Pharmacology, Toxicology and Environmental Health Commons^™

Testing The Substrate-Envelope Hypothesis With Designed Pairs Of Compounds, Yang Shen, Michael Altman, Akbar Ali, Madhavi Nalam, Hong Cao, Tariq Rana, Celia Schiffer, Bruce Tidor

Celia A. Schiffer

Acquired resistance to therapeutic agents is a significant barrier to the development of clinically effective treatments for diseases in which evolution occurs on clinical time scales, frequently arising from target mutations. We previously reported a general strategy to design effective inhibitors for rapidly mutating enzyme targets, which we demonstrated for HIV-1 protease inhibition [Altman et al. J. Am. Chem. Soc. 2008, 130, 6099-6113]. Specifically, we developed a computational inverse design procedure with the added constraint that designed inhibitors bind entirely inside the substrate envelope, a consensus volume occupied by natural substrates. The rationale for the substrate-envelope constraint is that it …

Development Of A Novel Screening Strategy Designed To Discover A New Class Of Hiv Drugs, Nancy Cheng, Sook-Kyung Lee, P. Donover, Mel Reichman, Celia Schiffer, Emily Hull-Ryde, Ronald Swanstrom, William Janzen

Celia A. Schiffer

Current antiretroviral treatments target multiple pathways important for human immunodeficiency virus (HIV) multiplication, including viral entry, synthesis and integration of the DNA provirus, and the processing of viral polyprotein precursors. However, HIV is becoming increasingly resistant to these "combination therapies." Recent findings show that inhibition of HIV Gag protein cleavage into its two structural proteins, matrix (MA) and capsid (CA), has a devastating effect on viral production, revealing a potential new target class for HIV treatment. Unlike the widely used HIV protease inhibitors, this new class of inhibitor would target the substrate, not the protease enzyme itself. This approach offers …

Hiv-1 Protease-Substrate Coevolution In Nelfinavir Resistance, Madhavi Kolli, Aysegul Ozen, Nese Yilmaz, Celia Schiffer

Celia A. Schiffer

Resistance to various human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. The virus accumulates mutations within the protease (PR) that render the PIs less potent. Occasionally, Gag sequences also coevolve with mutations at PR cleavage sites contributing to drug resistance. In this study, we investigated the structural basis of coevolution of the p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations by determining crystal structures of wild-type and NFV-resistant HIV-1 protease in complex with p1-p6 substrate peptide variants with L449F and/or S451N. Alterations of residue …

Substrate Envelope-Designed Potent Hiv-1 Protease Inhibitors To Avoid Drug Resistance, Madhavi Nalam, Akbar Ali, G. S. Kiran Kumar Reddy, Hong Cao, Saima Anjum, Michael Altman, Nese Yilmaz, Bruce Tidor, Tariq Rana, Celia Schiffer

Celia A. Schiffer

The rapid evolution of HIV under selective drug pressure has led to multidrug resistant (MDR) strains that evade standard therapies. We designed highly potent HIV-1 protease inhibitors (PIs) using the substrate envelope model, which confines inhibitors within the consensus volume of natural substrates, providing inhibitors less susceptible to resistance because a mutation affecting such inhibitors will simultaneously affect viral substrate processing. The designed PIs share a common chemical scaffold but utilize various moieties that optimally fill the substrate envelope, as confirmed by crystal structures. The designed PIs retain robust binding to MDR protease variants and display exceptional antiviral potencies against …

Pact/Rax Regulates The Migration Of Cerebellar Granule Neurons In The Developing Cerebellum, Yue Yong, Ya Meng, Hanqing Ding, Zhiqin Fan, Yifen Tang, Chenghua Zhou, Jia Luo, Zun-Ji Ke

Pharmacology and Nutritional Sciences Faculty Publications

PACT and its murine ortholog RAX were originally identified as a protein activator for the dsRNA-dependent, interferon-inducible protein kinase PKR. Recent studies indicated that RAX played a role in embryogenesis and neuronal development. In this study, we investigated the expression of RAX during the postnatal development of the mouse cerebellum and its role in the migration of cerebellar granule neurons (CGNs). High expression of RAX was observed in the cerebellum from postnatal day (PD) 4 to PD9, a period when the CGNs migrate from the external granule layer (EGL) to the internal granule layer (IGL). The migration of the EGL …

The Effects Of Environmental Prompts On Stair Usage, Lori Andersen, Tim Bungum, Sheniz Moonie Phd

Nevada Journal of Public Health

Experts have advocated exercise with little success, and have turned to encouraging physical activity by incorporating it into daily activities such as taking the stairs over elevators. Much literature exists suggesting that environmental prompts can encourage the use of stairs and literature has established that some messages may be more effective than others. This study aimed to assess the effects of selected signage prompts on stair usage. Methods: Stair and elevator use were monitored in three, two-story buildings. One building served as a control, while a fitness message was placed in another building, and the final building received a weight …

Development Of Irreversible Substrate Competitive Probes For Pka Activity, Robert A. Coover

Theses and Dissertations

The current environment for drug discovery and disease treatment relies heavily on genomic analysis, structural biology and chemical biology techniques. With the enormous advances in genomic analysis and structural biology, the use of and desire for targeted therapies has increased. However, as more genomic data for cancer disease state pathology becomes available we must ask increasingly difficult questions and even produce new technologies, such as activity-based probes, to answer these questions.

In particular, targeted kinase inhibitors for the treatment of cancer has become a mainstay for drug development for both industry and academia, but it is evident that the genomic …

Raman Micro-Spectroscopy For Rapid Screening Of Oral Squamous Cell Carcinoma, Luis Felipe Carvalho, Franck Bonnier, Kate O'Callaghan, Jeff O'Sullivan, Stephen Flint, Hugh Byrne, Fiona Lyng

Articles

Raman spectroscopy can provide a molecular-level fingerprint of the biochemical composition and structure of cells with excellent spatial resolution and could be useful to monitor changes in composition for dysplasia and early, non-invasive cancer diagnosis (carcinoma in situ), both ex-vivo and in vivo. In this study, we demonstrate this potential by collecting Raman spectra of nucleoli, nuclei and cytoplasm from oral epithelial cancer (SCC- 4) and dysplastic (pre-cancerous, DOK) cell lines and from normal oral epithelial primary cell cultures, in vitro, which were then analysed by principal component analysis (PCA) as a multivariate statistical method to discriminate the spectra. Results …

The Role Of E3 Ligase Parkin In Trafficking Of Monoamine Storage Vesicles In Rat Model Of Methamphetamine Neurotoxicity, Heli Dineshchandra Chauhan

Wayne State University Theses

Methamphetamine (METH), a psychostimulant, is a widely used drug of abuse. METH is toxic to dopaminergic (DAergic) and serotonergic (5-HT) nerve terminals in the striatum when administered at high doses. METH releases Dopamine (DA) from vesicular monoamine transporter 2 (VMAT2) containing synaptic vesicles and induces oxidative stress by auto-oxidation of DA. The VMAT2 plays a neurprotective role by sequestering cytoplasmic DA into vesicles for storage and protection from auto-oxidation. It has previously been shown that METH toxicity is associated with impaired VMAT2 trafficking and oxidative damage to the E3 ligase parkin. CDCrel1, a protein found to inhibit exocytosis, is regulated …

Novel Protein Phosphatase 2a Complexes In Skeletal Muscle From Obese Insulin Resistant Human Participants, Divyasri Damacharla

Wayne State University Theses

Type 2 Diabetes is a metabolic disorder associated with insulin resistance and consequent high blood glucose levels. Maximum glucose disposal takes place in skeletal muscle and studying skeletal muscle insulin resistance is crucial. Protein Phosphatase 2A (PP2A) is one of the major serine/threonine phosphatases belonging to PhosphoProteinPhosphatase (PPP) family. It constitutes about 80% of all serine/threonine phosphatases. It is regulated by numerous regulatory subunits as well as other substrate molecules and post translational modifications. This alters their localization, activity and also its target molecules. Many evidences show the effect of insulin on PP2Ac and its abnormal regulation in conditions of …

Contaminants Of Emerging Concern: Effects Of Known Neuroactive Agents, Antibiotics, And Chemically Uncharacterized Photodegredates On Behavior And Physiology Of Daphnia Pulex, Vibhuti Matta

Wayne State University Theses

Emerging contaminants such as pharmaceuticals and personal care products (PPCPs), herbicides, pesticides, plasticizers, fire retardants, polycyclic aromatic hydrocarbons (PAHs), and other organic waste are increasingly being detected in surface water and ground water. These contaminants can enter into the environment through wastewater treatment plant effluent and agriculture runoff. Many of these emerging contaminants tend to be biologically active at very low concentrations, typically occur in water as part of complex mixtures, and may impact biota at concentrations not detected using traditional toxicity tests (e.g. LC 50 tests).

This study focuses on utilizing novel Daphnid optical bioassays to examine the toxicity …

Protein Ubiquitination In Primary Human Skeletal Muscle Cells Under Hyperinsulinemic Hyperglycemic Conditions, Majed Abdullah Alharbi

Wayne State University Theses

Ubiquitin proteasome system is a relatively newly discovered pathway for protein degradation. Many studies have successfully pointed out the critical functions that UPS plays in regulating many physiological processes. On the other hand, recent studies suggested that abnormal UPS activities might be involved in the pathophysiology of several disorders including type 2 diabetes. However, the specific changes in UPS during the development of insulin resistance and consequently T2D are still unclear.

UPS is composed of two major steps, a reversible ubiquitin conjugation to the targeted substrate followed by proteasomal degradation of the ubiquitinated proteins. In this study, we examined the …

A Retrospective Cohort Study Of High Prevalence Of St131 Among Extended Spectrum Β-Lactamase Producing E. Coli Among Inpatients In The Metropolitan Detroit Area, Pansy Awasthy

Wayne State University Theses

ABSTRACT

HIGH PREVALENCE OF ST131 AMONG EXTENDED SPECTRUM Β-LACTAMASE PRODUCING E. COLI AMONG INPATIENTS IN THE METROPOLITAN DETROIT AREA

by

PANSY AWSTHY

2015

Advisor: Dr. Emily T. Martin

Major: Pharmaceutical Sciences

Degree: Master of Science

Objectives: E.coli ST131 multi-locus sequence type (MLST) has been associated with extended spectrum β-lactamase (ESBL) production, conferring antimicrobial resistance, with increased virulence and with healthcare-associated infection. The high prevalence of multidrug antimicrobial resistance in ESBL-producing ST131 E.coli infections creates unique challenges in the studying patient outcomes and analysis are required to study ST131 E.coli amongst a large population of ESBL-producers. Our objective was to determine …

Characterization Of A Non-Canonical Function For Threonyl-Trna Synthetase In Angiogenesis, Adam Christopher Mirando

Graduate College Dissertations and Theses

In addition to its canonical role in aminoacylation, threonyl-tRNA synthetase (TARS) possesses pro-angiogenic activity that is susceptible to the TARS-specific antibiotic borrelidin. However, the therapeutic benefit of borrelidin is offset by its strong toxicity to living cells. The removal of a single methylene group from the parent borrelidin generates BC194, a modified compound with significantly reduced toxicity but comparable anti-angiogenic potential. Biochemical analyses revealed that the difference in toxicities was due to borrelidin's stimulation of amino acid starvation at ten-fold lower concentrations than BC194. However, both compounds were found to inhibit in vitro and in vivo models of angiogenesis at …

Ubiquitin Ligase Trim32 And Chloride-Sensitive Wnk1 As Regulators Of Potassium Channels In The Brain, Eugene Miler Cilento

Graduate College Dissertations and Theses

The voltage-gated potassium channel Kv1.2 impacts membrane potential and therefore excitability of neurons. Expression of Kv1.2 at the plasma membrane (PM) is critical for channel function, and altering Kv1.2 at the PM is one way to affect membrane excitability. Such is the case in the cerebellum, a portion of the brain with dense Kv1.2 expression, where modulation of Kv1.2 at the PM can impact electrical activity of neurons and ultimately cerebellum-dependent learning. Modulation of Kv1.2 at the PM can occur through endocytic trafficking of the channel; however mechanisms behind this process in the brain remain to be defined.

The goal …

Challenges Posed By Tick-Borne Rickettsiae: Eco- Epidemiology And Public Health Implications, Marina E. Eremeeva, Gregory A. Dasch

Environmental Health Sciences Faculty Publications

Rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. Once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. However, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vertebrate hosts or affecting humans. We have analyzed the key features of tick-borne maintenance of rickettsiae, which may provide a deeper basis for understanding those complex invertebrate interactions and strategies that have permitted …

Full Issue: Volume 9, Number 1

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

Full Issue: Volume 8, Number 2

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

A Systematic Review And Meta-Regression Analysis Of Lung Cancer Risk And Inorganic Arsenic In Drinking Water., Steven H. Lamm, Hamid Ferdosi, Elisabeth K. Dissen, Ji Li, Jaeil Ahn

Epidemiology Faculty Publications

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1-1000 µg/L. The …

The Therapeutic Targeting Of Folate Receptor Alpha Positive Tumors Via Folate Receptor Selective Novel 5- And 6- Substituted Pyrrolo [2,3-D]Pyrimidine Antifolates", Shermaine Kimberly Mitchell-Ryan

Wayne State University Dissertations

Ovarian Cancer is the fifth leading cause of cancer-related death of women in the United States. Epithelial Ovarian Cancer (EOC) constitutes 85-90% of malignancies within the ovary, with an alarming majority of these cases diagnosed at advanced stage. While most patients are initially highly responsive to the current treatment standard, there is a very high probability that they will recur with a drug resistant fatal disease. Currently there is no validated comprehensive model of disease progression for ovarian cancer, although tremendous progress has been made in understanding the origin of this disease and a putative precursor lesion has been identified …