PON1 Status as a Susceptibility Factor in Pesticide Toxicity Structure and Function of the Human...
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PON1 Status as a Susceptibility Factor in Pesticide Toxicity Structure and Function of the Human PON1 Polymorphisms: A Detailed Look at One Set of Insecticides Clement E. Furlong Departments of Genome Sciences & Medicine, Division of Medical Genetics University of Washington, Seattle, WA
PON1 Status as a Susceptibility Factor in Pesticide Toxicity Structure and Function of the Human PON1 Polymorphisms: A Detailed Look at One Set of Insecticides
PON1 Status as a Susceptibility Factor in Pesticide Toxicity
Structure and Function of the Human PON1 Polymorphisms: A Detailed
Look at One Set of Insecticides Clement E. Furlong Departments of
Genome Sciences & Medicine, Division of Medical Genetics
University of Washington, Seattle, WA
Slide 2
CYTOCHROME P450-PARAOXONASE PATHWAY FOR O.P. DETOXICATION
CYTOCHROME P450-PARAOXONASE PATHWAY FOR O.P. DETOXICATION Davies et
al., Nature Genetics 1996; 14:334-336
Determining the molecular basis of the PON1 polymorphism
required: Purifying rabbit and human plasma PON1s to homogeneity
Gel purifying active rabbit PON1 Sequencing the purified rabbit
PON1 Designing probes and screening a rabbit liver cDNA library
Isolating and characterizing the rabbit PON1 cDNA Using rabbit PON1
cDNA to isolate the human cDNA Characterizing the human PON1 cDNAs
to reveal polymorphisms (M55L & Q192R) Determining which
polymorphism governed activity (Q192R)
Slide 5
PON1 Polymorphisms 5 promoter region polymorphisms 2 coding
region polymorphisms 1 intronic polymorphic CA repeat 4 3 UTR
polymorphisms L55M Q192RG-909C G-832A G-162A G-126C T-108C (CA) n
A/G C/T
Slide 6
Restriction Enzyme Analysis of the PON1 192 Polymorphism Met 55
Gln 192 (Low) ----5-GACATGGAC--------TTACAATCC----
----3-CAGTACCTG--------AATGTTAGG---- Cut with NlaIII No cut with
AlwI Leu 55 Arg 192 (High) ----5-GACTTGGAC--------TTACGATCC----
----3-CTGAACCTC--------AATGCTAGG---- No cut with NlaIII Cut with
AlwI
Slide 7
PON1 Status Q,Q Q,R R,R
Slide 8
Understanding the Role of PON1 in OP sensitivity: development
of an animal model Correlation of PON1 levels with OP resistance
Injection of purified PON1 into mice Sensitivity of PON1 knockout
mice to OPs Reconstitution of resistance in KO mice with PON1
Conclusions from the animal model studies
Slide 9
Half Life of Injected PON1
Slide 10
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Slide 12
Chlorpyrifos-oxon Toxicity in PON1 -/- Mice Shih et al., Nature
1998; 394:284-287
Slide 13
Diazoxon Toxicity in PON1 -/- Mice Li et al., Pharmacogenetics,
in press
Slide 14
Paraoxon Toxicity in PON1 -/- Mice Li et al., Pharmacogenetics
in press
Slide 15
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Slide 17
Catalytic Efficiency of PON1 192 Isoforms Data from Li et al.,
Pharmacogenetics in press
Slide 18
Yuknavage et al., J. Toxicol. Environ. Health 1997;
51:35-55
Slide 19
Slide 20
Time Course of PON1 Appearance in Infants Richter and Furlong,
unpublished data
Slide 21
Slide 22
Analysis of PON1 Promoter Haplotypes
Slide 23
PON1 Polymorphisms 5 promoter region polymorphisms 2 coding
region polymorphisms 1 intronic polymorphic CA repeat 4 3 UTR
polymorphisms L55M Q192RG-909C G-832A G-162A G-126C T-108C (CA) n
A/G C/T
Slide 24
Summary SNPs in PON1 contribute to determining PON1 status The
Q/R 192 polymorphism determines PON1 catalytic efficiency Promoter
SNPs contribute to determining PON1 levels PON1 status affects both
the normal physiological function of PON1 as well as OP metabolism
by PON1