Curcumin ameliorates high glucose‐induced acute vascular endothelial dysfunction in rat thoracic aorta

• 1 The aims of the present study were to explore the protective effect of curcumin against the acute vascular endothelial dysfunction induced by high glucose and to investigate the possible role of heme oxygenase (HO)‐1 in this protective action.
• 2 Thoracic aortic rings, with or without endothelium, obtained from male Sprague‐Dawley rats were mounted in an organ bath. Isometric contraction of the rings was recorded. After completion of the organ bath studies, rings were homogenized and centrifuged (30 000 g, 4°C, 15 min) and HO activity was determined in the supernatant.
• 3 After 2 h incubation of aortic rings in the presence of high glucose (44 mmol/L), the relaxation evoked by acetylcholine (3 × 10^?8 to 3 × 10^?5 mol/L) was significantly decreased only in rings with an intact endothelium. When rings were coincubated in the presence of curcumin (10^?13 to 10^?11 mol/L) and high glucose, curcumin reversed the vasodilator dysfunction induced by high glucose dose dependently.
• 4 Curcumin (10^?11 mol/L) increased HO activity in the aortic rings compared with activity in control rings (63.1 ± 3.6 vs control 43.2 ± 2.9 pmol/mg per h, respectively; P < 0.01). Protoporphyrin IX zinc (10^?6 mol/L), an inhibitor of HO‐1, offset the protective effects of curcumin. In addition, the non‐selective guanylate cyclase (GC) inhibitor methylene blue (10^?6 mol/L) completely abolished the protective effects of curcumin.
• 5 In conclusion, the results of the present study show that curcumin alleviates the acute endothelium‐dependent vasodilator dysfunction induced by high glucose in rat aortic rings. Increased HO‐1 activity and stimulation of GC may be involved in the protective effects of curcumin.

     

Role of heme oxygenase-1 in vascular disease

Great attention has been placed on the protective role of heme oxygenase-1 (HO-1) for several vascular diseases such as atherosclerosis. HO-1, by exerting anti-inflammatory, antiproliferative, anti-apoptotic and anti-oxidant effects on the vasculature, protects against atherosclerosis. The precise underlying mechanisms for HO-1-based protection are not yet completely understood, but appear to involve the protective effects of HO-1 by-products, carbon monoxide (CO), biliverdin/bilirubin and free iron. Among the HO-1 by-products, CO has been shown to mimic some protective actions of HO-1, specifically, in vascular system. There is evidence supporting that HO-1-derived CO also interacts with other gaseous molecules, such as nitric oxide (NO) and hydrogen sulfide (H2S) that may relate to either vascular protection or injury. CO, NO and H2S not only exert comparable biological actions but also compete with and are antagonists with each other for maintaining vascular homeostasis. This review will highlight the protective roles of HO-1/CO in vascular injury/disease, and emphasize the potential roles of CO in possible interplay among three gaseous molecules, which may be important to explore the overall protective roles of HO-1/CO system in the pathogenesis of human vascular disease.     

Auranofin protects against cocaine-induced hepatic injury through induction of heme oxygenase-1

Auranofin, a disease-modifying gold compound, has been empirically applying to the management of rheumatoid arthritis. We investigated a protective effect of auranofin against hepatic injury induced by cocaine. Cocaine (75 mg/kg) markedly increased serum alanine amino transferase (ALT) (4,130 IU/l) and aspartate amino transferase (AST) (1,730 IU/l) activities at 16 hr after treatment, and induced hepatic necrosis surrounding central veins in mice. Concurrently, overexpression of heme oxygenase-1 (HO-1), a rate-limiting enzyme for heme degradation and an oxidative stress marker, was identified at the edges of cocaine-mediated necrotic area. Auranofin (10 mg/ml, i.p.) significantly induced hepatic HO-1 protein in mice from 12 hr after treatment. Interestingly, pretreatment with auranofin resulted in the prevention of the increase of serum ALT and AST activities in a dose-dependent manner. On the other hand, although cocaine increased tumor necrosis factor α (TNFα) gene expression in mouse livers, cocaine-induced liver injury was observed in TNFα deficient mice as well as wild-type mice. Auranofin-inducted HO-1 gene expression was observed in human primary hepatocytes as well as mouse primary hepatocytes. The present findings suggest that auranofin is effective in preventing cocaine-induced hepatic injury, and HO-1 may contribute to protect against chemically-induced cytotoxicity.     

Overexpression of heme oxygenase-1 protects dopaminergic neurons against 1-methyl-4-phenylpyridinium-induced neurotoxicity

Heme oxygenase-1 (HO-1) is up-regulated in response to oxidative stress and catalyzes the degradation of pro-oxidant heme to carbon monoxide (CO), iron, and bilirubin. Intense HO-1 immunostaining in the Parkinsonian brain is demonstrated, indicating that HO-1 may be involved in the pathogenesis of Parkinsonism. We here locally injected adenovirus containing human HO-1 gene (Ad-HO-1) into rat substantia nigra concomitantly with 1-methyl-4-phenylpyridinium (MPP(+)). Seven days after injection of MPP(+) and Ad-HO-1, the brain was isolated for immunostaining and for measurement of dopamine content and inflammatory cytokines. It was found that overexpression of HO-1 significantly increased the survival rate of dopaminergic neurons; reduced the production of tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in substantia nigra; antagonized the reduction of striatal dopamine content induced by MPP(+); and also up-regulated brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) expression in substantia nigra. Apomorphine-induced rotation after MPP(+) treatment was also inhibited by Ad-HO-1. On the other hand, inhibition of HO enzymatic activity by zinc protoporphyrin-IX facilitated the MPP(+)-induced rotatory behavior and enhanced the reduction of dopamine content. HO-1 overexpression also protected dopaminergic neurons against MPP(+)-induced neurotoxicity in midbrain neuron-glia cocultures. Overexpression of HO-1 increased the expression of BDNF and GDNF in astrocytes and BDNF in neurons. Our results indicate that HO-1 induction exerts neuroprotection both in vitro and in vivo. Pharmacological or genetic approaches targeting HO-1 may represent a promising and novel therapeutic strategy in treating Parkinsonism.     

Curcumin attenuates fructose-induced vascular dysfunction of isolated rat thoracic aorta rings

Context: Consumption of high fructose is associated with metabolic abnormalities, insulin resistance, and hypertension. It is not known whether this hypertensive effect of fructose is related to metabolic abnormalities or due to the direct effect of fructose on blood vessels.

Objective: Here, we investigated the direct effect of fructose on rat isolated aorta and the possible protective effect of curcumin.

Materials and methods: The isolated rat thoracic aorta rings were used to measure the contractile responses to different concentrations of both phenylephrine and KCl, and the relaxant response to acetylcholine (Ach). The effect of curcumin (1?µM) alone or in combination with tempol (1?mM), a superoxide dismutase mimetic agent, and N-{[3(amino-methyl)-phenyl]-methyl} ethanimidamide dihydrochloride (1400?W), a specific inducible nitric oxide synthase (iNOS) inhibitor, (1?µM) on fructose-treated aorta was compared. The aortic rings were incubated with different treatments for 60?min before starting the experiment. Changes in the intracellular calcium in response to KCl and nitric oxide levels were also measured.

Results and discussion: Fructose strongly increased the contractile response of aortic rings to both phenylephrine and KCl (E_max was increased by 147.3% and 150.5%, respectively) but it did not affect the relaxant response to Ach. Curcumin significantly decreased the hyper responsiveness of arterial rings to both vasopressors (for phenylephrine, E_max decreased from 147.3% in fructose incubated aorta to 81%, and for KCl, E_max decreased from 150.5% in fructose-incubated aorta to 77.24% respectively). Curcumin also reduces the intracellular calcium level (85% reduction in intracellular calcium). A 1400?W was the only agent that potentiates the effect of curcumin.

Conclusion: Fructose has a direct deleterious effect on aortic vascular reactivity. Curcumin can partially protect against fructose-induced impairment in vascular contractility via an antioxidant effect and reduction of elevated intracellular calcium.     

Role of heme oxygenase-1 in cardiovascular function

Heme oxygenase (HO) is a cytoprotective enzyme that degrades heme (a potent oxidant) to generate carbon monoxide (a vasodilatory gas that has anti-inflammatory properties), bilirubin (an antioxidant derived from biliverdin), and iron (sequestered by ferritin). Due to the properties of inducible HO (HO-1) and its products, we hypothesized that HO-1 would play an important role in the regulation of cardiovascular function. In this article we will review the role of HO-1 in cardiovascular function, and highlight our previous studies using gene deletion and gene overexpression transgenic approaches in mice. These studies will include the investigation of HO-1 in the setting of hypertension (renovascular), atherosclerosis and vascular injury (vein graft stenosis), hypotension (endotoxemia), and ischemia/reperfusion injury (heart). In a chronic renovascular hypertension model, blood pressure elevation, cardiac hypertrophy, acute renal failure, and acute mortality induced by one kidney-one clip surgery are more severe in HO-1 null mice. Moreover, absence of HO-1 leads to accelerated atherosclerotic lesion formation and vein graft disease. In addition, HO-1 null mice with endotoxemia have earlier resolution of hypotension, yet the mortality and the incidence of end organ damage are higher in the absence of HO-1. In contrast, mice with cardiac-specific overexpression of HO-1 have an improvement in cardiac function, smaller myocardial infarcts, and reduced inflammatory and oxidative damage after coronary artery ligation and reperfusion. Taken together, these studies suggest that an absence of HO-1 has detrimental consequences, while overexpression of HO-1 plays a protective role in ischemia/reperfusion injury.     

Heme oxygenase-1 in diabetic vascular dysfunction

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Cudratricusxanthone A protects mouse hippocampal cells against glutamate-induced neurotoxicity via the induction of heme oxygenase-1

Cudratricusxantone A (CTXA), isolated from the roots of Cudrania tricuspidata Bureau (Moraceae), has potent hepatoprotective, antiproliferative, and monoamine oxidase inhibitory effects. In this study, we examined whether CTXA could protect HT22-immortalized hippocampal cells against glutamate-induced oxidative stress through the induction of heme oxygenase (HO)-1 expression. CTXA induced the expression of HO-1 and increased HO activity dose- and time-dependently. CTXA also suppressed glutamate-induced ROS generation in HT22 cells. Interestingly, treatment of neuronal cells with CTXA enhanced cellular resistance to glutamate oxidative stress. The protective effect of CTXA was abrogated by tin protoporphyrin IX, an HO inhibitor. In addition, treatment with the HO-1 inducer, cobalt protoporphyrin IX, and bilirubin, one of the enzymatic products of HO-1, produced comparable protection. These results demonstrate that CTXA protects neuronal cells from glutamate-induced oxidative stress via the induction of HO-1.     

Sequential induction of heme oxygenase-1 and manganese superoxide dismutase protects cultured astrocytes against nitric oxide

Nitric oxide (NO) is a widely recognized mediator of physiological and pathophysiological signal transmission. In an attempt to better understand the molecular actions of NO in astrocytes, stress protein expression in response to NO donor sodium nitroprusside was investigated. Heme oxygenase-1 (HO-1) has been identified as an inducer of manganese superoxide dismutase (MnSOD), playing a cytoprotective role under the condition of nitrosative stress. We present evidence that the sequential induction of HO-1 and MnSOD protects astrocytes from NO toxicity: (1) both HO-1 and MnSOD expression were induced by NO; (2) NO-mediated increase in MnSOD activity was partly abolished by HO-1 inhibitor Zn(II) protoporphyrin IX (ZnPP); (3) pretreatment of astrocytes with a nontoxic dose of NO protected the cells against the later treatment with a toxic dose of NO; (4) inhibition of HO-1 by ZnPP sensitized astrocytes to the nontoxic dose of NO resulting in a marked cytotoxicity; and (5) adenovirus-mediated overexpression of MnSOD protected astrocytes from the NO toxicity. The molecular action of NO in astrocytes appears to be dose-dependent. While a high dose of NO exerts cytotoxicity leading to the tissue damage in the central nervous system, a low dose of NO may act as an important signaling molecule in astrocytes with concurrent induction of cytoprotective proteins such as HO-1 and MnSOD.     

血红素加氧酶-1的表达对实验性肝硬化内毒素血症大鼠的影响

目的:探讨血红素加氧酶-1(HO-1)的表达对实验性肝硬化内毒素血症大鼠的影响。方法:32只健康雄性wistar大鼠,随机分为4组,正常+脂多糖(LPS)(对照组)、肝硬化+生理盐水对照组(TAA组)、肝硬化+LPS组(TAA+LPS组)、肝硬化+LPS+hemin(氯化高铁血红素)(HM组)。用硫代乙酰胺(TAA)诱导肝硬化模型时间共计10周,对照组自由饮清水。于模型造成后,向对照组、TAA+LPS组、HM组大鼠腹腔内注入LPS3 mg/kg;TAA组大鼠腹腔内注入等量的生理盐水;HM组于注射LPS 12 h前,腹腔注射HM(40 mg/kg),并在注入LPS 6 h后,各组动物经腹主动脉穿刺采全血观察血浆中丙氨酸氨基转移酶(ALT)、天门冬氨基酸转移酶(AST)、一氧化氮(NO)及丙二醛(MDA)的表达。留肝组织用免疫组织化学法观察HO-1的表达。结果:对照组、TAA组、TAA+LPS组、HM组血浆中的ALT/AST、MDA、NO依次升高差异有显著性(P<0.05),对照组、TAA、TAA+LPS、HM组各组大鼠的灰阶值显著依次降低,且有明显差别(P<0.05)。结论:在实验性的肝硬化内毒素中尽管HO-1的表达增加,但它未起到保护作用,它与内毒素对机体的损伤有关。     

Heme oxygenase-1 induction protects against hypertension associated with diabetes: effect on exaggerated vascular contractility

Disturbances in vascular reactivity are important components of diabetes-evoked hypertension. Heme oxygenase-1 (HO-1) is a homeostatic enzyme upregulated in stress. This study aims to investigate the protective effect of HO-1 against diabetes-evoked hypertension. Rats were left 8 weeks after diabetes induction with streptozotocin to induce vascular dysfunction in the diabetic groups. HO-1 inducers, hemin and curcumin, were daily administrated in the last 6 weeks in the treated groups after 2 weeks of induction. Then, at the end of the study (8 weeks), HO-1 protein level was assessed by immunofluorescence; blood pressure (BP) was recorded; isolated aorta reactivity to phenylephrine (PE) and KCl was studied; reactive oxygen species (ROS) generation was determined; and serum level of glucose, advanced glycation end products (AGEs), and tumor necrosis factor alpha (TNF-α) were determined. While not affected by diabetes, HO-1 protein expression was strongly induced by hemin or curcumin administration. Compared with control animals, diabetes increased systolic and pulse BP. Induction of HO-1 by hemin or curcumin significantly reduced elevated systolic BP and abolished elevated pulse BP without affecting the developed hyperglycemia or AGEs level. The possibility that alterations in vascular reactivity contributed to diabetes–HO-1 BP interaction was investigated. Diabetes increased contractile response of the aorta to PE and KCl, while HO-1 induction by curcumin or hemin prevented aorta-exaggerated response to PE and KCl. Furthermore, the competitive HO inhibitor, tin protoporphyrin, abolished the protective effect of hemin. Diabetes was accompanied with elevated level of TNF-α and ROS generation, while HO-1 induction abrogated increased TNF-α and ROS generation. Collectively, induction of HO-1 protects against hypertension associated with diabetes via ameliorating exaggerated vascular contractility by reducing TNF-α and aortic ROS levels.     

Heme oxygenase-1 against vascular insufficiency: roles of atherosclerotic disorders

Heme oxygenase (HO), an enzyme essential for heme degradation, shows anti-oxidative and anti-inflammatory properties via the production of bile pigments, carbon monoxide (CO) and ferritin induction under various pathophysiological conditions. A number of recent studies have shown biological effects of HO reaction in cardiovascular disorders. An inducible form of HO, HO-1, is induced by a variety of stresses such as oxidized lipoproteins, cytokines, hemodynamic changes, angiotensin II and nitric oxide (NO) in vascular wall. HO-1 induction seems to function as an adaptive response against these injurious stimuli. HO-1 induction in artery wall scavenges reactive oxygen species, which leads to the attenuation of monocyte adhesion and chemotaxis. HO-1 induction also reduces lipid peroxidation in plasma and artery wall. These properties of HO-1 suggest anti-atherogenic roles of this enzyme. In this review, roles of endothelial HO-1 expression and bilirubin in atherogenesis are also discussed. HO-1 also seems to play a significant role in restenosis after angioplasty, which is a major clinical problem associated with atherosclerosis. Recent progress in human HO-1 genetics supports these experimental results. This review aims to reaffirm current problems in the biological aspects of HO and suggest future research direction and clinical application.     

辛伐他汀对急性心肌梗死大鼠血红素加氧酶-1的影响

目的探讨大鼠急性心肌梗死后心肌内血红素加氧酶-1(HO-1)水平变化及辛伐他汀对HO-1表达的影响。方法结扎♂SD大鼠冠状动脉左前降支建立心肌梗死模型,24 h后存活大鼠随机分为心肌梗死组(MI组)、辛伐他汀(Sim组)和假手术组(Sham组,只穿线不结扎)。Sim组以辛伐他汀40 mg.kg-1.d-1灌胃,MI组和Sham组以等体积生理盐水灌胃。术后24 h、7 d、28 d处死动物,RT-PCR及Western bolt测定心肌非梗死区HO-1 mRNA和蛋白表达水平,并测非梗死区心肌超氧化物岐化酶(SOD)活性、丙二醛(MDA)含量。结果HO-1 mRNA和蛋白表达水平均在心梗后24 h开始升高,7 d达峰,28 d恢复至基线水平。3个时间点MI组上述指标均高于Sham组;术后7 d和28 d Sim组上述指标均高于MI组(P<0.05)。随HO-1 mRNA和蛋白表达水平升高,SOD活性升高,MDA含量降低。结论心肌内HO-1水平在急性心肌梗死后28 d内呈现动态变化。辛伐他汀可诱导HO-1表达,发挥抗氧化损伤的心脏保护作用。     

Upregulation of heme oxygenase-1 by degranulation in rat basophilic leukemia cells

Heme oxygenase (HO)-1, which is a rate-limiting enzyme involved in the catabolism of heme, is upregulated by a variety of stresses including oxidative stresses and inflammatory cytokines, in many cell types. Recent studies have suggested that upregulation of HO-1 might provide cytoprotection and immunomodulatory functions in addition to its obvious role in heme metabolism. In this study, we examined whether HO-1 was upregulated following degranulation in mast cells that initiate vigorous immunity reactions. To trigger degranulation, rat basophilic leukemia (RBL)-2H3 cells were passively sensitized using an antiserum collected from ovalbumin (OA) immunized-Brown Norway rats, and the cells were stimulated by treatment with OA. Degranulation was confirmed by measuring the release of beta-hexosaminidase. HO-1 mRNA and presence of HO-1 protein were detected using Northern blot and Western blot analyses, respectively. The effect of the antioxidant N-acetyl-L-cysteine (NAC) on HO-1 expression was also tested. HO-1 mRNA transiently increased at 1--2 h after RBL-2H3 cells were stimulated to degranulate. Its mRNA increases were dependent on the extent of degranulation. Following the upregulation of HO-1 mRNA, HO-1 protein was also increased. We also detected intracellular production of reactive oxygen species following degranulation in RBL-2H3 cells. NAC attenuated the HO-1 expression in a dose-dependent manner. This is the first report to reveal induction of both HO-1 mRNA and protein by degranulation in RBL-2H3 cells. We showed that NAC inhibited HO-1 upregulation. These results suggest that oxidative stress in activated RBL-2H3 cells results in the upregulation of HO-1.     

Puerarin suppresses AGEs-induced inflammation in mouse mesangial cells: A possible pathway through the induction of heme oxygenase-1 expression

Puerarin is a natural product isolated from Puerarin lobata and has various pharmacological effects, including anti-hyperglycemic and anti-allergic properties. In the present study, we investigated the effect of puerarin against advanced glycation end products (AGEs)-induced inflammation in mouse mesangial cells. Puerarin acts by inducing the expression of heme oxygenase-1 (HO-1) in a dose- and time-dependent manner. Puerarin was able to enhance phosphorylation of protein kinase C (PKC) δ, but not PKC α/β II, in a time-dependent manner. Induction of HO-1 expression by puerarin was suppressed by GF109203X, a general inhibitor of PKC, and by rottlerin, a specific inhibitor of PKC δ. However, induction was not suppressed by Gö6976, a selective inhibitor for PKC α/β II. Additionally, the knockdown of endogenous PKC δ by small interfering RNA (siRNA) resulted in the inhibition of HO-1 expression and Akt phosphorylation. Puerarin increased antioxidant response element (ARE)-Luciferase activity in a dose- and time-dependent manner in transfected mouse mesangial cells. Mutation of the ARE sequence abolished puerarin-induced HO-1 expression. Furthermore, puerarin treatments resulted in a marked increase in NF-E2 related factor-2 (Nrf-2) translocation, leading to up-regulation of HO-1 expression. However, transfection of Nrf-2 specific siRNA abolished HO-1 expression. Pretreatment with puerarin inhibited the expressions of COX-2, MMP-2 and MMP-9. But, these effects were reversed by ZnPP, an inhibitor of HO-1. Taken together, our results demonstrate that puerarin-induced expression of HO-1 is mediated by the PKC δ-Nrf-2-HO-1 pathway and inhibits N-carboxymethyllysine (CML)-induced inflammation in mouse mesangial cells.     

诱导血红素氧化酶表达对乙醇所致人原代肝细胞氧化损伤的保护作用

目的　探讨乙醇暴露与诱导血红素氧化酶(HO 1)表达之间的关系。方法　经体外灌流、分离培养人原代肝细胞 ,观察 10 0mmol·L- 1乙醇暴露 9h后谷胱甘肽 (GSH) ,谷草转氨酶 (GOT) ,乳酸脱氢酶 (LDH)和丙二醛 (MDA)的变化以反应人原代肝细胞的氧化损伤 ,用RT PCR及Western印迹方法检测乙醇对人原代肝细胞HO 1mRNA及蛋白表达的影响。结果 10 0mmol·L- 1乙醇暴露 9h后可导致人原代肝细胞明显的氧化损伤 ,肝细胞中的GSH明显降低 ,而MDA明显升高 ,GOT和LDH ,此外 ,急性乙醇暴露下 ,HO 1表达开始应激升高 ,随后慢慢降低 ,肝细胞经HO 1诱导剂预处理后再与乙醇作用 ,能减轻乙醇对肝细胞的氧化损伤作用 ,并且这种作用可被HO 1抑制剂所抵消。结论　诱导HO 1对乙醇所致人原代肝细胞的氧化损伤有保护作用。     

Serum iron increases with acute induction of hepatic heme oxygenase-1 in mice

Heme oxygenase (HO)-1 is induced by oxidative stress and protects against oxidant injury. We examined the effect of rapid induction of hepatic HO-1 on serum iron level. Serum iron was approximately doubled within 6 h when HO-1 was induced by phenobarbital treatment of selenium-deficient mice. Blocking heme synthesis with diethyl 1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC) prevented the induction of HO-1 and the rise in serum iron. DDC did not block HO-1 induction by hemin. Inhibition of HO activity by tin protoporphyrin prevented a rise in serum iron that occurred following phorone treatment. These results indicate that heme synthesis or an exogenous source of heme is needed to allow induction of HO-1. Further, they link HO-1 induction with a rise in serum iron, suggesting that the iron resulting from catabolism of heme by HO-1 is released by the liver.     

阿霉素对大鼠肺缺血再灌注损伤中血红素加氧酶-1的影响

目的观察阿霉素对大鼠肺缺血再灌注损伤(LIRI)中血红素加氧酶-1(HO-1)的影响。方法32只雄性Wistar大鼠随机分成4组:手术对照组(C)、阿霉素组(ADM)、缺血再灌注组(IR)、阿霉素+缺血再灌注组(ADM-IR)。复制大鼠单侧肺缺血再灌注损伤模型,观察肺组织病理形态变化,对比观察各组肺干湿质量比(D/W)、肺泡损伤数(IAR)、HO-1活性、HO-1蛋白的表达。结果IR组与ADM-IR组D/W、IAR均比C组与ADM组高(P<0.01),但ADM-IR组显著低于IR组(P<0.01),C组与ADM组之间差异无统计学意义(P>0.05);与C组相比,ADM组、IR组与ADM-IR组HO-1活性、HO-1蛋白表达增加(P<0.01),ADM-IR组上升更加显著(P<0.01)。结论阿霉素能增加HO-1的活性,上调HO-1蛋白的表达,可能通过HO-1的抗氧化作用减轻肺缺血再灌注损伤;小剂量阿霉素对大鼠肺脏未造成明显损害。     

Neferine inhibits angiotensin Ⅱ-stimulated proliferation in vascular smooth muscle cells through heme oxygenase-1

Aim:

To explore the effect of neferine on angiotensin II (Ang II)-induced vascular smooth muscle cell (VSMC) proliferation.

Methods:

Human umbilical vein smooth muscle cells (HUVSMCs) were used. Cell proliferation was determined by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis. Heme oxygenase (HO)-1 protein expression was tested by Western blot analysis. Extracellular signal-regulated protein kinase 1/2 (ERK1/2) activation was determined by using immunoblotting.

Results:

Pre-incubation of HUVSMCs with neferine (0.1, 0.5, 1.0, and 5.0 μmol/L) significantly inhibited Ang II-induced cell proliferation in a concentration-dependent manner and neferine 5.0 μmol/L increased HO-1 expression by 259% compared with control. The antiproliferative effect of neferine was significantly attenuated by coapplication of zinc protoporphyrin IX (ZnPP IX, an HO-1 inhibitor) with neferine. Ang II-enhanced ERK1/2 phosphorylation was markedly reversed by neferine. By inhibiting HO-1 activity with ZnPP IX, the inhibitive effect of neferine on ERK1/2 phosphorylation was significantly attenuated. Cobalt-protoporphyrin (CoPP), an HO-1 inducer, significantly decreased Ang II-induced ERK1/2 phosphorylation and inhibited Ang II-induced cell proliferation. The ERK1/2 pathway inhibitor PD98059 significantly blocked Ang II-enhanced ERK1/2 phosphorylation and inhibited cell proliferation.

Conclusion:

These findings suggest that neferine can inhibit Ang II-induced HUVSMC proliferation by upregulating HO-1, leading to the at least partial downregulation of ERK1/2 phosphorylation.