Medical Biochemistry Commons^™

Fungal Mediator Tail Subunits Contain Classical Transcriptional Activation Domains, Zhongle Liu, Lawrence C. Myers

Dartmouth Scholarship

Classical activation domains within DNA-bound eukaryotic transcription factors make weak interactions with coactivator complexes, such as Mediator, to stimulate transcription. How these interactions stimulate transcription, however, is unknown. The activation of reporter genes by artificial fusion of Mediator subunits to DNA binding domains that bind to their promoters has been cited as evidence that the primary role of activators is simply to recruit Mediator. We have identified potent classical transcriptional activation domains in the C termini of several tail module subunits of Saccharomyces cerevisiae, Candida albicans, and Candida dubliniensis Mediator, while their N-terminal domains are necessary and sufficient for their …

Epigenetics As An Answer To Darwin’S “Special Difficulty,” Part 2: Natural Selection Of Metastable Epialleles In Honey Bee Castes, Douglas M. Ruden, Pablo E. Cingolani, Arko Sen, Wen Qu, Luan Wang, Marie-Claude Senut, Mark D. Garfinkel, Vincent E. Sollars, Xiangyi Lu

Biochemistry and Microbiology

In a recent perspective in this journal, Herb (2014) discussed how epigenetics is a possible mechanism to circumvent Charles Darwin’s “special difficulty” in using natural selection to explain the existence of the sterile-fertile dimorphism in eusocial insects. Darwin’s classic book “On the Origin of Species by Means of Natural Selection” explains how natural selection of the fittest individuals in a population can allow a species to adapt to a novel or changing environment. However, in bees and other eusocial insects, such as ants and termites, there exist two or more castes of genetically similar females, from fertile queens to multiple …

Overview Of Microrna Biology, Ashley M. Mohr, Justin L. Mott

Journal Articles: Biochemistry & Molecular Biology

In considering an overview of microRNA biology, it is useful to consider microRNAs as a part of cellular communication. At the simplest level, microRNAs act to decrease the expression of mRNAs that contain stretches of sequence complementary to the microRNA. This function can be likened to the function of endogenous or synthetic short interfering RNA (siRNA). However, microRNA function is more complicated and nuanced than this ‘on-off’ model would suggest. Further, many microRNA targets are themselves non-coding RNAs. In this review, we will discuss the role of microRNAs in shaping the proteome of the cell in a way that is …

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 …

The Effects Of Curcumin On The Expression Of P53 And Bcl-2 Oncoproteins On The Human Breast Carcinoma Cell Line Mda-Mb 468, Angelin S. Shajan

Theses and Dissertations

We studied the effects of curcumin on the proliferation and viability of MDA-MB-468 breast cancer cells and its effects on the expression ofBcl-2 and p53 proteins in these cells. Based on previous studies, we predicted a dose-dependent increase in p53 (tumor suppressor) expression, and a decrease in Bcl-2 (anti-apoptotic oncoprotein) expression. Briefly, MDA-MB468 cells were seeded into 12-well plates at 2.0 * 104 cells/well and allowed to grow for 72 hrs. Cells were treated with curcumin at 0, 25, 50 and 100 pM in triplicate at time zero and cultured for another 24 hours. All data were obtained using a …

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 …

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 …

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 …

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 …

ความสัมพันธ์ระหว่างความหลากหลายทางพันธุกรรมบริเวณยีน Pnpla3 และยีน Ncan กับการเกิดมะเร็งตับ, มณีรัตน์ รักษายศ

Chulalongkorn University Theses and Dissertations (Chula ETD)

มะเร็งตับมีอุบัติการณ์เพิ่มขึ้นในประเทศไทย เป็นมะเร็งที่พบบ่อยที่สุดในผู้ชายไทย และเป็นอันดับสามในผู้หญิงไทย การสะสมไขมันในตับเป็นสาเหตุหนึ่งของการเกิดมะเร็งตับ และมีแนวโน้มพบผู้ป่วยจากไขมันสะสมในตับเพิ่มขึ้น ปัจจุบันเชื่อว่าความหลากหลายทางพันธุกรรมของยีนต่างๆ ส่งผลต่อการสะสมไขมันในตับ การวิจัยนี้จึงมีจุดประสงค์เพื่อศึกษาความสัมพันธ์ระหว่างความหลากหลายทางพันธุกรรมของยีน PNPLA3 ตำแหน่ง rs738409 และยีน NCAN ตำแหน่ง rs2228603 ในผู้ป่วยมะเร็งตับ กลุ่มตัวอย่างที่ศึกษาประกอบด้วยกลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบบี จำนวน 302 ราย กลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบซี จำนวน 153 ราย กลุ่มผู้ป่วยมะเร็งตับจาก ASH/NASH จำนวน 116 ราย และกลุ่มควบคุมสุขภาพดี จำนวน 200 ราย งานวิจัยนี้ใช้เทคนิค TaqMan probe real-time PCR หาความหลากหลายทางพันธุกรรมของยีน ผลการวิเคราะห์ข้อมูลพบว่า ความถี่จีโนไทป์ GG ของยีน PNPLA3 ในกลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบบีเป็น 32 (10.6%) กลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบซีเป็น 17 (11.1%) กลุ่มผู้ป่วยมะเร็งตับจาก ASH/NASH เป็น 23 (19.8%) และกลุ่มควบคุมสุขภาพดี เป็น 22 (11.0%) โดยจีโนไทป์ GG ในกลุ่มผู้ป่วยมะเร็งตับจาก ASH/NASH สูงกว่ากลุ่มควบคุมสุขภาพดี (OR (95%CI) = 2.24 (1.12-4.47), P=0.022) นอกจากนั้นจีโนไทป์ GG ในกลุ่มผู้ป่วยมะเร็งตับจาก ASH/NASH เมื่อเทียบกับกลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบบี และกลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบซี พบว่ามีค่าสูงกว่า (OR (95%CI) = 0.45(0.24-0.86) P= 0.015 และ OR (95%CI) = 0.43(0.21-0.9), P= 0.025 ตามลำดับ) ส่วนยีน NCAN ความถี่จีโนไทป์ CC, CT และ TT ในกลุ่มผู้ป่วยมะเร็งตับจากไวรัสตับอักเสบบีเป็น 282 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …