Significant increases in serum and plasma concentrations of matrix metalloproteinases 3 and 9 in patients with rapidly destructive osteoarthritis of the hip

Increased bone resorption that outpaces increased bone formation: An important pathology of rapidly destructive coxarthrosis

Rapid joint destruction caused by rapidly destructive coxarthrosis (RDC) can increase surgical complexity and intraoperative blood loss. This single-center retrospective study investigates osteoporosis-related biomarkers for early RDC diagnosis and explores new treatment targets. We included 398 hip joints from patients who underwent total hip arthroplasty, examining medical records for preoperative patient demographics, bone mineral density of the hip and lumbar spine from dual-energy X-ray absorptiometry scans, and osteoporosis-related biomarkers including TRACP-5b, total P1NP, intact parathyroid hormone, and homocysteine. We compared RDC and osteoarthritis (OA) patients, and univariate analysis showed that RDC patients were older (p < 0.001) and had lower serum levels of albumin (p < 0.001) and higher serum levels of TRACP-5b, total P1NP (p < 0.001), and homocysteine (p = 0.006). Multivariable analysis showed that the ratio of serum TRACP-5b to total P1NP had a more significant difference in RDC patients than in OA patients (p = 0.04). Serum TRACP-5b levels were negatively correlated with the time between RDC onset and blood collection, and Japanese Orthopedic Association pain score. Receiver operating characteristic curve analysis revealed that the ratio of serum TRACP-5b to total P1NP had the highest area under the curve value. This study is the first to demonstrate that the ratio of serum TRACP-5b to total P1NP-increased bone resorption that outpaces increased bone formation-is significantly elevated in patients with RDC and that TRACP-5b is higher in the early stages of RDC. Inhibiting serum levels of TRACP-5b, activated osteoclasts, during early RDC may suppress disease progression.

Rapidly Progressive Osteoarthritis of the Hip: A Prospective Study

Background: Rapidly progressive osteoarthritis of the hip (RPOH) is a rare syndrome that involves the femoral head and acetabulum. Methods: We analyzed the incidence of RPOH in 2022. The inclusion criteria included a clinical history of pain for 1-6 months and a decrease in joint space of > 2 mm within one year or a decrease in joint space by 50% in that time accompanied by femoral and/or acetabular bone destruction. Exclusion: There are no other destructive arthropathies and no evolutionary radiological image sequence. Results: There were 15 patients, 16 hips, an incidence around 3.17%, a 1:1 laterality ratio, and 1 bilateral affected. The mean average age is 77.35 years. The male/female ratio is 1:2. The average BMI is 31.2. The time of the onset of the symptoms to the patient's diagnosis is 5 months. The functionally modified Harris scale (MHS) had an average score of 30 points. They had surgery hip arthroplasty with a cementless cup in all cases, a revision cup in one of them, and a double mobility cup in the other, with the stem cemented three times. There were no post-surgical complications. Functionally was achieved at 3 months. The average MHS is 70 at 12 months. The average MHS is 85. Conclusions: RPOH is an idiopathic entity characterized by great clinical involvement and rapid radiological evolution. It is most common in women around 77 years of age. The bone quality requires surgical alternatives to implants, and it has good functional recovery post-surgery.

Electrogenerated Chemiluminescence Biosensor for Quantization of Matrix Metalloproteinase-3 in Serum via Target-Induced Cleavage of Oligopeptide

A highly sensitive and selective electrogenerated chemiluminescence (ECL) biosensor was developed for the determination of matrix metalloproteinase 3 (MMP-3) in serum via the target-induced cleavage of an oligopeptide. One ECL probe (named as Ir-peptide) was synthesized by covalently linking a new cyclometalated iridium(III) complex ([(3-pba)2Ir(bpy-COOH)](PF6)) (3-pba = 3-(2-pyridyl) benzaldehyde, bpy-COOH = 4'-methyl-2,2'-bipyridine-4-carboxylic acid) with an oligopeptide (CGVPLSLTMGKGGK). An ECL biosensor was fabricated by firstly casting Nafion and gold nanoparticles (AuNPs) on a glassy carbon electrode and then self-assembling both of the ECL probes, 6-mercapto-1-hexanol and zwitterionic peptide, on the electrode surface, from which the AuNPs could be used to amplify the ECL signal and Ir-peptide could serve as an ECL probe to detect the MMP-3. Thanks to the MMP-3-induced cleavage of the oligopeptide contributing to the decrease in ECL intensity and the amplification of the ECL signal using AuNPs, the ECL biosensor could selectively and sensitively quantify MMP-3 in the concentration range of 10-150 ng·mL-1 and with both a limit of quantification (26.7 ng·mL-1) and a limit of detection (8.0 ng·mL-1) via one-step recognition. In addition, the developed ECL biosensor showed good performance in the quantization of MMP-3 in serum samples, with a recovery of 92.6% ± 2.8%-105.6% ± 5.0%. An increased level of MMP-3 was found in the serum of rheumatoid arthritis patients compared with that of healthy people. This work provides a sensitive and selective biosensing method for the detection of MMP-3 in human serum, which is promising in the identification of patients with rheumatoid arthritis.

Investigating sagittal spinopelvic alignment and equivalent stress on the femoral head in patients with rapidly destructive coxarthrosis

PURPOSE

Rapidly destructive coxarthrosis (RDC) is a rare syndrome of unknown etiology. This study evaluated sagittal spinopelvic alignment (SSPA) in patients with RDC and compared it with that in patients with hip osteoarthritis (HOA). In addition, finite element analysis (FEA) was performed to investigate the distribution of stress on the femoral head in RDC versus HOA.

METHODS

This retrospective study included patients who had undergone primary total hip arthroplasty for RDC (n = 33) and HOA (n = 99; age- and sex-matched to patients with RDC) at three hospitals from June 2014 to September 2020. Preoperative SSPA parameters and inflammatory blood markers were compared between the two groups. FEA on the computed tomography data was performed for four patients from each group with similar pelvic tilt (PT) and lateral center-edge angle (LCEA). The distribution of Drucker-Prager equivalent stress was assessed at the loaded area of the femoral head.

RESULTS

Patients with RDC had significantly higher PT, lower sacral slope, decreased lumbar lordosis (LL), higher sagittal vertical axis, and higher pelvic incidence minus LL than patients with HOA, indicating sagittal spinal imbalance. Blood test revealed patients with RDC had higher levels of inflammation markers than patients with HOA. FEA revealed no statistically significant difference in the degree of stress concentration or the maximum equivalent stress between the two groups when PT and LCEA were comparable.

CONCLUSION

Patients with RDC tend to have sagittally imbalanced spine. Decreased acetabular coverage of the femoral head may heighten mechanical load of the hip joint in patients with RDC.

T1 pelvic angle is associated with rapid progression of hip arthrosis

PURPOSE

To evaluate the association between global spinal malalignment and rapid progression of hip arthrosis.

METHODS

This was a retrospective, case-control study including 90 patients, contributing 90 hips, who underwent hemi- or total hip arthroplasty at our institution. For analysis, hips were classified into a rapid progression group, defined as ≥ 2 mm destruction of the femoral head or loss of the hip joint space within a 12-month period (n = 30), and a non-rapid progression group, defined by no observable hip disease progression over a period more than 12 months (n = 60). Logistic regression analysis identified factors that predicted rapid progression, with a receiver operating characteristic curve analysis used to confirm factors.

RESULTS

Significant between-group differences were identified for the following parameters: pelvic tilt (P = 0.002, PT), sagittal vertical axis (P = 0.002, SVA), and T1 pelvic angle (P < 0.001, TPA). On multiple logistic regression, PT (P = 0.002), SVA (P = 0.002), and TPA (P < 0.001) were predictive of a rapid progression on hip arthrosis, with the area under the curve being greater for TPA than PT (P = 0.035).

CONCLUSION

Global spinal alignment is associated with rapid progression of hip arthrosis. TPA could assist in identifying patients at risk for rapid progression of hip arthrosis, allowing for time management.

Decreased serum MMP-9 levels in patients with nontraumatic osteonecrosis of the femoral head

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) are involved in the pathological mechanism of osteonecrosis of the femoral head (ONFH). This study aimed to investigate the relationship of serum MMP-9, TIMP-1, and the MMP-9/TIMP-1 ratio with disease severity in patients with nontraumatic ONFH.

METHODS

Serum levels of MMP-9 and TIMP-1 among 102 nontraumatic ONFH patients and 96 healthy individuals were determined by enzyme-linked immunosorbent assay (ELISA). Imaging severity was determined using the FICAT classification system. The Harris hip score (HHS) and visual analogue scale (VAS) were used to evaluate clinical progress. The correlations of serum MMP-9 and TIMP-1 levels with imaging severity and clinical progress was evaluated statistically. The diagnostic value of MMP-9 for NONFH disease severity was evaluated by examining receiver operating characteristic (ROC) curves.

RESULTS

The serum MMP-9 levels and the MMP-9/TIMP-1 ratio were significantly increased in patients with ONFH compared to normal controls, and TIMP-1 levels did not differ between the two groups. Serum MMP-9 levels and the MMP-9/TIMP-1 ratio were positively correlated with FICAT stage and VAS and were negatively correlated with the HHS score. The ROC curve results indicated that MMP-9 could be used as a potential marker of nontraumatic ONFH imaging progression.

CONCLUSIONS

We hypothesize that increased MMP-9 expression and an imbalance in the MMP-9/TIMP-1 ratio play a role in the development of ONFH and are correlate with the severity of ONFH. The determination of MMP-9 can be a useful tool to assess the severity of the disease in patients with nontraumatic ONFH.

A rapid, selective, and ultrasensitive voltammetric and gravimetric protocol for MMP-1 active form detection

In this paper a rapid, selective, and ultrasensitive protocol for the detection of the active form of matrix metalloproteinase-1 (MMP-1), which is a novel predictive and prognostic biomarker, was presented, which might strengthen the current predictive systems. The biosensor construction procedure was extremely simple, economical, and time-saving, as it involved only the chemisorption step of the voltammetrically active receptor (tripeptide (Cys-Gly-Ile) labeled with methylene blue (MB) and the sealing thiol. The active form of MMP-1 was recognized based on its hydrolytic activity; as a consequence, the receptor fragment (-Ile-MB) was removed from the sensor surface. The biosensors constructed were characterized by a wide dynamic concentration response range (1.0 pg mL^-1-1.0 μg mL^-1) and a low detection limit (33 fg mL^-1), especially the biosensor with voltammetric detection, without the amplification step. One of the important advantages of the proposed biosensors is that they can be directly used to analyze the content of the active form of MMP-1 in clinical samples without the dilution step and any other preparation step.

Analysis of the Anti-Inflammatory and Anti-Osteoarthritic Potential of Flonat Fast®, a Combination of Harpagophytum Procumbens DC. ex Meisn., Boswellia Serrata Roxb., Curcuma longa L., Bromelain and Escin (Aesculus hippocastanum), Evaluated in In Vitro Models of Inflammation Relevant to Osteoarthritis

Osteoarthritis (OA) is a joint disease characterized by inflammation of the synovium, angiogenesis, cartilage degradation, and osteophyte formation. Harpagophytum Procumbens DC. ex Meisn., Boswellia Serrata Roxb., Curcuma longa L., Bromelain and Escin (Aesculus hippocastanum) are plants which extracts, together to Bromelain and Escin (Aesculus hippocastanum) are traditionally used in OA. However, their mechanistic role remains unclear. We aimed to investigate whether these bioactives alone or in combination (as in Flonat Fast^®) can suppress TNF-α-induced inflammation, angiogenesis, and osteophyte formation using two cell models involved in OA: endothelial cells and monocytes. Each plant extract was evaluated for its polyphenol content, antioxidant activity, and toxicity. In endothelial cells and monocytes, expression of genes involved in OA was assessed, functional assays for inflammation and angiogenesis were performed, and impairment of reactive oxygen species production (ROS) was evaluated. Exposure of cells to the bioactives alone and in combination before cytokine stimulation resulted in differential counterregulation of several gene and protein expressions, including those for cyclooxygenases-2, metalloproteinase-9, transforming growth factor β1, and bone morphogenic protein-2. We demonstrated that these bioactives modulated monocyte adhesion to endothelial cells as well as cell migration and endothelial angiogenesis. Consistent with radical scavenging activity in the cell-free system, the bioactives curbed TNF-α-stimulated intracellular ROS production. We confirmed the potential anti-inflammatory and antiangiogenic effects of the combination of Harpagophytum procumbens, Boswellia, Curcuma, Bromelain, and Escin and provided new mechanistic evidence for their use in OA. However, further clinical studies are needed to evaluate the true clinical utility of these bioactives as supportive, preventive, and therapeutic agents.

Concentration of Selected Metalloproteinases and Osteocalcin in the Serum and Synovial Fluid of Obese Women with Advanced Knee Osteoarthritis

The aim of the study was to evaluate the levels of selected MMPs (matrix metalloproteinases) and osteocalcin in the serum and synovial fluid of obese women with osteoarthritis and their correlations with clinical status. The studied group consisted of 39 overweight females undergoing primary total knee arthroplasty due to osteoarthritis (OA). The staging of knee OA was evaluated according to the Ahlbӓck and Kellgren–Lawrence scores. Synovial fluid and peripheral blood samples were obtained. The levels of selected MMPs and osteocalcin were assessed using commercial ELISA kits. The mean value of MMP3 was significantly higher in patients with more advanced disease in both serum (p = 0.0067) and synovial fluid (p = 0.0328). The pro-MMP13 level tended to be higher in synovial fluid in the case of more advanced stages (p = 0.0882), with no tendency regarding the serum level (p = 0.9595). The synovial level of pro-MMP1 was significantly correlated with the synovial concentration of MMP9 and MMP3. The synovial level of MMP9 also showed a significant correlation with the synovial level of MMP3 and pro-MMP13. Furthermore, it was found that the serum level of MMP3 was significantly correlated with the synovial pro-MMP13 level. A correlation between the osteocalcin level in serum and its synovial level was determined. The serum MMP9 level showed a significant correlation with BMI, whereas the synovial MMP9 level was notably correlated with age. Our results showed that the levels of MMP3, MMP9, and pro-MMP13 increased in more advanced radiological stages of OA, indicating the underlying inflammatory process of OA.

Progressive Bone Destruction in Rapidly Destructive Coxopathy Is Characterized by Elevated Serum Levels of Matrix Metalloprotease-3 and C-Reactive Protein

OBJECTIVE

Rapidly destructive coxopathy (RDC) is a rare condition characterized by rapid joint space narrowing; however, its pathology remains unclear. This study aimed to clarify the association of laboratory biomarkers with the radiological progression of RDC.

METHODS

We examined 34 female and 4 male patients with RDC between October 2010 and April 2018. Patients were divided into 3 groups according to the progressive radiographic staging of RDC. Group 1 patients had progressive obliteration of the joint space without subchondral destruction (n = 11), group 2 had progressed subchondral destruction (n = 18), and group 3 had cessation of bone destruction observed for more than 6 months (n = 9). Clinical evaluation results were assessed using the Japanese Orthopedic Association hip score. Blood test results, including serum matrix metalloproteinase-3 (MMP-3), and C-reactive protein (CRP), were also evaluated.

RESULTS

There were no significant differences in patient background or Japanese Orthopedic Association hip scores among the groups. However, there were significant differences in MMP-3 levels among groups, with MMP-3 levels in group 2 being significantly higher than those in group 3 (group 2, 118.4 ± 81.2 ng/mL; group 3, 42.5 ± 15.1 ng/mL, p < 0.001). The CRP levels in group 2 were also significantly higher than those in group 3 (group 2, 0.77 ± 0.92 mg/dL; group 3, 0.13 ± 0.07 mg/dL, p = 0.019), but elevated CRP levels in group 2 decreased back to the reference range.

CONCLUSIONS

Matrix metalloproteinase-3 and CRP are the biomarkers of RDC progression but not of its occurrence. Severe inflammatory response may be associated with bone destruction in RDC.

Increased MMP-9 levels with strain-dependent stress resilience and tunnel handling in mice

Increased perineuronal net (PNN) deposition has been observed in association with corticosteroid administration and stress in rodent models of depression. PNNs are a specialized form of extracellular matrix (ECM) that may enhance GABA-mediated inhibitory neurotransmission to potentially restrict the excitation and plasticity of pyramidal glutamatergic neurons. In contrast, antidepressant administration increases levels of the PNN-degrading enzyme matrix metalloproteinase-9 (MMP-9), which enhances glutamatergic plasticity and neurotransmission. In the present study, we compare pro-MMP-9 levels and measures of stress in females from two mouse strains, C57BL/6 J and BALB/cJ, in the presence or absence of tail grasping versus tunnel-associated cage transfers. Prior work suggests that C57BL/6 J mice show relatively enhanced neuroplasticity and stress resilience, while BALB/c mice demonstrate enhanced susceptibility to adverse effects of stress. Herein we observe that as compared to the C57BL/6 J strain, BALB/c mice demonstrate a higher level of baseline anxiety as determined by elevated plus maze (EPM) testing. Moreover, as determined by open field testing, anxiety is differentially reduced in BALB/c mice by a choice-driven tunnel-entry cage transfer technique. Additionally, as compared to tail-handled C57BL/6 J mice, tail-handled BALB/c mice have reduced brain levels of pro-MMP-9 and increased levels of its endogenous inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1); however, tunnel-associated cage transfer increases pro-MMP-9 levels in BALB/c mice. BALB/c mice also show increases in Western blot immunoreactive bands for brevican, a constituent of PNNs. Together, these data support the possibility that MMP-9, an effector of PNN remodeling, contributes to the phenotype of strain and handling-associated differences in behavior.

Bone turnover markers in the early stage of rapidly progressive osteoarthritis of the hip

OBJECTIVE

Previous reports have demonstrated that patients with end-stage rapidly progressive osteoarthritis of the hip (RPOH) show significantly higher serum levels of bone turnover markers than those with osteoarthritis (OA). However, the characteristics of bone turnover markers in the early stage of RPOH remain unclear. This study aimed to elucidate the association of bone turnover markers with disease progression in the early stage of RPOH.

METHODS

This study included 29 postmenopausal female patients with joint space narrowing >2 mm demonstrated on a series of radiographs and computed tomography within 1 year following the onset of hip pain. The study also included 9 postmenopausal female patients with hip OA secondary to developmental dysplasia showing femoral head destruction. Cortical thickness index (CTI) associated with bone mineral density of the hip was analyzed. Serum concentrations of tartrate-resistant acid phosphatase-5b (TRACP-5b) and bone alkaline phosphatase (BAP) were evaluated.

RESULTS

RPOH was classified into two types on the basis of the absence (type 1, n=13) or presence (type 2, n=16) of subsequent destruction of the femoral head within 1 year following disease onset. TRACP-5b and BAP significantly increased in RPOH type 2 compared with type 1 and OA. Receiver operating characteristic curve analyses indicated that TRACP-5b and BAP could differentiate RPOH type 2 from type 1 within 1 year following the onset. CTI showed no difference among the RPOH types 1 and 2 and OA.

CONCLUSION

High serum levels of bone turnover markers may be associated with destruction of the femoral head in the early stage of RPOH.

Evaluation of serum MMP-2 and MMP-3, synovial fluid IL-8, MCP-1, and KC concentrations as biomarkers of stifle osteoarthritis associated with naturally occurring cranial cruciate ligament rupture in dogs

The purpose of this study was to evaluate matrix metalloproteinases (MMP) -2 and MMP-3 in serum, and keratinocyte-derived chemoattractant (KC), interleukin 8 (IL-8) and monocyte chemoattractant 1 (MCP-1) in synovial fluid (SF) as stifle osteoarthritis (OA) biomarkers in dogs. Dogs with naturally occurring cranial cruciate ligament (CrCL) rupture (OA group) and healthy controls were recruited. Stifles with CrCL deficiency were surgically stabilized. Serum, SF, and synovial biopsy samples were collected from the OA group preoperatively, whereas samples were collected once from control dogs. A blinded veterinary pathologist graded synovial biopsies. Serum and SF analyses were performed using xMAP technology. General linear regression was used for statistical comparisons of serum biomarkers, and mixed linear regression for SF biomarkers and temporal concentration changes. The overall discriminative ability was quantified using area under curve (AUC). Spearman's correlation coefficient was used to assess correlations between synovial histology grades and the biomarkers. Samples from 62 dogs in the OA group and 50 controls were included. The MMP-2 and MMP-3 concentrations between the OA and control groups were not significantly different, and both with an AUC indicating a poor discriminative ability. All three SF biomarker concentrations were significantly different between the OA group and controls (P <0.05). The MCP-1 was the only biomarker showing an acceptable discriminative performance with an AUC of 0.91 (95% confidence interval: 0.83-0.98). The sum of the inflammatory infiltrate score was significantly correlated with all three SF biomarkers (P <0.01). Summed synovial stroma, and all scores combined were significantly correlated with IL-8 and MCP-1 concentrations (P <0.003), and the summed synoviocyte scores were significantly correlated with MCP-1 concentrations (P <0.001). Correlations between MCP-1 concentrations and synovial histopathologic grading and its discriminative ability suggest its potential as a synovitis biomarker in canine stifle OA associated with CrCL rupture.

Activities and polymorphisms of MMP-2 and MMP-9, smoking, diabetes and risk of prostate cancer

Matrix metalloproteinases (MMPs) are a group of zinc dependent enzymes that are involved in tumor cell invasion and metastasis. The role of MMP-2 and -9 genetic polymorphism in different malignancies has been the subject of numerous studies. The present research has attempted to discover any positive correlation between MMP-2 and MMP-9 SNPs and prostate cancer (PCa) in patients with a history of either diabetes or smoking habits. 112 PCa-patients and 150 unrelated healthy-controls that matched for age and sex were selected for present case-control study. MMP-2 -1575G/A and MMP-9 -1562 C/T polymorphisms detected by PCR-RFLP, serum tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2), testosterone, prostate-specific antigen (PSA), free-prostate-specific-antigen (fPSA), and fPSA/PSA levels were detected by ELISA and enzyme assay, respectively. MMP-2 and MMP-9 activities were measured by gelatin-zymography. Covariates were considered as age, status of cigarette smoking, and a possible history of diabetes mellitus (DM). The frequency of -1575 MMP-2 A/A + A/G and -1562 MMP-9 C/T + T/T genotypes were higher in PCa-patients with DM (74.3%,p = 0.003) and with smoking habits (72.5%,p = 0.005). These genotypes were associated with the increased risk of prostate cancer in smokers (3.52-folds) and in individuals with history of DM (4.34-folds). A significant positive association was found between level of TIMPs (TIMP -1 and TIMP-2) and BMI in PCa-patients and also between testosterone levels and MMP-9 activity in healthy control subjects. For the first time, this study demonstrated that activities of MMP-2 -1575G/A and MMP-9 -1562C/T variants in association with smoking and diabetes are considered significant risk factors for PCa.

Transcriptional profiling of murine macrophages stimulated with cartilage fragments revealed a strategy for treatment of progressive osteoarthritis

Accumulating evidence suggests that synovitis is associated with osteoarthritic process. Macrophages play principal role in development of synovitis. Our earlier study suggests that interaction between cartilage fragments and macrophages exacerbates osteoarthritic process. However, molecular mechanisms by which cartilage fragments trigger cellular responses remain to be investigated. Therefore, the current study aims at analyzing molecular response of macrophages to cartilage fragments. To this end, we analyzed the transcriptional profiling of murine macrophages exposed to cartilage fragments by RNA sequencing. A total 153 genes were differentially upregulated, and 105 genes were down-regulated in response to cartilage fragments. Bioinformatic analysis revealed that the most significantly enriched terms of the upregulated genes included scavenger receptor activity, integrin binding activity, TNF signaling, and toll-like receptor signaling. To further confirm our results, immunohistochemical staining was performed to detected regulated molecules in synovial tissues of OA patients. In consistence with RNA-seq results, MARCO, TLR2 and ITGα5 were mainly detected in the intima lining layer of synovial tissues. Moreover, blockade of TLR2 or ITGα5 but not Marco using specific antibody significantly reduced production of TNF-α in stimulated macrophages by cartilage fragments. Our data suggested that blocking TLR2 or ITGα5 might be promising therapeutic strategy for treating progressive osteoarthritis.

Characterization of rapidly progressive osteoarthritis of the hip in its early stage

OBJECTIVE

This study aimed to characterize the process of disease progression in the early stage of rapidly progressive osteoarthritis of the hip (RPOH) and clarify its association with potential pathological factors of RPOH.

METHODS

This monocentric retrospective study included 41 female patients who met the criteria for RPOH, chondrolysis >2 mm during 12 months from the onset of hip pain based on a series of radiographs and computed tomography. This study also included 9 female patients with osteoarthritis secondary to developmental dysplasia of the hip (DDH) who demonstrated chondrolysis >2 mm during 12 months from the onset of hip pain. Cortical thickness index (CTI) correlated with bone mineral density of the hip, pelvic tilt, and serum concentrations of matrix metalloproteinase (MMP)-3 were analyzed.

RESULTS

RPOH was classified into two types based on the absence (type 1, n=17) and presence (type 2, n=24) of subsequent femoral head destruction within 12 months after the onset of hip pain. MMP-3 significantly increased in RPOH type 2 compared with type 1 and DDH. Increased posterior pelvic tilt was found in RPOH type 2 compared with DDH. Logistic regression and receiver operating characteristic curve analyses indicated that MMP-3 may be associated with differentiation between RPOH types 1 and 2. No difference was found in the CTI between the RPOH types and DDH.

CONCLUSION

Disease progression of RPOH during 12 months after the onset of hip pain could be classified into two distinct types based on the absence (type 1) and presence (type 2) of femoral head destruction in association with MMP-3 and pelvic tilt as biological and mechanical factors, respectively. MMP-3 may be helpful to differentiate these two types in the early stage of RPOH.

Heparinized chitosan stabilizes the bioactivity of BMP-2 and potentiates the osteogenic efficacy of demineralized bone matrix

Background

Demineralized bone matrix (DBM), an allograft bone processed to better expose osteoinductive factors such as bone morphogenetic proteins (BMPs), is increasingly used for clinical bone repair. However, more extensive use of DBM is limited by its unpredictable osteoinductivity and low bone formation capacity. Commercial DBM products often employ polymeric carriers to enhance handling properties but such carriers generally do not possess bioactive functions. Heparin is a highly sulfated polysaccharide and is shown to form a stable complex with growth factors to enhance their bioactivities. In this study, a new heparinized synthetic carrier for DBM is developed based on photocrosslinking of methacrylated glycol chitosan and heparin conjugation.

Results

Heparinized chitosan exerts protective effects on BMP bioactivity against physiological stressors related to bone fracture healing. It also enhances the potency of BMPs by inhibiting the activity of BMP antagonist, noggin. Moreover, heparinized chitosan is effective to deliver bone marrow stromal cells and DBM for enhanced osteogenesis by sequestering and localizing the cell-produced or DBM-released BMPs.

Conclusions

This research suggests an essential approach of developing a new hydrogel carrier to stabilize the bioactivity of BMPs and improve the clinical efficacy of current bone graft therapeutics for accelerated bone repair.

An ex vivo tissue model of cartilage degradation suggests that cartilage state can be determined from secreted key protein patterns

The pathophysiology of osteoarthritis (OA) involves dysregulation of anabolic and catabolic processes associated with a broad panel of proteins that ultimately lead to cartilage degradation. An increased understanding about these protein interactions with systematic in vitro analyses may give new ideas regarding candidates for treatment of OA related cartilage degradation. Therefore, an ex vivo tissue model of cartilage degradation was established by culturing tissue explants with bacterial collagenase II. Responses of healthy and degrading cartilage were analyzed through protein abundance in tissue supernatant with a 26-multiplex protein profiling assay, after exposing the samples to a panel of 55 protein stimulations present in synovial joints of OA patients. Multivariate data analysis including exhaustive pairwise variable subset selection identified the most outstanding changes in measured protein secretions. MMP9 response to stimulation was outstandingly low in degrading cartilage and there were several protein pairs like IFNG and MMP9 that can be used for successful discrimination between degrading and healthy samples. The discovered changes in protein responses seem promising for accurate detection of degrading cartilage. The ex vivo model seems interesting for drug discovery projects related to cartilage degradation, for example when trying to uncover the unknown interactions between secreted proteins in healthy and degrading tissues.

Correlation between synovial fluid cytokine concentrations and limb function in normal dogs and in dogs with lameness from spontaneous osteoarthritis

OBJECTIVE

To determine the relationship between synovial biomarker concentrations and severity of lameness and to assess the ability to differentiate normal from osteoarthritic joints with synovial biomarker concentrations.

STUDY DESIGN

Prospective clinical study.

SAMPLE POPULATION

Twelve hounds with no evidence of osteoarthritis (OA) and 27 client-owned dogs with unilateral lameness and joint pain in a single joint from naturally occurring OA.

METHODS

Enrollment in the OA group required a history of lameness, radiographic evidence of OA on orthogonal joint radiographs, and ≥6% gait asymmetry between contralateral limbs. The concentrations of 14 synovial OA biomarkers in synovial samples obtained after gait analysis were measured with enzyme-linked immunosorbent assays and compared between normal and OA joints.

RESULTS

Concentrations of monocyte chemoattractant protein (MCP)-1, substance P, interleukin (IL)-6, IL-8, KC-like, matrix metalloproteinase (MMP)-1, and MMP-3 were greater (P ≤ .05) in OA than in normal joints. The concentrations of bradykinin and tissue inhibitors of metalloproteinase-4 were decreased in OA compared with normal joints. Monocyte chemoattractant protein 1 was identified as the most accurate marker to distinguish OA from normal joints. No correlation was detected between any OA biomarker concentration, individually or in combination, and severity of gait asymmetry at the walk.

CONCLUSION

Differences in proinflammatory and anti-inflammatory biomarkers were detected between OA and normal joints, but no relationship was identified between biomarker concentrations and gait asymmetry in dogs with OA.

CLINICAL IMPACT

This information will help guide future studies to elucidate how factors such as disease chronicity, severity, and etiology affect these relationships.

Rapidly progressive hip disease-A rare entity in Korean population

INTRODUCTION

The pathophysiology of rapidly progressive hip disease is still unclear. It is a rare subset of osteoarthritis that mainly affects elderly women and presents with new- onset severe hip pain and dysfunction. It is assumed to be triggered by extremely rapid osteoarthritic changes resulting in impaction of the femoral head into the acetabulum, with successive osteonecrosis and insufficiency of the femoral head.

PRESENTATION OF THE CASE

A 62- year-old woman reported of right hip pain which succeeded an acetabular fracture for which open reduction and fixation was done. Initial radiographs, post fixation, showed no obvious abnormality. After 2 months of conservative therapy for her right hip pain, radiographs showed joint space reduction and subchondral bone loss. T1 MRI images revealed marrow oedema pattern and depression of the articular surface of the femoral head.

DISCUSSION

Differential diagnosis includes conditions which potentially lead to rapid hip destruction, such as metabolic bone diseases, autoimmune inflammatory arthritis and classical osteonecrosis. In patients with rapid worsening of hip symptoms successive X-rays and a high degree of clinical suspicion towards RPHD is essential to avoid extensive joint destruction and to facilitate better arthroplasty outcomes.

CONCLUSION

The authors propose that this case represent an uncommon subset of osteoarthritis. Regular review, both clinically and radiologically, is required to assess speed of progression and to prevent rapid loss of bone stock without the surgeon being aware.

Serum levels of matrix metalloproteinase-3 and autoantibodies related to rheumatoid arthritis in the general Japanese population and their association with osteoporosis and osteoarthritis: the ROAD study

To purpose of this study was to reveal the mean levels and positive proportion of serological markers related to rheumatoid arthritis, and clarify their relationship with osteoporosis and hand osteoarthritis (OA). A total of 1546 participants from the third survey of the research on osteoarthritis/osteoporosis against disability study were enrolled in the current study. Using participant blood samples, the levels of anti-cyclic citrullinated protein (CCP) antibody, rheumatoid factor (RF), matrix metalloproteinase-3 (MMP-3), C-reactive protein (CRP), and high-sensitivity CRP (hsCRP) were measured. Subjects with higher than normal levels were defined as being positive. Osteoporosis was defined according to the recommendations set by World Health Organization criteria in 1994. Radiographic hand OA was evaluated using the modified Kellgren-Lawrence (KL) scale. The positive proportion of anti-CCP antibody, RF, MMP-3, CRP, and hsCRP was 1.8, 7.1, 15.0, 6.7, and 6.4%, respectively. MMP-3 was associated with age, and was significantly higher in men than in women. Positive MMP-3 was not significantly related to osteoporosis or severe hand OA (KL grade ≥3) after adjustment for other factors including age, sex, and body mass index. The results from this study clarified the values and positive proportion of RA-related markers and revealed their relationship with osteoporosis and hand OA.

HPLC-MS/MS method optimisation for matrix metalloproteinase 3 and matrix metalloproteinase 9 determination in human blood serum using target analysis

A quantitative analysis of zinc endopeptidases matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 3 (MMP3) from human blood serum are presented. Both matrix metalloproteinases (MMP) are present in human blood serum and can be used as biomarkers for different diseases. The analysis was performed using LC-MS/MS with a triple quadrupole mass spectrometer, based on two specific peptides of each MMP in comparison with an enzyme-linked immunosorbent assay (ELISA). While the conditions for the LC-MS/MS analysis of MMP9 peptides were previously reported for bronchoalveolar lavage fluid, the analysis of MMP3 peptides was newly quantified for human blood serum herein for the first time. For MMP3, the linear behaviour was determined in the concentration range from 1.0-200.0ng/mL (R²=0.997) with an LLOD of 0.5ng/mL. For MMP9, linearity was determined in the concentration range from 6.5-65.0ng/mL (R²=0.995) with an LLOD of 2.0ng/mL.

Characteristics of bone turnover markers in rapidly destructive coxopathy

The purpose of this study was to clarify bone turnover marker levels in rapidly destructive coxopathy (RDC). Twenty patients with RDC (mean age, 72 ± 11 years; 3 men, 17 postmenopausal women), 111 with osteoarthritis (OA) (age, 60 ± 10 years; 15 men, 13 premenopausal women, 83 postmenopausal women), and 18 with osteonecrosis of femoral head (ON) (55 ± 14 years; 11 men, 3 premenopausal women, 4 postmenopausal women), and 100 patients with femoral neck fracture (FNF) (81 ± 10 years; 27 men, 73 postmenopausal women) were included. Serum tartrate-resistant acid phosphatase 5b (TRACP-5b), bone alkaline phosphatase (BAP), matrix metalloproteinase-3 (MMP-3) levels, and bone mineral density (BMD) of proximal femur and lumbar spine were investigated. TRACP-5b levels were significantly higher in RDC than in OA and ON, whereas BAP levels were higher in RDC than in OA (P < 0.05). MMP-3 levels were higher in RDC and ON than in OA (P < 0.05). TRACP-5b were higher in RDC than OA (P < 0.05) and FNF (P < 0.05) in performing propensity score matching; there were no differences in BMD between RDC and OA. TRACP-5b showed the largest area under the curve (AUC, 0.82) according to receiver operating characteristic (ROC) curve analysis for diagnosing RDC against OA and ON. AUCs of BAP and MMP-3 were 0.78 and 0.74. The respective sensitivities and specificities were 70.0 % and 85.3 % for TRACP-5b (cutoff, 623 mU/dl), 95.0 % and 57.1 % for BAP (13.8 U/l), and 70.0 % and 76.4 % for MMP-3 (52.7 ng/ml). The lack of differences in BMD suggested that high bone turnover marker levels may reflect osteoclast cell activation in RDC hips. Serum TRACP-5b and BAP could be RDC markers.

MicroRNA-181 inhibits proliferation and promotes apoptosis of chondrocytes in osteoarthritis by targeting PTEN

Objective: To investigate the effects of microRNA-181 (miR-181) on the proliferation and apoptosis of chondrocytes in osteoarthritis (OA) by targeting PTEN. Methods: The chondrocytes in logarithmic growth phase were selected and divided into 6 test groups: the normal, blank, negative control, miR-181 mimic, miR-181 inhibitor, and miR-181 inhibitor + PTEN-siRNA groups. Reverse transcription qPCR was used to detect the expressions of miR-181 and PTEN mRNA. MTT assay and flow cytometry were performed to detect cell proliferation and apoptosis. The protein expressions of PARP and caspase-3 and the activity of MMP-2 and MMP-9 were detected by Western blotting and gelatin zymography assay. Results: The miR-181 mimic group showed increased miR-181 expression and decreased PTEN expression compared with the other 5 groups. Also, by comparison with the other 5 groups, the cell proliferation rate declined and the rate of cell apoptosis was elevated in the miR-181 mimic group. The MiR-181 mimic group showed remarkably increased protein expression of caspase-3 and PARP compared with the other 5 groups. The activity of MMP-2 and MMP-9 was higher in the miR-181 mimic group than the other 5 groups. Conclusion: MiR-181 could up-regulate the expressions of caspase-3, PARP, MMP-2, and MMP-9, and thereby inhibit cell proliferation and promote apoptosis of chondrocytes in OA by targeting PTEN.

Critical overview on the application of sensors and biosensors for clinical analysis

Sensors and biosensors have been increasingly used for clinical analysis due to their miniaturization and portability, allowing the construction of diagnostic devices for point-of-care testing. This paper presents an up-to-date overview and comparison of the analytical performance of sensors and biosensors recently used in clinical analysis. This includes cancer and cardiac biomarkers, hormones, biomolecules, neurotransmitters, bacteria, virus and cancer cells, along with related significant advances since 2011. Some methods of enhancing the analytical performance of sensors and biosensors through their figures of merit are also discussed.

Levels of Matrix Metalloproteinases in Arthroplasty Patients and Their Correlation With Inflammatory and Thrombotic Activation Processes

An imbalance of matrix metalloproteinases (MMPs) and their inhibitors is thought to play a major role in the pathophysiology of joint diseases. The aim of this study is to provide additional insights into the relevance of MMP levels in arthroplasty patients in relation to inflammation and thrombosis. Deidentified plasma samples from 100 patients undergoing total hip arthroplasty or total knee arthroplasty were collected preoperatively, on postoperative day 1, and on postoperative day 3. Tissue inhibitor of MMP 4, tumor necrosis factor α (TNF-α), pro-MMP1, MMP3, MMP9, MMP13, and d-dimer were measured using enzyme-linked immunosorbent assay kits. A biochip array was used to profile interleukin (IL) 2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), interferon gamma, TNF-α, IL-1α, IL-1β, monocyte chemoattractant protein 1, and endothelial growth factor (EGF) levels. The levels of MMP1, MMP9, MMP13, and TNF-α were elevated preoperatively in arthroplasty patients when compared to healthy individuals. The concentrations of MMP1 and MMP9 increased slightly in postsurgical samples. d-Dimer levels were elevated preoperatively, increased postoperatively, and started decreasing on postoperative day 3. Significant correlations between MMP9 with TNF-α, IL-6, IL-8, VEGF, and EGF were identified. Elevated preoperative MMP1, MMP9, and MMP13 concentrations suggest that they may play a role in the pathogenesis of arthritis. There is also evidence of increased coagulation activity and possible upregulation of several MMPs postsurgically. Correlation analysis indicates that MMP9 levels may potentially be related to inflammation and thrombosis in arthroplasty patients.

What is the effect of nicotinic acetylcholine receptor stimulation on osteoarthritis in a rodent animal model?

OBJECTIVES

Despite the rising number of patients with osteoarthritis, no sufficient chondroprotective and prophylactic therapy for osteoarthritis has been established yet. The purpose of this study was to verify whether stimulation of the nicotinic acetylcholine receptor via nicotine has a beneficial effect on cartilage degeneration in the development of osteoarthritis and is capable of reducing the expression of proinflammatory cytokines and cartilage degrading enzymes in synovial membranes after osteoarthritis induction.

METHODS

Experimental osteoarthritis was induced in Lewis rats using a standardized osteoarthritis model with monoiodoacetate. A total of 16 Lewis rats were randomized into four groups: control, sham + nicotine application, osteoarthritis, and osteoarthritis + nicotine application. Nicotine (0.625 mg/kg twice daily) was administered intraperitoneally for 42 days. We analyzed histological sections, radiological images and the expression of the proinflammatory cytokines, such as interleukin-1β, tumor necrosis factor-α and interleukin-6, and of matrix metalloproteases 3, 9 and 13 and tissue inhibitors of metalloprotease-1 in synovial membranes via quantitative polymerase chain reaction.

RESULTS

Histological and x-ray examination revealed cartilage degeneration in the osteoarthritis group compared to control or sham + nicotine groups (histological control vs osteoarthritis: p = 0.002 and x-ray control vs osteoarthritis: p = 0.004). Nicotine treatment reduced the cartilage degeneration without significant differences. Osteoarthritis induction led to a higher expression of proinflammatory cytokines and matrix metalloproteases as compared to control groups. This effect was attenuated after nicotine administration. The differences of proinflammatory cytokines and matrix metalloproteases did not reach statistical significance.

CONCLUSION

With the present small-scale study, we could not prove a positive effect of nicotinic acetylcholine receptor stimulation on osteoarthritis due to a conservative statistical analysis and the consecutive lack of significant differences. Nevertheless, we found promising tendencies of relevant parameters that might prompt further experiments designed to evaluate the potency of stimulation of this receptor system as an additional treatment approach for osteoarthritis.

Identification of shoulder osteoarthritis biomarkers: comparison between shoulders with and without osteoarthritis

BACKGROUND

The biologic factors associated with shoulder osteoarthritis (OA) have not been elucidated. The purpose of this study was to investigate osteoarthritic biomarkers of the shoulder. To our knowledge, this is the first study to analyze shoulder cartilage for OA-associated genes and to examine human shoulder cartilage for a possible biomarker, connexin 43 (Cx43).

MATERIALS AND METHODS

Cartilage from 16 osteoarthritic and 10 nonosteoarthritic humeral heads was assessed for expression of the following genes by real-time polymerase chain reaction: types I, II, and X collagen; matrix metalloproteinases (MMPs); tissue inhibitors of MMP (TIMPs); interleukins; versican; cyclooxygenase 2 (Cox-2); inducible nitric oxide synthase (iNOS); tumor necrosis factor α (TNF-α); aggrecanase 2 (ADAMTS5); and Cx43.

RESULTS

In osteoarthritic shoulders, Cx43, Cox-2, versican, collagen type I, ADAMTS5, MMP-3, and TNF-α expressions were significantly increased compared with controls. TIMP-3 and iNOS trended toward significance, with robust expression in osteoarthritic shoulders and low expression in nonosteoarthritic shoulders. In osteoarthritic shoulders, gene expression of Cx43, ADAMTS5, collagen type I, Cox-2, versican, and TIMP-3 showed predominance (85-, 33-, 13-, 12-, 11.5-, and 3-fold increases, respectively) relative to nonosteoarthritic controls. Spearman correlation analysis showed significant correlations between Cx43 and collagen (types I, II, and X), MMP-9, TIMP-2 and TIMP-3, versican, Cox-2, iNOS, and ADAMTS5.

CONCLUSIONS

Certain genes are markedly upregulated in osteoarthritic shoulders compared with nonosteoarthritic shoulders, with Cx43, Cox-2, versican, collagen type I, ADAMTS5, MMP-3, and TNF-α expression being significantly increased. These genes might be useful biomarkers for examining shoulder OA.

CLINICAL RELEVANCE

Identification of osteoarthritic biomarkers can help us better understand shoulder OA and build the foundation for future research on disease progression and treatments.

Matrix Degradative Enzymes and Their Inhibitors during Annular Inflammation: Initial Step of Symptomatic Intervertebral Disc Degeneration

Objective

Symptomatic disc degeneration develops from inflammatory reactions in the annulus fibrosus (AF). Although inflammatory mediators during annular inflammation have been studied, the roles of matrix metalloproteinases (MMPs) and their inhibitors have not been fully elucidated. In this study, we evaluated the production of MMPs and tissue inhibitors of metalloproteinase (TIMPs) during annular inflammation using an in vitro co-culture system. We also examined the effect of notochordal cells on annular inflammation.

Methods

Human AF (hAF) pellet was co-cultured for 48 hours with phorbol myristate acetate-stimulated macrophage-like THP-1 cells. hAF pellet and conditioned media (CM) from co-cultured cells were assayed for MMPs, TIMPs, and insulin-like growth factor (IGF)-1 levels using real-time reverse-transcriptase polymerase chain reaction and enzyem-linked immunosorbent assay. To evaluate whether notochordal cells affected MMPs or TIMPs production on annular inflammation, hAF co-cultured with notochordal cells from adult New Zealand White rabbits, were assayed.

Results

MMP-1, -3, -9; and TIMP-1 levels were significantly increased in CM of hAF co-cultured with macrophage-like cells compared with hAF alone, whereas TIMP-2 and IGF-1 levels were significantly decreased (p<0.05). After macrophage exposure, hAF produced significantly more MMP-1 and -3 and less TIMP-1 and -2. Interleukin-1β stimulation enhanced MMP-1 and -3 levels, and significantly diminished TIMP-2 levels. Co-culturing with rabbit notochordal cells did not significantly influence MMPs and TIMPs production or COL1A2 gene expression.

Conclusion

Our results indicate that macrophage-like cells evoke annular degeneration through the regulation of major degradative enzymes and their inhibitors, produced by hAF, suggesting that the selective regulation of these enzymes provides future targets for symptomatic disc degeneration therapy.

The effect of local anaesthetics on synoviocytes: a possible indirect mechanism of chondrolysis

PURPOSE

While the effect of local anaesthetics on chondrocyte viability is widely documented, the effect of these medications on synoviocytes is largely unknown. The purpose of this study was to understand the effect of 0.5 % bupivacaine and 0.5 % bupivacaine with epinephrine on synoviocyte viability, cytokine and growth factor release, and breakdown product formation.

METHODS

Rabbit fibroblast-like synoviocyte (Type B) cultures were perfused with 0.5 % bupivacaine or 0.5 % bupivacaine with epinephrine (1:200,000) for 24 h. Cell viability was evaluated using a two-colour fluorescence assay. The supernatant was analysed using multiplex inflammatory and matrix metalloproteinase assays.

RESULTS

Synoviocytes treated for 24 h with 0.5 % bupivacaine with epinephrine demonstrated a significant decrease in viability (31.3 ± 19.4 % cell death) when compared with synoviocytes cultured in control media (3.8 ± 1.3 % cell death, p = 0.000) and those cultured in 0.5 % bupivacaine alone (12.6 ± 11.1 % cell death, p = 0.003). No significant decrease in cell viability was observed in synoviocytes treated with 0.5 % bupivacaine compared to those in control media (12.6 ± 11.1 % vs 3.8 ± 1.3 % cell death, p = 0.194). Significantly greater amounts of MMP-1 (47.0 ± 9.2 pg/ml) and MMP-3 (250.0 ± 68.8 pg/ml) were observed in 0.5 % bupivacaine cultures compared with controls (14.3 ± 14.3, p = 0.023 and 72.0 ± 84.9, p = 0.045, respectively).

CONCLUSIONS

0.5 % bupivacaine with epinephrine caused a significant increase in cell death of the synoviocytes, while 0.5 % bupivacaine alone produced cell injury and a significant release of matrix metalloproteinases, which may also lead to indirect injury of the surrounding chondrocytes. These results may help explain the onset of chondrolysis observed in patients who have been treated with intra-articular local anaesthetics.

An intra-articular salmon calcitonin-based nanocomplex reduces experimental inflammatory arthritis

Prolonged inappropriate inflammatory responses contribute to the pathogenesis of rheumatoid arthritis (RA) and to aspects of osteoarthritis (OA). The orphan nuclear receptor, NR4A2, is a key regulator and potential biomarker for inflammation and represents a potentially valuable therapeutic target. Both salmon calcitonin (sCT) and hyaluronic acid (HA) attenuated activated mRNA expression of NR4A1, NR4A2, NR4A3, and matrix metalloproteinases (MMPs) 1, 3 and 13 in three human cell lines: SW1353 chondrocytes, U937 and THP-1 monocytes. Ad-mixtures of sCT and HA further down-regulated expression of NR4A2 compared to either agent alone at specific concentrations, hence the rationale for their formulation in nanocomplexes (NPs) using chitosan. The sCT released from NP stimulated cAMP production in human T47D breast cancer cells expressing sCT receptors. When NP were injected by the intra-articular (I.A.) route to the mouse knee during on-going inflammatory arthritis of the K/BxN serum transfer model, joint inflammation was reduced together with NR4A2 expression, and local bone architecture was preserved. These data highlight remarkable anti-inflammatory effects of sCT and HA at the level of reducing NR4A2 mRNA expression in vitro. Combining them in NP elicits anti-arthritic effects in vivo following I.A. delivery.

Recent findings on the role of gelatinases (matrix metalloproteinase-2 and -9) in osteoarthritis

Several studies dealing with the pathomechanisms of OA refer to MMP-1, -3, -7, -8, and -13 whereas a smaller number of investigations have pointed out the pathogenic role of gelatinases in OA. These gelatinases are best known for their involvement in pulmonary, myocardial, and neoplastic disease but they are emerging as important proteases implicated in the OA progression. This paper highlights the role of the gelatinases as emerging factors in OA pathogenesis through the regulation of subchondral bone resorption and microvascular invasion. The most significant new findings over the last year that add to our knowledge of the activity of these proteins in OA have been reported.

Injection of AAV2-BMP2 and AAV2-TIMP1 into the nucleus pulposus slows the course of intervertebral disc degeneration in an in vivo rabbit model

BACKGROUND CONTEXT

Intervertebral disc degeneration (IDD) is a common cause of back pain. Patients who fail conservative management may face the morbidity of surgery. Alternative treatment modalities could have a significant impact on disease progression and patients' quality of life.

PURPOSE

To determine if the injection of a virus vector carrying a therapeutic gene directly into the nucleus pulposus improves the course of IDD.

STUDY DESIGN

Prospective randomized controlled animal study.

METHODS

Thirty-four skeletally mature New Zealand white rabbits were used. In the treatment group, L2-L3, L3-L4, and L4-L5 discs were punctured in accordance with a previously validated rabbit annulotomy model for IDD and then subsequently treated with adeno-associated virus serotype 2 (AAV2) vector carrying genes for either bone morphogenetic protein 2 (BMP2) or tissue inhibitor of metalloproteinase 1 (TIMP1). A nonoperative control group, nonpunctured sham surgical group, and punctured control group were also evaluated. Serial magnetic resonance imaging (MRI) studies at 0, 6, and 12 weeks were obtained, and a validated MRI analysis program was used to quantify degeneration. The rabbits were sacrificed at 12 weeks, and L4-L5 discs were analyzed histologically. Viscoelastic properties of the L3-L4 discs were analyzed using uniaxial load-normalized displacement testing. Creep curves were mathematically modeled according to a previously validated two-phase exponential model. Serum samples obtained at 0, 6, and 12 weeks were assayed for biochemical evidence of degeneration.

RESULTS

The punctured group demonstrated MRI and histologic evidence of degeneration as expected. The treatment groups demonstrated less MRI and histologic evidence of degeneration than the punctured group. The serum biochemical marker C-telopeptide of collagen type II increased rapidly in the punctured group, but the treated groups returned to control values by 12 weeks. The treatment groups demonstrated several viscoelastic properties that were distinct from control and punctured values.

CONCLUSIONS

Treatment of punctured rabbit intervertebral discs with AAV2-BMP2 or AAV2-TIMP1 helps delay degenerative changes, as seen on MRI, histologic sampling, serum biochemical analysis, and biomechanical testing. Although data from animal models should be extrapolated to the human condition with caution, this study supports the potential use of gene therapy for the treatment of IDD.

Regulation of osteoarthritis by omega-3 (n-3) polyunsaturated fatty acids in a naturally occurring model of disease

OBJECTIVE

To examine effects of high omega-3 (n-3) polyunsaturated fatty acid (PUFA) diets on development of osteoarthritis (OA) in a spontaneous guinea pig model, and to further characterise pathogenesis in this model. Modern diets low in n-3 PUFAs have been linked with increases in inflammatory disorders, possibly including OA. However, n-3 is also thought to increases bone density, which is a possible contributing factor in OA. Therefore we aim to determine the net influence of n-3 in disease development.

METHOD

OA-prone Dunkin-Hartley (DH) Guinea pigs were compared with OA-resistant Bristol Strain-2s (BS2) each fed a standard or an n-3 diet from 10 to 30 weeks (10/group). We examined cartilage and subchondral bone pathology by histology, and biochemistry, including collagen cross-links, matrix metalloproteinases (MMPs), alkaline phosphatase, glycosaminoglycan (GAG), and denatured type II collagen.

RESULTS

Dietary n-3 reduced disease in OA-prone animals. Most cartilage parameters were modified by n-3 diet towards those seen in the non-pathological BS2 strain - significantly active MMP-2, lysyl-pyridinoline and total collagen cross-links - the only exception being pro MMP-9 which was lower in the BS2, yet increased with n-3. GAG content was higher and denatured type II lower in the n-3 group. Subchondral bone parameters in the DH n-3 group also changed towards those seen in the non-pathological strain, significantly calcium:phosphate ratios and epiphyseal bone density.

CONCLUSION

Dietary n-3 PUFA reduced OA in the prone strain, and most disease markers were modified towards those of the non-OA strain, though not all significantly so. Omega-3 did not increase markers of pathology in either strain.

The role of synovitis in pathophysiology and clinical symptoms of osteoarthritis

Osteoarthritis (OA), one of the most common rheumatic disorders, is characterized by cartilage breakdown and by synovial inflammation that is directly linked to clinical symptoms such as joint swelling, synovitis and inflammatory pain. The gold-standard method for detecting synovitis is histological analysis of samples obtained by biopsy, but the noninvasive imaging techniques MRI and ultrasonography might also perform well. The inflammation of the synovial membrane that occurs in both the early and late phases of OA is associated with alterations in the adjacent cartilage that are similar to those seen in rheumatoid arthritis. Catabolic and proinflammatory mediators such as cytokines, nitric oxide, prostaglandin E(2) and neuropeptides are produced by the inflamed synovium and alter the balance of cartilage matrix degradation and repair, leading to excess production of the proteolytic enzymes responsible for cartilage breakdown. Cartilage alteration in turn amplifies synovial inflammation, creating a vicious circle. As synovitis is associated with clinical symptoms and also reflects joint degradation in OA, synovium-targeted therapy could help alleviate the symptoms of the disease and perhaps also prevent structural progression.

Suppression of matrix metalloproteinase production from synovial fibroblasts by meloxicam in-vitro

The aim of this study was to evaluate the influence of meloxicam on the production of both matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) from human synovial fibroblasts by TNF-α stimulation in-vitro. Synovial fibroblasts (2 times 104 cells/mL) derived from patients with osteoarthritis were stimulated with 20.0 ng mL−1 TNF-α in the presence of various concentrations of meloxicam. After 24 h, the culture supernatants were obtained and assayed for MMP-1, MMP-2, MMP-3, MMP-13, TIMP-1 and TIMP-2 by ELISA. mRNA expression for MMPs and TIMPs in 4-h-cultured cells were examined by real-time polymerase chain reaction. Transcriptional factor (NF-κB and AP-1) activation in 2-h-cultured cells was also examined by ELISA. Meloxicam could suppress MMP production in a dose-dependent manner. The minimum concentration of the agent that showed significant suppression was 0.6 times 10−6  m for MMP-1, MMP-2 and MMP-3, and 1.3 times 10−6  m for MMP-13. The ability of synovial fibroblasts to produce TIMPs was also suppressed by meloxicam as in the case of MMP production. Addition of meloxicam into synovial fibroblast cultures inhibited dose-dependently mRNA expression for MMPs and TIMPs, which were increased by TNF-α stimulation, through the suppression of NF-κB and AP-1 activation. The suppressive effect of meloxicam on the production of MMPs and TIMPs may partly be involved in attenuation of the clinical conditions of osteoarthritis and rheumatoid arthritis.

Treatment with ephrin B2 positively impacts the abnormal metabolism of human osteoarthritic chondrocytes

Introduction

Members of the ephrin system, the ephrin receptor erythropoietin-producing hepatocellular B4 (EphB4) and its specific ligand, ephrin B2, appear to be involved in the bone remodelling process. We recently showed that their interaction inhibits the resorptive activity of human osteoarthritic (OA) subchondral bone osteoblasts. Hence, we further investigated the possible implication of these ephrin members on the catabolic/anabolic activities of human OA chondrocytes.

Methods

EphB4 receptor and ephrin B2 levels were determined by quantitative PCR and immunohistochemistry, and the effects of ephrin B2 on the expression/production of factors involved in the OA process.

Results

EphB4 receptors and ephrin B2 ligands are expressed and produced by human normal and OA chondrocytes. Ephrin B2 protein was found at similar levels in both cartilage types, whereas EphB4 receptor expression (P < 0.0001) and production (P < 0.01) levels were significantly increased in OA chondrocytes/cartilage. Ephrin B2 treatment significantly inhibited the interleukin (IL)-1beta, IL-6, matrix metalloproteinase-1 (MMP-1), MMP-9, MMP-13, and proteinase-activated receptor-2 (PAR-2) gene expression levels, whereas MMP-2 was unaffected, and significantly increased collagen type II, a cartilage specific macromolecule. It also inhibited the IL-1beta stimulated protein production of IL-6, MMP-1 and MMP-13.

Conclusions

Our study is the first to provide data on the presence and role of ephrin B2/EphB4 receptors in human chondrocytes/cartilage. Data showed that ephrin B2 treatment positively impacts the abnormal metabolism of OA cartilage by inhibiting important catabolic factors involved in this disease at the same time as increasing anabolic activity.

Bilateral chondrolysis of the hip following liver transplantation

A 32-year-old woman with bilateral hip chondrolysis diagnosed 2 years following allogeneic liver transplantation is described. Severe osteoarthritis was demonstrated on physical examination, serial radiographs and magnetic resonance imaging. Only four cases of chondrolysis in solid organ recipients have been described in the literature.

Evaluation of serum chondroitin sulfate and hyaluronan: biomarkers for osteoarthritis in canine hip dysplasia

Hip dysplasia (HD) is one of the most important bone and joint diseases in dogs. Making the radiographic diagnosis is sometime possible when the disease has markedly progressed. Chondroitin sulfate (CS) and hyaluronan (HA) are the most important cartilage biomolecules that are elevated in the serum taken from dogs with osteoarthritis. The serum CS and HA can be detected by an ELISA technique, with using monoclonal antibodies against CS epitope 3B3 and WF6 and the HA chain as the primary antibodies. The aim of this study was to compare the levels of serum CS (both epitopes) and HA in non-HD and HD dogs. All 123 dogs were categorized into 2 groups. The non-HD group was composed of 98 healthy dogs, while the HD group was comprised of 25 HD dogs. Blood samples were collected for analyzing the serum CS and HA levels with using the ELISA technique. The results showed that the average serum level of the CS epitope WF6 in the HD group (2,594 ± 3,036.10 ng/ml) was significantly higher than that in the non-HD group (465 ± 208.97 ng/ml) (p < 0.01) while the epitope 3B3 in the HD group (105 ± 100.05 ng/ml) was significantly lower than that in the non-HD group (136 ± 142.03 ng/ml) (p < 0.05). The amount of serum HA in the HD group (134.74 ± 59.71 ng/ml) was lower than that in the non HD group (245.45 ± 97.84 ng/ml) (p < 0.05). The results indicate that the serum CS and HA levels might be used as biomarkers for osteoarthritis in HD dogs.

Increased level of cytokines and matrix metalloproteinases in osteoarthritic subchondral bone

OBJECTIVE

The aim of this study was to investigate the expression of several cytokines, matrix metalloproteinases (MMPs), and tissue inhibitor of matrix metalloproteinases (TIMP)-1 in osteoarthritis (OA) and control sera and different joint tissues.

METHODS

Serum, synovial fluid, cartilage, synovial and subchondral bone tissues were examined in OA and control subjects. The protein level of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1alpha, IL-8, IL-10 and MMP-2, MMP-3, MMP-9, and TIMP-1 were measured by immunoanalysis.

RESULTS

Serum levels of TNF-alpha, MMP-3 and -9 were significantly higher in OA patients than in controls. Conversely, serum IL-10 was decreased in OA patients. CRP was elevated when compared to healthy controls and decreased significantly 6 months after the surgery. In contrast to control samples, OA cartilage and synovium revealed significantly higher MMP-2, -3, -9 and IL-10. IL-1alpha was significantly higher in OA cartilage and IL-8 in OA synovium. Interestingly, MMP-3, -9, TIMP-1 and all tested cytokines were up-regulated in OA subchondral bone.

DISCUSSION

This study demonstrates pro-inflammatory condition of OA pathology and supports the idea that vascularized subchondral region may increase the synthesis of cytokines and MMPs leading to degradation of adjacent cartilage.