Quantitative Real-Time PCR Analysis of YKL-40 and Its Comparison with Mammalian Chitinase mRNAs in Normal Human Tissues Using a Single Standard DNA.
YKL-40 (YKL for the first three N-terminal residues of a 40 kDa protein) belongs to a group of human chitinase-like proteins (CLPs), which are similar to chitinases but lack chitinolytic activity. YKL-40 mRNA and its protein levels have been reported elevated in multiple disorders including asthma, cystic fibrosis, rheumatoid arthritis and malignant tumors. Here, we quantified the YKL-40 mRNA levels and compared them with chitinases and housekeeping genes in normal human tissues. To establish the quantitative real-time PCR (qPCR) system for evaluation of relative YKL-40 mRNA levels, we constructed a human standard DNA molecule by ligating cDNAs of YKL-40, two mammalian chitinases and two housekeeping genes in a one-to-one ratio. We generated cDNAs from various normal human tissues and analyzed the YKL-40 mRNA expression levels using a qPCR system with the standard DNA. We found that YKL-40 mRNA is present widely in human tissues while its expression patterns exhibit clear tissue specificity. Highest YKL-40 mRNA levels were detected in the liver, followed by kidney, trachea and lung. The levels of YKL-40 mRNA in the kidney and liver were more than 100-times higher than those of chitotriosidase mRNA. Our study provides for the first time a comprehensive analysis of the relative expression levels of YKL-40 mRNA versus mammalian chitinases in normal human tissues.
Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo 192-0015, Japan. bd13001@ns.kogakuin.ac.jp.|Research Fellow of Japan Society for the Promotion of Science (DC2), Koujimachi, Chiyoda-ku, Tokyo 102-0083, Japan. bd13001@ns.kogakuin.ac.jp.
Misa
M
Ohno
Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA. bauer.peter@mayo.edu.
Peter O
PO
Bauer
Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo 192-0015, Japan. yuta.maldini@blue.email.ne.jp.
Yuta
Y
Kida
Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo 192-0015, Japan. bt11532@ns.kogakuin.ac.jp.
Masayoshi
M
Sakaguchi
Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo 192-0015, Japan. bt79310@ns.kogakuin.ac.jp.
Yasusato
Y
Sugahara
Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo 192-0015, Japan. f-oyama@cc.kogakuin.ac.jp.
Fumitaka
F
Oyama
D054392:Adipokines / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D000071451:Chitinase-3-Like Protein 1; D002688:Chitinases / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020043:Genes, Essential; D006801:Humans; D037102:Lectins / Q000235:genetics* / Q000378:metabolism; D008322:Mammals / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results
D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins; D012333:RNA, Messenger; D004247:DNA; D002688:Chitinases