Cell Biology Commons^™

Molecular Mechanisms Regulating Neonatal Oocyte Survival And Primordial Follicle Formation In The Mouse Ovary, Robin L. Jones

Biology - Dissertations

In mammals, formation of the primordial follicle is a complex process involving the breakdown of germ cell cysts, where oocytes must separate from each other and subsequently become surrounded by somatic cells. As cysts separate, a large number of germ cells are lost by apoptosis, however the mechanisms by which cyst breakdown and germ cell death occur are not well understood. We first hypothesized that two anti-apoptotic regulators from the BCL2 family of proteins, BCL2 and MCL1, may be responsible for regulating neonatal oocyte survival. To elucidate the effects of BCL2 in the neonatal ovary, we examined ovaries of both …

Expansion Of Human Induced Pluripotent Stem Cells On Synthetic Substrate In Defined Medium, Huantong Yao

Graduate Theses and Dissertations

Human induced pluripotent stem cells (hiPSCs) have the potential to generate patient-specific cells to treat many incurable diseases by cell replacement therapy. However, so far the culture of hiPSCs depends greatly on feeder cells or Matrigel which has safety issues. Thus, chemically defined substrates that could provide niches necessary for cell attachment and proliferation are preferred for clinical application of hiPSCs. Recently, Corning Life Sciences has developed synthetic peptide-functionalized cell culture surface, referred to as Corning® Synthemax that support self-renewal and differentiation of human embryonic stem cell (hESC). In this work, we have collaborated with Corning to investigate the attachment, …

Biochemical Characterization Of Binding Partners Of Two Hsp70 Co-Chaperones In Saccharomyces Cerevisiae, Jacob Verghese

Dissertations and Theses (Open Access)

Cells are exposed to a variety of environmental and physiological changes including temperature, pH and nutrient availability. These changes cause stress to cells, which results in protein misfolding and altered cellular protein homeostasis. How proteins fold into their three-dimensional functional structure is a fundamental biological process with important relevance to human health. Misfolded and aggregated proteins are linked to multiple neurodegenerative diseases, cardiovascular disease and cystic fibrosis. To combat proteotoxic stress, cells deploy an array of molecular chaperones that assist in the repair or removal of misfolded proteins.

Hsp70, an evolutionarily conserved molecular chaperone, promotes protein folding and helps maintain …

Characterization Of A Novel Role For The To Usled- Like Kinase In Kinetochore Assembly And Function In Caenorhabditis Elegans, Jessica M. De Orbeta

Dissertations and Theses (Open Access)

Chromosome segregation is a critical step during cell division to avoid aneuploidy and promote proper organismal development. Correct sister chromatid positioning and separation during mitosis helps to achieve faithful transmission of genetic material to daughter cells. This prevents improper chromosome partitioning that can potentially result in extrachromosomal fragments, increasing the tumorigenic potential of the cells. The kinetochore is a protenaicious structure responsible for the initiation and orchestration of chromosome movement during mitosis. This highly conserved structure among eukaryotes is required for chromosome attachment to the mitotic spindle and failure to assemble the kinetochore results in aberrant chromosome segregation. Thus elucidating …

Reactive Oxygen Species Mediated Dna Damage In Human Lung Alveolar Epithelial (A549) Cells From Exposure To Non-Cytotoxic Mfi-Type Zeolite Nanoparticles, Kunal Bhattacharya, Pratap Naha, Izabela Naydenova, Svetlana Mintova, Hugh Byrne

Articles

Increasing utilization of engineered nanoparticles in the field of electronics and biomedical applications demands an assessment of risk associated with deliberate or accidental exposure. Metal based nanoparticles are potentially most important of all the nanoparticles in terms of health risks. Microporousalumino-silicates and pure silicates named as zeolites and zeo-type materials with variety of structures, chemical compositions, particle sizes and morphologies have a significant number of industrial uses such as in catalysis, sorption and ion-exchange processes. In particular, the nanosized particles due to their unique properties are used in hybrid organic-inorganic materials for photography, photonics, electronics, labeling, imaging, and sensing. The …

Blt1 And Mid1 Provide Overlapping Membrane Anchors To Position The Division Plane In Fission Yeast, Merce Guzman-Vendrell, Suzanne Baldissard, Maria Almonacid, Adeline Mayeux, Anne Paoletti, James B. Moseley

Dartmouth Scholarship

Spatial control of cytokinesis is essential for proper cell division. The molecular mechanisms that anchor the dynamic assembly and constriction of the cytokinetic ring at the plasma membrane remain unclear. In the fission yeast Schizosaccharomyces pombe, the cytokinetic ring is assembled in the cell middle from cortical node precursors that are positioned by the anillin-like protein Mid1. During mitotic entry, cortical nodes mature and then compact into a contractile ring positioned in the cell middle. The molecular link between Mid1 and medial cortical nodes remains poorly defined. Here we show that Blt1, a previously enig- matic cortical node protein, promotes …

Scribble Acts In The Drosophila Fat-Hippo Pathway To Regulate Warts Activity, Shilpi Verghese, Indrayani Waghmare, Hailey Kwon, Katelin Hanes, Madhuri Kango-Singh

Biology Faculty Publications

Epithelial cells are the major cell-type for all organs in multicellular organisms. In order to achieve correct organ size, epithelial tissues need mechanisms that limit their proliferation, and protect tissues from damage caused by defective epithelial cells. Recently, the Hippo signaling pathway has emerged as a major mechanism that orchestrates epithelial development. Hippo signaling is required for cells to stop proliferation as in the absence of Hippo signaling tissues continue to proliferate and produce overgrown organs or tumors. Studies in Drosophila have led the way in providing a framework for how Hippo alters the pattern of gene transcription in target …

Spectral Cross Correlation As A Supervised Approach For The Analysis Of Complex Raman Datasets: The Case Of Nanoparticles In Biological Cells, Mark Keating, Franck Bonnier, Hugh Byrne

Articles

Spectral Cross-correlation is introduced as a methodology to identify the presence and subcellular distribution of nanoparticles in cells. Raman microscopy is employed to spectroscopically image biological cells previously exposed to polystyrene nanoparticles, as a model for the study of nano-bio interactions. The limitations of previously deployed strategies of K-means clustering analysis and principal component analysis are discussed and a novel methodology of Spectral Cross Correlation Analysis is introduced and compared with the performance of Classical Least Squares Analysis, in both unsupervised and supervised modes. The previous study demonstrated the feasibility of using Raman spectroscopy to map cells and identify polystyrene …

Tributyltin And Dibutyltin Alter Secretion Of Tumor Necrosis Factor Alpha From Human Natural Killer Cells And A Mixture Of T Cells And Natural Killer Cells, Kelsi Hurt, Tasia Hurd-Brown, Margaret Whalen

Chemistry Faculty Research

Butyltins (BTs) have been in widespread use. Tributyltin (TBT) has been used as a biocide in a variety of applications and is found in human blood samples. Dibutyltin (DBT) has been used as a stabilizer in polyvinyl chloride plastics and as a de-worming agent in poultry. DBT, like TBT, is found in human blood. Human natural killer (NK) cells are the earliest defense against tumors and viral infections and secrete the cytokine tumor necrosis factor-alpha (TNF-α). TNF-α is an important regulator of adaptive and innate immune responses. TNF-α promotes inflammation and an association between malignant transformation and inflammation has been …

Intracellular Expression Of An Ice Nucleation Protein Reduces Cryoinjury In Insect Cells, Avril M. Harder

Student Honors Theses

Exposure of insect cells to subzero temperatures typically leads to cell membrane disruption and lethal intracellular ice formation. This study seeks to examine the cryoprotective value of trangenically expressing a bacterial ice nucleation protein (INP) in Spodoptera frugiperda (Sf-21) cells. The bacterium Pseudomonas syringae naturally produces a membrane-bound INP (inaZ), capable of structuring water and initiating ice formation at temperatures as high as -2 °C. I hypothesized that intracellular expression of an altered form of inaZ (PsINP) in Sf-21 cells will mediate highly regulated ice nucleation when cells are cooled to -80 °C in a slow, controlled manner, …

Evaluation Of Gut Modulatory And Bronchodilator Activities Of Amaranthus Spinosus Linn., Mueen Ahmad Chaudhary, Imran Imran, Samra Bashir, Malik Hassan Mehmood, Najeeb -Ur Rehman, Anwar Hassan Gilani

Department of Biological & Biomedical Sciences

Background

The aqueous-methanolic extract of Amaranthus spinosus (A. spinosus Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses.

Methods

The crude extract of A. spinosus was studied in-vivo for bronchodilator and laxative activities and in-vitro using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms.

Results

In the in-vivo experiments in mice, the administration of A. spinosus increased fecal output at doses of 100 …

Real-Time Analysis Of Brain Tumor Cell Dynamics: Novel Thermoelectric Detection Of L-Glutamate And Cell Metabolism Using Microfluidics, Siva Mahesh Tangutooru

Doctoral Dissertations

This study describes the design, fabrication and applications of a novel thermoelectric microfluidic bio-sensor. The bio-sensor is used for real time detection of the L-glutamate (L-glu) dynamics and metabolism for brain tumor cells immobilized in a microfluidic device. The microfluidic device is fabricated using a polymer/glass laminating technique (Xurography). An antimony-bismuth thin-film thermopile (primary sensing element) is integrated to the microfluidic device. The brain tumor cells are immobilized over the thermopile covering measuring and reference junctions of the thermopile using a poly-l-lysine coating layer. L-glutamate oxidase (L-GLOD) is immobilized over the measuring junctions of the thermopile prior to the immobilization …

Transient Inhibition Of Cell Proliferation Does Not Compromise Self-Renewal Of Mouse Embryonic Stem Cells, Ruoxing Wang, Yan-Lin Guo

Faculty Publications

Embryonic stem cells (ESCs) have unlimited capacity for self-renewal and can differentiate into various cell types when induced. They also have an unusual cell cycle control mechanism driven by constitutively active cyclin dependent kinases (Cdks). In mouse ESCs (mESCs). It is proposed that the rapid cell proliferation could be a necessary part of mechanisms that maintain mESC self-renewal and pluripotency, but this hypothesis is not in line with the finding in human ESCs (hESCs) that the length of the cell cycle is similar to differentiated cells. Therefore, whether rapid cell proliferation is essential for the maintenance of mESC state remains …

Analysis Of Crossover Interference In Yeast, Hanna Morris

Undergraduate Research Posters 2012

Meiosis is one type of cell division that produces germ cells. In Meiosis I, the DNA in a diploid cell is doubled and homologous chromosomes separate. In Meiosis II, each pair of sister chromatids are separated, resulting in four haploid daughter cells. The nine intervals were analyzed under several conditions and the number, timing, and distribution of crossovers was determined. Results and their compatibility with current models of synaptonemal complex functions will be discussed.

The Effect Of Acp1-Ada1 Genetic Interaction On Human Life Span, Nazzareno Lucarini, Valerio Napolioni, Andrea Magrini, Fulvia Gloria

Human Biology Open Access Pre-Prints

Acid phosphatase (ACP1) is a polymorphic enzyme which catalyzes the conversion of flavinmononucleotide (FMN) to riboflavin and regulates the cellular concentration of flavin-adeninedinucleotide (FAD) and, consequently, energy metabolism. Its activity is modulated by adenosine deaminase (ADA1) genotype. Aim of our work is to verify whether individuals with a high proportion of ACP1 f isozyme and carrying ADA*2 allele, displaying the highest phosphatase activity, may have a higher life expectancy. Genomic DNA was extracted from peripheral blood of 569 females and 509 males (18-106 years) randomly recruited from Central Italy. These samples were subdivided into three sexspecific age groups …

Endogenous Inhibitor Proteins That Connect Ser/Thr Kinases And Phosphatases In Cell Signaling., Masumi Eto, David L Brautigan

Department of Molecular Physiology and Biophysics Faculty Papers

Protein phosphatase activity acts as a primary determinant of the extent and duration of phosphorylation of cellular proteins in response to physiological stimuli. Ser/Thr protein phosphatase-1 (PP1) belongs to the PPP superfamily, and is associated with regulatory subunits that confer substrate specificity, allosteric regulation, and subcellular compartmentalization. In addition, all eukaryotic cells contain multiple heat-stable proteins that originally were thought to inhibit phosphatase catalytic subunits released from the regulatory subunits, as a fail-safe mechanism. However, discovery of C-kinase-activated PP1 inhibitor, Mr of 17 kDa (CPI-17) required fresh thinking about the endogenous inhibitors as specific regulators of particular phosphatase complexes, acting …

Rapid Range Expansion In The Great Plains Narrow-Mouthed Toad (Gastrophryne Olivacea) And A Revised Taxonomy For North American Microhylids, Jeffrey W. Streicher, Christian L. Cox, Jonathan A. Campbell, Eric N. Smith, Rafael O. De Sá

Biology Faculty Publications

We investigated genetic variation within the Great Plains narrow-mouthed toad, Gastrophryne olivacea, across its geographic range in the United States and Mexico. An analysis of mitochondrial DNA (mtDNA) from 105 frogs revealed remarkably low levels of genetic diversity in individuals inhabiting the central United States and northern Mexico. We found that this widespread matrilineal lineage is divergent (ca. 2% in mtDNA) from haplotypes that originate from the western United States and western coast of Mexico. Using a dataset that included all five species of Gastrophryne and both species of the closely related genus Hypopachus, we investigated the phylogenetic …

Endothelin-1 Induced Phosphorylation Of Erk1/2 In Bovine Corneal Endothelial Cells, Akhila Bethi

Masters Theses & Specialist Projects

The purpose of this study was to determine whether Endothelin-1 (ET-1) induced cellular responses in bovine corneal endothelial cells (BCECs) involves MAPK pathway by phosphorylating ERK1/2 protein kinase and to find out the phosphorylation patterns of ERK1/2 in confluent and sub-confluent cells. BCECs were isolated from bovine corneas and cultured in medium supplemented with 10% serum. Confluent (contact inhibited) and sub-confluent (actively growing cells) serum starved cells grown in T-75 flasks were treated with 10nM Endothelin-1. The control cells were left untreated. Total cellular protein was isolated using RIPA buffer and quantified according to the Peterson modification of the Lowry …

Plant-Like Cryptochrome Does Not Promote Blue Light-Induced Resetting Of The Circadian Clock In Chlamydomonas Reinhardtii, Jonathan Howton

Masters Theses & Specialist Projects

The circadian clock is an endogenous timer that allows an organism to anticipate and properly prepare for the daily changes in the environment. This preparation occurs in the form of daily rhythms in metabolism, physiology, and behavior. These approximately 24-hour rhythms are reset upon environmental time cues such as the daily light/dark and temperature cycles. The unicellular green alga Chlamydomonas reinhardtii is a useful model organism for circadian clock research. It shows several well-characterized circadian rhythms of behavior, and the monitoring of its rhythm of phototaxis, or swimming towards light, has been automated. The receptors involved in entraining the clock …

Next Generation Sequencing Reveals Gene Expression Patterns In The Zebrafish Inner Ear Following Growth Hormone Injection, Gopinath Rajadinakaran

Masters Theses & Specialist Projects

Loss of hair cells due to acoustic trauma results in the loss of hearing. In humans, unlike other vertebrates, the mechanism of hair cell regeneration is not possible. The molecular mechanisms that underlie this regeneration in nonmammalian vertebrates remain elusive. To understand the gene regulation during hair cell regeneration, our previous microarray study on zebrafish inner ears found that growth hormone (GH) was significantly upregulated after noise exposure. In this current study, we utilized Next Generation Sequencing (NGS) to examine the genes and pathways that are significantly regulated in the zebrafish inner ear following sound exposure and GH injection. Four …

Inhibition Of Burkholderia Multivorans Adhesion To Lung Epithelial Cells By Bivalent Lactosides, Ciara Wight, Rosaria Leyden, Paul V. Murphy, Máire Callaghan, Trinidad Velasco-Torrijos, Siobhan Mcclean

Articles

Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in cystic fibrosis patients which is inherently resistant to antimicrobial agents. The mechanisms of attachment and pathogenesis of Bcc, a group of 17 species, are poorly understood. The most commonly identified Bcc species in newly colonised patients, Burkholderia multivorans, continues to be acquired from the environment. Development of therapies which can prevent or reduce the risk of colonization on exposure to Bcc in the environment would be a better alternative to antimicrobial agents. Previously, it has been shown that Bcc strains bound to many glycolipid receptors on lung epithelia. Using a …

Condensin Ii Promotes The Formation Of Chromosome Territories By Inducing Axial Compaction Of Polyploid Interphase Chromosomes, Christopher R. R. Bauer, Tom A. Hartl, Giovanni Bosco

Dartmouth Scholarship

The eukaryotic nucleus is both spatially and functionally partitioned. This organization contributes to the maintenance, expression, and transmission of genetic information. Though our ability to probe the physical structure of the genome within the nucleus has improved substantially in recent years, relatively little is known about the factors that regulate its organization or the mechanisms through which specific organizational states are achieved. Here, we show that Drosophila melanogaster Condensin II induces axial compaction of interphase chromosomes, globally disrupts interchromosomal interactions, and promotes the dispersal of peri-centric heterochromatin. These Condensin II activities compartmentalize the nucleus into discrete chromosome territories and indicate …

Role Of Stat3 In Keratinocyte Stem Cells During Skin Tumorigenesis, Dharanija Rao

Dissertations and Theses (Open Access)

STATs play crucial roles in a wide variety of biological functions, including development, proliferation, differentiation, migration and in cancer development. In the present study, we examined the impact of Stat3 deletion or activation on behavior of keratinocytes, including keratinocyte stem cells (KSCs). Deletion of Stat3 specifically in the bulge region of the hair follicle using K15.CrePR1 X Stat3^fl/fl mice led to decreased tumor development by altering survival of bulge region KSCs. To further understand the role of KSCs in skin tumorigenesis, K5.Stat3C transgenic (Tg) mice which express a constitutively active/dimerized form of Stat3 called Stat3C via the bovine keratin …

Identification And Analysis Of A Novel Role For The To Usled-Like Kinase In Regulating Mitotic Spindle Dynamics, Jason R. Ford

Dissertations and Theses (Open Access)

Deregulation of kinase activity is one example of how cells become cancerous by evading evolutionary constraints. The Tousled kinase (Tsl) was initially identified in Arabidopsis thaliana as a developmentally important kinase. There are two mammalian orthologues of Tsl and one orthologue in C. elegans, TLK-1, which is essential for embryonic viability and germ cell development. Depletion of TLK-1 leads to embryonic arrest large, distended nuclei, and ultimately embryonic lethality. Prior to terminal arrest, TLK-1-depleted embryos undergo aberrant mitoses characterized by poor metaphase chromosome alignment, delayed mitotic progression, lagging chromosomes, and supernumerary centrosomes.

I discovered an unanticipated requirement for TLK-1 …

The Role Of Acetyl-Coa Carboxylase In The Survival Of Trypanosoma Brucei During Infection, Ciara Mcknight

All Theses

This master's thesis focuses on how disruption of fatty acid metabolism affects both host adaptation and immune evasion in the deadly eukaryotic parasite, Trypanosoma brucei. In Chapter 1, I review the current literature on African trypanosomiasis, fatty acid synthesis, immune evasion, and lipid metabolism. In Chapter 2, I investigate how disruption of the fatty acid synthesis pathway affects the parasite's ability to evade the host immune defenses. When T. brucei acetyl-CoA carboxylase (TbACC) is knocked down by RNA interference (RNAi), fluid phase and receptor mediated endocytosis pathways are greatly affected, suggesting that fatty acid synthesis is necessary for both endocytic …

Cell Bioenergetics In Leghorn Male Hepatoma Cells And Immortalized Chicken Liver Cells In Response To 4-Hydroxynonenal Induced Oxidative Stress, Alissa Laura Piekarski

Graduate Theses and Dissertations

Bioenergetic mechanisms responsible for ATP production are essential in carrying out maintenance and cell-specific functions. In this study, hepatocytes (liver cells) were used to test both endogenous and exogenous stress on cellular respiration. The secondary lipid peroxide, 4-hydroxynonenal (HNE), was used because it alters bioenergetics by increasing mitochondrial proton leak that attenuates mitochondrial radical production and, therefore, endogenous oxidative stress. The major objective of this study was to demonstrate effects of HNE-induced oxidative stress on avian hepatocyte bioenergetics. Various chemical which help enable the determination of oxygen (O2) consumption linked to ATP synthesis (oligomycin), maximal O2 consumption (FCCP), and proton …

An Analysis Of The Redox Properties And Stability Of Chlamydomonas Reinhardtii Cytochrome F, Cytochrome C6, And Mutants Thereof, Nicole Lynn Vanderbush

Graduate Theses and Dissertations

This body of work presents mutagenesis studies conducted on two c-type cytochromes from Chlamydomonas reinhardtii. Cytochrome f, a unique c-type cytochrome, is investigated in regards to its redox potential, the dependence of the redox potential, and the thermal stability of the protein. The mutations made were Y1F, Y9F, Y160F, Y160L, R156L, and R156K. The residues that were mutated surround the heme. It was found that, relative to the wild-type, only the Y160L and R156 mutants showed any difference in midpoint potential at pH 7. Wild-type and mutants both had a midpoint potential that was dependent upon pH indicating that none …

Plant Lectin Can Target Receptors Containing Sialic Acid, Exemplified By Podoplanin, To Inhibit Transformed Cell Growth And Migration, Jhon Ochoa-Alvarez, Harini Krishnan, Yongquan Shen, Nimish Acharya, Min Han, Dean Mcnulty, Hitoki Hasegawa

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN) is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors …

Inhibitors Of Polyisoprenylated Methylated Protein Methyl Esterase (Pmpmease) Cause Neurodegeneration By Altering Microtubules And Gβγ In Pc12 Cells, Jose A. Rivas Jr., Rebekah M. Bach, Jessica Martinez-Jurado, Jorge A. Siera-Fonseca, Sukla Roychowdhury

COURI Symposium Abstracts, Summer 2012

Neurodegeneration, a progressive loss of nerve cells (neurons), occurs in many neurological disorders including Alzheimer’s disease, Parkinson’s disease, Schizophrenia and drug addiction. Disruption of Microtubules (MTs), a major component of cytoskeleton and aggregation of proteins associated with them is the hallmark of neurodegeneration. Gβγ, an important component of G protein signaling has been shown to induce neurite outgrowth of PC12 cells by interacting with microtubules. The goal of the present study is to understand whether interfering with Gβγ-MT mediated pathway causes neurodegeneration. Because prenylation of γ subunits is important for the interaction of Gβγ with MTs, we used inhibitors (L-23 …

Gβγ-Microtubule Interaction And Neurodegeneration, Jane K. Martinez, Jorge Sierra, Sukla Roychowdhury Ph.D.

COURI Symposium Abstracts, Summer 2012

Aberrant organization of microtubules (MTs) is known to be a feature of neurodegeneration, which occurs in many neurological disorder including Alzheimer’s disease, Parkinson’s disease, neuropsychiatric illness such as schizophrenia, and drug addiction. Previously, Gβγ, an important component of G protein-coupled signaling pathways, has been shown to regulate neurite outgrowth by interacting with MTs. The aim of the present study is to understand the Gβγ regulation of MT assembly and its relation to neurodegeneration, using GRK-ct peptide (consists of the carboxy terminus of G protein-coupled-receptor kinase) which is known to inhibit Gβγ-dependent signaling by binding to and sequestering Gβγ. PC12 cells …