Correlation Analysis of C-terminal telopeptide of collagen type II and Interleukin-1β for Early Diagnosis of Knee Osteoarthritis

Pachymic acid suppresses the inflammatory response of chondrocytes and alleviates the progression of osteoarthritis via regulating the Sirtuin 6/NF-κB signal axis

Articular cartilage degeneration is a characteristic pathological change of osteoarthritis (OA). Pachymic acid (PA) is an active ingredient found in Poria cocos. Previous studies have shown that PA has anti-inflammatory effects on a variety of diseases. However, the role of PA in OA and its underlying mechanisms has not been clearly elucidated. In this study, we investigated potential protective effect of PA on OA through cell experiments in vitro and animal experiments in vivo. PA inhibited interleukin-1β-induced inflammatory mediator production in chondrocytes, which includes nitric oxide, inducible nitric oxide synthase, prostaglandin E2, cyclooxygenase-2, tumor necrosis factor alpha and interleukin-6. Meanwhile, PA also reversed the up-regulation of matrix metalloproteinase-3 and thrombospondin motifs 5, and the down-regulation of collagen type II and aggrecan in IL-1β-treated chondrocytes. Mechanistically, our findings revealed that PA-mediated overexpression of SIRT6 inhibited the NF-κB signaling pathway. In vivo, PA contributes to improve cartilage damage in the mouse OA model. In summary, PA inhibited IL-1β-induced inflammation and extracellular matrix degeneration by promoting SIRT6 expression and inhibiting the NF-κB signaling pathway, which indicates that PA is beneficial for the treatment of OA.

sCTX II is a better biomarker than sMMP-3 to identify early knee osteoarthritis

The aim of this study is to assess the ability of serum MMP-3 and serum CTX-II levels to differentiate between normal and early knee osteoarthritis case (eKOA). Subjects with clinical features of primary knee osteoarthritis of K-L Grade I and K-L Grade II with ages more than 45 years were included in the case group (98), and healthy adults with ages less than 40 years were included in the control group (80). Those having knee pain for the last 3 months but having no radiological features were labeled as K-L grade I and those having minimal osteophytes on radiographs were labeled as K-L Grade II. Antero-posterior views of knee and serum levels of MMP-3 and CTX II were estimated. Cases show significantly higher values of both biomarkers than in controls (p < 0.0001). Both biomarkers show significantly higher values with an increase in K-L Grades, that is, K-L Grade 0 versus I (MMP-3: p = 0.003; CTX-II: p = 0.002), K-L Grade I versus II (MMP-3: p < 0.000; CTX-II: p < 0.000). Multivariate analysis shows the dependence of both biomarkers only on K-L Grades. ROC analysis suggests cutoff value between KL Grade 0 and Grade I (MMP-3: 12.25 ng/mL; CTX II: 407.50 pg/mL) and between K L Grade I and Grade II (MMP-3: 18.37 ng/mL; CTX II: 528.00 pg/mL). The discriminating ability of CTX II is superior between normal population and eKOA (CTX II: Accuracy: 66.83%, p = 0.0002; MMP-3: Accuracy: 50.39%, p = 0.138), but MMP-3 is superior than CTX II between eKOA and mild KOA (CTX II:67.52%, p < 0.000; MMP-3: 70.69%, p < 0.000).

Emerging molecular biomarkers in osteoarthritis pathology

Osteoarthritis (OA) is the most common form of arthritis resulting in joint discomfort and disability, culminating in decline in life quality. Attention has been drawn in recent years to disease-associated molecular biomarkers found in readily accessible biofluids due to low invasiveness of acquisition and their potential to detect early pathological molecular changes not observed with traditional imaging methodology. These biochemical markers of OA have been found in synovial fluid, blood, and urine. They include emerging molecular classes, such as metabolites and noncoding RNAs, as well as classical biomarkers, like inflammatory mediators and by-products of degradative processes involving articular cartilage. Although blood-based biomarkers tend to be most studied, the use of synovial fluid, a more isolated biofluid in the synovial joint, and urine as an excreted fluid containing OA biomarkers can offer valuable information on local and overall disease activity, respectively. Furthermore, larger clinical studies are required to determine relationships between biomarkers in different biofluids, and their impacts on patient measures of OA. This narrative review provides a concise overview of recent studies of OA using these four classes of biomarkers as potential biomarker for measuring disease incidence, staging, prognosis, and therapeutic intervention efficacy.

Soluble and EV-Associated Diagnostic and Prognostic Biomarkers in Knee Osteoarthritis Pathology and Detection

Osteoarthritis (OA) is the most common degenerative disease of the connective tissue of the human musculoskeletal system. Despite its widespread prevalence, there are many limitations in its diagnosis and treatment. OA diagnosis currently relies on the presence of clinical symptoms, sometimes accompanied by changes in joint X-rays or MRIs. Biomarkers help not only to diagnose early disease progression but also to understand the process of OA in many ways. In this article, we briefly summarize information on articular joints and joint tissues, the pathogenesis of OA and review the literature about biomarkers in the field of OA, specifically inflammatory cytokines/chemokines, proteins, miRNA, and metabolic biomarkers found in the blood, synovial fluid and in extracellular vesicles.

Serum periostin level is not sufficient to serve as a clinically applicable biomarker of osteoarthritis

BACKGROUND

Emerging knowledge has highlighted the role of periostin (POSTN) in osteoarthritis (OA) process; however, whether POSTN is suitable as a biomarker of OA remains unclear. This study aimed to investigate the potential value of POSTN as a biomarker of OA.

METHODS

Ten 6-month-old female Sprague-Dawley (SD) rats were used in this study. Five rats underwent ovariectomy (OVX) operation and the others were carried out sham operation. Thirty-two patients with OA and eighteen patients who had meniscus injuries or ligament injuries but with intact articular cartilages were recruited in this study from January to July 2019 at the Peking University International Hospital. We first detected the expression of POSTN in the cartilage of OVX induced OA rats and different compartments of the knee joint in patients with OA using immunohistochemistry. Besides, serum POSTN levels in patients with or without OA were examined using enzyme-linked immunosorbent assay (ELISA). The associations among serum POSTN levels, clinical symptoms, and radiological severity were assessed according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and, Kellgren-Lawrence (KL) grading, respectively. Finally, multivariable cumulative link models were established to evaluate the validity of serum POSTN level as a predictor of knee OA.

RESULTS

The significantly higher POSTN expression was found in OVX-OA rats than Sham rats, while, the expression of POSTN was significantly higher in the torn cartilage of patients with OA. However, the serum POSTN level did not differ significantly between patients with and without OA. Additionally, we found no remarkable associations between serum POSTN level and WOMAC scores and KL grading. Subsequent analysis revealed that serum POSTN was not a significant predictor of OA.

CONCLUSION

Thus, although POSTN may be involved OA process and local POSTN is valuable in disease diagnosis and distinguishing of the severity of disease, its serum level is not sufficient to serve as a candidate biomarker of OA given the current analysis technology.

Effects of Moxibustion Combined with Ultrashort Wave on Pain and Oxidative Stress in Elderly Patients with Knee Osteoarthritis

Objective

To explore the effect of moxibustion instrument combined with ultrashort wave on pain and oxidative stress in elderly patients with knee osteoarthritis (KOA).

Method

84 elderly patients with knee osteoarthritis treated in our hospital from May 2020 to June 2021 were randomly divided into observation group (n = 42) and control group (n = 42). The observation group was treated with moxibustion instrument combined with ultrashort wave, while the control group was treated with moxibustion instrument. The clinical efficacy of the two groups was compared, and the pain of the two groups was evaluated by visual analogue scale (VAS). Lysholm knee joint score scale and osteoarthritis index (WOMAC) scale of Western Ontario and McMaster University were used to evaluate the knee joint function of the two groups, and the levels of interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), serum superoxide dismutase (SOD), serum malondialdehyde (MDA), serum miR-155, and NLRP3 were detected in the two groups, and the comprehensive quality of life assessment questionnaire-74 was used, and the adverse reactions were compared between the two groups.

Results

The total effective rate of observation group (90.48%) was higher than that of control group (69.05%) (P < 0.05). After treatment, VAS, Lysholm knee joint, WOMAC, quality of life scores, IL-1β, TNF-α, SOD, MDA, miR-155, and NLRP3 in the observation group were better than those in the control group, and the differences were statistically significant (P < 0.05). There were no obvious adverse reactions in both groups. Conclusion. Moxibustion instrument combined with ultrashort wave can effectively improve knee joint pain, knee joint function, inflammatory reaction, oxidative stress reaction, and quality of life in elderly KOA patients, and the therapeutic effect is good.

Common Biochemical and Magnetic Resonance Imaging Biomarkers of Early Knee Osteoarthritis and of Exercise/Training in Athletes: A Narrative Review

Knee osteoarthritis (OA) is the most common joint disease of the world population. Although considered a disease of old age, OA also affects young individuals and, more specifically among them, those practicing knee-joint-loading sports. Predicting OA at an early stage is crucial but remains a challenge. Biomarkers that can predict early OA development will help in the design of specific therapeutic strategies for individuals and, for athletes, to avoid adverse outcomes due to exercising/training regimens. This review summarizes and compares the current knowledge of fluid and magnetic resonance imaging (MRI) biomarkers common to early knee OA and exercise/training in athletes. A variety of fluid biochemical markers have been proposed to detect knee OA at an early stage; however, few have shown similar behavior between the two studied groups. Moreover, in endurance athletes, they are often contingent on the sport involved. MRI has also demonstrated its ability for early detection of joint structural alterations in both groups. It is currently suggested that for optimal forecasting of early knee structural alterations, both fluid and MRI biomarkers should be analyzed as a panel and/or combined, rather than individually.

Identification of Diagnostic Biomarkers of Osteoarthritis Based on Multi-Chip Integrated Analysis and Machine Learning

The pathogenesis of osteoarthritis (OA) is still unclear. It is therefore important to identify relevant diagnostic marker genes for OA. We performed an integrated analysis with multiple microarray data cohorts to identify potential transcriptome markers of OA development. Further, to identify OA diagnostic markers, we established gene regulatory networks based on the protein-protein interaction network involved in these differentially expressed genes (DEGs). Using support vector machine (SVM) pattern recognition, a diagnostic model for OA prediction and prevention was established. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that 190 DEGs were mainly enriched in pathways like the tumor necrosis factor signaling pathway, interleukin-17 signaling pathway, mitogen-activated protein kinase signaling pathway, nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway, and osteoclast differentiation. Eight hub genes (POSTN, MMP2, CTSG, ELANE, COL3A1, MPO, COL1A1, and COL1A2) were considered potential diagnostic biomarkers for OA, the area under curve (AUC) was >0.95, which showed high accuracy. The sensitivity and specificity of the SVM model of OA based on these eight genes reached 100% in multiple external verification cohorts. Our research provides a theoretical basis for OA diagnosis for clinicians.