Erinacine C Activates Transcription from a Consensus ETS DNA Binding Site in Astrocytic Cells in Addition to NGF Induction
BIOMOLECULES
Authors: Rascher, Monique; Wittstein, Kathrin; Winter, Barbara; Rupcic, Zeljka; Wolf-Asseburg, Alexandra; Stadler, Marc; Koester, Reinhard W.
Abstract
Medicinal mushrooms of the genus Hericium are known to produce secondary metabolites with homeostatic properties for the central nervous system. We and others have recently demonstrated that among these metabolites cyathane diterpenoids and in particular erinacine C possess potent neurotrophin inducing properties in astrocytic cells. Yet, the signaling events downstream of erinacine C induced neurotrophin acitivity in neural-like adrenal phaeochromocytoma cells (PC12) cells have remained elusive. Similar, signaling events activated by erinacine C in astrocytic cells are unknown. Using a combination of genetic and pharmacological inhibitors we show that erinacine C induced neurotrophic activity mediates PC12 cell differentiation via the TrkA receptor and likely its associated PLC gamma-, PI3K-, and MAPK/ERK pathways. Furthermore, a small library of transcriptional activation reporters revealed that erinacine C induces transcriptional activation mediated by DNA consensus binding sites of selected conserved transcription factor families. Among these, transcription is activated from an ETS consensus in a concentration dependent manner. Interestingly, induced ETS-consensus transcription occurs in parallel and independent of neurotrophin induction. This finding helps to explain the many pleiotropic functions of cyathane diterpenoids. Moreover, our studies provide genetic access to cyathane diterpenoid functions in astrocytic cells and help to mechanistically understand the action of cyathanes in glial cells.
Phosphoinositide-specific phospholipase C isoforms are conveyed by osteosarcoma-derived extracellular vesicles
JOURNAL OF CELL COMMUNICATION AND SIGNALING
Authors: Urciuoli, Enrica; Leopizzi, Martina; Di Maio, Valeria; Petrini, Stefania; D'Oria, Valentina; Giorda, Ezio; Scarsella, Marco; Della Rocca, Carlo; Lo Vasco, Vincenza Rita; Peruzzi, Barbara
Abstract
Cancer cells are able to release high amounts of extracellular vesicles, thereby conditioning the normal cells in the surrounding tissue and/or in distant target organs. In the context of bone cancers, previous studies suggested that osteosarcoma cancer cells produce transforming extracellular vesicles able to induce a tumour-like phenotype in normal recipient cells. Indeed, phosphoinositide-specific phospholipase C (PI-PLC) enzymes are differentially expressed in osteosarcoma cell lines with increasing aggressiveness, thus providing helpful insights to better define their role and functions in this bone tumour. By confocal microscopy analysis, we demonstrated that osteosarcoma-derived extracellular vesicles convey all the assessed PI-PLC isoforms, and that they localize into cell membrane bubble-like structures, resembling extracellular vesicles about to be released, as conveyed and/or membrane protein. Cytofluorimetric analysis confirmed the presence of PI-PLC isoforms in the extracellular vesicles collected from conditioned media of osteosarcoma cells. These findings suggest the feasibility to use circulating extracellular vesicles as biomarkers of osteosarcoma progression and/or the monitoring of this distressing disease.