Medical Biochemistry Commons^™

Mechanisms Of Therapeutic Resistance In Castration Resistant Prostate Cancer, Sarah Katherine Martin

Theses and Dissertations--Molecular and Cellular Biochemistry

Taxane based chemotherapy is an effective treatment for castration-resistant prostate cancer (CRPC) via stabilization of microtubules. Progression to castration-resistant prostate cancer is characterized by increased androgen receptor (AR), elevated intra-prostatic androgens and activated AR signaling despite castrate levels of androgens.

Previous studies identified that the inhibitory effect of microtubule targeting chemotherapy on AR activity was conferred by interfering with AR intracellular trafficking. The N-terminal domain (NTD) of AR was identified as a tubulin interacting domain that can be effectively targeted by the novel small molecular inhibitor, EPI. Taken together, this evidence provided the rationale that targeting AR nuclear translocation and …

Mdivi-1, A Mitochondrial Division Inhibitor, Exerts Cardioprotective Effects In Myocardial Ischemia/Reperfusion (Mi/R) When Given At Reperfusion, Devon P. Stutzman

PCOM Biomedical Studies Student Scholarship

Acute myocardial infarction (MI) remains a leading cause of morbidity and mortality worldwide. Accompanying MI is myocardial ischemia/reperfusion (MI/R) injury, which results in cardiac contractile dysfunction and additional myocardial cell death. MI/R injury is initiated in part by mitochondrial-derived reactive oxygen species due to mitochondrial membrane potential collapse and uncoupling of the electron transport chain, which may be due to mitochondrial fission in MI/R. Mitochondrial fission is in turn associated with shortening/fragmentation of mitochondria, decreased ATP production, and is thought to promote cardiac contractile dysfunction and post-reperfused cardiomyocyte loss, leading to increased infarct size. Therefore, inhibiting mitochondrial fission may be …

Interaction Between Atm Kinase And P53 In Determining Glioma Radiosensitivity, Syed F. Ahmad

Theses and Dissertations

Glioblastoma multiforme (GBM) is the most common primary brain tumor. Studies have shown that targeting the DNA damage response can sensitize cancer cells to DNA damaging agents. Ataxia telangiectasia mutated (ATM) is involved in signaling DNA double strand breaks. Our group has previously shown that ATM inhibitors (ATMi) sensitize GBM cells and tumors to ionizing radiation. This effect is greater when the tumor suppressor p53 is mutated.

The goals of this work include validation of a new ATM inhibitor, AZ32, and elucidation of how ATMi and p53 status interact to promote cell death after radiation. We propose that ATMi and …

Inhibition Of Mtor Signaling Protects Against Myocardial Reperfusion Injury, Acute Myocardial Infarction, Scott M. Filippone

Theses and Dissertations

Acute myocardial infarction (AMI) is the leading cause of death worldwide. Currently, the best method of treating cardiac ischemia is early reperfusion which, itself, induces myocardial damage. The mTOR complex is a key regulator of cardioprotection against cell stressors. We hypothesized that reperfusion therapy with Rapamycin, a potent mTOR inhibitor, would reduce infarct size in adult mouse hearts. Rapamycin was administered at the onset of reperfusion following 30 min in situ LAD ligation. After 24 hours of reperfusion, myocardial infarct size and apoptosis were significantly reduced in rapamycin-treated mice compared to control. Rapamycin inhibited pro-apoptotic protein Bax and phosphorylation of …

Drug Interactions With Glutaredoxin Orthologues, Kahlilah R. Napper, Thomas C. Leeper, Ram Khattri, Daniel Morris, Caroline Davis

Williams Honors College, Honors Research Projects

Glutaredoxin, an enzymatic protein, is an important component of cell viability and function. It catalyzes reactions involved in DNA synthesis and innate immunity [1,4]. Glutaredoxin is also essential in antibiotic resistance in pathogenic bacterial species. Pseudomonas aeruginosa in particular is responsible for infecting the lung tissue of its human hosts, resulting in the development of pneumonia and cystic fibrosis [3]. Because glutaredoxin is pertinent in cell proliferation of eukaryotic and bacterial cells alike, medicinal fragments that take advantage of the subtle differences in protein structure of the orthologous proteins can be synthesized and enhanced to bind bacterial glutaredoxins, without inhibiting …

Design, Synthesis, Antiviral Activity, And Pre-Formulation Development Of Poly-Larginine- Fatty Acyl Derivatives Of Nucleoside Reverse Transcriptase Inhibitors, Bhanu P. Pemmaraju, Swapnil Malekar, Hitesh K. Agarwal, Rakesh Tiwari, Donghoon Oh, Gustavo F. Doncel, David R. Worthen, Keykavous Parang

Pharmacy Faculty Articles and Research

The objective of this work was to design conjugates of anti-HIV nucleosides conjugated with fatty acids and cell-penetrating poly-L-arginine (polyArg) peptides. Three conjugates of polyArg cell-penetrating peptides with fatty acyl derivatives of alovudine (FLT), lamivudine (3TC), and emtricitabine (FTC) were synthesized. In general, the compounds exhibited anti-HIV activity against X4 and R5 cell-free virus with EC50 values of 1.5–16.6 μM. FLT-CO-(CH2)12-CO-(Arg)7 exhibited EC50 values of 2.9 μM and 3.1 μM against X4 and R5 cell-free virus, respectively. The FLT conjugate was selected for further preformulation studies by determination of solution state degradation and lipid solubility. The compound was found to …

Analysis Of Drug Interactions With Lipoproteins By High Performance Affinity Chromatography, Matthew R. Sobansky

Department of Chemistry: Dissertations, Theses, and Student Research

High density lipoprotein (HDL), low density lipoprotein (LDL), and very low density lipoprotein (VLDL) are lipoproteins previously shown to bind many basic and neutral hydrophobic drugs in serum. These interactions impact the distribution, delivery, metabolism, and excretion of drugs and are important in determining drug activity, pharmacokinetics, and toxicity in the human body. Information about drug-lipoprotein interactions and the strength of these interactions can be useful in determining the distribution of drugs following administration.

The research presented in this dissertation uses high performance affinity chromatography (HPAC) and packed columns to study binding of the drug propranolol to immobilized lipoproteins such …

Novel Insights Into The Role Of The Smoothened Cysteine Rich Domain In Hedgehog Signalling, Rajashree Rana

Theses and Dissertations (ETD)

The Hedgehog (Hh) signal transduction pathway functions as one of the key developmental pathways and deranged Hh signalling is associated with numerous cancer and tumor conditions. The Smoothened (Smo) G protein coupled receptor (GPCR) functions as the signal transducer of the Hh pathway and is the most attractive drug target of the pathway. The structure of the Smo receptor includes seven membrane spanning domains, extracellular and intracellular loops connecting the membranous domains and the extracellular cysteine rich domain (CRD). The extracellular CRD of the Smo receptor is homologous to the Frizzled (FzD) CRD. The FzD CRD interacts with the physiological …

Saturated Free Fatty Acids Induce Cholangiocyte Lipoapoptosis, Sathish Kumar Natarajan, Sally A. Ingham, Ashley M. Mohr, Cody J. Wehrkamp, Anuttoma Ray, Sohini Roy, Sophie C. Cazanave, Mary A. Smith, Justin L. Mott

Journal Articles: Biochemistry & Molecular Biology

Recent studies have identified a cholestatic variant of nonalcoholic fatty liver disease (NAFLD) with portal inflammation and ductular reaction. Based on reports of biliary damage, as well as increased circulating free fatty acids (FFAs) in NAFLD, we hypothesized the involvement of cholangiocyte lipoapoptosis as a mechanism of cellular injury. Here, we demonstrate that the saturated FFAs palmitate and stearate induced robust and rapid cell death in cholangiocytes. Palmitate and stearate induced cholangiocyte lipoapoptosis in a concentration-dependent manner in multiple cholangiocyte-derived cell lines. The mechanism of lipoapoptosis relied on the activation of caspase 3/7 activity. There was also a significant up-regulation …

Screening For Novel Inhibitors Of Αlpha-Ynuclein Seeded Nucleation-Dependent Aggregation And Toxicity As A Potential Therapeutic Strategy For Parkinson’S Disease, Mustafa Taleb Ardeh

Dissertations

α-Synuclein aggregation is the key pathogenic event in several important neurological disorders including Parkinson’s Disease, dementia with Lewy bodies and multiple system atrophy, giving rise to a distinct group of neurodegenerative diseases known as synucleinopathies. Although the molecular basis of α-syn toxicity has not been precisely elucidated, recent studies indicate that α-syn toxicity is mediated by a nucleation-dependent aggregation process. To elucidate the structural basis of α-synuclein mediated toxicity, we developed various methods to prepare different α-synuclein species of a defined size and morphology distribution, and we investigated their toxicity in different human dopaminergic cell lines. We observed that crude …

Mrp4-Dependent Regulation Of Fibroblast Migration, Chandrima Sinha

Theses and Dissertations (ETD)

Roles of cyclic nucleotides and cyclic nucleotide-dependent signaling molecules in regulating several signaling pathways including cell migration have long been known. However, the new and revolutionary concept is that it is not just the absence or presence of cyclic nucleotides, but a highly coordinated balance between these molecules regulates cell migration. Multi-drug resistance protein 4 (MRP4), is a member of the large family of ATP binding cassette (ABC) transporter proteins, that localizes to the plasma membrane and functions as a nucleotide efflux transporter and thus plays a pivotal role in the regulation of intracellular cyclic nucleotide dynamics. In our study …

Strengths And Weaknesses Of Hybrid Tpr Technology For Obtaining Structural And Mechanistic Insights Into Tpr Proteins, Shanshan Yu

Theses and Dissertations (ETD)

Tetratricopeptide (TPR) repeats are a 34-residue helix-turn-helix motif that when repeated pack into a superhelical structure. TPR domains are frequently found mediating protein-protein interactions, often through a central groove. One protein complex bearing numerous TPR repeats is the Anaphase Promoting Complex (APC). The anaphase-promoting complex (APC) is a multi-subunit complex, which orchestrates mitotic cell cycles. APC is an E3 ligase in the ubiquitin cascade, and directs the 26S proteosome degradation of cell-cycle regulators. Throughout mitotic progression, proteins that are key regulators of the cell cycle are assembled with polyubiquitin chains by APC.

One domain of the human APC is comprised …

Modulation Of T Lymphocytes By Tumor-Released Survivin, Jessica Marie Jutzy

Loma Linda University Electronic Theses, Dissertations & Projects

The tumor microenvironment is an area of intense interaction between normal and malignant cells. Factors and cell types within this environment can play a crucial role in the progression or regression of the tumor. Of primary interest are tumor-infiltrating T lymphocytes, which have been shown to have a key role in modifying the dynamics of the tumor microenvironment to promote or prevent tumor growth. While there is much in vitro and in vivo evidence for a modification of the tumor infiltrating T cell population toward a pro-tumor environment, what induces these changes within the tumor microenvironment has remained elusive. Our …

Role Of Host Micrornas In Kaposi's Sarcoma-Associated Herpesvirus Pathogenesis, Zhiqiang Qin, Francesca Peruzzi, Krzysztof Reiss, Lu Dai

School of Medicine Faculty Publications

MicroRNAs (miRNAs) are small non-coding RNA species that can bind to both untranslated and coding regions of target mRNAs, causing their degradation or post-transcriptional modification. Currently, over 2500 miRNAs have been identified in the human genome. Burgeoning evidence suggests that dysregulation of human miRNAs can play a role in the pathogenesis of a variety of diseases, including cancer. In contrast, only a small subset of human miRNAs has been functionally validated in the pathogenesis of oncogenic viruses, in particular, Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV is the etiologic agent of several human cancers, such as primary effusion lymphoma (PEL) and Kaposi's …

Computer-Aided Structure-Based Drug Discovery: Cxcl12, P. Aeruginosa Lpxa, And The Tiam1 Pdz Domain, Emmanuel William Smith

USF Tampa Graduate Theses and Dissertations

For structure-based drug discovery, structural information of a target protein is necessary. NMR, or X-ray crystallography can provide necessary information on active site configuration that can lead a successful virtual screening campaign into identifying binders that may then be optimized into potent inhibitors. However, many challenges exist in the structure-based drug discovery cycle. For instance, structure determination of a protein of interest can many times be a daunting task. In addition, complex structure determination, which can allow essential characterization of protein-ligand interactions, is also challenging and many times impossible. Virtual screening heavily relies on such structural information, but hit-to-lead optimization …

Peptide Arrays For Detecting Naphthenic Acids In Oil Sands Process Affected Water, Kamaljit Kaur, Subir Bhattacharjee, Rajesh G. Pillai, Sahar Ahmed, Sarfuddin Azmi

Pharmacy Faculty Articles and Research

Naphthenic acids (NAs) are water-soluble components of petroleum. The characterization and quantification of NAs by analytical methods have proved quite challenging, whilst the toxic effects of these water-soluble compounds on a variety of organisms adversely affecting reproduction and steroid production is becoming apparent. In this study, we report a fluorescence-based competitive binding method for rapid sensing of the presence of NAs using cellulosic peptide array strips as sensors. The peptide array was designed from sequences derived from the estrogen receptor (ER). Several of these peptides were able to detect the presence of NAs at low micromolar (∼5 mg L^{−1 …}

Rgs16, A Novel P53 And Prb Cross-Talk Candidate Inhibits Migration And Invasion Of Pancreatic Cancer Cells, Miranda B. Carper, James Denvir, Goran Boskovic, Donald A. Primerano, Pier Paolo Claudio

Biochemistry and Microbiology

Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting …

Er-Associated Degradation And Cadmium Dependent Rescue Of Pca1, Nathan Smith

Department of Biochemistry: Dissertations, Theses, and Student Research

Protein synthesis and proper folding is an essential process for all organisms. In eukaryotes proteins of the secretory pathway are synthesized and inserted into the lumen or membrane of the endoplasmic reticulum. Eukaryotic cells maintain a mechanism for removal of proteins unable to fold properly. This process is known as ER-associated degradation (ERAD). A poorly functioning ERAD can lead to a build-up of misfolded proteins which has been implicated in several degenerative diseases such as Alzheimer’s, Amyotrophic lateral sclerosis, and Parkinson’s. Thus, the study of how proteins are recognized, extracted from the ER, and degraded is essential for determining methods …

Helicobacter-Pylori Negative Gastritis In Children—A New Clinical Enigma, Yoram Elitsur, Deborah L. Preston

Biochemistry and Microbiology

The decrease in the prevalence of Helicobacter pylori (Hp) infection in children in the world gave rise to a new pathological finding termed as Hp-negative gastritis. Unfortunately, the term “Hp-negative gastritis” has not been identified as a pathological process and has the status of a “second cousin”; in most publications it was never mentioned as a subject to be dealt with, but was “left over” data that was never the topic of the manuscripts’ discussions. Only recently has the topic captured the attention of the pathologists who described this phenomenon in adults, yet the pathological and/or clinical spectrum or significance …

Mmu-Mir-615-3p Regulates Lipoapoptosis By Inhibiting C/Ebp Homologous Protein., Yasuhiro Miyamoto, Amy S Mauer, Swarup Kumar, Justin L. Mott, Harmeet Malhi

Journal Articles: Biochemistry & Molecular Biology

Lipoapoptosis occurring due to an excess of saturated free fatty acids such as palmitate is a key pathogenic event in the initiation of nonalcoholic fatty liver disease. Palmitate loading of cells activates the endoplasmic reticulum stress response, including induction of the proapoptotic transcription factor C/EBP homologous protein (CHOP). Furthermore, the loss of microRNAs is implicated in regulating apoptosis under conditions of endoplasmic reticulum (ER) stress. The aim of this study was to identify specific microRNAs regulating CHOP expression during palmitate-induced ER stress. Five microRNAs were repressed under palmitate-induced endoplasmic reticulum stress conditions in hepatocyte cell lines (miR-92b-3p, miR-328-3p, miR-484, miR-574-5p, …