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1.
AtCOX17 genes encode Arabidopsis thaliana homologs of the yeast metallochaperone Cox17p, involved in the delivery of copper for cytochrome c oxidase (COX) assembly. Two different AtCOX17 genes, located in chromosomes 1 and 3, are present in the Arabidopsis genome. Sequences available in data banks indicate that the presence of two genes is a common feature in monocots, but not in dicots, suggesting that Arabidopsis genes may be the result of a recent duplication. Sequences upstream from the translation start sites of AtCOX17 genes, which include an intron located in the 5' leader region, were introduced into plants in front of the gus gene. For both genes, expression was localized preferentially in young roots and anthers, but almost 10-fold higher β-glucuronidase activity levels were observed in plants transformed with AtCOX17-1 upstream regions. Both promoters were induced to different extents by wounding, treatment of leaves with the bacterial pathogen Pseudomonas syringae and incubation with agents that produce oxidative stress and metals. AtCOX17-2 showed similar responses to these factors, while AtCOX17-1 was more strongly induced by relatively low (10–100 μ M ) copper. The results indicate that both AtCOX17 genes have similar, though not identical, expression characteristics and suggest the existence in their promoters of elements involved in tissue-specific expression and in responses to factors that may produce mitochondrial or cell damage. It can be speculated that Arabidopsis COX17 accumulates under stress conditions to actively replace damaged or inactive cytochrome c oxidase to sustain cyanide-sensitive respiration in plant cells. 相似文献
2.
Cristiana Iosef Claudio M. Martin Marat Slessarev Carolina Gillio-Meina Gediminas Cepinskas Victor K. M. Han Douglas D. Fraser 《Journal of cellular and molecular medicine》2023,27(1):141-157
Coronavirus disease 2019 (COVID-19) is a systemic inflammatory condition with high mortality that may benefit from personalized medicine and high-precision approaches. COVID-19 patient plasma was analysed with targeted proteomics of 1161 proteins. Patients were monitored from Days 1 to 10 of their intensive care unit (ICU) stay. Age- and gender-matched COVID-19-negative sepsis ICU patients and healthy subjects were examined as controls. Proteomic data were resolved using both cell-specific annotation and deep-analysis for functional enrichment. COVID-19 caused extensive remodelling of the plasma microenvironment associated with a relative immunosuppressive milieu between ICU Days 3–7, and characterized by extensive organ damage. COVID-19 resulted in (1) reduced antigen presentation and B/T-cell function, (2) increased repurposed neutrophils and M1-type macrophages, (3) relatively immature or disrupted endothelia and fibroblasts with a defined secretome, and (4) reactive myeloid lines. Extracellular matrix changes identified in COVID-19 plasma could represent impaired immune cell homing and programmed cell death. The major functional modules disrupted in COVID-19 were exaggerated in patients with fatal outcome. Taken together, these findings provide systems-level insight into the mechanisms of COVID-19 inflammation and identify potential prognostic biomarkers. Therapeutic strategies could be tailored to the immune response of severely ill patients. 相似文献
3.
Bradley E. Hiller Yongjun Yin Yi-Chieh Perng Ítalo de Araujo Castro Lindsey E. Fox Marissa C. Locke Kristen J. Monte Carolina B. Lpez David M. Ornitz Deborah J. Lenschow 《PLoS pathogens》2022,18(6)
Influenza A virus (IAV) preferentially infects conducting airway and alveolar epithelial cells in the lung. The outcome of these infections is impacted by the host response, including the production of various cytokines, chemokines, and growth factors. Fibroblast growth factor-9 (FGF9) is required for lung development, can display antiviral activity in vitro, and is upregulated in asymptomatic patients during early IAV infection. We therefore hypothesized that FGF9 would protect the lungs from respiratory virus infection and evaluated IAV pathogenesis in mice that overexpress FGF9 in club cells in the conducting airway epithelium (FGF9-OE mice). However, we found that FGF9-OE mice were highly susceptible to IAV and Sendai virus infection compared to control mice. FGF9-OE mice displayed elevated and persistent viral loads, increased expression of cytokines and chemokines, and increased numbers of infiltrating immune cells as early as 1 day post-infection (dpi). Gene expression analysis showed an elevated type I interferon (IFN) signature in the conducting airway epithelium and analysis of IAV tropism uncovered a dramatic shift in infection from the conducting airway epithelium to the alveolar epithelium in FGF9-OE lungs. These results demonstrate that FGF9 signaling primes the conducting airway epithelium to rapidly induce a localized IFN and proinflammatory cytokine response during viral infection. Although this response protects the airway epithelial cells from IAV infection, it allows for early and enhanced infection of the alveolar epithelium, ultimately leading to increased morbidity and mortality. Our study illuminates a novel role for FGF9 in regulating respiratory virus infection and pathogenesis. 相似文献
4.
The evolutionary forces that determine genome size in bacteria and archaea have been the subject of intense debate over the last few decades. Although the preferential loss of genes observed in prokaryotes is explained through the deletional bias, factors promoting and preventing the fixation of such gene losses often remain unclear. Importantly, statistical analyses on this topic typically do not consider the potential bias introduced by the shared ancestry of many lineages, which is critical when using species as data points because of the potential dependence on residuals. In this study, we investigated the genome size distributions across a broad diversity of bacteria and archaea to evaluate if this trait is phylogenetically conserved at broad phylogenetic scales. After model fit, Pagel’s lambda indicated a strong phylogenetic signal in genome size data, suggesting that the diversification of this trait is influenced by shared evolutionary histories. We used a phylogenetic generalized least-squares analysis (PGLS) to test whether phylogeny influences the predictability of genome size from dN/dS ratios and 16S copy number, two variables that have been previously linked to genome size. These results confirm that failure to account for evolutionary history can lead to biased interpretations of genome size predictors. Overall, our results indicate that although bacteria and archaea can rapidly gain and lose genetic material through gene transfers and deletions, respectively, phylogenetic signal for genome size distributions can still be recovered at broad phylogenetic scales that should be taken into account when inferring the drivers of genome size evolution. 相似文献
5.
Isabel C.M. Fensterseifer Mário R. Felício Eliane S.F. Alves Marlon H. Cardoso Marcelo D.T. Torres Carolina O. Matos Osmar N. Silva Timothy K. Lu Maurício V. Freire Natan C. Neves Sónia Gonçalves Luciano M. Lião Nuno C. Santos William F. Porto Cesar de la Fuente-Nunez Octavio L. Franco 《生物化学与生物物理学报:生物膜》2019,1861(7):1375-1387
Infections caused by Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa foremost among them, constitute a major worldwide health problem. Bioinformatics methodologies are being used to rationally design new antimicrobial peptides, a potential alternative for treating these infections. One of the algorithms used to develop antimicrobial peptides is the Joker, which was used to design the peptide PaDBS1R6. This study evaluates the antibacterial activities of PaDBS1R6 in vitro and in vivo, characterizes the peptide interaction to target membranes, and investigates the PaDBS1R6 structure in contact with mimetic vesicles. Moreover, we demonstrate that PaDBS1R6 exhibits selective antimicrobial activity against Gram-negative bacteria. In the presence of negatively charged and zwitterionic lipids the structural arrangement of PaDBS1R6 transits from random coil to α-helix, as characterized by circular dichroism. The tertiary structure of PaDBS1R6 was determined by NMR in zwitterionic dodecylphosphocholine (DPC) micelles. In conclusion, PaDBS1R6 is a candidate for the treatment of nosocomial infections caused by Gram-negative bacteria, as template for producing other antimicrobial agents. 相似文献
6.
De Felice B Argenziano C Guida M Trifuoggi M Russo F Condorelli V Inglese M 《Molecular biotechnology》2009,41(2):123-132
Little is known about pharmaceutical and personal care products pollutants (PPCPs), but there is a growing interest in how they might impact the environment and microbial communities. The widespread use of Viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. Until now information regarding the impact of Viagra on microbial community in water environment has not been reported. In this research, for the first time, the genetic profile of the microbial community, developing in a Viagra polluted water environment, was evaluated by means of the 16S and 18S rRNA genes, for bacteria and fungi, respectively, amplified by polymerase chain reaction (PCR) and separated using the denaturing gradient gel electrophoresis (DGGE) technique. The DGGE results revealed a complex microbial community structure with most of the population persisting throughout the experimental period. DNA sequences from bands observed in the different denaturing gradient gel electrophoresis profiles exhibited the highest degree of identity to uncultured bacteria and fungi found previously mainly in polluted environmental and treating bioreactors. Biotransformation ability of sildenafil citrate by the microbial pool was studied and the capability of these microorganisms to detoxify a polluted water ecosystem was assessed. The bacterial and fungal population was able to degrade sildenafil citrate entirely. Additionally, assays conducted on Daphnia magna, algal growth inhibition assay and cell viability determination on HepG2 human cells showed that biotransformation products obtained from the bacterial growth was not toxic. The higher removal efficiency for sildenafil citrate and the lack of toxicity by the biotransformation products obtained showed that the microbial community identified here represented a composite population that might have biotechnological relevance to retrieve sildenafil citrate contaminated sites. 相似文献
7.
Rojas P Serrano-García N Medina-Campos ON Pedraza-Chaverri J Ogren SO Rojas C 《Neurochemistry international》2011,59(5):628-636
EGb761 is a well-defined mixture of active compounds extracted from Ginkgo biloba leaves. This extract is used clinically due to its neuroprotective effects, exerted probably via its potent antioxidant or free radical scavenger action. Previous studies suggest that oxidative stress, via free radical production, may play an important role in depression and animal models for depression-like behavior. Preclinical studies have suggested that antioxidants may have antidepressants properties. The aim of this study was to investigate the antidepressant-like of EGb761 due to its antioxidant role against oxidative stress induced in the forced swimming test, the most widely used preclinical model for assessing antidepressant-like behavior. Male BALB/c mice were pretreated with EGb761 (10 mg/kg, ip) daily for 17 days followed by the forced swimming test and spontaneous locomotor activity. Animals were sacrificed to evaluate lipid peroxidation, different antioxidant enzyme activities, serotonin and dopamine content in midbrain, hippocampus and prefrontal cortex. EGb761 significantly decreased the immobility time (39%) in the forced swimming test. This antidepressant-like effect of EGb761 was associated with a reduction in lipid peroxidation and superoxide radical production (indicated by a downregulation of Mn-superoxide dismutase activity), both of which are indicators of oxidative stress. The protective effect of EGb761 is not related to excitatory or inhibitory effects in locomotor activity, and was also associated with the modulation of serotonergic and dopaminergic neurotransmission. It is suggested that EGb761 produces an antidepressant-like effect, and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects. 相似文献
8.
9.
A new species of Thraulodes from Mexico is described from male and female imagines. The male imagines of this species have very characteristic genitalia that allow its easy separation from the other known species of the genus. 相似文献
10.
Carolina C. Lisboa Richard T. Conant Michelle L. Haddix Carlos Eduardo P. Cerri Carlos C. Cerri 《Ecosystems》2009,12(7):1212-1221
The effect of conversion from forest-to-pasture upon soil carbon stocks has been intensively discussed, but few studies focus
on how this land-use change affects carbon (C) distribution across soil fractions in the Amazon basin. We investigated this
in the 20 cm depth along a chronosequence of sites from native forest to three successively older pastures. We performed a
physicochemical fractionation of bulk soil samples to better understand the mechanisms by which soil C is stabilized and evaluate
the contribution of each C fraction to total soil C. Additionally, we used a two-pool model to estimate the mean residence
time (MRT) for the slow and active pool C in each fraction. Soil C increased with conversion from forest-to-pasture in the
particulate organic matter (>250 μm), microaggregate (53–250 μm), and d-clay (<2 μm) fractions. The microaggregate comprised
the highest soil C content after the conversion from forest-to-pasture. The C content of the d-silt fraction decreased with
time since conversion to pasture. Forest-derived C remained in all fractions with the highest concentration in the finest
fractions, with the largest proportion of forest-derived soil C associated with clay minerals. Results from this work indicate
that microaggregate formation is sensitive to changes in management and might serve as an indicator for management-induced
soil carbon changes, and the soil C changes in the fractions are dependent on soil texture. 相似文献