Down-regulation of L-selectin expression in neutrophils by nonsteroidal anti-inflammatory drugs: role of intracellular ATP concentration.
L-selectin is an adhesion molecule that plays an essential role in the early events of the inflammatory response. Our group has recently described that several nonsteroidal anti-inflammatory drugs (NSAIDs) are able to induce both in vivo and in vitro the shedding of L-selectin in neutrophils through an unknown mechanism. In this work, we have studied potential mechanisms involved in the shedding of L-selectin induced by NSAIDs. This effect of NSAIDs did not involve any detectable intracellular calcium flux. Pretreatment of neutrophils either with Ro 31-8220 and H7, 2 specific inhibitors of protein kinase C (PKC), or with inhibitors of protein tyrosine kinases such as tyrphostin A25 or herbimycin A did not prevent the NSAID-mediated L-selectin shedding. However, the KD-IX-73-4, an inhibitor of L-selectin proteolysis was able to block the effect of NSAIDs on L-selectin expression. Remarkably, NSAIDs caused a variable reduction in the neutrophil intracellular ATP concentration that highly correlated with the differential ability of NSAIDs to trigger L-selectin shedding (r = 0.8, P <.01). In agreement with this finding, azide plus 2-deoxy-D-glucose, 2 metabolic blockers, also induced a rapid L-selectin shedding (65% +/- 8%) without affecting the neutrophil viability, activation, or expression level of other surface molecules with soluble isoforms such as CD16 and CD59. These data indicate that the maintenance of L-selectin on the neutrophil surface requires energy consumption, which suggests that L-selectin is shed in neutrophils by default. Interestingly, NSAIDs seem to cause the shedding of L-selectin, at least in part, through the reduction of the intracellular ATP concentration.
Gómez-Gaviro
M V
MV
Servicio de Reumatología e Inmunología, Hospital de la Princesa, Universidad Autónoma de Madrid, Servicio de Reumatología, Hospital Tenerife, Spain.
Domínguez-Jiménez
C
C
Carretero
J M
JM
Sabando
P
P
González-Alvaro
I
I
Sánchez-Madrid
F
F
Díaz-González
F
F
D000255:Adenosine Triphosphate / Q000378:metabolism / Q000502:physiology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D004075:Diglycerides / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects*; D004734:Energy Metabolism; D004791:Enzyme Inhibitors; D005434:Flow Cytometry; D006801:Humans; D020128:Inhibitory Concentration 50; D007424:Intracellular Fluid / Q000737:chemistry; D019041:L-Selectin / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009504:Neutrophils / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D011493:Protein Kinase C / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000494:pharmacology; D019810:Sodium Azide / Q000494:pharmacology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004075:Diglycerides; D004791:Enzyme Inhibitors; D019041:L-Selectin; D000255:Adenosine Triphosphate; D019810:Sodium Azide; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D008666:Metalloendopeptidases