scholarly journals Adiponectin Stimulates Proliferation of Adult Hippocampal Neural Stem/Progenitor Cells through Activation of p38 Mitogen-activated Protein Kinase (p38MAPK)/Glycogen Synthase Kinase 3β (GSK-3β)/β-Catenin Signaling Cascade

2011 ◽  
Vol 286 (52) ◽  
pp. 44913-44920 ◽  
Author(s):  
Di Zhang ◽  
Ming Guo ◽  
Wei Zhang ◽  
Xin-Yun Lu
2000 ◽  
Vol 151 (1) ◽  
pp. 117-130 ◽  
Author(s):  
Syed Haq ◽  
Gabriel Choukroun ◽  
Zhao Bin Kang ◽  
Hardeep Ranu ◽  
Takashi Matsui ◽  
...  

Hypertrophy is a basic cellular response to a variety of stressors and growth factors, and has been best characterized in myocytes. Pathologic hypertrophy of cardiac myocytes leads to heart failure, a major cause of death and disability in the developed world. Several cytosolic signaling pathways have been identified that transduce prohypertrophic signals, but to date, little work has focused on signaling pathways that might negatively regulate hypertrophy. Herein, we report that glycogen synthase kinase-3β (GSK-3β), a protein kinase previously implicated in processes as diverse as development and tumorigenesis, is inactivated by hypertrophic stimuli via a phosphoinositide 3-kinase–dependent protein kinase that phosphorylates GSK-3β on ser 9. Using adenovirus-mediated gene transfer of GSK-3β containing a ser 9 to alanine mutation, which prevents inactivation by hypertrophic stimuli, we demonstrate that inactivation of GSK-3β is required for cardiomyocytes to undergo hypertrophy. Furthermore, our data suggest that GSK-3β regulates the hypertrophic response, at least in part, by modulating the nuclear/cytoplasmic partitioning of a member of the nuclear factor of activated T cells family of transcription factors. The identification of GSK-3β as a transducer of antihypertrophic signals suggests that novel therapeutic strategies to treat hypertrophic diseases of the heart could be designed that target components of the GSK-3 pathway.


2000 ◽  
Vol 20 (24) ◽  
pp. 9356-9363 ◽  
Author(s):  
Mingtao Li ◽  
Xiaomin Wang ◽  
Mary Kay Meintzer ◽  
Tracey Laessig ◽  
Morris J. Birnbaum ◽  
...  

ABSTRACT Agents that elevate intracellular cyclic AMP (cAMP) levels promote neuronal survival in a manner independent of neurotrophic factors. Inhibitors of phosphatidylinositol 3 kinase and dominant-inactive mutants of the protein kinase Akt do not block the survival effects of cAMP, suggesting that another signaling pathway is involved. In this report, we demonstrate that elevation of intracellular cAMP levels in rat cerebellar granule neurons leads to phosphorylation and inhibition of glycogen synthase kinase 3β (GSK-3β). The increased phosphorylation of GSK-3β by protein kinase A (PKA) occurs at serine 9, the same site phosphorylated by Akt. Purified PKA is able to phosphorylate recombinant GSK-3β in vitro. Inhibitors of GSK-3 block apoptosis in these neurons, and transfection of neurons with a GSK-3β mutant that cannot be phosphorylated interferes with the prosurvival effects of cAMP. These data suggest that activated PKA directly phosphorylates GSK-3β and inhibits its apoptotic activity in neurons.


2015 ◽  
Vol 36 (5) ◽  
pp. 731-741 ◽  
Author(s):  
Nydia Tejeda-Muñoz ◽  
Héctor González-Aguilar ◽  
Paula Santoyo-Ramos ◽  
M. Cristina Castañeda-Patlán ◽  
Martha Robles-Flores

The molecular events that drive Wnt-induced regulation of glycogen synthase kinase 3β (GSK-3β) activity are poorly defined. In this study, we found that protein kinase Cζ (PKCζ) and GSK-3β interact mainly in colon cancer cells. Wnt stimulation induced a rapid GSK-3β redistribution from the cytoplasm to the nuclei in malignant cells and a transient PKC-mediated phosphorylation of GSK-3β at a different site from serine 9. In addition, while Wnt treatment induced a decrease in PKC-mediated phosphorylation of GSK-3β in nonmalignant cells, in malignant cells, this phosphorylation was increased. Pharmacological inhibition and small interfering RNA (siRNA)-mediated silencing of PKCζ abolished all of these effects, but unexpectedly, it also abolished the constitutive basal activity of GSK-3β.In vitroactivity assays demonstrated that GSK-3β phosphorylation mediated by PKCζ enhanced GSK-3β activity. We mapped Ser147 of GSK-3β as the site phosphorylated by PKCζ, i.e., its mutation into alanine abolished GSK-3β activity, resulting in β-catenin stabilization and increased transcriptional activity, whereas phosphomimetic replacement of Ser147 by glutamic acid maintained GSK-3β basal activity. Thus, we found that PKCζ phosphorylates GSK-3β at Ser147 to maintain its constitutive activity in resting cells and that Wnt stimulation modifies the phosphorylation of Ser147 to regulate GSK-3β activity in opposite manners in normal and malignant colon cells.


2004 ◽  
Vol 287 (6) ◽  
pp. H2768-H2776 ◽  
Author(s):  
John P. Konhilas ◽  
Alexander H. Maass ◽  
Stephen W. Luckey ◽  
Brian L. Stauffer ◽  
Eric N. Olson ◽  
...  

How an individual's sex and genetic background modify cardiac adaptation to increased workload is a topic of great interest. We systematically evaluated morphological and physiological cardiac adaptation in response to voluntary and forced exercise. We found that sex/gender is a dominant factor in exercise performance (in two exercise paradigms and two mouse strains) and that females of one of these strains have greater capacity to increase their cardiac mass in response to similar amounts of exercise. To explore the biochemical mechanisms for these differences, we examined signaling pathways previously implicated in cardiac hypertrophy. Ca2+/calmodulin-dependent protein kinase (CaMK) activity was significantly greater in males compared with females and increased after voluntary cage-wheel exposure in both sexes, but the proportional increase in CaMK activity was twofold higher in females compared with males. Phosphorylation of glycogen synthase kinase-3β (GSK-3β) was evident after 7 days of cage-wheel exposure in both sexes and remained elevated in females only by 21 days of exercise. Despite moderate increases in myocyte enhancer factor-2 (a downstream effector of CaMK) transcriptional activity and phosphorylation of Akt with exercise, there were no sex differences. Mitogen-activated protein kinase signaling components (p38 mitogen-activated protein kinase and extracellular regulated kinase 1/2) were not different between male and female mice and were not affected by exercise. We conclude that females have increased exercise capacity and increased hypertrophic response to exercise. We have also identified sex-specific differences in hypertrophic signaling within the cardiac myocyte that may contribute to sexual dimorphism in exercise and cardiac adaptation to exercise.


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