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1.
Jennifer MP Woo Zhuofeng Lin Mohamad Navab Casey Van Dyck Yvette Trejo-Lopez Krystal MT Woo Hongyun Li Lawrence W Castellani Xuping Wang Noriko Iikuni Ornella J Rullo Hui Wu Antonio La Cava Alan M Fogelman Aldons J Lusis Betty P Tsao 《Arthritis research & therapy》2010,12(3):R93
Introduction
The purpose of this study was to evaluate the effects of L-4F, an apolipoprotein A-1 mimetic peptide, alone or with pravastatin, in apoE-/-Fas-/-C57BL/6 mice that spontaneously develop immunoglobulin G (IgG) autoantibodies, glomerulonephritis, osteopenia, and atherosclerotic lesions on a normal chow diet.Methods
Female mice, starting at eight to nine weeks of age, were treated for 27 weeks with 1) pravastatin, 2) L-4F, 3) L-4F plus pravastatin, or 4) vehicle control, followed by disease phenotype assessment.Results
In preliminary studies, dysfunctional, proinflammatory high-density lipoproteins (piHDL) were decreased six hours after a single L-4F, but not scrambled L-4F, injection in eight- to nine-week old mice. After 35 weeks, L-4F-treated mice, in the absence/presence of pravastatin, had significantly smaller lymph nodes and glomerular tufts (PL, LP < 0.05), lower serum levels of IgG antibodies to double stranded DNA (dsDNA) (PL < 0.05) and oxidized phospholipids (oxPLs) (PL, LP < 0.005), and elevated total and vertebral bone mineral density (PL, LP < 0.01) compared to vehicle controls. Although all treatment groups presented larger aortic root lesions compared to vehicle controls, enlarged atheromas in combination treatment mice had significantly less infiltrated CD68+ macrophages (PLP < 0.01), significantly increased mean α-actin stained area (PLP < 0.05), and significantly lower levels of circulating markers for atherosclerosis progression, CCL19 (PL, LP < 0.0005) and VCAM-1 (PL < 0.0002).Conclusions
L-4F treatment, alone or with pravastatin, significantly reduced IgG anti-dsDNA and IgG anti-oxPLs, proteinuria, glomerulonephritis, and osteopenia in a murine lupus model of accelerated atherosclerosis. Despite enlarged aortic lesions, increased smooth muscle content, decreased macrophage infiltration, and decreased pro-atherogenic chemokines in L-4F plus pravastatin treated mice suggest protective mechanisms not only on lupus-like disease, but also on potential plaque remodeling in a murine model of systemic lupus erythematosus (SLE) and accelerated atherosclerosis. 相似文献2.
Molecular architecture of the ribosome‐bound Hepatitis C Virus internal ribosomal entry site RNA
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Justus Loerke Jochen Ismer Andrea Schmidt Tarek Hilal Thiemo Sprink Kaori Yamamoto Thorsten Mielke Jörg Bürger Tanvir R Shaikh Marylena Dabrowski Peter W Hildebrand Patrick Scheerer Christian MT Spahn 《The EMBO journal》2015,34(24):3042-3058
Internal ribosomal entry sites (IRESs) are structured cis‐acting RNAs that drive an alternative, cap‐independent translation initiation pathway. They are used by many viruses to hijack the translational machinery of the host cell. IRESs facilitate translation initiation by recruiting and actively manipulating the eukaryotic ribosome using only a subset of canonical initiation factor and IRES transacting factors. Here we present cryo‐EM reconstructions of the ribosome 80S‐ and 40S‐bound Hepatitis C Virus (HCV) IRES. The presence of four subpopulations for the 80S•HCV IRES complex reveals dynamic conformational modes of the complex. At a global resolution of 3.9 Å for the most stable complex, a derived atomic model reveals a complex fold of the IRES RNA and molecular details of its interaction with the ribosome. The comparison of obtained structures explains how a modular architecture facilitates mRNA loading and tRNA binding to the P‐site. This information provides the structural foundation for understanding the mechanism of HCV IRES RNA‐driven translation initiation. 相似文献
3.
Increased mercury in forest soils under elevated carbon dioxide 总被引:1,自引:0,他引:1
Fossil fuel combustion is the primary anthropogenic source of both CO2 and Hg to the atmosphere. On a global scale, most Hg that enters ecosystems is derived from atmospheric Hg that deposits
onto the land surface. Increasing concentrations of atmospheric CO2 may affect Hg deposition to terrestrial systems and storage in soils through CO2-mediated changes in plant and soil properties. We show, using free-air CO2 enrichment (FACE) experiments, that soil Hg concentrations are almost 30% greater under elevated atmospheric CO2 in two temperate forests. There were no direct CO2 effects, however, on litterfall, throughfall or stemflow Hg inputs. Soil Hg was positively correlated with percent soil organic
matter (SOM), suggesting that CO2-mediated changes in SOM have influenced soil Hg concentrations. Through its impacts on SOM, elevated atmospheric CO2 may increase the Hg storage capacity of soils and modulate the movement of Hg through the biosphere. Such effects of rising
CO2, ones that transcend the typically studied effects on C and nutrient cycling, are an important next phase for research on
global environmental change. 相似文献
4.
5.
Isoprene emission from plants is one of the principal ways in which plant processes alter atmospheric chemistry. Despite
the importance of this process, few long-term controls over basal emission rates have been identified. Stress-induced changes
in carbon allocation within the entire plant, such as those produced by defoliation, have not been examined as potential mechanisms
that may control isoprene production and emission. Eastern cottonwood (Populus deltoides) saplings were partially defoliated and physiological and growth responses were measured from undamaged and damaged leaves
7 days following damage. Defoliation reduced isoprene emission from undamaged and damaged leaves on partially defoliated plants.
Photosynthetic rates and leaf carbon and nitrogen pools were unaffected by damage. Photosynthetic rate and isoprene emission
were highly correlated in undamaged leaves on undamaged plants and damaged leaves on partially defoliated plants. There was
no correlation between photosynthetic rate and isoprene emission in undamaged leaves on partially defoliated plants. Isoprene
emission was also highly correlated with the number of source leaves on the apical shoot in damage treatments. Increased carbon
export from source leaves in response to defoliation may have depleted the amount of carbon available for isoprene synthesis,
decreasing isoprene emission. These results suggest that while isoprene emission is controlled at the leaf level in undamaged
plants, emission from leaves on damaged plants is controlled by whole-branch allocation patterns.
Received: 12 May 1998 / Accepted: 9 November 1998 相似文献
6.
Ecological and evolutionary aspects of isoprene emission from plants 总被引:14,自引:0,他引:14
Isoprene (2-methyl-1,3,-butadiene), produced by many woody and a few herbaceous plant species, is the dominant volatile organic
compound released from vegetation. It represents a non-trivial carbon loss to the plant (typically 0.5–2%, but much higher
as temperatures exceed 30°C), and plays a major role in tropospheric chemistry of forested regions, contributing to ozone
formation. This review summarizes current knowledge concerning the occurrence of isoprene production within the plant kingdom,
and discusses other aspects of isoprene biology which may be of interest to the ecological community. The ability to produce
significant amounts of isoprene may or may not be shared by members of the same plant family or genus, but emitting species
have been found among bryophytes, ferns, conifers and Ephedra and in approximately one-third of the 122 angiosperm families examined. No phylogenetic pattern is obvious among the angiosperms,
with the trait widely scattered and present (and absent) in both primitive and derived taxa, although confined largely to
woody species. Isoprene is not stored within the leaf, and plays no known ecological role as, for example, an anti-herbivore
or allelopathic agent. The primary short-term controls over isoprene production are light and temperature. Growth in high
light stimulates isoprene production, and growth in cool conditions apparently inhibits isoprene, production of which may
be induced upon transfer to warmer temperatures. The stimulation of isoprene production by high irradiance and warm temperatures
suggests a possible role in ameliorating stresses associated with warm, high-light environments, a role consistent with physiological
evidence indicating a role in thermal protection.
Received: 1 April 1998 / Accepted: 9 November 1998 相似文献
7.
Nitrogen (N) availability is a major factor limiting plant production in many terrestrial ecosystems and is a key regulator of plant response to elevated CO2. Plant N status is a function of both soil N availability and plant N uptake and assimilation capacity. As a rate-limiting step in nitrate assimilation, the reduction of nitrate is an important component of plant physiological response to elevated CO2 and terrestrial carbon sequestration. We examine the effects of elevated CO2 and N availability on the activity of nitrate reductase, the enzyme catalyzing the reduction of nitrate to nitrite, in two temperate forests—a closed canopy sweetgum (Liquidambar styraciflua) plantation in Tennessee (Oak Ridge National Laboratory (ORNL)) and a loblolly pine (Pinus taeda) stand in North Carolina (Duke). Both CO2 and N enrichment had species specific impacts on nitrate reductase activity (NaR). Elevated CO2 and N fertilization decreased foliar NaR in P. taeda, but there were no treatment effects on L. styraciflua NaR at ORNL or Duke. NaR in 1-year P. taeda needles was significantly greater than in 0-year old needles across treatments. P. taeda NaR was negatively correlated with bio-available molybdenum concentrations in soils, suggesting that CO2 and N-mediated changes in soil nutrient status may be altering soil-plant N-dynamics. The variation in response among species may reflect different strategies for acquiring N and suggests that elevated CO2 may alter plant N dynamics through changes in NaR. 相似文献
8.
Jennifer S. Powers Rebecca A. Montgomery E. Carol Adair Francis Q. Brearley Saara J. DeWalt Camila T. Castanho Jerome Chave Erika Deinert Jörg U. Ganzhorn Matthew E. Gilbert José Antonio González-Iturbe Sarayudh Bunyavejchewin H. Ricardo Grau Kyle E. Harms Ankila Hiremath Silvia Iriarte-Vivar † Eric Manzane Alexandre A. de Oliveira Lourens Poorter Jean-Baptiste Ramanamanjato Carl Salk Amanda Varela George D. Weiblen Manuel T. Lerdau 《Journal of Ecology》2009,97(4):801-811
9.
Renato M Salgado Luciane P Capelo Rodolfo R Favaro Jocelyn D Glazier John D Aplin Telma MT Zorn 《Reproductive biology and endocrinology : RB&E》2009,7(1):60