Opposite Regulation of Adenylyl Cyclase by Protein Kinase C in Astrocyte and Microglia Cultures

Patrizio, Mario; Slepko, Natalia; Levi, Giulio

doi:10.1046/j.1471-4159.1997.69031267.x

Cited by 23 publications

(19 citation statements)

References 57 publications

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“…Basal as well as forskolin-and AlF 4 --stimulated AC activity was determined in cerebrocortical homogenates prepared from both age groups. Before measurement of AC activity, the samples were either untreated (control) or treated with phorbol myristate acetate or pervanadate in order to induce phosphorylation catalysed by PKC or protein tyrosine kinases (PTKs), respectively [29,30]. However, we did not find any significant difference in AC activity in any tested samples after activation of these protein kinases.…”

Section: Discussionmentioning

confidence: 62%

“…Therefore it was of interest to assess the potential effect of AC phosphorylation catalysed by protein kinase C (PKC) as well as by protein tyrosine kinases (PTKs). For this purpose, phorbol myristate acetate (PMA) and pervanadate (PV) were employed as effective activators of PKC and PTKs, respectively [29,30]. We determined basal as well as foskolin-and AlF 4 --stimulated AC activity in cerebrocortical homogenates prepared from both young and adult rats.…”

Section: Effect Of Phosphorylationmentioning

confidence: 99%

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Modulation of adenylyl cyclase activity in young and adult rat brain cortex. Identification of suramin as a direct inhibitor of adenylyl cyclase

et al. 2005

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Adenylyl cyclase (AC) in brain cortex from young (12‐day‐old) rats exhibits markedly higher activity than in adult (90‐day‐old) animals. In order to find some possibly different regulatory features of AC in these two age groups, here we modulated AC activity by dithiothreitol (DTT), Fe2+, ascorbic acid and suramin. We did not detect any substantial difference between the effects of all these tested agents on AC activity in cerebrocortical membranes from young and adult rats, and the enzyme activity was always about two‐fold higher in the former preparations. Nevertheless, several interesting findings have come out of these investigations. Whereas forskolin‐ and Mn2+‐stimulated AC activity was significantly enhanced by the addition of DTT, increased concentrations of Fe2+ ions or ascorbic acid substantially suppressed the enzyme activity. Lipid peroxidation induced by suitable combinations of DTT/Fe2+ or by ascorbic acid did not influence AC activity. We have also observed that PKC‐ or protein tyrosine kinase‐mediated phosphorylation apparently does not play any significant role in different activity of AC determined in cerebrocortical preparations from young and adult rats. Our experiments analysing the presumed modulatory role of suramin revealed that this pharmacologically important drug may act as a direct inhibitor of AC. The enzyme activity was diminished to the same extent by suramin in membranes from both tested age groups. Our present data show that AC is regulated similarly in brain cortex from both young and adult rats, but its overall activity is much lower in adulthood.

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Section: Discussionmentioning

confidence: 62%

Section: Effect Of Phosphorylationmentioning

confidence: 99%

Modulation of adenylyl cyclase activity in young and adult rat brain cortex. Identification of suramin as a direct inhibitor of adenylyl cyclase

et al. 2005

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“…Reasons for the differential effects of CART on cAMP accumulation in GCs vs. ␤-cells are unclear. There are precedents for differential regulation of cAMP synthesis by the same factor in different cell types/species (55,56). Also, differential CART regulation of specific adenylate cyclase and phosphodiesterase isoforms (44,57) in the two cell types and (or) differential effects of acute (␤-cells) vs. 24 h CART stimulation used in the present studies cannot be discounted.…”

Section: Discussionmentioning

confidence: 76%

Cocaine- and Amphetamine-Regulated Transcript Regulation of Follicle-Stimulating Hormone Signal Transduction in Bovine Granulosa Cells

et al. 2007

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Regulation of estradiol production, central to ovarian follicular development and reproductive function, is mediated by a complex interaction of pituitary gonadotropins such as FSH with locally produced regulatory molecules. We previously demonstrated a negative association of expression of cocaine-and amphetamine-regulated transcript (CART) with follicle health status and a novel local negative role for CART in regulation of basal estradiol production by bovine granulosa cells. However, effects of CART on FSH-induced estradiol production and the underlying mechanism(s) mediating the physiological actions of CART on granulosa cells are not known. Objectives of the present study were to determine effects of CART on basal and FSH-induced intracellular cAMP levels, aromatase mRNA, estradiol accumulation, calcium signaling, and the intracellular signaling pathways involved using primary cultures of bovine granulosa cells. CART treatment potently inhibits the FSH-induced rise in granulosa cell cAMP levels, estradiol accumulation, and aromatase mRNA. Furthermore, results show that calcium is essential for FSH-induced cAMP and estradiol accumulation, and CART significantly inhibits FSH-induced calcium influx. Select G protein and protein kinase inhibitors were used to elucidate pathways involved in CART actions. The inhibitory actions of CART on FSH signaling and estradiol production are mediated via a G(o/i)-dependent pathway, whereas none of the other signaling inhibitors had any effect on CART actions. Results demonstrate novel potent inhibitory effects of CART on multiple components of the FSH signaling pathway linked to estradiol production and follicular development and shed new insight into the mechanism of action of CART potentially pertinent within and beyond the reproductive system.

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“…Conversely, adenylyl cyclase was substantially inhibited in microglial cells treated with PMA or calphostin C for 4 hours (Patrizio et al 1997). Experiments with astrocyte or microglia cultures showed different, almost opposite regulations of cAMP responses: in astrocytes, a lO-min treatment with the phorbol esters phorbol 12-myristate 13-acetate (PMA) and 4/3phorbol-12-13 didecanoate (4/3-PDD; but not with the inactive isomer 4a-PDD), or with diacylglycerol, all of which activate PKC, caused a dose-dependent increase in the accumulation of cAMP induced by isoproterenol and forskolin.…”

Section: Regulation Of the Camp System In Microgliamentioning

confidence: 96%

“…We investigated the interaction with the protein kinase C (PKC) system (Patrizio et al 1997). We investigated the interaction with the protein kinase C (PKC) system (Patrizio et al 1997).…”

Section: Regulation Of the Camp System In Microgliamentioning

confidence: 99%

Neuro-Immune Interactions in Neurologic and Psychiatric Disorders

Patterson¹,

Kordon²,

Christen³

2000

Research and Perspectives in Neurosciences

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The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Product liability: The publishers cannot guarantee the accuracy of any information about the application of operative techniques and medications contained in this book. In every individual case the user must check such information by consulting the relevant literature. Production: PRO EDIT GmbH, D-69126 Heidelberg Cover design: Design & Production, D-69121 Heidelberg Typesetting: K+V Fotosatz GmbH, D-64743 Beerfelden SPIN 10716205 27/3136-5 4 3 2 1 0 PrefaceThe idea that the brain is an "immune-privileged site" has perhaps served to slow our realization that the intact brain can generate its own inflammatory reactions. These responses can be to peripheral infection, or they can arise from local, internal causes, for instance as a response to stress or to the severe changes in neuronal activity in seizure or the loss of oxygen in stroke. We are also becoming increasingly aware of the contribution of local inflammatory reactions to certain neurodegenerative diseases such as Alzheimer's disease (AD). In fact, evidence is accumulating that inflammatory processes contribute to the progression of AD, suggesting the possibility of using currently available or novel anti-inflammatory agents to interfere with this terrible disease. Correlations are also being made between inflammatory signs and mental illness, which is a new frontier of research.This book presents the current state of knowledge in a variety of areas relevant to neuro-immune interactions, with particular attention to AD. These chapters summarize presentations made at the October 5, 1998 meeting of the Fondation IPSEN, in Paris. Inflammation has been linked to AD both from epidemiological work and from neuropathological studies of the brain. Correlations have been made between taking anti-inflammatory drugs and postponing the onset of AD, and a variety of inflammatory markers have been localized to the senile plaques, the latter being diagnostic for AD pathology. These and related topics are discussed by Joseph Rogers and Sue Griffin in this volume. The use of transgenic mice to study AD is described by Lennert Mucke and Paul Patterson, who present new findings on the interplay of cytokines and apolipoprotein E (ApoE), and the use of anti-inflammatory drugs in this animal model. Mucke also presented novel work on the use of inducible promoters in controlling amyloid precursor protein (APP) and ApoE in new mouse models. The involvement of microglia, the phagocytic inflammatory cells of the brain, in this inflammatory reaction is discussed by Barbara Cordell, who is investigating the role of cytokines in the interaction between neurons and glia in culture. Giulio Levi also reports on the control of microglial activation and the role of cAMP. The role of the inflammatory regulator NF-KB in the micr...

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Opposite Regulation of Adenylyl Cyclase by Protein Kinase C in Astrocyte and Microglia Cultures

Cited by 23 publications

References 57 publications

Modulation of adenylyl cyclase activity in young and adult rat brain cortex. Identification of suramin as a direct inhibitor of adenylyl cyclase

Modulation of adenylyl cyclase activity in young and adult rat brain cortex. Identification of suramin as a direct inhibitor of adenylyl cyclase

Cocaine- and Amphetamine-Regulated Transcript Regulation of Follicle-Stimulating Hormone Signal Transduction in Bovine Granulosa Cells

Neuro-Immune Interactions in Neurologic and Psychiatric Disorders

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