title: Nucleotides in neuroregeneration and neuroprotection.
abstract: Brain injury generates the release of a multitude of factors including extracellular nucleotides, which exhibit bi-functional properties and contribute to both detrimental actions in the acute phase and also protective and reparative actions in the later recovery phase to allow neuroregeneration. A promising strategy toward restoration of neuronal function is based on activation of endogenous adult neural stem/progenitor cells. The implication of purinergic signaling in stem cell biology, including regulation of proliferation, differentiation, and cell death has become evident in the last decade. In this regard, current strategies of acute transplantation of ependymal stem/progenitor cells after spinal cord injury restore altered expression of P2X4 and P2X7 receptors and improve functional locomotor recovery. The expression of both receptors is transcriptionally regulated by Sp1 factor, which plays a key role in the startup of the transcription machinery to induce regeneration-associated genes expression. Finally, general signaling pathways triggered by nucleotide receptors in neuronal populations converge on several intracellular kinases, such as PI3K/Akt, GSK3 and ERK1,2, as well as the Nrf-2/heme oxigenase-1 axis, which specifically link them to neuroprotection. In this regard, regulation of dual specificity protein phosphatases can become novel mechanism of actions for nucleotide receptors that associate them to cell homeostasis regulation. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Miras-Portugal
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain. Electronic address: marosa@vet.ucm.es.
authors.forename: Rosa
authors.initials: R
authors.lastname: Gomez-Villafuertes
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Gualix
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Juan Ignacio
authors.initials: JI
authors.lastname: Diaz-Hernandez
authors.affiliation: Department of Toxicology and Pharmacology, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Antonio R
authors.initials: AR
authors.lastname: Artalejo
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Ortega
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Esmerilda G
authors.initials: EG
authors.lastname: Delicado
authors.affiliation: Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Perez-Sen
mesh_terms: D000818:Animals; D001930:Brain Injuries / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D020935:MAP Kinase Signaling System; D009416:Nerve Regeneration; D058953:Neural Stem Cells / Q000378:metabolism* / Q000637:transplantation; D009474:Neurons / Q000378:metabolism*; D011983:Receptors, Purinergic / Q000378:metabolism*; D058469:Receptors, Purinergic P2X / Q000378:metabolism; D058470:Receptors, Purinergic P2Y / Q000378:metabolism; D015398:Signal Transduction; D013119:Spinal Cord Injuries / Q000378:metabolism*
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D011983:Receptors, Purinergic; D058469:Receptors, Purinergic P2X; D058470:Receptors, Purinergic P2Y; D038362:Glycogen Synthase Kinase 3
keywords: DUSP; GSK3; MAPK signaling; Nrf-2; P2X7 receptors; P2Y(13) receptors; Sp1; Stem/progenitor cells