Co-induction of hepatic IGF-I and progranulin mRNA by growth hormone in tilapia, Oreochromis mossambiccus.
Like IGF-I, progranulin (pgrn) is a growth factor involved in tumorigenesis and wound healing. We report here the identification and characterization of pgrn cDNA in tilapia and the regulation of its expression by growth hormone (GH). The tilapia pgrn cDNA was cloned by RT-PCR amplification, using gene specific oligonucleotides as amplification primers. The cDNA contains an open reading frame encoding a peptide of 206 amino acid residues (aa) that contains a presumptive signal peptide (23 aa) and two repeat units of granulin (grn, 51 and 52 aa, respectively) franked by a GAP of 49 aa and the carboxyl terminus with 31 aa. The two predicted grn peptides are arranged in tandem repeats interrupted by a GAP peptide. RT-PCR analysis revealed that high levels of prgn mRNA were present in several tissues such as spleen, gastric cecum, intestine, fat tissue, gill, kidney, eye and pancreas, and lower levels in liver, muscle, heart, brain, skin and stomach. Administration of a single dose (500 ng/g body weight) of recombinant seabream growth hormone (rbGH) by intraperitoneal (ip) injection into one-month-old tilapia resulted in an obvious increase of IGF-I and pgrn mRNA (2.7-fold and 2.5-fold, respectively) in the liver at three hours post-GH treatment. The peptide levels of pgrn in the liver of GH-treated fish also were substantially induced over controls at 12h post-GH treatment as detected by western immuno-blot analysis. The co-induction of IGF-I and pgrn following GH treatment may suggest the involvement of pgrn in GH regulated growth in tilapia.
Chen
Mark Hung-Chih
MH
Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan. blackfish@sunrise.hk.edu.tw <blackfish@sunrise.hk.edu.tw>
Li
Yen-Hsing
YH
Chang
Yvonne
Y
Hu
Shao-Yang
SY
Gong
Hong-Yi
HY
Lin
Gen-Hwa
GH
Chen
Thomas T
TT
Wu
Jen-Leih
JL
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern / Q000662:veterinary; D015153:Blotting, Western / Q000662:veterinary; D003001:Cloning, Molecular; D029941:Fish Proteins / Q000096:biosynthesis* / Q000235:genetics; D005786:Gene Expression Regulation; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000235:genetics; D008099:Liver / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D000077153:Progranulins; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017210:Tilapia / Q000235:genetics* / Q000378:metabolism
D029941:Fish Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000077153:Progranulins; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I