Is MMP-7 gene polymorphism a possible risk factor for chronic obstructive pulmonary disease in Turkish patients

Association of MMP7 T > C Gene Variant (rs10502001) and Expression in Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) have obstructed airflow through their lungs. Single nucleotide polymorphisms in matrix metalloproteinases (MMPs) genes and the risk of COPD have been the subject of numerous studies, with conflicting results. This investigation was conducted to determine whether the MMP7 (T>C) gene variant (rs10502001) was associated with an increased risk of COPD. A case-control study was conducted with 360 subjects (180 healthy controls and 180 COPD cases). The polymerase chain reaction (PCR)-restriction fragment length polymorphism method was used to genotype the SNP rs1050200. mRNA expression of MMP7 was performed using RT-PCR. The genotypic/allelic frequencies and carriage rates of rs10502001 (T>C) polymorphism were evaluated in 180 each of healthy controls and COPD cases. Cases have higher TC/CC genotype frequencies than controls. The "CC" genotype was found to be significantly associated with increased COPD risk (p = 0.016). The "C" allele frequency was higher in cases than in controls and showed significant association with COPD (p = 0.005). The carriage rate frequencies of T(-) and C(+) were significantly higher in cases than in controls (p = 0.031 and 0.047, respectively). MMP7 expression was significantly upregulated (p = 0.001) in COPD cases as compared with the controls. In addition, comparisons of MMP7 expression between the COPD cases with different genotypes showed that the "CC" genotype cases had significantly higher expression than those with "TT" genotype. The present findings showed statistically significant correlation of MMP7 (T>C) polymorphism and expression with COPD. Therefore, MMP7 responsible for degradation of elastin has been strongly linked to the progression of COPD.

Matrix Metalloproteinases Retain Soluble FasL-mediated Resistance to Cell Death in Fibrotic-Lung Myofibroblasts

A prominent feature of obstructed tissue regeneration following injury in general, and fibrotic lung tissue in particular, is fibroblast proliferation and accumulation. The Fas/FasL apoptotic pathway has been shown to be involved in human idiopathic pulmonary fibrosis (IPF) and bleomycin-induced lung fibrosis in rodents. We previously showed that in normal injury repair, myofibroblasts' accumulation is followed by their decline by FasL⁺ T cell-induced cell death. In pathological lung fibrosis, myofibroblasts resist cell death and accumulate. Like other members of the tumor necrosis factor (TNF) family, membrane-bound FasL can be cleaved from the cell surface to generate a soluble form (sFasL). Metalloproteinases (MMPs) are known to convert the membrane-bound form of FasL to sFasL. MMP-7 knockout (KO) mice were shown to be protected from bleomycin (BLM)-induced lung fibrosis. In this study, we detected increased levels of sFasL in their blood serum, as in the lungs of patients with IPF, and IPF-lung myofibroblast culture medium. In this study, using an MMP-inhibitor, we showed that sFasL is decreased in cultures of IPF-lung myofibroblasts and BLM-treated lung myofibroblasts, and in the blood serum of MMP-7KO mice. Moreover, resistant fibrotic-lung myofibroblasts, from the lungs of humans with IPF and of BLM-treated mice, became susceptible to T-cell induced cell death in a co-culture following MMP-inhibition- vs. control-treatment or BLM-treated MMP-7KO vs. wild-type mice, respectively. sFasL may be an unrecognized mechanism for MMP-7-mediated decreased tissue regeneration following injury and the evolution of lung fibrosis.

Association of the MMP7 -181A>G Promoter Polymorphism with Early Onset of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by decreased air flow and is associated with abnormal chronic inflammation in the airways and extensive tissue remodeling. Matrix metalloproteinase-7 (MMP7) is produced primarily by the epithelium of many organs, including the lungs. A functional MMP7 -181A>G (rs11568818) promoter polymorphism influences the binding of nuclear regulatory proteins modulating the transcription of the gene. In this study, we genotyped 191 patients with COPD for MMP7 -181A>G single nucleotide polymorphism (SNP) and 215 control subjects using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and explored the role of that polymorphism as a risk factor for COPD. There were no differences in the genotype and allele distribution of the MMP7 -181A>G SNP between the COPD patients and control groups (p = 0.341 and p = 0.214). However, the carries of the G allele (AG and GG genotypes), appeared to develop COPD significantly earlier than those with the AA genotype (61.01 ± 10.11 vs. 64.87 ± 9.00 years, p = 0.032). When the genotype distribution was studied only in the groups of patients (n = 76) and controls (n = 106) younger than 60 years, we found significantly higher frequency of the carriers of the G allele in COPD patients than in the controls, determining about a 3-fold higher risk for COPD [odds ratio (OR) -3.33, 1.36-8.14, p = 0.008 for GG, and OR = 2.91, 1.38-6.13, p = 0.005 for AG+GG]. Based on our results, the MMP7 -181A>G promoter variant may influence early development of COPD. This effect could be attributed to the increased production of the enzyme resulting in enhanced airway wall protein degradation and injury.

Matrix metalloproteinases in emphysema

Several studies have implicated a causative role for specific matrix metalloproteinases (MMPs) in the development and progression of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) and its severe sequela, emphysema. However, the precise function of any given MMP in emphysema remains an unanswered question. Emphysema results from the degradation of alveolar elastin - among other possible mechanisms - a process that is often thought to be caused by elastolytic proteinases made by macrophages. In this article, we discuss the data suggesting, supporting, or refuting causative roles of macrophage-derived MMPs, with a focus on MMPs-7, -9, -10, -12, and 28, in both the human disease and mouse models of emphysema. Findings from experimental models suggest that some MMPs, such as MMP-12, may directly breakdown elastin, whereas others, particularly MMP-10 and MMP-28, promote the development of emphysema by influencing the proteolytic and inflammatory activities of macrophages.

Functional single nucleotide polymorphisms of matrix metalloproteinase 7 and 12 genes in idiopathic recurrent spontaneous abortion

PURPOSE

The aim of this study was to investigate the potential association of matrix metalloproteinase 7 (MMP7) -181 A/G and MMP12 -82 A/G functional single nucleotide polymorphisms (SNP) with idiopathic recurrent spontaneous abortion (IRSA) in Slovenian reproductive couples.

METHODS

A case-control study was conducted on 149 couples with 3 or more consecutive idiopathic spontaneous pregnancy loses and 149 women and men with at least 2 live births and no history of pregnancy complications. Genotyping of MMP7 -181 A/G and MMP12 -82 A/G SNPs was performed using polymerase chain reaction and restriction fragment length polymorphism methods.

RESULTS

There were no statistically significant differences in the distribution of MMP7 -181 A/G and MMP12 -82 A/G genotype, allele, or haplotype frequencies between IRSA patients and controls, as well as patients' primary and secondary IRSA. We also found no association of MMP7 -181 A/G and MMP12 -82 A/G genotypes, alleles, and haplotypes with IRSA.

CONCLUSIONS

We found no evidence to support the association between IRSA and MMP7 -181 A/G and MMP12 -82 A/G SNPs in Slovenian reproductive couples.

Relationships of COX2 and MMP12 genetic polymorphisms with chronic obstructive pulmonary disease risk: a meta-analysis

We performed the present meta-analysis in an attempt to confirm the correlation of genetic polymorphisms in the COX2 and MMP12 genes with the susceptibility to chronic obstructive pulmonary disease (COPD). We searched English database such as PubMed, CISCOM, CINAHL, Web of Science, Google Scholar and several Chinese database for meta-analysis. There were no specific language restrictions. Two investigators systematically extracted relevant data within those included studies. Crude ORs with its corresponding 95 % CI were calculated. STATA 12.0 software was adopted for statistical analysis. The impact of COX2 and MMP12 genetic polymorphisms on the pathogenesis of COPD was investigated in the current study with a total of 10 case-control studies, which includes 1,751 COPD patients and 2,472 healthy subjects. Four common polymorphisms, including rs689466 G > A and rs20417 G > C in the COX2 gene, rs652438 A > G and rs2276109 A > G were evaluated in the MMP12 gene. Pooled OR of the present studies and results showed that the frequency of COX2 rs20417 polymorphism was prevalent in COPD patients than those of healthy subjects (C allele vs. G allele OR = 1.33, 95 % CI 1.06-1.67, P = 0.014; GC + CC vs. GG OR = 1.86, 95 % CI 1.07-3.24, P = 0.029; respectively). However, we found no significant correlation between COX2 rs689466 polymorphism and the risk of COPD (all P > 0.05). Furthermore, our meta-analysis illustrated that individuals with MMP12 rs652438 polymorphism had significantly increased risk of developing COPD (G allele vs. A allele OR = 1.62, 95 % CI 1.08-2.42, P = 0.020; AG + GG vs. AA OR = 2.14, 95 % CI 1.12-4.09, P = 0.021; respectively). Nevertheless, no positive relation was detected between MMP12 rs2276109 variant and the risk of COPD. Our meta-analysis indicates that COX2 and MMP12 genetic polymorphisms may be strongly implicated in the development of COPD, especially for the COX2 rs20417 and MMP12 rs652438 polymorphisms. Thus, COX2 and MMP12 genetic polymorphisms could potentially be utilized as helpful biomarkers for early diagnosis of COPD.