Research progress on long non‑coding RNAs in non‑infectious spinal diseases (Review)

Abstract

Spinal diseases, including intervertebral disc degeneration (IDD), ankylosing spondylitis, spinal cord injury and other non‑infectious spinal diseases, severely affect the quality of life of patients. Current treatments for IDD and other spinal diseases can only relieve symptoms and do not completely cure the disease. Therefore, there is an urgent need to explore the causes of these diseases and develop new treatment approaches. Long non‑coding RNA (lncRNA), a form of non‑coding RNA, is abundant in diverse sources, has numerous functions, and plays an important role in the occurrence and development of spinal diseases such as IDD. However, the mechanism of action of lncRNAs has not been fully elucidated, and significant challenges remain in the use of lncRNAs as new therapeutic targets. The present article reviews the sources, classification and functions of lncRNAs, and introduces the role of lncRNAs in spinal diseases, such as IDD, and their therapeutic potential.

Keywords: ankylosing spondylitis; intervertebral disc degeneration; long non‑coding RNAs; non‑coding RNAs; spinal cord injury.

Figure 1.

Classification of lncRNAs by location, shape and source. lncRNAs account for >60% of the genome. According to their location, they can be classified as nuclear lncRNA, cytoplasmic lncRNA or mitochondrial lncRNA. According to their shape, they can be classified as linear lncRNA or circular lncRNA. Finally, according to their source, they can be classified as i) sense transcript, ii) antisense transcript, iii) bidirectional transcript, iv) long intergenic ncRNA, v) intron region or vi) promoter region and enhancer region lncRNA. ncRNA, non-coding RNA; lncRNA, long non-coding RNA.

Figure 2.

Functions of lncRNA. The functions of lncRNA in the nucleus include providing scaffolding for DNA, RNA and proteins, recruiting chromatin remodelling complexes to remodel chromatin, preventing RNA polymerase II from attaching to the gene promoter and interfering with transcription, and alternative splicing. The functions of lncRNA in the cytoplasm include recruiting proteins that promote mRNA degradation and affect mRNA stability, sequestering specific miRNAs through the competing endogenous RNA mechanism to regulate translation, interfering with post-translational modifications, and affecting the structure and function of proteins. lncRNA, long non-coding RNA; miRNA, microRNA.

Figure 3.

Research progress of lncRNAs in IDD. The intervertebral disc is composed of CEP, AF and NP. Under the combined action of environment, heredity, smoking, physical activity and poor living habits, degeneration occurs, leading to NP protrusion and a decrease in intervertebral space height. lncRNAs mainly regulate the progression of IDD by affecting inflammation, the ECM, cell death and ageing of NP cells. lncRNA, long non-coding RNA; IDD, intervertebral disc degeneration; CEP, cartilage endplate; AF, annulus fibrosus; NP, nucleus pulposus; IVD, intervertebral disc; ECM, extracellular matrix.