Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apha2-antiplasmin (AP), the main physiological plasmin inhibitor in mammalian plasma, is a 70 kDa single chain serpin (serine proteinase inhibitor) with reactive site peptide bond Arg-Met. It inhibits plasmin very rapidly (second-order inhibition rate constant of = 2 x 107 M-1.s-1) following formation of an inactive 1:1 stoichiometric complex. The high reaction rate requires the presence of a free active site and free lysine-binding site(s) in plasmin. The pathophysiologic relevance of AP is suggested by the finding that homozygous deficient patients show a bleeding tendency; heterozygotes, in contrast, frequently have no or only mild bleeding complications. Inactivation of the AP gene in mice was achieved by replacing, via homologous recombination in embryonic stem cells, a 7 kb genomic sequence encoding the entire murine protein with the neomycin resistance expression cassette. Homozygous AP deficient mice display normal fertility, viability and development. They have an enhanced endogenous fibrinolytic capacity without overt bleeding; this is reflected by a higher spontaneous lysis rate of experimental pulmonary emboli, by a reduced fibrin deposition in the kidneys following challenge with endotoxin, by more limited photochemically induced arterial thrombosis, and by reduced infarct size following induction of focal cerebral ischemia by ligation of the left middle cerebral artery. In a vascular injury restenosis model, AP deficiency has no significant effect on smooth muscle cell migration and neointima formation. These data suggest that, at least in the murine system, the main role of alpha2-antiplasmin is in regulating plasmin activity in the circulating blood and in controlling intravascular fibrinolysis.
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PMID:Gene targeting in hemostasis. Alpha2-antiplasmin. 1117 50

Neuroserpin is a member of the serine proteinase inhibitor (serpin) gene family that reacts preferentially with tissue-type plasminogen activator (tPA) and is primarily localized to neurons in regions of the brain where tPA is also found. Outside of the central nervous system (CNS) tPA is predominantly found in the blood where its primary function is as a thrombolytic enzyme. However, tPA is also expressed within the CNS where it has a very different function, promoting events associated not only with synaptic plasticity but also with cell death in a number of settings, such as cerebral ischemia and seizures. Neuroserpin is released from neurons in response to neuronal depolarization and plays an important role in the development of synaptic plasticity. Following the onset of cerebral ischemia there is an increase in both tPA activity and neuroserpin expression in the area surrounding the necrotic core (ischemic penumbra), and treatment with neuroserpin following ischemic stroke or overexpression of the neuroserpin gene results in a significant decrease in the volume of the ischemic area as well as in the number of apoptotic cells. TPA activity and neuroserpin expression are also increased in specific areas of the brain by seizures, and treatment with neuroserpin slows the progression of seizure activity throughout the CNS and results in significant neuronal survival in the hippocampus. Mutations in human neuroserpin result in a form of autosomal dominant inherited dementia which is characterized by the presence of intraneuronal inclusion bodies and is known as Familial Encephalopathy with Neuroserpin Inclusion Bodies.
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PMID:Neuroserpin: a selective inhibitor of tissue-type plasminogen activator in the central nervous system. 1498 20

Tissue-type plasmingen activator (tPA) is a highly specific serine proteinase that activates the zymogen plasminogen to the broad-specificity proteinase plasmin. tPA is found in the blood, where its primary function is as a thrombolytic enzyme, as well as in the central nervous system (CNS), where it promotes events associated with synaptic plasticity and cell death in a number of settings, such as cerebral ischemia and seizures. Neuroserpin is a fully inhibitory serine proteinase inhibitor (serpin) that reacts preferentially with tPA, and is located in regions of the brain where either tPA message or tPA protein are also found, suggesting that neuroserpin is the selective inhibitor of tPA in the CNS. There is a growing body of evidence demonstrating the participation of tPA in a number of physiologic and pathologic events in the CNS, and the role of neuroserpin as the natural regulator of tPA's activity in these processes.
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PMID:Tissue-type plasminogen activator and neuroserpin: a well-balanced act in the nervous system? 1526 88

Proteinases and their inhibitors play important roles in neural development, homeostasis and disease. Neuroserpin is a member of the serine proteinase inhibitor (serpin) superfamily that is secreted from the growth cones of neurons and inhibits the enzyme tissue-type plasminogen activator (tPA). The temporal and spatial pattern of neuroserpin expression suggests a role in synaptogenesis and is most prominent in areas of the brain that participate in learning, memory and behaviour. Neuroserpin also provides neuronal protection in pathologies such as cerebral ischaemia and epilepsy by preventing excessive activity of tPA. Point mutations in neuroserpin cause aberrant conformational transitions and the formation of loop-sheet polymers that are retained within the endoplasmic reticulum of neurons, forming inclusion bodies that underlie an autosomal dominant dementia that we have called familial encephalopathy with neuroserpin inclusion bodies or FENIB. We review here the role of neuroserpin and other proteinase inhibitors in brain development, function and disease.
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PMID:Neuroserpin: a serpin to think about. 1646 51