Fumiya Yamaide
,
Department of Public Health, Graduate School of Medicine, Chiba University, Chiba, Japan
Yoichi Mashimo
,
Department of Public Health, Graduate School of Medicine, Chiba University, Chiba, Japan
Naoki Shimojo, MD, PhD
,
Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan
Takayasu Arima, MD, PhD
,
Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan
Yoshinori Morita, MD, PhD
,
Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan
Tomomitsu Hirota
,
Laboratory for Respiratory Diseases, Center for Genomic Medicine, RIKEN, Yokohama, Japan
Satoru Doi
,
Osaka Prefectural Medical Center for Respiratory and Allergic Diseases, Habikino, Japan
Kazuki Sato
,
Department of Pediatrics, National Shimoshizu Hospital, Yotsukaido, Japan
Shuichi Suzuki
,
Department of Pediatrics, National Shimoshizu Hospital, Yotsukaido, Japan
Toshiyuki Nishimuta
,
Department of Pediatrics, National Shimoshizu Hospital, Yotsukaido, Japan
Hiroko Watanabe
,
Department of Pediatrics, National Shimoshizu Hospital, Yotsukaido, Japan
Akira Hoshioka, MD, PhD
,
Department of Allergy and Rheumatology, Chiba Children's Hospital, Chiba, Japan
Minako Tomiita, MD, PhD
,
Department of Allergy and Rheumatology, Chiba Children's Hospital, Chiba, Japan
Akiko Yamaide
,
Department of Allergy and Rheumatology, Chiba Children's Hospital, Chiba, Japan
Misa Watanabe
,
The First Department of Pediatrics, Toho University Omori Medical Center, Tokyo, Japan
Yoshitaka Okamoto, MD, PhD
,
Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
Yoichi Kohno, MD, PhD
,
Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan
Mayumi Tamari
,
Laboratory for Respiratory Diseases, Center for Genomic Medicine, RIKEN, Yokohama, Japan
Akira Hata
,
Department of Public Health, Graduate School of Medicine, Chiba University, Chiba, Japan
Yoichi Suzuki, MD, PhD
,
Department of Public Health, Graduate School of Medicine, Chiba University, Chiba, Japan
Background: Genetic variants influencing lung function or immune system may be involved in the development of asthma and/or its symptoms. Matrix metalloproteinases (MMPs) contribute to both normal and pathological tissue remodeling and also act as regulatory molecules by processing cytokines or adhesion molecules. In animal models, growing evidences suggest that MMPs play important roles in asthma phenotypes. Some
MMP genes (e.g.
MMP-9 and MMP-12) have recently been shown to be associated with asthma in Caucasian populations. We investigated whether single nucleotide polymorphisms (SNPs) in
MMP-7 and MMP-
12 could affect the susceptibility to and clinical phenotypes of asthma in the Japanese population.
Methods: We conducted a case-control study between SNPs in MMP-7 and MMP-12 genes and asthma-related phenotypes using childhood and adult Japanese populations (653 childhood asthma patients and 423 controls, and 428 adult asthma patients and 646 controls, respectively). To investigate the effects of amino acid substitutions by SNPs on MMPs' enzymatic activity, MMP activity assays were performed using commercially available kits based on fluorescence resonance energy transfer (FRET) peptide. We also evaluated the effect of 3’UTR SNP in MMP-7 on its mRNA stability and the effect of SNP in MMP-12 on its antimicrobial activity.
Results: We found that, in the Japanese population, SNPs of MMP-7 (rs10502001, G/A, Arg77His; rs14983, C/T, 3’UTR) (P = 0.006; odds ratio (OR), 1.46; 95 % confidential interval (CI), 1.126 - 1.903) and MMP-12 (rs652438, A/G, Asn357Ser) (P = 0.015; OR, 1.60; 95 % CI, 1.002 - 2.556) showed significant association with adult and childhood asthma, respectively. We also found that the SNP (rs652438) in MMP-12 was associated with severity in adult asthma (P = 0.010). Using supernatant from cultured HEK293 cells stably transfected with the pcDNA3.1(+)-MMP-7 or MMP-12 as MMP proteins, we evaluated activation kinetics, rate of proteolytic cleavage of FRET peptide, Michaelis constant, and substrate specificity of the enzyme. In this system, we couldn’t detect the functional effects of amino acid substitutions by SNPs on the enzymatic activity.
Conclusions: Our association study suggested that genetic variants of MMP7 and MMP12 conferred risk for development of asthma in the Japanese population.
