Enhancement of phagocytosis and cytotoxicity in macrophages by tumor-derived IL-18 stimulation.

Inoculation of mice with the murine NFSA cell line caused the formation of large tumors with necrotic tumor cores. FACS analysis revealed accumulations of CD11b(+) cells in the tumors. Microarray analysis indicated that the NFSA cells expressed a high level of the pro-inflammatory factor interleukin-18 (il-18), which is known to play a critical role in macrophages. However, little is known about the physiological function of IL-18-stimulated macrophages. Here, we provide direct evidence that IL-18 enhances the phagocytosis of RAW264 cells and peritoneal macrophages, accompanied by the increased expression of tumor necrosis factor (tnf-α), interleukin-6 (il-6) and inducible nitric oxide synthase (Nos2). IL-18-stimulated RAW264 cells showed an enhanced cytotoxicity to endothelial F-2 cells via direct cell-to-cell interaction and the secretion of soluble mediators. Taken together, our results demonstrate that tumor-derived IL-18 plays an important role in the phagocytosis of macrophages and that IL-18-stimulated macrophages may damage tumor endothelial cells.

miR-370 is stage-specifically expressed during mouse embryonic development and regulates Dnmt3a.

MicroRNAs (miRNAs) are small non-coding RNAs that participate in a large variety of biological processes. In this paper, the spatiotemporal expression pattern of miR-370 was characterized during mouse embryonic development, and was found to be stage- and tissue-specifically expressed. In addition, through luciferase reporter assays and western blot analyses, DNA methyltransferase 3A (Dnmt3a) was identified as a directly regulated target of miR-370. Altogether, our results indicate that miR-370 may play important roles in the morphogenesis of diverse organs, especially brain and adrenal glands, by mediating Dnmt3a expression during mouse development.

Expression patterns of ubiquitin conjugating enzyme UbcM2 during mouse embryonic development.

Ubiquitin conjugating enzyme UbcM2 (Ubiquitin-conjugating enzymes from Mice, the number reveals the identification order) has been implicated in many critical processes, such like growth-inhibiting, mediating cell proliferation and regulation of some transcription factor, but the expression profile during mouse embryo development remains unclear. Hereby, during mid-later embryonic stage, the expression patterns of UbcM2 were examined using in situ hybridization and quantitative real-time PCR (qRT-PCR). The signals were significantly intense in central nervous system and skeletal system, weak in tongue, heart, lung, liver, and kidney. In the central nervous system, UbcM2 was principally expressed in thalamus, external germinal layer of cerebellum (EGL), mitral cell layer of olfactory bulb, hippocampus, marginal zone and ventricular zone of cerebral cortex, and spinal cord. In the skeletal system, UbcM2 was primarily expressed in proliferating cartilage. Furthermore, qRT-PCR analysis displayed that the expression of UbcM2 was ubiquitous at E15.5, most prominent in brain, weaker in lung liver and kidney, accompanied by the lowest level in tongue and heart. During brain development, the expression level of UbcM2 first ascended and then decreased from E12.5 to E18.5, the peak of which sustained starting at E14.5 until E16.5. Together, these results suggest that UbcM2 may play potential roles in the development of mouse diverse tissues and organs, particularly in the development of brain and skeleton.

Expression patterns of imprinted gene Inpp5f-v3 during mouse brain development.

Inpp5f-v3 is a transcriptional variant of Inpp5f (inositol polyphosphate-5-phosphatase F) and locates in distal mouse chromosome 7. It is a paternally expressed imprinted gene in mouse. In this study, we examined the spatiotemporal patterns of Inpp5f-v3 gene during the mouse development. The northern blotting analysis revealed that only one transcript approx 2.7 kb of Inpp5f-v3 was detected in brain. The signals were only observed in brain by the whole-mount in situ hybridization at embryonic day 11.5 (E11.5). The results of quantitative real-time PCR (QRT-PCR) showed that the expression of Inpp5f-v3 increased gradually from the E11.5 to E17.5 and reached the highest at E17.5, then decreased at E18.5 during the brain development. Inpp5f-v3 gene was strongly expressed in the cerebral cortex, olfactory bulb, external germinal layer of cerebellum and ventricular zone (Vz) during the embryonic development (E15.5-E19.5), whereas the expression increased in the olfactory bulb and the cerebellum after birth by using in situ hybridization. The results also demonstrated that the expression of Inpp5f-v3 gene mainly located in olfactory bulb and hippocampus at postnatal day 7 (P7) and adulthood. These results suggest that Inpp5f-v3 is specifically expressed in mouse brain, and may function in the development of mouse brain.