Medical Cell Biology Commons^™

Mechanical Loading As Potential Treatment For Wnt Inhibitor Induced Bone Loss, Juraj Zahatnansky Md, Daniel Dick, Gabrielle Foxa, Robert Baker, Bart Williams Phd

Research Day

The Wnt signaling pathway has been shown to play a role in bone homeostasis and carcinogenesis. On the one hand, a decrease in signaling has been associated with a decrease in bone mass, on the other, an increase in signaling with cancer development. LGK974 is a Wnt signaling inhibitor currently being investigated as a potential cancer therapeutic agent. This molecule inhibits Porcupine, a transmembrane protein necessary for Wnt ligand secretion. In light of the above and based on our preliminary data, treatment with LGK974 leads to bone mass loss. Our investigation aims to address whether such bone loss can be …

Fdg Avid Breast Cancer Bone Metastases Silent On Ct And Scintigraphy: A Case Report With Radiologic-Pathologic Correlation, Daniel Jeong, Marilyn Bui, Daniel Peterson, Jaime Montilla-Soler, Kenneth L. Gage

Pathology and Cell Biology Faculty Publications

Bone is the one of the most common distant metastatic sites in breast cancer. Routine initial breast cancer staging evaluation typically includes computed tomography (CT) and skeletal scintigraphy while 18F fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is reserved for clinically high-risk cases. Since FDG PET-CT is not routinely performed during staging or surveillance evaluations, it is important for radiologists and clinicians to appreciate the limitations of bone metastasis detection on CT and scintigraphy. We present a case of bony metastases of invasive ductal carcinoma of the breast which were not detected on diagnostic CT or skeletal scintigraphy but were …

The Cytotoxicity Of Essential Oils On Mcf-7 Breast Cancer Cells, Desalyn Johnson, Shaylee Green

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Telomerase Reverse Transcriptase In Atherosclerosis, Hua Qing

Theses and Dissertations--Pharmacology and Nutritional Sciences

Telomerase reverse transcriptase (TERT) is the catalytic subunit of telomerase and the limiting factor for the enzyme activity. The expression of TERT and telomerase activity is increased in atherosclerotic plaques. However, the role of TERT dysregulation during atherosclerosis formation remains unknown.

The work herein first identified a multi-tiered regulation of TERT expression in smooth muscle cells (SMC) through histone deacetylase (HDAC) inhibition. HDAC inhibition induces TERT transcription and promoter activation. At the protein level in contrast, HDAC inhibition decreases TERT protein abundance through enhanced degradation, which decreases telomerase activity and induces senescence. Furthermore, during vascular remodeling in vivo, TERT protein …

Characterization Of The Role Of Insulin-Like Growth Factor Binding Protein 7 (Igfbp7) Using A Genetic Knockout Mouse Model, Maaged A. Akiel

Theses and Dissertations

In the US, the incidence and mortality rates of hepatocellular carcinoma (HCC) are alarmingly increasing since no effective therapy is available for the advanced disease. Activation of IGF signaling is a major oncogenic event in diverse cancers, including HCC. Insulin-like growth factor binding protein-7 (IGFBP7) inhibits IGF signaling by binding to IGF-1 receptor (IGF-1R) and functions as a potential tumor suppressor for hepatocellular carcinoma (HCC). IGFBP7 abrogates tumors by inducing cancer-specific senescence and apoptosis and inhibiting angiogenesis. We now document that Igfbp7 knockout (Igfbp7-/- ) mouse shows constitutive activation of IGF signaling, presents with pro-inflammatory and immunosuppressive microenvironment, and develops …

Role Of Translation Initiation In Regulation Of Epithelial Junctions And Cell Motility, Fahda Fawaz Alsharief

Theses and Dissertations

The integrity and barrier properties of intestinal epithelium are determined by specialized adhesive structures known as intercellular junctions; composed of adherens junctions (AJs), tight junctions (TJs) and focal adhesions that mediate cell-cell and cell matrix interactions, respectively. These two types of epithelial cell adhesions regulate each other during disruption and restitution of the epithelial barrier. Inflammatory cytokines such as interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) are elevated during intestinal inflammation. The most notable effects of IFNγ and TNFα on intestinal epithelial homeostasis involve disruption of apical junctions and attenuation of cell migration. Although molecular mechanisms underlying these …

Decellularized Wharton's Jelly From Human Umbilical Cord As A Novel 3d Scaffolding Material For Tissue Engineering Applications., Sushma Jadalannagari, Gabriel Converse, Eric Buse, Michael Filla, Maria T. Villar, Antonio Artigues, Adam J. Mellot, Jinxi Wang, Michael S. Detamore, Richard A. Hopkins, Omar S. Aljitawi, C Mcfall

Manuscripts, Articles, Book Chapters and Other Papers

In tissue engineering, an ideal scaffold attracts and supports cells thus providing them with the necessary mechanical support and architecture as they reconstruct new tissue in vitro and in vivo. This manuscript details a novel matrix derived from decellularized Wharton's jelly (WJ) obtained from human umbilical cord for use as a scaffold for tissue engineering application. This decellularized Wharton's jelly matrix (DWJM) contained 0.66 ± 0.12 μg/mg sulfated glycosaminoglycans (GAGs), and was abundant in hyaluronic acid, and completely devoid of cells. Mass spectroscopy revealed the presence of collagen types II, VI and XII, fibronectin-I, and lumican I. When seeded onto …

Yap And The Hippo Pathway In Pediatric Cancer., Atif Ahmed, Abdalla D. Mohamed, Melissa Gener, Weijie Li, Eugenio Taboada

Manuscripts, Articles, Book Chapters and Other Papers

The Hippo pathway is an important signaling pathway that controls cell proliferation and apoptosis. It is evolutionarily conserved in mammals and is stimulated by cell-cell contact, inhibiting cell proliferation in response to increased cell density. During early embryonic development, the Hippo signaling pathway regulates organ development and size, and its functions result in the coordinated balance between proliferation, apoptosis, and differentiation. Its principal effectors, YAP and TAZ, regulate signaling by the embryonic stem cells and determine cell fate and histogenesis. Dysfunction of this pathway contributes to cancer development in adults and children. Emerging studies have shed light on the upregulation …

Comparative Genetic Screens In Human Cells Reveal New Regulatory Mechanisms In Wnt Signaling, Andres M. Lebensohn, Ramin Dubey, Leif Neitzel, Ofelia Tacchelly-Benites

Dartmouth Scholarship

The comprehensive understanding of cellular signaling pathways remains a challenge due to multiple layers of regulation that may become evident only when the pathway is probed at different levels or critical nodes are eliminated. To discover regulatory mechanisms in canonical WNT signaling, we conducted a systematic forward genetic analysis through reporter-based screens in haploid human cells. Comparison of screens for negative, attenuating and positive regulators of WNT signaling, mediators of R-spondin-dependent signaling and suppressors of constitutive signaling induced by loss of the tumor suppressor adenomatous polyposis coli or casein kinase 1α uncovered new regulatory features at most levels of the …

Calcium Uptake Hotspots In The Mitochondria Of Cardiac Muscle At The Interface With Dyadic Sr, Sergio De La Fuente, Celia Fernandez-Sanz, Caitlin Vail, Elorm J. Agra, Kira Holmstrom, Junhui Sun, Jyotsna Mishra, Toren Finkel, Elizabeth Murphy, Suresh K. Joseph, Shey-Shing Sheu, György Csordás

Department of Pathology, Anatomy, and Cell Biology Posters

Introduction

• Control of the mitochondrial ATP production by SR-derived Ca2+ signals includes local, nanodomain Ca2+ transfer from ryanodine receptors (RyR2) to the mitochondrial matrix (excitation-bioenergetics coupling).

• Ca2+ crosses the inner mitochondrial membrane (IMM) via the mtCU, a low-affinity Ca2+-activated Ca2+ channel complex.

• The surface area of cardiac IMM is extensively enhanced by cristae folding; however, mitoplast patch clamp studies showed mtCU current density the lowest amongst a range of tissues (Fieni 2012. Nat Commun).

Retinal Ganglion Cell Neuroprotection Induced By Neuropharmacological Agents In An In-Vivo Model Of Glaucoma, Quinn Ameel

Honors Theses

Recent discoveries from this lab have demonstrated that activation of alpha7 nicotinic acetylcholine receptors (α7 nAChRs) on retinal ganglion cells (RGCs) in the retina is linked to neuroprotection of RGCs that are typically lost in glaucoma-like conditions. Various chemical agents have been produced to increase overall neurotransmission of ACh from cholinergic neurons. DMP-543 is an agent that increases calcium release from cholinergic synaptic terminals. Donepezil is an acetylcholinesterase inhibitor that inhibits the breakdown of ACh in the synaptic cleft, prolonging ACh’s effect. In this study, the neuroprotective activity of these two agents was analyzed at the synapse between starburst amacrine …

An Examination Into The Relationship Between Iron Deficiency And Postpartum Depression, Sara A. Burroughs

Senior Honors Theses

Postpartum depression is recognized as the most common complication of childbearing; however, its etiology remains fairly undetermined. Many different influences have been hypothesized as to what may cause postpartum depression, including changes in levels of various hormones (such as estrogen and progesterone), a decrease in serotonin, low levels of vitamin D, social factors, and iron deficiency. The lack of strong evidence for one specific cause makes it fairly clear that there are many factors that play a role in the development of postpartum depression. Iron deficiency is one issue that is thought to contribute to the development of postpartum depression …

Environmental Signaling Through The Target Of Rapamycin Complex 1 (Torc1) And The Regulation Of Epigenetic Mechanisms, Jason J. Workman

Theses and Dissertations (ETD)

The gene expression profile of a eukaryotic cell is responsive to a variety of extracellular stimuli, including nutrient availability, which allows cells to toggle between anabolism and catabolism based on the favorability of their environment. Much of this information is relayed through signaling complexes, such as the target of rapamycin complex 1 (TORC1), to downstream chromatin modifying enzymes. These enzymes impact the gene regulatory process through altered histone post-translation modifications, changes in chromatin structure, and docking of chromatin regulatory complexes. Yet, despite preliminary studies suggesting that TORC1 affects epigenetic mechanisms, including histone H3 lysine 56 acetylation (H3K56ac), almost nothing is …

Role Of Occludin In The Regulation Of Epithelial Tight Junctions, Bhargavi Manda

Theses and Dissertations (ETD)

Tight junctions (TJ) constitute the primary component of epithelial barrier function, a disruption of which is involved in the pathogenesis of many gastrointestinal, pulmonary and renal diseases. Occludin is the major transmembrane protein of TJ, a deletion of which leads to a complex phenotype including chronic inflammation in several epithelial tissues of occludin deficient mice and poor TJ integrity in epithelial cell lines. Its down regulation was seen in Crohn’s disease, tumors of the colon, brain, endometrium and breast cancer. Occludin is also known to be a target that enables Hepatitis C Virus infection and bacterial pathogenesis. But the specific …

The Nucleolar Protein Nucleophosmin Undergoes Liquid-Liquid Phase Separation With Arginine-Rich Nucleolar Proteins Through Weak, Multivalent Electrostatic Interactions, Jaclyn Alicia Cika

Theses and Dissertations (ETD)

Nucleoli are nuclear membrane-less organelles that are the sites for ribosome biogenesis and serve as sensors of cellular stress. Weak, multivalent protein-protein interactions and interactions between disordered, low complexity domains (LCDs) and rRNA have been shown to promote liquid-liquid phase separation (LLPS) in vitro, suggesting a basis for the liquid-like behavior of nucleoli. Nucleophosmin (NPM1), a multifunctional and highly abundant nucleolar protein, exhibits structural features associated with LLPS suggesting a role in nucleolar organization. Specifically, NPM1 forms a pentamer through its N-terminal oligomerization domain and can bind to rRNA through its C-terminal nucleic acid binding domain. Multiple acidic tracts throughout …

The Influence Of Age On The Diagnostic Performance Of White Blood Cell Count And Absolute Neutrophil Count In Suspected Pediatric Appendicitis., Richard G. Bachur, Peter S. Dayan, Nanette C. Dudley, Lalit Bajaj, Michelle D. Stevenson, Charles G. Macias, Manoj K. Mittal, Jonathan Bennett, Kelly A. Sinclair, Michael C. Monuteaux, Anupam B. Kharbanda

Manuscripts, Articles, Book Chapters and Other Papers

OBJECTIVE: White blood cell (WBC) count and absolute neutrophil count (ANC) are a standard part of the evaluation of suspected appendicitis. Specific threshold values are utilized in clinical pathways, but the discriminatory value of WBC count and ANC may vary by age. The objective of this study was to investigate whether the diagnostic value of WBC count and ANC varies across age groups and whether diagnostic thresholds should be age-adjusted.

METHODS: This is a multicenter prospective observational study of patients aged 3-18 years who were evaluated for appendicitis. Receiver operator characteristic curves were developed to assess overall discriminative power of …

Single-Cell Transcriptional Analysis Reveals Novel Neuronal Phenotypes And Interaction Networks Involved In The Central Circadian Clock., James Park, Haisun Zhu, Sean O'Sullivan, Babatunde A Ogunnaike, David R Weaver, James S. Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Single-cell heterogeneity confounds efforts to understand how a population of cells organizes into cellular networks that underlie tissue-level function. This complexity is prominent in the mammalian suprachiasmatic nucleus (SCN). Here, individual neurons exhibit a remarkable amount of asynchronous behavior and transcriptional heterogeneity. However, SCN neurons are able to generate precisely coordinated synaptic and molecular outputs that synchronize the body to a common circadian cycle by organizing into cellular networks. To understand this emergent cellular network property, it is important to reconcile single-neuron heterogeneity with network organization. In light of recent studies suggesting that transcriptionally heterogeneous cells organize into distinct cellular …

Mirna-145 Increases Therapeutic Sensibility To Gemcitabine Treatment Of Pancreatic Adenocarcinoma Cells., Yong Lin, Xin Ge, Yiyang Wen, Zhu-Mei Shi, Qiu-Dan Chen, Min Wang, Ling-Zhi Liu, Bing-Hua Jiang, Yuan Lu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Pancreatic adenocarcinoma is one of the most leading causes of cancer-related deaths worldwide. Although recent advances provide various treatment options, pancreatic adenocarcinoma has poor prognosis due to its late diagnosis and ineffective therapeutic multimodality. Gemcitabine is the effective first-line drug in pancreatic adenocarcinoma treatment. However, gemcitabine chemoresistance of pancreatic adenocarcinoma cells has been a major obstacle for limiting its treatment effect. Our study found that p70S6K1 plays an important role in gemcitabine chemoresistence. MiR-145 is a tumor suppressor which directly targets p70S6K1 for inhibiting its expression in pancreatic adenocarcinoma, providing new therapeutic scheme. Our findings revealed a new mechanism underlying …

Peroxiredoxin Catalysis At Atomic Resolution, Arden Perkins, Derek Parsonage, Kimberly J. Nelson, O. Maduka Ogba, Paul Ha-Yeon Cheong, Leslie B. Poole, P. Andrew Karplus

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peroxiredoxins (Prxs) are ubiquitous cysteine-based peroxidases that guard cells against oxidative damage, are virulence factors for pathogens, and are involved in eukaryotic redox regulatory pathways. We have analyzed catalytically active crystals to capture atomic resolution snapshots of a PrxQ-subfamily enzyme (from Xanthomonas campestris) proceeding through thiolate, sulfenate, and sulfinate species. These analyses provide structures of unprecedented accuracy for seeding theoretical studies, and show novel conformational intermediates giving insight into the reaction pathway. Based on a highly non-standard geometry seen for the sulfenate intermediate, we infer that the sulfenate formation itself can strongly promote local unfolding of the active site to …

Ehd1 As A Positive Regulator Of Macrophage Colony-Stimulating Factor-1 Receptor, Luke R. Cypher

Theses & Dissertations

The master regulator of the macrophage development, differentiation, proliferation, survival, phagocytosis, cytokine secretion, motility, adhesion, migration, and spreading is the receptor tyrosine kinase (RTK) colony stimulating factor-1 receptor (CSF-1R). Aberrant CSF-1R signaling is present amongst a variety of highly prevalent and devastating human diseases in the United States such as atherosclerosis, cancer, inflammatory bowel disease, arthritis, and neuro-demyelination/neuro-degeneration. A better understanding of basic mechanisms that govern macrophage development and function is of vital importance in treating patients afflicted with these conditions/diseases. CSF-1R presentation on the macrophage cell surface is a required precursor for CSF1- induced RTK dimerization (activation) and downstream …