The vagus nerve as a modulator of intestinal inflammation - TI Pharma

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Chapter 4 A B C Figure 4. Nicotine inhibits NF-kB transactivation and p65 translocation to the nucleus. (A) RAW macrophages expressing a NF-kB luciferase reporter construct were incubated with 1µM nicotine 30 min. prior to 100ng/ml LPS stimulation. NF-kB activity was determined after 3hrs LPS using luminescence. (B) Western analyses of p65 in nuclear and cytosolic fractions of RAW cells pretreated with nicotine (1µM) or medium prior to 30min 100ng/ml LPS stimulation.Asterisks indicate significant differences (P < .05) vs LPS . (C) RAW cells were pretreated with stattic, prior to LPS stimulation, and the specific NF-κB pathways p65RelA, RelB, c-Rel, p52 and p50 were analyzed by using the TransAM DNA-Binding. * represents p
DISCUSSION Deciphering STAT3 signaling in cholinergic immune-modulation The JAK2-STAT3 pathway is an essential modulator of the immune response and plays also an important role in cell proliferation, migration, differentiation and apoptosis. However, the implications of this pathway in inflammatory disorders have remained elusive. We previously reported that the JAK2-STAT3 pathway is involved in mediating the anti-inflammatory action of nicotinic receptor activation in peritoneal macrophages 2 . Nicotine induced STAT3 phosphorylation and SOCS-3 activation and did not decrease TNF production in macrophages transfected with an inactive form of STAT3 2 . Moreover, stimulation of the vagus nerve failed to reduce inflammation in mice LysM-Stat3 fl/- mice 2 . The present study reveals that pharmacological inhibition of JAK2-STAT3 activation using AG490 prevents NF-kB transactivation and TNF production in peritoneal macrophages. In contrast, several studies demonstrate that genetic deletion of STAT3 increases inflammatory responses. Stat3 deficient macrophages secrete large amounts of cytokines including TNFa, IL-1, IL-6, and IL-12 in response to inflammatory stimuli. In addition, LysMcre/Stat3 flox/− mice, which were designed for cell type-specific STAT3 disruption in macrophages and neutrophils, are born normal, but are very susceptible to endotoxemia 10 and sepsis 17 , and develop lethal chronic inflammatory bowel disease at ~20 weeks age 10 . Two factors appear to contribute to the higher inflammatory responses of these mice. First, STAT3-depletion sustains early inflammatory responses by inhibiting IL-10 signaling. The inhibitory activity of IL-10 on LPS-induced production of pro-inflammatory cytokines from STAT-3 deficient macrophages was completely blocked. Second, nontreated lysMcre/ Stat3 flox/- mice are characterized by macrophages which exhibit an constitutively activated phenotype. Similar to the results in conditional knockout mice, our results with siRNA confirm that STAT3 silencing enhances inflammatory responses. The finding that pharmacological inhibition of the JAK2-STAT3 pathway reduces inflammation seems to be contradictory to the STAT3 silencing data. Possibly, the JAK2 inhibitor AG490 affects other signaling pathways as well. Indeed, it is shown that AG490 not only inhibits JAK2, but also JAK3 activity, STAT5a and 5b signaling 18 . These data suggest that AG490, especially at high dosages, can inhibit other signaling pathways than JAK2-STAT3 signaling alone. We previously revealed that nicotine exerts its anti-inflammatory effects on macrophages via JAK2 mediated phosphorylation of STAT3. However, the interpretation of these data is not straightforward, because phosphorylation of STAT3 is fluctuating in time. Moreover, it appears that the use of immunoblotting as a readout for STAT3 activation does not correlate well with the response at the level of gene expression 8 . Therefore, the use of dominant negative constructs is a more reliable tool to determine the role of STAT3 phosphorylation in mediating the cholinergic anti-inflammatory effect. In RAW264.7 macrophages, we show that 73
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The vagus nerve as a modulator ofin
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The vagus nerve as a modulator of i
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Promotiecommissie Promotores: Prof.
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Table of contents Chapter 1 Introdu
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Introduction and outline The aim of
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Introduction and outline Hence, the
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Introduction and outline 18. van de
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Chapter 2 ABSTRACT The cholinergic
Page 17 and 18: Chapter 2 neurotransmitter ACh with
Page 19 and 20: Chapter 2 THE VAGUS NERVE AND CHOLI
Page 21 and 22: Chapter 2 nicotine treatment impair
Page 23 and 24: Chapter 2 Figure 1. Hypothetical sc
Page 25 and 26: Chapter 2 unclear whether this hybr
Page 27 and 28: Chapter 2 reduction of NF-κB activ
Page 29 and 30: Chapter 2 CONCLUDING REMARKS The hy
Page 31 and 32: Chapter 2 34 17. The FO, Boeckxstae
Page 33 and 34: Chapter 2 55. Moser N, Mechawar N,
Page 35 and 36: Chapter 2 93. Shafique S, Dalsing M
Page 37 and 38: Chapter 3 ABSTRACT Acetylcholine re
Page 39 and 40: Chapter 3 by bowel manipulation 12
Page 41 and 42: Chapter 3 for preparation of whole
Page 43 and 44: Chapter 3 Figure 1. Nicotine attenu
Page 45 and 46: Chapter 3 Figure 2. Inhibition of m
Page 47 and 48: Chapter 3 macrophage cell lysates s
Page 49 and 50: Chapter 3 reports 2 . We next incub
Page 51 and 52: Chapter 3 Figure 5. Perioperative e
Page 53 and 54: Chapter 3 Figure 7. Stimulation of
Page 55 and 56: Chapter 3 Activation of the STAT3 c
Page 57 and 58: Chapter 3 REFERENCE LIST 60 1. Trac
Page 59 and 60: 4 CHAPTER Deciphering STAT3 signali
Page 61 and 62: INTRODUCTION Deciphering STAT3 sign
Page 63 and 64: Deciphering STAT3 signaling in chol
Page 65 and 66: Deciphering STAT3 signaling in chol
Page 67: Deciphering STAT3 signaling in chol
Page 71 and 72: REFERENCES Deciphering STAT3 signal
Page 73 and 74: Chapter 5 ABSTRACT Background and A
Page 75 and 76: Chapter 5 METHODS Reagents and anti
Page 77 and 78: Chapter 5 described previously 6 .
Page 79 and 80: Chapter 5 Figure 1 Cholinergic agon
Page 81 and 82: Chapter 5 Figure 3 Cholinergic agon
Page 83 and 84: Chapter 5 we analyzed whether nicot
Page 85 and 86: Chapter 5 Zymosan induced formation
Page 87 and 88: Chapter 5 marker CD11 c (Fig. 7E),
Page 89 and 90: Chapter 5 Our data demonstrate that
Page 91 and 92: Chapter 5 REFERENCE LIST 96 1. Boro
Page 93 and 94: Thesis E.P.M. van der Zanden The va
Page 95 and 96: Summary and conclusions The goal of
Page 97 and 98: Summary and conclusions whether the
Page 99 and 100: Summary and conclusions exposure co
Page 101 and 102: REFERENCE LIST Summary and conclusi
Page 103 and 104: Nederlandse samenvatting
Page 105 and 106: Chapter 7 van STAT3 in de ‘cholin
Page 107 and 108: Chapter 7 De bevinding dat nicotine
Page 109 and 110: Chapter 7 macrofagen aan te tonen (
Page 111 and 112: Chapter 7 18. Yu Z, Zhang W, Kone B
Page 113 and 114: Shizuo Akira Department of Host Def
Page 115 and 116: List of publications
Page 117 and 118: Dankwoord
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om de ene keer olijfolie te drinken
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Curriculum Vitae Curriculum Vitae E
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