Association of MMP3 genotype with susceptibility to frozen shoulder: a case-control study in a Chinese Han population

Matrix metalloproteinase-1 and matrix metalloproteinase-9 are highly expressed in the joint capsule of diabetic frozen shoulder

BACKGROUND

The pathophysiology of frozen shoulder (FS) involves abnormal expressions of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) that lead to capsular fibrosis. However, there has been little concern for why diabetic FS has more protracted fibrotic condition. The objective of this study was to compare the expression levels of MMPs and TIMPs in the joint capsule of patients with diabetic and nondiabetic FS.

MATERIALS AND METHODS

Samples of capsular tissue were collected from 20 patients with FS (10 diabetic patients; diabetic group and 10 nondiabetic patients; nondiabetic group) and 10 patients (control group) with chronic anterior shoulder instability. Quantitative real-time reverse transcriptase-polymerase chain reaction and Western blot analysis were performed to determine the expression levels of mRNA and protein for MMP-1, 3, 9, 13, 14, and TIMP-1, 2.

RESULTS

The results of quantitative real-time reverse transcriptase-polymerase chain reaction showed significantly higher expression levels of all MMPs and TIMP-1 and significantly lower expression levels of TIMP-2 in the joint capsule of patients in the diabetic or nondiabetic groups compared with the control group. Significantly higher expression levels of MMP-1, 9, 14, and TIMP-1 were detected in the diabetic group compared with the nondiabetic group. The results of Western blot analysis showed significantly higher levels of MMP-3, 13, 14, and TIMP-1 in the joint capsule of patients in the diabetic or nondiabetic groups compared with the control group. However, no significant differences of protein levels of them were observed between diabetic and nondiabetic groups.

CONCLUSIONS

The findings of this study demonstrate the potential involvement of MMP-1 and 9 in the pathophysiology of diabetic FS. These findings may be helpful in identification of therapeutic targets for development of novel treatments for this protracted chronic fibrosing condition.

Exploring the potential relationship between frozen shoulder and Dupuytren's disease through bioinformatics analysis and machine learning

Background

Frozen shoulder (FS) and Dupuytren's disease (DD) are two closely related diseases, but the mechanism of their interaction is unknown. Our study sought to elucidate the molecular mechanism of these two diseases through shared gene and protein interactions.

Methods

GSE75152 and GSE140731 data were downloaded from the Gene Expression Omnibus (GEO) database, and shared genes between FS and DD were selected by using R packages. Then, we used Cytoscape software and the STRING database to produce a protein-protein interaction (PPI) network. Important interaction networks and hub genes were selected through MCODE and cytoHubba algorithms. To explore the potential mechanisms of the development of the two diseases, the hub genes were further enriched by GO and KEGG analyses. We predicted the transcription factors (TFs) of hub genes with Transcriptional Regulatory Relationships Unraveled by Sentence-based Text mining (TRRUST). Moreover, we identified candidate genes for FS with DD with cytoHubba and machine learning algorithms. Finally, we analyzed the role of immunocyte infiltration in FS and constructed the relationship between candidate genes and immunocytes in FS.

Results

We identified a total of 321 shared genes. The results of GO and KEGG enrichment of shared genes showed that extracellular matrix and collagen fibril tissue play a certain role in the occurrence and development of disease. According to the importance of genes, we constructed the key PPI network of shared genes and the top 15 hub genes for FS with DD. Then, we predicted that five TFs are related to the hub genes and are highly expressed in the FS group. Machine learning results show that the candidate genes POSTN and COL11A1 may be key for FS with DD. Finally, immune cell infiltration revealed the disorder of immunocytes in FS patients, and expression of candidate genes can affect immunocyte infiltration.

Conclusion

We identified a PPI network, 15 hub genes, and two immune-related candidate genes (POSTN and COL11A1) using bioinformatics analysis and machine learning algorithms. These genes have the potential to serve as diagnostic genes for FS in DD patients. Furthermore, our study reveals disorder of immunocytes in FS.

A shared genetic architecture between adhesive capsulitis and Dupuytren disease

BACKGROUND

The etiology of adhesive capsulitis involves inflammation, thickening, and fibrosis of the shoulder capsule. The underlying genetic factors are poorly understood. The purpose of this study was to identify genetic variants associated with adhesive capsulitis using the UK Biobank (UKB) cohort and compare them with variants associated with Dupuytren disease investigating a common etiology between the 2 fibrotic disorders.

METHODS

A genome-wide association study (GWAS) was performed using data from UKB with 10,773 cases of adhesive capsulitis, and a second GWAS was performed with 8891 cases of Dupuytren disease. Next, a comparison of association statistics was performed between adhesive capsulitis and Dupuytren disease using the data from both GWAS. Finally, single-nucleotide polymorphisms (SNPs) previously reported from candidate gene studies for adhesive capsulitis and Dupuytren disease were tested for association with adhesive capsulitis and Dupuytren disease using the summary statistics from their respective GWAS.

RESULTS

The UKB GWAS for adhesive capsulitis identified 6 loci that reached genome-wide statistical significance: a cluster of 11 closely linked SNPs on chromosome 1; a single SNP on chromosome 2; a single SNP on chromosome 14; 2 closely linked SNPs on chromosome 21; 33 closely linked SNPs on chromosome 22; and 3 closely linked SNPs on the X chromosome. These SNPs were associated with 8 different genes including TSPAN2/NGF, SATB2, MRPL52/MMP14, ERG, WNT7B, and FGF13. A GWAS for Dupuytren disease was performed and a comparison to the adhesive capsulitis GWAS showed 13 loci significantly associated with both phenotypes. A validation attempt of 6 previously reported SNPs associated with adhesive capsulitis using UKB summary statistics was unable to confirm any of the previously reported SNPs (all P > .19). All 23 previously reported SNPs associated with Dupuytren disease were confirmed using the UKB summary statistics (P < 2.1 × 10^-3) CONCLUSION: This GWAS investigating adhesive capsulitis has identified 6 novel loci involving 8 different genes to be associated with adhesive capsulitis. A GWAS investigating Dupuytren disease was performed and compared to the adhesive capsulitis GWAS, and 13 common loci were identified between the 2 disorders with genes involved in pathologic fibrosis. We were unable to validate the SNPs in candidate genes previously reported to be associated with adhesive capsulitis although we were able to confirm all previously reported SNPs associated with Dupuytren disease. The strong genetic overlap between the adhesive capsulitis and Dupuytren disease loci suggests a similar etiology between the 2 diseases.

Risk factors for shoulder pain after stroke: A clinical study

Objectives:

To investigate the risk factors for shoulder pain after stroke, and prevent its occurrence effectively.

Methods:

The patients with stroke treated in our hospital between September 2016 and October 2020 were reviewed retrospectively. The medical records of the included patients including age, gender, lesion side, stroke duration, hospital stay, diabetes, hypertension, heart disease, limitation of shoulder joint activity, alcohol abuse, smoking, type of stroke, Ashworth scale, Brunnstrom stage, sensory disorders, and motor arm score of National Institutes of Health Stroke Scale (NIHSS) were collected and analyzed to determine the risk factors for shoulder pain after stroke.

Results:

A total of 1390 patients were included based on the inclusion and exclusion criteria, consisting of 162 patients with shoulder pain after stroke and the prevalence was 11.6%. The included patients were divided into shoulder pain group and non-shoulder pain group. There were significant differences in age, stroke duration, hospital stay, diabetes, limitation of shoulder joint activity, Ashworth scale, Brunnstrom stage, sensory disorders, and motor arm score of NIHSS between the two groups (P < 0.05). Based on the multivariate regression analysis, the independent risk factors for shoulder pain after stroke included diabetes, limited shoulder joint activity, Brunnstrom grade I-III period, Ashworth 3-4 grade, motor arm score of NIHSS 3-4 points, and sensory disturbance.

Conclusion:

Great emphasis should be placed on the stroke patients with diabetes, limited shoulder joint activity, Brunnstrom grade I-III period, Ashworth 3-4 grade, motor arm score of NIHSS 3-4 points, or sensory disturbance, as these patients have higher risks for shoulder pain after stroke.

Identification of the Resveratrol Potential Targets in the Treatment of Osteoarthritis

Objectives

Osteoarthritis (OA) is a chronic joint degenerative disease and has become an important health problem for the elderly. However, there is still a lack of effective drugs for the treatment of OA. Our research combines bioinformatics and experimental strategies to determine the target of resveratrol for OA treatment.

Methods

First, the differentially expressed genes (DEGs) of OA joint tissues were obtained from the related microarray gene expression data. Second, resveratrol, a natural polyphenol compound, was used to screen the drug treatment target genes. Third, the drug-disease network was established, and the resveratrol target genes for OA treatment were obtained and verified through experimental verification.

Results

A total of 300 differentially expressed genes with 246 upregulated and 54 downregulated were found in OA joint tissues, and 310 resveratrol potential target genes were obtained. Finally, six genes, namely, CXCL1, HIF1A, IL-6, MMP3, NOX4, and PTGS2, were selected to validate the treatment effects of the resveratrol. The results showed that all six genes in human OA chondrocytes were significantly increased. In addition, in these chondrocytes, CXCL1, HIF1A, IL-6, MMP3, NOX4, and PTGS2 were reduced considerably, but HIF1A was significantly increased after resveratrol treatment.

Conclusions

Our data indicates that CXCL1, HIF1A, IL-6, MMP3, NOX4, and PTGS2 are all targets of resveratrol therapy. Our findings may provide valuable information for the mechanism and therapeutic of OA.

Biomarkers associated with idiopathic frozen shoulder: a systematic review

Background: The pathophysiology of idiopathic frozen shoulder (FS) remains poorly described. There is a lack of differentiation between idiopathic and secondary cause. The aim of this systematic review was to summarize the evidence regarding the pathophysiology of idiopathic FS on a molecular level and emphasize the clinical relevance. Methods: A database search of Medline, EMBASE and Cochrane Central Register of Controlled Trials from inception to April 2018 was performed. Participants who underwent previous injections or surgeries were excluded. A thorough selection and quality assessment process using the Cochrane Risk of Bias assessment tool and the Joanna Briggs Institute Critical Appraisal Checklist was conducted by two reviewers independently. Results: A total of 15 studies analyzing 333 study subjects were included. Twelve studies evaluated capsular tissue and three studies investigated blood samples. The tissue samples revealed increased expression of various inflammatory cytokines including interleukins, cyclooxygenase and tumor necrosis factor. Several types of acid-sensing ion channels (ASIC1 and ASIC3) were associated with disturbed neurogenesis and melatonin-regulated pain mechanism. The blood samples showed prevalence of specific interleukin and metalloproteinase genotypes. A decreased matrix metalloproteinase/tissue inhibitor of metalloproteinase ratio was found both in tissue and blood. Conclusion: The findings indicate an abnormal local neurogenesis with possible regulation through melatonin. The disturbance in remodeling of the extracellular matrix and in collagen translation, together with a persistent inflammation and an impaired healing, all interact in the process that leads to persistent fibrosis. There is global fibroplasia with localized anterior capsule contracture.

Increased elastic modulus of the synovial membrane in a rat ACLT model of osteoarthritis revealed by atomic force microscopy

This study aimed to explore changes in nanoscale elastic modulus of the synovium using atomic force microscopy (AFM) in addition to investigate changes in synovial histomorphology and secretory function in osteoarthritis (OA) in a rat anterior cruciate ligament transection (ACLT) model. Sprague-Dawley rats were randomly assigned to sham control and ACLT OA groups. All right knee joints were harvested at 4, 8, or 12 weeks (W) after surgery for histological assessment of cartilage damage and synovitis in both the anterior and posterior capsules. AFM imaging and nanoscale biomechanical testing were conducted to measure the elastic modulus of the synovial collagen fibrils. Immunohistochemistry was used to visualize the expression of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase-3 (MMP-3) in the synovium. The OA groups exhibited progressive development of disease in the cartilage and synovium. Histopathological scores of the synovium in the OA groups increased gradually. Significant differences were observed between all OA groups except for the posterior 4W group. The synovial fibril arrangement in all OA groups was significantly disordered. The synovial fibrils in all ACLT OA groups at each time point were stiffer than those in the sham controls. OA rats displayed a significantly higher expression of IL-1β and MMP3 in the anterior capsule. In summary, synovial stiffening was closely associated with joint degeneration and might be a factor contributing to synovitis and increased production of proinflammatory mediators. Our data provided insights into the role of synovitis, particularly stiffening of the synovium, in OA pathogenesis.

Genetic Aspects in Shoulder Disorders

The influence of genetic inheritance has been increasingly investigated in shoulder disorders, such as rotator cuff injury, instability and frozen shoulder. Although the initial findings are enlightening, it is necessary to progressively build a database of genetic markers to catalog genomic profiles that, later, may contribute for predicting the risk of the disease, as well as to the development of better diagnostic and treatment tools. The present article seeks to update what is evidence of genetic studies in the literature for these diseases, from polymorphism analyses, expression of candidate genes in tissues and broad genomic association studies (GWAS). However, it is necessary to point out that there is great difficulty in replicating and using the findings, mainly due to the lack of statistical power, the high rate of false-positive results and the large number of variables involved.

Interactions between the MMP-3 gene rs591058 polymorphism and occupational risk factors contribute to the increased risk for lumbar disk herniation: A case-control study

Objective

Lumbar disk herniation (LDH) is a complex condition based on lumbar disk degeneration (LDD). Previous studies have shown that genetic factors are highly associated with the severity and risk for LDH. This case‐control study was aimed to evaluate the association between the matrix metalloproteinase (MMP)‐3 gene rs591058 C/T polymorphism and LDH risk in a southern Chinese population.

Methods

A total of 231 LDH patients and 312 healthy controls were recruited in this study. Genotyping was analyzed using a standard polymerase chain reaction and restriction fragment length polymorphism (PCR‐RFLP).

Results

It was observed that TT genotype or T allele carriers of the MMP‐3 gene rs591058 C/T polymorphism was more likely associated with an increased risk for LDH. Subgroup analyses showed the following characteristics increased the risk for LDH: female sex; cigarette smoking; and alcohol consumption. Furthermore, individuals with high whole body vibration, bending/twisting, and lifting were associated with an increased risk for LDH.

Conclusion

Taken together, these data indicated that the MMP‐3 gene rs591058 C/T polymorphism was associated with an increased risk for LDH. The MMP‐3 gene rs591058 C/T polymorphism might serve as a clinical indicator and marker for LDH risk in the Chinese population.

Association of the matrix metalloproteinase 3 (MMP3) single nucleotide polymorphisms with tendinopathies: case-control study in high-level athletes

BACKGROUND

Matrix metalloproteinases (MMPs) play an important role in matrix remodelling, as well as in tendon integrity. Due to overuse, athletes often develop chronic tendinopathies. If not treated, they lead to severe impairment, even complete tendon ruptures.

AIM

The main purpose of this study was to investigate whether three functional polymorphisms within the MMP3 gene are associated with increased risk of developing tendinopathies in high-level Croatian athletes.

METHODS

We have recruited one hundred fifty-five (63 high-level athletes with diagnosed tendinopathies and 92 asymptomatic controls) unrelated Caucasians for this case-control genetic study. All participants were genotyped for three single nucleotide polymorphisms (SNP) within the MMP3 gene: rs591058 C/T, rs650108 A/G and rs679620 G/A using the pyrosequencing method.

RESULTS

The MMP3 rs650108 GG (P = 0.0074) and rs679620 AA (P = 0.0119) genotypes were significantly over-represented in cases compared with controls, while rs591058 TT (P = 0.0759), as well as haplotype variant T - G - A (P = 0.06), implicated that there is an indication of predisposition for tendinopathies.

CONCLUSION

These results support association between functional variants within the MMP3 gene and the risk of tendinopathies in high-level athletes. Further research is needed to replicate these results in a larger population.

Genetic variants involved in extracellular matrix homeostasis play a role in the susceptibility to frozen shoulder: A case-control study

Frozen shoulder is a condition of loss of active and passive motion as result of inflammatory contracture and fibrosis of the joint capsule. We hypothesize that genetic variants in genes involved in these processes such as genes that play a role in extracellular matrix homeostasis (collagens, glycoproteins, genes involved in TGFβ signaling, and metalloproteinases and its inhibitors) may contribute to the susceptibility to frozen shoulder. We evaluated eighteen SNPs of genes involved in extracellular matrix homeostasis in 186 cases (N_females  = 114; N_males  = 72) of frozen shoulder and 600 age-matched controls (N_females  = 308; N_males  = 292). Multivariate logistic regressions were carried out with age, gender, genetic ancestry, and common comorbidities as covariates. Carriers of the C allele of MMP13 rs2252070 and G/G MMP9 (rs17576 A>G/rs17577 G>A) haplotype may have an increased risk of frozen shoulder (p = 0.002, OR = 1.64, 95%CI = 1.20-2.26, and p = 0.046, OR = 1.40, 95%CI = 1.01-1.95, respectively), especially in females (p = 0.005, OR = 1.91, 95%CI = 1.22-2.99, and p = 0.046, OR = 1.59, 95%CI = 1.01-2.51, respectively). In females, the G allele of MMP9 rs17576 tended to contribute to the susceptibility to the studied disease (p = 0.05, OR = 1.51, 95%CI = 0.97-2.33). In contrast, the presence of the C allele of TGFB1 rs1800470 seems to be associated with a reduced risk (p = 0.04, OR = 0.47, 95%CI = 0.23-0.96) while the GG-genotype of TGFBR1 rs1590 was associated with increased risk (p = 0.027, OR = 4.11, 95%CI = 1.17-14.38) to frozen shoulder development in males. Thus, we identified genetic variants that were independent risk factors that can aid in the risk assessment of frozen shoulder reinforcing the involvement of MMP and TGFβ signaling in disease development. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Curcumin Inhibits Proliferation of Synovial Cells by Downregulating Expression of Matrix Metalloproteinase-3 in Osteoarthritis

Objective

To investigate the association between curcumin and the differentially expressed genes (DEG) in synovial tissues of osteoarthritis.

Methods

Microarray analysis was used to screen for the DEG in osteoarthritis synovial cells. Curcumin‐related genes were identified through the drug–gene interaction network STITCH (http://stitch.embl.de/cgi/input.pl). Expression levels of fibronectin 1 (FN1) and collagen III protein were measured by western blot. MTT assay was used to examine the effects of different concentrations of curcumin on cell viability. Western blot and quantitative real‐time polymerase chain reaction were used to validate the different expression levels of matrix metalloproteinase‐3 (MMP3). Clone formation assay, flow cytometry, and the TUNEL method were conducted for detecting the cell proliferation and apoptosis rate.

Results

In the two chips of GSE1919 and GSE55235, the average expression of MMP3 in the osteoarthritis group was 63.7% and 12.9% higher than that of the healthy control, respectively. The results of western blot also showed that the average expression of MMP3 in 30 osteoarthritis patients was 132% higher than that of the healthy group, which confirmed that MMP3 was highly expressed in osteoarthritis group. The results of MTT showed that at 72 h, the cell viability of 40 μmol/L curcumin was the lowest and 79.6% lower than for the 0 μmol/L group, so the final curcumin concentration of 40 μmol/L was selected for subsequent experiments. Western blot results further showed that the expression of MMP3 was 44% lower in the untreated groups compared with the curcumin group, and the expressions of FN1 and collagen III were increased by 112% and 84%, respectively, which indicated that curcumin inhibited MMP3 expression and decreased osteoarthritis synovial cell activity. Cloning formation experiments showed that cell numbers increased by 75% and 20.5% in untreated and curcumin groups, and compared with the untreated group, the cells in the curcumin group decreased by 30.8%. Flow cytometry showed that the apoptotic rate in the curcumin group increased by 85.1% compared with the untreated group, but for a single group, MMP3 decreased the apoptotic rate by 53.9% and 46.7%, respectively.

Conclusions

MMP3 was highly expressed in osteoarthritis synovial cells. Curcumin could reduce cell viability, inhibit cell proliferation, increase cell apoptosis, and eventually alleviate inflammation of osteoarthritis by inhibiting the expression of MMP3.

Asian ethnicity: a risk factor for adhesive capsulitis?

Objective

The aim of this study was to evaluate whether Asian ethnicity is a risk factor for the development of adhesive capsulitis. The secondary aim was to describe the distribution of cases of capsulitis by age group.

Methods

A cross-sectional study comparing the rate of adhesive capsulitis in individuals of Asian ethnicity with that of other ethnicities. We excluded patients with fractures and those with symptoms not involving the shoulder. The odds ratio was adjusted for confounding factors by binary logistic regression.

Results

A total of 1331 patient records were evaluated and after applying the selection criteria, 814 patients remained. We found 134 cases of adhesive capsulitis (15.6%). The peak of incidence was at 60-64 years in the patients of Asian ethnicity and at 55-59 years in the other patients. The unadjusted odds ratio was 4.2 (CI 95%, 2.4-7.4), while the odds ratio adjusted for sex and diabetes mellitus was 3.6 (CI 95%, 2.0-6.5).

Conclusion

Patients of Asian ethnicity showed an independent risk factor for the development of adhesive capsulitis, with an adjusted odds ratio of 3.6. Adhesive capsulitis was more common between 55 and 64 years.

Biological Aspect of Pathophysiology for Frozen Shoulder

It is fairly well understood that frozen shoulder involves several stages, which reflect the series of process from capsular inflammation and fibrosis to spontaneous resolution of this fibrosis. However, the underlying pathophysiologic process remains poorly determined. For this reason, management of frozen shoulder remains controversial. Determining the pathophysiological processes of frozen shoulder is a pivotal milestone in the development of novel treatment for patients with frozen shoulder. This article reviews what is known to date about the biological pathophysiology of frozen shoulder. Although articles for the pathophysiology of frozen shoulder provide inconsistent and inconclusive results, they have suggested both inflammation and fibrosis mediated by cytokines, growth factors, matrix metalloproteinases, and immune cells. Proinflammatory cytokines and growth factors released from immune cells control the action of fibroblast and matrix remodeling is regulated by the matrix metalloproteinases and their inhibitors. To improve our understanding of the disease continuum, better characterizing the biology of these processes at clearly defined stages will be needed. Further basic studies that use standardized protocols are required to more narrowly identify the role of cytokines, growth factors, matrix metalloproteinases, and immune cells. The results of these studies will provide needed clarity into the control mechanism of the pathogenesis of frozen shoulder and help identify new therapeutic targets for its treatment.

MMP-3 and MMP-8 single-nucleotide polymorphisms are related to alcohol-induced osteonecrosis of the femoral head in Chinese males

Our study investigated the association between MMP-3 and MMP-8 single-nucleotide polymorphisms (SNPs) and alcohol-induced osteonecrosis of the femoral head (ONFH) in 695 Chinese males (299 cases and 396 control subjects). The minor allele of MMP-3 rs650108 was associated with a 0.78-fold decrease in alcohol-induced ONFH risk in the allelic model (95% CI = 0.63-0.97, P = 0.026). In the genetic model adjusted for age, rs650108 was associated with decreased risk of alcohol-induced ONFH in the dominant model (OR = 0.68, 95% CI = 0.49-0.95, P = 0.022) and log-additive model (OR = 0.78, 95% CI = 0.63-0.98, P = 0.030); MMP-8 rs11225394 was associated with increased risk in the codominant model (OR = 1.72, 95% CI = 1.15-2.58, P= 0.010), dominant model (OR = 1.67, 95% CI = 1.12-2.48, P = 0.012), over-dominant model (OR = 1.73, 95% CI = 1.16-2.59, P = 0.007) and log-additive model (OR = 1.57, 95% CI= 1.07-2.32, P = 0.022); and MMP-8 rs2012390 was associated with decreased risk in the dominant model (OR = 0.72, 95% CI = 0.53-0.97, P = 0.032) and log-additive model (OR = 0.77, 95% CI = 0.60-0.98, P = 0.035). Haplotype analysis showed that the CGATATGT sequence mediated decreased alcohol-induced ONFH risk (OR = 0.75, 95% CI = 0.57-0.97, P = 0.029). Therefore, among Chinese males, MMP-3 rs650108 and MMP-8 rs2012390 decrease alcohol-induced ONFH risk and MMP-8 rs11225394 increases it. Further study is needed to validate our conclusion.

MMP-3 gene polymorphisms are associated with increased risk of osteoarthritis in Chinese men

Osteoarthritis (OA) is the most common late-onset degenerative joint disease., It is characterized by progressive degradation of articular cartilage. We investigated the association between OA occurrence and single nucleotide polymorphisms (SNPs) in the matrix metalloproteinase-3 (MMP-3) gene involved in the breakdown of extra-cellular matrix proteins. The study included 100 male OA patients and 197 healthy men from the north area of China. Eight MMP-3 SNPs were genotyped. Odds ratios (ORs) with 95% confidence intervals (95%CIs) and multivariate logistic regression analysis were used to assess the association. Multivariate logistic regression analysis was used to identify SNPs that correlated with OA susceptibility. We found that rs639752 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.00, 95% CI: 1.03-3.88, P = 0.037); rs520540 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.00, 95% CI: 1.03-3.88, P = 0.037); rs602128 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.01, 95% CI: 1.03-3.89, P = 0.037); and rs679620 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.04, 95% CI: 1.05-3.96, P = 0.033) were associated with the increased risk of OA. Our results suggest that these SNPs may contribute to OA development, and could serve as molecular markers of OA susceptibility.

A Study of IL-1β, MMP-3, TGF-β1, and GDF5 Polymorphisms and Their Association with Primary Frozen Shoulder in a Chinese Han Population

Primary frozen shoulder (PFS) is a common condition of uncertain etiology that is characterized by shoulder pain and restriction of active and passive glenohumeral motions. The pathophysiology involves chronic inflammation and fibrosis of the joint capsule. Single nucleotide polymorphisms (SNPs) at IL-1β, MMP3, TGF-β1, and GDF5 have been associated with risk of a variety of inflammatory diseases; however, no studies have examined these SNPs with susceptibility to PFS. We investigated allele and genotype frequencies of rs1143627 at IL-1β, rs650108 at MMP-3, rs1800469 at TGF-β1, and rs143383 at GDF5 in 42 patients with PFS and 50 healthy controls in a Chinese Han population. Serum samples from both cohorts were evaluated to determine the expression levels of IL-1β. We found that the IL-1β rs1143627 CC genotype was associated with a decreased risk of PFS compared to the TT genotype (P = 0.022) and that serum IL-1β was expressed at a significantly higher level in the PFS cohort compared to that found in the control group (P < 0.001). Our findings indicated no evidence of an association between rs650108, rs1800469, or rs143383 and PFS. IL-1β is associated with susceptibility to PFS and may have a role in its pathogenesis in a Chinese Han population.