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)

Single nucleotide polymorphisms (SNPs) in the human EPHX2 gene have recently been implicated in susceptibility to cardiovascular disease, including stroke. EPHX2 encodes for soluble epoxide hydrolase (sEH), an important enzyme in the metabolic breakdown of arachidonic acid-derived eicosanoids referred to as epoxyeicosatrienoic acids (EETs). We previously demonstrated that EETs are protective against ischemic cell death in culture. Therefore, we tested the hypothesis that polymorphisms in the human EPHX2 gene alter sEH enzyme activity and affect neuronal survival after ischemic injury in vitro. Human EPHX2 mutants were recreated by site-directed mutagenesis and fused downstream of TAT protein transduction domain. Western blot analysis and immunocytochemistry staining revealed high-transduction efficiency of human TAT-sEH variants in rat primary cultured cortical neurons, associated with increased metabolism of 14,15-EET to corresponding 14,15-dihydroxyeicosatrienoic acid. A human variant of sEH with Arg103Cys amino acid substitution, previously demonstrated to increase sEH enzymatic activity, was associated with increased cell death induced in cortical neurons by oxygen-glucose deprivation (OGD) and reoxygenation. In contrast, the Arg287Gln mutation was associated with reduced sEH activity and protection from OGD-induced neuronal cell death. We conclude that sequence variations in the human EPHX2 gene alter susceptibility to ischemic injury and neuronal survival in a manner linked to changes in the hydrolase activity of the enzyme. The findings suggest that human EPHX2 mutations may in part explain the genetic variability in sensitivity to ischemic brain injury and stroke outcome.
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PMID:Polymorphisms in the human soluble epoxide hydrolase gene EPHX2 linked to neuronal survival after ischemic injury. 1746 77

Neuroglobin (Ngb) is a heme protein that is primarily localised in the retina and the brain. Its physiological role is largely unknown. It has been reported that its overexpression protects neurons from hypoxia in vitro and in vivo, suggesting that the rapid modulation of the Ngb level in the nerve cells may be a promising stroke treatment strategy. In this study, we used a novel approach to overexpress Ngb and evaluate its ability to promote neuronal survival under hypoxic conditions. We constructed a human recombinant Ngb fused to the cell penetrating peptide (CPP) derived from HIV-1 TAT. Purified recombinant TAT-Ngb was able to efficiently transduce CHO and SHSY5Y cells, when added to the culture media. The potential neuroprotective action of Ngb was then examined by using an in vitro model of ischemia. The two neuronal cell lines RGC-5 and SH-SY5Y were subjected to oxygen glucose deprivation (OGD) after pre-treatment with TAT-Ngb. In both cell types, however, the treatment with the TAT-Ngb fusion protein did not show any effect on cell viability. This discrepancy to earlier reports might be due to the experimental model for oxygen glucose deprivation we employed. Alternatively, intracellular delivery of Ngb by the TAT/CPP might not have beneficial effects in the treatment of ischemic pathology.
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PMID:Intracellular delivery of Neuroglobin using HIV-1 TAT protein transduction domain fails to protect against oxygen and glucose deprivation. 1756 57

Many practical therapies have been explored as clinical applications for ischemic cerebral infarction; however, most are still insufficient to treat acute stroke. We show here a potential combination therapy in a rat focal ischemic model to improve neurological symptoms as well as to reduce infarct volumes at the maximum level. We applied protein transduction technology using artificial anti-death Bcl-xl derivative with three amino acid-substitutions (Y22F, Q26N and R165K) (FNK) protein fused with a protein-transduction-domain peptide (PTD-FNK). When PTD-FNK was administrated 1 h after initiating ischemia followed by the administration of an immunosuppressant FK506 with a 30-min time lag, infarct volumes of the total brain and cortex were markedly reduced to 27% and 14%, respectively. This procedure not only reduced the infarct volume and edema, but also markedly improved neurological symptoms. The therapeutic effect continued for at least 1 week after ischemia. FK506 inhibited the transduction of PTD-FNK in vitro, which explains the requirement of a time lag for the administration of FK506. An additional in vitro experiment showed that PTD-FNK, when administered 30 min before FK506, gave the maximal protective effect by reducing the intracellular calcium concentration. We propose that this combination therapy would provide a synergistic protective effect by both drugs, reducing adverse the effects of FK506.
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PMID:Combination therapy with transductive anti-death FNK protein and FK506 ameliorates brain damage with focal transient ischemia in rat. 1836 25

Rapid prototyping (RP) is a useful method for designing and fabricating a wide variety of devices used for neuroscience research. The present study confirms the utility of using fused deposition modeling, a specific form of RP, to produce three devices commonly used for basic science experimentation. The accuracy and precision of the RP method varies according to the type and quality of the printer as well as the thermoplastic substrate. The printer was capable of creating device channels with a minimum diameter of 0.4 or 0.6mm depending on the orientation of fabrication. RP enabled the computer-aided design and fabrication of three custom devices including a cortical recording/stroke induction platform capable of monitoring electrophysiological function during ischemic challenge. In addition to the recording platform, two perfusion chambers and a cranial window device were replicated with sub-millimeter precision. The ability to repeatedly modify the design of each device with minimal effort and low turn-around time is helpful for oft-unpredictable experimental conditions. Results obtained from validation studies using both the cortical recording platform and perfusion chamber did not vary from previous results using traditional hand-fabricated or commercially available devices. Combined with computer-aided design, rapid prototyping is an excellent alternative for developing and fabricating custom devices for neuroscience research.
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PMID:Rapid prototyping for neuroscience and neural engineering. 1856 90

We describe an apparatus for dielectric spectroscopy (DS) experiments on ultrathin (<100 nm) molecular films in an ultrahigh vacuum (UHV) environment. The apparatus is capable of measurements of ex situ prepared films, as well as in situ physisorbed or chemisorbed layers. Pressures of 5x10(-10) Torr are typical, and the audiofrequency DS measurements can be performed over a range of temperatures 7-500 K, using a continuous-flow cold finger. The combination of turbomolecular pump, differentially pumped quick-access door, and backfilling with dry N(2) affords vent-exchange-pump cycle times under an hour. The system pressure returns to the 10(-9) Torr scale within 48 h, without a high-temperature bake. Since the cold finger is mounted on a long-stroke translation stage, the apparatus can be attached to other analytical UHV equipment, and the sample may be transferred for additional in situ measurements. Film dielectric properties are probed via coplanar interdigital electrode capacitors, which are microfabricated on fused SiO(2) wafers. Besides permitting the usual equilibrium dielectric measurements, the system also provides a novel way to study adsorption/desorption phenomena and film growth.
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PMID:A surface-sensitive UHV dielectric spectrometer for studies of nanoscale molecular systems on a planar surface. 1904 26

Recent reports have shown that bone marrow-derived cells (BMDCs) contribute to the formation of vasculature after stroke. However, the mechanism by which mural cells are formed from BMDC remains elusive. Here, we provide direct evidence that the cell fusion process contributes to the formation of pericytes after stroke. We generated mouse bone marrow chimeras using a cre/lox system that allows the detection of fusion events by X-gal staining. In these mice, we detected X-gal-positive cells that expressed vimentin and desmin, specific markers of mature murine pericytes. Electron microscopy confirmed that fused cells possessed basal lamina and characteristics of pericytes. Furthermore, induction of stroke increased significantly the presence of fused cells in the ischemic area. These cells expressed markers of developing pericytes such as NG2. We conclude that cell fusion participates actively in the generation of vascular tissue through pericyte formation under normal as well as pathologic conditions.
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PMID:Cell fusion contributes to pericyte formation after stroke. 1906 13

A new generation of multifunctional fusion proteins presents a potential solution to overcome the challenges associated with brain drug delivery and development of treatments for neurological disorders, including stroke, Alzheimer's disease, Parkinson's disease and inherited mucopolysaccharidosis. These biotherapeutics are engineered i) to cross the blood-brain barrier (BBB) following i.v. administration and ii) to produce a brain therapeutic effect. These fusion proteins are comprised of both a transport and a therapeutic domain. The transport domain is a monoclonal antibody (MAb) directed to an exofacial epitope of the BBB human insulin receptor (HIR), which uses the BBB endogenous insulin transport system to gain access to the brain via receptor-mediated transcytosis without interfering with the normal transport of insulin. Both human-chimeric and fully humanized versions of the anti-human HIRMAb have already been produced. The therapeutic domain of these fusion proteins consists of the peptide or protein of interest fused to the carboxyl terminus of the C(H)3 region of the heavy chain of the anti-human HIRMAb. A variety of HIRMAb fusion proteins were engineered aiming at the development of therapeutics for the central nervous system (CNS), i.e., stroke and Parkinson's disease, as in the case of HIRMAb-BDNF and HIRMAb-GDNF, respectively, HIRMAb-IDUA for the treatment of Hurler's disease, HIRMAb-A beta single chain antibody for passive immunotherapy of Alzheimer's disease, and HIRMAb-avidin as delivery system for biotinylated drugs, like siRNAs. The multifunctionality of these fusion proteins has been validated in preclinical work, including brain update in primates. Pending further development into pharmacological and toxicological studies, and clinical trials, members of the biotherapeutic family discussed in the present review, designed to overcome the brain drug delivery hurdle, are positioned to become a new generation of neuropharmaceutical drugs for the treatment of human CNS disorders.
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PMID:A new generation of neurobiological drugs engineered to overcome the challenges of brain drug delivery. 1918 Feb 67

Cerebral ischemia stimulates endogenous neurogenesis within the subventricular zone and the hippocampal dentate gyrus of the adult rodent brain. However, such newly generated cells soon die after cerebral ischemia. To enhance postischemic survival of neural precursor cells (NPC) and long-lasting neural regeneration, we applied the antiapoptotic chaperone heat shock protein 70 (Hsp70) fused to a cell-penetrating peptide derived from the HIV TAT to ensure delivery across the blood-brain barrier and the cell membrane. After transient focal cerebral ischemia in mice, TAT-Hsp70 was intravenously injected concomitant with reperfusion and additionally on day 14 after stroke. TAT-Hsp70 treatment resulted in smaller infarct size (27.1+/-9.0 versus 109.0+/-14.0 and 88.5+/-26.0 mm(3) in controls) and in functional improvement as assessed by the rota rod, tight rope, and water maze tests when compared with saline- and TAT-hemagglutinin-treated controls. In addition, postischemic survival of endogenous doublecortin (Dcx)-positive NPC was improved within the lesioned striatum of TAT-Hsp70-treated animals for up to 4 weeks after stroke without changing overall cell proliferation of BrdU(+) cells. Thus, TAT-Hsp70 treatment after stroke may be a promising tool to act neuroprotective and improve postischemic functional outcome, and also to increase survival of endogenous NPC after stroke.
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PMID:TAT-Hsp70-mediated neuroprotection and increased survival of neuronal precursor cells after focal cerebral ischemia in mice. 1938 35

An ideal therapeutic for stroke or spinal cord injury should promote survival and regeneration in the CNS. Arginase 1 (Arg1) has been shown to protect motor neurons from trophic factor deprivation and allow sensory neurons to overcome neurite outgrowth inhibition by myelin proteins. To identify small molecules that capture Arg1's protective and regenerative properties, we screened a hippocampal cell line stably expressing the proximal promoter region of the arginase 1 gene fused to a reporter gene against a library of compounds containing clinically approved drugs. This screen identified daidzein as a transcriptional inducer of Arg1. Both CNS and PNS neurons primed in vitro with daidzein overcame neurite outgrowth inhibition from myelin-associated glycoprotein, which was mirrored by acutely dissociated and cultured sensory neurons primed in vivo by intrathecal or subcutaneous daidzein infusion. Further, daidzein was effective in promoting axonal regeneration in vivo in an optic nerve crush model when given intraocularly without lens damage, or most importantly, when given subcutaneously after injury. Mechanistically, daidzein requires transcription and induction of Arg1 activity for its ability to overcome myelin inhibition. In contrast to canonical Arg1 activators, daidzein increases Arg1 without increasing CREB phosphorylation, suggesting its effects are cAMP-independent. Accordingly, it may circumvent known CNS side effects of some cAMP modulators. Indeed, daidzein appears to be safe as it has been widely consumed in soy products, crosses the blood-brain barrier, and is effective without pretreatment, making it an ideal candidate for development as a therapeutic for spinal cord injury or stroke.
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PMID:A large-scale chemical screen for regulators of the arginase 1 promoter identifies the soy isoflavone daidzeinas a clinically approved small molecule that can promote neuronal protection or regeneration via a cAMP-independent pathway. 2007 39

The optimum conditions for arc-fusion splicing of single-mode fibers with core eccentricity of a few microns are investigated in detail. A narrow, quick fusion method, where the fiber-fused region is restricted by the narrowing of the electrode gap and the arc-discharge time is short compared with the conventional multi-mode fiber splice, is presented that will reduce the surface tension effect. The optimum values of electrode gap, prefusion time, and discharge duration are found to be 0.7 mm, 0.2 sec, and 1 sec, respectively, when the discharge current is 18 mA. The optimum pressing stroke of a fiber after the fiber end faces contact each other is determined to be 20 microm. Splice loss <0.1 dB is achieved in the present conditions for fibers with 2-microm core eccentricity and +/-3-microm o.d. discrepancy.
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PMID:Arc-fusion splicing of single-mode fibers. 1: Optimum splice conditions. 2038 54


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