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

An essential part of gene expression and regulation is the binding of a regulatory protein (transcription factor) to the recognition sequence of the appropriate gene. A novel protein motif for nucleic acid recognition (called 'zinc finger') is one of such transcription factors. A relationship between gene expressions of a transcription factor and heat shock protein (HSP) 70 has been suggested. Possible inductions of mRNA for 'zinc finger' and HSP70 were examined after transient focal ischemia in rat cerebral cortex by Northern blot analysis using a synthetic oligonucleotide probe for 'zinc finger' gene expression, and a human genomic DNA probe for HSP70 gene expression. After 30 min of middle cerebral artery (MCA) occlusion, the rats recovered for 1, 3, 8h, 1, 2, and 7 days (n = 5). Zinc finger gene is normally expressed in rat cerebral cortex, and is induced by transient ischemia with a maximum at 1 h after the reperfusion. In contrast, HSP70 mRNA is not expressed in normal condition, but is greatly induced by transient ischemia with a maximum at 8 h of reperfusion. These results indicate that the gene expression for a transcription factor changes in the early stage of reperfusion after cerebral ischemia before HSP70 induction begins.
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PMID:Induction of the 'zinc finger' gene after transient focal ischemia in rat cerebral cortex. 202 39

We immunohistochemically investigated the induction and localization of a low-molecular weight stress protein, HSP27, in the rat brain following 1 hr of middle cerebral artery occlusion in comparison with those of HSP70. The brains were perfusion-fixed after 4 h, 1 day, 3 days, 7 days, and 14 days of reperfusion. Frozen sections were then prepared and used for immunohistochemistry. In normal brains, we observed no immunoreactivities to HSP70 and HSP27. HSP70 was localized predominantly in neurons in areas peripheral to the ischemic center after 1 day and 3 days, and in endothelial cells and perivascular cells within the ischemic center after 1 day. In contrast, HSP27 was induced in microglia in the ischemic center after 4 h, and then in reactive astrocytes distributed widely in the ipsilateral hemisphere and in part of the contralateral hemisphere after 1 through 14 days. In the center of ischemia where infarction developed, only nonspecific staining was seen. Thus, the expression patterns of HSP70 and HSP27 were quite different with regard to cell type, distribution, and time course following focal cerebral ischemia. HSP70 may be a sensitive marker of acute neuronal stress in the penumbral areas, whereas HSP27, which was most prominently induced in reactive astrocytes in periischemic and remote areas, may be a component of glial reaction to injury.
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PMID:Immunohistochemical localization of the low molecular weight stress protein HSP27 following focal cerebral ischemia in the rat. 764 52

Immunohistochemical changes of heat shock protein 70 (HSP 70) and glial fibrillary acidic protein (GFAP) were investigated in the gerbil hippocampus 1 h-7 days after 10 min of cerebral ischemia. Transient cerebral ischemia caused HSP 70 expression in GFAP-positive astrocytes in a delayed fashion, as compared with a rapid induction in vulnerable neurons such as hilar neurons. The present results may offer clues to elucidate the mechanisms of ischemic neuronal damage.
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PMID:Induction of heat shock protein 70 and glial fibrillary acidic protein in the postischemic gerbil hippocampus. 789 3

We report here the time-dependent expression of several classes of HSP mRNAs following focal cerebral ischemia in rats. HSP70, GRP78, HSP27, HSP90 and HSP47 have been reported to possess distinct functions under normal and/or stress conditions. These different classes of HSP mRNAs were differentially induced by ischemia, as determined by Northern blot analysis. Messenger RNAs of the HSP70 family proteins were induced within 4 h after ischemia and then rapidly decreased, whereas HSP27 and HSP47 mRNAs reached a maximum level of expression at 24 h and 48 h after ischemic treatment, respectively. In situ hybridization showed that the expression of inducible HSP70 mRNA was observed predominantly in regions adjacent to the ischemic core except during the early periods of ischemia. HSP27 mRNA was expressed over a broad area of the ipsilateral cerebral neocortex except for the ischemic center 24 h after ischemia. The unique induction kinetics for each HSP mRNA species may reflect their distinct roles in the brain during various physiological stresses. We will also discuss that stress proteins may be involved in the central nervous system after ischemia in two important aspects: early protection against stress and restoration of damaged lesions in the brain at later stages after ischemia.
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PMID:Differential induction of mRNA species encoding several classes of stress proteins following focal cerebral ischemia in rats. 795 88

For the understanding of pathophysiology of the cerebral ischemia, we made a transient intraluminal occlusion of the middle cerebral artery in the rat and investigated the appearance of collapsed dark neurons and the extravasation of serum proteins using argyrophil III method and immunohistochemistry. In the acute stage (minutes to 3 days), dark neurons appeared in the lateral half of the ipsilateral striatum and adjacent cortex which formed the ischemic core of this model. Dark neurons also appeared in the ipsilateral reticular thalamic nucleus, hippocampus, and amygdala. The extravasation of serum proteins, albumin, leucocyte common antigen, immunoglobulin G, complement factor C3, as well as heat shock protein 70, was observed not only in the ischemic but sometimes also in the contralateral hemisphere. Among these, the expression of IgG and C3 was most prominent in the ischemic core. In the chronic stage (1 to 3 months), the ischemic core changed into the porencephaly, and the ventrobasal nucleus of the thalamus got also involved in the necrosis. A strong microgliosis was observed in the substantia nigra pars reticulata. Data suggest, that among many mechanisms that contribute to ischemic neuronal death, the activation of immune response, due to the damage of blood-brain barrier and the extravasation of serum proteins could promote the ischemic cell death in the brain.
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PMID:Pathophysiological process after transient ischemia of the middle cerebral artery in the rat. 795 57

Preconditioning the brain with sublethal cerebral ischemia induces tolerance to subsequent lethal periods of ischemia (ischemic tolerance). The purpose of this study is to investigate the role of low-molecular weight stress proteins, 27-kDa heat shock protein (HSP27) and alpha B crystallin, in ischemic tolerance. We measured the content of these proteins with enzyme immunoassay in the rat hippocampus and cerebral cortex following 6 min of ischemia with and without preconditioning with 3 min of ischemia and 3 days of reperfusion. We also visualized the localization of HSP27 immunohistochemically in comparison with that of HSP70. A 3-min period of ischemia caused a 2.4-fold increase in HSP27 content in the hippocampus after 3 days. Immunohistochemical localization of HSP27 was found in glial cells in all subregions of the hippocampus, whereas HSP70 immunostaining was seen only in CA1 pyramidal neurons. HSP27 content in the hippocampus decreased 2 h after 6 min of ischemia. HSP27 content progressively increased in the unpreconditioned hippocampus after 1 and 3 days, but returned to preischemic levels in the preconditioned hippocampus. HSP27 and HSP70 immunostaining was seen in CA1 pyramidal neurons after 1 day both with and without preconditioning. After 3 and 7 days, an intense HSP27 staining was observed in reactive glial cells in the CA1 without preconditioning, whereas the staining decreased in the preconditioned hippocampus. HSP70 staining was seen only in neurons at these time points. We observed no significant changes in HSP27 content in the cerebral cortex although neurons in the third and fifth layers were immunostained after 1 and 3 days. We observed no alterations in alpha B crystallin content after ischemia both in the hippocampus and the cortex. The present study demonstrated that cerebral ischemia induces HSP27 expression but not alpha B crystallin. Both HSP27 and HSP70 induction had a good temporal correlation with the induction of ischemic tolerance. However, different sites of action were suggested because the localization and cell types of HSP27 induction were quite different from those of HSP70 induction. The result suggests that it is unlikely that HSP27 is directly involved in the protection afforded by ischemic preconditioning.
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PMID:Induction of 27-kDa heat shock protein following cerebral ischemia in a rat model of ischemic tolerance. 813 Oct 73

Inductions of mRNAs for heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 were examined in the cerebral cortex, cerebellum, heart, lung, kidney, and liver of gerbils after a 10-min transient forebrain ischemia. HSP70 mRNA was normally expressed in a small amount in the cerebellum, lung, and kidney, but was not expressed in the heart or liver in a detectable amount. A very small amount of HSP70 mRNA was also present in the cerebral cortex. HSC70 mRNA was normally present in all the organs examined with a variety in the amount. Eight hours after the cerebral ischemia, the level of HSP70 mRNA increased in the cerebral cortex, lung, and kidney. HSC70 mRNA levels also increased in all the organs. However, the increase of HSC70 mRNA was remarkable in the heart. Transient cerebral ischemia caused subsequent hyperthermia. Treatment of gerbils with an artificial hyperthermia without cerebral ischemia increased the HSP70 and HSC70 mRNA levels as well. However, the HSC70 mRNA level in the heart after cerebral ischemia was much higher than that in the case with hyperthermic treatment. These results suggest that HSC70 mRNA was preferentially induced in the heart after transient forebrain ischemia that was not only due to the subsequent hyperthermia.
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PMID:Preferential expression of HSC70 heat shock mRNA in gerbil heart after transient brain ischemia. 826 47

Cerebral ischaemia causes activation of ornithine decarboxylase followed by accumulation of putrescine, and these biochemical phenomena have been thought to contribute to the development of neuronal damage. We have used a transgenic mouse line overexpressing the human ornithine decarboxylase gene in their neurons with constitutively high putrescine to study the possible role of putrescine in development of neuronal damage in forebrain ischaemia. An incomplete forebrain ischaemia model was developed in which common carotid arteries were bilaterally occluded and reduction of blood pressure caused by orthostatic reaction was used as a way of decreasing cerebral circulation. Cerebral high-energy metabolites, intracellular pH and lactate were monitored by means of 31P and 1H nuclear magnetic resonance spectroscopy respectively. Incomplete ischaemia for 15 min resulted in severe energy failure, as indicated by an increase in the inorganic phosphate/phosphocreatine ratio, intracellular acidification from a pH of approximately 7.1 to approximately 6.5 and an increase in lactate concentration from < 1 to approximately 10 mmol/kg in both syngenic and transgenic mice. Following deocclusion, recovery of energy metabolites intracellular pH and lactate were identical in both animal groups. Ornithine decarboxylase activity rose 9- and 3-fold in syngenic and transgenic mice respectively 6 h after ischaemia, which was approximately 50-fold greater than the basal level in syngenic mice. In situ hybridization experiments revealed induction of transcription factors c-Fos and zif-268 in the hippocampus, throughout the cerebral cortex and striatum 1-3 h after ischaemia. Messenger RNA of heat shock protein 70 was induced in dentate gyrus and CA3 and CA4 subfields of the hippocampus 1 h after ischaemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cerebral energy metabolism and immediate early gene induction following severe incomplete ischaemia in transgenic mice overexpressing the human ornithine decarboxylase gene: evidence that putrescine is not neurotoxic in vivo. 852 57

Previous studies have shown that brief exposures of rodents to high gravitational forces (+Gz) in a specifically designed centrifuge cause global cerebral ischemia. In the present study, the effect of +Gz exposure to +22.5Gz for 15 to 60 s on c-fos and HSP70 gene expression was examined. Northern and RT-PCR analyses to total RNA isolated from brains of rats in different post-exposure times revealed a significant, time-dependent increase in the c-fos mRNA level which returned to near normal by 180 min. The HSP70 mRNA level was increased two-fold at 30 min post exposure, and remained elevated until 180 min. The transient stimulation of c-fos and HSP70 gene expression should serve as useful biomarkers for hypergravic stress on the brain. The present results should aid in design of future experiments in our understanding of the pathophysiology of the high +Gz challenges.
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PMID:c-fos and HSP70 gene expression in rat brains in high gravitation-induced cerebral ischemia. 861 68

We studied the temporal profile of nerve growth factor-like immunoreactivity (NGF-LI) in the rat brains following 30 min of middle cerebral artery occlusion. The rats were decapitated at 4 h, 1, 3, 7, and 14 days of recirculation. Brain sections at the level of striatum were immunostained against NGF as well as a stress protein, HSP70. Also, double immunostaining of NGF and glial fibrillary acidic protein was performed. In the sham-control rats, NGF-LI was normally present in the cortical and striatal neurons. However, at 4 h of recirculation, there was a significant decrease of NGF-LI in the ischemic cortex and striatum. From 1 day, NGF-LI was absent completely in the ischemic striatum. However, in the ischemic cortex, NGF-LI decreased to the lowest level at 1 day, but it recovered gradually from 3 days and increased significantly to above sham-control level at 7 days. At 14 days of recirculation, NGF-LI returned to a near sham-control level. In the non-ischemic cortex, NGF-LI increased gradually from 4 h with a peak at 7 days, and returned to the sham-control level at 14 days of recirculation. A HSP70 was induced in the ischemic cortex at 1 and 3 days, when there was a significant reduction of NGF-LI. The number of reactive astrocytes increased gradually and NGF-LI in the reactive astrocytes became gradually intense after ischemia. The present finding showing that NGF-LI can be recovered in the stressed cortical neurons suggests a possible involvement of NGF in the process of neuronal survival after focal cerebral ischemia. The expression of NGF in reactive astrocytes indicates that astrocyte may also play a role in supporting neuronal survival after ischemia.
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PMID:Temporal profile of nerve growth factor-like immunoreactivity after transient focal cerebral ischemia in rats. 872 92


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