Expression profiles of extracellular superoxide dismutase during mouse organogenesis Mi-Ra Kim a , Jung-Min Yon a , Se-Ra Lee a , In-Jeoung Baek b , Jong-Soo Kim a , Jin Tae Hong c , Beom Jun Lee a , Young Won Yun a , Sang-Yoon Nam a,⇑ a College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea b Laboratory of Mammalian Molecular Genetics, Dept. of Biochemistry, College of Science, Yonsei University, Seoul 120-749, Republic of Korea c College of Pharmacy, Chungbuk National University, Cheongju 361-763, Republic of Korea article info Article history: Received 12 August 2010 Received in revised form 2 December 2010 Accepted 7 December 2010 Available online 13 December 2010 Keywords: EC-SOD Mouse Embryo Extraembryonic tissue Antioxidant enzyme Organogenesis Quantitative RT-PCR Western blotting In situ hybridization abstract Although extracellular superoxide dismutase (EC-SOD), which scavenges the superoxide anion in extra- cellular spaces, has previously been implicated in the prenatal pulmonary response to oxidative stress in the developing lungs, little is currently known regarding the schematic expression pattern and the roles played by EC-SOD during embryogenesis. In an effort to characterize the pattern of EC-SOD expression during mouse organogenesis, quantitative RT-PCR, Western blotting, and in situ hybridization analyses were conducted in mouse embryos and extraembryonic tissues including placenta on embryonic days (Eds) 7.5–18.5. EC-SOD mRNA and protein were expressed in all the embryos and extraembryonic tissues examined. The mRNA level was higher in the embryos than the extraembryonic tissues on Eds 7.5–10.5, but after Ed 13.5, it evidenced an increasing pattern in the extraembryonic tissues. EC-SOD immunoreac- tivity also increased in the extraembryonic tissues after Ed 13.5. During organogenesis, EC-SOD mRNA was expressed principally in the ectoplacental cone, amnion, and neural ectoderm on Ed 7.5 and in the neural folds and primitive streak on Ed 8.5. On Eds 9.5–12.5, EC-SOD mRNA was expressed abundantly in the nervous tissues and forelimb and hindlimb buds. On Eds 13.5–18.5, EC-SOD mRNA was observed at high levels in the airway epithelium of lung, liver, the intestinal epithelium, skin, vibrissae, the meta- nephric corpuscle of kidney, the nasal cavity, and the labyrinth trophoblast, spongiotrophoblast, and blood cells in placenta. Our overall results indicate that EC-SOD is expressed spatiotemporally in devel- oping embryos and surrounding extraembryonic tissues during mouse organogenesis, thus suggesting that EC-SOD may be relevant to organogenesis, playing the role of an antioxidant enzyme against endog- enous and exogenous oxygen stresses. Ó 2010 Elsevier B.V. All rights reserved. Cells generate reactive oxygen species (ROS) both as a meta- bolic byproduct and for the signaling of certain cellular processes. Excessive ROS are scavenged by endogenous antioxidant defenses that protect the tissue against oxidative damage. The balance be- tween ROS production and antioxidant capacity is quite delicate, and its disruption contributes to the pathophysiology of a number of diseases (Allen and Tresini, 2000; Valko et al., 2006). A number of antioxidant enzymes are developmentally regulated in the em- bryo in preparation for birth, including catalase, glutathione perox- idase (GPx), and superoxide dismutase (SOD) (Asikainen et al., 1998; Clerch and Massaro, 1992; Frank and Groseclose, 1984; Frank and Sosenko, 1987; Nozik-Grayck et al., 2000). SODs are metalloenzymes that are capable of catalyzing the rapid dismutation of superoxide radical to hydrogen peroxide and oxygen (McCord and Fridovich, 1969). Mammals employ three distinct forms of SOD, which are characterized by their me- tal ions and their different localizations. Copper, zinc-SOD (CuZn- SOD) is present in the cytosol and contains copper and zinc ions, whereas manganese-SOD (Mn-SOD) is located within the mito- chondria, and harbors a manganese ion. A great deal is currently known regarding the biochemical and physiological properties of these two isoenzymes (Ookawara et al., 1998). Extracellular SOD (EC-SOD) was first discovered by Marklund (1982). EC-SOD also harbors Cu and Zn within its active site (Marklund, 1984). EC- SOD is predominantly localized within the extracellular matrix of tissues including vascular tissues, the lungs, and the uterus, as well as extracellular fluids, depending on the presence of a 1567-133X/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.gep.2010.12.001 ⇑ Corresponding author. Address: Laboratory of Veterinary Anatomy/RIVM (Core Res. Institute of NRF), College of Veterinary Medicine, Chungbuk National Univer- sity, Cheongju 361-763, Republic of Korea. Tel.: +82 43 261 2596; fax: +82 43 271 3246. E-mail address: synam@cbu.ac.kr (S.-Y. Nam). Gene Expression Patterns 11 (2011) 207–215 Contents lists available at ScienceDirect Gene Expression Patterns journal homepage: www.elsevier.com/locate/gep