ATPγS Enhances the Production of Inflammatory Mediators by a Human Dermal Endothelial Cell Line via Purinergic Receptor Signaling

Abstract

Adenosine 5'-triphosphate (ATP) affects multiple intra- and extracellular processes, including vascular tone and immune responses. Microvascular endothelial cells (EC) play a central role in inflammation by recruitment of inflammatory cells from blood to tissues. We hypothesized that ATP (secreted by neurons and/or released after perturbation of cutaneous cells) may influence secretion of inflammatory messengers by dermal microvascular EC through actions on purinergic P2 receptors. Addition of the hydrolysis-resistant ATP analogue, adenosine 5'-O-(3-thiotriphosphate) (ATPgammaS), to subconfluent cultures of the human microvascular endothelial cell-1 (HMEC-1) cell line led to a dose- and time-dependent increase in release of IL-6, IL-8, monocyte chemoattractant protein-1, and growth-regulated oncogene alpha. Both ATPgammaS-induced release and basal production of these proteins were significantly inhibited by the purinergic antagonists pyridoxal-5'-phosphate-6-azophenyl-2',5'-disulfonic acid (PPADS), pyridoxal-5'-phosphate-6(2'-naphthylazo-6-nitro-4',8'-disulfonate), and suramin. ATPgammaS increased expression of intercellular adhesion molecule-1 (ICAM-1), whereas suramin and PPADS decreased both ATPgammaS-induced and basal ICAM-1 expression. Using PCR, we found that HMEC-1 strongly express mRNA for the P2X(4), P2X(5), P2X(7), P2Y(2), and P2Y(11) receptors and weakly express mRNA for P2X(1) and P2X(3) receptors. Purinergic nucleotides may mediate acute inflammation in the skin and thus contribute to physiological and pathophysiological inflammation. For example, ATP may contribute to both the vasodilation and the inflammation associated with rosacea.

Endothelial P2Y2 receptor regulates LPS-induced neutrophil transendothelial migration in vitro

“…However, several hours of stimulation are required to induce a significant upregulation of ICAM-1 expression. For example, it takes ~12 h for a significant increase of ICAM-1 expression in the lungs challenged with LPS while 24 h stimulation was needed for a 2-fold increase of ICAM-1 expression in ATPγS-stimulated human dermal microvascular endothelial cells-1 (HMEC-1) (Yan et al, 2002;Seiffert et al, 2006). In our TEM assays carried out for 3 h, only low increase of ICAM-1 expression was detected which could explain the ~15% decrease of neutrophil TEM by ICAM-1 blocking antibodies.…”

ATP Activates Regulatory T Cells In Vivo during Contact Hypersensitivity Reactions

“…These elevated levels of ATP in the skin can further be augmented by keratinocytes and endothelial cells, which both have been shown to be a source for ATP (35)(36)(37). Thus, this localized immune reaction is able to produce enough ATP, which may reach the serum causing activation of Tregs in the blood.…”

Reduced Atherosclerotic Lesions in P2Y 1 /Apolipoprotein E Double-Knockout Mice

“…Several findings indicate that adenine nucleotides may contribute to an inflammatory state of the endothelium. Thus, these molecules have been reported to increase the expression of E-selectin on primary porcine or bovine aortic endothelial cells 35 ; to upregulate the secretion and expression of interleukin-6, interleukin-8, monocyte chemoattractant protein-1, and intercellular adhesion molecule-1 in dermal endothelial cells 36 ; and to increase the adhesion of leukocytes to endothelial cells. 37,38 It remains to be determined whether the endothelial P2Y 1 receptor could contribute to these phenomena.…”