【大杂烩】导语，您眼前所欣赏的此篇文章共有15730文字，由卞皓丽专心修订后，上传于范万文网！范万文小百科：
ACID，是指数据库管理系统（DBMS）在写入或更新资料的过程中，为保证事务（transaction）是正确可靠的，所必须具备的四个特性：原子性（atomicity，或称不可分割性）、一致性（consistency）、隔离性（isolation，又称独立性）、持久性（durability）。
Adrenomedullin Regulates Cellular Glutathione Content via Modulation of -Glutamate-Cysteine Ligase C五篇如果你对这文章感觉哪里不好，可以发表分享给大家！
第一篇 Adrenomedullin Regulates Cellular Glutathione Content via Modulation of -Glutamate-Cysteine Ligase C
【关键词】 glutamate
department of pathology (j.-y.k., j.-h.l., j.-h.ko., j.-k.n., j.-h.p.) and pharmacology (s.p.), medical research center for bioreaction to reactive oxygen species, college of medicine, kyung hee university, seoul 130-701, korea
department of orthopedic surgery (j.-h.ki., j.-h.c.), college of medicine, inje university, busan 614-735, korea
abstract
adrenomedullin (am) participates in a wide range of physiological and pathological processes including vasorelaxation, angiogenesis, cancer promotion, and apoptosis. recently, it has been reported that am protects a variety of cells against oxidative stress induced by stressors such as hypoxia, ischemia/reperfusion, and hydrogen peroxide through the phosphatidylinositol 3-kinase (pi3k)-dependent pathway. however, the molecular mechanis underlying the pathway of cell survival against hypoxic injury are largely unknown. in an effort to investigate the survival mechani against hypoxic injury, we studied the effects of am on cellular levels of reactive oxygen species, well-known mediators of cell death after oxidative stress, and the mechani involved in the regulation of reactive oxygen species levels. here, we show that am increases -glutamate-cysteine ligase (-gcl) activity under both hypoxic and normoxic conditions, resulting in an up-regulation of cellular glutathione levels to more than 2-fold higher than basal expression. in addition, we demonstrate that am induces concentration-dependent expression of the catalytic subunit of -gcl (-gclc) at the mrna and protein levels through the activation of the -gclc promoter fragment sequence from 597 to 320. however, when treated with the pi3k inhibitors, the effects of am on -gclc expression were completely abrogated, suggesting that a pi3k pathway linked am with the transcriptional activation of the -gclc promoter. taken together, our data suggests that am participates in the regulation of cellular redox status via glutathione synthesis. these results may explain, in part, the mechani by which am protects cells against oxidative stress.
introduction
adrenomedullin (am), initially identified in human pheochromocytoma (1), is a member of the calcitonin gene-related peptide family. it is synthesized as an inactive, 185-residue precursor protein and released as a mature, 52-residue amide structure peptide (2). upon secretion, it binds to the g protein-coupled calcitonin receptor-like receptor (crlr) (3) and exerts autocrine and paracrine effects. many lines of evidence have shown that am possesses several other biological effects in addition to its well-known vasoactive activity (4). these include cell proliferation (5), differentiation (6), and oxidative stress-induced cell death inhibition (7). recently, the inhibition of the redox-sensitive c-jun amino-teminal kinase (jnk) has been suspected as a putative pathway responsible for the antioxidant effects of am (8). however, the underlying cellular mechanis in the regulation of cellular redox status have not yet been clarified.
glutathione [l--glutamyl-cysteinyl-glycine (gsh)] is an abundant tripeptide thiol involved in the maintenance of cellular redox balance inside mammalian cells (9). it is present in either a reduced or oxidized form, with the reduced form predominating under normal physiological conditions (10). in addition to redox status, imbalance in gsh expression has been implicated in a variety of circumstances, including cancer and neurodegenerative diseases (11). hence, tight regulation of cellular gsh content is imperative to normal physiological cellular function.
the de novo synthesis of gsh is regulated at several levels in cells and requires the consecutive action of two atp-dependent enzymes: -glutamate-cysteine ligase (-gcl) and gsh synthase (gs) (10). -gcl is the first and rate-limiting enzyme in gsh synthesis; it combines glutamate and cysteine through the -carboxyl moiety. structurally, -gcl is a heterodimer composed of a catalytically active heavy subunit (-gclc) and a regulatory subunit (-gclm) (12, 13). -gclm modulates the km of the enzyme for glutamate and its sensitivity to feedback inhibition by gsh (14, 15). increased de novo synthesis of gsh is primarily a result of increased synthesis of the -gclc subunit through a combination of increased transcription and mrna stability (16). the regulation of gsh biosynthesis by -gcl in response to various environmental and oxidative stresses is currently the focus of much investigation.
the purpose of this study was to investigate the molecular mechanis by which am inhibits hypoxia-induced cell death in association with the redox regulator gsh and its synthetic pathway.
materials and methods
cell culture, hypoxic conditions, and reagents
the human type ii alveolar epithelial cell line, a549, was purchased from american type culture collection (rockville, md) and cultured in rpmi medium containing 10% fbs in a 5% co2 atmosphere. for hypoxic conditions, cells in medium degassed with 95% n2 and 5% co2 were transferred to a hypoxic chamber (ruskinn, bridgend, uk) equipped with an air lock and continuously gassed with 0.5% o2 and 5% co2 (with the remainder as nitrogen). human am and goat antihuman am antibodies were purchased from bachem (bubendorf, switzerland). 4-hydroxynonenal and protein kinase inhibitors (ly294002, wortmannin, bisindolylmaleimide, and autocamtide-2) were purchased from cayman chemical (ann arbor, mi) and calbiochem (san diego, ca), respectively. all other reagents were obtained from sigma-aldrich, inc. (st. louis, mo), unless otherwise specified.
cell death assay
hypoxia-induced cell death was evaluated by the morphological observation of pyknotic, shrunken nuclei and fragmented apoptotic bodies after 4',6-diamidino-2-phenylindole (dapi) staining. the second method for evaluating damaged cells was performed using the trypan blue exclusion test.
detection of reactive oxygen species (ros)
2',7'-dichlorofluorescin diacetate (dcf-da), shown to be relatively specific for hydrogen peroxide, was used to measure ros. the cells were harvested and suspended in culture medium with 0.2% fetal bovine serum. twenty micromolar dcf-da was then added and incubated for 20 min at 37 c. the fluorescent intensity was measured by flow cytometry (facscalibur, becton-dickinson, franklin lakes, nj) or observed using a fluorescence microscope.
determination of gsh levels and assay for gs and -gcl activity
total intracellular gsh content was measured using an assay kit obtained from oxis international inc. (portland, or) according to the manufacturer’s protocol. gs activity was determined by measuring the formation of adp in reaction mixtures containing the enzyme and its substrates (17). the reaction mixture contained 100 mm tris-hcl buffer (ph 8.2), 50 mm kcl, 5 mm l--glutamyl-l--aminobutyrate, 10 mm atp, 5 mm glycine, 20 mm mgcl2, 2 mm edta, and extract in a final volume of 0.1 ml. the assay mixture was incubated for 2.530 min at 37 c. to measure adp levels, the reaction mixtures were treated with 0.02 ml 10% sulfosalicylic acid and 0.9 ml of a solution containing 0.5 mm phosphoenolpyruvate, 0.2 mm reduced nicotinamide adenine dinucleotide (nadh), 1 u pyruvate kinase, 40 mm magnesium chloride, 50 mm potassium chloride, and 250 mm potassium phosphate buffer (ph 7.0). the amount of adp formed was calculated from the observed change in absorbance at 340 nm after the addition of 0.1 ml (1 u) lactate dehydrogenase. enzymatic activity was measured as change in absorbance per minute per milligram protein. -gcl activity was determined as described previously (18). briefly, enzyme activity was determined at 37 c in reaction mixtures of 1.0 ml containing 100 mm tris-hcl buffer (ph 8.2), 150 mm kcl, 5 mm atp, 2 mm phosphoenolpyruvate, 10 mm l-glutamate, 10 mm l--aminobutyrate, 20 mm mgcl2, 2 mm edta, 0.2 mm nadh, 17 μg pyruvate kinase, and 17 mg lactate dehydrogenase. the reaction was initiated by adding extract, and the rate of absorbance decrease at 340 nm was monitored. enzyme-specific activity was measured as micromoles of nadh oxidized per minute per milligram protein; this is equal to 1 iu. for each assay, bsa was added to the cell extracts to determine the specificity of the -gcl assay.
real-time rt-pcr of -gclc and -gclm mrna
-gclc and -gclm mrna levels were quantified with real-time pcr using the level of glyceraldehyde-3-phosphate dehydrogenase (gapdh) mrna as an internal standard. total rna (1 μg) was reverse transcribed using moloney murine leukemia virus reverse transcriptase (gibco brl, carlad, ca) with random hexamer priming. the resultant cdna was amplified using a lightcycler (roche diagnostics ltd., lewes, uk). real-time pcr ysis was carried out with the lightcycler-faststart dna master sybr green i mix (roche diagnostics) and specific primers for gapdh, -gclc, and -gclm. the sequences of the gene-specific primers were as follows: -gclc (nm 001498) sense, 5'-agt tca ata cag ttg agg-3', and antisense, 5'-tac tga tcc tat agt tat-3'; gclm (nm 002061) sense, 5'-cag ttg aca tgg cct gtt cag-3', and antisense, 5'-tca aat ctg gtg gca tca cac-3'; gapdh sense, 5'-aac cat gag aag tat gac aac-3', and antisense, 5'-ctg ctt cac cac ctt ctt gat-3'. the expression level of each mrna and their estimated crossing points were determined relative to the standard preparation using the lightcycler computer software.
western blot
a549 cells were harvested and suspended in a lysis buffer containing 10 mm tris-hcl (ph 7.4), 1% triton x-100, 0.1% sodium deoxycholate, 0.1% sds, 150 mm nacl, 1 mm edta, 1 mm egta, 0.5 mm phenylmethylsulfonyl fluoride, 1.1 mm na3vo4, and 10 mm naf. extracted proteins were separated by sds-page on 12% polyacrylamide gels and electrophoretically transferred onto nylon membranes. the membranes were probed with anti--gclc or antitubulin antibody (abcam, cambridge, uk), followed by incubation with antirabbit igg horseradish peroxidase-coupled secondary antibody. detection was performed with an ecl system (intron, seoul, korea).
promoter assay
the -gclc promoter and its fragments were amplified by pcr from genomic dna using the upstream oligonucleotides f1 (5'-ttt aat gag ata ttt aca-3') (pgl-gclc-1), f2 (5'-atg ata aat aca cac ttt-3') (pgl-gclc-2), f3 (5'-tga gtt cga cat tga ttc-3') (pgl-gclc-3), f4 (5'-tcc tga gcc ccc gtt-3') (pgl-gclc-4), and f5 (5'-agc ggc acg cgc ctt ctg-3') (pgl-gclc-5) and the r1 downstream oligonucleotide (5'-act aca gag tta aca ttt-3'); these were sequenced and cloned into the pgl2 luciferase assay vector (promega, san luis obispo, ca). the luciferase reporter vector was transiently transfected using transfast (promega). luciferase activity was measured on samples containing equivalent amounts of protein using a luminometer (perkinelmer, fremont, ca) and luciferase assay reagents (promega).
statistical ysis
all data are presented as mean ± sd from three or more independent experiments. statistical significance was assessed with one-way anova, followed by dunnett’s multiple-range test. p values less than 0.05 were considered statistically significant.
results
effects of am on hypoxia-induced apoptotic cell death
to evaluate the effects of am on hypoxia-induced cell death, a549 lung epithelial cells were subjected to hypoxia (0.5% o2) for different time intervals in the presence and absence of 109 m am. hypoxia reduced cell viability, resulting in 38% cell death after 12 h (fig. 1a). the death induced by 0.5% hypoxic treatment appeared to be characteristic of apoptosis; cells shrunk and their nuclei were condensed or fragmented (fig. 1b, left). however, treatment with 109 m am, which was added to culture medium 3 h before hypoxia, decreased the cell death rate to 8% after 12 h of hypoxia (fig. 1, a and b, right). to confirm the effects of am on hypoxic cell death, cells were treated with the indicated concentration of am and subjected to hypoxia for 12 h. the rate of cell death decreased in a concentration-dependent manner (fig. 1c). our results show that am suppressed hypoxia-induced apoptotic cell death in a concentration-dependent manner.
am attenuates hypoxia-induced cellular increases in ros
although hypoxic stress signals through a variety of effector molecules, ros is central in hypoxia-induced cytotoxic injury. the results described above led us to examine whether am affects ros levels during hypoxic injury. to this end, a549 cells were exposed to hypoxia for 6 h in the presence and absence of 109 m am and the ros level was determined using dcfh-da fluorescent dye. pretreatment of cells with am 3 h before hypoxia attenuated hypoxia-induced increases in ros levels (fig. 2a). next, we determined whether am was effective in the suppression of increases in ros levels by exogenous h2o2. a549 cells were pretreated with 108 m am for 3 h or untreated and then exposed to 100 nm h2o2. as shown in fig. 2b, am efficiently suppressed increases in ros levels by exogenous h2o2. however, cotreatment of am with hypoxia or h2o2 was not effective in suppressing ros increases, suggesting that prior activation of the signaling pathways was needed for ros scavenging activity of am (data not shown). our data may suggest that the increases of intracellular ros scavenging activity contributed to am-induced ros attenuation.
effect of am on cellular gsh content
gsh is the most abundant low-molecular-weight thiol found in mammalian cells, and it participates in the scavenging of free radicals. therefore, we next decided to examine whether ros attenuation driven by am treatment was associated with cellular gsh content. a549 cells were exposed to hypoxia (2% o2 for the maintenance of cell viability) or normoxia for different time intervals in the presence and absence of 109 m am and were subjected to a measurement of total gsh content. as shown in fig. 3, am increased gsh levels by up to 59% over the untreated control cells after 4 h of treatment (h1). furthermore, the increased levels of gsh were maintained for 6 h against hypoxia in am-treated cells; on the other hand, gsh levels in untreated cells decreased to 73% of those seen in normoxic cells after 6 h of hypoxia (p < 0.01). cell viability remained over 90% after all hypoxic treatments. together, our data imply that am increased gsh levels (even in normoxic cells) and maintained them against hypoxic stress.
effect of am on -gcl and gs activity
the synthesis of gsh from its constituent amino acids results from the concerted effort of two atp-dependent enzymes, -gcl and gs (19). to investigate whether the up-regulation of gsh levels by am resulted from increased activity of gsh synthetic enzymes, we determined the effects of am on the activity of -gcl and gs. cells were cultured in normoxia or hypoxia (2% o2) in the presence and absence of 109 m am for different time intervals; -gcl activities were then determined. as shown in fig. 4, -gcl activity was significantly elevated in am-treated cells irrespective of oxygen concentration (normoxia or hypoxia) (p < 0.01), compared with untreated cells. cell viability did not affect enzyme activity, because it remained above 90% after all of the treatments. we next determined the activity of gs in association with am-induced gsh up-regulation. however, a significant increase in gs activity was not noted (data not shown).
effect of am on -gcl protein and mrna expression
to investigate the mechanis involved in the increase in -gcl activity, we examined changes in -gclc expression after am treatment at both the mrna and protein levels, because -gcl activity is regulated by the expression of the catalytic subunit of -gcl (20). to determine the quantitative difference in -gclc mrna expression between am-treated and untreated cells, we performed real-time pcr. steady-state levels of -gclc mrna were determined and normalized to gapdh. as shown in fig. 5a, a significant increase in -gclc mrna levels (relative to the controls) was detected in am-treated cells in a concentration-dependent manner. 4-hydroxynonenal (hne), known to induce -gclc mrna expression, was used as a positive control (21). protein levels of -gclc, as detected by immunoblot, were in line with mrna expression levels (fig. 5b). our data indicate that am increased the expression of both -gclc mrna and protein.
effect of am on -gclc promoter construct-derived luciferase activity
next, to determine whether the increased -gclc mrna levels induced by am reflected mrna stabilization or increased transcriptional rate, we performed a functional ysis of partial -gclc promoter fragments subcloned into pgl2 luciferase reporter plaids. the transcriptional activities of various pgl-luc reporter plaids containing successively deleted 5'-flanking sequences of the -gclc gene were determined in am-treated and untreated cells (fig. 6a). as shown in fig. 6b, the transcriptional activities of pgl-gclc-1, -2, -3, -4, and -5 in am-treated cells were 4- to 6-fold higher than those observed in untreated cells. however, the transcriptional activity of the reporter plaid was decreased to the level of pgl-basic when the sequence from 597 to 320 bp was deleted, suggesting that this sequence was responsible for am-induced transcriptional up-regulation. this region contains activator protein 2 (ap2), sequence-specific dna-binding protein 1 (sp1), metal response element (mre), and gc factor (gcf) transcriptional factor binding sites. however, deletion of each binding site did not completely abolish luciferase activity, relative to pgl-gclc-1 (data not shown).
inhibition of phosphatidylinositol 3-kinase (pi3k) abolishes the effects of am on -gclc
it has been known that a pi3k-dependent pathway plays a pivotal role in am-associated cell survival against cytotoxic signals such as ischemia and reperfusion (22). to investigate the signaling pathways responsible for the am-induced transcriptional up-regulation of -gclc, we treated cells with the various protein kinase inhibitors including pi3k and measured -gclc expression and -gcl activity in am-treated and untreated cells. as shown in fig. 7a, pi3k inhibitors abolished the increase of -gcl activity induced by am to near basal levels whereas protein kinase a, protein kinase c, and calmon kinase inhibitors failed to suppress the -gcl activity. in addition, transcriptional induction of -gclc mrna and protein was suppressed by pi3k inhibitors (fig. 7, bd). these results suggest that am exerted its modulatory effects on -gcl through a pi3k-dependent pathway.
discussion
induction of intracellular gsh synthesis occurs in response to various cellular stresses, including hypoxia and ischemia. it may play a pivotal role in cellular tolerance to oxidative stress. in the present study, we demonstrated that am up-regulated cellular gsh contents through the induction of -gcl, the regulatory and rate-limiting enzyme in gsh biosynthesis. we also showed that the am-associated increase in -gcl was a result of direct transcriptional activation of the -gclc promoter region via a pi3k-dependent pathway.
there is a growing body of evidence demonstrating that am exerts a wide range of effects on cell growth and apoptotic death and that these effects are dependent on cell type, stress type, and experimental conditions. recently, it has been reported that am may protect against oxidative stress as an endogenous antioxidant (8, 23); furthermore, diverse signaling molecules, such as pi3k and protein tyrosine kinase(s), have been suspected as putative mediators in cell survival pathways (7, 22, 24, 25). however, much remains unknown about the cellular mechanis underlying oxidation-reduction status regulation by am.
although cellular oxidative stresses result in the activation of several signaling pathways, such as c-jun nh2-terminal kinase (jnk) and erk, elevated ros levels are central in their cytotoxic pathways (26). our initial data showed that am rescued cells against hypoxia and suppressed ros elevation induced by oxidative stress. in line with our data, it has been reported that the degree of ros elevation induced by hypoxia was higher and resulted in more severe tissue damage in am+/ mice than in am+/+ mice (27). ros attenuation by am raises two possibilities: 1) the direct suppression of ros production by am or 2) the activation of intracellular ros-scavenging systems. our data showed that am efficiently suppresses increases in ros levels caused by exogenous h2o2, suggesting that it activates ros scavenging systems rather than acting as an antioxidant. however, the mechanis appear to be more complex, because am acted as an endogenous antioxidant against angiotensin ii-induced ros generation (8). this finding led us to the hypothesis that am may regulate one or more intracellular ros scavenging systems. to this end, we focused on the gsh system, because gsh is a key regulator of cellular redox balance based on the fact that its cellular concentration is about 500- to 1000-fold higher than other redox systems, such as thioredoxin and nicotinamide adenine dinucleotide phosphate (28).
the precise mechanis of ros inhibition by am have not yet been clarified. our results from the enzyme assays, real-time pcr, and immunoblots showed that am elevated cellular gsh levels via an up-regulation of its rate-limiting synthetic enzyme, -gcl. this finding suggests that gsh may be one of the candidate molecules that links am with redox regulation systems. however, there are several reports showing that am suppresses ros production through different signaling pathways, such as the activation of the camp-protein kinase a pathway in mesangial cells (29) and the inhibition of nicotinamide adenine dinucleotide phosphate oxidase via the nitric oxide-cgmp signaling pathway (30). it is unclear whether these pathways are activated in concert or sequentially, depending on cell type or the severity of oxidative stress. however, the effect of am on -gcl was rapid and potent enough to overcome initial feedback inhibition by gsh under normoxic conditions (figs. 3 and 4). it may be that am affects the activity or expression of gsh-modifying enzymes such as gsh reductase or peroxidase, because the function of gsh as an intracellular redox buffer depends on the relative amounts of the reduced and oxidized forms.
we next elucidated the transcriptional regulatory mechanis by which am exerted its effects on the induction of -gcl. although it has been reported that -gcl activity can be modulated positively or negatively by posttranscriptional mechanis including phosphorylation, oxidation, and s-nitrosation, increased -gcl activity involves a transcriptional component in a majority of documented cases (31). this transcriptional regulation may involve one or both of the catalytic and modulatory subunits depending on the specific stimuli. however, a variety of stresses, including oxidants, ionizing radiation, and tnf-, induce catalytic subunit expression (32, 33, 34). by using 5'-flanking deletion fragments of -gclc promoter, we showed that a sequence of about 280 bp (from 597 to 320 bp) responded to am. this region is highly gc rich and contains three ap2 binding sites, two sequence-specific dna-binding protein 1 (sp1) binding sites, two metal response element (mre) binding sites, and two gcf binding sites (35). however, it seems to be unlikely that a single transcriptional binding site in this region is critically responsible for transcriptional up-regulation of the -gclc gene by am because deletion of each transcriptional binding site in this region decreased luciferase activity to about 8090% of pgl-gclc-1 (data not shown). this result suggests that more than one transcriptional factor participates in the up-regulation of -gclc gene in response to am; multiple positive and negative regulatory elements, such as ap1, ap2, nuclear factor-b, antioxidant responsive element (are), gcf, and electrophile response element (epre), contribute to the basal transcriptional activity of the -gclc gene (35).
am acts as a trigger of multiple signaling cascades, including the camp (29), nuclear factor-b (36), tyrosine kinase (24), protein phosphatase 2a (37), and pi3k/akt pathways (7, 22). depending on cell types or experimental conditions, am may activate or inhibit more than two signaling cascades. for example, am may either increase or decrease intracellular calcium concentration independent of camp (38, 39), and it stimulates mapk in vascular ooth muscle cells and inhibits mapk activity in mesangial cells (25, 29). individually or in concert, these pathways tranit diverse survival signals from am to target molecules. our results suggest that a pi3k-dependent pathway plays a pivotal role in the am-induced transcriptional activation of the -gclc gene even though other signaling cascades are partly involved (fig. 7). identification and characterization of the transcriptional factor(s) responsible for -gclc gene induction are in progress.
in conclusion, we have shown that am participates in the regulation of gsh synthesis by increasing -gcl activity via pi3k-dependent transcriptional activation of the -gclc promoter. our data may explain, in part, the mechani by which am rescues a variety of cells from oxidative stress.
footnotes
this work was supported by the korea science and engineering foundation through the medical research center for bioreaction to reactive oxygen species at kyung hee university (no. r13-20xx-020-01002-0).
first published online december 1, 20xx
abbreviations: am, adrenomedullin; ap2, activator protein 2; dcf-da, 2',7'-dichlorofluorescin diacetate; gapdh, glyceraldehyde-3-phosphate dehydrogenase; gcf, gc factor; -gcl, -glutamate-cysteine ligase; -gclc, catalytic subunit of -gcl; -gclm, regulatory subunit of -gcl; gs, gsh synthase; gsh, l--glutamyl-cysteinyl-glycine; hne, 4-hydroxynonenal; nadh, reduced nicotinamide adenine dinucleotide; pi3k, phosphatidylinositol 3-kinase; ros, reactive oxygen species.
accepted for publication november 8, 20xx.
references
kitamura k, kangawa k, kawamoto m, ichiki y, nakamura s, matsuo h, eto t 1993 adrenomedullin: a novel hypotensive peptide isolated from human pheochromocytoma. biochem biophys res commun 192:553560
eipper ba, stoffers da, mains re 1992 the biosynthesis of neuropeptides: peptide -amidation. annu rev neurosci 15:5785
kamitani s, asakawa m, shimekake y, kuwasako k, nakahara k, sakata t 1999 the ramp2/crlr complex is a functional adrenomedullin receptor in human endothelial and vascular ooth muscle cells. febs lett 448:111114
nagaya n, satoh t, nishikimi t, uematsu m, furuichi s, sakamaki f, oya h, kyotani s, nakanishi n, goto y, masuda y, miyatake k, kangawa k 2000 hemodynamic, renal, and hormonal effects of adrenomedullin infusion in patients with congestive heart failure. circulation 101:498503
belloni as, trejter m, malendowicz lk, nussdorfer gg 20xx adrenomedullin stimulates proliferation and inhibits apoptosis of immature rat thymocytes cultured in vitro. peptides 24:295300
garayoa m, bodegas e, cuttitta f 20xx adrenomedullin in mammalian embryogenesis. microsc res tech 57:4057
yin h, chao l, chao j 20xx adrenomedullin protects against myocardial apoptosis after ischemia/reperfusion through activation of akt-gsk signaling. hypertension 43:109116
yoshimoto t, fukai n, sato r, sugiyama t, ozawa n, shichiri m, hirata y 20xx antioxidant effect of adrenomedullin on angiotensin ii-induced reactive oxygen species generation in vascular ooth muscle cells. endocrinology 145:33313337
arrigo ap 1999 gene expression and the thiol redox state. free radic biol med 27:936944
meister a, anderson me 1983 glutathione. annu rev biochem 52:711760
townsend dm, tew kd, tapiero h 20xx the importance of glutathione in human disease. biomed pharmacol 57:145155
sierra-rivera e, dasouki m, krishnamani mr, phillips ja, freeman ml 1995 assignment of the gene (glclc) that encodes the heavy subunit of -glutamylcysteine synthetase to human chromosome 6. cytogenet cell genet 70:278279
sierra-rivera e, dasouki m, summar ml, krishnamani mr, meredith m, rao pn, phillips 3rd ja, freeman ml 1996 assignment of the human gene (glclr) that encodes the regulatory subunit of -glutamylcysteine synthetase to chromosome 1p21. cytogenet cell genet 72:252254
huang cs, chang ls, anderson me, meister a 1993 catalytic and regulatory properties of the heavy subunit of rat kidney -glutamylcysteine synthetase. j biol chem 268:1967519680
tu z, anders mw 1998 expression and characterization of human glutamate-cysteine ligase. arch biochem biophys 354:247254
griffith ow 1999 biologic and pharmacologic regulation of mammalian glutathione synthesis. free radic biol med 27:922935
meister a 1985 glutathione synthetase from rat kidney. methods enzymol 113:393399
seelig gf, meister a 1984 -glutamylcysteine synthetase. interactions of an essential sulfhydryl group. j biol chem 259:35343538
lee y, kim h, jung h, shin y, hong s, park e, sa j, lim c 20xx activities of antioxidant and redox enzymes in human normal hepatic and hepatoma cell lines. mol cells 14:305311
rahman i, ith ca, lawson mf, harrison dj, macnee w 1996 induction of -glutamylcysteine synthetase by cigarette oke is associated with ap-1 in human alveolar epithelial cells. febs lett 396:2125
liu rm, borok z, forman hj 20xx 4-hydroxy-2-nonenal increases -glutamylcysteine synthetase gene expression in alveolar epithelial cells. am j respir cell mol biol 24:499505
okumura h, nagaya n, itoh t, okano i, hino j, mori k, tsukamoto y, ishibashi-ueda h, miwa s, tambara k, toyokuni s, yutani c, kangawa k 20xx adrenomedullin infusion attenuates myocardial ischemia/reperfusion injury through the phosphatidylinositol 3-kinase/akt-dependent pathway. circulation. 109:242248
shimosawa t, shibagaki y, ishibashi k, kitamura k, kangawa k, kato s, ando k, fujita t 20xx adrenomedullin, an endogenous peptide, counteracts cardiovascular damage. circulation 105:106111
iwasaki h, shichiri m, marumo f, hirata y 20xx adrenomedullin stimulates proline-rich tyrosine kinase 2 in vascular ooth muscle cells. endocrinology 142:564572
iwasaki h, eguchi s, shichiri m, marumo f, hirata y 1998 adrenomedullin as a novel growth-promoting factor for cultured vascular ooth muscle cells: role of tyrosine kinase-mediated mitogen-activated protein kinase activation. endocrinology 139:34323441
kaneto h, kawamori d, nakatani y, gorogawa s, matsuoka ta 20xx oxidative stress and the jnk pathway as a potential therapeutic target for diabetes. drug news perspect 17:447453
matsui h, shimosawa t, itakura k, guanqun x, ando k, fujita t 20xx adrenomedullin can protect against pulmonary vascular remodeling induced by hypoxia. circulation 109:22462251
schafer fq, buettner gr 20xx redox environment of the cell as viewed through the redox state of the glutathione disulfide/glutathione couple. free radic biol med 30:11911212
chini en, chini cc, bolliger c, jougasaki m, grande jp, burnett jr jc, dousa tp 1997 cytoprotective effects of adrenomedullin in glomerular cell injury: central role of camp signaling pathway. kidney int 52:917925
kato k, yin h, agata j, yoshida h, chao l, chao j 20xx adrenomedullin gene delivery attenuates myocardial infarction and apoptosis after ischemia and reperfusion. am j physiol 285:h1506h1514
wild ac, mulcahy rt 2000 regulation of -glutamylcysteine synthetase subunit gene expression: insights into transcriptional control of antioxidant defenses. free radic res 32:281301
morales a, miranda m, sanchez-reyes a, colell a, biete a, fernandez-checa jc 1998 transcriptional regulation of the heavy subunit chain of -glutamylcysteine synthetase by ionizing radiation. febs lett 427:1520
ochi t 1995 hydrogen peroxide increases the activity of -glutamylcysteine synthetase in cultured chinese hamster v79 cells. arch toxicol 70:96103
rahman i, antonicelli f, macnee w 1999 molecular mechani of the regulation of glutathione synthesis by tumor necrosis factor- and dexamethasone in human alveolar epithelial cells. j biol chem 274:50885096
tomonari a, nishio k, kurokawa h, fukumoto h, fukuoka k, iwamoto y, usuda j, suzuki t, itakura m, saijo n 1997 proximal 5'-flanking sequence of the human -glutamylcysteine synthetase heavy subunit gene is involved in cisplatin-induced transcriptional up-regulation in a lung cancer cell line c-3. biochem biophys res commun 236:616621
pleguezuelos o, hagi-pavli e, crowther g, kapas s 20xx adrenomedullin signals through nf-b in epithelial cells. febs lett 577:249254
parameswaran n, nambi p, hall cs, brooks dp, spielman ws 2000 adrenomedullin decreases extracellular signal-regulated kinase activity through an increase in protein phosphatase-2a activity in mesangial cells. eur j pharmacol 388:133138
shimekake y, nagata k, ohta s, kambayashi y, teraoka h, kitamura k, eto t, kangawa k, matsuo h 1995 adrenomedullin stimulates two signal transduction pathways, camp accumulation and ca2+ mobilization, in bovine aortic endothelial cells. j biol chem 270:44124417
mazzocchi g, rebuffat p, gottardo g, nussdorfer gg 1996 adrenomedullin and calcitonin gene-related peptide inhibit aldosterone secretion in rats, acting via a common receptor. life sci 58:839844
第二篇 中国医疗前沿_医学期刊
办刊宗旨
本刊以坚持创新、坚守前沿为办刊宗旨，秉承专业精神和开放态度，为读者提供最权威的政策解读、最深度的新闻事件、最具操作性的经营管理案例以及最前沿的技术动态，立志迅速成长为中国医疗行业最领先的主流媒体。Www.0519news.coM
主要栏目政策法规、改革与探索 、专题、实验研究、论著 、综述与讲座 、医学工程 、医疗设备与器械 、医学影像 、检验与病理 、药物研究 、外科进展 、康复理论与实践、医技与临床 、公共卫生研究 、护理管理 、产品信息、医学教育 、医技交流等。
第三篇 海峡药学_医学期刊
本刊系中国药学会福建分会主办，福建省食品药品监督管理局主管。为中国学术期刊综合评价数据库统计来源期刊。主要报道药剂学、药理学、药物化学、药物、中药与天然药物等
方面的研究论文。读者对象主要是从事药品生产、教学、科研、检验和临床药学工作者。
《海峡药学》由中国药学会福建分会主办，cn35-1173/r，issn1006-3765，国内外公开发行的综合药学刊物。主要报道药剂学、药理学、药物化学、药物、中药与天然药物等方面的
研究论文。wWW.0519news.COM
《海峡药学》为中国学术期刊综合评价数据库统计源期刊、《中国核心期刊（遴选）数据库》收录期刊、万方数据化期刊群、中文科技期刊数据库、《caj-cd规范》执行优秀期刊。
第四篇 中华医院感染学杂志_医学期刊
>
外文名称： chinese journal of nosocomiology
语言： 中文
类别： 出版，医学期刊
主管单位： 解放军总医院
主办单位： 解放军总医院、中华预防医学会
编辑单位： 中华医院感染学杂志编辑部
创刊时间： 1991年
出版周期： 半月刊
国内刊号： cn：11-3456/r
国际刊号： issn：1005-4529
邮发代号： 82-747
定价： 18.00元/期；432.00元/年
出版地： 市
历史荣誉
《中华医院感染学杂志》系中国科技论文统计源期刊cstpcd，《中国学术期刊（光盘版）》入编期刊，再次获中国中文核心期刊(20xx版)、中国首届高校特色科技期刊、中国生物医学核心期刊、中国感染学优秀期刊等殊荣。wWW.0519news.cOm
办刊宗旨
中华医院感染学杂志在于加强医院感染控制，提高全国医院感染管理水平，在全国医院感染管理、消毒灭菌、抗菌药物使用等工作中起导向作用，在业界公认有以下两个特点：一是高学术水平，注重内容的科学性和创新性；二是普及性，指导医院感染管理、监控，提高全国医院感染监控的整体水平。
主要栏目
辟有“基础研究”、“调查研究”、“医院感染管理”、“临床微生物”、“消毒与灭菌”、“抗菌药物与医院感染”、“技术方法”、“综述”、“国际交流”、“短篇报道”等栏目。
第五篇 中国医院药学杂志_医学期刊
主要栏目
设有研究论文（制剂研究、新药研究、治疗药物监测、药动学、药品质量、药物配伍和相互作用，新药临床应用及药物应用再评价）、药物与临床（临床疗效观察、临床用药、临床合理用药、药物不良反应及其防治）、综述、医院制剂、药事管理、医院调剂、药物不良反应、科技简报、读者园地及其他。WWw.0519news.CoM
获奖情况本刊影响因子为0.538。1996 年被评为中国科协优秀期刊，20xx、20xx、20xx年被评为湖北省优秀期刊，中国科协精品期刊。
读者对象主要面向全国医院药学工作者、医务人员和广大药学工作者。
Adrenomedullin Regulates Cellular Glutathione Content via Modulation of -Glutamate-Cysteine Ligase C相关文章：
呵护自然，守护安全——保育员视角下的工作纪实作为一名民警化身的保育员，我有幸能够亲身参与到呵护自然、守护环境安全的工作中。这份工作不仅让我深刻感受到自然的美丽与伟力，也让我深刻认识到环境保护的重要性。每一次出行前，我都会仔细检查装备，确保能够应对各种突况。毕竟，保育员的工作并不仅仅是欣赏大自然，更是
水务乡村振兴：深化改革 推动可持续发展随着乡村振兴战略的实施和人民生活水平的不断提高，水务在乡村发展中的重要性日益凸显。为了实现乡村振兴的目标，必须深化改革，推动可持续发展，使水务事业更好地支撑乡村发展。首先，要深化改革，建立健全现代水务管理体制。乡村水务在过去的发展中存在着基础设施建设滞后、管理体
【护士节干净治愈文案 第一篇】护士节范文：白衣天使的使命，尽在干净治愈在这个特殊的日子里，我们向全球的护士们致以崇高的敬意和最诚挚的祝福。护士节是一年一度表彰护士们辛勤付出和无私奉献的日子，也是我们全社会共同表达对护士事业的尊重和感激之情的时刻。在这个特殊的时期，让我们以“干净治愈”为中心，向所有护
【护士预备党员入党转正申请书 第一篇】尊敬的党组织：我是一名护士，身为医护工作者，工作多年来，深知党的优秀品质和伟大事业的重要性。我怀着坚定的信念和热爱，感到自己应该主动申请加入中国，以更好地为人民服务，为实现中华伟大复兴的中国梦贡献力量。作为一名护士，我一直把自己的职责和使命视为神圣的事业。每天面
【护士职业规划书 第一篇】护士职业规划书一、个人简介大家好，我叫张丽，我对护理工作充满热情。我毕业于某某医学院护理专业，并获得了护士执业资格证书。我有着良好的专业素养和扎实的基础知识，也拥有相关实践经验。我自信自己具备成为一名优秀护士的潜质，但我也清楚自己需要不断提升来适应不断变化的医疗环境和社会需
【护士节干净治愈文案 第一篇】护士节干净治愈文案范文：亲爱的护士们：在这个特别的日子里，我愿向你们致以最崇高的敬意和最真挚的祝福！我代表全国人民，向你们表示最衷心的感谢和最深沉的敬佩。正是由于你们的辛勤付出，我们才能享受到健康与安全。护士节是向世界各地的护士们致敬的日子，也是向一群平凡而伟大的人们致
【护理大学生职业规划 第一篇】护理大学生职业规划职业规划是每个大学生都需要面对和完成的重要任务，尤其对于学习护理的大学生来说，职业规划的重要性更加凸显。护理专业是一个综合性较强的学科，它培养的是一支具备专业知识和技能，具有较高职业要求和人文精神的护理人才队伍。下面，我将以护理大学生职业规划为中心，谈
【护士节干净治愈文案 第一篇】护士节：干净治愈的守护者5月12日，是我们共同的节日，护士节。这一天，我们向那些用爱心和关怀呵护着病患的护士们献上最崇高的敬意。他们是医疗团队中最亲近患者、最频繁接触病情的人，同时也是干净治愈的守护者。干净，是护士工作中的重要一环。他们经常面临各种疾病的传染风险，因此必
校地合作：助力就业，共谋未来近年来，随着社会经济的持续发展和教育事业的持续进步，校地合作已经成为高校与地方、企业之间一种有效的合作模式。以校地合作为中心，助力就业，共谋未来，将为高校学生提供更多的就业机会和实践机会，同时也为地方经济的发展注入不竭的活力。下面，本文将从助力就业、推动创新发展和深化校地
【护士顶岗实结 第一篇】护士顶岗实习是护理专业学生在医疗机构接受实际操作和临床实践的阶段性教育，是将理论知识与实际工作相结合的重要环节。护士顶岗实习对于护理专业学生的成长和职业素养的培养具有重要意义。以下是一篇关于护士顶岗实习的范文：护士顶岗实习是护理专业学生在医疗机构接受实际操作和临床实践的阶段性
