Decrease in circulating autotaxin by oral administration of prednisolone.
BACKGROUND
Autotaxin (ATX), secreted mainly from adipose tissue, functions as a lysophospholipase D (lysoPLD) to hydrolyze lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA). ATX-LPA signaling is implicated in a wide range of physiological and pathophysiological processes including immune response.


METHODS
The present study measured serum ATX antigen levels in patients with various autoimmune diseases using a recently developed automated enzyme immunoassay. In addition, serum lysoPLD activity was assessed by measuring choline liberation from the substrate LPC. Moreover, the effect of prednisolone (PSL) on mRNA expression of ATX was evaluated using cultured adipose tissue from mice.


RESULTS
Decreased serum ATX antigen levels were observed after the initiation of treatment with PSL. The decreased levels recovered during tapering of PSL dose in a dose-dependent manner without exacerbation of disease activity. Moreover, decreased ATX mRNA expression in PSL-treated cultured murine adipose tissue suggested that the effect of PSL on serum ATX may have resulted from changes in adipose tissue ATX expression.


CONCLUSIONS
Our results suggest that measurement of serum ATX antigen level may be clinically useful for the assessment of steroid treatment effect and drug compliance with steroids. Furthermore, our findings provide many novel insights into the biosynthesis, physiological functions, pathological roles, and clinical significance of circulating ATX.
Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. sumida-tky@umin.ac.jp
Hayakazu
H
Sumida
Kazuhiro
K
Nakamura
Keisuke
K
Yanagida
Ryunosuke
R
Ohkawa
Yoshihide
Y
Asano
Takafumi
T
Kadono
Kunihiko
K
Tamaki
Koji
K
Igarashi
Junken
J
Aoki
Shinichi
S
Sato
Satoshi
S
Ishii
Takao
T
Shimizu
Yutaka
Y
Yatomi
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D000284:Administration, Oral; D000818:Animals; D001327:Autoimmune Diseases / Q000097:blood* / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D054316:Biomarkers, Pharmacological / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005938:Glucocorticoids / Q000493:pharmacokinetics* / Q000494:pharmacology; D006801:Humans; D007124:Immunoenzyme Techniques; D008244:Lysophosphatidylcholines / Q000097:blood; D008246:Lysophospholipids / Q000097:blood; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010727:Phosphoric Diester Hydrolases / Q000097:blood* / Q000235:genetics / Q000378:metabolism*; D011239:Prednisolone / Q000493:pharmacokinetics* / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D046509:Tissue Culture Techniques; D000099189:Lysophospholipase D
D054316:Biomarkers, Pharmacological; D005938:Glucocorticoids; D008244:Lysophosphatidylcholines; D008246:Lysophospholipids; D010727:Phosphoric Diester Hydrolases; D011239:Prednisolone; D000099189:Lysophospholipase D; C032881:lysophosphatidic acid