Circulating MicroRNAs Highly Correlate to Expression of Cartilage Genes Potentially Reflecting OA Susceptibility—Towards Identification of Applicable Early OA Biomarkers

Abstract

Objective: To identify and validate circulating micro RNAs (miRNAs) that mark gene expression changes in articular cartilage early in osteoarthritis (OA) pathophysiology process. Methods: Within the ongoing RAAK study, human preserved OA cartilage and plasma (N = 22 paired samples) was collected for RNA sequencing (respectively mRNA and miRNA). Spearman correlation was determined for 114 cartilage genes consistently and significantly differentially expressed early in osteoarthritis and 384 plasma miRNAs. Subsequently, the minimal number of circulating miRNAs serving to discriminate between progressors and non-progressors was assessed by regression analysis and area under receiver operating curves (AUC) was calculated with progression data and plasma miRNA sequencing from the GARP study (N = 71). Results: We identified strong correlations (ρ ≥ |0.7|) among expression levels of 34 unique plasma miRNAs and 21 genes, including 4 genes that correlated with multiple miRNAs. The strongest correlation was between let-7d-5p and EGFLAM (ρ = −0.75, P = 6.9 × 10−5). Regression analysis of the 34 miRNAs resulted in a set of 7 miRNAs that, when applied to the GARP study, demonstrated clinically relevant predictive value with AUC > 0.8 for OA progression over 2 years and near-clinical value for progression over 5 years- (AUC = 0.8). Conclusions: We show that plasma miRNAs levels reflect gene expression levels in cartilage and can be exploited to represent ongoing pathophysiological processes in articular cartilage. We advocate that identified signature of 7 plasma miRNAs can contribute to direct further studies toward early biomarkers predictive for progression of osteoarthritis over 2 and 5 years.

Emerging molecular biomarkers in osteoarthritis pathology

“…Using hip and KOA subjects from Research Arthritis and Articular Cartilage (RAAK) ( n = 22) and Genetics osteoARthritis and Progression (GARP) ( n = 71) study cohorts, a panel of 7 miRNAs in plasma (miR140-3p, miR-1307-5p, miR-181a-3p, miR-221-5p, miR-4326, miR-443, and miR-99a-5p) was capable of predicting OA progression over 2 and 5 years. 50 Furthermore, in a KOA patient sample from the Osteoarthritis Initiative (OAI) cohort ( n = 106), an association was found between plasma levels of the miR-320 family (miR-320b/c/d/e) and fast-progressing radiographic KOA subjects over a 4-year period. 51 Finally, in a sample of KOA patients (KL II-IV, n = 136), baseline levels of 3 miRNAs (miR-146a-5p, miR-145-5p, and miR-130b-3p) were higher in individuals with lower pain relief, with mir-146a-5p trending as an independent predictor of postoperative pain relief.…”

Investigating the Differential Circulating microRNA Expression in Adolescent Females with Severe Idiopathic Scoliosis: A Proof-of-Concept Observational Clinical Study

“…Overall, circulating miRNAs may provide useful diagnostic and therapeutic information because of their role in orthopedic disorders. They may reflect the disease state and are differentially affected by therapeutic treatment [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. Small-RNA sequencing studies evidenced a series of circulating miRNAs differentially expressed in the AIS patients compared to the HC.…”

MicroRNA Signatures in Cartilage Ageing and Osteoarthritis

“…Chondrocyte-specific deletion of DICER in the growth plate of mice reduced the number of proliferating chondrocytes, increased hypertrophic chondrocytes and led to severe skeletal defects and premature death [ 15 ]. Several miRNAs have been associated with cartilage development and homeostasis and dysregulation of these is linked with ageing and OA [ 16 , 17 , 18 , 19 ]. miR-140 is one of the most important miRNAs in cartilage.…”