Phenotypes in Osteoarthritis

P13-516M14.1 Regulates Autophagy Through miR-429 via Both a ceRNA Network and Direct Interaction

Osteoarthritis (OA), characterized by progressive cartilage degradation, is a leading cause of chronic disability in older adults. Although the molecular mechanisms underlying OA remain incompletely understood, emerging evidence suggests that long non-coding RNAs (lncRNAs) play critical regulatory roles. Recently, we identified a previously uncharacterized lncRNA, RP13-516M14.1, that regulates autophagy in OA chondrocytes. In this study, we aimed to elucidate the mechanism of RP13-516M14.1 in OA pathogenesis. The expression of RP13-516M14.1 was assessed in OA cartilage samples. Its biological functions were investigated using RNA sequencing, RT-qPCR, western blotting, LC3 puncta imaging, transmission electron microscopy (TEM), and atomic force microscopy (AFM) nanoindentation. Its interactions with miR-429 were verified by RNA pull-down assays, RNA immunoprecipitation, fluorescence in situ hybridization (FISH), and dual-luciferase reporter assays. RP13-516M14.1 was identified as key regulator of autophagy, maintaining cartilage homeostasis through modulation of miR-429. Knockdown of RP13-516M14.1 exacerbated OA phenotypes both in vitro and in vivo, while its overexpression protected cartilage by promoting autophagy via miR-429/DDIT4 axis. Notebly, RP13-516M14.1 functioned both as a competitive endogenous RNA (ceRNA) sponging miR-429 and directly regulating its expression. Our study highlights the critical role of RP13-516M14.1 in regulating autophagy in chondrocytes and suggests its potential as a therapeutic target for OA treatment.

Multidimensional Analysis of Preoperative Patient-Reported Outcomes Identifies Distinct Phenotypes in Total Knee Arthroplasty: Secondary Analysis of the SHARKS Registry in a Public Hospital Department

Traditional research on total knee arthroplasty (TKA) relies on preoperative patient-reported outcome measures (PROMs) to predict postoperative satisfaction. We aim to identify distinct patient phenotypes among TKA candidates, and investigate their correlations with patient characteristics. Between 2017 and 2021, patients with primary knee cases at a metropolitan public hospital were enrolled in a clinical quality registry. Demographics, clinical data, and the Veterans Rand 12 and Oxford Knee Score were collected. Imputed data were utilized for the primary analysis, employing k-means clustering to identify four phenotypes. Analysis of variance assessed differences in scores between clusters, and nominal logistic regression determined relationships between phenotypes and patient age, sex, body mass index (BMI), and laterality. The sample comprised 389 patients with 450 primary knees. Phenotype 4 (mild symptoms with good mental health) exhibited superior physical function and overall health. In contrast, patients in phenotype 2 (severe symptoms with poor mental health) experienced the most knee pain and health issues. Phenotype 1 (moderate symptoms with good mental health) reported high mental health scores despite knee pain and physical impairment. Patient characteristics significantly correlated with phenotypes; those in the severe symptoms with poor mental health phenotype were more likely to be younger, female, have a higher BMI, and bilateral osteoarthritis (p < 0.05). This multidimensional analysis identified TKA patient phenotypes based on common PROMs, revealing associations with patient demographics. This approach has the potential to inform prognostic models, enhancing clinical decision-making and patient outcomes in joint replacement.

Innate Immunity and Synovitis: Key Players in Osteoarthritis Progression

Osteoarthritis (OA) is a chronic progressive disease of the joint. Although representing the most frequent cause of disability in the elderly, OA remains partly obscure in its pathogenic mechanisms and is still the orphan of resolutive therapies. The concept of what was once considered a "wear and tear" of articular cartilage is now that of an inflammation-related disease that affects over time the whole joint. The attention is increasingly focused on the synovium. Even from the earliest clinical stages, synovial inflammation (or synovitis) is a crucial factor involved in OA progression and a major player in pain onset. The release of inflammatory molecules in the synovium mediates disease progression and worsening of clinical features. The activation of synovial tissue-resident cells recalls innate immunity cells from the bloodstream, creating a proinflammatory milieu that fuels and maintains a damaging condition of low-grade inflammation in the joint. In such a context, cellular and molecular inflammatory behaviors in the synovium could be the primum movens of the structural and functional alterations of the whole joint. This paper focuses on and discusses the involvement of innate immunity cells in synovitis and their role in the progression of OA.

Effect of l-Carnitine Supplementation on Osteoarthritis: A Systematic Review

SCOPE

Comprehensive assessment of l-carnitine's safety and effectiveness in reducing inflammatory markers in osteoarthritis (OA) patients.

METHODS AND RESULTS

Journal articles on l-carnitine for OA are gathered using computer searches of PubMed, Embase, the Cochrane Library, and Web of Science. The kind of literature that is found is restricted to clinical randomized controlled trials (RCTs). The Cochrane Handbook risk of bias assessment tool RevMan 5.4 software is used to conduct a meta-analysis. The systematic assessment comprises eight trials totaling 619 patients; the included studies' quality is mediocre. The study's findings demonstrate that OA patients' Western Ontario and McMaster University (WOMAC) function improves and that treatment efficacy outperforms that of the control group (mean difference [MD] = -7.75, 95% CI [-14.63, -0.86]; Z = 2.21; p = 0.03), WOMAC total (MD = -10.24, 95% CI [-18.97, -1.51]; Z = 2.30; p = 0.02), and visual analogue scale (VAS) pain (MD = -14.01, 95% CI [-16.16, -11.85]; Z = 12.74; p < 0.00001). The studies that are methodically reviewed also discover heterogeneity, which may have resulted from the created pooled data and requires more analysis.

CONCLUSION

In patients with OA, l-carnitine effectively decreases clinical signs and symptoms, inflammatory markers, pain, and stiffness indicators, and significantly improves WOMAC and VAS scores.

Osteoarthritis year in review 2023: Epidemiology & therapy

OBJECTIVE

To highlight some important findings from osteoarthritis (OA) epidemiology and therapy research undertaken over the past year.

METHODS

Search of MEDLINE and EMBASE databases between April 1, 2022 to March 3, 2023 using "exp *Osteoarthritis/" as the preliminary search term. The search was limited to articles published in English and including human subjects. Final inclusions were based on perceived importance and results that may inform improved identification of risk factors or OA treatments, as well as OA subgroups of potential relevance to risk factors or treatment approaches.

RESULTS

3182 studies were screened, leaving 208 eligible for inclusion. This narrative review of thirty-three selected studies was arranged into: a) OA predictors - population-based studies, b) Specific predictors of OA and OA outcome; c) Intra-articular injections, and d) OA phenotypes. There was some suggestion of sex differences in predictors of incidence or outcomes. Body mass index changes appear largely to affect knee OA outcomes. Evidence points to a lack of benefit of viscosupplementation in knee OA; findings were variable for other injectables. Studies of OA phenotypes reveal potentially relevant clinical and pathophysiological differences.

CONCLUSIONS

Identifying risk factors for the incidence/progression of OA represents an ongoing and important area of OA research. Sex may play a role in this understanding and bears consideration and further study. For knee injectables other than viscosupplementation, additional high-quality trials appear warranted. Continued investigation and application of phenotyping across the OA disease, illness and care spectrum may be key to developing disease-modifying agents and their appropriate selection for individuals.

Intervertebral disc degeneration and osteoarthritis: a common molecular disease spectrum

Intervertebral disc degeneration (IDD) and osteoarthritis (OA) affecting the facet joint of the spine are biomechanically interdependent, typically occur in tandem, and have considerable epidemiological and pathophysiological overlap. Historically, the distinctions between these degenerative diseases have been emphasized. Therefore, research in the two fields often occurs independently without adequate consideration of the co-dependence of the two sites, which reside within the same functional spinal unit. Emerging evidence from animal models of spine degeneration highlight the interdependence of IDD and facet joint OA, warranting a review of the parallels between these two degenerative phenomena for the benefit of both clinicians and research scientists. This Review discusses the pathophysiological aspects of IDD and OA, with an emphasis on tissue, cellular and molecular pathways of degeneration. Although the intervertebral disc and synovial facet joint are biologically distinct structures that are amenable to reductive scientific consideration, substantial overlap exists between the molecular pathways and processes of degeneration (including cartilage destruction, extracellular matrix degeneration and osteophyte formation) that occur at these sites. Thus, researchers, clinicians, advocates and policy-makers should consider viewing the burden and management of spinal degeneration holistically as part of the OA disease continuum.

Osteoarthritis, an old wine in a new bottle!

Osteoarthritis (OA) is the most common form of arthritis that has a major impact on patient morbidity and health care services. Despite its prevalence and impact, we do not have any effective management strategy to prevent or control their manifestations. Several decades of pharmacological development have failed to deliver a disease-modifying solution to OA. This editorial article outlines the lacunae in the research efforts of the past, the challenges that we are facing at present, and the exciting opportunities we have in the future for the management of OA. OA research has to be made more personalized concerning the phenotypic and endotypic disease variants. To begin with, robust disease classification criteria need to be defined for early OA, and biomarkers to detect such early diseases to aid in patient stratification. We also need to refine our clinical research design to make them more objective to meet the demands of the patient and the regulatory agencies. Embracing the current technologies such as artificial intelligence along with the use of genomic profiling from the omics platforms, the future of OA is more promising in developing appropriate management of OA.