Dataset Information

Production of proteoglycans by human lung fibroblasts (IMR-90) maintained in a low concentration of serum.

ABSTRACT: Maintenance of fibroblasts in 0.5% serum results in viable but non-proliferative cells that may be analogous to fibroblasts in vivo. The synthesis of proteoglycans by human embryo lung fibroblasts in Eagle's minimal essential medium with 0.5% newborn-bovine serum or with 10% serum has been compared. A similar amount of [35S]sulphate-labelled glycosaminoglycan per cell was secreted by fibroblasts in 10% or 0.5% serum. 35SO42-incorporation into sulphated glycosaminoglycans was enhanced in 0.5% serum when expressed per mg of cell protein, but [3H]glucosamine incorporation was decreased. The charge density of these glycosaminoglycans was not changed as determined by ion-exchange chromatography. It was concluded that decreased protein/ cell resulted in an apparent increase in 35S-labelled glycosaminoglycan synthesis/mg of cell protein, whereas decreased uptake of [3H]glucosamine resulted in a decrease in their glucosamine labelling. The proteoglycans secreted by fibroblasts in 0.5% serum were similar in glycosaminoglycan composition, chain length and buoyant density to the dermatan sulphate proteoglycan, which is the major secreted component of cells in 10% serum. Larger heparan sulphate and chondroitin sulphate proteoglycans, which comprise about 40% of the total secreted proteoglycans of cultures in 10% serum, were greatly diminished in the medium of cultures in 0.5% serum. The proteoglycan profile of medium from density-inhibited cultures in 10% serum resembles that of proliferating cultures, indicating that lack of proliferation was not responsible for the alteration. The dermatan sulphate proteoglycan, participating in extracellular matrix structure, may be the primary tissue product of lung fibroblasts in vivo.

SUBMITTER: Vogel KG

PROVIDER: S-EPMC1153875 | biostudies-other | 1982 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BackgroundThe existence of a radiation bystander effect, in which non-irradiated cells respond to signals from irradiated cells, is well established. To understand early signaling and gene regulation in bystander cells, we used a bio-informatics approach, measuring global gene expression at 30 minutes and signaling pathways between 30 minutes and 4 hours after exposure to alpha-particles in IMR-90 fibroblasts.MethodsWe used whole human genome microarrays and real time quantitative PCR to measure and validate gene expression. Microarray analysis was done using BRB-Array Tools; pathway and ontology analyses were done using Ingenuity Pathway Analysis and PANTHER, respectively. We studied signaling in irradiated and bystander cells using immunoblotting and semi-quantitative image analysis.ResultsGene ontology suggested signal transduction and transcriptional regulation responding 30 minutes after treatment affected cell structure, motility and adhesion, and interleukin synthesis. We measured time-dependent expression of genes controlled by the NF-kappaB pathway; matrix metalloproteinases 1 and 3; chemokine ligands 2, 3 and 5 and interleukins 1beta, 6 and 33. There was an increased response of this set of genes 30 minutes after treatment and another wave of induction at 4 hours. We investigated AKT-GSK3beta signaling and found both AKT and GSK3beta are hyper-phosphorylated 30 minutes after irradiation and this effect is maintained through 4 hours. In bystander cells, a similar response was seen with a delay of 30 minutes. We proposed a network model where the observed decrease in phosphorylation of beta-catenin protein after GSK3beta dependent inactivation can trigger target gene expression at later times after radiation exposureConclusionsThese results are the first to show that the radiation induced bystander signal induces a widespread gene expression response at 30 minutes after treatment and these changes are accompanied by modification of signaling proteins in the PI3K-AKT-GSK3beta pathway.

Dataset Information

Production of proteoglycans by human lung fibroblasts (IMR-90) maintained in a low concentration of serum.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets