Tuftelin Expression is Induced by Hypoxia: In-Vivo and In-Vitro Study

The tuftelin gene is thought to play an important role during the development and mineralization of enamel. Our search of EST databases and our previous studies have shown that tuftelin mRNA and protein are also expressed in various normal soft tissues, such as morula, embryonic stem cells, kidney, lung, eye, peripheral nerve, brain and in several cancers. In the mouse brain tuftelin was differentially expressed at different regions, and the level of tuftelin mRNA expression increases significantly with age from prenatal to 7 months old mice. Sirkku et al 2002, showed that tuftelin was induced in vitro in different cancer cell lines during hypoxia. These data suggest that tuftelin may have a universal role and/or is multifunctional. The objective: was to examine the expression of the tuftelin gene in-vivo and in-vitro during hypoxia Methods: Quantification of the tuftelin mRNA was performed using the real-time quantitative PCR (LightCycler, Roche). Mice were intra-peritoneal injected with CoCl2 (mimics hypoxia). To induce in-vitro oxygen deprivation, PC12 cells were either introduced into a hypoxic device (1% oxygen, Abu-Raya et al., 1999) or exposed to different concentrations of CoCl2. Results: The results showed that 12 hours after in vivo induction of hypoxia the tuftelin mRNA and protein levels in the mouse brain increased significantly. In vitro studies using CoCl2 on the neuronal cell line model PC12, showed a significant increase in tuftelin expression (mRNA and protein) at concentrations of 100ƒÝM, also the expression of tuftelin was induced significantly during exposure to 1% O2 as compared to control. Conclusion: The present results show in-vivo and in-vitro induction of the tuftelin gene in mouse brain and in PC12 cell line respectively. The present results and ongoing structural and functional studies will contribute to the understanding of tuftelin biological role. Partially supported by E.U. Framework5 "MATRIX" grant no:QLK3-CT-2001-00090.