lncRNAs: novel players in intervertebral disc degeneration and osteoarthritis.

The term long non-coding RNA (lncRNA) refers to a group of RNAs with length more than 200 nucleotides, limited protein-coding potential, and having widespread biological functions, including regulation of transcriptional patterns and protein activity, formation of endogenous small interfering RNAs (siRNAs) and natural microRNA (miRNA) sponges. Intervertebral disc degeneration (IDD) and osteoarthritis (OA) are the most common chronic, prevalent and age-related degenerative musculoskeletal disorders. Numbers of lncRNAs are differentially expressed in human degenerative nucleus pulposus tissue and OA cartilage. Moreover, some lncRNAs have been shown to be involved in multiple pathological processes during OA, including extracellular matrix (ECM) degradation, inflammatory responses, apoptosis and angiogenesis. In this review, we summarize current knowledge concerning lncRNAs, from their biogenesis, classification and biological functions to molecular mechanisms and therapeutic potential in IDD and OA.