Literature
首页医源资料库在线期刊动脉硬化血栓血管生物学杂志2007年第27卷第4期

Nrf2 Gene Transfer Induces Antioxidant Enzymes and Suppresses Smooth Muscle Cell Growth In Vitro and Reduces Oxidative Stress in Rabbit Aorta In Vivo

来源:《动脉硬化血栓血管生物学杂志》
摘要:NuclearfactorE2-relatedfactor-2(Nrf2)isatranscriptionfactororchestratingantioxidantandcytoprotectiveresponsesonoxidativeandelectrophilicstress,andithasbeenshowntohaveantiinflammatoryeffectsinvascularcellsinvitro。WethereforepostulatedthatNrf2genetransferwou......

点击显示 收起

【摘要】  Background- Reactive oxygen species (ROS) play a major role in vascular inflammation and pathophysiology of many vascular diseases such as atherosclerosis and injury-induced neointima formation after balloon angioplasty. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor orchestrating antioxidant and cytoprotective responses on oxidative and electrophilic stress, and it has been shown to have antiinflammatory effects in vascular cells in vitro. We therefore postulated that Nrf2 gene transfer would have salutary effects on vascular inflammation after angioplasty.

Methods and Results- Transduction of vascular smooth muscle cells (VSMCs) with Nrf2-expressing adenovirus increased the expression of several antioxidant enzymes including heme oxygenase-1 (HO-1) compared with ß-galactosidase (AdLacZ)-transduced controls. Moreover, Nrf2 gene transfer also inhibited vascular smooth muscle cell (VSMC) proliferation, and the effect was partially reversed by the HO inhibitor Sn(IV) protoporphyrin. In vivo, adenoviral gene transfer effectively reduced oxidative stress determined by antibody staining against oxidized epitopes of LDL, as well as inhibited vascular inflammation assessed by the macrophage cell count and monocyte chemoattractant protein-1 (MCP-1) staining. However, the antiproliferative effects of Nrf2 in vivo were counterbalanced with diminished apoptosis in neointimal VSMCs, resulting in no change in neointimal hyperplasia.

Conclusions- Nrf2 gene transfer or Nrf2-inducing drugs may have therapeutic applications in vascular diseases in which inflammation and oxidative stress play a role. However, the contrasting growth inhibitory and antiapoptotic effects of Nrf2 need to be considered in pathological conditions in which SMC proliferation plays a critical role.

We studied the effect of gene transfer of Nrf2, a transcription factor regulating antioxidant genes on VSMC growth, oxidative stress, and inflammation. Nrf2 overexpression induced antioxidant genes and inhibited VSMC proliferation in vitro, and reduced oxidative stress in vivo determined by oxLDL and inflammation assessed by macrophage number.

【关键词】  angioplasty antioxidants free radicals gene therapy restenosis


Introduction


Reactive oxygen species (ROS) play a role in a number of cardiovascular pathologies, including response to arterial injury after balloon angioplasty. ROS derived mainly from vascular smooth muscle cells (VSMCs) contribute to the proliferation and migration of medial VSMCs leading to neointimal hyperplasia and adverse remodeling and ultimately, vessel restenosis. 1 Particularly, the role of NAD(P)H oxidases as a source of ROS in VSMCs leading to neointimal hyperplasia has been demonstrated. 2 Also, sustained downregulation of the expression of extracellular superoxide dismutase (EC-SOD) has been shown to occur after balloon angioplasty, contributing to the imbalance between the production and disposal of ROS and constrictive remodelling. 3 Importantly, therapeutic approaches aiming at augmenting the antioxidant defense, such as gene therapy with antioxidant genes heme oxygenase-1 (HO-1) 4 or EC-SOD, 5 inhibit injury-induced neointima formation in animal models of restenosis. Although the evidence for the role of oxidative stress in restenosis from human studies is weaker, an antioxidant probucol and its stable modification AGI-1067 have been shown to reduce restenosis after percutaneous coronary intervention (PCI). 6 Interestingly, it has been recently shown in animal models of atherosclerosis and restenosis that the beneficial effects of probucol are likely not mediated via its direct antioxidant actions but through induction of HO-1, 7 suggesting that the augmentation of endogenous antioxidant defense may have potential for their treatment.


Nuclear factor E2-related factor-2 (Nrf2) is a member of CNC (cap ?n? collar) family of b-Zip transcription factors and an indispensable positive regulator of many antioxidant and phase II detoxifying enzymes. 8 On activation by oxidative or electrophilic stress, Nrf2 protein stabilizes, translocates to the nucleus, heterodimerizes with small Maf proteins, and binds to the so-called antioxidant response element (ARE), a common regulatory element found in the 5'-flanking regions of antioxidant and detoxification enzymes. 8 There is a large number of genes regulated by ARE, including enzymes involved in glutathione (GSH) metabolism, such as the subunits of the rate-limiting enzyme of glutathione synthesis, glutamate-cysteine ligase catalytic (GCLC) and modifier (GCLM) subunit genes. Also NAD(P)H:quinone oxidoreductase-1 (NQO1), which not only detoxifies xenobiotic quinones, but also reduces antioxidants vitamin E 9 and coenzyme Q 10 10 to their active form, is a Nrf2 target gene. 8 In addition, HO-1 has been shown to be positively regulated by Nrf2. 8


Gene therapy with transcription factors enables concerted induction or repression of multiple target genes, which may be beneficial when aiming at integrated responses in situations requiring the interplay of several factors having a common regulatory pathway. Examples of such approaches include the use of constitutively active hypoxia inducible factor-1 (HIF-1 ) 11 for the induction of angiogenic growth factors and therapeutic revascularization, or Sonic hedgehog (Shh) gene transfer 12 for the augmentation of multiple trophic factors and myocardial tissue regeneration. In analogy, simultaneous induction of antioxidant genes in situations in which oxidative stress contributes to the pathophysiology may be a better approach than gene transfer with individual antioxidant genes. Our goal was therefore to test a novel approach for augmenting antioxidant defenses by using concerted induction of antioxidant genes by adenoviral Nrf2 gene transfer. To this end, we first tested the efficacy of Nrf2 gene transfer in vitro to induce antioxidant genes in VSMCs, followed by studies assessing the in vivo effects of Nrf2 in the rabbit aortic balloon denudation model.


Materials and Methods


The expression of Nrf2, HO-1, GCLC, GCLM, and NQO1 in human aortic smooth muscle cells (HASMCs) transduced with Nrf2 or LacZ expressing adenovirus was studied using real time-PCR or Western blotting. The mRNA expression of HO-1 in transduced rabbit aortic smooth muscle cells (RaASMCs) was assessed by real time-PCR and the HO-1 activity spectrophotometrically. Cell proliferation was determined by [3H]-thymidine incorporation assay. The intraarterial gene transfer was performed as previously described, 13 and the arteries were harvested for RNA and histological analyses 7 days, 14 days, and 28 days after gene transfer. For more details, please see the supplemental materials, available online at http://atvb.ahajournals.org.


Results


AdNrf2 Overexpression Induces Antioxidant Genes in HASMCs and RaASMCs


The VSMCs is the primary cell type transduced by adenovirus in the rabbit balloon denudation model, 14 and also the major cell type contributing to neointimal hyperplasia after balloon injury. We therefore first studied the effect of Nrf2 gene transfer on antioxidant gene expression in HASMCs. The cells were transduced with Nrf2 expressing or LacZ control adenovirus, and the gene expressions of Nrf2, HO-1, GCLC, GCLM, and NQO1 were studied at the RNA and protein levels 48 hour post-transduction using real time-PCR and Western blotting. Transduction of HASMCs with increasing MOIs of AdNrf2 effectively increased both Nrf2 mRNA and protein expression ( Figure 1A and 1 C). Furthermore, Nrf2 gene transfer was able to induce the known target genes of Nrf2, most notably HO-1 ( Figure 1B, 1 C; supplemental Figures I and II). Also AdLacZ caused a small but significant increase in the expression of HO-1 mRNA in comparison to no virus controls ( Figure 1 B). HO-1 is a stress-inducible gene highly responsive not only to ROS but also to a large number of other internal and external factors causing cellular stress. 15 It is therefore conceivable that adenoviral transduction causes cell stress which results in an increase in HO-1 mRNA. However, the change in HO-1 mRNA expression is significantly higher in Nrf2-transduced cells in comparison to respective LacZ-controls. Although we did not see a significant increase of NQO1 mRNA at 48 hours, the NQO1 mRNA as well as the other target genes were induced at 24 hours after transduction (supplemental Figure I). Also NQO1 protein was dose-dependently increased in HASMCs ( Figure 1 C). In Nrf2-transduced RaASMCs, the increase in the HO-1 expression with respective MOIs is less than in HASMCs because of their lower transduction efficiency. However, the HO-1 mRNA expression was significantly increased in comparison to LacZ control with MOI 500 ( Figure 1 D). AdNrf2 also increased the HO-1 activity is RaASMCs. With MOI 500, the increase in the activity was 2.2±0.7 fold in comparison to LacZ control ( P =0.037).


Figure 1. Adenoviral transduction of human Nrf2 in human aortic smooth muscle cells (HASMCs) and rabbit aortic smooth muscle cells (RaASMCs) increases antioxidant gene expression. A, The expression of Nrf2 mRNA measured by real time-PCR (logarithmic scale) at 48 hours after transduction with different multiplicities of infection (MOI). B, The mRNA expression of heme oxygenase 1 (HO-1), glutamate-cysteine ligase modifier (GCLM) and catalytic subunits (GCLC) 48 hours after transduction with AdNrf2 in HASMCs.* P <0.05 in comparison to no virus controls; #significant change in comparison to respective LacZ controls. The data are combined from 2 experiments performed in triplicate wells. C, The protein expressions of Nrf2, HO-1, GCLM, GCLC, NQO1, and ß-actin in HASMCs 48 hours after transduction. D, The mRNA expression of HO-1 in RaASMCs assessed by real time-PCR. The data in panels A, B, and D are presented as mean±SEM.


Nrf2 Overexpression Inhibits HASMC and RaASMC Proliferation


Adenoviral overexpression of HO-1 has been shown to inhibit SMC growth in vitro. 16 Inasmuch as Nrf2 gene transfer induced HO-1 expression in both HASMCs and RaASMCs, we hypothesized that Nrf2 overexpression would impact on SMC proliferation. In RaASMC, AdNrf2 transduction significantly inhibited proliferation assessed by [3H]-thymidine incorporation ( Figure 2 A). To assess the role of HO-1 in the growth inhibitory effect of Nrf2 gene transfer, we used tin protoporphyrin IX to inhibit HO activity. 5 µmol/L tin protoporphyrin IX inhibited the activity by 64.9±18.7% ( P =0.01) and 10 µmol/L by 51.2±14.3% ( P =0.027). The inhibition of cell growth in RaASMCs was significantly reversed by the inhibitor ( Figure 2 B), showing that the growth inhibition was at least partially mediated by HO-1. Also in HASMCs, Nrf2 transduction inhibited proliferation. Thymidine incorporation was decreased by 15.3±2.6% ( P =0.012) with MOI 100 and by 18.4±3.1% ( P =0.027) with MOI 250 in Nrf2 transduced cells in comparison to LacZ controls.


Figure 2. AdNrf2 inhibits proliferation of RaASMCs. A, Proliferation of growth-stimulated RaASMCs is assessed by [3H]-thymidine incorporation assay. The data are expressed as CPM/µg protein. B, The effect of the HO-1 inhibitor on RaASMC proliferation. The data are presented as mean±SEM. * P <0.05 compared with respective LacZ control.


AdNrf2 Increases the Expression of NQO1 and Decreases Oxidative Stress in Balloon Injured Rabbit Arteries In Vivo


After having established the ability of Nrf2 gene transfer to induce antioxidant enzymes in vitro, we next wanted to examine the impact of Nrf2 gene transfer on oxidative stress in vivo in the rabbit aortic balloon denudation model. To this end, the previously established rabbit model of balloon injury and intraarterial gene transfer 13 was used. We used very clean clinical grade adenoviral vectors devoid of any contaminants. Furthermore, the viral dose had been optimized in our previous studies to avoid potential proinflammatory effects. 5,13 AdNrf2 gene transfer resulted in transgene expression, which was detectable by RT-PCR at 7 days and 14 days but no longer detectable at 28 days after transduction ( Figure 3 A). To assess the ability of Nrf2 gene transfer to induce antioxidant enzymes and to assess oxidative stress in the vessel wall, the expression of NQO1 and the amount of oxidatively modified LDL which readily accumulates in the injured rabbit vessels 17 was determined by immunostaining. The number of NQO1 positive cells present in the intima was significantly higher in Nrf2 transduced vessels compared with LacZ controls 7 days and 14 days after gene transfer ( Figure 3B and 3 C). The NQO1 positive cells are localized near to the lumen of the aorta, and they colocalize with VSMCs identified as such by HHF35 staining (not shown). Interestingly, the number of NQO1 positive cells increased in both LacZ as well as Nrf2 transduced vessels at 28 days as the lesions matured and acquired a more organized appearance. NQO1 was constitutively expressed in medial SMCs (not shown), supporting the notion that NQO1 is constitutively expressed in quiescent, but not in phenotypically altered, proliferating SMCs.


Figure 3. The expression of human Nrf2 as determined by RT-PCR in injured rabbit aorta after gene transfer and the expression of the target gene NQO1 in the aortic wall A, Representative data showing the expression of human Nrf2 7 and 14 days after gene transfer. The size of the product is 802 bp. Lane 1: Molecular weight marker, lane 2: negative control, lane 3: 7 days after AdLacZ transfer, lane 4: 7 days after AdNrf2 transfer, lane 5: 14 days AdLacZ transfer, lane 6: 14 days after AdNrf2 transfer, lane 7: 28 days after AdLacZ transfer, lane 8: 28 days after AdNrf2 transfer, lane 9: Control without reverse transcriptase, lane 10: Positive control (human Nrf2 cDNA), lane 11: Molecular weight marker. B and C, The percentage of intimal cells expressing NQO1 and representative images from sections immunostained against NQO1. Original magnification 200 x. Bars=100 µm. The data in bar graphs is depicted as mean percentage of NQO1 positive intimal cells±SEM. * P <0.05 and ** P <0.01 compared with LacZ control.


To evaluate the extent of oxidative stress by determining LDL oxidation, antibodies against oxidatively-modified apoB (Ox4e6) or HNE-modified LDL (HNE7) were used. Nrf2 gene transfer significantly reduced the accumulation of oxidized LDL in the injured vessel wall assessed by both antibodies at 14 days after transduction ( Figure 4A through 4 D). The Ox4e6 positivity colocalized with macrophage-rich areas of the lesions, whereas HNE7 staining was more diffusely spread in the neointima ( Figure 4B and 4 D).


Figure 4. Nrf2 gene transfer reduces immunoreactivity against oxidized LDL in the aortic wall. A and B, Staining with the antibody against oxidized apoB100 (mAb Ox4e6) and representative images from Ox4e6-immunostained sections at 14 days after gene transfer. C and D, Staining with the antibody recognizing hydroxynonenal-modified LDL (HNE7) and representative images at 14 days after gene transfer. The data in panels A and C are depicted mean percentage of the stained area±SEM; * P <0.05 compared with LacZ control.


AdNrf2 Reduces Inflammation in Balloon Injured Rabbit Arteries but Has No Impact on Reendothelialization


Next we examined the effect of AdNrf2 gene transfer on injury-induced inflammation by immunostainings against a macrophage-specific marker RAM-11 and a proinflammatory chemokine MCP-1. The number of macrophages normalized to the area was significantly smaller at 14 days in AdNrf2 transduced vessels in comparison to AdLacZ controls ( Figure 5A and 5 B). In addition, the staining for MCP-1, which was diffusely spread within neointima, was significantly reduced at 14 days in Nrf2 transduced aortas ( Figure 5C and 5 D). Nrf2 had no impact on reendothelialization assessed by the percentage CD31-positive endothelium of luminal circumference (43±7 versus 37±6 14 days and 59±19 versus 53±9 28 days after transduction in LacZ versus Nrf2-transduced vessels).


Figure 5. Nrf2 gene transfer reduces inflammation in Nrf2 transduced arteries. A, Inflammation in balloon-injured aorta after LacZ or Nrf2 gene transfer is assessed by counting the number of RAM-11-positive macrophages/mm 2 in the intima (mean±SEM). * P <0.05. B, Representative images from RAM-11 immunostained sections at 14 days after gene transfer. C, The expression of MCP-1 in injured aorta after LacZ or Nrf2 gene transfer assessed by percentage of positively stained area of the intima (mean±SEM). * P <0.05. D, Representative images from MCP-1 immunostained sections at 14 days after gene transfer. Original magnification 200 x. Bars=100 µm.


Nrf2 Gene Transfer Inhibits Neointimal SMC Proliferation With Concomitant Decrease in Apoptosis and No Net Effect on I/M Ratio


Nrf2 gene transfer inhibited VSMC proliferation in cultured human and rabbit VSMCs. To assess whether AdNrf2 is also able to inhibit cell proliferation in vivo, the injured aortas were immunostained against BrdU-labeled cells. The number of BrdU-positive cells in the intimal layer was significantly ( P <0.05) reduced at 7 days and 14 days after transduction ( Figure 6A and 6 B). However, the number of apoptotic cells in the neointima was decreased concomitantly, reaching statistical significance at 14 days after transduction ( Figure 6C and 6 D). When assessing the intima area (not shown) or the I/M ratio, there was no change in Nrf2-transduced versus controls in any of the time points studied ( Figure 6E and 6 F). There were also no significant changes in other morphological parameters, including the luminal circumference and area, the medial area, and the circumference of internal or external elastic lamina (data not shown).


Figure 6. Nrf2 gene transfer reduces cell proliferation and apoptosis in injured aortas but has no effect on the intima/media (I/M) ratio. A, The percentage of proliferating cells in the intima after gene transfer with AdLacZ or AdNrf2. B, Representative images of sections immunostained for BrdU-labeled cells at 14 days after transduction. C, The percentage of apoptotic cells within the intima assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-staining after gene transfer of LacZ or Nrf2. D, representative images of TUNEL-stained sections at 14 days after gene transfer with AdLacZ or AdNrf2. Arrows indicate TUNEL-positive nuclei. E, I/M ratio of AdNrf2 or AdLacZ transduced vessels after gene transfer. F, Representative HE-stained histological sections at 14 days after gene transfer. Arrowheads indicate the internal elastic lamina. The data in panels A, C, and E are depicted as mean±SEM; * P <0.05 and ** P <0.01. Original magnification 200 x. Bars=100 µm.


Discussion


Nrf2 has recently been shown to have antiinflammatory effects in the vasculature. In cultured endothelial cells, Nrf2 is activated by shear stress, a potent antiinflammatory force. 18 Overexpression of Nrf2 downregulates the tumor necrosis factor (TNF)- -induced expression of vascular cell adhesion molecule (VCAM)-1 at the transcriptional level. 18,19 In addition, adenoviral Nrf2 overexpression protects from oxidant injury and inhibits monocyte adhesion in endothelial cells in vitro. 20 Nrf2 mediates adaptive augmentation of antioxidant defenses of vascular cells on exposure to lipid oxidation products such as oxidized LDL, a lipid-derived aldehyde 4-hydroxynonenal, or cyclopentenone prostaglandins and isoprostanes. 21-24 The impact of Nrf2 on vascular inflammatory processes in vivo has not been studied to date, but in the acute pleural inflammatory model, Nrf2 gene ablation has been shown to exacerbate inflammation. 25 In addition, in the cutaneous wound repair model, which shares many similarities with the healing process after balloon injury, the expression of several important factors involved in wound healing was significantly reduced in early wounds of the Nrf2 knockout animals, and the late phase of repair was characterized by prolonged inflammation. 26 Thus Nrf2-dependent antioxidant defenses appear to play a significant role in the inflammation in vascular as well as in other tissues. To our knowledge, our study is the first to show antioxidant and antiinflammatory effects of Nrf2 gene transfer in vivo in the vessel wall.


In the present study, Nrf2 gene transfer decreased oxidative stress assessed by the accumulation of oxLDL in the arteries of cholesterol-fed animals. This may be explained by the fact that Nrf2 target genes having direct antioxidant functions limit the oxidation of LDL. Also the increased GSH synthetic capacity via induction of the rate-limiting enzyme GCL may impact on LDL oxidation, as GSH inhibits cell-mediated oxidation of LDL. 27 In addition, Nrf2 target genes may also include genes that are involved in hydrolysis of oxLDL. For example, in the gene expression analysis of Nrf2-overexpressing human endothelial cells (Jyrkkänen et al, unpublished, 2005), aldose reductase and fatty aldehyde dehydrogenase, which catalyze decomposition of lipid-derived aldehydes and oxidized phospholipids, 28,29 are induced by Nrf2. Also several glutathione S-transferases which are involved in detoxification of short-chain aldehydes derived from lipid peroxidation 30 are Nrf2 target genes, and combined increase in their activity and GSH concentration thereby potentially limits oxLDL accumulation.


In this study, Nrf2 inhibited VSMC proliferation through a mechanism partially dependent on HO activity. To our knowledge, this is the first study to show antiproliferative effects of Nrf2. Previous studies have shown that HO-1 inhibits VSMC proliferation through multiple mechanisms. The end products of HO catalyzed reaction, carbon monoxide (CO), bilirubin, and biliverdin inhibit VSMC growth. 16,31,32 Whether the growth inhibition of HO-1 or its catalytic products occurs through induction of apoptosis, inhibition of cell cycle progression, or both is unclear, but there is strong evidence that both CO and bilirubin inhibit VSMC proliferation by arresting the cell cycle progression at the G 1 phase. 16,32 At this juncture, it is of interest to note that the antiproliferative effects of probucol and rapamycin are at least partially mediated by HO-1. 7,33 Besides HO-1, there are also other potential mechanisms by which Nrf2 overexpression exerts its effects on VSMC growth. As exogenous ROS as well as ROS derived from the activation of NAD(P)H oxidases by various growth factors and cytokines contribute to the VSMC growth, it is conceivable that the augmentation of other antioxidant defenses such as the enhancement of the GSH synthetic capacity contribute to the growth inhibitory effects.


Despite the fact that Nrf2 gene transfer was able to inhibit SMC proliferation in vitro and reduce the number of proliferating cells determined by BrdU staining in vivo, it had no impact on I/M ratio. This may be explained by the fact that also the number of apoptotic cells in neointima decreased in Nrf2-transduced vessels. Although the role of apoptosis in neointimal growth is still somewhat controversial, it is generally accepted that the early wave of apoptosis of medial VSMCs occurring within hours after injury provokes a greater wound healing response thus exacerbating neointima lesion formation. However, the second wave of apoptosis confined to neointimal VSMCs and taking place days to weeks after injury may limit lesion growth and is thus considered beneficial. This notion is supported by studies in which gene transfer of proapoptotic proteins such as p53 or Fas ligand inhibit restenosis. 34 It is therefore possible that Nrf2, which has been shown to protect against apoptosis in vascular cells, 20,35 may despite its antiinflammatory and antiproliferative effects have no impact on restenosis via inhibiting apoptosis of the intimal VSMCs needed for the appropriate remodeling of the injured vessel.


There is experimental evidence in the literature indicating that oxLDL could contribute to the pathophysiology of restenosis by, eg, promoting VSMC proliferation and migration via activation of the platelet derived growth factor (PDGF) pathway. 36 Inflammatory cells contribute to the stenotic process not only by producing ROS and oxidizing LDL, but also by releasing cytokines and other inflammatory factors promoting VSMC recruitment and proliferation. 37 However, it should be noted that despite the similarities, atherosclerosis and restenosis are fundamentally different processes, oxLDL and macrophages having a key role in the former but not the latter. One of the earliest hallmarks of atherosclerosis is the accumulation of macrophage foam cells in the artery wall, whereas restenosis is primarily driven by VSMCs. 37,38 We propose that the effect of Nrf2 on VSMC apoptosis overdrives the possible beneficial effects the reduction of inflammation and oxLDL accumulation could have on neointima formation. Furthermore, in our study, Nrf2 transduction did not improve endothelial cell recovery. This may contribute to the lack of an effect on I/M ratio, as endothelium-derived NO is a critical factor suppressing the VSMC growth. 37 The catheter-mediated gene transfer method used in this study does not effectively target endothelial cells in balloon-injured vessels, which is a limitation as Nrf2 overexpression could potentially enhance reendothelialization of injured arteries. It is also noteworthy that the limited gene transfer efficiency of intraarterial gene transfer 14 favors the therapeutic use of secreted proteins and other genes that transduce their effects outside the cell, such as nitric oxide synthase or HO-1. Although many target genes induced by Nrf2 such as HO-1 have that potential, the transduction efficiency may be inadequate in the in vivo setting for therapeutic effects. 39


In summary, our results show that adenoviral gene delivery of Nrf2, a transcription factor responsible for concerted induction of antioxidant and cytoprotective genes on oxidative or electrophilic stress, is able to induce antioxidant genes and inhibit proliferation in VSMCs in vitro. In addition, this study is the first to show in vivo that Nrf2 gene transfer reduces inflammation and oxidative stress in the vessel wall. These results demonstrate the applicability of transcription factor gene therapy in vascular pathologies, in which oxidative stress plays an important role.


Acknowledgments


We thank Mervi Nieminen, Anne Martikainen, Sari Järveläinen, Tiina Koponen, and Seija Sahrio as well as the staff of the National Laboratory Animal Center at Kuopio University for their skillful technical assistance.


Sources of Funding


This study was supported by the Academy of Finland, the Sigrid Juselius Foundation, the Finnish Foundation for Cardiovascular Research, the Maire Taponen Foundation, and the Aarne Koskelo Foundation.


Disclosures


None.

【参考文献】
  Griendling KK, FitzGerald GA. Oxidative stress and cardiovascular injury: Part II: animal and human studies. Circulation. 2003; 108: 2034-2040.

Jacobson GM, Dourron HM, Liu J, Carretero OA, Reddy DJ, Andrzejewski T, Pagano PJ. Novel NAD(P)H oxidase inhibitor suppresses angioplasty-induced superoxide and neointimal hyperplasia of rat carotid artery. Circ Res. 2003; 92: 637-643.

Leite PF, Danilovic A, Moriel P, Dantas K, Marklund S, Dantas AP, Laurindo FR. Sustained decrease in superoxide dismutase activity underlies constrictive remodeling after balloon injury in rabbits. Arterioscler Thromb Vasc Biol. 2003; 23: 2197-2202.

Tulis DA, Durante W, Liu X, Evans AJ, Peyton KJ, Schafer AI. Adenovirus-mediated heme oxygenase-1 gene delivery inhibits injury-induced vascular neointima formation. Circulation. 2001; 104: 2710-2715.

Laukkanen MO, Kivela A, Rissanen T, Rutanen J, Karkkainen MK, Leppanen O, Brasen JH, Yla-Herttuala S. Adenovirus-mediated extracellular superoxide dismutase gene therapy reduces neointima formation in balloon-denuded rabbit aorta. Circulation. 2002; 106: 1999-2003.

Tardif JC, Gregoire J, Schwartz L, Title L, Laramee L, Reeves F, Lesperance J, Bourassa MG, L?Allier PL, Glass M, Lambert J, Guertin MC. Effects of AGI-1067 and probucol after percutaneous coronary interventions. Circulation. 2003; 107: 552-558.

Wu BJ, Kathir K, Witting PK, Beck K, Choy K, Li C, Croft KD, Mori TA, Tanous D, Adams MR, Lau AK, Stocker R. Antioxidants protect from atherosclerosis by a heme oxygenase-1 pathway that is independent of free radical scavenging. J Exp Med. 2006; 203: 1117-1127.

Motohashi H, Yamamoto M. Nrf2-Keap1 defines a physiologically important stress response mechanism. Trends Mol Med. 2004; 10: 549-557.

Siegel D, Bolton EM, Burr JA, Liebler DC, Ross D. The reduction of alpha-tocopherolquinone by human NAD(P)H: quinone oxidoreductase: the role of alpha-tocopherolhydroquinone as a cellular antioxidant. Mol Pharmacol. 1997; 52: 300-305.

Beyer RE, Segura-Aguilar J, di Bernardo S, Cavazzoni M, Fato R, Fiorentini D, Galli MC, Setti M, Landi L, Lenaz G. The role of DT-diaphorase in the maintenance of the reduced antioxidant form of coenzyme Q in membrane systems. Proc Natl Acad Sci U S A. 1996; 93: 2528-2532.

Kelly BD, Hackett SF, Hirota K, Oshima Y, Cai Z, Berg-Dixon S, Rowan A, Yan Z, Campochiaro PA, Semenza GL. Cell type-specific regulation of angiogenic growth factor gene expression and induction of angiogenesis in nonischemic tissue by a constitutively active form of hypoxia-inducible factor 1. Circ Res. 2003; 93: 1074-1081.

Kusano KF, Pola R, Murayama T, Curry C, Kawamoto A, Iwakura A, Shintani S, Ii M, Asai J, Tkebuchava T, Thorne T, Takenaka H, Aikawa R, Goukassian D, von Samson P, Hamada H, Yoon YS, Silver M, Eaton E, Ma H, Heyd L, Kearney M, Munger W, Porter JA, Kishore R, Losordo DW. Sonic hedgehog myocardial gene therapy: tissue repair through transient reconstitution of embryonic signaling. Nat Med. 2005; 11: 1197-1204.

Hiltunen MO, Laitinen M, Turunen MP, Jeltsch M, Hartikainen J, Rissanen TT, Laukkanen J, Niemi M, Kossila M, Hakkinen TP, Kivela A, Enholm B, Mansukoski H, Turunen AM, Alitalo K, Yla-Herttuala S. Intravascular adenovirus-mediated VEGF-C gene transfer reduces neointima formation in balloon-denuded rabbit aorta. Circulation. 2000; 102: 2262-2268.

Hiltunen MO, Turunen MP, Turunen AM, Rissanen TT, Laitinen M, Kosma VM, Yla-Herttuala S. Biodistribution of adenoviral vector to nontarget tissues after local in vivo gene transfer to arterial wall using intravascular and periadventitial gene delivery methods. FASEB J. 2000; 14: 2230-2236.

Ryter SW, Alam J, Choi AM. Heme oxygenase-1/carbon monoxide: from basic science to therapeutic applications. Physiol Rev. 2006; 86: 583-650.

Otterbein LE, Zuckerbraun BS, Haga M, Liu F, Song R, Usheva A, Stachulak C, Bodyak N, Smith RN, Csizmadia E, Tyagi S, Akamatsu Y, Flavell RJ, Billiar TR, Tzeng E, Bach FH, Choi AM, Soares MP. Carbon monoxide suppresses arteriosclerotic lesions associated with chronic graft rejection and with balloon injury. Nat Med. 2003; 9: 183-190.

Arakawa H, Qian JY, Baatar D, Karasawa K, Asada Y, Sasaguri Y, Miller ER, Witztum JL, Ueno H. Local expression of platelet-activating factor-acetylhydrolase reduces accumulation of oxidized lipoproteins and inhibits inflammation, shear stress-induced thrombosis, and neointima formation in balloon-injured carotid arteries in nonhyperlipidemic rabbits. Circulation. 2005; 111: 3302-3309.

Chen XL, Varner SE, Rao AS, Grey JY, Thomas S, Cook CK, Wasserman MA, Medford RM, Jaiswal AK, Kunsch C. Laminar flow induction of antioxidant response element-mediated genes in endothelial cells. A novel anti-inflammatory mechanism. J Biol Chem. 2003; 278: 703-711.

Banning A, Brigelius-Flohe R. NF-kappaB, Nrf2, and HO-1 interplay in redox-regulated VCAM-1 expression. Antioxid Redox Signal. 2005; 7: 889-899.

Chen XL, Dodd G, Thomas S, Zhang X, Wasserman MA, Rovin BH, Kunsch C. Activation of the Nrf2/ARE Pathway Protects Endothelial Cells from Oxidant Injury and Inhibits Inflammatory Gene Expression. Am J Physiol Heart Circ Physiol. 2006; 290: H1862-H1870.

Bea F, Hudson FN, Chait A, Kavanagh TJ, Rosenfeld ME. Induction of glutathione synthesis in macrophages by oxidized low-density lipoproteins is mediated by consensus antioxidant response elements. Circ Res. 2003; 92: 386-393.

Ishii T, Itoh K, Ruiz E, Leake DS, Unoki H, Yamamoto M, Mann GE. Role of Nrf2 in the regulation of CD36 and stress protein expression in murine macrophages: activation by oxidatively modified LDL and 4-hydroxynonenal. Circ Res. 2004; 94: 609-616.

Levonen AL, Dickinson DA, Moellering DR, Mulcahy RT, Forman HJ, Darley-Usmar VM. Biphasic effects of 15-deoxy-delta(12,14)-prostaglandin J(2) on glutathione induction and apoptosis in human endothelial cells. Arterioscler Thromb Vasc Biol. 2001; 21: 1846-1851.

Levonen AL, Landar A, Ramachandran A, Ceaser EK, Dickinson DA, Zanoni G, Morrow JD, Darley-Usmar VM. Cellular mechanisms of redox cell signalling: role of cysteine modification in controlling antioxidant defences in response to electrophilic lipid oxidation products. Biochem J. 2004; 378: 373-382.

Itoh K, Mochizuki M, Ishii Y, Ishii T, Shibata T, Kawamoto Y, Kelly V, Sekizawa K, Uchida K, Yamamoto M. Transcription factor Nrf2 regulates inflammation by mediating the effect of 15-deoxy-Delta(12,14)-prostaglandin j(2). Mol Cell Biol. 2004; 24: 36-45.

Braun S, Hanselmann C, Gassmann MG, auf dem KU, Born-Berclaz C, Chan K, Kan YW, Werner S. Nrf2 transcription factor, a novel target of keratinocyte growth factor action which regulates gene expression and inflammation in the healing skin wound. Mol Cell Biol. 2002; 22: 5492-5505.

Rosenblat M, Coleman R, Aviram M. Increased macrophage glutathione content reduces cell-mediated oxidation of LDL and atherosclerosis in apolipoprotein E-deficient mice. Atherosclerosis. 2002; 163: 17-28.

Demozay D, Rocchi S, Mas JC, Grillo S, Pirola L, Chavey C, Van Obberghen E. Fatty aldehyde dehydrogenase: potential role in oxidative stress protection and regulation of its gene expression by insulin. J Biol Chem. 2004; 279: 6261-6270.

Srivastava S, Spite M, Trent JO, West MB, Ahmed Y, Bhatnagar A. Aldose reductase-catalyzed reduction of aldehyde phospholipids. J Biol Chem. 2004; 279: 53395-53406.

Awasthi YC, Yang Y, Tiwari NK, Patrick B, Sharma A, Li J, Awasthi S. Regulation of 4-hydroxynonenal-mediated signaling by glutathione S-transferases. Free Radic Biol Med. 2004; 37: 607-619.

Nakao A, Murase N, Ho C, Toyokawa H, Billiar TR, Kanno S. Biliverdin administration prevents the formation of intimal hyperplasia induced by vascular injury. Circulation. 2005; 112: 587-591.

Ollinger R, Bilban M, Erat A, Froio A, McDaid J, Tyagi S, Csizmadia E, Graca-Souza AV, Liloia A, Soares MP, Otterbein LE, Usheva A, Yamashita K, Bach FH. Bilirubin: a natural inhibitor of vascular smooth muscle cell proliferation. Circulation. 2005; 112: 1030-1039.

Deng YM, Wu BJ, Witting PK, Stocker R. Probucol protects against smooth muscle cell proliferation by upregulating heme oxygenase-1. Circulation. 2004; 110: 1855-1860.

Walsh K, Smith RC, Kim HS. Vascular cell apoptosis in remodeling, restenosis, and plaque rupture. Circ Res. 2000; 87: 184-188.

Brunt KR, Fenrich KK, Kiani G, Tse MY, Pang SC, Ward CA, Melo LG. Protection of human vascular smooth muscle cells from H2O2-induced apoptosis through functional codependence between HO-1 and AKT. Arterioscler Thromb Vasc Biol. 2006; 26: 2027-2034.

Stiko-Rahm A, Hultgardh-Nilsson A, Regnstrom J, Hamsten A, Nilsson J. Native and oxidized LDL enhances production of PDGF AA and the surface expression of PDGF receptors in cultured human smooth muscle cells. Arterioscler Thromb. 1992; 12: 1099-1109.

Costa MA, Simon DI. Molecular basis of restenosis and drug-eluting stents. Circulation. 2005; 111: 2257-2273.

Glass CK, Witztum JL. Atherosclerosis. the road ahead. Cell. 2001; 104: 503-516.

Yla-Herttuala S, Alitalo K. Gene transfer as a tool to induce therapeutic vascular growth. Nat Med. 2003; 9: 694-701.


作者单位:Departments of Biotechnology and Molecular Medicine (A.-L.L., M.I., T.H., S.J., H.-K.J., E.K., K.M., E.R., P.T., J.R., S.Y.-H.), A.I. Virtanen Institute, Kuopio University; Department of Medicine, Kuopio University (S.Y.-H.); and Gene Therapy Unit, Kuopio University Hospital (S.Y.-H.), Kuopio, Finla

作者: Anna-Liisa Levonen; Matias Inkala; Tommi Heikura;
医学百科App—中西医基础知识学习工具
  • 相关内容
  • 近期更新
  • 热文榜
  • 医学百科App—健康测试工具