bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of RNA‐binding protein HuR and CUGBP1 in LPS‐induced Interleukin‐6 Expression in Macrophages
Authors: Zha Weibin , Wang Guangji , Pecora Beth S. , Studer Elaine , Hylemon Phillip B , Pandak Williams M , Zhou Huiping 
Published: June 2021

Interleukin 6 (IL6) is an important proinflammatory cytokine involved in the pathogenesis of many inflammatory diseases. RNA‐binding proteins, HuR and CUGBP1, regulate the mRNA stability and protein translation through direct binding to the AU‐rich domain or CUG repeats in the 3 untranslated region (3 UTR) of target genes. However, the exact role of HuR and CUGBP1 in LPS‐induced IL6 expression remains unknown. The current study examined the potential role of HuR and CUGBP1 in posttranscriptional regulation of IL6 expression during LPS‐mediated inflammatory response in macrophages.MethodsMouse macrophages were used in this study. The IL6 mRNA and protein levels were determined by real time RT‐PCR and ELISA, respectively. Protein levels of HuR and CUGBP1 were determined by Western blot analysis. The interaction between RNA binding proteins and IL6 mRNA was identified by pull‐down assay and immunoprecipitation.ResultsLPS increased cytosolic HuR and CUGBP1 protein levels and the binding of HuR and CUGBP1 to 3 UTR of IL6 mRNA. LPS‐mediated IL6 expression was promoted by HuR overexpression and CUGBP1 silencing, but inhibited by HuR silencing and CUGBP1 overexpression.ConclusionHuR and CUGBP1 compete for binding to the 3 UTR of IL6 mRNA and differentially regulate IL6 expression at the posttranscriptional level during LPS‐mediated inflammatory response. This work is supported by NIH and Jeffress grant.
Global identification of the Gene‐Specific Association of the Exon‐Exon Junction Complex in Drosophila
Authors: Haque Nazmul , Blanchette Marco 
Published: June 2021

Exon Junction Complex (EJC) is a large multi‐protein complex that assembles 20‐24nt upstream of exon‐exon junction following splicing of pre‐mRNAs. EJC is involved in several aspects of mRNA metabolism, including mRNA export, translation and Nonsense Meditated mRNA Decay (NMD). We have recently found in Drosophila that EJCs assemble on specific spliced mRNAs, which prompted us to globally characterize the mRNAs bound by EJCs in Drosophila S2 cells.RNAs bound to eIF4AIII and Y14, two of the core components of EJC, were immunopurified from stable S2 cell lines expressing affinity‐tag version of the proteins and used to hybridize Drosophila whole genome tiling array. We have identified that only ~10% of expressed mRNAs associate with an EJC. Surprisingly, our global analysis have reveal that some mRNAs are bound only by eIF4AIII or Y14, suggesting that these proteins might be part of complexes distinct from EJCs. In addition, global gene expression analysis in eIF4AIII‐depleted S2 cells by RNAi identified an over‐represented population of mRNAs bound by eIF4AIII with reduced expression while no significant overlap was observed in the up‐regulated mRNAs, suggesting a role for eiF4AIII in stabilizing these mRNAs. Bio‐computational analyses are underway to identify cis‐acting elements that could trigger gene‐specific EJC deposition.This project is supported by Stowers Institute for Medical Research
Expression, Purification, and Characterization of a New Sulfhydryl Oxidase from Trypanosoma brucei
Authors: Styer Amy , Kodali Vamsi , Daithankar Vidyadhar , Thorpe Colin 
Published: June 2021

A sulfhydryl oxidase from Trypanosoma brucei was expressed, purified and studied enzymologically for the first time. The protein is homologous to ALR (augmenter of liver regeneration), an essential flavin‐linked enzyme which catalyzes disulfide bond formation in the mitochondrial intermembrane space (IMS) of eukaryotes. Trypanosomes lack a gene for Mia40, a necessary redox partner with ALR in yeast and mammals. Future research will determine how trypanosomes compensate for the lack of Mia40, and if this sulfhydryl oxidase has the same biological localization and function as ALR.We have shown that six of seven cysteines in the 33 kDa trypanosomal ALR are present as disulfide bonds. In oxygen electrode assays, the enzyme catalyzed disulfide‐bond formation in the model substrate dithiothreitol (DTT), but not in the monothiols glutathione and cysteine. Molecular oxygen was a much better terminal electron acceptor for trypanosome ALR than for human ALR (TbALR Km = 15±1μM; some 15‐fold lower than the human enzyme). Further studies are aimed at characterizing the kinetic mechanism of this flavoenzyme by stopped flow spectrophotometry.Understanding trypanosome redox biochemistry is important because Trypanosoma brucei, the causative agent of African Sleeping sickness, kills nearly fifty thousand people annually and current treatments are expensive and incur serious side reactions. This exploration of trypanosome mitochondrial IMS disulfide‐bond formation may lead to biomedical advances in the fight against trypanosome diseases.Funded by a Beckman Scholars Fellowship to A.S. and NIH GM26643 to C.T.
Nuclear‐mediated function of Chmp1A in the regulation of ATM signaling activity for the control of human pancreatic tumor cell growth
Authors: Manohar Sumanth , Harlow Matthew , Mackie Christopher Ryan , Li Jing , Park Maiyon 
Published: June 2021

Chmp1A is a member of the ESCRT‐III family that functions in the sorting of membrane proteins. Chmp1A was shown to regulate cell cycle progression and chromatin condensation. We recently reported that Chmp1A functions as a tumor suppressor by regulating P53 in pancreatic tumor cells. P53 is a substrate of ataxia‐telangiectasia mutated (ATM) kinase and the dynamics of ATM activation is closely related to chromatin modification. Thus, we hypothesize that Chmp1A, through its nuclear localization, regulates ATM signaling activity and subsequently pancreatic tumor growth. Our preliminary data indicates that Chmp1A overexpression led to an increase in phospho‐ATM. Immuno‐staining identified the co‐localization of ectopically induced Chmp1A with phospho‐ATM and P53 whose intensity closely reflected that of Chmp1A expression. ATM kinase assay indicates that Chmp1A overexpression increased ATM kinase activity as shown by an increase in the level of phospho‐P53 compared to control. In addition, ATM inhibitor‐treatment partly abolished Chmp1A mediated‐growth inhibition and P53 stabilization. We are testing the significance of nuclear localization signal (NLS) of Chmp1A by using various deletion constructs. We will discuss the significance of the NLS domain of Chmp1A on signaling activity of ATM and P53, and tumor cell growth.This research is supported by NIH 5P20RR016477, WV‐INBRE and RR020180‐02, COBRE.
Proximity of proregion anionic residues to the mature region maintains proCryptdin‐4 inhibition
Authors: FIGUEREDO SHAREL MENEZES , Gable Jonathan E , Kim Judy E , Ouellette Andre J 
Published: June 2021

α‐Defensins are synthesized as inactive precursors that must undergo proteolytic conversion to mature bactericidal peptides. Acidic amino acids near the proCrp4 N terminus mediate inhibition of proCrp4 as shown by selective deletion and charge neutralizing mutagenesis (J. Biol. Chem. 284: 6826–6831, 2009). To study the inhibitory mechanism, we have compared the proximity of those anionic residues to the Crp4 component of native and mutant proCrp4 molecules using Förster resonance energy transfer (FRET). To provide FRET probes and enable FRET conformational studies in native and charge neutralized proCrp4, single Crp4 Trp substitutions were introduced in the α‐defensin moiety at V58W, F66W, and at the C terminus, and a Cys residue was added to proCrp4 N terminus (CN) for IAEDANS labeling. ProCrp variants had bactericidal activities comparable to the parent molecules and were processed correctly by MMP‐7. FRET efficiency and distances between the FRET pairs in native and charge‐neutralized proCrp4 were determined. The N and C‐terminal regions of inactive CN(V58W)‐proCrp4 are closest with a FRET pair distance of 11.5 Å. In the active, bactericidal CN‐(DE/G‐V58W)‐proCrp4 mutant, this distance increased to 14.3 Å. Thus, mutations that relieve proCrp4 inhibition do so without markedly repositioning the relation of the proregion N terminus to the Crp4 component of the precursor.Supported by NIH grants DK044632 and AI059346..
Mitotic arrest induced by propargylic enol ethers derivatives
Authors: Luci Carla Patricia Rios , León Leticia G. , Montero Juan C. , Tejedor David , Pandiella Atanasio , García‐Tellado Fernando , Padrón José M. 
Published: June 2021

The generation of diversity‐oriented libraries is a valuable tool for the discovery of new anticancer agents. The objective was to evaluate the anti‐proliferative activity of a set of 27 propargylic enol ethers derivatives in cancer cells. The antiproliferative activity was performed against the human solid tumor cell lines SW1573, HBL‐100 and HeLa. Additionally, cell cycle phase distribution was investigated by flow cytometry and protein expression by western blotting. The most active compound gave GI50 values in the range of 0.24–2.8 μM in all the cell lines. Cell cycle studies showed the ability of the drug to induce a prominent G2/M arrest. The cell arrest occurred with little evidence of DNA damage, as determined by the lack of γ‐H2AX signal. The persistence of cyclin B1 in HeLa cells correlates with their entry into mitosis. High levels of histone H3 phosphorylated at serine 10 confirmed that cells accumulate in mitosis in a time‐dependent manner. Mitotic arrest was consistent with the activation of BubR1 which delayed the progression to anaphase. Our findings provide insight into the mechanism of chemotherapeutic action of this family of compounds.Funding co‐financed by EU‐FEDER: MICIIN (CTQ2008‐06806‐C02–01/BQU, CTQ2008‐06806‐C02–02/BQU, BFU2006‐01813/BMC), MSC (RTICC RD06/0020/1046, RD06/0020/0041); ACIISI (PI 2007/021); FUNCIS(PI 01/06, 35/06). LGL: MSC‐FIS contract. JMP: MEC‐FSE RyC contract.
Identification of the putative drug binding site for novel agonists of the integrin CD11b/CD18
Authors: Stoub Darren G. , Gupta Vineet , Faridi Mohd. , Maiguel Dony , Barth Constantinos , Schurer Stephan 
Published: June 2021

CD11b/CD18, one of the α/β integrin heterodimers, is the predominant integrin found in neutrophils, macrophages and monocytes and is involved in important cellular functions, such as cell signaling and cell‐ECM adhesion. We report the discovery of a class of small molecules that contain a 5‐(furanyl‐2‐methylene)‐2,3‐dioxo‐thiazolidine motif. Using an in vitro cell‐adhesion assay and an in vivo murine inflammation assay, the compounds behave as agonists of integrin activation with maximum ex vivo EC50 values of 10.5 μM and high in vitro selectivity for CD11b/CD18 integrins. Using in silico and site‐directed mutagenesis experiments, we report the location of the drug binding site for these compounds in a hydrophobic cleft of the ligand‐binding αA domain, implying an allosteric mechanism on the integrin activation mechanism. These small molecule agonists of integrin function have potential as anti‐inflammatory drugs and could be utilized to treat renal ischemia and reperfusion injury.The work was supported in part by two NIH grants and the Van Houten Memorial Fund.
Improved HPLC method for vitamin C analysis in serum
Authors: Craft Neal E. , Park Heasoon 
Published: June 2021

Vitamin C (VC) is necessary for development of normal connective tissue and human health. VC HPLC separations have remained nearly the same for 25 yrs. Recent advances in column technology have permitted some improvements in the methodology.ObjectiveTo improve serum VC separation, sensitivity and reproducibility w/o ion‐pairing agents or gradients.MethodsSeveral HPLC columns, possible internal standards and two buffers at different concentrations were examined. Both UV and electrochemical (EC) detection was used.ResultsMost columns offered poor retention and peak shape of VC. Phenomenex Synergi Hydro‐RP column provided good retention (k=1.3) symmetry (A=1.1) and tailing (T=1.15). Tris(2‐carboxyethyl)phosphine (TCEP) was used as an alternate reducing agent to dithiothreitol. Hypoxanthine, selected as an internal standard, eluted isocratically at k=3.2 with UV absorbance at 245nm but no EC.DiscussionThe HPLC method modifications yield good retention and peak shape. TCEP provides a cost effective and superior reducing agent. Efficiency and reproducibility were improved by incorporation of an internal standard. The method is amenable to short narrow bore columns.
Long‐term, physiological dose of prednisolone treatment alters vitamin B6 metabolism in vivo
Authors: Chang Hsin‐Yueh , Chiang En‐Pei Isabel 
Published: June 2021

Earlier studies reported that B6 metabolic enzymes were reduced in adrenalectomized rats that could be restored by short‐term injection of very high dose glucocorticoids. Prednisolone (PSL) is a glucocorticoid commonly used for long‐term treatment of chronic inflammatory and autoimmune disorders. In the present study we investigated the impacts of long‐term physiological dose of PSL on vitamin B6 metabolism in vivo. Male C57BL/6J mice received either PBS (control), 0.1 mg PSL/kg (low dose), or 1 mg PSL/kg (medium dose) i.p. once every other day for up to 7 months, to mimic the regimen of PSL in humans with chronic disorders. PSL did not alter steady state B6 vitamers or B6 metabolic enzymes in erythrocytes. However, PSL (1mg/kg) significantly increased plasma pyridoxal 5′‐phosphate (PLP), pyridoxal (PL) and 4‐pyridoxic acid (PA) levels (P<0.05). Furthermore, PSL increased PL level in the muscle in a dose dependent manner. PSL significantly induced hepatic pyridoxal kinase (PDXK) and pyridoxamine 5′‐phosphate oxidase activity (PMPO), but reduced hepatic pyridoxamine 5′‐phosphate (PMP) concentrations. Our study suggests that long‐term low/medium dose PSL can induce hepatic PDXK and PMPO activities that may convert hepatic PMP to PLP, leading to increased PL in the circulation and promote mobilization of B6 vitamers among tissues. ( This project was supported by Dept of Health in Taiwan DOH 97‐TD‐D‐113‐97011)Grant Funding Source: ASN
Blood Mineral levels of Mexican Adults, Results of a National probabilistic survey
Authors: Levy Teresa Shamah , Villalpando Salvador , Mejía‐Rodríguez Fabiola 
Published: June 2021

Objectiveto evaluate the prevalence of some serum minerals in Mexican population.MethodsFor this analysis were extracted from the data base of the Mexican National Nutrition Survey, 2006. Households stratified by clusters were randomly selected from the National Household Sampling Frame. Venous blood samples were drawn and the micro minerals, ferritin, TfR concentrations were measured in 5,056 women (weighted 32,795,990 subjects) and 2,143 men (weighted 27,126,621 subjects). Deficiencies were categorized as Ferritin (<12 mcg/L), Zinc (<75 mcg/L), Cupper (<70 mcg/dL), and TfR (>6 mcg/L). Relationship of each nutrient (Ferritin, Zinc and Cupper only in women) was evaluated with participation in food assistance programs (FAP) using logistic regression after adjustment for socioeconomic status level (SEL) and some nutrient associated.ResultsThe prevalence of low Ferritin was 19.8%‐W and 3.6%‐M, high TfR 5.5%‐W and 1.4%‐M, low Zinc 23.7%‐W and 17.5%‐M, and Cupper 22.5%W and 25.4%M. Iron deficiency was higher in women with low SEL (p=0.045). Cupper deficiency was negatively associated with dietetic fiber intake (p=0.02), FAP (p=0.05), and age (p<0.001).ConclusionsPrevalence of mineral deficiency was higher in women than in men, except cupper. Mineral deficiencies are still high in low SEL.
Saponins from Yerba Mate (Ilex paraguariensis St. Hilaire) leaves inhibit markers of inflammation in vitro through NFκB pathways
Authors: Puangpraphant Sirima , Berhow Mark , de Mejia Elvira Gonzalez 
Published: June 2021

Saponins are naturally occurring phytochemicals present in Yerba mate and other plant sources that have been associated with several health benefits. The objective was to extract and partially purify saponins from yerba mate dry leaves and assess their anti‐inflammatory effects on macrophages (RAW 264.7). HPLC and LC/ESI‐MS‐MS were used to identify saponins in chromatographic fractions of methanol extracts. Six fractions A, B, C, D, E, and F, were obtained. Fractions D, E and F had characteristic mate saponin spectra between 800–1200 m/z and major saponins in these fractions were matesaponin 1 [M‐H]− =911and matesaponin 2 [M‐H]− =1057, with minor amounts of matesaponin 3 [M‐H]−=1073, matesaponin 4 [M‐H]− =1219, and matesaponin 5 [M‐H]− =1383. It was determined that dry yerba mate leaves have 10–15 mg total saponins/g, predominately matesaponins 1 and 2. Fractions A, B, and C did not reduce inflammatory markers. Fractions D, E, and F significantly inhibited iNOS (IC35 = 36.3, 29.5, 43.7 μM), PGE2 (IC35 = 23.1, 22.3, 11.7 μM) and COX‐2 (IC35 = 45.7, 32.4, 17.0 μM). Treatments with fraction F (25 μM) resulted in the reduction of LPS‐induced nuclear translocation of nuclear factor‐κB (NFκB) subunits p50 (49.8%) and p65 (49.0%) indicating that mate saponins inhibit inflammation through NFκB pathways. Chemical structure of saponins influenced the inhibition of inflammatory markers in vitro.Research Board, U IllinoisGrant Funding Source: Research Board, University of Illinois
Molecular structures of citrus polymethoxylated flavonoids (PMFs) determine their inhibitory effect on apoB secretion in HepG2 cells
Authors: Vermeer Mario A. , Lin Yuguang , Bos Wil , van Buren Leo , Schuurbiers Eric , Miret‐Catalan Silvia , Trautwein Elke A. 
Published: June 2021

BackgroundCitrus PMFs, such as nobiletin and tangeretin, have been shown to modulate cholesterol (CH) homeostasis in vitro and in vivo, although the underlying mechanism of action has not yet been fully elucidated. We explored the structure‐activity relationship of PMFs regarding apoB secretion.MethodsHepG2 cells were incubated with 20 natural and synthetic PMFs (0–100 μM), while lovastatin (3 μM) and mevalonate (10 mM) were used as controls to modulate cellular CH‐metabolism. Apolipoprotein B (apoB) secretion was determined by using ELISA and 14C‐acetate and 14C‐glycerol were used to monitor cellular CH and triglyceride (TG) synthesis, respectively. LDL‐receptor expression was measured by ELISA and its activity by monitoring fluorescent‐labelled LDL uptake.ResultsCitrus PMFs and their natural 4′‐demethylated metabolites most strongly reduced apoB secretion (IC50 10–60μM). The most active PMFs have a fully methoxylated A‐ring (see structure), while the methoxylation of the B‐ring seemed less important for apoB‐secretion. In addition, PMFs with a fully methoxylated A‐ring more strongly inhibited TG‐ and CH‐synthesis compared to other citrus flavonoids. PMFs did not up‐regulate LDL‐receptor expression or activity.ConclusionCitrus PMFs (nobiletin, tangeretin and their metabolites) with a fully methoxylated Aring have the strongest inhibitory effect on apoB‐secretion in HepG2 cells.
PFKFB3/iPFK2 links nutrient metabolism and overnutrition‐associated adipocyte inflammatory response through controlling oxidative stress
Authors: Guo Xin , Li Honggui , Wu Chaodong 
Published: June 2021

Overnutrition‐associated adipose inflammation is a common cause of many metabolic diseases such as diabetes and atherosclerosis. However, precisely how overnutrition disturbs nutrient metabolism to stimulate the adipocyte inflammatory response remains unknown. The objective of this study is to elucidate the molecular link between nutrient metabolism and the adipocyte inflammatory response. In adipocytes, PFKFB3/iPFK2 is a master regulator of nutrient metabolism. Using cultured 3T3‐L1 adipocytes, we showed that knockdown of PFKFB3/iPFK2 caused a decrease in the rate of glucose incorporation into lipid. Additionally, knockdown of PFKFB3/iPFK2 increased inflammatory signaling through JNK and NFκB p65 and enhanced the production of proinflammatory cytokines. These effects were accompanied by an increase in the production of reactive oxygen species (ROS) under both basal and palmitate‐stimulated conditions, indicating increased oxidative stress. When treated with etomoxir, an inhibitor of fatty acid oxidation, the production of ROS in PFKFB3/iPFK2‐knockdown adipocytes was lowered down to the levels comparable with those brought about by N‐acetyl‐L‐cysteine, a compound that suppresses most pathways for ROS production. Together, these data suggest that PFKFB3/iPFK2 links nutrient metabolism and overnutrition‐associated adipocyte inflammatory response by controlling oxidative stress.Grant Funding Source: none
Effects of Maternal Bitter Melon (Momordica charantia) Supplementation on Hepatic Lipid Metabolism of Fructose Fed Dams and Their Progeny
Authors: Ching Hiu Ha , Li Edmund Tsze Shing 
Published: June 2021

Bitter melon (BM) reduces blood lipids, slows tissue fat accumulation and improves insulin sensitivity in rat fed diets high in fat or fructose (F). We hypothesized that progeny of fructose fed dams will benefit from maternal BM supplementation. Virgin female Sprague‐Dawley rats were given control (C), fructose (F: 60%) or BM supplemented (1% BM juice) F diet (FBM) for 8‐wk before mating, throughout gestation and lactation. Weaned male pups were fed either C or F for 11wk to generate C/C, F/C, FBM/C, F/F, FBM/F diet groups (dam/pup). FBM dams had lower serum cholesterol (CHL); liver weight and triglyceride (TG) level (F vs FBM, n=11, p < 0.002). Litter size and birth weight of pups were similar. At weaning (wk3), pups of FBM dams had lower serum TG than those of F dams (p < 0.005). At wk 11, hepatic TG and CHL of FBM/C rats were lower than that of F/C rats (n=9, p < 0.001). Although all F‐fed young rats had higher liver weight, for those of FBM dams, they had elevated hepatic fatty acid binding protein 1, carnitine palmitoyltransferase la and very long chain acyl‐Coenzyme A dehydrogenase mRNA expression (FBM/F vs F/F, n=9, p < 0.05), suggesting a mechanistic setup to reduce hepatic fat accumulation. Hence, maternal BM supplementation leads to favorable changes in lipid handling of progeny. These could be direct actions of bioactive compounds in BM or consequence of improved metabolic controls of dams. (Supported by a HKU grant)Grant Funding Source: The University of Hong Kong
The role of TNFα in circadian rhythmic responses and regulation of metabolic regulator SIRT1 in liver
Authors: Menio Jade , Hines Ian N , Wheeler Michael D 
Published: June 2021

A feedback loop exist between the expression of circadian control genes and regulators of metabolic and energy homeostasis, involving the histone deacetylase SIRT1. We show here that TNFα regulates the expression of SIRT1 in liver. Thus, we hypothesize that a relationship exists between hepatic immune response and circadian control genes through the expression of SIRT1. For these experiments C57Bl6/J control mice and mice lacking TNFα receptor (TNFR1−/−) were fasted for 24 hours. Under fed conditions, wild type mice have low SIRT1 expression in liver but SIRT mRNA is increaded 4‐fold after fasting. In TNFR1−/− mice, SIRT1 expression is increased nearly 10‐fold under basal conditions as well as after fasting, suggesting that TNF suppresses SIRT expression. TNFR1−/− mice greater running wheel activity, consume nearly 30% more chow, and exhibit higher respiratory exchange rate than the wild type mice. Importantly, TNFR1−/− mice have altered hepatic circadian Bmal and Per2 expression compared to wild type mice. Most importantly, when the mice were housed in constant darkness, TNFR1−/− mice exhibited greater circadian phase‐shift compared to wild type mice, indicating a faster circadian period in TNFR1−/− mice. In conclusion, these data suggest that TNFα is an important regulator of hepatic circadian gene expression and circadian behavior and may involve the suppression of SIRT.Grant Funding Source: Internal