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1
Visceral hypersensitivity and gastrointestinal inflammation
Benedicte De Winter
Laboratory of Experimental Medicine and Pediatrics
University of Antwerp
Antwerp, Belgium
From Elsenbruch, Brain Behav Immun 2011
Brain-gut axis
Visceral hypersensitivity:
� peripheral mechanisms
� central mechanisms
� inhibitory or facilitatingdescending pathways
2
IBD and IBS
Inflammatory bowel disease (IBD)
= a chronic disease� acute inflammation / flares (= inflammatory)
� remission (= post-inflammatory)
33-57% of IBD patients have symptoms of IBS
Irritable bowel syndrome (IBS)
= a functional bowel disease� affecting 15-19% of the general population
� 50-94% shows visceral hypersensitivity to colorectal distension
� ± 30% develops IBS after acute gastroenteritis (PI-IBS)
INFLAMMATIINFLAMMATIINFLAMMATIINFLAMMATIONONONON
damaged tissue
peripheral afferents
inflammatory cells
recruitment silent nociceptors
activation / sensitization peripheral afferents
inflammatory cells mast cells platelets
vasodilatation edema
MEDIATORS
Role of inflammation
3
InflammationInflammation
TNBS-colitisTNBS-colitis
7,5-15 mg trinitrobenzene sulphonic acid
(TNBS) in 40-50% of ethanol ↔ NaCl
(control)
Follow-upFollow-up
ColonoscopyColonoscopy
•ocular
Follow-upFollow-up
Control Complications
TNBS-induced ulceration
Vermeulen et al, AGB 2011
4
Gut reflexes
Methodology
altered gut reflexes
Dorsal root ganglionPeripheralPeripheral levellevel
•De De Schepper et al., Gut 2007
Visceral perceptionaltered visceral perception
SupraspinalSupraspinal levellevel
SpinalSpinal levellevel
Acute colitis pelvic afferent set-up
Amplif
Pressurecontrolleddistension
device
ADC
S1
Amplif
Pressurecontrolleddistension
device
ADC Amplif
Pressurecontrolleddistension
device
ADC
S1S1
� female Wistar rat (200-225 g)
� 3 days post TNBS
� anaesthesia: pentobarbital
induction: 45 mg/kg ip
maintenance 7.5 mg/kg/u iv
� vital support:
- heating path (37°C)
- trachea cannulation
- continuous registr art bloodpressure (a car)
- ABP < 80 mmHg � 1 mL 5% dextrose iv
� sacrifice - overdose pentobarbital
5
Effect of inflammation on afferent signalling
De Schepper et al, J Physiol 2008
Effect of TRPV1 inhibition
pre-d
rug
vehic
le
BCTC
0.2
5
BCTC
0.5
BCTC
1
BCTC
2
BCTC
5
0
5
10
15
20
25 control (12)
TNBS (12)* *
## #
Sp
ike r
ate
(H
z)
De Schepper et al, J Physiol 2008
6
Effect of inflammation on afferent signalling& the effect of TRPV1 inhibition
pre-d
rug
vehic
le
BCTC
0.2
5
BCTC
0.5
BCTC
1
BCTC
2
BCTC
5
0
5
10
15
20
25
TNBS (7)
control (7)
* *
# # #
Sp
ike r
ate
(H
z)
pre-d
rug
vehic
le
BCTC
0.2
5
BCTC
0.5
BCTC
1
BCTC
2
BCTC
5
0
5
10
15
20
25
TNBS (5)
control (5)
Sp
ike r
ate
(H
z)
C-fibres Aδ-fibres
De Schepper et al, J Physiol 2008
Conclusion 1
Acute colitis:
� sensitisation of pelvic afferent C-fibres after colorectal distension
� mediated via TRPV1 receptors
� no effect on Aδ fibres
7
Clinical relevance – TRPV1
� Increased TRPV1 expression in sensory neurons in IBD patients.
Yiangou et al, Lancet 2001
� Increased TRPV1-immunoreactive nerve fibers in in IBS patients and in quiescent IBD patients correlate with abdominal pain scores.
Akbar et al, Gut 2008 & Gut 2010
� NCT00461682 ~ SB 705498, a selective TRPV1 antagonist, in phase 2 for rectal pain; two groups faecal urgency ↔ IBS
Clinical trials.gov
Gut reflexes
Methodology
altered gut reflexes
Dorsal root ganglionPeripheralPeripheral levellevel
•De De Schepper et al., Gut, 2007
Visceral perceptionaltered visceral perception
SupraspinalSupraspinal levellevel
SpinalSpinal levellevel
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VMR – visceromotor responses
Pre
ssu
re (
mm
Hg
) Distention protocol
Electrodes S pike 2 s oftware
B aros tat
Balloon
Analog dig ital c onverter
Amplifier / F ilter
O s c illos cope
Electrodes S pike 2 s oftware
B aros tat
Balloon
Analog dig ital c onverter
Amplifier / F ilter
O s c illos cope
***
******
***
*
(n = 10)
(n = 6/18 )
10 20 30 40 60 80
Control
TNBS
Distension pressure (mmHg)
AU
C
0.0
0.25
0.50
0.75
1.00
1.25
1.50***
******
***
*
(n = 10)
(n = 6/18 )
10 20 30 40 60 80
Control
TNBS
Distension pressure (mmHg)
AU
C
0.0
0.25
0.50
0.75
1.00
1.25
1.50
Vermeulen et al., EJP 2013
Experimental protocol
Day 0Day -1Day -2Day -8
Training • Fasting
Day 3
Colitis-Predrug
Saline-Predrug
30 minControl Colitis-Postdrug
Saline-Postdrug
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Effect of TRPV1 blockade on VMR
Vermeulen et al., EJP 2013
10 20 30 40 60 80
0
500
1000
1500
Control Colitis (day 3)
Colitis (day 3) + BCTC 5mg/kg i.p.
§§§*
Distension pressure (mmHg)
AU
C (
µV
/.20
s)
10 20 30 40 60 80
0
500
1000
1500
Control Colitis (day 3)
Colitis (day3)+ BCTC 100µg i.t.
§*
Distension pressure (mmHg)
AU
C (
µV
/ 20 s
)
IP IT
Effect of TRPA1 blockade on VMR
10 20 30 40 60 80
0
500
1000
1500
2000
Control Colitis (day 3)
Colitis (day 3) + TCS-5861528 15mg.kg-1 i.p.
§§§*
Distension pressure (mmHg)
AU
C (
µV
/ 20 s
)
10 20 30 40 60 80
0
500
1000
1500
2000
Control Colitis (day 3)
Colitis (day 3) + TCS-5861528 20 µg i.t.
§*
Distension pressure (mmHg)
AU
C (
µV
/ 20 s
)
IP IT
Vermeulen et al., EJP 2013
10
Conclusion 2
Acute colitis:
� sensitisation of visceromotor responses (VMR) after colorectal distension
� mediated via TRPV1 receptors
� mediated via TRPA1 receptors
� Effect located in the periphery and at the level of the spinal cord.
Clinical relevance – TRPA1
� Increased TRPA1 expression in colorectal DRGs and associated visceral hypersensitivity after neonatal colonic irritation in mice.
Christianson et al, Pain 2010
� Increased mesenteric afferent firing in mice after administration of AITC, a TRPA1 agonist.
Jiang et al, NGM 2012
� Colorectal distension initiate an inhibitory rectovesical reflex that can be abolished by lidocaine and increased by AITC, a TRPA1 agonist.
Wyndaele et al, J Urol 2013
11
IBD and IBS
Inflammatory bowel disease (IBD)
= a chronic disease� acute phase (= inflammatory)
� remission (= post-inflammatory)
33-57% of IBD patients have symptoms of IBS
Irritable bowel syndrome (IBS)
= a functional bowel disease� affecting 15-19% of the general population
� 50-94% shows visceral hypersensitivity to colorectal distension
� ± 30% develops IBS after acute gastroenteritis (PI-IBS)
Role of inflammation and stress
stress
mast cell
immune cell
visceral afferent nerve
spinal cord
visceral
hypersensitivityIrritable bowel syndrome (IBS)
- Pathogenesis largely unknown
- Several implicated factors:• Stress
• Mucosal mast cells
• Low-grade inflammation
• Dysregulated brain-gut axis
12
Van Diest, 2012
Role of mast cells
Mast cells (MCs) appear to be involved
� located in close proximity to nerve endings
� bidirectional communication between MCs and nerves
� increased number of MCs, increased mediator release
� effect of MC stabilizers and histamine H1 receptor antagonist
Van Diest, 2012
Role of mast cells
13
Experimental protocol
+3d +7d
Visceral
sensitivity+3d
30 min prior
drug/vehicle ip
Healed
+4d
MC numbers
Histamine release
Conclusion 3
Post-inflammatory colitis:
� sensitisation of visceromotor responsesafter colorectal distension
� mediated via histamine 1 receptors
� peripheral and DRG level
� mediated via histamine 4 receptors
� peripheral mechanism via a reduction of colonic histamine release
14
Clinical relevance - histamine
� Beneficial effect of ketotifen on visceral hypersensitivity in IBS patients.
Klooker et al, Gut 2010
� IBS-biopsy supernatans induced H1R-dependent mesenteric afferent nerve discharge in rat
Barbara et al, Gastroenterology 2007
� Mediators from colonic biopsies from IBS-D but not IBS-C patients sensitised colonic nociceptive DRG neurons mediated via PAR 2 signalling.
Valdez-Morales et al, Am J Gastroenterol 2013
From Elsenbruch, Brain Behav Immun 2011
Visceralhypersensitivity
Inflammation:
� peripheral level
� DRG level
15
Acknowledgements
Lab of Gastroenterology
- Prof. Dr. P. Pelckmans
- Prof. Dr. B. De Winter
- Prof. Dr. T. Moreels
- Ing. Joris De Man
- Dr. Nathalie Ruyssers
- Dr. Heiko De Schepper
- Dr. Wim Vermeulen
- Dr. Annemie Deiteren
- Ap. Marthe Heylen
- Dr. Sara Nullens
LEMP
- Prof. Em. Verpooten
- Petra Aerts
- Angelika Jürgens
- Marleen Vinckx
- André Van Daele
Physiopharmacology
- Rita Van Den Bossche
- Min Fret
Janssen Research & Development
- Dr Thurmond