bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of intrinsic factors on amyloid formation
Authors: Ridinger Katherine , Scholtz J Martin
Published: June 2021

Amyloid fibrils consist of misfolded proteins or peptides that are aggregated into an ordered, beta‐sheet structure. Since amyloid fibrils are associated with many diseases, it is important to understand what causes peptides or proteins to misfold and aggregate. We chose an eleven residue segment from the Alzheimer's peptide, A‐beta(1‐42), to use in our study of the intrinsic factors of the sequence that contribute to amyloidosis: hydrophobicity, residue charge, solubility, and beta‐strand propensity. Within this shorter peptide, A‐beta(25‐35) (GSNKGAIIGLM), we made several mutations to change one specific intrinsic factor at a time so that we can determine the effect of each factor on amyloid formation. Partial scrambles and truncated mutants of the peptide were also made in an attempt to identify the critical region, or amyloid core, which is necessary for amyloid formation. Our results suggest that hydrophobicity may not have as significant effect on amyloid formation as previously hypothesized. Conversely, when beta‐strand propensity increases, the aggregation propensity of the A‐beta(25‐35) peptide significantly increases, and when solubility increases, amyloid formation is significantly perturbed. Also, the amyloid core of the peptide has been narrowed to a five‐residue segment at the C‐terminus of the A‐beta(25‐35) peptide. This study should aid in understanding the importance of the factors involved in this disease‐associated type of aggregation.
Involvement of ERp44 and Ero‐L in the Maturation of Serotonin Transporter
Authors: Freyaldenhoven Samuel , Kilic Fusun
Published: June 2021

The serotonin transporter (SERT) is a glycoprotein responsible for the uptake of extracellular serotonin [(5‐hydroxytryptamine (5HT)] and has been attributed to disorders such as obsessive‐compulsive, depression, and primary pulmonary hypertension. Furthermore, it has been shown that SERT assembles into higher order complexes and functions most favorably in oligomeric form. However, while glycosylation by sialic acid has been shown to facilitate SERT oligomerization, no additional mediators of SERT oligomerization have yet been identified. In our current study, we have identified ERp44, a novel endoplasmic reticulum chaperone involved in thiol‐mediated retention, which colocalizes and binds to SERT. However, the SERT mutants, C200S or C209S could neither associate with ERp44 nor with each other. Based on our preliminary data we hypothesize that two critical, ER‐located chaperones, ERp44 and Ero1‐Lα? play a defined role in the assembly of SERT proteins in an oligomeric form via mediating the formation of an intramolecular disulfide bridge in the SERT protein backbond between C200 and C209 residues. Following the maturation, SERT proteins in an oligomeric form first dissociate from ERp44‐Ero1‐Lα ?complex and pass the ER quality control mechanism to enter the membrane trafficking pathway.
Intein‐mediated creation of a cyclic acyl carrier protein
Authors: Volkmann Gerrit , Murphy Peter W. , Rowland Elden E. , Liu Xiang‐Qin , Byers David M.
Published: June 2021

Acyl carrier protein (ACP) is an essential protein in bacterial metabolism, where it acts as the major donor for fatty acyl groups in the synthesis of lipids and other specialized products. As such, ACP is an attractive anti‐microbial drug target. ACP normally encloses attached fatty acyl groups in a hydrophobic pocket within its three mainα‐helices, but the exact mechanism of interaction and acyl transfer from ACP to partner enzymes is poorly understood. ACP interacts with most proteins through its acidic helix II, and acyl transfer must involve partial or full unfolding of ACP in order to present the acyl chain to the partner enzyme. To examine the requirement of ACP unfolding for acyl transfer, we created a cyclic version of Vibrio harveyi ACP using split‐intein technology. Mass spectrometry, circular dichroism and fluorescence studies suggest that cyclic ACP (cACP) is trapped in a folded conformation. In vitro characterization indicates that cACP can be modified by holo‐ACP synthetase yielding an active ACP. Furthermore, in vivo complementation assays suggest that cACP is able to replace the linear wild‐type ACP and support growth. Our results thus suggest that cACP is able to interact with and transfer its acyl chain to its many partner enzymes within the bacterial cell despite constraining of its N‐ and C‐termini. (Supported by CIHR, NSERC, and an IWK Studentship).
Interactions of native and aggregated HypF‐N with lipid monolayers and supported bilayers of varied lipid composition
Authors: Marano Nadia , Mackay Fraser , Nichino Daniela , Relini Annalisa , Rolandi Ranieri , Gliozzi Alessandra , Stefani Massimo
Published: June 2021

We studied the effect of the model amyloid‐forming protein, HypF‐N (the N‐terminal domain of the prokaryotic hydrogenase maturation factor HypF), in its native and aggregated form on the integrity of model lipid membranes, including those more representative of natural membranes, using AFM and surface pressure measurements. Using fluorescence spectroscopy, we studied the effect of lipids on the structure of HypF‐N. We find that native protein has a larger effect on model membranes than aggregated protein. Model membranes composed of lipid raft forming mixtures (phosphatidylcholine: sphingomyelin: cholesterol, 1:1:1) were much more resistant to insertion of protein and membrane disruption than those composed of a 1:1 mixture of phosphatidylcholine (PC) and phosphatidylserine (PS). Addition of cholesterol to the latter mixture made the membranes less resistant to protein insertion. Liposomes containing the negatively charged lipid PS induced a strong quenching in fluorescence of HypF‐N (indicating a change in the environment of tryptophan and tyrosine residues) while those containing only PC had little effect. Preliminary denaturation experiments indicate relatively strong binding of HypF‐N to PS:PC liposomes.

Research was supported by Saint Lawrence University, University of Genoa and University of Florence.
Effects of Asn152 mutation on substrate selectivity of P99 cephalosporinase
Authors: Ruble James F. , Tomlinson Jenna M. , Lefurgy Scott T. , Cornish Virginia W. , Powers Rachel A.
Published: June 2021

In the past, physicians were able to combat bacterial infection by administration of beta‐lactam antibiotics. These drugs destroy bacteria by disrupting the final stage of cell wall synthesis. Bacteria, however, evolved resistance to these compounds by producing beta‐lactamase enzymes, which hydrolyze the lactam ring and render it inactive. Of major concern are bacteria that have become resistant by acquiring mutations in their beta‐lactamase genes. These mutations alter the selectivity of enzyme for substrate, thereby allowing the mutant enzyme to effectively break apart many different beta‐lactams, either in addition to, or at the expense of, their "preferred substrate". For the enzyme P99 cephalosporinase, it has been shown that mutation of the conserved asparagine residue at position 152 can have a substantial effect on substrate selectivity of the enzyme (Lefurgy, 2007). In this study, a full kinetic characterization of the N152G mutant was performed using several beta‐lactams. Attempts to crystallize the mutant are being performed under published conditions as well as new conditions obtained from high‐throughput screening techniques. Further studies of mutational effects on the Asn152 will help to elicit the detailed structure and function relationship for this residue and could potentially allow researchers to develop improved antibacterial drugs for clinical use.
Unusal Glycine Triad Key for GSH Synthetase Activity
Authors: Brown Teresa , Dinescu Adriana , Slavens Kerri , De Jesus Margarita , Cundari T.R. , Anderson M.E.
Published: June 2021

The antioxidant glutathione (γ‐glutamylcysteinylglycine; GSH) is an important tripeptide found in almost all living cells. The intracellular biosynthesis of GSH occurs in two ATP‐dependent steps: (1) γ‐glutamylcysteine synthetase catalyzes the formation of γ‐glutamylcysteine from glutamate and cysteine (2) glutathione synthetase (GS) catalyzes the ligation of γ‐glutamylcysteine to glycine. Human GS (hGS), a homodimer, has conserved loops (G, A and S‐loops) near the active site. The glycine‐rich (G‐loop; Q366‐Y375) is flexible and highly conserved, especially the glycine triad in eukaryotic GS. The role of the glycine triad residues (G369, G370, G371) was studied using site‐ directed mutagenesis coupled with computational analysis by separately changing each of the glycine triad residues to valine. After expression, purification, and assay, the glycine triad mutant enzymes (G369V, G370V and G371V) were found to have significantly less activity than wild type GS (0.7%, 0.3% and 13%; respectively). Computations show that mutations decrease substrate binding and prevent loop closure during the catalytic cycle. Our studies further the understanding of the role of the G‐loop for glutathione synthetase catalysis. (Support: Faculty Enhancement Program Grant TWU (MEA), Welch Foundation Grant (Chem. Dept. TWU), U.S. Dept. Ed (CASCaM UNT, TRC), Faculty Research Grant UNT (TRC).
AQP4 role in renal K+ transport
Authors: Zelenin Sergey , Zelenina Marina , Li Yanhong , Kamali‐Zare Padideh , Bondar Alexander , Brismar Hjalmar , Aperia Anita
Published: June 2021

The collecting duct principle cells (PC) play a major role for concentration of urine and regulation of K+ homeostasis. Two water channels, AQP3 and AQP4, are expressed in the PC basolateral membrane (BLM). Here we present evidence that AQP4 participates in regulation of renal K+ transport. K+ enters the cell via Na+,K+‐ATPase mediated transport in BLM. The presence of K+ channels in BLM, which is deeply infolded, thus providing a diffusion limited space, permits K+ recirculation, considered important for maintenance of membrane potential. Here we show with co‐immunoprecipitation and GST pulldown assays, that in rat renal papilla, AQP4, but not AQP3, assembles with Na+,K+‐ATPase and the K+ channel Kir7.1. This led us to hypothesize that AQP4, Na+,K+‐ATPase and Kir7.1 form a K+ transporting microdomain, where AQP4 water transport maintains a favorable gradient for K+ efflux and stabilizes membrane potential. A mathematical model of K+ transport across an epithelial cells with a deeply infolded BLM supported the hypothesis and predicted an even higher impact of AQP water transport on K+ transport if AQP water permeability is sensitive to fluctuations in extracellular K+ concentration ([K+]o). To test this, AQP3 and AQP4 were expressed in MDCK cells, a cell line with much in common with PC. Water permeability was increased when [K+]o was 12mM in cells expressing AQP4 but not in cells expressing AQP3.
The Role of Dynamin in the Clearance of Apoptotic Cells
Authors: Zhou Zheng , Yu Xiaomeng , He Bin , Lu Nan , Danino Dganit
Published: June 2021

In animals, cells undergoing apoptosis are rapidly engulfed and degraded by phagocytes. The removal of apoptotic cells provides a safe means for eliminating unwanted and dangerous cells from the body. Furthermore, it prevents tissue injury, and inflammatory and auto‐immune responses induced by the lingering dead cells. In a genetic screen for mutations that affect the removal of apoptotic cells in the nematode C. elegans. We isolated fourteen loss‐of‐function alleles of dyn‐1, which encodes the C. elegans ortholog of large GTPase dynamin. Our cell biological characterizations indicate that DYN‐1 is essential for both the engulfment and degradation of apoptotic cells. DYN‐1 promotes the incorporation of endosomes to the extending pseudopods during engulfment, and the recruitment and incorporation of both endosomes and lysosomes to phagosomes containing apoptotic cells. Phosphatidylinositol 3‐phosphate (PI(3)P) and the small GTPase RAB‐7 mediate the specific function of DYN‐1 in phagosome maturation. Our in vitro and in vivo analyses demonstrate that the GTP hydrolysis and self‐assembly activities of DYN‐1 control distinct aspects of DYN‐1's function in phagosome maturation. Furthermore, the phagocytic receptor CED‐1 recruits DYN‐1 to the site of engulfment. These findings indicate that DYN‐1 is a key component of a pathway that regulates vesicle transport during the removal of apoptotic cells.
Hepatic steatosis induced by methionine‐choline deficiency alters the response to ischemia/reperfusion
Authors: Tevar Amit D , Clark Calissia , Wang Jiang , Edwards Michael , Lentsch Alex B
Published: June 2021

Hepatic steatosis has been associated with poor outcomes in liver surgery and transplantation. The mechanism of this has not been fully elucidated.

In the present study, we examined the effect of liver steatosis, induced by a methionine‐choline deficient (MCD) diet, on the response to hepatic ischemia/reperfusion. MCD mice and controls were sacrificed at 3, 6 and 9 weeks and pathologic examination was performed to determine degree of steatosis, inflammation and fibrosis. Mice at these times also underwent 90 min of partial hepatic ischemia followed by 1, 4 and 8 hours of reperfusion. Serum and histological analyses were performed to assess functional and pathologic injury to the liver.

At 3, 6 and 9 weeks MCD mice showed progressive fibrosis and consistent severe hepatic macrosteatosis. In control mice, hepatocellular damage, as measured by serum transaminases, was increased as reperfusion time increased. Surprisingly, MCD mice had less necrotic liver injury than control mice. In contrast, liver accumulation of neutrophils, as measured by myeloperoxidase content, was increased in MCD mice compared to controls.

The data suggest that the response to ischemia/reperfusion in steatosis induced by the MCD diet is different than other steatotic models. This may be due to progressive inflammatory and fibrotic change and warrants further investigation of the MCD diet model.
Hepatic Stearoyl‐CoA desaturase 1 safeguards liver from inflammation induced by a high carbohydrate low‐fat diet
Authors: Liu Xueqing , Flowers Matthew , Miyazaki Makoto , Sampath Hirini , Chu Kiki , Ntambi James
Published: June 2021

High carbohydrate feeding causes liver steatosis and inflammation. Using liver‐specific SCD1 knock‐out mice (SCD1‐LKO) fed with a high‐sucrose‐very‐low‐fat (HSVLF) diet for 10 days, we identified dramatic liver inflammation, liver injury, ER stress and activation of liver macrophages in these mice with no sign of steatosis. Given the minimal fat content in HSVLF, adipose tissue with intact SCD1 in LKO mice was, however, inert in mobilizing fatty acids. Conversely, supplementation of oleate (18:1), but not stearate (18:0), to HSVLF prevented the inflammation and ER stress in the liver, suggesting a distinct role of hepatic SCD1 in maintaining liver function when the diet is deficient of unsaturated fatty acids. Furthermore, analysis on mitochondria ROS production and membrane potential revealed no damage of liver mitochondria in SCD1‐LKO mice. However, electro‐microscopy analysis detected reduced ribosome in ER in the liver of SCD1‐LKO mice, indicating decreased protein production. As a result, we then identified that the plasma albumin was significantly lower in these mice, which likely led to the inability of adipose to mobilize fatty acids. Moreover, SCD1‐LKO mice fed with HSVLF for 10 weeks still exhibited liver inflammation. These data indicate that hepatic SCD1 is both necessary and sufficient in preventing liver inflammation induced by high carbohydrate low fat diet.
The effects of adrenomedullin and methylated‐adrenomedullin treatments on some antioxidative enzyme activities and malondialdehyde levels in rat liver
Authors: Yurekli Muhittin , Esrefoglu Mukaddes , Tumer Nihal , Dogru Ilker Mehmet , Gul Mehmet , Dogru Arzu , Yýldýrým Nuran
Published: June 2021

Adrenomedullin (AdM) has many important effects such as vasorelaxant, natriuretic, proliferative/antiproliferative, regulator of adrenal hormones and ACTH secretion, antiapoptotic and antioxidant. The aim of this study is to investigate the effects of AdM and methylated‐AdM (M‐AdM) on benzo(a)pyrene (B(a)p) and heavy metals (Cd, Pb, Hg) induced oxidative stress in the rat liver. For this purpose, at first AdM was methylated. Catalase (CAT), superoxide dismutase (SOD), glutation peroxidase (GSH‐Px), and MDA levels were assessed by spectrophotometrically. Administration of M‐AdM in the Pb‐treated rats significantly increased MDA levels compared with Pb‐treated group. While AdM further decreased Pb‐induced attenuation of SOD activity, MAdM did not change. However, MAdM significantly increased SOD activity compared with AdM in Pb‐treated rats. Hg‐induced decrease of SOD activity was reversed by M‐AdM administration significantly. The administration of AdM and MAdM in B(a)p‐treated rats increased SOD, CAT and GSH‐Px activities significantly compared with B(a)p‐treated group and the increases of antioxidant enzyme activities in MAdM group more than the AdM group. These results suggest that M‐AdM may have more potent protective effect than AdM against B(a)p or heavy metal‐induced oxidative stress (Supported by The Scientific and Technological Research Council of Turkey, Project No:106T112).
Inhibition of Epidermal Growth Factor stimulated ERK phosphorylation by inositol trisphosphate kinase inhibitor
Authors: Sekar M. Chandra , Leloup Ludovic , Shao Hanshuang , Wells Alan
Published: June 2021

We have used an IP3‐kinase [IP3K] inhibitor, 2‐trifluoromethyl [6‐(4‐nitrobenzyl)‐purine] to dissect the role of inositol (1,3,4,5)P4 [IP4] in epidermal growth factor [EGF] signaling. Screening of cDNA with IP3 kinase enzyme primers indicated that at least one subtype of IP3K is present in both endothelial [EC] and fibroblast [FB] cells. Quiescent EC and FB cells were stimulated with EGF in presence and absence of IP3K inhibitor. Cell were lysed, and proteins separated by SDS gel electrophoresis; the western blots were probed with polyclonal antibody. The phosphorylation level of ERK stimulated by EGF for short time period (15 min) was significantly inhibited by 10 µM IP3K inhibitor. Phospho‐ERK was blocked by 36% in EC and 28% in FB. No consistent inhibition was observed following long term [16 h] EGF stimulation. As ERK‐phosphorylation is essential for m‐calpain activation, rear cell detachment and cell motility, our data suggests that IP4 may play a role in modulating one or more of these steps. (Supported by a grant from the National Institute of General Medical Sciences (NIH) to Alan Wells).
Identification and distribution of inositol trisphosphate receptor subtypes in catecholaminergic cell groups in rat brainstem and midbrain
Authors: Kumar Natasha N , Goodchild Ann K
Published: June 2021

Catecholaminergic (tyrosine hydroxylase immunoreactive, TH‐ir) cell groups in the brainstem are important gateways for regulating and setting blood pressure (BP), whilst those in the midbrain are involved in voluntary motor control, and diverse cognitive and behavioural functions. We have examined the distribution of inositol trisphosphate receptors subtype (IP3R1, IP3R2 and IP3R3) mRNA and protein expression in brainstem (A1, C1, A5) and midbrain (A8, A9, A10) cell groups. Digoxigenin‐labeled riboprobes encoding rat IP3R1‐3 were synthesized and validated by sequencing cDNA. Following anaesthesia and perfusion (4%PFA/0.1MPB) coronal brain sections (40 μm) of male Sprague Dawley rats were processed for in situ hybridization for IP3R1, IP3R2 and IP3R3 mRNA and immunohistochemistry (IHC) for IP3R1 and IP3R3 combined with IHC for TH‐ir. The main findings are about 30% of A8, A9, A10 cell groups contain IP3R1 (31% ± 4%, 28% ± 2% and 31% ± 1% neurons respectively, n=3) whereas IP3R1 was absent in all brainstem TH‐ir cell groups. IP3R2 was absent in all brain TH‐ir cell groups. IP3R3 mRNA was present in a subpopulation of A1, C1 and A5 neurons (3 ± 2%, 16 ± 6 % and 31 ± 8% respectively, n=3) as well as A8, A9 and A10 neurons (17%, 10% and 8% of TH‐ir neurons respectively, n=2) but IP3R3 protein was absent in all TH‐ir somata. Brainstem signaling systems using IP3R do not appear to play a major role in BP regulation, except IP3R3 in a small subpopulation. IP3R1 and IP3R3 potentially regulate the activity of a specific population of neurons controlling motor and cognitive function. Research funded by NHMRC (457068).
Phospholipase C Regulates Transcription by Modifying Histone Acetylation Levels
Authors: Galdieri Luciano , Hadi Sara , Vancura Ales
Published: June 2021

In Saccharomyces cerevisiae, phospholipase C (Plc1p encoded by PLC1 gene) is the only source of inositol polyphosphates (InsPs). Deletion of PLC1 (plc1Δ) results in slow growth, defective expression of number of inducible genes, benomyl sensitivity and several other phenotypes. The benomyl sensitivity of plc1Δ cells is caused by a defect in the expression of FLR1 gene that encodes a plasma membrane transporter. The aim of this study was to use FLR1 as a model inducible gene and elucidate why it is not expressed in plc1Δ cells. Our results showed that plc1Δ cells display a decreased level of recruitment of SWI/SNF chromatin remodeling complex and SAGA histone acetyltransferase complex and decreased acetylation of histone H3 in FLR1 promoter. Our kinetic studies indicate that histone acetylation and occupancy of SWI/SNF at the FLR1 promoter are required for its sustained expression. The mechanism of SWI/SNF occupancy might involve interaction of acetylated histones with a bromodomain in the SWI/SNF complex. The results are consistent with a model in which Plc1p and InspPs‐supported acetylation of histones are important for bromodomain‐mediated SWI/SNF retention and FLR1 expression.
Sildenafil Ameliorates Cardiomyopathy in mdx Mice
Authors: Parchen Candace M. , Percival Justin M. , Dai Dao‐Fu , Gray Heidi N , Froehner Stanley C. , Beavo Joseph A.
Published: June 2021

Duchenne muscular dystrophy (DMD) is the most prevalent type of muscular dystrophy and is the result of an X‐linked mutation in the dystrophin gene. The progression of skeletal muscle damage is rapid in DMD patients and cardiomyopathy soon follows. We have investigated whether or not sildenafil citrate, a phosphodiesterase 5 (PDE5) inhibitor, can be used to ameliorate the age‐related cardiac dysfunction in dystrophin‐null (mdx) mice, a mouse model of DMD. Using echocardiography, we show that chronic sildenafil treatment improves several functional deficits in the cardiac performance of aged mdx mice. Collagen VI levels are also lower in the hearts of sildenafil‐treated mdx mice, suggesting a remodeling of the extracellular matrix. This is the first study to report a cardioprotective effect of PDE5 inhibition in aged mdx mice. Overall, the data suggest that PDE5 inhibitors could be a useful treatment for the cardiomyopathy suffered by DMD patients. This work was supported by NIH grants DK21723 (JAB), NS059514 (SCF), MDA Development Grant (JMP) and Charley's Fund (SCF and JAB).
Comparative Study of Tissues Oxidative Stress in Hydrocotyl bonariensis Treated Rats Fed Dietary Galactose
Authors: Adebawo Olugbenga Obajimi , Ajani Emmanuel Oladipupo
Published: June 2021

Studies on toxicity of galactose and its management have been largely concentrated on the lens. The present study compared the oxidative stress that occured in various tissues of rats placed on dietary galactose and simultaneously administered with different doses of Hydrocotyl bonariensis leaf extract. Male wealing rats placed on dietary galactose and administered (orally) with different doses of the extract were used in the study. After 4 weeks of study, a significant increased level of lens and liver peroxidation with reduced activities of catalase, superoxide dismutase and reduced glutathione (GSH) were observed in rats placed on dietary galactose whereas the kidney was not significantly affected though superoxide dismutase activity of the kidney increased. Administration of 500mg/kg of extract lowered the level of peroxidation of these tissues and significantly increased the catalase activity and GSH level while superoxide dismutase activity only increased in the lens and the kidney. Our findings suggest that the lens and liver were the most at risk of oxidative stress generated with dietary galactose. The Hydrocotyl bonariensis leaf possesses active components that may be beneficial in reducing the effect of the oxidative stress.
Analysis of the cellular uptake of a novel cell penetrating peptide and peptoid
Authors: Pietak Maria‐Claire , Chaput Dale I. , Zamore Elizabeth , Goldberg Bradley , Danowski Barbara , Kehlbeck Joanne
Published: June 2021

Intracellular drug delivery is restricted by the selective permeability of the plasma membrane. This can be overcome with cell penetrating peptides (CPPs) which are short peptide sequences that can traverse the cell membrane with attached cargo. Here, we investigate the uptake of a novel CPP, thought to be more permeable due to increased polarizability, by employing an enzyme substrate assay with a fluorescence read‐out. Swiss 3t3 and Madin Darby Canine Kidney (MDCK) cells will be transfected with an enzyme. The experimental CPP, along with positive and negative controls, will be conjugated to the substrate for the enzyme, and incubated with live, transfected cells. The ideal substrate (the 'cargo') will only fluoresce once inside the cell, allowing us to compare uptake efficiencies. We will be using endocytosis inhibitors to identify the mechanism of uptake. Thus far, we have optimized DNA transfection in both cell lines by comparison of transfection reagents, cell confluence, and incubation time. Next, we will focus on perfecting the enzyme detection assay and evaluating our CPPs. Supported by Union College IEF, Merck/AAAS Summer Fellowship, and Sciortino Summer Fellowship, Union College.
Comparison between Mediterranean type diet and Mediterranean fat effects in rats neoplastic lesions
Authors: Pereira Paula Cardoso , Cabrita António Silvério , Vicente Filipa
Published: June 2021

Research had shown some implication of dietary factors in breast cancer, according to epidemiologic and experimental results. This study pretends to establish a relationship between the consumption of a diet with olive oil and a Mediterranean diet in the number and volume of breast cancer tumours. A total of 72 female rats 50 days old constituted the sample. These were divided in three groups of 24 and housed 5 in each plastic cage in a holding room under constant conditions of 22±2 °C, 55±10% humidity and a 12 h light/dark cycle. All the animals were submitted to the administration of 20 mg of 7, 12 dimethylbenzanthracene (DMBA) in olive oil, by gavages and were feed with standard diet. The Group II also received a Mediterranean‐type supplement (mixture of sardine, pepper, tomato, potato, onion lyophilized) while Group III received Olive oil in the standard food (50ml/Kg).

After 150days the animals were sacrificed and the neoplastic lesions were evaluated according to the general score and the volume. In this series we can observe a non‐significant variation in the tumours number between the three groups but the tumours volume were significantly different between the groups two and three (p<0,05). The olive oil supplemented group suffered from a greater number of neoplastic lesions but the size was significantly smaller than the other groups.
Regulation of LIV‐1 expression in breast cancer cells
Authors: Grattan Bruce J , Sankavaram Kavitha , Freake Hedley C
Published: June 2021

LIV‐1 was originally described in MCF7 breast cancer cells as an estrogen regulated transcript and then subsequently identified as a zinc transporter (SLC39A6/ZIP‐6). Given the requirements of zinc for growth, we hypothesized that LIV‐1 might be increased by factors stimulating cell division, both in MCF7 estrogen receptor positive and in receptor negative MDA‐MB‐231 cells. Cells were treated with 17 β‐estradiol, insulin, IGF‐1 and EGF and LIV‐1 mRNA concentrations assessed by RT‐PCR. Contrary to previous studies, neither estradiol nor insulin at physiological concentrations induced LIV‐1 expression in MCF7 cells, though expression was reduced by the anti‐estrogen fulvestrant. In MDA‐MB‐231 cells, insulin exposure enhanced LIV‐1 mRNA levels whereas treatment with EGF induced LIV‐1 at low concentrations and inhibited the expression of this gene at higher concentrations. As a ZIP family transporter, it was hypothesized that sequestering of extracellular zinc using the zinc specific chelator diethylenetriaminepentaacetate (DTPA) would enhance the expression of LIV‐1. However, it was found that while treatment with DTPA increased LIV‐1 mRNA concentrations in MCF7 cells, it reduced expression in MDA‐MB‐231 cells. Thus, LIV‐1 is differentially regulated in these two breast cancer cell lines, both by hormones and by zinc availability.
Resistin, but not adiponectin is elevated in Caucasian prostate cancer patients
Authors: Smith Brennan Kerr , Robinson Lindsay , Nam Robert , Ma David
Published: June 2021

Emerging evidence suggests that adipokines, such as resistin and adiponectin, play a role in modulating cancer risk. However, the role of resistin and adiponectin in prostate cancer (PCa) risk is poorly understood. 275 archived plasma samples consisting of 138 PCa cases and 137 controls were analyzed for resistin and total adiponectin protein using a Bio‐Plex human adipokine assay and xMAP technology. Overall, resistin, but not adiponectin, was significantly elevated (p=0.02) in PCa patients compared with controls. Future studies are warranted to determine the functional role of resistin in PCa. When examined by ethnicity, there was no difference between cases (n=16) and controls (n=8) in African American subjects for either adipokine. In contrast, among Caucasians, adiponectin (p=0.07) and resistin (p=0.03) were higher in PCa patients (n=114) compared with controls (n=110). Our data suggests that differences in circulating adipokines may exist between ethnic groups, but this requires further study in a larger population. (D. Ma. is funded by an NSERC Discovery grant. B.K. Smith is funded by an OGS and Sun Life Financial Research Fund)

Grant Funding Source

Ontario Graduate Scholarship and Sun Life Financial Research Fund
Dietary fat intake and lung cancer: results from the Lower Mississippi River Interagency Cancer Study
Authors: Zhang Zhenzhen , Su Joseph L. , Luckett Brian G. , Fontham Elizabeth T. H.
Published: June 2021

Lung cancer remains to be the leading cause of cancer deaths in the United States. Besides smoking, many dietary factors can also influence the development of lung cancer. This analysis is based on a population‐based case‐control study designed to assess lung cancer risk associated with occupational and/or environmental exposures. The relationship between dietary fat intake and lung cancer is examined. A food frequency questionnaire was used to assess nutrient intake prior to cancer diagnosis for cases and prior to interview for controls. After excluding subjects with extreme daily caloric intakes, 420 cases (average age 61; 51% men) and 401 controls (average age 60; 49% men) were included in the analysis. After adjusting for age, sex, race, marital status, body mass index, total caloric intake and smoking, odds ratios (OR) and 95% confidence intervals(CI) for upper quartile versus lower three quartiles of daily intake of cholesterol, saturated fat and total fat were calculated using multiple logistic regression. ORs (95% CI) for intakes of cholesterol (> 357 mg/day), saturated fat (> 28 mg/day), and total fat (> 83 mg/day) were 1.93 (1.30, 2.87), 1.77 (1.19, 2.63), and 1.62 (1.09, 2.42), respectively. In conclusion, consumption of high cholesterol, saturated fat and total fat was associated with an increased risk of lung cancer, even after controlling for cigarette smoking.

Supported by the U.S. EPA Fund R825548.
Anti‐Oxidant and Anti‐Inflammatory Properties of Purple Sweet Potato Phenolics
Authors: Cohen Sara D , Summers Caroline R , Watkins Ruth H , Huang Zhengyue , Truong Van den , Harris Gabriel K
Published: June 2021

Purple sweet potatoes (PSP) are widely consumed in Asia and are growing in popularity in the US. Past research has shown that PSP contain high phenolic content. Phenols in purple sweet potato extracts (PSPX) are thought to be anti‐inflammatory agents. The PSPX were extracted using freeze dried purple sweet potatoes and an acidified water‐ethanol extract. Determination of the total phenol concentration of the PSPX was performed using the Folin‐Ciocalteau method. The PSPX treated cells were tested for viability using the MTT assay and Trypan Blue assay. The BCA assay was done to determine protein concentration for Western Blotting. Western Blotting tested for the amount of cyclooxygenase‐2 (COX‐2) in the samples. ELISA was used to test for PGE2, a downstream product of the COX‐2 enzyme. We hypothesize that increasing concentrations of purple sweet potato phenolics will demonstrate enhanced anti‐oxidant and anti‐inflammatory effects during LPS‐induced inflammation of RAW 264.7 mouse macrophage cells. Preliminary results show that PSPX stimulated PGE2 production in the cells. This project was funded by the state of North Carolina.
Immunomodulatory effect of Avian 3000 in chickens
Authors: Lohani Madhukar , Maurice Denzil , Scott Thomas
Published: June 2021

Our study evaluated the immunomodulatory and performance properties of a nanotechnology‐based product Avian 3000® administered in drinking water to broilers. In this field trial, 48 broilers were selected from grower farms representing control and treated groups. Body and organ weights, feathering score, leg score, and bone density were the performance indicators. The immune response was assessed by measurement of serum alpha‐1‐acid glycoprotein (AGP), IgG, IgA and IgM concentrations.

Statistically significant differences were not detected in any of the performance variables measured but among the organ weights, spleen weights approached significant difference between the two groups of broilers. Serum IgG and alpha‐1‐ acid glycoprotein concentration were found to be higher in the treated as compared to the untreated (P< 0.0003 and P<0.03, respectively) but serum IgM concentration was higher (P< 0.01) in the untreated birds. The groups did not differ in serum IgA (P>0.65) and total serum protein (P>0.11). The results indicate that Avian 3000® has immunomodulatory properties in chickens and controlled experiments are needed to reproduce and expand the findings.
Restoring Proteostasis via Chaperone Networks in Ageing and Neurodegenerative Disease
Authors: Morimoto Richard , Prahlad Veena , Ben‐Zvi Anat , Gidalevitz Tali , Westerheide Sandy , Anckar Julius , Sistonen Lea , Guisbert Eric , Czyz Daniel , Voisine Cindy , Silva Catarina , Beam Monica
Published: June 2021

The health of the proteome places a demand upon protein quality control and the proteostasis network to sense misfolded proteins. Whether due to mutations in disease‐associated genes, errors from missense mutations and post‐translational modifications, ageing, and exposure to physiological and environmental stress, this represents a profound challenge. Protein conformational diseases including expression of Huntingtin and polyQ‐proteins, mutant SOD1, or Aβ result in toxic, gain‐of‐function, oligomers and aggregates that interfere with folding and clearance mechanisms and the stability of proteome. In turn, this leads to disruption of signaling pathways and results in cellular dysfunction. In C. elegans this can be restored by specific members of the chaperome and activation of stress response transcription factors Hsf1 and Daf‐16 that enhance cell protective pathways to restore protein homeostasis. This also has long‐term benefits to the healthspan of the organism. At the organismal level in C. elegans, the heat shock response is regulated by the AFD thermosensory neurons that sense temperature to regulate Hsf1 and expression of heat shock genes in all somatic tissues. The transmission of the heat shock signal requires active neuronal activity, that serves to integrate temperature‐dependent behavioral, metabolic, and stress‐related responses with direct effects on lifespan.
Use of simple anthropometrical measurements as predictors of cardiovascular risk factors in Mexican children
Authors: Caamaño Maria del Carmen , García Olga Patricia , Arellano María del Rocío , Rosado Jorge Luis
Published: June 2021

The objective of this study was to examine different anthropometric measurements to develop better predictors of cardiovascular risk (CVR) factors in obese children . In 905 children weight, height, waist, hip circumference and triceps and subscapular skinfolds were measured. 307 children were randomly selected to measure lipid profile. Logistic regressions and the Receivers Operating Characteristics (ROC) analysis were performed to determine the best anthropometry predictors of CVR. 35% of children had BMI‐for‐age> 85 percentile and 18% > 95 percentile. In logistic regressions, triceps and subescapular skinfolds predicted the presence of CVR. In ROC analysis triglycerides was the CVR factor that was best predicted by anthropometric measurements; subscapular skinfold had the highest Area Under the Curve (AUC =70) . Among boys, triglycerides and LDL cholesterol were best predicted by waist‐to‐hip ratio and triceps skinfold respectively. Among girls, only high triglycerides was well predicted by subscapular skinfold, waist‐to‐height ratio, BMI, waist circumference and the sum of both skinfolds. In conclusion, skinfolds measurement may be a simple way to accurately predict CVR factors in children.
Energy intake from snacks by children in public primary schools in 11 States in Mexico
Authors: Ramírez‐Silva Claudia Ivonne , Campirano_Nuñez Fabricio , Hernadez‐Cordero Sonia , Herrera de Vicente Verónica , Concha‐Caloca Karina , Rivera‐Dommarco Juan
Published: June 2021

Introduction

Children attending public primary schools (PPS) in Mexico spend 4‐6 h at school every day. Some schools offer breakfast but none of them offer lunch.

Objective

To evaluate the caloric content of foods and beverages consumed as a snack by children in PPS in Mexico, excluding breakfast.

Methods

The caloric intake from snacks of 309 children in 44 PPS in 11 States in the North, Center and South regions was assessed. Energy content of foods was estimated based on weight and preparation methods. Mean energy intakes were computed and adjusted for sex, age and BMI using linear regression models

Results

The average energy intake of children from snacks while at schools was 463 Kcal or 24% of the energy daily recommendations (EDR) for children. Children in the Center region had the highest energy intake (495 Kcal) (p<0.05) compared to the North (396 Kcal) and South (376 Kcal) regions. It was found that 26.9% of children brought foods from home (BFH), 42.5% purchased the foods at scchool (PFE) and the remaining 30.5% did both (MIX). The energy content of the FBH (130 Kcal) was lower (p<0.05) than FPE (249.7 Kcal) and MIX (281 Kcal).

Conclusion

The energy contribution of snacks consumed at school is higher that the recommended intake of 15%‐20% of snacks at school. On average, FBH usually have a lower caloric content. These findings call for regulation of the foods and beverages sold in PPS in Mexico.
Frequency of fruits and vegetable consumption among adult Kuwaiti population
Authors: Zaghloul Sahar , Waslien Carol , Al Somaie Mona , Al Hamad Nawal , Prakash Prasanna
Published: June 2021

Prevalence of obesity and chronic diseases are on the rise among Kuwaiti adults. Kuwait National Nutrition Surveillance data (2006‐2007) were analyzed to compare selected dietary indicators between 6235 subjects, age < 20 years, 20‐49 years and >50 years. The indicators selected were frequency of consumption of fried potato, fresh fruits, carrots, other vegetables and fruit drinks. The younger group consumed fried potatoes four times as often and around 20% more fruit drinks than those > 50 years. However the > 50 years subjects consumed carrots and fresh fruits twice as often. Other vegetables were more frequently consumed among >50 group than the youngest group. However, the oldest group has the highest body mass index, blood glucose and cholesterol levels which were not explained by the selected dietary indicators. Thus, it is important to further investigate alternative explanations to these health risks.
Dietary behaviors are associated with stress after immigration in Vietnamese marriage immigrants in South Korea
Authors: Hwang Ji‐yun , Lee Sang‐Eun , Chung Hye‐Won , Kim Wha‐Young
Published: June 2021

This study was to investigate the association between dietary behaviors and the risk of stress after immigration in female Vietnamese immigrants. Cross‐sectional analysis of a prospective cohort was conducted on 582 Vietnamese wives visiting 13 clinical centers from Nov. 2006 to 2007. Stress after immigration was measured by Psychological Well‐being Index‐Short Form. Subjects were categorized into two groups: healthy (25.3%) and potentially stressed (60.7%) or stressed (14.0%). Multivariate logistic regression was used. Subjects whose education was less than completion of middle school had 1.562 times (95%CI=1.033‐2.363) higher risk of stress than the more educated. As length of residence in Korea increased, the risk increased (OR=1.237; 95%CI=1.067‐1.433). Underweight ones (BMI<18.5) were more likely to be stressed than overweight (BMI=23) (OR=2.164; 95%CI=1.100‐4.259). Subjects with irregular meals had 1.506 times (95%CI=1.001‐2.268) greater risk than ones without. The risk was higher in subjects who changed meal patterns after immigration (OR=2.114; 95%CI=1.408‐3.174). Subjects with a balanced diet had a 36.5% lower risk than ones without (OR=0.635; 95%CI=0.418‐0.967). Dietary behaviors might be independent risk factors of stress in Vietnamese immigrants. (Supported by a grant of Korea Centers for Disease Control and Prevention (2007‐090‐091‐4854‐300) & 2nd stage of BK21 Project in 2008)
Micronutrient Deficiencies Among School Girls from Tigray, Northern Ethiopia
Authors: Mulugeta Afework , Gebre Mehari , Abdulkadir Mahmud , Tsadik Asfaw G , Yesus Araya G , Stoecker Barbara J.
Published: June 2021

A total of 413 girls, 10‐15 y, were randomly selected from nine schools. Age and exam scores were collected from the school register. Anthropometric measurements, clinical assessments and biological samples were obtained using standard techniques. The prevalence of stunting was 24.5%, and 26.4% of girls had BMI = ‐2z scores. Entamoeba histolytica (19.8%) and Hymenolepis nana (6.3%) were the common intestinal parasites. Only 4% of the girls had hematocrits of =36%. Goiter as assessed by palpation was 45.3% and Bitot's spot prevalence was 2.4%. The local term "hima", describing night blindness, was mentioned by 27.4% of the girls, suggesting that the problem is occurring with some regularity in the study communities. Girls without goiter performed better in math than the goitrous girls (57.6% vs. 53.5%, p=0.007). Stunted girls had lower MUAC (18.1 vs. 18.8 cm, p=0.0038) and hematocrit levels (42.1 vs. 43.2%, p=0.0075). Age was correlated inversely to HAZ (r=‐0.1886, p = 0.0001) and positively to BMI (r=0.5092, p<0.0001). Maternal education was significantly associated with MUAC (p=0.0008) and BMIz scores (p=0.0221). Age (p<0.0001) and hematocrit levels (p=0.0201) were the main predictors of girls' stunting. Iodine and vitamin A, but not iron deficiency anemia, were public health problems in adolescent girls from the study communities. (Supported by Norwegian Agency for Development Cooperation, Mekelle Univ., Ethiopia, and Oklahoma State Univ., USA).
Effect of iron status on olfactory uptake of manganese and its distribution in the brain
Authors: Kim Jonghan , Böhlke Mark , Thompson Khristy , Takahashi Masaya , Phattanarudee Siripan , Maher Timothy , Wessling‐Resnick Marianne
Published: June 2021

Behavioral and motor dysfunction are associated with airborne manganese (Mn) exposures. We have previously found that iron deficiency enhances olfactory Mn uptake. We further investigated the effect of iron deficiency on brain distribution of intranasally‐instilled manganese using MRI. Weanling rats were fed either control chow (220 ppm Fe) or iron‐deficient diet (5 ppm Fe) for 4 weeks. MnCl2 (30‐60 mg/kg) or water (control) was repeatedly instilled through the right nostril for 1‐3 weeks and T1‐weighted MRI for brain Mn was obtained. Most brain areas accumulated more Mn in iron‐deficient rats compared with control rats, but with no preferential regional distribution. Normalized signal intensities indicated olfactory Mn uptake was doubled in iron‐deficient rats. Microdialysis was used to determine dopamine concentrations in the striatum (AP+0.07, LR‐0.28, DV‐0.38 cm) in a similar cohort of rats. Neither iron status nor intra‐nasal Mn instillation altered potassium‐evoked striatal dopamine levels, suggesting that neurological effects associated with Mn exposure do not result from dopamine depletion. Supported by NIH grant ES014638.
Immunohistochemical expression of estrogen receptor α and β in pituitary adenomas
Authors: Manoranjan Branavan , Salehi Fateme , Scheithauer Bernd W , Rotondo Fabio , Kovacs Kalman , Cusimano Michael D
Published: June 2021

Estrogen is involved in pituitary tumorigenesis, acting through estrogen receptors alpha (ERα) and beta (ERβ). Our study investigated the prognostic value of ERα/ERβ as markers in pituitary adenomas. Tissue samples and clinico‐pathological data (patient age and sex, tumor size, invasiveness and recurrence) were obtained from 78 patients with pituitary adenomas. Immunohistochemistry was performed using the streptavidin‐biotin‐peroxidase complex method. A monoclonal and polyclonal antibody were used for ERα and ERβ expression respectively. Intensity of ERα/ERβ expression was evaluated using a scale of 0 to 3. Percentage of positive cells was evaluated on a scale of 0 to 4. ERα immunopositivity was evident in 40 of 78 cases (51%), while ERβ stained positive in 49 of 78 cases (63%). No correlation was found between ERβ expression and pituitary tumor cell types or clinico‐pathological factors. A significant difference was present in ERα expression between different tumor types. ERα positivity was present to a greater extent in macroadenomas. This finding supports the role of ERα in tumor growth and progression. Elevated ERα positivity and intensity were also found in non‐invasive adenomas. It appears that ERα may be a valuable biological marker for tumor size and invasiveness, while ERβ is a poor marker. The role of ERα expression in pituitary tumor initiation and progression warrants further investigation.
Diverse effects of DNMT1 inhibition and MBD2 knockdown on gene expression in Hep3B and HepG2 cells
Authors: Lee Kyung‐Seon , Lobo Rebecca C. , Her Cindy , Young Stephanie , Green Ralph , Miller Joshua W.
Published: June 2021

Cancer cell DNA is globally hypomethylated, but has regions of hypermethylation. Such regional hypermethylation, mediated by methylated DNA binding (MBD) proteins, inhibits gene expression. Demethylation of DNA or inhibition of MBD proteins may prove beneficial in treating cancers. We are investigating the effects on gene expression of 5‐aza‐2′‐deoxycytidine (ADC), an inhibitor of DNA methyltransferase 1 (DNMT1), and siRNA directed against MBD protein 2 (MBD2) in the human liver cancer cell lines, Hep3B and HepG2. Cells are treated in vitro for 72h with 1 µM ADC in dimethylsulfoxide (DMSO) or with DMSO alone, or are transfected for 72h with siRNA directed against MBD2 or with scrambled siRNA. RNA is then isolated for microarray analysis (Affymetrix). ADC‐treated Hep3B and HepG2 cells exhibited increased expression (≥2‐fold) of 168 and 166 genes, respectively. Only 10 of these genes were the same in both cell lines. There was no overlap between the two cell lines in classes of genes that were induced by ADC. MBD2 siRNA induced in Hep3B cells increased expression (≥2‐fold) of 351 genes. Only 5 of these genes were also induced by ADC in Hep3B cells. Inhibition of DNMT1 by ADC and knockdown of MBD2 by siRNA lead to unique molecular responses in liver cancer cells. The ramifications of these findings with respect to therapies that target epigenetic factors remain to be determined. American Cancer Society