Search results for "HSp70"
showing 10 items of 206 documents
Effects of dichlorvos aquaculture treatments on selected biomarkers of gilthead sea bream (Sparus aurata L.) fingerlings
2007
Abstract The gilthead sea bream ( Sparus aurata ) is the most important marine cultured species in the Mediterranean. Dichlorvos is one of the main chemical agents used in bath treatments against ectoparasites of marine farmed fish. The main objective of this study was to investigate the effects of 24 h dichlorvos baths on selected biomarkers that are involved in important physiological functions or indicative of gilthead sea bream fingerlings growth. To attain this objective, the in vivo effects of dichlorvos on cholinesterases' activity (ChE), lipid peroxidation (TBARS), RNA/DNA ratio, glutathione S -transferases activity (GST) and heat shock proteins HSP70 were studied. The characterizat…
Phytochemical Profile and Apoptotic Activity of Onopordum cynarocephalum.
2012
A phytochemical investigation of acetone and chloroform extracts of the aerial parts of Onopordum cynarocephalum Boiss. et Blanche was carried out. It led to the isolation of two new sesquiterpenes, the elemane aldehyde (2) and the eudesmane (11), together with 15 known compounds: two lignans (1 and 15) and 13 sesquiterpenes (3–10, 12–14, 16, 17). The structures were elucidated by spectroscopic analyses, especially 1D and 2D NMR spectra. The anti-growth effect against three human melanoma cell lines, M14, A375, and A2058, of the different extracts and compounds of O. cynarocephalum was also investigated. Among them, the chloroform extract exhibited the strongest biological activity, while t…
Different Efficiency of Heat Shock Proteins (HSP) to Activate Human Monocytes and Dendritic Cells: Superiority of HSP60
2002
Abstract One essential immunoregulatory function of heat shock protein (HSP) is activation of the innate immune system. We investigated the activation of human monocytes and monocyte-derived dendritic cells (DC) by recombinant human HSP60, human inducible HSP72, and preparations of human gp96 and HSP70 under stringent conditions, in the absence of serum and with highly purified monocytes. HSP60 induced human DC maturation and activated human DC to secrete proinflammatory cytokines. HSP72 induced DC maturation to a lesser extent, but activated human monocytes and immature DC as efficiently as HSP60 to release proinflammatory cytokines. The independence of the effects of HSP60 and HSP72 from …
Modulation of 2′-5′oligoadenylate synthetase by environmental stress in the marine spongeGeodia cydonium
1997
Recently we established the presence of relatively high amounts of 2′-5′oligoadenylates (2′-5′A) and 2′-5′oligoadenylate synthetase (2′-5′A synthetase) in the marine sponge Geodia cydonium. Here we determined by applying radioimmunoassay and high-performance liquid chromatographical methods that the concentration of 2′-5′A and the activity of 2′-5′A synthetase change following exposure of G. cydonium tissue to environmental stress. The 2′-5′A content and the activity of 2′-5′A synthetase, present in crude sponge extract, increase by up to three-fold after treating sponge cubes for 2 h with natural stressors including heat shock (26°C), cold shock (6°C), pH shock (pH 6), and hypertonic shock…
Constitutive hsp70 is essential to mitosis during early cleavage of Paracentrotus lividus embryos: The blockage of constitutive hsp70 impairs mitosis
1999
Localization of constitutive hsp70 in eggs and early embryos of sea urchin Paracentrotus lividus is shown by means of in situ immunostaining. An accumulation of this protein is shown in the mitotic structures (asters, spindles and centrosomes). Microinjection of anti-hsp70 antibodies into eggs causes impairment of formation of mitotic structures and of cell division. This impairment goes from a complete mitotic block, to irregular mitotic apparatus formation with irregular cleavage, depending upon the antibody concentration. The localization of hsp70 after antibody microinjection is also described. Blockage of mitotic apparatus formation by nocodazole also blocks the concentration of hsp70 …
Coelomocytes and post-traumatic response in the common sea star Asterias rubens.
2008
Coelomocytes are recognized as the main cellular component of the echinoderm immune system. They are the first line of defense and their number and type can vary dramatically during infections or following injury. Sea stars have been used as a model system to study the regeneration process after autotomy or predation. In the present study we examined the cellular and biochemical responses of coelomocytes from the European sea star Asterias rubens to traumatic stress using immunochemical and biochemical approaches. In terms of trauma and post-traumatic stress period, here we consider the experimental arm amputation and the repair phase involved in the first 24 hours post-amputation, which mi…
Adhesion and adaptive response of osteoblastlike cells (SAOS-2) grown on dfferent ti-6al-4v surfaces.
2004
Osteoblastic-like cells (SAOS-2) were seeded on three differently treated surfaces of Ti- 6Al-4V (T1: not treated; T2: chemically treated; T3: electrochemically treated). After 6h, the cells grown on T1 and T2 surfaces showed a typical poligonal morphology, they were strongly adherent to the surface and after 24h-48h they spread and formed a confluent monolayer. On the contrary, cells seeded on T3 showed heterogeneous morphology, decreased adhesion, loss of thin cellular expansions, and showed cellular shrinkage and apoptotic blebbing; only after 48h they were able to attach and form a monolayer after 4 days of seeding. Cell proliferation was significantly lower on T3 than T1 and T2 surface…
Adaptive response of osteoblasts grown on a titanium surface: morphology, cell proliferation and stress protein synthesis.
2005
Titanium is one of the most widely used biomaterials in orthopaedic, dental and trauma surgery. Superficial adhesion and cell proliferation represent the first steps of cell-biomaterial interactions. The efficacy of this early phase influences the subsequent ability to differentiate, and hence the knowledge of these cell activities is important for studying and improving the biocompatibility of biomaterials. The aim of this study was to test the adaptive ability of osteoblastic cells grown on titanium surfaces, including morphologic, proliferative and adaptative aspects.
The dnaK operon of Streptomyces coelicolor encodes a novel heat-shock protein which binds to the promoter region of the operon
1995
Transcriptional studies have demonstrated that the dnaK gene of Streptomyces coelicolor A3(2) is contained within a 4.3 kb operon. The operon is transcribed from a single (transiently) heat-inducible promoter, dnaKp, that resembles the typical vegetative (sigma 70-recognized) eubacterial consensus promoter sequence. dnaK transcription was found to be heat-inducible at all stages of development in surface-grown cultures. In addition, at the normal growth temperature of 30 degrees C, dnaK transcript levels were shown to vary at different stages of development, being more abundant in young germinating cultures and in mycelium undergoing sporogenesis. The nucleotide sequence of the dnaK operon …
Oxidative stress induces distinct physiological responses in the two Trebouxia phycobionts of the lichen Ramalina farinacea
2010
† Background and Aims Most lichens form associations with Trebouxia phycobionts and some of them simultaneously include genetically different algal lineages. In other symbiotic systems involving algae (e.g. reef corals), the relative abundances of different endosymbiotic algal clades may change over time. This process seems to provide a mechanism allowing the organism to respond to environmental stress. A similar mechanism may operate in lichens with more than one algal lineage, likewise protecting them against environmental stresses. Here, the physiological responses to oxidative stress of two distinct Trebouxia phycobionts (provisionally named TR1 and TR9) that coexist within the lichen R…