SLEEP 2011 Abstract Supplement

A. Basic Science II. Cell and Molecular Biology and Genetics
important for either induction or emergence from anesthesia, confirming
that these are path dependent processes.
Support (If Any): The Harold Amos Medical Faculty Development
Program -Parker B. Francis Fellowship Program -Transdisciplinary
Awards Program from Institute for Translational Medicine and Therapeutics
at the University of Pennsylvania -NIGMS and NHLBI -Department
of Anesthesiology and Critical Care Medicine
0021
BTBD9 EXPRESSION INFLUENCES BOTH DOPAMINE AND
FERRITIN EXPRESSION
Freeman A 1 , Pranski E 2,3 , Betarbet R 2,3 , Rye DB 3 , Jinnah H 3,4 , Sanyal S 1
1
Department of Cell Biology, Emory University School of Medicine,
Atlanta, GA, USA, 2 Center for Neurodegenerative Disease, Emory
University School of Medicine, Atlanta, GA, USA, 3 Department
of Neurology, Emory University School of Medicine, Atlanta, GA,
USA, 4 Department of Human Genetics, Emory University School of
Medicine, Atlanta, GA, USA
Introduction: The roles of dopamine and iron in the pathophysiology of
Restless Legs Syndrome (RLS) are poorly understood. Clinical observations
of symptom relief have led to the use of dopamine agonists as a
first-line therapy for RLS. Both clinical and epidemiological observations
have identified an association between iron deficiency and both
primary RLS symptoms and known causes of secondary RLS. More
recently, low serum ferritin levels have been correlated with the at-risk
variant of the BTBD9 gene. However the causal link remains unknown.
We investigated the interplay between dopamine, iron, and BTBD9 expression
using both a Drosophila model and mammalian cultured cells.
Methods: HPLC was used to measure dopamine levels in the head of
Drosophila with deletion mutations in the fly homolog of BTBD9 (gene
CG1826). Human embryonic kidney cells (HEK293) were grown in medium
with altered iron concentrations and were transfected with human
BTBD9 plasmids. Both immunoblot and immunocytochemical assays
were used to measure resulting BTBD9 and ferritin expression.
Results: Deletion mutations of CG1826/BTBD9 yields viable animals
that have significantly decreased dopamine levels. While growing
HEK293 cells in either iron enriched or iron depleted media did not alter
BTBD9 expression, overexpression of BTBD9 in HEK293 cells did result
in increased ferritin expression. These results suggest that BTBD9
plays a role in regulation of both dopamine levels and ferritin levels.
Conclusion: Our results suggest that the roles of dopamine and iron
in the pathophysiology of RLS are downstream of BTBD9 expression.
However, the precise regulatory mechanisms remain unknown. Our
ongoing efforts to determine the molecular function of CG1826 should
continue to illuminate the roles of dopamine, iron, and BTBD9 in RLS
and sleep regulation.
0022
DISRUPTION OF PERIPHERAL LIPID METABOLISM GENES
ALTERS THE RESPONSE TO SLEEP DEPRIVATION
Thimgan M, Gottschalk L, Shaw P
Anatomy and Neurobiology, Washington University Medical School,
St. Louis, MO, USA
Introduction: : Insufficient sleep results in adverse effects including increased
adiposity and cognitive impairments. While it is clear that sleep
loss can alter genes involved in lipid metabolism, recent studies indicate
that mutations in lipid metabolism genes can, in turn, protect flies from
the negative consequences of sleep deprivation. To further understand
the relationship between lipids and sleep deprivation, we conducted a
microarray experiment and identified genes involved in various aspects
of lipid handling. Using genetics, we manipulated these genes and evaluated
sleep homeostasis and short-term memory following 12 h of sleep
deprivation.
Methods: Flies mutant for the clock gene timeless (tim 01 ) do not show
a sleep rebound after 3 and 6 h of sleep deprivation but display a sleep
rebound after 9 and 12 h of sleep loss. mRNA was collected from tim 01
flies after 3, 6, 9 and 12 h of sleep deprivation. cDNA microarrays revealed
several classes of lipid metabolism genes that were significantly
modified by 9 and 12 h of sleep loss were identified. These genes were
manipulated by expressing UAS-RNAi lines in a tissue and circuit dependent
manner. Flies were subjected to 12 h of sleep deprivation using
the SNAP and sleep homeostasis and short-term memory were evaluated
as previously described.
Results: We found several classes of lipid metabolism genes, including
acyl-CoA and lipases that significantly altered sleep rebound and
prevented cognitive impairments as measured by Aversive Phototaxic
Suppression. Interestingly, we identified mutants that reduced sleep homeostasis
but that did not prevent the cognitive impairments. Finally,
we show that lipid metabolism genes can alter sleep homeostasis when
manipulated in peripheral tissues.
Conclusion: These data emphasize that while sleep loss may increase
the risk for obesity and metabolic syndrome, genes involved in lipid
metabolism can mitigate or attenuate negative consequences that accrue
during waking.
0023
GENETIC ANALYSIS REVEALS A MOLECULAR
LINK BETWEEN REGULATION OF SLEEP AND LIPID
METABOLISM
Ollila HM 1,2 , Kronholm E 3 , Aho V 1 , Partonen T 2 , Peltonen L 1,4 ,
Perola M 2 , Kaprio J 2 , Salomaa V 2 , Porkka-Heiskanen T 1 , Paunio T 1,2
1
University of Helsinki, Helsinki, Finland, 2 National Institute for
Helath and Welfare, Helsinki, Finland, 3 National Institute for Helath
and Welfare, Turku, Finland, 4 Institute for Molecular Medicine Finland,
University of Helsinki, Helsinki, Finland
Introduction: Epidemiological studies show that short sleep is related
to increased mortality and metabolic diseases that manifest pathological
blood lipid levels. In addition, genome-wide association studies on
T2DM and obesity have identified genes that link to regulation of sleep.
Lipid metabolism is also involved in recovery from sleep loss. However,
the role of genetic variants relevant to lipid metabolism has not been
examined previously in regulation of sleep.
Methods: Here we examined (i) association of blood lipid profiles with
total sleep time at population level and (ii) association of 60 genetic
variants previously associated with lipid traits with TST. The analyses
were performed in Finnish samples comprising 12524 participants and
genetic analysis with 6334 participants and replicated in 2189 twins. Finally
we studied the RNA expression in sleep restriction study (4 hours
of sleep for five nights) of nineteen healthy men.
Results: We found that both short and long sleepers had increased triglyceride
levels. In the genetic analysis we identified two variants that
independently contributed to blood lipid levels and to sleep duration
(P