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At least 685 records · Page 38

Resveratrol induces dynamic changes to the microglia transcriptome, inhibiting inflammatory pathways and protecting against microglia-mediated photoreceptor apoptosis

Highlights: • Resveratrol blocks the pro-inflammatory response of microglia on the transcriptome level. • Resveratrol reduces microglial phagocytosis, migration, and radical secretion. • Resveratrol prevents microglia-induced photoreceptor apoptosis. Microglia activation is central to the pathophysiology of retinal degenerative disorders. Resveratrol, a naturally occurring non-flavonoid phenolic compound present in red wine has potent anti-inflammatory and immunomodulatory properties. However, molecular mechanisms by which resveratrol influences microglial inflammatory pathways and housekeeping functions remain unclear. Here, we first studied the immuno-modulatory effects of resveratrol on BV-2 microglial cells at the transcriptome level using DNA-microarrays and selected qRT-PCR analyses. We then analyzed resveratrol effects on microglia morphology, phagocytosis and migration and estimated their neurotoxicity on 661 W photoreceptors by quantification of caspase 3/7 levels. We found that resveratrol effectively blocked gene expression of a broad spectrum of lipopolysaccharide (LPS)-induced pro-inflammatory molecules, including cytokines and complement proteins. These transcriptomic changes were accompanied by potent inhibition of LPS-induced nitric oxide secretion and reduced microglia-mediated apoptosis of 661 W photoreceptor cultures. Our findings highlight novel targets involved in the anti-inflammatory and neuroprotective action of resveratrol against neuroinflammatory responses.

60 APPLIED LIFE SCIENCES↗

ELK1-induced upregulation of lncRNA HOXA10-AS promotes lung adenocarcinoma progression by increasing Wnt/β-catenin signaling

In recent years, increasing number of lncRNAs have been studied in lung adenocarcinoma (LAD). LncRNA HOXA10-AS was found to be upregulated in LAD tissues. Based on the data of TCGA database, HOXA10-AS was a prognostic factor for lung adenocarcinoma. This study aims to reveal the biological function of HOXA10-AS in LAD. qRT-PCR was applied to test expression levels of HOXA10-AS in both LAD tissues and cell lines. Next, transcription factor ELK1 was demonstrated to upregulate HOXA10-AS in LAD cells through performing bioinformatics analysis and dual luciferase activity. Loss of function assays were performed in two different LAD cell lines. Silenced HOXA10-AS was proved to inhibit LAD progression by affecting cell proliferation, cell apoptosis and cell metastasis and EMT progress. Western blot analysis revealed that HOXA10-AS increased Wnt/β-catenin signaling in LAD cell lines. Finally, rescue assays were carried out to identify the biological function of HOXA10-AS-Wnt/β-catenin signaling in LAD progression. In conclusion, ELK1-induced upregulation of HOXA10-AS improved LAD progression through increasing Wnt/β-catenin signaling.

60 APPLIED LIFE SCIENCES↗

Cav-1 promotes atherosclerosis by activating JNK-associated signaling

Highlights: • Cav-1 expression is up-regulated in endothelial cells of atherosclerotic lesions. • Cav-1 deficiency inhibits HFD-induced inflammation in ApoE–/– mice. • Cav-1 deletion is able to suppress HFD-induced oxidative stress and dyslipidemia in ApoE–/– mice. • JNK signaling is involved in Cav-1-modulated atherosclerosis. The objective of the study is to calculate the role and underlying the molecular mechanisms of caveolin-1 (Cav-1) in atherosclerosis (AS). Cav-1 was mainly expressed in the endothelial cells of atherosclerotic lesions in both human patients and apolipoprotein E deficient (ApoE{sup –/–}) mice. Cav-1 deficiency (Cav-1{sup –/–}) attenuated high-fat diet (HFD)-induced atherosclerotic lesions in ApoE{sup –/–} mice, supported by the reduced aortic plaques. Cav-1{sup –/–} reduced the macrophage content and decreased the release of inflammation-related cytokines or chemokine in serum or abdominal aortas, accompanied with the inactivation of inhibitor κB kinase κ (IKKβ)/p65/IκBα signaling pathway. Also, the activity of mitogen-activated protein kinases 7/c-Jun-N-terminal kinase (MKK7/JNK) signaling was decreased by Cav-1{sup –/–}. In addition, oxidative stress induced by HFD in ApoE{sup –/–} mice was alleviated by Cav-1{sup –/–}. In response to HFD, Cav-1{sup –/–} markedly reduced triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDLC) and very low-density lipoprotein-cholesterol (VLDLC) in serum of HFD-fed ApoE{sup –/–} mice, whereas enhanced high-density lipoprotein-cholesterol (HDLC) contents. Consistent with these findings, haematoxylin and eosin (H&E) and Oil Red O staining showed fewer lipid droplets in the liver of Cav-1-deficient mice. Further, real time-quantitative PCR (RT-qPCR) analysis indicated that Cav-1{sup –/–} alleviated dyslipidemia both in liver and abdominal aortas of ApoE{sup −/-} mice fed with HFD. Cav-1 inhibition-induced attenuation of inflammatory response, oxidative stress and dyslipidemia were confirmed in vitro using mouse vascular smooth muscle cells (VSMCs) treated with ox-LDL. Surprisingly, the processes regulated by Cav-1-knockdown could be abolished through promoting JNK activation in ox-LDL-treated VSMCs. In conclusion, Cav-1 expression could promote HFD-induced AS in a JNK-dependent manner.

60 APPLIED LIFE SCIENCES↗

Identification and expression pattern analysis of BoMYB51 involved in indolic glucosinolate biosynthesis from broccoli (Brassica oleracea var. italica)

Highlights: • Overexpression of BoMYB51 in Arabidopsis increases indolic glucosinolate production by upregulating biosynthetic genes. • Overexpression of BoMYB51 in Arabidopsis results in enhanced flagellin22 (Flg22) induced callose deposition. • BoMYB51 is upregulated by SA, JA, ABA and ET. GA represses BoMYB51 expression in true leaves, but not in cotyledons. • BoMYB51 is induced by both biotic and abiotic stresses. Glucosinolates are a class of amino acid-derived specialized metabolites characteristic of the Brassicales order. Trp derived indolic glucosinolates are essential for the effective plant defense responses to a wide range of pathogens and herbivores. In Arabidopsis, MYB51 is the key transcription factor positively regulates indolic glucosinolate production by activating certain biosynthetic genes. In this study, we report the isolation and identification of a MYB51 from broccoli designated as BoMYB51. Overexpression of BoMYB51 in Arabidopsis increased indolic glucosinolate production by upregulating biosynthetic genes and resulted in enhanced flagellin22 (Flg22) induced callose deposition. The spatial expression pattern and responsive expression of BoMYB51 to several hormones and stress treatments were investigated by expressing the β-glucuronidase (GUS) reporter gene driven by BoMYB51 promotor in Arabidopsis and quantitative real-time PCR analysis in broccoli. Our study provides information on molecular characteristics of BoMYB51 and possible physiological process BoMYB51 may involve.

60 APPLIED LIFE SCIENCES↗

TGF-β1 induced fascin1 expression facilitates the migration and invasion of kidney carcinoma cells through ERK and JNK signaling pathways

Highlights: • In 769-P and OSRC cell lines, TGF-β1 can increase the expression of fascin1. • TGF-β1 promoted the invasive and migratory capabilities of the two cell lines via increased the expression of fascin1. • TGF-β1 induced fascin1 expression through ERK and JNK signal pathways. Transforming growth factor-β1 (TGF-β1) plays a crucial role in the signaling network that controls cellular invasion and motility capability during tumor development. To investigate whether fascin1 plays a crucial role in TGF-β1-facilitated invasion and migration of kidney cancer cells (KCC), real-time PCR and western blotting were used to test the fascin1 expression after TGF-β1 treatment (10 ng/ml) in 769-P and OSRC cells. Fascin1 was silenced using the small interfering RNA (siRNA) technique. Cytoskeleton staining was used to test the change of Cytoskeleton. Cell migration and invasion changes were measured by wound-healing and Transwell assay. The results indicate that mRNA and protein levels of fascin1 were dramatically increased after treatment with 10 ng/ml TGF-β1 in 769-P and OSRC cells. TGF-β1 promoted the occurrence of EMT (Epithelial-Mesenchymal Transition) and the invasive and migratory capabilities of the two cell lines after treatment with 10 ng/ml TGF-β1. In addition, fascin1 siRNA dramatically attenuated the invasiveness and migration induced by TGF-β1. Furthermore, we identified that specific inhibitors of ERK and JNK signaling pathways, FR180204 and SP600125, can suppress TGF-β1-induced fascin1 expression. In conclusion, these results reveal that fascin1 is an important mediator of TGF-β1-induced invasion and migration of KCC through ERK and JNK signal pathways.

60 APPLIED LIFE SCIENCES↗

Identification and characterization of circular RNAs in rapid atrial pacing dog atrial tissue

Highlights: • Revealed the expression characterization of circRNAs in dog atrial tissue. • Compared differentially expressed circRNAs between atrial fibrillation and control dog. • Found extensive interaction among circRNAs and AF related miRNAs and mRNAs. Circular RNAs (circRNAs) have emerged as novel molecules of interest in gene regulation as other noncoding RNAs, and participating in the process of many diseases. However, the expression and functions of circRNAs in Rapid atrial pacing (RAP) dog atrial tissue still unknown. 12 canines were randomly assigned to control and pacing group. RAP at 500 beats per minute was maintained 14 days in the pacing group. The expression characterization of circRNAs were revealed by high-throughput sequencing. We totally predicted 15,990 circRNAs in dog atrial tissues. Moreover, we found 146 differentially expressed circRNAs between control and RAP dogs. Five circRNAs were selected for subsequent RT-PCR validation, and four circRNAs confirmed with the high throughput sequencing analysis. GO analysis showed that the differentially expressed circRNAs might involve in the process of “structural constituent of cytoskeleton, ion channel activity”. We explored the circRNA-miRNA interaction network, and found extensive interaction among differentially expressed circRNAs and AF related miRNAs and mRNAs. Our work firstly identified the characterization of circRNAs in the dog atrial, and revealed the differentially expressed circRNAs in the RAP dog, this might lay a solid foundation on the function of circRNA in the mechanisms of AF.

60 APPLIED LIFE SCIENCES↗

ATP6V1H regulates the growth and differentiation of bone marrow stromal cells

Highlights: • Lack of ATP6V1H inhibits the proliferation of bone marrow stromal cells (BMSCs). • Partial loss of ATP6V1H inhibits osteogenic differentiation and promotes adipogenic differentiation of BMSCs. • ATP6V1H interacts with TGF-β receptor I and AP-2 complex to regulate the proliferation and differentiation of BMSCs. ATP6V1H encodes subunit H of vacuolar ATPase (V-ATPase) and may regulate osteoclastic function. The deficiency of ATP6V1H caused bone loss in human, mouse and zebrafish. In this report, we identified the mechanisms by which ATP6V1H regulates proliferation and differentiation of bone marrow stromal cells (BMSCs). We found that ATP6V1H was expressed in BMSCs, and Atp6v1h{sup +/-} BMSCs exhibited the lower proliferation rate, cell cycle arrest and reduced osteogenic differentiation capacity, as well as the increased adipogenic potentials. Histologic analysis confirmed less bone formation and more fatty degeneration in Atp6v1h{sup +/-} mice in the different age groups. Q-PCR analysis revealed that loss of ATP6V1H function downregulated the mRNA level of TGF-β1 receptor, and its binding molecule, subunit β of adaptor protein complex 2 (AP-2), suggesting ATP6V1H regulates the proliferation and differentiation of BMSCs by interacting with TGF-β receptor I and AP-2 complex.

60 APPLIED LIFE SCIENCES↗

Effect of long non-coding RNA H19 on oxidative stress and chemotherapy resistance of CD133+ cancer stem cells via the MAPK/ERK signaling pathway in hepatocellular carcinoma

Highlights: • The H19 expression is higher in HCC tissues than in adjacent normal tissues. • CD133-positive Huh7 cells account for (99.4 ± 3.6)% by flow cytometry. • Inhibition of H19 induces OS in CD133 + cancer stem cells. • Inhibition of H19 reverses chemoresistance in CD133 + cancer stem cells. • Inhibition of H19 contributes to inactivation of MAPK/ERK signaling pathway. We explored the ability of a long non-coding RNA H19, to influence oxidative stress (OS) and chemotherapy resistance of CD133 + cancer stem cells via the MAPK/ERK signaling pathway in HCC. HCC tissues with corresponding adjacent normal tissues were collected. CD133 + HuH7 cells were sorted and assigned into five groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were performed to determine expression levels mRNAs and proteins. Levels of reactive oxygen species (ROS) and malonaldehyde (MDA), and activity of superoxide dismutase (SOD) were measured. Cell viability was analyzed by MTT assay and cell apoptosis by flow cytometry. Compared with adjacent normal tissues, the H19 expression level was higher and MAPK and ERK protein levels were lower in HCC tissues. Compared with the blank group, in the pcDNA-H19 group, H19 expression level, MAPK and ERK protein levels, MDR1 and GST-π expression levels were increased, ROS and MDA levels were decreased, SOD activity was weakened, cell viability was promoted, and cell apoptosis was inhibited; in the siH19 group, H19 expression level, MAPK and ERK protein levels, MDR1 and GST-π expression levels were reduced, ROS and MDA levels were elevated, SOD activity was enhanced, cell viability was inhibited, and cell apoptosis was promoted. There was no significant difference among blank, NC and pcDNA-H19 + PD98059 groups. The study provides evidence that downregulation of H19 may induce OS and reverse chemotherapy resistance of CD133 + cancer stem cells by blocking the MAPK/ERK signaling pathway in HCC.

60 APPLIED LIFE SCIENCES↗

Cardiac extracellular matrix hydrogel together with or without inducer cocktail improves human adipose tissue-derived stem cells differentiation into cardiomyocyte–like cells

Studies have demonstrated that differentiation of stem cells into cardiomyocytes is a complex phenomenon that requires sufficient inducing factors at various time points. Cardiac extracellular matrix (cECM) could provide tissue specific microenvironment and act as an inductive template for efficient cell differentiation. The aim of this study was to investigate the effect of cECM on differentiation of human adipose tissue-derived stem cells (hADSCs) into cardiomyocytes using cECM hydrogel in combination with a cardiac inductive cocktail. hADSCs were cultured on ECM-coated plates with and without inductive cocktail for 3weeks. qRT-PCR and western blot analysis were used to evaluate the expression pattern of special cardiac genes and proteins. When hADSCs were cultured in the presence of cECM cardiac genes including GATA4, HAND1, HAND2, NKX2.5, Troponin I, βMHC, Connexin43 were highly expressed in differentiated cells. Also Connexin43, cTnI and βMHC proteins were expressed as well. We could show that cECM by itself could affect viability, proliferation and differentiation of hADSCs. However, combination of cECM with a cardiac inducing cocktail could improve the results.

60 APPLIED LIFE SCIENCES↗

MicroRNA 148a-3p promotes Thrombospondin-4 expression and enhances angiogenesis during tendinopathy development by inhibiting Krüppel-like factor 6

Highlights: • MiR-148a-3p is downregulated in tendinopathy and positively correlated with CD34. • KLF6 is identified as a novel target of miR-148a-3p. • MiR-148a-3p/KLF6 regulates Tsp-4 expression of Tenocyte mediating angiogenesis during tendinopathy development. • The first study investigates the role of miR-148a-3p in angiogenesis of tendinopathy. Tendinopathy is a common musculoskeletal disorder with characteristic hypervascularity. The mechanism of angiogenesis in tendinopathy remains unclear. The present study aimed to investigate the roles of miR-148a-3p in angiogenesis development of tendinopathy. In this study, we demonstrated that miR-148a-3p expression was increased in tendinopathy tissues and positively correlated with CD34 levels which is a specific marker for angiogenesis. We identified Krüppel-like factor 6 (KLF6) as a direct target gene of miR-148a-3p in tenocytes. Furthermore, reduced levels of KLF6 in tendinopathy tissues was showed using qRT-PCR and immunohistochemical analysis, compared with controls. A negative correlation between the levels of KLF6 mRNA and miR-148a-3p was observed. Then, we verified that miR-148a-3p could regulate Tsp-4 expression by targeting KLF6 in tenocyte and was positively correlated with Tsp-4 levels in tendinopathy tissues. In a coculture system of tenocytes with endothelial cells (ECs), we observed that transfection of Lv-miR-148a-3p markedly upregulated EC angiogenesis. In summary, our data establish a novel molecular mechanism by which miR-148a-3p upregulates Tsp-4 expression in tenocytes to promote EC angiogenesis by targeting KLF6, which could be helpful for the treatment of tendinopathy in the future.

60 APPLIED LIFE SCIENCES↗

Expression and effects of TSP50 in mouse embryo and cardiac myocyte development

Highlights: • TSP50 expression increases during early embryonic development. • TSP50 expression decreases during embryonic heart and P19 myocardial development. • Higher or lower TSP50 causes abnormal zygote and P19 myocardial differentiation. TSP50, a testis-specific gene encoding a serine protease-like protein, was specifically expressed in the spermatocytes of testes but abnormally activated and expressed in many different kinds of cancers. Here, we aimed to analyze the expression of TSP50 in mouse embryo and its function in early embryonic development. Firstly, the distribution of TSP50 in oocytes and embryonic development was characterized by immunofluorescence, RT-PCR and western blotting, and the results showed that TSP50 was detected at all studied stages with a dynamic expression pattern. When overexpressed TSP50 in zygotes by microinjection, the zygotes development was highly accelerated. On the contrary, knocking down TSP50 expression by RNA interference greatly retarded the zygote development. Furthermore, TSP50 expression at embryonic day 6.5 (E6.5), day 8.5 (E8.5) and day 10.5 (E10.5) were increasingly enhanced, However, the expression of TSP50 decreased gradually in the development and differentiation of cardiac myocyte from E12.5 to postnatal (P0). Additionally, we found that TSP50 expression was decreased during cardiac myocyte differentiation of P19 cells. Overexpression of TSP50 could decrease the expression of GATA-4, and knockdown of TSP50 markedly increase the expression of GATA-4. Taken together, our data indicate that TSP50 may play an important role during the process of mouse embryonic development as well as myocardial cell differentiation.

60 APPLIED LIFE SCIENCES↗

FOXP4-AS1 participates in the development and progression of osteosarcoma by downregulating LATS1 via binding to LSD1 and EZH2

Highlights: • We first confirmed that FOXP4-AS1 is overexpressed in OS, and is the independent risk factor in OS prognosis. • We further clarified that Upregulated FOXP4-AS1 promotes the proliferation, migration and cell cycle, but inhibits apoptosis of OS cells. • Finally, we demonstrated that FOXP4-AS1 participates in the development and progression of OS by downregulating LATS1. Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. LncRNA has been confirmed to participate in a variety of cancers. The purpose of this study was to explore the effect of FOXP4-AS1 on the development of osteosarcoma (OS) and its underlying mechanism. FOXP4-AS1 expressions in 60 OS tissues and paracancerous tissues were detected by qRT-PCR (quantitative real-time polymerase chain reaction). We confirmed that FOXP4-AS1 was overexpressed in OS tissues than that of paracancerous tissues. The disease-free survival and overall survival of OS patients were not correlated with age, gender and tumor location, but remarkably correlated with FOXP4-AS1 expression, tumor size and lung metastasis. For in vitro experiments, MG63 cells expressed a higher expression of FOXP4-AS1, whereas U2OS cells expressed a lower expression, which were selected for the following studies. Overexpressed FOXP4-AS1 led to enhanced proliferation, migration and invasion, shortened G0/G1 phase, as well as inhibited cell cycle. Knockdown of FOXP4-AS1 in MG63 cells obtained the opposite results. Furthermore, RIP assay indicated that FOXP4-AS1 could inhibit LATS1 expression by binding to LSD1 and EZH2, so as to participate in OS development. In conclusion, these results revealed that FOXP4-AS1 is overexpressed in OS, and is the independent risk factor in OS prognosis. Upregulated FOXP4-AS1 promotes the proliferation, migration and cell cycle, but inhibits apoptosis of OS cells. Furthermore, FOXP4-AS1 participates in the development and progression of OS by downregulating LATS1 via binding to LSD1 and EZH2.

60 APPLIED LIFE SCIENCES↗

TKTL1 modulates the response of paclitaxel-resistant human ovarian cancer cells to paclitaxel

Highlights: • TKTL1 expression is associated with ovarian cancer cell chemoresistance. • The chemo-resistant mechanism of TKTL1 played in cells was investigated. • Metabolomics was used to find the role of TKTL1 in PPP pathway. • The function of TKTL1 was investigated in vivo. Transketolase-like 1 (TKTL1) plays an important role in the pentose phosphate pathway (PPP) branch. The main obstacle of ovarian cancer treatment is chemotherapeutic resistance. We investigated whether inhibiting TKTL1 in OC3/TAX300 cells could re-sensitize paclitaxel-resistant cells to paclitaxel and proposed a mechanism of action. Western blotting revealed that TKTL1 expression levels in OC3/Tax300 cells were significantly higher than those in OC3 cells. Inhibition of TKTL1 significantly decreased the cellular proliferation rate and IC50 for paclitaxel. Metabolomics revealed that NADPH levels were reduced in the si-TKTL1 group, whereas NADP{sup +} was increased compared with the level in the negative si-TKTL1 group. A 2.2-fold increase in the ROS level and an obvious increase in the cell apoptosis rate were observed in the si-TKTL1+paclitaxel group compared with those in the negative si-TKTL1+paclitaxel and OC3/Tax300 + paclitaxel groups. Western blotting revealed that Bax and Caspase 3 proteins were up-regulated, whereas Bcl-2 expression was down-regulated. Quantitative RT-PCR revealed no changes in gst-π or mrp1 gene expression in the three groups, whereas GSH levels were reduced in the si-TKTL1 group as verified by metabolomics. TKTL1 inhibition also reduced tumor growth in vivo. Collectively, TKTL1 down-regulation sensitized paclitaxel-resistant OC3/Tax300 ovarian cancer cells to paclitaxel.

60 APPLIED LIFE SCIENCES↗

LRP4 promotes proliferation, migration, and invasion in papillary thyroid cancer

Dysregulation of cell proliferation and death is considered the foundation of the malignant biological characteristics of cancer. In this study, we conducted a comprehensive analysis of a massively parallel whole transcriptome resequencing of paired papillary thyroid cancer and normal thyroid tissues from 19 patients. In addition, we found that LRP4, a member of the low-density lipoprotein receptor-related protein family, is significantly overexpressed in thyroid carcinoma. We demonstrated through quantitative real-time polymerase chain reaction (qRT-PCR) that LRP4 is upregulated in papillary thyroid cancer (PTC) tissues. This observation was also consistent with data analyzed from The Cancer Genome Atlas (TCGA) cohort. Thus, the biological role of LRP4 in the thyroid cancer in the present study was investigated using the PTC cell lines TPC1, BCPAP and KTC-1. In these cell lines, the mRNA level of LRP4 was higher than normal thyroid cancer cell named HTORI3. In vitro experiments demonstrated that LRP4 downregulation significantly inhibited the colony formation, proliferation, migration, and invasion of the three PTC cell lines. Knockdown of LRP4 by small interfering RNA (siRNA) in those cell lines decreased the protein expression of N-cadherin, Enhancer of zeste homolog 2 (EZH2), and Zinc finger E-box-binding home-box 1 (ZEB1). Furthermore, LRP4 knockdown significantly reduced the levels of phosphorylated PI3K in the PTC cell lines. In conclusion, the present study indicated that LRP4 is a gene associated with PTC and might become a potential therapeutic target.

60 APPLIED LIFE SCIENCES↗

Functional characterization of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Arabidopsis thaliana and its potential in providing flood tolerance

Ethylene is a phytohormone that has gained importance through its role in stress tolerance and fruit ripening. In our study we evaluated the functional potential of the enzyme involved in ethylene biosynthesis of plants called ACC (aminocyclopropane-1-carboxylic acid) oxidase which converts precursor ACC to ethylene. Studies on ethylene have proven that it is effective in improving the flood tolerance in plants. Thus our goal was to understand the potential of ACC oxidase gene overexpression in providing flood tolerance in transgenic plants. ACC oxidase gene was PCR amplified and inserted into the pBINmgfp5-er vector, under the control of a constitutive Cauliflower Mosaic Virus promoter. GV101 strain of Agrobacterium tumefaciens containing recombinant pBINmgfp5-er vector (referred herein as pBIN-ACC) was used for plant transformation by the ‘floral dip’ method. The transformants were identified through kanamycin selection and grown till T3 (third transgenic) generation. The flood tolerance was assessed by placing both control and transgenic plants on deep plastic trays filled with tap water that covered the soil surface. Our result shows that wild-type Arabidopsis could not survive more than 20 days under flooding while the transgenic lines survived 35 days, suggesting development of flood tolerance with overexpression of ACC oxidase. Further molecular studies should be done to elucidate the role and pathways of ACC oxidase and other phytohormones involved in the development of flood adaptation.

60 APPLIED LIFE SCIENCES↗

MIF protects against oxygen-glucose deprivation-induced ototoxicity in HEI-OC1 cochlear cells by enhancement of Akt-Nrf2-HO-1 pathway

Highlights: • MIF attenuates OGD-induced cochlear cells injury. • MIF enhances Nrf2 and inhibit oxidative stress in cochlear cells. • Enhanced Akt-Nrf2-HO-1 pathway may mediates cochlear protection by MIF. Ischemia and oxidative stress play crucial roles in the pathophysiology of sudden sensorineural hearing loss (SSNHL). Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine and serves an important role in hearing function. The present study was designed to evaluate the effect of MIF on oxygen-glucose deprivation (OGD)-induced ototoxicity and to elucidate its molecular mechanism. In HEI-OC1 auditory cells, OGD reduced cell viability and increased supernatant lactate dehydrogenase (LDH) and MIF in a time-dependent manner. However, the reduced cell viability exerted by OGD was attenuated by antioxidant and MIF. Luciferase reporter assay demonstrated that MIF could activate NF-E2-related factor 2 (Nrf2), and real-time PCR showed increased mRNA expressions of Nrf2 and two Nrf2-responsive genes, including heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). MIF also suppressed oxidative stress induced by OGD, as demonstrated by decreased MDA and increased GSH in cellular supernatant. Inhibition of Nrf2 using siRNA suppressed HO-1 protein expression, the protective effect on OGD-induced injury and decrease in oxidative stress by MIF. Moreover, MIF prevented OGD-induced reduction of Akt1 phosphorylation at Ser473. LY294002, an inhibitor of PI3K/Akt signaling, attenuated the enhancement of Nrf2 protein and protective effect of MIF in OGD-treated cochlear cells. We demonstrate that MIF protects cochlear cells against OGD-induced injury through activation of Akt-Nrf2-HO-1 pathway.

60 APPLIED LIFE SCIENCES↗

Shelterin differentially respond to oxidative stress induced by TiO2-NPs and regulate telomere length in human hepatocytes and hepatocarcinoma cells in vitro

Highlights: • Exposed to TiO{sub 2}-NPs caused telomere shortening and chromosome instability in normal cells but not in cancer cells. • The shelterin and Nrf-2 of normal and cancer cells differentially respond to oxidative stress induced by TiO{sub 2}-NPs. • The upregulation of Nrf-2 and shelterin protect telomere and chromosome stability against TiO{sub 2}-NPs exposure. Titanium dioxide nanoparticles (TiO{sub 2}-NPs) have raised serious attention for their widely use and potential adverse effects on human mainly due to producing ROS. However, the influence of TiO{sub 2}-NPs on telomere maintaining has not been studied clearly. Shelterin plays core roles in telomere length (TL) regulation. Abnormal TL are associated with chromosome instability (CIN) and high risk of diseases. This study investigated whether TiO{sub 2}-NPs affect TL to induce CIN through ROS generation and the possible mechanisms. Human hepatocyte L-02 and hepatocarcinoma cells QGY were exposed to TiO{sub 2}-NPs (0, 40, 80 μg/mL) for 72 h. The intracellular hydrogen dioxide (H{sub 2}O{sub 2}) concentration were measured. The TL, Nrf-2, and three core shelterin components (TRF1, TRF2, and POT1) transcription level were determined by quantitative real-time PCR. CIN was measured by cytokinesis-block micronucleus assay. TiO{sub 2}-NPs exposure increased intracellular H{sub 2}O{sub 2} in both L-02 and QGY cells, and induced Nrf-2, TRF1, TRF2, POT1 downregulated transcription compared with control (P P P P Nrf-2 to oxidative stress induced by TiO{sub 2}-NPs led to the weakened telomere protection in normal cells and effective telomere maintenance in cancer cells, respectively. The upregulation of Nrf-2 and shelterin could protect TL and chromosome stability against TiO{sub 2}-NPs exposure.

60 APPLIED LIFE SCIENCES↗

Early emergence of de novo EGFR T790M gatekeeper mutations during erlotinib treatment in PC9 non-small cell lung cancer cells

The emergence of the T790M gatekeeper mutation in the Epidermal Growth Factor Receptor (EGFR) gene is an important mechanism that can lead to the acquired resistance to EGFR-targeted tyrosine kinase inhibitors such as erlotinib or gefitinib. These drugs have been used in treating a subset of non-small cell lung cancer (NSCLC) patients harboring EGFR activating mutations. Here we investigated the paths leading to the acquisition of the T790M mutation by establishing an erlotinib resistant PC9 cell model harboring ectopically introduced EGFR cDNA. We detected the emergence of T790M mutation within the EGFR cDNA in a subset of erlotinib resistant PC9 cell models through Sanger sequencing and droplet digital PCR-based methods, demonstrating that T790M mutation can emerge via de novo events following treatment with erlotinib. In addition, we show that the de novo T790M bearing erlotinib resistant PC9 cells are sensitive to the 3rd generation EGFR-targeted drug, WZ4002. Furthermore, GFP-based competition cell proliferation assays reveal that PC9 cells ectopically expressing EGFR mutant become more rapidly resistant to erlotinib than parental PC9 cells through the acquisition of the T790M mutation. Taken together, we believe that our findings expand upon the previous notion of evolutionary paths of T790M development, providing an important clue to designing a therapeutic strategy to overcome drug resistance.

60 APPLIED LIFE SCIENCES↗