• Animal Bioscience
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• v.36 no.6
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• pp.851-860
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• 2023

Objective: This study aims to evaluate the target genes of gga-miR-20a-5p and the regulated immune responses in the chicken macrophage cell line, HD11, by the exosome-mediated delivery of miR-20a-5p. Methods: Exosomes were purified from the chicken macrophage cell line HD11. Then, mimic gga-miR-20p or negative control miRNA were internalized into HD11 exosomes. HD11 cells were transfected with gga-miR-20a-5p or negative control miRNA containing exosomes. After 44 h of transfection, cells were incubated with or without 5 ㎍/mL poly(I:C) for 4 h. Then, expression of target genes and cytokines was evaluated by quantitative realtime polymerase chain reaction. Results: Using a luciferase reporter assay, we identified that gga-miR-20a-5p directly targeted interferon gamma receptor 2 (IFNGR2), mitogen-activated protein kinase 1 (MAPK1), mitogen-activated protein kinase kinase kinase 5 (MAP3K5), and mitogen-activated protein kinase kinase kinase 14 (MAP3K14). Moreover, the exosome-mediated delivery of gga-miR-20a-5p successfully repressed the expression of IFNGR2, MAPK1, MAP3K5, and MAP3K14 in HD11 cells. The expressions of interferon-stimulated genes (MX dynamin like GTPase 1 [MX1], eukaryotic translation initiation factor 2A [EIF2A], and oligoadenylate synthase-like [OASL]) and proinflammatory cytokines (interferon-gamma [IFNG], interleukin-1 beta [IL1B], and tumor necrosis factor-alpha [TNFA]) were also downregulated by exosomal miR-20a-5p. In addition, the proliferation of HD11 cells was increased by exosomal miR-20a-5p. Conclusion: The exosome-mediated delivery of gga-miR-20a-5p regulated immune responses by controlling the MAPK and apoptotic signaling pathways. Furthermore, we expected that exosomal miR-20a-5p could maintain immune homeostasis against highly pathogenic avian influenza virus H5N1 infection by regulating the expression of proinflammatory cytokines and cell death.

• Journal of Radiation Protection and Research
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• v.24 no.1
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• pp.17-22
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• 1999

This study was carried out to evaluate the biochemical and morphological effects of ionizing radiation on mouse ovarian follicles. Immature mice (ICR, 3 week-old) were irradiated with a dose of $LD_{80(30)}$ at KAERI. The ovaries were collected after 6 hours, 12 hours, 1 day, and 2 days post irradiation. With the morphological basis of the histological staining with hematoxylin-eosin, immunohistochemical preparation using in situ 3'-end labeling was evaluated. Flowcytometric evaluation of DNA extracted from the whole ovary was performed. The percentage of $A_0$ (subpopulation of cells with degraded DNA and with lower DNA fluorescence than $G_0/G_1$ cells), apoptotic, cells in the cell cycle was significantly higher in the irradiated group than in the control group. The number of in situ 3'-end labeled follicles increased at 6 hours post irradiation. All the analyses represented that the ionizing radiation-induced follicular atresia was taken place via an apoptotic degeneration. Such a degeneration underwent very fast and acutely. Therefore, it is concluded that the radiation-induced follicular degeneration is, like the spontaneous atresia, mediated by an acute apoptosis of follicular granulosa cells. Flowcytometric evaluation of cell cycles can make the role for quantifying the atretic follicles and understanding the mechanism of the radiation-induced cell death.

• Journal of Life Science
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• v.16 no.4
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• pp.571-578
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• 2006

HtrA2/Omi, a mitochondrial trypsin-like serine protease, is pivotal in regulating apoptotic cell death. Several lines of recent evidence suggest that HtrA2 is associated with the pathogenesis of neurodegenerative disorders; however, the physiological function of HtrA2 still remains elusive. For studying physiological function of HtrA2 in depth, it is necessary to develop a suitable expression system in the model animal. We therefore utilized the zebrafish as a model animal to establish expression of human HtrA2 (hHtrA2) in vivo. For expression of mature HtrA2 as GFP fusion in zebrafish embryos, the HtrA2 (WT) or (S306A) cDNAs with the C-terminal GFP tag were inserted into the pCS2+ plasmid. Expression patterns of HtrA2 in HEK293 cells were first monitored by immunofluorescence staining and immunoblot assays, showing approximately 64 kDa of the HtrA2-GFP fusion proteins. Subsequently, the hHtrA2 plasmid DNA or in vitro transcribed mRNA was microinjected into zebrafish embryos. The expression patterns of HtrA2 in Zebrafish embryos were monitored by GFP fluorescence in 24 hours-post-fertilization (hpf). Although expression patterns of HtrA2-GFP in developing embryos were different between the injected DNA and mRNA, both nucleic acids revealed good expression levels to further study the physiological role of HtrA2 in vivo. This study provides a suitable condition for expressing hHtrA2 in the zebrafish embryos as well as a method for generating useful system to investigate physiological properties of the specific human genes.