In vivo imaging of hepatic growth hormone signaling.
We developed a system to noninvasively and repeatedly image in vivo hepatic GH signaling. GH regulates postnatal growth and metabolism. It affects numerous tissues, but has major effects in liver. We used nude mice for adenoviral-mediated delivery of a signal transducer and activator of transcription 5-dependent GH response element, a luciferase reporter to detect GH signaling pathway activation. We detected by noninvasive bioluminescence imaging GH-induced hepatic GH signaling serially within intact mice. Statistically significant effects of GH dose and time dependence were detected in the liver luciferase signal that peaked 3 h after GH injection. Codelivery of GH receptor significantly enhanced GH response, an effect that was further augmented by fasting. Our imaging system allows detailed in vivo analysis of GH signaling and action and may be a paradigm for studies of additional signaling pathways in liver and other tissues.
Frank
Stuart J
SJ
University of Alabama at Birmingham, 1530 3rd Avenue South, BDB 861, Birmingham, Alabama 35294-0012, USA. sjfrank@uab.edu
Wang
Xiangdong
X
He
Kai
K
Yang
Ning
N
Fang
Peng
P
Rosenfeld
Ron G
RG
Hwa
Vivian
V
Chaudhuri
Tandra R
TR
Deng
Luqin
L
Zinn
Kurt R
KR
D000256:Adenoviridae / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D008164:Luminescent Proteins / Q000032:analysis; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008822:Mice, Transgenic; D008954:Models, Biological; D011986:Receptors, Somatotropin / Q000378:metabolism; D012107:Research Design; D050799:STAT5 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D015533:Transcriptional Activation
D008164:Luminescent Proteins; D011986:Receptors, Somatotropin; D050799:STAT5 Transcription Factor; D013006:Growth Hormone; D008156:Luciferases