1. Cartilage intermediate layer protein is regulated by mechanical stress and affects extracellular matrix synthesis
- Author
-
Chencheng Feng, Jing Sun, Tongwei Chu, Yong Pan, Jinyue He, Kang Lu, and Yue Zhou
- Subjects
Cancer Research ,Nucleus Pulposus ,Cell ,Intervertebral Disc Degeneration ,Matrix (biology) ,Biochemistry ,Extracellular matrix ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,medicine ,Humans ,Aggrecans ,Pyrophosphatases ,Intervertebral Disc ,Collagen Type II ,Molecular Biology ,Aggrecan ,030203 arthritis & rheumatology ,Regulation of gene expression ,Extracellular Matrix Proteins ,Oncogene ,Chemistry ,Intervertebral disc ,Extracellular Matrix ,Cell biology ,Blot ,medicine.anatomical_structure ,Gene Expression Regulation ,Oncology ,Molecular Medicine ,RNA Interference ,Stress, Mechanical ,Intervertebral Disc Displacement ,030217 neurology & neurosurgery - Abstract
Lumbar disc disease (LDD) is common in aged populations, and it is primarily caused by intervertebral disc degeneration (IDD). Cartilage intermediate layer protein (CILP), which is specifically expressed in intervertebral discs (IVDs), is suspected to be associated with IDD. However, it remains unclear whether CILP contributes to IDD in humans. Furthermore, the regulation of CILP in human IVDs is poorly understood, especially by mechanical stimuli, which are regarded as primary factors promoting IDD. To address these issues, the present study collected nucleus pulposus (NP) cells from patients undergoing lumbar spinal surgery for degenerative disc disease (DDD). Subsequently, CILP expression was measured in human NP cells in response to mechanical stimuli, including cyclic compressive stress and cyclic tensile strain (CTS), by reverse transcription‑quantitative polymerase chain reaction and western blotting. Aggrecan and collagen II, which are the main components of the extracellular matrix (ECM) and traditional degenerative markers for IDD, were detected following the treatment with CILP small interfering (si)RNA or recombinant human CILP (rhCILP) at various concentrations to determine whether CILP contributes to IDD by negatively regulating expression of the ECM. The results revealed that CILP expression in loaded NP cells was significantly increased compared with that in non‑loaded cells under compressive loading, and that it was markedly decreased in cells under tensile loading, in contrast with the expression of aggrecan and collagen II in response to the same stimuli. Furthermore, CILP siRNA effectively inhibited CILP expression and significantly increased the expression of aggrecan and collagen II. In addition, treatment of NP cells with a high concentration of rhCILP resulted in significantly decreased expression of aggrecan and collagen II. In conclusion, these results demonstrated for the first time, to the best of our knowledge, that in human NP cells, CILP is regulated by mechanical stress and that its expression affects ECM synthesis. Therefore, CILP represents a promising therapeutic target for preventing loss of the matrix during IDD as a novel treatment strategy.
- Published
- 2018