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Korean J Intern Med > Volume 28(6); 2013 > Article
Kim, Kim, Kim, Hong, Min, Cho, and Park: A polymorphism in the histone deacetylase 1 gene is associated with the response to corticosteroids in asthmatics

Abstract

Background/Aims

Recent investigations suggest that histone deacetylase 1 (HDAC1) and HDAC2 may be target molecules to predict therapeutic responses to corticosteroids. We evaluated the effects of variation in HDAC1 and HDAC2 on the response to corticosteroids in asthmatics.

Methods

Two single nucleotide polymorphisms (SNPs) were selected after resequencing HDAC1 and HDAC2. For the first analysis, we evaluated the association between those SNPs and asthma severity in 477 asthmatics. For the second analysis, we evaluated the effects of these SNPs on lung function improvements in response to corticosteroid treatment in 35 independent adult asthmatics and 70 childhood asthmatics.

Results

We found that one SNP in HDAC1 (rs1741981) was significantly related to asthma severity in a recessive model (corrected p = 0.036). Adult asthmatics who were homozygous for the minor allele of rs1741981 showed significantly lower % forced expiratory volume in 1 second (%FEV1) increases in response to systemic corticosteroids treatment compared with the heterozygotes or those homozygous for the major allele (12.7% ± 7.2% vs. 37.4% ± 33.7%, p = 0.018). Similarly, childhood asthmatics who were homozygous for the minor allele of rs1741981 showed significantly lower %FEV1 increases in response to inhaled corticosteroid treatment compared with the heterozygotes or those homozygous for the major allele (14.1% ± 5.9% vs. 19.4% ± 8.9%, p = 0.035).

Conclusions

The present study demonstrated that rs1741981 in HDAC1 was significantly associated with the response to corticosteroid treatment in asthmatics.

INTRODUCTION

Asthma, a chronic airway inflammatory disease, is an important source of morbidity and mortality worldwide [1]. Current guidelines recommend corticosteroid treatment for the management of asthma [2-4]. Endogenous corticosteroid levels and therapeutic responses to exogenous corticosteroids are known to be influenced by genetics, with heritability ranged from 0.40 to 0.56 [5-7]. This suggests a pharmacogenetic basis for the intraindividual variability of corticosteroid responsiveness in asthmatics [8].
Histone deacetylase (HDAC) plays a key role in the regulation of inflammatory genes by removing acetyl groups from histones [9,10]. It has been reported that conditional deletion of HDAC1 in T cells resulted in enhanced airway inflammation and increased Th2 cytokine production [11]. Moreover, HDAC is involved in the mechanism of action of corticosteroids. For example, recruitment of HDAC2 to activated inflammatory genes is an important mechanism of inflammatory gene repression by corticosteroids and HDAC2 activity is reduced in some diseases in which patients showed poor responses to corticosteroids treatment [12]. Together, HDAC1 and HDAC2 may be target molecules to predict therapeutic responses to corticosteroids. However, to date, any genetic effects of HDAC1 and HDAC2 on the response to corticosteroids in asthmatics have remained unknown.
In the present study, we evaluated associations between asthma severity, which is related to reduced responsiveness to corticosteroids [13], and single nucleotide polymorphisms (SNPs) in HDAC1 and HDAC2 in adult asthmatics. Then, we further assessed the effects of those SNPs on responsiveness to corticosteroids, as measured in terms of the change in lung function, in independent adult and childhood asthmatics.

METHODS

All subjects enrolled in this study provided written informed consent. The study protocol was approved by the Institutional Review Board of Seoul National University Hospital (H-1110-130-384).

Primary analysis

In total, 477 asthmatics were enrolled at Seoul National University Hospital, Seoul, Korea. The diagnosis of asthma was made at least 6 months prior to enrollment, according to current guidelines [2-4]: episodic symptoms including wheezing, coughing, and dyspnea plus a positive bronchodilator response (an increase in forced expiratory volume in 1 second [FEV1], from baseline that was more than 200 mL and more than 15% of the prebronchodilator value), or a provocative concentration of methacholine causing a 20% reduction in FEV1 (PC20) ≤ 16 mg/mL [2-4]. Enrolled asthmatics were treated with conventional medications based on the The Global Initiative for Asthma guideline according to their asthma control status [2]. Asthma severity was determined based on lung function and the medication use index needed to obtain control, as described previously [14,15].

Secondary analysis

To generalize the results obtained in the primary analysis, we enrolled adult (treatment-naïve 35 subjects, systemic corticosteroid group) and childhood asthmatics (treatment-naïve 70 subjects, inhaled corticosteroid group) in a secondary analysis. Adult asthmatics visited our clinic first with dyspnea and decreased lung function (FEV1 ≤ 80% predicted value) and were diagnosed with asthma based on positive bronchodilator responses. They were treated with short-term systemic steroids alone for prompt relief of their symptoms (oral prednisolone 15 mg, twice per day for 7 days). Childhood asthmatics enrolled at the Asan Medical Center, Seoul, Korea, were diagnosed with asthma according to current treatment guidelines [2-4]. All were treated with inhaled corticosteroids for 8 weeks according to their asthma control status. Treatment responses in both groups were measured by the degree of increase in FEV1: %FEV1 increase = (FEV1 after treatment - FEV1 at baseline)/FEV1 at baseline × 100.

Genotyping

The assessment of the SNPs in HDAC1 and HDAC2 was described in our previous study [16]. Briefly, after isolating genomic DNA from the peripheral blood of 24 healthy Korean subjects using the QIAamp DNA blood kit following the manufacturer's protocol (Qiagen, Hilden, Germany), we amplified 2 kb of the 5'-upstream region in the promoter and all exons, including the exon-intron boundaries, of HDAC1 and HDAC2 by polymerase chain reaction (PCR; reference genome sequences; NM_004964.2 [HDAC1] and NM_001527.3 [HDAC2]). Amplified PCR products were sequenced using a Big Dye Terminator Cycle Sequencing Ready Reaction Kit (Applied Biosystems, Foster City, CA, USA) in both directions according to standard protocols. After sequencing of HDAC1 and HDAC2, we identified five SNPs in HDAC1 and 14 SNPs in HDAC2 (Supplementary Tables 1 and 2). Among these, two SNPs (rs1741981 in HDAC1 and rs58677352 in HDAC2) were selected for scoring after considering minor allele frequencies (higher than 5%) and location (in exons and 5', near the gene). Scoring was conducted with the high throughput single base-pair extension method (SNP-IT assay) using an SNPstream25K system, which was customized to automatically genotype DNA samples in 384-well plates and to provide a colorimetric readout (Orchid Biosciences, Princeton, NJ, USA) as described previously [17].

Statistical analyses

An association analysis, based on a case-control design, was performed for each SNP using a genetic model approach: an allele model (A [major allele] vs. B [minor allele]), a dominant model (AA vs. AB + BB), and a recessive model (BB vs. AA + AB). Hardy-Weinberg equilibrium was tested using 2 × 2 tests. All statistical analyses were performed with the R version 2.15.3 (http://www.R-project.org/). p values of less than 0.05 were considered to indicate statistical significance.

RESULTS

The characteristics of the asthmatics enrolled in the primary and secondary analyses are shown in Tables 1 and 2, respectively. Rs1741981 in HDAC1 and rs58677352 in HDAC2 were in Hardy-Weinberg equilibrium. The primary analysis revealed that rs1741981 was significantly related to asthma severity in a recessive model (p = 0.006) (Table 3). This relationship was still significant after the Bonferroni correction (multiplied by 6 [2 SNPs × 3 models]; corrected p = 0.036). However, rs58677352 showed no relationship with asthma severity (data not shown). As rs1741981 showed a significant relation with asthma severity in a recessive model, the secondary analysis was done using the same (recessive) model. Adult asthmatics with the CC genotype of rs1741981 (n = 12) showed significantly lower %FEV1 increases in response to systemic corticosteroid treatment compared with those with the CT or TT genotype (12.7% ± 7.2% vs. 37.4% ± 33.7%, p = 0.018) (Fig. 1A). The same tendency was observed in childhood asthmatics. Subjects with the CC genotype of rs1741981 (n = 15) showed significantly lower %FEV1 increases in response to inhaled corticosteroid treatment compared with those with the CT or TT genotype (14.1% ± 5.9% vs. 19.4% ± 8.9%, p = 0.035) (Fig. 1B). The combined p value, calculated from the one-sided p values of the secondary populations using Stouffer z-transform test [18], was 0.0019. However, rs58677352 showed no relationship with lung function improvement in response to corticosteroid treatment adults or childhood asthmatics (data not shown).

DISCUSSION

The present study demonstrated that rs1741981 in HDAC1 is significantly associated with the response to corticosteroid treatment in asthmatics. To our knowledge, this is the first report of a genetic association between HDAC1 and response to corticosteroids in asthmatics.
Corticosteroids are among the most effective treatments for asthma [19], and reduce inflammation via glucocorticoid receptor-mediated recruitment of HDAC2 [20]. Because reduced HDAC2 expression was observed in bronchial biopsies of asthmatic patients [21] and HDAC2-mediated deacetylation of the corticosteroid receptor enabled nuclear factor-κB suppression in airway epithelial cell line and alveolar macrophages [22], the discussion of the corticosteroid response in asthma has to date focused on HDAC2 alone. However, several investigators have argued that corticosteroid action in asthma is explained partially by inhibition of T cell activation [23-25]. Recently, it has been reported that that T cell-specific loss of HDAC1 resulted in enhanced allergic airway inflammation, by modulating cytokine production [11]. Moreover, HDAC1 was localized within most airway cells and infiltrating inflammatory cells in the lung in a murine asthma model, and the HDAC inhibitor TSA attenuated allergic airway inflammation in mice by reducing T cell infiltration and Th2 cytokine production [26]. Taken together, HDAC1 may play an important role in mediating the anti-inflammatory action of corticosteroids. Accordingly, our data provide pharmacogenetic evidence that a genetic polymorphism in HDAC1 can predict the response to corticosteroid treatment in asthmatics.
Functional variants strengthen the reliability of results of a pharmacogenetic study. Rs1741981 is located in the 5' near gene region of HDAC1. We used a web-based tool to evaluate the functional relevance of rs1741981. The Functional Single Nucleotide Polymorphism (F-SNP; http://compbio.cs.queensu.ca/F-SNP/) database integrates information obtained from 16 bioinformatics tools and databases about the functional effects of SNPs [27]. For rs1741981, F-SNP used TFSearch (http://www.cbrc.jp/research/db/TFSEARCH.html) [28] and Consite (http://asp.ii.uib.no:8090/cgi-bin/CONSITE/consite) [29] tools. Both tools computationally predict changes in transcription factor binding according to the allele of re1741981 (T allele vs. C allele) (Fig. 2 and Supplementary Fig. 1). F-SNP indicated 0.268 for the FS score of rs1741981. The FS score is a functional SNP scoring system provided by F-SNP to distinguish features of disease-related SNPs versus neutral SNPs [30]. The median FS score for neutral SNPs is 0.1764, whereas for disease-related SNPs, the median rises to 0.5 [30]. Thus, rs1741981 may be functionally important.
There are several potential limitations to our results. First, sufficient statistical power, conferred by a large sample size, is an important aspect of genetic studies. The small number of patients enrolled in the present study limits the scope of our results. Second, subsequent replication studies should consider as many clinical and demographic confounding factors as possible and should be performed in diverse ethnic backgrounds. Third, haplotype approaches for HDAC1 would result in more precise associations. For example, one previous study showed the advantage of examining both individual SNPs and haplotypes to further pin-point a potential causal SNP [31]. Finally, although a computational method suggested that rs1741981 may be functionally important, further mechanistic studies are needed to clarify the precise role of rs1741981 and HDAC1 in the response to corticosteroid treatment.

KEY MESSAGE

1. In the present study, we identified rs1741981 in HDAC1, which showed a significant relationship with asthma severity.
2. We also found that this genetic variation was associated significantly with lung function improvements in response to systemic corticosteroid treatment in adult asthmatics and in response to inhaled corticosteroids treatment in childhood asthmatics.
3. This is the first report of a significant association between a genetic variation in HDAC1 and the response to corticosteroid treatment in asthmatics.

Acknowledgments

This work was supported financially by a grant from Seoul National University Hospital (No. 0420071100) and by a grant of the Korean Health 21 R&D Project, Ministry of Health and Welfare, Republic of Korea (No. A070001).

Conflict of interest

No potential conflict of interest relevant to this article is reported.

Supplementary Materials

Supplementary Table 1

Screened single nucleotide polymorphisms in HDAC1
kjim-28-708-s001.pdf

Supplementary Table 2

Screened single nucleotide polymorphisms in HDAC2
kjim-28-708-s002.pdf

Supplementary Figure 1

Changes in transcription factor binding according to the allele of rs1741981 in HDAC1. (A) -1332T. (B) -1332C. Predicted results from TFSearch (http://www.cbrc.jp/research/db/TFSEARCH.html).
kjim-28-708-s003.pdf

References

1. Bahadori K, Doyle-Waters MM, Marra C, et al. Economic burden of asthma: a systematic review. BMC Pulm Med 2009;9:24. PMID : 19454036.
crossref pmid pmc
2. The Global Initiative for Asthma. The guideline for asthma management and prevention 2010 [Internet]. [place unknown]: The Global Initiative for Asthma, [cited 2013 Jan 28]. Available from: http://www.ginasthma.org/guidelines-pocket-guide-for-asthma-management.html.

3. National Asthma Education and Prevention Program. Expert Panel Report 3: guidelines for the diagnosis and management of asthma full report 2007 [Internet]. Bethesda (MD): The National Heart, Lung, and Blood Institute (NHLBI) Health Information Center, 2007;[cited 2013 Jan 28]. Available from http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.pdf.

4. British Thoracic Society, Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma [Internet]. London: British Thoracic Society, 2012;[cited 2013 Jan 28]. Available from http://www.sign.ac.uk/pdf/sign101.pdf.

5. Inglis GC, Ingram MC, Holloway CD, et al. Familial pattern of corticosteroids and their metabolism in adult human subjects: the Scottish Adult Twin Study. J Clin Endocrinol Metab 1999;84:4132–4137PMID : 10566661.
crossref pmid
6. Ober C, Abney M, McPeek MS. The genetic dissection of complex traits in a founder population. Am J Hum Genet 2001;69:1068–1079PMID : 11590547.
crossref pmid pmc
7. Schwartz JT, Reuling FH, Feinleib M, Garrison RJ, Collie DJ. Twin heritability study of the effect of corticosteroids on intraocular pressure. J Med Genet 1972;9:137–143PMID : 5065285.
crossref pmid pmc
8. Drazen JM, Silverman EK, Lee TH. Heterogeneity of therapeutic responses in asthma. Br Med Bull 2000;56:1054–1070PMID : 11359637.
crossref pmid
9. Adcock IM, Ford P, Ito K, Barnes PJ. Epigenetics and airways disease. Respir Res 2006;7:21. PMID : 16460559.
crossref pmid pmc
10. Bhavsar P, Ahmad T, Adcock IM. The role of histone deacetylases in asthma and allergic diseases. J Allergy Clin Immunol 2008;121:580–584PMID : 18234319.
crossref pmid
11. Grausenburger R, Bilic I, Boucheron N, et al. Conditional deletion of histone deacetylase 1 in T cells leads to enhanced airway inflammation and increased Th2 cytokine production. J Immunol 2010;185:3489–3497PMID : 20702731.
crossref pmid pmc
12. Barnes PJ, Ito K, Adcock IM. Corticosteroid resistance in chronic obstructive pulmonary disease: inactivation of histone deacetylase. Lancet 2004;363:731–733PMID : 15001333.
crossref pmid
13. Barnes PJ. Corticosteroid resistance in patients with asthma and chronic obstructive pulmonary disease. J Allergy Clin Immunol 2013;131:636–645PMID : 23360759.
crossref pmid
14. Boulet LP, Becker A, Berube D, Beveridge R, Ernst P. The Canadian Asthma Consensus Group. Canadian asthma consensus report, 1999. CMAJ 1999;161(11 Suppl):S1–S61PMID : 10906907.

15. Ungar WJ, Chapman KR, Santos MT. Assessment of a medication-based asthma index for population research. Am J Respir Crit Care Med 2002;165:190–194PMID : 11790653.
crossref pmid
16. Park HW, Shin ES, Lee JE, et al. Association between genetic variations in prostaglandin E2 receptor subtype EP3 gene (Ptger3) and asthma in the Korean population. Clin Exp Allergy 2007;37:1609–1615PMID : 17877755.
crossref pmid
17. Park HW, Lee JE, Shin ES, et al. Association between genetic variations of vascular endothelial growth factor receptor 2 and atopy in the Korean population. J Allergy Clin Immunol 2006;117:774–779PMID : 16630933.
crossref pmid
18. Stouffer SA, Suchman EA, DeVinney LC, et al. Studies in social psychology in World War II. Vol 1:The American Soldier: Adjustment during Army Life. Princeton: Princeton University Press, 1949.

19. Barnes PJ. How corticosteroids control inflammation: Quintiles Prize Lecture 2005. Br J Pharmacol 2006;148:245–254PMID : 16604091.
crossref pmid pmc
20. Barnes PJ, Adcock IM. Glucocorticoid resistance in inflammatory diseases. Lancet 2009;373:1905–1917PMID : 19482216.
crossref pmid
21. Ito K, Caramori G, Lim S, et al. Expression and activity of histone deacetylases in human asthmatic airways. Am J Respir Crit Care Med 2002;166:392–396PMID : 12153977.
crossref pmid
22. Ito K, Yamamura S, Essilfie-Quaye S, et al. Histone deacetylase 2-mediated deacetylation of the glucocorticoid receptor enables NF-kappaB suppression. J Exp Med 2006;203:7–13PMID : 16380507.
crossref pmid pmc
23. Corrigan CJ, Brown PH, Barnes NC, et al. Glucocorticoid resistance in chronic asthma: glucocorticoid pharmacokinetics, glucocorticoid receptor characteristics, and inhibition of peripheral blood T cell proliferation by glucocorticoids in vitro. Am Rev Respir Dis 1991;144:1016–1025PMID : 1952426.
crossref pmid
24. Haczku A, Alexander A, Brown P, et al. The effect of dexamethasone, cyclosporine, and rapamycin on T-lymphocyte proliferation in vitro: comparison of cells from patients with glucocorticoid-sensitive and glucocorticoid-resistant chronic asthma. J Allergy Clin Immunol 1994;93:510–519PMID : 8120277.
crossref pmid
25. Spahn JD, Landwehr LP, Nimmagadda S, Surs W, Leung DY, Szefler SJ. Effects of glucocorticoids on lymphocyte activation in patients with steroid-sensitive and steroid-resistant asthma. J Allergy Clin Immunol 1996;98(6 Pt 1):1073–1079PMID : 8977508.
crossref pmid
26. Choi JH, Oh SW, Kang MS, Kwon HJ, Oh GT, Kim DY. Trichostatin A attenuates airway inflammation in mouse asthma model. Clin Exp Allergy 2005;35:89–96PMID : 15649272.
crossref pmid
27. Lee PH, Shatkay H. F-SNP: computationally predicted functional SNPs for disease association studies. Nucleic Acids Res 2008;36(Database issue):D820–D824PMID : 17986460.
crossref pmid pmc
28. Heinemeyer T, Wingender E, Reuter I, et al. Databases on transcriptional regulation: TRANSFAC, TRRD and COMPEL. Nucleic Acids Res 1998;26:362–367PMID : 9399875.
crossref pmid pmc
29. Sandelin A, Wasserman WW, Lenhard B. ConSite: web-based prediction of regulatory elements using cross-species comparison. Nucleic Acids Res 2004;32(Web Server issue):W249–W252PMID : 15215389.
crossref pmid pmc
30. Lee PH, Shatkay H. An integrative scoring system for ranking SNPs by their potential deleterious effects. Bioinformatics 2009;25:1048–1055PMID : 19228803.
crossref pmid
31. Lima JJ, Holbrook JT, Wang J, et al. The C523A beta2 adrenergic receptor polymorphism associates with markers of asthma severity in African Americans. J Asthma 2006;43:185–191PMID : 16754519.
crossref pmid
Figure 1
Forced expiratory volume in 1 second (FEV1) improvement in response to corticosteroid treatment according to the genotype of rs174198 in HDAC1 in the secondary analysis. (A) Adult asthmatics treated with oral prednisolone 15 mg, twice per day for 7 days. (B) Childhood asthmatics treated with inhaled corticosteroids according to their asthma control status. %FEV1 increase = (FEV1 after treatment - FEV1 at baseline) / FEV1 at baseline × 100.
kjim-28-708-g001
Figure 2
Changes in transcription factor binding according to the allele of rs1741981 in HDAC1. (A) -1332T. (B) -1332C. Predicted results from Consite (http://asp.ii.uib.no:8090/cgi-bin/CONSITE/consite).
kjim-28-708-g002
Table 1
Characteristics of asthmatics enrolled in the primary analysis
kjim-28-708-i001

Values are presented as number (%) or mean ± SD.

FEV1, forced expiratory volume in 1 second.

aGeometric mean.

Table 2
Characteristics of asthmatics enrolled in the secondary analysis
kjim-28-708-i002

Values are presented as number (%) or mean ± SD.

FEV1, forced expiratory volume in 1 second; NA, not applicable.

aGeometric mean.

Table 3
Genotype frequency of rs174198 in HDAC1 and rs58677352 in HDAC2 among asthmatics in the primary analysis
kjim-28-708-i003

Values are presented as number (%). Rs174198 genotyping failed in four moderate to severe asthmatics.

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