Upstream stimulatory factor 1 regulates OPNmRNA expression in odontoblasts

Li-an Wu, DDS, PhD, Ling-ying Wen, DDS, Fu-sheng Yang, DDS, and Xiao-jing Wang, DDS, PhD

Department of Pediatric Dentistry, College of Stomatology, The Fourth Military Medical University, Xi’an, P. R. China

Purpose: To detect the effects of upstream stimulatory factor 1 (USF1) on the expression of osteopontin (OPN) in odontoblasts, and explore its biological functions in tooth development.
Materials and Methods: Odontoblasts MDPC-23 were cultured and stably transfected with PCMV-USF1 or A-USF expression plasmids. The mountings of odontoblast coverslips in each group were prepared and total RNA was extracted. Immunofluorescence staining was performed with specific anti-USF1 and anti-HA tag antibodies. Semi-quantitative RT-PCR was carried out to detect the expression of OPN and β-actin in each group. Gray value of OPN and β-actin in each group was calculated and statistically analyzed.
Results: Clones of stable PCMV-USF1 and A-USF plasmids transfection were achieved. Positive staining of HA was shown in the cytoplasm of odontoblasts in A-USF transfection group. Compared with the control, PCMV-USF1 transfection group appeared stronger staining. Electrophoresis of semi-quantitative RT-PCR showed that OPN was upregulated in PCMV-USF1 transfection group, while it was downregulated in A-USF transfection group.
Conclusion: USF1 could regulate the expression of OPN in odontblasts, which could be blocked partially by A-USF. (Int Chin J Dent 2007; 7: 59-63.)

Key Words: immunofluorescence staining, odontoblast, OPN, RT-PCR, USF1.