Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P39060 (endostatin)
 2,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3). Growth with urea is restricted by 18.8 mm NO(3) (-), 50 mm methylammonia, 10 mm citrate or 100 mum hydroxyurea, substances which are much less restrictive or nonrestrictive in the presence of ammonia nitrogen source. The restrictive conditions of urea assimilation were examined as possible bases for selection schemes to recover urease-overproducing mutants. Since urease has higher methionine levels than the soybean seed proteins among which it is found, such selections may be a model for improving seed protein quality by plant cell culture techniques.Callus will not grow with 1 mm urea plus 18.8 mm KNO(3). Urease levels decrease 80% within two divisions after transfer from MS nitrogen source to 1 mm urea plus 18.8 mm KNO(3). Hydroxyurea is a potent inhibitor of soybean urease and this appears to be the basis for its inhibition of urea utilization by callus cells.Stationary phase suspension cultures grown with MS nitrogen source exhibit trace or zero urease levels. Soon after transfer to fresh medium (24 hours after escape from lag), urease levels increase in the presence of both MS or urea nitrogen source. However, the increase is 10 to 20 times greater in the presence of urea. NH(4)Cl (50 mm) lowers urease induction by 50% whereas 50 mm methylammonium chloride results in more drastic reductions in urea-stimulated urease levels. Citrate (10 mm) completely blocks urease synthesis in the presence of urea.Ammonia and methylammonia do not inhibit soybean urease nor do they appreciably inhibit urea uptake by suspension cultures. It appears likely that methylammonia inhibits urea utilization in cultured soybean cells primarily due to its "repressive" effect on urease synthesis.Citrate does not inhibit urease activity in vitro and exhibits only a partial inhibition (0-50% in several experiments) of urea uptake. It appears likely that the citrate elimination of urease production by cultured soybean cells is due to its chelation of trace Ni(2+) in the growth medium. Dixon et al. (J. Am. Chem. Soc. 97: 4131-4133, 1975) have reported that jack bean (Canavalia ensiformis) urease contains nickel at the active site.
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PMID:Nitrogen metabolism in soybean tissue culture: I. Assimilation of urea. 1665 77

As hypoxia-induced inflammatory angiogenesis may contribute to the manifestations of sickle cell disease, we compared the angiogenic molecular profiles of plasma from sickle cell disease individuals and correlated these with in vitro endothelial cell-mediated angiogenesis-stimulating activity and in vivo neovascularization. Bioplex demonstrated that plasma from patients with steady-state sickle cell anemia contained elevated concentrations of pro-angiogenic factors (angiopoietin-1, basic fibroblast growth factor, vascular endothelial growth factor, vascular endothelial growth factor-D and placental growth factor) and displayed potent pro-angiogenic activity, significantly increasing endothelial cell proliferation, migration and capillary-like structure formation. In vivo neovascularization of Matrigel plugs was significantly greater in sickle cell disease mice than in non-sickle cell disease mice, consistent with an up-regulation of angiogenesis in the disease. In plasma from patients with hemoglobin SC disease without proliferative retinopathy, anti-angiogenic endostatin and thrombospondin-2 were significantly elevated. In contrast, plasma from hemoglobin SC individuals with proliferative retinopathy had a pro-angiogenic profile and more significant effects on endothelial cell proliferation and capillary formation than plasma from patients without retinopathy. Hydroxyurea therapy was associated with significant reductions in plasma angiogenic factors and inhibition of endothelial cell-mediated angiogenic mechanisms and neovascularization. Thus, individuals with sickle cell anemia or hemoglobin SC disease with retinopathy present a highly angiogenic circulating milieu, capable of stimulating key endothelial cell-mediated angiogenic mechanisms. Combination anti-angiogenic therapy to prevent the progression of unregulated neovascularization and associated manifestations in sickle cell disease, such as pulmonary hypertension, may be indicated; furthermore, the benefits and drawbacks of the potent anti-angiogenic effects of hydroxyurea should be clarified.
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PMID:Key endothelial cell angiogenic mechanisms are stimulated by the circulating milieu in sickle cell disease and attenuated by hydroxyurea. 2576 45