Association of a polymorphism of the matrix metalloproteinase-9 gene with bone mineral density in Japanese men

Destroy to Rebuild: The Connection Between Bone Tissue Remodeling and Matrix Metalloproteinases

Bone is a dynamic organ that undergoes constant remodeling, an energetically costly process by which old bone is replaced and localized bone defects are repaired to renew the skeleton over time, thereby maintaining skeletal health. This review provides a general overview of bone’s main players (bone lining cells, osteocytes, osteoclasts, reversal cells, and osteoblasts) that participate in bone remodeling. Placing emphasis on the family of extracellular matrix metalloproteinases (MMPs), we describe how: (i) Convergence of multiple protease families (including MMPs and cysteine proteinases) ensures complexity and robustness of the bone remodeling process, (ii) Enzymatic activity of MMPs affects bone physiology at the molecular and cellular levels and (iii) Either overexpression or deficiency/insufficiency of individual MMPs impairs healthy bone remodeling and systemic metabolism. Today, it is generally accepted that proteolytic activity is required for the degradation of bone tissue in osteoarthritis and osteoporosis. However, it is increasingly evident that inactivating mutations in MMP genes can also lead to bone pathology including osteolysis and metabolic abnormalities such as delayed growth. We argue that there remains a need to rethink the role played by proteases in bone physiology and pathology.

A translational approach from an animal model identifies CD80 as a candidate gene for the study of bone phenotypes in postmenopausal women

This study represented a translational study that first compared gene expression of B cells of BM from ovariectomized and control mice, and then analyzed some of the differentially expressed genes in women. Results showed novel genetic associations with bone phenotypes and points to the CD80 gene as relevant in postmenopausal bone loss.

INTRODUCTION

Osteoporosis is a multifactorial disease with a strong genetic component. However, to date, research into osteoporosis has only been able to explain a small part of its heritability. Moreover, several components of the immune system are involved in the regulation of bone metabolism. Among them, B cells occupy a prominent place.

METHODS

The study consisted of two stages. In the first, gene expression in bone marrow B cells is compared between ovariectomized and SHAM control mice using microarrays. In the second, we studied the association of polymorphisms in some differentially expressed genes (DEG) in a cohort of postmenopausal women.

RESULTS

The present study has found 2791 DEG (false discovery rate (FDR) <5%), of which 1569 genes were upregulated (56.2%) and 1122 genes (43.8%) were downregulated. Among the most altered pathways were inflammation, interleukin signaling, B cell activation, TGF-beta signaling, oxidative stress response, and Wnt-signaling. Sixteen DEG were validated by MALDI-TOF mass spectrometry or qPCR. The translational stage of the study genotyped nine single nucleotide polymorphisms (SNPs) of DEG or related and detected association with bone mineral density (BMD) (nominal P values), while adjusting for confounders, for SNPs in the CD80, CD86, and HDAC5 genes. In the logistic regression analysis adjusted for confounders, in addition to the SNPs in the aforementioned genes, the SNPs in the MMP9 and SOX4 genes were associated with an increased risk of osteoporosis. Finally, two SNPs (in the CD80 and SOX6 genes) were associated with an increased risk of bone fragility fracture (FF). However, after Bonferroni correction for multiple testing, only the association between CD80 with BMD and risk of osteoporosis remained significant.

CONCLUSION

These results show that the use of animal models is an appropriate method for identifying genes associated with human bone phenotypes.

Matrix Metalloproteinases in Bone Resorption, Remodeling, and Repair

Matrix metalloproteinases (MMPs) are the major protease family responsible for the cleavage of the matrisome (global composition of the extracellular matrix (ECM) proteome) and proteins unrelated to the ECM, generating bioactive molecules. These proteins drive ECM remodeling, in association with tissue-specific and cell-anchored inhibitors (TIMPs and RECK, respectively). In the bone, the ECM mediates cell adhesion, mechanotransduction, nucleation of mineralization, and the immobilization of growth factors to protect them from damage or degradation. Since the first description of an MMP in bone tissue, many other MMPs have been identified, as well as their inhibitors. Numerous functions have been assigned to these proteins, including osteoblast/osteocyte differentiation, bone formation, solubilization of the osteoid during bone resorption, osteoclast recruitment and migration, and as a coupling factor in bone remodeling under physiological conditions. In turn, a number of pathologies, associated with imbalanced bone remodeling, arise mainly from MMP overexpression and abnormalities of the ECM, leading to bone osteolysis or bone formation. In this review, we will discuss the functions of MMPs and their inhibitors in bone cells, during bone remodeling, pathological bone resorption (osteoporosis and bone metastasis), bone repair/regeneration, and emergent roles in bone bioengineering.

Matrix Metalloproteinase-1 and -9 Promoter Polymorphisms Are Not Associated With an Increased Risk of Uterine Leiomyomas in a Japanese Population

OBJECTIVE

Matrix metalloproteinases (MMPs) play an important role in modeling and remodeling the extracellular matrix in leiomyomas. Hence, we investigated whether associations exist between leiomyomas and promoter polymorphisms in the MMP-1 and MMP-9 genes in a Japanese population.

METHODS

We compared the distribution of polymorphisms in the promoter regions of MMP-1 (-1607 1G/2G) and MMP-9 (-1562 C/T) in 267 leiomyoma patients and 184 control patients using polymerase chain reaction-fragment-length polymorphism (PCR-RFLP) analysis.

RESULTS

The allele frequencies of the MMP-1 -1607 2G and MMP-9 -1562 T polymorphisms were 74.6% and 18.6% in leiomyoma patients, and 71.3% and 18.6% in control patients, respectively. No significant differences in allele frequencies or genotype distributions were found between leiomyoma and control patients. Moreover, no associations were found between MMP-1 and MMP-9 genotypes and leiomyoma size or a family history of the condition.

CONCLUSION

These findings suggest that MMP-1 and MMP-9 promoter polymorphisms are unlikely to be associated with an increased risk of uterine leiomyomas in Japanese women.

Matrix Metalloproteinase-1 and -9 Promoter Polymorphisms and Endometrial Carcinoma Risk in a Japanese Population

OBJECTIVE

The matrix metalloproteinases (MMPs) are a family of zinc-dependent proteases that degrade all the components of the extracellular matrix (ECM). Several studies have demonstrated association between MMP gene polymorphisms and various cancers. The object of this study was to investigate whether the MMP-1 and MMP-9 gene promoter polymorphisms are associated with endometrial carcinomas in a Japanese population.

METHODS

We compared the allele frequencies and genotype distributions of each single nucleotide polymorphism in the promoter regions of MMP-1 (-1607 1G/2G) and MMP-9 (-1562 C/T) in 107 endometrial carcinoma cases and 213 controls using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) analysis.

RESULTS

The allele frequencies of MMP-1 -1607 2G and MMP-9 -1562T were 64.0% and 10.7% in the cases and 70.0% and 16.7% in the controls, respectively. No significant differences in the allele frequencies or genotype distributions were found between cases and controls for the MMP-1 -1607 1G/2G polymorphism. However, a small but significant difference in the allele frequency of the MMP-9 -1562T allele was noted between cases and controls (P = .046; odds ratio [OR] = 1.01; 95% confidence interval [CI], 1.01 to 2.73). Stratification by histology revealed a significant difference in the frequency of the MMP-9 -1562T allele between endometrioid carcinoma cases (10.2%) and controls (P = .043; OR = 1.76; 95% CI, 1.02 to 3.03); we did not find a significant difference in the frequency of the MMP-9 -1562T allele between non-endometrioid carcinoma cases (13.2%) and controls.

CONCLUSION

These results suggest that the MMP-9 -1562 C/T polymorphism may be associated with susceptibility to endometrioid carcinoma in the Japanese population.

Type I collagen and matrix metalloproteinase 1, 3 and 9 gene polymorphisms in the predisposition to pelvic organ prolapse

AIM

To evaluate whether the presence of specific polymorphism in the gene promoter of collagen and some matrix metalloproteinases was associated with the risk of developing pelvic organ prolapse.

METHODS

A case-control study was carried on 233 women: 137 were cases with ≥ stage II pelvic organ prolapse and 96 were matched controls without pelvic pathologies. Allele and genotype frequencies related to polymorphisms at the Sp1 site of type I collagen and some functional polymorphisms in the promoters of metalloproteinases-1, -3 and -9 have been compared between groups. It has been shown that these single-insertions/deletions polymorphisms located in the promoter region of the genes have a functional significance in the regulation of their transcriptional level and local expression. Genotypes were determined by polymerase chain reaction (PCR) amplification and sequence analysis. SPSS 14.0 software was used for data analysis. Probability values of <0.05 were considered statistically significant.

RESULTS

No difference between groups was found in the genotype distribution polymorphisms for COL1A1, metalloproteinases-9 and -3, while the distribution of the polymorphism of metalloproteinases-1 was significantly increased in the cases when compared with controls (p = 0.04).

CONCLUSIONS

Our findings suggest that the polymorphism of metalloproteinases-1 might have a role in mediating susceptibility to pelvic organ prolapse.

Are polymorphisms of molecules involved in bone healing correlated to aseptic femoral and tibial shaft non-unions?

Fracture healing is a well-organized process between several molecules and mediators. As known from other diseases, genetic polymorphisms may exhibit different expression patterns in these mediators. Concerning fracture healing, this may lead to an extended healing process or non-union. We investigated the incidence of polymorphisms in patients with aseptic non-unions after femoral and tibial shaft fractures as compared to patients with uneventful healing. Exclusion criteria were smoking, diabetes, bilateral fractures, systemic corticoid therapy, and septic non-unions. Analysis of allele frequencies and genotype distribution of various mediators were carried out following PCR. Clinical parameters such as injury severity and in-hospital were analyzed. Fifty patients following non-union (group NU) were enrolled, the control group consisted of 44 patients (group H). A significant association of a PDGF haplotype and non-unions following fracture could be observed. There was a significantly increased in-hospital time and amount of surgical procedures in group NU. Polymorphisms within the PDGF gene seem to be a genetic risk factor for the development of non-unions of the lower extremity following fracture. The early identification of high risk patients could result in an adapted therapeutical strategy and might contribute to a significant decrease of posttraumatic non-unions.

Differential effects between the loss of MMP-2 and MMP-9 on structural and tissue-level properties of bone

Matrix metalloproteinases (MMPs) are capable of processing certain components of bone tissue, including type 1 collagen, a determinant of the biomechanical properties of bone tissue, and they are expressed by osteoclasts and osteoblasts. Therefore, we posit that MMP activity can affect the ability of bone to resist fracture. To explore this possibility, we determined the architectural, compositional, and biomechanical properties of bones from wild-type (WT), Mmp2(-/-) , and Mmp9(-/-) female mice at 16 weeks of age. MMP-2 and MMP-9 have similar substrates but are expressed primarily by osteoblasts and osteoclasts, respectively. Analysis of the trabecular compartment of the tibia metaphysis by micro-computed tomography (µCT) revealed that these MMPs influence trabecular architecture, not volume. Interestingly, the loss of MMP-9 improved the connectivity density of the trabeculae, whereas the loss of MMP-2 reduced this parameter. Similar differential effects in architecture were observed in the L(5) vertebra, but bone volume fraction was lower for both Mmp2(-/-) and Mmp9(-/-) mice than for WT mice. The mineralization density and mineral-to-collagen ratio, as determined by µCT and Raman microspectroscopy, were lower in the Mmp2(-/-) bones than in WT control bones. Whole-bone strength, as determined by three-point bending or compression testing, and tissue-level modulus and hardness, as determined by nanoindentation, were less for Mmp2(-/-) than for WT bones. In contrast, the Mmp9(-/-) femurs were less tough with lower postyield deflection (more brittle) than the WT femurs. Taken together, this information reveals that MMPs play a complex role in maintaining bone integrity, with the cell type that expresses the MMP likely being a contributing factor to how the enzyme affects bone quality.

MMP9 limits apoptosis and stimulates branching morphogenesis during kidney development

Early events in kidney organogenesis involve reciprocal interactions between the ureteric bud and the metanephric mesenchyme, which lead to remodeling of the extracellular matrix. This remodeling involves matrix metalloproteases (MMPs), but the specific roles of individual MMPs in kidney development are not completely understood. Here, we analyzed MMP9-deficient mice at the first step of kidney development and found that MMP9 deficiency delayed embryonic kidney maturation and increased apoptosis ex vivo by 2.5-fold. These early defects resulted in a 30% decrease in nephron number, a 20% decrease in adult kidney weight, and altered kidney function and morphology at 12 mo. The membrane form of stem cell factor (SCF) increased, whereas the activated form of the SCF receptor, c-kit, decreased in MMP9-deficient embryonic kidneys. In organotypic culture, MMP9-deficient kidneys failed to secrete SCF, and addition of recombinant SCF partially rescued both apoptosis and the branching defect. In conclusion, these data show that MMP9 protects mesenchymal cells from apoptosis during kidney development and stimulates ureteric bud branching morphogenesis, most likely by releasing the soluble form of SCF, suggesting that normal renal development requires MMP9.

Quantitative trait loci, genes, and polymorphisms that regulate bone mineral density in mouse

This is an in silico analysis of data available from genome-wide scans. Through analysis of QTL, genes and polymorphisms that regulate BMD, we identified 82 BMD QTL, 191 BMD-associated (BMDA) genes, and 83 genes containing known BMD-associated polymorphisms (BMDAP). The catalogue of all BMDA/BMDAP genes and relevant literatures are provided. In total, there are substantially more BMDA/BMDAP genes in regions of the genome where QTL have been identified than in non-QTL regions. Among 191 BMDA genes and 83 BMDAP genes, 133 and 58 are localized in QTL regions, respectively. The difference was still noticeable for the chromosome distribution of these genes between QTL and non-QTL regions. These results have allowed us to generate an integrative profile of QTL, genes, polymorphisms that determine BMD. These data could facilitate more rapid and comprehensive identification of causal genes underlying the determination of BMD in mouse and provide new insights into how BMD is regulated in humans.

Functional Polymorphisms in the Matrix Metalloproteinase-9 Gene in Relation to Severity of Chronic Periodontitis

BACKGROUND

Members of the matrix metalloproteinase (MMP) family are implicated in the chronic remodeling in periodontal diseases. Therefore, we performed a case-control study to investigate a plausible association between susceptibility to chronic periodontitis (CP) and the polymorphisms in the MMP-9 (gelatinase B) gene.

METHODS

Using polymerase chain reaction with subsequent restriction analyses, MMP-9 -1562C/T and R+279Q variants were determined in 304 subjects (169 patients with CP, 76 with a mild to moderate form and 93 with severe generalized CP, and 135 age- and gender-matched unrelated control subjects).

RESULTS

The distribution of the MMP-9 -1562C/T and R+279Q genotypes and alleles did not significantly differ between cases and controls. However, the frequency of the T variant at position -1562 was marginally higher in patients with severe disease compared to those with mild to moderate forms (P <0.05; P(corr) >0.05). In further analysis, the -1562T allele was associated with a severe form of CP in men (odds ratio: 3.87; 95% confidence interval: 1.40 to 10.65; P <0.01 and P(corr) <0.05 for allele; P <0.05 and P(corr) >0.05 for genotype) but not in women.

CONCLUSION

These findings suggest that genetic polymorphisms of the MMP-9 gene are not associated with the susceptibility to CP in the Czech population; however, the promoter variant may influence the severity of the disease in men.

Molecular genetic studies of gene identification for osteoporosis: a 2004 update

This review summarizes comprehensively the most important and representative molecular genetics studies of gene identification for osteoporosis published up to the end of December 2004. It is intended to constitute a sequential update of our previously published review covering the available data up to the end of 2002. Evidence from candidate gene association studies and genome-wide linkage studies in humans, as well as quantitative trait locus mapping animal models are reviewed separately. Studies of transgenic and knockout mice models relevant to osteoporosis are summarized. An important extension of this update is incorporation of functional genomic studies (including DNA microarrays and proteomics) on osteogenesis and osteoporosis, in light of the rapid advances and the promising prospects of the field. Comments are made on the most notable findings and representative studies for their potential influence and implications on our present understanding of genetics of osteoporosis. The format adopted by this review should be ideal for accommodating future new advances and studies.

Association of Matrix Metalloproteinase-9 Promoter Gene Polymorphism With Chronic Periodontitis

BACKGROUND

Matrix metalloproteinases (MMPs) are related to tissue destruction and remodeling events in periodontal diseases. A single nucleotide polymorphism in the promoter region of human MMP-9 gene is associated with the risk of some inflammatory diseases. Therefore, the aim of this study was to investigate the association between MMP-9 promoter polymorphism and severe generalized chronic periodontitis in a Turkish population.

METHODS

Samples of venous blood and DNA were obtained from 70 severe generalized chronic periodontitis patients and 70 healthy subjects. The alleles of the C/T polymorphism at position -1562 in the promoter region of the MMP-9 gene were distinguished by cutting with the SphI restriction enzyme. Genotype and allele frequencies were calculated, and data were analyzed by the chi2 test.

RESULTS

There was a significant difference in MMP-9 genotypes between chronic periodontitis patients and healthy controls. The odds ratios for the CT genotype and the combination of CT and TT genotypes were 0.4 (95% confidence interval, 0.17 to 0.93; P=0.02) and 0.37 (95% confidence interval, 016 to 0.85; P=0.01) relative to the subjects with the CC genotype, respectively.

CONCLUSION

MMP-9 promoter gene polymorphism seems to be associated with severe generalized chronic periodontitis.

Genome-wide scan identified QTLs underlying femoral neck cross-sectional geometry that are novel studied risk factors of osteoporosis

A genome-wide screen was conducted using a large white sample to identify QTLs for FNCS geometry. We found significant linkage of FNCS parameters to 20q12 and Xq25, plus significant epistatic interactions and sex-specific QTLs influencing FNCS geometry variation.

INTRODUCTION

Bone geometry, a highly heritable trait, is a critical component of bone strength that significantly determines osteoporotic fracture risk. Specifically, femoral neck cross-sectional (FNCS) geometry is significantly associated with hip fracture risk as well as genetic factors. However, genetic research in this respect is still in its infancy.

MATERIALS AND METHODS

To identify the underlying genomic regions influencing FNCS variables, we performed a remarkably large-scale whole genome linkage scan involving 3998 individuals from 434 pedigrees for four FNCS geometry parameters, namely buckling ratio (BR), cross-sectional area (CSA), cortical thickness (CT), and section modulus (Z). The major statistical approach adopted is the variance component method implemented in SOLAR.

RESULTS

Significant linkage evidence (threshold LOD = 3.72 after correction for tests of multiple phenotypes) was found in the regions of 20q12 and Xq25 for CT (LOD = 4.28 and 3.90, respectively). We also identified eight suggestive linkage signals (threshold LOD = 2.31 after correction for multiple tests) for the respective geometry traits. The above findings were supported by principal component linkage analysis. Of them, 20q12 was of particular interest because it was linked to multiple FNCS geometry traits and significantly interacted with five other genomic loci to influence CSA variation. The effects of 20q12 on FNCS geometry were present in both male and female subgroups. Subgroup analysis also revealed the presence of sex-specific quantitative trait loci (QTLs) for FNCS traits in the regions such as 2p14, 3q26, 7q21 and 15q21.

CONCLUSIONS

Our findings laid a foundation for further replication and fine-mapping studies as well as for positional and functional candidate gene studies, aiming at eventually finding the causal genetic variants and hidden mechanisms concerning FNCS geometry variation and the associated hip fractures.

Gene polymorphisms involved in the regulation of bone quality

Osteoporotic fractures in subjects at advanced age constitute a tremendous and growing problem. Established lifestyle risk factors can explain only a modest proportion of the liability to osteoporotic fractures. Bone mineral density (BMD) is considered the best established risk factor for osteoporotic fractures. The importance of genetic factors in the quality of bone is substantial, but no consensus exists yet on the genes that are involved. However, concomitant diseases, balance disorders and lifestyle habits are more important for fractures in elderly subjects. The abundance of common sequence variations, so-called polymorphisms, in the human genome and their high frequency in the population have made them targets to explain variation in the risk. Some genes have been identified that appear to be involved in the regulation of bone mass and in the pathogenesis of osteoporosis. Among these are those coding for the two estrogen receptors (ERalpha and ERbeta), the androgen receptor (AR) and the vitamin D receptor (VDR). In addition, enzymes involved in the biogenesis of estrone and estradiol have attracted attention as well as polymorphisms in the regulatory region of the type I collagen gene, COLIA1, affecting the binding site for the transcription factor Specificity protein 1 (Sp1). Although evidence suggests that the quality of bone is determined to a large extent by genetic factors, research so far has not been able to unequivocally identify genes involved in this matter. Over the last years a large number of studies have pointed to the variability in many genes and their relation with BMD, bone-related symptoms or specific therapies. The findings emphasize the complexity of the genetics of bone mass and bone loss.

Matrix metalloproteinase-9 polymorphisms and renal cell carcinoma in a Japanese population

Matrix metalloproteinase-9 (MMP-9) plays a pivotal role in cancer invasion and metastasis. Recently, experimental study has shown that MMP-9 is also implicated in early carcinogenesis. We hypothesized that MMP-9 polymorphisms influence the predisposition to develop renal cell carcinoma (RCC). To test the hypothesis, we determined MMP-9 C-1562T and R279Q genotypes in Japanese RCC cases (n=179) and controls (n=211). Furthermore, we investigated the relationship between MMP-9 polymorphisms and clinicopathological features. The distribution of C-1562T and R279Q genotypes was not significantly associated with the risk of RCC (odds ratio [OR]=1.14, 95% confidence interval [CI]=0.73-1.77 for -1562 CT/TT genotypes versus CC genotype; OR=1.29, 95% CI=0.86-1.93 for 279 RQ/QQ genotypes versus RR genotype). However, the distribution of R279Q genotypes was significantly associated with the histological grade (P<0.01). The present results suggest that MMP9 R279Q polymorphism has influence on the malignant potential of RCC.