Activation of protein kinase C attenuates prostaglandin E2 responses in a colonic cell line

1988 ◽  
Vol 255 (1) ◽  
pp. G27-G32 ◽  
Author(s):  
G. Warhurst ◽  
N. B. Higgs ◽  
M. Lees ◽  
A. Tonge ◽  
L. A. Turnberg
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Prostaglandin E2 ◽  
Cell Line ◽  
Cellular Response ◽  
Short Circuit ◽  
Regulatory Subunit ◽  
Epithelial Cell Line ◽  
Kinase C

We examined the possibility that the protein kinase C pathway may interact with the adenosine 3',5'-cyclic monophosphate (cAMP) pathway in intestinal epithelium by studying the influence of phorbol esters on the response to prostaglandin E2 (PGE2) in a colonic epithelial cell line. Pretreatment of T84 cells with 4 beta-phorbol 12,13-dibutyrate (PDB) markedly attenuated the rise in short-circuit current provoked by PGE2, a receptor-mediated cAMP agonist. The EC50 of this effect was 52 nM PDB with a half time of 4-6 min. The responses to nonreceptor-mediated agonists, forskolin and dibutyryl cAMP, were unaffected by phorbol ester. PDB also reduced the ability of PGE2 to stimulate adenylate cyclase activity in these cells. The accumulation of cAMP in response to PGE2 was inhibited by PDB (EC50 38 nM), an effect mimicked by the diacylglycerol analogue 1-oleoyl-2-acetyl-sn-glycerol. In addition, PGE2 stimulation of adenylate cyclase in membranes from PDB-treated cells was reduced by 30-40%. Inhibition was not mediated via the catalytic or regulatory subunit of the adenylate cyclase, implying an action involving desensitization of PGE2 receptors. These results provide evidence of a complex interrelationship between protein kinase C- and cAMP-mediated pathways that might be important in regulating the cellular response to secretagogues.

scholarly journals Insulin and vasopressin elicit inhibition of cholera-toxin-stimulated adenylate cyclase activity in both hepatocytes and the P9 immortalized hepatocyte cell line through an action involving protein kinase C

1995 ◽  
Vol 312 (3) ◽  
pp. 769-774 ◽  
Author(s):  
L Zeng ◽  
M D Houslay
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Cell Line ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
3T3 Cells ◽  
Kinase C ◽  
Nih 3T3

Incubation of hepatocytes or the SV40-DNA-immortalized hepatocyte P9 cell line with cholera toxin led to a time-dependent activation of adenylate cyclase activity, which occurred after a defined lag period. When added together with cholera toxin, each of the hormones insulin and vasopressin was capable of attenuating the maximum stimulatory effect achieved by cholera toxin over a period of 60 min through a process which could be blocked by the compounds staurosporine and chelerythrine. Attenuating effects on cholera-toxin-stimulated adenylate cyclase activity could also be elicited by using either the protein kinase C (PKC)-stimulating phorbol ester PMA (phorbol 12-myristate 13-acetate) or the protein phosphatase inhibitor okadaic acid. Alkaline phosphatase treatment of membranes reversed the inhibitory effect of PMA. Cholera toxin also stimulated the adenylate cyclase activity of intact CHO (Chinese-hamster ovary) and NIH-3T3 cells, but this activity was insensitive to the addition of PMA. Overexpression of various PKC isoforms in CHO cell lines did not confer sensitivity to inhibition by PMA upon cholera-toxin-stimulated adenylate cyclase activity. Rather, overexpression of the gamma isoform of PKC allowed PMA to stimulate adenylate cyclase activity in CHO cells. It is suggested that the PKC-mediated phosphorylation of a membrane protein attenuates cholera-toxin-stimulated adenylate cyclase activity in hepatocytes and P9 cells. The cellular selectivity of such an action may be due to the target for this inhibitory action of PKC being a particular isoform of adenylate cyclase which provides the major activity in hepatocytes and P9 cells, but not in either CHO or NIH-3T3 cells.

Suppression of Protein Kinase C?? Triggers Apoptosis Through Down-Regulation of BCL-XL in a Rat Hepatic Epithelial Cell Line

Shock ◽  
2003 ◽  
Vol 19 (6) ◽  
pp. 582-587 ◽  
Author(s):  
Ya-Ching Hsieh ◽  
Hsiao-Ching Jao ◽  
Rei-Cheng Yang ◽  
Hseng-Kuang Hsu ◽  
Chin Hsu
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cell ◽  
Cell Line ◽  
Epithelial Cell Line ◽  
Down Regulation ◽  
Kinase C

Role of protein kinase C in the pigment cell of the lizard (Anolis carolinensis)

1987 ◽  
Vol 112 (2) ◽  
pp. 283-287 ◽  
Author(s):  
A. M. Lucas ◽  
A. J. Thody ◽  
S. Shuster
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Pigment Cell ◽  
Anolis Carolinensis ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Kinase C

ABSTRACT The role of protein kinase C in melanosome dispersion was examined using the melanophores of the lizard Anolis carolinensis and an in-vitro rate method of bioassay. The phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which directly activates protein kinase C, was able to potentiate the melanophore response to α-MSH in a dose-dependent manner. Similarly, the stimulatory response to forskolin, which activates the adenylate cyclase catalytic subunit, was also potentiated by TPA. The response of the melanophore to cyclic AMP, however, remained unaltered by any dose of TPA. We thus propose that the potentiation of α-MSH potency by TPA is through an interaction of protein kinase C with adenylate cyclase and, more specifically, that this interaction may be at the level of the linkage of the nucleotide regulatory subunit Ns with the catalytic moiety C of adenylate cyclase. J. Endocr. (1987) 112, 283–287

Muscarinic regulation of potassium transport in a human submandibular epithelial cell line

1990 ◽  
Vol 259 (2) ◽  
pp. C340-C348 ◽  
Author(s):  
J. A. Ship ◽  
L. L. Patton ◽  
R. B. Wellner
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cell ◽  
Cell Line ◽  
Calcium Ionophore ◽  
Epithelial Cell Line ◽  
Ionophore A23187 ◽  
Muscarinic Agonist ◽  
Kinase C ◽  
86Rb Influx

Results of previous studies suggest that the transport of K+ by salivary ducts is under muscarinic control. The mechanisms by which this regulation occurs have not been well defined, however. In this paper, we describe mechanisms involved in the muscarinic regulation of K+ (86Rb) transport in HSG-PA, an epithelial cell line derived from human submandibular gland duct. Stimulation of HSG-PA cells by carbachol, a muscarinic agonist, increases both 86Rb influx and efflux, which results in a decrease in the equilibrium content of 86Rb within the cells. Increases in both fluxes are dose dependent with respect to carbachol concentration, and both responses can be blocked by atropine, a muscarinic antagonist. The carbachol-stimulated 86Rb fluxes appear to be calcium dependent since 1) the calcium ionophore A23187 increases 86Rb fluxes in these cells, 2) cells loaded with 1,2-bis(2-aminophenoxy)ethane- N,N,N',N'-tetraacetic acid (BAPTA; a calcium chelator) exhibit a reduced ability to respond to carbachol stimulation, and 3) removal of extracellular calcium concentration reduces the carbachol-stimulated effects. Treatment of HSG-PA cells with 10(-7) M phorbol myristate acetate (PMA) partially blocks the carbachol-stimulated changes in 86Rb fluxes, suggesting that protein kinase C plays a role in this response. PMA also partially blocks A23187-stimulated 86Rb influx, suggesting that activation of protein kinase C inhibits muscarinic-stimulated K+ influx by blocking either the Ca2+ signal (X. He, X. Wu, and B.J. Baum. Biochem. Biophys. Res. Commun. 152: 1062-1069, 1988), steps subsequent to this effect, or both.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Dual role for protein kinase C α as a regulator of ion secretion in the HT29cl.19A human colonic cell line

1992 ◽  
Vol 285 (2) ◽  
pp. 673-679 ◽  
Author(s):  
N van den Berghe ◽  
A B Vaandrager ◽  
A G M Bot ◽  
P J Parker ◽  
H R de Jonge
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Line ◽  
Phorbol Esters ◽  
Prolonged Exposure ◽  
Electrical Response ◽  
Short Circuit ◽  
Ion Secretion ◽  
Kinase C ◽  
Pkc Alpha

The involvement of protein kinase C (PKC) in the regulation of intestinal ion secretion was studied in polarized monolayers of the HT29cl.19A human colon carcinoma cell line. Carbachol, phorbol esters [PMA (phorbol 12-myristate 13-acetate) and PDB (phorbol 12,13-dibutyrate)] and 8-bromo cyclic AMP (8-Br-cAMP) induced Cl secretion, as measured by a rise in the short-circuit current (ISC). The electrical response to carbachol coincided with a transient translocation of PKC alpha from the soluble to the particulate fraction. The carbachol-, PDB- and 8-Br-cAMP-induced ISC responses were inhibited by pretreatment of the cells with PMA (0.5 microM) for 2 h, a time period in which PKC alpha, beta 1 and gamma levels were not changed. As shown by 86Rb+ and 125I- efflux studies, the main targets for this inhibition were basolateral K+ transporters rather than apical Cl- channels. Prolonged exposure to PMA (24 h) led to a 60% recovery of the 8-Br-cAMP response, but not of the carbachol- or PDB-provoked secretion. As shown by immunoblotting with PKC-isoenzyme-specific antisera, the recovery of the 8-Br-cAMP response coincided with the down-regulation of PKC alpha, whereas the levels of PKC beta 1 and gamma were unmodified. These results suggest that PKC alpha, but not PKC beta 1 or gamma, is involved in both acute stimulation and chronic inhibition of ion secretion in the HT29cl.19A colonic cell line.

ANF and bradykinin synergistically inhibit transport in M-1 cortical collecting duct cell line

1992 ◽  
Vol 263 (1) ◽  
pp. F1-F6 ◽  
Author(s):  
B. A. Stoos ◽  
O. A. Carretero ◽  
J. L. Garvin
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Line ◽  
Collecting Duct ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Duct Cell ◽  
Cortical Collecting Duct ◽  
Water Excretion ◽  
Kinase C

Previous data suggest that atrial natriuretic factor (ANF) and bradykinin (BK) interact to increase Na+ and water excretion. We propose that this interaction is due to a synergistic action that inhibits Na+ absorption in the distal nephron. We examined the effects of BK and ANF on transport by monolayers of a cortical collecting duct cell line, M-1. BK (10(-8) M) had no effect on short-circuit current (Isc). Similarly, ANF (10(-8) M) did not inhibit Isc. In contrast, Isc decreased by 18% (from 57 +/- 8 to 46 +/- 6 microA/cm2) when BK and ANF were added simultaneously at this concentration (P less than 0.05). Because guanosine 3',5'-cyclic monophosphate (cGMP) and protein kinase C are implicated in the second messenger cascades of ANF and BK, we investigated their potential roles in mediating this interaction. Dibutyryl-cGMP (10(-4) M) inhibited Isc from 33 +/- 4 to 22 +/- 3 microA/cm2 (P less than 0.05) in the presence of BK but not in its absence. Staurosporine and calphostin C, inhibitors of protein kinase C, completely blocked the decrease in Isccaused by simultaneous addition of ANF and BK. cAMP levels in M-1 cells were not affected by either ANF alone or BK alone; however, when cultures were treated with both hormones, cAMP decreased from 856 +/- 56 to 332 +/- 26 fmol/10(6) cells (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

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