Thirteen outbreaks of foot-and-mouth disease (FMD) were reported in pigs and cattle in Korea between 8 April and 4 June 2010. The FMD virus (FMDV) isolates were of serotype O, indicating that they were related to the virus strains of the Southeast Asia topotype that are circulating in East Asian countries. Animals carrying the viruses were identified by reverse transcriptase-polymerase chain reaction (RT-PCR) during a 29-day period between 8 April and 6 May, 2010. Prior to this outbreak, these FMDVs had not been detected in Korea and may therefore have been introduced from neighbouring countries into Ganghwa Island and subsequently spread inland to other areas, including Gimpo, Chungju and Cheongyang. Tests conducted to lift restrictions on animal movements lead to detection of two additional FMD-positive farms. Through appropriate responses, including swift diagnoses and culling policies, Korea was able to quickly regain its recognition as being free of FMD, without vaccination, by the World Organization for Animal Health (OIE) on 27 September 2010.

Chicken ovalbumin upstream promoter transcription factor 2 (COUP-TFII), an orphan nuclear receptor belonging to the steroid-thyroid hormone receptor superfamily, plays an important role in cell fate determination of various tissues. However, the specific role of COUP-TFII in tooth development has not yet been elucidated. In the present study, we aimed to explore the role of COUP-TFII in dentin sialophosphoprotein (DSPP) expression and matrix mineralization in odontoblast-lineage cells. In primary human dental pulp cells (HDPCs) and murine dental papilla-derived cells (MDPC-23) cultured in a mineralizing medium, the expression of COUP-TFII was induced along with the increased odontoblast-specific dentin matrix protein-1 (DMP-1) and DSPP expression. Endogenous expression of COUP-TFII in maxillary second molar germs of rats showed an increasing tendency as development of the tooth progressed. Also, COUP-TFII protein was detected in greater quantity in the odontoblastic layer of second molar germs than in that of third molar germs of rats. Overexpression of COUP-TFII using an adenoviral system upregulated the expression of odontoblast-specific genes with increased alkaline phosphatase activity and matrix mineralization in odontoblast-lineage cells. In contrast, knockdown of COUP-TFII using small interfering RNA decreased the expression of odontoblast-specific genes, which reduced matrix mineralization. Mechanistic studies revealed that COUP-TFII increased DSPP transcription by direct binding on the DSPP promoter. In addition, COUP-TFII physically interacted with the homeodomain transcription factor Msx2 and antagonistically regulated the Msx2 effect on DSPP promoter activity. Taken together, these results suggest that COUP-TFII has a stimulatory role in DSPP expression and matrix mineralization in odontoblast-lineage cells.