Methylation Controlled J Protein Is A Master Regulator Of Mitochondrial Metabolism

Methylation controlled J protein (MCJ) is a negative regulator of mitochondrial metabolism that has a substantial impact on overall cell metabolism and function. MCJ is highly expressed by naïve CD8+ T cells, however its role in their immune effector functions was unknown. In this dissertation, it will be demonstrated that MCJ restricts the mitochondrial metabolism of CD8+ T cells, in part by reducing respiratory supercomplex formation. MCJ deficiency enhances the immune effector functions and memory responses of CD8+ T cells in a mitochondrial ATP dependent manner. As a consequence, protection to influenza virus infection is substantially improved. Reduced expression of MCJ therefore promotes viral immunity, however the loss of MCJ is not always beneficial. In cancer, decreased MCJ expression is correlated with ATP binding cassette (ABC) transporter mediated chemotherapy resistance and poor patient responses. This dissertation will also address the role of MCJ in chemoresistance. Increased mitochondrial ATP production due to MCJ deficiency is sufficient to fuel ABC transporter activity, thereby directly promoting chemoresistance. This can be reversed by restoration of MCJ function in chemoresistant cells. Overall, the results presented in this dissertation identify MCJ as a potential therapeutic target, as modulating MCJ expression can significantly affect the severity of viral infections and the responses to chemotherapy

Optical activity in the Drude helix model

An old classical one-particle helix model for optical activity, first proposed by Drude, is reconsidered here. The quantum Drude model is very instructive because the optical activity can be calculated analytically without further approximations apart from the Rosenfeld long wavelength approximation. While it was generally believed that this model, when treated correctly, is optically inactive, we show that it leads to optical activity when the motion of the particle is quantum mechanically treated. We also find that optical activity arises even in the classical regime at non-zero energy, while for zero energy the model is inactive, in accordance with previous results. The model is compared with other one-electron models and it is shown that its predicted optical activity is qualitatively different from those of other one-electron systems. The vanishing of optical activity in the classical zero-energy limit for the Drude model is due to the localization of the particle at the equilibrium position, whereas in the analogous model of a particle moving freely on a helix without a definite equilibrium position, optical activity does not vanish but the spectrum is rescaled. The model under study leads to interesting predictions about the optical properties of e. g. helicene derivatives

Mitochondrial ATP fuels ABC transporter-mediated drug efflux in cancer chemoresistance

Chemotherapy remains the standard of care for most cancers worldwide, however development of chemoresistance due to the presence of the drug-effluxing ATP binding cassette (ABC) transporters remains a significant problem. The development of safe and effective means to overcome chemoresistance is critical for achieving durable remissions in many cancer patients. We have investigated the energetic demands of ABC transporters in the context of the metabolic adaptations of chemoresistant cancer cells. Here we show that ABC transporters use mitochondrial-derived ATP as a source of energy to efflux drugs out of cancer cells. We further demonstrate that the loss of methylation-controlled J protein (MCJ) (also named DnaJC15), an endogenous negative regulator of mitochondrial respiration, in chemoresistant cancer cells boosts their ability to produce ATP from mitochondria and fuel ABC transporters. We have developed MCJ mimetics that can attenuate mitochondrial respiration and safely overcome chemoresistance in vitro and in vivo. Administration of MCJ mimetics in combination with standard chemotherapeutic drugs could therefore become an alternative strategy for treatment of multiple cancers

miR-873-5p targets mitochondrialGNMT-Complex II interface contributing tonon-alcoholic fatty liver disease

Objective:Non-alcoholic fatty liver disease (NAFLD) is a complex pathology in which several dysfunctions, including alterations in metabolicpathways, mitochondrial functionality and unbalanced lipid import/export, lead to lipid accumulation and progression to inflammation andfibrosis.The enzyme glycine N-methyltransferase (GNMT), the most important enzyme implicated in S-adenosylmethionine catabolism in the liver, isdownregulated during NAFLD progression. We have studied the mechanism involved in GNMT downregulation by its repressor microRNA miR-873-5p and the metabolic pathways affected in NAFLD as well as the benefit of recovery GNMT expression.Methods:miR-873-5p and GNMT expression were evaluated in liver biopsies of NAFLD/NASH patients. Differentin vitroandin vivoNAFLD murinemodels were used to assess miR-873-5p/GNMT involvement in fatty liver progression through targeting of the miR-873-5p as NAFLD therapy.Results:We describe a new function of GNMT as an essential regulator of Complex II activity in the electron transport chain in the mitochondria.In NAFLD, GNMT expression is controlled by miR-873-5p in the hepatocytes, leading to disruptions in mitochondrial functionality in a preclinicalmurine non-alcoholic steatohepatitis (NASH) model. Upregulation of miR-873-5p is shown in the liver of NAFLD/NASH patients, correlating withhepatic GNMT depletion. Importantly, NASH therapies based on anti-miR-873-5p resolve lipid accumulation, inflammation andfibrosis byenhancing fatty acidb-oxidation in the mitochondria. Therefore, miR-873-5p inhibitor emerges as a potential tool for NASH treatment.Conclusion:GNMT participates in the regulation of metabolic pathways and mitochondrial functionality through the regulation of Complex II activityin the electron transport chain. In NAFLD, GNMT is repressed by miR-873-5p and its targeting arises as a valuable therapeutic option for treatment

miR-873-5p targets mitochondrial GNMT-Complex II interface contributing to non-alcoholic fatty liver disease

Objective: Non-alcoholic fatly liver disease (NAFLD) is a complex pathology in which several dysfunctions, including alterations in metabolic pathways, mitochondrial functionality and unbalanced lipid import/export, lead to lipid accumulation and progression to inflammation and fibrosis. The enzyme glycine N-methyltransferase (GNMT), the most important enzyme implicated in S-adenosylmethionine catabolism in the liver, is downregulated during NAFLD progression. We have studied the mechanism involved in GNMT downregulation by its repressor microRNA miR-873-5p and the metabolic pathways affected in NAFLD as well as the benefit of recovery GNMT expression. Methods: miR-873-5p and GNMT expression were evaluated in liver biopsies of NAFLD/NASH patients. Different in vitro and in vivo NAFLD murine models were used to assess miR-873-5p/GNMT involvement in fatty liver progression through targeting of the miR-873-5p as NAFLD therapy. Results: We describe a new function of GNMT as an essential regulator of Complex II activity in the electron transport chain in the mitochondria. In NAFLD, GNMT expression is controlled by miR-873-5p in the hepatocytes, leading to disruptions in mitochondria! functionality in a preclinical murine non-alcoholic steatohepatitis (NASH) model. Upregulation of miR-873-5p is shown in the liver of NAFLD/NASH patients, correlating with hepatic GNMT depletion. Importantly, NASH therapies based on anti-miR-873-5p resolve lipid accumulation, inflammation and fibrosis by enhancing fatty acid beta-oxidation in the mitochondria. Therefore, miR-873-5p inhibitor emerges as a potential tool for NASH treatment. Conclusion: GNMT participates in the regulation of metabolic pathways and mitochondria! functionality through the regulation of Complex II activity in the electron transport chain. In NAFLD, GNMT is repressed by miR-873-5p and its targeting arises as a valuable therapeutic option for treatment. (C) 2019 The Authors. Published by Elsevier GmbH.This work was supported by grants from NIH (US Department of Health and Human services)-R01AT001576 (to S.C.L., J.M.M., and M.L.M.-C.), Ministerio de Economia, Industria y Competitividad: SAF2017-87301-R (to M.L.M.-C.), SAF2015-64352-R (to P.A.), Gobierno Vasco-Departamento de Salud 2013111114 (to M.L.M.-C.), Gobierno Vasco-Departamento de Educacion IT-336-10 (to PA), BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/BD (M.L.M.-C.), ELKARTEK 2016, Departamento de Industria del Gobierno Vasco (to M.L.M.-C), Asociacion Espanola contra el Cancer (to T.C.D., P.F.-T. and M.L.M.-C.), Mitotherapeutix (to M.L.M.-C.), Daniel Alagille award from EASL (to T.C.D), Fundacion Cientifica de la Asociacion Espanola Contra el Cancer (AECC Scientific Foundation) Rare Tumor Calls 2017 (to M.L.M.-C.), La Caixa Foundation Program (to M.L.M.-C.), Ayudas Fundacion BBVA a Equipos de Investigacion Cientifica 2019 (to M.L.M.-C.). Ciberehd_ISCIII_MINECO is funded by the Instituto de Salud Carlos III. We thank this work produced with the support of a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (to M.V.R.). This work was supported by Fonds National de la Recherche Luxembourg and the Deutsche Forschungsgemeinschaft (C12/BM/3975937, FL/997/7-1, Inter "HepmiRSTAT", to I.B. and F.L.). We thank MINECO for the Severo Ochoa Excellence Accreditation (SEV2016-0644)

Catching Element Formation In The Act

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions.Comment: 14 pages including 3 figure

Catching Element Formation In The Act

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions

Catching element formation in the act

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions

SASS Cast, Episode 4- Men\u27s Basketball

Trent Champagne and Kevin Caldwell are both basketball players at Lindenwood University. They have joined us to discuss how they juggle school and athletics. Enjoy this discussion as we discuss things like COVID-19, the conference, and how they stay so connected during these crazy times!https://digitalcommons.lindenwood.edu/sass_cast/1003/thumbnail.jp