Search results for "Vesicle"

Development of day-night rhythmicity in "synaptic" ribbon numbers in the pinealocytes of posthatch chicks kept under either natural photoperiodic con…

1991

: Pineal synaptic ribbons (SR) undergo characteristic changes over a period of 24 hr under natural photoperiodic conditions in various vertebrates, being low in number during daytime and elevated at night. During posthatch development of chicks, the rhythmicity of SR numbers is reported to appear at the age of about 2 weeks. Because the influence of external light during the growth phase of chicks on the development of day-night rhythmicity in SR numbers is unknown, we studied day-night differences in SR numbers in the pinealocytes of chicks at the posthatch ages of 15, 17, and 19 days; chicks had previously been kept under natural photoperiodic conditions or continuous illumination. Under …

Exercise-Induced Extracellular Vesicles Delay the Progression of Prostate Cancer

2022

Increasing evidence suggests that regular physical exercise not only reduces the risk of cancer but also improves functional capacity, treatment efficacy and disease outcome in cancer patients. At least partially, these effects are mediated by the secretome of the tissues responding to exercise. The secreted molecules can be released in a carrier-free form or enclosed into extracellular vesicles (EVs). Several recent studies have shown that EVs are actively released into circulation during physical exercise. Here, we for the first time investigated the effects of exercise-induced EVs on the progression of cancer in an F344 rat model of metastatic prostate cancer. Although we did not observe…

Physical exercise induces rapid release of small extracellular vesicles into the circulation

2015

Cells secrete extracellular vesicles (EVs) by default and in response to diverse stimuli for the purpose of cell communication and tissue homeostasis. EVs are present in all body fluids including peripheral blood, and their appearance correlates with specific physiological and pathological conditions. Here, we show that physical activity is associated with the release of nano-sized EVs into the circulation. Healthy individuals were subjected to an incremental exercise protocol of cycling or running until exhaustion, and EVs were isolated from blood plasma samples taken before, immediately after and 90 min after exercise. Small EVs with the size of 100–130 nm, that carried proteins character…

Overview and Update on Extracellular Vesicles: Considerations on Exosomes and their Application in Modern Medicine

2022

In recent years, there has been a rapid growth in the knowledge of cell-secreted extracellular vesicle functions. They are membrane enclosed and loaded with proteins, nucleic acids, lipids, and other biomolecules. After being released into the extracellular environment, some of these vesicles are delivered to recipient cells; consequently, the target cell may undergo physiological or pathological changes. Thus, extracellular vesicles as biological nano-carriers, have a pivotal role in facilitating long-distance intercellular communication. Understanding the mechanisms that mediate this communication process is important not only for basic science but also in medicine. Indeed, extracellular …

Adenocarcinomas and their derived lymphovascular emboli contain dual compartmental populations of tumor microvesicles which differ in size and possib…

2016

Adenocarcinomas and their associated lymphovascular emboli metastasize as tight aggregates of tumor cells. Using a xenograft model of human inflammatory breast cancer (Mary-X), which exhibited florid lymphovascular emboli in mice and high density tumor aggregates (spheroids) in vitro, we previously demonstrated that both emboli and spheroids are mediated by an intact overexpressed E-cadherin axis which regulates homotypic tumor cell adhesion. We now report that Mary-X spheroids secrete 5-10 fold higher levels of microvesicles (MVs) than most other carcinoma cell lines. Despite the high density of tumor cells and the strong juxtaposition of tumor cells to each other in the spheroids, interce…

Extracellulare membrane vesicles as vehicles for cell-to-cell and cell-to-extracellular matrix functional interactions

2012

In vitro models of BBB: a tool for the analysis of cell to cell communication in the brain

2008

Many researchers have been trying to set in vitro models of the blood-brain barrier (BBB) aimed at analyzing, in simplified terms, the molecular mechanisms responsible for formation, maintenance and functioning of the BBB, as well as the capability of specific drugs and pro-drugs to cross BBB. We did it, starting with a simpler system of co-culture that allowed us to analyze the effects of neurons on differentiation of brain capillary endothelial cells (RBE4.B cells) in culture, and setting then a more complex model, that includes three cell types (endothelial cells, neurons and astrocytes). The reciprocal geometrical organization of brain cells in this model system is similar to the one ob…

Shedding of extracellular membrane vesicles from both normal and tumor cells in culture

2009

Tumor cells of different origins shed extracellular membrane vesicles (MVs), that contain angiogenetic- and pro-apoptotic-factors as well as matrix metalloproteases (MMPs). In addition, also neurons and astrocytes in culture produce VEGF- and FGF2- containing MVs, while oligodendroglioma (G26/24) cells release FasL-containing MVs that inhibit neurite sprouting and cause neuronal apoptosis. Starting from these observations, we have been analyzing composition of MVs produced by both normal and tumor cells in culture. We found that MVs from G26/24 cells contain TRAIL, Hsp70, and VEGF. We also traced the route of shed MVs, by adding vesicles that contain 35S-labeled proteins to unlabeled neuron…

Effect of extracellular vesicles from CSF of multiple sclerosis patients and healthy controls on astrocytes in culture

2017

INTRODUCTION Secretion of extracellular vesicles (EVs) and EV-mediated exchange of molecules among brain cells, under physiological conditions, has been described years ago. At the same time, ability of EVs to transfer proteins and nucleic acids to the surrounding cells, thus modifying their phenotypes, has been clearly demonstrated for tumor cells of different origins, including brain cancers. More recently, involvement of EVs in pathological processes affecting the Central Nervous System (CNS), and their capacity of transferring damaging cargoes have been also suggested. To explore these functions, we exposed primary cultures of astrocytes to EVs isolated from cerebral spinal fluid (CSF) …

Paracrine roles of extracellular vesicles released by mouse mesoangioblasts

2017

Extracellular vesicles (EV) represent an important mediator of cell-to-cell communication and are involved in both autocrine and paracrine signaling, with a critical role in a number of physiological and pathological conditions.1 The bioactive molecules contained within EV simultaneously activate several different pathways resulting in the synergistic stimulation of target cells. The discovery and characterization of EV have added a novel understanding to regenerative medicine, namely the finding that stem cells are an abundant source of EV.1-2 A6 mouse mesoangioblasts, vessel-associated multipotent progenitor stem cells that are capable of differentiating into different mesodermal cell typ…