title: The expression of 15-lipoxygenase gene and the presence of functional enzyme in cytoplasm and nuclei of pregnancy human myometria.
abstract: The expression of the 15-lipoxygenase (15-LO) gene in pregnancy human myometria, from messenger RNA (mRNA) to the product of the enzyme reaction, was investigated. In situ hybridization with antisense riboprobe synthesized from human reticulocyte 15-LO complementary DNA has revealed the presence of mRNA in myometrial smooth muscle as well as in myometrial blood vessels. Immunoblot analysis with a polyclonal antibody to recombinant human 15-LO enzyme showed a single 110-kilodalton immunoreactive protein in myometria. Light microscope immunocytochemistry using polyclonal antibodies has demonstrated the presence of immunoreactive 15-LO protein and 15-hydroxyeicosatetraenoic acid (15-HETE), the primary product of the 15-LO pathway. While myometrial blood vessels did not show any obvious change, myometrial smooth muscle showed lower 15-LO mRNA, 15-LO immunoreactive protein, and 15-HETE at term pregnancy and during labor. Immunogold electron microscopy showed the presence of immunoreactive 15-LO in rough endoplasmic reticulum and 15-HETE in myofilaments. Quite unexpectedly, both are also present in nuclear chromatin. In summary, the present study demonstrates for the first time the expression of 15-LO gene in pregnancy human myometria and the mRNA and catalytically active enzyme are lower at term pregnancy and during labor. Quite unexpectedly, catalytically active 15-LO is also present in nuclear chromatin. These findings suggest that 15-LO/15-HETE may have genomic as well as nongenomic actions, both of which may either initiate and/or facilitate the progression of labor in women.
authors.affiliation: Department of Obstetrics and Gynecology, University of Louisville School of Medicine, Kentucky 40292.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Lei
authors.forename: C V
authors.initials: CV
authors.lastname: Rao
mesh_terms: D016375:Antisense Elements (Genetics); D001093:Arachidonate 15-Lipoxygenase / Q000032:analysis / Q000235:genetics*; D002467:Cell Nucleus / Q000201:enzymology* / Q000648:ultrastructure; D002585:Cesarean Section; D003593:Cytoplasm / Q000201:enzymology / Q000648:ultrastructure; D005260:Female; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000032:analysis; D015151:Immunoblotting; D007150:Immunohistochemistry; D007743:Labor, Obstetric; D016253:Microscopy, Immunoelectron; D009215:Myometrium / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization; D011247:Pregnancy / Q000502:physiology*; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics
chemical_list: D016375:Antisense Elements (Genetics); D006893:Hydroxyeicosatetraenoic Acids; D015347:RNA Probes; D012333:RNA, Messenger; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D001093:Arachidonate 15-Lipoxygenase