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Treatment with LPS plus INF‐γ induces the expression and function of muscarinic acetylcholine receptors, modulating NIH 3 T 3 cell proliferation: participation of NOS and COX
Author(s) -
Español A J,
Maddaleno M O,
Lombardi M G,
Cella M,
Martínez Pulido P,
Sales M E
Publication year - 2014
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.12834
Subject(s) - muscarinic acetylcholine receptor , acetylcholine , receptor , function (biology) , chemistry , microbiology and biotechnology , muscarinic acetylcholine receptor m3 , cell growth , acetylcholine receptor , pharmacology , endocrinology , medicine , biology , biochemistry
Background and Purpose LPS and IFN ‐γ are potent stimuli of inflammation, a process in which fibroblasts are frequently involved. We analysed the effect of treatment with LPS plus IFN ‐γ on the expression and function of muscarinic acetylcholine receptors in NIH 3 T 3 fibroblasts with regards to proliferation of these cells. We also investigated the participation of NOS and COX , and the role of NF ‐κ B in this process. Experimental Approach NIH 3 T 3 cells were treated with LPS (10 ng·mL −1 ) plus IFN ‐γ (0.5 ng·mL −1 ) for 72 h (iNIH3T3 cells). Cell proliferation was evaluated with MTT and protein expression by Western blot analysis. NOS and COX activities were measured by the Griess method and radioimmunoassay respectively. Key Results The cholinoceptor agonist carbachol was more effective at stimulating proliferation in i NIH 3 T 3 than in NIH 3 T 3 cells, probably due to the de novo induction of M 3 and M 5 muscarinic receptors independently of NF ‐κB activation. i NIH 3 T 3 cells produced higher amounts of NO and PGE 2 than NIH 3 T 3 cells, concomitantly with an up‐regulation of NOS 1 and COX ‐2, and with the de novo induction of NOS 2/3 in inflamed cells. We also found a positive feedback between NOS and COX that could potentiate inflammation. Conclusions and Implications Inflammation induced the expression of muscarinic receptors and, therefore,stimulated carbachol‐induced proliferation of fibroblasts. Inflammation also up‐regulated the expression of NOS and COX ‐2, thus potentiating the effect of carbachol on NO and PGE 2 production. A positive crosstalk between NOS and COX triggered by carbachol in inflamed cells points to muscarinic receptors as potential therapeutic targets in inflammation.