|Budget Amount *help
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
We have previously established 33 bone marrow stromal cell lines from SV 40 T-antigen transgenic mice. Of these, 27 clones supported erythroid colony formation, while 6 clones did not. To identify the molecules which determine the erythroid colony forming activities, we compared the gene expression profiling by DNA microarray between cell lines which support erythropoiesis (E+; TBR9, 184, 31-2) and cell lines which do not (E-; TBR17, 33, 511). Among the differentially expressed genes, we selected one of the upregulated genes, tenascin-C (TN-C), as a candidate in the last project, and demonstrated that it plays an important role in the stromal cell-dependent erythropoiesis (Exp Hematol 34:519-527, 2006). In this project, we have selected 2810021G24 and delta-like 1 among other candidate genes, and examined the function of these two molecules.
The expressions of 2810021G24 in E+ cell lines were 14.0 times higher than in E- cell lines. The number of erythroid colonies in the presence of 2810021G24 small interfering RNA (siRNA) was significantly lower than that of control siRNA in TBR9, suggesting that 2810021G24 is also involved in the stromal-cell dependent erythropoiesis. To confirm this hypothesis, we have attempted to establish knockout mice of 2810021G24, but it was not successful.
The expressions of delta-like 1 in E- cell lines were 20.0 time higher than E+ cell lines. However, the addition of delta-like 1 siRNA did not result in the increase of the number of erythroid colonies in TBR17, suggesting that delta-like 1 is not the exclusive inhibitory factor of stromal-cell dependent erythropoiesis in the E- stromal cell lines.