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At least 1,081 records · Page 60

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DOE OSTI2016

Fluid shear stress suppresses TNF-α-induced apoptosis in MC3T3-E1 cells: Involvement of ERK5-AKT-FoxO3a-Bim/FasL signaling pathways

TNF-α is known to induce osteoblasts apoptosis, whereas mechanical stimulation has been shown to enhance osteoblast survival. In the present study, we found that mechanical stimulation in the form of fluid shear stress (FSS) suppresses TNF-α induced apoptosis in MC3T3-E1 cells. Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family that has been implicated in cell survival. We also demonstrated that FSS imposed by flow chamber in vitro leads to a markedly activation of ERK5, which was shown to be protective against TNF-α-induced apoptosis, whereas the transfection of siRNA against ERK5 (ERK5-siRNA) reversed the FSS-medicated anti-apoptotic effects. An initial FSS-mediated activation of ERK5 that phosphorylates AKT to increase its activity, and a following forkhead box O 3a (FoxO3a) was phosphorylated by activated AKT. Phosphorylated FoxO3a is sequestered in the cytoplasm, and prevents it from translocating to nucleus where it can increase the expression of FasL and Bim. The inhibition of AKT-FoxO3a signalings by a PI3K (PI3-kinase)/AKT inhibitor (LY294002) or the transfection of ERK5-siRNA led to the nuclear translocation of non-phosphorylated FoxO3a, and increased the protein expression of FasL and Bim. In addition, the activation of caspase-3 by TNF-α was significantly inhibited by aforementioned FSS-medicated mechanisms. In brief, the activation of ERK5-AKT-FoxO3a signaling pathways by FSS resulted in a decreased expression of FasL and Bim and an inhibition of caspase-3 activation, which exerts a protective effect that prevents osteoblasts from apoptosis. - Highlights: • Fluid shear stress inhibits osteoblast apoptosis induced by TNF-α. • Inhibition of ERK5 activity by transfection of ERK5 siRNA blocks FSS-mediated anti-apoptotic effect in osteoblast. • Activated ERK5-AKT-FoxO3a-Bim/FasL signaling pathways by FSS is required to protect osteoblast from apoptosis.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2017

NOR1 promotes hepatocellular carcinoma cell proliferation and migration through modulating the Notch signaling pathway

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Previous studies have reported that the oxidored-nitro domain containing protein 1 (NOR1) is a novel tumor suppressor in several tumors. Recent evidence suggests that NOR1 is strongly expressed in HCC cells. However, its role and mechanism in HCC are unclear. In the current study, Western blot and qPCR detected strong NOR1 mRNA and protein expression in HepG2 and Hep3B cells. After transfection with NOR1 siRNA or pcDNA3.1-myc-his-NOR1, the proliferation and migration of HepG2 and Hep3B cells were analyzed in vitro. HepG2 or Hep3B cells overexpressing NOR1 showed an increased proliferation and migration, whereas siRNA-mediated silencing of NOR1 showed the opposite effect. Furthermore, NOR1 activated the Notch signaling pathway, indicated by increased levels of Notch1, NICD, Hes1, and Hey1 in protein. Importantly, the Notch inhibitor DAPT downregulated Notch activation and further enhanced siNOR1-induced reduction of cell proliferation and migration in HepG2 and Hep3B cells, whereas DAPT reversed the effect of NOR1 overexpression on cell proliferation and migration. In conclusion, these results indicate that NOR1 may be involved in the progression of HCC and thus may be a potential target for the treatment of liver cancer. - Highlights: • NOR1 expression is up-regulated in HCC cells. • NOR1 promotes the proliferation and migration of HCC cells. • NOR1 promotes the progression of HCC cells by activating Notch pathway.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2017

LincRNA-p21 knockdown enhances radiosensitivity of hypoxic tumor cells by reducing autophagy through HIF-1/Akt/mTOR/P70S6K pathway

Hypoxic conditions are common in solid tumors and have a significant effect on tumor progression, therapeutic and prognosis. Long noncoding RNAs (lncRNAs) are longer than 200 nucleotides and cannot be translated into proteins, which play important roles in some diseases including cancer. Although previous analysis have showed that long intergenic non-coding RNA (lincRNA)-p21 is hypoxia-responsive and functions as a new regulator of cell cycle, apoptosis and warburg effect in cervical cancer, its biological roles in hypoxic hepatoma and glioma are unknown. In this work, we found that X-ray irradiation or hypoxia treatment elevated lincRNA-p21 expression in SMMC7721 hepatoma and U251MG glioma cells. Knockdown of lincRNA-p21 induced G2/M phase arrest, promoted apoptosis, decreased cell proliferation and motility, and reduced autophagy through HIF-1/Akt/mTOR/P70S6K pathway in hypoxic tumor cells. Our results delineated a novel mechanism of lincRNA-p21 in enhancing hypoxic tumor cell radiosensitivity, which might provide valuable targets for radiation therapy for solid tumors, such as hepatoma and glioma. - Highlights: • LincRNA-p21 is induced by irradiation and hypoxia. • LincRNA-p21 knockdown enhances radiosensitivity via downregulation of autophagy. • LincRNA-p21 knockdown inhibits autophagy by activating Akt/mTOR/P70S6K pathway.

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 OSTI2018

Serelaxin inhibits differentiation and fibrotic behaviors of cardiac fibroblasts by suppressing ALK-5/Smad2/3 signaling pathway

Highlights: • Serelaxin inhibits differentiation of cardiac fibroblasts towards myofibroblasts. • Serelaxin suppresses ALK-5/Smad2/3 signaling pathway. • Serelaxin up-regulates MMP-2/TIMP-2 ratio and IL-10 secretion. Serelaxin, a recombinant form of human relaxin-2, is currently regarded as a novel drug for treatment of acute heart failure. However, whether therapeutic effects of serelaxin are achieved by inhibiting cardiac fibrosis remains unclear. In this study, we investigate effects of serelaxin on inhibiting cardiac fibrosis. Cardiac fibroblasts (CFs) were isolated from the hearts of adult rats. Effects of serelaxin on differentiation of CFs towards myofibroblasts (MFs) and their fibrotic behaviors after induction with TGF-β1 were examined. Synthesis and degradation of collagens, secretion of IL-10, and expression of ALK-5 and p-Smad2/3 of TGF-β1-induced cells were assessed after treatment with serelaxin. Serelaxin inhibited differentiation of TGF-β1-induced CFs towards MFs, and reduced proliferation and migration of the induced cells. Moreover, serelaxin down-regulated expression of collagen I/III and TIMP-2, and up-regulated expression of MMP-2 and MMP-9 in the cells. After treatment with serelaxin, activity of MMP-2 and MMP-9 and secretion of IL-10 increased, expression of ALK-5 and the level of Smad2/3 phosphorylation was reduced significantly. These results suggest that serelaxin can inhibit differentiation of TGF-β1-induced CFs towards MFs, reduce production of collagens by suppressing ALK-5/Smad2/3 signaling pathway, and enhance extracellular matrix degradation by increasing MMP-2/TIMP-2 ratio and IL-10 secretion. Serelaxin may be a potential therapeutic drug for inhibiting cardiac fibrosis.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2017

Msi2 plays a carcinogenic role in esophageal squamous cell carcinoma via regulation of the Wnt/β-catenin and Hedgehog signaling pathways

Highlights: • Msi2 is upregulated in ESCC tissues and cell lines. • Msi2 is associated with tumor progression and poor prognosis of ESCC patients. • Msi2 promotes ESCC cell proliferation, EMT and migration. • Msi2 functions by regulating the Wnt/β-catenin and Hh signaling pathways. Msi2 has been widely reported to be upregulated and strongly associated with fast progress and poor prognosis in many cancers. However, the expression and role of Msi2 in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we found that Msi2 was upregulated in ESCC clinical samples, and was significantly associated with tumor size, differentiation status, and lymph node metastasis in ESCC patients. Multivariate Cox regression analysis showed that Msi2 was an independent predictor for disease-free survival (DFS) and overall survival (OS). Moreover, knockdown of Msi2 impaired ESCC cell proliferation, epithelial-mesenchymal transition (EMT) and migration, while overexpression of Msi2 promoted ESCC cell proliferation, EMT and migration in vitro. Animal experiments also confirmed that Msi2 promoted ESCC cell proliferation in vivo. Mechanistically, Msi2 promoted ESCC cell proliferation, EMT and migration via regulation of the Wnt/β-catenin and Hedgehog (Hh) signaling pathways. Taken together, our study suggested that Msi2 could serve as a candidate for diagnosis and prognosis and as a potential therapeutic target in ESCC.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2017

PPARγ agonist efatutazone and gefitinib synergistically inhibit the proliferation of EGFR-TKI-resistant lung adenocarcinoma cells via the PPARγ/PTEN/Akt pathway

Highlights: • The low expression of PPARG predicts poor overall survival for patients with lung adenocarcinoma. • Treatment with efatutazone and gefitinib produced a synergistic effect on inhibiting proliferation of EGFR-TKI-resistant cells. • The PPARγ/PTEN/Akt/p21 signaling pathway might be involved in above synergistic effect. • Efatutazone is a potential therapeutic agent for the NSCLC patients who develop acquired resistance to EGFRT-KI. Development of acquired resistance to EGFR-TKI therapy continues to be a serious clinical problem in Lung adenocarcinoma management. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists demonstrate anti-tumor activity likely via transactivating genes that regulate cell proliferation, differentiation and apoptosis. Efatutazone, a novel later generation PPARγ agonist, selectively activates PPARγ target genes and has antiproliferative effects in a range of malignancies. However, the exact function and molecular mechanism of PPARγ agonists efatutazone in EGFR-TKI gefitinib-resistance of Lung adenocarcinoma has not been determined. In this study, we studied the development of acquired resistance to an EGFR-TKI gefitinib in lung adenocarcinoma cells and investigated the antiproliferative effects of efatutazone in the acquired resistant cells. The treatment of gefitinib-resistant cells with efatutazone reduced the growth of gefitinib-resistant cells in a dose- and time-dependent manner, and facilitated the anti-proliferative effects of gefitinib. Mechanistic investigations suggested that efatutazone acted by upregulating protein expression of PPARγ, phosphatase and tensin homolog (PTEN), inactivating the Akt pathway, followed by dephosphorylation of p21Cip1 at Thr145 without affecting the transcriptional levels. Our results suggested that efatutazone, alone or in combination with gefitinib, might offer therapeutic effects in lung adenocarcinoma.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Inhibition of TGF-β pathway reverts extracellular matrix remodeling in T. cruzi-infected cardiac spheroids

Highlights: • A model of cardiac spheroids to study fibrosis in pathological processes is proposed. • The study evaluates a TGF-β inhibitor in restoring extracellular matrix balance disrupted by T. cruzi infection. • Inhibition of TGF-β signaling reduces fibrosis and hypertrophy in infected-cardiac spheroids. • The extracellular matrix remodeling is achieved through regulation of MMP-2 activity and TIMP-1 expression. Chagasic cardiomyopathy (CC) is the main manifestation of Chagas Disease (CD). CC is a progressive dysfunctional illness, in which transforming growth factor beta (TGF-β) plays a central role in fibrogenesis and hypertrophy. In the present study, we tested in a three-dimensional (3D) model of cardiac cells culture (named cardiac spheroids), capable of mimicking the aspects of fibrosis and hypertrophy observed in CC, the role of TGF-β pathway inhibition in restoring extracellular matrix (ECM) balance disrupted by T. cruzi infection. Treatment of T. cruzi-infected cardiac spheroids with SB 431542, a selective inhibitor of TGF-β type I receptor, resulted in a reduction in the size of spheroids, which was accompanied by a decrease in parasite load and in fibronectin expression. The inhibition of TGF-β pathway also promoted an increase in the activity of matrix metalloproteinase (MMP)-2 and a decrease in tissue inhibitor of matrix metalloproteinase (TIMP)-1 expression, which may be one of the mechanisms regulating extracellular matrix remodeling. Therefore, our study provides new insights into the molecular mechanisms by which inhibition of TGF-β signaling reverts fibrosis and hypertrophy generated by T. cruzi during CC and also highlights the use of cardiac spheroids as a valuable tool for the study of fibrogenesis and anti-fibrotic compounds.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

E4BP4 inhibits AngII-induced apoptosis in H9c2 cardiomyoblasts by activating the PI3K-Akt pathway and promoting calcium uptake

Highlights: • E4BP4 expression in H9c2 significantly attenuates AngII-induced apoptosis. • E4BP4 inhibits AngII-induced IGF-II expression & caspase cleavage through PI3K-Akt pathway. • E4BP4 enhances calcium reuptake into SR by up-regulating p-PKA and p-PLB proteins. • E4BP4 thus acts as a survival factor in H9c2, regulating IGF-II and calcium cycling. The bZIP transcription factor E4BP4 is a survival factor that is known to be elevated in diseased heart and promote cell survival. In this study the role of E4BP4 on angiotensin-II (AngII)-induced apoptosis has been examined in in vitro cell model. H9c2 cardiomyoblast cells that overexpressed E4BP4 were exposed to AngII to observe the cardio-protective effects of E4BP4 on hypertension related apoptosis. The results from TUNEL assays revealed that E4BP4 significantly attenuated AngII-induced apoptosis. Further analysis by Western blot and RT-PCR showed that E4BP4 inhibited AngII-induced IGF-II mRNA expression and cleavage of caspase-3 through the PI3K-Akt pathway. In addition, E4BP4 enhanced calcium reuptake into the sacroplasmic reticulum by down-regulating PP2A and by up-regulating the phosphorylation of PKA and PLB proteins. Our findings indicate that E4BP4 functions as a survival factor in cardiomyoblasts by inhibiting IGF-II transcription and by regulating calcium cycling.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Capn4 promotes colorectal cancer cell proliferation by increasing MAPK7 through activation of the Wnt/β-Catenin pathway

Highlights: • Capn4 is upregulated in colorectal cancer (CRC) tissues and is closely correlated with clinical outcomes. • Capn4 knockdown significantly suppresses CRC cell growth in vitro and in vivo. • MAPK7 acts as the downstream component of Capn4 and contributes the effects of Capn4 in CRC cells. • Capn4 positively regulates MAPK7 expression through the Wnt/β-Catenin pathway in CRC cells. Increasing evidence has suggested that Capn4 is upregulated and functions as a potential tumor promoter in several human cancer types. However, the potential biological roles and regulatory mechanisms of Capn4 in colorectal cancer (CRC) remains unclear. Here, we found that Capn4 expression was elevated in CRC tissues than adjacent noncancerous tissues. Additionally, we also found that overexpression of Capn4 is significantly correlated with tumor progression and poor survival in CRC patients. Furthermore, our experimental data revealed that increased expression of Capn4 was observed in CRC cell lines and ectopic expression of Capn4 significantly enhanced in vitro cell proliferation, whereas knockdown of Capn4 suppressed CRC cells growth in vitro and in vivo. Moreover, our results indicate that Capn4 promotes cell proliferation by increasing MAPK7 expression, which has been reported to control the proliferation of many cancers. Mechanistically, Capn4 upregulates MAPK7 expression through activation of the Wnt/β-Catenin pathway in CRC cells. Therefore, we identified a tumorigenic role of Capn4 in CRC and suggested a potential therapeutic target for CRC patients.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Inhibition of miR-361-5p suppressed pulmonary artery smooth muscle cell survival and migration by targeting ABCA1 and inhibiting the JAK2/STAT3 pathway

Highlights: • MiR-361-5p was significantly increased in hypoxia-induced hPASMCs. • Inhibition of miR-361-5p suppressed hypoxia-induced hPASMCs proliferation and migration. • miR-361-5p targeted ABCA1. • Overexpression of ABCA1 enhanced the effect of anti-miR-361-5p on hPASMCs proliferation and migration. • miR-361-5p inhibited JAK2/STAT3 pathway. MicroRNAs play a crucial role in the progression of pulmonary arterial hypertension (PAH). The aim of this study was to investigate the effect of miR-361-5p on the proliferation, migration and apoptosis of pulmonary artery smooth muscle cells (PASMCs) that under the treatment of hypoxia and explore the underlying mechanisms. The results proved that hypoxia noticeably up-regulated the expression of miR-361-5p in PASMCs in comparison to the normoxia-treated cells, while TNF-α and IL-6 stimulation had no obvious effects on miR-361-5p level. Hypoxia induced miR-361-5p elevation in a HIF-1α-dependent manner. Inhibition of miR-361-5p dramatically inhibited hypoxia-induced cell proliferation and migration. miR-361-5p inhibition also rescued hypoxia exposure caused suppression of PASMCs apoptosis. In addition, the results showed that ABCA1 was a direct target of miR-361-5p and was down-regulated in hypoxia-induced PASMCs. Hypoxia and TNF-α or IL-6 stimulation significantly inhibited ABCA1 expression. In addition, overexpression of ABCA1 enhanced the effect of miR-361-5p on hPASMCs. Furthermore, the inhibition of miR-361-5p significantly down-regulated the expression level of p-JAK2 and p-STAT3. In conclusion, it may suggest that the suppression of miR-361-5p suppressed PASMC survival and migration by targeting ABCA1 and inhibiting the JAK2/STAT3 pathway.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Ruta graveolens water extract inhibits cell-cell network formation in human umbilical endothelial cells via MEK-ERK1/2 pathway

Highlights: • RGWE inhibits HUVEC ability to form tubes on matrigel in vitro. • RGWE interferes, through MEK/ERK, with the VEGF-mediated signaling that leads to angiogenesis. • RGWE is proposed as a new therapeutic tool to prevent pathological angiogenesis. Angiogenesis is a process encompassing several steps such as endothelial cells proliferation, differentiation and migration to form a vascular network, involving different signal transduction pathways. Among these, ERK1/2 signaling mediates VEGF-dependent signaling pathway. Here we report that the water extract of Ruta graveolens (RGWE), widely known as a medicinal plant, is able to impair in a dose-dependent manner, cell network formation without affecting cell viability. Biochemical analysis showed that the major component of RGWE is rutin, unable to reproduce RGWE effect. We found that RGWE inhibits ERK1/2 phosphorylation and that this event is crucial in cell network formation since the transfection of HUVEC with a constitutively active MEK (caMEK), the ERK1/2 activator, induces a robust cell network formation as compared to untransfected and/or mock transfected cells and, more importantly, caMEK transfected cells became unresponsive to RGWE. Moreover, RGWE inhibits VEGF and nestin gene expression, necessary for vessel formation, and the caMEK transfection induces their higher expression. In conclusion, we report that RGWE is able to significantly impair vessels network formation without affecting cell viability, preventing ERK1/2 activation and, in turn, down-regulating VEGF and nestin expression. These findings point to RGWE as a potential therapeutic tool capable to interfere with pathologic angiogenesis.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Aberrant endoplasmic reticulum stress mediates coronary artery spasm through regulating MLCK/MLC2 pathway

Coronary artery spasm (CAS) is a pathophysiological phenomenon that may cause myocardial infarction and lead to circulatory collapse and death. Aberrant endoplasmic reticulum (ER) stress causes accumulation of misfolding proteins and has been reported to be involved in a variety of vascular diseases. The present study investigated the role of ER stress in the development of CAS and explored the possible molecular mechanisms. Initially, it was found that ER stress markers were elevated in response to drug-induced vascular smooth muscle cells (VSMCs) contraction. Pharmacologic activation of ER stress using Tunicamycin (Tm) persistently induced CAS and significantly promoted Pituitrin-induced CAS in mice as well as in a collagen gel contraction assay. On the contrary, pharmacologic inhibition of ER stress using 4-phenylacetic acid (4-PBA) completely blunted Pituitrin-induced CAS development in mice. Moreover, during the drug-induced VSMCs contraction, expression of ER stress markers were increased in parallel to those of myosin light chain kinase (MLCK) and phosphor-MLC2 (p-MLC2, at Ser19). After inhibiting MLCK activity by using its specific inhibitor ML-7, the ER stress activator Tm failed to activate the MLCK/MLC2 pathway and could neither trigger CAS in mice nor induce VSMCs contraction in vitro. Our results suggested that aberrant ER stress mediated CAS via regulating the MLCK/MLC2 pathway. ER stress activators might be more robust than the common drugs (Pituitrin or acetylcholine) as to induce vasocontraction and thus may serve as potential therapeutics against chronic bleeding, while its inhibitor might be useful for treatment of severe CAS caused by other medication.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

LZ205, a newly synthesized flavonoid compound, exerts anti-inflammatory effect by inhibiting M1 macrophage polarization through regulating PI3K/AKT/mTOR signaling pathway

Highlights: • LZ205 reduced M1[HYPHEN]associated cytokines secretion without affecting M2 macrophages. • LZ205 significantly blocked expression of PI3K, p-Akt and p-mTOR in macrophages. • LZ205 significantly inhibited M1 macrophages polarization in DSS-induced colitis and alum-induced murine peritonitis. Macrophage polarization is involved in the process of inflammation. Regulation of macrophage polarization is considered to be an effective method for the treatment of various inflammatory diseases. In our study, we investigated the potential molecular mechanism of the flavonoid compound LZ205, which exhibits anti-inflammatory property. Results showed that LZ205 significantly reduced M1 macrophage-associated proinflammatory cytokines secretion by regulating PI3K/AKT/mTOR signaling pathway without affecting M2 macrophage-associated cytokines mRNA levels. In vivo studies showed that LZ205 significantly inhibited M1 macrophages polarization in DSS-induced colitis and alum-induced murine peritonitis. Consistent with in vitro studies, LZ205 significantly blocked expression of PI3K, p-AKT and p-mTOR in colon tissues and peritoneal macrophages. Taken together, LZ205 exerts anti-inflammatory effect by inhibiting M1 macrophage polarization via regulating PI3K/AKT/mTOR signaling pathway.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Deregulation of Nrf2/ARE signaling pathway causes susceptibility of dystrophin-deficient myotubes to menadione-induced oxidative stress

Highlights: • Dystrophin knock-down myotubes are more vulnerable to oxidative stress than control myotubes. • Activation of Nrf2 is impaired in dystrophin knock-down myotubes. • Akt signaling is responsible for Nrf2 translocation into the nucleus. • Bcl-2 expression is regulated by nuclear Nrf2. • Sulforaphane can prevent the damage of dystrophin knock-down myotubes under menadione-induced oxidative stress. Duchenne muscular dystrophy (DMD) is an X chromosome-linked disorder caused by a mutation in the dystrophin gene. Many previous studies reported that the skeletal muscles of DMD patients were more susceptible to oxidative stress than those of healthy people. However, not much has been known about the responsible mechanism of the differential susceptibility. In this study, we established dystrophin knock-down (DysKD) cell lines by transfection of dystrophin shRNA lentiviral particles into C2 cells and found that DysKD myotubes are more vulnerable to menadione-induced oxidative stress than control myotubes. We focused on the nuclear erythroid 2-related factor 2 (Nrf2) which is a transcription factor that regulates the expression of phase II antioxidant enzymes by binding to the antioxidant response element (ARE). Under menadione-induced oxidative stress, the translocation of Nrf2 to the nucleus is significantly decreased in the DysKD myotubes. In addition, the binding of Nrf2 to ARE site of Bcl-2 gene as well as protein expression of Bcl-2 is decreased compared to the control cells. Interestingly, sulforaphane increased Akt activation and Nrf2 translocation to the nucleus in the DysKD myotubes. These results suggest that the Nrf2 pathway might be the responsible pathway to the oxidative stress-induced muscle damage in DMD.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

ISG15 promotes esophageal squamous cell carcinoma tumorigenesis via c-MET/Fyn/β-catenin signaling pathway

Highlights: • ISG15 is highly expressed in ESCC tissues and plasma, representing a promising diagnostic marker. • ISG15 positively regulated the proliferation, invasion and migration in vitro and in vivo. • ISG15 mediates the tumorigenesis via c-MET/Fyn/β-catenin pathway. Esophageal squamous cell carcinoma (ESCC) is one of the most malignant tumors in China with a poor prognosis. Most ESCC patients were diagnosed at advanced stages, losing the opportunity for surgical excision. Hence, it remains a pressing work to identify biomarkers for early detection, prognosis prediction and targeting therapies in ESCC. Interferon-stimulated gene 15 (ISG15) encodes a 15-kDa protein, and is involved in the post-translational modification (PTMs) of multiple proteins. However, the molecular functions of ISG15 in ESCC remain unclear. In this work, we found that ISG15 was aberrantly expressed in ESCC tissues and cell lines. Enhanced protein level of ISG15 promoted cellular malignant phenotypes including proliferation, migration, invasion and tumor formation in vivo. Consistently, reduction of ISG15 attenuated the cellular malignant phenotype in ESCC cell lines. Furthermore, gene-expression profiles suggested that the differentially expressed ISG15 affected the expression of a panel of genes enriched in the cell adherens junction, such as c-MET. Notably, as a secreted protein, the concentration of ISG15 was elevated in ESCC plasma than healthy individuals, acting as a potential diagnostic marker. Taken together, our results suggested a tumor promotion role of ISG15 in ESCC via c-MET/Fyn/β-catenin pathway.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Glycyrrhizin ameliorates inflammatory pain by inhibiting microglial activation-mediated inflammatory response via blockage of the HMGB1-TLR4-NF-kB pathway

Highlights: • Glycyrrhizin (Gly) represses LPS-induced microglial activation without cell toxicity. • Glycyrrhizin dose-dependently inhibits LPS-triggered inflammatory response. • Elevation of HMGB1 reverses glycyrrhizin-inhibited inflammatory response in microglia. • HMGB1-mediated TLR4-NF-κB activation account for gly-restrained inflammation. • Gly alleviates CFA-induced pain hypersensitivity, inflammation, microglia activation. Chronic inflammatory pain is a severe clinical problem that greatly affects patients’ quality of life and causes huge economic burden. Microglia-mediated neuroinflammation exerts critical roles in the pathogenic progression of inflammatory pain. Recent evidence corroborates the anti-inflammatory and neuroprotective efficacy of glycyrrhizin; however, its function in inflammatory pain remains poorly elucidated. In the present study, glycyrrhizin suppressed LPS-induced activation of microglial cell BV2 by inhibiting NO production and expression of microglial marker IBA-1. Intriguingly, LPS-induced high expression and generation of inflammatory cytokines (i.e., IL-6, TNF-α and IL-1β) was notably reversed by glycyrrhizin pre-treatment. Mechanistic analysis confirmed that high expression of high-mobility group box 1 (HMGB1) in LPS-activated microglia was inhibited following glycyrrhizin. More importantly, restoring HMGB1 expression by recombinant adenovirus vector of Ad-HMGB1 counteracted glycyrrhizin-restrained inflammatory response in microglia upon LPS stimulation. Furthermore, glycyrrhizin dampened the activation of subsequent TLR4-NF-κB pathway in LPS-stimulated microglia, which was abrogated by HMGB1 elevation. Furthermore, blocking this pathway by si-TLR4 transfection reversed the effects of HMGB1 overexpression on the inhibitor roles of glycyrrhizin in microglia-triggered inflammation. Additionally, glycyrrhizin administration also alleviated CFA-evoked mechanical allodynia and thermal hyperalgesia in inflammatory pain model of mice, concomitant with suppression in inflammatory response and microglial activation. Simultaneously, elevation of HMGB1, TLR4 and p65-NF-κB protein expression induced by CFA injection was also abrogated after glycyrrhizin. Accordingly, this study reveal that glycyrrhizin may act as a promising therapeutic avenue for the treatment of inflammatory pain.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Staphylococcal enterotoxin C2 stimulated the maturation of bone marrow derived dendritic cells via TLR-NFκB signaling pathway

Highlights: • SEC2 stimulate the maturation of BMDCs. • SEC2 induce the production of pro-inflammation cytokines in BMDCs. • SEC2 activate NF-κB signaling pathway in BMDCs. As a kind of superantigen, staphylococcal enterotoxin C2 (SEC2) is well known as a powerful immunomodulator. However, most previous studies about SEC2 focus on its T cell activating characters. But the direct effect of SEC2 on antigen-presenting cells (APCs) which are important for the T cell activation is not clearly. In this study, we investigated the effect of SEC2 on murine bone marrow-derived dendritic cells (BMDCs) which are known as the specialized professional APCs. Contrary to its effects on T cells, SEC2 could not induce proliferation or cytotoxicity to BMDCs even in high concentrations. While SEC2 could promote the mature of BMDCs with increased expression of co-stimulatory molecules on cell membrane such as CD80, CD86, and MHC II. The production of pro-inflammatory cytokines such as TNF-α, IFN-γ and IL-6 were also increased in BMDCs treated with SEC2. We also found that SEC2 enhanced the genes expression of pattern recognition receptors including toll-like receptors 2 (TLR2) and TLR4 in BMDCs, and up-regulated the key signal molecule MyD88 in both mRNA and protein levels. In addition, SEC2 also caused IκBα degradating and NFκB p65 translocating from the cytoplasm to the nucleus in BMDCs. The siRNAs for both TLR2 and TLR4, as well as NFκB specific inhibitor BAY 11–7085 could inhibit the co-stimulatory molecules expression and pro-inflammatory cytokines releasing induced by SEC2. Moreover, TLR2/4 specific siRNAs inhibited p65 and MyD88 upregulation induced by SEC2. In summary, all our results indicated that SEC2 could stimulate BMDCs maturation through TLR-NFκB signaling pathways.

60 APPLIED LIFE SCIENCES↗