Evidence that elastase is the TNF‐R75 shedding enzyme in resting human polymorphonuclear leukocytes

FEBS Letters

Menegazzi, Renzo¹  Patriarca, Pierluigi¹  Dri, Pietro¹  Gasparini, Chiara¹ 

[1] Department of Physiology and Pathology, University of Trieste, Via A. Fleming 22, Trieste, Italy

关键词: Neutrophil;    Human;    Elastase;    Shedding;    TNF receptor;    TNF;    tumor necrosis factor;    TNF-R75;    75-kDa TNF receptor;    TNF-R55;    55-kDa TNF receptor;    FMLP;    N-formyl-L-methionyl-L-leucyl-L-phenylalanine;    DFP;    diisopropylfluorophosphate;   

DOI  :  10.1016/S0014-5793(03)01046-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We previously showed that a metalloprotease and a serine protease mediate shedding of the TNF-R75 (75-kDa tumor necrosis factor receptor) in neutrophils. Here we show that elastase is the TNF-R75 solubilizing serine protease. Release of the TNF-R75 by resting cells was almost totally inhibited by the serine protease inhibitor diisopropylfluorophosphate (DFP), by two synthetic, chemically unrelated, elastase-specific inhibitors and by α1-protease inhibitor. Release after TNF or FMLP (N-formyl-L-methionyl-L-leucyl-L-phenylalanine) stimulation was blocked by DFP and a metalloprotease inhibitor used in combination. Supernatants from resting neutrophils contained a 28-kDa fragment of the receptor, compatible with that generated by elastase, whose appearance was inhibited by DFP. Upon FMLP stimulation, the release of 28-kDa and 40-kDa fragments was observed, which was inhibited by DFP and a metalloprotease inhibitor, respectively. We conclude that elastase is the TNF-R75 sheddase of resting neutrophils and that it contributes to shedding of this receptor in stimulated cells.

【 授权许可】

Unknown