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101.
Enolases from Gram-positive bacterial pathogens and commensal lactobacilli share functional similarity in virulence-associated traits 总被引:1,自引:0,他引:1
Antikainen J Kuparinen V Lähteenmäki K Korhonen TK 《FEMS immunology and medical microbiology》2007,51(3):526-534
Enolase occurs as a cytoplasmic and a surface-associated protein in bacteria. Enolases of the bacterial pathogens Streptococcus pyogenes, Streptococcus pneumoniae and Staphylococcus aureus, as well as of the commensal lactic acid bacteria, Lactobacillus crispatus and Lactobacillus johnsonii, were purified as His(6)-fusion proteins from recombinant Escherichia coli. The fusion proteins were compared for putative virulence-associated functions, i.e., binding of human plasminogen, enhancement of plasminogen activation by human plasminogen activators, as well as binding to immobilized laminin, fibronectin and collagens. The individual enolases showed varying efficiencies in these functions. In particular, highly and equally effective interactions with plasminogen and laminin were seen with lactobacillar and staphylococcal enolases. 相似文献
102.
Alila-Johansson A Eriksson L Soveri T Laakso ML 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2004,138(2):119-131
The aim of the study was to differentiate the impact of lighting conditions and feeding times on the regulation of lipid metabolism of goats under different photoperiods throughout the year. Seven Finnish landrace goats were kept under artificial lighting that simulated the annual changes of photoperiod at 60 degrees N (the longest light period 18 h, the shortest 6 h). Ambient temperature and feeding regime were kept constant. Blood samples were collected six times a year at 2-h intervals for 2 days, first in light/dark (LD) conditions and then after 3 days in constant darkness (DD). Significant daily variations were detected in the concentrations of plasma free fatty acids (FFA) and glycerol throughout the year. The nocturnal decrease and morning rise of FFA levels were related to the photoperiod, while the trough levels of glycerol were associated with the concentrate meal times. In DD conditions, FFA and glycerol rhythms were unstable. A significant seasonal variation was detected in the overall FFA and glycerol levels suggesting decreased lipogenesis in winter, increased lipolysis in spring and high lipogenesis in summer and fall. There was no significant daily rhythm in serum leptin levels, nor did the profiles in LD and DD conditions differ. The leptin level was slightly lower in early fall than in the other seasons, paralleling a small decrease of body mass in the goats after the grazing season. The daily or annual variations of FFA and glycerol levels were not clearly related to leptin concentrations. The results suggest that lipid metabolism of goats is regulated by light even in constant temperature and feeding conditions; however, no significant contribution of leptin levels could be shown. 相似文献
103.
Drabek K van Ham M Stepanova T Draegestein K van Horssen R Sayas CL Akhmanova A Ten Hagen T Smits R Fodde R Grosveld F Galjart N 《Current biology : CB》2006,16(22):2259-2264
In motile fibroblasts, stable microtubules (MTs) are oriented toward the leading edge of cells. How these polarized MT arrays are established and maintained, and the cellular processes they control, have been the subject of many investigations. Several MT "plus-end-tracking proteins," or +TIPs, have been proposed to regulate selective MT stabilization, including the CLASPs, a complex of CLIP-170, IQGAP1, activated Cdc42 or Rac1, a complex of APC, EB1, and mDia1, and the actin-MT crosslinking factor ACF7. By using mouse embryonic fibroblasts (MEFs) in a wound-healing assay, we show here that CLASP2 is required for the formation of a stable, polarized MT array but that CLIP-170 and an APC-EB1 interaction are not essential. Persistent motility is also hampered in CLASP2-deficient MEFs. We find that ACF7 regulates cortical CLASP localization in HeLa cells, indicating it acts upstream of CLASP2. Fluorescence-based approaches show that GFP-CLASP2 is immobilized in a bimodal manner in regions near cell edges. Our results suggest that the regional immobilization of CLASP2 allows MT stabilization and promotes directionally persistent motility in fibroblasts. 相似文献
104.
Janne Leinonen Vappu Rantalaiho Terho Lehtimäki Timo Koivula Ole Wirta Amos Pasternack 《Free radical research》2013,47(4):273-281
Oxidative stress may be an important pathogenetic factor in the development of diabetic vascular complications. The total antioxidative potential of plasma reflects the ability of an individual to resist oxidative stress. We measured the plasma total peroxyl radical-trapping potential (TRAP) and the concentrations of four plasma chain-breaking antioxidants in 81 patients with non-insulin-dependent diabetes mellitus (NIDDM) nine years after diagnosis and in 102 well-matched non-diabetic control subjects. The association between the total antioxidative potential and the presence of coronary heart disease (CHD) and diabetic kidney disease were also studied. There were no significant differences in plasma TRAP between NIDDM patients and control subjects (1250 ± 199 vs. 1224 ± 198 μM). Nor were there any significant differences in the concentrations of plasma uric acid, ascorbic acid, α-tocopherol, and protein thiols between NIDDM patients and control subjects. Patients with a low glomerular filtration rate and/or high urinary albumin excretion had elevated plasma uric acid. Plasma TRAP was not, however, associated with renal dysfunction. The plasma of NIDDM patients with CHD had a significantly higher value of unidentified antioxidative potential than that of patients without CHD. This relation was strongly dependent upon smoking. In conclusion, these data demonstrate that there are no major defects in the antioxidative potential of plasma caused by NIDDM per se. CHD and diabetic renal dysfunction were not associated with changes in plasma TRAP. 相似文献
105.
Mahban Irandoust Julian Alvarez Zarate Isabelle Hubeek Ellen M. van Beek Karin Schornagel Aart J. F. Broekhuizen Mercan Akyuz Arjan A. van de Loosdrecht Ruud Delwel Peter J. Valk Edwin Sonneveld Pamela Kearns Ursula Creutzig Dirk Reinhardt Eveline S. J. M. de Bont Eva A. Coenen Marry M. van den Heuvel-Eibrink C. Michel Zwaan Gertjan J. L. Kaspers Jacqueline Cloos Timo K. van den Berg 《PloS one》2013,8(1)
Background
Recent studies show the importance of interactions between CD47 expressed on acute myeloid leukemia (AML) cells and the inhibitory immunoreceptor, signal regulatory protein-alpha (SIRPα) on macrophages. Although AML cells express SIRPα, its function has not been investigated in these cells. In this study we aimed to determine the role of the SIRPα in acute myeloid leukemia.Design and Methods
We analyzed the expression of SIRPα, both on mRNA and protein level in AML patients and we further investigated whether the expression of SIRPα on two low SIRPα expressing AML cell lines could be upregulated upon differentiation of the cells. We determined the effect of chimeric SIRPα expression on tumor cell growth and programmed cell death by its triggering with an agonistic antibody in these cells. Moreover, we examined the efficacy of agonistic antibody in combination with established antileukemic drugs.Results
By microarray analysis of an extensive cohort of primary AML samples, we demonstrated that SIRPα is differentially expressed in AML subgroups and its expression level is dependent on differentiation stage, with high levels in FAB M4/M5 AML and low levels in FAB M0–M3. Interestingly, AML patients with high SIRPα expression had a poor prognosis. Our results also showed that SIRPα is upregulated upon differentiation of NB4 and Kasumi cells. In addition, triggering of SIRPα with an agonistic antibody in the cells stably expressing chimeric SIRPα, led to inhibition of growth and induction of programmed cell death. Finally, the SIRPα-derived signaling synergized with the activity of established antileukemic drugs.Conclusions
Our data indicate that triggering of SIRPα has antileukemic effect and may function as a potential therapeutic target in AML. 相似文献106.
Endostatin inhibits human tongue carcinoma cell invasion and intravasation and blocks the activation of matrix metalloprotease-2, -9, and -13 总被引:29,自引:0,他引:29
Nyberg P Heikkilä P Sorsa T Luostarinen J Heljasvaara R Stenman UH Pihlajaniemi T Salo T 《The Journal of biological chemistry》2003,278(25):22404-22411
Endostatin, a 20-kDa collagen XVIII fragment, inhibits angiogenesis and tumor growth in vivo, but the mechanisms are still unclear. Matrix metalloproteases (MMPs), a family of extracellular and membrane-associated endopeptidases, collectively digest almost all extracellular matrix and basement membrane components, and thus play an important role in tumor progression. We studied the effects of recombinant human endostatin on human MMP-2, -9, -8, and -13. We found that endostatin inhibited the activation and catalytic activity of pro-MMP-9 and -13 as well as recombinant pro-MMP-2. It prevented the fragmentation of pro-MMP-2 that was associated with reduction of catalytic activity. Endostatin had no effect on MMP-8 as shown by collagenase activity assays. An in vitro migration assay and an in vivo chicken chorioallantoic membrane intravasation assay with the human tongue squamous cell carcinoma cell line HSC-3 revealed the biphasic nature of endostatin; low endostatin concentrations inhibited intravasation and migration of these cells in a dose-dependent manner, but at increased concentrations, the inhibitory effect was far less efficient. The results show that endostatin blocks the activation and activities of certain tumor-associated pro-MMPs, such as pro-MMP-2, -9, and -13, which may explain, at least in part, the antitumor effect of endostatin. Our results also suggest that endostatin inhibits tumor progression by directly affecting the tumor cells and not just acting via endothelial cells and blockage of angiogenesis. 相似文献
107.
Wahlroos T Soukka J Denesyuk A Wahlroos R Korpela T Kilby NJ 《Genesis (New York, N.Y. : 2000)》2003,35(2):125-132
We have established a versatile method for studying the interaction of the oleosin gene product with oil bodies during oil body biogenesis in plants. Our approach has been to transiently express a green fluorescent protein (GFP)-tagged Arabidopsis oleosin gene fusion in tobacco leaf cells containing bona fide oil bodies and then to monitor oleosin-GFP expression using real-time confocal laser scanning microscopy. We show that normally non-oil-storing tobacco leaf cells are able to synthesize and then transport oleosin-GFP fusion protein to leaf oil bodies. Synthesis and transport of oleosin-GFP fusion protein to oil bodies occurred within the first 6 h posttransformation. Oleosin-GFP fusion protein exclusively associated with the endoplasmic reticulum and was trafficked in a Golgi-independent manner at speeds approaching 0.5 microm sec(-1) along highly dynamic endoplasmic reticulum positioned over essentially static polygonal cortical endoplasmic reticulum. Our data indicate that oil body biogenesis can occur outside of the embryo and that oleosin-GFP can be used to monitor early events in oil body biogenesis in real-time. 相似文献
108.
Petteri Vihervaara Timo Kumpula Ari Tanskanen Benjamin Burkhard 《Ecological Complexity》2010,7(3):410-420
The concept of ecosystem services (ESs) is a relatively new scientific methodology, offering a possible approach to the prevention of ecological problems caused by human action and to the resolution of conflicts arising from land-use questions. Since ESs were launched as a major conceptual tool in the Millennium Ecosystem Assessment (MA, 2005), interest in them has been increasing. Despite the scientific as well as economic and political enthusiasm for the ES approach, only few case studies have as yet been published. We studied the interface between ESs and landscape planning in Forest Lapland, in northern Finland. In the article, we present a methodology and various databases which can be used in applied research on ESs. We classify the ESs offered by various biotopes of the study area, and examine the effects of different land-use forms on the provision of ESs. On the basis of our results, we suggest possible uses of the European CORINE land cover database in case studies. 相似文献
109.
110.
de Araujo Junior Raimundo Fernandes Eich Christina Jorquera Carla Schomann Timo Baldazzi Fabio Chan Alan B. Cruz Luis J. 《Molecular and cellular biochemistry》2020,468(1-2):153-168
Molecular and Cellular Biochemistry - Accumulating evidence indicates that ceramide (Cer) and palmitic acid (PA) possess the ability to modulate switching of macrophage phenotypes and possess... 相似文献