Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0012739 (disseminated intravascular coagulation)
 8,673 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acutely, hemin sensitizes endothelial cells to oxidants but chronically protects the endothelium through the induction of ferritin. By releasing its heme, methemoglobin can sensitize endothelial cells in a fashion similar to free hemin. Furthermore, prolonged incubation with the endothelium allows methemoglobin to induce heme oxygenase and ferritin and concomitantly to modulate oxidant-mediated cytotoxicity. Methemoglobin but not hemoglobin, metmyoglobin or cytochrome c induces heme oxygenase and ferritin. Heme needs to be released from methemoglobin, since sodium cyanide, haptoglobin, and hemopexin inhibit the induction of these proteins. Neutrophils can oxidize hemoglobin to methemoglobin, which can subsequently induce both heme oxygenase and ferritin. We speculate that in shock with disseminated intravascular coagulation, marginated PMNs oxidize hemoglobin to heme-releasing methemoglobin. If critical defenses such as haptoglobin and hemopexin are overwhelmed, heme enters the endothelin cells, sensitizing them to oxidant damage. Endothelial cell adaptation via heme-induced heme oxygenase and ferritin production might limit ultimate progression to pulmonary and other vascular leak syndromes.
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PMID:Endothelial cell heme oxygenase and ferritin induction by heme proteins: a possible mechanism limiting shock damage. 130 86

Heme oxygenase-1 (HO-1) is a stress-induced enzyme that catalyses the oxidation of heme to biliverdin. The primary deficiency of this enzyme has been shown in HO-1 knockout mice, and is characterized by intrauterine death and chronic inflammation. The first case of human HO-1 deficiency was reported in 1999. Human HO-1 deficiency has been observed to involve the endothelial cells more severely, resulting in hemolysis and disseminated intravascular coagulation. We report another case of human HO-1 deficiency in a young girl with congenital asplenia, who presented with severe hemolysis, inflammation, nephritis, which was refractory to therapy with corticosteroids, cyclophosphamide, and rituximab.
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PMID:Human heme oxygenase-1 deficiency presenting with hemolysis, nephritis, and asplenia. 2108 18

Heme is an iron ion-containing molecule found within hemoproteins such as hemoglobin and cytochromes that participates in diverse biological processes. Although excessive heme has been implicated in several diseases including malaria, sepsis, ischemia-reperfusion, and disseminated intravascular coagulation, little is known about its regulatory and signaling functions. Furthermore, the limited understanding of heme's role in regulatory and signaling functions is in part due to the lack of curated pathway resources for heme cell biology. Here, we present two resources aimed to exploit this unexplored information to model heme biology. The first resource is a terminology covering heme-specific terms not yet included in standard controlled vocabularies. Using this terminology, we curated and modeled the second resource, a mechanistic knowledge graph representing the heme's interactome based on a corpus of 46 scientific articles. Finally, we demonstrated the utility of these resources by investigating the role of heme in the Toll-like receptor signaling pathway. Our analysis proposed a series of crosstalk events that could explain the role of heme in activating the TLR4 signaling pathway. In summary, the presented work opens the door to the scientific community for exploring the published knowledge on heme biology.
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PMID:A Computational Approach for Mapping Heme Biology in the Context of Hemolytic Disorders. 3221 83