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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

The effects of levofloxacin on rabbit fibroblast-like synoviocytes in vitro

It is widely accepted that tendon and cartilage are adversely affected with the toxic effects of quinolones. However, the effects of quinolones on synovium have not been deciphered completely. In this study, our main objective was to investigate the effects of levofloxacin, a typical quinolone antibiotic drug, on fibroblast-like synoviocytes (FLSs) in vitro. FLSs of rabbits were treated with levofloxacin at different concentrations (0, 14, 28, 56, 112 and 224 μM). The possible cytotoxic effects of levofloxacin on FLS were determined. Levofloxacin significantly reduced the cell viabilities, gene expression of hyaluronan synthase-2 (HAS-2), and the level of hyaluronan in FLSs. Moreover, levofloxacin-induced concentration-dependent increases of apoptosis and active caspase-3 were determined in this study. Ultrastructural damages of FLSs were observed by electron microscopy. The mRNA expression levels of matrix metalloproteinase (MMP)-3 and MMP-13 were increased in FLSs treated with levofloxacin. In addition, levofloxacin played a role in suppressing the expression of interleukin (IL)-1 and IL-6. Our data suggest that the cytotoxic effects of levofloxacin on FLS were shown to be able to affect cell viability and HA synthesis capacity. The potential mechanisms of the cytotoxic effects may be attributed to the apoptosis and increased expression of MMPs. -- Highlights: ► Levofloxacin decreases hyaluronic acid synthesis in fibroblast-like synoviocytes. ► Levofloxacin exerts pro-apoptosis effects on fibroblast-like synoviocytes. ► Levofloxacin increases gene expression of MMPs in fibroblast-like synoviocytes. ► Levofloxacin exerts anti-inflammatory effects on fibroblast-like synoviocytes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Endocrine disruptors found in food contaminants enhance allergic sensitization through an oxidative stress that promotes the development of allergic airway inflammation

In the past few decades, there has been a significant increase in incidence of allergic diseases. The hygiene hypothesis may provide some clues to explain this rising trend, but it may also be attributable to other environmental factors that exert a proallergic adjuvant effects. However, there is limited information on the risks of developing allergic asthma and related diseases through the ingestion of environmental chemicals found in food contaminants. In the present study, we have shown that oral administration of tributyltin, used as a model environmental chemical, induced oxidative-stress status in the bronchial lymph node, mesenteric lymph node and spleen, but not in the lung, where the initial step of allergic asthma pathogenesis takes place. Mice exposed to tributyltin exhibited heightened Th2 immunity to the allergen with more severe airway inflammation. Tributyltin also induced Treg cells apoptosis preferentially over non-Treg cells. All these effects of tributyltin exposure were canceled by the administration of glutathione monoethyl ester. Meanwhile, tributyltin did not affect airway inflammation of mice transferred with allergen-specific Th2 cells. Collectively, these results suggest that tributyltin exerts its pathological effect during the sensitization phase through oxidative stress that enhances the development of allergic diseases. The current study dissects the pathogenic role of oxidative stress induced by oral exposure to an environmental chemical during the sensitization phase of allergic airway inflammation and would be important for developing therapeutics for prevention of allergic diseases. - Highlights: • Oral exposure to TBT exacerbates airway inflammation. • TBT induces oxidative stress in secondary lymphoid organs, but not in the lung. • TBT preferentially induces regulatory T cell apoptosis over non-Treg cells. • TBT does not enhance pre-existing airway inflammation in sensitized mice. • Chemicals in food contaminants contribute to allergic asthma via oxidative stress.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: A role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications. - Highlights: • DCA modulates tumor progression and chemoresistance. • DCA alters molecules regulating cell survival, glucose metabolism and MDR. • DCA reconstitutes biophysical and cellular composition of tumor microenvironment. • DCA augments BMC cellularity, differentiation and repolarization of macrophages.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Ochratoxin A induces rat renal carcinogenicity with limited induction of oxidative stress responses

Ochratoxin A (OTA) has displayed nephrotoxicity and renal carcinogenicity in mammals, however, no clear mechanisms have been identified detailing the relationship between oxidative stress and these toxicities. This study was performed to clarify the relationship between oxidative stress and the renal carcinogenicity induced by OTA. Rats were treated with 70 or 210 μg/kg b.w. OTA for 4 or 13 weeks. In the rats administrated with OTA for 13 weeks, the kidney was damaged seriously. Cytoplasmic vacuolization was observed in the outer stripe of the outer medulla. Karyomegaly was prominent in the tubular epithelium. Kidney injury molecule-1 (Kim-1) was detected in the outer stripe of the outer medulla in both low- and high-dose groups. OTA increased the mRNA levels of clusterin in rat kidneys. Interestingly, OTA did not significantly alter the oxidative stress level in rat liver and kidney. Yet, some indications related to proliferation and carcinogenicity were observed. A dose-related increase in proliferating cell nuclear antigen (PCNA) was observed at 4 weeks in both liver and kidney, but at 13 weeks, only in the kidney. OTA down-regulated reactive oxygen species (ROS) and up-regulated vimentin and lipocalin 2 in rat kidney at 13 weeks. The p53 gene was decreased in both liver and kidney at 13 weeks. These results suggest that OTA caused apparent kidney damage within 13 weeks but exerted limited effect on oxidative stress parameters. It implies that cell proliferation is the proposed mode of action for OTA-induced renal carcinogenicity. - Highlights: • We studied OTA toxicities in both the rat liver and kidney for 13 weeks. • OTA exerts limited effects on oxidative stress in the rat liver and kidney. • OTA induced renal carcinogenicity resulting from cell proliferation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Biphasic influence of dexamethasone exposure on embryonic vertebrate skeleton development

Dexamethasone (Dex) has anti-inflammatory and immunomodulatory properties against many conditions. There is a potential teratogenic risk, however, for pregnant women receiving Dex treatment. It has been claimed that Dex exposure during pregnancy could affect osteogenesis in the developing embryo, which still remains highly controversial. In this study, we employed chick embryos to investigate the effects of Dex exposure on skeletal development using combined in vivo and in vitro approach. First, we demonstrated that Dex (10{sup −8}–10{sup −6} μmol/egg) exposure resulted in a shortening of the developing long bones of chick embryos, and it accelerated the deposition of calcium salts. Secondly, histological analysis of chick embryo phalanxes exhibited Dex exposure inhibited the proliferation of chondrocytes, increased apoptosis of chondrocytes and osteocytes, and led to atypical arranged hypertrophic chondrocytes. The expression of genes related to skeletogenesis was also analyzed by semi-quantitative RT-PCR. The expression of ALP, Col1a2 and Col2a1 was decreased in the Dex treated phalanxes. A detectable increase was observed in Runx-2 and Mmp-13 expression. We next examined how Dex affected the different stages of skeletogenesis in vitro. Utilizing limb bud mesenchyme micromass cultures, we determined that Dex exposure exerted no effect on apoptosis but impaired chondrogenic cell proliferation. Interestingly, low dose of Dex moderately prompted nodule formation as revealed by alcian blue staining, but higher doses of Dex significantly inhibited similar chondrogenic differentiation. Dex exposure did not induce apoptosis when the chondrogenic precursors were still at the mesenchymal stage, however, cell viability was suppressed when the mesenchyme differentiated into chondrocytes. Alizarin red staining revealed that the capacity to form mineralized bone nodules was correspondingly enhanced as Dex concentrations increased. The mRNA level of Sox-9 was slightly increased in mesenchymal cell mass treated by low concentration of Dex. Mmp-13 expression was obviously up-regulated by Dex in both mesenchymal cells and primary chondrocyte cultures. And Col10a1 expression was also increased by Dex exposure in chondrocyte. In summary, we have revealed that different concentrations of Dex exposure during early gestation could exert a biphasic effect on vertebrate skeletal development. - Highlights: • Chick embryos occurred shortening of the long bone following Dex exposure. • Dex suppressed chondrocytes proliferation and promoted apoptosis. • Dex exposure decreased ALP production and up-regulated Runx-2 and Mmp-13. • Dex exhibited biphasic effects on chondrogenic proliferation and nodule formation. • The hypertrophy and ossification were accelerated by Dex both in vivo and in vitro.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Induction of HO-1 by carbon monoxide releasing molecule-2 attenuates thrombin-induced COX-2 expression and hypertrophy in primary human cardiomyocytes

Carbon monoxide (CO) is one of the cytoprotective byproducts of heme oxygenase (HO)-1 and exerts anti-inflammatory action in various models. However, the detailed mechanisms underlying CO-induced HO-1 expression in primary human cardiomyocytes remain largely unidentified. We used primary left ventricle myocytes as a model and applied CO releasing molecule (CORM)-2 to investigate the relationship of CO and HO-1 expression. We herein used Western blot, real-time PCR, promoter activity and EIA to investigate the role of HO-1 expression protecting against thrombin-mediated responses. We found that thrombin-induced COX-2 expression, PGE{sub 2} release and cardiomyocyte hypertrophy markers (increase in ANF/BNP, α-actin expression and cell surface area) was attenuated by pretreatment with CORM-2 which was partially reversed by hemoglobin (Hb) or ZnPP (an inhibitor of HO-1 activity), suggesting that HO-1/CO system may be of clinical importance to ameliorate heart failure through inhibition of inflammatory responses. CORM-2-induced HO-1 protein expression, mRNA and promoter was attenuated by pretreatment with the inhibitors of Pyk2 (PF431396), PDGFR (AG1296), PI3K (LY294002), Akt (SH-5), p38 (SB202530), JNK1/2 (SP600125), FoxO1 (AS1842856) and Sp1 (mithramycin A). The involvement of these signaling components was further confirmed by transfection with respective siRNAs, consistent with those of pharmacological inhibitors. These results suggested that CORM-2-induced HO-1 expression is mediated through a Pyk2/PDGFR/PI3K/Akt/FoxO1/Sp1-dependent manner and exerts a cytoprotective effect in human cardiomyocytes. - Graphical abstract: In summary, CORM-2 treatment induces Pyk2 transactivated PDGFR, which induces PI3K/Akt/MAPK activation, and then recruits Sp1/Foxo1 transcriptional factors to regulate HO-1 gene expression in primary human cardiomyocytes. - Highlights: • CORM-2 induces HO-1 expression. • Pyk2-dependent PDGFR activates PI3K/Akt/MAPK pathway in CORM-2-induced HO-1 expression. • Transcriptional regulation of HO-1 expression is mediated by Sp1/Foxo1. • CO/HO-1 systems ameliorate thrombin-induced human cardiomyocyte hypertrophy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Effect of diosgenin on metabolic dysfunction: Role of ERβ in the regulation of PPARγ

The present study was designed to investigate the effect of diosgenin (DSG) on metabolic dysfunction and to elucidate the possible molecular mechanisms. High fat (HF) diet-fed mice and 3T3-L1 preadipocytes was used to evaluate the effect of DSG. We showed that DSG attenuated metabolic dysfunction in HF diet-fed mice, as evidenced by reduction of blood glucose level and improvement of glucose and insulin intolerance. DSG ameliorated oxidative stress, reduced body weight, fat pads, and systematic lipid profiles and attenuated lipid accumulation. DSG inhibited 3T3-L1 adipocyte differentiation and reduced adipocyte size through regulating key factors. DSG inhibited PPARγ and its target gene expression both in differentiated 3T3-L1 adipocytes and fat tissues in HF diet-fed mice. Overexpression of PPARγ suppressed DSG-inhibited adipocyte differentiation. DSG significantly increased nuclear expression of ERβ. Inhibition of ERβ significantly suppressed DSG-exerted suppression of adipocyte differentiation and PPARγ expression. In response to DSG stimulation, ERβ bound with RXRα and dissociated RXRα from PPARγ, leading to the reduction of transcriptional activity of PPARγ. These data provide new insight into the mechanisms underlying the inhibitory effect of DSG on adipocyte differentiation and demonstrate that ERβ-exerted regulation of PPARγ expression and activity is critical for DSG-inhibited adipocyte differentiation. - Highlights: • Diosgenin (DSG) attenuated metabolic dysfunction in high fat (HF) diet-fed mice. • DSG reduced oxidative stress and lipid accumulation in HF diet-fed mice. • DSG inhibited 3T3-L1 adipocyte differentiation and reduced adipocyte size. • DSG induced the binding of ERβ with RXRα. • DSG-induced activation of ERβ dissociated RXRα from PPARγ and reduced PPARγ activity.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders. - Highlights: • An Alzheimer's disease model was successfully established by transfecting APP gene into neural stem cells in vitro. • Roles of osthole in experimental AD cells were studied. • Osthole promotes proliferation and differentiation into neurons and inhibits accumulation of Aβ{sub 1–42} peptide and apoptosis. • Osthole exerts protection via Wnt/β-catenin signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Protective effect of Ac-SDKP on alveolar epithelial cells through inhibition of EMT via TGF-β1/ROCK1 pathway in silicosis in rat

The epithelial–mesenchymal transition (EMT) is a critical stage during the development of silicosis fibrosis. In the current study, we hypothesized that the anti-fibrotic tetrapeptide, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) may exert its anti-fibrotic effects via activation of the TGF-β1/ROCK1 pathway, leading to inhibition of EMT. To address this hypothesis, we first examined the effect of Ac-SDKP upon EMT using an in vivo rat silicosis model, as well as in an in vitro model of TGF-β1-induced EMT. Confocal laser scanning microscopy was used to examine colocalization of surfactant protein A (SP-A), fibroblast specific protein-1 (FSP-1) and α-smooth muscle actin (α-SMA) in vivo. Western blot analysis was used to examine for changes in the protein levels of E-cadherin (E-cad) and SP-A (epithelial cell markers), vimentin (mesenchymal cell marker), α-SMA (active myofibroblast marker), and collagen I and III in both in vivo and in vitro experiments. Secondly, we utilized Western blot analysis and confocal laser scanning microscopy to examine the protein expression of TGF-β1 and ROCK1 in in vivo and in vitro studies. The results revealed that Ac-SDKP treatment prevented increases in the expression of mesenchymal markers as well as TGF-β1, ROCK1, collagen I and III. Furthermore, Ac-SDKP treatment prevented decreases in the expression of epithelial cell markers in both in vivo and in vitro experiments. Based on the results, we conclude that Ac-SDKP inhibits the transition of epithelial cell-myofibroblast in silicosis via activation of the TGF-β1/ROCK1 signaling pathway, which may serve as a novel mechanism by which it exerts its anti-fibrosis properties. - Highlights: • EMT is a critical stage during the development of silicosis fibrosis. • Ac-SDKP inhibits the EMT process in silicosis both in vivo and in vitro. • Ac-SDKP inhibits the EMT process in silicosis via TGF-β1/ROCK1 pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Effects of a human recombinant alkaline phosphatase on renal hemodynamics, oxygenation and inflammation in two models of acute kidney injury

Two small clinical trials indicated that administration of bovine intestinal alkaline phosphatase (AP) improves renal function in critically ill patients with sepsis-associated acute kidney injury (AKI), for which the mechanism of action is not completely understood. Here, we investigated the effects of a newly developed human recombinant AP (recAP) on renal oxygenation and hemodynamics and prevention of kidney damage and inflammation in two in vivo AKI models. To induce AKI, male Wistar rats (n = 18) were subjected to renal ischemia (30 min) and reperfusion (I/R), or sham-operated. In a second model, rats (n = 18) received a 30 min infusion of lipopolysaccharide (LPS; 2.5 mg/kg), or saline, and fluid resuscitation. In both models, recAP (1000 U/kg) was administered intravenously (15 min before reperfusion, or 90 min after LPS). Following recAP treatment, I/R-induced changes in renal blood flow, renal vascular resistance and oxygen delivery at early, and cortical microvascular oxygen tension at late reperfusion were no longer significantly affected. RecAP did not influence I/R-induced effects on mean arterial pressure. During endotoxemia, recAP treatment did not modulate the LPS-induced changes in systemic hemodynamics and renal oxygenation. In both models, recAP did exert a clear renal protective anti-inflammatory effect, demonstrated by attenuated immunostaining of inflammatory, tubular injury and pro-apoptosis markers. Whether this renal protective effect is sufficient to improve outcome of patients suffering from sepsis-associated AKI is being investigated in a large clinical trial. - Highlights: • Human recombinant alkaline phosphatase (recAP) is a potential new therapy for sepsis-associated acute kidney injury (AKI). • RecAP can modulate renal oxygenation and hemodynamics immediately following I/R-induced AKI. • RecAP did not modulate endotoxemia-induced changes in systemic hemodynamics and renal oxygenation. • RecAP did exert a clear renal protective anti-inflammatory effect in both models.

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

Inhibition of nicotinamide phosphoribosyltransferase and depletion of nicotinamide adenine dinucleotide contribute to arsenic trioxide suppression of oral squamous cell carcinoma

Emerging evidence suggests that increased nicotinamide phosphoribosyltransferase (NAMPT) expression is associated with the development and prognosis of many cancers, but it remains unknown regarding its role in oral squamous cell carcinoma (OSCC). In the present study, the results from tissue microarray showed that NAMPT was overexpressed in OSCC patients and its expression level was directly correlated with differential grades of cancer. Interestingly, treatment of OSCC cells with chemotherapy agent arsenic trioxide (ATO) decreased the levels of NAMPT protein and increased cellular death in an ATO dose- and time-dependent manner. Most importantly, combination of low concentration ATO with FK866 (a NAMPT inhibitor) exerted enhanced inhibitive effect on NAMPT protein and mRNA expressions, leading to synergistic cytotoxicity on cancer cells through increasing cell apoptosis and depleting intracellular nicotinamide adenine dinucleotide levels. These findings demonstrate the crucial role of NAMPT in the prognosis of OSCC and reveal inhibition of NAMPT as a novel mechanism of ATO in suppressing cancer cell growth. Our results suggest that ATO can significantly enhance therapeutic efficacy of NAMPT inhibitor, and combined treatment may be a novel and effective therapeutic strategy for OSCC patients. - Highlights: • Level of overexpressed NAMPT is associated with differential grade of OSCC patients. • Arsenic trioxide (ATO) exerts anti-cancer effects through NAMPT inhibition. • ATO enhances tumor cell killing efficacy of NAMPT inhibitor through depleting NAD. • Combined ATO/NAMPT inhibitor may be a novel therapy for advanced OSCC patients.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Region of Nipah virus C protein responsible for shuttling between the cytoplasm and nucleus

Nipah virus (NiV) causes severe encephalitis in humans, with high mortality. NiV nonstructural C protein (NiV-C) is essential for its pathogenicity, but its functions are unclear. In this study, we focused on NiV-C trafficking in cells and found that it localizes predominantly in the cytoplasm but partly in the nucleus. An analysis of NiV-C mutants showed that amino acids 2, 21–24 and 110–139 of NiV-C are important for its localization in the cytoplasm. Inhibitor treatment indicates that the nuclear export determinant is not a classical CRM1-dependent nuclear export signal. We also determined that amino acids 60–75 and 72–75 were important for nuclear localization of NiV-C. Furthermore, NiV-C mutants that had lost their capacity for nuclear localization inhibited the interferon (IFN) response more strongly than complete NiV-C. These results indicate that the IFN-antagonist activity of NiV-C occurs in the cytoplasm. -- Highlights: •Nipah virus (NiV) infection resulted in high mortality, but effective treatment has not been established. •Several reports revealed that NiV nonstructural C protein (NiV-C) was essential for NiV pathogenicity, however, whole of NiV-C function is still unknown. •Although nonstructural C proteins of other Paramyxoviruses are expressed in similar mechanism and exert similar activity, subcellular localization and cellular targets are different. In this study, we evaluated the subcellular localization of NiV-C. •To our knowledge, this is the first report showing that NiV-C shuttles between the nucleus and cytoplasm. We also clarified that NiV-C has nuclear export signal and nuclear localization signal using NiV-C deleted, alanine substitution mutants and enhanced green fluorescent protein (EGFP) fused proteins. •And we also showed that interferon (IFN) antagonist activity of NiV-C related to its subcellular localization. Our results indicate that NiV-C exert IFN antagonist activity in the cytoplasm.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Geraniin suppresses RANKL-induced osteoclastogenesis in vitro and ameliorates wear particle-induced osteolysis in mouse model

Wear particle-induced osteolysis and subsequent aseptic loosening remains the most common complication that limits the longevity of prostheses. Wear particle-induced osteoclastogenesis is known to be responsible for extensive bone erosion that leads to prosthesis failure. Thus, inhibition of osteoclastic bone resorption may serve as a therapeutic strategy for the treatment of wear particle induced osteolysis. In this study, we demonstrated for the first time that geraniin, an active natural compound derived from Geranium thunbergii, ameliorated particle-induced osteolysis in a Ti particle-induced mouse calvaria model in vivo. We also investigated the mechanism by which geraniin exerts inhibitory effects on osteoclasts. Geraniin inhibited RANKL-induced osteoclastogenesis in a dose-dependent manner, evidenced by reduced osteoclast formation and suppressed osteoclast specific gene expression. Specially, geraniin inhibited actin ring formation and bone resorption in vitro. Further molecular investigation demonstrated geraniin impaired osteoclast differentiation via the inhibition of the RANKL-induced NF-κB and ERK signaling pathways, as well as suppressed the expression of key osteoclast transcriptional factors NFATc1 and c-Fos. Collectively, our data suggested that geraniin exerts inhibitory effects on osteoclast differentiation in vitro and suppresses Ti particle-induced osteolysis in vivo. Geraniin is therefore a potential natural compound for the treatment of wear particle induced osteolysis in prostheses failure. - Highlights: • Geraniin suppresses osteoclasts formation and function in vitro. • Geraniin impairs RANKL-induced nuclear factor-κB and ERK signaling pathway. • Geraniin suppresses osteolysis in vivo. • Geraniin may be used for treating osteoclast related diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Cycling with BRCA2 from DNA repair to mitosis

Genetic integrity in proliferating cells is guaranteed by the harmony of DNA replication, appropriate DNA repair, and segregation of the duplicated genome. Breast cancer susceptibility gene BRCA2 is a unique tumor suppressor that is involved in all three processes. Hence, it is critical in genome maintenance. The functions of BRCA2 in DNA repair and homology-directed recombination (HDR) have been reviewed numerous times. Here, I will briefly go through the functions of BRCA2 in HDR and focus on the emerging roles of BRCA2 in telomere homeostasis and mitosis, then discuss how BRCA2 exerts distinct functions in a cell-cycle specific manner in the maintenance of genomic integrity. - Highlights: • BRCA2 is a multifaceted tumor suppressor and is crucial in genetic integrity. • BRCA2 exerts distinct functions in cell cycle-specific manner. • Mitotic kinases regulate diverse functions of BRCA2 in mitosis and cytokinesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Analysis of migration rate and chemotaxis of human adipose-derived mesenchymal stem cells in response to LPS and LTA in vitro

Mesenchymal stem cells (MSC) are able to stimulate the regeneration of injured tissue. Since bacterial infections are common complications in wound healing, bacterial pathogens and their components come into direct contact with MSC. The interaction with bacterial structures influences the proliferation, differentiation and migratory activity of the MSC, which might be of relevance during regeneration. Studies on MSC migration in response to bacterial components have shown different results depending on the cell type. Here, we analyzed the migration rate and chemotaxis of human adipose-derived MSC (adMSC) in response to the basic cell-wall components lipopolysaccharide (LPS) of Gram-negative bacteria and lipoteichoic acid (LTA) of Gram-positive bacteria in vitro. To this end, we used transwell and scratch assays, as well as a specific chemotaxis assay combined with live-cell imaging. We found no significant influence of LPS or LTA on the migration rate of adMSC in transwell or scratch assays. Furthermore, in the µ-slide chemotaxis assay, the stimulation with LPS did not exert any chemotactic effect on adMSC. - Highlights: • LPS increased the release of IL-6 and IL-8 in adMSC significantly. • The migration rate of adMSC was not influenced by LPS or LTA. • LPS or LTA did not exert a chemotactic effect on adMSC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Cannabidiol restores differentiation capacity of LPS exposed adipose tissue mesenchymal stromal cells

Highlights: • LPS increases amount of oxidized proteins and lipids in homogenisates of MSCs. • LPS inhibits MSC adipogenic and chondrogenic differentiation. • CBD reduces oxidative stress and restores adipogenesis and chondrogenesis of MSCs upon LPS exposure. Multipotent mesenchymal stromal cells (MSCs) support wound healing processes. These cells express toll-like receptors (TLRs). TLRs perform important key functions when the immune system is confronted with danger signals. TLR ligation by lipopolysaccharides (LPS) activates MSCs and induces intracellular signaling cascades, which affect their differentiation profile, increase the release of inflammatory cytokines and the production of reactive oxygen species. Continuing exposure to LPS triggers prolonged inflammatory reactions, which may lead to deleterious conditions, e.g. non-healing wounds. Cannabidiol (CBD) exerts anti-inflammatory processes through cannabinoid receptor dependent and independent mechanisms. In the present study, we examined whether CBD could influence the inflammatory MSC phenotype. Exposure to LPS increased the release of IL-6, as well as other soluble factors, and elevated levels of oxidized macromolecules found in cell homogenisates. While the amount of IL-6 was unaffected, co-treatment with CBD reduced the oxidative stress acting on the cells. LPS inhibited adipogenic as well as chondrogenic differentiation, which was attenuated by CBD treatment. In the case of adipogenesis, the disinhibitory effect probably depended on CBD interaction with the peroxisome proliferator-activated receptor-γ. CBD could exert mild immunosuppressive properties on MSCs, while it most effectively acted anti-oxidatively and by restoring the differentiation capacity upon LPS treatment.

60 APPLIED LIFE SCIENCES↗