DNA Damage in Nijmegen Breakage Syndrome Cells Leads to PARP Hyperactivation and Increased Oxidative Stress

Nijmegen Breakage Syndrome (NBS), an autosomal recessive genetic instability syndrome, is caused by hypomorphic mutation of the NBN gene, which codes for the protein nibrin. Nibrin is an integral member of the MRE11/RAD50/NBN (MRN) complex essential for processing DNA double-strand breaks. Cardinal features of NBS are immunodeficiency and an extremely high incidence of hematological malignancies. Recent studies in conditional null mutant mice have indicated disturbances in redox homeostasis due to impaired DSB processing. Clearly this could contribute to DNA damage, chromosomal instability, and cancer occurrence. Here we show, in the complete absence of nibrin in null mutant mouse cells, high levels of reactive oxygen species several hours after exposure to a mutagen. We show further that NBS patient cells, which unlike mouse null mutant cells have a truncated nibrin protein, also have high levels of reactive oxygen after DNA damage and that this increased oxidative stress is caused by depletion of NAD+ due to hyperactivation of the strand-break sensor, Poly(ADP-ribose) polymerase. Both hyperactivation of Poly(ADP-ribose) polymerase and increased ROS levels were reversed by use of a specific Poly(ADP-ribose) polymerase inhibitor. The extremely high incidence of malignancy among NBS patients is the result of the combination of a primary DSB repair deficiency with secondary oxidative DNA damage

TNFAIP3 (A20) is a tumor suppressor gene in Hodgkin lymphoma and primary mediastinal B cell lymphoma

Proliferation and survival of Hodgkin and Reed/Sternberg (HRS) cells, the malignant cells of classical Hodgkin lymphoma (cHL), are dependent on constitutive activation of nuclear factor κB (NF-κB). NF-κB activation through various stimuli is negatively regulated by the zinc finger protein A20. To determine whether A20 contributes to the pathogenesis of cHL, we sequenced TNFAIP3, encoding A20, in HL cell lines and laser-microdissected HRS cells from cHL biopsies. We detected somatic mutations in 16 out of 36 cHLs (44%), including missense mutations in 2 out of 16 Epstein-Barr virus–positive (EBV+) cHLs and a missense mutation, nonsense mutations, and frameshift-causing insertions or deletions in 14 out of 20 EBV− cHLs. In most mutated cases, both TNFAIP3 alleles were inactivated, including frequent chromosomal deletions of TNFAIP3. Reconstitution of wild-type TNFAIP3 in A20-deficient cHL cell lines revealed a significant decrease in transcripts of selected NF-κB target genes and caused cytotoxicity. Extending the mutation analysis to primary mediastinal B cell lymphoma (PMBL), another lymphoma with constitutive NF-κB activity, revealed destructive mutations in 5 out of 14 PMBLs (36%). This report identifies TNFAIP3 (A20), a key regulator of NF-κB activity, as a novel tumor suppressor gene in cHL and PMBL. The significantly higher frequency of TNFAIP3 mutations in EBV− than EBV+ cHL suggests complementing functions of TNFAIP3 inactivation and EBV infection in cHL pathogenesis

Comparative evaluation of methods for estimating retinal ganglion cell loss in retinal sections and wholemounts

To investigate the reliability of different methods of quantifying retinal ganglion cells (RGCs) in rat retinal sections and wholemounts from eyes with either intact optic nerves or those axotomised after optic nerve crush (ONC). Adult rats received a unilateral ONC and after 21 days the numbers of Brn3a+ , bIII-tubulin+ and Islet-1+ RGCs were quantified in either retinal radial sections or wholemounts in which FluoroGold (FG) was injected 48 h before harvesting. Phenotypic antibody markers were used to distinguish RGCs from astrocytes, macrophages/microglia and amacrine cells. In wholemounted retinae, counts of FG+ and Brn3a+ RGCs were of similar magnitude in eyes with intact optic nerves and were similarly reduced after ONC. Larger differences in RGC number were detected between intact and ONC groups when images were taken closer to the optic nerve head. In radial sections, Brn3a did not stain astrocytes, macrophages/microglia or amacrine cells, whereas βIII-tubulin and Islet-1 did localize to amacrine cells as well as RGCs. The numbers of βIII-tubulin+ RGCs was greater than Brn3a+ RGCs, both in retinae from eyes with intact optic nerves and eyes 21 days after ONC. Islet-1 staining also overestimated the number of RGCs compared to Brn3a, but only after ONC. Estimates of RGC loss were similar in Brn3astained radial retinal sections compared to both Brn3a-stained wholemounts and retinal wholemounts in which RGCs were backfilled with FG, with sections having the added advantage of reducing experimental animal usage

Proteolytic Processing of Interleukin-1 Family Cytokines: Variations on a Common Theme

Members of the extended interleukin-1 (IL-1) cytokine family, such as IL-1, IL-18, IL-33, and IL-36, play a pivotal role in the initiation and amplification of immune responses. However, deregulated production and/or activation of these cytokines can lead to the development of multiple inflammatory disorders. IL-1 family members share a broadly similar domain organization and receptor signaling pathways. Another striking similarity between IL-1 family members is the requirement for proteolytic processing in order to unlock their full biological potential. Although much emphasis has been put on the role of caspase-1, another emerging theme is the involvement of neutrophil- and mast cell-derived proteases in IL-1 family cytokine processing. Elucidating the regulation of IL-1 family members by proteolytic processing is of great interest for understanding inflammation and immunity. Here, we review the identity of the proteases involved in the proteolytic processing of IL-1 family cytokines and the therapeutic implications in inflammatory disease

Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels

[EN] In this work some relevant processes for the preparation of liquid hydrocarbon fuels and fuel additives from cellulose, hemicellulose and triglycerides derived platform molecules are discussed. Thus, it is shown that a series of platform molecules such as levulinic acid, furans, fatty acids and polyols can be converted into a variety of fuel additives through catalytic transformations that include reduction, esterification, etherification, and acetalization reactions. Moreover, we will show that liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenolysis, hydrogenation, decarbonylation/descarboxylation etc.) with the adjustment of the molecular weight via C C coupling reactions (e.g. aldol condensation, hydroxyalkylation, oligomerization, ketonization) of the reactive platform molecules.This work has been supported by the Spanish Government-MINECO through Consolider Ingenio 2010-Multicat and CTQ.-2011-27550, ITQ thanks the "Program Severo Ochoa" for financial support.Climent Olmedo, MJ.; Corma Canós, A.; Iborra Chornet, S. (2014). Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels. Green Chemistry. 16(2):516-547. https://doi.org/10.1039/c3gc41492bS51654716

Rehabilitation of Cardiovascular Disorders and Sleep Apnea

Obstructive sleep apnea (OSA) is present in more than 50% of patients referred to cardiac rehabilitation units. However, it has been under-recognized in patients after stroke and heart failure. Those with concurrent OSA have a worse clinical course. Early treatment of coexisting OSA with continuous positive airway pressure (CPAP) results in improved rehabilitation outcomes and quality of life. Possible mechanisms by which CPAP may improve recovery include decreased blood pressure fluctuations associated with apneas, and improved left ventricular function, cerebral blood flow, and oxygenation. Early screening and treatment of OSA should be integral components of patients entering cardiac rehabilitation units

THE PHYSIOLOGICAL AND PHARMACOLOGICAL CHARACTERISTICS OF THE NEURONS OF THE NUCLEUS RAPHE MAGNUS.

THE PHYSIOLOGICAL AND PHARMACOLOGICAL CHARACTERISTICS OF THE NEURONS OF THE NUCLEUS RAPHE MAGNUS