No association between markers of inflammation and osteoarthritis of the hands and knees

Association of peripheral inflammatory indicators with osteoarthritis risk

Objectives

Numerous studies have established the role of inflammation in osteoarthritis (OA) progression, yet limited research explores the association between systemic inflammatory indicators and pre-diagnosis OA risk. This study aimed to investigate the association between peripheral inflammatory indicators and the risk of OA using data from the UK Biobank.

Methods

The study analyzed data from 417,507 participants in the UK Biobank, including neutrophil count, lymphocyte count, monocyte count, platelet count, and C-reactive protein meter. Additionally, derived ratios such as NLR(neutrophils-lymphocytes ratio), PLR(Platelets-lymphocytes ratio), SII(systemic immune-inflammation index), and LMR (lymphocytes-monocytes ratio) were examined. Cox proportional hazards models and restricted cubic spline models were used to assess both linear and nonlinear associations.

Results

Over a mean follow-up period of 12.7 years, a total of 49,509 OA events were identified. The findings revealed that CRP (HR:1.06, 95%CI:1.05-1.07), NLR (HR:1.02, 95%CI:1.01-1.03), PLR (HR:1.02, 95%CI:1.01-1.03), and SII (HR:1.03, 95%CI:1.01-1.04) were associated with an increased risk of OA, while LMR (HR:0.97, 95%CI:0.96-0.99) showed a significant negative correlation with OA risk. Subgroup analyses further emphasized that these associations were significant across most of the population. Although neutrophils, lymphocytes, monocytes, and platelets showed a nominal association with the risk of OA, the results were unreliable, especially for specific joint OA.

Conclusion

The study provides evidence of a significant association between elevated peripheral inflammatory indicators and OA risk. These findings underscore the importance of low-grade chronic inflammation in OA development. The potential clinical utility of these indicators as early predictors of OA is suggested, warranting further exploration.

The Significant Role of Alcohol in the Relationship between C-Reactive Protein and Self-Reported Osteoarthritis

BACKGROUND

Despite the known inflammatory nature of osteoarthritis (OA) and the established role of C-reactive protein (CRP) as an inflammation marker, the influence of alcohol consumption on the CRP-OA relationship remains uncertain, with previous research providing conflicting results.

OBJECTIVES

This study aims to examine the potential moderating effect of alcohol on the association between CRP concentrations and self-reported OA.

METHODS

We conducted a cross-sectional study involving 50,259 participants, all data collected from NHANES between 2005-2010 and 2015-2018. A multivariable logistic regression model was used to analyze the relationship between CRP and OA.

RESULTS

We found a nonsignificant positive association between CRP concentration and prevalence of self-reported OA after adjusting for covariates in the raw dataset or 5 multiple imputed datasets. In the stratified analysis by alcohol drinking, for every 10 mg/L higher in CRP concentration, the prevalence of self-reported OA was higher by 13 % in nondrinkers (P = 0.007, adjusted for covariates). Conversely, for every 10 mg/L higher in CRP concentration, the prevalence of self-reported OA was lower by 59 % in drinkers (P = 0.005, adjusted for covariates). Furthermore, we discovered that the directions of the association between CRP concentrations (10 mg/L) and prevalence of self-reported OA [odds ratio (OR) < 1 in the drinking subgroup and OR > 1 in the no-drinking subgroup] were stable in both the main and sensitivity analyses. The significant interaction between CRP concentration and alcohol drinking on the prevalence of self-reported OA was shown in most of our analyses (P-interaction < 0.05).

CONCLUSION

Alcohol consumption may be an interaction factor between CRP and self-reported OA. To our knowledge, our findings are the first to highlight the importance of incorporating analysis of alcohol consumption differences into future studies of CRP and self-reported OA.

Novel Therapeutic Mechanism of Adipose-Derived Mesenchymal Stem Cells in Osteoarthritis via Upregulation of BTG2

BACKGROUND

Osteoarthritis (OA) is a debilitating and degenerative joint disease, which is characterized by progressive destruction of articular cartilage. Mesenchymal stem cells (MSCs) have been implicated in the treatment of OA. However, the function of adipose-derived MSCs (AD-MSCs) in OA and its underlying mechanism remain obscure.

AIM

We aimed to explore the function of AD-MSCs in OA and investigate its potential regulatory mechanism.

METHODS

A guinea pig model of OA was constructed. AD-MSCs injected into the articular cavity of OA guinea pigs were viewed by in vivo bioluminescence imaging. The effect of AD-MSCs on the gonarthritis of OA guinea pigs was evaluated through both macroscopic and microscopic detections. The detailed molecular mechanism was predicted by GEO databases and bioinformatics tools and then verified via mechanism experiments, including ChIP assay, DNA pulldown assay, and luciferase reporter assay.

RESULTS

AD-MSCs had a significant positive therapeutic effect on the gonarthritis of the OA model, and the overall effects of it was better than that of sodium hyaluronate (SH). B-cell translocation gene 2 (BTG2) was significantly downregulated in the articular cartilage of the OA guinea pigs. Furthermore, BTG2 was positively regulated by Krüppel-like factor 4 (KLF4) in AD-MSCs at the transcriptional level. AD-MSCs performed an effect on KLF4 expression at the transcriptional levels.

CONCLUSION

AD-MSCs suppresses OA progression through KLF4-induced transcriptional activation of BTG2. Our findings revealed an AD-MSCs-dominated therapeutic method for OA.

Frequency, pattern, and associations of generalized osteoarthritis among Nigerians with knee osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a common degenerative condition leading to significant pain, functional limitation, and economic loss. Generalized OA (GOA) is associated with greater morbidity and accounts for 5-25% of total OA cases depending on definition used. This paper aims to determine the frequency and pattern of GOA, compare clinical and laboratory parameters of GOA and non-GOA subjects, then identify independent associations of GOA among Nigerians with knee OA.

METHODS

A cross-sectional study of 180 knee OA patients with knee and generalized OA defined using ACR criteria. Questionnaire administration was followed by physical examination and appropriate radiographs. Data was summarized using tables and figures. Multivariate regression was done to identify independent GOA associations with statistical significance p<0.05. Ethical approval was obtained for the study.

RESULTS

There were 180 participants with mean age 59.7±9.1 years. Twenty-eight patients (15.6%) had GOA of which 26 were female. The hip/knee/spine pattern was the commonest while hand OA was rare. Comparisons showed that GOA patients were significantly older with longer pain duration, higher pain score, more Heberden's nodes, and greater fatigue. There were no significant differences between both groups in levels of inflammatory markers and other laboratory parameters. Further analysis identified joint stiffness as the only independent association of GOA (OR 3.34, p=0.01).

CONCLUSION

A 15.6% frequency of GOA was identified among knee OA sufferers with the hip/knee/spine pattern most frequent. Nigerians with GOA are predominantly females with a large joint phenotype. Joint stiffness was the only independent association of GOA observed. Key Points • Generalized osteoarthritis occurs in 15.6% of Nigerian patients with knee osteoarthritis. • Females are predominantly affected with a large joint phenotype involving the hip/knee/spine. • Joint stiffness is an independent association of generalized osteoarthritis.

Increased adiponectin levels are associated with higher radiographic scores in the knee joint, but not in the hand joint

Several studies have evaluated the association between serum adiponectin levels and knee and hand osteoarthritis (OA); mixed results have been reported. We investigated the relationship between OA and serum adiponectin levels according to the radiographic features of knee and hand OA. A total of 2402 subjects was recruited from the Dong-gu Study. Baseline characteristics were collected via a questionnaire, and X-rays of knee and hand joints were scored using a semi-quantitative grading system. The relationship between serum adiponectin levels and radiographic severity was evaluated by linear and logistic regression analysis. Subjects in the higher serum adiponectin levels tertiles were older and had a lower body mass index (BMI) than those in the lower tertiles. Regarding knee joint scores, serum adiponectin levels was positively associated with the total (P < 0.001), osteophyte (P = 0.003), and joint space narrowing (JSN) scores (P < 0.001) after adjustment for age, sex, BMI, smoking, alcohol consumption, education, and physical activity. In terms of hand joint scores, no association was found between serum adiponectin levels and the total, osteophyte, JSN, subchondral cyst, sclerosis, erosion, or malalignment score after the above-mentioned adjustments. Similarly, subjects with serum adiponectin levels above the median had higher total radiographic scores in the knee joints, but not in the hand joints, after adjustment. An increased serum adiponectin levels was associated with a higher radiographic score in the knee joint, but not in the hand joint, suggesting the involvement of different pathophysiologic mechanisms in the development of OA between those joints.

The association of the progression of knee osteoarthritis with high-sensitivity CRP in community-dwelling people-the Yakumo study

OBJECTIVE

We aimed to investigate the relationship between high-sensitivity CRP (hs-CRP) levels and the knee osteoarthritis (KOA) status and whether high hs-CRP levels predict the progression of clinical KOA in community-dwelling people.

METHODS

We enrolled 247 subjects (male, n = 99; female, n = 148) who participated in the "Yakumo study" at least twice from 2003 to 2008. The KOA was evaluated by knee X-ray using the knee osteoarthritis computer-aided diagnosis (KOACAD) measurement system to obtain the mJSW, the size of the osteophyte area (OPA), and femorotibial angle (FTA). The pain intensity of the knee joint was measured using a visual analog scale (VAS, 0-100). First, we performed a multiple regression analysis to assess the relationship between the initial hs-CRP and mJSW, OPA, FTA, and VAS. Second, we examined the correlated coefficients between the amount of change hs-CRP and radiographic progressions and VAS changes. Third, we divided into two groups. Group H elevated hs-CRP levels (> 0.1 mg/dl). We picked up the subject matched to Group H according to BMI, age, sex, and medial mJSW at baseline in a 1:1 ratio; these participants were classified as the control group (Group L). The Mann-Whitney U test was used to compare the demographic data between the two groups. P values of < 0.05 were considered to indicate statistical significance.

RESULTS

The initial hs-CRP was a significant explanatory factor for mJSW and VAS change in multiple regression analysis. The change of VAS value negatively correlated with the change of hs-CRP. Besides, the change of hs-CRP did not correlate with the radiographical change. Among these subjects, 55 had elevated hs-CRP levels (> 0.1 mg/dl) (Group H). Among the 192 subjects whose hs-CRP levels were ≤ 0.1 mg/dl, 55 subjects were matched to patients in Group H according to the age, sex, BMI, and average minimum joint space width (mJSW) at baseline and were used as a control group (Group L). The narrowing of the medial mJSW and the amount of change in OPA in group H were significantly greater than group L. The amount of change in FTA and VAS scores did not differ between the two groups.

CONCLUSION

Hs-CRP levels would be significantly associated with the progression of knee osteoarthritis. Key Points • We investigated the relationship between hs-CRP levels and the progression and the pain of osteoarthritis knee. • We used a KOACAD system, which can measure the medial and lateral joint space narrowing, osteophyte, and femoral-tibia angle from plain radiographs automatically. • Hs-CRP levels were significantly associated with the progression of knee osteoarthritis.

Association of Visceral Adiposity With Pain but Not Structural Osteoarthritis

OBJECTIVE

Osteoarthritis (OA) and pain are both made more severe by low-grade inflammation. This study was undertaken to examine whether visceral fat, a major source of inflammatory cytokines and adipokines, is associated with an increased risk of knee OA or musculoskeletal pain.

METHODS

Subjects in the Multicenter Osteoarthritis Study cohort, who were age 50-79 years and had or were at high risk of knee OA, underwent whole-body dual x-ray absorptiometry (DXA) at baseline. At baseline, 30 months, and 60 months radiographs and magnetic resonance images (MRIs) of the knees were obtained, and patients were asked to score the severity of their knee pain and to identify sites of joint pain using a body homunculus. Baseline DXA scans were used to measure total body fat and visceral and subcutaneous fat in the torso. The association of fat depot size with structural outcomes (incident radiographic OA and cartilage loss and synovitis on MRI) and with pain outcomes (worsening knee pain, number of painful joints, and widespread pain) was assessed. Regression analyses were adjusted for age, sex, race, education level, smoking status, physical activity, body mass index (BMI), and depressive symptoms.

RESULTS

Of the 2,961 participants at baseline, 60.7% were women. The mean age was 62.5 years and mean BMI was 30.5 kg/m² . After adjustment for covariates, no fat measures were associated with any structural outcomes. However, total and visceral, but not subcutaneous, fat were positively associated with worsening knee pain (P = 0.0005 for total fat and P = 0.007 for visceral fat) and widespread pain (P = 0.001 for total fat and P = 0.02 for visceral fat), and the amount of visceral fat was associated with the number of painful joints (P = 0.07).

CONCLUSION

Our findings indicate that visceral fat is associated with an increased risk of musculoskeletal and widespread pain.

Methodological quality of cohort study on rheumatic diseases in China: A systematic review

Objective

To evaluate systematically the quality of the cohort studies on rheumatic diseases in China.

Methods

Relevant databases were searched to find cohort studies on rheumatic diseases in China, and the basic information included in the literature was extracted and analyzed. Chinese and English literature were then compared with regard to methodological quality, according to the Newcastle–Ottawa Scale (NOS).

Results

In total, we included 46 cohort studies, with 19 studies published in English and 27 studies published in Chinese. With regard to the basic characteristics of the literature, 78.26% of the studies were published in the past four years; 16 studies were associated with hyperuricemia, followed by eight studies involving systemic lupus erythematosus. The sample size of the studies in Chinese was lower than that in English studies (P< 0.05). The English literature was superior to the Chinese literature in terms of informed consent, ethical review and selection of statistical analysis methods. The methodology quality of the 46 included studies showed that the English and Chinese NOS scores were 5.59 ± 1.25 and 6.06 ± 1.11, respectively, and the difference was significant (P< 0.01). The “representativeness of the exposed group”, “demonstration that outcome of interest was not present at start of study”, and the “adequacy of follow up of cohorts” scores were relatively low in Chinese and English studies. The score for “was follow-up long enough for outcomes to occur” item in English was higher than that in the Chinese studies; however, the “study controls for the most important factor” score for Chinese papers was better than that for the English papers.

Conclusion

The Chinese rheumatic disease cohort studies started late, with a small sample size and fewer types of rheumatism. The quality of Chinese studies was better than English studies, and all reports were insufficient. In particular, “selecting exposed groups”, “controlling the outcomes before study implementation” and “adequacy of follow-up” needed improvement.

Possible association between circulating CTRP3 and knee osteoarthritis in postmenopausal women

BACKGROUND

Osteoarthritis (OA) is considered as one of the most common cause of chronic pain and functional disabilities in the elderly.

AIM

To examine serum levels of complement-C1q TNF-related protein 3 (CTRP3) in postmenopausal women with knee OA.

METHODS

A population-based cross-sectional study was performed in women who complained of chronic knee pain. All subjects were followed by clinical and weight-bearing bilateral anteroposterior radiographical examinations. The Kellgren and Lawrence (K&L) score was used for knee OA classification. Two groups of postmenopausal women were chosen to investigate CTRP3 as an OA marker who had the K&L score ≥ 3 as a case group and K&L ≤ 1 as a control group. Serum levels of CTRP3 were measured in two groups.

RESULTS

According to K&L classification, 36 subjects with knee OA and 54 age-matched without or mild OA were selected. After adjusting the obtained data for taking NSAID drugs, the concentration of Ln CTRP3 in serum of patients with OA was lower compared to control group [mean ± SE, (0.39 ± 0.05 ng/ml vs. 0.48 ± 0.03 ng/ml, respectively, p = 0.04)].

DISCUSSION

There is a possible role for CTRP3 as an anti-inflammatory mediator in knee OA in postmenopausal women.

CONCLUSIONS

Our results indicate an association between CTRP3 and knee OA. However, a much more robust study is required to draw that circulating CTRP3 could be a clinical marker for osteoarthritis.

Body Mass Index Mediates the Association between Dietary Fiber and Symptomatic Knee Osteoarthritis in the Osteoarthritis Initiative and the Framingham Osteoarthritis Study

Background

Dietary fiber reduces body weight and inflammation in clinical trials. It is unclear whether body mass index (BMI) and inflammation might explain the observed association between higher fiber intake and the lower risk of symptomatic knee osteoarthritis (SXKOA).

Objectives

We quantified the extent to which BMI and inflammation influenced the relation between dietary fiber and SXKOA.

Methods

We used longitudinal data from the Osteoarthritis Initiative (OAI) and the Framingham Offspring Osteoarthritis Study. At baseline of each study, men and women (mean age: 61 y) with or at risk of knee osteoarthritis were followed for 48 mo in the OAI. Adults (mean age: 53 y) were followed for 9.5 y in the Framingham study. Dietary fiber intake was estimated using a validated food-frequency questionnaire. Measured weight and height were used to calculate BMI. Serum high-sensitivity C-reactive protein (CRP) was measured in the Framingham study only. Incident SXKOA was defined as new onset of a combination of knee pain and radiographic osteoarthritis. We applied marginal structural models to quantify the mediation through BMI in the OAI and the sequential mediation through BMI and CRP in the Framingham study.

Results

Incident SXKOA occurred in 861 knees among 2876 persons in the OAI and in 143 knees among 971 persons in the Framingham study. In persons whose fiber intake was ≥21 g/d compared with those with intakes <21 g/d, the OR (95% CI) was 0.70 (0.53, 0.91) for the overall association with SXKOA and was 0.93 (0.92, 0.95) for the mediation via BMI (per kg/m2) in the OAI. In the Framingham study, the overall association was 0.57 (0.30, 1.09), the mediation through BMI (via BMI and the influence of BMI on CRP) was 0.94 (0.85, 1.02), and the mediation through CRP (per milligram per liter) was 0.99 (0.84, 1.19).

Conclusion

Our findings suggest that the inverse association of fiber intake and the risk of incident symptomatic knee osteoarthritis is partially mediated by BMI.

New insights into the natural course of knee osteoarthritis: early regulation of cytokines and growth factors, with emphasis on sex-dependent angiogenesis and tissue remodeling. A pilot study

OBJECTIVE

This study was conducted to identify cytokine profiles associated with radiographic phenotypes of knee osteoarthritis (rKOA) with a focus on early stage of the disease.

METHODS

The pilot population study involved 60 middle-aged patients (mean age 50 ± 7.3y.). Standardized weight-bearing anteroposterior and axial radiographs were used to assess rKOA severity in tibiofemoral (TFJ) of patellofemoral joint (PFJ) by grading system (grades 0-3). Luminex (xMAP^®) technology was used to simultaneously assess 60 biomarkers (BMs).

RESULTS

Several pathways of angiogenic (CXCL10/IP-10, FGF1/2, PDGF-AA/BB, ANG1, RANTES), tissue remodeling/fibrosis (MMP1/3, TIMP2/3/4, TGFβ), and fat tissue (leptin) BMs associated with rKOA severity already in very early phase (grade 1). We identified several sets of cytokines as key markers of early knee osteoarthritis (KOA) predicting radiographic features in logistic-regression models (AUC = 0.80-0.97). Marked sex-specificity of rKOA course was detected: upregulation of angiogenesis dominated in females, whereas the activation of tissue remodeling was dominant in males. Several of these shifts, e.g., decrease of CXCL10/IP-10, took place only in grade 1 KOA and disappeared or reversed in later stages. OA of different knee-joint compartments has distinct profiles of cytokines. A broad list of BMs (TIMP2/3/4, MMP1/3, TGFβ1/2, vWF-A2, sE-selectin and leptin) associated with OA in the PFJ.

CONCLUSION

Our results demonstrate that substantial and time-limited shifts in the angiogenic and TIMP/MMP systems occur in the early stage of KOA. Our study findings highlight the sex-, grade- and compartment-dependent shifts in above processes. The data may contribute to the individualized prevention of KOA in the future.

Prospective associations of C-reactive protein (CRP) levels and CRP genetic risk scores with risk of total knee and hip replacement for osteoarthritis in a diverse cohort

OBJECTIVE

To examine associations of high-sensitivity C-reactive protein (CRP) levels and polygenic CRP genetic risk scores (GRS) with risk of end-stage hip or knee osteoarthritis (OA), defined as incident total hip (THR) or knee replacement (TKR) for OA.

DESIGN

This study included a cohort of postmenopausal white, African American, and Hispanic women from the Women's Health Initiative. Women were followed from baseline to date of THR or TKR, death, or December 31, 2014. Medicare claims data identified THR and TKR. Hs-CRP and genotyping data were collected at baseline. Three CRP GRS were constructed: 1) a 4-SNP GRS comprised of genetic variants representing variation in the CRP gene among European populations; 2) a multilocus 18-SNP GRS of genetic variants significantly associated with CRP levels in a meta-analysis of genome-wide association studies; and 3) a 5-SNP GRS of genetic variants significantly associated with CRP levels among African American women.

RESULTS

In analyses conducted separately among each race and ethnic group, there were no significant associations of ln hs-CRP with risk of THR or TKR, after adjusting for age, body mass index, lifestyle characteristics, chronic diseases, hormone therapy use, and non-steroidal anti-inflammatory drug use. CRP GRS were not associated with risk of THR or TKR in any ethnic group.

CONCLUSIONS

Serum levels of ln hs-CRP and genetically-predicted CRP levels were not associated with risk of THR or TKR for OA among a diverse cohort of women.

The value of high-sensitivity C-reactive protein in hand and knee radiographic osteoarthritis: data from the Dong-gu Study

Due to the inconsistent association between high-sensitivity C-reactive protein (hs-CRP) and osteoarthritis (OA), we evaluated the relationship between hs-CRP and various radiographic findings in older adults with OA. This cross-sectional study recruited 2376 participants from the population-based Dong-gu cohort. The scores of radiographic features in OA on X-rays of the knees and hands were computed using a semi-quantitative grading system. The hs-CRP levels were measured using a particle-enhanced immunonephelometry assay. Correlations showing the relationship between hs-CRP and OA were calculated using multiple linear correlation analysis. The hs-CRP levels were significantly higher in older subjects (p < 0.001), those with a higher body mass index (BMI) (p < 0.001), current smokers (p < 0.001), current alcohol drinkers (p = 0.011), those who were less physically active (p = 0.002), and those with a lower level of education (p = 0.043). After adjusting for BMI and other confounders, the total OA scores (knee, p = 0.022; hand, p = 0.029) and sclerosis score (knee, p = 0.007; hand, p = 0.030) in the knees and hands were all significantly positively correlated with hs-CRP. A significant association was also observed between hs-CRP and hand erosion score (p = 0.045), hand malalignment score (p = 0.015), and tibial attrition score (p = 0.039). In this large cross-sectional study, a higher hs-CRP level was significantly associated with radiographic OA severity. Of the various types of radiographic damage, all of sclerosis, erosion, and malalignment were significantly associated with hs-CRP levels.

Rapamycin Maintains the Chondrocytic Phenotype and Interferes with Inflammatory Cytokine Induced Processes

Osteoarthritis (OA) is hallmarked by a progressive degradation of articular cartilage. Besides risk factors including trauma, obesity or genetic predisposition, inflammation has a major impact on the development of this chronic disease. During the course of inflammation, cytokines such as tumor necrosis factor-alpha(TNF-α) and interleukin (IL)-1β are secreted by activated chondrocytes as well as synovial cells and stimulate the production of other inflammatory cytokines and matrix degrading enzymes. The mTORC1 inhibitor rapamycin is a clinical approved immunosuppressant and several studies also verified its chondroprotective effects in OA. However, the effect of blocking the mechanistic target of rapamycin complex (mTORC)1 on the inflammatory status within OA is not well studied. Therefore, we aimed to investigate if inhibition of mTORC1 by rapamycin can preserve and sustain chondrocytes in an inflammatory environment. Patient-derived chondrocytes were cultured in media supplemented with or without the mTORC1 inhibitor rapamycin. To establish an inflammatory environment, either TNF-α or IL-1β was added to the media (=OA-model). The chondroprotective and anti-inflammatory effects of rapamycin were evaluated using sulfated glycosaminoglycan (sGAG) release assay, Caspase 3/7 activity assay, lactate dehydrogenase (LDH) assay and quantitative real time polymerase chain reaction (PCR). Blocking mTORC1 by rapamycin reduced the release and therefore degradation of sGAGs, which are components of the extracellular matrix secreted by chondrocytes. Furthermore, blocking mTORC1 in OA chondrocytes resulted in an enhanced expression of the main chondrogenic markers. Rapamycin was able to protect chondrocytes from cell death in an OA-model shown by reduced Caspase 3/7 activity and diminished LDH release. Furthermore, inhibition of mTORC1 preserved the chondrogenic phenotype of OA chondrocytes, but also reduced inflammatory processes within the OA-model. This study highlights that blocking mTORC1 is a new and promising approach for treating OA. Low side effects make rapamycin an attractive implementation to existing therapeutic strategies. We showed that rapamycin's chondroprotective property might be due to an interference with IL-1β triggered inflammatory processes.

Immunogenicity and immunomodulatory effects of the human chondrocytes, hChonJ

Background

Invossa™ (TissueGene-C) is a cell and gene therapy for osteoarthritis. It is composed of primary human chondrocytes (hChonJ cells) and irradiated human chondrocytes modified to express TGF-β1 (hChonJb#7 cells). The hChonJ cells were isolated from a polydactyly donor, and TGF-β1 cDNA was delivered to the cells, generating hChonJb#7 cells. Since the cells are allogeneic, the concern of immune response against cells has been raised. In this study, we investigated the immunogenicity of allogenic human chondrocyte, hChonJ cells.

Methods

The immunological properties of hChonJ cells were investigated through the analysis of surface marker expression and the effect on allogeneic T cell proliferation. Flow cytometry and RT-PCR analysis were performed to analyze the surface marker expression related to immune response, such as major histocompatibility complex (MHC) class I, class II, T cell co-stimulatory molecules and T cell co-inhibitory molecules. A mixed lymphocyte reaction (MLR) was conducted to evaluate how allogeneic T cells would respond to hChonJ cells.

Results

We observed that hChonJ cells did not express MHC class II and T cell co-stimulatory molecules, but expressed T cell co-inhibitory molecule PD-L2. IFN-γ treatment induced the expression of PD-L1, and up-regulated the expression of PD-L2. Also, we observed that hChonJ cells did not stimulate T cell proliferation from a MHC-mismatched donor. Further, they could suppress the proliferation of activated T cells. We also observed that the blockade of PD-L1 and/or PD-L2 with specific neutralizing antibody could lead to the restoration of allo-reactive T cell proliferation.

Conclusions

We showed that hChonJ cells were not immunogenic but immunosuppressive, and that this phenomenon was mediated by co-inhibitory molecules PD-L1 and PD-L2 on hChonJ cells in a contact-dependent manner.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1547-8) contains supplementary material, which is available to authorized users.

Systemic inflammation and painful joint burden in osteoarthritis: a matter of sex?

OBJECTIVE

We investigated the association between serum levels of C-reactive protein (CRP) and the extent of multijoint pain among individuals with hip/knee osteoarthritis (OA) and determined whether the association differs by sex.

DESIGN

Serum CRP and cartilage oligomeric matrix protein (COMP) were determined by enzyme-linked immunosorbent assay (ELISA) in 189 individuals (101 female, 88 male) scheduled for total hip/knee arthroplasty for OA. Patients indicated on a homunculus all painful joints; a summed count was derived. A series of negative binomial regression models was used to investigate the cross-sectional association between painful joint count (outcome) and serum CRP concentrations, adjusting for age, sex, body mass index (BMI), comorbidity count and COMP. An interaction between sex and these biomarkers was tested.

RESULTS

Mean age: 66 among women, 65 among men. Women had higher mean joint count (3.7 vs 2.5, P < 0.01; 4+ joint count reported by 37% women, 25% men). Median CRP concentration was higher in women (15.4 mg/l vs 9.3, P = 0.07). From adjusted analyses, the effects of both ln(CRP) and ln(COMP) were modified by sex (P < 0.05). Increasing ln(CRP) was associated with greater painful joint count among women, but not men.

CONCLUSIONS

There may be a dose-response association between painful joint burden in OA and systemic inflammation, and it appears the association is sex-specific, which may in part explain inconsistent findings in the literature. Our results underline the importance of showing sex-specific associations in OA, especially when studying the influence of inflammation.

Investigating the Causal Relationship of C-Reactive Protein with 32 Complex Somatic and Psychiatric Outcomes: A Large-Scale Cross-Consortium Mendelian Randomization Study

BACKGROUND

C-reactive protein (CRP) is associated with immune, cardiometabolic, and psychiatric traits and diseases. Yet it is inconclusive whether these associations are causal.

METHODS AND FINDINGS

We performed Mendelian randomization (MR) analyses using two genetic risk scores (GRSs) as instrumental variables (IVs). The first GRS consisted of four single nucleotide polymorphisms (SNPs) in the CRP gene (GRSCRP), and the second consisted of 18 SNPs that were significantly associated with CRP levels in the largest genome-wide association study (GWAS) to date (GRSGWAS). To optimize power, we used summary statistics from GWAS consortia and tested the association of these two GRSs with 32 complex somatic and psychiatric outcomes, with up to 123,865 participants per outcome from populations of European ancestry. We performed heterogeneity tests to disentangle the pleiotropic effect of IVs. A Bonferroni-corrected significance level of less than 0.0016 was considered statistically significant. An observed p-value equal to or less than 0.05 was considered nominally significant evidence for a potential causal association, yet to be confirmed. The strengths (F-statistics) of the IVs were 31.92-3,761.29 and 82.32-9,403.21 for GRSCRP and GRSGWAS, respectively. CRP GRSGWAS showed a statistically significant protective relationship of a 10% genetically elevated CRP level with the risk of schizophrenia (odds ratio [OR] 0.86 [95% CI 0.79-0.94]; p < 0.001). We validated this finding with individual-level genotype data from the schizophrenia GWAS (OR 0.96 [95% CI 0.94-0.98]; p < 1.72 × 10-6). Further, we found that a standardized CRP polygenic risk score (CRPPRS) at p-value thresholds of 1 × 10-4, 0.001, 0.01, 0.05, and 0.1 using individual-level data also showed a protective effect (OR < 1.00) against schizophrenia; the first CRPPRS (built of SNPs with p < 1 × 10-4) showed a statistically significant (p < 2.45 × 10-4) protective effect with an OR of 0.97 (95% CI 0.95-0.99). The CRP GRSGWAS showed that a 10% increase in genetically determined CRP level was significantly associated with coronary artery disease (OR 0.88 [95% CI 0.84-0.94]; p < 2.4 × 10-5) and was nominally associated with the risk of inflammatory bowel disease (OR 0.85 [95% CI 0.74-0.98]; p < 0.03), Crohn disease (OR 0.81 [95% CI 0.70-0.94]; p < 0.005), psoriatic arthritis (OR 1.36 [95% CI 1.00-1.84]; p < 0.049), knee osteoarthritis (OR 1.17 [95% CI 1.01-1.36]; p < 0.04), and bipolar disorder (OR 1.21 [95% CI 1.05-1.40]; p < 0.007) and with an increase of 0.72 (95% CI 0.11-1.34; p < 0.02) mm Hg in systolic blood pressure, 0.45 (95% CI 0.06-0.84; p < 0.02) mm Hg in diastolic blood pressure, 0.01 ml/min/1.73 m2 (95% CI 0.003-0.02; p < 0.005) in estimated glomerular filtration rate from serum creatinine, 0.01 g/dl (95% CI 0.0004-0.02; p < 0.04) in serum albumin level, and 0.03 g/dl (95% CI 0.008-0.05; p < 0.009) in serum protein level. However, after adjustment for heterogeneity, neither GRS showed a significant effect of CRP level (at p < 0.0016) on any of these outcomes, including coronary artery disease, nor on the other 20 complex outcomes studied. Our study has two potential limitations: the limited variance explained by our genetic instruments modeling CRP levels in blood and the unobserved bias introduced by the use of summary statistics in our MR analyses.

CONCLUSIONS

Genetically elevated CRP levels showed a significant potentially protective causal relationship with risk of schizophrenia. We observed nominal evidence at an observed p < 0.05 using either GRSCRP or GRSGWAS-with persistence after correction for heterogeneity-for a causal relationship of elevated CRP levels with psoriatic osteoarthritis, rheumatoid arthritis, knee osteoarthritis, systolic blood pressure, diastolic blood pressure, serum albumin, and bipolar disorder. These associations remain yet to be confirmed. We cannot verify any causal effect of CRP level on any of the other common somatic and neuropsychiatric outcomes investigated in the present study. This implies that interventions that lower CRP level are unlikely to result in decreased risk for the majority of common complex outcomes.

Joint instability leads to long-term alterations to knee synovium and osteoarthritis in a rabbit model

OBJECTIVES

Joint instability is believed to promote early osteoarthritic changes in the knee. Inflammatory reactions are associated with cartilage degradation in osteoarthritis (OA) but their possible synergistic or additive effects remain largely unexplored. The goal of the present study was to investigate the in vivo effects of Botulinum Toxin A (BTX-A) induced joint instability on intraarticular alterations in an otherwise intact rabbit knee joint model.

METHODS

Ten 1-year-old female New Zealand White rabbits (average 5.7 kg, range 4.8-6.6 kg) were randomly assigned to receive three monthly unilateral intramuscular injections of BTX-A (experimental group), or no treatment (control group). After 90 days, all knees were analyzed for specific mRNA levels using RT-qPCR. The synovium and cartilage tissue was assessed for histological alterations using the OARSI scoring system.

RESULTS

Cartilage and synovial histology showed significant higher OARSI scores in the BTX-A group animals compared to the untreated controls and contralateral limbs. There were no differences between the untreated control and the contralateral experimental limbs. Gene expression showed significant elevations for collagen I, collagen III, nitric oxide, TGF-β, IL-1 and IL-6 compared to the healthy controls.

CONCLUSION

BTX-A induced joint instability in a muscle weakness model uniquely leads to alterations in gene expression and histological changes in the synovial membranes and cartilage in otherwise intact knee joints. These results lead to the conclusion that joint instability may promote an inflammatory intraarticular milieu, thereby contributing to the development of OA.

Can we identify patients with high risk of osteoarthritis progression who will respond to treatment? A focus on epidemiology and phenotype of osteoarthritis

Osteoarthritis is a syndrome affecting a variety of patient profiles. A European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis and the European Union Geriatric Medicine Society working meeting explored the possibility of identifying different patient profiles in osteoarthritis. The risk factors for the development of osteoarthritis include systemic factors (e.g., age, sex, obesity, genetics, race, and bone density) and local biomechanical factors (e.g., obesity, sport, joint injury, and muscle weakness); most also predict disease progression, particularly joint injury, malalignment, and synovitis/effusion. The characterization of patient profiles should help to better orientate research, facilitate trial design, and define which patients are the most likely to benefit from treatment. There are a number of profile candidates. Generalized, polyarticular osteoarthritis and local, monoarticular osteoarthritis appear to be two different profiles; the former is a feature of osteoarthritis co-morbid with inflammation or the metabolic syndrome, while the latter is more typical of post-trauma osteoarthritis, especially in cases with severe malalignment. Other biomechanical factors may also define profiles, such as joint malalignment, loss of meniscal function, and ligament injury. Early- and late-stage osteoarthritis appear as separate profiles, notably in terms of treatment response. Finally, there is evidence that there are two separate profiles related to lesions in the subchondral bone, which may determine benefit from bone-active treatments. Decisions on appropriate therapy should be made considering clinical presentation, underlying pathophysiology, and stage of disease. Identification of patient profiles may lead to more personalized healthcare, with more targeted treatment for osteoarthritis.

Is osteoarthritis a metabolic disorder?

BACKGROUND

Obesity is associated with an increased risk of developing osteoarthritis (OA), even in non-weight bearing joints. High levels of adipose tissue-associated inflammation may explain this association.

SOURCES OF DATA AND AREAS OF DEBATE

Published evidence looking at the associations between components of Metabolic Syndrome (MetS) and knee, hip or hand OA and the higher mortality described with knee OA.

EMERGING POINTS

Development of MetS and OA shares a relationship with adipose tissue-associated inflammation. This review supports this inflammatory pathway being part of the shared mechanism behind obesity as a risk factor for OA and the recently described OA-associated increased mortality.

TIMELY AREAS FOR DEVELOPMENT

In an era of an obesity epidemic, this review identifies a need for well-designed cohort studies assessing early metabolic changes in populations at high risk of OA and MetS, and to identify risk factors for increased mortality in patients with OA.

Effect of muscle weakness and joint inflammation on the onset and progression of osteoarthritis in the rabbit knee

OBJECTIVES

Interactions between mechanical and non-mechanical independent risk factors for the onset and progression of Osteoarthritis (OA) are poorly understood. Therefore, the goal of the present study was to investigate the in vivo effects of muscle weakness, joint inflammation and the combination on the onset and progression of OA in a rabbit knee joint model.

MATERIALS AND METHODS

Thirty 1-year-old female New Zealand White rabbits (average 5.7 kg, range 4.8-6.6 kg) were divided into four groups with one limb randomly assigned to be the experimental side: (1) surgical denervation of the vastus lateralis (VL) muscle; (2) muscle weakness induced by intramuscular injection of Botulinum toxin A (BTX-A); (3) intraarticular injection with Carrageenan to induce a transient inflammatory reaction; (4) combination of Carrageenan and BTX-A injection. After 90 days, cartilage histology of the articular surfaces were microscopically analyzed using the Osteoarthritis Research Society International (OARSI) histology scoring system.

RESULTS

VL denervation resulted in significantly higher OARSI scores in the patellofemoral joint (group 1). BTX-A administration resulted in significant cartilage damage in all four compartments of the knee (group 2). Carrageenan did not cause significant cartilage damage. BTX-A combined with Carrageenan lead to severe cartilage damage in all four compartments.

CONCLUSION

Muscle weakness lead to significant OA in the rabbit knee. A transient local inflammatory stimulus did not promote cartilage degradation nor did it enhance OA progression when combined with muscle weakness. These results are surprising and add to the literature the conclusion that acute inflammation is probably not an independent risk factor for OA in this rabbit model.

Identifying and treating preclinical and early osteoarthritis

Studies suggest that many persons with painful osteoarthritis already have extensive structural disease including malalignment, which may preclude successful stabilization or reversal of disease; this provides a strong rationale for developing strategies to prevent disease or to identify and treat it early. This article reviews a variety of approaches likely to capture those at high risk of or with early disease. However, given the absence of effective treatments, it is unclear whether structural disease could be successfully slowed or prevented in those with early symptoms or at high risk of disease.

Knee osteoarthritis and frailty: findings from the Multicenter Osteoarthritis Study and Osteoarthritis Initiative

BACKGROUND

Knee osteoarthritis (OA) and frailty are two conditions that are associated with functional limitation and disability in elders, yet their relation to one another is not known.

METHODS

We included participants from two large, multicenter studies enriched with community dwelling older adults with knee OA (Multicenter Osteoarthritis Study and Osteoarthritis Initiative). Knee OA was defined radiographically (ROA) and symptomatically (SOA). Frailty was defined using the Study of Osteoporotic Fracture index as the presence of ≥2 of the following: (i) weight loss >5% between two consecutive visits; (ii) inability to arise from chair five times without support; (iii) poor energy. Cross-sectional and longitudinal associations of knee OA with prevalent and incident frailty, respectively, were examined using binomial regression with robust variance estimation, adjusting for potential confounders.

RESULTS

In the cross-sectional analyses, frailty was more prevalent among participants with ROA (4.39% vs 2.77%; PR 1.60 [1.07, 2.39]) and SOA (5.88% vs 2.79%; PR 1.92 [1. 35, 2.74]) compared with those without ROA or SOA, respectively. In the longitudinal analyses, risk of developing frailty was greater among those with ROA (4.73% vs 2.50%; RR 1.45 [0.91, 2.30]) and SOA (6.30% vs 2.83%; RR 1.66 [1.11, 2.48]) than those without ROA or SOA, respectively.

CONCLUSIONS

Knee OA is associated with greater prevalence and risk of developing frailty. Understanding the mechanisms linking these two common conditions of older adults would aid in identifying novel targets for treatment or prevention of frailty.

"Generalized osteoarthritis": a systematic review

OBJECTIVES

Given the conflicting definitions of "generalized osteoarthritis" (GOA) in the literature, we performed a systematic review of GOA definitions, risk factors, and outcomes.

METHODS

We searched the MEDLINE literature with the terms osteoarthritis, generalized, polyarticular, multiple joint, and multi-joint to obtain articles related to GOA, following evidence-based guidelines. Titles and abstracts of 948 articles were reviewed, with full-text review of 108. Data were extracted based on pre-specified criteria for 74 articles plus 24 identified through bibliographic review (n = 98).

RESULTS

Twenty-four large cohorts (n ~ 30,000) were represented along with numerous clinical series (n ~ 9000), across 22 countries and 60 years (1952-2012). No less than 15 definitions of GOA were given in 30 studies with a stated GOA definition; at least 6 groups used a summed score of joints or radiographic grades. Prevalence estimates based on these GOA definitions were 1-80%, although most were 5-25%. Increased risk and progression of GOA was associated with age, female sex, and genetic/familial factors. Associations with increased body mass index or bone mineral density were not consistent. A study estimated the heritability of GOA at 42%. Collagen biomarker levels increased with the number of involved joints. Increased OA burden was associated with increased mortality and disability, poorer health, and function.

CONCLUSION

While there remains no standard definition of GOA, this term is commonly used. The impact on health may be greater when OA is in more than one joint. A descriptive term, such as multi-joint or polyarticular OA, designating OA of multiple joints or joint groups is recommended.

Associations between biomarkers of joint metabolism, hand osteoarthritis, and hand pain and function: the Johnston County Osteoarthritis Project

OBJECTIVE

To determine the associations between joint metabolism biomarkers and hand radiographic osteoarthritis [(rOA), based on Kellgren Lawrence (KL) grade ≥ 2], symptoms, and function.

METHODS

Cross-sectional data were available for 663 participants (mean age 63 yrs, 63% white, 49% women). Three definitions of hand rOA were considered: (1) a composite measure involving at least 3 hand joints distributed bilaterally with 2 of 3 in the same joint group, including ≥ 1 distal interphalangeal joint, without metacarpophalangeal (MCP) swelling; (2) rOA in at least 1 joint of a group; and (3) number of joints with KL ≥ 2. We assessed hand symptoms and the 15-item Australian Canadian Hand Osteoarthritis Index (AUSCAN; Likert format). We measured serum cartilage oligomeric matrix protein (sCOMP), hyaluronic acid (sHA), carboxy-terminal propeptide of type II collagen, type II collagen degradation product, urinary C-terminal crosslinked telopeptide of type II collagen, and urinary N-terminal crosslinked telopeptide. Linear regression models were performed to assess associations between each biomarker with hand rOA, AUSCAN, and symptoms, adjusting for age, sex, race, current smoking/drinking status, body mass index, and hip and knee rOA.

RESULTS

In adjusted analyses, MCP (p < 0.0001) and carpometacarpal rOA (p = 0.003), and a higher number of hand joints with rOA (p = 0.009), were associated with higher levels of sHA. Positive associations were seen between AUSCAN and hand symptoms and levels of sCOMP (p ≤ 0.003) and sHA (p ≤ 0.048).

CONCLUSION

Hand symptoms and higher AUSCAN scores were independently associated with higher levels of both sCOMP and sHA; hand rOA was associated only with sHA levels.

Is osteoarthritis a mechanical or inflammatory disease?

Traditionally considered "wear and tear" disease, the pathogenic mechanisms of osteoarthritis have not yet been elucidated. The increasing number of articles demonstrating the influence of inflammatory factors in the onset and progression of the disease currently raises great debate in the literature about the importance of each of the factors involved in the disease. Even the choice between the terms "Osteoarthritis" and "Osteoarthrosis" generates controversy, since the first term implies the presence of inflammation as the key generator of the disease, and the latter denotes a degenerative/mechanical causal factor. The aim of this revision article is to promote a debate on the influence of inflammatory factors and mechanical factors in the pathogenesis of OA.

Hand osteoarthritis in relation to mortality and incidence of cardiovascular disease: data from the Framingham heart study

OBJECTIVES

To study whether hand osteoarthritis (OA) is associated with increased mortality and cardiovascular events in a large community based cohort (Framingham Heart Study) in which OA, mortality and cardiovascular events have been carefully assessed.

METHODS

We examined whether symptomatic (≥1 joint(s) with radiographic OA and pain in the same joint) and radiographic hand OA (≥1 joint(s) with radiographic OA without pain) were associated with mortality and incident cardiovascular events (coronary heart disease, congestive heart failure and/or atherothrombotic brain infarction) using Cox proportional hazards models. In the adjusted models, we included possible confounding factors from baseline (eg, metabolic factors, medication use, smoking/alcohol). We also adjusted for the number of painful joints in the lower limb and physical inactivity.

RESULTS

We evaluated 1348 participants (53.8% women) with mean (SD) age of 62.2 (8.2) years, of whom 540 (40.1%) and 186 (13.8%) had radiographic and symptomatic hand OA, respectively. There was no association between hand OA and mortality. Although there was no significant relation to incident cardiovascular events overall or a relation of radiographic hand OA with events, we found a significant association between symptomatic hand OA and incident coronary heart disease (myocardial infarction/coronary insufficiency syndrome) (HR 2.26, 95% CI 1.22 to 4.18). The association remained after additional adjustment for pain in the lower limb or physical inactivity.

CONCLUSIONS

Symptomatic hand OA, but not radiographic hand OA, was associated with an increased risk of coronary heart disease events. The results suggest an effect of pain, which may be a possible marker of inflammation.

Prognostic biomarkers in osteoarthritis

PURPOSE OF REVIEW

Identification of patients at risk for incident disease or disease progression in osteoarthritis remains challenging, as radiography is an insensitive reflection of molecular changes that presage cartilage and bone abnormalities. Thus there is a widely appreciated need for biochemical and imaging biomarkers. We describe recent developments with such biomarkers to identify osteoarthritis patients who are at risk for disease progression.

RECENT FINDINGS

The biochemical markers currently under evaluation include anabolic, catabolic, and inflammatory molecules representing diverse biological pathways. A few promising cartilage and bone degradation and synthesis biomarkers are in various stages of development, awaiting further validation in larger populations. A number of studies have shown elevated expression levels of inflammatory biomarkers, both locally (synovial fluid) and systemically (serum and plasma). These chemical biomarkers are under evaluation in combination with imaging biomarkers to predict early onset and the burden of disease.

SUMMARY

Prognostic biomarkers may be used in clinical knee osteoarthritis to identify subgroups in whom the disease progresses at different rates. This could facilitate our understanding of the pathogenesis and allow us to differentiate phenotypes within a heterogeneous knee osteoarthritis population. Ultimately, such findings may help facilitate the development of disease-modifying osteoarthritis drugs (DMOADs).

The association of adipokine levels in plasma and synovial fluid with the severity of knee osteoarthritis

OBJECTIVE

We sought to determine the association between plasma and SF levels of leptin and adiponectin in patients with knee OA.

METHODS

Plasma and SF levels of adipokines and soluble leptin receptor (sOB-R) were determined by ELISA in 96 patients with knee OA at different stages, according to Ahlback's classification.

RESULTS

Levels of adiponectin, leptin, sOB-R and free leptin in plasma and SF did not differ significantly across categories of OA severity. However, the ratio of SF to plasma leptin was significantly lower in the advanced OA stage compared with early stages of the disease (P = 0.02). After adjustment for sex and BMI, plasma leptin positively correlated with categories of OA severity (r = 0.23, P = 0.02), whereas SF/plasma leptin negatively correlated with OA stage (r = -0.27, P = 0.01). Cluster analysis showed that all men were included in one cluster and distributed in different stages of OA, whereas women formed three clusters with similar BMI, but those who were older and had the highest plasma leptin levels suffered from advanced OA.

CONCLUSION

Plasma leptin positively correlated with the severity of knee OA. The ratio of SF to plasma leptin might be a marker related to the severity of knee OA. Further studies should investigate whether similar associations exist in other joints affected by OA.

Osteoarthritis as a disease of mechanics

Mechanics means relating to or caused by movement or physical forces. In this paper, I shall contend that osteoarthritis (OA) is almost always caused by increased physical forces causing damage to a joint. While examples of joint injury causing OA are numerous, I shall contend that most or almost all OA is caused in part by mechanically induced injury to joint tissues. Further, once joint pathology has developed, as is the case for almost all clinical OA, pathomechanics overwhelms all other factors in causing disease progression. Treatments which correct the pathomechanics have long lasting favorable effects on pain and joint function compared with treatments that suppress inflammation which have only temporary effects. I shall lastly contend that the mechanically induced joint injury leads to variable inflammatory responses but that the role of this inflammation in worsening structural damage in an already osteoarthritic joint has not yet been proven.

WIN-34B, a new herbal medicine, inhibits the inflammatory response by inactivating IκB-α phosphorylation and mitogen activated protein kinase pathways in fibroblast-like synoviocytes

ETHNOPHARMACOLOGICAL RELEVANCE

The dried flowers of Lonicera japonica Thunb and dried roots of Anemarrhena asphodeloides BUNGE have been used for the treatment of a variety of inflammatory diseases in traditional Korean medicine.

OBJECTIVE

The aim of the study is to evaluate the anti-inflammatory effects of WIN-34B, a new herbal medicine, in fibroblast-like synoviocytes (FLS) obtained from patients with osteoarthritis (OA).

MATERIALS AND METHODS

WIN-34B is isolated from the n-butanol fraction of dried flowers of L. japonica and dried roots of A. asphodeloides. The anti-inflammatory effects of WIN-34B on cell viability, the production and release of inflammatory mediators, matrix metalloproteinases (MMPs), aggrecanases, tissue inhibitor of matrix proteinases (TIMP) is compared with celecoxib in IL-1β-stimulated human OA FLS. Furthermore, the effect of WIN-34B on inhibitory kappa B-α (IκB-α) phosphorylation and mitogen-activated protein kinases (MAPK) in the IL-1β-stimulated OA FLS was also evaluated.

RESULTS

WIN-34B significantly inhibited the IL-1β-induced cell viability in human OA FLS without cytotoxicity. Compared to celecoxib, WIN-34B exhibited similar or better anti-inflammatory effects through significant suppression of inflammatory mediators (IL-1β, TNF-α, PGE2 and NO), MMPs (MMP-1, MMP-3 and MMP-13) and aggrecanases (ADAMTS-4 and ADAMTS-5), and enhancement of TIMPs (TIMP-1 and TIMP-3). Moreover, WIN-34B reduced the phosphorylation of IκB-α, ERK1/2, p38 and JNK1/2 in IL-1β-stimulated OA FLS.

CONCLUSIONS

WIN-34B exhibited similar or better anti-inflammatory properties in IL-1β-stimulated OA FLS compared to celecoxib. The anti-inflammatory effects of WIN-34B are due to inhibition of inflammatory mediators (IL-1β, TNF-α, PGE2 and NO) and regulation of MMPs, ADAMTSs and TIMPs via the inhibition of IκB-α and MAPK phosphorylation in IL-1β-stimulated OA FLS.

Efficacy of vitamin E in knee osteoarthritis management of North Indian geriatric population

BACKGROUND

Osteoarthritis (OA) is the most common cause of chronic pain and disability in the elderly. It involves progressive destruction of articular cartilage as a consequence of various factors including augmented oxidative stress with advancing age which has not yet been controlled. It is conceivable that exogenous vitamin E supplementation ameliorates the modifiable indexes via regulation of free radical production and the consumption of antioxidant reserve. The objectives of the present study were to investigate the therapeutic effect of vitamin E supplementation in ameliorating the altered activity of antioxidant enzymes (superoxide dismutase, ceruloplasmin, glutathione peroxidase and catalase), erythrocyte malondialdehyde level (MDA, i.e. marker of lipid peroxidation) and markers of systemic inflammation (plasma C-reactive protein [CRP] and synovial fluid interleukin 6 [IL-6]) in osteoarthritic elderly.

METHODS

Antioxidant enzymes status, MDA, IL-6 and CRP levels were estimated by using standard methods in 40 healthy individuals (control group) and in 40 osteoarthritic patients aged 50-70 years before and after 3 months of vitamin E supplementation, i.e. group I (nonsupplemented) and group II (200 mg/day vitamin E supplemented). The obtained values were compared statistically by using Student's t-test.

RESULTS

Marked alteration in antioxidant enzymes, MDA and inflammatory markers were observed in group I (p < 0.05) as compared with controls. These levels were ameliorated significantly after vitamin E supplementation (p < 0.05) in group II. However, elevated levels of serum CRP and synovial fluid IL-6 (r = 0.034; p < 0.05) were decreased insignificantly (p < 0.1) after vitamin E supplementation in knee OA patients.

CONCLUSIONS

These findings confirm the protective role of vitamin E supplementation against oxidative stress mediated biomolecular deterioration in OA. However, the anti-inflammatory role of vitamin E remains to be explored.

Inflammation in osteoarthritis

PURPOSE OF REVIEW

This review focuses on the novel stress-induced and proinflammatory mechanisms underlying the pathogenesis of osteoarthritis, with particular attention to the role of synovitis and the contributions of other joint tissues to cellular events that lead to the onset and progression of the disease and irreversible cartilage damage.

RECENT FINDINGS

Studies during the past 2 years have uncovered novel pathways that, when activated, cause the normally quiescent articular chondrocytes to become activated and undergo a phenotypic shift, leading to the disruption of homeostasis and ultimately to the aberrant expression of proinflammatory and catabolic genes. Studies in animal models and retrieved human tissues indicate that proinflammatory factors may be produced by the chondrocytes themselves or by the synovium and other surrounding tissues, even in the absence of overt inflammation, and that multiple pathways converge on the upregulation of aggrecanases and collagenases, especially MMP-13. Particular attention has been paid to the contribution of synovitis in posttraumatic joint injury, such as meniscal tears, and the protective role of the pericellular matrix in mediating chondrocyte responses through receptors, such as discoidin domain receptor-2 and syndecan-4. New findings about intracellular signals, including the transcription factors NF-κB, C/EBPβ, ETS, Runx2, and hypoxia-inducible factor-2α, and their modulation by inflammatory cytokines, chemokines, adipokines, Toll-like receptor ligands, and receptor for advanced glycation end-products, as well as CpG methylation and microRNAs, are reviewed.

SUMMARY

Further work on mediators and pathways that are common across different models and occur in human osteoarthritis and that impact the osteoarthritis disease process at different stages of initiation and progression will inform us about new directions for targeted therapies.