Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly(ADP-ribose) polymerase (PARP) is responsible for post-translational modification of proteins in the response to numerous endogenous and environmental genotoxic agents. PARP and poly(ADP-ribosyl)ation are proposed to be important for the regulation of many cellular processes such as DNA repair, cell death, chromatin functions and genomic stability. Activation of PARP is one of the early DNA damage responses, among other DNA sensing molecules, such as DNA-PK, ATM and p53. The generation and characterization of PARP deficient mouse models have been instrumental in defining the biological role of the molecule and its involvement in the pathogenesis of various diseases including diabetes, stroke, Parkinson disease, general inflammation as well as tumorigenesis, and have, therefore, provided information for the development of pharmaceutical strategies for the treatment of diseases.
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PMID:Functions of poly(ADP-ribose) polymerase (PARP) in DNA repair, genomic integrity and cell death. 1137 91

Hypoxia (low-oxygen tension) is an important physiological stress that influences responses to a wide range of pathologies, including stroke, infarction, and tumorigenesis. Prolonged or chronic hypoxia stimulates expression of the stress-inducible transcription factor gene c-jun and transient activation of protein kinase and phosphatase activities that regulate c-Jun/AP-1 activity. Here we describe evidence obtained by using wild-type and HIF-1 alpha nullizygous mouse embryonic fibroblasts (mEFs) that the induction of c-jun mRNA expression and c-Jun phosphorylation by prolonged hypoxia are completely dependent on the presence of the oxygen-regulated transcription factor hypoxia-inducible factor 1 alpha (HIF-1 alpha). In contrast, transient hypoxia induced c-jun expression in both types of mEFs, showing that the early or rapid induction of this gene is independent of HIF-1 alpha. These findings indicate that the c-jun gene has a biphasic response to hypoxia consisting of inductions that depend on the degree or duration of exposure. To more completely define the relationship between prolonged hypoxia and c-Jun phosphorylation, we used mEFs from mice containing inactivating mutations of critical phosphorylation sites in the c-Jun N-terminal region (serines 63 and 73 or threonines 91 and 93). Exposure of these mEFs to prolonged hypoxia demonstrated an absolute requirement for N-terminal sites for HIF-1 alpha-dependent phosphorylation of c-Jun. Taken together, these findings suggest that c-Jun/AP-1 and HIF-1 cooperate to regulate gene expression in pathophysiological microenvironments.
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PMID:The response of c-jun/AP-1 to chronic hypoxia is hypoxia-inducible factor 1 alpha dependent. 1190 46

Cavernous malformations are vascular anomalies that can cause severe neurological deficits, seizures and hemorrhagic stroke if these lesions are located in the brain. In patients with cavernomas, constitutional mutations of the KRIT1 gene have been identified. The pathogenetic mechanisms leading to cerebral cavernous malformations (CCM) development are poorly understood. CCM development might be induced in utero owing to the underlying KRIT1 defect, and is triggered by environmental factors. Another model suggests that CCM develop according to the two-hit model of tumorigenesis associated with biallelic inactivation of KRIT1. So far, CCM specimens themselves have not been subjected to mutation analysis. We identified two somatic mutations in the cavernoma of a sporadic case, suggesting that pathogenesis is associated with somatic KRIT1 alterations. To gain a better understanding of the role of KRIT1 during morphogenesis, the main goal of this study was to provide a detailed description of the spatio-temporal expression pattern of Krit1 and its interaction partner Rap1A during mouse embryogenesis. We did not observe enhanced expression of either gene in the heart or large vessels; however, their expression in the developing small vessels or capillaries could not be assessed by the methods applied. At early embryonic stages, Krit1 and, to a lesser extent, Rap1A are expressed in the developing nervous system. During later phases of fetal development, specific expression of both genes is observed in regions of ossification, the dermis, tendons and in the meninges. These findings provide evidence of differential Krit1 and Rap1A expression during mouse ontogenesis and suggest a more widespread functional significance of Krit1, not restricted to vascular endothelial cells.
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PMID:Mutation and expression analysis of the KRIT1 gene associated with cerebral cavernous malformations (CCM1). 1217 8

By the use of conventional anticoagulants, significant improvements were achieved in all fields of medicine. Although efficacious and widely used, their use is limited in several respects. In particular, the use of vitamin K antagonists is restricted in the clinical routine setting. The main reasons are the delayed on- and off-set of action, the narrow therapeutic window, the necessity of individual laboratory-controlled dosing, and interactions with food ingredients and drugs. The search for new antithrombotics with an improved safety/efficacy profile led to the development of the direct oral thrombin-inhibitor ximelagatran. It can be administered without routine monitoring of coagulation parameters and does not possess any of the previously mentioned limitations. The results from clinical phase II studies obtained so far are very encouraging. After completion of the clinical development program focussing on prevention and treatment of venous thromboembolism, on stroke prevention in atrial fibrillation and on acute coronary syndromes, it is desirable to continue with investigations with regard to long-term prophylaxis in high risk surgery, in chronic peripheral artery disease, in patients with left ventricular thrombi, artificial heart valves, or thrombophilia, as an alternative anticoagulant in heparin induced thrombocytopenia and for prevention of thromboembolic complications in oncology. Because of the mitogenic effects of thrombin on the proliferation of tumour cells, additional experimental studies aiming at a potential inhibition of thrombin-triggered oncogenesis is of uttermost interest.
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PMID:[Future potential indications for an oral thrombin inhibitor]. 1221 60

The development of small molecule kinase inhibitors as potential cancer therapeutics is an area of intense interest, and a subset of these agents target cyclin-dependent kinase (CDK) activity. Ten distinct CDKs (1-9, 11), when paired with their cyclin activators, are integral to such diverse processes as cell cycle control, neuronal development, and transcriptional regulation. Mutation and/or aberrant expression of certain CDKs and their regulatory counterparts are associated with uncontrolled proliferation and tumorigenesis. As such, CDK selective inhibitors (CDKIs) that attenuate or prevent tumor growth have been developed. Recently, interest in the therapeutic potential of CDKIs has expanded to include neurodegenerative diseases, where dysregulated CDK activity has been linked to the pathogenesis of Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and stroke. Specifically, aberrant activation of cell cycle CDKs or CDK5 is associated with apoptosis and neuronal dysfunction in response to various neuronal stressors. To date, CDKIs have shown promise as neuroprotective agents in the research laboratory and, in the future, may prove useful in the neurology clinic.
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PMID:Cyclin-dependent kinase inhibitors: cancer killers to neuronal guardians. 1257 Jun 97

The ischemic penumbra is a functionally depressed, structurally intact but potentially salvageable region in the brain following stroke. Several pathophysiological mechanisms dominate during various intervals after stroke onset. New promising clinical treatment possibilities include hemicraniectomy in younger patients with malignant media infarction (albeit no RCT data available as today); brain cooling during the acute phase; and constraint-induced therapy and physiotherapy enhanced either by psychotomimetics (amphetamine) to improve general function or by anesthesia of the shoulder and upper arm to improve chronic paretic hand function. In a further future perspective, promising results from animal experiments should be clinically translated. Such results include newborn neurons induced in the penumbra spontaneously after stroke (endogenous neurogenesis) or exogenously administered stem cells implanted directly, or alternatively migrating to the ischemic penumbra, where differentiation to functional neurons is hoped for. Several safety aspects are however crucial, especially with regard to minimizing the risk of tumorigenesis after application of exogenous stem cells, and further detailed experimental characterization is essential before large scale clinical trials are initiated.
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PMID:[New treatment modalities for stroke in the near future]. 1465 36

Poly (ADP-ribose) polymerase-1 (PARP-1)-deficient mice are protected against septic shock, type I diabetes, stroke and inflammation. It is now accepted that inflammation and related events, such as activation of NF-kappaB, are key components in the initiation and progression of epithelial cancer and in particular in the neoplastic transformation of keratinocytes and skin carcinogenesis. Here, we report that PARP-1-deficient mice display a strikingly reduced susceptibility to skin carcinogenesis. In parp-1(-/-) mice, development of papilloma-like premalignant lesions induced with DMBA and TPA, is strongly delayed and the final number of tumor-bearing mice and total tumor number were significantly reduced. In addition, epidermis of parp-1(-/-) mice did not show increased proliferation rates after treatment with carcinogen. Deregulated NF-kappaB is a hallmark for tumorigenesis together with the concomitant release of early inflammatory mediators. In the absence of PARP-1, NF-kappaB activation and induction kappaB-target genes did not take place during the promotion of tumor development. These results suggest that PARP-1 abolition impairs the promotion of skin carcinogenesis interfering with the activation of NF-kappaB and might have an important implication in targeting PARP-1 as a new antineoplastic therapeutic approach.
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PMID:Crosstalk between PARP-1 and NF-kappaB modulates the promotion of skin neoplasia. 1507 72

As the average age in many countries steadily rises, heart infarction, stroke, and cancer become the most common causes of death in the 21st century. The causes of these disorders are many and varied and include genetic predisposition and environmental influences, but they all share a common feature in that limitation of oxygen availability participates in the development of these pathological conditions. However, cells and organisms are able to trigger an adaptive response to hypoxic conditions that is aimed to help them to cope with these threatening conditions. This review provides a description of several systems able to sense oxygen concentration and of the responses they initiate both in the acute and also in long-term hypoxia adaptation. The role of hypoxia in three pathological conditions, myocardial and cerebral ischemia as well as tumorigenesis, is briefly discussed.
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PMID:Physiological and pathological responses to hypoxia. 1516 23

Here we review evidence of roles for NF-kappaB in the regulation of developmental and synaptic plasticity, and cell survival in physiological and pathological settings. Signaling pathways modulating NF-kappaB activity include those engaged by neurotrophic factors, neurotransmitters, electrical activity, cytokines, and oxidative stress. Emerging findings support a pivotal role for NF-kappaB as a mediator of transcription-dependent enduring changes in the structure and function of neuronal circuits. Distinct subunits of NF-kappaB may uniquely affect cognition and behavior by regulating specific target genes. NF-kappaB activation can prevent the death of neurons by inducing the production of antiapoptotic proteins such as Bcl-2, IAPs and manganese superoxide dismutase (Mn-SOD). Recent findings indicate that NF-kappaB plays important roles in disorders such as epilepsy, stroke, Alzheimer's and Parkinson's diseases, as well as oncogenesis. Molecular pathways upstream and downstream of NF-kappaB in neurons are being elucidated and may provide novel targets for therapeutic intervention in various neurological disorders.
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PMID:Roles for NF-kappaB in nerve cell survival, plasticity, and disease. 1639 79

Neuregulins are a family of growth factor domain proteins that are structurally related to the epidermal growth factor. Accumulating evidence has shown that neuregulins have cyto- and neuroprotective properties in various cell types. In particular, the neuregulin-1 Beta (NRG1-Beta) isoform is well documented for its antiinflammatory properties in rat brain after acute stroke episodes. Pentachlorophenol (PCP) is an organochlorine compound that has been widely used as a biocide in several industrial, agricultural, and domestic applications. Previous investigations from our laboratory have demonstrated that PCP exerts both cytotoxic and mitogenic effects in human liver carcinoma (HepG2) cells, primary catfish hepatocytes and AML 12 mouse hepatocytes. We have also shown that in HepG2 cells, PCP has the ability to induce stress genes that may play a role in the molecular events leading to toxicity and tumorigenesis. In the present study, we hypothesize that NRG1-Beta will exert its cytoprotective effects in PCP-treated AML 12 mouse hepatocytes by its ability to suppress the toxic effects of PCP. To test this hypothesis, we performed the MTT-cell respiration assay to assess cell viability, and Western-blot analysis to assess stress-related proteins as a consequence of PCP exposure. Data obtained from 48 h-viability studies demonstrated a biphasic response; showing a dose-dependent increase in cell viability within the range of 0 to 3.87 microg/mL, and a gradual decrease within the concentration range of 7.75 to 31.0 microg/mL in concomitant treatments of NRG1-Beta+PCP and PCP. Cell viability percentages indicated that NRG1-Beta+PCPtreated cells were not significantly impaired, while PCP-treated cells were appreciably affected; suggesting that NRG1-Beta has the ability to suppress the toxic effects of PCP. Western Blot analysis demonstrated the potential of PCP to induce oxidative stress and inflammatory response (c-fos), growth arrest and DNA damage (GADD153), proteotoxic effects (HSP70), cell cycle arrest as consequence of DNA damage (p53), mitogenic response (cyclin- D1), and apoptosis (caspase-3). NRG1-Beta exposure attenuated stress-related protein expression in PCP-treated AML 12 mouse hepatocytes. Here we provide clear evidence that NRG1-Beta exerts cytoprotective effects in AML 12 mouse hepatocytes exposed to PCP.
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PMID:Neuregulin 1-Beta cytoprotective role in AML 12 mouse hepatocytes exposed to pentachlorophenol. 1682 72


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