Skeletal muscle activation induces a slow calcium transient which is associated with gene expression. There has been shown that the release of ATP from cells participates in the signal transduction pathway that induces this response, but the specific receptors involved are unknown. The aim of this study was to gain a first insight into the receptors involved in this gene expression signaling pathway. Rat skeletal miotubes were incubated with specific receptors agonists (ATP, ADP, UTP, UDP and adenosine) at different concentrations. Thereafter, interleukin-6 (IL-6) and c-fos mRNAs were analyzed through the RT-PCR method, to determine the gene expression response to different extracellular receptors activation. High ATP (activates all purinergic receptors) concentrations induced increases in the gene expression of both IL-6 and c-fos, while high ADP (P2Y1 receptor) concentrations only induced increases in IL-6 mRNA. Neither UTP (receptors P2Y2 and P2Y4) nor UDP (receptor P2Y6) induced gene expression. Stimulation with adenosine (specific adenosine receptors) instead, showed a time and concentration gene expression response, increasing mRNA for both IL-6 and c-fos but under different conditions. Thus, the results show that P2Y1 and adenosine receptors activation leads to gene expression, suggesting their participation in the slow calcium signaling pathway.
Key words: slow calcium signal, nucleotide receptors, interleukin-6, c-fos
Key words: slow calcium signal, nucleotide receptors, interleukin-6, c-fos
Well done Rodrigo!!. We´ll discuss your abstract on Friday both in terms of content and form. You have done a very good job.
ResponderEliminarSee you then,
Claudia
I just have two questions.
ResponderEliminar¿Wich are the difference between the protein fraction of the cell with and without ATP?
¿What protein(s) do you think is(are) being upregulated in this system you propose?
Paula:
ResponderEliminarWe did not measure protein levels, we were just interested in gene expression changes (mRNA. For previous experiments we knew that the slow calcium transient stimulates gene expression and that ATP was involved, so we just wanted to know which ATP receptors were activated.
It is known that during exercise muscle cells produce and secretes IL-6 to the circulation. And we know that the slow calcium transient increases IL-6 mRNA, so this suggest that, al least, IL-6 protein expression should be upregulated through this pathway.