Search results for "recombinant"
showing 10 items of 1150 documents
Human recombinant vasostatin-1 may interfere with cell-extracellular matrix interactions
2006
Vasostatin-1 (VS-1), the N-terminal fragment derived from the cleavage of chromogranin A (CgA), has been shown to exert several biological activities on several tissues and organs. Recently, it has been reported that human recombinant VS-1 (STA-CGA(1-78)) may alter myocardial contractility in eel, frog., and rat hearts. In this article we have explored if STA-CGA(1-78) can induce intracellular cascades interacting both with adhesion molecules and/or extracellular matrix (ECM), components, that is, involvement of the heat shock protein 90 (HSP90) and the endothelial NOS (eNOS), known to be implicated in signal transduction mechanisms affecting myocardial contractility. We used 3D cultured ad…
Prolactin supplementation to culture medium improves beta-cell survival
2010
OBJECTIVES.: Recent studies demonstrated that prolactin (PRL) has beneficial effects on β cells for islet transplantation. We examined the effect of human recombinant PRL (rhPRL) supplementation to the culture media to determine its potential use in the context of clinical islet transplantation. MATERIALS AND METHODS.: Each human islet isolated from 14 deceased multiorgan donors was cultured in Miami modified media-1 supplemented with or without rhPRL (500 μg/L) for 48 hr. β-Cell survival and proliferation (BrdU and Ki-67) were determined by laser scanning cytometry. The cytoprotective effects of rhPRL against noxious stimuli were assessed by flow cytometry (tetramethylrhodamine ethyl ester…
Relaxation induced by N-terminal fragments of chromogranin A in mouse gastric preparations.
2007
Abstract A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro , the effects of the recombinant vasostatin 1–78 (VS-1), CGA 7–57 and CGA 47–66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7–57 and CGA 47–66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53–57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), b…
A new method to value efficiency of enzyme blends for pancreatic tissue digestion.
2010
Islet transplantation, since the 90’s, has been resulting to be one of the best successful example of human cell therapy. Nevertheless, islet isolation procedure is not completely standardized; in fact, more than fifty percent of islets procedures don’t arrive to their transplantation. This is due both to the variability of donor’s pancreas and to an unpredictable enzymatic blend efficiency. Enzymes used in pancreas digestion are extracted from Clostridium histolyticum bacteria and digest several substrates. In particular they have strong collagenolytic activity compared to vertebrate collagenases. However, several impediments persist in human islet isolation success probably due to the var…
A Novel Long-Term Graves’ Disease Animal Model Confirmed by Functional Thyrotropin Receptor Antibodies
2020
<b><i>Introduction:</i></b> A novel long-term murine model for Graves’ disease (GD) using repeated, long-term immunizations with recombinant adenovirus expressing the extracellular A-subunit of the human thyrotropin receptor (Ad-TSHR) was applied to evaluate the functional anti-TSHR-antibody (TSHR-Ab) profile. <b><i>Methods:</i></b> BALB/c mice received 7 immunizations with either 10<sup>10</sup> plaque-forming units of Ad-TSHR or control Ad-GFP. Naïve (nonimmuized native) mice were also studied. Three 3-weekly immunizations were followed by 4-weekly boosts until the 7th immunization. Blocking (TBAb) and stimulating (TSAb) TSHR-Ab …
Integrin-mediated Cell Adhesion to Type I Collagen Fibrils
2004
In the integrin family, the collagen receptors form a structurally and functionally distinct subgroup. Two members of this subgroup, α1β1 and α2β1 integrins, are known to bind to monomeric form of type I collagen. However, in tissues type I collagen monomers are organized into large fibrils immediately after they are released from cells. Here, we studied collagen fibril recognition by integrins. By an immunoelectron microscopy method we showed that integrin α2I domain is able to bind to classical D-banded type I collagen fibrils. However, according to the solid phase binding assay, the collagen fibril formation appeared to reduce integrin α1I and α2I domain avidity to collagen and to lower …
Production of an egg yolk antibody against Parietaria judaica 2 allergen
2009
Specific antibodies are essential tools for studying proteins as well as for diagnostic research in biomedicine. The egg yolk of immunized chicken is an inexpensive source of high-quality polyclonal antibodies. The 12-kDa Parietaria judaica 2 allergen was expressed as a fusion protein and was used to immunize Leghorn chickens. In this paper, we show, using 2-dimensional gel electrophoresis and immunoblotting, that chicken antibodies raised against a recombinant allergen can be used to recognize similar proteins from a pollen raw extract. Allergen identity was confirmed by nanoLC-nanospray-tandem mass spectrometry analysis. Our data demonstrate for the first time that a synergistic combinati…
Interaction of glutamic-acid-rich proteins with the cGMP signalling pathway in rod photoreceptors.
1999
The assembly of signalling molecules into macromolecular complexes (transducisomes) provides specificity, sensitivity and speed in intracellular signalling pathways. Rod photoreceptors in the eye contain an unusual set of glutamic-acid-rich proteins (GARPs) of unknown function. GARPs exist as two soluble forms, GARP1 and GARP2, and as a large cytoplasmic domain (GARP' part) of the beta-subunit of the cyclic GMP-gated channel. Here we identify GARPs as multivalent proteins that interact with the key players of cGMP signalling, phosphodiesterase and guanylate cyclase, and with a retina-specific ATP-binding cassette transporter (ABCR), through four, short, repetitive sequences. In electron mic…
Hydrophobin (HFBI): a potential fusion partner for one-step purification of recombinant proteins from insect cells
2008
Hydrophobins play an important role in binding and assembly of fungal surface structures as well as in medium-air interactions. These, hydrophobic properties provide interesting possibilities when purification of macromolecules is concerned. In aqueous micellar two-phase systems, based on surfactants, the water soluble hydrophobins are concentrated inside micellar structures and, thus, distributed to defined aqueous phases. This, one-step purification is attractive particularly when large-scale production of recombinant proteins is concerned. In the present study the hydrophobin HFBI of Trichoderma reesei was expressed as an N-terminal fusion with chicken avidin in baculovirus infected inse…
Iron Induces Proliferation and Morphogenesis in Primmorphs from the Marine SpongeSuberites domuncula
2002
Dissociated cells from marine demosponges retain their proliferation capacity if they are allowed to form special aggregates, the primmorphs. On the basis of incorporation studies and septin gene expression, we show that Fe3+ ions are required for the proliferation of cells in primmorphs from Suberites domuncula. In parallel, Fe3+ induced the expression of ferritin and strongly stimulated the synthesis of spicules. This result is supported by the finding that the enzymatic activity of silicatein, converting organosilicon to silicic acid, depends on Fe3+. Moreover, the expression of a scavenger receptor molecule, possibly involved in the morphology of spicules, depends on the presence of Fe3…