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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 1,441 records · Page 80
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DOE OSTI2018

Inhibition of mTOR ameliorates bleomycin-induced pulmonary fibrosis by regulating epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) plays a pivotal role in idiopathic pulmonary fibrosis (IPF). In bleomycin-induced pulmonary fibrosis mice, we observed that inhibition of mTOR (mammalia target of rapamycin) attenuated IPF. Rapamycin suppressed the down-regulation of E-cadherin and up-regulation of fibronectin in bleomycin-induced pulmonary fibrosis mice. In addition, dual immunofluorescence staining for E-cadherin and fibronectin demonstrated that rapamycin pretreatment decreased the proportions of AECs undergoing EMT in bleomycin-induced pulmonary fibrosis, indicating that mTOR inhibition suppressed EMT in vivo. In the setting of transforming growth factor (TGF)-β1-induced EMT in AECs, we found that mTOR inhibitor attenuated TGF-β1-induced EMT in AECs. This EMT was characterized by morphology and cell skeleton changes and the expression of EMT phenotype markers. Finally, mTOR blockade decreased S6k and TGF-β1-induced Smad2/3 phosphorylation. Bleomycin induced pulmonary fibrosis and EMT in mice, while mTOR repression inhibited bleomycin-induced pulmonary fibrosis and attenuated EMT in vivo. Hence, our study provided evidence of a novel mechanism by which mTOR inhibitor ameliorates pulmonary fibrosis. Suppression of mTOR and EMT may be a target for treatment of pulmonary fibrosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Evaluation of a self-regulated in vitro hypoxic system by using chemical reactions

Highlights: • A self-regulated in vitro hypoxic system has been established using chemical reactions. • The chemical reaction was able to sustain the basic requirements of CO{sub 2} and pH levels of cell culture. • The hypoxia box design may provide countless applications for the study of hypoxia. In this study, we established an in vitro hypoxic system driven by a self-regulated chemical reaction that proved effective for cell culture. The hypoxic device was modified from a 1.5 L polypropylene preservation box normally employed for food storage. Pyrogallic acid, sodium hydroxide, and sodium carbonate were dissolved in water and injected into the box. Sodium dihydrogen phosphate solution was injected into the box after 15 min. We measured the concentrations of oxygen and carbon dioxide in the box to determine viability of the hypoxic system. It maintained low levels of oxygen less than 0.2% and stabilizing levels of carbon dioxide at 5% for at least 96 h. Therefore, this device sustained a stable hypoxic environment that may be applicable for cell culture and in vitro studies of hypoxia.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

ROS mediated EGFR/MEK/ERK/HIF-1α Loop Regulates Glucose metabolism in pancreatic cancer

Highlights: • Difference in Glucose metabolism is related to cell proliferation and the clinical characteristics of pancreatic cancer. • ROS mediated EGFR/MEK/ERK/HIF-1α pathway is activated in high glucose metabolism level samples. • Suppressing of EGFR or HIF-1α regulates the glycometabolism and inhibits the invasion and metastasis of pancreatic cancer. To investigate the glycometabolism associated mechanism in invasion and metastasis of pancreatic cancer, We screened out genes involved in anaerobic glycolysis headed by HIF-1α,using pre-established a pair of pancreatic cancer cell lines. In this study, we further detected the glucose metabolism state not only in the cells but all also in two groups of patients with different SUVmax on {sup 18}F-FDG PET/CT. The data suggests that ROS mediated EGFR/MEK/ERK/HIF-1α loop is activated in high glucose metabolic samples both in vitro and in vivo: The increasing of HIF-1α expression is controlled by activation of EGFR/MEK/ERK pathway in hypoxia condition, HIF-1α inhibits excessive release of ROS, the reduction of ROS further activates EGFR to form a positive feedback loop. This difference is closely related to invasion and metastasis capacity of pancreatic cancer, and can be rescued by separate or combined inhibition of EGFR or HIF-1α in various degree. These results indicate a new clue to develop therapy of pancreatic cancer by regulating the glucose metabolism.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

SPG6 supports development of acute myeloid leukemia by regulating BMPR2-Smad-Bcl-2/Bcl-xl signaling

Highlights: • Up-regulated expression of SPG6 correlated with poor survival of AML patients. • Knockdown expression of SPG6 suppresses growth and promotes apoptosis of AML cells. • SPG6 regulates BMPR2-Smad-Bcl-2/Bcl-xl signaling in AML cells. Acute myeloid leukemia (AML) is the most common acute leukemia affecting adults. To effectively treat AML, new molecular targets and therapeutic approaches must be identified. In silico analysis of several available databases of AML patients showed that the expression of Spastic Paraplegia 6 Protein (SPG6) significantly inversely correlates with the overall survival of AML patients. To determine whether SPG6 supports AML development, we employed an shRNA-encoding lentivirus system to inhibit SPG6 expression in human AML cells including NB4 and MV4-11 cells. Knockdown expression of SPG6 resulted in decreased cell growth and elevated apoptosis of these leukemia cells. Notably, the SPG6 deficiency resulted in higher BMPR2 expression indicating that BMPR2 signaling contributes to AML pathogenesis. Furthermore, SPG6 deficiency promoted phosphorylation of Smad1/5/9 and decreased transcription of Bcl-2 and Bcl-xl. Our study suggests that SPG6 contributes to AML pathogenesis, and suggests that inhibition of SPG6 may be novel strategy for treating human AML.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

AFP2 as the novel regulator breaks high-temperature-induced seeds secondary dormancy through ABI5 and SOM in Arabidopsis thaliana

Imbibed seeds monitor environmental and endogenous signals to break dormancy and initiate growth under appropriate conditions. In Arabidopsis thaliana, high temperature (HT) induces secondary seed dormancy, but the underlying mechanism remains unclear. In this study, we found that the abi5-1 mutant was insensitive to high temperature, whereas plants overexpressing ABI5 displayed sensitivity. We then identified ABA-insensitive five-binding protein 2 (AFP2), which interacts with ABI5 and is involved in HT-induced secondary seed dormancy. Under HT stress, the loss-of-function afp2 mutant showed lower seeds germination frequency, reversely, AFP2 overexpressing lines (OE-AFP2) showed high germination frequency. Similar to the abi5 mutant, the crossed OE-AFP2 abi5 or afp2 abi5 lines showed high germination under HT, suggesting that ABI5 is epistatic to AFP2. SOM is reported to negatively regulate seeds germination by altering GA/ABA metabolism, here we found that AFP2 and ABI5 altered SOM transcription. Specifically, overexpressing AFP2 suppressed SOM transcription, resulting in high expression of GA biosynthesis-related genes and low expression of ABA biosynthesis-related genes, ultimately promoting seed germination under HT. Thus, our data demonstrate that AFP2 is a novel regulator to control HT-induced secondary seed dormancy through ABI5 and SOM.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-26a-5p potentiates metastasis of human lung cancer cells by regulating ITGβ8- JAK2/STAT3 axis

Highlights: • 90% of lung cancer patients die of metastasis. • miR-26a-5p enhances metastasis potential of lung cancer both in vitro and in vivo. • ITGβ8 is identified as a novel target of miR-26a-5p. • miR-26a-5p enhances lung cancer cell metastasis via activation of JAK2/STAT3 pathway. Most lung cancer patients die of metastasis. Recent studies have indicated that dysregulated microRNAs (miRNAs) are involved not only in tumorigenesis, but also in metastasis. In the present study, we found that over-expression of miR-26a-5p potentiated the migration and invasion of lung cancer cells evidenced by wound healing assay and transwell assay, and metastasis-related genes MMP-9 and CD44 were up-regulated. We identified integrin-beta8 (ITGβ8) as a novel target of miR-26a, and ITGβ8 expression was negatively correlated with miR-26a-5p expression in lung cancer specimens. Mechanism study showed that miR-26a-5p enhanced lung cancer cell metastasis via activation of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, and ITGβ8 mediated the activation of JAK2/STAT3 pathway by miR-26a-5p. By using in vivo imaging technology, we found that miR-26a-5p enhanced both tumor growth and metastasis in vivo; and activated JAK2/STAT3 pathway. Taken together, our results demonstrated that miR-26a-5p potentiated lung cancer cell metastasis via JAK2/STAT3 pathway by targeting ITGβ8. This finding provides insights into the mechanism underlying miRNAs regulation on lung cancer metastasis; and suggests miR-26a-5p as a therapeutic target for lung cancer treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

A miR-124/ITGA3 axis contributes to colorectal cancer metastasis by regulating anoikis susceptibility

Highlights: • Overexpression of miR-124 promotes CRC cell anoikis in vitro and in vivo. • ITGA3 is a novel target of miR-124 in CRC cells. • Silencing ITGA3 recapitulates the effect of miR-124 on anoikis sensitivity in CRC cells in vitro and in vivo. • High levels of ITGA3 are associated with poor prognosis in CRC patients. Metastasis is the major cause for the death of patients with colorectal cancer (CRC). Anoikis resistance enhances the survival of cancer cells during systemic circulation, thereby facilitating secondary tumor formation in distant organs. miR-124 is a pleiotropically tumor suppressive small non-coding molecule. However, its role and mechanism in the regulation of cancer cell anoikis are still unknown. Here, we found that overexpression of miR-124 promotes anoikis of CRC cells in vitro and in vivo. In silico analysis and the experimental evidence supported that ITGA3 is a bona fide target of miR-124. Moreover, we identifies that ITGA3 plays a critical role in the regulation of anoikis sensitivity in CRC cells. Finally, our analysis in TCGA datasets demonstrates that high levels of ITGA3 are closely associated with poor prognosis in CRC patients. Collectively, we establish a functional link between miR-124 and anoikis susceptibility and provide that a miR-124/ITGA3 axis could be a potential target for the treatment of metastatic CRC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-216a-5p/Hexokinase 2 axis regulates uveal melanoma growth through modulation of Warburg effect

Highlights: • microRNA-216a-5p (miR-216a-5p) inhibits HK2 expression by directly targeting its 3′-UTR in uveal melanoma cells. • miR-216a-5p dampens glycolysis in uveal melanoma cells via inhibition of HK2. • miR-216a-5p expression is negatively correlated with HK2 expression and predicts better outcome in uveal melanoma patients. Hexokinase-2 (HK2), the initial as well as the rate-limiting step in glycolysis, is overexpressed in many human cancers, and correlates with poor clinical outcomes. Aerobic glycolysis is a hallmark of cancer, and drugs targeting its enzymes, including HK2, are being developed. However, the mechanisms of HK2 inhibition and the physiological significance of the HK2 inhibitors in cancer cells are rarely reported. Here, we show that microRNA-216a-5p (miR-216a-5p) inhibits HK2 expression by directly targeting its 3′-UTR in uveal melanoma cells. Through inhibition of HK2, miR-216a-5p dampens glycolysis by reducing HK activity, glucose uptake, lactate production, ATP generation, extracellular acidification rate (ECAR), and increasing oxygen consumption rate (OCR) in uveal melanoma cells. Importantly, glycolysis regulated by miR-216a-5p is critical for its regulating uveal melanoma tumor growth both in vitro and in vivo. miR-216a-5p expression is negatively correlated with HK2 expression and predicts better outcome in uveal melanoma patients. Our findings provide clues regarding the role of miR-216a-5p as a tumor suppressor in uveal melanoma through the inhibition of HK2. Targeting HK2 through miR-216a-5p could be a promising therapeutic strategy in uveal melanoma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Roles of 14-3-3β and γ in regulation of the glucocorticoid receptor transcriptional activation and hepatic gluconeogenesis

The glucocorticoid receptor (GR) is a ligand-dependent transcription factor that mediates the effects of glucocorticoids, and plays a crucial role in cell growth, development, inflammation, and gluconeogenesis. The 14-3-3 proteins bind to target proteins via phosphorylation, and influence many cellular events by altering their subcellular localization or by acting as chaperones. However, the mechanisms by which 14-3-3 proteins regulate GR transactivation and their involvement in gluconeogenesis remain uncharacterized. We found that 14-3-3β and γ increased GR transcriptional activity and the promoter activities of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase in the presence of glucocorticoids. Inhibition of the endogenous 14-3-3β and γ decreased dexamethasone- and cAMP-stimulated PEPCK expression. Further, both 14-3-3β and γ increased glucose production in response to glucocorticoids. Our findings suggest that 14-3-3β and γ function as positive regulators of GR transactivation and glucocorticoid-mediated hepatic gluconeogenesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Lysophosphatidic acid receptor, LPA6, regulates endothelial blood-brain barrier function: Implication for hepatic encephalopathy

Highlights: • Serum autotaxin activity is elevated in the mouse with brain edema. • LPA{sub 6} is predominantly expressed in rat brain capillary endothelial cells. • LPA–LPA{sub 6}–G{sub 12/13}–Rho pathway regulates blood brain barrier permeability. Cerebral edema is a life-threatening neurological condition characterized by brain swelling due to the accumulation of excess fluid both intracellularly and extracellularly. Fulminant hepatic failure (FHF) develops cerebral edema by disrupting blood-brain barrier (BBB). However, the mechanisms by which mediator induces brain edema in FHF remain to be elucidated. Here, we assessed a linkage between brain edema and lysophosphatidic acid (LPA) signaling by utilizing an animal model of FHF and in vitro BBB model. Azoxymethane-treated mice developed FHF and hepatic encephalopathy, associated with higher autotaxin (ATX) activities in serum than controls. Using in vitro BBB model, LPA disrupted the structural integrity of tight junction proteins including claudin-5, occludin, and ZO-1. Furthermore, LPA decreased transendothelial electrical resistances in in vitro BBB model, and induced cell contraction in brain endothelial monolayer cultures, both being inhibited by a Rho-associated protein kinase inhibitor, Y-27632. The brain capillary endothelial cells predominantly expressed LPA{sub 6} mRNA, whose knockdown blocked the LPA-induced endothelial cell contraction. Taken together, the up-regulation of serum ATX in hepatic encephalopathy may activate the LPA–LPA{sub 6}–G{sub 12/13}–Rho pathway in brain capillary endothelial cells, leading to enhancement of BBB permeability and brain edema.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Moderate hypothermia protects increased neuronal autophagy via activation of extracellular signal-regulated kinase signaling pathway in a rat model of early brain injury in subarachnoid hemorrhage

Highlights: • Moderate hypothermia (MH) treatment has neuroprotective effect on SAH rats. • Moderate hypothermia can upregulate SAH-induced autophagy. • SAH-induced autophagy upregulated by moderate hypothermia depends on ERK signaling pathways. Moderate hypothermia (MH) used as treatment for neurological diseases has a protective effect; however, its mechanism remains unclear. Neuronal autophagy is a fundamental pathological process of early brain injury in subarachnoid hemorrhage (SAH). We found that moderate activation of autophagy can reduce nerve cells damage. In this study, We found that MH can moderately increase the level of autophagy in nerve cells and improve the neurological function in rats. This type of autophagy activation is dependent on extracellular signal-regulated kinase (ERK) signaling pathways. The level of neuronal autophagy was down-regulated significantly by using U0126, an ERK signaling pathway inhibitor. In summary, these results suggest that MH can moderately activate neuronal autophagy through ERK signaling pathway, reduce nerve cell death, and produce neuroprotective effects.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

RHCG suppresses cervical cancer progression through inhibiting migration and inducing apoptosis regulated by TGF-β1

Highlights: • Expression of RHCG is associated with human cervical cancer development. • RHCG regulates migration and apoptosis in human cervical cancer cell lines. • RHCG modulates TGF-β1 expressions to reduce migration and induce apoptosis in human cervical cancer cell lines. Cervical cancer is the second commonest cancer among women in the worldwide, and the majority cause of death in various countries, highlighting the importance of investigating new therapeutic targets. Rh family, C glycoprotein (RHCG) belongs to the Rhesus (Rh) family and was first identified as Rh blood group antigens. It has been confirmed to function in cancer progression, including prostate cancer and esophageal squamous cell carcinoma. However, its role in cervical cancer has never been explored. The present study indicated that RHCG was down-regulated in cervical cancers compared to that in normal cervical tissues, and further decreased in cervical cancer cell lines. Functionally, RHCG overexpression reduced cervical cancer cell proliferation and migration, as evidenced by the decreased transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-2 and MMP-9 expressions in cancer cells; however, an opposite effect was observed when RHCG was knocked down. Further, increase of RHCG markedly induced apoptosis in cervical cancer cells by improving the cleavage of Caspase-3 and poly (ADP-Ribose) polymerase (PARP). And cells transfected with RHCG siRNA exhibited a notable reduction of cleaved Caspase-3 and PARP. Moreover, nucleus nuclear factor-κB (NF-κB) and whole cell xIPA expressions were markedly reduced by over-expressing RHCG. Conversely, suppressing RHCG elevated NF-κB activation and xIPA expression in cervical cancer cells. Notably, we found that TGF-β1 treatment could abolish the effects of RHCG over-expression on the reduction of cell migration and enhancement of apoptosis in cervical cancer cells. Over-expressing RHCG-reduced NF-κB activation and xIPA expression were also abrogated by TGF-β1 pre-treatment. Additionally, enhancing NF-κB activity could restore xIPA expressions and decrease apoptotic response in cervical cancer cells over-expressing RHCG. In vivo, we also found that RHCG over-expression reduced cervical tumor growth through the same signaling pathways as we found in vitro. Therefore, RHCG may be a potential prognostic biomarker and therapeutic target for human cervical cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Quercetin inhibits the poly(dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed human keratinocytes

Highlights: • Pre-treatment with Quercetin inhibited poly(dA:dT)-induced IL-18 secretion in IFN-γ-primed keratinocytes. • Pre-treatment with Quercetin inhibited expression of AIM2 and pro-caspase-1 in poly(dA:dT)-treated and IFN-γ–primed keratinocytes. • Pre-treatment with Quercetin inhibited the JAK2/STAT1 pathway in poly(dA:dT)-treated and IFN-γ–primed keratinocytes. Quercetin, a polyphenol, belongs to a class of flavonoids that exerts anti-inflammatory effects. Interleukin (IL)-18 is a member of the IL-1 family cytokine that regulates immune responses and is implicated in various inflammatory skin diseases. Absent in melanoma 2 (AIM2) is a cytosolic double-stranded (ds) DNA sensor that recognizes the dsDNA of a microbial or host origin. Binding of dsDNA to AIM2 simulates caspase-1-dependent inflammasome activity, which leads to the production of IL-1β and IL-18. Increased levels of AIM2 have been observed in patients with inflammatory skin diseases. In the current study, we investigated the issue of whether or how Quercetin attenuates poly (dA:dT), a synthetic analog of microbial dsDNA, -induced IL-18 secretion in IFN-γ-primed human keratinocytes. Treatment with 5 and 10 μM of Quercetin inhibited the poly (dA:dT)-induced secretion of IL-18 after IFN-γ priming and before poly (dA:dT)-induced AIM2 activation. In addition, treatment with Quercetin at 10 μM, significantly inhibited the phosphorylation of JAK2 and STAT1, and the nuclear translocation of phosphorylated STAT1 in poly (dA:dT)-treated and IFN-γ-primed keratinocytes. These results suggest that treatment with Quercetin inhibits the poly (dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed keratinocytes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

PINK1 protects against oxidative stress induced senescence of human nucleus pulposus cells via regulating mitophagy

Intervertebral disc degeneration (IDD) is closely related with aging, whereas mitochondrial dysfunction is a common feature of aging in which results cell senescence. Phosphatase and tensin homolog (PTEN)-induced putative kinase protein 1 (PINK1) is a mitochondrial-targeted serine/threonine kinase, which plays a protective role against mitochondrial dysfunction with mitochondrial quality control by activating PINK1/Parkin mediated mitophagy. This study aimed to investigate the protective role of PINK1 against mitochondrial dysfunction and human nucleus pulposus cell (NPC) senescence. We found that mitochondrial dysfunction and NPC senescence could be induced under sublethal oxidative stress by 150 μM H{sub 2}O{sub 2}. Moreover, down-regulation of PINK1 tended to aggravate NPC senescence under oxidative stress. Therefore, mitophagy was evaluated in NPCs to further reveal the underlying mechanism. Results showed that sublethal oxidative stress induced mitochondria dysfunction and mitophagy in NPCs. Furthermore, depletion of PINK1 utilizing short hairpin RNA targeting PINK1 (PINK1-shRNA) impaired mitophagy, and exasperated NPC senescence under oxidative stress. In summary, these results suggested that PINK1 played as a protective role in clearance of damaged mitochondrial and alleviating cell senescence under oxidative stress, whose mechanism is associated with regulating mitophagy. These findings may provide a better understanding in pathomechanism of IDD and potential therapeutic approaches for IDD treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Induction of the mitochondrial NDUFA4L2 protein by HIF-1a regulates heart regeneration by promoting the survival of cardiac stem cell

The adult mammalian heart doesn't regenerate after cardiomyocyte injury, which was mainly caused by the severe and persistent effects of cardiomyopathy. Recently, some studies reported that the mammalian heart can regenerate under low oxygen environment. However, the mechanism that the mammalian heart can regenerate remains unknown. Here, we used cardiac stem cells (CSCs) to be planted in serum-free medium under hypoxia environment to understand the mechanism of HIF1α/NDUFA4L2 in the regulation of hypoxia-alleviated apoptosis. Our results revealed that hypoxia can alleviated CSCs apoptosis. Hypoxia inhibited the level of cleaved-caspase3 and stimulated the expression of stabilized HIF-1α. DMOG promotes the survival of CSCs and the protein expression of NDUFA4L2. 2-ME repressed the survival of CSCs and the protein expression of NDUFA4L2. CHIP assay showed that HIF-1α regulated the survival of CSCs by augmenting the combination of HIF-1α and NDUFA4L2's HRE. Knockdown of NDUFA4L2 reversed the role of hypoxia in the survival of CSCs. Taken together, hypoxia promotes the viability of CSCs in serum-free medium by HIF-1α/NDUFA4L2 signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Dual regulation of hEAG1 channels by phosphatidylinositol 4,5-bisphosphate

Highlights: • hEAG1 channels are PIP{sub 2} sensitive. • hEAG1 channels are inhibited either by PIP{sub 2} depletion or loading. • Optimum membrane PIP{sub 2} level is required for the proper functioning of hEAG1 channels. The ether-à-go-go1 (EAG1, Kv10.1) K{sup +} channel is a member of the voltage-gated K{sup +} channel family mainly expressed in the central nervous system and cancer cells. Membrane lipids regulate several voltage-gated K{sup +} channels but their influence on EAG1 channels has been poorly explored. Here we have studied the regulation of hEAG1 channels by phosphatidylinositol 4,5-bisfofate (PIP{sub 2}) by using different strategies to manipulate the levels of this lipid, and the patch clamp technique. We found that depletion of endogenous PIP{sub 2} by activation of the voltage-sensing phosphatase from Danio rerio (Dr-VSP) or the human muscarinic type-1 receptor (hM1R) inhibits hEAG1 currents; however, the application of exogenous PIP{sub 2} to increase the level of this lipid on the plasma membrane, also induced an inhibition of hEAG1. In summary, our results indicate that PIP{sub 2} have dual effects on hEAG1 channels and its action as activator or inhibitor depends on its initial level on the plasma membrane.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

NtRLK5, a novel RLK-like protein kinase from Nitotiana tobacum, positively regulates drought tolerance in transgenic Arabidopsis

Highlights: • NtRLK5 confers enhanced drought tolerance in transgenic Arabidopsis plants. • Overexpression of NtRLK5 decreases H{sub 2}O{sub 2}, MDA accumulation. • NtRLK5-overexpressing transgenic plants show higher antioxidant enzymes activity. Receptor-like protein kinase (RLKs) plays pivotal roles in plant growth and development as well as stress responses. However, little is known about the function of RLKs in Nitotiana tobacum. In the present study, we present data on NtRLK5, a novel RLK-like gene isolated from Hongda (Nitotiana tobacum L.). Expression profile analysis revealed that NtRLK5 was strongly induced by drought and salt stresses. Transient expression of NtRLK5-GFP fusion protein in protoplast showed that NtRLK5 was localized to plasma membrane. Overexpression of NtRLK5 conferred enhanced drought tolerance in transgenic Arabidopsis plants, which was attributed to not only the lower malondialdehyde (MDA) and H{sub 2}O{sub 2} contents, but also the higher antioxidant enzymes activities. Moreover, the expression of several antioxidation- and stress-related genes was also significantly up-regulated in NtRLK5 transgenic plants under drought condition. Taken together, the results suggest that NtRLK5 functions as a positive regulator in drought tolerance.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Up-regulation of TRAF2 inhibits chondrocytes apoptosis in lumbar facet joint osteoarthritis

Tumor necrosis factor receptor-associated factor 2 (TRAF2) has been demonstrated that it plays a significant role in cell death receptor signal transduction. The purpose of this study was to investigate the expression of TRAF2 and its possible role in FJOA. We observed an up-regulation of TRAF2 in FJOA by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) compared to normal tissues. In vitro, we used TNF-α to stimulate Human SW1353 chondrosarcoma cells to establish the chondrocytes injury model. Western blot analysis revealed significant expression of TRAF2 and cleaved caspase-3/8 in SW1353 cells. Co-localization of TRAF2/cleaved caspase-3/8 was detected in the cells injury model by double-labeling immunofluorescent staining. We demonstrated a possible anti-apoptotic effect of TRAF2 in chondrocyte apoptosis in FJOA by knockdown of its expression with siRNA. Moreover, TRAF2 knockdown was demonstrated to enhance TNF-α-induced apoptosis by flow cytometry assay. In conclusion, our results show that the up-regulation of TRAF2 may play an important role in the inhibition of chondrocyte apoptosis of FJOA.

60 APPLIED LIFE SCIENCES↗