Pituitary hormones influence polyphosphoinositide metabolism in rat brain

Jolles, J.; Wirtz, K.W.A.; Schotman, P.; Gispen, W.H.

doi:10.1016/0014-5793(79)80897-2

Cited by 89 publications

(18 citation statements)

References 27 publications

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“…In addition both DPI and TPI markedly increased pregnenolone synthesis by the mitochondrial preparation, suggesting that this may be a mechanism for control of corticosteroidogenesis. Other studies have demonstrated an effect of ACTH upon [ 14 C]choline accumulation by rat brain synaptosomes and upon the metabolism of phosphatidylinositol by a crude rat brain mitochondrial fraction (214,215). An effect of cortisol to inhibit the binding of ACTH to membrane receptors of adrenal cortex may also relate to corticoid actions upon membranes (216).…”

Section: Nelsonmentioning

confidence: 95%

Corticosteroid-Induced Changes in Phospholipid Membranes as Mediators of Their Action*

Nelson

1980

Endocrine Reviews

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T HIS SHORT review will describe mechanisms by which corticosteroid modification of cellular phospholipids and particularly the phospholipid-structure of a variety of membranes can produce some of the effects of the corticosteroids. In addition to these effects, many studies have demonstrated effects of other hormones to alter specific phospholipids, phospholipases, or for phospholipase action on cells to mimic hormone action. All actions of the corticosteroids are not thought to be produced by these lipid alterations, but such changes are capable of producing widespread effects on receptor activity, RNA and protein synthesis, enzymatic activity, and transport through membranes. The availability of new data indicating that phospholipids are altered considerably by corticosteroids in a number of tissues makes a review of this subject of interest at this time.Corticosteroids are secreted in response to a variety of "stresses" that represent alterations in the cellular environment that might result in death or injury to the exposed cells if proper adaptation did not occur. Thus, these hormones are increased in response to anoxia, very low or very high temperature, or hypoglycemia. Through mechanisms that have not been clearly understood the cell is protected by the increased hormones against potentially harmful alterations in its environment. Unicellular organisms, which lack a sophisticated endocrine system for response to stresses, undergo modifications in cellular membranes in response to stress. A decrease in the temperature at which the organism is grown would produce a decrease in the fluidity of the membrane with resulting marked effects upon membrane-bound enzymatic activities. Similarly, increased temperature would result in increased fluidity of the lipid membrane and similar alterations in its function. In order

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Section: Nelsonmentioning

confidence: 95%

Corticosteroid-Induced Changes in Phospholipid Membranes as Mediators of Their Action*

Nelson

1980

Endocrine Reviews

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“…A 10 ytL aliquot was removed for counting and the rest was divided into two parts. Each part was chromatographed on a potassium oxalate-coated silicagel plate (13) Inositol-labeled phospholipids from barley aleurone layers were mixed with a mixture of PtdIns, PtdInsP, and PtdInsP2 (3 mg total) and treated with 1.5 mL of methylamine: methanol:water:n-butanol (5:4:3:1, v/v) at 53°C for 30 min. To the concentrated residue was added 2 mL of water, and the fatty acid amides were extracted twice with 2.4 mL of nbutanol:hexane:ethyl formate (20:4:1, v/v).…”

Section: Phospholipid Extraction and Separationmentioning

confidence: 99%

Phosphoinositides in Barley Aleurone Layers and Gibberellic Acid-Induced Changes in Metabolism

Murthy¹,

Renders²,

Keranen³

1989

Plant Physiol.

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The plant hormone gibberellin is involved in the regulation ofa number ofdiverse processes, including germination, shoot elongation, and fruit formation. Gibberellin-induced a-amylase synthesis and secretion during germination has been extensively studied and the involvement of Ca2" in this process is well established (4,12,14). However, the molecular mechanism of hormone perception, message transduction, and biochemical regulation is unknown.Membrane-bound phosphoinositides mediate signal transduction across cell membranes in a wide variety of animal cells (3,6). In these systems, ligand-receptor interaction on the extracellular face of the membrane leads to activation of a membrane-bound phospholipase-C which cleaves PtdInsP22 to diacylglycerol and Ins(1,4,5)P3. Ins(1,4,5)P3 releases calcium from endoplasmic reticulum, thereby increasing intracellular free calcium levels. At these elevated levels, calcium modifies enzyme activity by binding directly or as a Ca2+_ calmodulin complex. In addition, the released diglyceride activates protein kinase-C. 'Supported by a grant from the National Science Foundation (DCB-8609038).2Abbreviations: PtdInsP2, phosphatidylinositol bisphosphate; Ins( 1, 4, 5)P3, myo-inositol-1,4,5-trisphosphate; PtdInsP, phosphatidylinositol phosphate; PtdCh, phosphatidylcholine; LPtdCH, lysophosphatidylcholine; LPtdIns, lysophosphatidylinositol; PtdIns, phosphatidylinositol; GroPIns, glycerophosphoinositol; GroPInsP, glycerophosphoinositol phosphate; GroPInsP2, glycerophosphoinositol bisphosphate. MATERIALS AND METHODS Labeling with Radioactive PrecursorsBarley seeds (Hordeum vulgare L. cv Himalaya, 1979) were deembryonated, surface-sterilized (for 30 min in 1% [w/v] NaOCl, made by 5-fold dilution of commercial bleach), washed with sterile water, and allowed to imbibe on wet sterile sand for 4 d at room temperature. To label the myo-inositolderived compounds with tritium, aleurone layers were removed from imbibed seeds as described by Chrispeels and Varner (7)

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“…The phospholipids in the trichloroacetic acid precipitate were extracted with 5.5 ml of chloroform/methanol/HCl, 12 N (2:1:0.0075), the extracts washed three times with I ml of chloroform/methanol/HCa, 0.6 N (3:48:47), and dried under a stream of air. Phosphoinositides were analyzed by thin-layer chromatography according to Jolles et al (22).…”

Section: Introductionmentioning

confidence: 99%

Chemotactic peptide activation of human neutrophils and HL-60 cells. Pertussis toxin reveals correlation between inositol trisphosphate generation, calcium ion transients, and cellular activation.

Krause¹,

Schlegel²,

Wollheim³

et al. 1985

J. Clin. Invest.

172

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IntroductionThe mechanism of neutrophil activation by the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP) has been studied by pretreatment of human neutrophils with pertussis toxin. Upon stimulation with FMLP, the cytosolic-free calcium concentration, [Ca2j1, is increased both by stimulation of calcium influx and mobilization of cellular calcium. We have measured [Ca2+h as well as the generation of the phospholipid breakdown product inositol trisphosphate (IP3), which is thought to mediate Ca2+ mobilization. As the phosphoinositide pool in human neutrophils is difficult to prelabel with I3Hlmyoinositol, experiments were also carried out in the cultured human promyelocytic leukemia cell line HL-60 after differentiation with dimethylsulfoxide. Pertussis toxin pretreatment of both cell types inhibited FMLP stimulated membrane depolarization, exocytosis, and superoxide production in a dose-dependent manner. This toxin effect was selective for the receptor agonist, since stimulation of these parameters by two substances bypassing the transduction mechanism, the calcium ionophore ionomycin and the phorbolester phorbol myristate acetate, were unaffected.Rises in ICa2+ji, as well as generation of IP3 in response to FMLP, were inhibited in parallel; for the inhibition of functional responses, slightly lower toxin concentrations were required. The attentuation of the ICa2+i rise was more marked in the absence of extracellular calcium, i.e., when the rise is due only to calcium mobilization.The results provide evidence that phospholipase C stimulation by FMLP resulting in IP3 generation is involved in the signal transduction mechanism. Coupling of FMLP receptor occupancy to phospholipase C activation is sensitive to pertussis toxin, suggesting the involvement of a GTP binding protein (N protein), which has been shown to be a pertussis toxin substrate. The interaction of the chemotactic peptide formyl-methionylleucyl-phenylalanin (FMLP)' with specific cell surface receptors in neutrophils leads to a rapid rise in cytosolic-free calcium ([Ca2+], which appears to be necessary for cellular activation (1, 2). Two recent observations suggest that inositol trisphosphate (UP3), a product ofthe hydrolysis ofthe plasma membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) by phospholipase C (also referred to as polyphosphoinositide phosphodiesterase), acts as a second messenger: IP3 is generated within seconds after chemotactic peptide stimulation of neutrophils (3, 4) and HL-60 cells (5) It remains, however, unclear how the stimulus receptor complex activates phospholipase C. Recent data in several systems suggest the involvement of nucleotide regulatory proteins, called N proteins (7) or G proteins (8), in receptor stimulation of PIP2 breakdown (9-1 1). Bacterial toxins, namely cholera toxin and pertussis toxin, have been used in the past to investigate the role of N proteins in receptor coupling, since they modify N protein function by ADP ribosylation (8). Pertussis toxin has been shown to...

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Pituitary hormones influence polyphosphoinositide metabolism in rat brain

Cited by 89 publications

References 27 publications

Corticosteroid-Induced Changes in Phospholipid Membranes as Mediators of Their Action*

Corticosteroid-Induced Changes in Phospholipid Membranes as Mediators of Their Action*

Phosphoinositides in Barley Aleurone Layers and Gibberellic Acid-Induced Changes in Metabolism

Chemotactic peptide activation of human neutrophils and HL-60 cells. Pertussis toxin reveals correlation between inositol trisphosphate generation, calcium ion transients, and cellular activation.

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