Search results for "Extracellular"

Unveiling neural stem cell quiescence: a crosstalk with the extracellular matrix niche

2023

Neural stem cells (NSCs) in the subependymal zone (SEZ) reside in a very specialized microenvironment that tightly regulates their activation state. Three NSC populations coexist in the niche, quiescent (qNSCs), primed and activated (aNSCs), which display unique, actively modulated, molecular identities. One of the specialized extrinsic properties that affect NSC quiescence-to-activation transitions is the extracellular matrix (ECM). The SEZ is the only region in the whole mouse brain that has two basement membrane (BM) structures: vascular and speckled BMs. Further, it displays higher stiffness compared to non-neurogenic areas, suggesting that both composition and ECM properties could part…

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…

Microbial role in dolomitic crust formation associated to Messinian gypsum, Monte Conca cave, Sicily.

2009

Microbial dolomite associated to gypsum stromatolites from a Messinian marginal section, Madonie mountains, Sicily.

2009

Extracellular vesicles from CS fluid are possible biomarkers of multiple sclerosis disease status

2018

Multiple sclerosis (MS) is an autoimmune disease and several researches have been focused on identifying molecular biomarkers that could reflect its heterogeneous clinical course and determine the best treatment option for patients. Some studies identified extracellular vesicles (EVs) in both the cerebrospinal fluid (CSF) and also in blood samples of patients affected by inflammatory neurodegenerative diseases and multiple sclerosis. To monitor the disease onset and its progression we compared the amount of CSF-EVs and their surface markers in subjects affected by either MS or other neurological disorders correlating the EVs with clinical indicators of MS disease severity. EVs isolated by u…

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…

SHEDDING OF EXTRACELLULAR VESICLES FROM BRAIN CELLS

2006

The Fibronectin RGD and synergy sites function in integrin interaction

2018

Fibronectin (FN) is a large glycoprotein component of the extracellular matrix (ECM). It presents two forms: soluble in plasma or insoluble (fibrillar) within the ECM surrounding the cells in tissues. FN is one of the most important proteins in the ECM, it directly mediates cell adhesion, and therefore is essential for several biological processes such as embryonic development or blood clotting. Its involvement in these processes relay in its interaction with the cellular receptors integrins. The major binding site for integrins in FN is the so-called RGD site located in the 10th FN type III repeat (FNIII10), which is recognized by a5b1, aIIbb3 and all the av-containing integrins. Additiona…