Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0022116 (ischemia)
91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the role of Na(+)-K(+)-Cl(-) cotransporter (NKCC1) in conjunction with Na(+)/Ca(2+) exchanger (NCX) in disruption of endoplasmic reticulum (ER) Ca(2+) homeostasis and ER stress development in primary cortical neurons following in vitro ischemia. Oxygen-glucose deprivation (OGD) and reoxygenation (REOX) caused a rise in [Na(+)](cyt) which was accompanied by an elevation in [Ca(2+)](cyt). Inhibition of NKCC1 with its potent inhibitor bumetanide abolished the OGD/REOX-induced rise in [Na(+)](cyt) and [Ca(2+)](cyt). Moreover, OGD significantly increased Ca(2+)(ER) accumulation. Following REOX, a biphasic change in Ca(2+)(ER) occurred with an initial release of Ca(2+)(ER) which was sensitive to inositol 1,4,5-trisphosphate receptor (IP(3)R) inhibition and a subsequent refilling of Ca(2+)(ER) stores. Inhibition of NKCC1 activity with its inhibitor or genetic ablation prevented the release of Ca(2+)(ER). A similar result was obtained with inhibition of reversed mode operation of NCX (NCX(rev)). OGD/REOX also triggered a transient increase of glucose regulated protein 78 (GRP78), phospho-form of the alpha subunit of eukaryotic initiation factor 2 (p-eIF2alpha), and cleaved caspase 12 proteins. Pre-treatment of neurons with NKCC1 inhibitor bumetanide inhibited upregulation of GRP78 and attenuated the level of cleaved caspase 12 and p-eIF2alpha. Inhibition of NKCC1 reduced cytochrome C release and neuronal death. Taken together, these results suggest that NKCC1 and NCX(rev) may be involved in ischemic cell damage in part via disrupting ER Ca(2+) homeostasis and ER function.
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PMID:Endoplasmic reticulum Ca2+ dysregulation and endoplasmic reticulum stress following in vitro neuronal ischemia: role of Na+-K+-Cl- cotransporter. 1850 37

Peritransplant ischemia and reperfusion (I/R) injury contributes to posttransplant vascular dysfunction and cardiac allograft vasculopathy (CAV). We have previously shown that cytochrome p450 (CYP) 2C inhibition significantly reduces I/R-induced myocardial infarction and postischemic vascular dysfunction. In the latter study, pretreatment with sulfaphenazole (SP), a specific inhibitor of CYP 2C, restored postischemic NO-mediated, endothelium-dependent vasodilation and reduced vascular superoxide production. Given the association between I/R injury, early vascular dysfunction and CAV, we hypothesized that CYP 2C may also contribute to the onset of CAV. Lewis-to-Fisher rat heterotopic heart transplants were performed. Donors and recipients were treated with 5 mg/kg SP or vehicle control 1 h prior to surgery. SP did not affect posttransplant morbidity, mortality or weight gain. Coronary blood vessels from rats treated with SP exhibited significantly reduced luminal narrowing and demonstrated a corresponding decrease in smooth muscle cell (SMC) proliferation compared to controls. SP did not reduce diffuse, focal, epicardial, endocardial or perivascular immune infiltration nor did it significantly alter TUNEL positivity in myocardial, endothelial or SMC populations. In conclusion, CYP 2C contributes to SMC proliferation CAV without affecting general immune infiltration.
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PMID:Cytochrome p450 2C enzymes contribute to peritransplant ischemic injury and cardiac allograft vasculopathy. 1855 30

Recent studies have suggested that neuronal apoptosis in cerebral ischemia could arise from dysfunction of endoplasmic reticulum (ER) and mitochondria. B-cell lymphoma/leukemia-2 gene (Bcl-2) has been described as an inhibitor both in programmed cell death (PCD) and ER dysfunction during apoptosis, and the Bcl-2 family play a key role in regulating the PCD, both locally at the ER and from a distance at the mitochondrial membrane. However, its signal pathways and concrete mechanisms in endoplasmic reticulum-initiated apoptosis remain incompletely understood. We therefore investigate whether ischemia/reperfusion (I/R) causes neuronal apoptosis in part via cross-talk between ER and mitochondria or not, and how the overexpression of Bcl-2 prevents this form of cell death. Here we show that analogous I/R-induced cell death occurs consequent to interactions of ER stress and mitochondrial death pathways. The participation of the mitochondrial pathway was demonstrated by the release of cytochrome C (cyt C) from mitochondrial into cytoplasmic fractions and caspase-9 cleavage. The involvement of ER stress was further supported by the observable increase of glucose-regulated protein 78(GRP78)/BiP expression and caspase-12 activity. Furthermore, prior to these changes, swelling of the ER lumen and dissociation of ribosomes from rough ER were detected by electron microscopy. Bcl-2 overexpression inhibits the release of cyt C and the activation of caspase-9/-8/-3 but not caspase-12 based on the results of Western blot. These suggest that cross-talk between ER and mitochondria participate in neuronal damage after ischemia/reperfusion. Bcl-2 overexpression could suppress I/R-induced neuronal apoptosis via influencing mitochondrial integrity.
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PMID:The protection of Bcl-2 overexpression on rat cortical neuronal injury caused by analogous ischemia/reperfusion in vitro. 1872 55

The pathways activated by post-conditioning may converge on the mitochondria, in particular on the mitochondrial permeability transition pore. We sought to characterize the inhibition status of the mitochondrial permeability transition early after the post-conditioning maneuver and before long reperfusion was established. We observed that post-conditioning maneuvers applied to isolated rat hearts, after a prolonged ischemia and before reperfusion, promoted cardiac mechanical function recovery and maintained mitochondrial integrity. These effects were evaluated by mitochondrial swelling, calcium transport, and NAD(+) content measurements; the improvements were established before restoring a long lasting reperfusion period. Mitochondrial integrity was associated with a diminution in oxidative stress, since carbonylation of proteins was prevented and aconitase activity was preserved in the post-conditioned hearts, implying that ROS might mediate mitochondrial dysfunction and mPTP opening. In addition, we found that cytochrome release was significantly abolished in the post-conditioned heart, in contrast with conventionally reperfused hearts.
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PMID:Relationship between oxidative stress and mitochondrial function in the post-conditioned heart. 1898 63

Hypoxia is a diminution of oxygen quantity delivered to tissue for cellular need to product energy. Hypoxia derives from two major conditions in health diseases: anemia and ischemia. Anemic hypoxia comes from damage to O(2) transport like red blood cells diminution or disease. Ischemic hypoxia is a diminution of blood flow following a diminution of blood volume after a hemorrhagic shock. After hypoxia, vessels dilate to increase blood flow allowing a better oxygenation of peripheral tissues. This vasodilation appears immediately after the beginning of hypoxia and can be maintained during several hours. Today, the molecular mechanisms of this vasodilation stay unclear. But it seems that potassic channels, ATP concentration and medium acidification in addition to vasodilator/vasoconstrictor balance play a great role to facilitate the oxygenation of the ischemic areas.As endothelial cells (EC) are lining the vasculature, they are always in contact with blood, which carries, amongst other compounds, oxygen. In this way, they are the first target for an oxygen partial pressure (PO(2)) diminution. EC, through different mechanosensors, can sense a variation in PO(2) and adapt their metabolism to maintain ATP production. Under hypoxia, EC switch into hypoxic metabolism, leading to the production of reactive oxygen species (ROS). Indeed, when PO(2) is low, the respiratory chain in the mitochondria runs slower. Furthermore, cytochrome C capacity to trap O(2) is reduced; this phenomenon alters the cellular redox potential and leads to the accumulation of electrons that induce the formation of ROS.This review presents an overview of the behaviour of endothelial cells face to hypoxia. We propose to focus on nitric oxide, hypoxia inducible factor (HIF), lactate and ROS productions. Then we present the different mode of culture of EC under hypoxia. Finally, we conclude on the difficulty to study hypoxia because of the various types of system developed to reproduce this phenomenon and the different signalling ways that can be activated.
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PMID:Review: behaviour of endothelial cells faced with hypoxia. 1906 37

Recent evidence suggests that progenitor cells in adult tissues and embryonic stem cells share a high resistance to hypoxia and ischemic stress. To study the ischemic resistance of adult liver progenitors, we characterized remaining viable cells in human liver tissue after cold ischemic treatment for 24-168 h, applied to the tissue before cell isolation. In vitro cultures of isolated cells showed a rapid decline of the number of different cell types with increasing ischemia length. After all ischemic periods, liver progenitor-like cells could be observed. The comparably small cells exhibited a low cytoplasm-to-nucleus ratio, formed densely packed colonies, and showed a hepatobiliary marker profile. The cells expressed epithelial cell adhesion molecule, epithelial-specific (CK8/18) and biliary-specific (CK7/19) cytokeratins, albumin, alpha-1-antitrypsin, cytochrome-P450 enzymes, as well as weak levels of hepatocyte nuclear factor-4 and gamma-glutamyl transferase, but not alpha-fetoprotein or Thy-1. In vitro survival and expansion was facilitated by coculture with mouse embryonic fibroblasts. Hepatic progenitor-like cells exhibit a high resistance to ischemic stress and can be isolated from human liver tissue after up to 7 days of ischemia. Ischemic liver tissue from various sources, thought to be unsuitable for cell isolation, may be considered as a prospective source of hepatic progenitor cells.
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PMID:Isolation and characterization of adult human liver progenitors from ischemic liver tissue derived from therapeutic hepatectomies. 1910 77

Prolonged ischemia amplified iscehemia/reperfusion (IR) induced renal apoptosis and autophagy. We hypothesize that ischemic conditioning (IC) by a briefly intermittent reperfusion during a prolonged ischemic phase may ameliorate IR induced renal dysfunction. We evaluated the antioxidant/oxidant mechanism, autophagy and apoptosis in the uninephrectomized Wistar rats subjected to sham control, 4 stages of 15-min IC (I15 x 4), 2 stages of 30-min IC (I30 x 2), and total 60-min ischema (I60) in the kidney followed by 4 or 24 hours of reperfusion. By use of ATP assay, monitoring O2-. amounts, autophagy and apoptosis analysis of rat kidneys, I60 followed by 4 hours of reperfusion decreased renal ATP and enhanced reactive oxygen species (ROS) level and proapoptotic and autophagic mechanisms, including enhanced Bax/Bcl-2 ratio, cytochrome C release, active caspase 3, poly-(ADP-ribose)-polymerase (PARP) degradation fragments, microtubule-associated protein light chain 3 (LC3) and Beclin-1 expression and subsequently tubular apoptosis and autophagy associated with elevated blood urea nitrogen and creatinine level. I30 x 2, not I15 x 4 decreased ROS production and cytochrome C release, increased Manganese superoxide dismutase (MnSOD), Copper-Zn superoxide dismutase (CuZnSOD) and catalase expression and provided a more efficient protection than I60 against IR induced tubular apoptosis and autophagy and blood urea nitrogen and creatinine level. We conclude that 60-min renal ischemia enhanced renal tubular oxidative stress, proapoptosis and autophagy in the rat kidneys. Two stages of 30-min ischemia with 3-min reperfusion significantly preserved renal ATP content, increased antioxidant defense mechanisms and decreased ischemia/reperfusion enhanced renal tubular oxidative stress, cytosolic cytochrome C release, proapoptosis and autophagy in rat kidneys.
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PMID:Ischemic conditioning by short periods of reperfusion attenuates renal ischemia/reperfusion induced apoptosis and autophagy in the rat. 1927 87

In addition to well-documented mood-stabilizing effects, lithium can be used in the treatment of acute brain injuries (ischemia) and chronic (neurodegenerative) diseases. Recent in vitro and in vivo studies reveal that the long-term treatment with lithium up-regulates cell survival molecules (Bcl-2, cAMP-responsive element binding protein, GRP 78, brain-derived neurotrophic factor, Hsp70) and down-regulates pro-apoptotic activities (e.g., excitotoxicity, p53, Bax, caspase, cytochrome C release, beta-amyloid peptide production and tau hyperphosphorylation) thus preventing or even reversing the neuronal cell death and neurogenesis retardation.
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PMID:[Neurobiology of lithium]. 1942 90

The mechanism of action of Hydrogen sulfide (H(2)S) as a novel endogenous gaseous messenger and potential cardioprotectant is not fully understood. We therefore investigated the prevention of cardiomyocyte apoptosis by exogenous H(2)S and the signaling pathways leading to cardioprotection. Using a simulated ischemia-reperfusion (I/Re) model with primary cultured rat neonatal cardiomyocytes, I/Re induced a rapid, time-dependent phosphorylation of c-Jun N-terminal kinase (JNK), with significant elevation at 0.25 h and a peak at 0.5h during reperfusion. NaHS (H(2)S donor) significantly inhibited the early phosphorylation of JNK, especially at 0.5h. Both NaHS and SP600125 (specific JNK inhibitor) decreased the number of apoptotic cells, lowered cytochrome C release and enhanced Bcl-2 expression. When NaHS application was delayed 1h after reperfusion, the inhibition of apoptosis by H(2)S was negated. In conclusion, this is novel evidence that early JNK inhibition during reperfusion is associated with H(2)S-mediated protection against cardiomyocyte apoptosis.
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PMID:Anti-apoptotic action of hydrogen sulfide is associated with early JNK inhibition. 1961 39

Although it is becoming increasingly common to accept livers from older donors for transplantation, old livers are more damaged by hepatic ischemia and reperfusion injury (HIRI) than young livers. We hypothesized that this age-related susceptibility to HIRI is due to increased hepatocellular apoptosis driven by tumor necrosis factor alpha (TNFalpha). Young (6-week-old) and old (60-week-old) mice underwent 60 minutes of hepatic ischemia and increasing periods of reperfusion. TNFalpha was determined by enzyme-linked immunosorbent assay. Liver injury (enzyme release), apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling staining, cytochrome C release, and caspase activation), and necrosis (hematoxylin and eosin staining) were assessed. We assessed the impact of apoptosis by blocking TNFalpha production or effect (pentoxifylline and TNFalpha receptor knockout), inhibiting apoptotic pathways (caspase inhibition), or imposing a hepatic protective strategy [glucose infusion with ischemic preconditioning (Glc/PC)]. In comparison with young livers, old livers subjected to HIRI had more pronounced liver aspartate aminotransferase release (6200 versus 3900 U/L, P = 0.02), necrosis (45% versus 25%, P = 0.03), and apoptosis with increased 30-minute TNFalpha release (19.02 versus 10.62 pg/mg, P = 0.03). Eliminating TNFalpha production reversed the effect of age, as did inhibition of apoptotic pathways with caspase inhibition. Glc/PC of old mice attenuated TNFalpha release (9.56 versus 19.02 pg/mg, P = 0.001) and age-related exaggerated HIRI and improved survival (60% versus 0%). In conclusion, the age-related susceptibility to HIRI is driven by an exaggerated induction of TNFalpha-dependent hepatocellular apoptosis. Targeting the apoptotic cascade has implications for the older donor liver population.
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PMID:Exaggerated up-regulation of tumor necrosis factor alpha-dependent apoptosis in the older mouse liver following reperfusion injury: targeting liver protective strategies to patient age. 1987 8


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