Lin Zhao1,2, Juedan Li1, Jiali Su1,3, Malcolm L Snead4, Jianping Ruan1. 1. a Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry , Stomatology Hospital, Xi'an Jiaotong University , Xi'an , PR China. 2. b Department of Oral Pathology, Stomatology Hospital, Ningxia Medical University , Yinchuan , PR China. 3. d Department of Endodontics, Yinchuan Stomatology Hospital , Yinchuan , PR China. 4. c Herman Ostrow School of Dentistry of USC, Center for Craniofacial Molecular Biology , University of Southern California , Los Angeles , CA , USA.
Abstract
OBJECTIVE: To investigate the possible biological mechanism of dental fluorosis at a molecular level. MATERIAL AND METHODS: Cultured LS8 were incubated with serum-free medium containing selected concentrations of NaF (0 ∼ 2 mM) for either 24 or 48 h. Subcellular microanatomy was characterized using TEM; meanwhile, selected biomolecules were analysed using various biochemistry techniques. Transient transfection was used to modulate a molecular pathway for apoptosis. RESULTS: Apoptosis of LS8 was induced by NaF treatment that showed both time and concentration dependency. The activity of caspase-3, -8, -9 was found to be increased with NaF in a dose-dependent manner. Western blot revealed that the protein expression of p-ERK and p-JNK were decreased, while the expression of p-P38 was increased. Inhibition of the p-ERK and p-JNK pathways resulted in a similar decrease for caspase-3. CONCLUSION: During NaF-induced apoptosis of LS8, p-ERK and p-JNK were closely associated with induction of apoptosis, which might be a mechanism of dental fluorosis.
OBJECTIVE: To investigate the possible biological mechanism of dental fluorosis at a molecular level. MATERIAL AND METHODS: Cultured LS8 were incubated with serum-free medium containing selected concentrations of NaF (0 ∼ 2 mM) for either 24 or 48 h. Subcellular microanatomy was characterized using TEM; meanwhile, selected biomolecules were analysed using various biochemistry techniques. Transient transfection was used to modulate a molecular pathway for apoptosis. RESULTS: Apoptosis of LS8 was induced by NaF treatment that showed both time and concentration dependency. The activity of caspase-3, -8, -9 was found to be increased with NaF in a dose-dependent manner. Western blot revealed that the protein expression of p-ERK and p-JNK were decreased, while the expression of p-P38 was increased. Inhibition of the p-ERK and p-JNK pathways resulted in a similar decrease for caspase-3. CONCLUSION: During NaF-induced apoptosis of LS8, p-ERK and p-JNK were closely associated with induction of apoptosis, which might be a mechanism of dental fluorosis.
Entities:
Keywords:
LS8; NaF; apoptosis; dental fluorosis; mitogen-activated protein kinase