Feedback Mechanism in Depolarization-Induced Sustained Activation of Extracellular Signal-Regulated Kinase in the Hippocampus

Maharana, Chinmoyee; Sharma, Kaushik; Sharma, Shiv K.

doi:10.1038/srep01103

Cited by 17 publications

(19 citation statements)

References 58 publications

(78 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With regards to ERK, it has been demonstrated to promote CM survival, and could be activated by the GPCR, Ras/Raf cascade [50]. Indeed, potassium-induced depolarization activated ERK and proline-rich tyrosine kinase in the central nervous system [51, 52] and a similar result was also found in CMs treated with potassium channel blockers [53]. In our study, ERK 1/2 was fairly consistent across both treatment groups; however activated ERK (pERK1/2) is upregulated in both potassium and ouabain groups.…”

Section: Discussionmentioning

confidence: 99%

Depolarization of Cellular Resting Membrane Potential Promotes Neonatal Cardiomyocyte Proliferation In Vitro

et al. 2014

View full text Add to dashboard Cite

Cardiomyocytes (CMs) undergo a rapid transition from hyperplastic to hypertrophic growth soon after birth, which is a major challenge to the development of engineered cardiac tissue for pediatric patients. Resting membrane potential (Vmem) has been shown to play an important role in cell differentiation and proliferation during development. We hypothesized that depolarization of neonatal CMs would stimulate or maintain CM proliferation in vitro. To test our hypothesis, we isolated postnatal day 3 neonatal rat CMs and subjected them to sustained depolarization via the addition of potassium gluconate or Ouabain to the culture medium. Cell density and CM percentage measurements demonstrated an increase in mitotic CMs along with a ~2 fold increase in CM numbers with depolarization. In addition, depolarization led to an increase in cells in G2 and S phase, indicating increased proliferation, as measured by flow cytometry. Surprisingly depolarization of Vmem with either treatment led to inhibition of proliferation in cardiac fibroblasts. This effect is abrogated when the study was carried out on postnatal day 7 neonatal CMs, which are less proliferative, indicating that the likely mechanism of depolarization is the maintenance of the proliferating CM population. In summary, our findings suggest that depolarization maintains postnatal CM proliferation and may be a novel approach to encourage growth of engineered tissue and cardiac regeneration in pediatric patients.

show abstract

Section: Discussionmentioning

confidence: 99%

Depolarization of Cellular Resting Membrane Potential Promotes Neonatal Cardiomyocyte Proliferation In Vitro

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Several studies have shown that ERK activity is indeed regulated by different stimuli, among which we chose three examples. (1) KCl depolarization induces sustained ERK activation in hippocampal neurons (27, 28). (2) Selective extrasynaptic NMDA receptor activation (as well as NMDA bath application) does not activate ERK pathways, whereas (3) synaptic NMDAR activation – to induce a chemical LTP – induces ERK activation (29).…”

Section: Resultsmentioning

confidence: 99%

REV, A BRET-Based Sensor of ERK Activity

Xu¹,

Peter²,

Bouquier³

et al. 2013

Front. Endocrinol.

View full text Add to dashboard Cite

Networks of signaling molecules are activated in response to environmental changes. How are these signaling networks dynamically integrated in space and time to process particular information? To tackle this issue, biosensors of single signaling pathways have been engineered. Bioluminescence resonance energy transfer (BRET)-based biosensors have proven to be particularly efficient in that matter due to the high sensitivity of this technology to monitor protein–protein interactions or conformational changes in living cells. Extracellular signal-regulated kinases (ERK) are ubiquitously expressed and involved in many diverse cellular functions that might be encoded by the strength and spatio-temporal pattern of ERK activation. We developed a BRET-based sensor of ERK activity, called Rluc8-ERKsubstrate-Venus (REV). As expected, BRET changes of REV were correlated with ERK phosphorylation, which is required for its kinase activity. In neurons, the nature of the stimuli determines the strength, the location, or the moment of ERK activation, thus highlighting how acute modulation of ERK may encode the nature of initial stimulus to specify the consequences of this activation. This study provides evidence for suitability of REV as a new biosensor to address biological questions.

show abstract

“…Male rats that were 6-8 weeks old were used for the experiments. For immediate ERK activation analysis, the slices were incubated for 1.5 h with the inhibitor (emetine, 20 mM [15], or actinomycin D, 25 mM [15]) during the recovery period and then treated with forskolin + Ro-20-1724 for 15 min, after which they were rinsed with aCSF and harvested in the lysis buffer. The animals were anaesthetized with halothane (Sigma-Aldrich, St. Louis, Missouri, USA) before killing.…”

Section: Preparation Of Hippocampal Slices and Treatmentmentioning

confidence: 99%

“…After treatments, the slices were washed with aCSF and the entire slice [15,16] was lysed in SDS containing lysis buffer (50 mM Tris-Cl, pH 7.5, 150 mM NaCl, 1 mM EDTA, 1 mM EGTA, 50 mM sodium fluoride, 1 mM sodium orthovanadate, 1 mM sodium butyrate, 2% SDS, and a protease inhibitor cocktail). After lysis, the samples were boiled for 5 min and clear supernatant containing solubilized proteins was collected after centrifugation.…”

Section: Sample Preparation and Immunoblottingmentioning

confidence: 99%

See 1 more Smart Citation

Mechanisms of cAMP-induced sustained activation of extracellular signal-regulated kinase in the hippocampus

Sharma¹,

Singh²,

Sharma³

2014

NeuroReport

Self Cite

View full text Add to dashboard Cite

Protein phosphorylation is known to regulate synaptic plasticity and memory. Protein kinases including protein kinase A and extracellular signal-regulated kinase (ERK) play important roles in these processes. Forskolin, a protein kinase A activator, induces long-term potentiation (LTP) in the hippocampus. Forskolin also induces ERK activation, which plays important roles in LTP. However, the mechanisms of forskolin-induced ERK activation are not clearly understood. Here we show that forskolin induces sustained ERK activation in the hippocampal slices. Further, blockade of protein synthesis or transcription inhibits forskolin-induced sustained ERK activation. In contrast, forskolin-induced immediate ERK activation is unaffected by inhibition of protein synthesis or transcription. Sustained ERK activation may contribute to forskolin-induced LTP in the hippocampus.

show abstract

Feedback Mechanism in Depolarization-Induced Sustained Activation of Extracellular Signal-Regulated Kinase in the Hippocampus

Cited by 17 publications

References 58 publications

Depolarization of Cellular Resting Membrane Potential Promotes Neonatal Cardiomyocyte Proliferation In Vitro

Depolarization of Cellular Resting Membrane Potential Promotes Neonatal Cardiomyocyte Proliferation In Vitro

REV, A BRET-Based Sensor of ERK Activity

Mechanisms of cAMP-induced sustained activation of extracellular signal-regulated kinase in the hippocampus

Contact Info

Product

Resources

About