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#P127
POSTER SESSION III:
OLFACTION DEVELOPMENT & CNS;
HUMAN PSYCHOPHYSICS; TASTE PERIPHERY
β-defensin 1 expression in the peripheral taste system
Devaki Kumarhia, Lynnette McCluskey
Georgia Health Sciences University/Institute of Molecular
Medicine and Genetics Augusta, GA, USA
β-defensin 1 is one of many antimicrobial peptides that protect
barrier epithelia from environmental pathogens. Expression of the
peptide has been reported in porcine lingual epithelium. However,
little is known about the expression of β-defensin in taste receptor
cells and its regulation by inflammatory stimuli. We observed β-
defensin immunoreactivity in taste receptor cells within fungiform
taste buds, as well as the extra-epithelial layer of the anterior
lingual epithelium. We administered the proinflammatory
endotoxin, lipopolysaccharide (LPS; 0.1 mg), by injection to the
ventral tongue of adult rats. Rats were also given overnight access
to LPS (200 µg; 20 ml diH2O) in drinking water. Both treatments
increased punctate β-defensin staining in taste buds, though
injected LPS was more effective. β-defensin positive neutrophils
were also more prominent after LPS injection, as expected. Work
in progress will test the regulation of β-defensin expression by taste
stimuli and the role of the antimicrobial peptide in taste function.
Acknowledgements: NIDCD DC005811
#P128
POSTER SESSION III:
OLFACTION DEVELOPMENT & CNS;
HUMAN PSYCHOPHYSICS; TASTE PERIPHERY
Regulatory roles of the BMP receptor Acvr1 in
lingual mesenchyme in the development of tongue and
gustatory papillae
Hong-Xiang Liu, Yoshihiro Komatsu, Yuji Mishina,
Charlotte M. Mistretta
Department of Biologic and Materials Sciences, School of
Dentistry, University of Michigan Ann Arbor, MI, USA
Development of the tongue and taste papillae requires interactions
between the epithelium and mesenchyme and involves molecular
signaling. Among multiple signaling pathways, stage- and tissue-
specific effects of BMP signaling are profound. We have recently
demonstrated a progressively dense distribution of neural crest
derived cells (NCDCs) in tongue mesenchyme, just under the
epithelium and in the mesenchymal core of taste papillae,
suggesting important roles of mesenchymal NCDCs in interactions
among epithelial and mesenchymal cells for taste papilla
development. To test for roles of BMP signaling in mesenchymal
NCDCs in taste organ formation, we used a
Wnt1-Cre
mouse line
that expresses Cre recombinase, primarily in tongue mesenchyme,
in a neural crest-specific manner. By crossing with mouse lines that
conditionally express a constitutively activated (ca) form of type I
BMP receptor
Acvr1
or conditional knockouts (cKO) of
Acvr1
,
we were able to generate
caAcvr1
and
Acvr1
cKO in lingual
mesenchymal NCDCs. In
Wnt1-Cre/caAcvr1
mouse embryos, there
is a dramatic alteration of the developing tongue. The tongue is
small and misshapen. Fewer fungiform papillae are seen on the
surface of the tongue, and they are less obvious than those in
littermate controls. In
Wnt1-Cre/Acvr1 cKO
mice, tongue shape and
patterns of fungiform papilla placodes are altered at E12.5 when
papilla placodes would typically emerge on a spatulate tongue.
Furthermore, tongue formation is impaired in 2 day cultures of
branchial arches of
Wnt1-Cre/Acvr1 cKO
embryos compared to
littermate controls. Thus, our data suggest that appropriate levels of
the type I BMP receptor Acvr1 in lingual mesenchymal NCDCs are
important in lingual epithelial-mesenchymal interactions for the
formation of tongue and taste papillae. Acknowledgements:
NIDCD, NIH Grant DC009055 to HXL
#P129
POSTER SESSION III:
OLFACTION DEVELOPMENT & CNS;
HUMAN PSYCHOPHYSICS; TASTE PERIPHERY
Characterization of Y Receptors Expression in Salivary Glands
(SG) and Modulation of Feeding Behavior by SG Gene Delivery
Maria D. Hurtado
1
, Andres Acosta
1
, Paola P. Riveros
2
, Bruice
Baum
2
, Alicia Brown
3
, Cedrick D. Dotson
3
, Herbert Herzog
4
1
University of Florida, Pediatrics Gainesville, FL, USA,
2
NIH/NIDCR, Molecular Physiology and Therapeutics Branch
Bethesda, MD, USA,
3
University of Florida, Neuroscience
Gainesville, FL, USA,
4
Garvan Institute of Medical Research,
Neuroscience Sydney, Australia
NPY family genes are represented by well-characterized hormones
Neuropeptide Y (NPY), Peptide YY (PYY), Pancreatic Polypeptide
(PP) and their cognate receptors. These genes are widely expressed
in the brain as well as in the periphery where they mediate multiple
metabolic functions. Recently, we have shown the presence of PYY
in saliva and the expression of its preferred receptor, Y2R in lingual
epithelia. We now extend our finding to all main NPY family
members and characterize their expression in von Ebner’s (VEG)
and submandibular (SMG) salivary glands. A single layer of the
cytokeratin-5 cells lining the VEG were shown to be Y1R/Y2R-
positive, suggesting a role for Y receptors in proliferation of
progenitor cells. In addition, acinar and mucous cells in VEG
express Y1R. In SMG, acinar cells were positive for Y1R,
myoepithelial cells for Y2R, while cells in excretory and
intercalated ducts expressed Y4R. The wide variety of cells
expressing genes of the NPY family suggests their functional
significance in mediating diverse physiological functions. To test a
possible role of salivary YR-signaling in energy metabolism, we
constructed a recombinant Adeno-associated viral vector encoding
gene for pre-pro-PYY. The vector was administered bi-laterally into
the SMG duct of germline PYY KO mice or in diet-induced obese
mice. In a long-term study, a sustained, two-fold increase in
salivary PYY
3-36
was achieved resulting in a significant reduction in
food intake and body weight, thus re-opening the potential of
PYY
3-36
for the treatment of obesity. Taken together, these
experiments characterize, for the first time, the expression of all
NPY family members in at least 2 types of salivary glands
suggesting multiple functions in the proliferation of epithelia cells,
mucosal secretion, and energy metabolism. Acknowledgements:
PI’s startup
70 | AChemS Abstracts 2012
Abstracts are printed as submitted by the author(s)
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