Association of MMP-1 -1607 1G/2G (rs1799750) polymorphism with primary knee osteoarthritis in the Greek population

Matrix Metalloproteinases in the Periodontium-Vital in Tissue Turnover and Unfortunate in Periodontitis

The extracellular matrix (ECM) is a complex non-cellular three-dimensional macromolecular network present within all tissues and organs, forming the foundation on which cells sit, and composed of proteins (such as collagen), glycosaminoglycans, proteoglycans, minerals, and water. The ECM provides a fundamental framework for the cellular constituents of tissue and biochemical support to surrounding cells. The ECM is a highly dynamic structure that is constantly being remodeled. Matrix metalloproteinases (MMPs) are among the most important proteolytic enzymes of the ECM and are capable of degrading all ECM molecules. MMPs play a relevant role in physiological as well as pathological processes; MMPs participate in embryogenesis, morphogenesis, wound healing, and tissue remodeling, and therefore, their impaired activity may result in several problems. MMP activity is also associated with chronic inflammation, tissue breakdown, fibrosis, and cancer invasion and metastasis. The periodontium is a unique anatomical site, composed of a variety of connective tissues, created by the ECM. During periodontitis, a chronic inflammation affecting the periodontium, increased presence and activity of MMPs is observed, resulting in irreversible losses of periodontal tissues. MMP expression and activity may be controlled in various ways, one of which is the inhibition of their activity by an endogenous group of tissue inhibitors of metalloproteinases (TIMPs), as well as reversion-inducing cysteine-rich protein with Kazal motifs (RECK).

Matrix metalloproteinases in rheumatoid arthritis and osteoarthritis: a state of the art review

Although the pathological mechanisms involved in osteoarthritis (OA) and rheumatoid arthritis (RA) are different, the onset and progression of both diseases are associated with several analogous clinical manifestations, inflammation, and immune mechanisms. In both diseases, cartilage destruction is mediated by matrix metalloproteinases (MMPs) synthesized by chondrocytes and synovium fibroblasts. This review aims to summarize recent articles regarding the role of MMPs in OA and RA, as well as the possible methods of targeting MMPs to alleviate the degradation processes taking part in OA and RA. The novel experimental MMP-targeted treatments in OA and RA are MMP inhibitors eg. 3-B2, taraxasterol, and naringin, while other treatments aim to silence miRNAs, lncRNAs, or transcription factors. Additionally, other recent MMP-related developments include gene polymorphism of MMPs, which have been linked to OA susceptibility, and the MMP-generated neoepitope of CRP, which could serve as a biomarker of OA progression.

Strategy to Estimate Sample Sizes to Justify the Association between MMP1 SNP and Osteoarthritis

Background: the impact of knee osteoarthritis (OA) poses a formidable challenge to older adults. Studies have reported that genetic factors, such as MMP1, are one of important risk factors for knee OA. Although the relationship between the genetic polymorphism of MMP1 rs1799750 and the risk of knee OA has been explored, conclusions have been nonunanimous and pending due to research sample sizes, one of determinants in studying genetic polymorphisms associated with disease. Objective: to establish a model to assess whether the genetic polymorphism of MMP1 rs1799750 is associated with knee OA based on an estimation of sample sizes. Methods: samples were collected from a case−control and meta-analysis study. In the case−control study, patients who underwent knee X-ray examinations based on the Kellgren−Lawrence Grading System (KL) as diagnostic criteria were recruited at the Health Examination Center of the Tri-Service General Hospital from 2015 to 2019. Gene sequencing was conducted using iPLEX Gold. Those with unsuccessful gene sequencing were excluded. Finally, there were 569 patients in the knee OA group (KL ≥ 2) and 534 participants in the control group (KL < 2). In the meta-analysis, we used the databases PubMed, EMBASE, and Cochrane to search for studies on the relationship between MMP1 rs1799750 and knee OA. Next, we adopted the trial sequential analysis (TSA) method to assess whether sample sizes were sufficient or not to determine the risk of the genetic polymorphism of MMP1 rs1799750 on knee OA in Caucasians and Asians. Results: in Caucasians, the MMP1 rs1799750 was not significantly associated with knee OA with an odds ratios (OR) of 1.10 (95% confidence interval, CI: 0.45−2.68). Some extra 8559 samples were needed to conclude this relationship in Caucasians by the TSA model. In Asians, neither our case−control study results (n = 1103) nor a combination of samples from the case−control and meta-analysis results showed an association between MMP1 rs1799750 and knee OA. The OR (95% CI) was 1.10 (0.81−1.49) in a combination of Asian samples. Some extra 5517 samples were needed to justify this relationship in Asians by the TSA model. Conclusions: this research shows that an extra 8559 and 5517 samples are needed in Caucasians and Asians, respectively, in order to justify the association between MMP1 rs1799750 and knee OA.

Association of Matrix Metalloproteinase (MMP) Gene Polymorphisms With Knee Osteoarthritis: A Review of the Literature

Progressive matrix metalloproteinase (MMP)-induced degradation of the extracellular matrix (ECM) of the articular cartilage is one of the major pathogenic osteoarthritis (OA) events. Several single nucleotide polymorphisms (SNPs) in genes encoding MMPs have been identified as affecting MMP expression, production, and enzymatic activity. This study systematically reviews the literature regarding the association between the SNPs of genes encoding MMPs and the risk of knee OA. An electronic search in the PubMed and Web of Science databases from conception to January 2021 was performed addressing studies relating MMPs genetic polymorphisms with the risk of knee OA. We included case-control studies that used validated genotyping methods to detect the SNPs’ association in MMP genes with primary knee OA risk. Ten studies were finally included in this systematic review, evaluating different SNPs in six MMP genes in terms of knee OA pathogenesis: MMP-1 (3 SNPs), MMP-2 (1 SNP), MMP-3 (9 SNPs), MMP-8 (10 SNPs), MMP-9 (6 SNPs), and MMP-13 (1 SNP). Among them, nine SNPs of four MMP genes have been associated with knee OA: (a) MMP-1 -1607 1G/2G (Turkish, Chinese), (b) MMP-3 rs650108, rs650108, rs520540, rs602128, rs679620 (Chinese), (c) MMP-8 rs1940475 and rs376520 (Finnish), and (d) MMP-13 77A/ (rs2252070) (Chinese). The present review summarizes all known SNPs of MMP genes related to a higher risk of knee OA. There are at least nine SNPs in four MMP genes associated with knee OA. No solid correlation between MMP genotype and knee OA phenotype exists. More high-quality studies and modern genetic testing methods are needed to fully elucidate the role of polymorphisms of MMP genes in knee OA pathogenesis.

Matrix Metalloproteinase Genes (MMP1, MMP10, MMP12) on Chromosome 11q22 and the Risk of Non-Contact Anterior Cruciate Ligament Ruptures

Background: Sequence variants within the matrix metalloproteinases genes remain plausible biological candidates for further investigation of anterior cruciate ligament (ACL) rupture risk. The aim of the present study was to establish whether variants within the MMP1 (rs1799750, ->G), MMP10 (rs486055, C > T) and MMP12 (rs2276109, T > C) genes were associated with non-contact ACL rupture in a Polish cohort. Methods: The unrelated, self-reported Polish Caucasian participants consisted of 228 (157 male) individuals with primary non-contact ACL rupture and 202 (117 male) participants without any history of ACL rupture. All samples were genotyped in duplicate using the Applied Biosystems TaqMan^® methodology. The statistical analyses were involved in determining the distribution of genotype and allele frequencies for the investigated polymorphisms between the diagnostic groups. Furthermore, pseudo-haplotypes were constructed to assess possible gene–gene interactions. Results: All genotype frequencies in the ACL rupture and control groups conformed to Hardy Weinberg Equilibrium expectations. None of the polymorphisms were associated with risk of non-contact ACL rupture under the codominant, dominant, recessive and over-dominant genetic models. Likewise, no genotype–genotype combinations inferred as “haplotypes” as a proxy of gene–gene interactions were associated with the risk of non-contact ACL ruptures. Conclusions: Despite the fact that the current study did not support existing evidence suggesting that variants within the MMP1, MMP10, and MMP12 genes influence non-contact ACL rupture risk, future work should include high-throughput sequencing technologies to identify potential targeted polymorphisms to fully characterize the 11q22 region with susceptibility to non-contact ACL rupture susceptibility in a Polish cohort.

Association between the MMP-1-1607 1G/2G Polymorphism and Osteoarthritis Risk: A Systematic Review and Meta-Analysis

Background

Osteoarthritis (OA) is a common disease characterized by articular cartilage degeneration and secondary hyperosteogenesis. Genetic factors are associated with the occurrence of OA. While several studies have shown that the matrix metalloproteinase-1- (MMP-1-) 1607 1G/2G (rs1799750) polymorphism may be related to the occurrence and development of OA, there is inconsistency in the literature. To better estimate the relationship between the MMP-1 gene polymorphism and OA, a comprehensive meta-analysis of relevant literature was carried out.

Results

In total, seven studies comprising 1245 OA patients and 1230 controls were included in this meta-analysis. The combined results revealed no significant association between the MMP-1-1607 1G/2G polymorphism and risk of OA in the five genetic models. However, after Bonferroni correction, the results of subgroup analysis revealed a significant correlation between the MMP-1-1607 1G/2G polymorphism and OA susceptibility in the temporomandibular joint (TMJ) OA subgroup (allelic: 2G vs. 1G: OR = 1.575, 95%CI = 1.259–1.972, P < 0.01; recessive: 2G2G vs. 1G1G+1G2G: OR = 2.411, 95%CI = 1.658–3.504, P < 0.01; and homozygote: 2G2G vs. 1G1G: OR = 2.313, 95%CI = 1.341, 3.991, P = 0.003), the younger subgroup (aged less than 60 years; allelic: 2G vs. 1G: OR = 1.635, 95%CI = 1.354, 1.974, P < 0.01; dominant: 2G1G+2G2G vs. 1G1G: OR = 1.622, 95%CI = 1.158, 2.271, P = 0.005; recessive: 2G2G vs. 1G1G+1G2G: OR = 2.209, 95%CI = 1.718, 2.840, P < 0.01; and homozygote: 2G2G vs. 1G1G: OR = 2.578, 95%CI = 1.798, 3.696, P < 0.01), the larger subgroup (N > 300), and the hospital-based case-control study (HCC) subgroup. The sensitivity analysis suggested that the results of the meta-analysis were stable and reliable. Begg's funnel plot and Egger's test indicated that there was no publication bias in this study.

Conclusion

Our meta-analysis indicated that although the MMP-1-1607 1G/2G polymorphism was not significantly associated with OA susceptibility among the whole sample, it played a key role in the etiology and development of TMJ OA and OA in people aged less than 60 years.

IL-6: An endogenous activator of MMP-9 in preterm birth

Preterm birth or PTB (<37 weeks) is a heterogeneous phenotype with numerous biological pathways. The lack of explanation due to complex pathways, inconsistent observations indicates the need for employing the role of genetic determinants to anticipate the danger of PTB. In this present study, we investigated the possible gene-gene interaction of five SNPs with PTB and its association with total MMP-9 levels. A total of 510 recruitments (250 terms and preterm each) were made and were genotyped by Restriction Fragment length polymorphism (RFLP). Generalized Multifactor Dimensionality Reduction (GMDR) method was carried out for determining gene-gene interaction. ANOVA and t-test were used to identify the association of IL-6 polymorphism with PTB alone and correspondingly with PTB and low birth weight infants (i.e. < 2500 kg). The combination of IL-6 and MMP-9 and MMP-1, MMP-8 and MMP-9 polymorphism was selected through GMDR analysis concerning mothers with preterm and term birth (accuracy 0.5921 and 0.8030 with Cross-Validation Consistency (CVC) 10/10 respectively). Increased expression of MMP-9 was reported in cases in those mothers carrying IL-6 G allele, which was profoundly associated with PTB independently. IL-6 polymorphisms showed synergistic effects in terms of increased total MMP-9 levels in the present study.

Lack of association between matrix metalloproteinase-1 gene rs1799750 polymorphism and osteoarthritis susceptibility: a meta-analysis

Background. A relationship between matrix metalloproteinase-1 (MMP-1)-1607 (rs1799750) gene polymorphism and osteoarthritis (OA) susceptibility was reported in the Bioscience Reports journal; however, these results were inconsistent. To evaluate the specific relationship, we used a meta-analysis study to clarify the controversy. Methods. The relevant articles were retrieved on 20 October 2018 from PubMed, Elsevier, Springer, Ebase (Ovid), and Google Scholar. The number of alleles and genotypes for MMP-1 was obtained. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the association between MMP-1-1607 (rs1799750) 1G/2G promoter polymorphism and OA, while the Egger’s test was used to assess heterogeneity among studies and publication bias. All statistical analyses were conducted using STATA 12.0 software. Results. A total of six case–control studies covering 1133 cases and 1119 controls were included in the final meta-analysis. There was no significant association between MMP-1-1607 1G/2G promoter polymorphism and OA in all genetic models (2G versus 1G: OR = 1.12, 95% CI = 0.78–1.60; 1G/2G versus 1G/1G: OR  = 0.73, 95% CI = 0.32–1.67; 2G/2G versus 1G/1G: OR  =  1.31, 95% CI = 0.57–2.98; the recessive model: OR  =  1.23, 95% CI = 0.63-2.41; and the dominant model: OR  =  1.25, 95% CI = 0.79–1.97). We obtained similar results for the subgroup analysis using ethnicity and type of disease. Conclusion. We systematically investigated the association between MMP-1-1607 (rs1799750) 1G/2G polymorphism and OA susceptibility; however, the results show no correlation.

Effects of MMP-1 1G/2G polymorphism on osteoarthritis: A meta-analysis study

Objective

The aim of this meta-analysis was to clarify the role of Matrix metalloproteinase 1 (MMP-1) -1607 1G/2G (rs1799750) polymorphism on the osteoarthritis (OA) risk.

Methods

Articles were selected by retrieving the Web of Science, Embase and Pubmed. The strength of the association between -1607 1G/2G polymorphism and OA risk was assessed by odds ratios (ORs) with the corresponding 95% confidence interval (CI) for each study.

Results

No significant association between -1607 1G/2G polymorphism and OA risk was found in all the models overall (2G2G vs 1G1G, OR (95%CI) = 0.69 (0.36–1.32), P = 0.54; 2G2G + 2G1G vs 1G1G, OR (95%CI) = 0.88 (0.47–1.63), P = 0.69; 2G2G vs 2G1G + 1G1G, OR (95%CI) = 1.30 (0.68–2.47), P = 0.41; 2 G vs 1G, OR (95%CI) = 0.90 (0.86–1.54), P = 0.66). By subgroup analysis, significant association was found in the “< 60 years” group (2G2G vs 1G1G, OR (95%CI) = 3.46 (2.13–5.62), P = 0.00; 2G2G + 2G1G vs 1G1G, OR (95%CI) = 0.49 (0.31–0.79), P = 0.00; 2G2G vs 2G1G + 1G1G, OR (95%CI) = 2.74 (1.80–4.16, P = 0.00; 2 G vs 1G, OR (95%CI) = 0.56 (0.35–0.89), P = 0.01).

Conclusions

This meta-analysis showed that -1607 1G/2G polymorphism may increase the susceptibility to OA among the younger populations (<60 years). More studies with detailed information are needed to validate our conclusion.

Level of Evidence

Level I Diagnostic Study.

Association of ADAMTS4 and ADAMTS5 polymorphisms with musculoskeletal degenerative diseases: a systematic review and meta-analysis

Objective: This meta-analysis and systematic review was performed with the aim of investigating the association between a disintegrin and metalloproteinase with thrombospondin motif (ADAMTS)4, AMDMTS5 polymorphisms and risk of musculoskeletal degenerative diseases.

Methods: PubMed, EMBASE, ISI Web of Science, Wanfang and CNKI were searched from their inception until May 2018 to identify eligible studies. Data from individual studies were extracted using a standardized data collection sheet. The estimate of association between ADAMTS4, AMDMTS5 polymorphisms and risk of musculoskeletal degenerative diseases was expressed as odds ratio (OR) along with its related 95% confidence interval (95%CI) under an allelic model of inheritance. Meta-analysis was conducted using RevMan 5.3 software. Subgroup-analyses by ethnicity and type of diseases were performed.

Results: Eight studies including ten cohorts were included in this meta-analysis. The meta-analyses results based on seven studies showed that rs226794 in ADAMTS5 gene was not associated with risk of musculoskeletal degenerative diseases (A vs. G: OR 1.07; 95%CI 0.97–1.19; P=0.16). Rs2830585 in ADAMTS5 was significantly associated with musculoskeletal degenerative diseases in only Asians (OR 1.41, 95%CI 1.18–1.68; P=0.0001), but not in Caucasians. Since only two of the collected studies referred to ADAMTS4, we did not perform meta-analysis for these comparisons.

Conclusion: Taken together, rs226794 and rs2830585 in ADAMTS5 gene were not associated with musculoskeletal degenerative diseases in overall population, but there seemed to be an ethnicity-dependent effect of rs2830585 in the risk of musculoskeletal degenerative diseases. Insufficient evidence was found to support the association of other single nucleotide polymorphisms and musculoskeletal degenerative diseases.

The association between MMP-1 gene rs1799750 polymorphism and knee osteoarthritis risk

Matrix metalloproteinase 1 (MMP-1) degrades cartilage, which may result in osteoarthritis (OA) development. Several studies have explored the association between MMP-1 gene rs1799750 polymorphism and OA in different populations. However, the results are inconsistent. The aim of this case–control study was to investigate the association between MMP-1 gene rs1799750 polymorphism and knee OA in a Chinese population. The present study included 308 cases and 404 controls. Genotyping was performed using standard polymerase chain reaction and restriction fragment length polymorphism. The present study found that 2G2G genotype (2G2G vs 1G1G: OR & 95% CI, 2.28 (1.47–3.53), P<0.001; 2G2G + 1G2G vs 1G1G: OR & 95% CI, 1.61 (1.15–2.24), P=0.005; 2G2G vs 1G2G + 1G1G: OR & 95% CI, 1.84 (1.26–2.68), P=0.002) or 2G allele carriers (2G vs 1G: OR & 95% CI, 1.48 (1.20–1.83), P<0.001) of MMP-1 gene rs1799750 polymorphism increased the risk of OA. In conclusion, this case–control study confirms that MMP-1 gene rs1799750 polymorphism increases the risk of knee OA in Chinese Han population.

Association of matrix metalloprotease 1, 3, and 12 polymorphisms with rheumatic heart disease in a Chinese Han population

BACKGROUND

Rheumatic heart disease (RHD) is an autoimmune disease triggered by acute rheumatic fever (ARF). Matrix metalloproteinases (MMPs) play an important role in the modulation of immune responses. The purpose of this study was to evaluate the association of MMP1, 3, and 12 promoter polymorphisms with RHD in a Han population in Southern China since the 3 genes are localized on the same chromosome and have a combined effect.

METHODS

DNA samples were obtained from 90 adult patients with RHD and 90 control subjects. Polymorphisms in MMP1 (rs1799750), MMP3 (rs3025058), and MMP12 (rs2276109) were genotyped by direct sequencing. Differences in genotype and allele frequencies of these polymorphisms were compared between the cases and the controls using Unconditional logistic regression models and Chi-squared test.

RESULTS

The 2G/2G genotype of rs1799750 in MMP1 was associated with a significantly higher risk of RHD when compared with the 1G/1G genotype (OR = 3.227; 95% CI:1.118-9.31; p = 0.03). The frequency of allele 2G was higher in patients with RHD compared to the controls (69.4% vs. 58.9%; p = 0.048) No significant differences in genotype and allele frequencies of rs3025058 in MMP3 and rs2276109 in MMP12 were found between the patients with RHD and the controls (p > 0.05).

CONCLUSIONS

Our results suggest that rs1799750 in MMP1 might be a risk factor for RHD in a Han population in Southern China, and individuals carrying the 2G/2G genotype are likely more susceptible to RHD. In contrast, rs3025058 in MMP3 and rs2276109 in MMP12 might not contribute to the risk of developing RHD in this population. Further studies with larger samples and other ethnic populations are required to confirm these findings.

Examining the association of MMP-1 gene -1607 (2G/1G) and -519 (A/G) polymorphisms with the risk of osteomyelitis: A case-control study

To investigate the effects of matrix metalloproteinase-1 (MMP-1) gene polymorphisms on the onset of osteomyelitis in Chinese Han population.In all, 80 osteomyelitis patients (case group) and 81 healthy people (control group) were recruited into this case-control study. Polymerase chain reaction-restriction fragment length polymorphism method was utilized to examine the genotypes of MMP-1 polymorphisms (-1607 2G/1G and -519A/G) in the 2 groups. Genotype and allele differences between the case and control groups were analyzed by chi-square test. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to present the association strength between MMP-1 gene polymorphisms and osteomyelitis.Frequencies of -1607 2G/2G genotype between the case and control groups were statistically significant (P = .025). Compared with 1G/1G genotype carriers, the 2G/2G genotype carriers had 1.605 times risk of developing osteomyelitis (OR 2.605, 95% CI 1.116-6.082). Meanwhile, the 2G allele significantly associated with the risk of osteomyelitis (OR 1.735, 95% CI 1.115-2.701). In addition, frequency of -519GG genotype was obviously higher in case group than that in control group (P = .024), and GG genotype related to an increased risk of osteomyelitis (OR 2.792, 95% CI 1.127-6.917). Whereas, the -519G allele may be a susceptible factor for osteomyelitis (OR 1.622, 95% CI 1.038-2.536).The MMP-1 -1607 (2G/1G) and -519 (A/G) polymorphisms may contribute to the onset of osteomyelitis.

TIMP-2 SNPs rs7342880 and rs4789936 are linked to risk of knee osteoarthritis in the Chinese Han Population

This study aimed to investigate whether functional polymorphisms in the tissue inhibitors of metalloproteinase-2 (TIMP-2) gene are associated with susceptibility to knee osteoarthritis (OA) in the Chinese Han population. Six TIMP-2 single nucleotide polymorphisms (SNPs) were assayed using MassARRAY in 300 patients clinically and radiographically diagnosed with knee OA and in 428 controls. Allelic and genotypic frequencies were compared between groups. Logistic regression adjusting for age and gender was used to estimate risk associations between specific genotypes and knee OA by computing odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that allele "A" in rs7342880 was significantly associated with increased risk of knee OA (OR = 1.44, 95%CI = 1.09-1.91, p = 0.035). In addition, in the over-dominant model, rs4789936 correlated with reduced risk of knee OA, adjusting for age and gender (OR = 0.69, 95%CI = 0.49-0.98, p = 0.036). Finally, rs7342880 correlated with increased risk of knee OA in females. This study provides evidence that TIMP-2 is a knee OA susceptibility gene in the Chinese population and a potential diagnostic and preventive marker for the disease.

Role of HIF-1α signaling pathway in osteoarthritis: a systematic review

Osteoarthritis (OA) is the most common form of arthritis and is frequently diagnosed and managed in primary care; it is characterized by loss of articular hyaline cartilage, which is a unique connective tissue that physiologically lacks blood vessels. Articular cartilage survives in a microenvironment devoid of oxygen, which is regulated by hypoxia inducible factor (HIF-1α). HIF-1α is considered the main transcriptional regulator of cellular and developmental response to hypoxia. To date, the relevance of HIF-1α in the assessment of cartilage has increased since its participation is essential in the homeostasis of this tissue. Taking into account the new emerging insights of HIF-1α in the scientific literature in the last years, we focused the present review on the potential role of HIF-1α signaling pathway in OA development, especially in how some genetic factors may influence the maintenance or breakdown of articular cartilage.

Estrogen receptor beta and truncated variants enhance the expression of transfected MMP-1 promoter constructs in response to specific mechanical loading

Background

Joint diseases such as osteoarthritis (OA) predominantly afflict post-menopausal women, suggesting a pertinent role for female hormones. Estrogen receptor beta (ER-β) has been detected in connective tissues of the knee joint suggesting that these tissues are responsive to the hormone estrogen. Matrix metalloproteinase-1 (MMP-1) activity contributes to cartilage degradation, a key factor leading to OA development in synovial joints. Two polymorphic forms of MMP-1 exist due to a deletion/insertion of the guanine residue in the promoter, and the 2G allelic variant of MMP-1 exhibits more activity than the 1G allele. Previous studies have demonstrated that the polymorphic forms of the human MMP-1 are influenced by the modulating effects of estrogen receptor isoforms. In addition to hormonal influences, physiological factors such as altered mechanical loading are also contributory features of OA. In the present study, the combined influence of biomechanical and hormonal variables on the activity of MMP-1 isoforms was evaluated. We hypothesized that the combined effects of ER-β and sheer stress will differentially activate the two allelic forms of MMP-1 in a hormone-independent manner.

Methods

HIG-82 synoviocytes were transiently transfected with 1G or 2G alleles (±) ER-β and subjected to either shear or equibiaxial stress. Next, 1G/2G promoter activity was measured to determine the combined influence of physiological stimuli. Truncated ER-β constructs were used to determine the importance of different domains of ER-β on 1G/2G activation.

Results

The 2G allele exhibited a constitutively higher activity than the 1G allele, which was further increased when the transfected cells were subject to shear stress, but not equibiaxial stress. Moreover, the combination of ER-β and shear stress further increased the activity levels of the 1G/2G allelic variants. Additionally, select AF-2 truncated ER-β variants led to increased activity levels for the 2G allele, indicating the AF-1 domain was likely involved in the response to mechanical stimulation.

Conclusions

These results suggest that the 1G/2G alleles of MMP-1 are influenced by specific mechanical stimuli like shear stress, as well as the ER-β receptor. These findings contribute to the potential allelic involvement in connective tissue diseases such as OA in females compared to males.