IGF-I, IGF-II, and IGF-receptor-1 transcript and IGF-II protein expression in myostatin knockout mice tissues.
Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry were performed to demonstrate whether a correlation exists between insulin-like growth factors (IGFs)-positive regulators of growth-and myostatin, a negative regulator of muscle growth. IGF-I, -II, and IGF-receptor-1 (IGF-R1) mRNA and IGF-II protein expressions were determined in control and myostatin knockout mice tissues. IGF-I gene expressions were similar between control and knockout mice tissues, whereas IGF-II mRNA levels were significantly higher in myostatin knockout mice kidney and soleus muscles than those of control mice (P <.01). IGF-R1 mRNA levels from control mice heart (P <.05) and kidney (P <.01) were significantly higher than in myostatin knockout mice, whereas levels were lower in pectoralis muscle of control mice than knockout mice (P <.01). The strongly IGF-II-positive cells in soleus muscle were more common in myostatin knockout mice and were seen in a few foci in control mice. IGF-II immunoreactivity in both control and myostatin knockout mice kidneys was localized to the epithelium of renal tubules and collecting ducts. Reciprocal changes in the expression of myostatin and IGF-II and IGF-R1 may underlie normal growth of skeletal muscle and other organs in mammals, and the changes in these tissues associated with disease.
Division of Histology and Embryology, Kafkas University, Kars, Turkey.
Hakan
H
Kocamis
Scott A
SA
Gahr
Lori
L
Batelli
Ann F
AF
Hubbs
John
J
Killefer
D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D055435:Myostatin; D009928:Organ Specificity; D012333:RNA, Messenger / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000172:deficiency* / Q000235:genetics
D000199:Actins; C525912:Mstn protein, mouse; D055435:Myostatin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D017526:Receptor, IGF Type 1