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Results for “superoxide”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Taurine zinc solid dispersions attenuate doxorubicin-induced hepatotoxicity and cardiotoxicity in rats

The clinical efficacy of anthracycline anti-neoplastic agents is limited by cardiac and hepatic toxicities. The aim of this study was to assess the hepatoprotective and cardioprotective effects of taurine zinc solid dispersions, which is a newly-synthesized taurine zinc compound, against doxorubicin-induced toxicity in Sprague–Dawley rats intraperitoneally injected with doxorubicin hydrochloride (3 mg/kg) three times a week (seven injections) over 28 days. Hemodynamic parameters, levels of liver toxicity markers and oxidative stress were assessed. Taurine zinc significantly attenuated the reductions in blood pressure, left ventricular pressure and ± dp/dtmax, increases in serum alanine aminotransferase and aspartate aminotransferase activities, and reductions in serum Zn{sup 2+} and albumin levels (P < 0.05 or 0.01) induced by doxorubicin. In rats treated with doxorubicin, taurine zinc dose-dependently increased liver superoxide dismutase activity and glutathione concentration, and decreased malondialdehyde level (P < 0.01). qBase{sup +} was used to evaluate the stability of eight candidate reference genes for real-time quantitative reverse-transcription PCR. Taurine zinc dose-dependently increased liver heme oxygenase-1 and UDP-glucuronyl transferase mRNA and protein expression (P < 0.01). Western blotting demonstrated that taurine zinc inhibited c-Jun N-terminal kinase phosphorylation by upregulating dual-specificity phosphoprotein phosphatase-1. Additionally, taurine zinc inhibited cardiomyocyte apoptosis as there was decreased TUNEL/DAPI positivity and protein expression of caspase-3. These results indicate that taurine zinc solid dispersions prevent the side-effects of anthracycline-based anticancer therapy. The mechanisms might be associated with the enhancement of antioxidant defense system partly through activating transcription to synthesize endogenous phase II medicine enzymes and anti-apoptosis through inhibiting JNK phosphorylation. - Highlights: • Dissolution of taurine zinc complex can be increased by solid dispersions (SDs). • Taurine zinc SDs blocked doxorubicin-induced hepatotoxicity and cardiotoxicity. • Taurine zinc SDs can alleviate oxidative stress and dampen JNK phosphorylation. • Taurine zinc SDs increased the expression of UGT, HO-1 at mRNA and protein level. • Taurine zinc SDs revealed greater hepatoprotective effects than silymarin.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats

Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration–response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT{sub 1} receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O{sub 2}{sup −} production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease. - Highlights: • Tributyltin chloride reduces estrogen levels in female rats. • Treatment with TBT resulted in increased contractile response to phenylephrine. • Collagen deposition could be responsible for vascular stiffness after TBT exposure.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Mustard vesicant-induced lung injury: Advances in therapy

Most mortality and morbidity following exposure to vesicants such as sulfur mustard is due to pulmonary toxicity. Acute injury is characterized by epithelial detachment and necrosis in the pharynx, trachea and bronchioles, while long-term consequences include fibrosis and, in some instances, cancer. Current therapies to treat mustard poisoning are primarily palliative and do not target underlying pathophysiologic mechanisms. New knowledge about vesicant-induced pulmonary disease pathogenesis has led to the identification of potentially efficacious strategies to reduce injury by targeting inflammatory cells and mediators including reactive oxygen and nitrogen species, proteases and proinflammatory/cytotoxic cytokines. Therapeutics under investigation include corticosteroids, N-acetyl cysteine, which has both mucolytic and antioxidant properties, inducible nitric oxide synthase inhibitors, liposomes containing superoxide dismutase, catalase, and/or tocopherols, protease inhibitors, and cytokine antagonists such as anti-tumor necrosis factor (TNF)-α antibody and pentoxifylline. Antifibrotic and fibrinolytic treatments may also prove beneficial in ameliorating airway obstruction and lung remodeling. More speculative approaches include inhibitors of transient receptor potential channels, which regulate pulmonary epithelial cell membrane permeability, non-coding RNAs and mesenchymal stem cells. As mustards represent high priority chemical threat agents, identification of effective therapeutics for mitigating toxicity is highly significant.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Aluminum exposure for one hour decreases vascular reactivity in conductance and resistance arteries in rats

Aims: Aluminum (Al) is an important environmental contaminant; however, there are not enough evidences of Al-induced cardiovascular dysfunction. We investigated the effects of acute exposure to aluminum chloride (AlCl{sub 3}) on blood pressure, vascular reactivity and oxidative stress. Methods and results: Male Wistar rats were divided into two groups: Untreated: vehicle (ultrapure water, ip) and AlCl{sub 3}: single dose of AlCl{sub 3} (100 mg/kg,ip). Concentration-response curves to phenylephrine in the absence and presence of endothelium, the nitric oxide synthase inhibitor L-NAME, the potassium channel blocker tetraethylammonium, and the NADPH oxidase inhibitor apocynin were performed in segments from aortic and mesenteric resistance arteries. NO released was assessed in aorta and reactive oxygen species (ROS), malondialdehyde, non-protein thiol levels, antioxidant capacity and enzymatic antioxidant activities were investigated in plasma, aorta and/or mesenteric arteries. After one hour of AlCl{sub 3} exposure serum Al levels attained 147.7 ± 25.0 μg/L. Al treatment: 1) did not affect blood pressure, heart rate and vasodilator responses induced by acetylcholine or sodium nitroprusside; 2) decreased phenylephrine-induced vasoconstrictor responses; 3) increased endothelial modulation of contractile responses, NO release and vascular ROS production from NADPH oxidase; 4) increased plasmatic, aortic and mesenteric malondialdehyde and ROS production, and 5) decreased antioxidant capacity and affected the antioxidant biomarkers non-protein thiol levels, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase enzymatic activities. Conclusion: AlCl{sub 3}-acute exposure reduces vascular reactivity. This effect is associated with increased NO production, probably acting on K{sup +} channels, which seems to occur as a compensatory mechanism against Al-induced oxidative stress. Our results suggest that Al exerts toxic effects to the vascular system. - Highlights: • One hour of aluminum exposure decreases vascular reactivity. • Vascular imbalance after aluminum exposure is related to increased oxidative stress. • Enhanced NO release is the first step against the effects of Al at vascular system.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

In vitro neuroprotective potential of lichen metabolite fumarprotocetraric acid via intracellular redox modulation

The lichen-forming fungi Cetraria islandica has been largely used in folk medicines, and it has recently showed promising in vitro antioxidant effects in glial-like cells. Current work aimed at investigating the neuroprotective potential of its major isolated secondary metabolite: the depsidone fumarprotocetraric acid (FUM). H{sub 2}O{sub 2} was used herein to induce oxidative stress (OS)-mediated cytotoxicity in two models of neurons and astrocytes cells (SH-SY5Y and U373-MG cell lines). We found that a pre-treatment with FUM significantly enhanced cell viability compared to H{sub 2}O{sub 2}-treated cells, and we selected the optimal concentrations in each model (1 and 25 μg/ml, respectively) for assessing its cytoprotective mechanisms. FUM, which exerted effective peroxyl radical scavenging effect in the chemical oxygen radical antioxidant capacity (ORAC) assay, alleviated the alterations in OS markers provoked by H{sub 2}O{sub 2}. It attenuated intracellular ROS formation, lipid peroxidation and GSH depletion. At mitochondrial level, FUM prevented from the dissipation of mitochondrial membrane potential and the increase in mitochondrial calcium, implying a protective role against oxidative damage in mitochondrial membrane. Similarly, FUM pre-treatment diminished H{sub 2}O{sub 2}-induced apoptosis, as evidenced by the reduction in caspase-3 activity and expression; inmunoblot analysis also revealed a decrease in Bax and an increase in Bcl-2 proteins levels. Furthermore, FUM up-regulated the expression of the antioxidant enzymes catalase, superoxide dismutase-1, and hemeoxigenase-1. These findings and the activation of Nrf2 binding activity in nuclear extracts suggest a plausible involvement of Nrf2 signaling pathway in the cytoprotection by FUM. In conclusion, FUM emerges as a potential drug candidate in the therapy of OS-related diseases, such as the neurodegenerative disorders. - Highlights: • FUM pre-treatment exerts significant cytoprotection against H{sub 2}O{sub 2}-mediated apoptosis. • ROS scavenger and mitochondria-targeted effects mediate its antioxidant properties. • A plausible involvement for the cytoprotective Nrf2 pathways is suggested.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

IN0523 (Urs-12-ene-3α,24β-diol) a plant based derivative of boswellic acid protect Cisplatin induced urogenital toxicity

The limiting factor for the use of Cisplatin in the treatment of different type of cancers is its toxicity and more specifically urogenital toxicity. Oxidative stress is a well-known phenomenon associated with Cisplatin toxicity. However, in Cisplatin treated group, abnormal animal behavior, decreased body weight, cellular and sub-cellular changes in the kidney and sperm abnormality were observed. Our investigation revealed that Cisplatin when administered in combination with a natural product derivative (Urs-12-ene-3α,24β-diol, labeled as IN0523) resulted in significant restoration of body weight and protection against the pathological alteration caused by Cisplatin to kidney and testis. Sperm count and motility were significantly restored near to normal. Cisplatin caused depletion of defense system i.e. glutathione peroxidase, catalase and superoxide dismutase, which were restored close to normal by treatment of IN0523. Reduction in excessive lipid peroxidation induced by Cisplatin was also found by treatment with IN0523. The result suggests that IN0523 is a potential candidate for ameliorating Cisplatin induced toxicity in the kidney and testes at a dose of 100 mg/kg p.o. via inhibiting the oxidative stress/redox status imbalance and may be improving the efflux mechanism. - Highlights: • Synthesis of a novel boswellic acid derivative (IN0523) • Counter oxidative stress induced due to Cisplatin • Protect against urogenital toxicity induced by Cisplatin.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheral neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P < 0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy. - Graphical abstract: Schematic representation neuroprotective mechanisms of carvedilol in oxaliplatin-induced peripheral neuropathy. - Highlights: • Oxaliplatin-induced mitochondrial dysfunction causes neurotoxicity. • Mitochondrial dysfunction leads to bioenergetic and functional deficits. • Carvedilol alleviated oxaliplatin-induced behavioural and functional changes. • Targeting mitochondria with carvedilol attenuated neuropathic pain.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Pre-clinical therapeutic development of a series of metalloporphyrins for Parkinson's disease

Reactive oxygen species are a well-defined therapeutic target for Parkinson's disease (PD) and pharmacological agents that catalytically scavenge reactive species are promising neuroprotective strategies for treatment. Metalloporphyrins are synthetic catalytic antioxidants that mimic the body's own antioxidant enzymes i.e. superoxide dismutases and catalase. The goal of this study was to determine if newly designed metalloporphyrins have enhanced pharmacodynamics including oral bioavailability, longer plasma elimination half-lives, penetrate the blood brain barrier, and show promise for PD treatment. Three metalloporphyrins (AEOL 11216, AEOL 11203 and AEOL 11114) were identified in this study as potential candidates for further pre-clinical development. Each of these compounds demonstrated blood brain barrier permeability by the i.p. route and two of three compounds (AEOL 11203 and AEOL 11114) were orally bioavailable. All of these compounds protected against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity, including dopamine depletion in the striatum, dopaminergic neuronal loss in the substantial nigra, and increased oxidative/nitrative stress indices (glutathione disulfide and 3-nitrotyrosine) in the ventral midbrain of the mice without inhibiting MPTP metabolism. Daily therapeutic dosing of these metalloporphyrins were well tolerated without accumulation of brain manganese levels or behavioral alterations assessed by open field and rotarod tests. The study identified two orally active metalloporphyrins and one injectable metalloporphyrin as clinical candidates for further development in PD. - Highlights: • A series of metalloporphyrins were optimized in a mouse model of parkinsonism. • Two novel orally active, brain permeable antioxidant metalloporphyrins were identified. • The identified metalloporphyrins were well tolerated.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Protection from Cr(VI)-induced malignant cell transformation and tumorigenesis of Cr(VI)-transformed cells by luteolin through Nrf2 signaling

Cr(VI) is a well known environmental carcinogen, but its mechanism of action and the measures required to mitigate its effects remain to be investigated. Our previous studies showed that exposure of human bronchial epithelial (BEAS-2B) cells to Cr(VI) caused malignant transformation, that these transformed cells progressed through tumorigenesis, and that luteolin, a natural compound, inhibited both of these processes. The present study investigates the underlying mechanisms by which luteolin protects cells against Cr(VI)-induced transformation and tumorigenesis. The present study shows that luteolin activates inducible Nrf2 to inhibit Cr(VI)-generated reactive oxygen species (ROS) in normal BEAS-2B cells. The decreased ROS level is likely responsible for the protective effect of luteolin against Cr(VI)-induced malignant cell transformation in normal cells. By contrast, in cells that have been transformed by Cr(VI), Nrf2 is constitutively activated, and its target proteins, heme oxygenase 1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), and superoxide dismutase 1/2 (SOD1/SOD2) are all constitutively activated, and ROS levels are low. Bcl-2, an anti-apoptotic protein and target protein of Nrf2 is elevated. Cr(VI)-transformed BEAS-2B cells develop apoptosis resistance, increasing the survival of these transformed cells. Luteolin decreases interactions between Nrf2 and the antioxidant response element sites of its target anti-apoptotic and antioxidant proteins, Bcl-2, Bcl-XL, and HO-1, which results in decreased constitutive Nrf2 activation. The decreased constitutive Nrf2 activation, decrease in Nrf2 target proteins and consequent apoptosis resistance by luteolin are possible mechanisms that mediate the protective effect of luteolin in Cr(VI)-transformed cells. - Highlights: • Constitutive Nrf2 activation in Cr(VI)-transformed cells is oncogenic. • Constitutive Nrf2 activation decreases ROS with development of apoptosis resistance. • Luteolin inhibits constitutive Nrf2 activation in Cr(VI)-transformed cell. • Dietary strategies using luteolin may prevent Cr(VI)-induced carcinogenesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Effects of a co-micronized composite containing palmitoylethanolamide and polydatin in an experimental model of benign prostatic hyperplasia

Palmitoylethanolamide (PEA), a fatty acid amide-signaling molecule has well-known anti-inflammatory and neuroprotective effects. Nevertheless, PEA does not possess the ability to prevent free radicals formation. Polydatin (PLD), a biological precursor of resveratrol, has antioxidant activity. A combination of PEA and PLD could, conceivably, have beneficial effects on oxidative stress produced by inflammatory processes. In the present study we investigated the effects of a co-micronized composite containing PEA and PLD (m(PEA/PLD)) in a model of testosterone-induced benign hyperplasia (BPH). BPH was provoked in rats by daily administration of testosterone propionate (3 mg/kg) for 14 days. This protocol leads to alterations in prostate morphology and increased levels of prostaglandin E2 and dihydrotestosterone as well as of 5α-reductase 1 and 5α-reductase 2 expression. Moreover, testosterone induced marked inflammation in terms of an increase in nuclear translocation of nuclear factor-κB p65 and consequently in IκB-α degradation as well as disregulation of inducible nitric oxide synthase, cyclooxygenase-2 and manganese superoxide dismutase expression and in the apoptosis pathway. Our results show, for the first time, that m(PEA/PLD) is capable of decreasing prostate weight and dihydrotestosterone production in BPH-induced rats. These effects were most likely correlated to the anti-inflammatory and apoptotic effects of m(PEA/PLD). Accordingly, these results support the view that m(PEA/PLD) should be further studied as a potent candidate for the management of BPH. - Highlights: • Chronic inflammation has emerged as a potential factor in the pathogenesis of BPH. • We evaluate the effects of m(PEA/PLD) in terms of impact on the inflammatory process and oxidative stress in BPH. • m(PEA/PLD) should be further explored as a valid candidate for the treatment of BPH.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Sildenafil protects against bile duct ligation induced hepatic fibrosis in rats: Potential role for silent information regulator 1 (SIRT1)

Hepatic fibrosis is a potential health problem that may end with life-threatening cirrhosis and primary liver cancer. Recent studies point out to the protective effects of silent information regulator1 (SIRT1), against different models of organs fibrosis. This work aimed to investigate the possible protective effect of sildenafil (SIRT1 activator) against hepatic fibrosis induced by bile duct ligation (BDL). Firstly, three different doses of sildenafil (5, 10, 20 mg/kg/day) were investigated; to detect the most protective one against BDL induced liver dysfunction and hepatic fibrosis. The most protective dose is then used; to study its effect on BDL induced SIRT1 downregulation, imbalance of oxidant/antioxidant status, increased inflammatory cytokines and fibrosis. Sildenafil (20 mg/kg/day) was the most protective one, it caused upregulation of SIRT1, reduction of hepatic malondialdehyde (MDA) content, increase in expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemeoxygenease (HO)-1, reduced glutathione (GSH) content and superoxide dismutase (SOD) activity. Hepatic content of tumor necrosis factor-α (TNF-α) and nuclear factor κB (NFκB) expression & content displayed significant reductions with sildenafil treatment, Furthermore, sildenafil caused marked reductions of transforming growth factor (TGF)-β content, expression of plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), α-smooth muscle actin (α-SMA), fibronectin, collagen I (α1) and hydroxyproline content. However, sildenafil protective effects were significantly reduced by co-administration of EX527 (SIRT1 inhibitor). Our work showed, for the first time that, sildenafil has promising protective effects against BDL induced liver dysfunction and hepatic fibrosis. These effects may be, in part, mediated by up regulation of SIRT1. - Highlights: • Bile duct ligation induced hepatic fibrosis associated with down regulation of SIRT1. • Sildenafil reduced hepatic fibrosis induced by bile duct ligation. • Sildenafil upregulated SIRT1 in the liver after bile duct ligation. • EX527, SIRT1 inhibitor, reduced sildenafil hepatoprotective effects. • Sildenafil hepatoprotective effects are SIRT1 dependent.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Mitochondrial reactive oxygen species mediate the lipopolysaccharide-induced pro-inflammatory response in human gingival fibroblasts

Although periodontal diseases are initiated by bacteria that colonize the tooth surface and gingival sulcus, the host response is believed to play an essential role in the breakdown of connective tissue and bone. Mitochondrial reactive oxygen species (mtROS) have been proposed to regulate the activation of the inflammatory response by the innate immune system. However, the role of mtROS in modulating the response of human gingival fibroblasts (HGFs) to immune stimulation by lipopolysaccharides (LPS) has yet to be fully elucidated. Here, we showed that LPS from Porphyromonas gingivalis stimulated HGFs to increase mtROS production, which could be inhibited by treatment with a mitochondrial-targeted exogenous antioxidant (mito-TEMPO) or transfection with manganese superoxide dismutase (MnSOD). A time-course study revealed that an increase in the concentration of mtROS preceded the expression of inflammatory cytokines in HGFs. Mito-TEMPO treatment or MnSOD transfection also significantly prevented the LPS-induced increase of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. Furthermore, suppressing LPS-induced mtROS generation inhibited the activation of p38, c-Jun N-terminal kinase, and inhibitor of nuclear factor-κB kinase, as well as the nuclear localization of nuclear factor-κB. These results demonstrate that mtROS generation is a key signaling event in the LPS-induced pro-inflammatory response of HGFs. - Highlights: • Inflammation is thought to promote pathogenic changes in periodontitis. • We investigated mtROS as a regulator of inflammation in gingival fibroblasts. • Targeted antioxidants were used to inhibit mtROS production after LPS challenge. • Inhibiting mtROS generation suppressed the secretion of pro-inflammatory cytokines. • JNK, p38, IKK, and NF-κB were shown to act as transducers of mtROS signaling.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Role of human amnion-derived mesenchymal stem cells in promoting osteogenic differentiation by influencing p38 MAPK signaling in lipopolysaccharide -induced human bone marrow mesenchymal stem cells

Periodontitis is a chronic inflammatory disease induced by bacterial pathogens, which not only affect connective tissue attachments but also cause alveolar bone loss. In this study, we investigated the anti-inflammatory effects of Human amnion-derived mesenchymal stem cells (HAMSCs) on human bone marrow mesenchymal stem cells (HBMSCs) under lipopolysaccharide (LPS)-induced inflammatory conditions. Proliferation levels were measured by flow cytometry and immunofluorescence staining of 5-ethynyl-2′-deoxyuridine (EdU). Osteoblastic differentiation and mineralization were investigated using chromogenic alkaline phosphatase activity (ALP) activity substrate assays, Alizarin red S staining, and RT-PCR analysis of HBMSCs osteogenic marker expression. Oxidative stress induced by LPS was investigated by assaying reactive oxygen species (ROS) level and superoxide dismutase (SOD) activity. Here, we demonstrated that HAMSCs increased the proliferation, osteoblastic differentiation, and SOD activity of LPS-induced HBMSCs, and down-regulated the ROS level. Moreover, our results suggested that the activation of p38 MAPK signal transduction pathway is essential for reversing the LPS-induced bone-destructive processes. SB203580, a selective inhibitor of p38 MAPK signaling, significantly suppressed the anti-inflammatory effects in HAMSCs. In conclusion, HAMSCs show a strong potential in treating inflammation-induced bone loss by influencing p38 MAPK signaling. - Highlights: • LPS inhibites osteogenic differentiation in HBMSCs via suppression of p38 MAPK signaling pathway. • HAMSCs promote LPS-induced HBMSCs osteogenic differentiation through p38 MAPK signaling pathway. • HAMSCs reverse LPS-induced oxidative stress in LPS-induced HBMSCs through p38 MAPK signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Sericin improves heart and liver mitochondrial architecture in hypercholesterolaemic rats and maintains pancreatic and adrenal cell biosynthesis

Hypercholesterolaemia is well known to be associated with mitochondrial dysfunction, subsequently leading to multiple organ failure. Similar to other natural products, sericin is a candidate for adjunctive therapy in hyperlipidaemic conditions. However, the cholesterol-lowering mechanisms of sericin are multifactorial and controversial. Here, a high-cholesterol-fed rat model with or without sericin treatment was established using a dosage of 1000 mg/kg/day for 30 days. Blood lipid profiles, oxidative stress markers (superoxide dismutase, SOD; malondialdehyde, MDA; nuclear factor erythroid 2-related factor, Nrf-2), dysmorphic mitochondria in relation to fission (dynamin-related protein-1; Drp-1) and fusion (guanosine triphosphatase mutated in dominant optic atrophy; OPA-1) markers and biosynthetic markers (aquaporin, AQP-1; tubulin-4β, Tb4B) in the pancreas and adrenal gland were evaluated. The results showed that sericin reduced blood cholesterol and increased high-density lipoprotein (HDL) by acting against oxidative stress. Hypocholesterolaemic and antioxidant conditions further preserved heart and liver mitochondrial architecture; however, this protection was not exhibited in the kidney, where a high level of renal mitophagy, indicating by LC-3 up-regulation, was presented. The steps of ultrastructural alteration of mitochondria from degenerative changes to necrosis were also demonstrated. Sericin also conserved AQP-1 and Tb4B levels in the exocrine pancreatic acinar cells and zona glomerulosa cells, which were positively correlated with serum lipase, HDL, antioxidative markers and mitochondrial integrity. The present study revealed that sericin not only has antioxidant capacity but also balances pancreatic and adrenal cell biosynthesis, especially lipase activity, which may have played an important role in improving lipid dysregulation in the hypercholesterolaemic rat model, leading to the reduction of dysmorphic mitochondria, particularly in the heart and liver. - Highlights: • Sericin preserves pancreatic cell biosynthesis in relation to lipase activity. • Sericin preserves heart and liver mitochondrial integrity. • Ultrastructural steps of cholesterol-induced mitochondrial defect are postulated.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Differences of lipid membrane modulation and oxidative stress by digoxin and 21-benzylidene digoxin

Cardiotonic steroids (CTS) are compounds which bind to the Na,K-ATPase, leading to its inhibition and in some cases initiating signaling cascades. Long utilized as a treatment for congestive heart disease, CTS have more recently been observed to inhibit proliferation and cause apoptosis in several cancer cell lines. A synthetic derivative of the CTS digoxin, called 21-benzylidene digoxin (21-BD), activates the Na,K-ATPase rather than cause its inhibition, as its parent compound does. Here, the mechanism behind the unique effects of 21-BD are further explored. In HeLa cancer cells, low (5 µM) and high (50 µM) doses of 21-BD activated and inhibited the Na,K-ATPase, respectively, without altering the membrane expression of the Na,K-ATPase. While digoxin did not affect HeLa membrane cholesterol or phospholipid content, 50 µM 21-BD increased both lipids via a mechanism reliant on an intact cell. Afterwards, the direct action of 21-BD was evaluated on erythrocyte membranes; however, no effect was observed. As CTS may generate reactive oxygen species (ROS) which can affect plasma membrane fluidity and therefore Na,K-ATPase activity, several markers involved in ROS generation were analyzed such as, lipid peroxidation (TBARS), reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD). GSH content and catalase activity were unaffected by digoxin or 21-BD. Surprisingly, TBARS and SOD activity was decreased with digoxin and with 50 µM 21-BD. Thus, 21-BD and digoxin altered components involved in ROS generation and inhibition in a similar fashion. This study suggests alterations to the Na,K-ATPase and membrane lipids by 21-BD is not reliant on ROS generation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

MicroRNA-140-5p attenuated oxidative stress in Cisplatin induced acute kidney injury by activating Nrf2/ARE pathway through a Keap1-independent mechanism

Oxidative stress was predominantly involved in the pathogenesis of acute kidney injury (AKI). Recent studies had reported the protective role of specific microRNAs (miRNAs) against oxidative stress. Hence, we investigated the levels of miR140-5p and its functional role in the pathogenesis of Cisplatin induced AKI. A mice Cisplatin induced-AKI model was established. We found that miR-140-5p expression was markedly increased in mice kidney. Bioinformatics analysis revealed nuclear factor erythroid 2-related factor (Nrf2) was a potential target of miR-140-5p, We demonstrated that miR-140-5p did not affect Kelch-like ECH-associated protein 1 (Keap1) level but directly targeted the 3′-UTR of Nrf2 mRNA and played a positive role in the regulation of Nrf2 expression which was confirmed by luciferase activity assay and western blot. What was more, consistent with miR140-5p expression, the mRNA and protein levels of Nrf2, as well as antioxidant response element (ARE)-driven genes Heme Oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase l (NQO1) were significantly increased in mice kidney tissues. In vitro study, Enforced expression of miR-140-5p in HK2 cells significantly attenuated oxidative stress by decreasing ROS level and increasing the expression of manganese superoxide dismutase (MnSOD). Simultaneously, miR-140-5p decreased lactate dehydrogenase (LDH) leakage and improved cell vitality in HK2 cells under Cisplatin-induced oxidative stress. However, HK2 cells transfected with a siRNA targeting Nrf2 abrogated the protective effects of miR-140-5p against oxidative stress. These results indicated that miR-140-5p might exert its anti-oxidative stress function via targeting Nrf2. Our findings showed the novel transcriptional role of miR140-5p in the expression of Nrf2 and miR-140-5p protected against Cisplatin induced oxidative stress by activating Nrf2-dependent antioxidant pathway, providing a potentially therapeutic target in acute kidney injury. - Highlights: • miR-140-5p expression was up-regulated in Cisplatin induced AKI. • miR-140-5p directly targeted the 3′-UTR of Nrf2 mRNA. • miR-140-5p activated the Nrf2/ARE signaling pathway and served as an early protective response against oxidative stress.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

Air-Enabled Electricity-Driven Depolymerization of Polyesters

This work describes the use of electrochemically generated superoxide (with air as the source of O 2 ) at carbon electrodes as a reagent for the depolymerization of polyesters. Here, we report the electricity-driven selective conversion of these common ester-based wastes into their foundational carboxylate and alkoxide building blocks. The results pave the way for an electrochemical approach to the recovery of molecular materials from ester wastes that uses air and electricity as key reagents for material recycling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2011

A Comparison of Two Yeast MnSODs: Mitochondrial Saccharomyces cerevisiae versus Cytosolic Candida albicans

Human MnSOD is significantly more product-inhibited than bacterial MnSODs at high concentrations of superoxide (O{sub 2}{sup -}). This behavior limits the amount of H{sub 2}O{sub 2} produced at high [O{sub 2}{sup -}]; its desirability can be explained by the multiple roles of H{sub 2}O{sub 2} in mammalian cells, particularly its role in signaling. To investigate the mechanism of product inhibition in MnSOD, two yeast MnSODs, one from Saccharomyces cerevisiae mitochondria (ScMnSOD) and the other from Candida albicans cytosol (CaMnSODc), were isolated and characterized. ScMnSOD and CaMnSODc are similar in catalytic kinetics, spectroscopy, and redox chemistry, and they both rest predominantly in the reduced state (unlike most other MnSODs). At high [O{sub 2}{sup -}], the dismutation efficiencies of the yeast MnSODs surpass those of human and bacterial MnSODs, due to very low level of product inhibition. Optical and parallel-mode electron paramagnetic resonance (EPR) spectra suggest the presence of two Mn{sup 3+} species in yeast Mn{sup 3+}SODs, including the well-characterized 5-coordinate Mn{sup 3+} species and a 6-coordinate L-Mn{sup 3+} species with hydroxide as the putative sixth ligand (L). The first and second coordination spheres of ScMnSOD are more similar to bacterial than to human MnSOD. Gln154, an H-bond donor to the Mn-coordinated solvent molecule, is slightly further away from Mn in yeast MnSODs, which may result in their unusual resting state. Mechanistically, the high efficiency of yeast MnSODs could be ascribed to putative translocation of an outer-sphere solvent molecule, which could destabilize the inhibited complex and enhance proton transfer from protein to peroxide. Our studies on yeast MnSODs indicate the unique nature of human MnSOD in that it predominantly undergoes the inhibited pathway at high [O{sub 2}{sup -}].

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗