Medical Cell Biology Commons^™

The Meiosis-Specific Cdc20 Family-Member Ama1 Promotes Binding Of The Ssp2 Activator To The Smk1 Map Kinase., Gregory Omerza, Chong Wai Tio, Timothy Philips, Aviva Diamond, Aaron M. Neiman, Edward Winter

Department of Biochemistry and Molecular Biology Faculty Papers

Smk1 is a meiosis-specific MAP kinase (MAPK) in budding yeast that is required for spore formation. It is localized to prospore membranes (PSMs), the structures that engulf haploid cells during meiosis II (MII). Similar to canonically activated MAPKs, Smk1 is controlled by phosphorylation of its activation-loop threonine (T) and tyrosine (Y). However, activation loop phosphorylation occurs via a noncanonical two-step mechanism in which 1) the cyclin-dependent kinase activating kinase Cak1 phosphorylaytes T207 during MI, and 2) Smk1 autophosphorylates Y209 as MII draws to a close. Autophosphorylation of Y209 and catalytic activity for substrates require Ssp2, a meiosis-specific protein that is …

The Effect Of Dna Methylation On Tp73 Expression In Tumorgenesis, Nujuma A. Moussa

UROP Posters

Abstract: The Effect of DNA Methylation on TP73 Expression in Tumorgenesis

Nujuma Moussa, Zhixing Yao, Zaki A. Sherif

Department of Biochemistry & Molecular Biology, Howard University College of Medicine

TP73 is a member of the TP53 family of proteins that acts as a transcription factor to help regulate cellular distress. This tumor protein may play a dual role as a tumor suppressor and tumor promoter. The TP73 gene is mapped to chromosome 1p36, a frequently deleted region in neuroblastoma and other types of tumors. While mutations in the TP53 gene are commonly known to cause noxious cancers, 30% of cancers …

Arl2bp, A Novel Ciliopathy Protein, Is Required For Cilia Microtubule Formation, Abigail Ruth Moye

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cilia are specialized organelles essential for cellular function. Not surprisingly, mutations in cilia- related genes are linked to multi-syndromic diseases termed ciliopathies. These include blinding diseases such as retinitis pigmentosa (RP). One such novel gene is ARL2BP (ARL2-binding protein) and is linked to RP and situs inversus (organ reversal) in humans, a phenotype produced by defects in the nodal cilia of developing embryos. Defects in photoreceptor cilia, as well as situs inversus in human patients, suggest that ARL2BP plays an invaluable role in the structure and function of cilia. However little is known about the role for this protein in …

The Cryopreservation Of Human Semen, And Subsequent Evaluation Of A Commercially-Available Device To Isolate Motile Sperm, Callum Andrew Robinson

Theses: Doctorates and Masters

The cryopreservation of human semen is a vital asset in assisted reproductive technologies (ART). Although advances have been in the freezing of sperm, further refinement is both necessary and ongoing. Computer-assisted semen analysis (CASA) has been increasingly utilised in both research and diagnostic however there are a range of variables that must first be controlled in order to produce reliable measurements. Following thawing, sperm must be isolated from both the original seminal plasma and the cryoprotectants; the two most used isolation methods include density gradient centrifugation (DGC) and the swim-up method.

The present thesis sought to investigate the following areas …

Cks1 Expression In Melanocytic Nevi And Melanoma, Anna A. Brożyna, Andrew Aplin, Cynthia Cohen, Grant Carlson, Andrew Joseph Page, Michael Murphy, Andrzej T. Slominski, J. Andrew Carlson

Department of Cancer Biology Faculty Papers

Cyclin-dependent kinase subunit 1 (Cks1) regulates the degradation of p27, an important G1-S inhibitor, which is up regulated by MAPK pathway activation. In this study, we sought to determine whether Cks1 expression is increased in melanocytic tumors and correlates with outcome and/or other clinicopathologic prognostic markers. Cks1 expression was assessed by immunohistochemistry in 298 melanocytic lesions. The frequency and intensity of cytoplasmic and nuclear expression was scored as a labeling index and correlated with clinico-pathological data. Nuclear Cks1 protein was found in 63% of melanocytic nevi, 89% primary and 90% metastatic melanomas with mean labeling index of 7 ± 16, …

Snf1 Dependent Destruction Of Med13 Is Required For Programmed Cell Death Following Oxidative Stress In Yeast, Stephen D Willis, David C Stieg, R. Shah, Randy Strich, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

All eukaryotic cells, when faced with unfavorable environmental conditions, have to decide whether to mount a survival or cell death response. The conserved cyclin C and its kinase partner Cdk8 play a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core mediator complex of RNA polymerase II. In S. cerevisiae, oxidative stress triggers Med13 destruction¹, which thereafter releases cyclin Ci nto the cytoplasm. Cytoplasmic cyclin C associates with mitochondria where it induces hyper-fragmentation and programmed cell death². This suggests a model in …

Novel Therapeutic Strategies For Treatment Of Castration-Resistant Prostate Cancer, Matthew A. Ingersoll

Theses & Dissertations

Prostate cancer (PCa) remains the most commonly diagnosed solid tumor and is the third leading cause of cancer-related death in United States men. While androgen deprivation therapy is the current standard-of-care treatment for metastatic PCa, most patients eventually relapse and develop castration-resistant (CR) tumors, for which there is currently no effective treatment. Therefore, synthesis of novel therapeutic agents and identification of alternative target proteins are necessary to improve treatment. Herein, I investigate the efficacy of novel imidazopyridine and statin derivatives as alternative therapeutic compounds. These molecules not only inhibit androgen receptor signaling, but also block activation of the AKT axis, …

The Role Of Yes-Associated Protein 1 In Ovarian Physiology And Pathology, Xiangmin Lv

Theses & Dissertations

Ovarian granulosa cells are the major somatic components of the ovarian follicle. Proper proliferation and differentiation of ovarian granulosa cells are essential for successful follicle development. Accumulating evidence indicates that the Hippo-YAP signaling pathway plays critical roles in both development and tumorigenesis of several organs. The present study aims to investigate the role of Yes-associated protein 1 (YAP) in ovarian granulosa cell proliferation, differentiation, and malignant transformation. At first, we found that nuclear YAP (active) was highly expressed in proliferative granulosa cells, whereas cytoplasmic YAP (inactive) was detected mainly in terminally-differentiated luteal cells. Further studies suggested that endogenous YAP activity …

A Simple And Accurate Rule-Based Modeling Framework For Simulation Of Autocrine/Paracrine Stimulation Of Glioblastoma Cell Motility And Proliferation By L1cam In 2-D Culture., Justin Caccavale, David Fiumara, Michael Stapf, Liedeke Sweitzer, Hannah J. Anderson, Jonathan Gorky, Prasad Dhurjati, Deni S. Galileo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Glioblastoma multiforme (GBM) is a devastating brain cancer for which there is no known cure. Its malignancy is due to rapid cell division along with high motility and invasiveness of cells into the brain tissue. Simple 2-dimensional laboratory assays (e.g., a scratch assay) commonly are used to measure the effects of various experimental perturbations, such as treatment with chemical inhibitors. Several mathematical models have been developed to aid the understanding of the motile behavior and proliferation of GBM cells. However, many are mathematically complicated, look at multiple interdependent phenomena, and/or use modeling software not freely available to the research …

Revealing A Non-Canonical Role Of Anti-Apoptotic Mcl-1 In Early Embryonic Development, Xue Yang

Theses and Dissertations (ETD)

MCL-1, a well-known pro-survival BCL-2 family member, is indispensable for the survival of various cellular lineages and is also among the most frequently amplified genes in a variety of human malignancies. Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In …

Induction Of Immune Surveillance Of The Dysmorphogenic Lens., Caitlin M. Logan, Caitlin J. Bowen, A. Sue Menko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The lens has been considered to be an immune privileged site not susceptible to the immune processes normally associated with tissue injury and wound repair. However, as greater insight into the immune surveillance process is gained, we have reevaluated the concept of immune privilege. Our studies using an N-cadherin lens-specific conditional knockout mouse, N-cadΔlens, show that loss of this cell-cell junctional protein leads to lens degeneration, necrosis and fibrotic change, postnatally. The degeneration of this tissue induces an immune response resulting in immune cells populating the lens that contribute to the development of fibrosis. Additionally, we demonstrate that the lens …

Niche Cadherins Control The Quiescence-To-Activation Transition In Muscle Stem Cells., Aviva J. Goel, Marysia-Kolbe Rieder, Hans-Henning Arnold, Glenn L. Radice, Robert S. Krauss

Department of Medicine Faculty Papers

Many adult stem cells display prolonged quiescence, promoted by cues from their niche. Upon tissue damage, a coordinated transition to the activated state is required because non-physiological breaks in quiescence often lead to stem cell depletion and impaired regeneration. Here, we identify cadherin-mediated adhesion and signaling between muscle stem cells (satellite cells [SCs]) and their myofiber niche as a mechanism that orchestrates the quiescence-to-activation transition. Conditional removal of N-cadherin and M-cadherin in mice leads to a break in SC quiescence, with long-term expansion of a regeneration-proficient SC pool. These SCs have an incomplete disruption of the myofiber-SC adhesive junction and …

Mechanism Of Transcription Anti-Termination In Human Mitochondria., Hauke S Hillen, Andrey V Parshin, Karen Agaronyan, Yaroslav I Morozov, James J Graber, Aleksandar Chernev, Kathrin Schwinghammer, Henning Urlaub, Michael Anikin, Patrick Cramer, Dmitry Temiakov

Rowan-Virtua School of Osteopathic Medicine Departmental Research

In human mitochondria, transcription termination events at a G-quadruplex region near the replication origin are thought to drive replication of mtDNA by generation of an RNA primer. This process is suppressed by a key regulator of mtDNA-the transcription factor TEFM. We determined the structure of an anti-termination complex in which TEFM is bound to transcribing mtRNAP. The structure reveals interactions of the dimeric pseudonuclease core of TEFM with mobile structural elements in mtRNAP and the nucleic acid components of the elongation complex (EC). Binding of TEFM to the DNA forms a downstream "sliding clamp," providing high processivity to the EC. …

A Mirna Signature For Cognitive Deficits And Alcohol Use Disorder In Persons Living With Hiv/Aids, Dorota Wyczechowska, Hui-Yi Lin, Andrea Laplante, Duane Jeansonne, Adam Lassak, Christopher H. Parsons, Patricia E. Molina, Francesca Peruzzi

School of Medicine Faculty Publications

HIV-associated neurocognitive disorders (HAND) affects more than half of persons living with HIV-1/AIDS (PLWHA). Identification of biomarkers representing the cognitive status of PLWHA is a critical step for implementation of successful cognitive, behavioral and pharmacological strategies to prevent onset and progression of HAND. However, the presence of co-morbidity factors in PLWHA, the most common being substance abuse, can prevent the identification of such biomarkers. We have optimized a protocol to profile plasma miRNAs using quantitative RT-qPCR and found a miRNA signature with very good discriminatory ability to distinguish PLWHA with cognitive impairment from those without cognitive impairment. Here, we have …

Endonucleolytic Cleavage In The Expansion Segment 7 Of 25s Rrna Is An Early Marker Of Low-Level Oxidative Stress In Yeast, Daniel Shedlovskiy, Jessica A Zinskie, Ethan Gardner, Dimitri G Pestov, Natalia Shcherbik

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The ability to detect and respond to oxidative stress is crucial to the survival of living organisms. In cells, sensing of increased levels of reactive oxygen species (ROS) activates many defensive mechanisms that limit or repair damage to cell components. The ROS-signaling responses necessary for cell survival under oxidative stress conditions remain incompletely understood, especially for the translational machinery. Here, we found that drug treatments or a genetic deficiency in the thioredoxin system that increase levels of endogenous hydrogen peroxide in the yeast Saccharomyces cerevisiae promote site-specific endonucleolytic cleavage in 25S ribosomal RNA (rRNA) adjacent to the c loop of …

Ros Control Mitochondrial Motility Through P38 And The Motor Adaptor Miro/Trak., Valentina Debattisti, Akos A. Gerencser, Masao Saotome, Sudipto Das, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial distribution and motility are recognized as central to many cellular functions, but their regulation by signaling mechanisms remains to be elucidated. Here, we report that reactive oxygen species (ROS), either derived from an extracellular source or intracellularly generated, control mitochondrial distribution and function by dose-dependently, specifically, and reversibly decreasing mitochondrial motility in both rat hippocampal primary cultured neurons and cell lines. ROS decrease motility independently of cytoplasmic [Ca2+], mitochondrial membrane potential, or permeability transition pore opening, known effectors of oxidative stress. However, multiple lines of genetic and pharmacological evidence support that a ROS-activated mitogen-activated protein kinase (MAPK), p38α, is …

Role Of Microglial Amylin Receptors In Mediating Beta Amyloid (Aβ)-Induced Inflammation, Wen Fu, Vlatka Vukojevic, Aarti Patel, Rania Soudy, David Mactavish, David Westaway, Kamaljit Kaur, Valeri Goncharuk, Jack Jhamandas

Pharmacy Faculty Articles and Research

Background: Neuroinflammation in the brain consequent to activation of microglia is viewed as an important component of Alzheimer’s disease (AD) pathology. Amyloid beta (Aβ) protein is known to activate microglia and unleash an inflammatory cascade that eventually results in neuronal dysfunction and death. In this study, we sought to identify the presence of amylin receptors on human fetal and murine microglia and determine whether Aβ activation of the inflammasome complex and subsequent release of cytokines is mediated through these receptors.

Methods: The presence of dimeric components of the amylin receptor (calcitonin receptor and receptor activity modifying protein 3) …

Evaluating The Therapeutic Effect Of Purslane Extract On The Submandibular Salivary Glands Of Cyclosporine-A Treated Rats, Heba Mahmoud, Rabab T. Mubarak, Iman M. Aboushady

Dentistry

Salivary glands are affected by immunosuppressive drugs, like Cyclosporine-A (CsA) which plays a major role in transplant medicine. Thus, this work aimed to study the possible therapeutic effect of purslane on CsA induced salivary gland alterations.

Materials & Methods: 30 adult male albino rats were equally divided into 3 groups: control group ] received a vehicle, CsA group received 20 mg/kg/day of CsA, and combination group received CsA and 400mg/kg/day of purslane. Three weeks later rats were sacrified then the submandibular salivary glands were prepared for histological andKi67 immunohistochemical analysis, then the studied groups were statistically evaluated.

Results: Histological examination …

Decorin-Evoked Paternally Expressed Gene 3 (Peg3) Is An Upstream Regulator Of The Transcription Factor Eb (Tfeb) In Endothelial Cell Autophagy., Thomas Neill, Catherine Sharpe, Rick T. Owens, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Macroautophagy is a fundamental and evolutionarily conserved catabolic process that eradicates damaged and aging macromolecules and organelles in eukaryotic cells. Decorin, an archetypical small leucine-rich proteoglycan, initiates a protracted autophagic program downstream of VEGF receptor 2 (VEGFR2) signaling that requires paternally expressed gene 3 (PEG3). We have discovered that PEG3 is an upstream transcriptional regulator of transcription factor EB (TFEB), a master transcription factor of lysosomal biogenesis, for decorin-evoked endothelial cell autophagy. We found a functional requirement of PEG3 for TFEB transcriptional induction and nuclear translocation in human umbilical vein endothelial and PAER2 cells. Mechanistically, inhibiting VEGFR2 or AMP-activated protein …

Effect Of Extracellular Survivin And Lymphoma Exosomes On Natural Killer Cells, Heather R. Ferguson Bennit

Loma Linda University Electronic Theses, Dissertations & Projects

Tumors alter their microenvironment to promote survival using methods such as angiogenesis promotion, growth signals, and immune suppression. The immune system becomes unresponsive to transformed neoplastic cells through a variety of methods including T cell suppression, increased myeloid-derived suppressor cells (MDSCs), and reduced natural killer (NK) cell activity. NK cells have inherent killing capabilities and thus are among the first responders in recognizing and destroying abnormal cells. However, many types of cancers inhibit the surveillance and cytotoxic abilities of NK cells by releasing exosomes, vesicles that can modulate the tumor microenvironment (TME) and intercellular communication for the purpose of enhancing …