Anoxic injury of endothelial cells causes divergent changes in protein kinase C and protein kinase A signaling pathways

1998 ◽  
Vol 33 (2) ◽  
pp. 113-124 ◽  
Author(s):  
Paula Grammas ◽  
Pete Moore ◽  
Robert E. Cashman ◽  
Robert A. Floyd
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Kinase C ◽  
Anoxic Injury ◽  
Kinase A

scholarly journals Cooperative Activation of Lipolysis by Protein Kinase A and Protein Kinase C Pathways in 3T3-L1 Adipocytes

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4940-4947 ◽  
Author(s):  
Katrin Fricke ◽  
Aleksandra Heitland ◽  
Erik Maronde
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Hormone Sensitive Lipase ◽  
Glycerol Release ◽  
Kinase C ◽  
Lipolytic Effect ◽  
Pka Pathway ◽  
Kinase A

Abstract In the present study, we investigate the coherence of signaling pathways leading to lipolysis in 3T3-L1 adipocytes. We observe two linear signaling pathways: one well known, acting via cAMP and protein kinase A (PKA) activation, and a second one induced by phorbol 12-myristate 13-acetate treatment involving protein kinase C (PKC) and MAPK. We demonstrate that both the PKA regulatory subunits RIα and RIIβ are expressed in 3T3-L1 adipocytes and are responsible for the lipolytic effect mediated via the cAMP/PKA pathway. Inhibition of the PKA pathway by the selective PKA inhibitor Rp-8-CPT-cAMPS does not impair lipolysis induced by PKC activation, and neither PD98059 nor U0126, as known MAPK kinase inhibitors, changes the level of glycerol release caused by PKA activation, indicating no cross-talk between these two pathways when only one is activated. However, when both are activated, they act synergistically on glycerol release. Additional experiments focusing on this synergy show no involvement of MAPK phosphorylation and cAMP formation. Phosphorylation of hormone-sensitive lipase is similar upon stimulation of either pathway, but we demonstrate a difference in the ability of both PKA and the PKC pathway activation to phosphorylate perilipin, which in turn may be an explanation for the different maximal lipolytic effect of both pathways.

scholarly journals Protein Kinase C Signaling in the Hypothalamic Arcuate Nucleus Regulates Sexual Receptivity in Female Rats

Endocrinology ◽  
2008 ◽  
Vol 149 (12) ◽  
pp. 5934-5942 ◽  
Author(s):  
Phoebe Dewing ◽  
Amy Christensen ◽  
Galyna Bondar ◽  
Paul Micevych
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Signaling ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Western Blotting ◽  
Arcuate Nucleus ◽  
Sexual Receptivity ◽  
Kinase C ◽  
Kinase A

Rapid membrane-mediated estradiol signaling regulating sexual receptivity requires the interaction of the estrogen receptor (ER)-α and the metabotropic glutamate receptor 1a (mGluR1a). A cell signaling antibody microarray revealed that estradiol activated 42 proteins in the arcuate nucleus of the hypothalamus (ARH). To begin an analysis of various signaling pathways, protein kinase A and protein kinase C (PKC)-θ, whose signaling pathways have been implicated in the estradiol regulation of sexual receptivity, were examined. In the ARH sample, the increase in phospho-protein kinase A could not be confirmed by Western blotting, in either cytosolic or membrane fractions. However, the increase in phosphorylated PKCθ seen with the pathway array was verified by Western blotting. To study whether rapid estradiol activation of PKC regulates the ARH-medial preoptic nucleus pathway regulating lordosis, μ-opioid receptor (MOR) internalization and lordosis reflex were tested. Blocking PKC in ARH with 2-[1-(3-dimethylaminopropyl)-1H-indol-3-yl]3-(1H-indol-3-yl) maleimide significantly attenuated estradiol-induced MOR internalization. Furthermore, disruption of PKC signaling within the ARH at the time of estradiol treatment significantly diminished the lordosis reflex. Moreover, blocking PKC prevented MOR internalization when the circuit was activated by the mGluR1a agonist, (RS)-3,5-dihydroxyphenylglycine. Activation of PKC with phorbol 12, 13-dibutyrate induced MOR internalization, indicating that PKC was a critical step for membrane ERα-initiated mGluR1a-mediated cell signaling and phorbol 12, 13-dibutyrate significantly facilitated the lordosis reflex. Together these findings indicate that rapid membrane ERα-mGluR1a interactions activate PKCθ cell signaling, which regulates female sexual receptivity.

Sign in / Sign up

Export Citation Format

Share Document