The '''G-CSF factor stem-loop destabilising element (SLDE)''' is an [[cis-regulatory element|RNA element]] secreted by [[fibroblast]]s and endothelial cells in response to the inflammatory mediators [[interleukin-1]] (IL-1) and [[tumour necrosis factor-alpha]] and by activated [[macrophage|macrophages]]. The synthesis of G-CSF is regulated both [[transcription (genetics)|transcriptionally]] and through control of [[mRNA]] stability. In unstimulated cells G-CSF mRNA is unstable but becomes stabilised in response to IL-1 or tumour necrosis factor alpha, and also in the case of [[monocyte|monocytes]] and macrophages, in response to [[lipopolysaccharide]]. It is likely that the presence of the SLDE in the G-CSF mRNA contributes to the specificity of regulation of G-CSF mRNA and enhances the rate of shortening of the [[polyadenylation|poly(A) tail]].<ref>{{cite journal | last = Putland | first = RA | coauthors = Sassinis TA, Harvey JS, Diamond P, Coles LS, Brown CY, Goodall GJ | year = 2002 | title = RNA destabilization by the granulocyte colony-stimulating factor stem-loop destabilizing element involves a single stem-loop that promotes deadenylation | journal = Mol Cell Biol | volume = 22 | pages = 1664–1673 | pmid = 11865046 | doi = 10.1128/MCB.22.6.1664-1673.2002 | issue = 6 | pmc = 135610}}</ref>
