Combinatorial effect of TIMP-1 and α 1 AT gene polymorphisms on development of chronic obstructive pulmonary disease Manish Kumar a, c , D.P. Bhadoria b , Koushik Dutta b , Seema Singh a, c , Jyotsana Gupta d , Ram Kumar a , Anil K. Chhillar e , Vibha Yadav f , Bharat Singh a , G.L. Sharma a, ⁎ a Institute of Genomics and Integrative Biology, University Campus, Mall Road Delhi-110007, India b Maulana Azad Medical College and Lok Nayak Jaiprakash Narayan Hospital New Delhi-110002, India c Department of Biotechnology, University of Pune, Pune-411007, India d Research Institute of the McGill University Health Centre, Montréal QC, Canada, H3G 1A4 e Centre for Biotechnology, M. D. University, Rohtak, Haryana-124001, India f National Institute of Health, Rockville Pike, Bethesda, MD 20892, USA abstract article info Article history: Received 31 January 2011 Received in revised form 13 June 2011 Accepted 19 June 2011 Available online 6 July 2011 Keywords: Alpha-1 antitrypsin Tissue inhibitor of metalloproteinase-1 Gene interaction Chronic obstructive pulmonary disease Objective: To study the role of α 1 AT and TIMP-1 gene polymorphisms in development of COPD. Design and methods: Blood samples from total 408 subjects (217 COPD patients and 191 controls) were used for genotyping and estimating biolevels of α 1 AT, TIMP-1 and inflammatory cytokines. Data was analyzed to determine the role of interaction of TIMP-1 and α 1 AT genes; and interplay between various genotypes and biolevels of α 1 AT, TIMP-1 and inflammatory cytokines in development of COPD. Results: Significantly low levels of α 1 AT and TIMP-1 were observed in COPD patients as compared to controls (P = 0.001), where as the inflammatory cytokines were found to be increased in patients. PIM3 allele of α 1 AT gene in COPD patients was found to be associated with low levels of α 1 AT (P = 0.001), the effect being more pronounced when PIM3 combined with rs6609533 of TIMP-1 gene (P = 0.0001). Combination of genotypes rs6609533 of TIMP-1 and PIM3 of α 1 AT containing the risk alleles was over-represented in patients (P = 0.005). Conclusion: The SNP rs6609533 of TIMP-1 gene interacted with PIM3 of α 1 AT to make a possible risk combination for development of COPD. © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. Introduction Increasing morbidity and mortality due to chronic obstructive pulmonary disease (COPD) are becoming an important concern among the healthcare providers [1]. It has been reported to be the fifth leading cause of deaths worldwide and considered to reach the third place by 2020 [2]. Protease–antiprotease imbalance has been implicated to play a major role in the pathogenesis of COPD [3]. Neutrophil elastase (NE) and matrix metallo proteinases (MMPs) are prominent proteolytic molecules released by neutrophils and alveolar macrophages (AM) during the inflammatory events in COPD. The alpha-1 antitrypsin (α 1 AT), primarily synthesized by hepatocytes, inhibits the activity of NE to maintain the lung structure and integrity. Deficiency of α 1 AT has been reported to cause accelerated elastin degradation of the alveolar tissues which leads to the loss of lung function and subsequently the development of COPD and emphysema [4]. The gene coding for α 1 AT has been reported to be highly polymorphic, the normal wild type allele being M, which has several subtypes such as PIM1, PIM2, PIM3 etc. [5]. The PIS, PIZ and PI null alleles of α 1 AT gene were reported to be the predisposing factors for the development of COPD [6–8]. The PISZ heterozygotes have been shown to have reduced α 1 AT serum level, besides being highly prone to the development of pulmonary diseases [9]. In one of our previous studies it was observed that the frequency of PIM3, otherwise a normal variant, was significantly increased in COPD patients as compared to healthy controls [10]. Also the patients of COPD had significantly decreased serum trypsin inhibitory capacity (STIC) than that in control subjects [11]. The MMPs had been reported to play a major role in regulating cell functions such as cell proliferation, migration, differentiation, angio- genesis, apoptosis and host defense. The concentration of MMPs is kept under tight control by their respective inhibitors called tissue inhibitor of metalloproteinases (TIMPs). The MMP-9 is the predom- inant protease in alveolar tissues, the activity of which is inhibited by Clinical Biochemistry 44 (2011) 1067–1073 ⁎ Corresponding author. Fax: + 91 11 27667471. E-mail addresses: manishkumarteo@gmail.com (M. Kumar), dharampbhadoria@yahoo.co.in (D.P. Bhadoria), sriduttakoushik@yahoo.com (K. Dutta), seema.acbrdu@gmail.com (S. Singh), jyotsanagupta4@gmail.com (J. Gupta), ramkumarbu@gmail.com (R. Kumar), anil.chhillar@gmail.com (A.K. Chhillar), vibhabio@gmail.com (V. Yadav), bharatsingh1601@gmail.com (B. Singh), drglsharma@hotmail.com (G.L. Sharma). 0009-9120/$ – see front matter © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.clinbiochem.2011.06.986 Contents lists available at ScienceDirect Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem