Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the distribution of 12-lipoxygenase mRNA in glial cells. First, mRNA was detected from cellular extracts by soluble-phase reverse transcriptase-polymerase chain reaction (RT-PCR). Taking into account that cell culture populations could not be 100% homogeneous, we then developed, for the first time, an in situ RT-PCR combined with immunocytochemistry with cell specific markers. Using this procedure we showed that 12-lipoxygenase mRNA was expressed both in mature oligodendrocytes and astrocytes.
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PMID:Localization of 12-lipoxygenase mRNA in cultured oligodendrocytes and astrocytes by in situ reverse transcriptase and polymerase chain reaction. 754 57

The 12-lipoxygenase (LO) pathway of arachidonic acid plays an important role in angiotensin II (AII)-mediated aldosterone synthesis. Several distinct isoforms of 12-LO have been cloned. However, in humans only the platelet form of 12-LO has been reported to be present. Western immunoblotting analysis in cultured human adrenal glomerulosa cells using polyclonal antibodies to porcine leukocyte 12-LO enzyme or peptide showed a specific 72-kilodalton band, which is identical to the molecular size of the porcine leukocyte form of 12-LO. In addition, AII (10(-7)) increased the intensity of the 72-kilodalton band nearly 2-fold over basal. In situ hybridization analysis indicated a strong positive reaction with the porcine leukocyte type of 12-LO antisense riboprobe in the zona glomerulosa of the adrenal cortex. The 12-LO probe also recognized a near 4-kilobase messenger RNA (mRNA) from human glomerulosa cells in Northern blots. Since the leukocyte type of 12-LO is highly homologous to human 15-LO, a reverse transcriptase and polymerase chain reaction was used to analyze the specific type of 12-LO mRNA in human cells. The mRNA for a porcine leukocyte type of 12-LO was detected in human adrenal glomerulosa cells, and the level of 12-LO transcripts was increased approximately 60-fold by AII (10(-7) M). The leukocyte type of 12-LO also was detected in human monocyte-like U937 cells, but not in IM-9 lymphocytes or human erythroleukemia cells. These results suggest that human adrenal glomerulosa cells and human monocyte-like U937 cells express a 12-LO which has immunological and molecular biological characteristics similar to the porcine leukocyte 12-LO.
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PMID:Evidence that a leukocyte type of 12-lipoxygenase is expressed and regulated by angiotensin II in human adrenal glomerulosa cells. 827 71

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.
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PMID:Decreased messenger RNA of arachidonate 12-lipoxygenase in platelets of patients with myeloproliferative disorders. 842 29

Hypoxic preconditioning (8% O2, 3 h) produces tolerance 24 h after hypoxic-ischemic brain injury in neonatal rats. To better understand the ischemic tolerance mechanisms induced by hypoxia, we used oligonucleotide microarrays to examine genomic responses in neonatal rat brain following 3 h of hypoxia (8% O2) and either 0, 6, 18, or 24 h of re-oxygenation. The results showed that hypoxia-inducible factor (HIF)-1- but not HIF-2-mediated gene expression may be involved in brain hypoxia-induced tolerance. Among the genes regulated by hypoxia, 12 genes were confirmed by real time reverse transcriptase-PCR as follows: VEGF, EPO, GLUT-1, adrenomedullin, propyl 4-hydroxylase alpha, MT-1, MKP-1, CELF, 12-lipoxygenase, t-PA, CAR-1, and an expressed sequence tag. Some genes, for example GLUT-1, MT-1, CELF, MKP-1, and t-PA did not show any hypoxic regulation in either astrocytes or neurons, suggesting that other cells are responsible for the up-regulation of these genes in the hypoxic brain. These genes were expressed in normal and hypoxic brain, heart, kidney, liver, and lung, with adrenomedullin, MT-1, and VEGF being prominently induced in brain by hypoxia. These results suggest that a number of endogenous molecular mechanisms may explain how hypoxic preconditioning protects against subsequent ischemia, and may provide novel therapeutic targets for treatment of cerebral ischemia.
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PMID:Brain genomic response following hypoxia and re-oxygenation in the neonatal rat. Identification of genes that might contribute to hypoxia-induced ischemic tolerance. 1214 88