title: The development of classically and alternatively activated macrophages has different effects on the varied stages of radiation-induced pulmonary injury in mice.
abstract: The classical and alternative activation of macrophages has been proposed to play a role in radiation-induced pneumonitis and fibrosis, respectively. To test this hypothesis, the thoraces of C57BL/6 mice were irradiated with 12 Gy X-rays, and irradiated and control mice were euthanized at 1, 8, 12, 24 and 72 hours, and 2, 4, 8, 16 and 24 weeks after irradiation. The expression of inducible nitric oxide synthase (iNOS) and arginase type 1 (Arg-1) was evaluated at the mRNA and protein levels at different stages post-irradiation. We demonstrated that the enhanced mRNA and protein expression of iNOS occurred within the pneumonic stage, whereas the high levels of Arg-1 expression occurred within the fibrotic phase. Immunohistochemistry revealed that iNOS and Arg-1 were mainly expressed in macrophages. The expression of iNOS and Arg-1 may be associated with acute radiation pneumonitis and the development of radiation fibrosis, respectively. Although the function of macrophages cannot explain the whole process of radiation-induced pulmonary injury development, it may play an important regulatory role during this process.
authors: Department of Radiation and Medical Oncology, Zhongnan Hospital, Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors, Wuhan, HuBei 430071, China.
authors: Hui
authors: H
authors: Zhang
authors: Guang
authors: G
authors: Han
authors: Hui
authors: H
authors: Liu
authors: Ji
authors: J
authors: Chen
authors: Xuemei
authors: X
authors: Ji
authors: Fuxiang
authors: F
authors: Zhou
authors: Yunfeng
authors: Y
authors: Zhou
authors: Conghua
authors: C
authors: Xie
mesh_terms: D000818:Animals; D001119:Arginase / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000528:radiation effects; D006909:Hydroxyproline / Q000378:metabolism; D008262:Macrophage Activation / Q000528:radiation effects*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011833:Radiation Injuries, Experimental / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D017564:Radiation Pneumonitis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C544448:Arg1 protein, mouse; D001119:Arginase; D006909:Hydroxyproline