Immunolocalization of Water Channel Proteins AQP1 and AQP4 in Rat Spinal Cord.
Aquaporin (AQP) is a water-selective channel protein. In the brain, AQPs play critical roles in the production of cerebrospinal fluid and in edema formation. In contrast, the expression and role of AQPs in spinal cord are unclear. We aimed to investigate the localization of AQP1 and AQP4 in normal rat spinal cord compared with the expression of marker proteins for astrocytes, neurons, and endothelial cells. Immunohistochemistry demonstrated that AQP1 and AQP4 are expressed along all levels of the spinal cord from the cervical to lumbar levels. AQP1 immunolabeling was observed in the dorsal horns in the gray matter, whereas the labeling was weak and mainly seen close to glia limitans in the white matter. AQP1 was co-labeled with marker proteins for unmyelinated neuronal fibers (peripherin) and endothelial cells (RECA-1) of blood vessels that had penetrated through the glia limitans. In contrast, AQP1 did not colocalize with GFAP, an astrocyte marker, at any level of the spinal cord. AQP4 was exclusively localized at the astrocytes, but AQP4 expression in spinal cord exhibited a less polarized and more spatial distribution than that of brain astrocytes. The observed characteristic localization and expression patterns of AQP1 and AQP4 could provide insights toward gaining an understanding of the role of AQPs in the spinal cord.
Department of Biochemistry and Cell Biology (MKO, JSL, HJC, PO, THK), School of Medicine, Kyungpook National University, Taegu, KoreaBK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (MKO, HJC, THK), School of Medicine, Kyungpook National University, Taegu, KoreaDepartment of Animal Physiology, University of Warmia and Mazury (MTS), Olsztyn, Poland.
Michal K
MK
Oklinski
Department of Biochemistry and Cell Biology (MKO, JSL, HJC, PO, THK), School of Medicine, Kyungpook National University, Taegu, KoreaBK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (MKO, HJC, THK), School of Medicine, Kyungpook National University, Taegu, KoreaDepartment of Animal Physiology, University of Warmia and Mazury (MTS), Olsztyn, Poland.
Jung-Suk
JS
Lim
Department of Biochemistry and Cell Biology (MKO, JSL, HJC, PO, THK), School of Medicine, Kyungpook National University, Taegu, KoreaBK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (MKO, HJC, THK), School of Medicine, Kyungpook National University, Taegu, KoreaDepartment of Animal Physiology, University of Warmia and Mazury (MTS), Olsztyn, Poland.
Hyo-Jung
HJ
Choi
Department of Biochemistry and Cell Biology (MKO, JSL, HJC, PO, THK), School of Medicine, Kyungpook National University, Taegu, KoreaBK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (MKO, HJC, THK), School of Medicine, Kyungpook National University, Taegu, KoreaDepartment of Animal Physiology, University of Warmia and Mazury (MTS), Olsztyn, Poland.
Paulina
P
Oklinska
Department of Biochemistry and Cell Biology (MKO, JSL, HJC, PO, THK), School of Medicine, Kyungpook National University, Taegu, KoreaBK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (MKO, HJC, THK), School of Medicine, Kyungpook National University, Taegu, KoreaDepartment of Animal Physiology, University of Warmia and Mazury (MTS), Olsztyn, Poland.
Mariusz T
MT
Skowronski
Department of Biochemistry and Cell Biology (MKO, JSL, HJC, PO, THK), School of Medicine, Kyungpook National University, Taegu, KoreaBK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (MKO, HJC, THK), School of Medicine, Kyungpook National University, Taegu, KoreaDepartment of Animal Physiology, University of Warmia and Mazury (MTS), Olsztyn, Poland thkwon@knu.ac.kr.
Tae-Hwan
TH
Kwon
D000818:Animals; D051398:Aquaporin 1 / Q000378:metabolism*; D051401:Aquaporin 4 / Q000378:metabolism*; D001253:Astrocytes / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D066128:Gray Matter / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000378:metabolism; D009928:Organ Specificity; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism*; D066148:Spinal Cord Dorsal Horn / Q000378:metabolism; D066127:White Matter / Q000378:metabolism
C496022:Aqp1 protein, rat; C496032:Aqp4 protein, rat; D051401:Aquaporin 4; D051398:Aquaporin 1
aquaporin; astrocyte; endothelial cell; spinal cord