Li W, Nagineni C N, Efiok B, Chepelinsky A B, Egwuagu C E
National Eye Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA.
Dev Biol. 1999 Jun 1;210(1):44-55. doi: 10.1006/dbio.1999.9267.
Interferon regulatory factors (IRFs) are a family of transcription factors involved in regulation of cell growth and immunological responses. Nine IRFs have been described and they are expressed in a variety of cells, except for ICSBP and LSIRF/Pip, which are thought to be expressed exclusively in immune cells. Here, we show that IRF-1, IRF-2, ICSBP, and LSIRF/Pip are constitutively expressed in the mouse lens. These IRFs are present in both the cytoplasm and the nuclei of lens cells. However, the nuclear and cytoplasmic proteins exhibit distinct mobilities on SDS/PAGE. We further show that in the developing mouse lens, IRF-1 and IRF-2 are expressed at high levels in differentiated lens fiber cells with very low and barely detectable levels in undifferentiated lens epithelial cells. Although the level of ICSBP expression is very low in the normal mouse lens, in transgenic mice with constitutive expression of interferon gamma in the lens, its level is markedly elevated and ICSBP expression is detected exclusively in the nuclei of undifferentiated lens cells. Taken together, our data suggest that expression of IRF transcription factors is spatially regulated in the lens and that distinct IRFs may contribute to differential gene regulation in the epithelial and fiber compartments of the vertebrate lens.
干扰素调节因子（IRFs）是一类参与细胞生长调节和免疫反应的转录因子家族。已描述了9种IRFs，它们在多种细胞中表达，但ICSBP和LSIRF/Pip除外，这两种因子被认为仅在免疫细胞中表达。在此，我们表明IRF-1、IRF-2、ICSBP和LSIRF/Pip在小鼠晶状体中组成性表达。这些IRFs存在于晶状体细胞的细胞质和细胞核中。然而，核蛋白和细胞质蛋白在SDS/PAGE上表现出不同的迁移率。我们进一步表明，在发育中的小鼠晶状体中，IRF-1和IRF-2在分化的晶状体纤维细胞中高水平表达，而在未分化的晶状体上皮细胞中表达水平极低且几乎检测不到。虽然ICSBP在正常小鼠晶状体中的表达水平很低，但在晶状体中组成性表达干扰素γ的转基因小鼠中，其水平显著升高，且ICSBP仅在未分化晶状体细胞的细胞核中表达。综上所述，我们的数据表明IRF转录因子的表达在晶状体中受到空间调控，并且不同的IRFs可能有助于脊椎动物晶状体上皮和纤维区室中的差异基因调控。
