A New Enzyme Immunoassay for the Quantitative Determination of Classical Autotaxins (ATX alpha, ATX beta, and ATX gamma) and Novel Autotaxins (ATX delta and ATX epsilon)

作者：Tokuhara Yasunori; Kurano Makoto; Shimamoto Satoshi; Igarashi Koji; Nojiri Takahiro; Kobayashi Tamaki; Masuda Akiko; Ikeda Hitoshi; Nagamatsu Takeshi; Fujii Tomoyuki; Aoki Junken; Yatomi Yutaka^*

来源：PLos One, 2015, 10(6): e0130074.

DOI：10.1371/journal.pone.0130074

Background
Autotaxin (ATX) is a secreted enzyme that converts lysophosphatidylcholine to lysophosphatidic acid, a potent bioactive lipid mediator, through its lysophospholipase D activity. Although five alternative splicing isoforms of ATX have been identified as ATX alpha, ATX beta, ATX gamma, ATX delta, and ATX epsilon and the expression patterns of each isoform differ among several tissues, the clinical significance of each isoform remains to be elucidated.
Methods
Anti-ATX beta and anti-ATX delta monoclonal antibodies were produced by immunization with recombinant human ATX beta and ATX delta expressed using a baculovirus system, respectively. We then developed enzyme immunoassays to measure (ATX alpha, ATX beta, and ATX gamma) the serum concentrations of "classical ATX" (ATX alpha, ATX beta, and ATX gamma) and "novel ATX" (ATX delta and ATX epsilon) antigens and evaluated the usefulness of these assays using human serum samples.
Results
The with-run and between-run precision, interference, detection limit, and linearity studies for the present assay were well validated. In healthy subjects, the serum concentrations of classical ATX and novel ATX were significantly (P < 0.01) higher in women than in men, while the ratios of classical ATX or novel ATX to total ATX were not different between women and men. The concentrations of both classical ATX and novel ATX in normal pregnant subjects and patients with chronic liver diseases or follicular lymphoma were significantly higher than those in healthy subjects, while the ratio of both ATX isoforms to total ATX did not vary among these groups.
Conclusions
We have developed a new enzyme immunoassay to determine the concentrations of classical ATX and novel ATX in human serum. These assays may be helpful for elucidating the distinct functional roles of each ATX isoform, which are largely unknown at present.

• 出版日期2015-6-17