Search results for "SIGNAL TRANSDUCTION"
showing 10 items of 2020 documents
Sterigmatocystin: Occurrence, toxicity and molecular mechanisms of action – A review
2020
The mycotoxin sterigmatocystin (STE) is produced mainly by Aspergillus fungi. It has been reported to occur in grains and grain-based products, cheese, coffee, spices and beer. The STE is a known biogenic precursor of aflatoxin B1, sharing with it several structural and biological similarities. The STE has been shown to be hepatotoxic and nephrotoxic in animals and it has been classified as possible human carcinogen (group 2B) by IARC. The STE has been reported to cause a marked decrease in cell proliferation in different mammalian cells. Data available on literature suggest that the cellular mechanisms underlying STE-induced toxicity include the induction of oxidative stress, mitochondrial…
Nuclear calcium signaling by inositol trisphosphate in GH3 pituitary cells
2008
It has been proposed that nuclear and cytosolic Ca2+ ([Ca2+]N and [Ca2+]C) may be regulated independently. We address here the issue of whether inositol trisphosphate (IP3) can, bypassing changes of [Ca2+]C, produce direct release of Ca2+ into the nucleoplasm. We have used targeted aequorins to selectively measure and compare the changes in [Ca2+]C and [Ca2+]N induced by IP3 in GH3 pituitary cells. Heparin, an IP3 inhibitor that does not permeate the nuclear pores, abolished the [Ca2+]C peaks but inhibited only partly the [Ca2+]N peaks. The permeant inhibitor 2-aminoethoxy-diphenyl-borate (2-APB) blocked both responses. Removal of ATP also inhibited more strongly the [Ca2+]C than [Ca2+]N pe…
A mutation in the second intracellular loop of the pituitary adenylate cyclase activating polypeptide type I receptor confers constitutive receptor a…
2000
AbstractThe pituitary adenylate cyclase activating polypeptide (PACAP) type I receptor belongs to the glucagon/secretin/vasoactive intestinal polypeptide (VIP) receptor family. We mutated and deleted an amino acid residue (E261) which is located within the second intracellular loop of the rat PACAP type I receptor and which is highly conserved among the receptor family. The wild-type receptor and the mutant receptors were efficiently expressed at the surface of COS-7 cells at nearly the same level and revealed the same high affinity for the agonist PACAP-27. The cAMP contents of COS cells transfected with the E261A, E261Q, and the deletion mutant receptor were 4.6-, 5.7-, and 6.7-fold highe…
Retinoids as a Perspective in Treatment of Alzheimer’s Disease
2010
<i>Background:</i> In the past, we demonstrated that the disintegrin metalloproteinase ADAM10 has α-secretase activity in vitro and in cultured cells. We also found out that moderate overexpression of this proteinase inhibits Aβ peptide production and prevents the formation of amyloid plaques in an Alzheimer’s disease (AD) mouse model. Moreover, it corrects early hippocampal defects like LTP impairment and increases cortical synaptogenesis. <i>Objective:</i> Upregulation of ADAM10 might be an alternative approach concerning AD therapy. Our current research therefore focuses on substances and/or pathways which regulate ADAM10 gene expression. <i>Methods:</i&g…
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…
Targeting the vascular endothelial growth factor system to prevent ovarian hyperstimulation syndrome
2008
BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) typically occurs when ovaries are primed with FSH/ LH and subsequently exposed to hCG. The ultimate pathophysiological step underlying this clinical picture is increased vascular permeability (VP). METHODS: A search of the literature was carried out using PubMed and the authors’ files. RESULTS: In rodents and humans, the expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2) mRNA increases during ovarian stimulation. With the administration of hCG, the expression of each rises to a maximum. Expression of VEGF/VEGFR-2 mRNAs correlates with enhanced VP, with both peaking 48 h following an injection of hCG. Imm…
The Inflammatory Feed-Forward Loop Triggered by the Complement Component C3 as a Potential Target in Endometriosis
2021
Copyright © 2021 Agostinis, Zorzet, Balduit, Zito, Mangogna, Macor, Romano, Toffoli, Belmonte, Morello, Martorana, Borelli, Ricci, Kishore and Bulla. The complement system is a major component of humoral innate immunity, acting as a first line of defense against microbes via opsonization and lysis of pathogens. However, novel roles of the complement system in inflammatory and immunological processes, including in cancer, are emerging. Endometriosis (EM), a benign disease characterized by ectopic endometrial implants, shows certain unique features of cancer, such as the capacity to invade surrounding tissues, and in severe cases, metastatic properties. A defective immune surveillance against…
1H, 13C and 15N NMR chemical shift assignments of cAMP-regulated phosphoprotein-19 and -16 (ARPP-19 and ARPP-16)
2020
Protein Phosphatase 2A, PP2A, the principal Serine/threonine phosphatase, has major roles in broad range of signaling pathways that include regulation of cell cycle, cell proliferation and neuronal signaling. The loss of function of PP2A is linked with many human diseases, like cancer and neurodegenerative disorders. Protein phosphatase 2A (PP2A) functions as tumor suppressor and its tumor suppressor activity is inhibited by the overexpression of PP2A inhibitor proteins in most of the cancers. ARPP-19/ARPP-16 has been identified as one of the potential PP2A inhibitor proteins. Here, we report the resonance assignment of backbone 1H, 13C and 15N atoms of human ARPP-19 and ARPP-16 proteins. T…
MiR-33a Controls hMSCS Osteoblast Commitment Modulating the Yap/Taz Expression Through EGFR Signaling Regulation
2019
Mesenchymal stromal cells (hMSCs) display a pleiotropic function in bone regeneration. The signaling involved in osteoblast commitment is still not completely understood, and that determines the failure of current therapies being used. In our recent studies, we identified two miRNAs as regulators of hMSCs osteoblast differentiation driving hypoxia signaling and cytoskeletal reorganization. Other signalings involved in this process are epithelial to mesenchymal transition (EMT) and epidermal growth factor receptor (EGFR) signalings through the regulation of Yes-associated protein (YAP)/PDZ-binding motif (TAZ) expression. In the current study, we investigated the role of miR-33a family as a (…
Involvement of Lipoxygenase-dependent Production of Fatty Acid Hydroperoxides in the Development of the Hypersensitive Cell Death induced by Cryptoge…
1999
Lipid peroxidation was investigated in relation with the hypersensitive reaction in cryptogein-elicited tobacco leaves. A massive production of free polyunsaturated fatty acid (PUFA) hydroperoxides dependent on a 9-lipoxygenase (LOX) activity was characterized during the development of leaf necrosis. The process occurred after a lag phase of 12 h, was accompanied by the concomitant increase of 9-LOX activity, and preceded by a transient accumulation of LOX transcripts. Free radical-mediated lipid peroxidation represented 10% of the process. Inhibition and activation of the LOX pathway was shown to inhibit or to activate cell death, and evidence was provided that fatty acid hydroperoxides ar…