Association of hsp70-2 (+ 1267A/G), hsp70-hom (+ 2437T/C), HMOX-1 (number of GT repeats) and TNF-alpha (+ 489G/A) polymorphisms with COPD in Croatian population

https://doi.org/10.1016/j.clinbiochem.2012.04.003Get rights and content

Abstract

Objective

To test for possible association of hsp70-2 (+ 1267A/G), hsp70-hom (+ 2437T/C), HMOX-1 (number of GT repeats) and TNF-α (+ 489G/A) polymorphisms with chronic obstructive pulmonary disease (COPD) in Croatian population.

Methods

Genotyping of DNA isolated from whole blood of 130 COPD patients (as defined by spirometry) and 95 healthy controls was performed. Fragment size analysis upon restriction enzyme digestion and/or sequencing was used for genotype/allele definition. Significance of findings was tested using χ2 test.

Results

hsp70-2 (+ 1267A/G) polymorphism was significantly associated with COPD. Results of genotyping analysis indicated that a genotype carrying G allele was preferentially associated with COPD; odds ratio (OR) = 1.50, 95% confidence interval (CI) = 1.00–2.24 and P = 0.061. OR for the GG genotype was 3.47 with CI = 1.26–9.56 and P = 0.04. No association for hsp70-hom (+ 2437T/C), TNF-α (+ 489G/A) and HMOX-1 (number of GT repeats) polymorphisms were found. In addition, comparison of genotype frequencies among different stages of disease severity (GOLD II-IV) revealed no discrimination for any of the tested polymorphisms.

Conclusion

This study is supporting the association of hsp70-2 (+ 1267A/G) polymorphism and COPD. Higher frequency of G allele and GG genotype in Croatian COPD patients was observed. There was no evidence for the association of hsp70-hom (+ 2437T/C), TNF-α (+ 489G/A) SNPs and HMOX-1 (number of GT repeats) polymorphism with COPD. Allele and genotype frequencies for all of the tested polymorphisms show no association with disease severity (GOLD II-IV).

Highlights

► We tested the association of hsp70-2, hsp70-hom, HMOX-1 and TNF-a SNPs with COPD. ► GG genotype of hsp70-2 (+ 1267A/G) showed higher frequency in Croatian COPD patients. ► No association of hsp70-hom, HMOX-1 and TNF-a SNPs with COPD was found. ► No association of the tested SNPs with disease severity (GOLD II- IV) was found.

Introduction

Chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis, is a complex disease in which genetic and environmental factors play a role [1].

Smokers are much more prone to development of the disease. About 15–20% of smokers develop COPD. Nevertheless, never smokers comprise substantial proportion of individuals with COPD [2]. This observation indicates that genetic factors play an important role in disease occurrence and development. A considerable interest exists in understanding genetic basis of the disease [3]. Definition of single nucleotide polymorphisms (SNPs) and other genetic polymorphisms associated with COPD is an important part of the overall effort to better understand disease pathogenesis. Recently, as a part of ECLIPSE study, a global SNP mapping was done on DNA extracted from sputum of COPD patients [4]. Another large genome-wide association study in COPD reported on identification of two major susceptibility loci [5].

Tumor necrosis factor alpha gene (TNF-α) is an inflammatory mediator that plays an important role in COPD pathogenesis and has also been in focus of scientific interest as a biomarker of the disease as well as a potential therapeutic target [6], [7]. Papatheodorou et al. studied possible association of five TNF-α SNPs and COPD and found no significant association in Greek patients [8]. In another study meta-analysis indicated that TNF‐α  308G/A SNP is associated with COPD risk among Asians but apparently not among Caucasians [9]. Related study done on Han Chinese population reported no significant difference in the frequencies of the TNF‐α  308G/A SNP [10]. Genotyping for the TNF‐α  308G/A SNP in Australian population was also performed and A allele was shown to be associated with a reduced forced expiratory flow (25–75%) (FEF25–75) [11]. Taken together, these examples clearly illustrate variability when testing different ethnic populations.

TNF‐α  863A allele has been indicated to confer a protective effect to the susceptibility to the disease in the Spanish population [12]. Similarly, in another study, TNF‐α  863A allele was found to confer a degree of resistance to the susceptibility to and muscle wasting of COPD among heavy smokers in Taiwan [13]. Kucukaycan et al. showed that COPD, especially in the case of COPD patients without radiological emphysema, is associated with TNF-α + 489G/A SNP [14].

Heat shock proteins (HSPs) are a family of proteins that can be expressed in response to a variety of stress stimuli, including reactive oxygen species and toxic metals, and play an important role in the maintenance of cellular integrity and viability [15]. hsp70-2 and hsp70-hom genes, investigated in this study, are physically part of the major histocompatibility (MHC) class III region on chromosome 6 and reside in close proximity of TNF-α gene (for review see [16]). Their role in pathogenesis of COPD is still poorly understood. Rumora et al. in a small study showed a decreased expression of Hsp70 and Hsp27 in blood leukocytes of COPD patients [17]. Analysis of the hsp70 gene polymorphism in Chinese COPD patients (Han nationality) has indicated no association with the disease [18]. HMOX-1 (hsp32), another stress protein that belongs to HSP family, is believed to generally play a protective role in lung diseases including COPD (for review see [19]). 5′-flanking region of human HMOX-1 gene shows length polymorphism (number of GT repeats in the promoter region) and it has been speculated that it could influence the level of gene expression [20]. It has been reported that the large size of dinucleotide (GT) repeat region may reduce inducibility of HMOX-1 and therefore be associated with susceptibility to emphysema [21]. Polymorphism of this gene was recently indicated to be associated with severity of COPD in Southwestern China population with class L allele linked to susceptibility of developing very severe COPD [22].

Section snippets

Subjects

A total of 225 subjects were enrolled in this study. 130 were COPD patients as determined by spirometry. 95 healthy controls were also recruited. COPD was diagnosed by pulmonology specialist according to clinical examination (chronic and progressive dyspnea, cough, and sputum production) and spirometry results FEV1/FVC < 0.70 and FEV1 < 80% predicted, as measured on first admission at the Department for Pulmonology at General Hospital “Dr. Ivo Pedišić”, Petrinja, and Clinic for Lung Diseases

Results

Relevant demographic characteristics of subject populations are shown in Table 1. COPD group as compared to control group showed statistically significant differences in age but not in sex distribution or smoking history. Differences in FEV1 (% predicted) and (FEV1 / FVC) × 100 (%) have shown clear distinction between healthy individuals and a group of subjects with COPD (Table 1).

Distributions of allele and genotype frequencies for polymorphisms of hsp70-hom + 2437T/C, HMOX-1 (GT)n and TNF-α + 

Discussion

Genetic association studies have become increasingly popular approach in understanding pathogenesis and epidemiology of diseases as well as for development of treatment approaches. Four genes (and their polymorphism) selected for the analysis in this research were chosen based on existing evidence of their importance for pathogenesis of inflammatory process. Inflammation and oxidative stress are widely accepted as major pathogenetic mechanism in development of COPD. In addition, all selected

Disclosure statement

Authors have no claims on potential conflicts of interest.

Acknowledgments

This study was supported by the Croatian Ministry of Science, Education and Sports (grant no: 006-0061117-1236). We would like to thank Dr. Vesna Musani, Ruđer Bošković Institute, for providing us with ABI PRISM 310 automatic sequencer analysis and Ana Malić for support and advise.

References (24)

  • S.A. Antoniu et al.

    Anti-TNF-alpha therapies in chronic obstructive pulmonary disease

    Expert Opin Investig Drugs

    (2008)
  • S. Zhang et al.

    Association between the tumour necrosis factor-α-308G/A polymorphism and chronic obstructive pulmonary disease: an update

    Respirology

    (2011)
  • Cited by (13)

    • Heat shock protein polymorphisms provide age-related cataract susceptibility for the population of Northern Iran

      2017, Meta Gene
      Citation Excerpt :

      Previous investigations have noted HSP70 participate in the proteasome mediated degradation of proteins under stress conditions (Garrido et al., 2006). Matokanović et al. reported an increased frequency of the HSPA1B + 1267GG genotype among chronic obstructive pulmonary patients (Matokanović et al., 2012). This result was also observed in other studies on multiple sclerosis (Boiocchi et al., 2014) and glaucoma (Salehi et al., 2017).

    • Polymorphisms of anti-lipopolysaccharide factors in the swimming crab Portunus trituberculatus and their association with resistance/susceptibility to Vibrio alginolyticus

      2013, Fish and Shellfish Immunology
      Citation Excerpt :

      Marker assisted selection (MAS) is a molecular method that uses DNA markers for selection based on genotype and makes the selection more convenient and cost-effective [5]. In recent years, different genes and polymorphisms have been reported to have association with pathogen or disease resistance in various invertebrates and vertebrates, such as Chlamys farreri [6], Argopecten irradians [7], Meretrix meretrix [8], Crassostrea virginica [9], Litopenaeus vannamei [10,11], Penaeus (Fenneropenaeus) chinensis [12], grass carp [13,14], sheep [15,16] and human [17–19]. Moreover, DNA markers including single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs) have been reported to be correlated with growth related traits [8,20,21].

    View all citing articles on Scopus
    View full text