title: Sulfhydryl modification induces calcium entry through IP₃-sensitive store-operated pathway in activation-dependent human neutrophils.
abstract: As the first line of host defense, neutrophils are stimulated by pro-inflammatory cytokines from resting state, facilitating the execution of immunomodulatory functions in activation state. Sulfhydryl modification has a regulatory role in a wide variety of physiological functions through mediation of signaling transductions in various cell types. Recent research suggested that two kinds of sulfhydryl modification, S-nitrosylation by exogenous nitric oxide (NO) and alkylation by N-ethylmaleimide (NEM), could induce calcium entry through a non-store-operated pathway in resting rat neutrophils and DDT₁MF-2 cells, while in active human neutrophils a different process has been observed by us. In the present work, data showed that NEM induced a sharp rising of cytosolic calcium concentration ([Ca²⁺](c)) without external calcium, followed by a second [Ca²⁺](c) increase with readdition of external calcium in phorbol 12-myristate 13-acetate (PMA)-activated human neutrophils. Meanwhile, addition of external calcium did not cause [Ca²⁺](c) change of Ca²⁺-free PMA-activated neutrophils before application of NEM. These data indicated that NEM could induce believable store-operated calcium entry (SOCE) in PMA-activated neutrophils. Besides, we found that sodium nitroprusside (SNP), a donor of exogenous NO, resulted in believable SOCE in PMA-activated human neutrophils via S-nitrosylation modification. In contrast, NEM and SNP have no effect on [Ca²⁺](c) of resting neutrophils which were performed in suspension. Furthermore, 2-Aminoethoxydiphenyl borate, a reliable blocker of SOCE and an inhibitor of inositol 1,4,5-trisphosphate (IP₃) receptor, evidently abolished SNP and NEM-induced calcium entry at 75 µM, while preventing calcium release in a concentration-dependent manner. Considered together, these results demonstrated that NEM and SNP induced calcium entry through an IP₃-sensitive store-operated pathway of human neutrophils via sulfhydryl modification in a PMA-induced activation-dependent manner.
authors: The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics School and School of Physics, Nankai University, Tianjin, People's Republic of China. plt@nankai.edu.cn
authors: Leiting
authors: L
authors: Pan
authors: Xian
authors: X
authors: Wu
authors: Dan
authors: D
authors: Zhao
authors: Nason Ma'ani
authors: NM
authors: Hessari
authors: Imshik
authors: I
authors: Lee
authors: Xinzheng
authors: X
authors: Zhang
authors: Jingjun
authors: J
authors: Xu
mesh_terms: D000328:Adult; D000818:Animals; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D004963:Estrenes / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D001896:Boron Compounds; D004963:Estrenes; D011760:Pyrrolidinones; D013438:Sulfhydryl Compounds; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D009599:Nitroprusside; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019284:Thapsigargin; D015544:Inositol 1,4,5-Trisphosphate; C109986:2-aminoethoxydiphenyl borate; D013755:Tetradecanoylphorbol Acetate; D005033:Ethylmaleimide; D002118:Calcium