Loading-Induced Heat-Shock Response in Bovine Intervertebral Disc Organ Culture

• Published in: PloS one Vol. 11; no. 8; p. e0161615
• Main Authors: Chooi, Wai Hon, Chan, Samantha Chun Wai, Gantenbein, Benjamin, Chan, Barbara Pui
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 31-08-2016; Public Library of Science (PLoS)
• Subjects: Analysis; Animals; Arthritis; Biology and Life Sciences; Biomechanics; Cattle; Cell culture; Cellular stress response; Cytoskeleton; Extracellular Matrix - metabolism; Gene expression; Gene Expression Regulation; Genes; Growth factors; Heat shock proteins; Heat-Shock Response; HSP70 Heat-Shock Proteins - biosynthesis; Hsp70 protein; Immunofluorescence; Intervertebral Disc - metabolism; Intervertebral discs; Joint surgery; Laboratories; Mechanical engineering; Mechanical loading; Nuclei; Nucleus pulposus; Organ culture; Physical Sciences; Physiological aspects; Physiological effects; Physiology; Proteins; Research and Analysis Methods; Smooth muscle; Stress; Stress response; Stress, Mechanical; Stresses; Studies; Tissue engineering; Weight-Bearing; United States; Hong Kong China; Switzerland; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0161615

Mechanical loading has been shown to affect cell viability and matrix maintenance in the intervertebral disc (IVD) but there is no investigation on how cells survive mechanical stress and whether the IVD cells perceive mechanical loading as stress and respond by expression of heat shock proteins. This study investigates the stress response in the IVD in response to compressive loading. Bovine caudal disc organ culture was used to study the effect of physiological range static loading and dynamic loading. Cell activity, gene expression and immunofluorescence staining were used to analyze the cell response. Cell activity and cytoskeleton of the cells did not change significantly after loading. In gene expression analysis, significant up-regulation of heat shock protein-70 (HSP70) was observed in nucleus pulposus after two hours of loading. However, the expression of the matrix remodeling genes did not change significantly after loading. Similarly, expressions of stress response and matrix remodeling genes changed with application and removal of the dynamic loading. The results suggest that stress response was induced by physiological range loading without significantly changing cell activity and upregulating matrix remodeling. This study provides direct evidence on loading induced stress response in IVD cells and contributes to our understanding in the mechanoregulation of intervertebral disc cells.