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121.
Gröbner S Autenrieth SE Soldanova I Gunst DS Schaller M Bohn E Müller S Leverkus M Wesselborg S Autenrieth IB Borgmann S 《Apoptosis : an international journal on programmed cell death》2006,11(11):1959-1968
Yersinia outer protein P (YopP) is a virulence factor of Yersinia enterocolitica that is injected into the cytosol of host cells where it targets MAP kinase kinases (MKKs) and inhibitor of κB kinase (IKK)-β
resulting in inhibition of cytokine production as well as induction of apoptosis in murine macrophages and dendritic cells
(DC). Here we show that DC death was only partially prevented by the broad spectrum caspase inhibitor zVAD-fmk, indicating
simultaneous caspase-dependent and caspase-independent mechanisms of cell death induction by YopP. Microscopic analyses and
measurement of cell size demonstrated necrosis-like morphology of caspase-independent cell death. Application of zVAD-fmk
prevented cleavage of procaspases and Bid, decrease of the inner transmembrane mitochondrial potential ΔΨm and mitochondrial release of cytochrome c. From these data we conclude that YopP-induced activation of the mitochondrial
death pathway is mediated upstream via caspases. In conclusion, our results suggest that YopP simultaneously induces caspase-dependent
apoptotic and caspase-independent necrosis-like death in DC. However, it has to be resolved if necrosis-like DC death occurs
independently from apoptotic events or as an apoptotic epiphenomenon. 相似文献
122.
123.
We investigated the effect of a herbicide resistance-conferring mutation on fitness in Amaranthus powellii. Morphological and histological observations were made. Growth and leaf appearance were recorded for six resistant and six susceptible populations. The competitiveness of a susceptible population was compared with that of a resistant population using a replacement series experiment. Leaves of the resistant plants were distorted and much smaller than those of susceptible plants. Additionally, they exhibited an abnormal morphological and structural pattern consisting of a mosaic of heterogeneous areas in the same leaf blade. The roots and stems had similar structures in susceptible and resistant plants, but the former were up to four times more developed. The resistant plants were slower to develop and produced 67% less biomass and 58% lower leaf area than susceptible plants. Under competitive conditions, one susceptible population outperformed one resistant population by 7-15 times. The Trp(574)Leu acetohydroxyacid synthase (AHAS) mutation appears to have considerable pleiotropic effects on the early growth and development of the plants which, in competitive conditions, greatly reduce fitness. 相似文献
124.
Duka A Duka I Gao G Shenouda S Gavras I Gavras H 《American journal of physiology. Endocrinology and metabolism》2006,291(2):E268-E274
With inhibition or absence of the bradykinin B2 receptor (B2R), B1R is upregulated and assumes some of the hemodynamic properties of B2R, indicating that both participate in the maintenance of normal vasoregulation or to development of hypertension. Herein we further evaluate the role of bradykinin in normal blood pressure (BP) regulation and its relationship with other vasoactive factors by selectively blocking its receptors. Six groups of Wistar rats were treated for 3 wk: one control group with vehicle alone, one with concurrent administration of B1R antagonist R-954 (70 microg x kg(-1) x day(-1)) and B2R antagonist HOE-140 (500 microg x kg(-1) x day(-1)), one with R-954 alone, one with HOE 140 alone, one with concurrent administration of both R-954 and HOE-140 plus the angiotensin antagonist losartan (5 mg x kg(-1) x day(-1)), and one with only losartan. BP was measured continuously by radiotelemetry. Only combined administration of B1R and B2R antagonists produced a significant BP increase from a baseline of 107-119 mmHg at end point, which could be partly prevented by losartan and was not associated with change in catecholamines, suggesting no involvement of the sympathoadrenal system. The impact of blockade of bradykinin on other vasoregulating systems was assessed by evaluating gene expression of different vasoactive factors. There was upregulation of the eNOS, AT1 receptor, PGE2 receptor, and tissue kallikrein genes in cardiac and renal tissues, more pronounced when both bradykinin receptors were blocked; significant downregulation of AT2 receptor gene in renal tissues only; and no consistent changes in B1R and B2R genes in either tissue. The results indicate that both B1R and B2R contribute to the maintenance of normal BP, but one can compensate for inhibition of the other, and the chronic inhibition of both leads to significant upregulation in the genes of related vasoactive systems. 相似文献
125.
Heuertz M De Paoli E Källman T Larsson H Jurman I Morgante M Lascoux M Gyllenstrand N 《Genetics》2006,174(4):2095-2105
DNA polymorphism at 22 loci was studied in an average of 47 Norway spruce [Picea abies (L.) Karst.] haplotypes sampled in seven populations representative of the natural range. The overall nucleotide variation was limited, being lower than that observed in most plant species so far studied. Linkage disequilibrium was also restricted and did not extend beyond a few hundred base pairs. All populations, with the exception of the Romanian population, could be divided into two main domains, a Baltico-Nordic and an Alpine one. Mean Tajima's D and Fay and Wu's H across loci were both negative, indicating the presence of an excess of both rare and high-frequency-derived variants compared to the expected frequency spectrum in a standard neutral model. Multilocus neutrality tests based on D and H led to the rejection of the standard neutral model and exponential growth in the whole population as well as in the two main domains. On the other hand, in all three cases the data are compatible with a severe bottleneck occurring some hundreds of thousands of years ago. Hence, demographic departures from equilibrium expectations and population structure will have to be accounted for when detecting selection at candidate genes and in association mapping studies, respectively. 相似文献
126.
Ma?gorzata Sowiak Karolina Bródka Alina Buczyńska Marcin Cyprowski Anna Kozajda Wojciech Sobala Irena Szadkowska-Stańczyk 《Aerobiologia》2012,28(2):121-133
The project was aimed at evaluating the potential occupational exposure of swine farm workers to dust and microorganisms present
in piggery bioaerosols (especially in its respirable fraction) under various breeding conditions. Sampling was carried out
in 14 buildings located at 13 pig breeding and production farms in Poland. Concentrations of inhalable and respirable dusts
in the air of the piggeries were low (means, respectively, 1.76 and 0.23 mg/m3). The concentration of microorganisms was generally high (mean = 3.53 × 105 cfu/m3). More than 96% of determined microorganisms were bacteria (mean = 3.42 × 105 cfu/m3). The fungal concentration was distinctly lower (mean = 2.71 × 103 cfu/m3). The concentration of bacteria in the respirable fraction of bioaerosol (mean = 1.51 × 105 cfu/m3) made up for 48.2% of their total concentration, while the level of fungi in that fraction (mean = 1.50 × 103 cfu/m3) formed 68.8% of the total fungal concentration. The concentration of inhalable dust was significantly modified by the type
of breeding system. The factors that significantly affected the total concentrations of microbes and bacteria, as well as
their levels in the bioaerosols’ respirable fraction were as follows: herd size, breeding system, feeding method and the type
of ventilation system. In the case of fungi, these were the livestock breeding system and the feeding method. Moreover, there
was a high positive correlation of inhalable dust concentrations with the fungal concentration, CO2 and relative humidity. A negative correlation was found between concentrations of each microbe group and the airflow velocity.
Swine farm workers are exposed to relatively low dust concentrations and high concentrations of microorganisms, bacteria in
particular. Fungi, to a much larger extent than bacteria, are correlated with the respirable particles of a piggery bioaerosol,
which may harm the respiratory system of exposed workers. 相似文献
127.
Asleh R Nakhoul FM Miller-Lotan R Awad H Farbstein D Levy NS Nakhoul N Iancu TC Manov I Laue M Traber MG Lebold KM Levy AP 《Free radical biology & medicine》2012,53(4):779-786
The haptoglobin (Hp) genotype is a major determinant of progression of nephropathy in individuals with diabetes mellitus (DM). The major function of the Hp protein is to bind and modulate the fate of extracorpuscular hemoglobin and its iron cargo. We have previously demonstrated an interaction between the Hp genotype and the DM on the accumulation of iron in renal proximal tubule cells. The primary objective of this study was to determine the intracellular localization of this iron in the proximal tubule cell and to assess its potential toxicity. Transmission electron microscopy demonstrated a marked accumulation of electron-dense deposits in the lysosomes of proximal tubules cells in Hp 2-2 DM mice. Energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy were used to perform elemental analysis of these deposits and demonstrated that these deposits were iron rich. These deposits were associated with lysosomal membrane lipid peroxidation and loss of lysosomal membrane integrity. Vitamin E administration to Hp 2-2 DM mice resulted in a significant decrease in both intralysosomal iron-induced oxidation and lysosomal destabilization. Iron-induced renal tubular injury may play a major role in the development of diabetic nephropathy and may be a target for slowing the progression of renal disease. 相似文献
128.
Kuhr FK Smith KA Song MY Levitan I Yuan JX 《American journal of physiology. Heart and circulatory physiology》2012,302(8):H1546-H1562
Pulmonary arterial hypertension (PAH) is a severe and progressive disease that usually culminates in right heart failure and death if left untreated. Although there have been substantial improvements in our understanding and significant advances in the management of this disease, there is a grim prognosis for patients in the advanced stages of PAH. A major cause of PAH is increased pulmonary vascular resistance, which results from sustained vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness. In addition to other signal transduction pathways, Ca(2+) signaling in pulmonary artery smooth muscle cells (PASMCs) plays a central role in the development and progression of PAH because of its involvement in both vasoconstriction, through its pivotal effect of PASMC contraction, and vascular remodeling, through its stimulatory effect on PASMC proliferation. Altered expression, function, and regulation of ion channels and transporters in PASMCs contribute to an increased cytosolic Ca(2+) concentration and enhanced Ca(2+) signaling in patients with PAH. This review will focus on the potential pathogenic role of Ca(2+) mobilization, regulation, and signaling in the development and progression of PAH. 相似文献
129.
Nongbri PL Johnson JM Sherameti I Glawischnig E Halkier BA Oelmüller R 《Molecular plant-microbe interactions : MPMI》2012,25(9):1186-1197
The growth-promoting and root-colonizing endophyte Piriformospora indica induces camalexin and the expression of CYP79B2, CYP79B3, CYP71A13, PAD3, and WRKY33 required for the synthesis of indole-3-acetaldoxime (IAOx)-derived compounds in the roots of Arabidopsis seedlings. Upregulation of the mRNA levels by P. indica requires cytoplasmic calcium elevation and mitogen-activated protein kinase 3 but not root-hair-deficient 2, radical oxygen production, or the 3-phosphoinositide-dependent kinase 1/oxidative signal-inducible 1 pathway. Because P. indica-mediated growth promotion is impaired in cyp79B2 cyp79B3 seedlings, while pad3 seedlings-which do not accumulate camalexin-still respond to the fungus, IAOx-derived compounds other than camalexin (e.g., indole glucosinolates) are required during early phases of the beneficial interaction. The roots of cyp79B2 cyp79B3 seedlings are more colonized than wild-type roots, and upregulation of the defense genes pathogenesis-related (PR)-1, PR-3, PDF1.2, phenylalanine ammonia lyase, and germin indicates that the mutant responds to the lack of IAOx-derived compounds by activating other defense processes. After 6 weeks on soil, defense genes are no longer upregulated in wild-type, cyp79B2 cyp79B3, and pad3 roots. This results in uncontrolled fungal growth in the mutant roots and reduced performance of the mutants. We propose that a long-term harmony between the two symbionts requires restriction of root colonization by IAOx-derived compounds. 相似文献
130.
Irena Kolouchová Olga Schreiberová Jan Masák Karel Sigler Tomá? ?ezanka 《Folia microbiologica》2012,57(6):473-483
We used reversed phase liquid chromatography?Celectrospray ionization tandem mass spectrometry for direct analysis of mycolic acids (MAs) from four different cultivations of Rhodococcus erythropolis. This technique enabled us to identify and quantify the specific molecular species of MAs directly from lipid extracts of the bacterium, including the determination of their basic characteristics such as retention time and mass spectra. We identified a total of 60 molecular species of MAs by means of LC/MS. In collision-induced dissociation tandem mass spectrometry, the [M-H]? ions eliminated two residues, i.e., meroaldehyde and carboxylate anions containing ??-alkyl chains. The structural information from these fragment ions affords structural assignment of the mycolic acids, including the lengths and number of double bond(s). Two strains, i.e., R. erythropolis CCM 2595 and genetically modified strain CCM 2595 pSRK 21 phe were cultivated on two different substrates (phenol and phenol with addition of humic acids as a sole carbon source). The addition of humic acids showed that there is a marked increase of unsaturated mycolic acids, mostly in the range of 20?C100?%. This effect is more pronounced in the R. erythropolis CCM 2595 strain. 相似文献