NFAT regulates CSF-1 gene transcription triggered by L-selectin crosslinking.

L-selectin is a member of the selectin family that play an important role both in mediating the initial capture and subsequent rolling of leukocytes along the endothelial cells. Furthermore, L-selectin can function as a signal molecule. In our previous studies, we reported that L-selectin ligation could regulate CSF-1 (colony-stimulating factor-1) gene transcription, in which AP-1 acts as a crucial transcriptional factor. Here we investigated the function of the NFAT in the CSF-1 gene transcriptional events. We found that overexpression of WT NFAT induce CSF-1 gene transcription greatly in the activated Jurkat cells. Furthermore, we found that NFAT can be recruited to the nucleus after L-selectin ligation, and the nuclear NFAT interacts with the CSF-1 promoter region to regulate CSF-1 gene transcription in the L-selectin ligation activated Jurkat cells. These results indicate that nuclear NFAT can activate CSF-1 gene transcription by connecting with the CSF-1 promoter in the signaling events induced by L-selectin ligation.