title: Alkaline phosphatase vs luciferase as secreted reporter molecules in vivo.
abstract: Secreted alkaline phosphatase (SEAP) and Metridia luciferase (MLuc) are useful reporter molecules in vitro, but little is understood about their usefulness in vivo. In this study, we investigated in vivo activity of recombinant SEAP and MLuc in blood and urine. When SEAP-transfected cells or recombinant SEAP were injected into rats, substantial increase in the level of serum SEAP was observed. In contrast, activity of SEAP was not detected in urine of rats injected with either the SEAP-transfected cells or recombinant SEAP. SEAP activity was also undetectable in urine of SEAP-injected Nagase analbuminemic rats in which glomerular permeability to macromolecules is enhanced. When MLuc-transfected cells were implanted into rats, activity of MLuc was undetectable not only in urine but also in serum. Even immediately after intravenous injection of recombinant MLuc, activity of MLuc was not detected in serum. Subsequent experiments revealed that, in contrast to SEAP, MLuc was rapidly inactivated either by rat serum, fetal bovine serum, or human serum. Albumin was identified as the molecule responsible for the inhibition of MLuc activity. These data elucidated advantages and limitations of secreted reporter molecules SEAP and MLuc under in vivo situations.
authors.affiliation: Department of Molecular Signaling, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Tamaho, Yamanashi 409-3898, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hiramatsu
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kasai
authors.forename: Yiman
authors.initials: Y
authors.lastname: Meng
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Hayakawa
authors.forename: Jian
authors.initials: J
authors.lastname: Yao
authors.forename: Masanori
authors.initials: M
authors.lastname: Kitamura
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism* / Q000652:urine; D000818:Animals; D015374:Biosensing Techniques; D002478:Cells, Cultured; D033342:Copepoda / Q000201:enzymology; D005920:Glomerular Mesangium / Q000166:cytology; D005921:Glomerulonephritis / Q000175:diagnosis / Q000473:pathology; D008156:Luciferases / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000097:blood / Q000652:urine; D012709:Serum Albumin / Q000494:pharmacology; D014162:Transfection
chemical_list: D011994:Recombinant Proteins; D012709:Serum Albumin; D008156:Luciferases; D000469:Alkaline Phosphatase