Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The neuroprotectant fructose-1,6-bisphosphate (FBP) preserves cellular [ATP] and prevents catastrophic increases in [Ca2+]i during hypoxia. Because FBP does not enter neurons or glia, the mechanism of protection is not clear. In this study, we show that FBP's capacity to protect neurons and stabilize [Ca2+]i during hypoxia derives from signaling by a phospholipase-C-intracellular Ca2+-protein kinases pathway, rather than Ca2+ chelation or glutamate receptor inhibition. FBP reduced [Ca2+]i changes in hypoxic hippocampal neurons, regardless of [Ca2+]e, and preserved cellular integrity as measured by trypan blue or propidium iodide exclusion and [ATP]. FBP also prevented hypoxia-induced increases in [Ca2+]i when glucose was absent and when [Ca2+]e was increased to negate Ca2+ chelation by FBP. These protective effects were observed equally in postnatal day 2 (P2) and P16 neurons. Inhibiting glycolysis with iodoacetate eliminated the protective effects of FBP in P16 neurons. FBP did not alter Ca2+ influx stimulated by brief applications of NMDA or glutamate during normoxia or hypoxia, but did reduce the increase in [Ca2+]i produced by 10 min of glutamate exposure during hypoxia. Because FBP increases basal [Ca2+]i and stimulates membrane lipid hydrolysis, we tested whether FBP's protective action was dependent on phospholipase C signaling. The phospholipase C inhibitor U73122 prevented FBP-induced increases in [Ca2+]i and eliminated FBP's ability to stabilize [Ca2+]i and increase survival during anoxia. Similarly, FBP's protection was eliminated in the presence of the mitogen/extracellular signal protein kinase (MEK) inhibitor U0126. We conclude that FBP may produce neuroprotection via activation of neuroprotective signaling pathways that modulate Ca2+ homeostasis.
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PMID:Neuroprotection and intracellular Ca2+ modulation with fructose-1,6-bisphosphate during in vitro hypoxia-ischemia involves phospholipase C-dependent signaling. 1164 Sep 1

An IL-10 responsive signal protein, termed IL-10E1, was cloned from human prostate cancer PC-3 ML cells based on its binding affinity for a novel enhancer element (i.e., HTE-1: 5'-CACGATGACTCATCACTGTTGAAAGACA-3') of the Tissue Inhibitor of metalloproteinase-1 (TIMP-1) gene. Electrophoretic mobility shift assays (EMSAs) and enzyme linked immuno-sandwich assays (ELISAs) showed that IL-10 stimulated the rapid translocation of IL-10E1 to the nucleus and the activation of TIMP-1 expression in 4 different androgen dependent primary prostate tumor lines generated in our laboratory (i.e. HPCA-5a, 5b, 5c and 5d lines). IL-10 signaling was blocked by a variety of agents, including IL-10 receptor antibodies, alpha-toxin, and Genistein. The inhibition of IL-10 signaling and IL-10E1 expression correlated directly with a significant decrease in TIMP-1 expression by the HPCA-5a, 5b, 5c and 5d cell lines. Following permanent transfection of HPCA-5a and 5c cells with the IL-10 gene the growth of tumor xenografts in SCID CB17 mice was severely retarded, yielding tiny, poorly vascularized tumors by approximately 90 days post-inoculation s.c. ELISAs showed that these tumors expressed elevated levels of IL-10, IL-10E1 and TIMP-1 compared with tumors from non-transfected or Mock transfected cell lines. We conclude that the IL-10/IL-10 receptor axis (and IL-10E1 signaling) regulation of TIMP-1 expression plays a key role in inhibiting tumor growth, perhaps by blocking tumor vascularization.
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PMID:IL-10/IL-10 receptor signaling regulates TIMP-1 expression in primary human prostate tumor lines. 1249 89

D-fructose-1,6-bisphosphate (FBP) is an endogenous intermediate of glycolytic pathway which has potent neuroprotective effect against various neurotoxic insults. This study examined whether FBP could antagonize the neurotoxicity induced by amyloid beta-peptide (Abeta) in rat hippocampal organotypic slice cultures, and the possible mechanism was also explored. Treatment with FBP (concentration ranges from 1.7 mM to 10 mM) significantly decreased the cell death in hippocampal slices in the presence of Abeta at 24h, 48 h and 72 h, and this neuroprotective effect of FBP against Abeta was not in a dose-dependent manner, FBP 3.5 mM has better neuroprotective effect than that of other FBP concentration groups. Treatment with FBP slightly but significantly increases the ATP levels in hippocampal slices in the presence of Abeta. However, the increment of ATP levels was similar among various FBP concentration groups. Neuroprotective effect of FBP 3.5 mM against Abeta induced neurotoxicity in hippocampal slices was attenuated by addition of phospholipase C (PLC) inhibitor, U73122, mitogen activated extracellular signal protein kinase (MEK) inhibitor, U0126, or extracellular signal activated protein kinase (ERK) inhibitor, PD98059 at 24 h, 48 h and 72 h. However, co-treatment with these three kinds of inhibitors did not change the FBP's effect on ATP levels. Our results suggested FBP has neuroprotective effect against Abeta induced neurotoxicity in hippocampal slice cultures, and FBP plays role not only as an alternative energy source, but also a modulator of PLC and MEK/ERK pathways to regulate the cellular response and survival.
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PMID:Neuroprotective effect of D-fructose-1,6-bisphosphate against beta-amyloid induced neurotoxicity in rat hippocampal organotypic slice culture: involvement of PLC and MEK/ERK signaling pathways. 1650 18

Human neutrophils are highly specialised for their primary function, i.e. phagocytosis and destruction of microorganisms. Leukocyte recruitment to sites of inflammation and infection is dependent upon the presence of a gradient of locally produced chemotactic factors. The bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) was one of the first of these to be identified and is a highly potent leukocyte chemoattractant. It interacts with its receptor on the neutrophil membrane, activating these cells through a G-protein-coupled pathway. Two functional fMLP receptors have thus far been cloned and characterized, namely FPR (formyl peptide receptor) and FPRL1 (FPR like-1), with high and low affinities for fMLP, respectively. FMLP is known to activate phospholipase C (PLC), PLD, PLA2 and phosphatidylinositol-3-kinase (PI3K), and it also activates tyrosine phosphorylation. The second messengers resulting from the fMLP receptor interaction act on various intracellular kinases, including protein kinase C (PKC) and mitogen-activated protein kinases (MAPKs). The activation of these signal transduction pathways is known to be responsible for various biochemical responses which contribute to physiological defence against bacterial infection and cell disruption. This review will consider the ability of selective analogues (ligands able to discriminate between different biological responses) to activate a single spectrum of signal transduction pathways capable of producing a unique set of cellular responses, hypothesising that a distinctive imprint of signal protein activation may exist. Through more complete understanding of intracellular signaling, new drugs could be developed for the selective inflammatory blockade.
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PMID:Signal transduction pathways triggered by selective formylpeptide analogues in human neutrophils. 1651 93