Hyperosmotic Stress Induces Cell Death in an Odontoblast-lineage Cell Line

• Published in: Journal of endodontics Vol. 38; no. 7; pp. 931 - 935
• Main Authors: Fujisawa, Mari, DDS, Tokuda, Masayuki, DDS, PhD, Morimoto-Yamashita, Yoko, DDS, PhD, Tatsuyama, Shoko, DDS, PhD, Arany, Szilvia, DDS, PhD, Sugiyama, Toshihiro, MD, PhD, Kitamura, Chiaki, DDS, PhD, Shibukawa, Yoshiyuki, DDS, PhD, Torii, Mitsuo, DDS, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2012
• Subjects: Animals; Caspase 3 - metabolism; Cell death; Cell Death - physiology; Cell Line; Cell Shape; Cell Survival - drug effects; Dentinal Fluid - physiology; Dentistry; Endocrinology & Metabolism; Extracellular Matrix Proteins - biosynthesis; Extracellular Signal-Regulated MAP Kinases - metabolism; Glucose - pharmacology; Hydrodynamics; hyperosmotic stress; JNK Mitogen-Activated Protein Kinases - metabolism; MAP Kinase Signaling System; MAPK; Mice; odontoblast cells; Odontoblasts - drug effects; Odontoblasts - metabolism; Osmotic Pressure - physiology; p38 Mitogen-Activated Protein Kinases - metabolism; Phosphoproteins - biosynthesis; Phosphorylation; Sialoglycoproteins - biosynthesis; Stress, Physiological; sucrose; hyperosmotic stress; MAPK; sucrose; Cell death; odontoblast cells
• ISSN: 0099-2399; 1878-3554
• DOI: 10.1016/j.joen.2012.03.023

Abstract Introduction Osmotic stress is one of the stimulations related to dental pain caused by caries or dentin hypersensitivity. The mechanism of osmotic-induced dental pain is not completely understood. The purpose of this study was to examine the responses of odontoblasts under sucrose-induced hyperosmotic stress. Methods We used an odontoblast-lineage cell (OLC) line in our experiments. OLCs were stimulated with sucrose to produce hyperosmotic stress. The expressions of dentin sialophosphoprotein (DSPP) and dentin matrix protein 1 (DMP 1) were detected by using reverse transcriptase polymerase chain reaction assay. The cell viability of OLCs was detected by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. The responses accompanied with cell death were detected by using 4-6-diamidino-2-phenylindole staining, Western blotting of caspase-3, and annexin V assay. The expression of mitogen-activated protein kinases (MAPKs) was detected by using Western blot analysis. Results DSPP and DMP 1 were not affected by hyperosmotic stress in OLCs. Cell viability decreased over 700 mOsm for 3 hours of cell culture. The shapes of cells and nuclei became irregular and vacuolar under hyperosmotic stress. The expression of cleaved caspase-3 was increased after treatment with hyperosmotic stress. Some propidium iodide–positive cells were detected in flow cytometry analysis. Phosphorylation of 3 MAPKs was induced by hyperosmotic stress. Inhibitors of 3 MAPKs inhibited the hyperosmotic stress–induced decline in cell viability at 500 and 700 mOsm. Conclusions Hyperosmotic stress induces cell death of OLCs with sucrose through a MAPK pathway.