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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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O{sub 2} for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via decreased glucose uptake and lipogenic protein expression and increased basal lipolysis. Such an hypoxia-induced decrease in lipogenesis may be an attractive therapeutic target against lipid-associated metabolic diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Crystal structure of cathepsin A, a novel target for the treatment of cardiovascular diseases

Graphical abstract: - Highlights: • The structures of active cathepsin A and the inactive precursor are very similar. • The only major difference is the absence of a 40 residue activation domain. • The termini of the active catalytic core are held together by a disulfide bond. • Compound 1 reacts with the catalytic Ser150, building a tetrahedral intermediate. • Compound 2 is cleaved by the enzyme and a fragment remained bound. - Abstract: The lysosomal serine carboxypeptidase cathepsin A is involved in the breakdown of peptide hormones like endothelin and bradykinin. Recent pharmacological studies with cathepsin A inhibitors in rodents showed a remarkable reduction in cardiac hypertrophy and atrial fibrillation, making cathepsin A a promising target for the treatment of heart failure. Here we describe the crystal structures of activated cathepsin A without inhibitor and with two compounds that mimic the tetrahedral intermediate and the reaction product, respectively. The structure of activated cathepsin A turned out to be very similar to the structure of the inactive precursor. The only difference was the removal of a 40 residue activation domain, partially due to proteolytic removal of the activation peptide, and partially by an order–disorder transition of the peptides flanking the removed activation peptide. The termini of the catalytic core are held together by the Cys253–Cys303 disulfide bond, just before and after the activation domain. One of the compounds we soaked in our crystals reacted covalently with the catalytic Ser150 and formed a tetrahedral intermediate. The other compound got cleaved by the enzyme and a fragment, resembling one of the natural reaction products, was found in the active site. These studies establish cathepsin A as a classical serine proteinase with a well-defined oxyanion hole. The carboxylate group of the cleavage product is bound by a hydrogen-bonding network involving one aspartate and two glutamate side chains. This network can only form if at least half of the carboxylate groups involved are protonated, which explains the acidic pH optimum of the enzyme.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

JAZF1 can regulate the expression of lipid metabolic genes and inhibit lipid accumulation in adipocytes

Highlights: • JAZF1 was significantly upregulated during the differentiation of 3T3-L1 preadipocytes. • JAZF1 overexpression inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes. • JAZF1 overexpression inhibited the expression of SREBP1, ACC, and FAS. • JAZF1 overexpression upregulated the expression of HSL and ATGL. • SREBP1 and JAZF1 could regulate each other in adipocytes. - Abstract: JAZF1 is a newly identified gene with unknown functions. A recent genome-wide association study showed that JAZF1 is associated with type 2 diabetes and is highly expressed in liver and adipose tissue. Studies have demonstrated that JAZF1 is the co-repressor for nuclear orphan receptor TAK1, whereas most nuclear orphan receptor family members are involved in the regulation of lipid metabolism. Therefore, JAZF1 could be closely related to glycolipid metabolism. In this study, JAZF1 was significantly upregulated during the induced differentiation process of 3T3-L1 preadipocytes. The overexpression of JAZF1 inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes and significantly inhibited the expression of SREBPl, ACC, and FAS, which were important in lipid synthesis, while upregulating the expression of key enzyme hormone-sensitive lipase in lipoclasis. Moreover, SREBPl exhibited an inhibitory function on the expression of JAZF1. SREBP1 reversed the inhibitory action on lipid accumulation of JAZF1. SREBP1 and JAZF1 were observed to regulate each other in adipocytes. Therefore, JAZF1 could regulate the expression of particular genes related to lipid metabolism and inhibit lipid accumulation in adipocytes. This result suggests that JAZF1 may be a potential target for the treatment of diseases, such as obesity and lipid metabolism disorders.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

22(R)-hydroxycholesterol and pioglitazone synergistically decrease cholesterol ester via the PPARγ–LXRα–ABCA1 pathway in cholesterosis of the gallbladder

Highlights: • Cholesterosis is a metabolic disease characterized by excessive lipid droplets. • Lipid droplet efflux is mediated by the ABCA1 transporter. • 22(R)-hydroxycholesterol can activate LXRα and up-regulate ABCA1. • Pioglitazone up-regulates ABCA1 in a PPARγ–LXRα–ABCA1-dependent manner. • 22(R)-hydroxycholesterol and pioglitazone synergistically decrease lipid droplets. - Abstract: Cholesterosis is a disease of cholesterol metabolism characterized by the presence of excessive lipid droplets in the cytoplasm. These lipid droplets are mainly composed of cholesterol esters derived from free cholesterol. The removal of excess cholesterol from gallbladder epithelial cells (GBECs) is very important for the maintenance of intracellular cholesterol homeostasis and the preservation of gallbladder function. Several lines of evidence have indicated that the activation of either peroxisome proliferator-activated receptor gamma (PPARγ) or liver X receptor α (LXRα) relates to cholesterol efflux. While pioglitazone can regulate the activation of PPARγ, 22(R)-hydroxycholesterol can activate LXRα and is a metabolic intermediate in the biosynthesis of steroid hormones. However, the effect of 22(R)-hydroxycholesterol in combination with pioglitazone on cholesterosis of the gallbladder is unclear. GBECs were treated with pioglitazone, 22(R)-hydroxycholesterol or PPARγ siRNA followed by Western blot analysis for ATP-binding cassette transporter A1 (ABCA1), PPARγ and LXRα. Cholesterol efflux to apoA-I was determined, and Oil Red O staining was performed to monitor variations in lipid levels in treated GBECs. Our data showed that 22(R)-hydroxycholesterol can modestly up-regulate LXRα while simultaneously increasing ABCA1 by 56%. The combination of 22(R)-hydroxycholesterol and pioglitazone resulted in a 3.64-fold increase in ABCA1 expression and a high rate of cholesterol efflux. Oil Red O staining showed an obvious reduction in the lipid droplets associated with cholesterosis in GBECs. In conclusion, the present findings indicate that the anti-lipid deposition action of 22(R)-hydroxycholesterol combined with pioglitazone involves the activation of the PPARγ–LXRα–ABCA1 pathway, increased ABCA1 expression and the efflux of cholesterol from GBECs. Thus, 22(R)-hydroxycholesterol synergistically combined with pioglitazone to produce a remarkable effect on lipid deposition in cholesterosis GBECs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Bile acids override steatosis in farnesoid X receptor deficient mice in a model of non-alcoholic steatohepatitis

Highlights: • FXR deficiency enhanced MCD diet-induced hepatic fibrosis. • FXR deficiency attenuated MCD diet-induced hepatic steatosis. • FXR deficiency repressed genes involved in fatty acid uptake and triglyceride accumulation. - Abstract: Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases, and the pathogenesis is still not well known. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily and plays an essential role in maintaining bile acid and lipid homeostasis. In this study, we study the role of FXR in the pathogenesis of NFALD. We found that FXR deficient (FXR{sup −/−}) mice fed methionine- and choline-deficient (MCD) diet had higher serum ALT and AST activities and lower hepatic triglyceride levels than wild-type (WT) mice fed MCD diet. Expression of genes involved in inflammation (VCAM-1) and fibrosis (α-SMA) was increased in FXR{sup −/−} mice fed MCD diet (FXR{sup −/−}/MCD) compared to WT mice fed MCD diet (WT/MCD). Although MCD diet significantly induced hepatic fibrosis in terms of liver histology, FXR{sup −/−}/MCD mice showed less degree of hepatic steatosis than WT/MCD mice. Moreover, FXR deficiency synergistically potentiated the elevation effects of MCD diet on serum and hepatic bile acids levels. The super-physiological concentrations of hepatic bile acids in FXR{sup −/−}/MCD mice inhibited the expression of genes involved in fatty acid uptake and triglyceride accumulation, which may be an explanation for less steatosis in FXR{sup −/−}/MCD mice in contrast to WT/MCD mice. These results suggest that hepatic bile acids accumulation could override simple steatosis in hepatic injury during the progression of NAFLD and further emphasize the role of FXR in maintaining hepatic bile acid homeostasis in liver disorders and in hepatic protection.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Sargahydroquinoic acid inhibits TNFα-induced AP-1 and NF-κB signaling in HaCaT cells through PPARα activation

Highlights: • SHQA increases PPARα/γ transactivation and inhibits MMP-2/-9 expression. • SHQA inhibits TNFα-induced AP-1 and MAPK signaling. • SHQA inhibits TNFα-induced p65 translocation and IκBα phosphorylation. • SHQA inhibits TNFα-induced AP-1 and NF-κB signaling via PPARα. - Abstract: Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors and expressed in various cell types in the skin, including keratinocytes, fibroblasts and infiltrating immune cells. Thus, their ligands are targets for the treatment of various skin disorders, such as photo-aging and chronological aging of skin. Intensive studies have revealed that PPARα/γ functions in photo-aging and age-related inflammation by regulating matrix metalloproteinases (MMPs) via activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB). However, the detailed mechanism of PPARα/γ’s role in skin aging has not yet been elucidated. In this study, we confirmed that sargahydroquinoic acid (SHQA) as a PPARα/γ ligand significantly decreased Tumor Necrosis Factor-alpha (TNFα)-induced MMP-2/-9 expression by downregulating TNFα-induced transcription factors, subsequently reducing IκBα degradation and blocking NF-κB p65 nuclear translocation in HaCaT human epidermal keratinocyte cells. Treatment of cells with SHQA and GW6471 (PPARα antagonist) not bisphenol A diglycidyl ether (PPARγ antagonists), reversed the effect on TNFα-induced inflammatory signaling pathway activation. Taken together, our data suggest that SHQA inhibit TNFα-induced MMP-2/-9 expression and age-related inflammation by suppressing AP-1 and NF-κB pathway via PPARα.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Effects of high glucose and advanced glycation end products on the expressions of sclerostin and RANKL as well as apoptosis in osteocyte-like MLO-Y4-A2 cells

In diabetes mellitus (DM), high glucose (HG) and advanced glycation end products (AGEs) are involved in bone quality deterioration. Osteocytes produce sclerostin and receptor activator of nuclear factor-kB ligand (RANKL) and regulate osteoblast and osteoclast function. However, whether HG or AGEs directly affect osteocytes and regulate sclerostin and RANKL production is unknown. Here, we examined the effects of HG, AGE2, and AGE3 on the expression of sclerostin and RANKL and on apoptosis in osteocyte-like MLO-Y4-A2 cells. Treatment of the cells with 22 mM glucose, 100 μg/mL either AGE2 or AGE3 significantly increased the expression of sclerostin protein and mRNA; however, both AGEs, but not glucose, significantly decreased the expression of RANKL protein and mRNA. Moreover, treatment of the cells with HG, AGE2, or AGE3 for 72 h induced significant apoptosis. These detrimental effects of HG, AGE2, and AGE3 on sclerostin and RANKL expressions and on apoptosis were antagonized by pretreatment of the cells with 10{sup −8} M human parathyroid hormone (PTH)-(1–34). Thus, HG and AGEs likely suppress bone formation by increasing sclerostin expression in osteocytes, whereas AGEs suppress bone resorption by decreasing RANKL expression. Together, these processes may cause low bone turnover in DM. In addition, HG and AGEs may cause cortical bone deterioration by inducing osteocyte apoptosis. PTH may effectively treat these pathological processes and improve osteocyte function. - Highlights: • AGEs are involved in bone quality deterioration in diabetes mellitus (DM). • AGEs increased sclerostin as well as apoptosis, and decreased RANKL in osteocytes. • The effects of AGEs on osteocyte function were antagonized by human PTH-(1–34). • AGEs may cause low bone turnover and cortical porosity in DM. • PTH may be effective in bone quality deterioration by improving osteocyte function.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Large-scale proteome analysis of abscisic acid and ABSCISIC ACID INSENSITIVE3-dependent proteins related to desiccation tolerance in Physcomitrella patens

Desiccation tolerance is an ancestral feature of land plants and is still retained in non-vascular plants such as bryophytes and some vascular plants. However, except for seeds and spores, this trait is absent in vegetative tissues of vascular plants. Although many studies have focused on understanding the molecular basis underlying desiccation tolerance using transcriptome and proteome approaches, the critical molecular differences between desiccation tolerant plants and non-desiccation plants are still not clear. The moss Physcomitrella patens cannot survive rapid desiccation under laboratory conditions, but if cells of the protonemata are treated by the phytohormone abscisic acid (ABA) prior to desiccation, it can survive 24 h exposure to desiccation and regrow after rehydration. The desiccation tolerance induced by ABA (AiDT) is specific to this hormone, but also depends on a plant transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3). Here we report the comparative proteomic analysis of AiDT between wild type and ABI3 deleted mutant (Δabi3) of P. patens using iTRAQ (Isobaric Tags for Relative and Absolute Quantification). From a total of 1980 unique proteins that we identified, only 16 proteins are significantly altered in Δabi3 compared to wild type after desiccation following ABA treatment. Among this group, three of the four proteins that were severely affected in Δabi3 tissue were Arabidopsis orthologous genes, which were expressed in maturing seeds under the regulation of ABI3. These included a Group 1 late embryogenesis abundant (LEA) protein, a short-chain dehydrogenase, and a desiccation-related protein. Our results suggest that at least three of these proteins expressed in desiccation tolerant cells of both Arabidopsis and the moss are very likely to play important roles in acquisition of desiccation tolerance in land plants. Furthermore, our results suggest that the regulatory machinery of ABA- and ABI3-mediated gene expression for desiccation tolerance might have evolved in ancestral land plants before the separation of bryophytes and vascular plants. - Highlights: • Large-scale proteomics highlighted proteins related to plant desiccation tolerance. • The proteins were regulated by both the phytohormone ABA and ABI3. • The proteins accumulated in desiccation tolerant cells of both Arabidopsis and moss. • Evolutionary origin of regulatory machinery for desiccation tolerance is proposed.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

The role of receptor topology in the vitamin D3 uptake and Ca{sup 2+} response systems

The steroid hormone, vitamin D{sub 3}, regulates gene transcription via at least two receptors and initiates putative rapid response systems at the plasma membrane. The vitamin D receptor (VDR) binds vitamin D{sub 3} and a second receptor, importin-4, imports the VDR-vitamin D{sub 3} complex into the nucleus via nuclear pores. Here we present evidence that the Homo sapiens VDR homodimer contains two transmembrane (TM) helices ({sup 327}E – D{sup 342}), two TM “half-helix” ({sup 264}K − N{sup 276}), one or more large channels, and 16 cholesterol binding (CRAC/CARC) domains. The importin-4 monomer exhibits 3 pore-lining regions ({sup 226}E – L{sup 251}; {sup 768}V – G{sup 783}; {sup 876}S – A{sup 891}) and 16 CRAC/CARC domains. The MEMSAT algorithm indicates that VDR and importin-4 may not be restricted to cytoplasm and nucleus. VDR homodimer TM helix-topology predicts insertion into the plasma membrane, with two 84 residue C-terminal regions being extracellular. Similarly, MEMSAT predicts importin-4 insertion into the plasma membrane with 226 residue extracellular N-terminal regions and 96 residue C-terminal extracellular loops; with the pore-lining regions contributing gated Ca{sup 2+} channels. The PoreWalker algorithm indicates that, of the 427 residues in each VDR monomer, 91 line the largest channel, including two vitamin D{sub 3} binding sites and residues from both the TM helix and “half-helix”. Cholesterol-binding domains also extend into the channel within the ligand binding region. Programmed changes in bound cholesterol may regulate both membrane Ca{sup 2+} response systems and vitamin D{sub 3} uptake as well as receptor internalization by the endomembrane system culminating in uptake of the vitamin D{sub 3}-VDR-importin-4 complex into the nucleus.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

The trophic effect of ouabain on retinal ganglion cells is mediated by IL-1β and TNF-α

Ouabain is a steroid hormone that binds to the enzyme Na{sup +}, K{sup +} – ATPase and stimulates different intracellular pathways controlling growth, proliferation and cell survival. IL-1β and TNF-α are pleiotropic molecules, conventionally regarded as pro-inflammatory cytokines with well-known effects in the immune system. In addition, IL-1β and TNF-α also play important roles in the nervous system including neuroprotective effects. Previous data from our group showed that ouabain treatment is able to induce an increase in retinal ganglion cell survival kept in mixed retinal cell cultures. The aim of this work was to investigate if IL-1β and TNF-α could be mediating the trophic effect of ouabain on retinal ganglion cells. Our results show that the trophic effect of ouabain on retinal ganglion cell was inhibited by either anti-IL-1β or anti-TNF-α antibodies. In agreement, IL-1β or TNF-α increased the retinal ganglion cells survival in a dose-dependent manner. Accordingly, ouabain treatment induces a temporal release of TNF-α and IL-1β from retinal cell cultures. Interestingly, TNF-α and IL-1β regulate each other intracellular levels. Our results suggest that ouabain treatment triggers the activation of TNF-α and IL-1β signaling pathways leading to an increase in retinal ganglion cell survival. - Highlights: • Pro-inflammatory cytokines regulates the ouabain effect on RGC survival. • Ouabain treatment modulates the intracellular levels of TNF-α and IL-1β. • Ouabain induces the release of TNF-α and IL-1β in retinal cell cultures.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Chloroplast protein PLGG1 is involved in abscisic acid-regulated lateral root development and stomatal movement in Arabidopsis

Highlights: • PLGG1, a chloroplast protein, regulates lateral root growth under ABA treatment. • PLGG1 is also involved in ABA-inhibited seed germination, ABA-mediated stomatal movement, and drought tolerance. • The deficiency of PLGG1 alters the expression of a set of ABA-responsive genes. The plant hormone abscisic acid (ABA) plays a crucial role in root architecture; however, the molecular mechanism of ABA-regulated lateral root (LR) growth is not well known. We screened an Arabidopsis thaliana mutant with LR growth that was sensitive to ABA from a T-DNA insertion mutant library, which was an allelic mutant of plgg1-1, termed plgg1-2. PLGG1 encodes a chloroplast protein that transports plastidic glycolate and glycerate. The length and number of LRs at the root-hypocotyl junction of plgg1-1 and plgg1-2 were significantly impaired under exogenous ABA treatment, and the transgenic plant complementary lines of plgg1-2 restored LR growth in response to ABA. In addition, we found that PLGG1 is involved in other major ABA responses, including ABA-inhibited seed germination, ABA-mediated stomatal movement, and drought tolerance. These findings open new perspectives on elucidating the mechanism of ABA response, and provide clues for analysing the functions of chloroplast proteins in regulating root growth.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

TRIP6 promotes cell proliferation in hepatocellular carcinoma via suppression of FOXO3a

Highlights: • TRIP6 was upregulated in HCC cells and tissue. • TRIP6 expression was correlated with HCC patients’ clinical stage and poor survival. • TRIP6 enhanced the proliferation of HCC cells via suppression of FOXO3a. • TRIP6 may serve as a novel prognostic biomarker and therapeutic target in HCC. Thyroid hormone receptor-interacting protein 6 (TRIP6), a member of LIM family, acts as an adaptor protein and is overexpressed in several tumor types. However, the clinical significance and biological role of TRIP6 in HCC remains unknown. In our study, we found that TRIP6 was markedly overexpressed in HCC cells and clinical specimens compared with normal hepatocytes and adjacent non-tumor tissues. Immunohistochemical and statistical analysis showed that the expression of TRIP6 significantly correlated with HCC patients' clinical stage and poor survival. Moreover, we demonstrated that overexpressing TRIP6 significantly enhanced, whereas silencing endogenous TRIP6 inhibited, the proliferation and the anchorage-independent growth ability of HCC cells. In addition, overexpression of TRIP6 accelerated, while inhibition of TRIP6 retarded, G1-S phase transition in HCC cells. We further found that overexpression of TRIP6 increased the activation of AKT and suppressed the transactivity of FOXO3a. Meanwhile, overexpression of TRIP6 leaded to the decreased expression of cyclin-dependent kinase inhibitors p21{sup Cip1} and p27{sup Kip1} and increased expression of the cell cycle regulator cyclin D1. While silencing TRIP6 triggered the opposite effect. Taken together, these findings showed that TRIP6 plays an important role in promoting HCC cells proliferation and may serve as a novel prognostic biomarker and therapeutic target in HCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Extracellular vesicle-encapsulated microRNA-761 enhances pazopanib resistance in synovial sarcoma

Highlights: • MiR-761 in EVs is abundant in pazopanib-resistant synovial sarcoma cells. • EVs derived from pazopanib-resistant cells spread resistance to recipient cells. • Increased miR-761 abundance in EVs is associated with pazopanib resistance. The development of drug resistance in tumor cells leads to relapse and distant metastasis. Secreted microRNAs (miRNAs) enclosed in extracellular vesicles (EVs) can act as intercellular messengers. The objective of our study was to elucidate the role of secreted miRNAs to better understand the regulatory network underlying pazopanib-resistance in synovial sarcoma cells. We performed a comprehensive analysis of secreted miRNA abundance in pazopanib treated/untreated synovial sarcoma cells from four different cell lines (SYO-1, HS-SYII, 1273/99, and YaFuSS) using microarray technology, and discovered miR-761 in EVs as a potential biomarker of pazopanib-resistance in synovial sarcoma. Furthermore, we showed that miR-761 putatively targeted three proteins, thyroid hormone receptor interactor 6 (TRIP6), lamin A/C (LMNA), and NAD-dependent protein deacetylase sirtuin-3 (SIRT3). Knockdown of any of these proteins was shown in previous studies to confer increased resistance to chemotherapeutic agents. Our findings provide new insight into the potential role of miR-761, an EV-secreted miRNA from synovial sarcoma cells, making it a potential candidate for use in sarcoma therapy in the future.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Chetomin induces apoptosis in human triple-negative breast cancer cells by promoting calcium overload and mitochondrial dysfunction

Highlights: • Chetomin induced apoptosis in human triple-negative breast cancer cells. • Chetomin promoted ER stress and cellular calcium overload. • Chetomin mediated mitochondrial dysfunction triggered intrinsic pathway of cell death. • Chetomin inhibited PI3K/mTOR pathways. Human triple-negative breast cancer (TNBC) is poorly diagnosed and unresponsive to conventional hormone therapy. Chetomin (CHET), a fungal metabolite synthesized by Chaetomium cochliodes, has been reported as a promising anticancer and antiangiogenic agent but the complete molecular mechanism of its anticancer potential remains to be elucidated. In our study, we explored the anti-neoplastic action of CHET on TNBC cells. Cytotoxicity studies were performed in human TNBC cells viz. MDA-MB-231 and MDA-MB-468 cells by Sulforhodamine B assay. It exhibited antiproliferative response and induced apoptosis in both the cell types. Cell cycle analysis revealed that it increases the sub G0/G1 phase cell population. Modulation of mitochondrial membrane potential, activation of caspase 3/7 and a remarkable increase in the expression of cleaved PARP and increased chromatin condensation was observed after CHET treatment in MDA-MB-231 and MDA-MB-468 cells. Additionally, an elevated level of intracellular Ca{sup 2+} played an important role in CHET mediated cell death response. Calcium overload in mitochondria led to release of cytochrome c which in turn triggered caspase-3 mediated cell death. Inhibition of calcium signalling using BAPTA-AM reduced apoptosis confirming the involvement of calcium signalling in CHET induced cell death. Chetomin also inhibited PI3K/mTOR cell survival pathway in human TNBC cells. The overall findings suggest that Chetomin inhibited the growth of human TNBC cells by caspase-dependent apoptosis and modulation of PI3K/mTOR signalling and could be used as a novel chemotherapeutic agent for the treatment of human TNBC in future.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

An update on oxysterol biochemistry: New discoveries in lipidomics

Highlights: • Oxysterols can regulate both the innate and adaptive immune systems. • Oxysterols can be tumour suppressors and on cometabolites. • Oxysterols can inhibit or activate the Hh signalling pathway. Oxysterols are oxidised derivatives of cholesterol or its precursors post lanosterol. They are intermediates in the biosynthesis of bile acids, steroid hormones and 1,25-dihydroxyvitamin D{sub 3.} Although often considered as metabolic intermediates there is a growing body of evidence that many oxysterols are bioactive and their absence or excess may be part of the cause of a disease phenotype. Using global lipidomics approaches oxysterols are underrepresented encouraging the development of targeted approaches. In this article, we discuss recent discoveries important in oxysterol biochemistry and some of the targeted lipidomic approaches used to make these discoveries.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Development of a functional thyroid model based on an organoid culture system

Highlights: • We developed a culture system for murine thyroid organoids. • TSH stimulated thyroid organoid formation and growth. • TSH-responsive thyroid organoids formed functional thyroid-like tissue in vivo. • NRAS{sup Q61R}-positive, p53{sup −/−} organoids gave rise to thyroid cancer. The low turnover rate of thyroid follicular cells and the lack of a long-term thyroid cell culture system have hampered studies of thyroid carcinogenesis. We have now established a thyroid organoid culture system that supports thyroid cell proliferation in vitro. The established mouse thyroid organoids performed thyroid functions including thyroglobulin synthesis, iodide uptake, and the production and release of thyroid hormone. Furthermore, transplantation of the organoids into recipient mice resulted in the formation of normal thyroid–like tissue capable of iodide uptake and thyroglobulin production in vivo. Finally, forced expression of oncogenic NRAS (NRAS{sup Q61R}) in thyroid organoids established from p53 knockout mice and transplantation of the manipulated organoids into mouse recipients generated a model of poorly differentiated thyroid cancer. Our findings suggest that this newly developed thyroid organoid culture system is a potential research tool for the study of thyroid physiology and pathology including thyroid cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

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↗