Aquaporin 9 expression and its localization in normal skeletal myofiber.
The examination was performed whether aquaporin (AQP) 9 is expressed in normal skeletal muscle at mRNA and protein levels. Gel electrophoresis of the reverse transcription-polymerase chain reaction (RT-PCR) product of total RNA samples of human normal muscles by oligonucleotide primers for human AQP9 showed a band of 221 basepairs, which corresponded to the basepair length between two primers of AQP9. The nucleotide sequence of RT-PCR product coincided with that of human AQP9. Immunoblot analysis revealed that the rabbit and sheep antibodies against the synthetic peptide of the C-terminal cytoplasmic domain of human AQP9 molecule reacted with a protein of approximately 30 kDa molecular weight in extracts of human normal skeletal muscles. Immunohistochemistry with our anti-AQP9 antibodies showed an immunoreaction at the myofiber surface of both type 1 and type 2 fibers with almost equal staining intensity in human skeletal muscles. The implication of AQP9 expression in skeletal myofibers was discussed.
Inoue
Masahiko
M
Department of Neurology, Showa University Fujigaoka Hospital, Aoba-ku, Yokohama 227-8501, Japan.
Wakayama
Yoshihiro
Y
Kojima
Hiroko
H
Shibuya
Seiji
S
Jimi
Takahiro
T
Hara
Hajime
H
Iijima
Shoji
S
Masaki
Hisatsugu
H
Oniki
Hiroaki
H
Matsuzaki
Yoko
Y
D000818:Animals; D000906:Antibodies / Q000276:immunology; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D021381:Protein Transport; D020133:Reverse Transcriptase Polymerase Chain Reaction
C109669:AQP9 protein, human; D000906:Antibodies; C491638:Aqp9 protein, mouse; D020346:Aquaporins