Project description:TNF-a is increased in the synovial fluid of patients with rheumatoid arthritis and osteoarthritis. TNF-a activates MEK/ERK in chondrocytes; however the overall functional relevance of MEK/ERK to TNF-a-regulated gene expression in chondrocytes is unknown. Chondrocytes were treated with TNF-a with or without the MEK1/2 inhibitor U0126 for 24 h. Microarray analysis was used to identify genes regulated by TNF-a in a MEK1/2-dependent fashion. Experiment Overall Design: Primary chondrocytes from the femoral condyles of neonatal rats were treated with DMSO (control sample), TNF-a, U0126 (selective MEK1/2 inhibitor) or TNF-a and U0126. Two biological replicates were collected for each treatment. Total RNA was collected and analyzed by Affymetrix Microarray.

2009-01-17 | E-GEOD-14402 | biostudies-arrayexpress

Rattus norvegicus

Project description:Stochastic ERK activation induced by noise and cell-to-cell propagation regulate cell density-dependent proliferation.

| PRJDB2631 | ENA

Rattus norvegicus

Project description:Global expression analysis identified a preferentially NGF-induced transcriptional program regulated by sustained MEK/ERK and AP-1 activation during PC12 differentiation.

| PRJNA148667 | ENA

Rattus norvegicus

Project description:Matrix-dependent cardiac progenitor cell fate is instructed by the early regulation of YAP and Plk2

| PRJNA309821 | ENA

Inflammation-Induced Stabilization of mRNA in Rheumatoid Arthritis

Project description:<p>During rheumatoid arthritis (RA), TNF activates fibroblast-like synoviocytes (FLS) inducing in a temporal order a constellation of genes, which perpetuate synovial inflammation. Although the molecular mechanisms regulating TNF-induced transcription are well characterized, little is known about the impact of mRNA stability on gene expression and the impact of TNF on decay rates of mRNA transcripts in FLS. To address these issues we performed RNA sequencing and genome-wide analysis of the mRNA stabilome in RA FLS. We found that TNF induces a biphasic gene expression program: initially, the inducible transcriptome consists primarily of unstable transcripts but progressively switches and becomes dominated by very stable transcripts. This temporal switch is due to: a) TNF-induced prolonged stabilization of previously unstable transcripts that enables progressive transcript accumulation over days and b) sustained expression and late induction of very stable transcripts. TNF- induced mRNA stabilization in RA FLS occurs during the late phase of TNF response, is MAPK-dependent, and involves several genes with pathogenic potential such as IL6, CXCL1, CXCL3, CXCL8/IL8, CCL2, and PTGS2. These results provide the first insights into genome-wide regulation of mRNA stability in RA FLS and highlight the potential contribution of dynamic regulation of the mRNA stabilome by TNF to chronic synovitis.</p>

| phs001371 | dbGaP

Ablation of the miRNA cluster 24 has profound effects on extracellular matrix protein abundance in cartilage

Project description:MicroRNAs (miRNAs) regulate cartilage differentiation and contribute to the onset and progression of joint degeneration. These small RNA molecules may affect extracellular matrix organization (ECM) in cartilage, but for only a few miRNAs has this role been defined in vivo. Previously, we showed that cartilage-specific genetic ablation of the Mirc24 cluster in mice leads to impaired cartilage development due to increased RAF/MEK/ERK pathway activation. Here, we studied the expression of the cluster in cartilage by LacZ reporter gene assays and determined its role for extracellular matrix homeostasis by proteome and immunoblot analysis. The cluster is expressed in prehypertrophic/hypertrophic chondrocytes of the growth plate and we now show that the cluster is also highly expressed in articular cartilage. Cartilage-specific loss of the cluster leads to increased proteoglycan 4 and matrix matrix metallopeptidase 13 levels and decreased aggrecan and collagen X levels in epiphyseal cartilage. Interestingly, these changes are linked to a decrease in SRY-related HMG box-containing (SOX) transcription factors 6 and 9, which regulate ECM production in chondrocytes. Our data suggests that the Mirc24 cluster is important for ECM homoeostasis and the expression of transcriptional regulators of matrix production in cartilage.

2020-06-18 | PXD019374 | Pride

miRNA-transcriptome profiling of growth plate cartilage

Project description:Cartilage originates from mesenchymal cell condensations that differentiate into chondrocytes of transient growth plate cartilage or permanent cartilage of the articular joint surface and trachea. MicroRNAs fine-tune the activation of entire signaling networks and thereby modulate complex cellular responses, but so far only limited data are available on miRNAs that regulate cartilage development. Here we characterize an miRNA which promotes the biosynthesis of a key component in the RAF/MEK/ERK pathway in cartilage. Specifically, by transcriptome profiling we identified miR-322 to be upregulated during chondrocyte differentiation. Among the various miR-322 target genes in the RAF/MEK/ERK pathway, only Mek1 was identified as a regulated target in chondrocytes. Surprisingly, an increased concentration of miR-322 stabilizes Mek1-mRNA to arise protein levels and dampen ERK1/2 phosphorylation, while cartilage-specific inactivation in mice linked the loss of miR-322 to decreased MEK1 levels and increased RAF/MEK/ERK pathway activation. Such mice died perinatally due to tracheal growth restriction and respiratory failure. Hence, a single miRNA can stimulate the production of an inhibitory component of a central signaling pathway to impair cartilage development.

2017-10-03 | GSE98036 | GEO

Rattus norvegicus

Project description:Regulation of liver regeneration by interference with TNF alpha mediated inflammation

| PRJNA311953 | ENA