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DOE OSTI2017

MiR-150 deficiency ameliorated hepatosteatosis and insulin resistance in nonalcoholic fatty liver disease via targeting CASP8 and FADD-like apoptosis regulator

The prevalence of Non-alcoholic fatty liver diseases (NAFLD) increased rapidly in the world. However, the pathogenesis of is still unclear. Hepatic steatosis and insulin resistance are considered to be central to the pathophysiology of NAFLD. MicroRNAs are short non-coding RNAs and has been reported to be involved in pathogenesis of NAFLD and related metabolic diseases. Here, we investigated the mechanisms by which miR-150 regulate hepatic steatosis and insulin resistance in high fat diet (HFD) induced NAFLD model. The expression of miR-150 was up-regulated dramatically in both human NAFLD patients and HFD mice model, as well as in hepatocytes treated with oleic acid. miR-150 deficiency ameliorated the hepatic steatosis and insulin resistance significantly in NAFLD mice. miR-150 deficiency decreased the expression of genes related to fatty acid uptake, synthesis and gluconeogenesis, while increased the expression of genes related to fatty acid β-oxidation. Further, we identified that CFLAR is a direct downstream target of miR-150. Overexpression of miR-150 reduced both the mRNA and protein levels of CFLAR in vitro. And overexpression of miR-150 significantly inhibited the luciferase activity of CFLAR 3′-UTR, while the effect of miR-150 was blocked when the binding site of miR-150 within the CFLAR 3′-UTR was mutated. We also found that miR-150 deficiency decreased the expression of p-Jnk1 and p-Ask1, while the effect of miR-150 on steatosis and insulin signaling was blocked by CFLAR overexpression. In conclusion, our data indicated that miR-150 potentially contributes to the hepatic steatosis and insulin resistance in NAFLD. miR-150/CFLAR pathway may be a new therapeutic strategy against NAFLD.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Effects of oral and subcutaneous administration of HSP60 on myeloid-derived suppressor cells and atherosclerosis in ApoE−/− mice

HSP60 has been proved to be closely related to atherosclerosis due to its antigenicity. To determine this antigenicity effect, the ApoE−/− mice were fed with western-type diet and HSP60 was administrated orally or subcutaneously (SC) for potential vaccine against atherosclerosis. Here, we observed the ApoE−/− mice with oral HSP60 administration group showed a significant reduction in plaque size at the aortic root; accompanied by increased MSDCs (CD11b{sup +}Gr1{sup +}) in peripheral blood and spleen which was mostly composed of M-MDSCs (CD11b{sup +}LY6G{sup −}LY6C{sup high}), and increased plasma IL-10 and splenic Foxp3, Arg1, iNOS mRNA as well as decreased plasma IFN-γ and splenic T-bet mRNA compared to control group. Surprisingly, ApoE−/− mice with subcutaneous HSP60 administration group showed contrary results and their MDSCs were mostly composed of G-MDSCs (CD11b{sup +}LY6G{sup +}LY6C{sup low}). As expected, both PBS-oral and PBS-SC groups showed no significant effects on both the immune response and atherosclerotic plaque formation. In contrast, subcutaneous administration of HSP60 causes the opposite response. Thus, we propose the proper method for administering HSP60 as a new immunologic agent for prevention and treatment of atherosclerosis.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Effect of eldecalcitol on articular cartilage through the regulation of transcription factor Erg in a murine model of knee osteoarthritis

Highlights: • Eldecalcitol slowed the progression of experimental osteoarthritis in mice. • This effect was observed at 4 weeks, but not at 12 weeks. • Effects were associated with increased Erg levels. • Eldecalcitol-treated cultured chondrocytes also upregulated Erg mRNA. Clinical studies have reported an association between low blood levels of 25-hydroxyvitamin D and the progression of osteoarthritis (OA), but the mechanism and effects of vitamin D signaling on articular chondrocytes and cartilage remains unclear. The purpose of this study was to investigate the effects of vitamin D on articular cartilage degeneration using eldecalcitol (ED-71), which is an active vitamin D{sub 3} analog. Eight-week old male C57BL/6NCrSlc mice were subjected to experimental surgery to induce OA and local treatments with 10 μL ED-71 (0.5 μg/mL) were administered weekly. Four and 12 weeks after surgery, joints were evaluated using histological scoring systems. In addition, gene expression was analyzed in chondrocytes that were isolated from wildtype neonatal mice, cultured, and treated with ED-71 (10{sup −8} M). Joints treated with ED-71 demonstrated slowed progression of OA at 4 weeks after surgery, but few effects were observed at 12 weeks after surgery. Ets-related gene (Erg) expression was upregulated in OA articular cartilage, and further increased by ED-71 treatment. In primary chondrocytes cultured with ED-71, the gene expression of Erg and lubricin/proteoglycan 4 significantly increased, as compared to that of cells cultured without ED-71. Local treatment with ED-71 reduced degenerative changes to the articular cartilage during the early phase of experimental OA. Regulation of Erg by ED-71 in articular cartilage could confer resistance to early osteoarthritic changes.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Profiling neuron-autonomous lncRNA changes upon ischemia/reperfusion injury

Highlights: • Tnxa-ps1 is up regulated after OGD/R. • Tnxa-ps1 knockdown promoted neuronal survival after OGD/R. • Tnxa-ps1 up-regulation is associated with the four mRNA changes after OGD/R. Extensive changes of neuronal transcriptome occur post ischemic stroke and during the following reperfusion. Although numerous studies focused on transcriptome changes of mRNAs associated with ischemic stroke, little is known about whether and how long non-coding RNAs (lncRNAs), which play critical roles in cellular homeostasis, are involved in this process. In this study, we performed high throughput screening to analyze expression changes of lncRNAs in primarily cultured hippocampal neurons under an oxygen-glucose deprivation/reperfusion (OGD/R) condition at 0 h, 6 h, 12 h, and 18 h, respectively. Knock down of one validated lncRNAs (Tnxa-ps1) promoted neuronal survival by inhibiting apoptosis. Coding non-coding co-expression network analysis revealed that the expression of Tnxa-ps1 was highly correlated with changes of a particular group of genes, many of which are associated with neural protection. Finally, we showed that down-regulation of Tnxa-ps1 reversed the expression changes of four mRNAs post OGD/R, revealing a regulatory effect between Tnxa-ps1 and selected genes. Together, our data revealed possible participation of lncRNAs in the pathophysiology of OGD/R and thereby provided new insights into the studies of potential therapeutic targets for ischemic stroke.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Characterization of human AlkB homolog 1 produced in mammalian cells and demonstration of mitochondrial dysfunction in ALKBH1-deficient cells

Highlights: • Mammalian produced ALKBH1 (ALKBH1{sub 293}) possesses m{sup 6}A demethylase and AP lyase activity. • ALKBH1{sub 293} forms an adduct with the 5′-product of the AP lyase reaction. • ALKBH1 localizes to the mitochondria in MSU1.1 and HEK293 cells. • ALKBH1-deficient cells exhibit mitochondrial dysfunction. Alkbh1 is a mammalian homolog of the Escherichia coli DNA repair enzyme AlkB, an Fe(II) and 2-oxoglutarate dependent dioxygenase that removes alkyl lesions from DNA bases. The human homolog ALKBH1 has been associated with six different enzymatic activities including DNA, mRNA, or tRNA hydroxylation, cleavage at abasic (AP) sites in DNA, as well as demethylation of histones. The reported cellular roles of this protein reflect the diverse enzymatic activities and include direct DNA repair, tRNA modification, and histone modification. We demonstrate that ALKBH1 produced in mammalian cells (ALKBH1{sub 293}) is similar to the protein produced in bacteria (ALKBH1{sub Ec}) with regard to its m{sup 6}A demethylase and AP lyase activities. In addition, we find that ALKBH1{sub 293} forms a covalent adduct with the 5′ product of the lyase product in a manner analogous to ALKBH1{sub Ec}. Localization and subcellular fractionation studies with the endogenous protein in two human cell strains confirm that ALKBH1 is primarily in the mitochondria. Two strains of CRISPR/Cas9-created ALKBH1-deficient HEK293 cells showed increases in mtDNA copy number and mitochondrial dysfunction as revealed by growth measurements and citrate synthase activity assays.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Sirtuin 7 is involved in the consolidation of fear memory in mice

Highlights: • SIRT7 is involved in many biological processes. • The functional role of SIRT7 in the brain is unknown. • We demonstrate that SIRT7 is expressed in the amygdala and hippocampus. • Fear memory consolidation was impaired in Sirt7 knockout mice. • SIRT7 is involved in the consolidation of fear memory. Sirtuin 7 (SIRT7) is an NAD{sup +}-dependent deacetylase/deacylase, and is involved in a variety of biological processes relevant to the transcription of rRNA, the DNA damage response, tumorigenesis, and metabolism. SIRT7 mRNA is expressed ubiquitously, including in the brain, but there is no detailed information about the anatomical distribution and functional role of SIRT7 in the brain. Here, we demonstrated that SIRT7 is widely expressed in the mouse brain, including in the cortex, striatum, thalamus, hippocampus, and amygdala. Behavioral examinations revealed that Sirt7 knockout (KO) and control mice showed similar levels of freezing behavior immediately after a fear response, but a significant decrease of freezing behavior at 24 h after fear conditioning was observed in Sirt7 KO mice. Histological analysis revealed that there is no apparent structural abnormality of the amygdala and hippocampus, which are regions involved in fear memory consolidation, in Sirt7 KO mice. Our results indicate that SIRT7 is involved in the consolidation of fear memory.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

SETDB1-mediated FosB regulation via ERK2 is associated with an increase in cell invasiveness during anticancer drug treatment of A549 human lung cancer cells

Highlights: • SETDB1 directly regulates FosB expression during doxorubicin treatment. • PD98059 restores the expression of SETDB1 and FosB by doxorubicin treatment. • SETDB1-mediated FosB regulation through ERK2 is responsible for cell survival. • Ectopic FosB expression increases transforming and migration activity. • ERK2-SETDB1-FosB pathway has an anti-therapeutic regulatory mechanism during anticancer drug treatment. We have determined a functional link to the inverse expression of SETDB1 and FosB following anticancer drug treatment. Doxorubicin treatment caused decreased SETDB1 expression and FosB overexpression both at the mRNA and protein levels. The decreased HMTase activity of SETDB1 coincided with altered occupancy across the promoter region of the FosB gene. SETDB1 overexpression decreased the luciferase reporter activity containing the FosB promoter region, but siSETDB1 increased the luciferase reporter activity, suggesting that SETDB1 directly and negatively regulated FosB expression. In addition, MEK inhibitor (PD98059) blocked the SETDB1 regulation of the FosB promoter activity via ERK2 activation during doxorubicin treatment. A microscopic analysis reveals that FosB expression was observed in living cells in spite of doxorubicin treatment. Ectopic FosB/ΔFosB expression increased the number of colonies and the migration of A549 cells compared to that in control. These results suggest that the ERK2-SETDB1-FosB signaling pathway might have an anti-therapeutic regulatory mechanism that increases the transformation and migration activity of cancer cells during anticancer drug treatment.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Salvianolic acid B inhibits myofibroblast transdifferentiation in experimental pulmonary fibrosis via the up-regulation of Nrf2

Highlights: • SalB inhibits TGF-β1-induced myofibroblast transdifferentiation in MRC-5 cells. • SalB ameliorates bleomycin-induced pulmonary fibrosis in rats. • SalB attenuates oxidative stress during experimental pulmonary fibrogenesis. • Nrf2 protein is absent in IPF fibroblasts and fibroblastic foci lesions. • SalB up-regulates the expression of Nrf2 in fibrotic fibroblasts in vitro and vivo. Salvianolic acid B (SalB) is one of the most bioactive components extracted from Salvia miltiorrhiza, and its antioxidant capacity corresponds with its protective effects against cell injury from oxidative stress. The aim of the present study was to evaluate the effect of SalB on experimental pulmonary fibrosis and its ability to ameliorate the oxidative/antioxidative imbalance during fibrosis pathogenesis. The anti-fibrotic activity of SalB was first confirmed in Transforming growth factor β1(TGF-β1)-stimulated MRC-5 cells. The protection of SalB against oxidative stress during fibrogenesis in vitro was verified by detecting ROS production, the levels of glutathione (GSH) and malondialdehyde (MDA). The Western blot and PCR results indicated that SalB could up-regulate nuclear factor erythroid-derived 2-like 2 (Nrf2) at both the protein and mRNA levels and induce Nrf2 nuclear translocation in vitro, which may be the mechanism underlying the anti-fibrotic capacity of SalB. Furthermore, the anti-fibrotic and antioxidant capacities of SalB in vivo were confirmed in rats with BLM-induced pulmonary fibrosis. The immunohistochemistry results showed that Nrf2 was absent in fibroblastic foci (FF) areas, while the SalB treatment could increase the expression of Nrf2 in lung tissues, especially in FF areas.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

The Pleckstrin homology like domain family member, TDAG51, is temporally regulated during skeletal muscle regeneration

Highlights: • TDAG51 expression is low but detectable in undamaged skeletal muscle. • Muscle expression of TDAG51 increases significantly in response to damage and insulin-like growth factor 1 (IGF-1). • Mice lacking TDAG51 display reduced functional capacity and a delay in the early regenerative phases of muscle repair. • Despite early delays in regeneration, TDAG51null mice can compensate and normalize muscle repair by 10 days post injury. The capacity for skeletal muscle to repair from daily insults as well as larger injuries is a vital component to maintaining muscle health over our lifetime. Given the importance of skeletal muscle for our physical and metabolic well-being, identifying novel factors mediating the growth and repair of skeletal muscle will thus build our foundational knowledge and help lead to potential therapeutic avenues for muscle wasting disorders. To that end, we investigated the expression of T-cell death associated gene 51 (TDAG51) during skeletal muscle repair and studied the response of TDAG51 deficient (TDAG51{sup -/-}) mice to chemically-induced muscle damage. TDAG51 mRNA and protein expression within uninjured skeletal muscle is almost undetectable but, in response to chemically-induced muscle damage, protein levels increase by 5 days post-injury and remain elevated for up to 10 days of regeneration. To determine the impact of TDAG51 deletion on skeletal muscle form and function, we compared adult male TDAG51{sup -/-} mice with age-matched wild-type (WT) mice. Body and muscle mass were not different between the two groups, however, in situ muscle testing demonstrated a significant reduction in force production both before and after fatiguing contractions in TDAG51{sup -/-} mice. During the early phases of the regenerative process (5 days post-injury), TDAG51{sup -/-} muscles display a significantly larger area of degenerating muscle tissue concomitant with significantly less regenerating area compared to WT (as demonstrated by embryonic myosin heavy chain expression). Despite these early deficits in regeneration, TDAG51{sup -/-} muscles displayed no morphological deficits by 10 days post injury compared to WT mice. Taken together, the data presented herein demonstrate TDAG51 expression to be upregulated in damaged skeletal muscle and its absence attenuates the early phases of muscle regeneration.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Hsa{sub c}irc{sub 0}009910 promotes carcinogenesis by promoting the expression of miR-449a target IL6R in osteosarcoma

Highlights: • Hsa{sub c}irc{sub 0}009910 plays oncogenic role in osteosarcoma cells. • Circ{sub 0}009910 acted as a sponge of miR-449a. • Inhibition of miR-449a impairs the tumor suppressor role of circ{sub 0}009910 silencing. • IL6R was a functional target of miR-449a. • JAK1/STAT3 signaling involves in circ{sub 0}009910/miR-449a/IL6R related tumorigenesis. Circular RNAs (circRNAs) have recently shown capabilities as gene regulators in mammals. Some of them interact with microRNAs (miRNAs) and function as sponges to affect related miRNAs' activities. In this study, the molecular function of circRNA{sub 0}009910 and its potential downstream miRNA targets were explored. The expression levels of hsa{sub c}irc{sub 0}009910 were found to be overexpressed in osteosarcoma (OS) cells. Knockdown of circ{sub 0}009910 induced cell proliferation inhibition, cell cycle arrest, and apoptosis in OS cells. The target miRNA was predicted to be miR-449a, whose expression was downregulated in OS cells. Inhibition of miR-449a abolished the effect of circ{sub 0}009910 knockdown on cell growth and apoptosis. The expression of miR-449a were found to be negatively correlated with that of circ{sub 0}009910 in OS tissues. Direct interaction of circ{sub 0}009910 and miR-449a was confirmed through dual-luciferase assays. Moreover, IL6R was predicted as a potential target of miR-449a. Overexpression of miR-449a decreased the mRNA and protein levels of IL6R. Restoration of IL6R impaired the miR-449a induced inhibition of cell proliferation, cell cycle arrest, and apoptosis. The mRNA expression of IL6R was inversely correlated with miR-449a in OS tissues. In addition, JAK1/STAT3 signaling pathway was regulated by circ{sub 0}009910/miR-449a/IL6R axis. Taken together, we suggested that circ{sub 0}009910 acted as a sponge of miR-449a and upregulated miR-449a functional target IL6R, thereby contributed to carcinogenesis of OS.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Upregulation of eIF6 inhibits cardiac hypertrophy induced by phenylephrine

Cardiac hypertrophy is determined by an increase of cell size in cardiomyocytes (CMCs). Among the cellular processes regulating the growth of cell size, the increase of protein synthesis rate represents a critical event. Most of translational factors promoting protein synthesis stimulate cardiac hypertrophy. In contrast, activity of translational repressor factors, in cardiac hypertrophy, is not fully determined yet. Here we report the effect of a translational modulator, eIF6/p27{sup BBP} in the hypertrophy of neonatal rat CMCs. The increase of eIF6 levels surprisingly prevent the growth of cell size induced by phenylephrine, through a block of protein synthesis without affecting skeletal rearrangement and ANF mRNA expression. Thus, this work uncovers a new translational cardiac regulator independent by other well-known factors such as mTOR signalling or eIF2β.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

SENP1 attenuates the liver fibrosis through down-regulating the expression of SMAD2

To investigate whether SENP1 could play a regulating role in the liver fibrosis process, the Sprague-Dawley (SD) rats were used to establish the liver fibrosis rat models by intraperitoneally injecting with 1 ml/kg of 10% CCl{sub 4}, while the control normal rats were injected with olive oil. Then confirmation experiments to verify the successful establishment of these models were conducted by detecting the cellular and lobular architecture, and liver function indexes using hematoxylin-eosin staining, Masson's trichrome staining and microplate method, respectively. In addition, the expression levels of fibrosis markers including collagen I, collagen III, α-SMA and TGF-β1 were inspected using quantitative real-time PCR (qRT-PCR), as well as SMAD2. Subsequently, the relative mRNA and protein level of SENP1 was also determined via qRT-PCR and western blot analysis. Next, the HSC-T6 cells of SENP1 knock-down were constructed and used to test the relative protein expression levels of α-SMA and SMAD2 in these cells. The results of hematoxylin-eosin staining, Masson's trichrome staining and microplate method turned out that the rat liver fibrosis models were constructed successfully, which was further confirmed by the increased expression of collagen I, collagen III, α-SMA and TGF-β1 in mRNA and protein level, as well as SMAD2. Then the expression of SENP1 was overexpressed in the rat liver fibrosis models induced by CCl{sub 4} and the TGF-β1 treatment could increase the protein expression level of collagen I, collagen III and α-SMA. Lastly, the SENP1 knockdown HSC-T6 cells were successfully constructed, while the silence of SENP1 down-regulated the protein expression of α-SMA and SMAD2. In conclusion, this study provided a new regulation mechanism about the liver fibrosis process.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Monoterpenoid perillyl alcohol impairs metabolic flexibility of Candida albicans by inhibiting glyoxylate cycle

Highlights: • PA is efficient inhibitor of glyoxylate cycle in Candida albicans which is absent in humans. • PA has negligible hemolytic activity making it viable drug candidate. • PA showed enhanced survival of C. albicans in nematode model, C. elegans demonstrating its in-vivo efficacy. The metabolic pathway such as glyoxylate cycle (GC) enables Candida albicans, to survive under glucose deficient conditions prevalent in the hostile niche. Thus its key enzymes (Isocitrate lyase; ICL and malate synthase; MLS) represent attractive targets against C. albicans. We have previously reported the antifungal potential of a natural monoterpenoid perillyl alcohol (PA). The present study uncovers additional role of PA as a potent GC inhibitor. We explored that PA phenocopied ICL1 deletion mutant and were hypersensitive under low carbon utilizing conditions. The effect of PA on GC was substantiated by molecular docking analyses, which reveals the in-silico binding affinity of PA with ICL and MLS and explored that PA binds to the active sites of both proteins with better binding energy in comparison to their known inhibitors 3-nitropropionate and bromopyruvate respectively. Enzyme kinetics by Lineweaver-Burk plot unravels that PA inhibits ICL and MLS enzymes in competitive and non-competitive manner respectively. Moreover, semi-quantitative RT-PCR indicated that PA inhibits ICL1 and MLS1 mRNA expressions. Lastly, we demonstrated the antifungal efficacy of PA by enhanced survival of Caenorhabditis elegans model and less hemolytic activity (10.6%) on human blood cells. Further studies are warranted for PA to be considered as viable drug candidate.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Transcriptional regulation of acetoacetyl-CoA synthetase by Sp1 in neuroblastoma cells

Highlights: • The core promoter of AACS is located in a region with 110 bps upstream from the TSS. • Sp1 interacts with an Sp1 binding site in the promoter region of AACS. • Overexpression of Sp1 upregulates AACS mRNA levels. • Knockdown of AACS results in downregulation of HDAC9. Acetoacetyl-CoA synthetase (AACS) is the enzyme responsible for cholesterol and fatty acid synthesis in the cytosol. We have previously shown that AACS has an important role in normal neuronal development and that knockdown of SREBP-2, which orchestrates cholesterol synthesis, resulted in the downregulation of AACS mRNA levels. In this study, we investigated the transcriptional mechanism of AACS in Neuro-2a, neuroblastoma cells. Luciferase assay showed that the minimal core promoter of the mouse AACS gene is located in a region with 110 bps upstream from the transcription start site. Mutagenesis studies showed that the Sp1 binding site was crucial for AACS promoter activity. ChIP assay and DNA affinity precipitation assay showed that Sp1 binds to the Sp1 binding site on the promoter region of AACS. Moreover, overexpression of Sp1 increased AACS mRNA levels. Knockdown of AACS resulted in a decrease in histone deacetylase 9, associated with gene silencing. These results suggest that Sp1 regulates gene expression of AACS in Neuro-2a cells and ketone body utilization affects the balance of histone acetylation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Interaction of Alpha-synuclein with Cytogaligin, a protein encoded by the proapoptotic gene GALIG

Highlights: • Cytogaligin interacts with αSynuclein, a major protein of Parkinson's disease. • Cytogaligin is an intracellular protein also secreted in the extracellular medium. • Cytogaligin-αSynuclein interaction decreases αSynuclein homodimerization. GALIG, an internal gene to the human galectin-3 gene, encodes two distinct proteins, Mitogaligin and Cytogaligin through translation of a unique mRNA in two overlapping alternative reading frames. When overexpressed GALIG induces apoptosis. In cultured cells, Mitogaligin destabilizes mitochondria membranes through interaction with cardiolipin. Little is known regarding the role of Cytogaligin. This protein displays multiple subcellular localizations; cytosol, nucleus, and mitochondria. We illustrate here that Cytogaligin is also secreted in the extracellular medium. Cytogaligin is shown to interact with α-Synuclein, the major component of Lewy bodies in Parkinson's disease. Overexpression of Cytogaligin reduces α-Synuclein dimerization raising a possible role in the evolution of α-Synuclein aggregation, a key molecular event underlying the pathogenesis of Parkinson's disease.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Co-treatment with a C1B5 peptide of protein kinase Cγ and a low dose of gemcitabine strongly attenuated pancreatic cancer growth in mice through T cell activation

Highlights: • Co-treatment of C1B5 peptide and gemcitabine inhibits pancreatic cancer cell growth in vitro. • Co-treatment of C1B5 peptide and a low dose of gemcitabine attenuates the growth of pancreatic cancer autografts in mice. • Co-treatment of C1B5 peptide and gemcitabine increases neutrophils and granzyme B{sup +} lymphocytes in tumor microenvironment. Although gemcitabine is an effective chemotherapeutic for pancreatic cancer, severe side effects often accompany its use. Since we have discovered that locally administered C1B domain peptides effectively control tumor growth without any side effects, the efficacy of co-treatment with this peptide and a low dose of gemcitabine on the growth of pancreatic cancer was examined. Two- and three-dimensional cell culture studies clarified that a co-treatment with C1B5 peptide and gemcitabine significantly attenuated growth of PAN02 mouse and PANC-1 human pancreatic cancer cells in 2D and 3D cultures. Although treatment with the low dose of gemcitabine alone (76%) or the C1B5 peptide alone (39%) inhibited tumor growth moderately, a co-treatment with C1B5 peptide and a low dose of gemcitabine markedly inhibited the growth of PAN02 autografts in the mouse peritoneal cavity (94% inhibition) without any noticeable adverse effect. The number of peritoneal cavity-infiltrating neutrophils and granzyme B{sup +} lymphocytes was significantly higher in the co-treatment group than in the control group. A significant increase of granzyme B mRNA expression was also detected in human T cells by the co-treatment. Taken together, the current study suggests that C1B5 peptide offers a remarkably effective combination treatment strategy to reduce side effects associated with gemcitabine, without losing its tumoricidal effect.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Interplay of adipocyte and hepatocyte: Leptin upregulates hepcidin

Highlights: • Plasma levels of hepcidin in ob/ob mice is significantly higher than those of control mice. • Leptin administration to ob/ob mice significantly increase in plasma and liver expression of Hanmp mRNA and iron content in the liver. • As well as the expression of Hanmp mRNA, hepcidin related genes (BMP6 mRNA, STAT3 mRNA) and iron transporters (DMT1 mRNA, TfR mRNA) in the liver also increased after administration of leptin to ob/ob mice. Conflicting evidence concerning leptin, an adipocyte-derived hormone, in atherogenesis and non-alcoholic fatty liver disease (NAFLD) has been reported. Iron metabolism and iron-mediated oxidative stress should be taken into consideration for the clarification of the pathogenesis of these diseases. In this study, we demonstrate that leptin receptor activation directly affects iron metabolism by the finding that serum levels of hepcidin, the master regulator of iron in the whole body, were significantly lower in leptin-deficient (ob/ob) and leptin receptor-deficient (db/db) mice. The administration of recombinant leptin to ob/ob mice for two weeks showed a significant increase in serum hepcidin and hepatic Hamp mRNA levels. Hamp mRNA levels were significantly correlated with hepatic iron content and BMP6 mRNA levels. Hepatic iron content was associated with the increase in mRNA levels of divalent metal transporter 1 and transferrin receptor. Our data provide evidence that the interplay of these two hormones could help improve the understanding of the pathogenesis of atherosclerosis and NAFLD.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Role of N-myristoylation in stability and subcellular localization of the CLPABP protein

Highlights: • N-myristoylation of the CLPABP protein was predicted to affect its stability. • N-myristoylation of CLPABP was not related to its mitochondrial localization. • Both PH domains of CLPABP may be necessary to colocalize with mitochondria. Cardiolipin and phosphatidic acid-binding protein (CLPABP) controls the stability of the mRNA harboring an AU-rich element (ARE) in the 3′ UTR with the help of the RNA stabilizer, human antigen R (HuR). Although CLPABP is localized on the mitochondrial surface as a large protein-RNA complex, its precise role is not yet known. Recently, CLPABP was identified as an N-myristoylated protein. Here, we demonstrate the effects of N-myristoylation on the functions of CLPABP. In the present study, compared to the wild-type protein that possessed the “MG” motif at the N-terminus for N-myristoylation, the mutant CLPABP protein that lacked N-myristoylation modification site was unstable. Furthermore, the expression of the G/A mutant of CLPABP, which lacked N-myristoylation site, induced morphological alterations in mitochondria. Because pleckstrin homology domain-deleted mutant, which was fused with the N-myristoylation site derived from intact CLPABP, could not colocalize with mitochondria, N-myristoylation of CLPABP was predicted to affect its stability onto the mitochondrial membrane rather than its subcellular localization.

60 APPLIED LIFE SCIENCES↗