Decreased messenger RNA of arachidonate 12-lipoxygenase in platelets of patients with myeloproliferative disorders.
On the basis of the previous work by Okuma and Uchino [Blood 54, 1258-1271, 1979], three patients with myeloproliferative disorders were investigated with a special reference to arachidonate 12-lipoxygenase in their platelets. The cytosol of the patients' platelets showed a markedly reduced activity of arachidonic acid oxygenation to 12-hydroperoxy acid. A peroxidase-linked immunoassay for the 12-lipoxygenase demonstrated only 7-12% of the normal level of the enzyme protein in the cytosol fraction of platelets. Furthermore, 12-lipoxygenase mRNA level was determined quantitatively by a reverse transcriptase-polymerase chain reaction with an internal standard cRNA which was synthesized by in vitro transcription of human platelet 12-lipoxygenase cDNA with a 105-bp deletion. The 12-lipoxygenase mRNA content was 4.7 +/- 2.0 (mean +/- S.D.) ng/10(11) platelets in 13 normal subjects. In contrast, the mRNA content was as low as 0.15, 0.11 and 0.10 ng/10(11) platelets in the three patients. Taken together, the 12-lipoxygenase deficiency in these patients was attributable to the decreased 12-lipoxygenase mRNA level and thus the impaired synthesis of the enzyme protein in their platelets.
Matsuda
S
S
Department of Biochemistry, Tokushima University School of Medicine, Japan.
Murakami
J
J
Yamamoto
Y
Y
Konishi
Y
Y
Yokoyama
C
C
Yoshimoto
T
T
Yamamoto
S
S
Mimura
Y
Y
Okuma
M
M
D000911:Antibodies, Monoclonal; D001092:Arachidonate 12-Lipoxygenase / Q000097:blood / Q000235:genetics*; D001483:Base Sequence; D001792:Blood Platelets / Q000201:enzymology*; D004277:DNA, Single-Stranded; D006801:Humans; D007124:Immunoenzyme Techniques; D008969:Molecular Sequence Data; D009196:Myeloproliferative Disorders / Q000097:blood / Q000201:enzymology*; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics*
D000911:Antibodies, Monoclonal; D004277:DNA, Single-Stranded; D012333:RNA, Messenger; D001092:Arachidonate 12-Lipoxygenase