Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.3.1 (NADPH oxidase)
 11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Efficient ex vivo/in vivo selection of genetically modified hematopoietic stem/progenitor cells (HPCs) and T lymphocytes could greatly improve several gene therapy strategies. We have previously reported that primary murine HPCs, transduced with a bicistronic retroviral vector, co-expressing the catalytic subunit of gamma-glutamylcysteine synthetase (gamma-GCSh) and eGFP, could be selected by l-buthionine-S,R-sulfoximine (BSO). Upon ex vivo transduction with a low, defined gene dosage and BSO selection, HPCs were able to repopulate the bone marrow of syngeneic myeloablated hosts, showing multi-lineage expression [Hum Gene Ther, 16 (2005), 711]. We now provide 'proof-of-principle' that the same strategy can be applied to the gene therapy of graft-vs.-host disease (GVHD) subsequent to allogeneic bone marrow transplantation (ABMT), and of chromosome X-associated chronic granulomatous disease (CGD). Transfer of the herpes simplex virus-thymidine kinase (HSV-Tk) 'suicide' gene into donor T lymphocytes is a potential method to control GVHD after ABMT. However, an efficient selection system is required to eliminate non-HSV-Tk-expressing T lymphocytes before administration to the patient. We now report that, upon transduction with a retroviral vector, co-expressing gamma-GCSh and eGFP, and subsequent selection by BSO, over 95% human T lymphocytes were found to express eGFP; moreover, upon transduction with a novel retroviral vector co-expressing gamma-GCSh and HSV-Tk, and subsequent BSO treatment, over 95% of T lymphocytes could be eliminated by ganciclovir. The efficacy of the gamma-GCSh-BSO selection strategy was then tested on an in vitro model of CGD. Upon transduction of gp91 (phox)-deficient PLBKO cells with a novel bicistronic retroviral vector co-expressing human gp91 (phox) and gamma-GCSh, exposure to BSO for 48 h eliminated most non-transduced cells, resulting in selection of gp91 (phox)-expressing cells, and reconstitution of NADPH oxidase activity.
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PMID:Gamma-glutamylcysteine synthetase-based selection strategy for gene therapy of chronic granulomatous disease and graft-vs.-host disease. 1733 Nov 33

FaO rat hepatoma cells show increased levels of the epidermal growth factor receptor (EGFR) ligands, when compared with adult normal hepatocytes, and higher activity of the TNF-alpha converting enzyme (TACE/ADAM17), which is required for EGFR ligand proteolysis and activation. In this work we have analysed the consequences of inhibiting the EGFR in FaO rat hepatoma cells, focusing the attention on autocrine growth and protection from apoptosis. Results have indicated that FaO cells show overactivation of the EGFR pathway, which induces basal growth (in the absence of serum) and protection from pro-apoptotic agents, such as doxorubicin, generating drug resistance. Treatment of cells with the combination of doxorubicin and the tyrphostin 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478, a potent and specific inhibitor of EGFR tyrosine kinase) potently inhibits autocrine growth and induces apoptosis. The apoptotic effect correlates with high expression and activation of the pro-apoptotic Bax and decreased transcript and protein levels of the anti-apoptotic Mcl-1 and Bcl-x(L). Furthermore, the combination of AG1478 and doxorubicin induces reactive oxygen species (ROS) production and glutathione depletion in FaO cells, coincident with up-regulation of the NADPH oxidase NOX4 and down-regulation of the gamma-glutamylcysteine synthetase (gamma-GCS), a key regulatory enzyme of the glutathione synthesis. Incubation of cells with glutathione ethyl ester attenuates the apoptosis induced by the combination of doxorubicin and AG1478, which indicates that glutathione depletion is required for an efficient cell death. In conclusion, targeting EGFR combined with other conventional pro-apoptotic drugs should potentially be effective in antineoplastic therapy towards liver cancer.
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PMID:Inhibition of the EGF receptor blocks autocrine growth and increases the cytotoxic effects of doxorubicin in rat hepatoma cells: role of reactive oxygen species production and glutathione depletion. 1837 37

Previously, we have demonstrated that leptin increases blood pressure (BP) in the rats through two oxidative stress-dependent mechanisms: stimulation of extracellular signal-regulated kinases (ERK) by H(2)O(2) and scavenging of nitric oxide (NO) by superoxide (O(2-.)). Herein, we examined if renal glutathione system and antioxidant enzymes determine the mechanism of prohypertensive effect of leptin. Leptin administered at 0.5 mg/kg/day for 4 or 8 days increased BP and renal Na(+),K(+)-ATPase activity and reduced fractional sodium excretion; these effects were prevented by NADPH oxidase inhibitor, apocynin. Superoxide scavenger, tempol, abolished the effect of leptin on BP and renal Na(+) pump in rats receiving leptin for 8 days, whereas ERK inhibitor, PD98059, was effective in animals treated with leptin for 4 days. Leptin administered for 4 days decreased glutathione (GSH) and increased glutathione disulfide (GSSG) in the kidney. In animals receiving leptin for 8 days GSH returned to normal level, which was accompanied by up-regulation of gamma-glutamylcysteine synthetase (gamma-GCS), a rate-limiting enzyme of the GSH biosynthetic pathway. In addition, superoxide dismutase (SOD) activity was decreased, whereas glutathione peroxidase (GPx) was increased in rats receiving leptin for 8 days. Cotreatment with gamma-GCS inhibitor, buthionine sulfoximine (BSO), accelerated, whereas GSH precursor, N-acetylcysteine (NAC), attenuated leptin-induced changes in gamma-GCS, SOD, and GPx. In addition, coadministration of BSO changed the mechanism of BP elevation from H(2)O(2)-ERK to (O(2-.))-NO dependent in animals receiving leptin for 4 days, whereas NAC had the opposite effect in rats treated with leptin for 8 days. These results suggest that initial change in GSH redox status induces decrease in SOD/GPx ratio, which results in greater amount of (O)2-.)) versus H(2)O(2) in later phase of leptin treatment, thus shifting the mechanism of BP elevation from H(2)O(2)-ERK to (O(2-.))-NO dependent.
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PMID:Renal antioxidant enzymes and glutathione redox status in leptin-induced hypertension. 1869 Apr 14

Glutathione, being a major intracellular redox regulator has been shown to be implicated in regulation of airway reactivity and inflammation. However, no study so far has investigated the effect of glutathione depletion/repletion during sensitization and challenge phases separately, which could provide an important insight into the pathophysiology of allergic asthma. The aim of the present study was to evaluate the role of glutathione depletion/repletion during sensitization and challenge phases separately in a mouse model of allergic asthma. Buthionine sulphoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase or N-acetyl cysteine (NAC), a thiol donor were used for depletion or repletion of glutathione levels respectively during both sensitization and challenge phases separately followed by assessment of airway reactivity, inflammation and oxidant-antioxidant balance in allergic mice. Depletion of glutathione with BSO during sensitization as well as challenge phase worsened allergen induced airway reactivity/inflammation and caused greater oxidant-antioxidant imbalance as reflected by increased NADPH oxidase expression/reactive oxygen species (ROS) generation/lipid peroxides formation and decreased total antioxidant capacity. On the other hand, repletion of glutathione pool by NAC during sensitization and challenge phases counteracted allergen induced airway reactivity/inflammation and restored oxidant-antioxidant balance through a decrease in NADPH oxidase expression/ROS generation/lipid peroxides formation and increase in total antioxidant capacity. Taken together, these findings suggest that depletion or repletion of glutathione exacerbates or ameliorates allergic asthma respectively by regulation of airway oxidant-antioxidant balance. This might have implications towards increased predisposition to allergy by glutathione depleting environmental pollutants.
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PMID:Glutathione modulation during sensitization as well as challenge phase regulates airway reactivity and inflammation in mouse model of allergic asthma. 2474 80