for inhibition of inclusion formation.

Results: Pep-1 had a concentration-dependent effect on chlamydial growth with 100% inhibition of inclusion formation at 8 mg/L peptide.

Molecular mechanism of tryptophan-dependent transcriptional regulation in Chlamydia trachomatis.

Tryptophan is an essential amino acid that is required for normal development in Chlamydia species, and tryptophan metabolism has been implicated in chlamydial persistence and tissue tropism. The ability to synthesize tryptophan is not universal among the Chlamydiaceae, but species that have a predicted tryptophan biosynthetic pathway also encode an ortholog of TrpR, a regulator of tryptophan metabolism in many gram-negative bacteria. We show that in Chlamydia trachomatis serovar D, TrpR regulates its own gene and trpB and trpA, the genes for the two subunits of tryptophan synthase.