배양 법랑질모세포 분화과정에서 아미노산 수송체 LAT1의 발현

Abstract

Enamel is a mineralized tissue formed by ameloblasts and ameloblast differentiation is controlled by sequential epithelial-mesemchymal interactions. The molecular mechanism of differentiation in ameloblasts remains unclear. Amino acid transporters play an important role in supplying nutrition to normal and cancer cells including ameloblasts, and for cell proliferation. Amino acid transport system L is a major nutrient transport system responsible for the Na+-independent transport of neutral amino acids including several essential amino acids. The system L is divided into two major subgroups, the L-type amino acid transporter 1 (LAT1) and the L-type amino acid transporter 2 (LAT2). In this study, the expression pattern and role of amino acid transport system L were, therefore, investigated in the ameloblast cultures. To determine the expression level of amino acid transport system L participating in intracellular transport of amino acids in the ameloblast cultures, it was examined by RT-PCR, observation of cell morphology, Alizaline red-S staining and uptake analysis after inducing experimental differentiation in ameloblast cell line. The results are as follows. 1. The LAT1 mRNA was expressed in ameloblast cultures and the expression level was gradually increased by time course. 2. The LAT2 mRNA was not observed in ameloblast cultures. 3. The 4F2hc mRNA, the cofactor of LAT1 and LAT2, was expressed in ameloblast cultures and the expression level was gradually increased by time course. 4. The amelogenin mRNA was expressed in the early stage of ameloblast cultures. The expression level was suddenly decreased by time course. 5. The L-leucine uptake was increased by time course from the early stage to the 14 days in ameloblast cultures. As the results, it is considered that among neutral amino acid transport system L in the ameloblast cultures, the LAT1 has a key role in cell differentiation and mineralization for providing cells with neutral amino acids including several essential amino acids.