Search results for "Vesicles"

In vitro effects of putative neurotransmitters on synaptic ribbon numbers and N-acetyltransferase activity in the rat pineal gland

1992

The pineal contains a large number of classical transmitters and neuropeptides. Some of these neurochemicals are involved in the regulation of serotonin N-acetyltransferase (NAT) activity and hence in melatonin synthesis. Synaptic ribbons present in the pineal gland also exhibit a numerical day/night rhythm parallel to that of NAT activity. There is scarcity of information regarding the regulation of synaptic ribbon (SR) numbers. In the present study, we have investigated in vitro effects of a number of classical neurotransmitters and neuropeptides. NAT activity was used to monitor melatonin synthesis under the experimental conditions used. Norepinephrine (NE), Delta sleep-inducing peptide …

"Synaptic" ribbons and spherules of the rat pineal gland: day/night changes in vitro?

1982

In the present study pineal glands of rats aged 69–71 days were studied in vivo and in vitro with respect to day/night changes of “synaptic” ribbons and spherules. It was found that ribbons outnumber spherules by a factor of 3. In vivo, both ribbons and spherules show a roughly 3-fold increase in number at 1 a.m. when compared to 1 p.m. Up to 39 h in vitro, the two structures in question did not reveal day/night differences in amount, suggesting that diurnal rhythmicity of the gland did apparently not persist in organ culture. After 3 h in organ culture, the spherules, but not the ribbons, showed a striking increase in number, showing that ribbons and spherules may be governed by different …

Investigations on day-night differences of vesicle densities in synapses of the rat suprachiasmatic nucleus

1990

The present study was conducted to test whether the well-known circadian alterations in physiological and metabolical parameters of the hypothalamic suprachiasmatic nucleus (SCN) are accompanied by day-night differences in the number of vesicles in intrinsic synapses of the nucleus. Two groups of 5 adult male rats each were killed at mid-light or mid-dark, respectively, by perfusion with Karnovsky's fluid. The SCN were removed and processed for routine electron microscopy. In medial parts of the nucleus, synapses were characterized as being of Gray type I (asymmetrical), Gray type II (symmetrical) or of intermediate form, and the vesicles per synaptic profile (VPSP) were counted over a defi…

Special considerations for studies of extracellular vesicles from parasitic helminths: A community-led roadmap to increase rigour and reproducibility.

2023

Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross-species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well-recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth-derived EVs in these processes and highlights EVs as an important participant in cross-phylum communication. While the mammalian EV field is guided by a community-agreed framework for studying EVs derived from model organisms or cell systems [e.g., Minimal Information for Studies of Extracellular Vesicles (MISEV)], the helminth community requires a supplem…

Light Scattering as an Easy Tool to Measure Vesicles Weight Concentration

2020

Over the last few decades, liposomes have emerged as promising drug delivery systems and effective membrane models for studying biophysical and biological processes. For all applications, knowing their concentration after preparation is crucial. Thus, the development of methods for easily controlling vesicles concentration would be of great utility. A new assay is presented here, based on a suitable analysis of light scattering intensity from liposome dispersions. The method, tested for extrusion preparations, is precise, easy, fast, non-destructive and uses a tiny amount of sample. Furthermore, the scattering intensity can be measured indifferently at different angles, or even by using the…

Nano-structured myelin: new nanovesicles for targeted delivery to white matter and microglia, from brain-to-brain

2021

Neurodegenerative diseases affect millions of people worldwide and the presence of various physiological barriers limits the accessibility to the brain and reduces the efficacy of various therapies. Moreover, new carriers having targeting properties to specific brain regions and cells are needed in order to improve therapies for the brain disorder treatment. In this study, for the first time, Myelin nanoVesicles (hereafter defined MyVes) from brain-extracted myelin were produced. The MyVes have an average diameter of 100–150 ​nm, negative zeta potential, spheroidal morphology, and contain lipids and the key proteins of the myelin sheath. Furthermore, they exhibit good cytocompatibility. The…

Shedding of membrane vesicles containing HSP70 and FGF-2 from A6 stem cells.

2007

The Role of Exosomes Derived From Mesenchymal Stromal Cells in Dermatology

2021

This study has been funded by the Carlos III Health Institute of Spain through the PI13/02576 and PI17/02083 projects [cofunded by European Regional Development Fund "A way to make Europe" and Andalusian Regional Government Finance (SAS PI-0458-2016)]. The work of MQ-V was supported by a predoctoral fellowship (BOE 22/10/2019) from the Spanish Ministry of Science, Innovation and Universities. This study is part of her doctoral research in the Biomedicine program at the University of Granada.

Analysis of MSCs' secretome and EVs cargo: Evaluation of functions and applications

2022

Mesenchymal stem cells (MSCs) can exert different functions and can be used in several medical fields. In the last years, MSC properties have been attributed to their secreted factors such as soluble proteins, cytokines and growth factors. Moreover, a key role is played by the extracellular vesicles (EVs) which lead a heterogeneous cargo of proteins, lipids and small and long non-coding RNAs that interfere with the pathways of the recipient cells. Due to the safeness and easiness in obtaining the secretome, its use is becoming a turning point for the application in physiological and pathological fields. This review summarizes the most recent studies on the use of MSCs secretome, focusing on…

Plasmatic extracellular vesicle microRNAs in malignant pleural mesothelioma and asbestos-exposed subjects suggest a 2-miRNA signature as potential bi…

2017

Background Malignant Pleural Mesothelioma (MPM) is an aggressive cancer mainly caused by asbestos exposure and refractory to current therapies. Specific diagnostic markers for early MPM diagnosis are needed. Changes in miRNA expression have been implicated in several diseases and cancers, including MPM. We examined if a specific miRNA signature in plasmatic extracellular vesicles (EV) may help to discriminate between malignant pleural mesothelioma patients (MPM) and subjects with Past Asbestos Exposure (PAE). Methodology/Principal findings We investigated 23 MPM patients and 19 cancer-free subjects with past asbestos exposure (PAE). We screened 754 miRNAs in plasmatic EVs by OpenArray and f…