The synthetic 15-mer arginine-glycine-aspartic acid (RGD) domain of osteopontin (OPN) is protective in vitro and in vivo against dopaminergic cell death and this protective effect may be mediated through interaction with integrin receptors to regulate neurotrophic factor levels. We now examine this concept in rat primary ventral mesencephalic (VM) cultures. 1-Methyl-4-phenylpyridinium (MPP+) exposure reduced tyrosine hydroxylase (TH)-positive cell number and activated glial cells as shown by increased glial fibrillary acidic protein (GFAP), oxycocin-42 (OX-42) and ectodermal dysplasia 1 (ED-1) immunoreactivity. Both OPN and the RGD domain of OPN were equally protective against MPP+ toxicity in VM cultures and both increased glial-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) levels. The effects of OPN and the RGD domain were accompanied by a decrease in numbers of activated microglia but with no change in astrocyte number. However, full-length OPN and the RGD domain of OPN remained protective against MPP+ toxicity in the presence of a GDNF neutralising antibody. This suggests that increased GDNF levels do not underlie the protective effect observed with OPN. Rather, OPN's protective effect may be mediated through decreased glial cell activation.
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http://dx.doi.org/10.1016/j.expneurol.2014.09.005 | DOI Listing |
Bioorg Chem
January 2025
Institute for Advanced Study, Department of Chemistry, School of Natural Sciences and Bavarian NMR Center (BNMRZ), Technical University Munich, Ernst-Otto-Fischer-Str. 2, 85748 Garching, Germany. Electronic address:
Integrins are well-characterized receptors involved in cell adhesion and signaling. With six approved drugs, they are recognized as valuable therapeutic targets. Here, we explore potential activation mechanisms that may clarify the agonist versus antagonist behavior of integrin ligands.
View Article and Find Full Text PDFDatabase (Oxford)
January 2025
Rat Genome Database, Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226, United States.
The Rat Genome Database (RGD) is a multispecies knowledgebase which integrates genetic, multiomic, phenotypic, and disease data across 10 mammalian species. To support cross-species, multiomics studies and to enhance and expand on data manually extracted from the biomedical literature by the RGD team of expert curators, RGD imports and integrates data from multiple sources. These include major databases and a substantial number of domain-specific resources, as well as direct submissions by individual researchers.
View Article and Find Full Text PDFJ Extracell Vesicles
November 2024
School of Human Sciences, Cell Communication in Disease Pathology, London Metropolitan University, London, UK.
During cell invasion, large Extracellular Vesicle (lEV) release from host cells was dose-dependently triggered by Trypanosoma cruzi metacyclic trypomastigotes (Mtr). This lEV release was inhibited when IP-mediated Ca exit from the ER and further Ca entry from plasma membrane channels was blocked, but whilst any store-independent Ca entry (SICE) could continue unabated. That lEV release was equally inhibited if all entry from external sources was blocked by chelation of external Ca points to the major contributor to Mtr-triggered host cell lEV release being IP/store-mediated Ca release, SICE playing a minor role.
View Article and Find Full Text PDFToxins (Basel)
November 2024
Laboratório de Matriz Extracelular e Biotecnologia de Venenos, Universidade Federal do Paraná, UFPR, Curitiba 81531-980, Brazil.
J Biomol Struct Dyn
November 2024
Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India.
A C-terminal fragment of the adhesion protein Fibulin7 (Fbln7-C) binds to monocytes and neutrophils integrin α5β1, regulating their adhesion and immunological functions through Erk and STAT signaling pathways. It also inhibits cell binding, spreading, and migration on fibronectin. However, the precise structural components of Fbln7-C that interact with various domains of integrin α5β1 and contribute to its regulatory effects are not entirely understood.
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