Oxidative Medicine and Cellular Longevity

Oxidative Medicine and Cellular Longevity / 2016 / Article

Research Article | Open Access

Volume 2016 |Article ID 2356853 | 8 pages | https://doi.org/10.1155/2016/2356853

BQ123 Stimulates Skeletal Muscle Antioxidant Defense via Nrf2 Activation in LPS-Treated Rats

Academic Editor: Ersin Fadillioglu
Received23 Jul 2015
Revised24 Sep 2015
Accepted11 Oct 2015
Published28 Dec 2015


Little is understood of skeletal muscle tissue in terms of oxidative stress and inflammation. Endothelin-1 is an endogenous, vasoconstrictive peptide which can induce overproduction of reactive oxygen species and proinflammatory cytokines. The aim of this study was to evaluate whether BQ123, an endothelin-A receptor antagonist, influences the level of TNF-α, IL-6, SOD-1, HO-1, Nrf2 mRNA, and NF-κB subunit RelA/p65 mRNA in the femoral muscle obtained from endotoxemic rats. Male Wistar rats were divided into 4 groups () and received iv (1) saline (control), (2) LPS (15 mg/kg), (3) BQ123 (1 mg/kg), (4) BQ123 (1 mg/kg), and LPS (15 mg/kg, resp.) 30 min later. Injection of LPS led to significant increase in levels of RelA/p65 mRNA, TNF-α, and IL-6, while content of SOD-1, HO-1, and Nrf2 mRNA was unchanged. Administration of BQ123 prior to LPS challenge resulted in a significant reduction in RelA/p65 mRNA, TNF-α, and IL-6 levels, as well as markedly elevated concentrations of SOD-1, HO-1, and Nrf2 mRNA. BQ123 appears to enhance antioxidant defense and prevent production of TNF-α and IL-6 in skeletal muscle of LPS-treated rat. In conclusion, endothelin-A receptor antagonism exerts significant impact on the skeletal muscle favouring anti-inflammatory effects and protection against oxidative stress.

1. Introduction

Sepsis is a severe systemic inflammation contributing to excessive generation of reactive oxygen species (ROS), overproduction of numerous inflammatory cytokines, and multiple organ failure, which often results in death [1]. This critical condition is a frequent cause of such neuromuscular disorders as critical illness myopathy (CIM), which may lead to rhabdomyolysis and muscle atrophy [2]. Lipopolysaccharide (LPS), the main causative agent inducing sepsis, stimulates macrophages to excrete large amounts of inflammatory biomarkers, for example, tumour necrosis factor-α (TNF-α), interleukin-1 (IL-1), IL-6, and IL-8. [1, 3]. High serum levels of TNF-α and IL-6 accompanying endotoxemia are believed to induce protein degradation in skeletal muscle contributing to muscular atrophy [4]. The appearance of these mediators in blood is in mostly the effect of activation of the nuclear factor-κB (NF-κB) pathway, a key regulator of immune system response [1, 3]. NF-κB is present in almost every mammalian cell, located as a heterodimer consisting of two subunits, p50 and RelA/p65. Under the influence of such factors as LPS and TNF-α, NF-κB translocates to the nucleus, where it initiates expression of inflammatory cytokines and the adhesion molecules involved in proliferation, apoptosis, and oxidative stress response [5].

The deleterious participation of ROS in myopathy has been studied by many authors [6, 7]. ROS accumulation, especially mitochondrial ROS, has been shown to play a significant role in muscle atrophy [7]. ROS can cause DNA damage, lipid peroxidation, and protein modification and may activate certain nuclear transcription factors such as NF-κB [8] and nuclear factor (erythroid-derived-2)-like 2 (Nrf2) [9]. Linke et al. indicated in skeletal muscle reduced activity of major antioxidant enzymes, that is, superoxide dismutase (SOD), catalases (CAT), and glutathione peroxidase (GPX) during oxidative stress [10]. Treatment with SOD and CAT or supplementation with antioxidant vitamin attenuated oxidative stress and skeletal muscle atrophy [11, 12].

Many authors demonstrated that endothelin-1 (ET-1), a vasoconstrictive, endothelial peptide, accelerates ROS formation in vascular smooth muscle cells (VSMC), endothelial cells, and other tissues [1315]. Skeletal muscle is one of the most vascularized tissues [16], but little is known about ET-1 participation in the development of oxidative stress in this tissue. What is more, LPS is known to increase endothelial permeability and intensify production of ET-1 in various tissues [17, 18]. Piechota et al. indicate that ET-1 levels are correlated with other parameters of sepsis such as C-reactive protein, procalcitonin, or natriuretic propeptide [19], implying that ET-1 is involved in pathogenesis of sepsis and blood levels of ET-1 may serve as a biomarker of severity of sepsis [20, 21]. Endothelin-1 acts through two types of G protein-coupled receptors, endothelin receptor A (ETA) and endothelin receptor B (ETB), both of which are present in multiple various cells and tissues. Under physiological conditions, ET-1 binding to the ETA receptors on VSMC triggers a potent vascular smooth muscle contraction [22], while a high level of ET-1 additionally results in intensified synthesis of ROS, mainly superoxide anion () [23]. Blockage of the ETA receptor with BQ123, a receptor antagonist, decreases the content of lipid peroxidation products [24, 25], alleviates LPS-induced oxidative stress [15, 26, 27], increases reduced glutathione (GSH) level, and enhances SOD activity [25, 28]. Virtually, no reports describe the influence of BQ123 on the Nrf2/heme oxygenase-1 (HO-1) signaling pathway.

Nrf2 is a crucial agent regulating the expression of antioxidant/detoxification genes encoding many cytoprotective proteins that act in synergy to remove ROS [29]. Under normal conditions, Nrf2 is found in the cytoplasm, coupled with the regulatory protein Keap1 [30]. In response to oxidative stress, Nrf2 dissociates from this complex and transfers to the nucleus, where it binds to the specific ARE sequence and upregulates the expression of antioxidant genes such as HO-1, which plays an important role protecting against oxidative stress and inflammatory processes [31]. Some authors suggest that potential cross talk may exist between Nrf2 and NF-κB pathways [30].

The present study investigates the influence of BQ123 on inflammatory process (RelA/p65 mRNA, TNF-α, and IL-6 levels) and antioxidant response (Nrf2 mRNA, HO-1, and SOD-1 levels) in the skeletal muscle of endotoxemic rats.

2. Materials and Methods

2.1. Animals

All experiments were carried out on male Wistar rats aged 3-4 months, weighing 270–330 g: the rats were weighed directly before the experiment. The animals were kept under standard laboratory temperature (20 ± 2°C) and lighting (light from 6:00 a.m. to 6:00 p.m.), with free access to lab chow and tap water, until being used in the experiments. All animals were maintained for 1 week in the laboratory for adaptation. The experimental procedures followed the guidelines for the care and use of laboratory animals and were approved by the Medical University of Lodz Ethics Committee number 7/ŁB699/2014.

2.2. Experimental Protocol

Animals were randomly divided into four groups ( per group). In group 1 (control), rats received iv 0.2 mL of 0.9% NaCl and 30 min later again 0.2 mL of 0.9% NaCl. In group 2 (LPS), rats received iv 0.2 mL of saline and 30 min later 0.2 mL of LPS (15 mg/kg). In group 3 (BQ123), rats received iv 0.2 mL of saline and 30 min later 0.2 mL of BQ123 (1 mg/kg). In group 4 (BQ123 + LPS), rats received iv a single dose of BQ123 (1 mg/kg) and a single dose of LPS (0.2 mL, 15 mg/kg) after 30 min. The animals were anesthetized by an intraperitoneal injection of urethane solution (1.5 g/kg of b.w.). When a sufficient level of anesthesia was achieved, the skin and subcutaneous tissues on the neck were infiltrated with 2% lidocaine hydrochloride solution (Polfa, Poland) and cut and a 2 cm-long polyethylene tube (2.00 mm O.D.) was inserted into the trachea. The right femoral vein was catheterized and a polyurethane cannula was inserted (0.41 mm O.D., 0.23 mm I.D.). All drugs were administrated directly into the femoral vein.

2.3. Tissue Preparation and Sample Collection

Five hours after the last injection, the rats were sacrificed. The femoral muscle was cut off at the right thigh and rinsed with ice-cold saline, dried by blotting between two pieces of filter paper, weighed, and frozen in −75°C until being used for measurements.

2.4. Determination of TNF-α, IL-6, and SOD-1 Levels

TNF-α, IL-6, and SOD-1 concentrations in the skeletal muscle were assayed by specific enzyme linked immunosorbent assay using a commercially available ELISA test kit containing a monoclonal antibody specific for rat TNF-α, IL-6, and SOD-1 (Cloud-Clone Corp., USA). Firstly, 50 mg portions of skeletal muscle were cut into small pieces and homogenized in 2 mL of ice-cold PBS with a glass homogenizer on ice. The resulting suspension was subjected to two freeze-thaw cycles to further break the cell membranes. The homogenates were centrifuged for 5 min at 5000 ×g in 4°C, and the supernatants were collected and assayed immediately according to the manufacturer’s instructions. Optical density at 450 nm was read using Victor x3 microplate reader (Perkin Elmer, USA). All tests were performed in duplicate. Protein concentration of the samples was determined using the Bio-Rad Protein Assay (Bio-Rad Laboratories, USA), according to the manufacturer’s instructions. The TNF-α and IL-6 concentrations were expressed as pg/mg protein. The concentration of SOD-1 was expressed as ng/mg protein.

2.5. Determination of HO-1 Level

An ELISA kit (Enzo Life Sciences, Cat. number ADI-EKS-810A) was used to evaluate the concentration of HO-1. Firstly, 50 mg portions of skeletal muscle were cut into small pieces and homogenized in 1 mL of extraction reagent with the addition of protease inhibitors. Tissues were homogenized in glass homogenizer on ice. The homogenates were centrifuged at 21,000 ×g in 4°C for 10 min. Supernatants were removed and assayed immediately according to the manufacturer’s instructions. Optical density was read at 450 nm using a Victor x3 microplate reader (Perkin Elmer, USA). All tests were performed in duplicate. Protein concentration of the samples was determined using the Bio-Rad Protein Assay (Bio-Rad Laboratories, USA), according to the manufacturer’s instructions. The HO-1 concentration was expressed as ng/mg protein.

2.6. RNA Isolation

Total RNA was extracted from samples using RNeasy mini kits (Qiagen). Briefly, frozen samples of rat femoral muscle were homogenized in 300 μL of RLT Buffer by Tissue Ruptor homogenizer (Qiagen). Then, 590 μL of Nuclease-Free Water (Ambion) and 10 μL of Qiagen Proteinase K solution were added. Homogenates were incubated at 55°C for 10 min and centrifuged for 3 min at 14000 rpm. The following part of protocol was performed as described by the manufacturer. RNA was quantified using a Pico Drop spectrophotometer (Picodrop Limited, UK). The quality of RNA samples was analyzed by measuring the ratio of absorptions at 260/280 nm. The purified total RNA was immediately used for cDNA synthesis or stored at −80°C. Generation of cDNA was performed with QuantiTect Reverse Transcription Kit (Qiagen) according to the protocol of the manufacturer, with 1 μg of total RNA used as starting material. Reverse transcription was performed in conditions optimized for use with this kit (25°C for 10 min, 37°C for 120 min, and 85°C for 5 min). The cDNA samples were kept frozen at −20°C.

2.7. Determination of Nrf2 and p65 mRNA Expressions: Real Time PCR Analysis

The mRNA quantification was done using standard TaqMan Gene Expression Assays (Applied Biosystems), Nfe2l2 (Assay ID: Rn00477784_m1), Rela (Assay ID: Rn01502266_m1), and Actb (Rn00667869_m1), as a control. The 20 μL qPCR included 50 ng cDNA, 10 μL TaqMan Universal PCR Master Mix, and 1 μL TaqMan Gene Expression Assay (20x). The reactions were incubated in a 96-well plate at 95°C for 10 min, followed by 40 cycles of 95°C for 15 s and 60°C for 1 min. All reactions were run in triplicate. TaqMan PCR assays were performed on a 7900HT Fast Real-Time PCR System (Applied Biosystems) and analyzed using Sequence Detection System Software. Fold induction values (RQ) were calculated according to the equation , where ΔCt represents the differences in cycle threshold numbers between the target gene (Nrf2, RelA) and endogenous control (β-actin) and ΔΔCt represents the relative change in these differences between examined and control groups.

2.8. Statistical Analysis

STATISTICA 12 (StatSoft) program was used to perform statistical calculations. The results were presented as means ± SEM. Statistical analyses of the difference between two groups were performed using independent Student’s t-test. Values of were accepted as statistically significant.

3. Results

3.1. BQ123 Pretreatment Lessens LPS-Induced Production of Inflammatory Biomarkers

Skeletal muscle levels of TNF-α and IL-6 are illustrated in Figures 1(a) and 1(b). LPS treatment led to increased tissue levels of TNF-α and IL-6 when compared to the control group ( and , resp.). Concomitant treatment with BQ123 significantly decreased the LPS-induced production of these cytokines as compared to the LPS group (). Moreover, BQ123 applied alone resulted in lowered level of TNF-α as compared to the control ().

3.2. BQ123 Administration Alters the Expression of Nrf2 and RelA/p65 mRNA during Endotoxemia

Figures 1(c) and 2(a) present RelA/p65 and Nrf2 mRNA expression levels in the rat skeletal muscle. RelA/p65 mRNA expression is significantly increased in LPS group when compared to the control (), while Nrf2 mRNA level is slightly and insignificantly decreased. However, administration of BQ123 alone successfully activated the expression of Nrf2 () compared to the control but did not affect RelA/p65 mRNA level. Otherwise, injection of BQ123 followed by LPS significantly elevated expression of Nrf2 () as compared to the LPS group, whereas RelA/p65 expression in the same group was substantially declined ().

3.3. BQ123 Pretreatment Enhanced Antioxidant Defense during Endotoxemia

ELISA results showed that concentration of SOD-1 was unchanged in the LPS group when compared to the control (Figure 2(b)). However, pretreatment with BQ123 resulted in increased SOD-1 levels compared with the LPS group () and the control (). Concentration of HO-1 in LPS and BQ123 groups was slightly different from the control group and showed no statistical significance (Figure 2(c)). However, the HO-1 level in BQ123 + LPS group turned out to be increased ().

4. Discussion

Our present findings are the first to demonstrate that BQ123, an ETA receptor blocker, increases expression of Nrf2 in femoral muscle of LPS-treated rats. The increased expression of Nrf2 was associated with enhanced levels of SOD-1 and HO-1 and decreased production of TNF-α and IL-6 in skeletal muscle.

It is well documented that LPS leads to the development of inflammation associated with oxidative stress that can cause tissue damage, including skeletal muscle damage [3234]. The markedly elevated concentrations of TNF-α and IL-6 in muscle tissue found in the present study after LPS challenge confirm the results of other authors, who demonstrated the same effect of LPS in rat skeletal muscle [35] and in L6 skeletal muscle cells [36]. Moreover, Olesen et al. observe that LPS injection (0.3 ng/kg b.w.) increased TNF-α and IL-6 mRNA content in the skeletal muscle of young, male volunteers [37]. LPS and ROS are well known to induce migration of NF-κB to the nucleus, where NF-κB stimulates the expression of proinflammatory genes. NF-κB activates TNF-α and IL-6 production, which in turn stimulates nuclear translocation of NF-κB, forming a loop feedback mechanism [38]. This was demonstrated by the substantially higher level of RelA/p65 mRNA observed in the present study in rats receiving LPS alone.

It was reported that the ETA receptor blockade reduces levels of oxidative stress parameters [3941]. Several studies have shown that BQ123 has a beneficial influence on the TNF-α level in the lung tissue of rats treated with cigarette smoke extract [42], in rat hearts with ischemia-reperfusion injury [28], and in patients after bypass grafting [43]. This ETA receptor antagonist also alleviates IL-6 production in human vascular smooth muscle cells [44]. The beneficial effects of BQ123 are probably associated with the inhibition of NF-κB expression observed in our present study through significant reduction of RelA/p65 mRNA, the NF-κB subunit, in LPS-treated rats. Pretreatment with BQ123 was also found to decrease LPS-elicited augmentation of TNF-α and IL-6, confirming that endothelin-1 mediates the activation of the NF-κB pathway and blocking ETA receptor exhibits an anti-inflammatory effect.

To avoid harmful effects triggered by ROS and inflammatory cytokines, the skeletal muscles control the antioxidant defense system, which includes the enzymatic antioxidants such as HO-1, SOD, CAT, and GPX and the nonenzymatic free radical scavengers, that is, glutathione, thioredoxin [45, 46]. The main activity of HO-1 is to metabolize heme to iron, carbon monoxide (CO), and biliverdin, which is immediately converted into bilirubin. It is an antioxidative phase II enzyme since the products of heme degradation have antiradical, anti-inflammatory, and antiapoptotic properties [47]. In addition, overexpression of HO-1 can negatively regulate inflammatory mediators, including TNF-α and IL-6 [48, 49]. Our findings indicate that LPS administration resulted in slightly lower level of HO-1 than control values. Likewise, Tran et al. report a nonsignificant decrease in HO-1 after LPS stimulation in murine BV2 microglia cell line [50]. On the other hand, Wang et al. indicate a decrease in HO-1 protein expression in the aorta of rats treated iv with 10 mg/kg LPS [51]. Similar results were presented by Seo et al. following 6 hours of LPS exposure in the RAW 264.7 macrophage cell line [52]. However, other authors demonstrated increase in HO-1 level in the diaphragmatic muscle after LPS stimulation. Barreiro et al. reported enhanced HO-1 protein expression within 6–24 h after LPS injection (20 mg/kg) [53]. Taillé et al. observed a similar effect after one day from LPS administration [54]. These differences in results may stem from differences in tissue type and location of its collection. Nevertheless, this is the first study to present enhanced HO-1 levels following BQ123 administration in endotoxemic rats.

The second major enzyme defending mammalian cells against free radicals is SOD, which is known to occur in three isoforms: cytoplasmic SOD-1 (Cu/ZnSOD), mitochondrial SOD-2 (MnSOD), and extracellular EcSOD. The SOD family catalyzes the dismutation of potentially toxic superoxide anion to hydrogen peroxide (H2O2) and oxygen (O2) [55]. Recent studies indicate that SOD-1 expression is upregulated by Nrf2 pathway in a similar way to HO-1 [56, 57].

In the present study using rat femoral muscle, while injection of LPS or BQ123 alone had no effect on SOD-1 concentration, concomitant LPS and BQ123 administration resulted in significantly increased SOD-1 level. Such enhanced level of SOD-1 may increase the capacity of myocytes to diminish the raised superoxide anion level generated after LPS administration. Likewise, other authors also report unaltered SOD-1 levels after LPS treatment. Visner et al. have shown such effect in rat pulmonary artery and microvascular endothelial cells [58]. Liu et al. also report unchanged SOD-1 values 24 hours after treating gingival fibroblasts with 5 to 50 mg/mL of LPS [59]. In other studies, LPS had no influence on SOD-1 mRNA level in rat kidney [60], astrocytes [61], and human epithelial alveolar and airway cells [62, 63]. On the other hand, some authors report a reduction [57, 64] or increase [65, 66] of SOD-1 levels after LPS administration. Therefore, the SOD-1 results are ambiguous and require further study. So far, few authors demonstrated protective features of BQ123. Briyal et al. observed that BQ123 stimulated SOD production in the brain of amyloid-β-treated rat [25]. Moreover, BQ123 enhanced SOD activity, which was decreased after endothelin-1 (1-31) stimulation in rat cardiomyocytes [67]. Likewise, SOD activity was also increased after BQ123 treatment in myocardial ischemia-reperfusion injury [28]. However, Emre et al. indicate that BQ123 administration did not improve SOD activity in rat liver after renal ischemia-reperfusion injury [68].

Transcriptional factor Nrf2 is activated in response to inflammation and ROS. It plays a central role in the defense against them, since it controls the expression of detoxifying enzymes such as HO-1 and probably SOD-1. In the current study, LPS administration did not affect Nrf2 gene expression in rat skeletal muscle. Some authors have shown that LPS activates Nrf2 translocation to the nucleus in various tissues [52, 69], but few reports present Nrf2 gene expression after LPS stimulation. Hao et al. indicated unaltered level of Nrf2 mRNA in the murine heart after LPS challenge [70]. Yu et al. demonstrated an elevated level of Nrf2 mRNA in the lung of a rabbit model of endotoxemia [71], while Song et al. presented decreased Nrf2 expression in the diaphragm of preterm lambs after 72 h of LPS exposure in utero [72]. Similar research is needed on muscle tissue to clarify the occurring processes.

In this study, both pretreatment and treatment with BQ123 substantially raised Nrf2 mRNA level. What is more, elevated Nrf2 expression in the BQ123 + LPS group was associated with higher levels of HO-1 and SOD-1. Nrf2 is widely known to induce HO-1 production. Our data may indicate a signal path connecting Nrf2 and SOD-1. These data also suggest that BQ123 may be able to protect skeletal muscle cells from inflammation and oxidative stress through upregulation of Nrf2 expression, enhanced HO-1 and SOD-1 levels, and inhibition of RelA/p65 expression.

Conflict of Interests

The authors declare that there is no conflict of interests.


This study was supported by Grant 503/0-079-03/503-01 from the Medical University of Lodz.


  1. M. Sagy, Y. Al-Qaqaa, and P. Kim, “Definitions and pathophysiology of sepsis,” Current Problems in Pediatric and Adolescent Health Care, vol. 43, no. 10, pp. 260–263, 2013. View at: Publisher Site | Google Scholar
  2. C. F. Bolton, “Neuromuscular manifestations of critical illness,” Muscle and Nerve, vol. 32, no. 2, pp. 140–163, 2005. View at: Publisher Site | Google Scholar
  3. J. Roth and G. E. P. De Souza, “Fever induction pathways: evidence from responses to systemic or local cytokine formation,” Brazilian Journal of Medical and Biological Research, vol. 34, no. 3, pp. 301–314, 2001. View at: Google Scholar
  4. C. Langhans, S. Weber-Carstens, F. Schmidt et al., “Inflammation-induced acute phase response in skeletal muscle and critical illness myopathy,” PLoS ONE, vol. 9, no. 3, Article ID e92048, 2014. View at: Publisher Site | Google Scholar
  5. M. J. Morgan and Z.-G. Liu, “Crosstalk of reactive oxygen species and NF-κB signaling,” Cell Research, vol. 21, no. 1, pp. 103–115, 2011. View at: Publisher Site | Google Scholar
  6. H. Kuwahara, T. Horie, S. Ishikawa et al., “Oxidative stress in skeletal muscle causes severe disturbance of exercise activity without muscle atrophy,” Free Radical Biology and Medicine, vol. 48, no. 9, pp. 1252–1262, 2010. View at: Publisher Site | Google Scholar
  7. F. L. Muller, W. Song, Y. C. Jang et al., “Denervation-induced skeletal muscle atrophy is associated with increased mitochondrial ROS production,” American Journal of Physiology—Regulatory, Integrative and Comparative Physiology, vol. 293, no. 3, pp. R1159–R1168, 2007. View at: Publisher Site | Google Scholar
  8. M. Meyer, H. L. Pahl, and P. A. Baeuerle, “Regulation of the transcription factors NF-κB and AP-1 by redox changes,” Chemico-Biological Interactions, vol. 91, no. 2-3, pp. 91–100, 1994. View at: Publisher Site | Google Scholar
  9. Q. Zhang, J. Pi, C. G. Woods, and M. E. Andersen, “A systems biology perspective on Nrf2-mediated antioxidant response,” Toxicology and Applied Pharmacology, vol. 244, no. 1, pp. 84–97, 2010. View at: Publisher Site | Google Scholar
  10. A. Linke, V. Adams, P. C. Schulze et al., “Antioxidative effects of exercise training in patients with chronic heart failure: increase in radical scavenger enzyme activity in skeletal muscle,” Circulation, vol. 111, no. 14, pp. 1763–1770, 2005. View at: Publisher Site | Google Scholar
  11. R. D. Bianca, N. S. Wayman, M. C. McDonald et al., “Superoxide dismutase mimetic with catalase activity, EUK-134, attenuates the multiple organ injury and dysfunction caused by endotoxin in the rat,” Medical Science Monitor, vol. 8, no. 1, pp. BR1–BR7, 2002. View at: Google Scholar
  12. H.-J. Appell, J. A. R. Duarte, and J. M. C. Soares, “Supplementation of vitamin E may attenuate skeletal muscle immobilization atrophy,” International Journal of Sports Medicine, vol. 18, no. 3, pp. 157–160, 1997. View at: Publisher Site | Google Scholar
  13. M. H. Sedeek, M. T. Llinas, H. Drummond et al., “Role of reactive oxygen species in endothelin-induced hypertension,” Hypertension, vol. 42, no. 4, pp. 806–810, 2003. View at: Publisher Site | Google Scholar
  14. N. Duerrschmidt, N. Wippich, W. Goettsch, H.-J. Broemme, and H. Morawietz, “Endothelin-1 induces NAD(P)H oxidase in human endothelial cells,” Biochemical and Biophysical Research Communications, vol. 269, no. 3, pp. 713–717, 2000. View at: Publisher Site | Google Scholar
  15. A. Kowalczyk, P. Kleniewska, M. Kolodziejczyk, B. Skibska, and A. Goraca, “The role of endothelin-1 and endothelin receptor antagonists in inflammatory response and sepsis,” Archivum Immunologiae et Therapiae Experimentalis, vol. 63, no. 1, pp. 41–52, 2015. View at: Publisher Site | Google Scholar
  16. K. E. LaBarbera, R. D. Hyldahl, K. S. O'Fallon, P. M. Clarkson, and S. Witkowski, “Pericyte NF-κB activation enhances endothelial cell proliferation and proangiogenic cytokine secretion in vitro,” Physiological Reports, vol. 3, no. 4, Article ID e12309, 2015. View at: Publisher Site | Google Scholar
  17. Y. Fujii, S. Magder, P. Cernacek, P. Goldberg, Y. Guo, and S. N. Hussain, “Endothelin receptor blockade attenuates lipopolysaccharide-induced pulmonary nitric oxide production,” American Journal of Respiratory and Critical Care Medicine, vol. 161, no. 3, part 1, pp. 982–989, 2000. View at: Publisher Site | Google Scholar
  18. J. A. Douthwaite, D. M. Lees, and R. Corder, “A role for increased mRNA stability in the induction of endothelin-1 synthesis by lipopolysaccharide,” Biochemical Pharmacology, vol. 66, no. 4, pp. 589–594, 2003. View at: Publisher Site | Google Scholar
  19. M. Piechota, M. Banach, R. Irzmanski et al., “Plasma endothelin-1 levels in septic patients,” Journal of Intensive Care Medicine, vol. 22, no. 4, pp. 232–239, 2007. View at: Publisher Site | Google Scholar
  20. J.-F. Pittet, D. R. Morel, A. Hemsen et al., “Elevated plasma endothelin-1 concentrations are associated with the severity of illness in patients with sepsis,” Annals of Surgery, vol. 213, no. 3, pp. 261–264, 1991. View at: Publisher Site | Google Scholar
  21. E. Weitzberg, J. M. Lundberg, and A. Rudehill, “Elevated plasma levels of endothelin in patients with sepsis syndrome,” Circulatory Shock, vol. 33, no. 4, pp. 222–227, 1991. View at: Google Scholar
  22. M. M. Hynynen and R. A. Khalil, “The vascular endothelin system in hypertension—recent patents and discoveries.,” Recent Patents on Cardiovascular Drug Discovery, vol. 1, no. 1, pp. 95–108, 2006. View at: Publisher Site | Google Scholar
  23. G. E. Callera, R. M. Touyz, S. A. Teixeira et al., “ETA receptor blockade decreases vascular superoxide generation in DOCA-salt hypertension,” Hypertension, vol. 42, no. 4, pp. 811–817, 2003. View at: Publisher Site | Google Scholar
  24. H. Xu, L. Lin, and W.-J. Yuan, “Antiarrhythmic effect of endothelin-a receptor antagonist on acute ischemic arrhythmia in isolated rat heart,” Acta Pharmacologica Sinica, vol. 24, no. 1, pp. 37–44, 2003. View at: Google Scholar
  25. S. Briyal, T. Philip, and A. Gulati, “Endothelin-a receptor antagonists prevent amyloid-β-induced increase in ET A receptor expression, oxidative stress, and cognitive impairment,” Journal of Alzheimer's Disease, vol. 23, no. 3, pp. 491–503, 2011. View at: Publisher Site | Google Scholar
  26. A. Andersson, J. Fenhammar, R. Frithiof, E. Weitzberg, A. Sollevi, and H. Hjelmqvist, “Mixed endothelin receptor antagonism with tezosentan improves intestinal microcirculation in endotoxemic shock,” Journal of Surgical Research, vol. 149, no. 1, pp. 138–147, 2008. View at: Publisher Site | Google Scholar
  27. B. M. Toney, A. J. Fisher, M. Albrecht et al., “Selective endothelin-A receptor blockade attenuates endotoxin-induced pulmonary hypertension and pulmonary vascular dysfunction,” Pulmonary Circulation, vol. 4, no. 2, pp. 300–310, 2014. View at: Publisher Site | Google Scholar
  28. R. Ozdemir, H. Parlakpinar, A. Polat, C. Colak, N. Ermis, and A. Acet, “Selective endothelin a (ETA) receptor antagonist (BQ-123) reduces both myocardial infarct size and oxidant injury,” Toxicology, vol. 219, no. 1–3, pp. 142–149, 2006. View at: Publisher Site | Google Scholar
  29. K. Fujita, M. Yamafuji, Y. Nakabeppu, and M. Noda, “Therapeutic approach to neurodegenerative diseases by medical gases: focusing on redox signaling and related antioxidant enzymes,” Oxidative Medicine and Cellular Longevity, vol. 2012, Article ID 324256, 9 pages, 2012. View at: Publisher Site | Google Scholar
  30. W. Li, T. O. Khor, C. Xu et al., “Activation of Nrf2-antioxidant signaling attenuates NFkappaB-inflammatory response and elicits apoptosis,” Biochemical Pharmacology, vol. 76, no. 11, pp. 1485–1489, 2008. View at: Publisher Site | Google Scholar
  31. Y. Jiang, Z. Zhou, Q. Meng et al., “Ginsenoside Rb1 treatment attenuates pulmonary inflammatory cytokine release and tissue injury following intestinal ischemia reperfusion injury in mice,” Oxidative Medicine and Cellular Longevity, vol. 2015, Article ID 843721, 12 pages, 2015. View at: Publisher Site | Google Scholar
  32. J. E. Nelson, A. Loukissa, C. Altschuller-Felberg, J. J. Monaco, J. T. Fallon, and C. Cardozo, “Up-regulation of the proteasome subunit LMP7 in tissues of endotoxemic rats,” Journal of Laboratory and Clinical Medicine, vol. 135, no. 4, pp. 324–331, 2000. View at: Publisher Site | Google Scholar
  33. M. Lappas, M. Permezel, and G. E. Rice, “Release of proinflammatory cytokines and 8-isoprostane from placenta, adipose tissue, and skeletal muscle from normal pregnant women and women with gestational diabetes mellitus,” Journal of Clinical Endocrinology and Metabolism, vol. 89, no. 11, pp. 5627–5633, 2004. View at: Publisher Site | Google Scholar
  34. M. Lappas, “GSK3β is increased in adipose tissue and skeletal muscle from women with gestational diabetes where it regulates the inflammatory response,” PLoS ONE, vol. 9, no. 12, Article ID e115854, 2014. View at: Publisher Site | Google Scholar
  35. H. Crossland, D. Constantin-Teodosiu, P. L. Greenhaff, and S. M. Gardiner, “Low-dose dexamethasone prevents endotoxaemia-induced muscle protein loss and impairment of carbohydrate oxidation in rat skeletal muscle,” Journal of Physiology, vol. 588, no. 8, pp. 1333–1347, 2010. View at: Publisher Site | Google Scholar
  36. J.-A. Kim, H.-S. Park, S.-R. Kang et al., “Suppressive effect of flavonoids from Korean Citrus aurantium L. on the expression of inflammatory mediators in L6 skeletal muscle cells,” Phytotherapy Research, vol. 26, no. 12, pp. 1904–1912, 2012. View at: Publisher Site | Google Scholar
  37. J. Olesen, R. S. Biensø, S. Meinertz et al., “Impact of training status on LPS-induced acute inflammation in humans,” Journal of Applied Physiology, vol. 118, no. 7, pp. 818–829, 2015. View at: Publisher Site | Google Scholar
  38. V. F. Cruzat, A. Bittencourt, S. P. Scomazzon, J. S. M. Leite, P. I. H. De Bittencourt, and J. Tirapegui, “Oral free and dipeptide forms of glutamine supplementation attenuate oxidative stress and inflammation induced by endotoxemia,” Nutrition, vol. 30, no. 5, pp. 602–611, 2014. View at: Publisher Site | Google Scholar
  39. J. Guo, Y. Li, Z. He et al., “Targeting endothelin receptors A and B attenuates the inflammatory response and improves locomotor function following spinal cord injury in mice,” International Journal of Molecular Medicine, vol. 34, no. 1, pp. 74–82, 2014. View at: Publisher Site | Google Scholar
  40. A. Piechota-Polańczyk and A. Gora̧ca, “Influence of specific endothelin-1 receptor blockers on hemodynamic parameters and antioxidant status of plasma in LPS-induced endotoxemia,” Pharmacological Reports, vol. 64, no. 6, pp. 1434–1441, 2012. View at: Publisher Site | Google Scholar
  41. S. N. Goyal, S. Bharti, S. Arora, M. Golechha, and D. S. Arya, “Endothelin receptor antagonist BQ-123 ameliorates myocardial ischemic-reperfusion injury in rats: a hemodynamic, biochemical, histopathological and electron microscopic evidence,” Biomedicine and Pharmacotherapy, vol. 64, no. 9, pp. 639–646, 2010. View at: Publisher Site | Google Scholar
  42. Y. Chen, M. Hanaoka, Y. Droma, P. Chen, N. F. Voelkel, and K. Kubo, “Endothelin-1 receptor antagonists prevent the development of pulmonary emphysema in rats,” European Respiratory Journal, vol. 35, no. 4, pp. 904–912, 2010. View at: Publisher Site | Google Scholar
  43. R. L. Ford, I. M. Mains, E. J. Hilton et al., “Endothelin-A receptor inhibition after cardiopulmonary bypass: cytokines and receptor activation,” Annals of Thoracic Surgery, vol. 86, no. 5, pp. 1576–1583, 2008. View at: Publisher Site | Google Scholar
  44. M. Browatzki, J. Schmidt, W. Kübler, and R. Kranzhöfer, “Endothelin-1 induces interleukin-6 release via activation of the transcription factor NF-kappaB in human vascular smooth muscle cells,” Basic Research in Cardiology, vol. 95, no. 2, pp. 98–105, 2000. View at: Publisher Site | Google Scholar
  45. C. J. Miller, S. S. Gounder, S. Kannan et al., “Disruption of Nrf2/ARE signaling impairs antioxidant mechanisms and promotes cell degradation pathways in aged skeletal muscle,” Biochimica et Biophysica Acta—Molecular Basis of Disease, vol. 1822, no. 6, pp. 1038–1050, 2012. View at: Publisher Site | Google Scholar
  46. R. M. Wu, Y. Y. Sun, T. T. Zhou et al., “Arctigenin enhances swimming endurance of sedentary rats partially by regulation of antioxidant pathways,” Acta Pharmacologica Sinica, vol. 35, no. 10, pp. 1274–1284, 2014. View at: Publisher Site | Google Scholar
  47. W. Durante, “Targeting heme oxygenase-1 in vascular disease,” Current Drug Targets, vol. 11, no. 12, pp. 1504–1516, 2010. View at: Publisher Site | Google Scholar
  48. E. J. Park, H. J. Jang, K. Tsoyi et al., “The Heme oxygenase-1 inducer THI-56 negatively regulates iNOS expression and HMGB1 release in LPS-activated RAW 264.7 cells and CLP induced septic mice,” PLoS ONE, vol. 8, no. 10, Article ID e76293, 2013. View at: Publisher Site | Google Scholar
  49. P. K. Datta, S. B. Koukouritaki, K. A. Hopp, and E. A. Lianos, “Heme oxygenasc-1 induction attenuates inducible nitric: oxide synthase expression and proteinuria in glomerulonephritis,” Journal of the American Society of Nephrology, vol. 10, no. 12, pp. 2540–2550, 1999. View at: Google Scholar
  50. T. A. Tran, A. D. Nguyen, J. Chang, M. S. Goldberg, J.-K. Lee, and M. G. Tansey, “Lipopolysaccharide and tumor necrosis factor regulate parkin expression via Nuclear factor-kappa B,” PLoS ONE, vol. 6, no. 8, Article ID e23660, 2011. View at: Publisher Site | Google Scholar
  51. Y.-L. Wang, K.-K. Lam, P.-Y. Cheng, and Y.-M. Lee, “Celastrol prevents circulatory failure via induction of heme oxygenase-1 and heat shock protein 70 in endotoxemic rats,” Journal of Ethnopharmacology, vol. 162, pp. 168–175, 2015. View at: Publisher Site | Google Scholar
  52. K. Seo, J. H. Yang, S. C. Kim, S. K. Ku, S. H. Ki, and S. M. Shin, “The antioxidant effects of isorhamnetin contribute to inhibit COX-2 expression in response to inflammation: a potential role of HO-1,” Inflammation, vol. 37, no. 3, pp. 712–722, 2014. View at: Publisher Site | Google Scholar
  53. E. Barreiro, A. S. Comtois, S. Mohammed, L. C. Lands, and S. N. A. Hussain, “Role of heme oxygenases in sepsis-induced diaphragmatic contractile dysfunction and oxidative stress,” American Journal of Physiology—Lung Cellular and Molecular Physiology, vol. 283, no. 2, pp. L476–L484, 2002. View at: Publisher Site | Google Scholar
  54. C. Taillé, R. Foresti, S. Lanone et al., “Protective role of heme oxygenases against endotoxin-induced diaphragmatic dysfunction in rats,” American Journal of Respiratory and Critical Care Medicine, vol. 163, no. 3, pp. 753–761, 2001. View at: Publisher Site | Google Scholar
  55. Z. Qin, K. J. Reszka, T. Fukai, and N. L. Weintraub, “Extracellular superoxide dismutase (ecSOD) in vascular biology: an update on exogenous gene transfer and endogenous regulators of ecSOD,” Translational Research, vol. 151, no. 2, pp. 68–78, 2008. View at: Publisher Site | Google Scholar
  56. Z. Zhang, W. Cui, G. Li et al., “Baicalein protects against 6-OHDA-induced neurotoxicity through activation of Keap1/Nrf2/HO-1 and involving PKCα and PI3K/AKT signaling pathways,” Journal of Agricultural and Food Chemistry, vol. 60, no. 33, pp. 8171–8182, 2012. View at: Publisher Site | Google Scholar
  57. X. Xu, H. Li, X. Hou et al., “Punicalagin induces Nrf2/HO-1 expression via upregulation of PI3K/AKT pathway and inhibits LPS-induced oxidative stress in RAW264.7 macrophages,” Mediators of Inflammation, vol. 2015, Article ID 380218, 11 pages, 2015. View at: Publisher Site | Google Scholar
  58. G. A.Visner, S. E. Chesrown, J. Monnier, U. S. Ryan, and H. S. Nick, “Regulation of manganese superoxide dismutase: IL-1 and TNF induction in pulmonary artery and microvascular endothelial cells,” Biochemical and Biophysical Research Communications, vol. 188, no. 1, pp. 453–462, 1992. View at: Publisher Site | Google Scholar
  59. T. Z. Liu, H. L. Yang, C. P. Chan, W. L. Pan, and S. K. Wu, “Induction of superoxide dismutase isozymes by tumor necrosis factor-alpha and lipopolysaccharide in cultured normal and hyperplastic gingival fibroblasts,” Journal of the Formosan Medical Association, vol. 95, no. 3, pp. 236–240, 1996. View at: Google Scholar
  60. C.-C. Yang, M.-C. Ma, C.-T. Chien, M.-S. Wu, W.-K. Sun, and C.-F. Chen, “Hypoxic preconditioning attenuates lipopolysaccharide-induced oxidative stress in rat kidneys,” Journal of Physiology, vol. 582, no. 1, pp. 407–419, 2007. View at: Publisher Site | Google Scholar
  61. I. Iitsuka, A. Motoyoshi-Yamashiro, M. Moriyama et al., “Extracellular superoxide dismutase in cultured astrocytes: decrease in cell-surface activity and increase in medium activity by lipopolysaccharide-stimulation,” Neurochemical Research, vol. 37, no. 10, pp. 2108–2116, 2012. View at: Publisher Site | Google Scholar
  62. F. Herzog, M. J. D. Clift, F. Piccapietra et al., “Exposure of silver-nanoparticles and silver-ions to lung cells in vitro at the air-liquid interface,” Particle and Fibre Toxicology, vol. 10, article 11, 2013. View at: Publisher Site | Google Scholar
  63. F. Herzog, K. Loza, S. Balog et al., “Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches,” Beilstein Journal of Nanotechnology, vol. 5, pp. 1357–1370, 2014. View at: Publisher Site | Google Scholar
  64. Y. Pang, Z. Cai, and P. G. Rhodes, “Analysis of genes differentially expressed in astrocytes stimulated with lipopolysaccharide using cDNA arrays,” Brain Research, vol. 914, no. 1-2, pp. 15–22, 2001. View at: Publisher Site | Google Scholar
  65. M. Marikovsky, V. Ziv, N. Nevo, C. Harris-Cerruti, and O. Mahler, “Cu/Zn superoxide dismutase plays important role in immune response,” The Journal of Immunology, vol. 170, no. 6, pp. 2993–3001, 2003. View at: Publisher Site | Google Scholar
  66. Y.-C. Tsai, C.-C. Huang, L.-M. Chu, and Y.-C. Liu, “Differential influence of propofol on different cell types in terms of the expression of various oxidative stress-related enzymes in an experimental endotoxemia model,” Acta Anaesthesiologica Taiwanica, vol. 50, no. 4, pp. 159–166, 2012. View at: Publisher Site | Google Scholar
  67. A.-J. Ren, X. Yuan, L. Lin, Y.-X. Pan, Y.-W. Qing, and W.-J. Yuan, “Effects of endothelin-11-31 on cell viabililty and [Ca2+]I in cultured neonatal rat cardiomyocytes,” Physiological Research, vol. 57, no. 3, pp. 373–378, 2008. View at: Google Scholar
  68. M. H. Emre, H. Erdogan, and E. Fadillioglu, “Effect of BQ-123 and nitric oxide inhibition on liver in rats after renal ischemia-reperfusion injury,” General Physiology and Biophysics, vol. 25, no. 2, pp. 195–206, 2006. View at: Google Scholar
  69. Y.-C. Lin, Y.-S. Lai, and T.-C. Chou, “The protective effect of alpha-lipoic acid in lipopolysaccharide-induced acute lung injury is mediated by heme oxygenase-1,” Evidence-Based Complementary and Alternative Medicine, vol. 2013, Article ID 590363, 12 pages, 2013. View at: Publisher Site | Google Scholar
  70. E. Hao, F. Lang, Y. Chen et al., “Resveratrol alleviates endotoxin-induced myocardial toxicity via the Nrf2 transcription factor,” PLoS ONE, vol. 8, no. 7, Article ID e69452, 2013. View at: Publisher Site | Google Scholar
  71. J.-B. Yu, J. Shi, L.-R. Gong et al., “Role of Nrf2/ARE pathway in protective effect of electroacupuncture against endotoxic shock-induced acute lung injury in rabbits,” PLoS ONE, vol. 9, no. 8, Article ID e104924, 2014. View at: Publisher Site | Google Scholar
  72. Y. Song, G. J. Pinniger, A. J. Bakker et al., “Lipopolysaccharide-induced weakness in the preterm diaphragm is associated with mitochondrial electron transport chain dysfunction and oxidative stress,” PLoS ONE, vol. 8, no. 9, Article ID e73457, 2013. View at: Publisher Site | Google Scholar

Copyright © 2016 Agata Kowalczyk et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

More related articles

874 Views | 477 Downloads | 2 Citations
 PDF  Download Citation  Citation
 Download other formatsMore
 Order printed copiesOrder

Related articles

We are committed to sharing findings related to COVID-19 as quickly and safely as possible. Any author submitting a COVID-19 paper should notify us at help@hindawi.com to ensure their research is fast-tracked and made available on a preprint server as soon as possible. We will be providing unlimited waivers of publication charges for accepted articles related to COVID-19. Sign up here as a reviewer to help fast-track new submissions.