Basic HTML Version
Abstracts | 19
Abstracts are printed as submitted by the author(s)
#29
PLATFORM PRESENTATIONS —
POLAK YOUNG INVESTIGATOR AWARD WINNERS
Therapeutic gene rescue of a mammalian ciliopathy
induced anosmia
Jeremy C McIntyre
1
, Ariell Joiner
1
, Corely L. Williams
1
,
Paul M. Jenkins
1
, Dyke P. McEwen
1
, Bradley K. Yoders
2
,
Randall R. Reed
3
, Jeffrey R. Martens
1
1
University of Michigan, Deparmtent of Pharmacology
Ann Arbor, MI, USA,
2
University of Alabama at Birmingham,
Deparment of Cell Biology Birmingham, AL, USA,
3
Johns Hopkins University, Department of Molecular Biology
and Genetics Baltimore, MD, USA
Cilia on olfactory sensory neurons (OSNs) compartmentalize the
signaling pathway components that are necessary for odor
transduction. In humans, alterations in cilia formation and function
clinically manifest as ciliopathies, a growing class of pleiotropic
genetic disorders. Recent publications from several labs have now
demonstrated anosmia as a phenotype associated with several
ciliopathy disorders. Despite significant progress identifying the
genes underlying ciliopathies, curative therapies are not yet
available to patients. We demonstrate that mice with a hypomorphic
mutation in the gene encoding the intraflagellar transport protein,
IFT88 (ORPK, ift88
Tg737Rpw
), lack olfactory cilia as determined by
both immunohistochemical and scanning electron microscopy
analysis. The loss of olfactory cilia in ORPK mice results in
anosmia, as measured by electro-olfactogram (EOG) recordings
and immunohistochemical analysis of expression S100a5 in the OE
and tyrosine hydroxylase (TH) in the olfactory bulb. Expression of
an ectopic IFT88:GFP fusion protein in OSNs by adenoviral
infection shows that IFT88 enriched in the proximal regions of
olfactory cilia in wildtype mice. Importantly, viral-mediated re-
expression of IFT88 in mature OSNs of ORPK mice is sufficient to
restore acetylated a-tubulin positive cilia structures. Using EOGs,
staining for S100a5 and TH, we show that odorant induced activity
is restored to infected OSNs. These studies represent the first in
vivo therapeutic treatment to reestablish cilia in a mammalian
ciliopathy, and show that gene therapy is a viable curative option
for functional rescue of the complex cilia organelle in established
differentiated cells. Acknowledgements: This work was support by
NIH grants R01DC009606 (to J.R.M), T32DC00011 and
1F32DC011990 (to J.C.M), R01DC004553 and R01DC008295
(to R.R.R) and R01DK75996 (to B.K.Y)
#30
PLATFORM PRESENTATIONS —
POLAK YOUNG INVESTIGATOR AWARD WINNERS
G-protein-coupled Odorant Receptors Underlie
Mechanosensitivity in Olfactory Sensory Neurons
Timothy Connelly
1
, Xavier Grosmaitre
1
, Agnes Savigner
1
,
Zhenshan Wang
2
, Daniel Storm
2
, Minghong Ma
1
1
University of Pennyslvania School of Medicine, Department of
Neuroscience Philadelphia, PA, USA,
2
University of Washington
School of Medicine, Department of Pharmacology
Seattle, WA, USA
Sensory receptors typically function in just a single stimulus
modality. However, in the olfactory system, mechanical processes
such as sniffing and respiration are known to affect odor
perception, and we previously demonstrated that olfactory sensory
neurons (OSNs) detect both chemical and mechanical stimuli.
While the G-protein-coupled receptor cascade underlying odor
detection is well established, the mechanical sensor and subsequent
transduction cascade are elusive. Here we used patch-clamp
recordings from the dendritic knobs of mouse OSNs that were
genetically labeled for defined odorant receptors to examine
olfactory mechanoreception. We found that knocking out key
signaling proteins in odor transduction completely eliminated
mechanical responses of OSNs to puffs of odor-free Ringer’s
solution. We also demonstrated that mechanosensitivity of OSNs is
associated with certain odorant receptor types: OSNs that expressed
SR1, M71, or I7 were mechanosensitive, while neurons labeled for
mOR23 or mOR-EG were not. Interestingly, mechanosensitive
OSNs expressing SR1, M71, and I7 had higher rates of basal firing
in loose-patch recordings than OSNs expressing mOR23 or mOR-
EG. Genetic ablation of SR1 reduced mechanosensitivity in OSNs,
and disruption of I7 receptor-G protein coupling in I7(RDY)
neurons eliminated both mechanosensitivity and basal firing.
These results provide strong evidence that some odorant receptors
(e.g. SR1 and I7) confer mechanosensitivity to their host OSNs.
Our findings reveal an exceptional case in which G-protein coupled
receptors serve as both chemical and mechanical sensors to carry
odor and airflow information into the brain. Acknowledgements:
Supported by R01 DC006213 from NIDCD, NIH.
#31
PLATFORM PRESENTATIONS —
POLAK YOUNG INVESTIGATOR AWARD WINNERS
Precise optical control of olfactory sensory neuron input
elucidates olfactory bulb circuit function in awake, freely
moving mice
David Gire
1,3
, Quang N Dang
1,3
, Jamie Costabile
2,3
,
Thomas Bozza
4,5
, Gidon Felsen
2,3
, Diego Restrepo
1,3
1
Department of Cell and Developmental Biology, School of
Medicine University of Colorado Aurora, CO, USA,
2
Department of
Physiology and Biophysics, School of Medicine University of
Colorado Aurora, CO, USA,
3
Rocky Mountain Taste and Smell
Center, Neuroscience Program, School of Medicine University of
Colorado Aurora, CO, USA,
4
Janelia Farm Research Campus,
Howard Hughes Medical Institute Ashburn, VA, USA,
5
Department
of Neurobiology, Northwestern University Evanston, IL, USA
Historically, olfaction has been a difficult sense to study in freely
moving animals due to both the inherent imprecision present in
odor plumes as well as difficulties in defining the spatial and
temporal patterns of sensory neuron input to the olfactory bulb.
Using a custom built array incorporating tetrodes and an optical
fiber (see Dang, et al., this meeting) and transgenic mice expressing
O R A L A B S T R A C T S