Other Biochemistry, Biophysics, and Structural Biology Commons^™

Intraperitoneal Nanotherapy For Metastatic Ovarian Cancer Based On Sirna-Mediated Suppression Of Dj-1 Protein Combined With A Low Dose Of Cisplatin, Canan Schumann, Stephanie Chan, Jess A. Miller, Yuliya Bortnyak, Katherine Carey, Alex Fedchyk, Leon Wong, Tetiana Korzun, Abraham S. Moses, Anna Lorenz, Delany Shea, Olena Taratula, Oleh Khalimonchuk, Oleh Taratula

Biochemistry -- Faculty Publications

Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth ...

Total Mercury Determination In Muscle And Liver Tissue Samples From Brazilian Amazon Fish Using Slurry Sampling, João Vitor De Queiroz, José Cavalcante Souza Vieira, Izabela Da Cunha Bataglioli, Alis Correia Bittarello, Camila Pereira Braga, Grasieli De Oliveira, Cilene Do Carmo Federici Padilha, Pedro De Magalhães Padilha

Biochemistry -- Faculty Publications

This paper presents a slurry sampling method for total mercury determination by graphite furnace atomic absorption spectrometry (GFAAS) in tissue of fish from the Amazon. The tissue samples were lyophilized and macerated, and then the slurry samples were prepared by putting 20 mg of tissue, added to a solution containing Triton X-100, Suprapur HNO₃, and zirconium nitrate directly in sampling vials of a spectrometer. Mercury standard solutions were prepared under the same conditions as the slurry samples. The slurry samples and the mercury standard solutions were sonicated for 20 s. Twenty microliters of slurry samples were injected into the ...

Cancerdiscover: An Integrative Pipeline For Cancer Biomarker And Cancer Class Prediction From High-Throughput Sequencing Data, Akram Mohammed, Greyson Biegert, Jiri Adamec, Tomáš Helikar

Biochemistry -- Faculty Publications

Accurate identification of cancer biomarkers and classification of cancer type and subtype from High Throughput Sequencing (HTS) data is a challenging problem because it requires manual processing of raw HTS data from various sequencing platforms, quality control, and normalization, which are both tedious and timeconsuming. Machine learning techniques for cancer class prediction and biomarker discovery can hasten cancer detection and significantly improve prognosis. To date, great research efforts have been taken for cancer biomarker identification and cancer class prediction. However, currently available tools and pipelines lack flexibility in data preprocessing, running multiple feature selection methods and learning algorithms, therefore, developing ...

Differential Effects Of Sodium And Magnesium Sulfate On Water Consumption By Beef Cattle, A. S. Grout, D. M. Veira, D. M. Weary, M. A. G. Von Keyserlingk, D. Fraser

David Fraser, Ph.D.

The existing guidelines for maximum sulfate (SO4) in cattle drinking water are based on Na2SO4, although many water sources contain greater concentrations of MgSO4. Two experiments compared the effect of different SO4 salts on water consumption and fecal DM of cattle. In Exp. 1, 8 yearling heifers (initial BW = 345 ± 8 kg; mean ± SD) were watered twice daily with tapwater or water containing Na2SO4 or MgSO4 at target levels of 1,500, 3,000, or 4,500 mg of SO4/L for 2-d treatment periods separated by 2 d of access to tapwater. In Exp. 2, 16 yearling cattle (initial ...

Mitochondrial Reactive Oxygen Species In Lipotoxic Hearts Induces Post-Translational Modifications Of Akap121, Drp1 And Opa1 That Promote Mitochondrial Fission, Kensuke Tsushima, Heiko Bugger, Adam R. Wende, Jamie Soto, Gregory A. Jenson, Austin R. Tor, Rose Mcglauflin, Helena C. Kenny, Yuan Zhang, Rhonda Souvenir, Xiao X. Hu, Crystal L. Sloan, Renata O. Pereira, Vitor A. Lira, Kenneth W. Spitzer, Terry L. Sharp, Kooresh I. Shoghi, Genevieve C. Sparagna, Eva A. Rog-Zielinska, Peter Kohl, Oleh Khalimonchuk, Jean E. Schaffer, E. Dale Abel

Biochemistry -- Faculty Publications

Rationale: Cardiac lipotoxicity, characterized by increased uptake, oxidation and accumulation of lipid intermediates, contributes to cardiac dysfunction in obesity and diabetes. However, mechanisms linking lipid overload and mitochondrial dysfunction are incompletely understood.

Objective: To elucidate the mechanisms for mitochondrial adaptations to lipid overload in postnatal hearts in vivo.

Methods and Results: Using a transgenic mouse model of cardiac lipotoxicity overexpressing long-chain acyl-CoA synthetase 1 in cardiomyocytes, we show that modestly increased myocardial fatty acid uptake leads to mitochondrial structural remodeling with significant reduction in minimum diameter. This is associated with increased palmitoyl-carnitine oxidation and increased reactive oxygen species (ROS) generation ...

Purification From Human Milk Of Matriptase Complexes With Secreted Serpins: Mechanism For Inhibition Of Matriptase Other Than Hai-1, I-Chu Tseng, Feng-Pai Chou, Sheng-Feng Su, Michael Oberst, Nandakumar Madayiputhiya, Ming-Shyue Lee, Jehng-Kang Wang, David E. Sloane, Michael Johnson, Chen-Yong Lin

Michael C. Johnson

Matriptase, a type 2 transmembrane serine protease, is predominately expressed by epithelial and carcinoma cells in which hepatocyte growth factor activator inhibitor 1 (HAI-1), a membrane-bound, Kunitz-type serine protease inhibitor, is also expressed. HAI-1 plays dual roles in the regulation of matriptase, as a conventional protease inhibitor and as a factor required for zymogen activation of matriptase. As a consequence, activation of matriptase is immediately followed by HAI-1-mediated inhibition, with the activated matriptase being sequestered into HAI-1 complexes. Matriptase is also expressed by peripheral blood leukocytes, such as monocytes and macrophages; however, in contrast to epithelial cells, monocytes and macrophages ...

Ydj1 Governs Fungal Morphogenesis And Stress Response, And Facilitates Mitochondrial Protein Import Via Mas1 And Mas2, Jinglin L. Xie, Iryna Bohovych, Erin O.Y. Wong, Jean-Philippe Lambert, Anne-Claude Gingras, Oleh Khalimonchuk, Leah E. Cowen, Michelle D. Leach

Biochemistry -- Faculty Publications

Mitochondria underpin metabolism, bioenergetics, signalling, development and cell death in eukaryotes. Most of the ~1,000 yeast mitochondrial proteins are encoded in the nucleus and synthesised as precursors in the cytosol, with mitochondrial import facilitated by molecular chaperones. Here, we focus on the Hsp40 chaperone Ydj1 in the fungal pathogen Candida albicans, finding that it is localised to both the cytosol and outer mitochondrial membrane, and is required for cellular stress responses and for filamentation, a key virulence trait. Mapping the Ydj1 protein interaction network highlighted connections with co-chaperones and regulators of filamentation. Furthermore, the mitochondrial processing peptidases Mas1 and ...

Identification Of Potential Tissue-Specific Cancer Biomarkers And Development Of Cancer Versus Normal Genomic Classifiers, Akram Mohammed, Greyson Biegert, Jiri Adamec, Tomáš Helikar

Biochemistry -- Faculty Publications

Machine learning techniques for cancer prediction and biomarker discovery can hasten cancer detection and significantly improve prognosis. Recent “OMICS” studies which include a variety of cancer and normal tissue samples along with machine learning approaches have the potential to further accelerate such discovery. To demonstrate this potential, 2,175 gene expression samples from nine tissue types were obtained to identify gene sets whose expression is characteristic of each cancer class. Using random forests classification and ten-fold cross-validation, we developed nine single-tissue classifiers, two multi-tissue cancer-versus-normal classifiers, and one multi-tissue normal classifier. Given a sample of a specified tissue type, the ...

Modulation Of The Heme Electronic Structure And Cystathionine Β-Synthase Activity By Second Coordination Sphere Ligands: The Role Of Heme Ligand Switching In Redox Regulation, Sangita Singh, Peter Madzelan, Jay Stasser, Colin L. Weeks, Donald Becker, Thomas G. Spiro, James Penner-Hahn, Ruma Banerjee

Colin L. Weeks

In humans, cystathionine β-synthase (CBS) is a hemeprotein, which catalyzes a pyridoxal phosphate (PLP)-dependent condensation reaction. Changes in the heme environment are communicated to the active site, which is ~20 Å away. In this study, we have examined the role of H67 and R266, which are in the second coordination sphere of the heme ligands, H65 and C52 respectively, in modulating the heme's electronic properties and in transmitting information between the heme and active sites. While the H67A mutation is comparable to wild-type CBS, interesting differences are revealed by mutations at the R266 site. The pathogenic mutant, R266K ...

Heme Regulation Of Human Cystathionine Β-Synthase Activity: Insights From Fluorescence And Raman Spectroscopy, Colin L. Weeks, Sangita Singh, Peter Madzelan, Ruma Banerjee, Thomas G. Spiro

Colin L. Weeks

Cystathionine β-synthase (CBS) plays a central role in cysteine metabolism, and malfunction of the enzyme leads to homocystinuria, a devastating metabolic disease. CBS contains a pyridoxal 5′- phosphate (PLP) cofactor which catalyzes the synthesis of cystathionine from homocysteine and serine. Mammalian forms of the enzyme also contain a heme group, which is not involved in catalysis. It may, however, play a regulatory role, since the enzyme is inhibited when CO or NO are bound to the heme. We have investigated the mechanism of this inhibition using fluorescence and resonance Raman spectroscopies. CO binding is found to induce a tautomeric shift ...

Dietary Phytochemicals As Inhibitors Of Primary Amine Oxidase, Padraig Shanahan, Jeffrey O'Sullivan, Keith F. Tipton, Gemma Kinsella, Barry J. Ryan, Gary T. Henehan

Articles

Phytochemicals such as methylxanthines, catechins and polyphenols show health benefits in a range of diseases although their mechanism of action is not fully understood. Primary Amine Oxidase (PrAO) is widely recognised as a therapeutic drug target for the treatment of inflammatory, vascular and neurodegenerative diseases. Previous work in our laboratories showed that caffeine inhibited bovine PrAO activity with a Ki of 1.0mM. In the present study we examined a range of methylxanthines and catechins as inhibitors of bovine PrAO. The methylxanthines tested were caffeine, paraxanthine, theophylline, theobromine and 7-methylxanthine. Of these, only theobromine was an inhibitor with an IC50 ...

Metalloproteases Of The Inner Mitochondrial Membrane, Roman M. Levytskyy, Iryna Bohovych, Oleh Khalimonchuk

Biochemistry -- Faculty Publications

The inner mitochondrial membrane (IM) is among most protein-rich cellular compartments. The metastable IM sub-proteome where the concentration of proteins is approaching oversaturation creates a challenging protein folding environment with high probability for protein malfunction or aggregation. Failure to maintain protein homeostasis in such a setting can impair functional integrity of the mitochondria and drive clinical manifestations. The IM is equipped with a series of highly conserved, proteolytic complexes dedicated to the maintenance of normal protein homeostasis within this mitochondrial sub-compartment. Particularly important is a group of membrane-anchored metallopeptidases commonly known as m-AAA and i-AAA proteases, and the ATP-independent Oma1 ...

The Role Of Interactions Of Long Non-Coding Rnas And Heterogeneous Nuclear Ribonucleoproteins In Regulating Cellular Functions, Xinghui Sun, Mohamed Sham Shihabudeen Haider Ali, Matthew Moran

Biochemistry -- Faculty Publications

Long non-coding RNAs (lncRNAs) are emerging as critical regulators of various biological processes and human diseases. The mechanisms of action involve their interactions with proteins, RNA and genomic DNA. Most lncRNAs display strong nuclear localization. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a large family of RNA-binding proteins that are important for multiple aspects of nucleic acid metabolism. hnRNPs are also predominantly expressed in the nucleus. This review discusses the interactions of lncRNAs and hnRNPs in regulating gene expression at transcriptional and post-transcriptional levels or by changing genomic structure, highlighting their involvements in glucose and lipid metabolism, immune response, DNA damage response ...

Elucidating Mechanisms Of Protein Aggregation In Alzheimer’S Disease Using Antibody-Based Strategies., Benjamin A. Colvin

Dissertations

Alzheimer’s Disease (AD) is a devastating neurodegenerative disorder. There are two characteristic histopathological hallmarks in the brain: senile plaques and neurofibrillary tangles, composed of insoluble aggregates of the amyloids Amyloid-β (Aβ) and tau protein, respectively. These diagnostic markers, though distinctive, are not apparent effectors of AD pathology. Evidence has mounted suggesting smaller soluble aggregates (oligomers) of Aβ or tau are the true drivers of disease progression. This dissertation presents several amyloid biophysics projects. Aggregate biophysical parameters such as weight, shape, and conformation were measured using a range of methodologies, including Multiangle Light Scattering, Dynamic Light Scattering, UV-Circular Dichroism, UV-Fluorescence ...

Correction For Sandai Et Al., The Evolutionary Rewiring Of Ubiquitination Targets Has Reprogrammed The Regulation Of Carbon Assimilation In The Pathogenic Yeast Candida Albicans, Doblin Sandai, Zhikang Yin, Laura Selway, David Stead, Janet Walker, Michelle D. Leach, Iryna Bohovych, Iuliana V. Ene, Stavroula Kastora, Susan Budge, Carol A. Munro, Frank C. Odds, Neil A.R. Gow, Alistair J.P. Brown

Janet Walker

No abstract provided.

The Evolutionary Rewiring Of Ubiquitination Targets Has Reprogrammed The Regulation Of Carbon Assimilation In The Pathogenic Yeast Candida Albicans, Doblin Sandai, Zhikang Yin, Laura Selway, David Stead, Janet Walker, Michelle D. Leach, Iryna Bohovych, Iuliana V. Ene, Stavroula Kastora, Susan Budge, Carol A. Munro, Frank C. Odds, Neil A.R. Gow, Alistair J.P. Brown

Janet Walker

Microbes must assimilate carbon to grow and colonize their niches. Transcript profiling has suggested that Candida albicans, a major pathogen of humans, regulates its carbon assimilation in an analogous fashion to the model yeast Saccharomyces cerevisiae, repressing metabolic pathways required for the use of alterative nonpreferred carbon sources when sugars are available. However, we show that there is significant dislocation between the proteome and transcriptome in C. albicans. Glucose triggers the degradation of the ICL1 and PCK1 transcripts in C. albicans, yet isocitrate lyase (Icl1) and phosphoenolpyruvate carboxykinase (Pck1) are stable and are retained. Indeed, numerous enzymes required for the ...

Industrial Grade 2d Molybdenum Disulphide (Mos2): An In-Vitro Exploration Of The Impact On Cellular Uptake, Cytotoxicity, And Inflammation, Caroline Moore, Hugh Byrne, Jonathan N. Coleman, Yuri Volkov, Jennifer Mcintyre

Articles

The recent surge in graphene research, since its liquid phase monolayer isolation and characterization in 2004, has led to advancements which are accelerating the exploration of alternative 2D materials such as molybdenum disulphide (MoS2), whose unique physico-chemical properties can be exploited in applications ranging from cutting edge electronic devices to nanomedicine. However, to assess any potential impact on human health and the environment, the need to understand the bio-interaction of MoS2 at a cellular and sub-cellular level is critical. Notably, it is important to assess such potential impacts of materials which are produced by large scale production techniques, rather than ...

Approaching Undergraduate Research With Students Who Are Deaf And Hard-Of-Hearing, Austin U. Gehret, Jessica W. Trussell, Lea V. Michel

Journal of Science Education for Students with Disabilities

An undergraduate research experience can provide a unique opportunity for students to learn and grow as scientists; when positive, this experience is often transformative and motivates students to pursue science, technology, engineering and mathematics (STEM) graduate degrees or careers. Conversely, negative research experiences can sour a student’s opinion of research, propagate misconceptions of graduate school, and lead to attrition from STEM fields. Negative research experiences can be equally devastating for faculty mentors and may result in reluctance to mentor future research students. Using a mentoring approach that has traditionally translated to positive research experiences for hearing students may not ...

Inquiry Into Perilipin-5a Expression In Triacylglycerol Rich Vs Normal Fed Mouse Tissue, Kobi Agyepong

Honors Thesis Projects

The steep rise in both childhood and adult obesity over the past three decades has moved to the forefront of public consciousness in recent years. This development has generated a marked increase in general health awareness and lifestyle changes for a vast number of individuals, most notably in the form of increased physical activity and diet alterations. The latter point is especially salient in a biochemical context, because of the myriad factors that can result in “fat accumulation”. Chief among these factors is the Perilipin 5A gene, (known as PLIN5A) which encodes the protein Perilipin 5A of the Perilipin family ...

The Effects Of Intrauterine Growth Restriction (Iugr) On The Pulmonary Surfactant And Lung Injury, Reza Khazaee

Western Research Forum

The Effects of Intrauterine Growth Restriction (IUGR) on the Pulmonary Surfactant and Lung Injury

Khazaee R¹, McCaig LA², Hardy D¹, Yamashita CM², Veldhuizen, RAW²

Department of Physiology and Pharmacology¹, Western University, London, ON, Canada. Lawson Health Research Institute², London, ON, Canada

Background: Acute respiratory distress syndrome (ARDS) is defined as severe lung dysfunction that occurs after an insult to the lung such as an infection. The lung dysfunction in ARDS is due to alterations to surfactant, a lipid-protein mixture coats the inside of the lung and maintains the lungs’ ability to expand easily ...