A simple portable somomicrometer, March - July 1966

Portable sonomicrometer for measuring heart dimension

Mikroszómális glukóz-6-foszfát szerepe granulocita apoptózisában = Apoptotic role of microsomal glucose-6-phosphate in granulocytes

Az endoplazmás retikulum glukóz-6-foszfát transzporterére specifikus poliklonális antitestet termeltettünk, amely patkány és humán glukóz-6-foszfát transzportert ismer fel. Western blottal és immunhisztomkémiai módszerekkel közvetlenül bizonyítottuk a transzporter jelenlétét humán májból, patkány májból és veséből származó mikroszómákban; humán granulocitákban, patkány agyban és harántcsíkolt izomszövetben. Kimutattuk, hogy humán granulociták és differenciálódott HL60-as sejtekben megtalálható a hexóz-6-foszfát dehidrogenáz, amelynek a működése függ a glukóz-6-foszfáttól, aktív centruma az endoplazmás retikulum lumenében található és NADPH-t generál. A keletkezett 6-foszfoglukonátot a granulocita mikroszómák nem metabolizálják tovább. mRNS és fehérje szinten kimutattuk 1-es típusú 11-béta-hidroxiszteriod dehidrogenáz jelenlétét granulociták mikroszómáiban. Az enzim granulocitákban is oxidoreduktázként működik, működéséhez intraluminális NADPH(NADP)-t használ fel. Az enzim NADPH-t generáló kortizol dehidrogenáz aktivitásával kivédtük a glukóz-6-foszfát transzport gátlásával létrehozott apoptózist. Eredményeink szerint a májhoz hasonlóan humán granulocitákban is megtalálható a glukóz-6-foszfát - hexóz-6-foszfát és 11-béta-hidroxiszeriod dehidrogenáz 1 funkcionális egysége. | We employed antibodies raised against the liver glucose-6-phoshphate transporter protein. With different immunodetection methods, we have shown that the protein is expressed in endoplasmic reticulum membranes derived from human and rat liver and rat kidney. The expression was also present in the following tissues: human granulocytes, rat brain and skeletal muscle. We have demonstrated the expression of hexose-6-phosphate dehydrogenase in human neutrophils and mature HL60-cells. Its catalytic subunit is intraluminal and activity of the enzyme was shown to be dependent on glucose-6-phosphate and produces NADPH. 6-phosphogluconate formed in this reaction was not metabolized further. The expression and activity of 11-beta-hydroxysteroid dehydrogenase type 1, another NADP(H)-dependent microsomal enzyme were also detected in human neutrophils. The NADPH-generating cortisol dehydrogenase activity of the enzyme prevented neutrophil apoptosis provoked by the inhibition of the glucose-6-phosphate transporter. The results show that granulocytes are equipped with a functional glucose-6-phosphate- hexose-6-phosphate dehydrogenase-11beta-hydroxysteroid dehydrogenase type 1 system

Pro- és antioxidáns hatások szerepe az endoplazmás retikulum eredetű stresszben és apoptózisban = Role of pro- and antioxidant effects in the endoplasmic reticulum stress and apoptosis

Az endoplazmás retikulum számos környezeti és metabolikus hatás szenzora. A jelátvitel gyakran a luminális redoxon keresztül valósul meg. Munkánk során azonosítottuk a hexóz-6-foszfát dehidrogenázt, mint a luminális piridin nukleotidok redox státuszának meghatározóját több sejttípusban. A luminális redox fontos a tápláltság érzékelésében, valamint a sejt apotózis/autofágia szabályozásában. A luminális redoxot befolyásoló antioxidánsok, hepatotoxinok, hormonanalógok és más környezeti hatások alapvetően befolyásolhatják a sejt életképességét. | The endoplasmic reticulum is an important sensor and integrator of environmental and metabolic stimuli. The signaling often involves the changes in luminal redox. We have identified the hexose-6-phosphate dehydrogenase as the main determinant of the redox state of luminal pyridine nucleotides in several cell types. Luminal redox is important in nutrient sensing, and in the regulation of programmed cell death. Antioxidants, hepatotoxins, endocrine disruptors and other environmental agents affecting luminal redox can profoundly alter the viability of the cell

Determination of Rod and Cone Influence to the Early and Late Dynamic of the Pupillary Light Response.

PURPOSE: This study aims to identify which aspects of the pupil light reflex are most influenced by rods and cones independently by analyzing pupil recordings from different mouse models of photoreceptor deficiency. METHODS: One-month-old wild type (WT), rodless (Rho-/-), coneless (Cnga3-/-), or photoreceptor less (Cnga3-/-; Rho-/- or Gnat1-/-) mice were subjected to brief red and blue light stimuli of increasing intensity. To describe the initial dynamic response to light, the maximal pupillary constriction amplitudes and the derivative curve of the first 3 seconds were determined. To estimate the postillumination phase, the constriction amplitude at 9.5 seconds after light termination was related to the maximal constriction amplitude. RESULTS: Rho-/- mice showed decreased constriction amplitude but more prolonged pupilloconstriction to all blue and red light stimuli compared to wild type mice. Cnga3-/- mice had constriction amplitudes similar to WT however following maximal constriction, the early and rapid dilation to low intensity blue light was decreased. To high intensity blue light, the Cnga3-/- mice demonstrated marked prolongation of the pupillary constriction. Cnga3-/-; Rho-/- mice had no pupil response to red light of low and medium intensity. CONCLUSIONS: From specific gene defective mouse models which selectively voided the rod or cone function, we determined that mouse rod photoreceptors are highly contributing to the pupil response to blue light stimuli but also to low and medium red stimuli. We also observed that cone cells mainly drive the partial rapid dilation of the initial response to low blue light stimuli. Thus photoreceptor dysfunction can be derived from chromatic pupillometry in mouse models

Antioxidáns anyagcsere és transzportfolyamatok az endo/szarkoplazmás retikulumban. = Antioxidant metabolism and transport processes in the endo/sarcoplasmic reticulum.

Kimutattuk, hogy a glutation-transzport sebessége jól korrelál a rianodin receptor kalcium csatorna (RyR) egyik izoformája, a RyR1 mennyiségével. Különböző RyR gátlószerek hatékonyan gátolták, RyR agonisták pedig aktiválták a transzportot. Összehasonlítottuk a glutation transzport sajátosságait RyR1 csatornát expresszáló transzfektált, illetve vad típusú HEK293 sejtekből izolált mikroszómákon. Eredményeink azt bizonyítják, hogy a RyR1 közvetlenül vesz részt a glutation transzportjában. Megállapítottuk továbbá, hogy a RyR1 csatorna magas intraluminális glutation szint esetén rezisztenssé válik egyes gátlószereivel szemben. Kimutattuk, hogy az ER lumenben elhelyezkedő hexóz-6-foszfát dehidrogenáz fenntartja a lokális redukált NADPH szintet. Igazoltuk, hogy a glutation reduktáz enzim, amely a sejt egyéb részein a tiol/diszulfid és a piridin nukleotid redox rendszerek közötti kapcsolatot biztosítja, nincs jelen az ER lumenben. Skorbutizált tengerimalacok májában a skorbut kialkulásával párhuzamosan az ER stressz jeleit és fokozott apoptózist észleltük. A kimutatott ER-stressz és apoptózis alátámasztja az aszkorbát szerepét a fehérje-foldingban. Kidolgoztunk egy új módszert, amely lehetővé teszi jelöletlen molekulák mikroszómális transzportjának tanulmányozását. Az új módszer több vegyület egyidejű transzportjának mérésére és a ligand stabilitásának nyomonkövetésére is alkalmas, érzékenysége hasonló a radioaktív detektáláséhoz, viszont gazdaságosabb annál. | We found a correlation between the rate of glutathione transport and the abundance of an isoform of ryanodine receptor calcium channel (RyR1). The transport was inhibited or activated by various RyR antagonists or agonists, respectively. The characteristics of glutathione transport were compared in microsomes prepared from RyR1 expressing transfected and wild type HEK293 cells. Our results prove the direct involvement of RyR1 in glutathione transport. In addition, we found that RyR1 channel becomes resistant to some of its inhibitors at high luminal glutathione levels. We observed that hexose 6-phosphate dehydrogenase maintains the reduced NADPH pool in the ER lumen. We proved that glutathione reductase - that couples the thiol/disulfide and pyridine nucleotide redox systems in other cellular compartments - is not present in the ER. We detected the indicators of ER stress and enhanced apoptosis in the liver of scorbutic guinea pigs. These findings further support the hypothesis that ascorbate participates in the process of protein folding in the ER. We developed a new method that allows the investigation of the microsomal transport of unlabeled compounds. The novel technique is suitable for the detection of simultaneous multiple transport processes and for the monitoring of the ligand stability. Its sensitivity is similar to that of the transport measurements based on radiodetection

NOA1, a Novel ClpXP Substrate, Takes an Unexpected Nuclear Detour Prior to Mitochondrial Import

The mitochondrial matrix GTPase NOA1 is a nuclear encoded protein, essential for mitochondrial protein synthesis, oxidative phosphorylation and ATP production. Here, we demonstrate that newly translated NOA1 protein is imported into the nucleus, where it localizes to the nucleolus and interacts with UBF1 before nuclear export and import into mitochondria. Mutation of the nuclear localization signal (NLS) prevented both nuclear and mitochondrial import while deletion of the N-terminal mitochondrial targeting sequence (MTS) or the C-terminal RNA binding domain of NOA1 impaired mitochondrial import. Absence of the MTS resulted in accumulation of NOA1 in the nucleus and increased caspase-dependent apoptosis. We also found that export of NOA1 from the nucleus requires a leptomycin-B sensitive, Crm1-dependent nuclear export signal (NES). Finally, we show that NOA1 is a new substrate of the mitochondrial matrix protease complex ClpXP. Our results uncovered an unexpected, mandatory detour of NOA1 through the nucleolus before uptake into mitochondria. We propose that nucleo-mitochondrial translocation of proteins is more widespread than previously anticipated providing additional means to control protein bioavailability as well as cellular communication between both compartments.Max Planck Society for the Advancement of Scienc

Evidence From The Fossil Record Of An Antipredatory Exaptation: Conchiolin Layers In Corbulid Bivalves

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137410/1/evo05139.pd

Infection of myofibers contributes to increased pathogenicity during infection with an epidemic strain of chikungunya virus

Chikungunya virus (CHIKV) is an alphavirus transmitted by mosquitoes that is known to cause severe arthritis and myositis in affected patients. The ongoing epidemic began in eastern Africa in 2004 and then spread to islands of the Indian Ocean, India, and Southeast Asia, ultimately afflicting millions. During this outbreak, more severe disease manifestations, including fatalities, have been documented. The reasons for this change in pathogenesis are multifactorial but likely include mutations that have arisen in the viral genome which could alter disease pathogenesis. To test this hypothesis, we used a murine model of CHIKV to compare the disease pathogeneses of two recombinant strains of CHIKV, the first derived from the La Reunion outbreak in 2006 (LR2006 OPY1) and the second isolated from Senegal in 1983 (37997). While the two strains exhibited similar growth in mammalian cells in vitro, we observed more severe clinical disease and pathology in mice infected with the LR2006 OPY1 strain of CHIKV, which included prolonged viremia and elevated viral titers and persistence in the muscle, resulting in devastating myonecrosis. Both CHIKV strains infected connective tissue fibroblasts of the muscle, but only the LR2006 OPY1 strain replicated within myofibers in vivo, despite similar growth of the two strains in these cell types in vitro. However, when the 37997 strain was administered directly into muscle, myofiber infection was comparable to that in LR2006 OPY1-infected mice. These results indicate that differences in the ability of the strain of CHIKV to establish infection in myofibers may contribute to the increased disease severity. IMPORTANCE CHIKV is an emerging pathogen that causes significant morbidity. Little is known about the pathogenesis of the disease, and this study suggests that the ability of a recent epidemic strain to infect myofibers results in increased disease severity. Better understanding of how CHIKV causes disease contributes to the ultimate goal of creating therapeutics to alleviate the impact of this debilitating virus

Research & Debate—Pier Competitor: Testimony on China’s Global Ports

The United States–China Economic and Security Review Commission convened a daylong hearing on the global power-projection capabilities of the People’s Liberation Army (PLA) on 20 February 2020. What follows is a version of the testimony with which the author responded to the commission’s questions on Chinese bases and access points, drawing on an original data set of the ninety-five overseas port terminals that Chinese firms—primarily three entities, two of which are central state–owned enterprises—own, operate, or both