Figure 1.

Gene transcription and protein expression of TREM2 in primary microglia. (A) RT-PCR for TREM2, DAP12, and GAPDH was performed from RNA of primary cultured microglia, neurons, and splenocytes. Gene transcripts of TREM2 and DAP12 were observed in microglia and weakly in splenocytes, but not in neurons. Molecular weight marker: 100-bp ladder. (B) Immunohistochemistry of cultured neurons, astrocytes, oligodendrocytes, and microglial cells. The distinct cell types were identified by specific antibodies (green fluorescence) directed against β tubulin–III, GFAP, O4, and CD11b. Cells were double labeled (red fluorescence) with specific polyclonal antibodies directed against TREM2. Expression of TREM2 was detected on 97.6 ± 2.4% (mean ± SEM) of microglial cells identified by double labeling with CD11b. No expression of TREM2 was detected on neurons, astrocytes, or oligodendrocytes. Bars, 10 μm.