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Published ahead of print on August 24, 2006, doi:10.1164/rccm.200509-1405OC
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American Journal of Respiratory and Critical Care Medicine Vol 174. pp. 1101-1109, (2006)
© 2006 American Thoracic Society
doi: 10.1164/rccm.200509-1405OC

Original Article

Sequence, Haplotype, and Association Analysis of ADRbeta2 in a Multiethnic Asthma Case-Control Study

Gregory A. Hawkins, Kelan Tantisira, Deborah A. Meyers, Elizabeth J. Ampleford, Wendy C. Moore, Barbara Klanderman, Stephen B. Liggett, Stephen P. Peters, Scott T. Weiss and Eugene R. Bleecker

Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, North Carolina; Channing Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; and Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio

Correspondence and requests for reprints should be addressed to Eugene Bleecker, M.D., Section of Pulmonary, Critical Care, Allergy and Immunologic Diseases Center for Human Genomics, Wake Forest University Health Sciences, Winston-Salem, NC 27157. E-mail: ebleeck{at}wfubmc.edu


   ABSTRACT
TOP
 ABSTRACT
AT A GLANCE COMMENTARY
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Rationale: The comprehensive evaluation of gene variation, haplotype structure, and linkage disequilibrium is important in understanding the function of beta2-adrenergic receptor gene (ADRbeta2) on disease susceptibility, pulmonary function, and therapeutic responses in different ethnic groups with asthma.

Objectives: To identify ADRbeta2 polymorphisms and haplotype structure in white and African American subjects and to test for genotype and haplotype association with asthma phenotypes.

Methods: A 5.3-kb region of ADRbeta2 was resequenced in 669 individuals from 429 whites and 240 African Americans. A total of 12 polymorphisms, representing an optimal haplotype tagging set, were genotyped in whites (338 patients and 326 control subjects) and African Americans (222 patients and 299 control subjects).

Results: A total of 49 polymorphisms were identified, 21 of which are novel; 31 polymorphisms (frequency > 0.03) were used to identify 24 haplotypes (frequency > 0.01) and assess linkage disequilibrium. Association with ratio (FEV1/FVC)2 for single-nucleotide polymorphism +79 (p < 0.05) was observed in African Americans. Significant haplotype association for (FEV1/FVC)2 was also observed in African Americans.

Conclusions: There are additional genetic variants besides +46 (Gly16Arg) that are important in determining asthma phenotypes. These data suggest that the length of a poly-C repeat (+1269) in the 3' untranslated region of ADRbeta2 may influence lung function, and may be important in delineating variation in beta-agonist responses, especially in African Americans.

Key Words: asthma • beta2-adrenergic receptor • beta-agonist therapy • DNA polymorphisms • pharmacogenomics



   AT A GLANCE COMMENTARY
TOP
 ABSTRACT
 AT A GLANCE COMMENTARY
METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Scientific Knowledge on the Subject
Gene variation and haplotypes relating to the effects of the gene ADRbeta2 on disease susceptibility and therapeutic responses had been previously studied in only a limited fashion.

What This Study Adds to the Field
There are additional ADRbeta2 genetic variants besides +46 (Gly16Arg) and +79 (Gln27Glu) that are important in determining asthma phenotypes.

 
beta-Agonists are the most common bronchodilators used to treat airflow limitation associated with obstructive airways diseases. Individual therapeutic responses to beta-agonists differ, and can be influenced by several factors, including degree of baseline airway obstruction, ethnicity, and age (1, 2). Therapeutic responses can also be affected by receptor desensitization produced by prolonged beta-agonist use during regular therapy (3, 4). The mechanisms responsible for heterogeneity in beta-agonist responsiveness have not been completely elucidated; however, there is evidence that genetic variation in the beta2-adrenergic receptor gene (ADRbeta2) may be one important factor (5).

The ADRbeta2 is located on chromosome 5q31 (6), a region that is genetically linked to asthma and related phenotypes (7, 8). Reihaus and coworkers (9) described nine coding polymorphisms in ADRbeta2, four of which (Gly16Arg, Gln27Glu, Val34Met, and Thr164Ile) create nonsynonymous changes in the amino acid sequence. In vitro studies by Green and coworkers (10) showed that beta2-adrenergic receptors containing Gly16/Gln27 and Gly16/Glu27 had greater down-regulation after isoproterenol exposure than did receptors containing Arg16/Gln27, whereas Arg16/Glu27 receptors exhibited no down-regulation. Several association studies have found that the Gly16 allele correlated with more severe asthma (11, 12), characterized by corticosteroid use and nocturnal symptoms (13–15), whereas subjects homozygous for Arg16 had lower lung function (16). In contrast, analysis of Gln27Glu found that the Glu27 allele was associated with a decrease in airway responses (17–19), whereas Gly16 was associated with asthma susceptibility (12, 20, 21). Other studies have not replicated these findings (22–24). Recent meta-analyses have reported inconsistent results that exist between different ADRbeta2 association studies (25, 26).

Current interest in ADRbeta2 has focused on the role of Gly16Arg and Gln27Glu variations in modulating responses to beta-agonist treatment. Martinez and coworkers (27) found that children homozygous for Arg16 were 5.3 times more likely to show reversibility to albuterol (> 15.3% of predicted FEV1) than were homozygous Gly16 subjects. Heterozygous Gly16/Arg16 children showed intermediate responses to albuterol, whereas variations at +79 (Gln27Glu) had no significant effect. A reduced response to beta-agonist therapy in homozygous Gly16 subjects has been replicated in other studies (28, 29). However, recent reports have shown adverse effects to treatment with beta-agonists in Arg16 homozygous patients with asthma. In an ACRN (Asthma Clinical Research Network; National Heart, Lung, and Blood Institute) study (30), subjects with asthma homozygous for Arg16 treated with regular, short-acting beta-agonist experienced significant declines in A.M. and P.M. PEF compared with Gly16 homozygous subjects. Taylor and coworkers observed similar effects, as well as increased exacerbations in Arg16 homozygous subjects on regular albuterol treatment, but did not report changes in Arg/Arg subjects receiving intermittent albuterol or the long-acting beta-agonist salmeterol (31). Subsequently, in a genotype-stratified, placebo-controlled, double-blind ACRN study (BARGE [beta-Agonist Response by Genotype]) (32), Arg16 homozygous subjects with asthma receiving regular, short-acting beta-agonist therapy had lower peak flow rates and increased symptoms compared with Arg16/Arg16 subjects treated with intermittent, short-acting anticholinergics (ipratropium). In contrast, Gly16/Gly16 subjects receiving regular albuterol experienced improvement in peak flow rates and fewer daily asthma symptoms. A recent report on the responses to salmeterol in two ACRN trials (33, 34) found that Arg16/Arg16 subjects had decreased responses to salmeterol in the presence or absence of concurrent inhaled corticosteroids (35).

Genetic variations other than Gly16Arg and Gln27Glu may also be important (36). In a family-based association study by Silverman and coworkers (37), polymorphisms –654 and +46 (Gly16Arg) were associated with post-bronchodilator FEV1, whereas the polymorphism +523 (Arg175Arg) was associated with bronchodilator response. Drysdale and coworkers (38) described the molecular haplotypic structure of ADRbeta2 in several ethnic groups and reported that haplotypes 2, 4, and 6 comprised 94.5% of the haplotypic variation in whites and haplotypes (1, 2, 4, and 6) comprised 92.3% of the haplotypic variation in African Americans. Although they also reported an affect of haplotype pairs on acute bronchodilator responses to albuterol, a recent report by Taylor and colleagues in 176 subjects with asthma reported no significant relationship between haplotype pairs and bronchodilator response (38).

The primary objective of this study was to comprehensively sequence ADRbeta2 to thoroughly evaluate gene variation, linkage disequilibrium (LD), and haplotype structure. Because of recent evidence concerning rare adverse effects of beta-agonist therapy in African Americans (39), we sequenced ADRbeta2 in a large sample of African Americans as well as whites (n = 669). Because these adverse events are infrequent, identification of rare ADRbeta2 variants could identify genetic variants or haplotypes that may be important in these adverse therapeutic responses. A secondary objective was to determine whether ADRbeta2 genetic variants and/or haplotypes were associated with asthma phenotypes, specifically pulmonary function, in a well-characterized, multiethnic case-control population.


   METHODS
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 ABSTRACT
 AT A GLANCE COMMENTARY
 METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Study Populations
Asthma cases consisted of unrelated subjects with either bronchial hyperresponsiveness (BHR) or bronchodilator reversibility (if FEV1 <= 60% predicted), less than 3 pack-years of tobacco exposure, appropriate asthma symptoms, and a physician's diagnosis of asthma (40). Control subjects had no personal or family history of asthma (46, 47). These genetic studies were approved by the institutional review board at the University of Maryland and Wake Forest University School of Medicine, and informed consent was obtained from all subjects (41, 46, 47).

The second population represented a subset of the Childhood Asthma Management Program (CAMP), which was a multicenter randomized, double-blinded clinical trial testing the safety and efficacy of inhaled corticosteroids compared with placebo and nedocromil. Trial design and methodology have previously been published (41–43). Children enrolled in CAMP were 5–12 yr of age, with mild to moderate persistent asthma that was characterized by asthma symptoms, medication use, and BHR. The CAMP Genetics Ancillary Study was approved by each study center's institutional review board, and informed consent/assent was obtained from all participants and their parents.

DNA sequencing was performed using a subset of samples from the case and control population (283 white and 180 African American) (44) and the CAMP study population (136 white and 60 African American) (37). Case-control association studies were performed on the adult asthma case-control subjects (45).

DNA Sequencing and Genotyping of ADRbeta2 Polymorphisms
The strategy and methods for generating and sequencing polymerase chain reaction products have been previously described (46). A 10,000-bp genomic reference sequence of ADRbeta2 was ascertained from the University of California Santa Cruz Genomic Browser website (available online at http://genome.ucsc.edu/) and aligned with the mRNA reference sequence M15169 (GenBank reference no.). A region –3,470 bp 5' of the ATG start site to +1,886 bp after the ATG start site was sequenced. DNA sequence data were aligned and polymorphisms identified using Sequencer DNA analysis software (Gene Codes Corporation, Ann Arbor, MI). Genotyping was performed using the MassARRAY genotyping system (Sequenom, Inc., San Diego, CA). CEPH (Centre d'Etude du Polymorphisme Humain) controls and blanks were included for quality control and error checking. The 3' untranslated region (UTR) poly-C polymorphism was genotyped by fragment analysis on an ABI 3700 DNA Analyzer (Applied Biosystems, Foster City, CA).

Statistical Methods
Hardy-Weinberg equilibrium testing was performed on genotyped polymorphisms using the GDA computer programs (47) and SAS/Genetics, 2002 (SAS Institute, Cary, NC). LD, in terms of D' and r2, were calculated using the program Haploview (http://www.broad.mit.edu/mpg/haploview/index.php) (48). t Tests and analyses of variance were performed for quantitative measurements of pulmonary function (% predicted FEV1, % predicted FVC, [FEV1/FVC]2 [ratio squared was used for normality], BHR [log of provocative concentration of methacholine causing a 20% drop in FEV1 (PC20)], bronchodilator reversibility, and post-bronchodilator FEV1) to test for association using the case and control populations. Association tests between haplotypes and asthma phenotypes were performed using Haplo.Score (http://mayoresearch.mayo.edu/mayo/research/biostat/schaid.cfm) (49).


   RESULTS
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 ABSTRACT
 AT A GLANCE COMMENTARY
 METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Case-Control Population
Subjects with asthma tended to be younger than the control subjects with higher IgE levels, and 90% had positive allergy skin test (see Table E1 in the online supplement). Percent-predicted FEV1 was slightly lower in the African-American subjects, but both ethnic groups had similar FEV1/FVC ratios and levels of BHR. Clinical data for the CAMP participants have been previously published (41, 42, 50).

Sequence Analysis Shows 49 Variants in ADRbeta2
ADRbeta2 polymorphisms were identified according to base pair numbering described by Drysdale and colleagues (38), in which the +1 position represents the first base in the ATG start codon. A total of 49 polymorphisms were identified (Figure 1 and Table 1), of which 21 were novel—1 of which was coding (+66; His22His). Polymorphism –709, identified by Drysdale and coworkers (38), was not detected. All novel polymorphisms had a minor allele frequency less than 10% in all ethnic groups, with the exception of –3159 (>= 15% in all ethnic groups). Allele frequencies of Gly16Arg, Gln27Glu, and Thr164Ile were similar to those reported for whites and African Americans (38, 51). A rare nonsynonymous polymorphism, Ser220Cys, was found in African Americans (allele frequency = 0.03), but was not detected in whites. Two novel insertion/deletions (InDels; –2051 and –376) were identified in African Americans. InDel –2051 consists of a 4 or 5 poly-C repeats, whereas InDel –376 consists of a 25-base duplication. Sequencing of the 3' UTR revealed a poly-C repeat starting 23 bases after the TAA stop and varying in size from 9–15 Cs, based on fragment analysis (see online supplement). This poly-C region was interrupted by polymorphisms at +1268 and +1277 (positions based on reference sequences). Based on sequence analysis, the poly-C length variation occurs between polymorphisms +1268 and +1277. Statistical analysis of poly-C lengths revealed a predominant bimodal distribution in whites at 11 Cs (frequency = 0.40) and 13 Cs (frequency = 0.34), whereas African Americans have predominantly 13 Cs (frequency = 0.64; Table E2).


Figure 1
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  		Figure 1. Position of polymorphisms in ADRbeta2.

 

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  		TABLE 1. ADRbeta2 POLYMORPHISMS IN WAKE FOREST PLUS CAMP STUDY POPULATIONS

 
ADRbeta2 Variants Exist as Multiple Haplotypes
LD (as D' and r2) was calculated separately for African Americans and whites using the polymorphisms used to define haplotype frequency (Table 2), with the exception of –709 (African American and white; frequency = 0) and +659 (whites; frequency = 0). Three additional polymorphisms (+1275, +1277, and +1278) were added to provide coverage in the 3' UTR. D' reflects whether a polymorphism is inherited in conjunction with a second polymorphism; however, it does not imply that the alleles at one polymorphism can predict the inheritance of an allele at another polymorphism. The correlation coefficient, r2, is calculated to reflect the relationship between two polymorphisms, and whether individual alleles can predict the inheritance of each other. LD (see Figures E1–E4) was generally strong across ADRbeta2 in both populations, except between rare polymorphisms in the 3' region of ADRbeta2, and was lower in African Americans. For example, LD between +46 and 5' polymorphisms (–3459, –3291, –3287, –2633, –2387, –2274, –1343, and –1023) was 0.95 or greater (D'), with an r2 of 0.44 or greater, whereas, in whites, D' was 0.21 or less, with an r2 of 0.04 or less. Similar values were observed for +79 (in strong LD with +46) and 5' polymorphisms.

A total of 31 polymorphisms genotyped from sequencing data (429 whites and 240 African Americans) were used to estimate haplotype frequency (Table 2). Polymorphisms used include those identified by Drysdale and colleagues (38) (except for –709 [frequency = 0 in this study]), polymorphisms identified in this study with frequencies of 0.03 or greater, and coding polymorphisms at +491 and +659. A total of 24 haplotypes with frequencies of 0.01 or greater were observed. When analysis was limited to the Drysdale polymorphisms, haplotypes 2, 4, 6, and 9 were observed in whites, whereas haplotypes 1, 2, 4, 6, 7, and 10 were observed in African Americans. Significant differences between Drysdale haplotype frequencies existed between whites and African Americans, especially haplotypes 1, 4, and 9, which encodes Arg16 at the +46 position. Drysdale haplotype 1 was only observed in African Americans, and Drysdale haplotypes 2 and 4 frequencies were higher in whites (frequency = 0.38 and 0.37, respectively) compared with African Americans (frequency = 0.12 and 0.21, respectively). Finally, Drysdale haplotype 6 was more than twice as frequent (frequency = 0.28) in African Americans than in whites (frequency = 0.12). Based on extended haplotype analyses, we were able to divide Drysdale haplotype 1 into three subhaplotypes, haplotype 2 into seven subhaplotypes, haplotype 4 into eight subhaplotypes, haplotype 6 into five subhaplotypes, and haplotype 10 into two subhaplotypes. Only one form of Drysdale haplotypes 7 and 9 were observed. All subhaplotypes were differentiated by polymorphisms in the 3' portion of ADRbeta2, except for subhaplotypes 2-6, 4-8, and 6-2. Drysdale haplotypes 2 and 4 accounted for the majority of white haplotypes (frequency = 0.38 and 0.37, respectively), whereas haplotype frequencies in African American were more evenly distributed between the four Drysdale haplotypes 1, 2, 4, and 6 (frequency = 0.17, 0.12, 0.21, and 0.28, respectively).

Association Results
ADRbeta2 polymorphisms –3459, –2387, –1818, –468, –47, +46, +79, +491, +523, +659, +1053, and +1269 were selected for genotyping in the adult asthma case and control population These polymorphisms, except for +491 and +659 (Table 3, highlighted in boxes ) represented an optimal tagging subset based on LD and haplotype analysis. Coding polymorphisms +491 and +659 were included because of their potential effect on receptor function. Association studies including the +1269 poly-C polymorphism were performed by dividing +1269 poly-C lengths into two pooled groups—short lengths (S) (poly-Cs <= 12 Cs) and long lengths (L; poly-Cs >= 13 Cs)—based on the bimodal distribution of poly-C length in whites. The genotyping success rate ranged from a low of 95.5% (single-nucleotide polymorphism [SNP] –3459) to greater than 99% (SNP –47), and there were no significant differences in genotyping success rates between whites and African Americans. Adjustments were made for age and sex. All subjects with asthma were adults with less than 5 pack-years of smoking. Adjustments for current medications were not made, although subjects withheld medications prior to testing.


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  		TABLE 2. HAPLOTYPE FREQUENCY IN WHITES AND AFRICAN AMERICANS

 

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  		TABLE 3. HAPLOTYPE ASSOCIATION WITH (FEV1/FVC)2 IN AFRICAN AMERICANS

 
For African Americans, polymorphism +79 was found to be significantly associated with (FEV1/FVC)2 after adjusting for multiple testing (p = 0.028; p = 0.007 before adjustment) (genotypes N: CC = 167, CG = 80, GG = 11; [FEV1/FVC]2 = 0.596 [SD, ± 0.16], 0.586 [SD, ± 0.16], 0.543 [SD, ± 0.16], respectively; Table E3). Associations with % predicted FEV1 (+79; p = 0.034), % predicted FVC (+79; p = 0.05), bronchodilator reversibility (+79; p = 0.02), and PC20 (+1,269 S vs. L; p = 0.03) were also observed before adjusting for multiple testing (Table E3). Using the conservative approach of adjusting the p values by the number of tests performed, only (FEV1/FVC)2 remained significant. There was no evidence for associations with measures of pulmonary function in the white population.

Haplotype Association Results
Haplotype association tests were performed using the 12 polymorphisms genotyped in our adult case-control populations. Haplotypes were labeled using the Drysdale haplotype numbering convention (38), followed by a letter signifying the +1269 poly-C repeat length (A = 10 Cs, B = 11 Cs, etc.). Additional SNP identifiers indicate SNPs that further subdivide haplotypes. No significant haplotype associations were found in the white population.

Significant association of haplotypes was also observed with (FEV1/FVC)2 (p = 0.006) in African Americans. Individual haplotypes 2D and 4D were associated with (FEV1/FVC)2 (p = 0.003 and 0.019, respectively; Table 3). (FEV1/FVC)2 was also associated with the three SNP haplotype G/C/C (SNPs +79/+491/+523; frequency = 0.189; p = 0.05). Significant haplotype association was observed for % predicted FEV1 (p = 0.05) in African Americans. Analysis of individual haplotypes revealed that haplotypes containing a 13 Cs repeat at +1269 were associated with % predicted FEV1 (haplotypes 2D and 4D; p = 0.002 and 0.01, respectively; Table E4). A three-SNP sliding window analysis identified a single three-SNP haplotype (C/G/13; SNPs +659/+1053/+1269; frequency = 0.326) that was associated with percent- predicted FEV1 (p = 0.014). Global association of haplotypes with % predicted FVC was not significant in African Americans. However, individual haplotypes 4C and 4D (Table E5) were associated with % predicted FVC (p = 0.02 and 0.025, respectively). Haplotypes 4C and 4D were differentiated by the length of the poly-C region at +1269. This analysis suggests that the length of the poly-C region may influence lung function in African Americans. A comparison of Drysdale haplotype pairs (38) with acute reversibility to albuterol found no significant correlations between haplotype pairs and percent reversibility (data not shown).


   DISCUSSION
TOP
 ABSTRACT
 AT A GLANCE COMMENTARY
 METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
In previous studies, DNA sequence and haplotype analysis of ADRbeta2 has been limited to a region approximately 1,430 bp 5' of the ATG start codon to approximately 1,200 bp 3' of the ATG start codon, leaving a significant portion of 5' regulatory sequence and 3' UTR uncharacterized (9, 38, 52–54). Many of these studies were inconsistent in their findings due to the smaller region of the gene that was sequenced and the limited size of the population samples. Recent clinical studies suggest that there may be a subset of patients with asthma, especially African Americans, who have adverse responses to beta-agonist therapy (39, 55). Our primary purpose in this study was to comprehensively resequence a 5.3-kb region of ADRbeta2 in 669 African American and white subjects. We identified 49 polymorphisms, 20 of which have not been previously reported, and found variations in regulatory regions, including the promoter region and the 3' UTR, that contribute to haplotypic structure and to genetic association with asthma-related phenotypes.

Whereas LD, as measured by D', is strong across the entire gene in both African American and white populations, measurements of r2 between 5' polymorphisms and +46 and +79 polymorphisms were not concordant between the two ethnic groups. For example, whites do not possess haplotype 1, which contains Arg16 (Table 3), whereas the frequency of haplotype 1 approaches 20% in African Americans. Haplotype 1 appears to have originated from a combination of haplotypes 2 and4, but only involving the polymorphisms –3291 to –654 (38). The consequence of this recombination is that African Americans possessing an Arg16/Gln27 haplotype are equally divided in frequency between haplotypes 1 and 4 (Table 3), whereas whites possessing an Arg16/Gln27 haplotype always have haplotype 4. Therefore, the 5' region of the gene will be different approximately 50% of the time when comparing African American individuals with the Arg16/Gln27 haplotype. Taking into account additional 3' UTR differences that occur due to variations in the poly-C region at +1269, regulation of gene expression and translation in African Americans could be more complex than in whites. These findings are potentially important considering recent studies showing increased mortality especially in African Americans during long-term beta-agonist therapy (55).

In addition to haplotype differences that may affect gene regulation, we also identified sequence variants unique to the African American subjects. Polymorphism +659 (Ser220Cys) was found in 3% of African Americans, with no homozygotes identified. This mutation occurs at the boundary of the cell membrane and the third intracytoplasmic loop, directly adjacent to a peptide region assigned to Gs coupling regulation. We could not find prior evidence that this mutation has been characterized functionally; thus, the possible biological effects of this mutation are unknown. We also identified a large InDel at –376 in African Americans (frequency = 0.02). This InDel, a duplication of 25 bases, occurs adjacent to a G-rich region at position –365 to –325, but does not alter the potential regulatory region. We can only speculate that this InDel could have effects on gene expression. There were no individuals homozygous for –376. Interestingly, polymorphisms –376 and +659 were never found in an individual, although nearly 5% of the African Americans carried one of these polymorphisms. In these individuals, there is the potential of alterations in ADRbeta2 expression or receptor function.

Single SNP associations observed with lung function phenotypes varied between ethnic groups. We did find an association between the +79 SNP and (FEV1/FVC)2, with the G/G subjects having lower values in African Americans. Interesting, +79 C/G heterozygous individuals did not show lower pulmonary function, suggesting a protective effect of the Gln27 allele, which has been suggested in previous in vitro studies (10). These results are consistent with the family-based results reported by Silverman and coworkers (37).

Drysdale and coworkers (38) were able to identify 12 haplotypes using a subset of 13 polymorphisms. Using the same subset of polymorphisms in our larger set of subjects, we were able to identify only seven of these haplotypes. There are multiple explanations for these discordant results, including the smaller number of subjects sequenced from each ethnic group in the Drysdale study, the absence of polymorphism –709 in our population samples, the estimation of haplotypes by different algorithms, and inclusion of Asians and Hispanics in the Drysdale study. Because we resequenced a larger set of subjects, some of the missing haplotypes may also be accounted for by very rare haplotypes (frequency < 0.01) that we excluded in our study, but were found in one of the Drysdale subjects. For instance, based on haplotype analysis (Table 3), 81% of African Americans (194 of 240) had the most common Drysdale haplotypes. An important component of our haplotype analysis is the subdivision of the "functionally" important Drysdale haplotypes 1, 2, and 4. Drysdale haplotypes 1and 4, both of which contain the risk Arg16 allele, were divided into three and eight subhaplotypes, respectively; however, only haplotype 1 was present in African Americans. With the addition of Drysdale haplotype 9 (occurring only in African Americans), there are 10 extended haplotypes (frequency >= 0.01) in African Americans that contain the risk Arg16 allele. Drysdale haplotype 2, which was the most common in whites, was divided into seven subhaplotypes. With the exceptions of extended haplotypes 2-6 and 4-8 (Table 3), all Drysdale haplotype subdivision was caused by variations at polymorphisms +1053, +1239, +1268, and the +1269 poly-C region in the 3' UTR of ADRbeta2, none of which have been included in prior haplotype analyses of ADRbeta2. Belfer and colleagues (51) have recently reported a haplotype analysis of ADRbeta2 in 96 whites and 96 African Americans using 11 polymorphisms. However, because of the small number of polymorphisms used in that study and the extragenic location of some polymorphisms, a direct comparison of these results with ours and those of the Drysdale study (38) is not possible.

We did not find an association between haplotype pairs and acute bronchodilator response that was reported by Drysdale. A recent report by Taylor and coworkers (56) also found no significant correlations between Drysdale haplotype pairs and bronchodilator response to albuterol in 176 subjects with asthma in New Zealand (38). Although we did not observe significant association of haplotypes with percent-predicted FEV1 and percent predicted FVC in African Americans, the analysis revealed an interesting trend in the association of poly-C lengths in polymorphism +1269 with FEV1 and percent-predicted FVC. For both measures, haplotypes 4C and 4D were significantly associated with lung function, but with opposite Hap-scores. The only difference between haplotypes 4C and 4D are the lengths of the +1,269 poly-C region. There is a trend for haplotype 2, with increasing the poly-C length from 11 to 13, to be associated with lower percent-predicted FEV1 and (FEV1/FVC)2. This poly-C region at +1269 lies only 20 bp 5' of an AU-rich element (ARE), which has been shown to affect mRNA stability and mRNA translation rates of several other genes (57–60). Tholanikunnel and coworkers have shown that DNA sequence changes in a similarly positioned ARE in the guinea pig ADRbeta2 3' UTR modulates the translation rates of beta2-receptor protein, reducing receptor density in the cell membrane (61). It is possible that this poly-C region could have an independent effect or a cooperative effect with the flanking ARE region in modulating mRNA stability and protein translation rates. This could explain the discrepancy in the Drysdale study that was observed for bronchodilator reversibility between haplotype pairs, as the poly-C region variation was not evaluated in the Drysdale haplotypes (38). The interruptions at positions 3 (+1268) and 10 (+1275) may also be important determinants modulating the poly-C region effects on gene expression. Although polymorphism +1268 is relatively rare, polymorphism +1275, has three alleles, is very common (frequency range, 0.29–0.54), mostly occurs in poly-C repeats of 13, 14, and 15 Cs, and further subdivides haplotypes containing long poly-C repeats (data not shown). If poly-C region variations do alter gene expression and/or translation, the use of ADRbeta2 polymorphisms to predict beta-agonist response will be complicated by the large number of haplotypes that must be considered.

The primary focus of this study was to accurately determine polymorphism content and haplotype structure in whites and African Americans; thus, the association results are considered secondary. However, we must note that there are several factors that affect the association results in this study. First, the degree of population stratification in these case and control populations has not been measured; thus, we do not know if population stratification affects these association results. However, it is not clear what effects population stratification may have on quantitative analyses that were performed in this study. This is particularly true in the African Americans, where population stratification can be more pronounced. Second, although our African American subjects constitute the largest case-control population evaluated for effects of ADRbeta2 variation and lung function, this population may still be underpowered for this type of association study. Finally, because numerous phenotypes were tested, multiple comparison adjustments reduced the significance of genetic primary associations. However, the measures of lung function FEV1, FVC, and (FEV1/FVC)2 are correlated, so our adjustments were conservative.

In this study, we have characterized ADRbeta2 in two ethnic populations demonstrating several new sequence features of the gene, and have identified a minimum of 27 haplotypes. Thus far, simple genotyping of the +46 (Gly16Arg) and +79 (Gln27Glu) ADRbeta2 polymorphisms has been used to characterize specific beta-agonist responses in a number of pharmacogenetic studies (30, 32, 62). The results of this study, however, suggest that additional genetic variants in ADRbeta2 may be important in asthma association and pharmacogenetic studies. There is also the possibility that genetic variants in ADRbeta2 will be more useful in more complex genomic studies investigating gene–gene interactions with other genes in the ADRbeta2 pathway. Although many of the new polymorphisms identified in this study are rare or are not found in all ethnic populations, the interindividual and interracial pharmacogenetic effects that these rare polymorphisms may have on ADRbeta2 expression or receptor function may be significant. Thus, the results of this study support the need for complete genetic analysis of ADRbeta2 in current and future pharmacogenetic studies that evaluate the relationship of ADRbeta2 variants and responses to the acute or chronic administration of beta-agonists. This study also demonstrates the genetic complexity that can be missed by genotyping only a few polymorphisms in a biologically or pharmacologically important gene. Although it may not be practical to sequence every portion of a gene, this study demonstrates the importance of sequencing a minimum, predefined region of the gene promoter region, all of the coding region, and the potential regulatory region in the 3' UTR. This is particularly important considering recent reports that severe adverse events and even increased mortality, although infrequent, have been observed, especially in African Americans receiving long-term beta-agonist therapy (39, 55). Thus, it is possible that variation in ADRbeta2 may represent an underlying genetic mechanism that contributes to variation in therapeutic responses and, possibly, adverse responses associated with chronic beta-agonist therapy.


   Acknowledgments
 
The authors thank Abdoulaye Diallo, Catherine Brewer, and Scott Binford for their technical expertise in sequencing and genotyping, and Ross Lazarus and Brent Richter for bioinformatics support. They also thank all of the study participants from the CAMP and Collaborative Study of the Genetics of Asthma studies, and all collaborators who helped in recruiting and characterizing the subjects in these two studies.


   FOOTNOTES
 
Supported by National Heart, Lung, and Blood Institute grants HL077916, HL76285, HL69167, HL65899, HL045967, and HL071609.

This article has an online supplement, which is accessible from this issue's table of contents at www.atsjournals.org

Originally Published in Press as DOI: 10.1164/rccm.200509-1405OC on August 24, 2006

Conflict of Interest Statement: G.A.H. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; K.T. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; D.A.M. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; E.J.A. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; W.C.M. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; B.K. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; S.B.L. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; S.P.P. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; S.T.W. received a grant for $900,065 (Asthma Policy Modeling Study) from AstraZeneca from 1997–2003, has been a coinvestigator on a grant from Boehringer Ingelheim to study a chronic obstructive pulmonary disease natural history model, which began in 2003, and has received no funds for his involvement in this project. He has been an advisor and chair on the advisory board to the TENOR Study for Genentech, and has received $10,000 for 2005–2003. He received a grant from Glaxo-Wellcome for $500,000 for genomic equipment from 2000–2003. He was a consultant for Roche Pharmaceuticals in 2000, and received no financial renumeration for this consultancy. He has also served as a consultant to: Pfizer (2000–2003), Schering Plough (1999–2000), Variagenics (2002), Genome Therapeutics (2003), and Merck Frost (2002); E.R.B. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript.

Received in original form September 8, 2005; accepted in final form August 24, 2006


   REFERENCES
TOP
 ABSTRACT
 AT A GLANCE COMMENTARY
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Palmer LJ, Silverman ES, Weiss ST, Drazen JM. Pharmacogenetics of asthma. Am J Respir Crit Care Med 2002;165:861–866.[Free Full Text]
  2. Lima JJ, Thomason DB, Mohamed MH, Eberle LV, Self TH, Johnson JA. Impact of genetic polymorphisms of the beta2-adrenergic receptor on albuterol bronchodilator pharmacodynamics. Clin Pharmacol Ther 1999;65:519–525.[CrossRef][Medline]
  3. Hadcock JR, Malbon CC. Down-regulation of beta-adrenergic receptors: agonist-induced reduction in receptor mRNA levels. Proc Natl Acad Sci USA 1988;85:5021–5025.[Abstract/Free Full Text]
  4. Nishikawa M, Mak JC, Shirasaki H, Harding SE, Barnes PJ. Long-term exposure to norepinephrine results in down-regulation and reduced mRNA expression of pulmonary beta-adrenergic receptors in guinea pigs. Am J Respir Cell Mol Biol 1994;10:91–99.[Abstract]
  5. Moore PE, Laporte JD, Abraham JH, Schwartzman IN, Yandava CN, Silverman ES, Drazen JM, Wand MP, Panettieri RA Jr, Shore SA. Polymorphism of the beta2-adrenergic receptor gene and desensitization in human airway smooth muscle. Am J Respir Crit Care Med 2000;162:2117–2124.[Abstract/Free Full Text]
  6. Kobilka BK, Dixon RA, Frielle T, Dohlman HG, Bolanowski MA, Sigal IS, Yang-Feng TL, Francke U, Caron MG, Lefkowitz RJ. cDNA for the human beta 2-adrenergic receptor: a protein with multiple membrane-spanning domains and encoded by a gene whose chromosomal location is shared with that of the receptor for platelet-derived growth factor. Proc Natl Acad Sci USA 1987;84:46–50.[Abstract/Free Full Text]
  7. Meyers DA, Postma DS, Stine OC, Koppelman GH, Ampleford EJ, Jongepier H, Howard TD, Bleecker ER. Genome screen for asthma and bronchial hyperresponsiveness: interactions with passive smoke exposure. J Allergy Clin Immunol 2005;115:1169–1175.[CrossRef][Medline]
  8. Postma DS, Meyers DA, Jongepier H, Howard TD, Koppelman GH, Bleecker ER. Genomewide screen for pulmonary function in 200 families ascertained for asthma. Am J Respir Crit Care Med 2005;172:446–452.[Abstract/Free Full Text]
  9. Reihsaus E, Innis M, MacIntyre N, Liggett SB. Mutations in the gene encoding for the beta2-adrenergic receptor in normal and asthmatic subjects. Am J Respir Cell Mol Biol 1993;8:334–339.[Medline]
  10. Green SA, Turki J, Innis M, Liggett SB. Amino-terminal polymorphisms of the human beta2-adrenergic receptor impart distinct agonist-promoted regulatory properties. Biochemistry 1994;33:9414–9419.[CrossRef][Medline]
  11. Turner SW, Khoo SK, Laing IA, Palmer LJ, Gibson NA, Rye P, Landau LI, Goldblatt J, Le Souef PN. beta2 adrenoceptor Arg16Gly polymorphism, airway responsiveness, lung function and asthma in infants and children. Clin Exp Allergy 2004;34:1043–1048.[CrossRef][Medline]
  12. Holloway JW, Dunbar PR, Riley GA, Sawyer GM, Fitzharris PF, Pearce N, Le Gros GS, Beasley R. Association of beta2-adrenergic receptor polymorphisms with severe asthma. Clin Exp Allergy 2000;30:1097–1103.[CrossRef][Medline]
  13. Turki J, Pak J, Green SA, Martin RJ, Liggett SB. Genetic polymorphisms of the beta2-adrenergic receptor in nocturnal and nonnocturnal asthma: evidence that Gly16 correlates with the nocturnal phenotype. J Clin Invest 1995;95:1635–1641.[Medline]
  14. Dai LM, Wang ZL, Zhang YP, Liu L, Fang LZ, Zhang JQ. Relationship between the locus 16 geontype of beta2 adrenergic receptor and the nocturnal asthma phenotype [in Chinese]. Sichuan Da Xue Xue Bao Yi Xue Ban 2004;35:32–34.[Medline]
  15. Santillan AA, Camargo CA Jr, Ramirez-Rivera A, Delgado-Enciso I, Rojas-Martinez A, Cantu-Diaz F, Barrera-Saldana HA. Association between beta2-adrenoceptor polymorphisms and asthma diagnosis among Mexican adults. J Allergy Clin Immunol 2003;112:1095–1100.[CrossRef][Medline]
  16. Summerhill E, Leavitt SA, Gidley H, Parry R, Solway J, Ober C. beta2-Adrenergic receptor Arg16/Arg16 genotype is associated with reduced lung function, but not with asthma, in the Hutterites. Am J Respir Crit Care Med 2000;162:599–602.[Abstract/Free Full Text]
  17. Hall IP, Wheatley A, Wilding P, Liggett SB. Association of Glu 27 beta2-adrenoceptor polymorphism with lower airway reactivity in asthmatic subjects. Lancet 1995;345:1213–1214.[CrossRef][Medline]
  18. D'amato M, Vitiani LR, Petrelli G, Ferrigno L, di Pietro A, Trezza R, Matricardi PM. Association of persistent bronchial hyperresponsiveness with beta2-adrenoceptor (ADRB2) haplotypes: a population study. Am J Respir Crit Care Med 1998;158:1968–1973.[Abstract/Free Full Text]
  19. Lipworth BJ, Hall IP, Aziz I, Tan KS, Wheatley A. beta2-adrenoceptor polymorphism and bronchoprotective sensitivity with regular short- and long-acting beta2-agonist therapy. Clin Sci (Lond) 1999;96:253–259.[Medline]
  20. Hopes E, McDougall C, Christie G, Dewar J, Wheatley A, Hall IP, Helms PJ. Association of glutamine 27 polymorphism of beta2 adrenoceptor with reported childhood asthma: population based study. BMJ 1998;316:664.[Free Full Text]
  21. Gao JM, Lin YG, Qiu CC, Gao J, Ma Y, Liu YW, Liu Y. Association of polymorphism of human beta 2-adrenergic receptor gene and bronchial asthma [in Chinese]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2002;24:626–631.[Medline]
  22. Hancox RJ, Sears MR, Taylor DR. Polymorphism of the beta2-adrenoceptor and the response to long-term beta2-agonist therapy in asthma. Eur Respir J 1998;11:589–593.[Abstract]
  23. Dewar JC, Wheatley AP, Venn A, Morrison JF, Britton J, Hall IP. beta2-Adrenoceptor polymorphisms are in linkage disequilibrium, but are not associated with asthma in an adult population. Clin Exp Allergy 1998;28:442–448.[CrossRef][Medline]
  24. Litonjua AA, Silverman EK, Tantisira KG, Sparrow D, Sylvia JS, Weiss ST. beta2-Adrenergic receptor polymorphisms and haplotypes are associated with airways hyperresponsiveness among nonsmoking men. Chest 2004;126:66–74.[CrossRef][Medline]
  25. Contopoulos-Ioannidis DG, Manoli EN, Ioannidis JP. Meta-analysis of the association of beta2-adrenergic receptor polymorphisms with asthma phenotypes. J Allergy Clin Immunol 2005;115:963–972.[CrossRef][Medline]
  26. Thakkinstian A, McEvoy M, Minelli C, Gibson P, Hancox B, Duffy D, Thompson J, Hall I, Kaufman J, Leung TF, et al. Systematic review and meta-analysis of the association between beta2-adrenoceptor polymorphisms and asthma: a HuGE review. Am J Epidemiol 2005;162:201–211.[Abstract/Free Full Text]
  27. Martinez FD, Graves PE, Baldini M, Solomon S, Erickson R. Association between genetic polymorphisms of the beta2-adrenoceptor and response to albuterol in children with and without a history of wheezing. J Clin Invest 1997;100:3184–3188.[Medline]
  28. Lipworth BJ, Hall IP, Tan S, Aziz I, Coutie W. Effects of genetic polymorphism on ex vivo and in vivo function of beta2-adrenoceptors in asthmatic patients. Chest 1999;115:324–328.[CrossRef][Medline]
  29. Tan S, Hall IP, Dewar J, Dow E, Lipworth B. Association between beta2-adrenoceptor polymorphism and susceptibility to bronchodilator desensitisation in moderately severe stable asthmatics. Lancet 1997;350:995–999.[CrossRef][Medline]
  30. Israel E, Drazen JM, Liggett SB, Boushey HA, Cherniack RM, Chinchilli VM, Cooper DM, Fahy JV, Fish JE, Ford JG, et al. The effect of polymorphisms of the beta2-adrenergic receptor on the response to regular use of albuterol in asthma. Am J Respir Crit Care Med 2000;162:75–80.[Abstract/Free Full Text]
  31. Taylor DR, Drazen JM, Herbison GP, Yandava CN, Hancox RJ, Town GI. Asthma exacerbations during long term beta agonist use: influence of beta2 adrenoceptor polymorphism. Thorax 2000;55:762–767.[Abstract/Free Full Text]
  32. Israel E, Chinchilli VM, Ford JG, Boushey HA, Cherniack R, Craig TJ, Deykin A, Fagan JK, Fahy JV, Fish J, et al. Use of regularly scheduled albuterol treatment in asthma: genotype-stratified, randomised, placebo-controlled cross-over trial. Lancet 2004;364:1505–1512.[CrossRef][Medline]
  33. Lazarus SC, Boushey HA, Fahy JV, Chinchilli VM, Lemanske RF Jr, Sorkness CA, Kraft M, Fish JE, Peters SP, Craig T, et al. Long-acting beta2-agonist monotherapy vs continued therapy with inhaled corticosteroids in patients with persistent asthma: a randomized controlled trial. JAMA 2001;285:2583–2593.[Abstract/Free Full Text]
  34. Lemanske RF Jr, Sorkness CA, Mauger EA, Lazarus SC, Boushey HA, Fahy JV, Drazen JM, Chinchilli VM, Craig T, Fish JE, et al. Inhaled corticosteroid reduction and elimination in patients with persistent asthma receiving salmeterol: a randomized controlled trial. JAMA 2001;285:2594–2603.[Abstract/Free Full Text]
  35. Wechsler ME, Lehman E, Lazarus SC, Lemanske RF Jr, Boushey HA, Deykin A, Fahy JV, Sorkness CA, Chinchilli VM, Craig TJ, et al. beta-Adrenergic receptor polymorphisms and response to salmeterol. Am J Respir Crit Care Med 2006;173:519–526.[Abstract/Free Full Text]
  36. Hawkins GA, Tantisira KG, Myers DA, Ampleford EJ, Peters SP, Liggett SB, Weiss ST, Bleecker ER. Analysis of ADR2 polymorphisms and haplotypes in Caucasian and African American asthma populations [abstract]. Proc Am Thorac Soc 2005;2:A30.
  37. Silverman EK, Kwiatkowski DJ, Sylvia JS, Lazarus R, Drazen JM, Lange C, Laird NM, Weiss ST. Family-based association analysis of beta2-adrenergic receptor polymorphisms in the childhood asthma management program. J Allergy Clin Immunol 2003;112:870–876.[CrossRef][Medline]
  38. Drysdale CM, McGraw DW, Stack CB, Stephens JC, Judson RS, Nandabalan K, Arnold K, Ruano G, Liggett SB. Complex promoter and coding region beta2-adrenergic receptor haplotypes alter receptor expression and predict in vivo responsiveness. Proc Natl Acad Sci USA 2000;97:10483–10488.[Abstract/Free Full Text]
  39. U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Pulmonary–Allergy Drugs Advisory Committee. Implications of recently available data related to the safety of long-acting beta-agonist bronchodilators (June 13, 2005). Available from: http://www.fda.gov/ohrms/dockets/AC/05/briefing/2005-4148%20index%20with%20disclaimer-13.htm
  40. Lester LA, Rich SS, Blumenthal MN, Togias A, Murphy S, Malveaux F, Miller ME, Dunston GM, Solway J, Wolf RL, et al. Ethnic differences in asthma and associated phenotypes: collaborative study on the genetics of asthma. J Allergy Clin Immunol 2001;108:357–362.[CrossRef][Medline]
  41. Childhood Asthma Management Program Research Group. Design and implementation of a patient education center for the Childhood Asthma Management Program. Ann Allergy Asthma Immunol 1998;81:571–581.[Medline]
  42. Childhood Asthma Management Program Research Group. The Childhood Asthma Management Program (CAMP): design, rationale, and methods. Control Clin Trials 1999;20:91–120.[CrossRef][Medline]
  43. Childhood Asthma Management Program Research Group. Long-term effects of budesonide or nedocromil in children with asthma. N Engl J Med 2000;343:1054–1063.[Abstract/Free Full Text]
  44. Howard TD, Postma DS, Jongepier H, Moore WC, Koppelman GH, Zheng SL, Xu J, Bleecker ER, Meyers DA. Association of a disintegrin and metalloprotease 33 (ADAM33) gene with asthma in ethnically diverse populations. J Allergy Clin Immunol 2003;112:717–722.[CrossRef][Medline]
  45. Basehore MJ, Howard TD, Lange LA, Moore WC, Hawkins GA, Marshik PL, Harkins MS, Meyers DA, Bleecker ER. A comprehensive evaluation of IL4 variants in ethnically diverse populations: association of total serum IgE levels and asthma in white subjects. J Allergy Clin Immunol 2004;114:80–87.[CrossRef][Medline]
  46. Hawkins GA, Amelung PJ, Smith RS, Jongepier H, Howard TD, Koppelman GH, Meyers DA, Bleecker ER, Postma DS. Identification of polymorphisms in the human glucocorticoid receptor gene (NR3C1) in a multi-racial asthma case and control screening panel. DNA Seq 2004;15:167–173.[Medline]
  47. Weir BS. Genetic data analysis II: methods for discrete population genetic data. Sunderland, MA: Sinauer Association Publishers; 1996.
  48. Barrett JC, Fry B, Maller J, Daly MJ. Haploview: analysis and visualization of LD and haplotype maps. Bioinformatics 2005;21:263–265.[Abstract/Free Full Text]
  49. Schaid DJ, Rowland CM, Tines DE, Jacobson RM, Poland GA. Score tests for association between traits and haplotypes when linkage phase is ambiguous. Am J Hum Genet 2002;70:425–434.[CrossRef][Medline]
  50. Childhood Asthma Management Program Research Group. Recruitment of participants in the childhood Asthma Management Program (CAMP): I. Description of methods: J Asthma 1999;36:217–237.[Medline]
  51. Belfer I, Buzas B, Evans C, Hipp H, Phillips G, Taubman J, Lorincz I, Lipsky RH, Enoch MA, Max MB, et al. Haplotype structure of the beta adrenergic receptor genes in US Caucasians and African Americans. Eur J Hum Genet 2005;13:341–351.[CrossRef][Medline]
  52. McGraw DW, Forbes SL, Kramer LA, Liggett SB. Polymorphisms of the 5' leader cistron of the human beta2-adrenergic receptor regulate receptor expression. J Clin Invest 1998;102:1927–1932.[Medline]
  53. McGraw DW, Liggett SB. Coding block and 5 leader cistron polymorphisms of the beta2-adrenergic receptor. Clin Exp Allergy 1999;29:43–45.[Medline]
  54. Scott MG, Swan C, Wheatley AP, Hall IP. Identification of novel polymorphisms within the promoter region of the human beta2 adrenergic receptor gene. Br J Pharmacol 1999;126:841–844.[CrossRef]
  55. Nelson HS, Weiss ST, Bleecker ER, Yancey SW, Dorinsky PM; SMART Study Group. The salmeterol multicenter asthma research trial (SMART): a comparison of usual pharmacotherapy for asthma or usual pharmacotherapy plus salmeterol. Chest 2006;129:15–26.[CrossRef][Medline]
  56. Taylor DR, Epton MJ, Kennedy MA, Smith AD, Iles S, Miller AL, Littlejohn MD, Cowan JO, Hewitt T, Swanney MP, et al. Bronchodilator response in relation to beta-adrenoceptor haplotype in patients with asthma. Am J Respir Crit Care Med 2005;172:700–703.[Abstract/Free Full Text]
  57. Schaaf MJ, Cidlowski JA. AUUUA motifs in the 3' UTR of human glucocorticoid receptor {alpha} and beta mRNA destabilize mRNA and decrease receptor protein expression. Steroids 2002;67:627–636.[CrossRef][Medline]
  58. Chen CY, Shyu AB. Selective degradation of early-response-gene mRNAs: functional analyses of sequence features of the AU-rich elements. Mol Cell Biol 1994;14:8471–8482.[Abstract/Free Full Text]
  59. Chen CY, Shyu AB. AU-rich elements: characterization and importance in mRNA degradation. Trends Biochem Sci 1995;20:465–470.[CrossRef][Medline]
  60. Chen CY, Xu N, Shyu AB. Highly selective actions of HuR in antagonizing AU-rich element–mediated mRNA destabilization. Mol Cell Biol 2002;22:7268–7278.[Abstract/Free Full Text]
  61. Tholanikunnel BG, Raymond JR, Malbon CC. Analysis of the AU-rich elements in the 3'-untranslated region of beta2-adrenergic receptor mRNA by mutagenesis and identification of the homologous AU-rich region from different species. Biochemistry 1999;38:15564–15572.[CrossRef][Medline]
  62. Taylor DR, Kennedy MA. Genetic variation of the beta2-adrenoceptor: its functional and clinical importance in bronchial asthma. Am J Pharmacogenomics 2001;1:165–174.[CrossRef][Medline]



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