Activation of APE1/Ref-1 is dependent on reactive oxygen species generated after purinergic receptor stimulation by ATP

Apurinic apyrimidinic endonuclease redox effector factor-1 (APE1/Ref-1) is involved both in the base excision repair (BER) of DNA lesions and in the eukaryotic transcriptional regulation. APE1/Ref-1 is regulated at both the transcriptional and post-translational levels, through control of subcellular localization and post-translational modification. In response to stress conditions, several cell types release ATP, which exerts stimulatory effects on eukaryotic cells via the purinergic receptors (P2) family. By using western blot and immunofluorescence analysis on a human tumour thyroid cell line (ARO), we demonstrate that purinergic stimulation by extracellular ATP induces quick cytoplasm to nucleus translocation of the protein at early times and its neosynthesis at later times. Continuous purinergic triggering by extracellular ATP released by ARO cells is responsible for the control of APE1/Ref-1 intracellular level. Interference with intracellular pathways activated by P2 triggering demonstrates that Ca(2+) mobilization and intracellular reactive oxygen species (ROS) production are responsible for APE1/Ref-1 translocation. The APE1/Ref-1 activities on activator protein-1 (AP-1) DNA binding and DNA repair perfectly match its nuclear enrichment upon ATP stimulation. The biological relevance of our data is reinforced by the observation that APE1/Ref-1 stimulation by ATP protects ARO cells by H(2)O(2)-induced cell death. Our data provide new insights into the complex mechanisms regulating APE1/Ref-1 functions

Identification of secondary targets of N-containing bisphosphonates in mammalian cells via parallel competition analysis of the barcoded yeast deletion collection

Growth competition assays using barcoded yeast deletion-mutants reveal the molecular targets of nitrogen containing bisphosphonates used for the treatment of bone cancers and osteoporosis

The 2022 South America report of The Lancet Countdown on health and climate change: trust the science. Now that we know, we must act

The health of South American populations is being severely impacted by increasing climate change-driven environmental changes. Exacerbated by increased social inequities and vulnerability, deforestation, land degradation, and global climate variabilities in sea temperature, can potentially lead to extreme weather and climate events, magnifying the negative effects of climate change on health. Understanding the direct and indirect exposure routes to climate hazards and the effects on health and wellbeing is critical to design successful and effective evidence-based adaptation and mitigation plans and policies. This report is part of the Lancet Countdown's broader efforts to develop expertise and understanding of the links between health and climate change at the regional level. The Lancet Countdown South America (LCSA), a newly launched chapter of the Lancet Countdown, is an independent, multidisciplinary academic collaboration dedicated to tracking the links between public health and climate change in South America (SA). This collaboration brings together 21 academic institutions and UN agencies with 28 researchers representing various disciplines. The data and results provided in this report for the 12 countries of the region,∗ explore in regional detail the results of the 2022 global Lancet Countdown report and provide the evidence to support targeted response strategies for decision-makers. Its findings and conclusions represent the consensus of experts across multiple fields, covering 25 indicators summarised below in four key messages

Caratterizzazione biochimica delle fasi organica e minerale del tessuto osseo nel ratto

Dottorato di ricerca in biochimica. 7. ciclo. Tutore L. Moro. Coordinatore B. De BernardConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

The Influence of Orchidectomy on Collagen Glycosylation of Trabecular Bone in Rat

Peer Reviewe

17β-Estradiol and Tamoxifen Prevent the Over-Glycosylation of Rat Trabecular Bone Collagen Induced by Ovariectomy

Peer Reviewe

Extracellular ATP stimulates the early growth response protein 1 (Egr-1) via a protein kinase C-dependent pathway in the human osteoblastic HOBIT cell line.

Extracellular nucleotides exert an important role in controlling cell physiology by activating intracellular signalling cascades. Osteoblast HOBIT cells express P2Y(1) and P2Y(2) G-protein-coupled receptors, and respond to extracellular ATP by increasing cytosolic calcium concentrations. Early growth response protein 1 (Egr-1) is a C(2)H(2)-zinc-finger-containing transcriptional regulator responsible for the activation of several genes involved in the control of cell proliferation and apoptosis, and is thought to have a central role in osteoblast biology. We show that ATP treatment of HOBIT cells increases Egr-1 protein levels and binding activity via a mechanism involving a Ca(2+)-independent protein kinase C isoform. Moreover, hypotonic stress and increased medium turbulence, by inducing ATP release, result in a similar effect on Egr-1. Increased levels of Egr-1 protein expression and activity are achieved at very early times after stimulation (5 min), possibly accounting for a rapid way for changing the osteoblast gene-expression profile. A target gene for Egr-1 that is fundamental in osteoblast physiology, COL1A2, is up-regulated by ATP stimulation of HOBIT cells in a timescale that is compatible with that of Egr-1 activation