Dataset Information

The Role of ERK1/2 Activation in Sarpogrelate-Mediated Neuroprotection.

ABSTRACT: Purpose:To characterize the mediators of 5-HT2A serotonin receptor-driven retinal neuroprotection. Methods:Albino mice were treated intraperitoneally with saline or sarpogrelate, a 5-HT2A antagonist, immediately before light exposure (LE). Following LE, retinas were harvested for a high-throughput phosphorylation microarray to quantify activated phosphorylated proteins in G protein-coupled receptor (GPCR) signaling. To confirm microarray results and define temporal changes, Western blots of select GPCR signaling proteins were performed. Since both methodologies implicated MAPK/ERK activation, the functional significance of sarpogrelate-mediated ERK1/2 activation was examined by inhibition of ERK1/2 phosphorylation via pretreatment with the MEK inhibitor (MEKi) PD0325901. The degree of neuroprotection was evaluated with spectral-domain optical coherence tomography (SD-OCT) and electroretinography (ERG). To determine the effects of sarpogrelate on gene expression, a qPCR array measuring the expression of 84 genes involved in oxidative stress and cell death was performed 48 hours post LE. Results:Sarpogrelate led to an activation of the MAPK/ERK pathway. Temporal analysis further demonstrated a transient activation of ERK1/2, starting with an early inhibition 20 minutes into LE, a maximum activation at 3 hours post LE, and a return to baseline at 7 hours post LE. Inhibition of ERK1/2 with MEKi pretreatment led to attenuation of sarpogrelate-mediated neuroprotection. LE caused significant changes in the expression of genes involved in iron metabolism, oxidative stress, and apoptosis. These changes were prevented by sarpogrelate treatment. Conclusions:Sarpogrelate-mediated retinal protection involves a transient activation of the MAPK/ERK pathway, although this pathway alone does not account for the full effect of neuroprotection.

SUBMITTER: Ku CA

PROVIDER: S-EPMC5786286 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Role of ERK1/2 Activation in Sarpogrelate-Mediated Neuroprotection.

Ku Cristy A CA Ryals Renee C RC Jiang Dan D Coyner Aaron S AS Weller Kyle K KK Sinha Wrik W Robb Bryan M BM Yang Paul P Pennesi Mark E ME

Investigative ophthalmology & visual science 20180101 1

<h4>Purpose</h4>To characterize the mediators of 5-HT2A serotonin receptor-driven retinal neuroprotection.<h4>Methods</h4>Albino mice were treated intraperitoneally with saline or sarpogrelate, a 5-HT2A antagonist, immediately before light exposure (LE). Following LE, retinas were harvested for a high-throughput phosphorylation microarray to quantify activated phosphorylated proteins in G protein-coupled receptor (GPCR) signaling. To confirm microarray results and define temporal changes, Wester ...[more]

PMID: 29368005

Similar Datasets

Project description:ObjectiveTo determine the Dynamin-related protein 1 (DRP1) regulation of mitochondrial fission in chondrocytes under pathological conditions, an area which is underexplored in osteoarthritis pathogenesis.DesignDRP1 protein expression was determined by immunohistochemistry (IHC) or immunofluorescence (IF) staining of cartilage sections. IL-1β-induced DRP1 mRNA expression in chondrocytes was quantified by qPCR and protein expression by immunoblotting. Mitochondrial fragmentation in chondrocytes was visualized by MitoTracker staining or IF staining of mitochondrial marker proteins or by transient expression of mitoDsRed. Mitochondrial reactive oxygen species (ROS) levels were determined by MitoSOX staining. Apoptosis was determined by lactate dehydrogenase (LDH) release assay, Caspase 3/7 activity assay, propidium iodide (PI), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and IF staining of cleaved caspase 3. Cytochrome c release was determined by confocal microscopy. Surgical destabilization of the medial meniscus (DMM) was used to induce osteoarthritis (OA) in mice.ResultsExpression of DRP1 and mitochondrial damage was high in human OA cartilage and in the joints of mice subjected to DMM surgery which also showed increased chondrocytes apoptosis. IL-1β-induced mitochondrial network fragmentation and chondrocyte apoptosis via modulation of DRP1 expression and activity and induce apoptosis via Bax-mediated release of Cytochrome c. Pharmacological inhibition of DRP1 activity by Mdivi-1 blocked IL-1β-induced mitochondrial damage and apoptosis in chondrocytes. Additionally, IL-1β-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) is crucial for DRP1 activation and induction of mitochondrial network fragmentation in chondrocytes as these were blocked by inhibiting ERK1/2 activation.ConclusionsThese findings demonstrate that ERK1/2 is a critical player in DRP1-mediated induction of mitochondrial fission and apoptosis in IL-1β-stimulated chondrocytes.

Dataset Information

The Role of ERK1/2 Activation in Sarpogrelate-Mediated Neuroprotection.

Publications

The Role of ERK1/2 Activation in Sarpogrelate-Mediated Neuroprotection.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets