Basic HTML Version
SCCs. Our experimental group consisted of patients that have pain
associated with chronic rhinosinusitis, while the control group
consisted of healthy patients undergoing nasal surgery. We used
PCR to determine expression of the downstream signaling effectors
α-gustducin, PLCβ2, and TrpM5 as correlated with pathogenic
states. Moreover, immunohistochemistry was used to reveal
anatomical features of these cells and possible innervation by
peptidergic fibers (polymodal nociceptors) of the trigeminal
nerve. Our preliminary findings indicate the presence of SCC
markers in the septum, inferior and middle turbinates, and
uncinate processes. Further investigation will test for an
association between the density and location of SCCs and patient
characteristics of local inflammation and pain. Acknowledgements:
Supported by NIH grants R01DC009820 and P30DC004657 and
by Dept. of Otolaryngology Resident Research Funds
#P48
POSTER SESSION II:
TRIGEMINAL SYSTEM; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Distribution of solitary chemosensory cells (SCCs) in the
nasal mucosa of mice
Mandy Scheibe
1
, Jessica Clark
2
, Adrian C. B. Meedeniya
2
,
Alan Mackay-Sim
2
1
Smell & Taste Clinic, Department of Otorhinolaryngology,
University of Dresden Medical School Dresden, Germany,
2
Eskitis Institute for Cellular & Molecular Therapies,
Griffith University Brisbane, Australia
Background:
Solitary chemosensory cells (SCCs) seem to have a
supporting function of the intranasal trigeminal system. SCCs are
isolated elements located in the epithelia of the respiratory and
digestive organs. Previous studies found SCCs at the surface of the
nasal mucosa in rats and mice which form synaptic contacts with
trigeminal afferent nerve fibers and express essential elements of
chemosensory transduction. Aim of this study was to investigate
the topographical distribution of these SCCs in mice in detail.
Material and Methods:
Noses of 10 mice, 5 2-years-old (3 female,
2 male) and 5 12-weeks-old (2 female, 3 male), were investigated
so far. Following euthanasia and perfusion the whole mouse nose
was carefully dissected, processed and cryostat sections (30µm)
were prepared for immuno-fluorescense. As primary antibody
rabbit anti-α-gustucin (1:1000) was used. Specimens were
visualised on a special epifluorescence microscope (Z, Mosaic)
and SCCs were counted (anterior-posterior and caudal-cranial).
Results:
SCCs were found in all mice. Preliminary analyses
indicate that SCCs are not distributed symmetrically in the nasal
cavity. They can appear singularly or arranged in groups. Their
numbers appear to decrease from anterior to posterior and from
caudal to cranial. Many SCCs are located in the anterior
vomeronasal duct.
Conclusions:
The present data indicate a
distinctive existence of SCCs in mice and suggest topographical
differences in their arrangement. Acknowledgements:
Acknowledgement: Supported by a grant from the Deutsche
Forschungsgemeinschaft (DFG) (SCHE 1737/1-1) to
Mandy Scheibe
#P49
POSTER SESSION II:
TRIGEMINAL SYSTEM; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Nasal epithelium inflammation: involvement of solitary
chemosensory cells after short term presentation of the
irritating compound denatonium benzoate
Marco Tizzano, Thomas E Finger
University of Colorado Denver/Rocky Mountain Taste and Smell
Center and Dept. Cell & Developmental Biology Aurora, CO, USA
Airways are continually assaulted by harmful compounds carried
on the incoming airstream. The airway epithelium houses a
population of trigeminally innervated solitary chemosensory cells
(SCCs) that express T2R taste receptors along with their
downstream signaling components: Gα-gustducin and TrpM5.
We have shown that nasal SCCs are necessary to evoke
trigeminally mediated respiratory reflex reactions to the T2R-ligand
denatonium benzoate and to acyl–homoserine lactones (AHL),
quorum-sensing molecules of Gram-negative bacteria (Gulbransen
2008, Tizzano 2010). These studies showed the necessity for SCCs
in triggering respiratory depression to certain types of irritants.
We investigated here the possibility that SCC activators, e.g.
denatonium, also trigger an inflammatory and immune response in
the nasal cavity. We exposed the nasal passageways to denatonium
benzoate (10mM) and injected the animals intravascularly with
fluorescently-conjugated albumin. Within 20 min., we detected
leakage of plasma albumin into the nasal epithelium. In addition,
we find that short term stimulation with denatonium of the nasal
epithelium, causes mast cells degranulation. Genetic deletion of
either Gα-gustducin or TrpM5, essential elements of the T2R
transduction cascade, eliminates the plasma leakage and deletion of
TrpM5 eliminates mast cells degranulation. These findings indicate
that activation of the SCCs can lead to rapid local inflammatory
responses in the nasal epithelium, likely via neurogenic
mechanisms, i.e. release of peptide mediators from the activated
nerve fibers. These fast inflammatory responses may represent a
defense mechanism to activate a local response of the epithelial
innate immune elements before a toxin can cause severe damage to
the airways and lungs. Acknowledgements: Supported by
NIH/NIDCD RO1DC009820 to TF
#P50
POSTER SESSION II:
TRIGEMINAL SYSTEM; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Chemosensory Brush Cells of the Trachea:
Turnover, Proliferation and Regeneration
CJ Saunders
1
, Thomas E Finger
1
, Susan D Reynolds
2
1
Rocky Mtn Taste & Smell Ctr, Neurosci Prog, Univ Colorado
Anschutz Med Campus Aurora, CO, USA,
2
Dept of Pediatrics,
National Jewish Medical and Research Center Denver, CO, USA
Tracheal chemosensory brush cells (CBCs) are specialized
epithelial chemosensors which utilize the canonical taste
transduction pathway (T2Rs, Gα-gustducin and TRPM5) to detect
irritants. To determine if CBCs turnover with the surrounding
epithelium, as do solitary chemosensory cells and taste receptor
cells, we used 5-bromo-2’-deoxyuridine (BrdU) to label dividing
cells in adult C57Bl6 mice. Although scattered BrdU labeled
tracheal epithelia cells (TECs) are present 5-20 days post-BrdU,
no CBCs were labeled at any time. These data suggest that CBCs
are a static population, an uncommon trait among epithelial
chemosensory cells. Since CBCs are not replaced in normal adult
trachea, we questioned at what time the cells were generated during
44 | AChemS Abstracts 2012
Abstracts are printed as submitted by the author(s)
P O S T E R P R E S E N T AT I O N S